Abstract
Purpose :
To investigate the role of IκB/NF-κB signaling pathway in uveoscleral outflow pathway with IκBα gene silencing mediated by the 3-(dimethylamino)-1-propylamine-conjugated glycogen (DMAPA-Glyp) derivative.
Methods :
The IκBα-siRNA-loaded DMAPA-Glyp complex was transfected into the ciliary muscles of rats by intracameral injection (labeled as the DMAPA-Glyp+siRNA group), in contrasted with Lipofectamine™ 2000/siRNA complex and naked siRNA as the controls. The mRNA and protein expression of IκBα, NF-κBp65, and MMP-2 were analyzed by real time-PCR, western blotting, and in situ gelatin zymography. Nuclear translocation of NF-κBp65 was analyzed by immunofluorescence. Rat intraocular pressure (IOP) was monitored pre- and post-injection. Gene transfection efficiency and toxicity of the DMAPA-Glyp derivative were also evaluated.
Results :
After RNA interference (RNAi), IκBα mRNA and protein expression were significantly inhibited. NF-κBp65 mRNA and protein expression showed no significant differences. Nevertheless, nuclear translocation of NF-κBp65 occurred in DMAPA-Glyp+siRNA group. Both mRNA expression and activity of MMP-2 increased, with the largest increase in DMAPA-Glyp+siRNA group. IOP in DMAPA-Glyp+siRNA group fell to the lowest level on day 3 after RNAi. The levels of Cy3-siRNA in ciliary muscle of DMAPA-Glyp+siRNA group did not significantly decrease over time. At 7 and 14d after RNAi, no significant pathological damage was detectable in the eyes injected with DMAPA-Glyp derivative or DMAPA-Glyp/siRNA complex.
Conclusions :
Downregulation of IκBα expression in ciliary muscle can reduce the IOP values of rats. IκBα may become a new molecular target for lowering IOP in glaucoma. The DMAPA-Glyp derivative is safe and feasible as an effective siRNA vector in rat eyes.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.