Glucose-depleted medium reduces the collagen content of human skin fibroblast cultures

Abstract

Glucose deprivation appeared to be a factor which induces oxygen regulated protein (ORP) 150 expression in the human skin fibroblasts cultures. Whereas glucose deprivation resulted in a slight (statistically insignificant) decrease of protein content in these cultures, a marked decrease of collagen content was observed, resulting in a distinct reduction of hydroxyproline: protein ratio. Furthermore, the appearance of ORP150 in glucose-deprived cultures coexisted with an increase of gelatinolytic activity and slight reduction in the expression of insulin-like growth factor-I (IGF-I) receptor. Since IGF-I is a main stimulator of collagen synthesis, the reduction in the expression of IGF-I receptor may result in a decrease of collagen synthesis. It is suggested that ORP 150 is a chaperon, which protects intracellular proteins against proteolytic effects exerted by hypoxia or glucose shortage. Since the total amount of protein in fibroblast cultures did not change much, it appears that collagen (in contrast to other proteins) was not efficiently protected. The decrease in collagen synthesis and the enhancement of collagen degradation by gelatinases may result in distinct reduction of collagen content in glucose-deprived fibroblast cultures.