2024 Articles

Understanding how cells and organisms keep time during development

Ebisuya M, Rayon T, Diaz-Cuadros M, Chalut KJ, Wu G, Dodd AN, Torres-Padilla ME, Levine M, Gladyshev VN.

Developmental cell

doi: 10.1016/j.devcel.2024.05.029

Abstract A classical question in biology is how different processes are controlled in space and time, with research pointing to different mechanisms as timers. In this collection of Voices, we asked researchers to define their scientific questions related to time-keeping and the approaches they use to answer them. More Information

Age-associated clonal B cells drive B cell lymphoma in mice

Castro JP, Shindyapina AV, Barbieri A, Ying K, Strelkova OS, Paulo JA, Tyshkovskiy A, Meinl R, Kerepesi C, Petrashen AP, Mariotti M, Meer MV, Hu Y, Karamyshev A, Losyev G, Galhardo M, Logarinho E, Indzhykulian AA, Gygi SP, Sedivy JM, Manis JP, Gladyshev VN.

Nature aging

doi: 10.1038/s43587-024-00671-7

Abstract Although cancer is an age-related disease, how the processes of aging contribute to cancer progression is not well understood. In this study, we uncovered how mouse B cell lymphoma develops as a consequence of a naturally aged system. We show here that this malignancy is associated with an age-associated clonal B cell (ACBC) population that likely originates from age-associated B cells. Driven by c-Myc activation, promoter hypermethylation and somatic mutations, IgM⁺ ACBCs clonally expand independently of germinal centers and show increased biological age. ACBCs become self-sufficient and support malignancy when transferred into young recipients. Inhibition of mTOR or c-Myc in old mice attenuates pre-malignant changes in B cells during aging. Although the etiology of mouse and human B cell lymphomas is considered distinct, epigenetic changes in transformed mouse B cells are enriched for changes observed in human B cell lymphomas. Together, our findings characterize the spontaneous progression of cancer during aging through both cell-intrinsic and microenvironmental changes and suggest interventions for its prevention. More Information

Nature of epigenetic aging from a single-cell perspective

Tarkhov AE, Lindstrom-Vautrin T, Zhang S, Ying K, Moqri M, Zhang B, Tyshkovskiy A, Levy O, Gladyshev VN.

Nature aging

doi: 10.1038/s43587-024-00616-0

Abstract Age-related changes in DNA methylation (DNAm) form the basis of the most robust predictors of age-epigenetic clocks-but a clear mechanistic understanding of exactly which aspects of aging are quantified by these clocks is lacking. Here, to clarify the nature of epigenetic aging, we juxtapose the dynamics of tissue and single-cell DNAm in mice. We compare these changes during early development with those observed during adult aging in mice, and corroborate our analyses with a single-cell RNA sequencing analysis within the same multiomics dataset. We show that epigenetic aging involves co-regulated changes as well as a major stochastic component, and this is consistent with transcriptional patterns. We further support the finding of stochastic epigenetic aging by direct tissue and single-cell DNAm analyses and modeling of aging DNAm trajectories with a stochastic process akin to radiocarbon decay. Finally, we describe a single-cell algorithm for the identification of co-regulated and stochastic CpG clusters showing consistent transcriptomic coordination patterns. Together, our analyses increase our understanding of the basis of epigenetic clocks and highlight potential opportunities for targeting aging and evaluating longevity interventions. More Information

Causality-enriched epigenetic age uncouples damage and adaptation

Ying K, Liu H, Tarkhov AE, Sadler MC, Lu AT, Moqri M, Horvath S, Kutalik Z, Shen X, Gladyshev VN.

Nature aging

doi: 10.1038/s43587-023-00557-0

Abstract Machine learning models based on DNA methylation data can predict biological age but often lack causal insights. By harnessing large-scale genetic data through epigenome-wide Mendelian randomization, we identified CpG sites potentially causal for aging-related traits. Neither the existing epigenetic clocks nor age-related differential DNA methylation are enriched in these sites. These CpGs include sites that contribute to aging and protect against it, yet their combined contribution negatively affects age-related traits. We established a new framework to introduce causal information into epigenetic clocks, resulting in DamAge and AdaptAge-clocks that track detrimental and adaptive methylation changes, respectively. DamAge correlates with adverse outcomes, including mortality, while AdaptAge is associated with beneficial adaptations. These causality-enriched clocks exhibit sensitivity to short-term interventions. Our findings provide a detailed landscape of CpG sites with putative causal links to lifespan and healthspan, facilitating the development of aging biomarkers, assessing interventions, and studying reversibility of age-associated changes. More Information

Depletion of loss-of-function germline mutations in centenarians reveals longevity genes

Ying K, Castro JP, Shindyapina AV, Tyshkovskiy A, Moqri M, Goeminne LJE, Milman S, Zhang ZD, Barzilai N, Gladyshev VN.

Nature communications

doi: 10.1038/s41467-024-52967-2

Abstract While previous studies identified common genetic variants associated with longevity in centenarians, the role of the rare loss-of-function (LOF) mutation burden remains largely unexplored. Here, we investigated the burden of rare LOF mutations in Ashkenazi Jewish individuals from the Longevity Genes Project and LonGenity study cohorts using whole-exome sequencing data. We found that centenarians had a significantly lower burden (11-22%) of LOF mutations compared to controls. Similar effects were also observed in their offspring. Gene-level burden analysis identified 35 genes with depleted LOF mutations in centenarians, with 14 of these validated in the UK Biobank. Mendelian randomization and multi-omic analyses on these genes identified RGP1, PCNX2, and ANO9 as longevity genes with consistent causal effects on multiple aging-related traits and altered expression during aging. Our findings suggest that a protective genetic background, characterized by a reduced burden of damaging variants, contributes to exceptional longevity, likely acting in concert with specific protective variants to promote healthy aging. More Information

The long and winding road of reprogramming-induced rejuvenation

Yücel AD, Gladyshev VN.

Nature communications

doi: 10.1038/s41467-024-46020-5

Abstract Organismal aging is inherently connected to the aging of its constituent cells and systems. Reducing the biological age of the organism may be assisted by reducing the age of its cells – an approach exemplified by partial cell reprogramming through the expression of Yamanaka factors or exposure to chemical cocktails. It is crucial to protect cell type identity during partial reprogramming, as cells need to retain or rapidly regain their functions following the treatment. Another critical issue is the ability to quantify biological age as reprogrammed older cells acquire younger states. We discuss recent advances in reprogramming-induced rejuvenation and offer a critical review of this procedure and its relationship to the fundamental nature of aging. We further comparatively analyze partial reprogramming, full reprogramming and transdifferentiation approaches, assess safety concerns and emphasize the importance of distinguishing rejuvenation from dedifferentiation. Finally, we highlight translational opportunities that the reprogramming-induced rejuvenation approach offers. More Information

Multi-omics characterization of partial chemical reprogramming reveals evidence of cell rejuvenation

Mitchell W, Goeminne LJE, Tyshkovskiy A, Zhang S, Chen JY, Paulo JA, Pierce KA, Choy AH, Clish CB, Gygi SP, Gladyshev VN.

eLife

doi: 10.7554/eLife.90579

Abstract Partial reprogramming by cyclic short-term expression of Yamanaka factors holds promise for shifting cells to younger states and consequently delaying the onset of many diseases of aging. However, the delivery of transgenes and potential risk of teratoma formation present challenges for in vivo applications. Recent advances include the use of cocktails of compounds to reprogram somatic cells, but the characteristics and mechanisms of partial cellular reprogramming by chemicals remain unclear. Here, we report a multi-omics characterization of partial chemical reprogramming in fibroblasts from young and aged mice. We measured the effects of partial chemical reprogramming on the epigenome, transcriptome, proteome, phosphoproteome, and metabolome. At the transcriptome, proteome, and phosphoproteome levels, we saw widescale changes induced by this treatment, with the most notable signature being an upregulation of mitochondrial oxidative phosphorylation. Furthermore, at the metabolome level, we observed a reduction in the accumulation of aging-related metabolites. Using both transcriptomic and epigenetic clock-based analyses, we show that partial chemical reprogramming reduces the biological age of mouse fibroblasts. We demonstrate that these changes have functional impacts, as evidenced by changes in cellular respiration and mitochondrial membrane potential. Taken together, these results illuminate the potential for chemical reprogramming reagents to rejuvenate aged biological systems and warrant further investigation into adapting these approaches for in vivo age reversal. More Information

The beginning of becoming a human

Loseva PA, Gladyshev VN.

Aging

doi: 10.18632/aging.205824

Abstract According to birth certificates, the life of a child begins once their body comes out of the mother’s womb. But when does their organismal life begin? Science holds a palette of answers-depending on how one defines a human life. In 1984, a commission on the regulatory framework for human embryo experimentation opted not to answer this question, instead setting a boundary, 14 days post-fertilization, beyond which any experiments were forbidden. Recently, as the reproductive technologies developed and the demand for experimentation grew stronger, this boundary may be set aside leaving the ultimate decision to local oversight committees. While science has not come closer to setting a zero point for human life, there has been significant progress in our understanding of early mammalian embryogenesis. It has become clear that the 14-day stage does in fact possess features, which make it a foundational time point for a developing human. Importantly, this stage defines the separation of soma from the germline and marks the boundary between rejuvenation and aging. We explore how different levels of life organization emerge during human development and suggest a new meaning for the 14-day stage in organismal life that is grounded in recent mechanistic advances and insights from aging studies. More Information

MethylGPT: a foundation model for the DNA methylome

Ying K, Song J, Cui H, Zhang Y, Li S, Chen X, Liu H, Eames A, McCartney DL, Marioni RE, Poganik JR, Moqri M, Wang B, Gladyshev VN.

bioRxiv : the preprint server for biology

doi: 10.1101/2024.10.30.621013

Abstract DNA methylation serves as a powerful biomarker for disease diagnosis and biological age assessment. However, current analytical approaches often rely on linear models that cannot capture the complex, context-dependent nature of methylation regulation. Here we present MethylGPT, a transformer-based foundation model trained on 226,555 (154,063 after QC and deduplication) human methylation profiles spanning diverse tissue types from 5,281 datasets, curated 49,156 CpG sites, and 7.6 billion training tokens. MethylGPT learns biologically meaningful representations of CpG sites, capturing both local genomic context and higher-order chromosomal features without external supervision. The model demonstrates robust methylation value prediction (Pearson R=0.929) and maintains stable performance in downstream tasks with up to 70% missing data. Applied to age prediction across multiple tissue types, MethylGPT achieves superior accuracy compared to existing methods. Analysis of the model’s attention patterns reveals distinct methylation signatures between young and old samples, with differential enrichment of developmental and aging-associated pathways. When finetuned to mortality and disease prediction across 60 major conditions using 18,859 samples from Generation Scotland, MethylGPT achieves robust predictive performance and enables systematic evaluation of intervention effects on disease risks, demonstrating potential for clinical applications. Our results demonstrate that transformer architectures can effectively model DNA methylation patterns while preserving biological interpretability, suggesting broad utility for epigenetic analysis and clinical applications. More Information

The mitochondrial-targeted peptide therapeutic elamipretide improves cardiac and skeletal muscle function during aging without detectable changes in tissue epigenetic or transcriptomic age

Mitchell W, Pharaoh G, Tyshkovskiy A, Campbell M, Marcinek DJ, Gladyshev VN.

bioRxiv : the preprint server for biology

doi: 10.1101/2024.10.30.620676

Abstract Aging-related decreases in cardiac and skeletal muscle function are strongly associated with various comorbidities. Elamipretide (ELAM), a novel mitochondrial-targeted peptide, has demonstrated broad therapeutic efficacy in ameliorating disease conditions associated with mitochondrial dysfunction across both clinical and pre-clinical models. ELAM is proposed to restore mitochondrial bioenergetic function by stabilizing inner membrane structure and increasing oxidative phosphorylation coupling and efficiency. Although ELAM treatment effectively attenuates physiological declines in multiple tissues in rodent aging models, it remains unclear whether these functional improvements correlate with favorable changes in molecular biomarkers of aging. Herein, we investigated the impact of 8-week ELAM treatment on pre- and post- measures of C57BL/6J mice frailty, skeletal muscle, and cardiac muscle function, coupled with post-treatment assessments of biological age and affected molecular pathways. We found that health status, as measured by frailty index, cardiac strain, diastolic function, and skeletal muscle force are significantly diminished with age, with skeletal muscle force changing in a sex-dependent manner. Conversely, ELAM mitigated frailty accumulation and was able to partially reverse these declines, as evidenced by treatment-induced increases in cardiac strain and muscle fatigue resistance. Despite these improvements, we did not detect statistically significant changes in gene expression or DNA methylation profiles indicative of molecular reorganization or reduced biological age in most ELAM-treated groups. However, pathway analyses revealed that ELAM treatment showed pro-longevity shifts in gene expression such as upregulation of genes involved in fatty acid metabolism, mitochondrial translation and oxidative phosphorylation, and downregulation of inflammation. Together, these results indicate that ELAM treatment is effective at mitigating signs of sarcopenia and heart failure in an aging mouse model, but that these functional improvements occur independently of detectable changes in epigenetic and transcriptomic age. Thus, some age-related changes in function may be uncoupled from changes in molecular biological age. More Information

High-dimensional Ageome Representations of Biological Aging across Functional Modules

Ying K, Tyshkovskiy A, Chen Q, Latorre-Crespo E, Zhang B, Liu H, Matei-Dediu B, Poganik JR, Moqri M, Kirschne K, Lasky-Su J, Gladyshev VN.

bioRxiv : the preprint server for biology

doi: 10.1101/2024.09.17.613599

Abstract The aging process involves numerous molecular changes that lead to functional decline and increased disease and mortality risk. While epigenetic aging clocks have shown accuracy in predicting biological age, they typically provide single estimates for the samples and lack mechanistic insights. In this study, we challenge the paradigm that aging can be sufficiently described with a single biological age estimate. We describe Ageome, a computational framework for measuring the epigenetic age of thousands of molecular pathways simultaneously in mice and humans. Ageome is based on the premise that an organism’s overall biological age can be approximated by the collective ages of its functional modules, which may age at different rates and have different biological ages. We show that, unlike conventional clocks, Ageome provides a high-dimensional representation of biological aging across cellular functions, enabling comprehensive assessment of aging dynamics within an individual, in a population, and across species. Application of Ageome to longevity intervention models revealed distinct patterns of pathway-specific age deceleration. Notably, cell reprogramming, while rejuvenating cells, also accelerated aging of some functional modules. When applied to human cohorts, Ageome demonstrated heterogeneity in predictive power for mortality risk, and some modules showed better performance in predicting the onset of age-related diseases, especially cancer, compared to existing clocks. Together, the Ageome framework offers a comprehensive and interpretable approach for assessing aging, providing insights into mechanisms and targets for intervention. More Information

Loss of epigenetic information as a cause of mammalian aging

Yang JH, Hayano M, Griffin PT, Amorim JA, Bonkowski MS, Apostolides JK, Salfati EL, Blanchette M, Munding EM, Bhakta M, Chew YC, Guo W, Yang X, Maybury-Lewis S, Tian X, Ross JM, Coppotelli G, Meer MV, Rogers-Hammond R, Vera DL, Lu YR, Pippin JW, Creswell ML, Dou Z, Xu C, Mitchell SJ, Das A, O’Connell BL, Thakur S, Kane AE, Su Q, Mohri Y, Nishimura EK, Schaevitz L, Garg N, Balta AM, Rego MA, Gregory-Ksander M, Jakobs TC, Zhong L, Wakimoto H, El Andari J, Grimm D, Mostoslavsky R, Wagers AJ, Tsubota K, Bonasera SJ, Palmeira CM, Seidman JG, Seidman CE, Wolf NS, Kreiling JA, Sedivy JM, Murphy GF, Green RE, Garcia BA, Berger SL, Oberdoerffer P, Shankland SJ, Gladyshev VN, Ksander BR, Pfenning AR, Rajman LA, Sinclair DA.

Cell

doi: 10.1016/j.cell.2024.01.049

Abstract More Information

Validation of biomarkers of aging

Moqri M, Herzog C, Poganik JR, Ying K, Justice JN, Belsky DW, Higgins-Chen AT, Chen BH, Cohen AA, Fuellen G, Hägg S, Marioni RE, Widschwendter M, Fortney K, Fedichev PO, Zhavoronkov A, Barzilai N, Lasky-Su J, Kiel DP, Kennedy BK, Cummings S, Slagboom PE, Verdin E, Maier AB, Sebastiano V, Snyder MP, Gladyshev VN, Horvath S, Ferrucci L.

Nature medicine

doi: 10.1038/s41591-023-02784-9

Abstract The search for biomarkers that quantify biological aging (particularly ‘omic’-based biomarkers) has intensified in recent years. Such biomarkers could predict aging-related outcomes and could serve as surrogate endpoints for the evaluation of interventions promoting healthy aging and longevity. However, no consensus exists on how biomarkers of aging should be validated before their translation to the clinic. Here, we review current efforts to evaluate the predictive validity of omic biomarkers of aging in population studies, discuss challenges in comparability and generalizability and provide recommendations to facilitate future validation of biomarkers of aging. Finally, we discuss how systematic validation can accelerate clinical translation of biomarkers of aging and their use in gerotherapeutic clinical trials. More Information

TIME-seq reduces time and cost of DNA methylation measurement for epigenetic clock construction

Griffin PT, Kane AE, Trapp A, Li J, Arnold M, Poganik JR, Conway RJ, McNamara MS, Meer MV, Hoffman N, Amorim JA, Tian X, MacArthur MR, Mitchell SJ, Mueller AL, Carmody C, Vera DL, Kerepesi C, Ying K, Noren Hooten N, Mitchell JR, Evans MK, Gladyshev VN, Sinclair DA.

Nature aging

doi: 10.1038/s43587-023-00555-2

Abstract Epigenetic ‘clocks’ based on DNA methylation have emerged as the most robust and widely used aging biomarkers, but conventional methods for applying them are expensive and laborious. Here we develop tagmentation-based indexing for methylation sequencing (TIME-seq), a highly multiplexed and scalable method for low-cost epigenetic clocks. Using TIME-seq, we applied multi-tissue and tissue-specific epigenetic clocks in over 1,800 mouse DNA samples from eight tissue and cell types. We show that TIME-seq clocks are accurate and robust, enriched for polycomb repressive complex 2-regulated loci, and benchmark favorably against conventional methods despite being up to 100-fold less expensive. Using dietary treatments and gene therapy, we find that TIME-seq clocks reflect diverse interventions in multiple tissues. Finally, we develop an economical human blood clock (R > 0.96, median error = 3.39 years) in 1,056 demographically representative individuals. These methods will enable more efficient epigenetic clock measurement in larger-scale human and animal studies. More Information

PRC2-AgeIndex as a universal biomarker of aging and rejuvenation

Moqri M, Cipriano A, Simpson DJ, Rasouli S, Murty T, de Jong TA, Nachun D, de Sena Brandine G, Ying K, Tarkhov A, Aberg KA, van den Oord E, Zhou W, Smith A, Mackall C, Gladyshev VN, Horvath S, Snyder MP, Sebastiano V.

Nature communications

doi: 10.1038/s41467-024-50098-2

Abstract DNA methylation (DNAm) is one of the most reliable biomarkers of aging across mammalian tissues. While the age-dependent global loss of DNAm has been well characterized, DNAm gain is less characterized. Studies have demonstrated that CpGs which gain methylation with age are enriched in Polycomb Repressive Complex 2 (PRC2) targets. However, whole-genome examination of all PRC2 targets as well as determination of the pan-tissue or tissue-specific nature of these associations is lacking. Here, we show that low-methylated regions (LMRs) which are highly bound by PRC2 in embryonic stem cells (PRC2 LMRs) gain methylation with age in all examined somatic mitotic cells. We estimated that this epigenetic change represents around 90% of the age-dependent DNAm gain genome-wide. Therefore, we propose the “PRC2-AgeIndex,” defined as the average DNAm in PRC2 LMRs, as a universal biomarker of cellular aging in somatic cells which can distinguish the effect of different anti-aging interventions. More Information

Epigenetic predictors of species maximum life span and other life-history traits in mammals

Li CZ, Haghani A, Yan Q, Lu AT, Zhang J, Fei Z, Ernst J, Yang XW, Gladyshev VN, Robeck TR, Chavez AS, Cook JA, Dunnum JL, Raj K, Seluanov A, Gorbunova V, Horvath S.

Science advances

doi: 10.1126/sciadv.adm7273

Abstract By analyzing 15,000 samples from 348 mammalian species, we derive DNA methylation (DNAm) predictors of maximum life span (R = 0.89), gestation time (R = 0.96), and age at sexual maturity (R = 0.85). Our maximum life-span predictor indicates a potential innate longevity advantage for females over males in 17 mammalian species including humans. The DNAm maximum life-span predictions are not affected by caloric restriction or partial reprogramming. Genetic disruptions in the somatotropic axis such as growth hormone receptors have an impact on DNAm maximum life span only in select tissues. Cancer mortality rates show no correlation with our epigenetic estimates of life-history traits. The DNAm maximum life-span predictor does not detect variation in life span between individuals of the same species, such as between the breeds of dogs. Maximum life span is determined in part by an epigenetic signature that is an intrinsic species property and is distinct from the signatures that relate to individual mortality risk. More Information

Comparative time-series multi-omics analyses suggest H1.2 involvement in anoxic adaptation and cancer resistance

Du J, Liu W, Li M, Li Z, Li X, Dai Y, Liu G, Wang X, Zhu P, Gladyshev VN, Zhou X.

PLoS biology

doi: 10.1371/journal.pbio.3002778

Abstract The naked mole rat (NMR), Heterocephalus glaber, is known as the longest-lived rodent and is extraordinarily resistant to hypoxia and cancer. Here, both NMR embryonic fibroblasts (NEFs) and their mouse counterparts (MEFs) were subjected to anoxic conditions (0% O2, 5% CO2). A combination of comparative transcriptomics and proteomics was then employed to identify differentially expressed genes (DEGs). Notably, we observed distinct levels of histone H1.2 (encoded by HIST1H1C) accumulation between NEFs and MEFs. Subsequent mechanistic analyses showed that higher H1.2 expression in NEFs was associated with the lower expression of its inhibitor, PARP1. Additionally, we discovered that H1.2 can directly interact with HIF-1α PAS domains, thereby promoting the expression of HIF-1α through facilitating the dimerization with HIF-1β. The overexpression of H1.2 was also found to trigger autophagy and to suppress the migration of cancer cells, as well as the formation of xenograft tumors, via the NRF2/P62 signaling pathway. Moreover, an engineered H1.2 knock-in mouse model exhibited significantly extended survival in hypoxic conditions (4% O2) and showed a reduced rate of tumor formation. Collectively, our results indicate a potential mechanistic link between H1.2 and the dual phenomena of anoxic adaptation and cancer resistance. More Information

Ribosome profiling reveals the role of yeast RNA-binding proteins Cth1 and Cth2 in translational regulation

Barlit H, Romero AM, Gülhan A, Patnaik PK, Tyshkovskiy A, Martínez-Pastor MT, Gladyshev VN, Puig S, Labunskyy VM.

iScience

doi: 10.1016/j.isci.2024.109868

Abstract Iron serves as a cofactor for enzymes involved in several steps of protein translation, but the control of translation during iron limitation is not understood at the molecular level. Here, we report a genome-wide analysis of protein translation in response to iron deficiency in yeast using ribosome profiling. We show that iron depletion affects global protein synthesis and leads to translational repression of multiple genes involved in iron-related processes. Furthermore, we demonstrate that the RNA-binding proteins Cth1 and Cth2 play a central role in this translational regulation by repressing the activity of the iron-dependent Rli1 ribosome recycling factor and inhibiting mitochondrial translation and heme biosynthesis. Additionally, we found that iron deficiency represses MRS3 mRNA translation through increased expression of antisense long non-coding RNA. Together, our results reveal complex gene expression and protein synthesis remodeling in response to low iron, demonstrating how this important metal affects protein translation at multiple levels. More Information

Longevity biotechnology: bridging AI, biomarkers, geroscience and clinical applications for healthy longevity

Lyu YX, Fu Q, Wilczok D, Ying K, King A, Antebi A, Vojta A, Stolzing A, Moskalev A, Georgievskaya A, Maier AB, Olsen A, Groth A, Simon AK, Brunet A, Jamil A, Kulaga A, Bhatti A, Yaden B, Pedersen BK, Schumacher B, Djordjevic B, Kennedy B, Chen C, Huang CY, Correll CU, Murphy CT, Ewald CY, Chen D, Valenzano DR, Sołdacki D, Erritzoe D, Meyer D, Sinclair DA, Chini EN, Teeling EC, Morgen E, Verdin E, Vernet E, Pinilla E, Fang EF, Bischof E, Mercken EM, Finger F, Kuipers F, Pun FW, Gyülveszi G, Civiletto G, Zmudze G, Blander G, Pincus HA, McClure J, Kirkland JL, Peyer J, Justice JN, Vijg J, Gruhn JR, McLaughlin J, Mannick J, Passos J, Baur JA, Betts-LaCroix J, Sedivy JM, Speakman JR, Shlain J, von Maltzahn J, Andreasson KI, Moody K, Palikaras K, Fortney K, Niedernhofer LJ, Rasmussen LJ, Veenhoff LM, Melton L, Ferrucci L, Quarta M, Koval M, Marinova M, Hamalainen M, Unfried M, Ringel MS, Filipovic M, Topors M, Mitin N, Roy N, Pintar N, Barzilai N, Binetti P, Singh P, Kohlhaas P, Robbins PD, Rubin P, Fedichev PO, Kamya P, Muñoz-Canoves P, de Cabo R, Faragher RGA, Konrad R, Ripa R, Mansukhani R, Büttner S, Wickström SA, Brunemeier S, Jakimov S, Luo S, Rosenzweig-Lipson S, Tsai SY, Dimmeler S, Rando TA, Peterson TR, Woods T, Wyss-Coray T, Finkel T, Strauss T, Gladyshev VN, Longo VD, Dwaraka VB, Gorbunova V, Acosta-Rodríguez VA, Sorrentino V, Sebastiano V, Li W, Suh Y, Zhavoronkov A, Scheibye-Knudsen M, Bakula D.

Aging

doi: 10.18632/aging.206135

Abstract The recent unprecedented progress in ageing research and drug discovery brings together fundamental research and clinical applications to advance the goal of promoting healthy longevity in the human population. We, from the gathering at the Aging Research and Drug Discovery Meeting in 2023, summarised the latest developments in healthspan biotechnology, with a particular emphasis on artificial intelligence (AI), biomarkers and clocks, geroscience, and clinical trials and interventions for healthy longevity. Moreover, we provide an overview of academic research and the biotech industry focused on targeting ageing as the root of age-related diseases to combat multimorbidity and extend healthspan. We propose that the integration of generative AI, cutting-edge biological technology, and longevity medicine is essential for extending the productive and healthy human lifespan. More Information

Disagreement on foundational principles of biological aging

Gladyshev VN, Anderson B, Barlit H, Barré B, Beck S, Behrouz B, Belsky DW, Chaix A, Chamoli M, Chen BH, Cheng K, Chuprin J, Churchill GA, Cipriano A, Colville A, Deelen J, Deigin Y, Edmonds KK, English BW, Fang R, Florea M, Gershteyn IM, Gill D, Goetz LH, Gorbunova V, Griffin PT, Horvath S, Borch Jensen M, Jin X, Jovanovska S, Kajderowicz KM, Kasahara T, Kerepesi C, Kulkarni S, Labunskyy VM, Levine ME, Libert S, Lu JY, Lu YR, Marioni RE, McCoy BM, Mitchell W, Moqri M, Nasirian F, Niimi P, Oh HS, Okundaye B, Parkhitko AA, Peshkin L, Petljak M, Poganik JR, Pridham G, Promislow DEL, Prusisz W, Quiniou M, Raj K, Richard D, Ricon JL, Rutledge J, Scheibye-Knudsen M, Schork NJ, Seluanov A, Shadpour M, Shindyapina AV, Shuken SR, Sivakumar S, Stoeger T, Sugiura A, Sutton NR, Suvorov A, Tarkhov AE, Teeling EC, Trapp A, Tyshkovskiy A, Unfried M, Ward-Caviness CK, Yim SH, Ying K, Yunes J, Zhang B, Zhavoronkov A.

PNAS nexus

doi: 10.1093/pnasnexus/pgae499

Abstract To gain insight into how researchers of aging perceive the process they study, we conducted a survey among experts in the field. While highlighting some common features of aging, the survey exposed broad disagreement on the foundational issues. What is aging? What causes it? When does it begin? What constitutes rejuvenation? Not only was there no consensus on these and other core questions, but none of the questions received a majority opinion-even regarding the need for consensus itself. Despite many researchers believing they understand aging, their understanding diverges considerably. Importantly, as different processes are labeled as “aging” by researchers, different experimental approaches are prioritized. The survey shed light on the need to better define which aging processes this field should target and what its goals are. It also allowed us to categorize contemporary views on aging and rejuvenation, revealing critical, yet largely unanswered, questions that appear disconnected from the current research focus. Finally, we discuss ways to address the disagreement, which we hope will ultimately aid progress in the field. More Information

Development and Optimization of a Redox Enzyme-Based Fluorescence Biosensor for the Identification of MsrB1 Inhibitors

Shim HB, Lee H, Cho HY, Jo YH, Tarrago L, Kim H, Gladyshev VN, Lee BC.

Antioxidants (Basel, Switzerland)

doi: 10.3390/antiox13111348

Abstract MsrB1 is a thiol-dependent enzyme that reduces protein methionine-R-sulfoxide and regulates inflammatory response in macrophages. Therefore, MsrB1 could be a promising therapeutic target for the control of inflammation. To identify MsrB1 inhibitors, we construct a redox protein-based fluorescence biosensor composed of MsrB1, a circularly permutated fluorescent protein, and the thioredoxin1 in a single polypeptide chain. This protein-based biosensor, named RIYsense, efficiently measures protein methionine sulfoxide reduction by ratiometric fluorescence increase. We used it for high-throughput screening of potential MsrB1 inhibitors among 6868 compounds. A total of 192 compounds were selected based on their ability to reduce relative fluorescence intensity by more than 50% compared to the control. Then, we used molecular docking simulations of the compound on MsrB1, affinity assays, and MsrB1 activity measurement to identify compounds with reliable and strong inhibitory effects. Two compounds were selected as MsrB1 inhibitors: 4-[5-(4-ethylphenyl)-3-(4-hydroxyphenyl)-3,4-dihydropyrazol-2-yl]benzenesulfonamide and 6-chloro-10-(4-ethylphenyl)pyrimido[4,5-b]quinoline-2,4-dione. They are heterocyclic, polyaromatic compounds with a substituted phenyl moiety interacting with the MsrB1 active site, as revealed by docking simulation. These compounds were found to decrease the expression of anti-inflammatory cytokines such as IL-10 and IL-1rn, leading to auricular skin swelling and increased thickness in an ear edema model, effectively mimicking the effects observed in MsrB1 knockout mice. In summary, using a novel redox protein-based fluorescence biosensor, we identified potential MsrB1 inhibitors that can regulate the inflammatory response, particularly by influencing the expression of anti-inflammatory cytokines. These compounds are promising tools for understanding MsrB1’s role during inflammation and eventually controlling inflammation in therapeutic approaches. More Information

DNA repair and anti-cancer mechanisms in the long-lived bowhead whale

Firsanov D, Zacher M, Tian X, Sformo TL, Zhao Y, Tombline G, Lu JY, Zheng Z, Perelli L, Gurreri E, Zhang L, Guo J, Korotkov A, Volobaev V, Biashad SA, Zhang Z, Heid J, Maslov A, Sun S, Wu Z, Gigas J, Hillpot E, Martinez J, Lee M, Williams A, Gilman A, Hamilton N, Haseljic E, Patel A, Straight M, Miller N, Ablaeva J, Tam LM, Couderc C, Hoopman M, Moritz R, Fujii S, Hayman DJ, Liu H, Cai Y, Leung AKL, Simons MJP, Zhang Z, Nelson CB, Abegglen LM, Schiffman JD, Gladyshev VN, Modesti M, Genovese G, Vijg J, Seluanov A, Gorbunova V.

bioRxiv : the preprint server for biology

doi: 10.1101/2023.05.07.539748

Abstract At over 200 years, the maximum lifespan of the bowhead whale exceeds that of all other mammals. The bowhead is also the second-largest animal on Earth, reaching over 80,000 kg¹. Despite its very large number of cells and long lifespan, the bowhead is not highly cancer-prone, an incongruity termed Peto’s Paradox². This phenomenon has been explained by the evolution of additional tumor suppressor genes in other larger animals, supported by research on elephants demonstrating expansion of the p53 gene^3-5. Here we show that bowhead whale fibroblasts undergo oncogenic transformation after disruption of fewer tumor suppressors than required for human fibroblasts. However, analysis of DNA repair revealed that bowhead cells repair double strand breaks (DSBs) and mismatches with uniquely high efficiency and accuracy compared to other mammals. The protein CIRBP, implicated in protection from genotoxic stress, was present in very high abundance in the bowhead whale relative to other mammals. We show that CIRBP and its downstream protein RPA2, also present at high levels in bowhead cells, increase the efficiency and fidelity of DNA repair in human cells. These results indicate that rather than possessing additional tumor suppressor genes as barriers to oncogenesis, the bowhead whale relies on more accurate and efficient DNA repair to preserve genome integrity. This strategy which does not eliminate damaged cells but repairs them may be critical for the long and cancer-free lifespan of the bowhead whale. More Information

The 18S rRNA Methyltransferase DIMT-1 Regulates Lifespan in the Germline Later in Life

Rothi MH, Haddad JA, Sarkar GC, Mitchell W, Ying K, Pohl N, Sotomayor R, Natale J, Dellacono S, Gladyshev VN, Greer EL.

Research square

doi: 10.21203/rs.3.rs-4421268/v1

Abstract Ribosome heterogeneity has emerged as an important regulatory control feature for determining which proteins are synthesized, however, the influence of age on ribosome heterogeneity is not fully understood. Whether mRNA transcripts are selectively translated in young versus old cells and whether dysregulation of this process drives organismal aging is unknown. Here we examined the role of ribosomal RNA (rRNA) methylation in maintaining appropriate translation as organisms age. In a directed RNAi screen, we identified the 18S rRNA N6′-dimethyl adenosine (m^6,2A) methyltransferase, dimt-1, as a regulator of C. elegans lifespan and stress resistance. Lifespan extension induced by dimt-1 deficiency required a functional germline and was dependent on the known regulator of protein translation, the Rag GTPase, raga-1, which links amino acid sensing to the mechanistic target of rapamycin complex (mTORC)1. Using an auxin-inducible degron tagged version of dimt-1, we demonstrate that DIMT-1 functions in the germline after mid-life to regulate lifespan. We further found that knock-down of dimt-1 leads to selective translation of transcripts important for stress resistance and lifespan regulation in the C. elegans germline in mid-life including the cytochrome P450 daf-9, which synthesizes a steroid that signals from the germline to the soma to regulate lifespan. We found that dimt-1 induced lifespan extension was dependent on the daf-9 signaling pathway. This finding reveals a new layer of proteome dysfunction, beyond protein synthesis and degradation, as an important regulator of aging. Our findings highlight a new role for ribosome heterogeneity, and specific rRNA modifications, in maintaining appropriate translation later in life to promote healthy aging. More Information

The 18S rRNA Methyltransferase DIMT-1 Regulates Lifespan in the Germline Later in Life

Hafiz Rothi M, Sarkar GC, Haddad JA, Mitchell W, Ying K, Pohl N, Sotomayor-Mena RG, Natale J, Dellacono S, Gladyshev VN, Lieberman Greer E.

bioRxiv : the preprint server for biology

doi: 10.1101/2024.05.14.594211

A disease similarity approach identifies short-lived Niemann-Pick type C disease mice with accelerated brain aging as a novel mouse model for Alzheimer’s disease and aging research

Gujjala VA, Klimek I, Abyadeh M, Tyshkovskiy A, Oz N, Castro JP, Gladyshev VN, Newton J, Kaya A.

bioRxiv : the preprint server for biology

doi: 10.1101/2024.04.19.590328

Abstract Since its first description in 1906 by Dr. Alois Alzheimer, Alzheimer’s disease (AD) has been the most common type of dementia. Initially thought to be caused by age-associated accumulation of plaques, in recent years, research has increasingly associated AD with lysosomal storage and metabolic disorders, and the explanation of its pathogenesis has shifted from amyloid and tau accumulation to oxidative stress and impaired lipid and glucose metabolism aggravated by hypoxic conditions. However, the underlying mechanisms linking those cellular processes and conditions to disease progression have yet to be defined. Here, we applied a disease similarity approach to identify unknown molecular targets of AD by using transcriptomic data from congenital diseases known to increase AD risk, namely Down Syndrome, Niemann Pick Disease Type C (NPC), and Mucopolysaccharidoses I. We uncovered common pathways, hub genes, and miRNAs across in vitro and in vivo models of these diseases as potential molecular targets for neuroprotection and amelioration of AD pathology, many of which have never been associated with AD. We then investigated common molecular alterations in brain samples from an NPC disease mouse model by juxtaposing them with brain samples of both human and mouse models of AD. Detailed phenotypic and molecular analyses revealed that the NPC ^mut mouse model can serve as a potential short-lived in vivo model for AD research and for understanding molecular factors affecting brain aging. This research represents the first comprehensive approach to congenital disease association with neurodegeneration and a new perspective on AD research while highlighting shortcomings and lack of correlation in diverse in vitro models. Considering the lack of an AD mouse model that recapitulates the physiological hallmarks of brain aging, the characterization of a short-lived NPC mouse model will further accelerate the research in these fields and offer a unique model for understanding the molecular mechanisms of AD from a perspective of accelerated brain aging. More Information

A single cell atlas of the mouse seminal vesicle

Sun F, Desevin K, Fu Y, Parameswaran S, Mayall J, Rinaldi V, Krietenstein N, Manukyan A, Yin Q, Galan C, Yang CH, Shindyapina AV, Gladyshev VN, Garber M, Schjenken JE, Rando OJ.

bioRxiv : the preprint server for biology

doi: 10.1101/2024.04.08.588538

Abstract During mammalian reproduction, sperm are delivered to the female reproductive tract bathed in a complex medium known as seminal fluid, which plays key roles in signaling to the female reproductive tract and in nourishing sperm for their onwards journey. Along with minor contributions from the prostate and the epididymis, the majority of seminal fluid is produced by a somewhat understudied organ known as the seminal vesicle. Here, we report the first single-cell RNA-seq atlas of the mouse seminal vesicle, generated using tissues obtained from 23 mice of varying ages, exposed to a range of dietary challenges. We define the transcriptome of the secretory cells in this tissue, identifying a relatively homogeneous population of the epithelial cells which are responsible for producing the majority of seminal fluid. We also define the immune cell populations – including large populations of macrophages, dendritic cells, T cells, and NKT cells – which have the potential to play roles in producing various immune mediators present in seminal plasma. Together, our data provide a resource for understanding the composition of an understudied reproductive tissue with potential implications for paternal control of offspring development and metabolism. More Information

AgeMeta: Quantitative Gene Expression Database of Mammalian Aging

Tikhonov S, Batin M, Gladyshev VN, Dmitriev SE, Tyshkovskiy A.

Biochemistry. Biokhimiia

doi: 10.1134/S000629792402010X

Abstract AgeMeta is a database that provides systemic and quantitative description of mammalian aging at the level of gene expression. It encompasses transcriptomic changes with age across various tissues of humans, mice, and rats, based on a comprehensive meta-analysis of 122 publicly available gene expression datasets from 26 studies. AgeMeta provides an intuitive visual interface for quantification of aging-associated transcriptomics at the level of individual genes and functional groups of genes, allowing easy comparison among various species and tissues. Additionally, all the data in the database can be downloaded and analyzed independently. Overall, this work contributes to the understanding of the complex network of biological processes underlying mammalian aging and supports future advancements in this field. AgeMeta is freely available at: https://age-meta.com/. More Information

Selenium, diabetes, and their intricate sex-specific relationship

Demircan K, Chillon TS, Bang J, Gladyshev VN, Schomburg L.

Trends in endocrinology and metabolism: TEM

doi: 10.1016/j.tem.2024.03.004

Abstract Selenium (Se) is an essential trace element, which is inserted as selenocysteine (Sec) into selenoproteins during biosynthesis, orchestrating their expression and activity. Se is associated with both beneficial and detrimental health effects; deficient supply or uncontrolled supplementation raises concerns. In particular, Se was associated with an increased incidence of type 2 diabetes (T2D) in a secondary analysis of a randomized controlled trial (RCT). In this review, we discuss the intricate relationship between Se and diabetes and the limitations of the available clinical and experimental studies. Recent evidence points to sexual dimorphism and an association of Se deficiency with gestational diabetes mellitus (GDM). We highlight the emerging evidence linking high Se status with improved prognosis in patients with T2D and lower risk of macrovascular complications. More Information

A torpor-like state (TLS) in mice slows blood epigenetic aging and prolongs healthspan

Jayne L, Lavin-Peter A, Roessler J, Tyshkovskiy A, Antoszewski M, Ren E, Markovski A, Sun S, Yao H, Sankaran VG, Gladyshev VN, Brooke RT, Horvath S, Griffith EC, Hrvatin S.

bioRxiv : the preprint server for biology

doi: 10.1101/2024.03.20.585828

Abstract Torpor and hibernation are extreme physiological adaptations of homeotherms associated with pro-longevity effects. Yet the underlying mechanisms of how torpor affects aging, and whether hypothermic and hypometabolic states can be induced to slow aging and increase health span, remain unknown. We demonstrate that the activity of a spatially defined neuronal population in the avMLPA, which has previously been identified as a torpor-regulating brain region, is sufficient to induce a torpor like state (TLS) in mice. Prolonged induction of TLS slows epigenetic aging across multiple tissues and improves health span. We isolate the effects of decreased metabolic rate, long-term caloric restriction, and decreased core body temperature (T_b) on blood epigenetic aging and find that the pro-longevity effect of torpor-like states is mediated by decreased T_b. Taken together, our findings provide novel mechanistic insight into the pro-longevity effects of torpor and hibernation and support the growing body of evidence that T_b is an important mediator of aging processes. More Information

Sendai virus persistence questions the transient naive reprogramming method for iPSC generation

De Los Angeles A, Hug CB, Gladyshev VN, Church GM, Velychko S.

bioRxiv : the preprint server for biology

doi: 10.1101/2024.03.07.583804

Abstract Since the revolutionary discovery of induced pluripotent stem cells (iPSCs) by Shinya Yamanaka, the comparison between iPSCs and embryonic stem cells (ESCs) has revealed significant differences in their epigenetic states and developmental potential. A recent compelling study published in Nature by Buckberry et al.¹ demonstrated that a transient-naive-treatment (TNT) could facilitate epigenetic reprogramming and improve the developmental potential of human iPSCs (hiPSCs). However, the study characterized bulk hiPSCs instead of isolating clonal lines and overlooked the persistent expression of Sendai virus carrying exogenous Yamanaka factors. Our analyses revealed that Sendai genes were expressed in most control PSC samples, including hESCs, which were not intentionally infected. The highest levels of Sendai expression were detected in samples continuously treated with naive media, where it led to overexpression of exogenous MYC, SOX2, and KLF4, altering both the expression levels and ratios of reprogramming factors. Our findings call for further research to verify the effectiveness of the TNT method in the context of delivery methods that ensure prompt elimination of exogenous factors, leading to the generation of bona fide transgene-independent iPSCs. More Information