Expression of caveolin-1 and -2 in differentiating PC12 cells and dorsal root ganglion neurons:: Caveolin-2 is up-regulated in response to cell injury
Expression of caveolin-1 and -2 in differentiating PC12 cells and dorsal root ganglion neurons:: Caveolin-2 is up-regulated in response to cell injury
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DOI：
10.1073/pnas.95.17.10257
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发表时间：
1998-08-18
影响因子：
11.1
通讯作者：
Lisanti, MP
中科院分区：
文献类型：
--
作者：
Galbiati, F;Volonté, D;Lisanti, MP
小凹是质膜上富含胆固醇/鞘脂的微结构域，与信号转导和囊泡运输有关。小窝蛋白是小窝相关的整合膜蛋白家族。 Caveolin-1 和 -2 显示最广泛的表达范围，而 Caveolin-3 的表达仅限于肌肉细胞类型。之前有报道称，通过 Northern blot 分析，在大脑中或在神经母细胞瘤细胞系中，很少或根本没有检测到 Caveolin mRNA 种类。然而，小窝蛋白是否在神经元细胞内表达仍不清楚。在这里，我们通过使用单特异性抗体探针展示了 Caveolin-1 和 -2 在分化 PC12 细胞和背根神经节 (DRG) 神经元中的表达。在 PC12 细胞中，caveolin-1 表达在神经生长因子 (NGF) 处理的第 4 天上调，而 Caveolin-2 表达在分化程序早期短暂上调，然后迅速下调。有趣的是，caveolin-2 在响应分化 PC12 细胞的机械损伤时上调；在这些条件下，caveolin-2 的上调严格依赖于 NGF 的持续治疗。在 DRG 神经元的整个细胞表面也观察到 Caveolin-1 和 -2 的强烈表达，包括生长锥上的高水平表达。这些发现表明神经元细胞表达小窝蛋白。
Caveolae are cholesterol/sphingolipid-rich microdomains of the plasma membrane that have been implicated in signal transduction and vesicular trafficking. Caveolins are a family of caveolae-associated integral membrane proteins. Caveolin-1 and -2 show the widest range of expression, whereas caveolin-3 expression is restricted to muscle cell types. It has been previously reported that little or no caveolin mRNA species are detectable in the brain by Northern blot analyses or in neuroblastoma cell lines. However, it remains unknown whether caveolins are expressed within neuronal cells. Here we demonstrate the expression of caveolin-1 and -2 in differentiating PC12 cells and dorsal root ganglion (DRG) neurons by using mono-specific antibody probes. In PC12 cells, caveolin-1 expression is up-regulated on day 4 of nerve growth factor (NGF) treatment, whereas caveolin-2 expression is transiently up-regulated early in the differentiation program and then rapidly down-regulated. Interestingly, caveolin-2 is up-regulated in response to the mechanical injury of differentiated PC12 cells; up-regulation of caveolin-2 under these conditions is strictly dependent on continued treatment with NGF. Robust expression of caveolin-1 and -2 is also observed along the entire cell surface of DRG neurons, including high levels on growth cones. These findings demonstrate that neuronal cells express caveolins.