Ghrelin抑制ox-LDL诱导的人脐静脉内皮细胞凋亡的机制

目的:研究ghrelin对ox-LDL诱导的人脐静脉内皮细胞(HUVEC)凋亡的抑制作用。方法:采用Ho-echst 33258荧光染色、Western blot法和硝酸还原酶法研究ghrelin对ox-LDL诱导的人脐静脉内皮细胞凋亡的抑制作用。结果:Hoechst 33258染色荧光检测发现,与正常对照组相比,ox-LDL组HUVEC中出现大量凋亡细胞,凋亡率明显增加,与ox-LDL组比较,ghrelin预处理组HUVEC细胞凋亡率呈剂量依赖性下降;Western blot检测结果表明,与对照组比较,ox-LDL可上调内细胞中Caspase-3表达,而经过ghrelin预处理后能剂量依赖性降低Caspase-3蛋白表达;硝酸还原酶法结果显示,ox-LDL可显著减少内皮细胞培养液中NO含量,经过ghrelin预处理后,ghrelin能剂量依赖性增加NO含量。结论:ghrelin对ox-LDL诱导的人脐静脉内皮细胞凋亡有拮抗作用,可能与其抑制ox-LDL引起的细胞内Caspase-3蛋白水平升高及NO合成下降有关。

Antagonist Effect of Ghrelin on ox-LDL-Induced HUVECs Apoptosis

Objective: To investigate the antagonist effect of ghrelin on ox-LDL-induced HUVECs apoptosis.Methods: Hoechst33258 fluorescein stain,Western-blot and nitrate reductase assay were used in this study.Results: Hoechst 33258 staining assay showed the number of cells with nuclear condensation increased significantly in ox-LDL group as compared with that in the control group.Pre-treatment with different concentrations(1,10 or 100 ng/ml) of ghrelin caused a decreased apoptotic proportion.As shown in Western-blot,compared with the control group,expression of Caspase-3 induced by ox-LDL(50 mg/L) increased significantly.The expression levels with different concentrations(1,10 or 100 μg/L) of ghrelin was decreased.As shown in nitrate reductase assay,compared with the control group,the NO production induced by ox-LDL(50 mg/L) increased significantly(P<0.01).Pre-treatment with different concentrations(1,10 or 100 μg/L) of ghrelin caused an increased NO production.Conclusion: Ghrelin has antagonist effect on ox-LDL induced HUVECs apoptosis,which contributes to inhibition of Caspase-3 expression and increasing of NO content.