Effects of 17β-estradiol on matrix metalloproteinase-1 synthesis by human dermal fibroblasts

BackgroundHormone replacement therapy (HRT) has been used in treatment of various menopausal disorders. It has been well documented that HRT increases the amount of dermal collagen and skin thickness in vivo. However little is known about the effects of female sex hormones on dermal fibroblasts in vitro.ObjectiveThe aim of this study is to determine whether or not 17β-estradiol affects mRNA expression and production of type I collagen, matrix metalloproteinases-1 (MMP-1), tissue inhibitor metalloproteinases-1 (TIMP-1) or transforming growth factor-β1 (TGF-β1) by human dermal fibroblasts.MethodsFibroblasts were cultured with and without 17β-estradiol for 6 h. We evaluated the changes of mRNA expressions and protein production of type I collagen, MMP-1, TIMP-1 and TGF-β1.ResultsThe mRNA expressions of collagen α1(I), MMP-1, TIMP-1, TGF-β1 were not changed by 17β-estradiol stimulations at a concentration of 10−12 to 10−8 M. However, 17β-estradiol at concentrations of 10−12 and 10−10 M exhibited inhibitory effects on proMMP-1, but not type I collagen or TIMP-1 synthesis. The synthesis of TGF-β1 by fibroblasts stimulated with 10−8 M of estradiol was significantly increased as compared with the control. However, the level of TGF-β type II receptor phosphorylation was not elevated under the same conditions.ConclusionSuppressed synthesis of MMP-1 at a low concentration of 17β-estradiol may be partly involved in the dermal tissue remodeling to inhibit the degradative change.