同型半胱氨酸对人脐静脉内皮细胞eNOS表达及NO含量的影响

Effects of homocysteine on the expression of eNOS and the production of NO in the human umbilical veins endothelial cells

目的通过观察同型半胱氨酸(Hcy)对人脐静脉内皮细胞(HUVECs)一氧化氮合酶(eNOS)表达及NO含量的影响,探讨Hcy诱导动脉粥样硬化形成的病理机制。方法将体外培养的人脐静脉内皮细胞分为5组,分别加入Hcy0、2.5、5、10及15 mmol/L,培养24 h。通过MTT比色法测定细胞活力,采用RT-PCR法检测eNOS mRNA的表达,通过硝酸还原酶法测NO含量。结果与对照组比较,Hcy(5～15 mmol/L)剂量处理组细胞活力明显下降(P<0.05,P<0.01),eNOS mRNA的表达显著降低(P<0.01);NO的含量明显下降(P<0.01),eNOS mRNA的表达变化及NO的含量变化呈现明显的剂量依赖性(P<0.01)。结论 Hcy可通过抑制eNOS mRNA的表达,使eNOS合成减少,活性降低,进而减少HUVECs内NO的生成,这可能是Hcy诱导动脉粥样硬化形成的病理机制之一。

Objective To investigate the effects of homocysteine on the expressions of eNOS and the production of NO in the human umbilical veins endothelial cells（HUVECs） and explore the role of homocysteine in the development of atherosclerosis.Methods The HUVECs were randomly divided into 5 groups,and each group was cultured with 0,2.5,5,10,15 mmol/L Hcy for 24 hours.MTT assay was used to detect cell viability.The expression of eNOS mRNA was tested by RT-PCR.The method of nitric acid reductase was used to measure the concentration of nitric oxide.Results After HUVECs were exposed to Hcy at different concentrations（5～15 mmol/L）,the HUVECs were inhibited compared with the control group（P0.05,P0.01） and the expression of eNOS mRNA was reduced significantly in a dose-dependent manner compared with the control group（P0.01）.The production of NO was reduced significantly dose-dependently compared with the control group（P0.01）.Conclusions Hcy can result in the downregulation of eNOS mRNA,reduce the synthesis of eNOS and then decrease eNOS activity.As a result,Hcy could reduce the production of NO in HUVECs.