Obesity-induced leptin resistance is directly involved in skin fragility by decreasing type I collagen synthesis.

The relationship between obesity-induced leptin resistance and skin function remains unclear. In this study, we examined the effects of leptin signaling on collagen production in mouse skin. Mice were divided into three groups: control diet, high-fat diet, and switching diet (from the high-fat diet to the control diet). We measured the expression of leptin signaling-related genes and type I tropocollagen levels in the skin. In an additional experiment, leptin was administered to leptin-deficient ob/ob mice to examine the direct effect of leptin signaling on type I collagen synthesis in the skin. Type I tropocollagen levels and Ob-Rb gene expression were decreased in the high-fat diet group. These abnormalities were reversed by the switching diet. We also observed that type I tropocollagen levels were decreased in ob/ob mice, but this abnormality was reversed by leptin administration. It is likely that leptin will help to improve obesity-induced skin fragility.