HIF-1α expression and retinal cell apoptosis in rat retina ischemia-reperfusion injury

AIM: To investigate the expression of hyporia inducing factor-1 alpha (HIF-1 alpha), apoptosis of retinal cells and the role of HIF-1 alpha in apoptosis in rats' retinal ischemia-reperfusion injury. METHODS: The rat model of experimental retinal ischemia-reperfusion injury was established by increasing the intraocular pressure to 110mmHg (1kPa = 7.5mmHg) in rat eyes. At different time points of post ischemia, the expression of HIF-1 alpha of the retina was detected by immunohistochemical staining, and the apoptosis of retinal cell was detected by terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphatebiotin nick end labeling (TUNEL) RESULTS: HIF-1 alpha appeared in the cells of retinal ganglion layer and inner nuclear layer at 2 hours after ischemia. The expression reached to a peak, 12 hours after retinal ischemia-reperfusion, then, the expression was declined. The apoptotic cells were mainly in inner nuclear layer and could be detected at the 12(th), 24(th) and 48(th) hour after ischemia, the peak value was the group of 24(th) hour. CONCLUSION: The expression of HIF-1 alpha in rats' retina is greatly enhanced after ischemia-reperfusion, which may be involved in the retinal injury; the injury of retinal neurons occurs partly in the form of apoptosis. The expression of HIF-1 alpha may play an important role in cell apoptosis.