α7-nAChR在海马星形胶质细胞上的表达

Expression of α7-nAChR on rat hippocampal astrocytes in vivo and in vitro

目的探讨α7-nAChR亚基在体内、体外海马星形胶质细胞上的表达。方法从大鼠脑中分离海马后进行冰冻切片,采用免疫荧光双染技术,首先用抗-GFAP抗体对星形胶质细胞进行鉴定,再观察α7-nAChR在星形胶质细胞上的表达。体外表达的研究在培养星形胶质细胞上进行,先分离获得新生SD大鼠的海马组织,提取并培养海马星形胶质细胞,纯化鉴定后,用配体结合实验和细胞免疫荧光双标分析α7-nAChR在星形胶质细胞上的表达。结果海马组织中抗-GFAP染色阳性的细胞抗-α7-nAChR染色也呈阳性,但仅部分抗-α7-nAChR染色阳性的细胞抗-GFAP染色也呈阳性。体外纯化后的星形胶质细胞既能与FITC标记的α-BTX结合,荧光染色呈阳性,同时,细胞免疫荧光双标分析显示星形胶质细胞抗-GFAP和抗-α7-nAChR染色均呈阳性。结论α7-nAChR在体内体外星形胶质细胞上均能正常表达。

Objective To investigate the expression of α7-nAChR on rat hippocampal astrocytes in vivo and in vitro. Methods Rat hippocampus was isolated and cut into 30-μm cryosections with anti-GFAP antibody staining followed by staining for α7-nAChR. The cultured astrocytes obtained from newborn rat （1-2 days old） hippocampus were identified with GFAP, and the expression of α7-nAChR was measured by fluorescein isothcyanate-tagged α-bungarotoxin staining analysis and double immunolabeling. Results The localization ofα7-nAChR was visualized in green with fluorescein isothiocyanate labeled IgG, whereas that of GFAP in red with Texas red-labeled IgG in the hippocampal slices, and the yellow spots indicating colocalization of the two fluorescent probes was shown in a merging image, α-bungarotoxin-binding nicotinic receptors were clustered, and the colocalization of α7-nAChR and GFAP on the cultured hippocampal astrocytes was visualized with the two fluorescent probes. Conclusion The expression of α7-nAChR is identified on hippocampal astrocytes in vivo and in vitro.