Publications
Comparative lifespan and healthspan of nonhuman primate species common to biomedical research
Hillary F Huber, Hannah C Ainsworth, Ellen Quillen, Adam Salmon, Corinna Ross, Adinda D Azhar, Karen Bales, Michele A Basso, Kris Coleman, Ricki Colman, Huda S Darusman, William Hopkins, Charlotte E Hotchkiss, Matt Jorgensen, Kylie Kavanagh, Cun Li, Julie A Mattison, Peter W Nathanielsz, Suryo Saputro, Diana Scorpio, Paul-Michael Sosa, Eric Vallender, Yaomin Wang, Caroline Zeiss, Carol Shively, Laura A Cox
bioRxiv [Preprint]. 2024 Aug 6:2024.07.31.606010. doi: 10.1101/2024.07.31.606010.
Abstract:
There is a critical need to generate age- and sex-specific survival curves to characterize chronological aging consistently across nonhuman primates (NHP) used in biomedical research. Accurate measures of chronological aging are essential for inferences into genetic, demographic, and physiological variables driving differences in NHP lifespan within and between species. Understanding NHP lifespans is relevant to public health because unraveling the demographic, molecular, and clinical bases of health across the life course in translationally relevant NHP species is fundamentally important to the study of human aging. Data from more than 110,000 captive individual NHP were contributed by 15 major research institutions to generate sex-specific Kaplan-Meier survival curves using uniform methods in 12 translational aging models: Callithrix jacchus (common marmoset), Chlorocebus aethiops sabaeus (vervet/African green), Macaca fascicularis (cynomolgus macaque), M. fuscata (Japanese macaque), M. mulatta (rhesus macaque), M. nemestrina (pigtail macaque), M. radiata (bonnet macaque), Pan troglodytes spp. (chimpanzee), Papio hamadryas spp. (baboon), Plecturocebus cupreus (coppery titi monkey), Saguinus oedipus (cotton-top tamarin), and Saimiri spp. (squirrel monkey). After employing strict inclusion criteria, primary analysis results are based on 12,269 NHP that survived to adulthood and died of natural/health-related causes. A secondary analysis was completed for 32,616 NHP that died of any cause. For the primary analyses, we report ages of 25th, 50th, 75th, and 85th percentiles of survival, maximum observed ages, rates of survivorship, and sex-based differences captured by quantile regression models and Kolmogorov-Smirnov tests. Our findings show a pattern of reduced male survival among catarrhines (African and Asian primates), especially macaques, but not platyrrhines (Central and South American primates). For many species, median lifespans were lower than previously reported. An important consideration is that these analyses may offer a better reflection of healthspan than lifespan. Captive NHP used in research are typically euthanized for humane welfare reasons before their natural end of life, often after diagnosis of their first major disease requiring long-term treatment with reduced quality of life (e.g., endometriosis, cancer, osteoarthritis). Supporting the idea that these data are capturing healthspan, for several species typical age at onset of chronic disease is similar to the median lifespan estimates. This data resource represents the most comprehensive characterization of sex-specific lifespan and age-at-death distributions for 12 biomedically relevant species, to date. The results clarify the relationships among NHP ages and will provide a valuable resource for the aging research community, improving human-NHP age equivalencies, informing investigators of the expected survival rates of NHP assigned to studies, providing a metric for comparisons in future studies, and contributing to our understanding of the factors that drive lifespan differences within and among species.
Intermittent clearance of p21-highly-expressing cells extends lifespan and confers sustained benefits to health and physical function
Binsheng Wang, Lichao Wang, Nathan S Gasek, Chia-Ling Kuo, Jia Nie, Taewan Kim, Pengyi Yan, Junyu Zhu, Blake L Torrance, Yueying Zhou, Lisa C Flores, Colton Allen, Allison M Andrade, Chun Guo, Rachel L Cohn, Evan R Jellison, Jenna M Bartley, George A Kuchel, Sheng Li, Tamar Pirtskhalava, Tamar Tchkonia, Sumit Yadav, Laura Haynes, James L Kirkland, Yuji Ikeno, Ming Xu
Cell Metab. 2024 Aug 6;36(8):1795-1805.e6. doi: 10.1016/j.cmet.2024.07.006.
Abstract:
A key challenge in aging research is extending lifespan in tandem with slowing down functional decline so that life with good health (healthspan) can be extended. Here, we show that monthly clearance, starting from 20 months, of a small number of cells that highly express p21Cip1 (p21high) improves cardiac and metabolic function and extends both median and maximum lifespans in mice. Importantly, by assessing the health and physical function of these mice monthly until death, we show that clearance of p21high cells improves physical function at all remaining stages of life, suggesting healthspan extension. Mechanistically, p21high cells encompass several cell types with a relatively conserved proinflammatory signature. Clearance of p21high cells reduces inflammation and alleviates age-related transcriptomic signatures of various tissues. These findings demonstrate the feasibility of healthspan extension in mice and indicate p21high cells as a therapeutic target for healthy aging.
Keywords: aging; cellular senescence; frailty; inflammation; morbidity compression.
A pilot study evaluating dosing tolerability of 17α-estradiol in male common marmosets (Callithrix jacchus)
Roshini Sathiaseelan, Jose V V Isola, Roberto Santín-Márquez, Daniel Adekunbi, Michal Fornalik, Adam B Salmon, Michael B Stout
Geroscience. 2024 Aug 6. doi: 10.1007/s11357-024-01311-z. Online ahead of print.
Abstract:
17α-estradiol extends healthspan and lifespan in male mice without significant feminization or deleterious effects on reproductive function, making it a candidate for human translation. However, studies in animal models that more accurately replicate human physiology are necessary to establish 17α-estradiol dosing standards for clinical trials. This study evaluated the tolerability of 17α-estradiol treatment in the common marmoset over a short treatment duration. We found that male marmosets tolerated two dosing regimens (0.37-0.47 or 0.62-0.72 mg/kg/day) as evidenced by the absence of gastrointestinal distress, changes in vital signs, or overall health conditions. 17α-estradiol treatment mildly decreased body mass, adiposity, and glycosylated hemoglobin, although these changes were not statistically significant in most instances. However, neither dose of 17α-estradiol elicited feminization in our study, thereby suggesting that optimized dosing regimens may provide health benefits without feminization in primates. Additional studies are needed to determine if longer duration treatments would also be nonfeminizing and elicit significant health benefits, which would aid in developing dosing regimens targeting healthy aging in humans.
Keywords: Androgen; Endocrinology; Estrogen; Follicle stimulating hormone; Luteinizing hormone; Nonhuman primate.
Wnt/Wingless signaling promotes lipid mobilization through signal-induced transcriptional repression
Mengmeng Liu, Rajitha-Udakara-Sampath Hemba-Waduge, Xiao Li, Xiahe Huang, Tzu-Hao Liu, Xianlin Han, Yingchun Wang, Jun-Yuan Ji
Proc Natl Acad Sci U S A. 2024 Jul 9;121(28):e2322066121. doi: 10.1073/pnas.2322066121. Epub 2024 Jul 5.
Abstract:
The Wnt/Wingless signaling pathway plays critical roles in metazoan development and energy metabolism, but its role in regulating lipid homeostasis remains not fully understood. Here, we report that the activation of canonical Wnt/Wg signaling promotes lipolysis while concurrently inhibiting lipogenesis and fatty acid β-oxidation in both larval and adult adipocytes, as well as cultured S2R+ cells, in Drosophila. Using RNA-sequencing and CUT&RUN (Cleavage Under Targets & Release Using Nuclease) assays, we identified a set of Wnt target genes responsible for intracellular lipid homeostasis. Notably, active Wnt signaling directly represses the transcription of these genes, resulting in decreased de novo lipogenesis and fatty acid β-oxidation, but increased lipolysis. These changes lead to elevated free fatty acids and reduced triglyceride (TG) accumulation in adipocytes with active Wnt signaling. Conversely, downregulation of Wnt signaling in the fat body promotes TG accumulation in both larval and adult adipocytes. The attenuation of Wnt signaling also increases the expression of specific lipid metabolism-related genes in larval adipocytes, wing discs, and adult intestines. Taken together, these findings suggest that Wnt signaling-induced transcriptional repression plays an important role in regulating lipid homeostasis by enhancing lipolysis while simultaneously suppressing lipogenesis and fatty acid β-oxidation.
Keywords: Drosophila; Wnt/Wg; lipid droplets; lipolysis; transcriptional repression.
Development of primary osteoarthritis during aging in genetically diverse UM-HET3 mice
Sher Bahadur Poudel, Ryan R Ruff, Gozde Yildirim, Richard A Miller, David E Harrison, Randy Strong, Thorsten Kirsch, Shoshana Yakar
Arthritis Res Ther. 2024 Jun 8;26(1):118. doi: 10.1186/s13075-024-03349-y.
Abstract:
Background: Primary osteoarthritis (OA) occurs without identifiable underlying causes such as previous injuries or specific medical conditions. Age is a major contributing factor to OA, and as one ages, various joint tissues undergo gradual change, including degeneration of the articular cartilage, alterations in subchondral bone (SCB) morphology, and inflammation of the synovium.
Methods: We investigated the prevalence of primary OA in aged, genetically diverse UM-HET3 mice. Articular cartilage (AC) integrity and SCB morphology were assessed in 182 knee joints of 22-25 months old mice using the Osteoarthritis Research Society International (OARSI) scoring system and micro-CT, respectively. Additionally, we explored the effects of methylene blue (MB) and mitoquinone (MitoQ), two agents that affect mitochondrial function, on the prevalence and progression of OA during aging.
Results: Aged UM-HET3 mice showed a high prevalence of primary OA in both sexes. Significant positive correlations were found between cumulative AC (cAC) scores and synovitis in both sexes, and osteophyte formation in female mice. Ectopic chondrogenesis did not show significant correlations with cAC scores. Significant direct correlations were found between AC scores and inflammatory markers in chondrocytes, including matrix metalloproteinase-13, inducible nitric oxide synthase, and the NLR family pyrin domain containing-3 inflammasome in both sexes, indicating a link between OA severity and inflammation. Additionally, markers of cell cycle arrest, such as p16 and β-galactosidase, also correlated with AC scores. In male mice, no significant correlations were found between SCB morphology traits and cAC scores, while in female mice, significant correlations were found between cAC scores and tibial SCB plate bone mineral density. Notably, MB and MitoQ treatments influenced the disease’s progression in a sex-specific manner. MB treatment significantly reduced cAC scores at the medial knee joint, while MitoQ treatment reduced cAC scores, but these did not reach significance.
Conclusions: Our study provides comprehensive insights into the prevalence and progression of primary OA in aged UM-HET3 mice, highlighting the sex-specific effects of MB and MitoQ treatments. The correlations between AC scores and various pathological factors underscore the multifaceted nature of OA and its association with inflammation and subchondral bone changes.
Keywords: Antioxidants; Cartilage; Methylene blue; Mitoquinone; Osteoarthritis; Sub-chondral bone; UM-HET3.
Hypothalamic sex-specific metabolic shift by canagliflozin during aging
Hashan S M Jayarathne, Ryan Sullivan, Lukas Stilgenbauer, Lucas K Debarba, Artur Kuchumov, Lisa Koshko, Sydney Scofield, Wanqing Liu, Brett C Ginsburg, Richard A Miller, Marianna Sadagurski
Geroscience. 2024 Oct;46(5):4479-4493. doi: 10.1007/s11357-024-01214-z. Epub 2024 May 27.
Abstract:
The hypothalamus undergoes significant changes with aging and plays crucial roles in age-related metabolic alterations. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are anti-diabetic agents that promote glucose excretion, and metabolic homeostasis. Recent studies have shown that a SGLT2i, Canagliflozin (Cana), can extend the median survival of genetically heterogeneous UM-HET3 male mice and improve central metabolic control via increases in hypothalamic insulin responsiveness in aged males, as well as reduced age-associated hypothalamic inflammation. We studied the long- and short-term effects of Cana on hypothalamic metabolic control in UM-HET3 mice. Starting the treatment from 7 months of age, we show that 4 weeks of Cana treatment significantly reduced body weight and fat mass in male but not female mice that was associated with enhanced glucose tolerance and insulin sensitivity observed by 12 months. Indirect calorimetry showed that Cana treatment increased energy expenditure in male, but not female mice, at 12 months of age. Long-term Cana treatment increased metabolic rates in both sexes, and markedly increasing formation of both orexigenic and anorexigenic projections to the paraventricular nucleus of the hypothalamus (PVH) mostly in females by 25 months. Hypothalamic RNA-sequencing analysis revealed increased sex-specific genes and signaling pathways related to insulin signaling, glycogen catabolic pathway, neuropeptide signaling, and mitochondrial function upregulated by Cana, with males showing a more pronounced and sustained effect on metabolic pathways at both age groups. Overall, our data provide critical evidence for sex-specific mechanisms that are affected by Cana during aging suggesting key targets of hypothalamic Cana-induced neuroprotection for metabolic control.
Keywords: Brain; Canagliflozin; Hypothalamus; Longevity; Metabolism.
Impact of long-term rapamycin treatment on age-related osteoarthritis in common marmoset
Dennis M Minton, Aditya R Ailiani, Michael D K Focht, Mariana E Kersh, Angela J Marolf, Kelly S Santangelo, Adam B Salmon, Adam R Konopka
bioRxiv [Preprint]. 2024 May 17:2024.05.14.594256. doi: 10.1101/2024.05.14.594256.
Abstract:
Objective: Pharmacologic inhibition of the mechanistic target of rapamycin (mTOR) can attenuate experimental osteoarthritis (OA) in young, male preclinical models. However, the potential of mTOR inhibition as a therapeutic mechanism for OA remains unknown. The goal of this study was to determine if mTOR-inhibition by oral rapamycin can modify OA pathology in the common marmoset, a translational model of age-associated OA.
Methods: microCT and histopathologic assessments of the knee were performed on formalin-fixed hindlimbs obtained from common marmosets treated with oral rapamycin (n=24; 1mg/kg/day) or parallel control group (n=41). Rapamycin started at 9.2±3.0 years old and lasted until death (2.1±1.5 years). In a subset of marmosets, contralateral hind limbs were collected to determine mTOR signaling in several joint tissues.
Results: Rapamycin decreased P-RPS6Ser235/36 and increased P-Akt2Ser473 in cartilage, meniscus, and infrapatellar fat pad, suggesting inhibition of mTORC1 but not mTORC2 signaling. Rapamycin-treated marmosets had lower lateral synovium score versus control but there was no difference in the age-related increase in microCT or cartilage OA scores. Subchondral bone thickness and thickness variability were not different with age but were lower in rapamycin-treated geriatric marmosets, which was largely driven by females. Rapamycin also tended to worsen age-related meniscus calcification in female marmosets.
Conclusion: Oral rapamycin attenuated mTORC1 signaling and may have caused feedback activation of mTORC2 signaling in joint tissues. Despite modifying site-specific aspects of synovitis, rapamycin did not modify the age-associated increase in OA in geriatric marmosets. Conversely, rapamycin may have had deleterious effects on meniscus calcification and lateral tibia subchondral bone, primarily in geriatric female marmosets.
Ketogenic diet induces p53-dependent cellular senescence in multiple organs
Sung-Jen Wei, Joseph R Schell, E Sandra Chocron, Mahboubeh Varmazyad, Guogang Xu, Wan Hsi Chen, Gloria M Martinez, Felix F Dong, Prethish Sreenivas, Rolando Trevino Jr, Haiyan Jiang, Yan Du, Afaf Saliba, Wei Qian, Brandon Lorenzana, Alia Nazarullah, Jenny Chang, Kumar Sharma, Erin Munkácsy, Nobuo Horikoshi, David Gius
Sci Adv. 2024 May 17;10(20):eado1463. doi: 10.1126/sciadv.ado1463. Epub 2024 May 17.
Abstract:
A ketogenic diet (KD) is a high-fat, low-carbohydrate diet that leads to the generation of ketones. While KDs improve certain health conditions and are popular for weight loss, detrimental effects have also been reported. Here, we show mice on two different KDs and, at different ages, induce cellular senescence in multiple organs, including the heart and kidney. This effect is mediated through adenosine monophosphate-activated protein kinase (AMPK) and inactivation of mouse double minute 2 (MDM2) by caspase-2, leading to p53 accumulation and p21 induction. This was established using p53 and caspase-2 knockout mice and inhibitors to AMPK, p21, and caspase-2. In addition, senescence-associated secretory phenotype biomarkers were elevated in serum from mice on a KD and in plasma samples from patients on a KD clinical trial. Cellular senescence was eliminated by a senolytic and prevented by an intermittent KD. These results have important clinical implications, suggesting that the effects of a KD are contextual and likely require individual optimization.
Mitochondrial ACSS1-K635 acetylation knock-in mice exhibit altered metabolism, cell senescence, and nonalcoholic fatty liver disease
Guogang Xu, Songhua Quan, Joseph Schell, Yucheng Gao, Mahboubeh Varmazyad, Prethish Sreenivas, Diego Cruz, Haiyan Jiang, Meixia Pan, Xianlin Han, Juan Pablo Palavicini, Peng Zhao, Xiaoli Sun, Erik D Marchant, Blake B Rasmussen, Guannan Li, Sakie Katsumura, Masahiro Morita, Erin Munkácsy, Nobuo Horikoshi, E Sandra Chocron, David Gius
Sci Adv. 2024 May 17;10(20):eadj5942. doi: 10.1126/sciadv.adj5942. Epub 2024 May 17.
Abstract:
Acetyl-CoA synthetase short-chain family member 1 (ACSS1) uses acetate to generate mitochondrial acetyl-CoA and is regulated by deacetylation by sirtuin 3. We generated an ACSS1-acetylation (Ac) mimic mouse, where lysine-635 was mutated to glutamine (K635Q). Male Acss1K635Q/K635Q mice were smaller with higher metabolic rate and blood acetate and decreased liver/serum ATP and lactate levels. After a 48-hour fast, Acss1K635Q/K635Q mice presented hypothermia and liver aberrations, including enlargement, discoloration, lipid droplet accumulation, and microsteatosis, consistent with nonalcoholic fatty liver disease (NAFLD). RNA sequencing analysis suggested dysregulation of fatty acid metabolism, cellular senescence, and hepatic steatosis networks, consistent with NAFLD. Fasted Acss1K635Q/K635Q mouse livers showed increased fatty acid synthase (FASN) and stearoyl-CoA desaturase 1 (SCD1), both associated with NAFLD, and increased carbohydrate response element-binding protein binding to Fasn and Scd1 enhancer regions. Last, liver lipidomics showed elevated ceramide, lysophosphatidylethanolamine, and lysophosphatidylcholine, all associated with NAFLD. Thus, we propose that ACSS1-K635-Ac dysregulation leads to aberrant lipid metabolism, cellular senescence, and NAFLD.
Lifespan effects in male UM-HET3 mice treated with sodium thiosulfate, 16-hydroxyestriol, and late-start canagliflozin
Richard A Miller, David E Harrison, Gino A Cortopassi, Ishmael Dehghan, Elizabeth Fernandez, Michael Garratt, John G Geisler, Brett C Ginsburg, Melissa L Han, Catherine C Kaczorowski, Navasuja Kumar, Scott F Leiser, Marisa Lopez-Cruzan, Ginger Milne, James R Mitchell, James F Nelson, Peter C Reifsnyder, Adam B Salmon, Ron Korstanje, Nadia Rosenthal, Randy Strong
Geroscience. 2024 Oct;46(5):4657-4670. doi: 10.1007/s11357-024-01176-2. Epub 2024 May 16.
Abstract:
Genetically heterogeneous UM-HET3 mice born in 2020 were used to test possible lifespan effects of alpha-ketoglutarate (AKG), 2,4-dinitrophenol (DNP), hydralazine (HYD), nebivolol (NEBI), 16α-hydroxyestriol (OH_Est), and sodium thiosulfate (THIO), and to evaluate the effects of canagliflozin (Cana) when started at 16 months of age. OH_Est produced a 15% increase (p = 0.0001) in median lifespan in males but led to a significant (7%) decline in female lifespan. Cana, started at 16 months, also led to a significant increase (14%, p = 0.004) in males and a significant decline (6%, p = 0.03) in females. Cana given to mice at 6 months led, as in our previous study, to an increase in male lifespan without any change in female lifespan, suggesting that this agent may lead to female-specific late-life harm. We found that blood levels of Cana were approximately 20-fold higher in aged females than in young males, suggesting a possible mechanism for the sex-specific disparities in its effects. NEBI was also found to produce a female-specific decline (4%, p = 0.03) in lifespan. None of the other tested drugs provided a lifespan benefit in either sex. These data bring to 7 the list of ITP-tested drugs that induce at least a 10% lifespan increase in one or both sexes, add a fourth drug with demonstrated mid-life benefits on lifespan, and provide a testable hypothesis that might explain the sexual dimorphism in lifespan effects of the SGLT2 inhibitor Cana.
Keywords: Alpha-ketoglutarate; Lifespan; SGLT2 inhibitor Canagliflozin.