线粒体单倍群谱系与环境硒的交互作用及其在长寿中的作用机制研究

Regional longevity exists in our country, and it is usually associated with genetic, geographical environment as well as many other factors. Current related research are scattered without a unified standard, and there is no organic combination between the genetic and environmental factors at the same time. MtDNA mutations causes decline in mitochondrial function, which is considered to be an important basis of aging and related diseases. Hence, this study proposed that some mtDNA variations would cause formations of mtDNA haplogroups under geographical environment such as selenium, affecting the generation of ROS and ATP in mitochondrion as well as inducing cell senescence, finally promote longevity. Therefore, this research intends to adopt large populations more than 80-year-old in Chongqing Jiangjin "longevity town" in China as experimental group and population more than 80-year-old in non-longevity area as control to detect geographical indicators such as climate, plasma and microelements in drinking water; Then we apply the genetic methods to analyze distributions of mitochondrial haplogroups; The interaction between selenium and mitochondria haplogroup was assessed by rho0 cell fusion experiments, which would be involved in the molecular mechanism of longevity. Finally, study the role of genetic and geographic interactions in longevity through data analysis, and explore the mechanism of longevity. Find out key factors that promote longevity of the population, and further develop and utilize, which are made to further promote the development of healthy aging and the health industry.

我国存在区域长寿现象，其通常与遗传、地理环境等诸多因素有关。目前相关研究都比较分散，标准不统一，同时没有有机的将遗传和环境因素结合起来。mtDNA变异导致线粒体功能减低，被认为是衰老及相关疾病发生的重要基础。为此，本课题提出mtDNA变异形成的一些单倍群，在地理环境(如硒元素)作用下，影响线粒体ROS、ATP等的生成，延缓细胞衰老，促进长寿的发生。因此，本研究拟采用大规模人群研究，以重庆市江津区“中国长寿之乡”80岁以上老人为实验，非长寿乡的80岁以上老人为对照，调查气候、血浆、饮用水微量元素等地理指标；然后采用遗传学手段分析区域长寿人群的线粒体单倍群谱系的分布情况；再通过rho0细胞融合实验，研究硒元素与线粒体单倍群交互作用，发生长寿的分子机制；最后通过数据分析，研究遗传与地理交互作用在长寿中的作用，探讨长寿发生的机制，寻找出促进人群长寿的关键因素，进一步促进健康老龄化和健康产业的发展。

本课题探索线粒体遗传因素与环境因素等在中国长寿老人（江津）的聚居地区中的作用。通过问卷调查、血浆生化检查、线粒体基因组深度测序、生物信息学实验等，反向距离权重(inverse distance weight, IDW)插值、皮尔森方程相关分析、多元线性回归进行分析等方法，发现：（1）江津区长寿水平整体上，空间总体分布为中部高向南部和北部递减。其中百岁老人男性和女性在空间上分布差异较大。江津区长寿水平中部和北部较高南部较低，中部中东面为指数高值区域，中西面白沙镇周围是绝对数量高值区域。（2）江津区血常规指标对长寿影响情况，长寿人群集中于男性HGB（134~146,147~160）、HCT（46.5~50.0）；女性HGB（110~123,124~136）、HCT（41.5~45.0）区间内。（3）江津区血液生化指标对长寿影响情况，从空间差异和年龄差异，最终筛选出Urea、ALT、GLU，（Y=72.497 + 0.395x15 − 0.192x4 + 0.545x1）影响因素，进一步多重比较后，Urea、ALT指标长寿人群与其他年龄段有显著差异。（4）江津区血清微量元素对长寿影响情况，≥90岁也就是广义的长寿人群在铁、铅和硒三项指标均中与其年龄段存在显著差异，发现硒元素仍然是正向的刺激元素。（5）对血细胞进行线粒体DNA深度测序，根据剑桥序列比对，发现长寿组有7个SNP位点变位有统计学差异（1694、2755、3504、7741、8856、10646、12950）（p<0.05）；单倍群仅有A13出现差异，长寿组更易出现（p<0.05）。通过细胞融合技术，研究 mtDNA3010A/G 基因型变异在缺氧条件下能够影响 lncＲNA-mＲNA 调控网络的变化，可能是其机制。（6）同时还发现医疗资源，如医院和保健中心的床位数，是延长寿命的最重要因素。发现长寿之乡和非长寿之乡在高血压的患病率和男女高血压的患病率不存在区域差异。环境因素是影响长寿及其相关表型的重要因素。.综合上述结果，本研究为探索mtDNA变异和环境因素藕合作用在长寿发生中奠定了坚实的基础，也为后续的深入研究工作开辟了新的方向和着力点。项目资助共发表论文11篇，其中SCI论文2篇，单篇最高影响因子34.915分，中文论文9篇。培养硕士研究生2名。