Figure 7.

siRNA treatment significantly decreased hyperglycemia-induced increase in connective tissue growth factor (CTGF) mRNA and protein, glial fibrillary acidic protein (GFAP), collagen IVα3 and laminin-β1 gene expression. mRNA expression for CTGF and selected genes in the retinas of the diabetic rats after 12 weeks of hyperglycemia were analyzed using real-time PCR and normalized to the TATA-binding protein (TBP). A: Real-time PCR revealed that 3 days post intravitreal injection, CTGF siRNA induced a decrease in CTGF (33%), GFAP (44%), collagen IVα3 (71%), and laminin β1 (63%) mRNAs. In contrast, CTGF siRNA did not affect the level of fibronectin or vascular endothelial growth factor (VEGF). B: Immunoblot analysis of CTGF levels in the retinas following a single intravitreal injection of CTGF siRNA or scrambled siRNA into left and right eye, respectively. The concentration of the CTGF protein is lower in eyes injected with CTGF siRNA. C: Densitometric analysis of three independent experiments revealed a 54% decrease in CTGF protein in retinas injected with CTGF siRNA compared to retinas injected with a scrambled (non-specific) siRNA. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used as loading control. D: Real-time PCR showed that CTGF siRNA had no effect on CTGF expression 10 days after injection. (*p<0.05). n=5/group.