嘌呤受体遗传变异及其与运动的交互作用在原发性骨质疏松症发生中的作用及机制

Osteoporosis (OP) is a serious bone metabolic disease in elderly women. Determining osteoporotic susceptible genes from the genomic level is of important significance in earlier screening individuals with high risk of OP. Studies have shown that P2X7, P2Y1 and P2Y2 receptor-mediated purinergic signals play important roles in regulating bone metabolism and bone turnover. Our preliminary experiments show that the expression of P2X7, P2Y1 and P2Y2 receptors was elevated in the osteoblast of ovariectomized rat, suggesting P2X7, P2Y1 and P2Y2 receptors are involved in the pathogenesis of OP. The case-control studies and genetic epidemiological investigations are adopted in this project to explore the association of three purinergic P2 receptor genetic polymorphisms and their interaction with environmental factors including the form of exercise, the amount of exercise, the intensity of exercise and the duration of exercise on the susceptibility to OP using a variety of techniques including PCR-RFLP, DNA sequencing, the luciferase reporter gene assay and Taqman methods. A preliminary study will be conducted to identify the function of the single nucleotide polymorphism (SNP) associated with OP and to search for potential susceptible genes and susceptible SNP loci to OP. Our results will contribute to clarify the genetic mechanisms of OP and provide new drug targets for personalized prevention and treatment of OP.

骨质疏松症（OP）是严重影响中老年妇女身体健康的骨代谢性疾病，从基因组水平确定OP易感基因对OP高危个体进行早期筛查有重要意义。研究显示P2X7、P2Y1和P2Y2受体介导的嘌呤信号在调节骨代谢和骨转换过程中发挥重要作用，且我们前期实验表明嘌呤P2X7、P2Y1和P2Y2受体在去卵巢骨质疏松大鼠成骨细胞表达升高，提示P2X7、P2Y1和P2Y2受体与OP发病相关。本项目应用PCR-RFLP、DNA序列测定、荧光素酶报告基因实验和Taqman等多种技术和方法，通过病例-对照研究和遗传流行病学调查，探讨3个嘌呤P2受体基因的遗传变异和包括运动形式、运动量、运动强度和运动时间等在内的环境因素间的交互作用与OP易感性的关系，并对出现关联的单核苷酸多态性（SNP）位点的功能进行初步研究，从而寻找OP潜在的易感基因和易感SNP位点，探讨OP发生的遗传学机制，为个性化的OP的防治提供新的药物作用靶点。

骨质疏松症（OP）是全世界关注的公共健康问题。遗传因素被认为是OP发病的主要原因。P2X7、P2Y1和P2Y2在成骨和破骨活动中起了重要的调控作用，是OP的重要候选基因。通过收集400例OP和400例对照样本的病例对照研究，我们研究了P2X7、P2Y1和P2Y2基因SNP与OP易感性的关系。主要研究结果：P2X7 Rs3751143多态基因型分布及其等位基因频率在OP组和正常对照组间比较差异有统计学意义 (p < 0.05)。P2X7 Rs3751143-C等位基因为OP风险等位基因 (P = 0.005, OR = 1.45, 95% CI: 1.17-1.78), CC/(AC+CC) 为OP风险基因型(CC versus AA, P = 0.003, OR = 1.72, 95% CI: 1.00-2.87; AC+CC versus AA, P = 0.002, OR = 1.41, 95% CI: 1.13-1.67)。P2X7 Rs3751143-Rs2230911-Rs1718119单体型CGG个体OP易感性增高 (OR = 3.762, 95 % CI: 1.21-11.68, p = 0.014)。P2X7 rs7958311和rs1718119与运动间存在显著相互作用(P = 0.001)。原代人成骨细胞、破骨细胞功能实验表明P2X7 Rs3751143 A<C变异可降低成骨和破骨细胞P2X7基因的表达、抑制成骨和破骨细胞P2X7通道功能及破骨细胞膜孔形成能力，抑制成骨细胞ALP、OCN和Collagen I表达，抑制破骨细胞caspase 1释放和LDH分泌，促进破骨细胞TRAP活性，从而与血清钙和ALP降低而血清TRAP增加相关。进一步证实在人群研究中筛选到的与OP易感相关的P2X7 Rs3751143 A<C多态性在OP发病中有着重要意义。课题完成时发表SCI论文5篇，中文核心论文1篇，会议论文2篇，培养研究生2名。