Role of the chloride channel blocker in the formation of filtering tract scars after glaucoma surgery in rats.

Filtration surgery is commonly performed for glaucoma treatment to reduce intraocular pressure (IOP); however, scarring of the filtering bleb is the main cause of failure. In this study, we evaluated the effects of the chloride channel blocker 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) on scar formation in filtering blebs. A glaucoma filtering surgery model was generated using Sprague-Dawley rats, divided into the control and NPPB groups receiving injections of different NPPB concentrations. The IOP of all rats decreased 1-day post-surgery and gradually increased afterward. However, IOP in rats from the NPPB groups recovered more slowly than that of the control group rats. In addition, the area and survival times of filtering blebs in rats from the NPPB groups were substantially larger and longer than those in the control group. Twenty-eight days after surgery, the protein and mRNA expression of collagen I, fibronectin and α-smooth muscle actin in the filtering area of rats from the NPPB groups were significantly lower than that in the control group rats. Collectively, our study demonstrates that NPPB inhibits filtering bleb scar formation, maintains filtering bleb morphology and prolongs filtering bleb survival time by inhibiting the differentiation of conjunctival fibroblasts and extracellular matrix synthesis.

The effect and mechanisms of chloride channel blocker NPPB on TGF-β1 induced HConF fibrosis / 中华实验眼科杂志

Objective To study the effect and mechanisms of chloride channel blocker 5-Nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) on thansforming growth factor β1 (TGF-β1) induced human conjunctival fibroblasts (HConF) fibrosis.Methods Cell counting kit (CCK-8) was used to screen out the optimal TGF-β1 treatment time and the optimal NPPB concentration.The cells were divided into control group,TGF-β1 treatment group and TGF-β1+NPPB group.Cell proliferation and cell cycle were detected by CCK-8 and flow cytometer,respectively.Cell migration ability were observed by scratch and transwell migration assays.Western blot and Real time-PCR were used to detect the expression of collagen Ⅰ (COL-Ⅰ),fibronectin (FN) and α-smooth muscle actin (α-SMA).The phosphorylation level of PI3K and Akt were measured by Western blot.Results TGF-β1 promotes cell proliferation in a time-dependent manner.There was no statistically significant difference in A values between 48 hours and 72 hours after TGF-β1 treatment (P =0.064).Forty-eight hours was selected as the most appropriate time for TGF-β1 treatment.NPPB inhibited HConF cell proliferation in a concentration-dependent manner.Compared with the control group,the proliferation A values of cells in the 50 mol/L and 100 mol/L NPPB groups were significantly reduced (P =0.020,0.000),and 100 mol/L was selected as the optimal concentration of NPPB.The cell proliferation A value,migration area and migration cell number of TGF-β1 +NPPB group were significantly lower than those of TGF-β1 treatment group (all at P＜0.05).Compared with the control group and TGF-β1 +NPPB group,the proportion of G1 phase cells in the TGF-β1 treatment group was reduced,and the proportion of cells in the S phase and G2/M phase were increased,with statistically significant differences between them (all at P ＜ 0.05).The protein and mRNA expression of α-SMA,COL-Ⅰ and FN in the TGF-β1 treatment group were higher than those in the control group and TGF-β1+NPPB group,with statistically significant differences between them(all at P＜0.05);the ratios of p-PI3K/PI3K and p-Akt/Akt in the TGF-β1 treatment group were significantly higher than those in the control group and TGF-β1 +NPPB group,with statistically significant differences between them (all at P＜0.05).Conclusions NPPB may inhibit TGF-β1 induced HConF fibrosis process by inhibiting phosphorylation of PI3K and Akt.

Effects of matrine on filtering bleb scarring after trabeculectomy in rabbit eyes / 眼科新进展

Objective To study the inhibitive effects of matrine on the formation of glaucoma filtration bleb scar.Methods A total of 40 New Zealand white rabbit were chosen and randomly divided into four groups(group A,B,C and D).Both eyes in four groups were treated with glaucoma filtration surgery.The cotton pieces under the sclera flap were made:1.0 g · L-1 matrine cotton piece in group A,0.4 g · L-1 matrine cotton piece in group B,0.2 mg · L-1 mitomycin cotton piece in group C and PBS cotton piece in group D.The intraocular pressure,filtering bleb,anterior chamber reaction and complications were observed at preoperative and postoperative 1 day,3 days,7 days,14 days,28 days in all groups.Two rabbits selected randomly from every group were killed at 1 day,3 days,7 days,14 days and 28 days after surgery.Tissue was harvested from the bleb area and made into pathological section,immunestaining and Masson trichromatic dyeing were used to observe the inflammatory cells,collagen,fibroblasts,the change of muscle fibroblasts and new collagen fibers under light microscope.The cornea was observed at 7 days under transmission electron microscope for drug toxic reaction,Results At postoperative 7 days,14 days,28 days,there were statistical difference in IOP between group A,B,C and group D group (P ＜ 0.05),and there were statistical difference between group A and group B (P ＜ 0.05).At postoperative 7 days,14 days,28 days,there were statistical difference in fibroblasts counting between group A,B,C and group D group (P ＜0.01),and there were statistical differences between group A and group B (P ＜ 0.05).Conclusion Matrine can inhibit fibroblasts hyperplasia,reduce the scar of filtration area and has no side effects on eye tissues.