Petitto J M, Huang Z
Department of Psychiatry, University of Florida College of Medicine, Gainesville 32610.
Brain Res. 1994 Jul 4;650(1):140-5. doi: 10.1016/0006-8993(94)90216-x.
While interleukin-2 (IL-2) has been shown to produce a variety of effects in the CNS and has recently been implicated as an endogenous brain neurokine, little is known about the molecular biology of IL-2 receptors in normal brain. The present investigation provides the first evidence that mRNA for IL-2 receptor-beta (IL-2R beta), an essential subunit for signal transduction by peripheral immune cells, is expressed in normal murine forebrain. Using polymerase chain reaction (PCR) cloning, a partial cDNA (349 bp) corresponding to the extracellular domain was cloned and found to have the identical sequence as the lymphocyte IL-2R beta. IL-2R beta mRNA expression was confirmed by a ribonuclease protection assay, and using in situ hybridization histochemistry, IL-2R beta mRNA was localized in the hippocampus where an intense signal was present over the neuron-rich granule cells of the dentate gyrus and Ammon's horn. Moreover, cDNA clones obtained from two murine neuroblastoma cell lines exhibited the same sequence as IL-2R beta cDNA from normal brain. IL-2R beta gene expression was also detected in the frontal cortex and striatum using PCR. Further in situ hybridization studies will be important to extend this initial observation to determine the brain regional localization and cell-specific anatomy of IL-2R beta mRNA in the CNS.
虽然白细胞介素-2（IL-2）已被证明在中枢神经系统中产生多种效应，并且最近被认为是一种内源性脑神经营养因子，但对于正常大脑中IL-2受体的分子生物学知之甚少。本研究提供了首个证据，表明外周免疫细胞信号转导所必需的亚基IL-2受体β（IL-2Rβ）的mRNA在正常小鼠前脑中表达。通过聚合酶链反应（PCR）克隆，克隆出了对应于细胞外结构域的部分cDNA（349 bp），发现其与淋巴细胞IL-2Rβ具有相同的序列。通过核糖核酸酶保护试验证实了IL-2Rβ mRNA的表达，并且使用原位杂交组织化学方法，将IL-2Rβ mRNA定位在海马体中，在齿状回和海马的富含神经元的颗粒细胞上存在强烈信号。此外，从两种小鼠神经母细胞瘤细胞系获得的cDNA克隆与来自正常大脑的IL-2Rβ cDNA具有相同的序列。使用PCR还在额叶皮质和纹状体中检测到了IL-2Rβ基因表达。进一步的原位杂交研究对于扩展这一初步观察结果以确定中枢神经系统中IL-2Rβ mRNA的脑区定位和细胞特异性解剖结构很重要。
