FIG. 4.

Wnt/β-catenin signaling was responsible for the high-glucose–induced CTGF overexpression. A: HTERT RPE-1 cells were exposed to high glucose for different durations as indicated. p-LRP6 levels were measured by Western blot analysis using 100 μg of total proteins with an antibody specific for p-LRPE6, and cytosolic β-catenin levels were determined by Western blot analysis using 20 μg cytosolic proteins. B: HTERT RPE-1 cells were exposed to low glucose and high glucose media with 100 nmol/l DKK1 or BSA. After 24-h treatment of the cells, CTGF levels were measured by Western blot analysis. C and D: The retinas were dissected from nondiabetic rats and diabetic rats. β-Catenin levels in the retinal homogenates were measured by Western blot analysis (C) and quantified by densitometry (D) (*P < 0.05, means ± SD, n = 6).