Hydrogen sulfide (H(2)S) can be endogenously generated from
cystathionine gamma-lyase (CSE) in cardiovascular system, offering a cardiovascular protection. It is also known that the lower risk of
cardiovascular diseases in female is partially attributed to the protective effect of
estrogen. The current study explores the interaction of H(2)S and
estrogen on smooth muscle cell (SMC) growth. In the present study, we found that the proliferation of cultured vascular SMCs isolated from wild-type mice (WT-SMCs) was inhibited, but that from CSE gene knockout mice (CSE-KO-SMCs) increased, by
estrogen treatments. The expression of
estrogen receptor α (ERα), but not ERβ, was significantly decreased in CSE-KO-SMCs compared with that in WT-SMCs. Exogenously applied H(2)S markedly increased ERα but not ERβ expression. In addition, the inhibition of ER activation and knockdown of ERα expression in WT-SMCs or the overexpression of ERα in CSE-KO-SMCs reversed the respective effects of
estrogen on cell proliferation. The expression of
cyclin D1 was reduced in WT-SMCs but increased in CSE-KO-SMCs after
estrogen treatments, which was reversed by knockdown of ERα in WT-SMCs or overexpression of ERα in CSE-KO-SMCs, respectively. The overexpression of
cyclin D1 in WT-SMCs or knockdown of
cyclin D1 expression in CSE-KO-SMCs reversed the effects of
estrogen on cell proliferation. These results suggest that H(2)S mediates
estrogen-inhibited proliferation of SMCs via selective activation of ERα/
cyclin D1 pathways.