色素上皮衍生因子对缺氧/复氧血管平滑肌细胞增殖及凋亡的影响

目的:观察重组人源性色素上皮衍生因子（Pigment epithelium-derived factor，PEDF）对缺氧/复氧(H/R)后平滑肌细胞（vascular smooth muscle cells，VSMCs）增殖和凋亡的影响。方法:以组织贴块法培养VSMCs后，随机分为3组，即对照组、H/R模型组及模型+PEDF组。模型+PEDF组又按PEDF的浓度(50、100、200及400 ng/ml)分为4组。用MTT比色法检测VSMCs增殖的变化；用Hoechst/PI双染色法和流式细胞仪法(FCM)检测VSMCs的凋亡；用Western blot法测定凋亡相关蛋白Bcl-2、Bax的表达。结果:①MTT比色法检测显示，缺氧、复氧可促进VSMCs增殖；PEDF能够抑制VSMCs增殖，以200 ng/ml的PEDF作用更显著。Hoechst/PI双染色法和FCM检测显示，经100、200 ng/ml的PEDF作用后，VSMCs的凋亡率较对照组和H/R组明显增高(P<0.01)。与对照组和H/R组比较，Western blot检测显示，100、200 ng/ml的PEDF能够下调Bcl-2蛋白表达并上调Bax蛋白表达(P<0.05，P<0.01)。结论:H/R后，VSMCs增殖增多，PEDF可抑制H/R后VSMCs增殖，其作用可能与Bcl-2、Bax通路促进VSMCs凋亡有关。

Effects of pigment epithelium-derived factor on proliferation and apoptosis of vascular smooth muscle cells after hypoxia/reoxygen

AIM: To explore the protective effect of recombinant human pigment epithelium-derived factor(PEDF) on vascular smooth muscle cell(VSMC) proliferation and apoptosis after hypoxia/reoxygen(H/R).METHODS: VSMCs were primarily cultured by tissue-sticking method and were randomly divided into control group,H/R model group and model+PEDF group.According to the concentration of PEDF,the model+PEDF group was subdivided into 50-,100-,200-and 400-ng/ml groups.VSMC proliferation was determined by MTT and cell apoptosis was detected by Hoechst/PI staining and flow cytometry.Bcl-2 and Bax protein expressions were tested by Western blot.RESULTS: MTT showed that H/R increased VSMC proliferation and PEDF inhibited VSMC proliferation.The inhibitory effect of 200 ng/ml PEDF was the most significant.After VSMCs were treated with 100 and 200 ng/ml PEDF,Hoechst/PI staining and flow cytometry demonstrated that the apoptosis rate of the cells significantly increased(P<0.01 vs.control group and H/R).Western blot demonstrated that 100 and 200 ng/ml PEDF downregulated Bcl-2 expression and upregulated Bax protein expression(P<0.05 or P<0.01 vs.control group and H/R group).CONCLUSION: H/R increases VSMC proliferation,whereas PEDF inhibits VSMC proliferation and promotes apoptosis after H/R,possibly through Bcl-2 and Bax pathways.