人脑动静脉畸形差异表达基因的筛选和研究

The screening study of the differentially expressed genes in human brain arteriovenous malformations

目的应用基因芯片技术分析人脑动静脉畸形的基因表达谱。方法收集4例脑动静脉畸形样本和4例难治性癫痫患者行颞叶切除后显微分离的脑血管对照样本,提取组织中的总RNA,分别标记荧光探针后与含有21522个基因的寡核苷酸芯片进行杂交,SAM软件筛选差异表达基因,最后应用在线生物分子功能注释系统分析其可能参与的分子信号通路。结果脑动静脉畸形样本中118个基因的表达存在显著性差异,表达上调的45个,下调的73个。丝裂原活化蛋白激酶(MARK)信号通路富集基因最多,差异基因MAPK3、RPS6KA1、DUSP14、DUSP2参与ERK1/ERK2MAPK信号传导。ITGA4基因表达显著上调,其平均表达水平是对照组的6.15倍。一些血管生成相关基因如血管内皮生长因子、血管生成素和Ephrin家族基因表达未见显著性差异。结论ERK1/ERK2MAPK信号通路可能参与脑动静脉畸形的血管生成和血管重构。ITGA4基因可能通过其产物介导纤维结合蛋白信号,促进血管内皮细胞的增殖,在脑动静脉畸形的血管生成中发挥重要作用。

Objective To analyze the gene expression profiles in brain AVM samples by gene microarray technique. Methods Four brain AVM samples and four control brain vascular samples obtained by temporal lobectomy for medically intractable seizure were collected. The total RNA was extracted and detected. Hybridization with oligonucleotide array containing 21 522 genes was performed after the RNA was labeled with fluorescent probe. The differentially expressed genes between the two groups and the significant pathways of brain AVM were analyzed using the signifiance analysis of microarrays （SAM） and a free web-based molecular annotation system（MAS）. Results 118 gene probes showed differential expression between brain AVMs and the controls. Among these genes, 45 genes were significantly up-regulated and 73 genes were significantly down-regulated. ERK1/ERK2 MAPK pathway had the most differential genes, including MAPK3.RPS6KA1 ,DUSP14,DUSP2. Compared with the controls, brain AVM samples showed a 6.5 fold higher expression level of mRNA for ITGA4. Genes relating to angiogenesis, such as vascular endothelial growth factor and angiopoietin and members of the ephrin family, were not significantly different between two groups. Conclusions ERK1/ERK2 MAPK pathway is especially involved in angiogensis or vascular remodeling of brain AVM. It may be postulated that the up-regulated ITGA4 gene plays a facilitating role during the angiogenesis of brain AVM via mediating fibronectin signal and promoting endotheliocyte proliferation by its product.