The Anti-fibrotic Effect of Nilotinib on Tenon's Capsule Fibroblasts in Vitro

ABSTRACT

PURPOSE: To evaluate the anti-fibrotic effects of nilotinib on the survival of cultured human Tenon's capsule fibroblasts (HTFs). METHODS: HTF primary cultures were obtained from samples following glaucoma surgery. Primarily cultured HTFs were exposed to 1, 5, 10, and 20 µM nilotinib for 24 hours. The effects of nilotinib on HTF proliferation and cell viability were determined using the 3-(4,5-dimethylthiazone-2-yl)-2,5-diphenyl tetrazolium (MTT) assay, and apoptosis was determined by flow cytometry using annexin-V/propidium iodide (PI) double staining. Apoptosis-related proteins were detected by western blotting. RESULTS: The MTT assay showed that nilotinib induced an inhibition of HTF proliferation at concentrations of 10 and 20 µM (p < 0.001 and p < 0.001, respectively). Annexin V/PI double staining showed significantly increased apoptosis in cells treated with nilotinib. Nilotinib activated caspase-3, -9, and poly adenosine diphosphate ribose polymerase cleavage, and downregulated the expression of B-cell lymphoma-extra large and Bax, which indicated that nilotinib-induced apoptosis was partly mediated through the mitochondrial pathway. In addition, treatment with nilotinib decreased the expression of α-smooth muscle actin and transforming growth factor-β. CONCLUSIONS: Nilotinib decreased cell survival of cultured HTFs and induced mitochondria-mediated apoptosis. The results suggested that nilotinib may exert antiproliferative effects on HTFs, making it a possible agent to control postoperative fibrosis in patients undergoing glaucoma surgery.