| Except for applying siRNA to treat retinal diseases, few reports describe the efficient transduction in the trabecular meshwork (TM) in vivo. In present study, we investigated the distribution of cy3-labeled siRNAs after anterior chamber (AC) injection and explored RhoA siRNA (siRhoA) to modulate intraocular pressure (IOP) through down-regulation of RhoA gene and protein. Cy3-labeled siRNAs were injected into the AC to investigate the distribution. In addition, siRhoA was applied to normal and DEX-induced elevated IOP mice. The RhoA gene was detected at 1d post-injection (PI) using real-time RT-PCR. Proteins were examined using immunofluorescence staining at 1, 2, and 3 day PI. The changes of IOP were observed pre- and post-injection by TONO-PEN. The toxicity was preliminarily assessed using clinical observation and hematoxylin-eosin staining. The study demonstrated the high density of cy3-labeled siRNAs in mouse TM in a dose-dependent manner that peaked at 24h PI. No visible siRNA fluorescence occurred in corneal endothelium, and it seldom occurred in iris. siRhoA caused dramatic decreases of RhoA mRNA and protein expression in mouse TM (p<0.01). In normal mice, IOP was falling at 2d and recovered to baseline at 3d PI. For DEX-treated animals, IOP significantly decreased from 2d to 5d PI (p<0.05). There was no obvious toxicity after the siRhoA application. These results suggest (1) the siRNA injection into AC prompts the ability of transient gene transfection in TM; (2) inhibiting RhoA expression in TM with siRNA is effective in suppressing elevated IOP in mice, suggesting siRhoA is a potentially pharmaceutical intervention for glaucoma. |
