bims-cesemi 2024-06-09 papers

bims-cesemi

Biomed News

on Cellular senescence and mitochondria

Issue of 2024‒06‒09
twelve papers selected by
Julio Cesar Cardenas, Universidad Mayor

Expression of mitochondrial oxidative stress response genes in muscle is associated with mitochondrial respiration, physical performance, and muscle mass in the Study of Muscle, Mobility, and Aging.
Skeletal muscle PGC-1α remodels mitochondrial phospholipidome but does not alter energy efficiency for ATP synthesis.
Redox regulation of UPR signalling and mitochondrial ER contact sites.
SenNet recommendations for detecting senescent cells in different tissues.
The effects of exercise and mitochondrial transplantation alone or in combination against Doxorubicin-induced skeletal muscle atrophy.
Czech Footprints in the Bioenergetics Research.
Circular RNA circMYLK4 shifts energy metabolism from glycolysis to OXPHOS by binding to the calcium channel auxiliary subunit CACNA2D2.
Ketogenic diet enhances the anti-cancer effects of PD-L1 blockade in renal cell carcinoma.
A novel senolytic drug for pulmonary fibrosis: BTSA1 targets apoptosis of senescent myofibroblasts by activating BAX.
Mitochondria Transplantation Promotes Corneal Epithelial Wound Healing.
Identification of nicotinamide N-methyltransferase as a promising therapeutic target for sarcopenia.
Neratinib stimulates senescence of mammary cancer cells by reducing the levels of SIRT1.

Aging Cell. 2024 Jun 03. e14114

Expression of mitochondrial oxidative stress response genes in muscle is associated with mitochondrial respiration, physical performance, and muscle mass in the Study of Muscle, Mobility, and Aging.

Gregory J Tranah, Haley N Barnes, Peggy M Cawthon, Paul M Coen, Karyn A Esser, Russell T Hepple, Zhiguang Huo, Philip A Kramer, Frederico G S Toledo, Xiping Zhang, Kevin Wu, Christopher A Wolff, Daniel S Evans, Steven R Cummings.

  Gene expression in skeletal muscle of older individuals may reflect compensatory adaptations in response to oxidative damage that preserve tissue integrity and maintain function. Identifying associations between oxidative stress response gene expression patterns and mitochondrial function, physical performance, and muscle mass in older individuals would further our knowledge of mechanisms related to managing molecular damage that may be targeted to preserve physical resilience. To characterize expression patterns of genes responsible for the oxidative stress response, RNA was extracted and sequenced from skeletal muscle biopsies collected from 575 participants (≥70 years old) from the Study of Muscle, Mobility, and Aging. Expression levels of 21 protein-coding RNAs related to the oxidative stress response were analyzed in relation to six phenotypic measures, including maximal mitochondrial respiration from muscle biopsies (Max OXPHOS), physical performance (VO2 peak, 400-m walking speed, and leg strength), and muscle size (thigh muscle volume and whole-body D3Cr muscle mass). The mRNA level of the oxidative stress response genes most consistently associated across outcomes are preferentially expressed within the mitochondria. Higher expression of mRNAs that encode generally mitochondria located proteins SOD2, TRX2, PRX3, PRX5, and GRX2 were associated with higher levels of mitochondrial respiration and VO2 peak. In addition, greater SOD2, PRX3, and GRX2 expression was associated with higher physical performance and muscle size. Identifying specific mechanisms associated with high functioning across multiple performance and physical domains may lead to targeted antioxidant interventions with greater impacts on mobility and independence.

Keywords:  aging; cohort study; gene expression; mitochondria; muscle; oxidative stress

DOI:  https://doi.org/10.1111/acel.14114
bioRxiv. 2024 May 26. pii: 2024.05.22.595374. [Epub ahead of print]

Skeletal muscle PGC-1α remodels mitochondrial phospholipidome but does not alter energy efficiency for ATP synthesis.

Takuya Karasawa, Ran Hee Choi, Cesar A Meza, J Alan Maschek, James E Cox, Katsuhiko Funai.

  Background: Exercise training is thought to improve the mitochondrial energy efficiency of skeletal muscle. Some studies suggest exercise training increases the efficiency for ATP synthesis by oxidative phosphorylation (OXPHOS), but the molecular mechanisms are unclear. We have previously shown that exercise remodels the lipid composition of mitochondrial membranes, and some of these changes could contribute to improved OXPHOS efficiency (ATP produced by O2 consumed or P/O). Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) is a transcriptional co-activator that coordinately regulates exercise-induced adaptations including mitochondria. We hypothesized that increased PGC-1α activity is sufficient to remodel mitochondrial membrane lipids and promote energy efficiency.Methods: Mice with skeletal muscle-specific overexpression of PGC-1α (MCK-PGC-1α) and their wildtype littermates were used for this study. Lipid mass spectrometry and quantitative PCR were used to assess muscle mitochondrial lipid composition and their biosynthesis pathway. The abundance of OXPHOS enzymes was determined by western blot assay. High-resolution respirometry and fluorometry analysis were used to characterize mitochondrial bioenergetics (ATP production, O2 consumption, and P/O) for permeabilized fibers and isolated mitochondria.
Results: Lipidomic analyses of skeletal muscle mitochondria from wildtype and MCK-PGC-1α mice revealed that PGC-1α increases the concentrations of cone-shaped lipids such as phosphatidylethanolamine (PE), cardiolipin (CL), and lysophospholipids, while decreases the concentrations of phosphatidylcholine (PC), phosphatidylinositol (PI) and phosphatidic acid (PA). However, while PGC-1α overexpression increased the abundance of OXPHOS enzymes in skeletal muscle and the rate of O2 consumption (JO2), P/O values were unaffected with PGC-1α in permeabilized fibers or isolated mitochondria.
Conclusions: Collectively, overexpression of PGC-1α promotes the biosynthesis of mitochondrial PE and CL but neither PGC-1α nor the mitochondrial membrane lipid remodeling induced in MCK-PGC-1α mice is sufficient to increase the efficiency for mitochondrial ATP synthesis. These findings suggest that exercise training may increase OXPHOS efficiency by a PGC-1α-independent mechanism, and question the hypothesis that mitochondrial lipids directly affect OXPHOS enzymes to improve efficiency for ATP synthesis.

Keywords:  exercise; mitochondria; phospholipids; skeletal muscle

DOI:  https://doi.org/10.1101/2024.05.22.595374
Cell Mol Life Sci. 2024 Jun 07. 81(1): 250

Redox regulation of UPR signalling and mitochondrial ER contact sites.

Jose C Casas-Martinez, Afshin Samali, Brian McDonagh.

  Mitochondria and the endoplasmic reticulum (ER) have a synergistic relationship and are key regulatory hubs in maintaining cell homeostasis. Communication between these organelles is mediated by mitochondria ER contact sites (MERCS), allowing the exchange of material and information, modulating calcium homeostasis, redox signalling, lipid transfer and the regulation of mitochondrial dynamics. MERCS are dynamic structures that allow cells to respond to changes in the intracellular environment under normal homeostatic conditions, while their assembly/disassembly are affected by pathophysiological conditions such as ageing and disease. Disruption of protein folding in the ER lumen can activate the Unfolded Protein Response (UPR), promoting the remodelling of ER membranes and MERCS formation. The UPR stress receptor kinases PERK and IRE1, are located at or close to MERCS. UPR signalling can be adaptive or maladaptive, depending on whether the disruption in protein folding or ER stress is transient or sustained. Adaptive UPR signalling via MERCS can increase mitochondrial calcium import, metabolism and dynamics, while maladaptive UPR signalling can result in excessive calcium import and activation of apoptotic pathways. Targeting UPR signalling and the assembly of MERCS is an attractive therapeutic approach for a range of age-related conditions such as neurodegeneration and sarcopenia. This review highlights the emerging evidence related to the role of redox mediated UPR activation in orchestrating inter-organelle communication between the ER and mitochondria, and ultimately the determination of cell function and fate.

Keywords:   C. elegans ; Contact-sites; Hormesis; Mitochondrial dynamics; Redox signalling; Skeletal muscle

DOI:  https://doi.org/10.1007/s00018-024-05286-0
Nat Rev Mol Cell Biol. 2024 Jun 03.

SenNet recommendations for detecting senescent cells in different tissues.

Vidyani Suryadevara, Adam D Hudgins, Adarsh Rajesh, Alberto Pappalardo, Alla Karpova, Amit K Dey, Ann Hertzel, Anthony Agudelo, Azucena Rocha, Bikem Soygur, Birgit Schilling, Chase M Carver, Cristina Aguayo-Mazzucato, Darren J Baker, David A Bernlohr, Diana Jurk, Dilyana B Mangarova, Ellen M Quardokus, Elizabeth Ann L Enninga, Elizabeth L Schmidt, Feng Chen, Francesca E Duncan, Francesco Cambuli, Gagandeep Kaur, George A Kuchel, Gung Lee, Heike E Daldrup-Link, Helene Martini, Hemali Phatnani, Iman M Al-Naggar, Irfan Rahman, Jia Nie, João F Passos, Jonathan C Silverstein, Judith Campisi, Julia Wang, Kanako Iwasaki, Karina Barbosa, Kay Metis, Kerem Nernekli, Laura J Niedernhofer, Li Ding, Lichao Wang, Lisa C Adams, Liu Ruiyang, Madison L Doolittle, Marcos G Teneche, Marissa J Schafer, Ming Xu, Mohammadjavad Hajipour, Mozhgan Boroumand, Nathan Basisty, Nicholas Sloan, Nikolai Slavov, Olena Kuksenko, Paul Robson, Paul T Gomez, Periklis Vasilikos, Peter D Adams, Priscila Carapeto, Quan Zhu, Ramalakshmi Ramasamy, Rolando Perez-Lorenzo, Rong Fan, Runze Dong, Ruth R Montgomery, Sadiya Shaikh, Sanja Vickovic, Shanshan Yin, Shoukai Kang, Sonja Suvakov, Sundeep Khosla, Vesna D Garovic, Vilas Menon, Yanxin Xu, Yizhe Song, Yousin Suh, Zhixun Dou, Nicola Neretti.

Once considered a tissue culture-specific phenomenon, cellular senescence has now been linked to various biological processes with both beneficial and detrimental roles in humans, rodents and other species. Much of our understanding of senescent cell biology still originates from tissue culture studies, where each cell in the culture is driven to an irreversible cell cycle arrest. By contrast, in tissues, these cells are relatively rare and difficult to characterize, and it is now established that fully differentiated, postmitotic cells can also acquire a senescence phenotype. The SenNet Biomarkers Working Group was formed to provide recommendations for the use of cellular senescence markers to identify and characterize senescent cells in tissues. Here, we provide recommendations for detecting senescent cells in different tissues based on a comprehensive analysis of existing literature reporting senescence markers in 14 tissues in mice and humans. We discuss some of the recent advances in detecting and characterizing cellular senescence, including molecular senescence signatures and morphological features, and the use of circulating markers. We aim for this work to be a valuable resource for both seasoned investigators in senescence-related studies and newcomers to the field.

DOI: https://doi.org/10.1038/s41580-024-00738-8
J Muscle Res Cell Motil. 2024 Jun 01.

The effects of exercise and mitochondrial transplantation alone or in combination against Doxorubicin-induced skeletal muscle atrophy.

Gokhan Burcin Kubat, Oner Ulger, Ozbeyen Atalay, Tugba Fatsa, Ibrahim Turkel, Berkay Ozerklig, Ertugrul Celik, Emrah Ozenc, Gulcin Simsek, Meltem Tuncer.

  Doxorubicin (DOX) is a chemotherapy drug used to treat various types of cancer, but it is associated with significant side effects such as skeletal muscle atrophy. Exercise has been found to prevent skeletal muscle atrophy through the modulation of mitochondrial pathways. Mitochondrial transplantation (MT) may mitigate toxicity, neurological disorders, kidney and liver injury, and skeletal muscle atrophy. The objective of this study was to evaluate the effects of MT, exercise, and MT with exercise on DOX-induced skeletal muscle atrophy. Male Sprague Dawley rats were randomly assigned to the following groups: control, DOX, MT with DOX, exercise with DOX, and exercise with MT and DOX. A 10-day treadmill running exercise and MT (6.5 µg/100 µL) to tibialis anterior (TA) muscle were administered prior to a single injection of DOX (20 mg/kg). Our data showed that exercise and MT with exercise led to an increase in cross-sectional area of the TA muscle. Exercise, MT and MT with exercise reduced inflammation and maintained mitochondrial enzyme activity. Additionally, exercise and MT have been shown to regulate mitochondrial fusion/fission. Our findings revealed that exercise and MT with exercise prevented oxidative damage. Furthermore, MT and MT with exercise decreased apoptosis and MT with exercise triggered mitochondrial biogenesis. These findings demonstrate the importance of exercise in the prevention of skeletal muscle atrophy and emphasize the significant benefits of MT with exercise. To the best of our knowledge, this is the first study to demonstrate the therapeutic effects of MT with exercise in DOX-induced skeletal muscle atrophy.

Keywords:  Doxorubicin; Exercise; Mitochondria; Mitochondrial transplantation; Skeletal muscle atrophy

DOI:  https://doi.org/10.1007/s10974-024-09676-6
Physiol Res. 2024 May 31.

Czech Footprints in the Bioenergetics Research.

Z Drahota, J Houštěk, A Pecinová.

Life manifests as growth, movement or heat production that occurs thanks to the energy accepted from the outside environment. The basis of energy transduction attracted the Czech researchers since the beginning of the 20th century. It further accelerated after World War II, when the new Institute of Physiology was established in 1954. When it was found that energy is stored in the form of adenosine triphosphate (ATP) that can be used by numerous reactions as energy source and is produced in the process called oxidative phosphorylation localized in mitochondria, the investigation focused on this cellular organelle. Although the Czech scientists had to overcome various obstacles including Communist party leadership, driven by curiosity, boldness, and enthusiasm, they characterized broad spectrum of mitochondrial properties in different tissues in (patho)physiological conditions in collaboration with many world-known laboratories. The current review summarizes the contribution of the Czech scientists to the bioenergetic and mitochondrial research in the global context. Keywords: Mitochondria, Bioenergetics, Chemiosmotic coupling.
J Biol Chem. 2024 May 30. pii: S0021-9258(24)01927-6. [Epub ahead of print] 107426

Circular RNA circMYLK4 shifts energy metabolism from glycolysis to OXPHOS by binding to the calcium channel auxiliary subunit CACNA2D2.

Haigang Cao, Chenchen Li, Xiaohui Sun, Jinjin Yang, Xiao Li, Gongshe Yang, Jianjun Jin, Xine Shi.

  Skeletal muscle is heterogeneous tissue, composed of fast-twitch fibers primarily relying on glycolysis and slow-twitch fibers primarily relying on oxidative phosphorylation (OXPHOS). The relative expression and balance of glycolysis and oxidative phosphorylation in skeletal muscle are crucial for muscle growth and skeletal muscle metabolism. Here, we employed multi-omics approaches including transcriptomics, proteomics, phosphoproteomics, and metabolomics to unravel the role of circMYLK4, a differentially expressed circRNA in fast and slow-twitch muscle fibers, in muscle fiber metabolism. We discovered that circMYLK4 inhibits glycolysis and promotes mitochondrial oxidative phosphorylation. Mechanistically, circMYLK4 interacts with the voltage-gated calcium channel auxiliary subunit CACNA2D2, leading to the inhibition of Ca2+ release from the sarcoplasmic reticulum. The decrease in cytoplasmic Ca2+ concentration inhibits the expression of key enzymes, PHKB and PHKG1, involved in glycogen breakdown, thereby suppressing glycolysis. On the other hand, the increased fatty acid β-oxidation enhances the tricarboxylic acid (TCA) cycle and mitochondrial oxidative phosphorylation. In general, circMYLK4 plays an indispensable role in maintaining the metabolic homeostasis of skeletal muscle.

Keywords:  calcium; circRNA; energy metabolism; fatty acid oxidation; glycolysis; skeletal muscle

DOI:  https://doi.org/10.1016/j.jbc.2024.107426
Front Endocrinol (Lausanne). 2024 ;15 1344891

Ketogenic diet enhances the anti-cancer effects of PD-L1 blockade in renal cell carcinoma.

Jeremy Richard, Céline Beauvillain, Maxime Benoit, Magalie Barth, Cécile Aubert, Cyrielle Rolley, Sarah Bellal, Jennifer Bourreau, Matthieu Ferragu, Souhil Lebdai, Arnaud Chevrollier, Daniel Henrion, Vincent Procaccio, Pierre Bigot.

  Introduction: Clear cell renal cell carcinoma (ccRCC) is characterized by a predominant metabolic reprogramming triggering energy production by anaerobic glycolysis at the expense of oxydative phosphorylation. Ketogenic diet (KD), which consists of high fat and low carbohydrate intake, could bring required energy substrates to healthy cells while depriving tumor cells of glucose. Our objective was to evaluate the effect of KD on renal cancer cell tumor metabolism and growth proliferation.Methods: Growth cell proliferation and mitochondrial metabolism of ACHN and Renca renal carcinoma cells were evaluated under ketone bodies (KB) exposure. In vivo studies were performed with mice (nude or Balb/c) receiving a xenograft of ACHN cells or Renca cells, respectively, and were then split into 2 feeding groups, fed either with standard diet or a 2:1 KD ad libitum. To test the effect of KD associated to immunotherapy, Balb/c mice were treated with anti-PDL1 mAb. Tumor growth was monitored.
Results: In vitro, KB exposure was associated with a significant reduction of ACHN and Renca cell proliferation and viability, while increasing mitochondrial metabolism. In mice, KD was associated with tumor growth reduction and PDL-1 gene expression up-regulation. In Balb/c mice adjuvant KD was associated to a better response to anti-PDL-1 mAb treatment.
Conclusion: KB reduced the renal tumor cell growth proliferation and improved mitochondrial respiration and biogenesis. KD also slowed down tumor growth of ACHN and Renca in vivo. We observed that PDL-1 was significantly overexpressed in tumor in mice under KD. Response to anti-PDL-1 mAb was improved in mice under KD. Further studies are needed to confirm the therapeutic benefit of adjuvant KD combined with immunotherapy in patients with kidney cancer.

Keywords:  PDL1; adjuvant ketogenic diet; immunotherapy; metabolic reprogramming; mitochondrial biogenesis; renal cell carcinoma

DOI:  https://doi.org/10.3389/fendo.2024.1344891
Aging Cell. 2024 Jun 03. e14229

A novel senolytic drug for pulmonary fibrosis: BTSA1 targets apoptosis of senescent myofibroblasts by activating BAX.

Mengxia Shen, Jiafeng Fu, Yunna Zhang, Yanfen Chang, Xiaohong Li, Haipeng Cheng, Yujia Qiu, Min Shao, Yang Han, Yan Zhou, Ziqiang Luo.

  Idiopathic pulmonary fibrosis is a progressive and age-related disease that results from impaired lung repair following injury. Targeting senescent myofibroblasts with senolytic drugs attenuates pulmonary fibrosis, revealing a detrimental role of these cells in pulmonary fibrosis. The mechanisms underlying the occurrence and persistence of senescent myofibroblasts in fibrotic lung tissue require further clarification. In this study, we demonstrated that senescent myofibroblasts are resistant to apoptosis by upregulating the proapoptotic protein BAX and antiapoptotic protein BCL-2 and BCL-XL, leading to BAX inactivation. We further showed that high levels of inactive BAX-mediated minority mitochondrial outer membrane permeabilization (minority MOMP) promoted DNA damage and myofibroblasts senescence after insult by a sublethal stimulus. Intervention of minority MOMP via the inhibition of caspase activity by quinolyl-valyl-O-methylaspartyl-[2,6-difluorophenoxy]-methyl ketone (QVD-OPH) or BAX knockdown significantly reduced DNA damage and ultimately delayed the progression of senescence. Moreover, the BAX activator BTSA1 selectively promoted the apoptosis of senescent myofibroblasts, as BTSA1-activated BAX converted minority MOMP to complete MOMP while not injuring other cells with low levels of BAX. Furthermore, therapeutic activation of BAX with BTSA1 effectively reduced the number of senescent myofibroblasts in the lung tissue and alleviated both reversible and irreversible pulmonary fibrosis. These findings advance the understanding of apoptosis resistance and cellular senescence mechanisms in senescent myofibroblasts in pulmonary fibrosis and demonstrate a novel senolytic drug for pulmonary fibrosis treatment.

Keywords:  BAX; BTSA1; apoptosis; cellular senescence; idiopathic pulmonary fibrosis; myofibroblast

DOI:  https://doi.org/10.1111/acel.14229
Invest Ophthalmol Vis Sci. 2024 Jun 03. 65(6): 14

Mitochondria Transplantation Promotes Corneal Epithelial Wound Healing.

Daniel Raz, Keren Ben-Yaakov, Michal Levi, Marina Bertolin, Stefano Ferrari, Diego Ponzin, Massimo Busin, Hana Leiba, Arie L Marcovich, Avital Eisenberg-Lerner, Ziv Rotfogel.

Purpose: The integrity of the corneal epithelium is essential in maintaining normal corneal function. Conditions disrupting the corneal epithelial layer range from chemical burns to dry eye disease and may result in impairment of both corneal transparency and sensation. Identifying factors that regulate corneal wound healing is key for the development of new treatment strategies. Here, we investigated a direct role of mitochondria in corneal wound healing via mitochondria transplantation.Methods: Human corneal epithelial cells (hCECs) were isolated from human corneas and incubated with mitochondria which were isolated from human ARPE-19 cells. We determined the effect of mitochondria transplantation on wound healing and proliferation of hCECs. In vivo, we used a mouse model of corneal chemical injury. Mitochondria were isolated from mouse livers and topically applied to the ocular surface following injury. We evaluated the time of wound repair, corneal re-epithelization, and stromal abnormalities.
Results: Mitochondria transplantation induced the proliferation and wound healing of primary hCECs. Further, mitochondria transplantation promoted wound healing in vivo. Specifically, mice receiving mitochondria recovered twice as fast as control mice following corneal injury, presenting both enhanced and improved repair. Corneas treated with mitochondria demonstrated the re-epithelization of the wound area to a multi-layer appearance, compared to thinning and complete loss of the epithelium in control mice. Mitochondria transplantation also prevented the thickening and disorganization of the corneal stromal lamella, restoring normal corneal dehydration.
Conclusions: Mitochondria promote corneal re-epithelization and wound healing. Augmentation of mitochondria levels via mitochondria transplantation may serve as an effective treatment for inducing the rapid repair of corneal epithelial defects.

DOI: https://doi.org/10.1167/iovs.65.6.14
Aging Cell. 2024 Jun 05. e14236

Identification of nicotinamide N-methyltransferase as a promising therapeutic target for sarcopenia.

Rui Liang, Qiao Xiang, Miao Dai, Taiping Lin, Dongmei Xie, Quhong Song, Yu Liu, Jirong Yue.

  Sarcopenia is a significant geriatric syndrome that involves the loss of skeletal muscle mass and strength. Due to its substantial endocrine role, the metabolic microenvironment of skeletal muscle undergoes changes with age. Examining the pathogenesis of sarcopenia through focusing on metabolic dysregulation could offer insights for developing more effective intervention strategies. In this study, we analyzed the transcriptomics data to identify specific genes involved in the regulation of metabolism in skeletal muscle during the development of sarcopenia. Three machine learning algorithms were employed to screen key target genes exhibiting strong correlations with metabolism, which were further validated using RNA-sequencing data and publicly accessible datasets. Among them, the metabolic enzyme nicotinamide N-methyltransferase (NNMT) was elevated in sarcopenia, and predicted sarcopenia with an area under the curve exceeding 0.7, suggesting it as a potential therapeutic target for sarcopenia. As expected, inhibition of NNMT improved the grip strength in aging mice and alleviated age-related decline in the mass index of the quadriceps femoris muscles and whole-body lean mass index. Additionally, the NNMTi treatment increased the levels of nicotinamide adenine dinucleotide (NAD+) content, as well as PGC1α and p-AMPK expression in the muscles of both the D-galactose-treated mouse model and naturally aging mouse model. Overall, this work demonstrates NNMT as a promising target for preventing age-related decline in muscle mass and strength.

Keywords:  NAD+; NNMT; diagnostic biomarker; metabolic dysregulation; sarcopenia

DOI:  https://doi.org/10.1111/acel.14236
Aging (Albany NY). 2024 May 31. 16

Neratinib stimulates senescence of mammary cancer cells by reducing the levels of SIRT1.

Wenhuan Li, Peng Fu, Pengfei Shi, Bo Hu, Hai Li.

  Neratinib, a typical small-molecule, pan-human tyrosine kinase inhibitor (TKI), has been licensed for the treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. However, the underlying pharmacological mechanism is still unknown. In the current study, we report a novel function of Neratinib by showing that its treatment stimulates senescence of the mammary cancer AU565 cells. Our results demonstrate that Neratinib induces mitochondrial injury by increasing mitochondrial reactive oxygen species (ROS) and reducing intracellular adenosine triphosphate (ATP). Also, we found that Neratinib induced DNA damage by increasing the levels of 8-Hydroxy-desoxyguanosine (8-OHdG) and γH2AX in AU565 cells. Additionally, Neratinib reduced the levels of telomerase activity after 7 and 14 days incubation. Importantly, the senescence-associated-β-galactosidase (SA-β-Gal) assay revealed that Neratinib stimulated senescence of AU565 cells. Neratinib decreased the gene levels of human telomerase reverse transcriptase (hTERT) but increased those of telomeric repeat-binding factor 2 (TERF2) in AU565 cells. Further study displayed that Neratinib upregulated the expression of K382 acetylation of p53 (ac-K382) and p21 but reduced the levels of sirtuin-1 (SIRT1). However, overexpression of SIRT1 abolished the effects of Neratinib in cellular senescence. These findings provide strong preclinical evidence of Neratinib's treatment of breast cancer.

Keywords:  SIRT1; breast cancer; cellular senescence; mammary cancer cells; neratinib

DOI:  https://doi.org/10.18632/aging.205882