Biological Pathways

Endothelial nitric oxide — vasodilation, blood pressure, cardiovascular health

Programmed cell death — dysregulation drives both cancer and age-related tissue loss

Tissue regeneration capacity — stem cell exhaustion is a hallmark of aging

Permanent cell cycle arrest — senescent cells accumulate with age, drive inflammaging via SASP

ROS management and antioxidant defense — Nrf2/ARE pathway central to cellular resilience

Intracellular calcium homeostasis — muscle contraction, neuronal function, apoptosis trigger

Biological clock regulation — disruption accelerates aging, affects metabolism and DNA repair

Formation of new mitochondria — driven by PGC-1α, AMPK, sirtuins; declines with aging

AMP-activated protein kinase — master energy sensor, activates catabolic pathways, inhibits mTOR

Genome integrity maintenance — DNA damage accumulates with age, drives mutation and senescence

Telomere length and telomerase activity — biomarker of cellular aging

PI3K-AKT-FOXO axis — reduced signaling associated with longevity in model organisms

Mechanistic target of rapamycin — nutrient/growth sensor, inhibition extends lifespan in multiple organisms

Hypothalamic-pituitary-adrenal axis — chronic stress accelerates aging via cortisol

Sex hormones, cortisol, thyroid — hormonal decline drives multiple aging phenotypes

Chronic low-grade inflammation associated with aging — NF-κB central mediator

Adaptive and innate immunity — immunosenescence drives aging vulnerability

Intestinal microbiota composition — impacts inflammation, metabolism, longevity signals

Blood glucose regulation and glycolytic flux — central to metabolic longevity

Cholesterol, triglyceride, and fatty acid homeostasis — cardiovascular risk and metabolic health

DNA methylation, histone modification — epigenetic clocks correlate with biological age

Nicotinamide adenine dinucleotide biosynthesis and salvage — declines with age, supports sirtuins and DNA repair

NAD+-dependent deacetylases (SIRT1-7) — regulate gene expression, DNA repair, mitochondrial biogenesis

Monoamine neurotransmitters — mood, motivation, reward; decline with aging

BDNF, NGF, neuroplasticity — neuroprotection and cognitive longevity

Protein homeostasis — chaperone-mediated folding, ubiquitin-proteasome degradation

Cellular self-cleaning — removal of damaged organelles and proteins, declines with age

Extracellular matrix integrity — collagen cross-linking, skin aging, tissue structure