bims-auttor Biomed News
on Autophagy and mTOR
Issue of 2024‒11‒03
sixty-five papers selected by
Viktor Korolchuk, Newcastle University
  1. Dysregulating mTORC1-4E-BP2 signaling in GABAergic interneurons impairs hippocampus-dependent learning and memory.
  2. TFEB agonist clomiphene citrate activates the autophagy-lysosomal pathway and ameliorates Alzheimer's disease symptoms in mice.
  3. Mitophagy: insights into its signaling molecules, biological functions, and therapeutic potential in breast cancer.
  4. Polygoni Cuspidati Rhizoma et Radix extract activates TFEB and alleviates hepatic steatosis by promoting autophagy.
  5. Ubiquitination regulates autophagy in cancer: simple modifications, promising targets.
  6. Pharmaceutical Agents for Targeting Autophagy and Their Applications in Clinics.
  7. Mitophagy in Cell Death Regulation: Insights into Mechanisms and Disease Implications.
  8. Lipids associated with autophagy: mechanisms and therapeutic targets.
  9. The essential role of CCT2 in the regulation of aggrephagy.
  10. Molecular mechanisms of escrt-mediated autophagosome maturation in plants.
  11. GCN2-SLC7A11 axis coordinates autophagy, cell cycle and apoptosis and regulates cell growth in retinoblastoma upon arginine deprivation.
  12. The Role of mTOR in Mycobacterium tuberculosis Infection.
  13. Cell-Type Resolved Protein Atlas of Brain Lysosomes Identifies SLC45A1-Associated Disease as a Lysosomal Disorder.
  14. Accumulation of F-actin drives brain aging and limits healthspan in Drosophila.
  15. Thioredoxin-1 protein interactions in neuronal survival and neurodegeneration.
  16. The dual role of autophagy in suppressing and promoting hepatocellular carcinoma.
  17. mTOR signaling pathway as a pathophysiologic mechanism in preclinical models of autism spectrum disorder.
  18. Autophagy Alterations in White and Brown Adipose Tissues of Mice Exercised under Different Training Protocols.
  19. Characterisation of autophagy induction by the thiopurine drugs azathioprine, mercaptopurine and thioguanine in THP-1 macrophages.
  20. Neuron-specific deficiency of autophagy increases neuronal loss in traumatic brain injury.
  21. Disrupting the interaction between AMBRA1 and DLC1 prevents apoptosis while enhancing autophagy and mitophagy.
  22. Autophagy deficiency exacerbated hypoxia-reoxygenation induced inflammation and cell death via a mitochondrial DNA/STING/IRF3 pathway.
  23. Benzo(a)pyrene promotes autophagy to impair endometrial decidualization via inhibiting CXCL12/CXCR4 axis.
  24. mTORC1 signaling and diabetic kidney disease.
  25. AAA+ ATPase chaperone p97/VCPFAF2 governs basal pexophagy.
  26. The role of host autophagy in intracellular protozoan parasites diseases.
  27. α-Synuclein disrupts microglial autophagy through STAT1-dependent suppression of Ulk1 transcription.
  28. Advances in Small-Molecule Fluorescent pH Probes for Monitoring Mitophagy.
  29. The Many Faces of Autophagy: Balancing Survival and Cell Death.
  30. Autophagy: a critical mechanism of N6-methyladenosine modification involved in tumor progression and therapy resistance.
  31. HSP90 N-terminal inhibition promotes mitochondria-derived vesicles related metastasis by reducing TFEB transcription via decreased HSP90AA1-HCFC1 interaction in liver cancer.
  32. The Knowns and Unknowns of Membrane Features and Changes During Autophagosome-Lysosome/Vacuole Fusion.
  33. Beclin-1 and LC3B expression in canine mast cell tumours: an immuno-ultrastructural and immunohistochemical study of autophagy.
  34. LSU family members and NBR1 are novel factors that contribute to homeostasis of catalases and peroxisomes in Arabidopsis thaliana.
  35. Ca+2 and Nε-lysine acetylation regulate the CALR-ATG9A interaction in the lumen of the endoplasmic reticulum.
  36. Stromal softness confines pancreatic cancer growth through lysosomal-cathepsin mediated YAP1 degradation.
  37. Modification of MWCNTs with Bi2WO6 nanoparticles targeting IL-1β and NLRP3 inflammasome via augmented autophagy.
  38. mTORC1 and 2 adrenergic regulation and function in brown adipose tissue.
  39. The Integrated Stress Response Suppresses PINK1-dependent Mitophagy by Preserving Mitochondrial Import Efficiency.
  40. Deciphering melanophagy: role of the PTK2-ITCH-MLANA-OPTN cascade on melanophagy in melanocytes.
  41. An mTOR-Tfeb-Fabp7a signaling axis can be harnessed to ameliorate bag3 cardiomyopathy in adult zebrafish.
  42. Pink1-Dependent Mitophagy in Vascular Smooth Muscle Cells: Implications for Arterial Constriction.
  43. Tripartite motif 25 inhibits protein aggregate degradation during PRRSV infection by suppressing p62-mediated autophagy.
  44. Cepharanthine sensitizes gastric cancer cells to chemotherapy by targeting TRIB3-FOXO3-FOXM1 axis to inhibit autophagy.
  45. History and Perspective of LAMP-2 Deficiency (Danon Disease).
  46. Malformin C preferentially kills glioblastoma stem-like cells via concerted induction of proteotoxic stress and autophagic flux blockade.
  47. Spatial memory in Alzheimer's disease 5XFAD mice is enhanced by XPO1 inhibitor KPT-330.
  48. Dihydro-resveratrol ameliorates NLRP3 inflammasome-mediated neuroinflammation via Bnip3-dependent mitophagy in Alzheimer's disease.
  49. Non-lytic spread of poliovirus requires the nonstructural protein 3CD.
  50. Rotating magnetic field improves cognitive and memory impairments in APP/PS1 mice by activating autophagy and inhibiting the PI3K/AKT/mTOR signaling pathway.
  51. Interconnection of CD133 Stem Cell Marker with Autophagy and Apoptosis in Colorectal Cancer.
  52. Targeting Lipid Metabolism in Cancer Stem Cells for Anticancer Treatment.
  53. An SLC12A9-dependent ion transport mechanism maintains lysosomal osmolarity.
  54. Liver CYP4A autophagic-lysosomal degradation (ALD): A major role for the autophagic receptor SQSTM1/p62 through an uncommon target interaction site.
  55. STAT6 promotes innate immunity against BEFV and VSV by inhibiting STUB1 and NIX-mediated MAVS degradation.
  56. Multi-omic analysis of a mucolipidosis II neuronal cell model uncovers involvement of pathways related to neurodegeneration and drug metabolism.
  57. METTL14-mediated m6A methylation regulates pathological retinal neovascularization by targeting autophagy.
  58. IRGQ-mediated autophagy in MHC class I quality control promotes tumor immune evasion.
  59. FBXO22 inhibits colitis and colorectal carcinogenesis by regulating the degradation of the S2448-phosphorylated form of mTOR.
  60. p75NTR mediated chronic restraint stress-induced depression-like behaviors in mice via hippocampal mTOR pathway.
  61. Regulation of Bacillus Calmette-Guérin-induced macrophage autophagy and apoptosis by the AMPK-mTOR-ULK1 pathway.
  62. Emerging Molecular-Genetic Families in Dystonia: Endosome-Autophagosome-Lysosome and Integrated Stress Response Pathways.
  63. The mTOR Pathway: A Common Link Between Alzheimer's Disease and Down Syndrome.
  64. Cooperative Substructure and Energetics of Allosteric Regulation of the Catalytic Core of the E3 Ubiquitin Ligase Parkin by Phosphorylated Ubiquitin.
  65. Brain mitophagy in space and time.
  1. Learn Mem. 2024 Oct-Nov;31(10-11):pii: a054018. [Epub ahead of print]31(10-11):
    Dysregulating mTORC1-4E-BP2 signaling in GABAergic interneurons impairs hippocampus-dependent learning and memory.
    Ziying Huang, Shane Wiebe, Anmol Nagpal, Junghyun Choi, Caleb Walters, Niaz Mahmood, Arkady Khoutorsky, Jean-Claude Lacaille, Nahum Sonenberg.
      Memory formation is contingent on molecular and structural changes in neurons in response to learning stimuli-a process known as neuronal plasticity. The initiation step of mRNA translation is a gatekeeper of long-term memory by controlling the production of plasticity-related proteins in the brain. The mechanistic target of rapamycin complex 1 (mTORC1) controls mRNA translation, mainly through phosphorylation of the eukaryotic initiation factor 4E (eIF4E)-binding proteins (4E-BPs) and ribosomal protein S6 kinases (S6Ks). mTORC1 signaling decreases throughout brain development, starting from the early postnatal period. Here, we discovered that in mice, the age-dependent decrease in mTORC1 signaling occurs selectively in excitatory but not inhibitory neurons. Using a gene conditional knockout (cKO) strategy, we demonstrate that either up- or downregulating the mTORC1-4E-BP2 axis in GAD65 inhibitory interneurons, but not excitatory neurons, results in long-term object recognition and object location memory deficits. Our data indicate that the mTORC1 pathway in inhibitory but not excitatory neurons plays a key role in memory formation.
    DOI:  https://doi.org/10.1101/lm.054018.124
  2. J Biol Chem. 2024 Oct 23. pii: S0021-9258(24)02431-1. [Epub ahead of print] 107929
    TFEB agonist clomiphene citrate activates the autophagy-lysosomal pathway and ameliorates Alzheimer's disease symptoms in mice.
    Jieru Lin, Yi Yuan, Chunhuan Huang, Jiayu Zi, Lu Li, Jiamiao Liu, Xiaoting Wu, Wei Li, Qing Zhao, Yuyin Li, Zhenxing Liu, Aipo Diao.
      Autophagy is a conserved eukaryotic cellular clearance and recycling process through the lysosome-mediated degradation of damaged organelles and protein aggregates to maintain homeostasis. Impairment of the autophagy-lysosomal pathway is implicated in the pathogenesis of Alzheimer's disease (AD). Transcription factor EB (TFEB) is a master regulator of autophagy and lysosomal biogenesis. Therefore, activating TFEB and autophagy provides a novel strategy for AD treatment. We previously described that clomiphene citrate (CC) promotes nuclear translocation of TFEB and increases autophagy and lysosomal biogenesis. In this study, 7 and 3-month-old APP/PS1 mice were treated with TFEB agonist CC and assessed. The behavioral tests were performed using Morris water maze and open field test. Additional changes in Aβ pathology, autophagy and inflammatory response were determined. We found that CC activated TFEB and the autophagy-lysosomal pathway in neuronal cells. Moreover, using mouse model of Alzheimer's disease, CC treatment promoted clearance of Aβ plaques and ameliorated cognitive function in both 7 and 3-month-old APP/PS1 mice. The CC-induced activation of TFEB occurs by promoting acetylation of TFEB for nuclear translocation. These findings provide a molecular mechanism for the TFEB-mediated activation of the autophagy-lysosome pathway by CC, which has the potential to be repurposed and applied in the treatment or prevention of AD.
    Keywords:  Alzheimer's disease; TFEB; autophagy; clomiphene citrate; lysosome
    DOI:  https://doi.org/10.1016/j.jbc.2024.107929
  3. Cell Death Discov. 2024 Oct 29. 10(1): 457
    Mitophagy: insights into its signaling molecules, biological functions, and therapeutic potential in breast cancer.
    Cong Chen, Aizhai Xiang, Xia Lin, Jufeng Guo, Jian Liu, Shufang Hu, Tao Rui, Qianwei Ye.
      Mitophagy, a form of selective autophagy that removes damaged or dysfunctional mitochondria, plays a crucial role in maintaining mitochondrial and cellular homeostasis. Recent findings suggest that defective mitophagy is closely associated with various diseases, including breast cancer. Moreover, a better understanding of the multifaceted roles of mitophagy in breast cancer progression is crucial for the treatment of this disease. Here, we will summarize the molecular mechanisms of mitophagy process. In addition, we highlight the expression patterns and roles of mitophagy-related signaling molecules in breast cancer progression and the potential implications of mitophagy for the development of breast cancer, aiming to provide better therapeutic strategies for breast cancer treatment.
    DOI:  https://doi.org/10.1038/s41420-024-02226-6
  4. Life Sci. 2024 Oct 23. pii: S0024-3205(24)00748-3. [Epub ahead of print] 123158
    Polygoni Cuspidati Rhizoma et Radix extract activates TFEB and alleviates hepatic steatosis by promoting autophagy.
    Chang Li, Chenyu Li, Yi Wang, Sikun You, Ka Yi Man, Zhunming Fan, Qian Yu, Meng Zhang, Kenneth King-Yip Cheng, Daniel Kam-Wah Mok, Shun-Wan Chan, Huan Zhang.
      Hepatic steatosis is a metabolic disorder characterized by excessive accumulation of lipid in the liver. The activation of autophagy shows a promising effect in the elimination of intracellular lipids, potentially improving steatosis. Polygoni Cuspidati Rhizoma et Radix (PCRR) has been used for thousands of years in treating atherosclerosis, hepatitis, and gallstone disease. We recently found that PCRR exerts a potent anti-hepatic steatosis effect, but the active compounds responsible for its effect and underlying mechanism remain unknown. This study aims to investigate whether PCRR water extract intervention improves steatosis by regulating hepatic autophagic flux. We demonstrated that PCRR water extract promoted autophagic flux, enhanced lysosomal biogenesis, and alleviated steatosis in hepatocytes and in the livers of rats with steatosis through autophagy induction. Mechanistic investigation revealed that PCRR water extract inhibited the activity of MTORC1, thereby dephosphorylating and hence inducing nuclear translocation of the lipophagy inducer TFEB. Notably, knockdown of TFEB attenuated the promoting effects of PCRR on lipophagy in hepatocytes. Furthermore, blockage of autophagy by chloroquine inhibited the therapeutic effect of PCRR against hepatic steatosis in HFD-fed rats. Our findings demonstrate the potential of PCRR water extract as a novel autophagy enhancer for treating hepatic steatosis.
    Keywords:  Polygoni Cuspidati Rhizoma et Radix extract; Steatosis; TFEB; autophagy
    DOI:  https://doi.org/10.1016/j.lfs.2024.123158
  5. J Transl Med. 2024 Oct 31. 22(1): 985
    Ubiquitination regulates autophagy in cancer: simple modifications, promising targets.
    Yihui Wu, Yifei Chen, Xianyan Tian, Genbao Shao, Qiong Lin, Aiqin Sun.
      Autophagy is an important lysosomal degradation process that digests and recycles bio-molecules, protein or lipid aggregates, organelles, and invaded pathogens. Autophagy plays crucial roles in regulation of metabolic and oxidative stress and multiple pathological processes. In cancer, the role of autophagy is dual and paradoxical. Ubiquitination has been identified as a key regulator of autophagy that can influence various steps in the autophagic process, with autophagy-related proteins being targeted for ubiquitination, thus impacting cancer progression and the effectiveness of therapeutic interventions. This review will concentrate on mechanisms underlying autophagy, ubiquitination, and their interactions in cancer, as well as explore the use of drugs that target the ubiquitin-proteasome system (UPS) and ubiquitination process in autophagy as part of cancer therapy.
    Keywords:  Autophagy; Cancer; E3 ligase; UPS; Ubiquitination
    DOI:  https://doi.org/10.1186/s12967-024-05565-1
  6. Pharmaceuticals (Basel). 2024 Oct 11. pii: 1355. [Epub ahead of print]17(10):
    Pharmaceutical Agents for Targeting Autophagy and Their Applications in Clinics.
    Ulash Kench, Susanna Sologova, Elena Smolyarchuk, Vladimir Prassolov, Pavel Spirin.
      Autophagy is the process by which damaged regions of the cytoplasm and intracellular pathogens are degraded. This mechanism often serves an adaptive role in cells, enhancing their survival. It plays a direct or indirect role in the development of various pathological conditions within the body. This phenomenon is common in various malignant diseases, where autophagy is associated with the resistance of transformed cells to chemotherapy. Conversely, abnormal activation of autophagy can trigger cell death, a process often seen in neurodegenerative conditions. Given that dysregulation of autophagy is associated with the progression of numerous pathological conditions, this is of significant interest to the developers of drugs that can effectively modulate autophagy for both basic research and clinical applications. Here, we provide a brief description of the mechanism of macroautophagy, the most prevalent form of autophagy identified in humans. We also discuss the clinical potential of drugs that can modulate autophagy, highlighting their use in combating diseases associated with direct or indirect dysregulation of this essential process.
    Keywords:  autophagy; autophagy modulators; diseases; lysosomes
    DOI:  https://doi.org/10.3390/ph17101355
  7. Biomolecules. 2024 Oct 09. pii: 1270. [Epub ahead of print]14(10):
    Mitophagy in Cell Death Regulation: Insights into Mechanisms and Disease Implications.
    Jiani Lin, Xinyao Chen, Yuyang Du, Jiapeng Li, Tingting Guo, Sai Luo.
      Mitophagy, a selective form of autophagy, plays a crucial role in maintaining optimal mitochondrial populations, normal function, and intracellular homeostasis by monitoring and removing damaged or excess mitochondria. Furthermore, mitophagy promotes mitochondrial degradation via the lysosomal pathway, and not only eliminates damaged mitochondria but also regulates programmed cell death-associated genes, thus preventing cell death. The interaction between mitophagy and various forms of cell death has recently gained increasing attention in relation to the pathogenesis of clinical diseases, such as cancers and osteoarthritis, neurodegenerative, cardiovascular, and renal diseases. However, despite the abundant literature on this subject, there is a lack of understanding regarding the interaction between mitophagy and cell death. In this review, we discuss the main pathways of mitophagy, those related to cell death mechanisms (including apoptosis, ferroptosis, and pyroptosis), and the relationship between mitophagy and cell death uncovered in recent years. Our study offers potential directions for therapeutic intervention and disease diagnosis, and contributes to understanding the molecular mechanism of mitophagy.
    Keywords:  cell death; intracellular homeostasis; mitochondria; mitophagy
    DOI:  https://doi.org/10.3390/biom14101270
  8. Cell Death Discov. 2024 Oct 30. 10(1): 460
    Lipids associated with autophagy: mechanisms and therapeutic targets.
    Michał Jarocki, Kacper Turek, Jolanta Saczko, Mounir Tarek, Julita Kulbacka.
      Autophagy is a molecular process essential for maintaining cellular homeostasis, with its impairment or dysregulation linked to the progression of various diseases in mammals. Specific lipids, including phosphoinositides, sphingolipids, and oxysterols, play pivotal roles in inducing and regulating autophagy, highlighting their significance in this intricate process. This review focuses on the critical involvement of these lipids in autophagy and lipophagy, providing a comprehensive overview of the current understanding of their functions. Moreover, we delve into how abnormalities in autophagy, influenced by these lipids, contribute to the pathogenesis of various diseases. These include age-related conditions such as cardiovascular diseases, neurodegenerative disorders, type 2 diabetes, and certain cancers, as well as inflammatory and liver diseases, skeletal muscle pathologies and age-related macular degeneration (AMD). This review aims to highlight function of lipids and their potential as therapeutic targets in treating diverse human pathologies by elucidating the specific roles of phosphoinositides, sphingolipids, and oxysterols in autophagy.
    DOI:  https://doi.org/10.1038/s41420-024-02224-8
  9. Front Aging Neurosci. 2024 ;16 1491001
    The essential role of CCT2 in the regulation of aggrephagy.
    Jie Luo, Ze-Sen Feng, Ji-Xin Tang.
      Protein aggregation, a defining characteristic of numerous human diseases, poses a significant challenge to cellular health. Autophagy, an essential cellular recycling process, specifically targets and degrades these harmful protein aggregates through a specialized mechanism known as aggrephagy. However, the precise mechanisms underlying the exquisite selectivity of aggrephagy in identifying and eliminating only aggregated proteins while sparing healthy cellular components have remained enigmatic. Here, in this mini review, we highlights the essential role of CCT2, a subunit of the chaperonin TRiC complex, in regulating aggrephagy. CCT2, traditionally viewed as a molecular chaperone, has emerged as a novel autophagy receptor that specifically targets solid protein aggregates for degradation. This ubiquitination-independent mode of recognition by CCT2 expands our understanding of protein degradation pathways. The functional switch of CCT2 from a chaperone to an autophagy receptor underscores its dynamic nature and ability to adapt to cellular stress. The selectivity of CCT2-mediated aggrephagy for solid aggregates has implications for neurodegenerative diseases. Further research is warranted to explore the therapeutic potential of enhancing CCT2-mediated aggrephagy in such diseases.
    Keywords:  CCT2; aggrephagy; chaperonin; neurodegenerative diseases; protein aggregate
    DOI:  https://doi.org/10.3389/fnagi.2024.1491001
  10. Autophagy. 2024 Oct 30.
    Molecular mechanisms of escrt-mediated autophagosome maturation in plants.
    Niccolò Mosesso, Erika Isono.
      Diverse environmental stress factors affect the functionality of proteins and membrane compartments within cells causing potentially irremediable damage to the cell. A major process to eliminate nonfunctional molecular aggregates or damaged organelles under stress conditions is macroautophagy/autophagy, thus making its regulation critical for cellular adaptation and survival. The formation of autophagosomes is coordinated by a wide range of cellular factors and culminates in the closure of the cup-shaped double membrane or phagophore. The endosomal sorting complex required for transport (ESCRT) machinery has been proposed to mediate the sealing of the autophagic membranes. However, the molecular basis for ESCRT recruitment to phagophores under stress conditions are not yet fully understood. We recently described the role of ALIX (ALG-2 interacting protein-X) and its interactor CALB1 (Ca2+-dependent Lipid Binding protein 1) in autophagosome maturation during salt stress in Arabidopsis. Our study shows that CALB1 is important for phagophore closure and thus to the subsequent delivery to the vacuole. CALB1 localizes on salt-induced phagophores together with ALIX. CALB1 stimulates the phase separation of ALIX, which can facilitate the further ESCRT recruitment to phagophore membranes.
    Keywords:  ALIX; Arabidopsis; C2 domain; ESCRT; molecular condensates; salt-induced autophagy
    DOI:  https://doi.org/10.1080/15548627.2024.2423327
  11. Cancer Metab. 2024 Oct 26. 12(1): 31
    GCN2-SLC7A11 axis coordinates autophagy, cell cycle and apoptosis and regulates cell growth in retinoblastoma upon arginine deprivation.
    Dan Wang, Wai Kit Chu, Jason Cheuk Sing Yam, Chi Pui Pang, Yun Chung Leung, Alisa Sau Wun Shum, Sun-On Chan.
      BACKGROUND: Arginine deprivation was previously shown to inhibit retinoblastoma cell proliferation and induce cell death in vitro. However, the mechanisms by which retinoblastoma cells respond to arginine deprivation remain to be elucidated.METHODS: The human-derived retinoblastoma cell lines Y79 and WERI-Rb-1 were subjected to arginine depletion, and the effects on inhibiting cell growth and survival were evaluated. This study investigated potential mechanisms, including autophagy, cell cycle arrest and apoptosis. Moreover, the roles of the general control nonderepressible 2 (GCN2) and mechanistic target of rapamycin complex 1 (mTORC1) signaling pathways in these processes were examined.
    RESULTS: We demonstrated that arginine deprivation effectively inhibited the growth of retinoblastoma cells in vitro. This treatment caused an increase in the autophagic response. Additionally, prolonged arginine deprivation induced G2 cell cycle arrest and was accompanied by an increase in early apoptotic cells. Importantly, arginine depletion also induced the activation of GCN2 and the inhibition of mTOR signaling. We also discovered that the activation of SLC7A11 was regulated by GCN2 upon arginine deprivation. Knockdown of SLC7A11 rendered retinoblastoma cells partially resistant to arginine deprivation. Furthermore, we found that knockdown of GCN2 led to a decrease in the autophagic response in WERI-Rb-1 cells and arrested more cells in S phase, which was accompanied by fewer apoptotic cells. Moreover, knockdown of GCN2 induced the constant expression of ATF4 and the phosphorylation of 70S6K and 4E-BP1 regardless of arginine deprivation.
    CONCLUSIONS: Collectively, our findings suggest that the GCN2‒SLC7A11 axis regulates cell growth and survival upon arginine deprivation through coordinating autophagy, cell cycle arrest, and apoptosis in retinoblastoma cells. This work paves the way for the development of a novel treatment for retinoblastoma.
    Keywords:  Arginine deprivation; GCN2; Retinoblastoma; SCL7A11
    DOI:  https://doi.org/10.1186/s40170-024-00361-3
  12. Biomedicines. 2024 Oct 01. pii: 2238. [Epub ahead of print]12(10):
    The Role of mTOR in Mycobacterium tuberculosis Infection.
    Ami Patel, Lannhi Nguyen, Christina Shea, Sunjum Singh, Vishwanath Venketaraman.
      Background/Objectives: Mycobacterium tuberculosis (M. tb) is a pathogen that causes tuberculosis (TB), an extremely infectious disease which is responsible for millions of deaths worldwide. The severity of this pathogen is further amplified with the emergence of multidrug-resistant strains that are becoming more prevalent at an alarming rate, and novel treatments are needed. Methods: In this paper, we discuss the pathology M. tb infection. We review the literature on the role that mTOR plays in autophagy and the immune system as well as its impact on M. tb infection. Lastly, we discuss the current therapies targeting mTOR and potential routes to explore for future treatments. Results: The mTOR protein acts as a negative regulator of the autophagy pathway and presents as a potent target to establish new treatments for TB. M. tb survival is affected by mTOR, the PI3K/mTOR/AKT pathway, and autophagy. M. tb evades destruction by manipulating host cellular mechanisms, which increases resistance and complicates treatment. Conclusions: Targeting mTOR can enhance autophagy and increase M. tb clearance. Existing drugs such as everolimus, rapamycin + CC214-2, and bazedoxifene are all being currently studied for effectiveness and show positive results. Alternative therapies, including Chinese herbs, baicalin, BTLA, glutathione, and precision medicine can modulate the PI3K/mTOR/AKT pathway and the host's immune response, resulting in increased M. tb clearance, and these may be the future treatments for M. tb infection.
    Keywords:  Mycobacterium tuberculosis; autophagy; mTOR
    DOI:  https://doi.org/10.3390/biomedicines12102238
  13. bioRxiv. 2024 Oct 14. pii: 2024.10.14.618295. [Epub ahead of print]
    Cell-Type Resolved Protein Atlas of Brain Lysosomes Identifies SLC45A1-Associated Disease as a Lysosomal Disorder.
    Ali Ghoochani, Julia C Heiby, Eshaan S Rawat, Uche N Medoh, Domenico Di Fraia, Wentao Dong, Marc Gastou, Kwamina Nyame, Nouf N Laqtom, Natalia Gomez-Ospina, Alessandro Ori, Monther Abu-Remaileh.
      Mutations in lysosomal genes cause neurodegeneration and neurological lysosomal storage disorders (LSDs). Despite their essential role in brain homeostasis, the cell-type-specific composition and function of lysosomes remain poorly understood. Here, we report a quantitative protein atlas of the lysosome from mouse neurons, astrocytes, oligodendrocytes, and microglia. We identify dozens of novel lysosomal proteins and reveal the diversity of the lysosomal composition across brain cell types. Notably, we discovered SLC45A1, mutations in which cause a monogenic neurological disease, as a neuron-specific lysosomal protein. Loss of SLC45A1 causes lysosomal dysfunction in vitro and in vivo. Mechanistically, SLC45A1 plays a dual role in lysosomal sugar transport and stabilization of V1 subunits of the V-ATPase. SLC45A1 deficiency depletes the V1 subunits, elevates lysosomal pH, and disrupts iron homeostasis causing mitochondrial dysfunction. Altogether, our work redefines SLC45A1-associated disease as a LSD and establishes a comprehensive map to study lysosome biology at cell-type resolution in the brain and its implications for neurodegeneration.
    DOI:  https://doi.org/10.1101/2024.10.14.618295
  14. Nat Commun. 2024 Oct 25. 15(1): 9238
    Accumulation of F-actin drives brain aging and limits healthspan in Drosophila.
    Edward T Schmid, Joseph M Schinaman, Naomi Liu-Abramowicz, Kylie S Williams, David W Walker.
      The actin cytoskeleton is a key determinant of cell structure and homeostasis. However, possible tissue-specific changes to actin dynamics during aging, notably brain aging, are not understood. Here, we show that there is an age-related increase in filamentous actin (F-actin) in Drosophila brains, which is counteracted by prolongevity interventions. Critically, decreasing F-actin levels in aging neurons prevents age-onset cognitive decline and extends organismal healthspan. Mechanistically, we show that autophagy, a recycling process required for neuronal homeostasis, is disabled upon actin dysregulation in the aged brain. Remarkably, disrupting actin polymerization in aged animals with cytoskeletal drugs restores brain autophagy to youthful levels and reverses cellular hallmarks of brain aging. Finally, reducing F-actin levels in aging neurons slows brain aging and promotes healthspan in an autophagy-dependent manner. Our data identify excess actin polymerization as a hallmark of brain aging, which can be targeted to reverse brain aging phenotypes and prolong healthspan.
    DOI:  https://doi.org/10.1038/s41467-024-53389-w
  15. Biochim Biophys Acta Mol Basis Dis. 2024 Oct 23. pii: S0925-4439(24)00542-8. [Epub ahead of print]1871(1): 167548
    Thioredoxin-1 protein interactions in neuronal survival and neurodegeneration.
    Md Imamul Islam, Shakila Sultana, Nirmala Padmanabhan, Mahamud-Ur Rashid, Tabrez J Siddiqui, Kevin M Coombs, Peter F Vitiello, Soheila Karimi-Abdolrezaee, Eftekhar Eftekharpour.
      Neuronal cell death remains the principal pathophysiologic hallmark of neurodegenerative diseases and the main challenge for treatment strategies. Thioredoxin1 (Trx1) is a major cytoplasmic thiol oxidoreductase protein involved in redox signaling, hence a crucial player in maintaining neuronal health. Trx1 levels are notably reduced in neurodegenerative diseases including Alzheimer's and Parkinson's diseases, however, the impact of this decrease on neuronal physiology remains largely unexplored. This is mainly due to the nature of Trx1 redox regulatory role which is afforded by a rapid electron transfer to its oxidized protein substrates. During this reaction, Trx1 forms a transient bond with the oxidized disulfide bond in the substrate. This is a highly fast reaction which makes the identification of Trx1 substrates a technically challenging task. In this project, we utilized a transgenic mouse model expressing a Flag-tagged mutant form of Trx1 that can form stable disulfide bonds with its substrates, hence allowing identification of the Trx1 target proteins. Autophagy is a vital housekeeping process in neurons that is critical for degradation of damaged proteins under oxidative stress conditions and is interrupted in neurodegenerative diseases. Given Trx1's suggested involvement in autophagy, we aimed to identify potential Trx1 substrates following pharmacologic induction of autophagy in primary cortical neurons. Treatment with rapamycin, an autophagy inducer, significantly reduced neurite outgrowth and caused cytoskeletal alterations. Using immunoprecipitation and mass spectrometry, we have identified 77 Trx1 target proteins associated with a wide range of cellular functions including cytoskeletal organization and neurodegenerative diseases. Focusing on neuronal cytoskeleton organization, we identified a novel interaction between Trx1 and RhoB which was confirmed in genetic models of Trx1 downregulation in primary neuronal cultures and HT22 mouse immortalized hippocampal neurons. The applicability of these findings was also tested against the publicly available proteomic data from Alzheimer's patients. Our study uncovers a novel role for Trx1 in regulating neuronal cytoskeleton organization and provides a mechanistic explanation for its multifaceted role in the physiology and pathology of the nervous system, offering new insights into the molecular mechanisms underlying neurodegeneration.
    Keywords:  F-actin; Fibrilization; G-actin; Neuronal homeostasis; Proteomics; Rapamycin; Redox; RhoB; RhoG
    DOI:  https://doi.org/10.1016/j.bbadis.2024.167548
  16. Front Cell Dev Biol. 2024 ;12 1472574
    The dual role of autophagy in suppressing and promoting hepatocellular carcinoma.
    Wasnaa H Mohammed, Ghassan M Sulaiman, Mosleh M Abomughaid, Daniel J Klionsky, Mohammed H Abu-Alghayth.
      The 5-year survival rate for hepatocellular carcinoma (HCC), a deadly form of liver cancer, is quite low. Although drug therapy is successful, patients with advanced liver cancer frequently develop resistance because of the significant phenotypic and genetic heterogeneity of these cells. The overexpression of drug efflux transporters, downstream adaptive responses, malfunctioning DNA damage repair, epigenetic modification, the tumor microenvironment, and the extracellular matrix can all be linked to drug resistance. The evolutionary process of autophagy, which is in charge of intracellular breakdown, is intimately linked to medication resistance in HCC. Autophagy is involved in both the promotion and suppression of cancer by influencing treatment resistance, metastasis, carcinogenesis, and the viability of stem cells. Certain autophagy regulators are employed in anticancer treatment; however, because of the dual functions of autophagy, their use is restricted, and therapeutic failure is increased. By focusing on autophagy, it is possible to reduce HCC expansion and metastasis, and enhance tumor cell reactivity to treatment. Macroautophagy, the best-characterized type of autophagy, involves the formation of a sequestering compartment termed a phagophore, which surrounds and encloses aberrant or superfluous components. The phagophore matures into a double-membrane autophagosome that delivers the cargo to the lysosome; lysosomes and autophagosomes fuse to degrade and recycle the cargo. Macroautophagy plays dual functions in both promoting and suppressing cancer in a variety of cancer types.
    Keywords:  autophagy; autophagy dual role; cancer; drug resistance; hepatocecllular carcimoa
    DOI:  https://doi.org/10.3389/fcell.2024.1472574
  17. Neuroscience. 2024 Oct 29. pii: S0306-4522(24)00567-0. [Epub ahead of print]
    mTOR signaling pathway as a pathophysiologic mechanism in preclinical models of autism spectrum disorder.
    Isabela Drehmer, Júlio Santos-Terra, Carmem Gottfried, Iohanna Deckmann.
      Autism spectrum disorder (ASD) is a highly prevalent multifactorial disorder characterized by social deficits and stereotypies. Despite extensive research efforts, the etiology of ASD remains poorly understood. However, studies using preclinical models have identified the mechanistic target of rapamycin kinase (mTOR) signaling pathway as a key player in ASD-related features. This review examines genetic and environmental models of ASD, focusing on their association with the mTOR pathway. We organize findings on alterations within this pathway, providing insights about the potential mechanisms involved in the onset and maintenance of ASD symptoms. Our analysis highlights the central role of mTOR hyperactivation in disrupting autophagic processes, neural organization, and neurotransmitter pathways, which collectively contribute to ASD phenotypes. The review also discusses the therapeutic potential of mTOR pathway inhibitors, such as rapamycin, in mitigating ASD characteristics. These insights underscore the importance of the mTOR pathway as a target for future research and therapeutic intervention in ASD. This review innovates by bringing the convergence of disrupted mTOR signaling in preclinical models and clinical data associated with ASD.
    Keywords:  Animal models; Autism spectrum disorder; Rapamycin kinase; mTOR
    DOI:  https://doi.org/10.1016/j.neuroscience.2024.10.050
  18. Front Biosci (Landmark Ed). 2024 Oct 08. 29(10): 348
    Autophagy Alterations in White and Brown Adipose Tissues of Mice Exercised under Different Training Protocols.
    Isaac Tamargo-Gómez, Manuel Fernández-Sanjurjo, Helena Codina-Martínez, Cristina Tomás-Zapico, Eduardo Iglesias-Gutiérrez, Benjamín Fernández-García, Álvaro F Fernández.
      BACKGROUND: Autophagy is a conserved catabolic process that promotes cellular homeostasis and health. Although exercise is a well-established inducer of this pathway, little is known about the effects of different types of training protocols on the autophagy levels of tissues that are tightly linked to age-related metabolic syndromes (like brown adipose tissue) but are not easily accessible in humans.METHODS: Here, we take advantage of animal models to assess the effects of short- and long-term resistance and endurance training in both white and brown adipose tissue, reporting distinct alterations on autophagy proteins microtubule-associated proteins 1A/1B light chain 3B (MAP1LC3B, or LC3B) and sequestosome-1 (SQSTM1/p62). Additionally, we also analyzed the repercussions of these interventions in fat tissues of mice lacking autophagy-related protein 4 homolog B (ATG4B), further assessing the impact of exercise in these dynamic, regulatory organs when autophagy is limited.
    RESULTS: In wild-type mice, both short-term endurance and resistance training protocols increased the levels of autophagy markers in white adipose tissue before this similarity diverges during long training, while autophagy regulation appears to be far more complex in brown adipose tissue. Meanwhile, in ATG4B-deficient mice, only resistance training could slightly increase the presence of lipidated LC3B, while p62 levels increased in white adipose tissue after short-term training but decreased in brown adipose tissue after long-term training.
    CONCLUSIONS: Altogether, our study suggests an intricated regulation of exercise-induced autophagy in adipose tissues that is dependent on the training protocol and the autophagy competence of the organism.
    Keywords:  ATG4B; LC3B; adipose tissue; autophagy; endurance training; exercise; p62; resistance training
    DOI:  https://doi.org/10.31083/j.fbl2910348
  19. Naunyn Schmiedebergs Arch Pharmacol. 2024 Nov 01.
    Characterisation of autophagy induction by the thiopurine drugs azathioprine, mercaptopurine and thioguanine in THP-1 macrophages.
    Connan D Masson, Fern Findlay-Greene, Filipa Henderson Sousa, Paul Henderson, Jennifer A Fraser, Peter G Barlow, Craig Stevens.
      Activating autophagy may be therapeutically beneficial, and we have previously shown that azathioprine (AZA), an immunomodulatory drug, induces autophagy. Here, we evaluated the induction of autophagy by the thiopurines AZA, mercaptopurine (6-MP) and thioguanine (6-TG) in THP-1 macrophages and investigated the mechanism of action in the context of this cellular process. The cytotoxicity of thiopurines was evaluated using an LDH assay. Induction of endogenous LC3 by thiopurines was evaluated using immunostaining. To confirm autophagy activation by thiopurines, a GFP-RFP-LC3 reporter plasmid was used to monitor the maturation of autophagosomes to autolysosomes. Induction of apoptosis by thiopurines was evaluated using Annexin V/PI staining, and ER stress was assessed via RT‒PCR analysis of XBP1 splicing. To gain insight into the mechanism of action of thiopurines, mTORC1 activity and eIF2α-S51 phosphorylation were evaluated by immunoblotting. Thiopurines were not cytotoxic to cells and induced strong time- and concentration-dependent autophagy. Thiopurines activate autophagy with complete progression through the pathway. Induction of autophagy by thiopurines occurred independently of apoptosis and ER stress. Immunoblotting revealed that AZA inhibited mTORC1 activity, and AZA and 6-TG increased eIF2α-S51 phosphorylation. In contrast, 6-MP had a minor effect on either signalling pathway. Thiopurines are strong inducers of autophagy, and autophagy induction should be considered among the mechanisms responsible for patient response to thiopurines.
    Keywords:  Autophagy; EIF2α; MTORC1; Thiopurines
    DOI:  https://doi.org/10.1007/s00210-024-03563-0
  20. PNAS Nexus. 2024 Oct;3(10): pgae457
    Neuron-specific deficiency of autophagy increases neuronal loss in traumatic brain injury.
    Chunying Pei, Bo Li, Sijia Wen, Kai Zhao, Shuxian Yu, Tao Li, Yu Li, Yanran Fu, Linlu Tian, Hongwei Xu, Huakun Cheng, Rui Li.
      The involvement of neuronal autophagy in traumatic brain injury (TBI) remains elusive. Previous investigations, as far as our knowledge extends, have modulated autophagy either through systemic administration of autophagy inhibitors/inducers or by eliminating key regulators of autophagy across all somatic cells, lacking specificity for neurons. Consequently, drawing conclusions from such studies may be muddled by inhibiting autophagy in other cell types, including astrocytes, microglia, and immune cells. To discern the precise role of neuronal autophagy in TBI, we generated tamoxifen-induced, neuron-specific, autophagy-deficient mice by crossing atg5 flox/flox mice with map2-CreERT2 mice. We then induced TBI in either control mice or mice with neuron-specific autophagy deficiency. Our findings revealed that the absence of autophagy, specifically in adult neurons, led to exaggerated neurologic-deficit syndromes and more pronounced neuronal loss. Additionally, we demonstrated that neuronal autophagy is orchestrated by immunity-related GTPase family M member 1 (Irgm1) in neural injury, as evidenced by neuron-specific irgm1 knockout mice displaying a significant reduction in neuronal autophagy and heightened neuronal loss compared with control mice. Collectively, our data provide more conclusive evidence that fortifies the neuroprotective role of autophagy in TBI.
    Keywords:  Atg5; autophagy; immune-related GTPase family M member 1; neuron; traumatic brain injury
    DOI:  https://doi.org/10.1093/pnasnexus/pgae457
  21. Biol Open. 2024 Oct 29. pii: bio.060380. [Epub ahead of print]
    Disrupting the interaction between AMBRA1 and DLC1 prevents apoptosis while enhancing autophagy and mitophagy.
    Kate Hawkins, Meg Watt, Sébastien Gillotin, Maya Hanspal, Martin Helley, Jill Richardson, Nicola Corbett, Janet Brownlees.
      AMBRA1 has critical roles in autophagy, mitophagy, cell cycle regulation, neurogenesis and apoptosis. Dysregulation of these processes are hallmarks of various neurodegenerative diseases and therefore AMBRA1 represents a potential therapeutic target. The flexibility of its intrinsically disordered regions allows AMBRA1 to undergo conformational changes and thus perform its function as an adaptor protein for various different complexes. Understanding the relevance of these multiple protein-protein interactions will allow us to gain information about which to target pharmacologically. To compare potential AMBRA1 activation strategies we have designed and validated several previously described mutant constructs in addition to characterising their effects on proliferation, apoptosis, autophagy and mitophagy in SHSY5Y cells. AMBRA1TAT, which is a mutant form of AMBRA1 that can't interact with DLC1 at the microtubules, produced the most promising results. Overexpression of this mutant protected cells against apoptosis and induced autophagy/mitophagy in SHSY5Y cells in addition to enhancing the switch from quiescence to proliferation in mouse NSCs. Future studies should focus on designing compounds that inhibit the protein-protein interaction between AMBRA1/DLC1 and thus have potential to be used as a drug strategy for neurodegeneration.
    Keywords:  Apoptosis; Autophagy; Mitophagy; Neurodegeneration
    DOI:  https://doi.org/10.1242/bio.060380
  22. Life Sci. 2024 Oct 24. pii: S0024-3205(24)00763-X. [Epub ahead of print]358 123173
    Autophagy deficiency exacerbated hypoxia-reoxygenation induced inflammation and cell death via a mitochondrial DNA/STING/IRF3 pathway.
    Eddie Tam, Erfei Song, Nina Noskovicova, Boris Hinz, Aimin Xu, Gary Sweeney.
      AIMS: Autophagy is an important cellular process for maintaining physiological homeostasis and is known to protect against cardiovascular diseases including ischemia reperfusion (I/R) injury. The underlying mechanisms behind its protection require further characterization.MATERIALS AND METHODS: Atg7 knock out (AKO) mice were generated and subjected to I/R injury, complemented by Atg7 KO in a H9c2 cardiomyoblast cellular model ± hypoxia-reoxygenation. Subsequently, in both models, inflammation and cell death were studied.
    KEY FINDINGS: We confirmed that Atg7 KO led to autophagy, including mitophagy, deficiency. Upon H/R, Atg7 KO cells exhibited increased cell death compared to WT cells. Notably, we found that autophagy deficiency increased stress-induced mitochondrial fission, release of mitochondrial DNA, and sterile inflammation, namely activation of a STING/IRF3 axis leading to elevated interferon-α. Following I/R injury, AKO mice showed elevated cell death which correlated with a gene expression profile indicative of decreased anti-inflammatory responses.
    SIGNIFICANCE: Autophagy deficiency in the cardiomyocyte setting results in detrimental effects during I/R injury in mice or H/R injury in cells, mediated in part via mtDNA/IRF3/STING pathway. As such, modulation of this pathway may yield novel and promising therapeutics to treat or prevent I/R injury.
    Keywords:  Atg7; Autophagy; Cell death; Heart; Hypoxia; Reoxygenation
    DOI:  https://doi.org/10.1016/j.lfs.2024.123173
  23. Chem Biol Interact. 2024 Oct 23. pii: S0009-2797(24)00434-4. [Epub ahead of print]405 111288
    Benzo(a)pyrene promotes autophagy to impair endometrial decidualization via inhibiting CXCL12/CXCR4 axis.
    Jiaying Huang, Fengxia Liu, Tao Qi, Rufei Gao, Hongye Xie, Lingyan Ruan, Junlin He, Fangfang Li, Taihang Liu, Hanting Xu, Xuemei Chen.
      Benzo(a)pyrene (BaP), a pervasive environmental pollutant with endocrine-disrupting properties, has been associated with detrimental effects on pregnancy. During early pregnancy, the endometrial decidualization process is critical for embryo implantation. Abnormal decidualization can lead to implantation failure, aberrant placental formation, and pregnancy loss. We previously revealed that BaP exposure impaired decidualization and implantation in mice, yet the underlying mechanisms remained elusive. Autophagy, a cellular mechanism pivotal for energy and material recycling, contributes to the decidualization process. The chemokine C-X-C motif chemokine ligand 12 (CXCL12), secreted by endometrium stromal cells (ESCs), is involved in regulating endometrial decidualization and autophagy. Therefore, this study aimed to explore the hypothesis that BaP disrupts the decidualization process by interfering with autophagic pathways via the CXCL12/CXCR4 axis during early pregnancy. We found that BaP inhibited CXCL12/CXCR4 expression, and induced autophagy by promoting autophagosome formation, which in turn impaired the decidualization in early pregnant mice uterus and decidual stromal cells (DSCs). Using autophagy inhibitors 3-methyladenine and chloroquine in combination with BaP to treat DSCs, successfully weakened BaP-induced autophagy, and relieved decidual injury. Additionally, activation of CXCL12/CXCR4 by recombinant protein CXCL12 attenuated BaP-induced autophagy, inhibited the PI3K/AKT signal activation caused by BaP, and partly rescued the expression of decidualization-related genes. In summary, this study demonstrates that BaP induces autophagy in DSCs by inhibiting the CXCL12/CXCR4 axis, leading to damage in endometrial decidualization during early pregnancy. The findings provide a critical chemokine-mediated regulatory mechanism involved in embryo implantation and contribute valuable knowledge to the reproductive toxicology of BaP.
    Keywords:  Autophagy; BaP; CXCL12/CXCR4; Decidualization; PI3K/AKT
    DOI:  https://doi.org/10.1016/j.cbi.2024.111288
  24. Diabetol Int. 2024 Oct;15(4): 707-718
    mTORC1 signaling and diabetic kidney disease.
    Vinamra Swaroop, Eden Ozkan, Lydia Herrmann, Aaron Thurman, Olivia Kopasz-Gemmen, Abhiram Kunamneni, Ken Inoki.
      Diabetic kidney disease (DKD) represents the most lethal complication in both type 1 and type 2 diabetes. The disease progresses without obvious symptoms and is often refractory when apparent symptoms have emerged. Although the molecular mechanisms underlying the onset/progression of DKD have been extensively studied, only a few effective therapies are currently available. Pathogenesis of DKD involves multifaced events caused by diabetes, which include alterations of metabolisms, signals, and hemodynamics. While the considerable efficacy of sodium/glucose cotransporter-2 (SGLT2) inhibitors or angiotensin II receptor blockers (ARBs) for DKD has been recognized, the ever-increasing number of patients with diabetes and DKD warrants additional practical therapeutic approaches that prevent DKD from diabetes. One plausible but promising target is the mechanistic target of the rapamycin complex 1 (mTORC1) signaling pathway, which senses cellular nutrients to control various anabolic and catabolic processes. This review introduces the current understanding of the mTOR signaling pathway and its roles in the development of DKD and other chronic kidney diseases (CKDs), and discusses potential therapeutic approaches targeting this pathway for the future treatment of DKD.
    Keywords:  Diabetic kidney disease (DKD); Diabetic nephropathy; Nutrients; Rapamycin; SGLT2 inhibitors; mTORC1
    DOI:  https://doi.org/10.1007/s13340-024-00738-1
  25. Nat Commun. 2024 Oct 29. 15(1): 9347
    AAA+ ATPase chaperone p97/VCPFAF2 governs basal pexophagy.
    Fumika Koyano, Koji Yamano, Tomoyuki Hoshina, Hidetaka Kosako, Yukio Fujiki, Keiji Tanaka, Noriyuki Matsuda.
      Peroxisomes are organelles that are central to lipid metabolism and chemical detoxification. Despite advances in our understanding of peroxisome biogenesis, the mechanisms maintaining peroxisomal membrane proteins remain to be fully elucidated. We show here that mammalian FAF2/UBXD8, a membrane-associated cofactor of p97/VCP, maintains peroxisomal homeostasis by modulating the turnover of peroxisomal membrane proteins such as PMP70. In FAF2-deficient cells, PMP70 accumulation recruits the autophagy adaptor OPTN (Optineurin) to peroxisomes and promotes their autophagic clearance (pexophagy). Pexophagy is also induced by p97/VCP inhibition. FAF2 functions together with p97/VCP to negatively regulate pexophagy rather than as a factor for peroxisome biogenesis. Our results strongly suggest that p97/VCPFAF2-mediated extraction of ubiquitylated peroxisomal membrane proteins (e.g., PMP70) prevents peroxisomes from inducing nonessential autophagy under steady state conditions. These findings provide insight into molecular mechanisms underlying the regulation of peroxisomal integrity by p97/VCP and its associated cofactors.
    DOI:  https://doi.org/10.1038/s41467-024-53558-x
  26. Arch Biochem Biophys. 2024 Oct 23. pii: S0003-9861(24)00308-4. [Epub ahead of print]761 110186
    The role of host autophagy in intracellular protozoan parasites diseases.
    Rafael Cardoso Maciel Costa Silva, Jhones Sousa Ribeiro, Thalita Santos de Moraes de Farias, Leonardo Holanda Travassos.
      Intracellular protozoan parasites are the etiologic agents of important human diseases, like malaria, Chagas disease, toxoplasmosis, and leishmaniasis. Inside host cells, these parasites manipulate the host metabolism and intracellular trafficking for their own benefits and, inevitably, induce several stress response mechanisms. In this review, we discuss autophagy as a stress response mechanism that can be both (i) explored by these intracellular parasites to acquire nutrients and (ii) to restrict parasite proliferation and survival within host cells. We also discuss the immunomodulatory role of autophagy as a strategy to reduce inflammatory-mediated damage, an essential player in the pathophysiology of these parasitic diseases. At last, we propose and discuss several known autophagy modulators as possible pharmaceuticals for adjunctive therapies.
    Keywords:  Autophagy; Chagas disease; Immune response; Leishmaniasis; Malaria; Toxoplasmosis
    DOI:  https://doi.org/10.1016/j.abb.2024.110186
  27. J Neuroinflammation. 2024 Oct 26. 21(1): 275
    α-Synuclein disrupts microglial autophagy through STAT1-dependent suppression of Ulk1 transcription.
    Chong-Shuang Pei, Xiao-Ou Hou, Zhen-Yuan Ma, Hai-Yue Tu, Hai-Chun Qian, Yang Li, Kai Li, Chun-Feng Liu, Liang Ouyang, Jun-Yi Liu, Li-Fang Hu.
      BACKGROUND: Autophagy dysfunction in glial cells is implicated in the pathogenesis of Parkinson's disease (PD). The previous study reported that α-synuclein (α-Syn) disrupted autophagy in cultured microglia. However, the mechanism of microglial autophagy dysregulation is poorly understood.METHODS: Two α-Syn-based PD models were generated via AAV-mediated α-Syn delivery into the mouse substantia nigra and striatal α-Syn preformed fibril (PFF) injection. The levels of microglial UNC-51-like kinase 1 (Ulk1) and other autophagy-related genes in vitro and in PD mice, as well as in the peripheral blood mononuclear cells of PD patients and healthy controls, were determined via quantitative PCR, western blotting and immunostaining. The regulatory effect of signal transducer and activator of transcription 1 (STAT1) on Ulk1 transcription was determined via a luciferase reporter assay and other biochemical studies and was verified through Stat1 knockdown or overexpression. The effect of α-Syn on glial STAT1 activation was assessed by immunohistochemistry and western blotting. Changes in microglial status, proinflammatory molecule expression and dopaminergic neuron loss in the nigrostriatum of PD and control mice following microglial Stat1 conditional knockout (cKO) or treatment with the ULK1 activator BL-918 were evaluated by immunostaining and western blotting. Motor behaviors were determined via open field tests, rotarod tests and balance beam crossing.
    RESULTS: The transcription of microglial ULK1, a kinase that controls autophagy initiation, decreased in both in vitro and in vivo PD mouse models. STAT1 plays a critical role in suppressing Ulk1 transcription. Specifically, Stat1 overexpression downregulated Ulk1 transcription, while Stat1 knockdown increased ULK1 expression, along with an increase in LC3II and a decrease in the SQSTM1/p62 protein. α-Syn PFF caused toll-like receptor 4-dependent activation of STAT1 in microglia. Ablation of Stat1 alleviated the decrease in microglial ULK1 expression and disruption of autophagy caused by α-Syn PFF. Importantly, the ULK1 activator BL-918 and microglial Stat1 cKO attenuated neuroinflammation, dopaminergic neuronal damage and motor defects in PD models.
    CONCLUSIONS: These findings reveal a novel mechanism by which α-Syn impairs microglial autophagy and indicate that targeting STAT1 or ULK1 may be a therapeutic strategy for PD.
    Keywords:  Autophagy; Microglia; Parkinson’s disease; STAT1; ULK1; α-synuclein
    DOI:  https://doi.org/10.1186/s12974-024-03268-4
  28. Chem Biomed Imaging. 2024 Feb 26. 2(2): 81-97
    Advances in Small-Molecule Fluorescent pH Probes for Monitoring Mitophagy.
    Yurui Liu, Duoteng Zhang, Yunwei Qu, Fang Tang, Hui Wang, Aixiang Ding, Lin Li.
      Mitochondria play a crucial role in regulating cellular energy homeostasis and cell death, making them essential organelles. Maintaining proper cellular functions relies on the removal of damaged mitochondria through a process called mitophagy. Mitophagy is associated with changes in the pH value and has implications for numerous diseases. To effectively monitor mitophagy, fluorescent probes that exhibit high selectivity and sensitivity based on pH detection have emerged as powerful tools. In this review, we present recent advancements in the monitoring of mitophagy using small-molecule fluorescence pH probes. We focus on various sensing mechanisms employed by these probes, including intramolecular charge transfer (ICT), fluorescence resonance energy transfer (FRET), through bond energy transfer (TBET), and photoelectron transfer (PET). Additionally, we discuss disease models used for studying mitophagy and summarize the design requirements for small-molecule fluorescent pH probes suitable for monitoring the mitophagy process. Lastly, we highlight the remaining challenges in this field and propose potential directions for the future development of mitophagy probes.
    DOI:  https://doi.org/10.1021/cbmi.3c00070
  29. Biomolecules. 2024 Oct 08. pii: 1268. [Epub ahead of print]14(10):
    The Many Faces of Autophagy: Balancing Survival and Cell Death.
    Barbara Canonico.
      Autophagy and apoptosis are two fundamental biological mechanisms that may cooperate or be antagonistic, and both are involved in deciding the fate of cells in physiological or pathological conditions [...].
    DOI:  https://doi.org/10.3390/biom14101268
  30. Cell Death Dis. 2024 Oct 28. 15(10): 783
    Autophagy: a critical mechanism of N6-methyladenosine modification involved in tumor progression and therapy resistance.
    Feiyang Wang, Qiudi Liao, Zihao Qin, Jingyi Li, Qingqing Wei, Mengna Li, Hongyu Deng, Wei Xiong, Ming Tan, Ming Zhou.
      N6-Methyladenosine (m6A) is an evolutionarily highly conserved epigenetic modification that affects eukaryotic RNAs, especially mRNAs, and m6A modification is commonly linked to tumor proliferation, progression, and therapeutic resistance by participating in RNA metabolism. Autophagy is an intracellular degradation and recycling biological process by which cells remove damaged organelles, protein aggregates, and other intracellular wastes, and release nutrients to maintain cell survival when energy is scarce. Recent studies have shown that m6A modification plays a critical role in the regulation of autophagy, affecting the initiation of autophagy, the formation and assembly of autophagosomes, and lysosomal function by regulating critical regulatory molecules involved in the process of autophagy. Moreover, autophagy can also affect the expression of the three types of regulators related to m6A, which in turn affects the levels of their target genes via m6A modification. Thus, m6A modification and autophagy form a sophisticated regulatory network through mutual regulation, which plays an important role in tumor progression and therapeutic resistance. In this manuscript, we reviewed the effects of m6A modification on autophagy as well as the effects of autophagy on m6A modification and the roles of the m6A-autophagy axis in tumor progression and therapy resistance. Additionally, we summarized the value and application prospects of key molecules in the m6A-autophagy axis in tumor diagnosis and therapy.
    DOI:  https://doi.org/10.1038/s41419-024-07148-w
  31. Autophagy. 2024 Oct 26.
    HSP90 N-terminal inhibition promotes mitochondria-derived vesicles related metastasis by reducing TFEB transcription via decreased HSP90AA1-HCFC1 interaction in liver cancer.
    Lixia Liu, Zhenming Zheng, Yaling Huang, Hairou Su, Guibing Wu, Zihao Deng, Yan Li, Guantai Xie, Jieyou Li, Fei Zou, Xuemei Chen.
      Cancer cells compensate with increasing mitochondria-derived vesicles (MDVs) to maintain mitochondrial homeostasis, when canonical MAP1LC3B/LC3B (microtubule associated protein 1 light chain 3 beta)-mediated mitophagy is lacking. MDVs promote the transport of mitochondrial components into extracellular vesicles (EVs) and induce tumor metastasis. Although HSP90 (heat shock protein 90) chaperones hundreds of client proteins and its inhibitors suppress tumors, HSP90 inhibitors-related chemotherapy is associated with unexpected metastasis. Herein, we find that HSP90 inhibitor causes mitochondrial damage but stimulates the low LC3-induced MDVs and the release of MDVs-derived EVs. However, why LC3 decreases and what is the transcriptional regulatory mechanism of MDVs formation under HSP90 inhibition remain unknown. Because TFEB (transcription factor EB) is the most important mitophagy transcription factor, and the HSP90 client HCFC1 (host cell factor C1) regulates TFEB transcription, there should be a hidden connection between TFEB, HCFC1 and HSP90 in MDVs formation. Our results support the idea that HSP90 N-terminal inhibition reduces TFEB transcription via decreased HSP90AA1-HCFC1 interaction, which prevents HCFC1 from binding to the TFEB proximal promoter region. Decreased TFEB transcription and consequently reduced LC3, ultimately promoted MDVs formation. Blocking MDVs formation with the microtubule inhibitor nocodazole (NOC) activates the HCFC1-TFEB-LC3 axis, weakens HSP90 inhibitors-induced MDVs and the release of MDVs-derived EVs, inhibits the growth of tumor cell spheres and primary liver tumors, and reduces the extravasation of cancer cells to secondary metastatic sites. Taken together, these data suggest that combination therapy should be used to reduce the metastatic risk of low TFEB-triggered-MDVs formation caused by HSP90 inhibitors.
    Keywords:  HCFC1/host cell factor C1; HSP90/heat shock protein 90; Mdvs/mitochondria-derived vesicles; Tfeb/transcription factor EB; metastasis; mitophagy
    DOI:  https://doi.org/10.1080/15548627.2024.2421703
  32. Int J Mol Sci. 2024 Oct 17. pii: 11160. [Epub ahead of print]25(20):
    The Knowns and Unknowns of Membrane Features and Changes During Autophagosome-Lysosome/Vacuole Fusion.
    Jinmeng Liu, Hanyu Ma, Zulin Wu, Yanling Ji, Yongheng Liang.
      Autophagosome (AP)-lysosome/vacuole fusion is one of the hallmarks of macroautophagy. Membrane features and changes during the fusion process have mostly been described using two-dimensional (2D) models with one AP and one lysosome/vacuole. The outer membrane (OM) of a closed mature AP has been suggested to fuse with the lysosomal/vacuolar membrane. However, the descriptions in some studies for fusion-related issues are questionable or incomplete. The correct membrane features of APs and lysosomes/vacuoles are the prerequisite for describing the fusion process. We searched the literature for representative membrane features of AP-related structures based on electron microscopy (EM) graphs of both animal and yeast cells and re-evaluated the findings. We also summarized the main 2D models describing the membrane changes during AP-lysosome/vacuole fusion in the literature. We used three-dimensional (3D) models to characterize the known and unknown membrane changes during and after fusion of the most plausible 2D models. The actual situation is more complex, since multiple lysosomes may fuse with the same AP in mammalian cells, multiple APs may fuse with the same vacuole in yeast cells, and in some mutant cells, phagophores (unclosed APs) fuse with lysosomes/vacuoles. This review discusses the membrane features and highly dynamic changes during AP (phagophore)-lysosome/vacuole fusion. The resulting information will improve the understanding of AP-lysosome/vacuole fusion and direct the future research on AP-lysosome/vacuole fusion and regeneration.
    Keywords:  2D models; 3D models; autophagic body; autophagosome; autophagosome–lysosome/vacuole fusion; double membrane; electron microscopy; lysosome; single membrane; vacuole
    DOI:  https://doi.org/10.3390/ijms252011160
  33. Vet Q. 2024 Dec;44(1): 1-15
    Beclin-1 and LC3B expression in canine mast cell tumours: an immuno-ultrastructural and immunohistochemical study of autophagy.
    Giovanna P Vicente, Leonardo Della Salda, Ricardo F Strefezzi.
      Mast cell tumours (MCTs) are common malignant neoplasms in dogs, for which prognosis and therapeutic decisions are based on histological features and proliferation markers. Autophagy is a cellular catabolic process responsible for degrading cytoplasmic components to maintain homeostasis, alterations in which are frequently linked to tumour growth and progression. This study was conducted to investigate the occurrence of autophagy in canine MCTs and to verify its value as a prognostic indicator for dogs with the disease. Beclin-1 and LC3B expressions were investigated using immunohistochemistry, and autophagy was ultrastructurally characterised. The autophagic phenomenon was successfully visualised in neoplastic mast cells under transmission electron and immunoelectron microscopy. MCTs from dogs that died due to the disease showed higher positivity for Beclin-1 and dogs with MCTs presenting a LC3B granular immunohistochemical pattern had a significantly shorter post-surgical survival. The occurrence of autophagy is an indicator of poor prognosis. Future studies are needed to elucidate the specific mechanisms and open new opportunities to treatments targeting this cancer cell advantage.
    Keywords:  Autophagy; Beclin-1; LC3; immunohistochemistry; prognosis; ultrastructure
    DOI:  https://doi.org/10.1080/01652176.2024.2419585
  34. Sci Rep. 2024 10 25. 14(1): 25412
    LSU family members and NBR1 are novel factors that contribute to homeostasis of catalases and peroxisomes in Arabidopsis thaliana.
    Anna Niemiro, Konrad Jurczewski, Marzena Sieńko, Anna Wawrzyńska, Marcin Olszak, Jarosław Poznański, Agnieszka Sirko.
      The short coiled-coil LSU (RESPONSE TO LOW SULFUR) proteins are linked to sulfur metabolism and have numerous protein partners. However, most of these partners lack direct links to sulfur metabolism, and the role of such interactions remains elusive. Here, we confirmed LSU binding to Arabidopsis catalase (CAT) and revealed that NBR1, a selective autophagy receptor, strongly interacts with LSU1 but not with CAT. Consequently, we observed the involvement of autophagy but not NBR1 in CAT removal. The lsu and nbr1 mutants differed from the wild-type plants in size and the number of yellow fluorescent protein (YFP)-CAT condensates, the number of peroxisomes, and photosynthetic pigments levels in the presence and absence of stress. We conclude that LSU family members and NBR1 contribute directly or indirectly to CAT and peroxisome homeostasis, and the overall fitness of plants. Our structural models of CAT-LSU complexes show at least two regions of interaction in CAT, one of which is at the N-terminus. Indeed, the N-terminally truncated variants of CAT2 and CAT3 interact more weakly with LSU1 than their full-length variants, but the extent of reduction is higher for CAT2, suggesting differences in recognition of CAT2 and CAT3 by LSU1.
    Keywords:  Catalase; LSU1; N-BODIPY; NBR1; Peroxisome; Protein structure modelling
    DOI:  https://doi.org/10.1038/s41598-024-76862-4
  35. Sci Rep. 2024 10 26. 14(1): 25532
    Ca+2 and Nε-lysine acetylation regulate the CALR-ATG9A interaction in the lumen of the endoplasmic reticulum.
    Megan M Braun, Brendan K Sheehan, Samantha L Shapiro, Yun Ding, C Dustin Rubinstein, Brent P Lehman, Luigi Puglielli.
      The acetylation of autophagy protein 9 A (ATG9A) in the lumen of the endoplasmic reticulum (ER) by ATase1 and ATase2 regulates the induction of reticulophagy. Analysis of the ER-specific ATG9A interactome identified calreticulin (CALR), an ER luminal Ca+2-binding chaperone, as key for ATG9A activity. Specifically, if acetylated, ATG9A is sequestered by CALR and prevented from engaging FAM134B and SEC62. Under this condition, ATG9A is unable to activate the autophagy core machinery. In contrast, when non-acetylated, ATG9A is released by CALR and able to engage FAM134B and SEC62. In this study, we report that Ca+2 dynamics across the ER membrane regulate the ATG9A-CALR interaction as well as the ability of ATG9A to trigger reticulophagy. We show that the Ca+2-binding sites situated on the C-domain of CALR are essential for the ATG9A-CALR interaction. Finally, we show that K359 and K363 on ATG9A can influence the ATG9A-CALR interaction. Collectively, our results disclose a previously unidentified aspect of the complex mechanisms that regulate ATG9A activity. They also offer a possible area of intersection between Ca+2 metabolism, acetyl-CoA metabolism, and ER proteostasis.
    Keywords:  ATG9A; Calcium; Calreticulin; Lysine acetylation; Proteostasis; Reticulophagy
    DOI:  https://doi.org/10.1038/s41598-024-76854-4
  36. Cell Mol Life Sci. 2024 Oct 26. 81(1): 442
    Stromal softness confines pancreatic cancer growth through lysosomal-cathepsin mediated YAP1 degradation.
    Tianci Zhang, Jingjing Chen, Huan Yang, Xiaoyan Sun, Yiran Ou, Qiang Wang, Mouad Edderkaoui, Sujun Zheng, Feng Ren, Ying Tong, Richard Hu, Jiaye Liu, Yun Gao, Stephen J Pandol, Yuan-Ping Han, Xiaofeng Zheng.
      The progression and malignancy of many tumors are associated with increased tissue stiffness. Conversely, the oncogenically transformed cells can be confined in soft stroma. Yet, the underlying mechanisms by which soft matrix confines tumorigenesis and metastasis remain elusive. Here, we show that pancreatic cancer cells are suppressed in the soft extracellular matrix, which is associated with YAP1 degradation through autophagic-lysosomal pathway rather than Hippo signal mediated proteasome pathway. In the soft stroma, PTEN is upregulated and activated, which consequently promotes lysosomal biogenesis, leading to the activation of cysteine-cathepsins for YAP1 degradation. In vitro, purified cathepsin L can directly digest YAP1 under acidic conditions. Lysosomal stress, either caused by chloroquine or overexpression of cystatin A/B, results in YAP1 accumulation and malignant transformation. Likewise, liver fibrosis induced stiffness can promote malignant potential in mice. Clinical data show that down-regulation of lysosomal biogenesis is associated with pancreatic fibrosis and stiffness, YAP1 accumulation, and poor prognosis in PDAC patients. Together, our findings suggest that soft stroma triggers lysosomal flux-mediated YAP1 degradation and induces cancer cell dormancy.
    Keywords:  Autophagy; Pancreatic ductal adenocarcinoma; Soft matrix; Tumor dormancy; Yes-associated protein 1
    DOI:  https://doi.org/10.1007/s00018-024-05466-y
  37. PLoS One. 2024 ;19(10): e0309389
    Modification of MWCNTs with Bi2WO6 nanoparticles targeting IL-1β and NLRP3 inflammasome via augmented autophagy.
    Zenaa R Rahoomi, Duha S Ahmed, Majid S Jabir, Haney Samir, Ayman A Swelum.
      This study reports the facile hydrothermal synthesis of pure Bi2WO6 and Bi2WO6\MWCNTs nanocomposite at specific molar ratio 1:2.5 of Bi2WO6:MWCNTs and elucidates their role in modulating the NLRP3 inflammasome pathway via autophagy induction. Comprehensive characterization techniques, including XRD, Raman, UV.Vis PL,FESEM,EDS and TEM, revealed the successful incorporation of MWCNTs into the Bi2WO6 structures, leading to enhanced crystattlinity, reduced band gap energy (2.4 eV) suppressed charge carrier recombination and mitigated nanoparticles aggregation. Notably, the reduced band gap facikitaed improved visible light harvesting, a crucial attribute for photocatalytic applications. Significantly, the nanocompsoite exhibited a remarkable capacity to augment autophagy in bone marrow-derived macrophages (BMDMs), consequently down-regulating the NLRP3 inflammasom activation and IL-1β secretion upon LPS and ATP stimulation. Immunofluorescence assays unveiled increased co-localization of LC3 and NLRP3, suggestion enhanced targeting of NLRP3 by autophagy. Inhibition of autophagy by 3-MA reversed these effects, confirming the pivotal role of autophagy induction. Furthermore, the nanocomposite attenuated caspase-1 activation and ASC oligomerzation, thereby impeding inflammasome assembly. Collectively, these findings underscore the potential of Bi2WO6\MWCNTs nanocompsite as a multifaceted therapeutic platform, levering its tailored optoelectronic properties and sbility to modulate the NLRP3 infalmmasome via autophagy augmentation. This work covers the way for the development of advanced nanomaterials with tunable functionalities for combating inflammatory disorders and antimicrobial applications.
    DOI:  https://doi.org/10.1371/journal.pone.0309389
  38. Physiology (Bethesda). 2024 Oct 29.
    mTORC1 and 2 adrenergic regulation and function in brown adipose tissue.
    William T Festuccia.
      Brown adipose tissue (BAT) thermogenesis results from the uncoupling of mitochondrial inner membrane proton gradient mediated by the uncoupling protein 1 (UCP-1), which is activated by lipolysis-derived fatty acids. Norepinephrine (NE) secreted by sympathetic innervation not only activates BAT lipolysis and UCP-1, but uniquely in brown adipocytes, promotes "futile" metabolic cycles and enhances BAT thermogenic capacity by increasing UCP-1 content, mitochondrial biogenesis and brown adipocyte hyperplasia. NE exerts these actions by triggering signaling in the canonical G protein coupled b adrenergic receptors, cAMP and protein kinase A (PKA) pathway which, in brown adipocyte, is under a complex and intricated crosstalk with important growth-promoting signaling pathways such as those of mechanistic target of rapamycin (mTOR) complexes 1 (mTORC1) and 2 (mTORC2). This article reviews evidence suggesting that mTOR complexes are modulated by and participate in the thermogenic, metabolic, and growth-promoting effects elicited by NE in BAT and discusses current gaps and future directions in this field of research.
    Keywords:  brown adipose tissue; mTORC1; mTORC2
    DOI:  https://doi.org/10.1152/physiol.00023.2024
  39. bioRxiv. 2024 Oct 17. pii: 2024.10.16.617214. [Epub ahead of print]
    The Integrated Stress Response Suppresses PINK1-dependent Mitophagy by Preserving Mitochondrial Import Efficiency.
    Mingchong Yang, Zengshuo Mo, Kelly Walsh, Wen Liu, Xiaoyan Guo.
      Mitophagy is crucial for maintaining mitochondrial health, but how its levels adjust to different stress conditions remains unclear. In this study, we investigated the role of the DELE1-HRI axis of integrated stress response (ISR) in regulating mitophagy, a key mitochondrial stress pathway. Our findings show that the ISR suppresses mitophagy under non-depolarizing mitochondrial stress by positively regulating mitochondrial protein import, independent of ATF4 activation. Mitochondrial protein import is regulated by the rate of protein synthesis under both depolarizing and non-depolarizing stress. Without ISR, increased protein synthesis overwhelms the mitochondrial import machinery, reducing its efficiency. Under depolarizing stress, mitochondrial import is heavily impaired even with active ISR, leading to significant PINK1 accumulation. In contrast, non-depolarizing stress allows more efficient protein import in the presence of ISR, resulting in lower mitophagy. Without ISR, mitochondrial protein import becomes severely compromised, causing PINK1 accumulation to reach the threshold necessary to trigger mitophagy. These findings reveal a novel link between ISR-regulated protein synthesis, mitochondrial import, and mitophagy, offering potential therapeutic targets for diseases associated with mitochondrial dysfunction.
    DOI:  https://doi.org/10.1101/2024.10.16.617214
  40. Autophagy. 2024 Oct 30.
    Deciphering melanophagy: role of the PTK2-ITCH-MLANA-OPTN cascade on melanophagy in melanocytes.
    Na Yeon Park, Doo Sin Jo, Hyun Jun Park, Ji-Eun Bae, Yong Hwan Kim, Joon Bum Kim, Ha Jung Lee, Sung Hyun Kim, Hyunjung Choi, Hyun-Shik Lee, Tamotsu Yoshimori, Dong-Seok Lee, Jin-A Lee, Pansoo Kim, Dong-Hyung Cho.
      Melanosomes play a pivotal role in skin color and photoprotection. In contrast to the well-elucidated pathway of melanosome biogenesis, the process of melanosome degradation, referred to as melanophagy, is largely unexplored. Previously, we discovered that 3,4,5-trimethoxycinnamate thymol ester (TCTE) effectively inhibits skin pigmentation by activating melanophagy. In this study, we discovered a new regulatory signaling cascade that controls melanophagy in TCTE-treated melanocytes. ITCH (itchy E3 ubiquitin protein ligase) facilitates ubiquitination of the melanosome membrane protein MLANA (melan-A) during TCTE-induced melanophagy. This ubiquitinated MLANA is then recognized by an autophagy receptor protein, OPTN (optineurin). Additionally, a phospho-kinase antibody array revealed that TCTE activates PTK2 (protein tyrosine kinase 2), which phosphorylates ITCH, enhancing the ubiquitination of MLANA. Furthermore, inhibition of either PTK2 or ITCH disrupts the ubiquitination of MLANA and the MLANA-OPTN interaction in TCTE-treated cells. Taken together, our findings highlight the critical role of the PTK2-ITCH-MLANA-OPTN cascade in orchestrating melanophagy progression.
    Keywords:  ITCH; MLANA; OPTN; PTK2; melanophagy; melanosome
    DOI:  https://doi.org/10.1080/15548627.2024.2421695
  41. bioRxiv. 2024 Oct 27. pii: 2024.10.24.620101. [Epub ahead of print]
    An mTOR-Tfeb-Fabp7a signaling axis can be harnessed to ameliorate bag3 cardiomyopathy in adult zebrafish.
    Yonghe Ding, Feixiang Yan, Baul Yoon, Wei Wei, David Mondaca Ruff, Yuji Zhang, Xueying Lin, Xiaolei Xu.
      Dysregulated proteostasis in cardiomyocytes is an important pathological event in BAG3 cardiomyopathy, which can be repaired by inhibiting mechanistic target of rapamycin (mTOR) for cardioprotective effects. Here, we aimed to uncover additional pathological events and therapeutic target genes via leveraging zebrafish genetics. We first assessed transcription factor EB ( tfeb ), a candidate gene that encodes a direct downstream phosphorylation target of mTOR signaling. We found that cardiomyocyte-specific transgenic overexpression of tfeb ( Tg[cmlc2:tfeb] ) is sufficient to repair defective proteostasis, attenuate accelerated cardiac senescence, a previously unrecognized phenotype in the bag3 cardiomyopathy model, and rescue cardiac dysfunction. Next, we compared cardiac transcriptomes between the Tg(cmlc2:tfeb) transgenic fish and the mtor xu015/+ mutant, and tested 4 commonly downregulated lipodystrophy genes using an F0-based genetic assay. We found that inhibition of the fatty acid binding protein a ( fabp7a ) gene, but not the other 3 genes, exerts therapeutic effects on bag3 cardiomyopathy. Conversely, fabp7a expression is elevated in bag3 cardiomyopathy model and cardiomyocyte-specific overexpression of fabp7a resulted in dysregulated proteostasis, accelerated cardiac senescence, as well as cardiac dysfunction. Together, these genetic studies in zebrafish uncovered Fabp7a activation and accelerated cardiac senescence as important pathological events in bag3 cardiomyopathy. The mTOR-Tfeb-Fabp7a signaling axis can be harnessed to repair these pathological changes and exert cardioprotective effects.
    DOI:  https://doi.org/10.1101/2024.10.24.620101
  42. Free Radic Biol Med. 2024 Oct 29. pii: S0891-5849(24)01014-1. [Epub ahead of print]
    Pink1-Dependent Mitophagy in Vascular Smooth Muscle Cells: Implications for Arterial Constriction.
    Dongliang Li, Shi Zhang, Jingqi Nie, Shengmiao Yu, Yang Li, Feifei Zheng, Shipeng Bo, Nan Wang, Yanqiu Zhang.
      Hypertension is a major global health issue, contributing to significant cardiovascular morbidity and mortality. Mitochondrial dysfunction, particularly through dysregulated mitophagy, has been implicated in the pathogenesis of hypertension. We wanted to find out the relationship between mitochondrial autophagy and changes in arterial smooth muscle cell tension and the molecular mechanism. Using RNA-seq analysis, we identified significant upregulation of autophagy-related genes, including Pink1, in the aortas of spontaneously hypertensive rats (SHR) compared to normotensive Wistar-Kyoto (WKY) rats. Further in vivo and in vitro studies revealed enhanced mitophagy, characterized by increased expression of Pink1 protein. Our experiments showed that knockdown of Pink1 expression by shRNA attenuated KPSS-induced vascular smooth muscle cells (VSMCs) contraction, suggesting that excessive mitophagy contributes to vascular dysfunction in hypertension. These findings highlight Pink1-mediated mitophagy as a crucial player in hypertensive vascular remodeling and present a potential therapeutic target for managing hypertension.
    Keywords:  Mitophagy; Pink1; arterial constriction; hypertension; smooth muscle cell
    DOI:  https://doi.org/10.1016/j.freeradbiomed.2024.10.306
  43. J Virol. 2024 Oct 31. e0143724
    Tripartite motif 25 inhibits protein aggregate degradation during PRRSV infection by suppressing p62-mediated autophagy.
    Jiahui Ren, Qiming Pei, Haoxin Dong, Xuedan Wei, Liangliang Li, Hong Duan, Gaiping Zhang, Angke Zhang.
      Viral infection causes endoplasmic reticulum stress and protein metabolism disorder, influencing protein aggregates formation or degradation that originate from misfolded proteins. The mechanism by which host proteins are involved in the above process remains largely unknown. The present study found that porcine reproductive and respiratory syndrome virus (PRRSV) infection promoted the degradation of intracellular ubiquitinated protein aggregates via activating autophagy. The host cell E3 ligase tripartite motif-containing (TRIM)25 promoted the recruitment and aggregation of polyubiquitinated proteins and impeded their degradation caused by PRRSV. TRIM25 interacted with ubiquitinated aggregates and was part of the aggregates complex. Next, the present study investigated the mechanisms by which TRIM25 inhibited the degradation of protein aggregates, and it was found that TRIM25 interacted with both Kelch-like ECH-associated protein 1 (KEAP1) and nuclear factor E2-related factor 2 (Nrf2), facilitated the nuclear translocation of Nrf2 by targeting KEAP1 for K48-linked ubiquitination and proteasome degradation, and activated Nrf2-mediated p62 expression. Further studies indicated that TRIM25 interacted with p62 and promoted its K63-linked ubiquitination via its E3 ligase activity and thus caused impairment of its oligomerization, aggregation, and recruitment for the autophagic protein LC3, leading to the suppression of autophagy activation. Besides, TRIM25 also suppressed the p62-mediated recruitment of ubiquitinated aggregates. Activation of autophagy decreased the accumulation of protein aggregates caused by TRIM25 overexpression, and inhibition of autophagy decreased the degradation of protein aggregates caused by TRIM25 knockdown. The current results also showed that TRIM25 inhibited PRRSV replication by inhibiting the KEAP1-Nrf2-p62 axis-mediated autophagy. Taken together, the present findings showed that the PRRSV replication restriction factor TRIM25 inhibited the degradation of ubiquitinated protein aggregates during viral infection by suppressing p62-mediated autophagy.IMPORTANCESequestration of protein aggregates and their subsequent degradation prevents proteostasis imbalance and cytotoxicity. The mechanisms controlling the turnover of protein aggregates during viral infection are mostly unknown. The present study found that porcine reproductive and respiratory syndrome virus (PRRSV) infection promoted the autophagic degradation of ubiquitinated protein aggregates, whereas tripartite motif-containing (TRIM)25 reversed this process. It was also found that TRIM25 promoted the expression of p62 by activating the Kelch-like ECH-associated protein 1 (KEAP1) and nuclear factor E2-related factor 2 (Nrf2) pathway and simultaneously prevented the oligomerization of p62 by promoting its K63-linked ubiquitination, thus suppressing its recruitment of the autophagic adaptor protein LC3 and ubiquitinated aggregates, leading to the inhibition of PRRSV-induced autophagy activation and the autophagic degradation of protein aggregates. The present study identified a new mechanism of protein aggregate turnover during viral infection and provided new insights for understanding the pathogenic mechanism of PRRSV.
    Keywords:  aggregates; autophagy; misfolded protein; porcine reproductive and respiratory syndrome virus; tripartite motif-containing 25
    DOI:  https://doi.org/10.1128/jvi.01437-24
  44. Phytomedicine. 2024 Oct 16. pii: S0944-7113(24)00818-3. [Epub ahead of print]135 156161
    Cepharanthine sensitizes gastric cancer cells to chemotherapy by targeting TRIB3-FOXO3-FOXM1 axis to inhibit autophagy.
    Yang-Yang Lu, Yuan-Yuan Fang, Sha-Sha Wang, Jing Guo, Jia-Lin Song, Liang Zhu, Zhong-Kun Lin, Rui Wang, Si-Yi Zhang, Wen-Sheng Qiu, Wei-Wei Qi.
      BACKGROUND: Gastric cancer is among the common solid tumors. Chemotherapy resistance is the most common issue in gastric cancer treatment. Inhibiting intracellular autophagy may be a feasible method for overcoming chemotherapy resistance. Cepharanthine (CEP), a natural small molecule extracted from the stephania cephalantha Hayata plant, has been demonstrated to significantly inhibit cancer growth and can regulate autophagy. Although CEP can significantly inhibit cancer growth, it remains unclear whether CEP can regulate autophagy in gastric cancer. This study aimed to investigate whether CEP can enhance the sensitivity of gastric cancer to chemotherapy and elucidate its molecular mechanism.METHODS: Three gastric cancer cell lines (AGS, SGC7901, and MFC) and one normal gastric mucosal epithelial cell line (GES-1) were used for in vitro experiments. The characterization of autophagy in gastric cancer cells included the detection of autophagy markers and autophagy flux through immunofluorescence staining and Western blotting, as well as the assessment of lysosomal function using fluorescence staining (LysoTracker Red DND-99, Acridine Orange staining) and Western blotting. The cytotoxicity of CEP, autophagy inhibitors (chloroquine [CQ] and 3-methyladenine [3MA]), and chemotherapy drugs (doxorubicin [DOX] and cisplatin [CIS]) was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, cell colony formation, and fluorescence staining techniques (H2DCFDA, Dihydroethidium, and JC-1 staining). The interaction between CEP and autophagy inhibitors was tested in a 615 mice model, and changes in the gut microbiota were determined through accurate 16S absolute quantification sequencing. The signaling pathway and autophagy regulatory target TRIB3-FOXO3-FOXM1 were confirmed through molecular docking, RNA sequencing, bioinformatic analysis, transfection techniques, and Western blotting.
    RESULTS: CEP blocked autophagic flux in gastric cancer cells without affecting lysosomal function. As a novel autophagy inhibitor, CEP could combine with conventional autophagy inhibitors (CQ and 3MA) to block intracellular autophagy, thereby inhibiting gastric cancer growth. During this process, changes in the gut microbiota were observed, including low-level changes in Odoribacterium, Erysipelatoclostridium, and ParaPrevotella and high-level changes in Ileibacterium, Enterorhabdus, and Bifidobacterium. Additionally, CEP synergistically inhibited the growth of gastric cancer when combined with chemotherapy drugs. Mechanistically, the TRIB3-FOXO3-FOXM1 signaling axis was found to be involved in the inhibition of gastric cancer by CEP combined with autophagy inhibitors and chemotherapy drugs, thereby mediating cell apoptosis.
    CONCLUSION: This study links the TRIB3-FOXO3-FOXM1 axis with chemotherapy efficacy. Our findings demonstrated that CEP inhibits autophagy by modulating the FOXO3-FOXM1 axis. When combined with chemotherapy drugs (DOX and CIS), CEP, as an autophagy inhibitor, can limit TRIB3 protein expression, thereby regulating the FOXO3-FOXM1 axis and enhancing its ability to prevent gastric cancer growth. These findings may contribute to improving the prognosis of patients with gastric cancer. Furthermore, these results enrich the fundamental understanding of how autophagy inhibition can enhance clinical cancer treatment efficacy and provide insights into the potential mechanisms by which CEP functions as an anti-tumor drug, thereby exploring its value for clinical application.
    Keywords:  Autophagy; Cepharanthine; FOXO3; Gastric cancer; TRIB3
    DOI:  https://doi.org/10.1016/j.phymed.2024.156161
  45. Biomolecules. 2024 Oct 09. pii: 1272. [Epub ahead of print]14(10):
    History and Perspective of LAMP-2 Deficiency (Danon Disease).
    Kazuma Sugie, Ichizo Nishino.
      Danon disease, an X-linked dominant vacuolar cardiomyopathy and skeletal myopathy, is caused by a primary deficiency of lysosome-associated membrane protein-2 (LAMP-2). This disease is one of the autophagy-related muscle diseases. Male patients present with the triad of cardiomyopathy, myopathy, and intellectual disability, while female patients present with cardiomyopathy. The disease's leading cause of death is heart failure, and its prognostic factor is cardiomyopathy. Pathologically, the disease is characterized by the appearance of unique autophagic vacuoles with sarcolemmal features (AVSFs). Twenty-six families have been found to have this disease in Japan. It has been over 40 years since the first report of this disease by Danon et al. and over 20 years since the identification of the causative gene, LAMP2, by Nishino et al. Although the pathogenetic mechanism of Danon disease remains unestablished, the first clinical trials using AAV vectors have finally begun in recent years. The development of novel therapies is expected in the future.
    Keywords:  Danon disease; LAMP-2; autophagic vacuole; autophagy; cardiomyopathy; lysosome; myopathy
    DOI:  https://doi.org/10.3390/biom14101272
  46. Mol Oncol. 2024 Oct 27.
    Malformin C preferentially kills glioblastoma stem-like cells via concerted induction of proteotoxic stress and autophagic flux blockade.
    Emma Phillips, Sizèd van Enk, Sara Kildgaard, Silja Schlue, Mona Göttmann, Victoria Jennings, Frederic Bethke, Gabriele Müller, Christel Herold-Mende, Daniel Pastor-Flores, Martin Schneider, Dominic Helm, Thomas Ostenfeld Larsen, Violaine Goidts.
      Glioblastoma is a highly aggressive brain tumor for which there is no cure. The dire prognosis of this disease is largely attributable to a high level of heterogeneity, including the presence of a subpopulation of tumor-initiating glioblastoma stem-like cells (GSCs), which are refractory to chemo- and radiotherapy. Here, in an unbiased marine-derived fungal extract screen, together with bioguided dereplication based on high-resolution mass spectrometry, we identified malformin C to preferentially induce cell death in patient-derived GSCs and explore the potential of this cyclic peptide as a therapeutic agent for glioblastoma. Malformin C significantly reduced tumor growth in an in vivo xenograft model of glioblastoma. Using transcriptomics and chemoproteomics, we found that malformin C binds to many proteins, leading to their aggregation, and rapidly induces the unfolded protein response, including autophagy, in GSCs. Crucially, chemical inhibition of translation using cycloheximide rescued malformin C-induced cell death in GSCs, demonstrating that the proteotoxic effect of the compound is necessary for its cytotoxicity. At the same time, malformin C appears to accumulate in lysosomes, disrupting autophagic flux, and driving cells to death. Supporting this, malformin C synergizes with chloroquine, an inhibitor of autophagy. Strikingly, we observed that autophagic flux is differentially regulated in GSCs compared with normal astrocytes. The sensitivity of GSCs to malformin C highlights the relevance of proteostasis and autophagy as a therapeutic vulnerability in glioblastoma.
    Keywords:  autophagy; cancer; compound screen; glioblastoma; proteostasis; stem cells; unfolded protein response
    DOI:  https://doi.org/10.1002/1878-0261.13756
  47. bioRxiv. 2024 Oct 22. pii: 2024.10.21.619493. [Epub ahead of print]
    Spatial memory in Alzheimer's disease 5XFAD mice is enhanced by XPO1 inhibitor KPT-330.
    Shi Quan Wong, Adia Ouellette, Avery McNamara, Rachel A Tam, Alexander Alexandrov, Acacia Nawrocik-Madrid, Jesus J Sanchez, Brett C Ginsburg, Arturo A Andrade, Louis R Lapierre.
      The proteostatic decline in Alzheimer's disease is well established and improvement in proteostasis could potentially delay cognitive impairment. One emerging entry point to modulate proteostasis is the regulation of nucleo-cytoplasmic partitioning of proteins across the nuclear pore via karyopherins. The nuclear exportin XPO1 is a key regulator of proteostasis by driving the assembly of ribosomes and by modulating the process of autophagy. We recently found that XPO1 inhibitor KPT-330 (Selinexor), an FDA approved drug against multiple myelomas, enhances proteostasis, leading to benefits in models of neurodegenerative diseases in C. elegans and Drosophila . Here, we find that KPT-330 increases autophagy in murine neuronal cells and improves spatial memory performance in a murine model of Alzheimer's disease (5XFAD). Unexpectedly, general amyloid deposition in several brain regions was significantly increased by KPT-330, but specific regions, especially the thalamus, displayed significantly lower deposition, suggesting that XPO1 inhibition has regional-specific effects on proteostasis and amyloid plaque formation. Altogether, we conclude that XPO1 inhibition can improve cognition via spatially-specific reductions in amyloid deposition.
    DOI:  https://doi.org/10.1101/2024.10.21.619493
  48. Br J Pharmacol. 2024 Oct 28.
    Dihydro-resveratrol ameliorates NLRP3 inflammasome-mediated neuroinflammation via Bnip3-dependent mitophagy in Alzheimer's disease.
    Guorong Tao, Xuebao Wang, Jian Wang, Yiru Ye, Minxue Zhang, Yan Lang, Saidan Ding.
      BACKGROUND AND PURPOSE: Dihydro-resveratrol (DHR), a polyphenol derivative, that has been demonstrated to suppress inflammation-mediated injury. However, it is still unknown whether it has anti-neuroinflammatory and neuroprotective effects, and a therapeutic action in Alzheimer's disease (AD).EXPERIMENTAL APPROACH: The anti-inflammatory and anti-Alzheimer's disease actions of dihydro-resveratrol were investigated using lipopolysaccharide (LPS) and AD mice models, and primary microglial cells. The changes in behaviour in mice were detected by the Morris water maze test and open-field test. Flow cytometry assay, western blotting, immunofluorescence assays and co-immunoprecipitation were used to investigate the changes in the NLRP3 inflammasome activation and mitophagy.
    KEY RESULTS: In this study, in vivo observations indicated that the administration of dihydro-resveratrol (DHR) dramatically restored spatial learning, memory ability, autophagy and mitophagy, attenuated NLRP3 inflammasome activation, neuroinflammation and amyloid precursor protein pathology in LPS mice and AD mice. In addition, the inhibition of autophagy and mitophagy, or the activation of NLRP3 in vivo greatly abolished DHR-generated therapeutic efficacy on neuroinflammation, amyloid precursor protein pathology and cognitive loss. Further examination indicated that the application of DHR after the LPS and ATP exposure significantly inhibited the NLRP3 inflammasome activation, neuroinflammation and enhanced autophagic and mitophagic activation in microglia. Additionally, in vitro results show that DHR protects microglial cells against LPS and ATP-induced cytotoxicity by inhibiting NLRP3 inflammasome through activating Bnip3-dependent mitophagy and ULK phosphorylation.
    CONCLUSIONS AND IMPLICATIONS: In summary, these findings suggest that dihydro-resveratrol (DHR) possesses potent anti-neuroinflammatory property and can act as a potential therapeutic agent for the treatment of AD.
    Keywords:  Alzheimer's disease; autophagy; dihydro‐resveratrol; inflammation; mitophagy
    DOI:  https://doi.org/10.1111/bph.17373
  49. bioRxiv. 2024 Oct 19. pii: 2024.10.18.619132. [Epub ahead of print]
    Non-lytic spread of poliovirus requires the nonstructural protein 3CD.
    David Aponte-Diaz, Jayden M Harris, Tongjia Ella Kang, Victoria Korboukh, Mohamad S Sotoudegan, Jennifer L Gray, Neela H Yennawar, Ibrahim M Moustafa, Andrew Macadam, Craig E Cameron.
      Non-enveloped viruses like poliovirus (PV) have evolved the capacity to spread by non-lytic mechanisms. For PV, this mechanism exploits the host secretory autophagy pathway. Virions are selectively incorporated into autophagosomes, double-membrane vesicles that travel to the plasma membrane, fuse, and release single-membrane vesicles containing virions. Loading of cellular cargo into autophagosomes relies on direct or indirect interactions with microtubule-associated protein 1B-light chain 3 (LC3) that are mediated by motifs referred to as LC3-interaction regions (LIRs). We have identified a PV mutant with a severe defect in non-lytic spread. An F-to-Y substitution in a putative LIR of the nonstructural protein 3CD prevented virion incorporation into LC3-positive autophagosomes and virion trafficking to the plasma membrane for release. Using high-angle annular dark-field scanning transmission electron microscopy to monitor PV-induced autophagosome biogenesis, for the first time, we show that virus-induced autophagic signals yield normal autophagosomes, even in the absence of virions. The F-to-Y derivative of PV 3CD was unable to support normal autophagosome biogenesis. Together, these studies make a compelling case for a direct role of a viral nonstructural protein in the formation and loading of the vesicular carriers used for non-lytic spread that may depend on the proper structure, accessibility, and/or dynamics of its LIR. The studies of PV 3CD protein reported here will hopefully provoke a more deliberate look at the presence and function of LIR motifs in viral proteins of viruses known to use autophagy as the basis for non-lytic spread.
    DOI:  https://doi.org/10.1101/2024.10.18.619132
  50. Exp Neurol. 2024 Oct 25. pii: S0014-4886(24)00355-8. [Epub ahead of print]383 115029
    Rotating magnetic field improves cognitive and memory impairments in APP/PS1 mice by activating autophagy and inhibiting the PI3K/AKT/mTOR signaling pathway.
    Mengqing Li, Yaxian Mo, Qinyao Yu, Umer Anayyat, Hua Yang, Fen Zhang, Yunpeng Wei, Xiaomei Wang.
      Alzheimer's disease (AD) is a geriatric disorder that can be roughly classified into sporadic AD and hereditary AD. The latter is strongly associated with genetic factors, and its treatment poses greater challenges compared to sporadic AD. Rotating magnetic fields (RMF) is a non-invasive treatment known to have diverse biological effects, including the modulation of the central nervous system and aging. However, the impact of RMF on hereditary AD and its underlying mechanism remain unexplored. In this study, we exposed APP/PS1 mice to RMF (2 h/day, 0.2 T, 4 Hz) for a duration of 6 months. The results demonstrated that RMF treatment significantly ameliorated their cognitive and memory impairments, attenuated neuronal damage, and reduced amyloid deposition. Furthermore, RNA-sequencing analysis revealed a significant enrichment of autophagy-related genes and the PI3K/AKT-mTOR signaling pathway. Western blotting further confirmed that RMF activated autophagy and suppressed the phosphorylation of proteins associated with the PI3K/AKT/mTOR signaling pathway in APP/PS1 mice. These protective effects and the underlying mechanism were also observed in Aβ25-35-exposed HT22 cells. Collectively, our findings indicate that RMF improves cognitive and memory dysfunction in APP/PS1 mice by activating autophagy and inhibiting the PI3K/AKT/mTOR signaling pathway, thus highlighting the potential of RMF as a clinical treatment for hereditary AD.
    Keywords:  APP/PS1 mice; Autophagy; Hereditary Alzheimer's disease; Rotating magnetic fields; The PI3K/AKT/mTOR pathway
    DOI:  https://doi.org/10.1016/j.expneurol.2024.115029
  51. Int J Mol Sci. 2024 Oct 18. pii: 11201. [Epub ahead of print]25(20):
    Interconnection of CD133 Stem Cell Marker with Autophagy and Apoptosis in Colorectal Cancer.
    Ferenc Sipos, Györgyi Műzes.
      CD133 protein expression is observable in differentiated cells, stem cells, and progenitor cells within normal tissues, as well as in tumor tissues, including colorectal cancer cells. The CD133 protein is the predominant cell surface marker utilized to detect cancer cells exhibiting stem cell-like characteristics. CD133 alters common abnormal processes in colorectal cancer, such as the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) and Wnt/β-catenin pathways. Autophagy is a cellular self-digestion mechanism that preserves the intracellular milieu and plays a dual regulatory role in cancer. In cancer cells, apoptosis is a critical cell death mechanism that can impede cancer progression. CD133 can modulate autophagy and apoptosis in colorectal cancer cells via several signaling pathways; hence, it is involved in the regulation of these intricate processes. This can be an explanation for why CD133 expression is associated with enhanced cellular self-renewal, migration, invasion, and survival under stress conditions in colorectal cancer. The purpose of this review article is to explain the complex relationship between the CD133 protein, apoptosis, and autophagy. We also want to highlight the possible ways that CD133-mediated autophagy may affect the apoptosis of colorectal cancer cells. Targeting the aforementioned mechanisms may have a significant therapeutic role in eliminating CD133-positive stem cell-phenotype colorectal cancer cells, which can be responsible for tumor recurrence.
    Keywords:  CD133; apoptosis; autophagy; colorectal cancer; stem cell
    DOI:  https://doi.org/10.3390/ijms252011201
  52. Int J Mol Sci. 2024 Oct 17. pii: 11185. [Epub ahead of print]25(20):
    Targeting Lipid Metabolism in Cancer Stem Cells for Anticancer Treatment.
    Manish Kumar Singh, Sunhee Han, Sungsoo Kim, Insug Kang.
      Cancer stem cells (CSCs), or tumor-initiating cells (TICs), are small subpopulations (0.0001-0.1%) of cancer cells that are crucial for cancer relapse and therapy resistance. The elimination of each CSC is essential for achieving long-term remission. Metabolic reprogramming, particularly lipids, has a significant impact on drug efficacy by influencing drug diffusion, altering membrane permeability, modifying mitochondrial function, and adjusting the lipid composition within CSCs. These changes contribute to the development of chemoresistance in various cancers. The intricate relationship between lipid metabolism and drug resistance in CSCs is an emerging area of research, as different lipid species play essential roles in multiple stages of autophagy. However, the link between autophagy and lipid metabolism in the context of CSC regulation remains unclear. Understanding the interplay between autophagy and lipid reprogramming in CSCs could lead to the development of new approaches for enhancing therapies and reducing tumorigenicity in these cells. In this review, we explore the latest findings on lipid metabolism in CSCs, including the role of key regulatory enzymes, inhibitors, and the contribution of autophagy in maintaining lipid homeostasis. These recent findings may provide critical insights for identifying novel pharmacological targets for effective anticancer treatment.
    Keywords:  autophagy; cancer stem cell; drug resistance; lipids; stemness; tumor microenvironment
    DOI:  https://doi.org/10.3390/ijms252011185
  53. Dev Cell. 2024 Oct 21. pii: S1534-5807(24)00604-X. [Epub ahead of print]
    An SLC12A9-dependent ion transport mechanism maintains lysosomal osmolarity.
    Roni Levin-Konigsberg, Koushambi Mitra, Kaitlyn Spees, AkshatKumar Nigam, Katherine Liu, Camille Januel, Pravin Hivare, Sophia M Arana, Laura M Prolo, Anshul Kundaje, Manuel D Leonetti, Yamuna Krishnan, Michael C Bassik.
      Ammonia is a ubiquitous, toxic by-product of cell metabolism. Its high membrane permeability and proton affinity cause ammonia to accumulate inside acidic lysosomes in its poorly membrane-permeant form: ammonium (NH4+). Ammonium buildup compromises lysosomal function, suggesting the existence of mechanisms that protect cells from ammonium toxicity. Here, we identified SLC12A9 as a lysosomal-resident protein that preserves organelle homeostasis by controlling ammonium and chloride levels. SLC12A9 knockout (KO) cells showed grossly enlarged lysosomes and elevated ammonium content. These phenotypes were reversed upon removal of the metabolic source of ammonium or dissipation of the lysosomal pH gradient. Lysosomal chloride increased in SLC12A9 KO cells, and chloride binding by SLC12A9 was required for ammonium transport. Our data indicate that SLC12A9 function is central for the handling of lysosomal ammonium and chloride, an unappreciated, fundamental mechanism of lysosomal physiology that may have special relevance in tissues with elevated ammonia, such as tumors.
    Keywords:  SLC12A9; ammonium; chloride; ion transport; lysosome metabolism; lysosome volume regulation
    DOI:  https://doi.org/10.1016/j.devcel.2024.10.003
  54. bioRxiv. 2024 Oct 14. pii: 2024.10.14.618315. [Epub ahead of print]
    Liver CYP4A autophagic-lysosomal degradation (ALD): A major role for the autophagic receptor SQSTM1/p62 through an uncommon target interaction site.
    Liang He, Doyoung Kwon, Michael J Trnka, Yi Liu, Jade Yang, Kathy Li, Rheem A Totah, Eric F Johnson, A L Burlingame, Maria Almira Correia.
      The hepatic P450 hemoproteins CYPs 4A are typical N-terminally anchored Type I endoplasmic reticulum (ER)-proteins, that are inducible by hypolipidemic drugs and other "peroxisome proliferators". They are engaged in the ω-/ω-1-oxidation of various fatty acids including arachidonic acid, prostaglandins and leukotrienes and in the biotransformation of some therapeutic drugs. Herein we report that of the mammalian liver CYPs 4A, human CYP4A11 and mouse Cyp4a12a are preferential targets of the ER-lysosome-associated degradation (ERLAD). Consequently, these proteins are stabilized both as 1%Triton X100-soluble and -insoluble species in mouse hepatocytes and HepG2-cells deficient in the autophagic initiation ATG5-gene. Although these proteins exhibit surface LC3-interacting regions (LIRs) that would target them directly to the autophagosome, they nevertheless interact intimately with the autophagic receptor SQSTM1/p62. Through structural deletion analyses and site-directed mutagenesis, we have identified the Cyp4A-interacting p62 subdomain to lie between residues 170 and 233, which include its Traf6-binding and LIM-binding subdomains. Mice carrying a liver-specific genetic deletion of p62 residues 69-251 (p62Mut) that includes the CYP4A-interacting subdomain also exhibit Cyp4a-protein stabilization both as Triton X100-soluble and -insoluble species. Consistently, p62Mut mouse liver microsomes exhibit enhanced ω- and ω-1-hydroxylation of arachidonic acid to its physiologically active metabolites 19- and 20-HETEs relative to the corresponding wild-type mouse liver microsomes. Collectively, our findings suggest that any disruption of CYP4A ERLAD results in functionally active P450 protein and consequent production of proinflammatory metabolites on one hand, and insoluble aggregates on the other, which may contribute to pathological aggregates i.e. Mallory-Denk bodies/inclusions, hallmarks of many liver diseases.
    DOI:  https://doi.org/10.1101/2024.10.14.618315
  55. Vet Microbiol. 2024 Oct 25. pii: S0378-1135(24)00312-2. [Epub ahead of print]298 110290
    STAT6 promotes innate immunity against BEFV and VSV by inhibiting STUB1 and NIX-mediated MAVS degradation.
    Fuzhen Zhang, Hongmei Wang, Hongbin He, Peili Hou.
      Signal transducers and activators of transcription 6 (STAT6), an essential member of the STAT protein family, plays vital roles in innate immunity, however, its function in regulating innate immunity through the degradation of MAVS has not been described. In this study, we found that STAT6 suppresses the replication of both bovine ephemeral fever virus (BEFV) and vesicular stomatitis virus (VSV). Further investigations revealed that STAT6 promotes the type I IFN (IFN-I) signaling pathway in the context of BEFV and VSV infection. Moreover, the knockout of STAT6 leads to the degradation of MAVS through both the ubiquitin-proteasome and autophagolysosomal pathways. Mechanistically, STAT6 results in the downregulation of E3 ubiquitin ligase STIP1 homology and Ubox-containing protein 1 (STUB1), inhibits the interaction between STUB1 and MAVS, and reduces STUB1- mediated K48-linked MAVS ubiquitination, thereby inhibiting the MAVS degradation through the ubiquitin-proteasome pathway. Furthermore, STAT6 also suppresses MAVS degradation through the autophagy receptor Bcl2 interacting protein 3 like (NIX)-mediated autophagy pathway. Taken together, our study unveils a novel mechanism by which STAT6 acts as a positive regulator of the type I IFN signaling pathway during BEFV and VSV infection, predominantly by inhibiting MAVS degradation and ultimately suppressing BEFV and VSV infection. These findings provide valuable insights into the regulation of MAVS degradation by STAT6, which may serve as a basis for the design of novel antiviral agents.
    Keywords:  Bovine ephemeral fever virus (BEFV); Mitochondrial antiviral signaling protein (MAVS); Signal transducers and activators of transcription 6 (STAT6); Vesicular stomatitis virus (VSV); Viral replication
    DOI:  https://doi.org/10.1016/j.vetmic.2024.110290
  56. Mol Genet Metab. 2024 Oct 22. pii: S1096-7192(24)00480-3. [Epub ahead of print]143(3): 108596
    Multi-omic analysis of a mucolipidosis II neuronal cell model uncovers involvement of pathways related to neurodegeneration and drug metabolism.
    Lorenzo Badenetti, Seok-Ho Yu, Maxwell B Colonna, Rony Hull, Jennifer R Bethard, Lauren Ball, Heather Flanagan-Steet, Richard Steet.
      Defining the molecular consequences of lysosomal dysfunction in neuronal cell types remains an area of investigation that is needed to understand many underappreciated phenotypes associated with lysosomal disorders. Here we characterize GNPTAB-knockout DAOY medulloblastoma cells using different genetic and proteomic approaches, with a focus on how altered gene expression and cell surface abundance of glycoproteins may explain emerging neurological issues in individuals with GNPTAB-related disorders, including mucolipidosis II (ML II) and mucolipidosis IIIα/β (ML IIIα/β). The two knockout clones characterized demonstrated all the biochemical hallmarks of this disease, including loss of intracellular glycosidase activity due to impaired mannose 6-phosphate-dependent lysosomal sorting, lysosomal cholesterol accumulation, and increased markers of autophagic dysfunction. RNA sequencing identified altered transcript abundance of several neuronal markers and genes involved in drug metabolism and transport, and neurodegeneration-related pathways. Using selective exo-enzymatic labeling (SEEL) coupled with proteomics to profile cell surface glycoproteins, we demonstrated altered abundance of several glycoproteins in the knockout cells. Most striking was increased abundance of the amyloid precursor protein and apolipoprotein B, indicating that loss of GNPTAB function in these cells corresponds with elevation in proteins associated with neurodegeneration. The implication of these findings on lysosomal disease pathogenesis and the emerging neurological manifestations of GNPTAB-related disorders is discussed.
    Keywords:  Amyloid precursor protein; Autophagy; Lysosomes; Mucolipidosis; Neurodegeneration; Neuronal cell model
    DOI:  https://doi.org/10.1016/j.ymgme.2024.108596
  57. Exp Cell Res. 2024 Oct 24. pii: S0014-4827(24)00382-3. [Epub ahead of print]443(1): 114291
    METTL14-mediated m6A methylation regulates pathological retinal neovascularization by targeting autophagy.
    Yang Yu, Huiling Nie, Xun Qin, Xi Chen, Xiumiao Li, Jin Yao.
      Pathological retinal neovascularization (RNV) is a prevalent characteristic of various ocular diseases, including proliferative diabetic retinopathy (PDR), retinopathy of prematurity (ROP), and retinal vein occlusion (RVO). While the importance of N6-methyladenosine (m6A) modification in diverse disease contexts is well-established, its functional role in pathological RNV remains unclear. Herein, we investigated the involvement of m6A modification and its core methyltransferase, METTL14, in a model of oxygen-induced retinopathy (OIR) to elucidate their contribution to retinal angiogenesis. In this study, we observed heightened levels of m6A modification and elevated expression of METTL14 in the OIR model, suggesting their potential implication in pathological RNV. Employing targeted knockdown of METTL14, we revealed that its depletion activated autophagy flux in human retinal vascular endothelial cells (HRVECs), consequently inhibiting the angiogenic capacity of endothelial cells. Mechanistically, we demonstrated that METTL14 exerts its regulatory influence on autophagy flux by modulating the stability of ATG7, a pivotal protein involved in autophagy. Specifically, METTL14 knockdown led to increased ATG7 expression at both mRNA and protein levels, accompanied by reduced m6A methylation of ATG7 mRNA and enhanced mRNA stability. Moreover, silencing of ATG7 counteracted the effects of METTL14 knockdown on endothelial cell functions, emphasizing ATG7 as a downstream target of METTL14-mediated autophagy in HRVECs. After all, our findings provide valuable insights into the pathogenesis of retinal pathological angiogenesis and potential therapeutic targets for the treatment of ocular neovascular diseases.
    Keywords:  Angiogenesis; Autophagy; METTL14; N6-methyladenosine modification; Ocular neovascular diseases; Retinal neovascularization
    DOI:  https://doi.org/10.1016/j.yexcr.2024.114291
  58. Cell. 2024 Oct 21. pii: S0092-8674(24)01148-6. [Epub ahead of print]
    IRGQ-mediated autophagy in MHC class I quality control promotes tumor immune evasion.
    Lina Herhaus, Uxía Gestal-Mato, Vinay V Eapen, Igor Mačinković, Henry J Bailey, Cristian Prieto-Garcia, Mohit Misra, Anne-Claire Jacomin, Aparna Viswanathan Ammanath, Ivan Bagarić, Jolina Michaelis, Joshua Vollrath, Ramachandra M Bhaskara, Georg Bündgen, Adriana Covarrubias-Pinto, Koraljka Husnjak, Jonathan Zöller, Ajami Gikandi, Sara Ribičić, Tobias Bopp, Gerbrand J van der Heden van Noort, Julian D Langer, Andreas Weigert, J Wade Harper, Joseph D Mancias, Ivan Dikic.
      The autophagy-lysosome system directs the degradation of a wide variety of cargo and is also involved in tumor progression. Here, we show that the immunity-related GTPase family Q protein (IRGQ), an uncharacterized protein to date, acts in the quality control of major histocompatibility complex class I (MHC class I) molecules. IRGQ directs misfolded MHC class I toward lysosomal degradation through its binding mode to GABARAPL2 and LC3B. In the absence of IRGQ, free MHC class I heavy chains do not only accumulate in the cell but are also transported to the cell surface, thereby promoting an immune response. Mice and human patients suffering from hepatocellular carcinoma show improved survival rates with reduced IRGQ levels due to increased reactivity of CD8+ T cells toward IRGQ knockout tumor cells. Thus, we reveal IRGQ as a regulator of MHC class I quality control, mediating tumor immune evasion.
    Keywords:  GABARAPL2; IRGQ; LC3B; MHC class I; autophagy; hepatocellular carcinoma; immune evasion; quality control
    DOI:  https://doi.org/10.1016/j.cell.2024.09.048
  59. Proc Natl Acad Sci U S A. 2024 Nov 05. 121(45): e2402035121
    FBXO22 inhibits colitis and colorectal carcinogenesis by regulating the degradation of the S2448-phosphorylated form of mTOR.
    Minle Li, Xuan Chen, Pengfei Qu, Zhiying Shao, Lei Shi, Haoyu Quan, Xue Zhao, Jian Xu, Luling Shi, Silu Chen, Junnian Zheng, Zhen-Qiang Pan, Jin Bai.
      Inflammatory bowel disease (IBD) is a considerable threat to human health with a significant risk for colorectal cancer (CRC). However, currently, both the molecular pathogenesis and therapeutic treatment of IBD remain limited. In this report, using both systemic and intestinal epithelium-specific gene knockout mouse models, we demonstrate that FBXO22, a substrate receptor within the SKP1-Cullin 1-F-box family of E3 ubiquitin ligases, plays an inhibitory role in the Azoxymethane/Dextran Sodium Sulfate-induced colorectal inflammatory responses and CRC. FBXO22 targets the serine 2448-phosphorylated form of mammalian mechanistic target of rapamycin (pS2448-mTOR) for ubiquitin-dependent degradation. This proteolytic targeting effect is established based on multiple lines of evidence including the results of colon tissue immunoblots, analysis of cultured cells with altered abundance of FBXO22 by depletion or overexpression, comparison of protein decay rate, effects on mTOR substrates S6K1 and 4E-BP1, analysis of protein-protein interactions, phosphor-peptide binding and competition, as well as reconstituted and cellular ubiquitination. Finally, we have shown that mTOR inhibitor rapamycin (RAPA) was able to alleviate the effects of fbxo22 deletion on colorectal inflammatory response and CRC. These RAPA effects are correlated with the ability of RAPA to inhibit pS2448-mTOR, pS6K1, and p4E-BP1. Collectively, our data support a suppressive role for FBXO22 in colorectal inflammation signaling and CRC initiation by targeting pS2448-mTOR for degradation.
    Keywords:  FBXO22; colitis; colorectal carcinogenesis; pS2448-mTOR
    DOI:  https://doi.org/10.1073/pnas.2402035121
  60. Life Sci. 2024 Oct 28. pii: S0024-3205(24)00765-3. [Epub ahead of print]358 123175
    p75NTR mediated chronic restraint stress-induced depression-like behaviors in mice via hippocampal mTOR pathway.
    Yu-Yuan Peng, Can Tang, Hai-Yan Wang, Yang Ding, Huan Yang, Xin-Mei Ma, Jie Gao, Sen Li, Zai-Yun Long, Xiu-Min Lu, Yong-Tang Wang.
      AIMS: Major depressive disorder (MDD) is an enduring and severe mood disorder. Previous studies have indicated that p75NTR is involved in neuronal survival and death. However, the specific mechanism of p75NTR in depression remains unknown. The present study aimed to explore the role and mechanism of p75NTR in depression, and try to provide a new target for the treatment of MDD.MAIN METHODS: The p75NTR knockout and overexpression mice were used to establish a mouse model of depression induced by chronic restraint stress (CRS), and the behavioral effects and potential mechanisms associated with p75NTR knockout/overexpression on CRS-induced depressive mice were investigated by animal behavior, histopathology, immunofluorescence and western blot, respectively.
    KEY FINDINGS: The results demonstrate that p75NTR knockout/overexpression can ameliorate the depressive-like behaviors observed in CRS-induced depressive mice. Furthermore, p75NTR knockout/overexpression safeguards the tissue morphology of the hippocampus, inhibits the mTOR signaling pathway to restore autophagy, and modulates apoptosis-related proteins (Bcl-2 and Bax) to reestablish normal levels of autophagy and apoptosis in hippocampal neurons of depressed mice. Importantly, p75NTR knockout/overexpression can improve synaptic plasticity through protecting the dendritic structure and dendritic spines of hippocampal neurons, and upregulating the expression of hippocampal synaptic-related proteins (PSD95 and SYN1).
    SIGNIFICANCE: These findings suggest that p75NTR knockout/overexpression can alleviate CRS-induced depression-like behaviors by reinstating autophagy and suppressing apoptosis in hippocampal neurons, and enhancing hippocampal synaptic plasticity via mTOR pathway. These insights may provide potential targets for clinical treatment of depression.
    Keywords:  Apoptosis; Autophagy; Hippocampal synaptic plasticity; Major depressive disorder; mTOR; p75NTR
    DOI:  https://doi.org/10.1016/j.lfs.2024.123175
  61. Microbiol Res. 2024 Oct 25. pii: S0944-5013(24)00353-7. [Epub ahead of print]290 127952
    Regulation of Bacillus Calmette-Guérin-induced macrophage autophagy and apoptosis by the AMPK-mTOR-ULK1 pathway.
    Ruiqian Li, Tianle He, Min Yang, Jinghua Xu, Yongqin Li, Xueyan Wang, Xuelian Guo, Mingzhu Li, Lihua Xu.
      Tuberculosis (TB) is a chronic wasting infectious disease caused by Mycobacterium tuberculosis (MTB) or Mycobacterium bovis that can be transmitted among people and domestic animals. During the development of TB, macrophages of the innate immune system can act against MTB via autophagy and apoptosis to prevent the spread of the disease. Among the many autophagy regulatory pathways, the adenosine monophosphate (AMP)-activated protein kinase (AMPK)-mammalian rapamycin target protein (mTOR)-Unc-51-like kinase 1 (ULK1) pathway has received considerable attention. This study investigates the regulatory role of the AMPK-mTOR-ULK1 pathway in attenuating M. bovis Bacillus Calmette-Guérin (BCG)-induced autophagy and apoptosis in murine monocyte macrophages (RAW264.7). Changes in macrophage autophagy and apoptosis were analyzed using the AMPK activator AICAR and inhibitor Compound C to interfere with the AMPK-mTOR-ULK1 pathway and siRNA to silence the pathway. Consequently, BCG stimulation of macrophages significantly activated the AMPK-mTOR-ULK1 pathway while BCG-induced macrophage AMPK activation promoted macrophage autophagy and apoptosis. Activation of the AMPK-mTOR-ULK1 pathway by AICAR significantly improved autophagy occurrence in BCG-induced macrophages and increased apoptosis while Compound C with siRNA produced opposing effects by attenuating autophagy and apoptosis in BCG-induced macrophages. Thus, the AMPK-mTOR-ULK1 pathway has a dual regulatory role in BCG-induced macrophage autophagy and apoptosis and may have synergistic effects. This study analyzes the mechanism of resistance of host cells to MTB and provides a theoretical basis for new therapeutic strategies and related drug development.
    Keywords:  AMPK–mTOR–ULK1 pathway; Apoptosis; Autophagy; Bacillus Calmette-Guérin; Macrophage
    DOI:  https://doi.org/10.1016/j.micres.2024.127952
  62. Mov Disord. 2024 Oct 28.
    Emerging Molecular-Genetic Families in Dystonia: Endosome-Autophagosome-Lysosome and Integrated Stress Response Pathways.
    Nicole Calakos, Michael Zech.
      Advances in genetic technologies and disease modeling have greatly accelerated the pace of introducing and validating molecular-genetic contributors to disease. In dystonia, there is a growing convergence across multiple distinct forms of the disease onto core biological processes. Here, we discuss two of these, the endosome-autophagosome-lysosome pathway and the integrated stress response, to highlight recent advances in the field. Using these two pathomechanisms as examples, we further discuss the opportunities that molecular-genetic grouping of dystonias present to transform dystonia care. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
    Keywords:  autophagy; endosomal trafficking; dystonia; eIF2 α; Eif2s1; HOPS complex; integrated stress response; ISR; lysosome.
    DOI:  https://doi.org/10.1002/mds.30037
  63. J Clin Med. 2024 Oct 17. pii: 6183. [Epub ahead of print]13(20):
    The mTOR Pathway: A Common Link Between Alzheimer's Disease and Down Syndrome.
    Abigail J Wohlfert, Jeremiah Phares, Ann-Charlotte Granholm.
      Down syndrome (DS) is a chromosomal condition that causes many systemic dysregulations, leading to several possible age-related diseases including Alzheimer's disease (AD). This may be due to the triplication of the Amyloid precursor protein (APP) gene or other alterations in mechanistic pathways, such as the mTOR pathway. Impairments to upstream regulators of mTOR, such as insulin, PI3K/AKT, AMPK, and amino acid signaling, have been linked to amyloid beta plaques (Aβ) and neurofibrillary tangles (NFT), the most common AD pathologies. However, the mechanisms involved in the progression of pathology in human DS-related AD (DS-AD) are not fully investigated to date. Recent advancements in omics platforms are uncovering new insights into neurodegeneration. Genomics, spatial transcriptomics, proteomics, and metabolomics are novel methodologies that provide more data in greater detail than ever before; however, these methods have not been used to analyze the mTOR pathways in connection to DS-AD. Using these new techniques can unveil unexpected insights into pathological cellular mechanisms through an unbiased approach.
    Keywords:  intellectual disability; mTOR; metabolomics; neurodegeneration; proteomics; spatial transcriptomics
    DOI:  https://doi.org/10.3390/jcm13206183
  64. Biomolecules. 2024 Oct 21. pii: 1338. [Epub ahead of print]14(10):
    Cooperative Substructure and Energetics of Allosteric Regulation of the Catalytic Core of the E3 Ubiquitin Ligase Parkin by Phosphorylated Ubiquitin.
    Xiang Ye, Sravya Kotaru, Rosana Lopes, Shannen Cravens, Mauricio Lasagna, A Joshua Wand.
      Mutations in the parkin gene product Parkin give rise to autosomal recessive juvenile parkinsonism. Parkin is an E3 ubiquitin ligase that is a critical participant in the process of mitophagy. Parkin has a complex structure that integrates several allosteric signals to maintain precise control of its catalytic activity. Though its allosterically controlled structural reorganization has been extensively characterized by crystallography, the energetics and mechanisms of allosteric regulation of Parkin are much less well understood. Allostery is fundamentally linked to the energetics of the cooperative (sub)structure of the protein. Herein, we examine the mechanism of allosteric activation by phosphorylated ubiquitin binding to the enzymatic core of Parkin, which lacks the antagonistic Ubl domain. In this way, the allosteric effects of the agonist phosphorylated ubiquitin can be isolated. Using native-state hydrogen exchange monitored by mass spectrometry, we find that the five structural domains of the core of Parkin are energetically distinct. Nevertheless, association of phosphorylated ubiquitin destabilizes structural elements that bind the ubiquitin-like domain antagonist while promoting the dissociation of the catalytic domain and energetically poises the protein for transition to the fully activated structure.
    Keywords:  Parkin E3 ubiquitin ligase; allostery; hydrogen exchange; protein ensemble; protein stability
    DOI:  https://doi.org/10.3390/biom14101338
  65. EMBO J. 2024 Oct 30.
    Brain mitophagy in space and time.
    Vassiliki Nikoletopoulou.
      
    DOI:  https://doi.org/10.1038/s44318-024-00275-2
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