Recently, we have identified a functional expression of farnesoid X receptor (FXR) in neurons in vitro and in vivo. However, whether the FXR is expressed in astrocytes remains unclear. In the present study, we addressed this issue by using an array of experimental methods such as immunofluorescence and western blot. Results showed that the FXR mRNA and protein were expressed in mouse brain primary cultured astrocytes. In mouse primary cultured astrocytes in vitro the FXR was predominantly localized in the nucleus with an obvious punctuate distribution property. Unlike its expressional characteristic in cultured astrocytes, the FXR was not detected in astrocytes in the mouse hippocampus and prefrontal cortex, suggesting that the FXR is not expressed in astrocytes at conditions in vivo. Functional studies in vitro showed that activation of the FXR in primary cultured astrocytes by chenodeoxycholic acid or GW4064 induced a marked increase in expression levels of small heterodimer partner mRNA and protein. Taken together, these findings show a differential expression of FXR in astrocytes at conditions in vitro but not in vivo, and in mouse primary cultured astrocytes the FXR can be activated by its ligands.

中文翻译：

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星形胶质细胞中法尼醇X受体表达的鉴定。

最近，我们在体外和体内鉴定了法尼醇 X 受体 (FXR) 在神经元中的功能表达。然而，FXR 是否在星形胶质细胞中表达仍不清楚。在本研究中，我们通过使用一系列实验方法（例如免疫荧光和蛋白质印迹）解决了这个问题。结果表明，FXR mRNA和蛋白在小鼠脑原代培养的星形胶质细胞中表达。在小鼠体外原代培养的星形胶质细胞中，FXR主要定位于细胞核，具有明显的点状分布特性。与其在培养的星形胶质细胞中的表达特征不同，在小鼠海马和前额皮质的星形胶质细胞中未检测到FXR，这表明FXR在体内条件下在星形胶质细胞中不表达。体外功能研究表明，鹅去氧胆酸或 GW4064 激活原代培养的星形胶质细胞中的 FXR 会诱导小异二聚体伴侣 mRNA 和蛋白质的表达水平显着增加。总而言之，这些发现表明，在体外条件下星形胶质细胞中 FXR 存在差异表达，但在体内条件下则不然，并且在小鼠原代培养的星形胶质细胞中，FXR 可以被其配体激活。