摘　要：Aβ1-42与小胶质细胞之间相互作用诱发的神经炎症反应已被视为阿尔茨海默病（AD）的重要病理指征，酸敏感离子通道（ASIC）参与了小胶质细胞的炎症应答和神经炎症免疫调节。为了探究Aβ1-42对小胶质细胞ASIC的表达和电生理特性的影响，本研究利用Aβ1-42孵育原代培养的SD大鼠大脑皮层小胶质细胞，免疫印迹技术和免疫荧光技术检测小胶质细胞ASIC1、ASIC2a、ASIC3的蛋白表达和分布情况，全细胞膜片钳记录Aβ1-42对ASIC电流特性的影响，钙离子成像技术分析ASIC钙离子通透性的变化。结果显示：Aβ1-42处理小胶质细胞后，能够诱导ASIC1的蛋白表达量增加，且其在细胞浆和细胞核中均有明显增加；胞外pH值快速降低诱发的ASIC电流，小胶质细胞胞内钙离子浓度明显增强，这种增强效应可被ASIC非特异性抑制剂阿米洛利和ASIC1特异性抑制剂PcTx1抑制。本研究结果表明，Aβ1-42诱导小胶质细胞ASIC1蛋白功能性表达增加，使得ASIC1易于被胞外快速酸化激活而表现出明显增强的电生理特性，进而影响小胶质细胞的炎症应答和免疫调节作用，为后续探究小胶质细胞感应通路和应答调节及神经退行性疾病发生提供了思路和参考。
关键词：Aβ1- 42；阿尔茨海默病；小胶质细胞；酸敏感离子通道；酸化
中图分类号：R965                              文献标志码：A                   DOI：10.3969/j.issn.1007-7146.2022.05.004

Abstract: The nerve inflammation induced by the interactions between Aβ1- 42 and microglia has been regarded as the important pathological indication of Alzheimer’s disease (AD). Acid-sensing ion channel (ASIC) involved in the inflammatory response and immune regulation of microglia. To observe the effects of the expression and electrophysiological properties of ASIC in microglia after exposure to Aβ1-42, primary cultured rat microglia were incubated with Aβ1-42. The protein expression and distribution of ASIC1, ASIC2a and ASIC3 were tested by Western blotting and immunofluorescence experiments. Whole-cell patch clamp was adopted to detect the ASIC current properties of microglia. Calcium imaging was performed to investigate the ion permeability of ASIC in microglia. The results showed that the protein expression of ASIC1 increased in Aβ1-42 stimulated microglia, the protein expression of ASIC1 in the cytoplasm and nucleus both increased. Meanwhile, acid-induced ASIC current and elevation of intracellular calcium increased, which could be inhibited by the nonspecific ASIC antagonist amiloride and specific ASIC1 blocker PcTx1. Therefore, this study confirmed that the functional expressed of ASIC1 increased in Aβ1-42 stimulated microglia, which make ASIC1 easily become activated by extracellular rapid acidification and produce more powerful inward current and acquire permeability to calcium ions, and thus affect the inflammatory response and immune regulation of microglia. This study provides valuable ideas and references for the further exploration of sensing pathway and response regulation of microglia and the occurrence of neurodegenerative diseases.
Key words: Aβ1- 42; Alzheimer,’s disease; microglia; ASIC; acidification
（Acta Laser Biology Sinica, 2022, 31(5): 404-410）