全反式维甲酸对角膜上皮损伤修复过程中细胞凋亡的影响

Effect of all-trans retinoic acid on apoptosis in corneal epithelial wound healing

目的探讨全反式维甲酸(ATRA)对大鼠角膜上皮损伤修复过程中细胞凋亡的影响,及其可能机制。方法建立大鼠角膜上皮损伤修复模型,ATRA溶液角膜点滴,拍照记录角膜损伤修复情况,并观察ATRA对大鼠角膜损伤修复速度的影响;原位末端凋亡法(TUNEL技术)测定损伤修复过程中角膜组织细胞凋亡情况;Western blot法测定ATRA处理后角膜上皮组织中丝裂原活化蛋白激酶(MAPK)信号通路蛋白以及细胞凋亡相关蛋白B细胞淋巴瘤/白血病-2相关X蛋白(Bax)、B细胞淋巴瘤/白血病-2(Bcl-2)、半胱天冬氨酸蛋白酶-3前体(Procaspases-3)、半胱天冬氨酸蛋白酶-3(Caspases-3)、Procaspases-9、Caspases-9表达水平。结果 0.5 mmol/L ATRA点滴处理损伤后角膜可促进角膜上皮损伤修复,可调节角膜上皮组织中MAPK信号通路p38的磷酸化水平;能有效抑制促凋亡蛋白Bax表达(P<0.05),上调凋亡抑制蛋白Bcl-2表达(P<0.05),表现出一定的抗凋亡作用;同时上调Procaspases-9、Procaspases-3表达(P<0.05),下调Caspases-3、Caspases-9表达(P<0.05)。结论 ATRA促进大鼠角膜上皮损伤修复的作用与其抑制角膜上皮组织细胞凋亡有关,其可能的机制与MAPK通路相关蛋白的激活有关。

Objective To investigate the effect of all-trans retinoic acid(ATRA)on apoptosis during the repair of rat corneal epithelial injury,and to explore the possible mechanism.Methods A rat corneal epithelial wound healing model was established followed by topical administration of ATRA solution to the cornea.The effect of ATRA on wound closure was observed by measuring the wound area of the cornea with a digital camera.The apoptosis of the corneal tissue during the repair process was determined by TUNEL.The expression of mitogen-activated protein kinase(MAPK)signaling pathway protein and apoptosis-related proteins Bax,Bcl-2,Procaspases-3,Caspases-3,Procaspases-9,Caspases-9 in corneal epithelial tissue after ATRA treatment were determined by Western blot.Results The repair of corneal epithelial damage was promoted by 0.5 mmol/L ATRA.ATRA regulated the expression of p38 in MAPK signaling pathway.ATRA effectively inhibited the expression of proapoptotic protein Bax(P<0.05),up-regulated the expression of apoptosis inhibitory protein Bcl-2(P<0.05),which showed a certain anti-apoptotic effect.Meanwhile,the expression of Procaspases-9 and Procaspases-3 was up-regulated(P<0.05),and the expression of Caspases-3 and Caspases-9 were down-regulated(P<0.05).Conclusion The effect of ATRA on the corneal epithelial wound healing of rat was related to the inhibition of apoptosis of corneal epithelial cells,which may relate to the activation of MAPK pathway-related proteins.