Expression and distribution of GABAA receptor subtypes in human alcoholic cerebral cortex
Expression and distribution of GABAA receptor subtypes in human alcoholic cerebral cortex
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DOI：
10.1111/j.1749-6632.2000.tb05183.x
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发表时间：
2000-01-01
期刊：
影响因子：
--
通讯作者：
Dodd, PR
中科院分区：
文献类型：
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作者：
Buckley, ST;Eckert, AL;Dodd, PR
众所周知，长期酒精滥用会针对大脑的特定区域，如上额叶皮层（SFC），导致神经元细胞丢失。抑制性神经递质GABA的异常传递可能导致这种损伤。本实验室前期工作发现GABA(A)受体某些α亚基基因在人酒精脑SFC中的表达和分布存在差异，提示GABA(A)受体亚基表达的差异可能导致GABA(A)药理学的局部改变，这与酒精滥用有关。一种竞争性的RT-PCR方法已经被开发出来，用于研究GABA(A)受体β亚基基因β(1)、β(2)和β(3)的表达。一组与所有三种β同型异构体序列同源的引物已被证明可以从尸检获得的人类脑组织中分离的mRNA中扩增每一种β同型异构体。设计了一种与靶标相同的内标，除了一个61-bp的缺失和一个独特的限制性内切酶（RE）位点。这是共同扩增的目标序列，以允许扩增效率进行评估，从而使基因表达的定量。一系列GABA(A)受体配体通过放射自显影术观察皮质层中受体亚型的差异分布。配体分布的差异被证明，与酒精诱导受体亚基表达变化的假设一致。
Long-term alcohol abuse is known to target specific areas of the brain such as the superior frontal cortex (SFC), resulting in neuronal cell loss. Abnormal transmission of the inhibitory neurotransmitter GABA may contribute to this damage. Previous work in our laboratory has found differential expression and distribution of certain alpha subunit genes of the GABA(A) receptor in the SFC of human alcoholic brain, suggesting that differences in GABA(A) receptor subunit expression could give rise to the locally altered GABA(A) pharmacology which is associated with alcohol abuse. A competitive RT-PCR assay has been developed to study the expression of the GABA(A) receptor beta -subunit genes beta (1), beta (2), and beta (3). A single set of primers homologous to all three beta isoform sequences has been shown to amplify each of the beta isoforms from mRNA isolated from human brain tissue obtained at autopsy. An internal standard has been designed which is identical to the target except for a 61-bp deletion and a unique restriction enzyme (RE) site. This is co-amplified with the target sequences to allow amplification efficiency to be assessed and thus enable the quantitation of gene expression. A range of GABA(A) receptor ligands were used to look at differential distribution of receptor subtypes in the cortical laminae by autoradiography. Differences in distribution of the ligands were demonstrated, consistent with a hypothesis of alcohol-induced variations in the expression of receptor subunits.