载脂蛋白E基因多态性对健康青年人群大脑容积的影响

The influence of apolipoprotein E gene polymorphism on brain volume in healthy young adults

目的 探讨载脂蛋白E基因多态性对健康青年人群脑容积的影响.方法 于2013年8月至2014年5月在中国医科大学附属盛京医院招募年龄为20 ～ 40岁的健康志愿者193名.采集其外周血2 ml,应用PCR产物直接测序法检测志愿者的载脂蛋白E（apoliprotein E,ApoE）基因型.同时对志愿者进行头颅MRI扫描,采用三维T1加权成像梯度回波序列获得高分辨率头颅磁共振数据.以ApoE e3/e4及ε4/ε4基因型为ε4携带者组,以ApoE最常见的基因型e3/e3型为对照组,运用基于体素的形态学测量方法（voxel-based morphometry,VBM）分析两组间的脑形态学差异.结果 ε4携带者所占比例为14.51％（28/193）.最终入组的ε4携带者组共20名,对照组45名.VBM分析结果显示ApoE e4携带者组共有10个脑区比ε3/e3组出现了脑灰质体积减少（P＜0.005,未校正,连续10个像素）,主要分布于右侧前扣带回、双侧尾状核、顶叶以及颞叶外侧面.结论 ApoE基因多态性对脑容积的影响在青年阶段就已显现,ε4基因的携带可与多部位的灰质体积降低有关.

Objective To explore the effect of apolipoprotein E （ApoE） gene polymorphism on brain volume in healthy young adults.Methods One hundred and ninety-three healthy young volunteers （age：20-40 years） were recruited in Shengjing Hospital of China Medical University between August 2013 and May 2014.Two milliliters of peripheral blood were collected for the determination of ApoE genotype using direct sequencing of polymerase chain reaction （PCR） products.Brain MRI scans were performed using three-dimensional T1-weighted turbo field echo imaging sequence.The diffcrences of brain morphometry between the ε4 carriers group （ε3/ε4 and ε4/ε4 genotype） and the ε4 non-carriers group （ε3/ε3 genotype） were analyzed using voxel based morphometry （VBM）.Results The ε4 carriers accounted for 14.51% （28/193） of the total population.Twenty of ε4 carriers and 45 of ε4 non-carriers were included in the final images analysis.VBM analysis showed that the ApoE ε4 carriers had 10 atrophic brain areas compared with the ε4 non-carriers （P 〈 0.005,uncorrected,10 continuous voxels）,which mainly located in the right anterior cingulate,the bilateral caudates,parietal lobes and lateral temporal lobes.Conclusions The influence of ApoE gene polymorphisms on brain volume has appeared in the youth.The ε4 gene is related to the reductions of the gray matter volume in multiple brain areas.