脑缺血时半乳糖凝集素-3对大鼠脑皮质中bcl-2、BAX及caspase-3表达的影响

Effect of galectin-3 on expression of B-cell lymphoma-2, Bcl-2-asociated X protein, and cysteine aspartic acid-specific protease 3 in rat cerebral cortex during cerebral ischemia

摘要:

目的 通过脑缺血/再灌注损伤模型，测定脑缺血时半乳糖凝集素-3（Gal-3）对B淋巴细胞瘤-2（bcl-2）、Bcl-2相关X蛋白（BAX）及含半胱氨酸的天冬氨酸蛋白水解酶-3（caspase-3）表达的影响，从而为脑缺血的发病机制提供一定的实验依据。方法 雄性SD大鼠18只，建立大鼠大脑中动脉阻塞（MCAO）模型，缺血1.5 h，再灌注至24 h。采用随机分组法分为假手术组（sham）、缺血/再灌注组（I/R）和Gal-3 RNA干扰组（siRNA）。采用real-time PCR及western blot检测大鼠脑皮质中Gal-3、bcl-2、BAX及caspase-3 mRNA及蛋白表达变化。结果 大鼠脑缺血/再灌注损伤后，脑皮质中Gal-3及bcl-2 mRNA及蛋白表达明显下调，分别为0.38、0.47和1.310、1.299；BAX及caspase-3 mRNA及蛋白表达明显上调，分别为1.41、1.55及1.076、1.155。而Gal-3 RNA干扰后，Gal-3及bcl-2 mRNA及蛋白表达明显下调，分别为0.24、0.14及1.014、1.058；BAX及caspase-3 mRNA及蛋白表达明显上调，分别为1.76、1.88及1.480、1.515。结论 Gal-3可能通过上调bcl-2、下调caspase-3及BAX mRNA及蛋白的表达，参与脑缺血/再灌注损伤的病理过程。

Abstract:

Objective To investigate the effect of galectin-3 (Gal-3) on the expression of B-cell lymphoma-2 (bcl-2), Bcl-2-associated X protein (BAX), and cysteine aspartic acid-specific protease 3 (caspase-3) during cerebral ischemia in a model of cerebral ischemia-reperfusion injury, and to provide an experimental basis for the pathogenesis of cerebral ischemia.Methods A total of 18 male Sprague-Dawley rats were given ischemic treatment for 1.5 hours followed by reperfusion to 24 hours to establish a model of middle cerebral artery occlusion, and then these rats were randomly divided into sham-operation group, ischemia-reperfusion (I/R) group, and Gal-3 RNA interference (siRNA) group. Real-time PCR and Western blot were used to measure the changes in the mRNA and protein expression of Gal-3, bcl-2, BAX, and caspase-3 in rat cerebral cortex.Results After cerebral ischemia-reperfusion injury, the I/R group had significant reductions in the mRNA and protein expression of Gal-3 (0.38 and 0.47) and bcl-2 (1.310 and 1.299) and significant increases in the mRNA and protein expression of BAX (1.41 and 1.55) and caspase-3 (1.076 and 1.155). After Gal-3 RNA interference, the siRNA group had significant reductions in the mRNA and protein expression of Gal-3 (0.24 and 0.14) and bcl-2 (1.014 and 1.058) and significant increases in the mRNA and protein expression of BAX (1.76 and 1.88) and caspase-3 (1.480 and 1.515).Conclusions Gal-3 may participate in the pathological process of cerebral I/R injury by upregulating the mRNA and protein expression of Bcl-2 and downregulating the mRNA and protein expression of caspase-3 and BAX.