Diabetes mellitus is a heterogeneous group of disorders characterized by high serum glucose levels and by disturbances of carbohydrate and lipid metabolism. There are many cutaneous signs of this common endocrinopathy, such as nercobiosis lipoidica diabeticorum, diabetic bullosis, shin spot, diabetic pruritus, etc.

In this study, we investigated whether extracellular matrix gene expression in cultured skin fibroblast is influenced by insulin and Insulin-like growth factor-I(IGF-I).

Total RNA was isolated from insulin or IGF-I treated human skin fibroblasts. The Northern blot and slot-blot hybridization were then conducted.

The mRNA levels of pro α1(I) collagen, pro α1(I11) collagen, fibronectin in insulin and IGF-I treated normal skin fibroblasts increased compared with untreated normal skin fibroblasts.

Our results show that insulin and IGF-I stimulate collagen formation in normal skin fibroblast at physiological concentrations. Therefore, these demonstrate that insulin can modulate the expression of extracellular matrix gene.