Genistein-3'-sodium sulfonate suppresses NLRP3-mediated cell pyroptosis after cerebral ischemia

Cerebral ischemia-induced pyroptosis contributes to the dissemination of neuroinflammation, and Nod-like receptor protein-3 (NLRP3) inflammasome plays a key role in this process. Previous studies have indicated that Genistein-3'-sodiumsulfonate (GSS) can inhibit neuroinflammation caused by cerebral ischemia, exert cerebroprotective effects, but its specific mechanism has not been comprehensively understood. The aim of this study was to explore the effect of GSS on ischemic stroke-induced cell pyroptosis. SD rats were randomly assigned to Sham group, transient middle cerebral artery occlusion (tMCAO) group, and tMCAO + GSS group. The open field test (OFT) was utilized to assess animals' spontaneous movement and anxiety-like behavior. Immunofluorescence was adopted to observe nod-like receptor pyrin domain containing 3 (NLRP3)/neuronal nuclei (NeuN) double-positive cells in the ischemic penumbra of each group. Western blot (WB) was conducted to detect levels of NLRP3 inflammasomes and pyroptosis-related proteins in the ischemic cortex tissue. Furthermore, the G protein-coupled estrogen receptor 1 (GPER1) inhibitor G15 was administered to monitor tMCAO rats' motor function, emotional state, and NLRP3 inflammasome activation. Compared with the Sham group, rats in the tMCAO group exhibited significant motor dysfunction and anxiety, increased NLRP3⁺/NeuN⁺ co-expressing cells in the ischemic penumbra, and elevated levels of NLRP3, apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC), pro-cysteinyl aspartate specific proteinase-1 (pro-caspase-1), cleaved-cysteinyl aspartate specific proteinase-1 (cleaved-caspase-1), gasdermin D (GSDMD), GSDMD-N-terminal domain (GSDMD-N), interleukin (IL)-1β, and IL-18 in the ischemic cortex. Treatment with GSS reversed these trends. Additionally, post G15 treatment, the therapeutic effects of GSS were reversed. GSS may inhibit NLRP3 inflammasome activation via GPER1, reducing membrane perforation and pro-inflammatory cytokine secretion, suppressing cell pyroptosis, and mitigating neuroinflammation, thereby improving chronic motor dysfunction and anxiety in tMCAO rats. Our study uncovers a potential novel mechanism for GSS treatment in ischemic stroke and provides new ideas for the treatment of ischemic stroke.