Aging is characterized by progressive molecular dysregulation across interconnected biological systems, involving alterations in epigenetic regulation, gene expression, protein homeostasis, and metabolic function. Although physical exercise is widely recognized as one of the most effective nonpharmacological interventions to promote healthy aging, the integrative molecular mechanisms underlying its systemic effects remain incompletely understood. This review proposes a multi-omic framework in which exercise acts as a coordinated biological stimulus capable of remodeling age-associated molecular dysfunction across genomic, epigenomic, transcriptomic, proteomic, and metabolomic layers. We discuss evidence showing that exercise modulates DNA methylation patterns associated with inflammation, oxidative stress, and tissue regeneration. Epigenetically, exercise is associated with attenuation of age-associated hypermethylation in promoter regions and modulation of genes involved in oxidative stress defense and tissue regeneration. Transcriptomic studies further show that exercise is associated with more youthful expression patterns while attenuating inflammatory and senescence-related gene programs. Proteomic studies reveal that training is associated with mitochondrial metabolism, extracellular matrix remodeling, and muscle contractile protein abundance, reducing proteostatic dysfunction. Metabolomic analyses demonstrate that exercise improves metabolic flexibility and remodels cellular energy networks. Importantly, the unique contribution of this review lies in synthesizing emerging evidence that these adaptations are highly cell- and tissue-specific, involving immune cells, skeletal muscle satellite cells, endothelial cells, microglia, and intestinal stem cells. Rather than acting through isolated pathways, exercise may induce convergent adaptations across interconnected molecular systems, supporting the concept that healthy aging is dynamically regulated and that age-associated molecular dysfunction retains a degree of biological plasticity.
This systematic review compared genetic evidence of pancreatic steatosis across African and non-African populations to illuminate ancestry-specific mechanisms and precision-prevention opportunities. Following PRISMA guidelines for reporting, a search was conducted across PubMed, Scopus, Web of Science, and NHGRI-EBI GWAS Catalog for studies spanning 2011 to 31st March 2026. Eligible studies included genome-wide association studies (GWAS), polygenic risk score (PRS), and Mendelian randomization (MR) analyses that reported genetic associations with pancreatic fat phenotypes and had explicit ancestry stratification or comparison. Narrative thematic synthesis was performed due to methodological heterogeneity. Six core genetic studies (N > 120,000 participants) were included. The only multi-ethnic GWAS found a strong protective variant of African ancestry, rs73449607 (near PDX1/PLUTO), which reduced pancreatic fat (β = -0.67, P = 4.50 × 10⁻⁸) and explained 14.3% of the variance in African Americans (versus 5.3% overall). UK Biobank race-stratified PRS analyses confirmed the lowest pancreatic fat fraction in Black participants, with the strongest HbA1c PRS-fat association in this group (ρ = 0.23, P < 0.0001). European-dominant GWAS highlighted risk loci, including FUT2 rs601338 (higher fat and chronic pancreatitis risk, OR 1.26). MR studies demonstrated causal links between genetically predicted intra-pancreatic fat deposition (IPFD) and pancreatic ductal adenocarcinoma (PDAC) (OR 2.46 per SD) but not diabetes. African-ancestry genomes confer substantial protection against pancreatic steatosis, whereas non-African genomes are enriched for risk alleles that amplify the non-alcoholic fatty pancreas disease (NAFPD)-to-PDAC cascade. These ancestry-differentiated mechanisms position NAFPD as a precision medicine target.
EspP is a potent serine protease that functions as a cytotoxin and is secreted by enterohemorrhagic Escherichia coli (EHEC). This bacterial toxin can cause significant colonic epithelial damage and mimic the pathophysiology of EHEC infection on human colonic organoids. However, transcriptomic changes within the intestinal epithelial cells and impacts on cell proliferation and differentiation are largely unknown. Here, using human colonic organoids, we defined the molecular and cellular changes that occur in response to acute EspP exposure, independent of microbiota, stroma, and immune cells. We performed droplet-based single cell RNA-sequencing to determine changes in epithelial cell lineages in response to EspP and demonstrated that there is a disruption in proliferation and a preferential differentiation of enteroendocrine cells (EECs). Higher resolution clustering revealed that the de novo EECs were primarily enterochromaffin or EEC progenitors. Interestingly, EECs induced from EspP treatment displayed an immune profile, expressing cytokines and chemokines associated with macrophage or neutrophil recruitment. These findings demonstrate that EspP, a potent EHEC cytotoxin, stimulates transcriptomic changes previously attributed to the whole bug infection and highlights the significance of crypts-based proliferative cells and secretory cell differentiation as major colonic responses to bacterial pathogens.
Non-additive interactions between environmental stressors, where biological responses to simultaneous stressors do not equal the sum of individual-stressor responses, commonly occur across organisms and environments. To enable predictions of organismal resilience to shifting patterns of environmental stressors, it is important to both identify these interactions and document the mechanisms underlying them. The supratidal copepod Tigriopus californicus demonstrates a non-additive, antagonistic pattern of increased heat tolerance when simultaneously exposed to high salinities. We investigated salinity's chronic and acute effects on heat tolerance in a northern population and quantified responses in protein abundance to hypersalinity and heat stress, both alone and in combination. The overall proteomic response to multiple stressors was non-additive and largely reflected that to high temperature. However, 42% of multi-stressor proteins were absent from either single-stressor response; we refer to these proteins that are only differentially abundant in the multi-stressor scenario as "emergent". Our results suggest that the increased heat tolerance of T. californicus conferred by hypersalinity may be driven by a combination of these emergent proteins, several proteins induced by hypersalinity in both single- and multi-stressor conditions that may contribute to cross-tolerance, and four proteins with additive abundance patterns (including a small heat shock protein). These candidate proteins play putative roles in several relevant processes including the heat shock response, protein folding, and regulation of metabolism and oxidative stress responses. Our results connect to prior whole-organism findings and highlight promising pathways for future investigation in the context of heat tolerance and multi-stressor interactions.
