Effects of αB-crystallin on axon regeneration of rats retinal ganglion cells following acute ocular hypertension

Abstract

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.

Keywords

• αB-crystallin
• acute ocular hypertension
• retinal ganglion cell
• growth associated protein-43
• electroretinogram