MMP14基因表达的调控在骨质疏松症发生发展中的作用机制

Genetic gene is closely related with osteoporosis(OP) which seriously hazard human health; our results of the previous project of National Nature Science fundation(NO.3081111) show that the polymorphisms of membrane-type 1 matrix metalloproteinase (MT1-MMP, MMP14) gene is closely related to OP in the elderly pepole of Zhuang ethnic groups in Guangxi province. However it is unclear that what role the regulation of MMP14 gene expression plays in the origin and development of OP. Up to now, the published documents about the mechanisms are absent. Based on the results of our previous research, we will detect the wide-band ultrasonic attenuation (BUA) of calcaneal bone; and genotypes of the MMP14 gene and plasma MMP14 protein levels will be measured by TaqMan-MGB probe technology and ELISA respectively; MMP14 mRNA and MMP14 protein in mononuclear cells from peripheral blood of samples with different genotypes and MMP14 protein in the periosteum of the samples with osteoporotic fracture will be detected with quantitative real-time PCR and western blot respectively. And MMP14 protein levels in osteoblasts and osteoclasts of periosteal will be detected by histological techniques and the number of osteoclasts in periosteal will be counted also. We will compare the differences of different genotype samples. The results will be used to analysis the effect of MMP14 gene polymorphism on its mRNA and protein expression, and further to reveal the molecular mechanisms of regulation of MMP14 gene expression in the origin and development of OP. Illuminating the molecular mechanisms will makes a significant contribution to the prevention and treatment of OP.

遗传基因与严重危害人类健康的骨质疏松症关联密切，在上个国家自然科学基金中我们发现MMP14基因多态性与骨质疏松症密切相关，但MMP14基因表达的调控在骨质疏松症发生发展中的作用机制尚不清楚；截至目前未见该方面的文献报道。在已有的前期基础上，本课题采用TaqMan-MGB探针技术对MMP14基因进行分型，用ELISA测定血浆MMP14蛋白水平，用RT-PCR和western blot技术分别检测不同基因型样本外周血单个核细胞中MMP14 mRNA和蛋白的表达水平及骨质疏松性骨折样本骨膜中MMP14蛋白水平，用组织学技术检测骨膜破骨细胞数量及成骨细胞和破骨细胞的MMP14蛋白水平，比较不同基因型样本间差异。多层面分析MMP14基因多态性对其mRNA和蛋白表达的影响，探讨MMP14基因表达的调控功能，揭示MMP14基因表达的调控在骨质疏松症发生发展中的分子作用机制，为预防和治疗骨质疏松症提供参考

研究发现MMP14参与调节骨代谢，课题组前期研究发现MMP14基因多态性可能与骨质疏松症相关，但MMP14基因表达的调控在骨质疏松症发生发展中的作用机制未明。因此课题组检测广西壮族人群MMP14基因rs3751488、rs1003349、rs2236303和rs743257位点的多态性和血浆MMP14蛋白水平，检测不同基因型样本外周血单个核细胞中MMP14 mRNA表达水平，骨膜破骨细胞数量及成骨细胞和破骨细胞的MMP14蛋白水平，比较不同基因型样本间上述指标的差异，分析MMP14基因多态性对其mRNA和蛋白表达的影响，探讨MMP14基因表达的调控在骨质疏松症发生发展中的作用机制。在增加样本量基础上获得了广西壮族人群的MMP14基因上述位点的基因频率分布状况，MMP14基因多态性与广西壮族人群骨质疏松症的相关性：rs1003349位点TT基因型的超声骨密度明显比GG基因型的低(P<0.05)，但其TT、GT、GG三种基因型在正常组和骨质疏松组中的分布没有明显差异；rs3751488位点AA基因型的超声骨密度明显比GG基因型的低(P<0.05)，且其AA、GA和GG三种基因型在正常组和骨质疏松组中的分布差异明显，存在统计学意义(P<0.05)，以及AA基因型发生骨质疏松的风险是GG基因型的8倍(P<0.05)；rs743257位点CC基因型和CT基因型的超声骨密度明显比TT基因型的低(P<0.05)，CC、CT和TT三种基因型在正常组和骨质疏松组中的分布差异明显，存在统计学意义(P<0.05)，以及CC和CT基因型发生骨质疏松的风险分别是TT基因型的3倍和4倍(P<0.05)。因部分研究工作进展不顺，导致进一步的分析尚不能进行。待获得后继研究结果，分析明确MMP14基因和表达水平对骨代谢的作用，成果将可能可应用于筛查壮族骨质疏松易感人群和为骨质疏松症的治疗拓展治疗方式。