HIF-1α through NLRP3/GSDMD pathway regulates the mechanism of acute ischemic stroke microglia scorching mechanism

Abstract

Abstract Introduction: HIF-1 α is an oxygen concentration-sensitive protein that regulates the emergency response to hypoxia. Microglial pyroptosis is closely related to cerebral ischemic injury. In this study, through in vitro cell modeling in order to elucidate the regulatory mechanism of HIF-1 α on microglial pyroptosis and inflammation in the acute phase of the cerebral ischemia and hypoxia. Methods: In vitro experiments with microglia, the acute phase oxyoxygenation model (oxygen-glucose deprivation / reoxygenation, OGD/R) was established, and the optimal time of intervention was determined by measuring the survival rate with CCK-8. Overexpression and suppressed expression of HIF-1α factors, and the experiment were divided into blank group (Group A), OGD/R model group (Group B), OGD/R model + FG-4592 intervention group (Group C),model + siRNA negative control group (Group D), and model + HIF-1 α -siRNA group (Group E). Cell proliferation and cell supernatant LDH concentration were measured in different groups. IL-1β and IL-18 levels in cell supernatants were determined by ELISA. Western blot The protein expression levels of HIF-1α, GSDMD-D, GSDMD-N, cle-Caspase-1, and NLRP3 were determined by the same method. Results: Finally, hypoxia for 6 h reoxygenation for 12 h was the optimal intervention time. Compared with groups B and D, group C increased cell proliferation and decrease in LDH, IL-1β and IL-18 was statistically significant (P<0.05), while group Edecreased cell proliferation and increase in LDH, IL-1β and IL-18 concentrations were statistically significant (P<0.05). Compared with groups B and D, GSDMD-D, GSDMD-N, clean-Caspase-1, and NLRP 3 proteins were significantly lower in group C but significantly increased in group E cells (P <0.05). Conclusion: BV2 cells in the acute phase of cerebral ischemia and hypoxia, found that upregulated HIF-1α expression would reduce microglial pyroptosis and modulation of inflammatory responses. Furthermore, we found that HIF-1α inhibited microglial pyroptosis by inhibiting the NLRP3/GSDMD pathway, and this conclusion provides a potential target for the clinical treatment of ischemic stroke in the acute phase.