Metabotropic glutamate receptor expression in cultured rat astrocytes and human gliomas
Metabotropic glutamate receptor expression in cultured rat astrocytes and human gliomas
复制标题
DOI：
10.1023/a:1027317319166
复制
发表时间：
1997-09-01
影响因子：
4.4
通讯作者：
Stella, AMG
中科院分区：
文献类型：
--
作者：
Condorelli, DF;DellAlbani, P;Stella, AMG
为了证实星形胶质细胞培养中是否存在代谢型谷氨酸受体，并提供不同受体亚型的信息，我们分析了在高度富含星形胶质细胞的培养中不同mGluRs的表达。Northern印迹分析未检测到来自全大脑半球、大脑皮层和纹状体的原代培养的1型星形胶质细胞mGluR1、2、3、4、7的mRNA水平。有趣的是，这些培养物表达了低水平但可检测到的mGluR5 mRNA。更灵敏的逆转录聚合酶链式反应(RT-PCR)证实了培养的星形胶质细胞中存在mGluR5转录本，此外，还发现了mGluR3mRNA的存在。在CG-4细胞中缺乏mGluR5的表达，这表明mGluR5的存在不是胶质起源细胞的一般特征。CG-4细胞系能够根据培养条件向2型星形胶质细胞或少突胶质细胞分化。此外，所有检测到的mGluR转录本在CG4细胞中均未检测到。为了证实mGluR5在胶质细胞中的可能表达，我们检测了手术切除后的人脑胶质瘤组织标本中mGluR5的mRNA水平：8例中只有1例(II级星形细胞瘤)检测到mGluR5的表达。总之，BUR数据表明，唯一与肌醇磷脂水解有关的克隆代谢性受体是mGluR5，该受体在培养的1型星形胶质细胞中可检测到表达。MGluR3的低水平表达是否可能是先前在培养的星形胶质细胞中观察到的II组代谢性谷氨酸受体活性的原因仍有待确定。
In order to confirm the existence of metabotropic glutamate receptors in astroglial cultures and to provide information on different receptor subtypes, the expression of different mGluRs was analysed in cultures highly enriched in rat astroglial cells. mRNA levels for mGluR1, 2, 3, 4, 7 were undetectable by Northern blot analysis in primary type-1 astroglial cultures derived from total cerebral hemispheres, cerebral cortex and striatum. Interestingly, these cultures expressed a low, but detectable, level of mGluR5 mRNA. The more sensitive technique Reverse Transcription-Polymerase Chain Reaction (RT-PCR) confirmed the presence of mGluR5 transcript in cultured astrocytes and, in addition, revealed the presence of mGluR3 mRNA. The lack of expression of mGluR5 in CG-4 cells, a rat cell line able to differentiate in type-2 astrocytes or oligodendrocytes depending on the culture conditions, suggested that the presence of mGluR5 was not a general feature of cells of glial origin. Moreover, all the examined mGluR transcripts were undetectable by RT-PCR in CG4 cells. In order to confirm the possible expression of mGluR5 in cell of glial origin we examined the mRNA levels for this receptor in tissue samples from human gliomas obtained after surgical resection of the tumors: only 1 sample (grade II astrocytoma), out of 8 examined, showed the presence of mGluR5 mRNA. In conclusion bur data show that the only cloned metabotropic receptor linked to phosphoinositide hydrolysis, whose expression is detectable in cultured type-1 astrocytes, is mGluR5. It remains to be established if the low level of expression of mGluR3 could be responsible for the group II metabotropic glutamate receptor activity previously observed in cultured astroglial cells.