【作者】 韦芳；

【导师】 王正荣；

【作者基本信息】 四川大学 ， 生物医学工程， 2003， 硕士

【摘要】 目的 缓激肽-组织激肽释放酶系统在维持体液平衡、调节血压、细胞增殖和炎症方面起着重要作用，是高血压疾病的相关或候选基因。在高加索人、非洲美国人和亚洲人群中，Qing Song等用核酸测序技术发现在人的组织激肽释放酶基因5′端启动子区域即-121至-133之间存在着一个高度变异的多态位点，有十种等位基因A、B、C、D、E、F、H、I、K、P，各型之间的差异仅在于单个碱基突变或插入，其中D和H类型的启动子经基因重组再转染人胚胎肾293细胞系后，细胞中组织激肽释放酶的表达量显著减少。为弄清该多态位点在我国汉族人群中的分布，并确定其与原发性高血压的关系，本课题率先开展组织激肽释放酶基因调控序列多态性与高血压的关联性研究。 方法 根据制定的入选和排除标准，分别选取正常人群与高血压患者人群共80例。取外周静脉血，分别提取外周血细胞的基因组DNA，经PCR扩增出180bp长度的目标DNA，再将该目标DNA与十种探针分别做点杂交检测。从而确定两组中的各种基因和基因型频率，并用x~2检验比较两组间的差异有无统计学意义，分析该多态位点与高血压的关系。结果在中国汉族人群中，组织激肤释放酶基因启动子区域只存在A、B、H、K四种等位基因，在对照组中各频率分别为45%、37.5%、17.5%和0%，而在高血压组中频率分别为45%、20%、33.75%和1.25%，两组比较有统计学意义(尸<0.025)。另外，高血压组AB、AH、BH、AA、HH、BK基因型分别为20%、35%、17.5%、17.5%、7.5%和2.5%;对照组AB、AH、BH、AA、 BB、HH基因型又分别为50%、5%、15%、17.5%、5%和7.5%，有显著差异(P<0.009)。结论本研究证实，人组织激肤释放酶基因启动子区一121至一133之间确实存在多态性，在我国汉族人群中只存在A、B、H和K四型。各等位基因在高血压患者和正常人群中的基因型及基因频率分布都有差异，尤以H基因型显著;该等位基因本身与原发性高血压的发病相关，为解释高血压的发生提供了新的遗传学依据。更多还原

【Abstract】 Objective The tissue kallikrein-kinin system has long been implicated in blood pressure regulation by genetic and physiological studies. Human tissue kallikrein gene polymorphisms were identified by Qing Song in the promoter region by polymerase chain reaction(PCR) and DNA sequencing in 1997. One polymorphic region was identified between nucleotides -121 and -133 with respect to the transcription initiation site of the tissue kallikrein gene. Ten alleles with length and nucleotide sequence variations were detected among Caucasians, African-Americans, and Asians. The promoter activity was analyzed in human embryonic kidney 293 cells by transient transfection assays, while alleles D and H had shown significantly lower promoter activities than the other alleles. In this study, we will detect the distribution of this SNP in Chinese Hans, and determine whether it is associated with essential hypertension.Methods Human genome was extracted from peripheral blood in 40 patients with EH and 40 healthy subjects. A 180-bp fragment containing the polymorphic region amplified by PCR using humangenome as the template, was analyzed by hybridizations with ten oligonucleotide probes.Results Only A, B, H, K alleles were detected in Chinese Hans. The frequencies of A, B, H, K alleles were respectively 45%, 37.5%, 17.5% and 0% in healthy subjects, while were 45%, 20%, 33.75% and 1.25% in patients. The frequencies of AB, AH, BH, AA, HH, BK were 20%, 35%, 17.5%, 17.5%, 7.5% and 2.5% respectively in patients, while the frequencies of AB, AH, BH, AA, BB, HH were 50%, 5%, 15%, 17.5%, 5% and 7.5% in healthy, with statistical difference(P<0.01) between two groups.Conclusion A, B, H and K alleles are four types of polymorphisms in Chinese Hans’s tissue kallikrein gene. The distributions of the four alleles are statistical difference between patients and healthy groups, with H allele especially higher in patients. These results suggest that the identified gene variants be associated with essential hypertension.更多还原