Protective effect of nanoparticle NLRP3 inhibitor (MCC950) on cranial nerves in rats with vascular cognitive impairment

Abstract

Background: Chronic cerebral hypoperfusion (CCH) is a common cause of Vascular cognitive impairment (VCI). The neuroinflammation caused by ischemia play a key role in the progression of the ailment process. The over activation of NLRP3/Caspase-1/IL-1β signaling aggravates the inflammatory response. We investigated whether NLRP3 inhibitors have a protective effect on cranial nerves in rats with VCI. Methods: Male SD rats were selected arbitrarily and categorized into the sham operation group, CCH group and CCH+MCC950 group (10 mg/kg). The rat model of CCH was formed by bilateral common carotid artery occlusion (BCCAO). The changes in rat’s cerebral blood flow were observed by laser speckle imaging after operation. The sham operation and the CCH group were given intraperitoneal (i.p) injection of normal saline, and the therapeutic group was given i.p having dose of MCC950 (10 mg/kg). The behavior of the rats was analyzed through the Y maze and open field experiments, and the hematoxylin-eosin (HE) staining technique was employed to analyze the behavior of the rats. The histological changes of the rat hippocampus were observed under the following conditions, cell apoptosis was observed by Tune staining, and the protein expressions of NLRP3, IL (interleukin)-1β, and cleaved-Caspase-1 in the hippocampus were analyzed by Western blot. Results: MCC950 treatment enhanced the working memory of CCH rats, and the rats in each group showed no motor deficit. As shown by HE staining, inhibition of NLRP3 reduced neuronal damage caused by pyroptosis. In addition, MCC950 diminishes the appearance of NLRP3, IL-1β, and cleaved-Caspase-1 in the brain tissue of CCH rats by inhibiting inflammasome formation. Conclusions: inhibitors can improve the learning and cognitive ability of rats with vascular cognitive impairment, and the mechanism might be linked to inhibiting the NLRP3/Caspase-1/IL-1β signaling and decreasing apoptosis.