重组人促红细胞生成素对眼挫伤后大鼠视网膜的保护机制

Protective mechanism of recombinant human erthropoietin on retina following eye contusion in rats

目的:探讨重组人促红细胞生成素(recombinant human erthropoietin,rhEPO)对挫伤视网膜Bcl-2和Bax的调节作用,明确重组rhEPO对挫伤视网膜的保护机制。方法:两月龄雄性大鼠45只,5只用于正常对照组,余下40只仿Allen重击法制作视网膜挫伤模型致左眼挫伤。将模型制备成功大鼠随机分为两组:模型组和rhEPO治疗组,每组各20只大鼠,每组又分12和24h;3和7d共四个时间点,每个时间点大鼠5只。rhEPO组大鼠iprhEPO,1次/d;模型组用同体积的生理盐水ip。各组各时段于给药给水停止后第2d取材,石蜡切片。应用免疫组织化学方法检测视网膜组织中Bcl-2和Bax蛋白的表达变化。结果:正常对照组视网膜内均有适量Bcl-2和Bax蛋白表达;模型组Bcl-2蛋白表达随时间推移逐渐下降,至3d时表达最低。除12h外,其余各组Bcl-2蛋白表达均比正常对照组低。而Bax蛋白表达逐渐上升,至3d达峰值。除12h外,其余各组Bax蛋白表达均比正常对照组高;rhEPO组Bcl-2蛋白表达均比模型组高,而Bax蛋白表达均比模型组低。结论:Bcl-2和Bax参与了眼挫伤视网膜病变过程;rhEPO能够上调挫伤后大鼠视网膜细胞Bcl-2蛋白表达和下调Bax蛋白的表达,以抑制损伤视网膜细胞的凋亡。

AIM：To explore regulative effect of recombinant human erthropoietin（rhEPO） on the expressin of Bcl-2 and Bax protein on retina following eye contusion, and to clear the protective mechanism of rhEPO for traumaic retina. METHODS： Of 45 two-month old male SD rats, 5 rats were obtained at random for normal control group.The left eye contusions were made by modified Allen＇s falling strike for the rest 40 rats.Successful model rats were randomly divided into model group and rhEPO group. Each group is subdivided into 4 groups according to the different time point （12,24 hours,3,7 days）, 5 rats per group.The rhEPO group animals were injected with rhEPO intraperitoneally,once a day. The model group animals were injected with physiological saline.The retina specimen were gotten after stopping giving rhEPO and physiological saline. Paraffin retinas sections were made and the expressions of Bcl-2 and Bax protein in the rat retinas were tested with immunohistochemistry staining. RESULTS： The expressions of Bcl-2 and Bax protein were modest in normal groups. With prolonging of time, The expression of Bcl-2 protein decreased gradually, and reached minimum at 3 days after ocular trauma in normal groups. Except for 12 hours, the expression of Bcl-2 protein was lower in model groups than that in normal groups at each time point, while the expression of Bax protein gradually increased and reached peak at 3 days after ocular trauma in model group. Except for 12 hours, the expression of Bax protein was higher in model groups than that in normal groups. The expression of Bcl-2 protein was obviously higher in rhEPO groups than that in model groups, while the expression of Bax protein was obviously higher in rhEPO groups than that in model groups at 24 hours, 3 days and 7 days. CONCLUSION：Bcl-2 and Bax take part in pathologic process of ocular trauma; rhEPO upregulates the expression of Bcl-2 and downregulates the exprssion of Bax on retina cells following ocular trauma, which maybe inhibits the apoptosis of retina cells.