Influence of high level TGF-β1 on scleral thickness

Abstract

In order to explore the role of TGF-β1 in scleral remodeling and the possible mechanism, the influence of high level TGF-β1 on scleral thickness and the expression of MMP-2 and TIMP-2 was investigated in a TGF-β1 transgenic mouse model. Alb/TGF-β1 (Cys^223,225Ser) TGF-β1 transgenic mice were used as experimental subjects and non-transgenic littermates as controls. Plasma levels of TGF-β1 were determined by ELISA. TGF-β1, MMP-2 and TIMP-2 levels in sclera were detected by using Western blot. The thickness of posterior sclera was measured by computerized image analysis of a midsagittal section. Mean difference was analyzed with independent t-test. The results showed plasma levels of TGF-β1 in transgenic mice were 1.68 times as much as that in the controls (P<0.01). TGF-β1 levels in the sclera of transgenic mice were 2.68 times of the controls (P<0.01). Posterior scleral thickness in transgenic mice were significantly thicker than in the controls. There was no significant difference in the MMP-2 levels between transgenic mice and controls, but the TIMP-2 levels were increased significantly in transsgenic mice as compared with those in the controls. It was suggested that high levels of TGF-β1 in transgenic mice could result in the increased scleral thickness by inducing the expression of TIMP-2 to suppress the activity of MMP-2, finally inhibiting the degradation of collagen.

Keywords

sclera / TGF-β1 / myopia