The expressions of Fas and FasL in rabbit retina with ischemia-reperfusion injury, and the effect of recombinant human basic fibroblast growth factor on its expression

Objective:To investigate the protective effects of recombinant human basic fibroblast growth factor(rh-bFGF) on retinal ischemia-reperfusion injury(RIRI) in rabbit.Methods:The models of RIRI in rabbit were established by elevating intraocular pressure.Sixty-six healthy rabbits with normal external ocular and fundus were randomly divided into the sham-operation group(6 rabbits), retinal ischemia-reperfusion injury group(RIRI group, 30 rabbits) and rh-bFGF treatment group(RIRI+rh-bFGF group, 30 rabbits).The right eye was selected as the experimental eye.RIRI group and RIRI+rh-bFGF group were treated with 0.9% sodium chloride injection and rh-bFGF, respectively.Morphological changes of retinal cells and the expressions of Fas and FasL of retinal tissue in sham-operation group, and at 6 h, 12 h, 24 h, 48 h and 72 h time-points of RIRI and RIRI+rh-bFGF groups were detected by HE staining and immunohistochemical method, respectively.Results:No apoptotic cells was found in sham-operation group.Apoptotic cells in RIRI group located mainly in the inner nuclear layer and the ganglion cell layer, and which arrived at peak at 24 h after reperfusion.No obvious expression of Fas in retinal tissue of the sham-operation group was found.After RIRI, little Fas expressing at 6 h, arriving at peak at 24 h, then begaining to decrease at 48 h and significant weakening at 72 h were found.No obvious expression of FasL in retinal tissue of the sham-operation group was found.After RIRI, FasL expression beginning to increase at 12 h, arriving at peak at 24 h, then beginning to decrease and still maintaining a high level at 72 h were found.Compared with the RIRI group, the positive expression trend of apoptotic factors at each time-point in RIRI+rh-bFGF group was similar, the expressions of Fas and FasL in RIRI group and RIRI+rh-bFGF group obviously decreased(P<0.05).The differences of the expression of Fas and FasL at 6 h, 12 h, 24 h, 48 h and 72 h between RIRI and RIRI+rh-bFGF group were statistical significance(P<0.01).Conclusions:The protective mechanism of rh-bFGF on RIRI in rabbit may be related to inhibit the expressions of Fas and FasL in retina.