Blood donation improves skin aging through the reduction of iron deposits and the increase of TGF-β1 in elderly skin

Skin aging is characterized by a wide range of physiological and structural changes, including wrinkling, dyschromia, and roughness, as well as the reduction of dermal thickness and collagen content. Here, we showed that blood donation increased dermal thickness and collagen content and decreased the number of senescent cells in old mice. Transcriptomic and metabolomic studies revealed blood donation significantly altered aging-related pathways in the skin of old mice. Molecular genes analysis indicated blood donation decreased the expression of genes associated with inflammation such as Fols1, Cox-2, and IL-1β, and increased the expression of collagen-associated genes including TGF-β1, TGF-β2, and Col3a1. The improvement of skin aging by blood donation was associated with the reduction of iron deposits and the increase of TGF-β1 in elderly skin. Our results suggested that appropriate blood donation could promote collagen re-synthesis and improve skin aging.