代谢调控因子SIRT1基因多态性与2型糖尿病早期肾病的关联研究

【作者】 李晨；

【导师】 李长贵； 栾健；

【作者基本信息】 青岛大学 ， 内分泌与代谢病， 2014， 硕士

【摘要】 研究背景：近年来,随着人们饮食、生活水平的不断提高,糖尿病的患病率逐年上升。慢性高血糖可导致机体多脏器功能障碍,特别是糖尿病肾病(DN)对机体损害严重,糖尿病肾病是常见的糖尿病微血管并发症之一,目前是导致世界范围内终末期肾病的主要病因,同时也是糖尿病的主要致死原因。DN是在长期慢性高血糖诱导下,多系统、多因素共同协同作用的复杂的多基因遗传性疾病,其中,遗传性因素已经被证实是DN发病、发生、发展的重要因素。Sirtuins,基因沉默信息调节因子-2(SIR2)家族,是NAD依赖的脱乙酰基酶,哺乳动物的sirtuins包括7个成员,SIRT1-SIRT7,这些成员,尤其是SIRT1,在调节年龄、存活力、或者年龄相关的代谢性疾病的发病机制中发挥重要作用,近些年发现,Sirtuins家族在肾脏中也有表达,研究显示SIRT1介导的能量限制的保护作用参与到在肾脏老化过程中。研究表明,在哺乳动物中,SIRT1基因可能是糖尿病肾病的易感基因。日本的研究显示,SIRT1在日本个体中糖尿病肾病的易感性中发挥重要作用,国内目前尚未有SIRT1基因多态性与糖尿病肾病相关性的报道。研究目的：探讨代谢调控因子SIRT1基因多态性与2型糖尿病早期肾病的相关性。研究方法：应用聚合酶链反应-单链构象多态性(Polymerase Chain reaction-single strand conformation polymorphic,PCR-SSCP)结合直接测序的方法,检测289例山东沿海地区汉族无亲缘关系的个体SIRT1的分布情况。受试对象分为三组：正常对照组(N组)146例,单纯2型糖尿病组(DM组)66例,2型糖尿病微量蛋白尿组(DN组)77例,对各组间的等位基因频率及基因型频率,进行对比分析。应用SPSS16.0统计软件进行统计学分析。研究结果:1.sirtl-rs2236319基因多态性的基因型频率的分布符合Hardy-Weinberg平衡。糖尿病组与对照组的基因型频率分布相比,差异无统计学意义(P=O.129)；而糖尿病组的等位基因G频率明显低于对照组,差异有统计学意义(P=0.038)。非条件logistic回归分析显示,以AA基因型为对照,AG和GG基因型与糖尿病的发病风险无关(P=0.261,OR0.692,95%CI:0.365-1.315和P=0.084, OR0.260,95%CI：0.570-1.197)。另外,以等位基因A为对照,等位基因G与糖尿病的发病风险降低有关(P=0.039, OR0.579,95%CI:0.344-0.973).2.糖尿病微量蛋白尿组和正常对照组的GG基因型频率分布无明显差异(P=0.166)；另外,糖尿病微量蛋白尿组的等位基因G分布频率高于对照组,但差异无统计学意义(P=0.066)。非条件logistic回归分析显示,以AA基因型为对照,AG和GG基因型与糖尿病微量蛋白尿组的发病风险无关(P=0.650,OR1.152,95%CI：0.625-2.2163和P=0.062, OR2.216,95%CI:0.960-5.115).另外,以等位基因A为对照,等位基因G也与糖尿病微量蛋白尿组的发病风险无关(P=0.067,OR1.482,95%CI:0.973-2.256)。3.在糖尿病患者中,GG基因型在糖尿病微量蛋白尿组患者的分布明显多于单纯糖尿病患者组,差异有统计学意义(P=0.006)；另外,糖尿病微量蛋白尿组的等位基因G频率明显高于单纯糖尿病组,差异有统计学意义(P<O.001)。非条件logistic回归分析显示,以AA基因型为对照,GG基因型与糖尿病微量蛋白尿组的发病风险增高有关(P=0.007, OR9.514,95%CI:1.818-39.876),而AG基因型与糖尿病微量蛋白尿组的发病风险无关(P=0.174, OR1.664,95%CI:0.799-3.468)。另外,以等位基因A为对照,等位基因G也与糖尿病微量蛋白尿组的发病风险增高有关(P=0.001, OR2.559,95%CI:1.464-4.473)。4.低密度脂蛋白、糖化血红蛋白、餐后2小时血糖的回归系数为正,OR)1,说明这些因素增加患DN的风险；高密度脂蛋白的回归系数为负,OR <1,说明其降低患DN的风险。研究结论：1.本研究结果提示SIRT1-rs2236319基因多态性的等位基因G与2型糖尿病的发病风险降低有关；而rs2236319基因多态性的GG基因型和等位基因G与2型糖尿病微量蛋白尿组的发病风险增高有关。2.除遗传因素外,糖脂代谢紊乱与2型糖尿病早期肾病发病的风险相关。更多还原

【Abstract】 Background:In recent years, the prevalence rate of diabetes is increasing worldwide. Diabetic nephropathy (DN) is a severe microvascular complication of diabetes. It’s a major cause of end-stage renal disease in western and Asian countries. And it’s the leading cause of death in diabetes. Diabetic nephropathy is a complex polygenic disease. The pathogenesis of DN is a result of interaction of multi gene, factors, and systems induced by hyperglycemia. Genetic factors have been proved to be an important factor for the occurrence of DN. Sirtuins, gene silent information regulator-2(SIR2) family, is an NAD dependent deacetylase enzymes. The sirtuins of mammal consists of7members:SIRT1-SIRT7. These members, especially SIRT1, play an important role in the pathogenesis in the regulation of age, viability, or age associated metabolic disease. It has being discovered in recent years that the family also has represented in kidney. Research found that the protective effect of energy restriction mediated by SIRT1participate in the aging process of the kidney. These discover suggest that, the SIRTl gene of mammal may be a susceptible gene of diabetic nephropathy. Also a study in Japan indicates that, SIRT1play an important role in susceptibility of diabetes nephropathy in Japanese individuals. There have been no reports of the correlation of SIRT1and early diabetic nephropathy at present.Objective:To explore the correlation between the gene polymorphism of metabolic regulation factor SIRT1and early type II diabetic nephropathy.Methods:Polymerase Chain reaction-single strand conformation polymorphic (PCR-SSCP), combined with direct sequencing, detecting the distribution of SIRT1in289unrelated cases of Han individuals in the coastal area of Shandong China. Subjects are divided into three groups:normal group (N group) of146cases, type2diabetic group (DM group) of66cases, and Microalbuminuria group (DN group) of77cases. Comparative analysis is used in each allele/genotype frequency. SPSS16.0statistical software for data analysis is applied.Results:l.The distribution of genotype frequencies of sirtl-rs2236319gene polymorphism complies with the Hardy-Weinberg equilibrium.There is no statistical significance between the distribution of gene frequency in diabetic group and control group (P=0.129); While there is statistical significance that the G allele frequency in diabetic group was significantly lower than the control group (P=0.038). Non conditional logistic regression analysis shows that, contrasted with the genotype AA, genotype AG and GG have no relationship with the risk of diabetes (P=0.261, OR0.692,95%CI:0.365-1.315and P=0.084, OR0.260,95%CI:0.570-1.197); while contrasted with the allele A, allele G relates with the decrease of the risk of diabetes (P=0.039, OR0.579,95%CI:0.344-0.973)2. There is no significant difference in the frequency distribution of genotype GG in early Microalbuminuria group and control group (P=0.166); The frequency distribution of allele G in early Microalbuminuria group is higher than the control group, while the difference has no statistical significance (P=0.066). Non conditional logistic regression analysis shows that, contrasted with the genotype AA, genotype AG and GG have no relationship with the risk of early diabetic nephropathy (P=0.650, OR1.152,95%CI:0.625-2.216and P=0.062, OR2.216,95%CI:0.960-5.115); while contrasted with the allele A, allele G also has no relationship with the risk of early diabetic nephropathy (P=0.067, OR1.482,95%CI:0.973-2.256)3.In diabetics, the distribution of genotype GG in early diabetic nephropathy is significantly higher than the type2diabetic group, and there is statistical significance (P=0.006). And there is statistical significance that the allele G frequency in early Microalbuminuria group is significantly higher than the type2diabetic group (P<0.001). Non conditional logistic regression analysis shows that, contrasted with the genotype AA, genotype GG relates with the increase of the risk of diabetes (P=0.007, OR9.514,95%CI:1.818-39.876), while the genotype AG has no relationship with the risk of early diabetic nephropathy (P=0.174, OR1.664,95%CI:0.799-3.468). Besides, contrasted with allele A, allele G relates with the increase of early diabetic nephropathy (P=0.001, OR2.559,95%CI:1.464-4.473)4. LDL-C、HbAlc and PBG are the risk factors to increase DN, if the regression coefficients of them are positive and the OR values are more than1; LDL-C、HbAlc and PBG are the protective factors to decrease DN, if the regression coefficients of them are negative and the OR values are less than1.Conclusion:1. The results of this study suggest that the allele G of SIRTl-rs2236319gene polymorphism relates with the decrease of the risk of diabetes; the genotype GG and allele G of SIRT1-rs2236319gene polymorphism relates with the increase of early diabetic nephropathy.2. Besides the genetic factor, the metabolic disorder of blood sugar and blood lipid are also the risk factors of type2diabetic nephropathy.更多还原