ABSTRACT
AIM: To study the effect of the subretinal fluid (SRF) on proliferation of retinal pigment epithelium (RPE) cells and retinal glial (RG) cells and associated activation and translocation of protein kinase C (PKC) as well as the application of PKC inhibitor.MTEHODS: RPE and RG cells were disintegrated to obtain PKC activity of cytoplasm and cellular membrane after being treated by the subretinal fluid (SRF) from the different stages of PVR patients (grade B and C) or being treated with PKC specific activator [phorbol-12-myris-tate-13-acetate (PMA)] or normal vitreous or DMEM culture medium. PKC activity in cytoplasm and cellular membrane was measured using radioactive isotope 32P labeling in a specific reaction of phosphorylation on PKC substrate. In addition, the PKC inhibitor, dequalinium chloride, was used to pretreat the RPE and RG cells before the cells exposed to SRF or PMA or normal vitreous. 3H-TdR (tritiated thymidine) was used to measure the levels of proliferation of RPE and RG cells with or without the activation and translocation.RESULTS: SRF and PMA promoted the proliferation of RPE and RG cells. SRF and PMA activated PKC in the cytoplasm of RPE and RG cells and the activated cytoplasm PKC translocated to the cellular membrane of RPE or RG cells. The cell proliferation or PKC activation or translocation were not equally active in RPE as in RG cells. However, PKC inhibitor which attenuated the cell proliferation did not show significant difference on inhibition of RPE and RG cell proliferation. (P ＞0.05).CONCLUSION: SRF can lead to the activation and translocation of PKC in RPE and RG cells, which promote the proliferation of RPE and RG cells. Dequalinium chloride can inhibit PKC activation and translocation hence slow down the cells proliferation.
ABSTRACT
AIM:In order to study the effects of retinal glial cells on glaucomatous retinal ganglion cells damage,expression of TNF-? and TNF-R1 in retinal glial cells was observed in rat model with chronic elevated intraocular pressure glaucoma.METHODS:(1)Rats were rendered elevated intraocular pressure by ligating 2 episcleral veins with subconjunctival injection of 5-Fu.(2)Four weeks after operation,immuno-histological assays were carried out on cryostat sections.The co-expressions of TNF-?-GFAP,TNF-?-OX42,TNFR-1-GFAP,and TNFR-1-NeuN were observed via a confocal laser scanning microscope,respectively.RESULTS:(1)Elevated intraocular pressure was consistently maintained for up to 4 weeks in model group.(2)The co-expressions of TNF-? and GFAP,TNF-? and OX42 were detected in retina in treatment group,respectively.(3)The co-expressions of TNFR-1 and GFAP were also detected in retina,but the co-expressions of TNFR-1 and NeuN were not detected in retina in treatment group.CONCLUSION:TNF-? that activated retinal glial cells may play an important role in glaucomatous retinal ganglion cell damage.