bims-kishpe 2024-12-22 papers

bims-kishpe

Biomed News

on HSP70 role in hypoxia and metabolism in ECs

Issue of 2024–12–22
eleven papers selected by
Alia Ablieh, Universität Heidelberg

Full-length direct RNA sequencing uncovers stress granule-dependent RNA decay upon cellular stress.
Endothelial Dysfunction and Liver Cirrhosis: Unraveling of a Complex Relationship.
Exosomal tRF-1003 induces angiogenesis via regulating the HIF1α/VEGF signaling in multiple myeloma.
Blue Light-Induced Mitochondrial Oxidative Damage Underlay Retinal Pigment Epithelial Cell Apoptosis.
Hypoxia-Inducible Factor-2α Promotes Liver Fibrosis by Inducing Hepatocellular Death.
Molecular and metabolomic characterization of hiPSC-derived cardiac fibroblasts transitioning to myofibroblasts.
Role of PI3K/AKT/MAOA in glucocorticoid-induced oxidative stress and associated premature senescence of the trabecular meshwork.
Nitric oxide modelling and its bioavailability influenced by red blood cells.
A hybrid epithelial-mesenchymal transition program enables basal epithelial cells to bypass stress-induced stasis and contributes to a metaplastic breast cancer progenitor state.
Shear stress-induced restoration of pulmonary microvascular endothelial barrier function following ischaemia reperfusion injury requires VEGFR2 signalling.
MicroRNAs and RNA-Binding Protein-Based Regulation of Bone Metastasis from Hepatobiliary Cancers and Potential Therapeutic Strategies.

Elife. 2024 Dec 19. pii: RP96284. [Epub ahead of print]13

Full-length direct RNA sequencing uncovers stress granule-dependent RNA decay upon cellular stress.

Showkat Ahmad Dar, Sulochan Malla, Vlastimil Martinek, Matthew John Payea, Christopher Tai-Yi Lee, Jessica Martin, Aditya Jignesh Khandeshi, Jennifer L Martindale, Cedric Belair, Manolis Maragkakis.

  Cells react to stress by triggering response pathways, leading to extensive alterations in the transcriptome to restore cellular homeostasis. The role of RNA metabolism in shaping the cellular response to stress is vital, yet the global changes in RNA stability under these conditions remain unclear. In this work, we employ direct RNA sequencing with nanopores, enhanced by 5' end adapter ligation, to comprehensively interrogate the human transcriptome at single-molecule and -nucleotide resolution. By developing a statistical framework to identify robust RNA length variations in nanopore data, we find that cellular stress induces prevalent 5' end RNA decay that is coupled to translation and ribosome occupancy. Unlike typical RNA decay models in normal conditions, we show that stress-induced RNA decay is dependent on XRN1 but does not depend on deadenylation or decapping. We observed that RNAs undergoing decay are predominantly enriched in the stress granule transcriptome while inhibition of stress granule formation via genetic ablation of G3BP1 and G3BP2 rescues RNA length. Our findings reveal RNA decay as a key component of RNA metabolism upon cellular stress that is dependent on stress granule formation.

Keywords:  RNA decay; cell biology; cell line; genetics; genomics; human; mouse; stress response

DOI:  https://doi.org/10.7554/eLife.96284
Int J Mol Sci. 2024 Nov 29. pii: 12859. [Epub ahead of print]25(23):

Endothelial Dysfunction and Liver Cirrhosis: Unraveling of a Complex Relationship.

Antonio Nesci, Vittorio Ruggieri, Vittoria Manilla, Irene Spinelli, Luca Santoro, Angela Di Giorgio, Angelo Santoliquido, Francesca Romana Ponziani.

  Endothelial dysfunction (ED) is the in the background of multiple metabolic diseases and a key process in liver disease progression and cirrhosis decompensation. ED affects liver sinusoidal endothelial cells (LSECs) in response to different damaging agents, causing their progressive dedifferentiation, unavoidably associated with an increase in intrahepatic resistance that leads to portal hypertension and hyperdynamic circulation with increased cardiac output and low peripheral artery resistance. These changes are driven by a continuous interplay between different hepatic cell types, invariably leading to increased reactive oxygen species (ROS) formation, increased release of pro-inflammatory cytokines and chemokines, and reduced nitric oxide (NO) bioavailability, with a subsequent loss of proper vascular tone regulation and fibrosis development. ED evaluation is often accomplished by serum markers and the flow-mediated dilation (FMD) measurement of the brachial artery to assess its NO-dependent response to shear stress, which usually decreases in ED. In the context of liver cirrhosis, the ED assessment could help understand the complex hemodynamic changes occurring in the early and late stages of the disease. However, the instauration of a hyperdynamic state and the different NO bioavailability in intrahepatic and systemic circulation-often defined as the NO paradox-must be considered confounding factors during FMD analysis. The primary purpose of this review is to describe the main features of ED and highlight the key findings of the dynamic and intriguing relationship between ED and liver disease. We will also focus on the significance of FMD evaluation in this setting, pointing out its key role as a therapeutic target in the never-ending battle against liver cirrhosis progression.

Keywords:  Krüppel-like factor; albumin; cirrhosis; endothelial dysfunction; endothelium; flow-mediated dilation; nitric oxide; shear stress; statins

DOI:  https://doi.org/10.3390/ijms252312859
Int Immunopharmacol. 2024 Dec 16. pii: S1567-5769(24)02384-1. [Epub ahead of print]146 113862

Exosomal tRF-1003 induces angiogenesis via regulating the HIF1α/VEGF signaling in multiple myeloma.

Yunfeng Fu, Jianyao Sang, Fangrong Zhang, Siyi Jiang, Fangfang Li, Ting Liang, Cong Xu.

   BACKGROUND: Multiple myeloma (MM) remains a therapeutically challenging hematologic malignancy characterized by frequent relapse and disease progression. Angiogenesis regulated by non-coding RNAs plays a vital role in MM pathogenesis. Despite the potential clinical applications of tsRNAs, the specific mechanisms by which they contribute to MM progression, particularly through angiogenesis within the bone marrow microenvironment, remain elusive.
METHODS: In this study, we focused on the role of exosomal tRF-1003 in MM progression. Serum and bone marrow samples from relapsed and refractory multiple myeloma (R/RMM) and newly diagnosed multiple myeloma (NDMM) patients were analyzed for tsRNA expression. Functional assays, including transwell migration, wound-healing assays, and in vivo tumor formation studies, were employed to assess the angiogenic potential of tRF-1003 in HUVEC. Mechanistic studies were conducted to understand how tRF-1003 modulates the HIF-1α/VEGF signaling pathway through interaction with MAPK1.
RESULTS: We found that tRF-1003 was significantly upregulated in serum exosomes derived from R/RMM patients. Exosomal tRF-1003 was efficiently delivered to endothelial cells, leading to enhanced angiogenesis both in vitro and in vivo. Mechanistically, tRF-1003 was shown to activate HIF-1α/VEGF signaling in endothelial cells by downregulating MAPK1 expression, thereby promoting angiogenesis. Overexpression of MAPK1 in endothelial cells partially reversed the angiogenic effects induced by exosomal tRF-1003.
CONCLUSION: Our findings reveal that exosomal tRF-1003 plays a pivotal role in MM angiogenesis by modulating the HIF-1α/VEGF signaling pathway through MAPK1. These insights provide a novel perspective on the mechanisms driving MM progression and highlight the potential therapeutic value of targeting tRF-1003 in managing multiple myeloma.

Keywords:  Angiogenesis; Exosome; Multiple myeloma; tsRNA

DOI:  https://doi.org/10.1016/j.intimp.2024.113862
Int J Mol Sci. 2024 Nov 24. pii: 12619. [Epub ahead of print]25(23):

Blue Light-Induced Mitochondrial Oxidative Damage Underlay Retinal Pigment Epithelial Cell Apoptosis.

Mohamed Abdouh, Yunxi Chen, Alicia Goyeneche, Miguel N Burnier.

  Reactive oxygen species (ROS) play a pivotal role in apoptosis. We reported that Blue Light (BL) induced oxidative stress in human retinal pigment epithelial (RPE) cells in vitro and increased drusen deposition and RPE cell apoptosis in human eyes. Here, we investigated the mechanisms underlying BL-induced damage to RPE cells. Cells were exposed to BL with or without the antioxidant N-acetylcysteine. Cells were analyzed for levels of ROS, proliferation, viability, and mitochondria membrane potential (ΔΨM) fluctuation. We performed proteomic analyses to search for differentially expressed proteins. ROS levels increased following RPE cell exposure to BL. While ROS production did not affect RPE cell proliferation, it was accompanied by decreased ΔΨM and increased cell apoptosis due to the caspase cascade activation in a ROS-dependent manner. Proteomic analyses revealed that BL decreased the levels of ROS detoxifying enzymes in exposed cells. We conclude that BL-induced oxidative stress is cytotoxic to RPE cells. These findings bring new insights into the involvement of BL on RPE cell damage and its role in the progression of age-related macular degeneration. The use of antioxidants is an avenue to block or delay BL-mediated RPE cell apoptosis to counteract the disease progression.

Keywords:  antioxidant; apoptosis; blue light; caspases activation; mitochondria damage; oxidative stress; retinal pigment epithelial cells

DOI:  https://doi.org/10.3390/ijms252312619
Int J Mol Sci. 2024 Dec 06. pii: 13114. [Epub ahead of print]25(23):

Hypoxia-Inducible Factor-2α Promotes Liver Fibrosis by Inducing Hepatocellular Death.

Raja Gopal Reddy Mooli, Dhanunjay Mukhi, Mikayla Watt, Veerababu Nagati, Sara M Reed, Nikita K Gandhi, Michael Oertel, Sadeesh K Ramakrishnan.

  The activation of hypoxia-inducible factors (HIF)-1α and 2α in the liver is closely linked to the progression of fatty liver diseases. Prior studies indicated that disrupting hepatocyte HIF-2α attenuates diet-induced hepatic steatosis, subsequently decreasing fibrosis. However, the direct role of hepatocyte HIF-2α in liver fibrosis has not been addressed. Hepatic HIF-2α expression was examined in mouse model of carbon tetrachloride (CCl4)-induced liver fibrosis. Conditional hepatocyte Hif-2α knockout mice were employed to investigate the role of hepatocyte HIF-2α in fibrosis. Markers of apoptosis, proliferation, inflammation, and fibrosis were assessed through biochemical, molecular, and histological analyses. We found an induction of HIF-2α in CCL4-injected liver injury and fibrosis mouse models. Hepatocyte-specific deletion of HIF-2α attenuated stellate cell activation and fibrosis, with no significant difference in inflammation. Disrupting hepatocyte HIF-2α led to reduced injury-mediated hepatocellular apoptosis. Surviving hepatocytes exhibited hypertrophy, which was strongly associated with the activation of c-JUN signaling. Our study demonstrates a direct role of hepatocyte HIF-2α in liver fibrosis by promoting hepatocyte apoptosis. The reduction in apoptosis and induction of hepatocyte hypertrophy following HIF-2α disruption is closely linked to enhanced c-JUN signaling, a survival mechanism in response to liver injury. These findings highlight HIF-2α as a potential therapeutic target for liver fibrosis.

Keywords:  apoptosis; fibrosis; hepatocyte; hypoxia; hypoxia-inducible factor-2α

DOI:  https://doi.org/10.3390/ijms252313114
Front Cell Dev Biol. 2024 ;12 1496884

Molecular and metabolomic characterization of hiPSC-derived cardiac fibroblasts transitioning to myofibroblasts.

Raghu Sundaresan Nagalingam, Farah Jayousi, Homa Hamledari, Saif Dababneh, Dina Hosseini, Chloe Lindsay, Ramon Klein Geltink, Philipp F Lange, Ian Michael Dixon, Robert Alan Rose, Michael Paul Czubryt, Glen Findlay Tibbits.

   Background: Mechanical stress and pathological signaling trigger the activation of fibroblasts to myofibroblasts, which impacts extracellular matrix composition, disrupts normal wound healing, and can generate deleterious fibrosis. Myocardial fibrosis independently promotes cardiac arrhythmias, sudden cardiac arrest, and contributes to the severity of heart failure. Fibrosis can also alter cell-to-cell communication and increase myocardial stiffness which eventually may lead to lusitropic and inotropic cardiac dysfunction. Human induced pluripotent stem cell derived cardiac fibroblasts (hiPSC-CFs) have the potential to enhance clinical relevance in precision disease modeling by facilitating the study of patient-specific phenotypes. However, it is unclear whether hiPSC-CFs can be activated to become myofibroblasts akin to primary cells, and the key signaling mechanisms in this process remain unidentified.
Objective: We aim to explore the notable changes in fibroblast phenotype upon passage-mediated activation of hiPSC-CFs with increased mitochondrial metabolism, like primary cardiac fibroblasts.
Methods: We activated the hiPSC-CFs with serial passaging from passage 0 to 3 (P0 to P3) and treatment of P0 with TGFβ1.
Results: Passage-mediated activation of hiPSC-CFs was associated with a gradual induction of genes to initiate the activation of these cells to myofibroblasts, including collagen, periostin, fibronectin, and collagen fiber processing enzymes with concomitant downregulation of cellular proliferation markers. Most importantly, canonical TGFβ1 and Hippo signaling component genes including TAZ were influenced by passaging hiPSC-CFs. Seahorse assay revealed that passaging and TGFβ1 treatment increased mitochondrial respiration, consistent with fibroblast activation requiring increased energy production, whereas treatment with the glutaminolysis inhibitor BPTES completely attenuated this process.
Conclusion: Our study highlights that the hiPSC-CF passaging enhanced fibroblast activation, activated fibrotic signaling pathways, and enhanced mitochondrial metabolism approximating what has been reported in primary cardiac fibroblasts. Thus, hiPSC-CFs may provide an accurate in vitro preclinical model for the cardiac fibrotic condition, which may facilitate the identification of putative anti-fibrotic therapies, including patient-specific approaches.

Keywords:  arrhythmia; cardiac ECM; cardiac fibrosis; cardiac remodeling; fibroblast; induced pluripotent stem cells; myofibroblast

DOI:  https://doi.org/10.3389/fcell.2024.1496884
Aging Cell. 2024 Dec 17. e14452

Role of PI3K/AKT/MAOA in glucocorticoid-induced oxidative stress and associated premature senescence of the trabecular meshwork.

Pengyu Zhang, Nan Zhang, Yixin Hu, Xizhi Deng, Min Zhu, Cheng Lai, Wen Zeng, Min Ke.

  The oxidative stress-induced premature senescence of trabecular meshwork (TM) represents a pivotal risk factor for the development of glucocorticoid-induced glaucoma (GIG). This study aimed to elucidate the pathogenesis of TM senescence in GIG. MethodsIntraocular pressure (IOP), transmission electron microscopy and senescence-associated protein expression in TM were evaluated in GIG mice. Protein expression of phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) and monoamine oxidase A (MAOA), phosphorylation of AKT were quantified. ROS and mitochondrial superoxide levels were measured to evaluate cellular oxidative stress. Cell cycle analysis, β-galactosidase staining, senescence-associated protein expression were employed to assess the aging status of primary human trabecular meshwork cells (pHTMs). ResultsmRNA-seq and KEGG analysis indicating PI3K/AKT pathway as a key regulator in TM of GIG. PI3K inhibitor significantly prevented IOP elevation and abnormal mitochondrial morphology of TM in the GIG mouse model. PI3K inhibitor or selective silencing of PIK3R1 alleviated dexamethasone (DEX)-induced oxidative stress, also mitochondrial dysfunction, inhibiting MAOA expression in pHTMs. The same phenomenon was observed in the GIG models with inhibition of MAOA. Further KEGG analysis indicates that cellular senescence is the key factor in the pathogenesis of GIG. TM senescence was observed in both GIG mouse and cell models. Inhibition of the PI3K/AKT/MAOA pathway significantly alleviated DEX-induced premature cellular senescence of TM in GIG models. Glucocorticoids activated the PI3K/AKT/MAOA pathway, leading to mitochondrial dysfunction, oxidative stress, and premature aging in TM, elevating IOP. This mechanism could be associated with the onset and progression of GIG, providing a potential approach for its treatment.

Keywords:  PI3K/AKT/MAOA; cell aging; glaucoma; glucocorticoid; mitochondria; oxidative stress; trabecular meshwork

DOI:  https://doi.org/10.1111/acel.14452
J R Soc Interface. 2024 Dec;21(221): 20240458

Nitric oxide modelling and its bioavailability influenced by red blood cells.

Ananta Kumar Nayak, Marco Canepari, Sovan Lal Das, Chaouqi Misbah.

  Nitric oxide (NO) is an important vasodilator responsible for maintaining vascular tone in the human body. Its production in endothelial cells (ECs) is regulated by the rise of cytoplasmic Ca2+ concentration and shear stress perceived by blood flow. The increase in cytoplasmic Ca2+ concentration is mainly activated by adenosine triphosphate (ATP) released from red blood cells (RBCs) and ECs. However, RBCs, which act as NO scavengers, can affect the bioavailability of NO in blood vessels. In this study, we developed a model that incorporates ATP and shear stress-dependent NO production, integrating various biochemical pathways. The model results are qualitatively consistent with the experimental findings. Given that ATP concentration and shear stress vary spatially within blood circulation, influenced by factors such as vessel width, flow strength and RBC concentration, these variations can significantly affect NO bioavailability. Here, we study RBC flow, ATP release from RBCs and ECs, and [Formula: see text] and NO dynamics in a two-dimensional channel using the immersed boundary lattice Boltzmann method. The main findings from the study include: (i) an increase in RBC concentration leads to a rise in ATP and cytoplasmic Ca2+ concentrations for all variation in channel widths, while NO concentration exhibits a decrease; (ii) NO bioavailability is significantly influenced by RBC distribution, particularly in strongly confined channels; and (iii) two phases of NO bioavailability are observed in different regions of the blood vessels: one with a significant concentration change at low RBC concentration and another with a minimal concentration change at high RBC concentration, across all confinements. The outcomes of this study may provide valuable insights into the mechanisms of NO-dependent vasodilation and the transport of oxygen by RBCs within microvascular networks for future studies.

Keywords:  adenosine triphosphate; calcium signalling; immersed boundary lattice Boltzmann method; nitric oxide; red blood cells; vasodilation

DOI:  https://doi.org/10.1098/rsif.2024.0458
Breast Cancer Res. 2024 Dec 18. 26(1): 184

A hybrid epithelial-mesenchymal transition program enables basal epithelial cells to bypass stress-induced stasis and contributes to a metaplastic breast cancer progenitor state.

Joseph A Caruso, Chira Chen-Tanyolac, Thea D Tlsty.

   BACKGROUND: Human mammary epithelial cell (HMEC) cultures encounter a stress-associated barrier termed stasis, during which most cells adopt a senescence-like phenotype. From these cultures, rare variants emerge from the basal epithelial population, re-initiating growth. Variants exhibit pre-malignant properties, including an aberrant epigenetic program that enables continued proliferation and acquisition of genetic changes. Following oncogenic transformation, variants produce tumors that recapitulate the histopathological characteristics of metaplastic breast cancer (MBC), a rare and aggressive subtype marked by the differentiation of neoplastic epithelium into squamous and mesenchymal elements.
METHODS: Using a serum-free HMEC culture system, we probed the capacity for phenotypic plasticity inherent to basal epithelial cell populations from human breast tissue as they navigated stasis and emerged as variant populations.
RESULTS: We observed robust activation of a TGF-β-dependent epithelial-mesenchymal transition (EMT) program in basal epithelial cells during stasis, followed by subsequent attenuation of this program in emerging variants. Inhibition of the TGF-β pathway or depleting the EMT regulators Snail or Slug allowed basal epithelial cells to collectively bypass stasis, demonstrating that cellular dysfunction and arrest resulting from TGF-β and EMT activation are central to this in vitro barrier. The spontaneous emergence of variants from stasis cultures was associated with a restricted EMT trajectory, characterized by the stabilization of hybrid EMT states associated with greater proliferative capacity, rather than progressing to a complete mesenchymal state characterized by irreversible growth arrest. Epigenetic mechanisms, which contributed to the dysregulated growth control characteristic of the variant phenotype, also contributed to the stability of the hybrid EMT program in variants. By overcoming the cellular dysfunction and growth arrest resulting from TGF-β and complete EMT, variants exhibited a higher oncogenic transformation efficiency compared to pre-stasis basal epithelial cells. Inhibiting the TGF-β pathway prior to stasis significantly reduced EMT in the basal epithelial population, alleviated selective pressure driving variant emergence, and also enhanced oncogenic transformation efficiency, resulting in tumors with markedly diminished metaplastic differentiation.
CONCLUSIONS: This study reveals how an epigenetic program governs basal epithelial cell fate decisions and contributes to the development of MBC progenitors by restricting access to terminal mesenchymal states that induce growth arrest and, instead, favoring hybrid EMT states with enhanced tumorigenic potential.

Keywords:  Basal; Epigenetic regulation; Epithelial-mesenchymal transition; Human mammary epithelial cells; Metaplastic breast cancer; Myoepithelial; TGF-β pathway

DOI:  https://doi.org/10.1186/s13058-024-01920-8
Am J Physiol Lung Cell Mol Physiol. 2024 Dec 19.

Shear stress-induced restoration of pulmonary microvascular endothelial barrier function following ischaemia reperfusion injury requires VEGFR2 signalling.

Don Walsh, Daria Kostyunina, Aoife Blake, John Boylan, Paul McLoughlin.

  Normal shear stress produced by blood flow is sensed by the vascular endothelium and required for maintenance of the homeostatic functions of the endothelium in systemic conduit and resistance vessels. Many critical illnesses are characterised by periods of abnormally reduced or absent shear stress in the lung (e.g. haemorrhagic shock, embolism, ischaemia reperfusion injury and lung transplantation) and are complicated by pulmonary oedema following reperfusion due to microvascular leak. The role of shear stress in regulating the pulmonary microvascular endothelial barrier in the intact vascular bed has not been previously examined. We tested the hypothesis that, in lungs injured by a period of ischaemia and reperfusion (IRI), reduced shear stress contributes to increased pulmonary microvascular endothelial barrier permeability and oedema formation. Furthermore, we examined the role of VEGFR2 as a mechanosensor mediating the endothelial response to this altered shear stress. Following IRI, we perfused isolated ventilated mouse lungs with a low viscosity solution (LVS) or a higher, physiological viscosity solution (PVS) at constant flow to produce differing endothelial shear stresses in of the intact microcirculation. Lungs perfused with LVS developed pulmonary oedema due to increased endothelial permeability whereas those perfused with PVS were protected from oedema formation by reduced endothelial permeability. This effect of PVS required normal VEGFR2 mechanoreceptor function. These data show for the first time that shear stress has an important role in restoring endothelial barrier function in the intact pulmonary microcirculation following injury and have important implications for the treatment of pulmonary oedema in critically ill patients.

Keywords:  endothelial permeability; microvascular circulation; non-cardiogenic pulmonary edema; pulmonary circulation; shear stress

DOI:  https://doi.org/10.1152/ajplung.00200.2024
Cells. 2024 Nov 21. pii: 1935. [Epub ahead of print]13(23):

MicroRNAs and RNA-Binding Protein-Based Regulation of Bone Metastasis from Hepatobiliary Cancers and Potential Therapeutic Strategies.

Sharmila Fagoonee, Ralf Weiskirchen.

  Hepatobiliary cancers, such as hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), are among the deadliest malignancies worldwide, leading to a significant number of cancer-related deaths. While bone metastases from these cancers are rare, they are highly aggressive and linked to poor prognosis. This review focuses on RNA-based molecular mechanisms that contribute to bone metastasis from hepatobiliary cancers. Specifically, the role of two key factors, microRNAs (miRNAs) and RNA-binding proteins (RBPs), which have not been extensively studied in the context of HCC and CCA, is discussed. These molecules often exhibit abnormal expression in hepatobiliary tumors, influencing cancer cell spread and metastasis by disrupting bone homeostasis, thereby aiding tumor cell migration and survival in the bone microenvironment. This review also discusses potential therapeutic strategies targeting these RNA-based pathways to reduce bone metastasis and improve patient outcomes. Further research is crucial for developing effective miRNA- and RBP-based diagnostic and prognostic biomarkers and treatments to prevent bone metastases in hepatobiliary cancers.

Keywords:  RNA-binding proteins; biomarkers; bone metastases; cholangiocarcinoma; extracellular vesicles; hepatocellular carcinoma; microRNAs; therapy

DOI:  https://doi.org/10.3390/cells13231935