2022 Articles

Kerepesi C, Meer MV, Ablaeva J, Amoroso VG, Lee SG, Zhang B, Gerashchenko MV, Trapp A, Yim SH, Lu AT, Levine ME, Seluanov A, Horvath S, Park TJ, Gorbunova V, Gladyshev VN (2022) Epigenetic aging of the demographically non-aging naked mole-rat. Nature Communications 13, 355.

AbstractThe naked mole-rat (NMR) is an exceptionally long-lived rodent that shows no increase of mortality with age, defining it as a demographically non-aging mammal. Here, we perform bisulfite sequencing of the blood of > 100 NMRs, assessing > 3 million common CpG sites. Unsupervised clustering based on sites whose methylation correlates with age reveals an age-related methylome remodeling, and we also observe a methylome information loss, suggesting that NMRs age. We develop an epigenetic aging clock that accurately predicts the NMR age. We show that these animals age much slower than mice and much faster than humans, consistent with their known maximum lifespans. Interestingly, patterns of age-related changes of clock sites in Tert and Prpf19 differ between NMRs and mice, but there are also sites conserved between the two species. Together, the data indicate that NMRs, like other mammals, epigenetically age even in the absence of demographic aging of this species. More Information

Zhang B, Trapp A, Kerepesi C, Gladyshev VN (2022) Emerging rejuvenation strategies-Reducing the biological age. Aging Cell 21, e13538.


Abstract Several interventions have recently emerged that were proposed to reverse rather than just attenuate aging, but the criteria for what it takes to achieve rejuvenation remain controversial. Distinguishing potential rejuvenation therapies from other longevity interventions, such as those that slow down aging, is challenging, and these anti-aging strategies are often referred to interchangeably. We suggest that the prerequisite for a rejuvenation intervention is a robust, sustained, and systemic reduction in biological age, which can be assessed by biomarkers of aging, such as epigenetic clocks. We discuss known and putative rejuvenation interventions and comparatively analyze them to explore underlying mechanisms. More Information

Shindyapina AV, Cho Y, Kaya A, Tyshkovskiy A, Castro JP, Gordevicius J, Poganik JR, Horvath S, Peshkin L, Gladyshev VN (2022) Rapamycin treatment during development extends lifespan and healthspan. bioRxiv, 10.1101/2022.02.18.481092


Abstract The possibility that pace of development is tightly connected to aging is supported by the fact that the onset of reproduction is associated with lifespan and that many longevity interventions target growth and development. However, it has been unknown whether targeting development with pharmacological intervention can lead to a longer lifespan. To test this possibility, we subjected genetically diverse UMHET3 mice to the mTOR inhibitor rapamycin for the first 45 days of life and followed them up until death. Treated mice grew slower, with most of the deceleration occurring in the first week, and remained smaller for their entire lives. Their reproductive age was delayed but without affecting offspring numbers. The treatment was sufficient to extend the median lifespan by 10%, with the most effect in males, and to preserve better health as measured by frailty index, gait speed, and glucose and insulin tolerance tests. Mechanistically, the liver transcriptome of treated mice was younger at the completion of treatment and stayed younger into the old ages in males. Rapamycin initially reduced DNA methylation age of livers, however, that effect was lost with aging. Analogous to mice, rapamycin exposure only during development robustly extended the lifespan of Daphnia magna as well as reduced their body size, suggesting evolutionary conserved mechanisms of this early life effect. Overall, the results demonstrate that short-term rapamycin treatment during early life is a novel longevity intervention that establishes causality between pace of development and longevity in evolutionary distant organisms. More Information

Mariotti M, Kerepesi C, Oliveros W, Mele M, Gladyshev VN (2022) Deterioration of the human transcriptome with age due to increasing intron retention and spurious splicing. bioRxiv, 10.1101/2022.03.14.484341


Abstract Adult aging is characterized by a progressive deterioration of biological functions at physiological, cellular and molecular levels, but its damaging effects on the transcriptome are not well characterized. Here, by analyzing splicing patterns in ∼1,000 human subjects sampled across multiple tissues, we found that splicing fidelity declines with age. Most prominently, genuine introns fail to be spliced out, manifesting as a broad surge in intron retention, and this is exacerbated by the increase in diverse spurious exon-exon junctions with age. Both of these effects are prominently detected in the majority of human tissues. Collectively, they result in the progressive deterioration of the active transcriptome, wherein functional mRNAs are increasingly diluted with non-functional splicing isoforms. We discuss the concept of “splicing damage” and formulate methods to quantify it. Using these tools, we show that splicing damage increases both with age and with the incidence of diseases. Altogether, this work uncovers transcriptome damage as a critical molecular indicator of human aging and healthspan. More Information

Meron E, Thaysen M, Angeli S, Antebi A, Barzilai N, Baur JA, Bekker-Jensen S, Birkisdottir M, Bischof E, Bruening J, Brunet A, Buchwalter A, Cabreiro F, Fortney K, Freund A, Georgievskaya A, Gladyshev VN, Glass D, Golato T, Gorbunova V, Hoejimakers J, Houtkooper RH, Jager S, Jaksch F, Janssens G, Jensen MB, Kaeberlein M, Karsenty G, de Keizer P, Kennedy B, Kirkland JL, Kjaer M, Kroemer G, Lee KF, Lemaitre JM, Liaskos D, Longo VD, Lu YX, MacArthur MR, Maier AB, Manakanatas C, Mitchell SJ, Moskalev A, Niedernhofer L, Ozerov I, Partridge L, Passegué E, Petr MA, Peyer J, Radenkovic D, Rando TA, Rattan S, Riedel CG, Rudolph L, Ai R, Serrano M, Schumacher B, Sinclair DA, Smith R, Suh Y, Taub P, Trapp A, Trendelenburg AU, Valenzano DR, Verburgh K, Verdin E, Vijg J, Westendorp RGJ, Zonari A, Bakula D, Zhavoronkov A, Scheibye-Knudsen M (2022) Meeting Report: Aging Research and Drug Discovery. Aging 14, 530-543.

Abstract Aging is the single largest risk factor for most chronic diseases, and thus possesses large socioeconomic interest to continuously aging societies. Consequently, the field of aging research is expanding alongside a growing focus from the industry and investors in aging research. This year’s 8th Annual Aging Research and Drug Discovery (ARDD) meeting was organized as a hybrid meeting from August 30th to September 3rd 2021 with more than 130 attendees participating on-site at the Ceremonial Hall at University of Copenhagen, Denmark, and 1800 engaging online. The conference comprised of presentations from 75 speakers focusing on new research in topics including mechanisms of aging and how these can be modulated as well as the use of AI and new standards of practices within aging research. This year, a longevity workshop was included to build stronger connections with the clinical community. More Information

Kang D, Lee J, Jung J, Carlson BA, Chang MJ, Chang CB, Kang SB, Lee BC, Gladyshev VN, Hatfield DL, Lee BJ, Kim JH (2022) Selenophosphate synthetase 1 deficiency exacerbates osteoarthritis by dysregulating redox homeostasis. Nature Communications 13, 779.


AbstractAging and mechanical overload are prominent risk factors for osteoarthritis (OA), which lead to an imbalance in redox homeostasis. The resulting state of oxidative stress drives the pathological transition of chondrocytes during OA development. However, the specific molecular pathways involved in disrupting chondrocyte redox homeostasis remain unclear. Here, we show that selenophosphate synthetase 1 (SEPHS1) expression is downregulated in human and mouse OA cartilage. SEPHS1 downregulation impairs the cellular capacity to synthesize a class of selenoproteins with oxidoreductase functions in chondrocytes, thereby elevating the level of reactive oxygen species (ROS) and facilitating chondrocyte senescence. Cartilage-specific Sephs1 knockout in adult mice causes aging-associated OA, and augments post-traumatic OA, which is rescued by supplementation of N-acetylcysteine (NAC). Selenium-deficient feeding and Sephs1 knockout have synergistic effects in exacerbating OA pathogenesis in mice. Therefore, we propose that SEPHS1 is an essential regulator of selenium metabolism and redox homeostasis, and its dysregulation governs the progression of OA. More Information

Lee HM, Choi DW, Kim S, Lee A, Kim M, Roh YJ, Jo YH, Cho HY, Lee HJ, Lee SR, Tarrago L, Gladyshev VN, Kim JH, Lee BC (2022) Biosensor-Linked Immunosorbent Assay for the Quantification of Methionine Oxidation in Target Proteins. ACS Sensors 7, 131-141.

 
Abstract Methionine oxidation is involved in regulating the protein activity and often leads to protein malfunction. However, tools for quantitative analyses of protein-specific methionine oxidation are currently unavailable. In this work, we developed a biological sensor that quantifies oxidized methionine in the form of methionine-R-sulfoxide in target proteins. The biosensor “tpMetROG” consists of methionine sulfoxide reductase B (MsrB), circularly permuted yellow fluorescent protein (cpYFP), thioredoxin, and protein G. Protein G binds to the constant region of antibodies against target proteins, specifically capturing them. Then, MsrB reduces the oxidized methionine in these proteins, leading to cpYFP fluorescence changes. We assessed this biosensor for quantitative analysis of methionine-R-sulfoxide in various proteins, such as calmodulin, IDLO, LegP, Sacde, and actin. We further developed an immunosorbent assay using the biosensor to quantify methionine oxidation in specific proteins such as calmodulin in animal tissues. The biosensor-linked immunosorbent assay proves to be an indispensable tool for detecting methionine oxidation in a protein-specific manner. This is a versatile tool for studying the redox biology of methionine oxidation in proteins. More Information

Tian R, Han K, Geng Y, Yang C, Shi C, Thomas PB, Pearce C, Moffatt K, Ma S, Xu S, Yang G, Zhou X, Gladyshev VN, Liu X, Fisher DO, Chopin LK, Leiner NO, Baker AM, Fan G, Seim I (2022) A chromosome-level genome of Antechinus flavipes provides a reference for an Australian marsupial genus with male death after mating. Molecular Ecology Resources 22, 740-754.

 
Abstract The 15 species of small carnivorous marsupials that comprise the genus Antechinus exhibit semelparity, a rare life-history strategy in mammals where synchronized death occurs after one breeding season. Antechinus males, but not females, age rapidly (demonstrate organismal senescence) during the breeding season and show promise as new animal models of ageing. Some antechinus species are also threatened or endangered. Here, we report a chromosome-level genome of a male yellow-footed antechinus Antechinus flavipes. The genome assembly has a total length of 3.2 Gb with a contig N50 of 51.8 Mb and a scaffold N50 of 636.7 Mb. We anchored and oriented 99.7% of the assembly on seven pseudochromosomes and found that repetitive DNA sequences occupy 51.8% of the genome. Draft genome assemblies of three related species in the subfamily Phascogalinae, two additional antechinus species (Antechinus argentus and A. arktos) and the iteroparous sister species Murexia melanurus, were also generated. Preliminary demographic analysis supports the hypothesis that climate change during the Pleistocene isolated species in Phascogalinae and shaped their population size. A transcriptomic profile across the A. flavipes breeding season allowed us to identify genes associated with aspects of the male die-off. The chromosome-level A. flavipes genome provides a steppingstone to understanding an enigmatic life-history strategy and a resource to assist the conservation of antechinuses. More Information