Expression of wild-type p53-induced phosphatase 1 in diabetic epiretinal membranes

OBJECTIVE: The aims of the present study were to investigate the expression and distribution of Wild-type p53-induced phosphatase 1 (Wip1) in diabetic patients with proliferative diabetic retinopathy (PDR) with epiretinal membranes (ERMs) meanwhile analyze the colocalization of Wip1 and nuclear factor kappa-B (NF-κB) p65 in ERMs. METHODS: ERMs samples were collected from patients with PDR (PDR group) or non-diabetic patients with idiopathic epiretinal membranes (iERMs) (control group) during pars plana vitrectomy. Real-Time PCR analysis was carried out to examine the mRNA expression of Wip1 in ERMs. Immunohistochemical analysis and Immunofluorescent analysis were performed to detect the protein expression of Wip1 in ERMs. Double immunofluorescent staining was performed to detect the colocalization of Wip1 and glial fibrillary acidic protein (GFAP) (retinal glial cells marker), also Wip1 and NF-κB. RESULTS: ERMs were obtained from 17 eyes of 17 patients with PDR (the PDR group) and 9 eyes of 9 nondiabetic patients (the control group) with iERMs. Our results showed high expression levels of Wip1 mRNAs in ERMs after PDR, but low in iERMs. In addition, both immunohistochemistry and immunofluorescence assay showed strong immunoreactivity for Wip1 in PDR ERMs. Furthermore, Wip1 and GFAP were coexpressed in PDR membranes. Finally, the expression of Wip1 was paralleled with NF-κB. CONCLUSION: These data support the notion that Wip1 contributes to the formation of the ERMs in PDR membranes via NF-κB signaling.