Table_1_Genistein Attenuates Acute Cerebral Ischemic Damage by Inhibiting the NLRP3 Inflammasome in Reproductively Senescent Mice.doc

Postmenopausal women have a higher incidence of stroke compared to the age-matched males, and the estrogen was thought to be the main cause of such difference. However, estrogen replacement therapy for the prevention of postmenopausal stroke shows controversial results and is widely disputed because of its serious side effects after chronic administration. Genistein (Gen), a natural phytestrogen with fewer side effects, has a protective effect against cerebral ischemia damage. However, whether Gen could effectively prevent postmenopausal stroke has not been elucidated. In the current study, reproductively senescent mice were treated with Gen (10 mg/kg) for 2 weeks before having transient cerebral ischemia insults. Neurological scores, infarct volumes, and cell apoptosis were evaluated 24 h after reperfusion. The levels of inflammatory factors and nod-like receptor protein 3 (NLRP3) inflammasome-related proteins were also examined. The results showed that Gen treatment reduced infarct volumes, improved neurological scores, attenuated apoptosis, and decreased inflammatory factor release. The expression of NLRP3 inflammasome-related proteins in microglia was downregulated by Gen. However, the overexpression of NLRP3 in microglia abrogated the Gen-induced inhibition of inflammatory factor release and reversed the neuroprotective effect of Gen. Taken together, the results suggest that Gen treatment could attenuate the acute injury induced by cerebral ischemia in reproductively senescent mice via the inhibition of the NLRP3 inflammasome in microglia, indicating that Gen could be a candidate drug for the treatment of stroke in postmenopausal women.

与同年龄段男性相比，绝经后女性的脑卒中发病率更高，此前学界认为雌激素是造成这一差异的主要原因。然而，采用雌激素替代疗法预防绝经后脑卒中的研究结果存在争议，且因长期给药后会产生严重不良反应而广受质疑。染料木黄酮（Genistein，Gen）作为一种天然植物雌激素，不良反应发生率更低，可对脑缺血损伤发挥保护作用。然而，Gen能否有效预防绝经后脑卒中，目前尚未阐明。在本研究中，生殖衰老小鼠在接受短暂性脑缺血损伤前，先以10 mg/kg剂量的Gen给药干预2周。于再灌注24小时后，对小鼠的神经功能评分、脑梗死体积以及细胞凋亡情况进行评估，同时检测了炎症因子以及核苷酸结合寡聚化结构域样受体蛋白3（nod-like receptor protein 3，NLRP3）炎症小体相关蛋白的表达水平。结果显示，Gen给药干预可缩小脑梗死体积、改善神经功能评分、减轻细胞凋亡，并减少炎症因子释放。Gen可下调小胶质细胞中NLRP3炎症小体相关蛋白的表达。然而，在小胶质细胞中过表达NLRP3，可抵消Gen介导的炎症因子释放抑制作用，并逆转Gen的神经保护作用。综上，本研究结果表明，Gen给药可通过抑制小胶质细胞中的NLRP3炎症小体，减轻生殖衰老小鼠脑缺血诱导的急性损伤，提示Gen有望成为治疗绝经后女性脑卒中的候选药物。