The Protective Effects of alpha B-Crystallin on Ischemia-Reperfusion Injury in the Rat Retina

To investigate whether alpha B-crystallin protects against acute retinal ischemic reperfusion injury (I/R) and elucidate the potential antioxidant mechanisms. Retinal I/R injury was made by elevating the intraocular pressure (IOP) 110 mmHg for 60 min, and aB-crystallin (1 x 10(-5) g/L) or vehicle solution was administered intravitreously immediately after I/R injury. The animal was sacrificed 24 h, 1 w, and 1 m after the I/R injury. The retina damage was detected by hematoxylin and eosin (HE) staining and electroretinography (ERG). The level of malondialdehyde (MDA), nitric oxide (NO), and the total superoxide dismutase (T-SOD) was determined. An immunohistochemical study was performed to detect the activation of inducible nitric oxide synthase (iNOS) and NF-(nuclear factor-) kappaB (NF-kappa B) p65. The decrease of retinal thickness and the number of retinal ganglion cells (RGCs) can be suppressed by alpha B-crystallin. And the amplitudes of a- and b-wave were remarkably greater without alpha B-crystallin. Similarly, alpha B-crystallin also significantly decreased the level of MDA and NO and enhanced the activities of T-SOD. The positive expression of iNOS and NF-kappaB p65 was obviously reduced while treated with alpha B-crystallin. alpha B-crystallin can inhibit the expression of NF-kappa B and its antioxidative effect to protect the retina from I/R injury.