Circulating factors induced by time-restricted eating drive metabolic reprogramming in endothelial cells

Age-related endothelial dysfunction in the cerebral microcirculation contributes significantly to the pathogenesis of vascular cognitive impairment and dementia (VCID). Time-restricted eating (TRE) has emerged as a promising lifestyle intervention with beneficial effects on metabolic and vascular health; however, the mechanisms by which TRE influences the brain microvasculature remain incompletely understood. In particular, the role of circulating factors induced by TRE in modulating endothelial function has not been systematically investigated. Here, we tested the hypothesis that circulating factors derived from humans practicing time-restricted eating (TRE) induce protective and adaptive responses in human cerebromicrovascular endothelial cells. Using a serum transfer bioassay, endothelial cells were treated with serum obtained from aged individuals with or without TRE, followed by transcriptomic profiling. We demonstrate that TRE-associated serum elicits a robust and coordinated transcriptional reprogramming in human cerebromicrovascular endothelial cells, characterized by activation of stress-responsive and metabolic pathways and suppression of anabolic programs. Gene set enrichment analysis revealed significant activation of the integrated stress response (ISR)/ATF4 axis and suppression of mTORC1 signaling, consistent with a shift toward a catabolic, stress-adaptive state. These changes were accompanied by marked induction of the stress-responsive cytokine GDF15. At the mitochondrial level, TRE serum promoted increased expression of mitochondrial DNA-encoded oxidative phosphorylation components without activation of canonical mitochondrial biogenesis pathways, suggesting functional remodeling. Upstream regulator analysis identified coordinated activation of stress- and metabolism-associated transcription factors, including ATF4, FOXO, and KLF family members, alongside inhibition of anabolic regulators such as SREBF1/2. Notably, canonical endothelial functional programs, including autophagy and blood-brain barrier maintenance, were not coordinately activated. While individual angiogenesis-related genes were modestly upregulated, these changes did not translate into a coordinated pathway-level response. Collectively, these findings demonstrate that circulating factors induced by TRE promote a distinct endothelial phenotype characterized by metabolic reprogramming and stress adaptation rather than classical inflammatory or reparative responses. This work provides new mechanistic insight into how lifestyle interventions may influence cerebrovascular aging and identifies circulating factors as key mediators linking systemic metabolic state to endothelial function.