PGC-1α基因MEF2C结构域482G／A变异参与2型糖尿病发病的机制研究  

Study of the 482G/A variation in PGC-1α gene domain MEF2C as possible mechanism of type 2 diabetes

作　　者：路文盛[1] 颜晓东[1] 黄勤[2] 胡映玉[1] 钟玫[1] 黄忠[1] 陈晖[1] 程桦[3] 

机构地区：[1]广西壮族自治区人民医院内分泌科, 南宁530021 [2]广西医科大学基础医学院生理学教研室 [3]中山大学附属第二医院内分泌科

出　　处：《中华医学遗传学杂志》2008年第6期616-623,共8页Chinese Journal of Medical Genetics

基　　金：国家自然科学基金（30860113）;广西医疗卫生重点科研课题基金（200736）;广西壮族自治区卫生厅自筹项目基金（Z2007144）

摘　　要：目的了解中国人PGC-1α基因肌肉增强因子2C（muscle enhance factor 2C，MEF2C）结构域内的482G／A变异与2型糖尿病的关系，探讨该位点变异对PGC-1α与其生物学配体MEF2C间结合力的影响，评估PGC-1α．MEF2C—GLUT4通路参与糖尿病发病的可能性。方法从350例2型糖尿病先证者及其一级亲属外周血抽提DNA。应用聚合酶链反应一限制性片段长度多态性分析结合DNA直接测序技术鉴定PGC-1α基因型。基于2型糖尿病家庭，采用单倍型相对危险度分析（haplotype relative risk，HRR）和传递不平衡检验（transmission disequilibriumtest，TDT）分析482G／A变异与2型糖尿病的相关性。大肠杆菌双杂交实验定性、定量检测482位点变异所导致的PGC-1α与其配体MEF2C间结合力的变化。结果HRR分析显示，在2型糖尿病家系中，基于等位基因，传递与未传递组比较，PGC-1α基因482G／A变异的A等位基因由父母更多地向患者传递，差异具有统计学意义（Y07．2170，P=0．0072，HRR=1．4496）；TDT-扩展传递不平衡检验分析显示482A等位基因由杂合子父母传递给患病子代的频率显著偏离0．5（219个家庭，P=0．0310；350个家庭，P=0．0292）。大肠杆菌双杂交实验显示482A可引起PGC-1α与其配体MEF2C间结合力明显下降（62．1±8．97，P〈0．05）。结论482A变异可能增加了中国人患2型糖尿病的风险，这一作用可能是通过降低PGC-1α-MEF2C．GLUT4通路活性，进而影响骨骼肌对葡萄糖摄取而实现的。Objective To investigate the association of the 482G/A polymorphism of the PGC-1α gene with type 2 diabetes by family-based study in the Han population in South China, and to analyze the quantitative and qualitative binding force changes between the PGC-1α domain mutant and MEF2C, as well as to evaluate the possibility of PGC-la- MEF2C-GLUT4 pathway in the pathogenesis of type 2 diabetes. Methods Blood samples were collected from 350 pa- tients with type 2 diabetes and their first-degree relatives. Genomie DNA was extracted and polymorphic PGC-1α genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism and direct DNA sequencing. The results were analyzed by family-based transmission disequilibrium test （TDT） and haplotype relative risk （HRR）. The protein-protein interaction between PGC-1α and MEF2C was detected by means of the site-directed mutagenesis kit and bacteriomatch two-hybrid system kit. Results In the family-based study, HRR analyses demonstrated that the 482A allele was more often transmitted to patients than predicted by chance （x2 = 7. 2170, P = 0. 0072, HRR = 1.4496）. TDT-extended test（ETDT） analyses also revealed that PGC-1α 482A allele was significantly deviated from 0.5 from heterozygous parents to patients than expected （219 trios, P = 0.0310; 350 trios, P = 0.0292）. BacterioMatch Two-Hybrid System showed that 482A variation could lead to decreased binding force between PGC-la and MEF2C （62.1 ± 8.97, P 〈 0.05）. Conclusion The 482A polymorphism increases the risk of developing type 2 diabetic mellitus in the South China Han population, which might be mediated by the PGC-1α-MEF2C-GLUT4 pathway.

关 键 词：PGC-1Α基因 单核苷酸多态性 2型糖尿病 大肠杆菌双杂交 蛋白质相互作用 

分 类 号：R686[医药卫生—骨科学]