Abstract
Abstract: :
Purpose: The aim of this study is to determine the effects of retinal pigment epithelium (RPE) in glial cell proliferation and activation. Methods: The posterior poles from the right eyes of C57BL/6 mice were subjected to organ culture as previously presented (Fujisawa et al., ARVO 2001). The RPE of the left eyes were dissociated by trypsin. The dissociated RPE were mixed with neurobasal media, including B27 and antibiotic, and added to the retinal explants. The organ cultures were maintained at 5% CO2 for up to 7 days, fixed, and subjected to immunohistochemical analysis using antibodies for p27, glial fibrillary acidic protein (GFAP), and glutamine synthetase. Bromodeoxyuridine (BrdU) was applied to the samples 4 hours before fixing to label proliferating cells. Results: The dissociated RPE in the vitreous cavity were surrounded by activated astrocytes expressing GFAP within 1 day. The p27 expression of Müller cells was dramatically reduced within 24 hours. BrdU- and GFAP-positive Müller cells were also detected within 24 hours. Few BrdU- and GFAP-positive Müller cells were p27 positive. Conclusion: Our results indicate that dispersed RPE in the vitreous cavity can stimulate the activation and proliferation of the retinal glial cells. This effect may be mediated through regulation of p27. RPE may play an important role in the pathogenesis of gliosis in proliferative vitreoretinopathy.
Keywords: 524 proliferative vitreoretinopathy • 567 retinal pigment epithelium • 479 Muller cells