Project description:Bats have attracted considerable interest for their extraordinary longevity and ability to withstand infection by a range of pathogens without major harm. Yet, little is known about the relationship between these two characteristics, or the extent to which they vary between individuals of the same species. We investigated sources of immune variation in wild greater spear-nosed bats, Phyllostomus hastatus, via transcriptome sequencing of blood samples before and after ex vivo exposure to lipopolysaccharide, a membrane component of gram-negative bacteria. We estimated bat ages from a combination of banding records and a methylation clock. We assessed immune variation across both sexes, males of contrasting social status, and the full range of ages in each sex. We observe striking immune variation associated with sex and age, with males and older bats mounting stronger inflammatory responses. These two factors interacted significantly, revealing male-biased slopes of age-related variation in immunity, the magnitude of which is consistent with male-biased ageing, supporting the predicted association between immunity and ageing.
Project description:We aim to improve anti-ageing drug discovery, currently achieved through laborious and lengthy longevity analysis. Recent studies demonstrated that the most accurate molecular method to measure human age is based on CpG methylation profiles, as exemplified by several epigenetics clocks that can accurately predict an individual’s age. Here, we developed CellAge, a new epigenetic clock that measures subtle ageing changes in primary human cells in vitro. As such it provides a unique tool to measure effects of relatively short pharmacological treatments on ageing. We validated our CellAge clock against known longevity drugs such as rapamycin and trametinib. Moreover, we uncovered novel anti-ageing drugs, torin2 and Dactolisib (BEZ-235), demonstrating the value of our approach as a screening and discovery platform for anti-ageing strategies. CellAge outperforms other epigenetic clocks in measuring subtle ageing changes in primary human cells in culture. The tested drug treatments reduced senescence and other ageing markers, further consolidating our approach as a screening platform. Finally, we showed that the novel anti-ageing drugs we uncovered in vitro, indeed increased longevity in vivo. Our method expands the scope of CpG methylation profiling from measuring human chronological and biological age from human samples in years, to accurately and rapidly detecting anti-ageing potential of drugs using human cells in vitro, providing a novel accelerated discovery platform to test sought after geroprotectors.
Project description:The aim of the study is to identify genetic mechanisms of longevity and to characterize their interaction with the environment. Using the results the future health of people without familial longevity can be improved in old age. Long-lived siblings of European descent were recruited together with their offspring and the partners of the offspring. Families were recruited if at least two long-lived siblings were alive and fulfilled the age criterion of 89 years or older for males and 91 years or older for females, representing less than 0.5% of the Dutch population in 2001.
Project description:Neurons are central to lifelong learning and memory, but ageing disrupts their morphology and function, leading to cognitive decline. Although epigenetic mechanisms are known to play crucial roles in learning and memory, neuron-specific genome-wide epigenetic maps into old age remain scarce, often being limited to whole-brain homogenates and confounded by glial cells. Here, we mapped H3K4me3, H3K27ac, and H3K27me3 in mouse neurons across their lifespan. This revealed stable H3K4me3 and global losses of H3K27ac and H3K27me3 into old age. We observed patterns of synaptic function gene deactivation, regulated through the loss of the active mark H3K27ac, but not H3K4me3. Alongside this, embryonic development loci lost repressive H3K27me3 in old age. This suggests a loss of a highly refined neuronal cellular identity linked to global chromatin reconfigu-ration. Collectively, these findings indicate a key role for epigenetic regulation in neurons that is inextricably linked with ageing.
Project description:Finding the critical pathophysiological processes that promote disease risk with age is needed to uncover effective targets for preventive medicine. Despite being essential for physiology at all levels, the behaviour of protons in bodily fluids is understudied in ageing. Here, we investigate how extracellular pH changes with age and its impact on longevity, using Drosophila melanogaster and rodent models. Extracellular acidification occurs in flies during ageing and correlates with mortality rate, independently of strain, sex and diet. With age, flies also become more susceptible to die from acidotic stress, which can be prevented by alkalotic treatment. Acidification is caused by insufficient acid excretion, linked to downregulation of genes in the fly excretory tract that control pH and ATP production, essential for active secretion initiation. In rodents, we demonstrate that lymph also acidifies with age. Genes whose pathogenic variants cause tubular acidosis in humans are downregulated in the kidneys of ageing mice. Overall, this study sheds light on dysregulated systemic acid-base balance as a conserved pathophysiological mechanism of ageing.
Project description:The nutrient-sensing Target of Rapamycin complex 1 (TORC1) is an evolutionarily conserved regulator of longevity. S6 kinase (S6K) is an essential downstream mediator for the effect of TORC1 on longevity. However, mechanistic insights on how TORC1-S6K signalling promotes lifespan and healthspan are still limited. Here we show that activity of S6K in the Drosophila fat body is essential for rapamycin-mediated longevity. Fat-body-specific activation of S6K blocked lifespan extension upon rapamycin feeding and induced accumulation of multilamellar lysosomal enlargements. Besides, fat body-specific S6K knockdown extended lifespan in files. We performed proteomics for Drosophila fat body to explore the fat body-specific regulation of protein expression by two separate datasets: fat body-specific S6K activation (Lsp2GS>S6KCA) with rapamycin treatment; and fat body-specific S6K inhibition (Lsp2GS>S6KRNAi). To assess if the age-prolonging mechanisms of TORC1-S6K signalling are conserved between flies and mammals, we assessed the impact of rapamycin treatment in the proteome of liver from C3B6F1 mice (F1 hybrids of C3H/HeOuJ females and C57Bl/6N males).
Project description:Modulation of histone levels is commonly seen during ageing in many species. However, any role for histone levels in longevity of multicellular organisms remains undiscovered. Here we show that inhibition of mTORC1 by rapamycin post-transcriptionally increases expression of histone proteins H3 and H4 in Drosophila intestine. Expression of H3/H4 in enterocytes alters chromatin organization, induces intestinal autophagy through transcriptional regulation, and prevents age-related structural and functional decline in the intestine. Increased H3/H4 expression in enterocytes is essential for rapamycin-dependent longevity and intestinal health. Histones H3/H4 regulate expression of a selective autophagy cargo adaptor Bchs (ALFY in mammals), increased expression of which in enterocytes is necessary and sufficient for increased H3/H4-dependent healthy longevity. In mice, rapamycin treatment increases expression of histone proteins and ALFY transcript, and alters chromatin organisation in small intestine, suggesting the mTORC1-histone axis is at least partially conserved in mammals and may offer new targets for anti-ageing interventions.
Project description:Mitochondrial complex I, the largest enzyme complex of the mitochondrial oxidative phosphorylation machinery, has been proposed to contribute to variety of age-related pathological alterations as well as longevity. The enzyme complex-consisting proteins are encoded by both nuclear- (nDNA) and mitochondrial DNA (mtDNA). While some association studies of mtDNA-encoded complex I genes and lifespan in humans have been reported, experimental evidence and functional consequence of such variants are limited to studies using invertebrate models. Here, we present experimental evidence that a homoplasmic mutation in mitochondrially encoded complex I gene, mt-Nd2, modulates lifespan by altering cellular tryptophan levels and consequently ageing-related pathways in mice. A conplastic mouse strain carrying a mutation at m.4738C>A in mt-Nd2 lived significantly shorter than the controls. The same mutation led to higher susceptibility to glucose intolerance induced by high fat diet feeding. These phenotypes were not observed in mice carrying a mutation in another mtDNA-encoded complex I gene, mt-Nd5, suggesting functional relevance of particular mutations in complex I to ageing and age-related diseases.