HETEROGENEOUS EXPRESSION OF CARBOXYPEPTIDASE-E AND PROENKEPHALIN MESSENGER-RNAS BY CULTURED ASTROCYTES
HETEROGENEOUS EXPRESSION OF CARBOXYPEPTIDASE-E AND PROENKEPHALIN MESSENGER-RNAS BY CULTURED ASTROCYTES
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DOI：
10.1016/0006-8993(92)90643-n
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发表时间：
1992-01-13
期刊：
影响因子：
2.9
通讯作者：
FRICKER, LD
中科院分区：
文献类型：
--
作者：
KLEIN, RS;FRICKER, LD
已发现培养的星形胶质细胞表达神经肽、神经肽加工酶及其mRNAs。尽管星形胶质细胞在这些mRNAs的表达上表现出区域性差异，但目前尚不清楚来自同一脑区的所有星形胶质细胞是否表达相似的mRNAs，或者这种表达是否是不同的。我们用原位杂交法检测了不同脑区培养的星形胶质细胞的个体异质性。取新生大鼠额叶皮质、下丘脑和小脑的星形胶质细胞培养3周，用S-35标记的羧基肽酶E(CPE)、脑啡肽原(PE)和亲环素(LB15)基因的cRNA探针和大鼠18S rRNA的前45个碱基互补的寡核苷酸探针进行原位杂交。通过对乳胶包被细胞产生的颗粒进行计数产生的频率直方图显示，星形胶质细胞群体表达CPE和PE的高水平mRNA，以及表达低水平到背景水平的这些mRNAs的群体。相反，所有培养的星形胶质细胞都表达高水平的Lb15mRNA和18SRRNA。培养的星形胶质细胞高表达CPE mRNA的比例额叶星形胶质细胞为42%，小脑星形胶质细胞为23%。虽然培养的星形胶质细胞高表达PE mRNA的百分比在不同脑区之间差异很小(24-28%)，但每个细胞的PE mRNA表达水平在不同区域之间差异较大。同时考察了培养密度对PE基因表达的影响。在低密度培养中，约有55%的细胞表达PE mRNA，而在高密度培养中，仅有5.10%的细胞表达该mRNA。这些结果表明，培养的星形胶质细胞在神经肽的生物合成方面表现出个体的异质性，这些细胞对神经肽的表达是受调控的。
Cultured astrocytes have been found to express neuropeptides, neuropeptide processing enzymes and their mRNAs. Although astrocytes were shown to display regional variation in their expression of these mRNAs, it was unclear whether all astrocytes cultured from the same brain region express similar mRNA levels or if this expression is heterogeneous. We examined the individual heterogencity of astrocytes cultured from several brain regions by in situ hybridization. Astrocytes derived from the frontal cortex, hypothalamus and cerebellum of neonatal rat brains were cultured for 3 weeks and then analyzed by in situ hybridization using S-35-labeled cRNA probes to carboxypeptidase E (CPE), proenkephalin (PE), and cyclophilin (LB15) mRNAs and an oligomeric probe complimentary to the first 45 bases of rat 18S rRNA. Frequency histograms generated by counting the grains produced over emulsion-coated cells demonstrated populations of astrocytes expressing high levels of mRNA for CPE and PE and a population expressing low to background levels of these mRNAs. In contrast, all cultured astrocytes expressed high levels of LB15 mRNA and 18S rRNA. The percentage of cultured astrocytes expressing high levels of CPE mRNA was 42% for frontal cortex astrocytes and 23% for cerebellar astrocytes. While the percentages of cultured astrocytes expressing high levels of PE mRNA varied slightly between brain regions (24-28%), the level of PE mRNA expression per cell showed greater variation between regions. The effect of culture density on the expression of PE mRNA was also examined. Approximately 55% of the cells in low density cultures expressed PE mRNA, while only 5.10% of the cells in high density cultures expressed this mRNA. These results indicate that cultured astrocytes display individual heterogeneity with regard to neuropeptide biosynthesis and that the expression of neuropeptides by these cells is regulated.