目的：研究αB-晶体蛋白对大鼠急性高眼压后视网膜组织中αB-晶体蛋白含量，视网膜神经节细胞(retinal ganglion cells， RGCs)中生长相关蛋白-43(growth associated protein-43， GAP-43)表达和全视野视网膜电流图(full-field ERG，F-ERG)的b波振幅差异，探讨αB-晶体蛋白对急性高眼压后RGCs轴突再生的影响。

方法：采用随机分组设计的实验研究。本实验选择120只健康、无眼疾SD大鼠，随机分为以下4组：αB晶体蛋白组(αB)30只，生理盐水组(S)30只，假手术组(P)30只，急性高眼压组(H)30只，均以右眼为实验眼，分别于术后7d和14d各取5只术眼的视网膜，行Western-blot法，观察急性高眼压后视网膜中αB-晶体蛋白的表达； 术后7，14，21d各取5只术眼的视网膜，行免疫组织化学法，观察急性高眼压后RGCs的GAP-43表达； 术前和术后1mo时应用全视野ERG的b波振幅变化测定视网膜功能。组间数据比较采用单因素方差分析(One-way ANOVA)，组间两两比较采用SNK-q检验。

结果：αB组视网膜中αB-晶体蛋白的表达于术后7d较高，14d时表达减弱(P =0.000)，但同一时间点明显高于其他三组(P=0.006，P=0.024，P=0.007； P=0.006，P=0.008，P=0.010)； αB组RGCs的GAP-43表达于术后7d达高峰，14d时表达减弱，21d时仍有少量表达(P=0.000)，但各时间点明显高于其他三组(P=0.001，P=0.002，P=0.001； P=0.015，P=0.002，P=0.006； P=0.005，P=0.003，P=0.005)； ERG- b波振幅于术后1mo较低(P=0.014，P=0.004，P=0.003，P=0.006)，其中术前各组ERG-b波振幅无明显差异(P=0.993)，术后1mo时αB组ERG-b波振幅明显高于其他三组(P=0.000，P=0.004，P=0.002)。

结论：外源性αB-晶体蛋白能够提高视网膜αB-晶体蛋白的表达； αB-晶体蛋白通过促进RGCs中GAP-43的表达，从而促进RGCs的轴突再生； αB-晶体蛋白可促进视网膜功能的恢复，对大鼠视网膜无毒性作用。

AIM: To study the effects of αB-crystallin on the αB-crystallin content in retina, growth associated protein-43(GAP-43)expression of retinal ganglion cells(RGCs), amplitude of electroretinogram(ERG)b-wave, and to investigate the promotive effect of αB-crystallin on axonal regeneration of RGCs after acute ocular hypertension(AOH).

METHODS: One hundred and twenty male Sprague-Dawley(SD)rats(220±10g)were randomly divided into four groups(thirty in each group). αB group,(AOH following intravitreal injection of αB crystallin group, n=30). S group,(AOH following intravitreal injection of normal saline solution group, n=30). P group,(AOH following vitreous puncture group, n=30). H group,(AOH group, n=30). Western blot was assayed αB-crystallin content 7 and 14 days after model; Immunohistochemistry was observed GAP-43 expression 7, 14 and 21 days after model established; Amplitude of ERG b-wave was tested retinal function before and 1 month after model.

RESULTS: The αB content in retina of αB group was higher 7 days after model established, fewer 14 days after model(P=0.000, P=0.000, P=0.001, P=0.000). But the αB content in retina of αB group was more serious compared with other groups at the same time points(P=0.019,P=0.016); The GAP-43 expression of RGCs in αB group was highest 7 days after model established, started to decrease 14 days after model established, which was fewest 21 days after model established(P=0.000, P=0.000, P=0.000, P=0.000). But the GAP-43 expression of RGCs in αB group was significantly higher than in other groups at each time point(P =0.002, P =0.011, P =0.009); The amplitude of ERG b-wave was lower 1 month after model(P=0.014, P=0.004, P=0.003, P=0.006). There were no statistical differences among groups on amplitude of ERG b-wave before model established(P=0.993). The amplitude of ERG b-wave in αB group was higher than others 1 month after model(P=0.002).

CONCLUSION: Exogenous αB-crystallin could improve αB-crystallin expression of retinas; αB-crystallin contributed to the increase of GAP-43 expression of RGCs and RGCs axonal regeneration; αB-crystallin could promote the recovery of retinal function and was non-toxic on retinas of rat.

中国博士后科学基金(No.20080430444)