Alteration of UCP2 and ZO-1 expression in trabecular meshwork of neovascular glaucoma patients.

PURPOSE: The aim of this study was to investigate the expression of uncoupling protein 2 (UCP2) and zonula occludens-1 (ZO-1) in the trabecular meshwork (TM) of neovascular glaucoma (NVG) patients treated with trabeculectomy. MATERIALS AND METHODS: Six eyes with NVG underwent trabeculectomy for therapeutic purposes. The data consisted of patient demographics, presurgical and postsurgical visual acuity, intraocular pressure, gonioscopy, and neovascularization of iris and/or the anterior chamber angle. TM samples were obtained from the NVG eyes that had undergone surgery. Immunofluorescence and confocal laser scanning microscopy were carried out to determine the expression of UCP2 and ZO-1 in the TM cells. RESULTS: The baseline median visual acuity was light perception, and the mean intraocular pressure (standard error) was 52.5 (8.3) mm Hg. All eyes displayed neovascularization of the iris and the anterior chamber angle. The expression of UCP2 was significantly decreased in TM cells of NVG compared with the control (P=0.000), whereas increase in ZO-1 expression was detected in staining cells with NVG in comparison with the control (P=0.000). The necrotic cells in the TM were increased (P=0.000), whereas the viable cells were reduced (P=0.000) in comparison with the control. CONCLUSIONS: The decreased UCP2 expression and increased ZO-1 expression suggest that the oxidative stress-induced mitochondrial dysfunction and tight junction formation may play pivotal roles in the progress of NVG.

Overexpression of CDKN1B inhibits fibroblast proliferation in a rabbit model of experimental glaucoma filtration surgery.

PURPOSE: To investigate the potential antiproliferative effect of cyclin-dependent kinase inhibitor 1B (CDKN1B) overexpression in a rabbit model of glaucoma filtration surgery (GFS). METHODS: The recombinant adenovector expressing exogenous CDKN1B was delivered to Tenon's capsule by subconjunctival injection during unilateral filtration surgery. The time course of CDKN1B expression was monitored by immunohistochemistry and Western blot analysis. Evaluation of proliferating activity was performed by proliferating cell nuclear antigen (PCNA), argyrophilic nucleolar organizing region (AgNOR) staining, and fibroblast-specific protein 1 (FSP-1). Cyclin-dependent kinase 2 (Cdk2) and Cdk4 expression were detected with immunohistochemical analysis. RESULTS: The overexpression of CDKN1B in Tenon's capsule was monitored throughout the experimental period. Immunoreactivity to CDKN1B was mainly observed in the nucleus of fibroblasts. The increased expression of CDKN1B in sclera was detected up to 21 days after viral infection, whereas the level of CDKN1B protein in corneal stroma was not significantly increased. The overexpression of CDKN1B induced a significant decrease in AgNOR number/nucleus and area/nucleus, PCNA staining, FSP-1 positive cells, and the decreased expressions of Cdk2 and Cdk4, as evidenced by nuclear and cytoplasmic immunoreactivity to Cdk2 and Cdk4 antibodies in positive fibroblasts. CONCLUSIONS: The persistent overexpression of CDKN1B mediated by the recombinant adenovector expressing exogenous CDKN1B in Tenon's fibroblasts after GFS may lead to the inhibition of fibroblast proliferation and the downregulation of Cdk2 and Cdk4 activity, thereby reducing the severity of scar formation and the surgical outcome.