Effect of Vitamin C, Silicon and Iron on Collagen Synthesis and Break-Down Enzyme Expression in the Human Dermal Fibroblast Cell (HS27)

Collagen is the major matrix protein in dermis and consists of proline and lysine, which are hydroxylated by prolyl hydroxylase (PH) and lysyl hydroxylase (LH) with cofactors such as vitamin C, oxygen, iron (Fe2+), ketoglutarate and silicon. The collagen degradation is regulated by matrix metalloproteinase-1 (MMP-1), of which is the major collagen-degrading proteinase whereas tissue inhibitors of metalloproteinase-1 (TIMP-1) bind to MMP-1 thereby inhibiting MMP-1 activity. In this study, we investigated the effects of vitamin C, silicon and iron on mRNA, protein expressions of PH, LH, MMP-1 and TIMP-1. The physiological concentrations of vitamin C (0-100 micrometer), silicon (0-50 micrometer) and iron (Fe2+:0-50 micrometer) were treated to human dermal fibroblast cells (HS27 cells) for 3 or 5days. The expression level of mRNA and protein was increased in not only PH but also LH when cells were incubated with vitamin C. A similar increase in LH mRNA or protein expression occurred when cells were incubated with silicon. Our results suggest that treatment of vitamin C and silicon increased mRNA and protein expression of PH and LH in human dermal fibroblast.

The Effect of Minoxidil on Cultured Mouse Fibroblast

Proliferative vitreoretinopathy is characterized by proliferation of retinal pigment epithelial cells, fibroblasts, glial cells and excessive fibrous tissue production. Recently minoxidil has been found to inhibit the proliferation of cultured fibroblast and retinal pigment epithelium. Minoxidil also inhibits the mRNA expression and protein production of lysyl hydroxylase, a key-enzyme involved in cross-linking of collagen. Therefore, the author investigated the effects of minoxidil on cultured mouse fibroblast and the result was compared with those of 5-fluorouracil and dexamethasone. Dexamethasone demonstrated bimodal effect of stimulation of proliferation at low concentrations and inhibition at higher concentrations. Fifty percent inhibition of growth (ID50) was seen at a concentration of 316mg/L. 5-fluorouracil had the most potent antiproliferative activity with ID50 of 0.8mg/L. Minoxidil had more potent antiproliferative properties on cultured mouse fibroblasts than dexamethasone. Fifty percent inhibition of growth (ID50) was 200mg/L. Reduction in cell number was seen after a 30 minute treatment and was half-maximal after 48 hours of treatment with 1000mg/L minoxidil.