The MIRACLE study aims to investigate age-related mitochondrial dysfunction, mitochondrial RNA (mtRNA) release, inflammation, and cellular senescence in adult participants across three age groups. Skin-derived fibroblasts and peripheral blood mononuclear cells (PBMCs) will be isolated from skin biopsy and blood samples to characterize age-related cellular and molecular changes and to test experimental therapeutic strategies identified in preclinical studies. Serum, plasma, and whole-blood RNA will be used for protocol-defined analyses of circulating inflammatory mediators and systemic transcriptional signatures related to inflammation, type I interferon activation, mitochondrial stress response, immune aging, and senescence-associated pathways.