朊病毒感染的仓鼠脑组织中NLRP3介导的炎症反应机制的初步探索

Preliminary Exploration of the NLRP3⁃mediated Inflammatory Response in Prion⁃infected Hamster Brain Tissue

神经炎症主要由活化的胶质细胞介导,是大多数神经退行性疾病的共同特征。为了探究朊病毒感染后的大脑神经炎症反应与核苷酸结合寡聚化结构域样受体蛋白3(NOD-like receptor protein 3, NLRP3)炎症小体形成是否相关,本研究以朊病毒感染的仓鼠脑组织为研究对象,通过Western blot、免疫组织荧光方法检测了脑组织中NLRP3的生成和分布;同时借助免疫共沉淀方法检测了NLRP3炎症小体的形成情况。结果显示:朊病毒感染后,仓鼠脑组织中大脑皮层和海马区NLRP3的合成均明显增加,海马区的含量明显高于大脑皮层;NLRP3与星形胶质细胞存在明显共定位的现象,与小胶质细胞及神经元细胞几乎不存在共定位;感染后的仓鼠脑组织中炎症小体的另外两种组成成分半胱氨酸蛋白酶前体(Procaspase1,proCas1)和凋亡相关颗粒样蛋白(Apoptosis-associated granuloid proteins, ASC)也明显高于正常仓鼠。这些结果表明:朊病毒感染后,仓鼠脑组织中NLRP3及炎症小体合成明显增多,NLRP3炎症小体的组装主要发生在星形胶质细胞中。

Neuroinflammation is a common feature of most neurodegenerative diseases.It is mediated primarily by activated glial cells.We investigated whether neuroinflammation is related to formation of the NOD‐like receptor protein 3(NLRP3)inflammasome in the brain after prion infection.Prion‐infected hamster brain tissue was the research object.The content and distribution of NLRP3 in brain tissue were measured by western blotting and immunofluorescence staining.Formation of the NLRP3 inflammasome was detected by co‐immunoprecipitation.The synthesis of NLRP3 in the cerebral cortex and hippocampus was increased significantly,and its content in the hippocampus was significantly higher than that in the cerebral cortex,after prion infection.NLRP3 was co‐localized with astrocytes,but co‐localization with microglia and neurons was absent.Expression of the other two components of the NLRP3 inflammasome(procaspase1 and ASC)was significantly higher in infected hamsters than in healthy hamsters.These results indicate that the syntheses of NLRP3 and the NLRP3 inflammasome are increased significantly in hamster brain tissue after prion infection,and that assembly of the NLRP3 inflammasome occurs mainly in astrocytes.