LAUSR

INTRODUCTION Skin is susceptible to senescence-associated secretory phenotype (SASP) and inflamm-ageing partly owing to the degeneration of mitochondria. AdipoRon (AR) has protective effects on mitochondria in metabolic diseases such as diabetes. We explored the role of AR on mitochondria damage induced by skin inflamm-ageing and its underlying mechanism. METHODS Western blot, immunofluorescence and TUNEL staining were used to detect inflammatory factors and apoptosis during skin ageing. Transmission electron microscopy, ATP determination kit, CellLight Mitochondria GFP (Mito-GFP), mitochondrial stress test, MitoSOX and JC-1 staining were used to detect mitochondrial changes. Western blot was applied to explore the underlying mechanism. Flow cytometry, scratch test, Sulforhodamine B assay and wound healing test were used to detect the effects of AR on cell apoptosis, migration and proliferation. RESULTS AR attenuated inflammatory factors and apoptosis that increased in aged skin, and improved mitochondrial morphology and function. This process at least partly depended on the suppression of dynamin-related protein 1 (Drp1)-mediated excessive mitochondrial division. More specifically, AR up-regulated the phosphorylation of Drp1 at Serine 637 by activating AMP-activated protein kinase (AMPK), thereby inhibiting the mitochondrial translocation of Drp1. Moreover, AR reduced mitochondrial fragmentation and the production of superoxide, preserved the membrane potential and permeability of mitochondria and accelerated wound healing in aged skin. CONCLUSION AR rescues the mitochondria in aged skin by suppressing its excessive division mediated by Drp1.