Study On The Effect Of Salvianolic Acid A On The Canonical Pathway Of Pyroptosis After Ischemic Stroke

Objective: Previous studies on the mechanism of cell death after ischemic stroke are often only related to cell necrosis and apoptosis.The purpose of this study was to explore whether Salvianolic acid A(SalA)exerts pyroptosis through the canonical NLRP3 inflammasome-dependent pathway of pyroptosis,so as to provide a basis for the application of neuroprotective drugs in clinic.Methods: 40 adult SD rats were randomly divided into 4 groups: Sham operation group(n=10),Control group(n=10),SalA treatment group(n=10)and MCC950 treatment group(n=10).After tail vein puncture,normal saline,normal saline,SalA and MCC950 were injected into each group according to body weight.Using the rat model of middle cerebral artery ischemia-reperfusion(MCAO/R),the neurological function was evaluated by modified Neurological Severity Scores(m NSS).The related markers such as NLRP3,ASC,Caspase-1,IL-18 and IL-1 β were detected by immunohistochemistry,real-time quantitative PCR and Western blot to evaluate the effect of SalA on the canonical NLRP3 inflammasome-dependent pathway of pyroptosis.Results:(1)SalA can reduce the m NSS score of MCAO/R rat model on the 3rd and 7th day after ischemia(p < 0.05);(2)SalA can reduce the histological injury of cerebral cortex of MCAO/R rat model,reduce the NLRP3 positive staining area of MCAO/R rat model(p < 0.001),reduce the number of astrocytes(p < 0.01),decrease the number of microglia(p < 0.01),and increase the number of immature neurons(p < 0.01).(3)The expression of pyroptosis related genes(NLRP3,ASC,Caspase-1,IL-18 and IL-1 β)was up-regulated in MCAO/R rat model after ischemic stroke,and SalA could reduce the expression of pyroptosis related genes(p < 0.001);(4)After ischemic stroke,pyroptosis related proteins(NLRP3,ASC,Caspase-1,Caspase-1-p10)were up-regulated in MCAO/R rats,and SalA could reduce the expression of pyroptosis related proteins(p < 0.05).Conclusion: The canonical NLRP3 inflammasome-dependent pathway of pyroptosis can be activated after ischemic stroke.SalA may play a neuroprotective role by reducing neuronal pyrolysis and inhibiting microglial activation.