The mechanism of butyrate-induced collagen biosynthesis in cultured fibroblasts.

The data showing that butyrate may play an important role in cellular metabolism led us to study its effect on collagen biosynthesis in cultured fibroblasts. Since insulin-like growth factor-I (IGF-I) is the most potent stimulator of collagen biosynthesis in fibroblasts, the effect of butyrate on IGF-I receptor (IGF-IR) expression was evaluated. Confluent human dermal fibroblasts were treated with millimolar concentrations of sodium butyrate (NaB) for 48 hours. It was found that butyrate induced collagen biosynthesis and prolidase activity. It was found that the exposure of the cells to 4 mM butyrate contributed to a distinct increase in IGF-IR. It was accompanied by a parallel increase in the expression of Sos protein and MAP-kinases (ERK1, ERK2). It was found that the MEK inhibitor decreased collagen biosynthesis and expression of MAP-kinases (ERK1, ERK2), while NaB counteracted the process. The data suggests that butyrate-dependent stimulation of collagen biosynthesis in cultured human skin fibroblasts undergoes through IGF-IR signaling.