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Objective:To investigate the effects of vascular endothelial growth factor (VEGF) on the expression of secreted protein acidic and rich in cysteine (SPARC) and the fibrosis in cultured human Tenon's fibroblast (HTF) in vitro. Methods:HTF cells were obtained from Tenon's capsule tissues of patients undergoing strabismus surgery. Immunofluorescence was used to identify the HTF cells. HTF cells were cultured with different concentrations of VEGF, and which were divided into four groups, i.e., 0 ng/mL group, 25 ng/mL group, 50 ng/mL group and 100 ng/mL group. The expression of SPARC, collagen- , and matrix metalloprotein 9 (MMP-9) and the activity of extracellular signal-regulated kinase (ERK) pathway were analyzed by Western blotting and real-time quantitative PCR (qPCR). The abilities of proliferation and migration of HTF cells were detected by MTS assay and scratch test, respectively. Results:HTF cells were observed and identified by inverted phase contrast microscope and immunofluorescence. Under the stimulation of VEGF, the expression of protein and mRNA of SPARC, collagen-I and MMP-9 of HTF cells in other three groups were increased compared with 0 ng/mL group; the phosphorylation activities of ERK pathway were up-regulated, and the proliferation and migration abilities of HTF cells were up-regulated. And the effect was the most obvious in the 50 ng/mL group. Conclusion:VEGF is involved in promoting the fibrosis of HTF cells accompanied by the up-regulation of the SPARC, which suggests SPARC may become a potential regulatory site.
RESUMO
BACKGROUND: Conjunctival filtering bleb scar formation is the main reason for the failure of glaucoma filtration surgery. Cytoglobin (Cygb) has been reported to play an important role in extracellular matrix (ECM) remodeling, fibrosis and tissue damage repairing. This study aimed to investigate the role of Cygb in anti-scarring during excessive conjunctival wound healing after glaucoma filtration surgery. METHODS: Cygb was overexpressed in human tenon fibroblasts (hTFs) by transfecting hTFs with lentiviral particles encoding pLenti6.2-FLAG-Cygb. Changes in the mRNA and protein levels of fibronectin, collagen I, collagen III, TGF-ß1, and HIF1α were determined by RT-PCR and western blotting respectively. RESULTS: After Cygb overexpression, hTFs displayed no significant changes in visual appearance and cell counts compared to controls. Whereas, Cygb overexpression significantly decreased the mRNA and protein expression levels of collagen I, collagen III and fibronectin compared with control (p < 0.01). There was also a statistically significant decrease in the mRNA and protein levels of TGF-ß1 and HIF-1α in hTFs with overexpressed Cygb compared with control group (p < 0.05). CONCLUSION: Our study provided evidence that overexpression of Cygb decreased the expression levels of fibronectin, collagen I, collagen III, TGF-ß1 and HIF-1α in hTFs. Therefore, therapies targeting Cygb expression in hTFs may pave a new way for clinicians to solve the problem of post-glaucoma surgery scarring.