Exogenous IGF-1 Promotes Hair Growth by Stimulating Cell Proliferation and Downregulating TGF-β1 in C57BL/6 Mice In Vivo

The document describes a study where local injections of Insulin-like growth factor 1 (IGF-1) were administered to male C57BL/6 mice, with ten mice in each experimental group. The study demonstrated that IGF-1 increased the number of hair follicles and extended the anagen phase of the hair cycle. It was observed that IGF-1 stimulated cell proliferation within the hair follicle matrix and downregulated Transforming Growth Factor Beta 1 (TGF-β1), which is known to negatively regulate hair growth. These results indicate that IGF-1 could be a potential treatment for hair loss, as it promotes hair growth by enhancing cell proliferation and inhibiting TGF-β1. The research was funded by the National Natural Science Foundation of China under grant number 31070451.