宿主单核苷酸多态性及血浆miRNA与结核病易感性的分子流行病学研究

发布时间：2018-05-05 02:11

本文选题：结核病 + SNP　；参考：《北京协和医学院》2014年博士论文

【摘要】：结核病是严重危害人类健康的重要传染病之一。过去二十年随着现代结核病控制策略的普及,我国结核病防控工作取得了显著成效。但是,作为全球二十二个结核病高负担国家之一,我国的结核病疫情仍然非常严峻。面对这种形势,寻找有效的方法控制结核病,降低结核病发病率和死亡率成为当务之急。然而,目前结核病诊防治领域面临着很多瓶颈问题：耐药患者数量增多、新药研发迟缓；诊断方法耗时且敏感性差,难以满足临床工作需要；唯一可选的预防性疫苗(卡介苗)对成年人保护效果不佳。新药物、新诊断技术以及新疫苗的研发都离不开分子标识研究,尤其是具有我国自主知识产权的分子标识不仅仅是应用研究的基础,也将为高危人群鉴定以及疾病发生发展的机制研究提供线索和证据。本研究旨在通过分子流行病学研究方法,采用病例-对照的研究设计,分析宿主单核苷酸多态性(Single Nucleotide Polymorphism, SNP)及血浆microRNA (miRNA)与结核分枝杆菌感染状态及结核病发生之间的相关性,探讨结核分枝杆菌感染到结核病发生的进程中有潜在应用价值的宿主分子标识。结核病发病相关宿主SNP的病例-对照研究纳入三组调查对象(涂阳活动性肺结核患者组,结核分枝杆菌潜伏感染组和感染阴性对照组)共计600例,应用Illumina公司的Goldengate芯片对44个候选SNP进行检测。研究结果发现,IFNG2109G/A位点GG基因型与结核病发病风险的降低显著相关(OR=0.54,95%CI:0.30-0.98); TLR91174A/G位点GG基因型(OR=1.87,95%CI:1.08-3.23),及TLR91635位点AA基因型(OR=1.90,95%CI:1.09-3.31)均与较高的结核病发病风险显著相关。同时,TLR91174G/G和IFNG2109A/A基因型表现出协同效应。其余候选SNP在本研究中未表现出与结核分枝杆菌感染或者结核病发病的显著相关性。以上结果提示在中国人群中TLR9和IFN-γ的基因多态性可能与肺结核的发病风险相关,为进一步探讨TLR9/IFN-γ通路在从结核分枝杆菌感染到致病的过程中所发挥的调控作用提供了思路。结核病发病与血浆miRNA表达水平的相关性研究纳入三组调查对象(涂阳活动性肺结核患者组,结核分枝杆菌潜伏感染组和感染阴性对照组)共计34例。针对调查对象的血浆样本,应用Agilent human miRNA芯片对1887个人类miRNA的表达水平进行检测,随后对筛选得到的11个差异表达miRNA应用Real-time qPCR (Fold Change4, P0.01)方法进行验证,最后对通过验证的差异表达miRNA进行靶基因预测和调控网络构建。研究结果发现,在与对照组(潜伏感染组和感染阴性对照组)的比较中,hsa-let-7b-5p和hsa-miR-30b-5p在结核病患者血浆中的表达水平显著上调(P0.05),基于统计模型的靶基因调控网络预测结果进一步提示,这两个miRNA可能通过调控炎症因子、细胞凋亡因子等的表达而参与结核病的发生。该研究结果为深入研究血浆miRNA在结核病发病过程中的调控作用及其作为诊断分子标识的应用价值提供了线索,也为进一步的大样本验证以及分子标识的优化组合提供了科学依据。
[Abstract]:Tuberculosis is one of the important infectious diseases seriously endangering human health. With the popularization of modern tuberculosis control strategy in the past twenty years, the tuberculosis prevention and control work has achieved remarkable results. However, as one of the twenty-two countries with high tuberculosis burden in the world, the epidemic situation in China is still very severe. Effective methods to control tuberculosis and reduce the incidence and mortality of tuberculosis have become the top priority. However, there are many bottlenecks in the field of tuberculosis treatment and prevention: the number of drug resistant patients, the slow development of new drugs, the time-consuming and poor sensitivity of the diagnostic methods, and the difficulty of meeting the needs of clinical work; the only optional preventive vaccine ( Bacillus Calmette Guerin (BCG) is not effective in protecting adults. New drugs, new diagnostic techniques and new vaccine research and development can not be separated from molecular identification research. Especially, molecular markers with independent intellectual property rights in China are not only the basis of application research, but also provide clues and evidence for the study of high-risk population and the mechanism of disease and development. The purpose of this study is to analyze the correlation between the Single Nucleotide Polymorphism (SNP) and the plasma microRNA (miRNA) and the infection status of Mycobacterium tuberculosis and the occurrence of tuberculosis through a case control study. The purpose of this study is to explore the infection of Mycobacterium tuberculosis to tuberculosis. There are potentially valuable host molecular markers in the process of being born.
A case-control study of the host SNP of tuberculosis associated with three groups of subjects (smear positive pulmonary tuberculosis patients, Mycobacterium tuberculosis latent infection group and negative control group) totaled 600 cases, and 44 candidate SNP were tested with the Goldengate chip of Illumina company. The results of the study found that the IFNG2109G/A locus GG genotypes There was a significant correlation with the reduction of the risk of tuberculosis (OR=0.54,95%CI:0.30-0.98); the TLR91174A/G locus GG genotype (OR=1.87,95%CI:1.08-3.23) and the TLR91635 locus AA genotype (OR=1.90,95%CI:1.09-3.31) were significantly related to the higher risk of tuberculosis. At the same time, the co effect of the TLR91174G/G and IFNG2109A/A genotypes showed a synergistic effect. The candidate SNP did not show a significant correlation with Mycobacterium tuberculosis or tuberculosis in this study. The above results suggest that the genetic polymorphism of TLR9 and IFN- gamma may be associated with the risk of tuberculosis in Chinese people, so as to further explore the process of TLR9/IFN- gamma pathway in the process of infection from Mycobacterium tuberculosis to disease. It provides a way of thinking to play the role of regulation and control.
The correlation of tuberculosis incidence and plasma miRNA expression level was included in three groups of subjects (smear positive pulmonary tuberculosis patients, Mycobacterium tuberculosis latent infection group and negative control group) in total 34 cases. The expression level of 1887 human miRNA was examined by Agilent human miRNA chip. Then, the selected 11 differential expression miRNA applications, Real-time qPCR (Fold Change4, P0.01), were verified. Finally, the target gene prediction and regulation network were constructed by the differential expression of the verified miRNA. The results were found in the comparison with the control group (latent infection group and infection negative control group), hsa-let-7b-5p and The expression level of hsa-miR-30b-5p in the plasma of the patients with tuberculosis was significantly up-regulated (P0.05). The prediction results of the target gene regulation network based on the statistical model suggest that these two miRNA may be involved in the development of tuberculosis by regulating the expression of inflammatory factors and apoptosis factors. The result of this study is to study the plasma miRNA in tuberculosis. The regulatory role in the pathogenesis of the disease and its application value as a diagnostic molecular marker provides a clue, and provides a scientific basis for further large sample validation and the optimization of molecular markers.

【学位授予单位】：北京协和医学院
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R52

【参考文献】