G蛋白信号传导通路和颅内动脉瘤的关系

Relationship between G protein signal transduction pathway and intracranial aneurysm

目的采用基因芯片技术探讨G蛋白信号传导通路与颅内动脉瘤的相关性。方法采集50例颅内动脉瘤患者的外周血，且将10例正常成人作为对照组，分离其血液单核细胞，另外收集6例手术切除的颅内动脉瘤组织标本和3例正常成人的脑动脉血管，提取总RNA．分别与含22215个人类基因的寡核苷酸基因芯片杂交、洗脱、染色和扫描，分析检测数据，荧光定量RT-PCR法验证芯片检测结果。结果在检测的22215个基因中，颅内动脉瘤患者血液中共差异表达的基因有325个，颅内动脉瘤组织中差异表达水平均达2倍以上的基因有571个，生物信息学分析发现多个G蛋白信号传导通路的相关基因存在上调或下调表达，其中3个基因在动脉瘤组织和血液中均有差异表达，即上调表达的RAB31和下调表达的ARHGAP8和CENTG2。结论G蛋白信号传导通路可能是颅内动脉瘤的一种重要发病机制，RAB31、ARHGAP8和CENTG2与颅内动脉瘤的关系值得进一步研究。

Objective To identify G protein signal transduction pathway related genes in peripheral blood mononuclear cells and aneurysm tissues from intracranial aneurysm patients using oligo-microarrays. Methods Blood samples from 50 intracranial aneurysms and 10 healthy human donors were obtained atter informed consent. Peripheral blood mononuclear cells （PBMCs） were isolated from blood using Ficoll method. And aneurysm tissue samples from 6 intracranial aneurysms and 3 healthy human intracranial arteries were obtained. The cDNA were retrotranscribed from the extracted RNA and the biotin-labeled cRNA derived from the transcription of cDNA were fragmented as probes. Then, the probes were hybridized with Affymetrix Human Genome U133A Array. GeneArray Scanner was used to screen the signals of hybridization and Microarray Suite software 5.0 was applied to analyze the expression of genes. Results There were 325 genes differently expressed in PBMCs from intracranial aneurysm patients compared to healthy human. And 571 genes were differently expressed above 2-fold level in aneurysmal tissue from intracranial aneurysm patients compared to healthy human intracranial arteries. Function analysis was confirmed from upregulated genes and downregulated genes, and among these genes, there were several genes invovled in G protein signal transduction pathway. There were 3 genes directionally expressed （RAB31 upregulated and ARHGAP8, CENTG2 downregulated） both in PBMCs and aneurysm tissues from intracranial aneurysm patients. Conclusions The methodologies of genechip will provide a new powerful approach to help identify the molecular mechanisms of intracranial aneurysm. G protein signal transduction pathway may be the possible mechanism for the pathogenesis of intracranial aneurysms in Chinese.