Chitosan/siRNA nanoparticles targeting PARP-1 attenuate Neuroinflammation and apoptosis in hyperglycemia-induced oxidative stress in Neuro2a cells.

Hyperglycemia induces an excessive production of superoxide by the mitochondria's electron-transport chain triggers several pathways of injury contributing to the development of diabetic complications. This increase in oxidative and nitrosative stress triggers the activation of PARP-1, a nuclear enzyme, through mechanisms such as DNA damage. siRNA-chitosan nanoparticles were formed based on electrostatic interaction, their particle size, zeta potential, STEM, and cellular uptake were characterized. Neuro2a cells were treated with low glucose (LG) and high glucose (HG) for 24 and 48 h. Neuro2a cells were pre-treated with negative siRNA, naked siRNA, siRNA-Lipofectamine™3000, and ChNPs-5. qRT-PCR was used to analyze the expression of regulatory, inflammatory, and apoptotic biomarkers. The siRNA-chitosan complex at the weight ratio 1:3000 were approximately uniform spheres with particle size 150.5 nm and a positive zeta potential of about +41.5 mV. The uptake of FITC-labeled siRNA nanoparticles into Neuro2a cells was significantly higher compared to naked siRNA, as visualized using fluorescence microscopy, with no notable cytotoxicity compared to normal cells. High glucose stimulation of Neuro2a cells increased PARP1 expression, and with siRNA-ChNP (1:3000) treatment, significant inhibition of PARP1 expression is observed that consequently reversed the expression of regulatory genes like SIRT1, FOXO1, FOXO3, and p53. PARP-1 inhibition reduced HG-induced inflammatory response, including NF-kB, IL6, IL1β, TNFα, iNOS, and TGF-β expression, and HG-induced apoptosis response, such as Cas-3, Cas-9, BAK, BAX, and AIF expression. This study highlights the crucial role of siRNA delivery via ChNPs and PARP-1 inhibition in hyperglycemia-induced oxidative stress in Neuro2a cells and PARP-1 inhibition may be a feasible strategy for the treatment of hyperglycemia-induced oxidative stress.