姜黄素抗内皮细胞缺血/再灌注损伤的机制研究

目的探讨姜黄素(curcumin,Cur)抗人脐静脉内皮细胞(HUVEC)缺血/再灌注(I/R)损伤的作用机制。方法建立缺氧/复氧(hypoxia/reoxygenation,H/R)损伤模型,MTT法检测不同的缺氧和复氧时间对内皮细胞的损伤作用及Cur对HUVEC的保护作用;预先给予Cur(5μmol.L-1),用免疫荧光和Western blot法检测H/R对HUVEC微管相关蛋白LC3、溶酶体酶cathepsin B、L及促凋亡蛋白Bax、抗凋亡蛋白Bcl-2表达的影响。结果Cur(1.25~5μmol.L-1)可剂量依赖性的保护H/R的HUVEC;H/R能增加LC3、cathepsinB、Bax/Bcl-2的表达,并且使cathepsin L发生核转位;而用Cur预处理后,在进一步增强LC3表达的同时,明显抑制ca-thepsin B和Bax/Bcl-2的表达及cathepsin L的核转位现象。结论Cur能有效提高HUVEC在缺血/再灌注损伤中的存活率,并通过诱导其自噬活性、抑制cathepsins以及Bax/Bcl-2的表达保护内皮细胞。

Mechanisms of curcumin protecting endothelial cells against ischemia and reperfusion injury

Aim To investigate the mechanisms in protecting HUVEC against ischemia/reperfusion(I/R) injury directed by curcumin.Methods Hypoxia/reoxgenation(H/R) model was established on HUVEC.MTT colorimetric assay was used to observe the injury degree of hypoxia and reoxygenation at the different time.With preconditioning by different concentration of Cur,the survival rate of HUVEC subjected to H/R was assessed by MTT colorimetric assay.Pretreated with Cur(5 μmol·L-1),the expression of LC3,cathepsin B,cathepsin L,Bax and Bcl-2 were observed by fluorescent staining and Western blot in HUVEC during H/R process.Results Cur(1.25~5 μmol·L-1) played a protective role during H/R in HUVEC in a dose-dependent manner.During H/R,the expressions of LC3,cathepsin B and the ratio of Bax/Bcl-2 increased,and the nuclear translocation of cathepsin L was induced;when cur was pretreated,LC3 was furtherstrengthened,at the same time,the up-regulation of cathepsin B,the ratio of Bax/Bcl-2 and the nuclei-location of cathepsin L were inhibited partly by Cur.Conclusions Cur can raise the survival rate of HUVEC in the process of H/R.Cur increases the autophagy activity,depresses cathepsins and Bax/Bcl-2 to protect the endothelial cells.