Longevity Papers

This study reveals that acute aerobic exercise enhances memory formation through a controlled DNA damage mechanism, offering crucial insights into Alzheimer\'s disease (AD) prevention. This work challenges the traditional view that DNA damage is inherently harmful, demonstrating that minor, reversible DNA single-strand breaks (SSBs) induced by exercise serve as necessary primers for memory consolidation - a mechanism that may be impaired in AD pathogenesis. AD affects 1 in 9 adults over 65, with ~95% being late-onset cases where up to 40% of risk factors are modifiable through lifestyle interventions like exercise. While exercise demonstrably lowers AD risk, underlying mechanisms remain unclear. This study provides a missing mechanistic link by showing how exercise-induced DNA damage repair systems could counteract the DNA damage accumulation and repair dysregulation that are established hallmarks of brain aging and AD. In data presented herein, young mice showed significantly higher SSB rates in active genomic regions compared to aged mice, suggesting the decline of a protective mechanism (i.e., hormesis) with aging - potentially explaining increased AD susceptibility in older adults. The present study also suggests that exercise-induced SSBs are not random cellular damage but precisely targeted events that occur at genes essential for neuroplasticity, synaptic function, and memory formation. These breaks activate PARP1 (Poly ADP ribose polymerase 1), a crucial DNA damage sensor that simultaneously initiates repair processes while facilitating transcriptional programs necessary for memory consolidation. This mechanism may represent how exercise \"primes\" the brain against the pathological DNA damage accumulation seen in AD. In support of this, in behavioral experiments, a single exercise bout converted sub-threshold learning into robust long-term memory formation. This memory enhancement correlated with upregulation of both neurotrophic genes (BDNF, Fos) and DNA repair enzymes (PARP1, PARP2), demonstrating coordinated damage-repair processes that appear compromised in AD. We identify HPF1 as a critical cofactor enabling PARP1 to perform trans-ADP-ribosylation of histones, linking DNA damage sensing to epigenetic chromatin remodeling required for memory-related gene expression. This pathway represents a novel therapeutic target for AD, as restoring efficient DNA repair mechanisms might slow or prevent memory loss.

Microbial genetic variation plays a crucial role in shaping host-microbe interactions; however, its impact on healthy aging remains largely unexplored. This study investigates how genetic variations in gut-residing Saccharomyces cerevisiae affect the health and lifespan of Drosophila melanogaster. This study identifies 14 yeast mutants that significantly extended the lifespan of D. melanogaster, with 13 mutants enhancing locomotor function in aged flies and two mutants improving reproductive capacity. Metabolomic and proteomic analyses reveal that these mutant yeasts rejuvenate the metabolic state of the aging gut and alter protein levels in tissues outside the gut. Most of the proteins with at least a two-fold change are upregulated. The data also highlights mitochondrial energy metabolism as a key anti-aging mechanism driven by the yeast. Notably, terpenoid metabolites such as ergosterol acetate showed strong lifespan-extending effects and may influence energy metabolism. In conclusion, these findings establish a strong link between gut metabolic status and healthy aging, underscoring the significance of the microbial-host mitochondrial axis as a key mechanism by which gut microbes promote host health and longevity. Furthermore, genetically engineered probiotics in model organisms offer a promising potential strategy for extending healthy lifespan, thus meriting further investigation in translational research models.

Small molecular food components contribute to the health benefits of diets rich in fruits, vegetables, herbs and spices. The cellular mechanisms by which noncaloric bioactives promote healthspan are not well understood, limiting their use in disease prevention. Here, we deploy a whole-organism, high-content screen in zebrafish to profile food-derived compounds for activation of autophagy, a cellular quality control mechanism that promotes healthy aging. We identify thymol and carvacrol as activators of autophagy and mitophagy through a transient dampening of the mitochondrial membrane potential. Chemical stabilization of thymol-induced mitochondrial depolarization blocks mitophagy activation, suggesting a mechanism originating from the mitochondrial membrane. Supplementation with thymol prevents excess liver fat accumulation in a mouse model of diet-induced obesity, improves pink-1-dependent heat stress resilience in Caenorhabditis elegans, and slows the decline of skeletal muscle performance while delaying epigenetic aging in SAMP8 mice. Thus, terpenoids from common herbs promote autophagy during aging and metabolic overload, making them attractive molecules for nutrition-based healthspan promotion.

Ubiquitin is a conserved modifier regulating the stability and function of numerous target proteins. In all eukaryotes, polyubiquitin precursors are generated and processed into ubiquitin monomers. The final ubiquitin unit always contains a C-terminal extension, but its physiological significance is unknown. Here, we show that C-terminally extended ubiquitin, termed CxUb, is essential for stress resistance, mitophagy, and longevity in Saccharomyces cerevisiae and Caenorhabditis elegans. CxUb forms ubiquitin chains and binds to a previously undescribed region within the ubiquitin chain-elongating E4 enzyme Ufd2, which also functions during stress and aging. Ufd2 recognizes CxUb and conjugates it to substrate proteins, triggering their degradation. By contrast, CxUb is not required for basal housekeeping functions of the ubiquitin-proteasome system. These data suggest that the CxUb encodes a functionally unique ubiquitin form, specialized for proteostasis defects, expanding the code of post-translational modification processes.

Mammalian maximum lifespan (MLS) varies over a hundred-fold, yet the molecular mechanisms underlying this diversity remain unclear. We present a cross-species analysis of alternative splicing (AS) across six tissues in 26 mammals, identifying hundreds of conserved AS events significantly associated with MLS, with the brain containing twice as many tissue-specific events as peripheral tissues. MLS-AS events are enriched in pathways related to mRNA processing, stress response, neuronal functions, and epigenetic regulation, and are largely distinct from genes whose expression correlates with MLS, indicating that AS captures unique lifespan-related signals. The brain exhibits certain associations divergent from peripheral tissues and reduced overlap with body mass (BM)-associated splicing; neither is observed at the gene expression level. While MLS- and age-associated AS events show limited overlap, the shared events are enriched in intrinsically disordered protein regions, suggesting a role in protein flexibility and stress adaptability. Furthermore, MLS-associated AS events display stronger RNA-binding protein (RBP) motif coordination than age-associated ones, highlighting a more genetically programmed adaptation for lifespan determination, in contrast to the more variable splicing changes seen with chronological aging. These findings suggest alternative splicing as a distinct, transcription-independent axis of lifespan regulation, offering new insights into the molecular basis of longevity.

The molecular correlates of Alzheimer\'s disease (AD) are increasingly being defined by omics. Yet, the findings from different data types or cohorts are often difficult to reconcile. Collecting multiple omics from the same individuals allows a comprehensive view of disease-related molecular mechanisms, while addressing conflicting findings derived from single omics. Such same-sample multi-omics can reveal, for instance, when changes observed in the transcriptome share distinct but coordinated signals in epigenetics and proteomics, relationships otherwise unclear. Here, we apply a data-driven multi-omic framework to integrate epigenomic, transcriptomic, proteomic, metabolomic, and cell-type-specific population data from up to 1,358 aged human brain samples from the Religious Orders Study (ROS) and Rush Memory and Aging Project (MAP). We demonstrate the existence of sprawling cross-omics cross-system biological factors that also relate to AD phenotypes. The strongest AD-associated factor (factor 8) involved elevated immune activity at the epigenetic level, decreased expression of heat shock genes in the transcriptome, and disrupted energy metabolism and cytoskeletal dynamics in the proteome. We also showed immune-related factors (factors 2 and 3) with discordant enrichments, reflecting reactive-like glial subpopulations and protective contributions from surveillance microglia. Both were negatively associated with AD pathology, suggesting potential immune resilience mechanisms. Finally, unsupervised clustering of participants revealed eleven molecular subtypes of the aging brain, including three clusters strongly associated with AD but displaying distinct molecular signatures and phenotypic characteristics. Our findings provide a comprehensive map of molecular mechanisms underlying AD heterogeneity, highlighting the complex role of neuroinflammatory processes, and yielding potential novel biomarkers and therapeutic targets for precision medicine approaches to AD treatment.

Microglia are essential regulators of myelin integrity and repair, yet their regenerative capacity declines with ageing and in neurodegenerative diseases such as multiple sclerosis (MS). Neonatal microglia retain a uniquely reparative program that may offer insight into restoring lost functions in the adult CNS. Here we show that transplantation of neonatal microglia ameliorates disability, reduces leukocyte infiltration, and promotes remyelination in both inflammatory (EAE) and non-inflammatory (cuprizone) models, and reverses cognitive decline in aged mice. These benefits persisted even when transplanted cells remained confined to the meninges and were reproduced by the neonatal microglia secretome, indicating a paracrine mechanism. Multi-omic profiling revealed that the neonatal secretome is enriched in trophic factors and membrane-building lipids compared to adult microglia, while transcriptomic analyses of treated aged brains showed reactivation of developmental repair pathways and suppression of inflammatory signatures. Together, these results demonstrate that neonatal microglia re-engage rejuvenation-like programs in the adult CNS and highlight the importance of multifactorial strategies, integrating trophic, metabolic, and immunomodulatory cues, over single-target approaches. Our findings establish early microglial programs as a paradigm for designing new regenerative therapies for CNS disorders.