Activin: A novel player in tissue repair processes

Recent studies have demonstrated a strong expression of activin in repair p rocesses of various tissues arid organs, including the skin, the lung, the intestine, the cardiovascular system, and even the brain. Although little i s as yet known about the function of activin in tissue repair, first result s suggest a role of activin in epithelial differentiation, fibroblast proli feration and expression of matrix molecules by these cells, and also in neu roprotection. Whereas a transient overexpression of activin after tissue in jury might be beneficial for the repair process, sustained expression of ac tivin could lead to fibrotic processes. Therefore, the modulation of the av ailability or biological activity of activin could be of particular importa nce for the treatment of impaired tissue repair on the one hand and tissue fibrosis on the other hand.