Differential expression of glutamate and GABA-A receptor subunit mRNA in cortical dysplasia
Differential expression of glutamate and GABA-A receptor subunit mRNA in cortical dysplasia
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DOI：
10.1212/wnl.56.7.906
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发表时间：
2001-04-10
期刊：
影响因子：
9.9
通讯作者：
White, R
中科院分区：
文献类型：
--
作者：
Crino, PB;Duhaime, AC;White, R
目的：局灶性皮质发育不良的特征是皮质分层紊乱，发育不良和异位神经元，并与癫痫有关。发育不良和异位神经元对局灶性皮质发育不良癫痫发生的贡献尚不清楚，这些细胞的表型可能不同。作者假设，编码谷氨酸能（谷氨酸[GluR]和N-甲基-D-天冬氨酸NMDA受体[NR]）和γ-氨基丁酸A受体（GABA（A）R）亚单位的基因表达在发育不良和异位神经元中是不同的，受体基因表达的变化可以以细胞特异性模式定义。研究方法：从癫痫手术中获得的人类局灶性皮质发育不良标本中显微解剖单个化学标记的发育不良和异位神经元。从死后对照皮质和颞叶切除术中切除的无发育不良的颞叶皮质显微解剖锥体神经元。扩增单个神经元的Poly（A）信使RNA（mRNA），放射性标记，并用于探测含有GluR（1-6）、NR 1A，1B、NR 2A-D和GABA（A）R α（1-6）和-R β（1-3）亚基cDNA的互补DNA（cDNA）阵列。通过磷光成像定量每个mRNA-cDNA杂交体的相对杂交强度。结果：正常对照组和非发育不良性癫痫组神经元GluR、NR和GABA（A）R亚单位mRNA表达无明显差异。与锥体细胞和异位神经元相比，发育不良神经元中GluR（4）、NR 2B和NR 2C亚单位mRNA表达增加，NR 2A和GABA（A）R β（1）亚单位mRNA表达减少。相反，在发育不良和异位神经元中，GABA（A）R α（1）、-R α（2）和-R β（2）以及GluR（1）mRNA水平均降低。结论：发育不良和异位神经元中GluR、NR和GABA（A）R mRNA的差异表达表明局灶性皮质发育不良中细胞特异性基因转录的变化。这些结果表明，发育不良和异位神经元可能是不同的，并作出不同的贡献癫痫发生局灶性皮质发育不良。
Objective: Focal cortical dysplasia is characterized by disorganized cortical lamination, dysplastic and heterotopic neurons, and an association with epilepsy. The contribution that dysplastic and heterotopic neurons make to epileptogenesis in focal cortical dysplasia is unknown and the phenotype of these cells may be distinct. The authors hypothesized that the expression of genes encoding glutamatergic (glutamate [GluR] and N-methyl-D-aspartate NMDA receptors [NR]) and gamma -aminobutyric acid A receptor (GABA(A)R) subunits is distinct in dysplastic and heterotopic neurons and that changes in receptor gene expression could be defined in a cell-specific pattern. Methods: Single immunohistochemically labeled dysplastic and heterotopic neurons were microdissected from human focal cortical dysplasia specimens obtained during epilepsy surgery. Pyramidal neurons were microdissected from postmortem control cortex and from temporal cortex without dysplasia resected during temporal lobectomy. Poly (A) messenger RNA (mRNA) from single neurons was amplified, radiolabeled, and used to probe complementary DNA (cDNA) arrays containing GluR(1-6), NR1A,1B, NR2A-D, and GABA(A)R alpha (1-6), and -R beta (1-3) subunit cDNAs. The relative hybridization intensities of each mRNA-cDNA hybrid were quantified by phosphorimaging. Results: GluR, NR, and GABA(A)R subunit mRNA expression did not differ between control neurons and nondysplastic epilepsy specimens. Expression of GluR(4), NR2B, and NR2C subunit mRNA was increased, and NR2A and GABA(A)R beta (1) subunit mRNA was decreased in dysplastic compared with pyramidal and heterotopic neurons. In contrast, GABA(A)R alpha (1), -R alpha (2), and -R beta (2) as well as GluR(1) mRNA levels were reduced in both dysplastic and heterotopic neurons. Conclusions: Differential expression of GluR, NR, and GABA(A)R mRNA in dysplastic and heterotopic neurons demonstrates cell specific gene transcription changes in focal cortical dysplasia. These results suggest that dysplastic and heterotopic neurons may be pharmacologically distinct and make differential contributions epileptogenesis in focal cortical dysplasia.