Increased expression of low-affinity NGF receptor in rat retinal Müller cells after ischemia and reperfusion.

Abstract

Low affinity nerve growth factor receptor (p75LNGFR) it is thought to play an important role in recovering damaged nerve. To investigate the possible role of p75LNGFR in transient retinal ischemia, we investigated p75LNGFR gene expression and localization. Using rats under anesthetized conditions, we incised the bulbar conjunctive around the limbus, and then clamped the eyes. A sham operation was performed on the contralateral eyes. Ocular ischemia was maintained for 90 minutes. The p75LNGFR gene expression in ischemic rat retinas was examined by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) at 0, 3, 6, and 72 hours after reperfusion, and the localization of p75LNGFR protein in rat retinas was examined by light and electron microscopic immunohistochemistry. The expression of p75LNGFR gene in ischemic rat retinas increased, as compared with that of the contralateral eyes after 6 hours and 3 days of reperfusion. The p75LNGFR protein increased in the outer plexiform layer and in the outer limiting membrane by immunohistochemical technique. Electron microscopic immunohistochemistry demonstrated that the staining is present in the Müller glial cells. The fact that p75LNGFR gene expression increased in Müller cells after reperfusion suggested that p75LNGFR expression may play a curative role in ischemic injury.