碱性成纤维细胞生长因子对谷氨酸诱导的豚鼠视网膜内Caspase-3和Bcl-2表达的影响

Effects of basic fibroblast growth factor on glutamate-induced expression of Caspase-3 and Bcl-2 in the guinea pig retina

目的：探讨过量谷氨酸毒性损伤后视网膜天冬氨酸蛋白酶-3（Caspase-3）和凋亡相关蛋白Bcl-2的表达及碱性成纤维细胞生长因子（bFGF）对兴奋毒性损伤的保护作用.方法： 豚鼠随机分为正常对照组、谷氨酸损伤组、bFGF治疗组.采用免疫组织化学方法和图像分析技术,对各组豚鼠视网膜内Caspase-3和Bcl-2的表达进行检测.结果： 对照组Caspase-3无明显表达,损伤组在节细胞层、内核层、内界膜和外界膜等处Caspase-3表达阳性面积百分率和密度明显上调,bFGF治疗组Caspase-3表达明显降低.对照组Bcl-2在节细胞层、神经纤维层及内核层内有弱阳性表达,损伤后变化不明显,bFGF治疗组Bcl-2的表达阳性面积百分率和密度明显上调,不仅在节细胞层、内核层和外界膜,在内界膜、外网状层、外核层也有明显表达.结论： bFGF能选择性减少视网膜兴奋毒性损伤后Caspase-3的表达,增加Bcl-2的表达,bFGF抗过量谷氨酸诱导的节细胞凋亡的机制之一可能是调节Mǘller细胞及节细胞内Caspase-3和Bcl-2的表达.

Objective： To assess the expression of Bcl-2 and Caspase-3 in the retina after superabundant glutamate injury and investigate the neural protective effect of basic fibroblast growth factor （bFGF） on retinal excitotoxicity damage in guinea pigs. Methods： Guinea pigs were randomly divided into a glutamate injury model group, a normal control group and a bFGF treatment group. The expression of Bcl-2 and Caspase-3 in the retina was detected by immunohistochemical method and image analysis. Results： A few of Caspase-3 positive cells were found in the normal control group; the expression of Caspase-3 was significantly increased in the injury group; and Bcl-2 showed weak expression in the retina of the normal control group and there was no significant change after damage. The expression of Bcl-2 significantly increased and the expression of Caspase-3 reduced in the treatment group received bFGF injection beforehand. There was significant difference between the treatment group and model group. Conclusion： bFGF might selectively reduce the expression of Caspase-3 and up-regulate the expression of Bcl-2 in the retina after supera- bundant glutamate injury, and one of the possible mechanisms is the inhibition of glutamate-injured RGCs apoptosis by bFGF.