同型半胱氨酸对血管钙化的促进作用

Studies on homocysteine and cardiovascular ectopic calcification

目的 在体外血管钙化模型基础上探讨同型半胱氨酸 (HCY)对血管钙化的影响。方法建立牛主动脉平滑肌细胞体外钙化模型 (钙化BASMCs) ,检测HCY对细胞层钙含量、培养上清骨钙素浓度及碱性磷酸酶活性的影响 ,并检测骨钙素、骨桥蛋白及Ⅰ型胶原 (ColⅠ )mRNA表达的变化及抗氧化剂N 乙酰半胱氨酸对HCY促钙化作用的影响。结果 HCY剂量依赖性促钙化BASMCs钙沉积 ,但不促进非钙化的BASMCs钙沉积 ;N 乙酰半胱氨酸抑制HCY对钙化BASMCs钙沉积的促进作用 ,但在钙化BASMCs中单纯加入等剂量的N 乙酰半胱氨酸对钙沉积无影响 ;HCY促钙化BASMCs培养上清骨钙素含量增加 ,且使骨桥蛋白、骨钙素、ColⅠmRNA表达分别增加 56 33 %、86 48%及 1 1 0 64 % ,但对正常培养的BASMCs培养上清骨钙素含量及骨桥蛋白、骨钙素mRNA表达无影响 ,仅使ColⅠmRNA表达增加 1 0 8 33 % ;HCY不影响正常及钙化BASMCs碱性磷酸酶活性。结论 (1 )HCY是钙化的促进因子 ,而非启动因子 ;(2 )HCY的促钙化作用可能部分是通过细胞外基质途径实现的 ;(3)N 乙酰半胱氨酸阻断HCY的促钙化作用 ,间接提示氧化反应参与此过程 ;(4)

Objective To explore internal relation between homocysteine(HCY) and cardiovascular ectopic calcification in vitro. Methods A model of vascular calcification was established in vitro: calcium deposition in the cellular layer, osteocalcin (OC) in cultured supernatant and ALP activity were analyzed, the expression of osteopontin (OP)?OC?collagenⅠ(ColⅠ) mRNA and the effect of NAC on calcium deposition in the cellular layer were detected when HCY was used in calcified BASMCs Results HCY increased calcium deposition of calcified BASMCs in a dose dependent manner and had no effects on that of BASMCs;NAC inhibited the effects of HCY on calcified BASMCs and had no effects on that of calcified BASMCs;OC in cultured supernatant by HCY increased and the expression of OP?OC?ColⅠmRNA of calcified BASMCs increased by 56 33%?86 48% and 110 64%, but no effects of HCY on OC in cultured supernatant and the expression of OP?OC mRNA of BASMCs were found HCY increased ColⅠmRNA of BASMCs by 108 33%;but had no effects on ALP activity of BASMCs and calcified BASMCs Conclusions (1) HCY improved calcium deposition in the cellular layer and the expression of OP?OC?ColⅠmRNA of calcified BASMCs, it may be a promoting factor for calcification, but not an initialing factor; (2) The effects of HCY on calcified BASMCs maybe partially achieved by pathway of extracellular matrix; (3) NAC inhibited the effects of HCY on calcified BASMCs which suggested the probability of oxidative response involved; (4) The effects of HCY on calcified BASMCs maybe not associated with ALP activity