本文選題：原發(fā)性干燥綜合征　切入點：GTF2I　出處：《吉林大學(xué)》2017年碩士論文

【摘要】：原發(fā)性干燥綜合征(primary Sj(?)gren's Syndrome,pSS)是一種常見的慢性系統(tǒng)性自身免疫病,主要由于T和B淋巴細胞浸潤和損害外分泌腺體,引起口干、眼干、皮膚或者鼻腔干燥等癥狀;同時也可累及腎臟、肺、血管等其他重要器官,發(fā)生病變。該病確切的發(fā)病機制尚未闡明,研究表明遺傳傾向是影響其發(fā)病的重要因素。2013年發(fā)表的一份全基因組關(guān)聯(lián)分析(GWAS)報告指出:在pSS的易感基因中,GTF2IRD1-GTF2I基因區(qū)間是中國漢族人群特有的,并且通過精確作圖(fine mapping)確定GTF2I基因內(nèi)含子上的rs117026326位點為該區(qū)間與pSS相關(guān)最強位點。但GTF2I基因多態(tài)性影響原發(fā)性干燥綜合征易感性的機制尚不清楚。本論文的目的旨在研究中國北方漢族人群中GTF2IRD1-GTF2I基因多態(tài)性與pSS易感性的關(guān)聯(lián)程度,并且進一步探究GTF2I基因在pSS發(fā)病機制中的作用以及該基因影響pSS易感性的潛在機制。實驗方法如下:通過Taq Man探針基因分型技術(shù)和Sanger Seqencing技術(shù)對603例pSS患者和1204例健康對照的rs117026326(GTF2I)、rs112502846(GTF2IRD1-GTF2I)和rs113066392(GTF2IRD1-GTF2I)位點進行基因分型,再通過連鎖不平衡關(guān)系Imputed得到與這3個SNPs高度連鎖的4個SNPs位點的基因分型結(jié)果,檢測上述七個位點與pSS易感性間的相關(guān)性;同時結(jié)合臨床檢驗的抗體結(jié)果,分析上述SNPs與pSS抗體情況的相關(guān)性。應(yīng)用實時定量PCR技術(shù),檢測樣本PBMC中總GTF2I和不同亞型GTF2I基因m RNA的表達情況,并探討其與rs117026326位點多態(tài)性間的關(guān)聯(lián);本實驗還進一步探究c-fos基因m RNA表達水平與rs117026326位點多態(tài)性的相關(guān)性,并在HEK-293T細胞系中分別過表達了不同亞型的GTF2I基因,研究不同亞型對c-fos基因的調(diào)控作用。以上實驗得到如下結(jié)果:GTF2IRD1-GTF2I基因區(qū)間內(nèi)包括rs117026326位點在內(nèi)7個SNPs都與中國北方漢族人群pSS相關(guān)聯(lián)(P5×10-5),且相互連鎖,Conditional Assays證明這些連鎖的SNP是此區(qū)間內(nèi)唯一的單一遺傳關(guān)聯(lián)信號。這組相關(guān)聯(lián)的SNPs,既與抗體陽性的pSS相關(guān),也與抗體陰性的pSS有顯著關(guān)聯(lián)。pSS患者PBMC中,GTF2I基因m RNA表達量明顯高于健康對照(P0.001),但其表達水平與rs117026326的基因型不相關(guān)(P0.05);GTF2I基因亞型GTF2Iγ和GTF2IΔ及其下游調(diào)控基因c-fos m RNA表達水平與SNP rs117026326基因型相關(guān)。與rs117026326T/T(risk allele)基因型相比,C/C基因型攜帶者c-fos基因m RNA的水平顯著降低(P0.05)。將不同亞型的GTF2I基因瞬時轉(zhuǎn)染到HEK-293T細胞系中,結(jié)果發(fā)現(xiàn)與GTF2IΔ相比,GTF2Iγ能夠顯著激活c-fos基因m RNA表達。實驗結(jié)果證明,GTF2IRD1-GTF2I基因為中國北方漢族pSS易感基因;SNP rs117026326的基因型與GTF2Iγ和GTF2IΔm RNA表達水平的相關(guān),為該位點參與調(diào)控GTF2I pre-m RNA剪切提供證據(jù);當rs117026326攜帶T(risk allele)基因型時,GTF2Iγm RNA表達水平升高,激活c-fos基因而發(fā)生細胞內(nèi)的慢性炎癥反應(yīng),這可能是導(dǎo)致pSS發(fā)生的因素。
[Abstract]:Primary Sjogren Syndrome (PSS) is a common chronic systemic autoimmune disease, which is mainly caused by infiltration of T and B lymphocytes and damage of exocrine glands, causing dry mouth, dry eye, dry skin or nasal cavity.At the same time can also involve the kidney, lung, blood vessels and other important organs, pathological changes.The exact pathogenesis of the disease has not yet been clarified.Studies have shown that genetic predisposition is an important factor in the pathogenesis of pSS. A report published in 2013 on the whole genome association analysis (GWAS) showed that the GTF2IRD1-GTF2I gene interval in the susceptible genes of pSS is unique to Chinese Han population.The rs117026326 locus in the intron of GTF2I gene was determined to be the strongest site associated with pSS by precise mapping.However, the mechanism of GTF2I gene polymorphism affecting susceptibility to primary Sjogren's syndrome remains unclear.The purpose of this study was to investigate the association between GTF2IRD1-GTF2I gene polymorphism and pSS susceptibility in Han population in northern China, and to explore the role of GTF2I gene in the pathogenesis of pSS and the underlying mechanism of pSS susceptibility.瀹為獙鏂規(guī)硶濡備笅:閫氳繃Taq Man鎺㈤拡鍩哄洜鍒嗗瀷鎶，

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