IgA肾病中FUT2基因无义突变的作用及其机制研究

The pathogenesis of IgA nephropathy is closely related to intestinal flora imbalance,nevertheless FUT2 gene carrying nonsense mutation plays a role in intestinal flora imblance. Based on that, it is supposed that FUT2 gene with nonsense mutation is associated with IgA nephropathy.Our previous study found that correction of nonsenses mutation can produce again the synthesis of functional protein, which can be used to treat the diseases.To verify that hypothesis and find the new way of treating IgA nephropathy, our study will collect the blood of patients with IgA nephropathy to test the expression of FUT2 gene and make the analysis of the correlation between nonsense mutation of FUT2 gene and IgA nephropathy. Next in vitro we will build the intestinal epithelial cell line or kidney 293T cell line carrying nonsense mutation on FUT2 gene and in vivo will construct the mouse model with nonsense mutation on FUT2 gene in order to explore the mechanism how nonsense mutation of FUT2 gene induces IgA nephropathy. Finally, we will incubate the aforementioned mouse model by the drugs which our previous study has found, observe the biochemical and pathological indexes of kidney and discuss the effect of drugs on IgA nephropathy. Our study has great significance for declaring the new pathogenice genes of IgA nephropathy and providing the new therapeutic method of IgA nephropathy.

IgA肾病与肠道微生态异常有关，岩藻糖转移酶2(FUT2)基因无义突变是导致肠道菌群失调及肠道粘膜免疫降低的病因之一，故推测FUT2基因无义突变与IgA肾病发病有相关性。本项目前期研究发现，纠正基因无义突变可促进原已缺失、且有生物功能的相关蛋白合成增加，并可改善器官病变。为验证该推论，本项目将在收集IgA肾病临床病例基础上提取基因组DNA，检测FUT2基因表达，行FUT2基因无义突变与IgA肾病发病的相关性分析；利用CRISPR/Cas9技术体外构建携带FUT2基因无义突变的肠道上皮细胞（FHC）和肾脏细胞（HMC），并体内构建携带有FUT2基因无义突变的小鼠模型，以研究FUT2基因无义突变与IgA肾病发病的相关性及其分子机制，探讨纠正基因无义突变的药物对IgA肾病的治疗价值。为进一步揭示IgA肾病新的致病基因及其分子机制奠定理论基础，为治疗IgA肾病提供新的治疗方向。

IgA肾病与肠道微生态异常有关，岩藻糖转移酶2(FUT2)基因无义突变是导致肠道菌群失调及肠道粘膜免疫降低的病因之一，故推测FUT2基因无义突变与IgA肾病发病有相关性。本项目收集IgA肾病临床病例提取血清基因组DNA，检测FUT2基因表达，行FUT2基因无义突变与IgA肾病发病的相关性分析，发现FUT2突变可增加异常糖基化IgA1、炎症因子、增加肠道通透性，而减少发挥正常功能的短链脂肪酸浓度，与IgA肾病疾病进展密切相关。利用CRISPR/Cas9技术体外构建携带FUT2基因无义突变的肠道上皮细胞（FHC）和人B细胞淋巴瘤细胞DOHH2,发现FUT2基因突变可通过增加炎症因子表达，减少Cl GalT1及其分子伴侣Cosmc表达，进而产生异常糖基化IgA1。体内实验构建携带有FUT2基因无义突变的小鼠模型成功，发现以研究FUT2基因无义突变与IgA观察携带FUT2无义突变小鼠8周后，可见IgA在肾脏沉积。该项目证明FUT2基因与IgA肾病发病及疾病进展密切相关，进一步揭示IgA肾病新的致病基因及其分子机制奠定理论基础，为治疗IgA肾病提供新的治疗方向。.本项研究在中华杂志发表论文3篇，SCI1篇，已投稿论文1篇，待投稿论文1篇。