Association Study Between PRKCH-NOS2A Pathway Genes And Ischemic Stroke

Ischemic stroke (IS), a common neurological disease, is one of the leading causes ofsevere disability and death. Recently, accumulating evidence supports that atherosclerosis(AS) plays an important role in the development of IS, and that the disruption of the fibrouscap of vulnerable atheromatous plaques leads to intravascular thrombosis and acutecerebrovascular events. It is known that atherosclerosis is a chronic vascular inflammatoryprocess with the participation of several inflammatory cells and pathways. By retrieving thepathway database, we find the PRKCH-NOS2A pathway genes play a role in arterialendothelial inflammation. PRKCH gene, located in the upper sequence of NOS2A, is aregulator of NOS2A. This gene also encodes the protein kinase C η(PKC η), which isexpressed in the foam macrophages and smooth muscle cells of AS plaque. And induciblenitric oxide synthase (iNOS), coding by NOS2A gene, is a significant inflammatory factorwhich is released by macrophages and is responsible for endothelial inflammation. Therefore,we choose the PRKCH-NOS2A pathway as a candidate gene to discuss its relationship withischemic stroke.We recruited505unrelated patients with ischemic stroke, admitted to the First Hospitalof Jilin University, Changchun, China in the period between2009and2010for thecase-control study. They were diagnosed as having ischemic stroke based on strictneurological examination, brain CT/MRI, which meet the International Classification ofDiseases (NCHS2007). The505controls came from the physical examination center, theFirst Hospital of Jilin University, in the period between2009and2010. Through readingliterature, browsing dbSNP database of the human genome data and SNPs map of thePRKCH-NOS2A pathway genes, we found exon9of the PRKCH gene, promoter and exon1of the NOS2A gene might play a role in the pathogenesis of ischemic stroke. Sequencinganalysis of these two gene segments was applied to genotype SNPs of them.We found3other SNPs, except1425G/A (rs2230500) and1427A/C (rs2230501), inexon9of the PRKCH gene, and they were rs57887308, rs58360439and rs17098394. Bysequencing the promoter and exon1of the NOS2A gene, we found both-969G/C and-1173C/T were not SNPs of Chinese Han descent, but we found another3variants in thisNOS2A gene fragment:-277T/C(rs2779248),-1026C/A(rs2779249) and 38C/G(rs10459953). According to A-S-C-O classification standard, the case group wasdivided into aortic atherosclerotic stroke and lacunar infarction two subgroups. But thecocaphase analysis showed no significant differences in allele frequency and genotypefrequency between IS group, subgroups and control group (P>0.05). But, in the quantitiveanalysis we found that NOS2A gene C allele of SNP8(rs10459953) together with higherplasma low-density lipoprotein cholesterol level (P=0.009) was associated with IS. Wespeculate that groups with C allele may have higher iNOS expression level. And thisover-expressed iNOS may cooperate with higher plasma LDL-c and cholesterol level tocause endothelial dysfunction, increase inflammatory reaction, aggravate the process of AS,and finally increase the risk of ischemic stroke.The data of our study suggests:①P olymorphisms ofrs2230500, rs2230501,rs57887038, rs58360439and rs17098394of the PRKCH gene is not associated withischemic stroke in a northern Chinese Han population;②Polymorphisms of rs2779248,rs2779249and rs10459953of the NOS2A gene is not associated with ischemic stroke in anorthern Chinese Han population;③NOS2A gene C allele of SNP8(rs10459953) togetherwith higher plasma low-density lipoprotein cholesterol level (P=0.009) may be associatedwith IS.Our study is based on A-S-C-O classification standard combined with multiple vesselexaminations to divide stroke subtypes, avoiding case classification judgment uniformity byTOAST classification. The results are more reliable. Quantitive analysis of traditional IS riskfactors and candidate pathway genes is also applied in this study to uncover the character ofpolygenic diseases. In addition, gene sequencing is also a hot method in molecular genetics.A mass of information of SNPs gets from this simple and quick method. For ischemic stroke,as a polygenic disease, gene sequencing gains more advantages in the candidate genescreening.