bims-cesemi 2024-06-23 papers

bims-cesemi

Biomed News

on Cellular senescence and mitochondria

Issue of 2024‒06‒23
fourteen papers selected by
Julio Cesar Cardenas, Universidad Mayor

Senescence and tissue fibrosis: opportunities for therapeutic targeting.
Looking for the philosopher's stone: Emerging approaches to target the hallmarks of aging in the skin.
Therapy-induced senescence is finally escapable, what is next?
Resistance to Spindle Inhibitors in Glioblastoma Depends on STAT3 and Therapy Induced Senescence.
Therapy-induced senescence through the redox lens.
Nutrient-sensitizing drug repurposing screen identifies lomerizine as a mitochondrial metabolism inhibitor of chronic myeloid leukemia.
hnRNPH1 maintains mitochondrial homeostasis by establishing NRF1/DRP1 retrograde signaling under mitochondrial stress.
Intrinsic aerobic capacity modulates Alzheimer's disease pathological hallmarks, brain mitochondrial function and proteome during aging.
Mitochondria and cell death.
Metabolic Profiling of Glioblastoma Stem Cells Reveals Pyruvate Carboxylase as a Critical Survival Factor and Potential Therapeutic Target.
PDZD8-FKBP8 tethering complex at ER-mitochondria contact sites regulates mitochondrial complexity.
The association of circulating bioenergetic metabolites with healthy human aging.
A tripartite organelle platform links growth factor receptor signaling to mitochondrial metabolism.
The transcription factor PAX5 activates human LINE1 retrotransposons to induce cellular senescence.

Trends Mol Med. 2024 Jun 17. pii: S1471-4914(24)00134-5. [Epub ahead of print]

Senescence and tissue fibrosis: opportunities for therapeutic targeting.

Steven O'Reilly, Pei-Suen Tsou, John Varga.

  Cellular senescence is a key hallmark of aging. It has now emerged as a key mediator in normal tissue turnover and is associated with a variety of age-related diseases, including organ-specific fibrosis and systemic sclerosis (SSc). This review discusses the recent evidence of the role of senescence in tissue fibrosis, with an emphasis on SSc, a systemic autoimmune rheumatic disease. We discuss the physiological role of these cells, their role in fibrosis, and that targeting these cells specifically could be a new therapeutic avenue in fibrotic disease. We argue that targeting senescent cells, with senolytics or senomorphs, is a viable therapeutic target in fibrotic diseases which remain largely intractable.

Keywords:  SASP; fibrosis; myofibroblasts; senescence; systemic sclerosis

DOI:  https://doi.org/10.1016/j.molmed.2024.05.012
J Eur Acad Dermatol Venereol. 2024 Jul;38 Suppl 4 5-14

Looking for the philosopher's stone: Emerging approaches to target the hallmarks of aging in the skin.

Jean-Marc Lemaitre.

Senescence and epigenetic alterations are two important hallmarks of cellular aging. During aging, cells subjected to stress undergo many cycles of damage and repair before finally entering either apoptosis or senescence, a permanent state of cell cycle arrest. The first biomarkers of senescence to be identified were increased ß-galactosidase activity and induction of p16INK4a. Another feature of senescent cells is the senescence-associated secretory phenotype (SASP), a complex secretome containing more than 80 pro-inflammatory factors including metalloproteinases, growth factors, chemokines and cytokines. The secretome is regulated through a dynamic process involving a self-amplifying autocrine feedback loop and activation of the immune system. Senescent cells play positive and negative roles depending on the composition of their SASP and may participate in various processes including wound healing and tumour suppression, as well as cell regeneration, embryogenesis, tumorigenesis, inflammation and finally aging. The SASP is also a biomarker of age, biological aging and age-related diseases. Recent advances in anti-age research have shown that senescence can be now prevented or delayed by clearing the senescent cells or mitigating the effects of SASP factors, which can be achieved by a healthy lifestyle (exercise and diet), and senolytics and senomorphics, respectively. An alternative is tissue rejuvenation, which can be achieved by stimulating aged stem cells and reprogramming deprogrammed aged cells. These non-clinical findings will open up new avenues of clinical research into the development of treatments capable of preventing or treating age-related pathologies in humans.

DOI: https://doi.org/10.1111/jdv.19820
Cell Cycle. 2024 Jun 16. 1-9

Therapy-induced senescence is finally escapable, what is next?

Tareq Saleh.

  Several breakthrough articles have recently confirmed the ability of tumor cells to escape the stable cell cycle arrest imposed by Therapy-Induced Senescence (TIS). Subsequently, accepting the hypothesis that TIS is escapable should encourage serious reassessments of the fundamental roles of senescence in cancer treatment. The potential for escape from TIS undermines the well-established tumor suppressor function of senescence, proposes it as a mechanism of tumor dormancy leading to disease recurrence and invites for further investigation of its unfavorable contribution to cancer therapy outcomes. Moreover, escaping TIS strongly indicates that the elimination of senescent tumor cells, primarily through pharmacological means, is a suitable approach for increasing the efficacy of cancer treatment, one that still requires further exploration. This commentary provides an overview of the recent evidence that unequivocally demonstrated the ability of therapy-induced senescent tumor cells in overcoming the terminal growth arrest fate and provides future perspectives on the roles of TIS in tumor biology.

Keywords:  Senescence; cancer; dormancy; escape; reversible; senolytic

DOI:  https://doi.org/10.1080/15384101.2024.2364579
bioRxiv. 2024 Jun 09. pii: 2024.06.09.598115. [Epub ahead of print]

Resistance to Spindle Inhibitors in Glioblastoma Depends on STAT3 and Therapy Induced Senescence.

Natanael Zarco, Athanassios Dovas, Virginea de Araujo Farias, Naveen Kh Nagaiah, Ashley Haddock, Peter A Sims, Dolores Hambardzumyan, Christian T Meyer, Peter Canoll, Steven S Rosenfeld, Rajappa S Kenchappa.

While mitotic spindle inhibitors specifically kill proliferating tumor cells without the toxicities of microtubule poisons, resistance has limited their clinical utility. Treating glioblastomas with the spindle inhibitors ispinesib, alisertib, or volasertib creates a subpopulation of therapy induced senescent cells that resist these drugs by relying upon the anti-apoptotic and metabolic effects of activated STAT3. Furthermore, these senescent cells expand the repertoire of cells resistant to these drugs by secreting an array of factors, including TGFβ, which induce proliferating cells to exit mitosis and become quiescent-a state that also resists spindle inhibitors. Targeting STAT3 restores sensitivity to each of these drugs by depleting the senescent subpopulation and inducing quiescent cells to enter the mitotic cycle. These results support a therapeutic strategy of targeting STAT3-dependent therapy-induced senescence to enhance the efficacy of spindle inhibitors for the treatment of glioblastoma.Highlights: • Resistance to non-microtubule spindle inhibitors limits their efficacy in glioblastoma and depends on STAT3.• Resistance goes hand in hand with development of therapy induced senescence (TIS).• Spindle inhibitor resistant glioblastomas consist of three cell subpopulations-proliferative, quiescent, and TIS-with proliferative cells sensitive and quiescent and TIS cells resistant.• TIS cells secrete TGFβ, which induces proliferative cells to become quiescent, thereby expanding the population of resistant cells in a spindle inhibitor resistant glioblastoma• Treatment with a STAT3 inhibitor kills TIS cells and restores sensitivity to spindle inhibitors.

DOI: https://doi.org/10.1101/2024.06.09.598115
Redox Biol. 2024 Aug;pii: S2213-2317(24)00206-4. [Epub ahead of print]74 103228

Therapy-induced senescence through the redox lens.

Matius Robert, Brian K Kennedy, Karen C Crasta.

  Therapy-induced senescent tumor cells have emerged as significant drivers of tumor recurrence and disease relapse. Interestingly, reactive oxygen species (ROS) production and its associated redox signaling networks are intertwined with initiation and establishment of therapy-induced senescence. Therapy-induced senescent cells influence neighboring cells and the tumor microenvironment via their bioactive secretome known as the senescence-associated secretory phenotype (SASP). The intracellular effects of ROS are dose and context-dependent. Under normal physiological conditions, ROS is involved in various signalling pathways and cellular processes important for maintenance of cellular homeostasis, such as redox balance, stress response, inflammatory signalling, cell proliferation and cell death among others. However excess ROS accompanied by a pro-oxidant microenvironment can engender oxidative DNA damage, triggering cellular senescence. In this review, we discuss the role of ROS and the redox state dynamics in fine-tuning homeostatic processes that drive therapy-induced cell fate towards senescence establishment, as well as their influence in stimulating inflammatory signalling and SASP production. We also offer insights into interventional strategies, specifically senotherapeutics, that could potentially leverage on modulation of redox and antioxidant pathways. Lastly, we evaluate possible implications of redox rewiring during escape from therapy-induced senescence, an emerging area of research. We envision that examining therapy-induced senescence through the redox lens, integrated with time-resolved single-cell RNA sequencing combined with spatiotemporal multi-omics, could further enhance our understanding of its functional heterogeneity. This could aid identification of targetable signalling nodes to reduce disease relapse, as well as inform strategies for development of broad-spectrum senotherapeutics. Overall, our review aims to delineate redox-driven mechanisms which contribute to the biology of therapy-induced senescence and beyond, while highlighting implications for tumor initiation and recurrence.

Keywords:  Oxidative stress; ROS; Redox; SASP; Senescence; Therapy

DOI:  https://doi.org/10.1016/j.redox.2024.103228
Sci Transl Med. 2024 Jun 12. 16(751): eadi5336

Nutrient-sensitizing drug repurposing screen identifies lomerizine as a mitochondrial metabolism inhibitor of chronic myeloid leukemia.

Ahmed Khalaf, Lucie de Beauchamp, Eric Kalkman, Kevin Rattigan, Ekaterini Himonas, Joe Jones, Daniel James, Engy Shokry Abd Shokry, Mary T Scott, Karen Dunn, Saverio Tardito, Mhairi Copland, David Sumpton, Emma Shanks, G Vignir Helgason.

In chronic myeloid leukemia (CML), the persistence of leukemic stem cells (LSCs) after treatment with tyrosine kinase inhibitors (TKIs), such as imatinib, can lead to disease relapse. It is known that therapy-resistant LSCs rely on oxidative phosphorylation (OXPHOS) for their survival and that targeting mitochondrial respiration sensitizes CML LSCs to imatinib treatment. However, current OXPHOS inhibitors have demonstrated limited efficacy or have shown adverse effects in clinical trials, highlighting that identification of clinically safe oxidative pathway inhibitors is warranted. We performed a high-throughput drug repurposing screen designed to identify mitochondrial metabolism inhibitors in myeloid leukemia cells. This identified lomerizine, a US Food and Drug Administration (FDA)-approved voltage-gated Ca2+ channel blocker now used for the treatment of migraines, as one of the top hits. Transcriptome analysis revealed increased expression of voltage-gated CACNA1D and receptor-activated TRPC6 Ca2+ channels in CML LSCs (CD34+CD38-) compared with normal counterparts. This correlated with increased endoplasmic reticulum (ER) mass and increased ER and mitochondrial Ca2+ content in CML stem/progenitor cells. We demonstrate that lomerizine-mediated inhibition of Ca2+ uptake leads to ER and mitochondrial Ca2+ depletion, with similar effects seen after CACNA1D and TRPC6 knockdown. Through stable isotope-assisted metabolomics and functional assays, we observe that lomerizine treatment inhibits mitochondrial isocitrate dehydrogenase activity and mitochondrial oxidative metabolism and selectively sensitizes CML LSCs to imatinib treatment. In addition, combination treatment with imatinib and lomerizine reduced CML tumor burden, targeted CML LSCs, and extended survival in xenotransplantation model of human CML, suggesting this as a potential therapeutic strategy to prevent disease relapse in patients.

DOI: https://doi.org/10.1126/scitranslmed.adi5336
Cell Death Differ. 2024 Jun 19.

hnRNPH1 maintains mitochondrial homeostasis by establishing NRF1/DRP1 retrograde signaling under mitochondrial stress.

Lili Zhao, Xiaotian Zou, Jiaqiang Deng, Bin Sun, Yan Li, Li Zhao, Hong Zhao, Xiao Zhang, Xieyong Yuan, Xudong Zhao, Fangdong Zou.

Mitochondrial homeostasis is coordinated through communication between mitochondria and the nucleus. In response to stress, mitochondria generate retrograde signals to protect against their dysfunction by activating the expression of nuclear genes involved in metabolic reprogramming. However, the mediators associated with mitochondria-to-nucleus communication pathways remain to be clarified. Here, we identified that hnRNPH1 functions as a pivotal mediator of mitochondrial retrograde signaling to maintain mitochondrial homeostasis. hnRNPH1 accumulates in the nucleus following mitochondrial stress in a 5'-adenosine monophosphate-activated protein kinase (AMPK)-dependent manner. Accordingly, hnRNPH1 interacts with the transcription factor NRF1 and binds to the DRP1 promoter, enhancing the transcription of DRP1. Furthermore, in the cytoplasm, hnRNPH1 directly interacts with DRP1 and enhances DRP1 Ser616 phosphorylation, thereby increasing DRP1 translocation to mitochondrial outer membranes and triggering mitochondrial fission. Collectively, our findings reveal a novel role for hnRNPH1 in the mitochondrial-nuclear communication pathway to maintain mitochondrial homeostasis under stress and suggest that it may be a potential target for mitochondrial dysfunction diseases.

DOI: https://doi.org/10.1038/s41418-024-01331-4
Geroscience. 2024 Jun 13.

Intrinsic aerobic capacity modulates Alzheimer's disease pathological hallmarks, brain mitochondrial function and proteome during aging.

Benjamin A Kugler, Colton R Lysaker, Edziu Franczak, Brittany M Hauger, Vivien Csikos, Julia A Stopperan, Julie A Allen, John A Stanford, Lauren G Koch, Steven L Britton, John P Thyfault, Heather M Wilkins.

  Low aerobic capacity is strongly associated with all-cause mortality and risk for Alzheimer's disease (AD). Individuals with early dementia and AD have lower aerobic capacity compared to age-matched controls. The mechanism by which aerobic capacity influences AD risk is unknown but is likely mediated by sexual dimorphism and tissue-level differences in mitochondrial energetics. Here, we used rats selectively bred for large differences in intrinsic aerobic exercise capacity. Brain tissue from 18-month and 24-month-old female and male low-capacity runner (LCR) and high-capacity runner (HCR) rats were analyzed for markers of mitochondrial function and AD-associated pathologies. LCR rats, irrespective of sex, exhibited a greater increase in brain amyloid beta (Aβ42) and tau hyperphosphorylation (pTauthr181/total tau) with aging. In female LCR rats, brain mitochondrial respiration at states 3, 4, and FCCP-induced uncoupling, when stimulated with pyruvate/malate, was reduced at 18 and 24 months, leading to lower ATP-linked mitochondrial respiration compared to mitochondria from HCR rats. Male LCR rats also showed reduced complex II-stimulated mitochondrial respiration (succinate + rotenone) at 24 months compared to HCR rats. Differences in mitochondrial respiration were associated with tau hyperphosphorylation and Aβ42 alterations in both HCR and LCR strains. Proteomic analysis unveiled a distinct difference in the mitochondrial proteome, wherein female LCR rats displayed diminished mitochondrial translation and oxidative phosphorylation (OXPHOS) proteins at 18 months compared to female HCR rats. Conversely, male LCR rats exhibited increased OXPHOS protein abundance but reduced tricarboxylic acid (TCA) cycle proteins compared to male HCR rats. These findings underscore a robust association between intrinsic aerobic exercise capacity, brain mitochondrial function, and AD pathologies during aging.

Keywords:  Aerobic capacity; Aging; Alzheimer’s disease; Amyloid beta; Bioenergetics; Mitochondria; Tau

DOI:  https://doi.org/10.1007/s11357-024-01248-3
Nat Cell Biol. 2024 Jun 20.

Mitochondria and cell death.

Hannah L Glover, Annabell Schreiner, Grant Dewson, Stephen W G Tait.

Mitochondria are cellular factories for energy production, calcium homeostasis and iron metabolism, but they also have an unequivocal and central role in intrinsic apoptosis through the release of cytochrome c. While the subsequent activation of proteolytic caspases ensures that cell death proceeds in the absence of collateral inflammation, other phlogistic cell death pathways have been implicated in using, or engaging, mitochondria. Here we discuss the emerging complexities of intrinsic apoptosis controlled by the BCL-2 family of proteins. We highlight the emerging theory that non-lethal mitochondrial apoptotic signalling has diverse biological roles that impact cancer, innate immunity and ageing. Finally, we delineate the role of mitochondria in other forms of cell death, such as pyroptosis, ferroptosis and necroptosis, and discuss mitochondria as central hubs for the intersection and coordination of cell death signalling pathways, underscoring their potential for therapeutic manipulation.

DOI: https://doi.org/10.1038/s41556-024-01429-4
Neuro Oncol. 2024 Jun 13. pii: noae106. [Epub ahead of print]

Metabolic Profiling of Glioblastoma Stem Cells Reveals Pyruvate Carboxylase as a Critical Survival Factor and Potential Therapeutic Target.

Ophélie Renoult, Mélanie Laurent-Blond, Hala Awada, Lisa Oliver, Noémie Joalland, Mikaël Croyal, François Paris, Catherine Gratas, Claire Pecqueur.

  BACKGROUND: Glioblastoma (GBM) is a highly aggressive tumor with unmet therapeutic needs, which can be explained by extensive intra-tumoral heterogeneity and plasticity. In this study, we aimed to investigate the specific metabolic features of Glioblastoma stem cells (GSC), a rare tumor subpopulation involved in tumor growth and therapy resistance.METHODS: We conducted comprehensive analyses of primary patient-derived GBM cultures and GSC-enriched cultures of human GBM cell lines using state-of-the-art molecular, metabolic and phenotypic studies.
RESULTS: We showed that GSC-enriched cultures display distinct glycolytic profiles compared with differentiated tumor cells. Further analysis revealed that GSC relies on pyruvate carboxylase activity for survival and self-renewal capacity. Interestingly, inhibition of pyruvate carboxylase led to GSC death, particularly when the glutamine pool was low, and increased differentiation. Finally, while GSC displayed resistance to the chemotherapy drug etoposide, genetic or pharmacological inhibition of pyruvate carboxylase restored etoposide sensitivity in GSC, both in vitro and in orthotopic murine models.
CONCLUSION: Our findings demonstrate the critical role of pyruvate carboxylase in GSC metabolism, survival and escape to etoposide. They also highlight pyruvate carboxylase as a therapeutic target to overcome therapy resistance in GBM.

Keywords:  Cancer stem cells; glioblastoma; metabolic vulnerability; mitochondrial metabolism; pyruvate carboxylation

DOI:  https://doi.org/10.1093/neuonc/noae106
bioRxiv. 2024 Jun 03. pii: 2023.08.22.554218. [Epub ahead of print]

PDZD8-FKBP8 tethering complex at ER-mitochondria contact sites regulates mitochondrial complexity.

Koki Nakamura, Saeko Aoyama-Ishiwatari, Takahiro Nagao, Mohammadreza Paaran, Christopher J Obara, Yui Sakurai-Saito, Jake Johnston, Yudan Du, Shogo Suga, Masafumi Tsuboi, Makoto Nakakido, Kouhei Tsumoto, Yusuke Kishi, Yukiko Gotoh, Chulhwan Kwak, Hyun-Woo Rhee, Jeong Kon Seo, Hidetaka Kosako, Clint Potter, Bridget Carragher, Jennifer Lippincott-Schwartz, Franck Polleux, Yusuke Hirabayashi.

Mitochondria-ER membrane contact sites (MERCS) represent a fundamental ultrastructural feature underlying unique biochemistry and physiology in eukaryotic cells. The ER protein PDZD8 is required for the formation of MERCS in many cell types, however, its tethering partner on the outer mitochondrial membrane (OMM) is currently unknown. Here we identified the OMM protein FKBP8 as the tethering partner of PDZD8 using a combination of unbiased proximity proteomics, CRISPR-Cas9 endogenous protein tagging, Cryo-Electron Microscopy (Cryo-EM) tomography, and correlative light-EM (CLEM). Single molecule tracking revealed highly dynamic diffusion properties of PDZD8 along the ER membrane with significant pauses and capture at MERCS. Overexpression of FKBP8 was sufficient to narrow the ER-OMM distance, whereas independent versus combined deletions of these two proteins demonstrated their interdependence for MERCS formation. Furthermore, PDZD8 enhances mitochondrial complexity in a FKBP8-dependent manner. Our results identify a novel ER-mitochondria tethering complex that regulates mitochondrial morphology in mammalian cells.

DOI: https://doi.org/10.1101/2023.08.22.554218
Exp Gerontol. 2024 Jun 15. pii: S0531-5565(24)00130-X. [Epub ahead of print]194 112488

The association of circulating bioenergetic metabolites with healthy human aging.

C Navas-Enamorado, X Capo, A M Galmes-Panades, A Ortega-Moral, A Sánchez-Polo, L Masmiquel, M Torrens-Mas, P Navas, M Gonzalez-Freire.

  Aging is an inevitable and gradual decline in several biological functions. Mitochondrial dysfunction is one of the most important hallmarks of aging. In this context, alterations in metabolites associated with mitochondrial dysfunction may serve as a significant biomarker. This study aimed to investigate the existence of a relationship between the key metabolites involved in bioenergetics metabolism and aging. 53 volunteers ranged 20-85 years participated in the study. We tested the association between different tricarboxylic acid (TCA) cycle metabolites, fatty acid metabolism, and amino acid metabolism with age, sex, body composition, and proxy markers of aging such as walking speed, grip strength and chair test. We found that lactic acid negatively correlated with age while several fatty acid metabolites, such as azelaic, sebacic, and linoleic acids, showed positive correlations with age (p < 0.05). Sex-specific trends, such as glycerol, and dodecanoic acid, were also observed for certain metabolites. Furthermore, citric acid levels were found to have a significant association with physical function and body composition measures. Participants with higher citric acid levels displayed improved performance in physical tests and favorable body composition indices. Additionally, fumaric acid and adipic acid showed positive correlations with fat-free body mass, while sebacic acid was negatively associated with measures of fat mass. These findings underscore the importance of understanding the role of circulating bioenergetics metabolites with age, sex variations, and their potential implications in body composition and physical performance.

Keywords:  Aging; Citric acid; Lactic acid; Metabolites; TCA cycle

DOI:  https://doi.org/10.1016/j.exger.2024.112488
Nat Commun. 2024 Jun 15. 15(1): 5119

A tripartite organelle platform links growth factor receptor signaling to mitochondrial metabolism.

Deborah Mesa, Elisa Barbieri, Andrea Raimondi, Stefano Freddi, Giorgia Miloro, Gorana Jendrisek, Giusi Caldieri, Micaela Quarto, Irene Schiano Lomoriello, Maria Grazia Malabarba, Arianna Bresci, Francesco Manetti, Federico Vernuccio, Hind Abdo, Giorgio Scita, Letizia Lanzetti, Dario Polli, Carlo Tacchetti, Paolo Pinton, Massimo Bonora, Pier Paolo Di Fiore, Sara Sigismund.

One open question in the biology of growth factor receptors is how a quantitative input (i.e., ligand concentration) is decoded by the cell to produce specific response(s). Here, we show that an EGFR endocytic mechanism, non-clathrin endocytosis (NCE), which is activated only at high ligand concentrations and targets receptor to degradation, requires a tripartite organelle platform involving the plasma membrane (PM), endoplasmic reticulum (ER) and mitochondria. At these contact sites, EGFR-dependent, ER-generated Ca2+ oscillations are sensed by mitochondria, leading to increased metabolism and ATP production. Locally released ATP is required for cortical actin remodeling and EGFR-NCE vesicle fission. The same biochemical circuitry is also needed for an effector function of EGFR, i.e., collective motility. The multiorganelle signaling platform herein described mediates direct communication between EGFR signaling and mitochondrial metabolism, and is predicted to have a broad impact on cell physiology as it is activated by another growth factor receptor, HGFR/MET.

DOI: https://doi.org/10.1038/s41467-024-49543-z
EMBO Rep. 2024 Jun 12.

The transcription factor PAX5 activates human LINE1 retrotransposons to induce cellular senescence.

Huanyin Tang, Jiaqing Yang, Junhao Xu, Weina Zhang, Anke Geng, Ying Jiang, Zhiyong Mao.

  As a hallmark of senescent cells, the derepression of Long Interspersed Elements 1 (LINE1) transcription results in accumulated LINE1 cDNA, which triggers the secretion of the senescence-associated secretory phenotype (SASP) and paracrine senescence in a cGAS-STING pathway-dependent manner. However, transcription factors that govern senescence-associated LINE1 reactivation remain ill-defined. Here, we predict several transcription factors that bind to human LINE1 elements to regulate their transcription by analyzing the conserved binding motifs in the 5'-untranslated regions (UTR) of the commonly upregulated LINE1 elements in different types of senescent cells. Further analysis reveals that PAX5 directly binds to LINE1 5'-UTR and the binding is enhanced in senescent cells. The enrichment of PAX5 at the 5'-UTR promotes cellular senescence and SASP by activating LINE1. We also demonstrate that the longevity gene SIRT6 suppresses PAX5 transcription by directly binding to the PAX5 promoter, and overexpressing PAX5 abrogates the suppressive effect of SIRT6 on stress-dependent cellular senescence. Our work suggests that PAX5 could serve as a potential target for drug development aiming to suppress LINE1 activation and treat senescence-associated diseases.

Keywords:  Cellular Senescence; LINE1; PAX5; SIRT6

DOI:  https://doi.org/10.1038/s44319-024-00176-9