从重要的骨基质蛋白代谢通路探索原发性骨质疏松症早期诊治的新靶点

Osteoporosis is a systemic bone disease characterized by reduced bone mass, destruction of bone microarchitecture, which will lead to a decrease in bone strength and an increase in fracture risk. With the aging of population in China, osteoporosis is becoming a public health problem because of its rapid increase in prevalence and great harm. However, in prevention and treatment of osteoporosis in China, the diagnosis is rough and delayed, and the treatment is insufficient. Bone matrix protein is an important component of bone, which is mainly composed by type I collagen. It plays essential roles in maintaining bone structure integrity and biomechanical properties. However, researches in osteoporosis pay little attention on bone matrix protein. This study will detect the single nucleotide polymorphisms of multiple candidate genes in metabolic pathway of type I collagen using a new high-throughput technology of the next generation sequencing in large sample of patients with osteoporosis. The detailed phenotypic information of the patients is evaluated by the high-resolution peripheral quantitative computed tomography, and so on. The relationship between genotype and phenotype is in-depth analyzed in order to find out the valuable molecular markers for early prediction of osteoporosis and osteoporotic fracture. With further CRISPR/Cas9 gene editing technology, mouse model is established, which carry the variations in genes of type I collagen metabolic pathway. We evaluate the metabolism and microstructure of type I collagen, bone mineral density, microarchitecture and biomechanical properties of bone, in order to confirm the application value of molecular markers of type I collagen metabolic pathway in early diagnosis and treatment of osteoporosis. This study will possess important significance and practical value for the early and accurate prevention, diagnosis, treatment of osteoporosis and for the improvement of its prognosis.

骨质疏松症是以骨强度下降、骨折危险性升高为特征的全身性骨骼疾病。随着我国社会老龄化，骨质疏松症正成为患病率急剧增加、危害巨大的公众健康问题。然而，我国骨质疏松症防治面临诊断粗放滞后，治疗不足的难题。以I型胶原为主的骨基质蛋白是骨骼的重要组分，对骨结构完整性和生物力学性能至关重要，而骨质疏松领域对其的研究十分匮乏。本研究采用新型二代靶向测序技术检测大样本骨质疏松患者I型胶原代谢通路多种基因的单核苷酸多态性，并采用先进的高分辨外周定量CT等技术获得患者细致表型信息，深入分析基因型与表型的关系，寻找早期预测骨质疏松的分子标志物。并采用CRISPR/Cas9基因编辑技术，构建带有I型胶原代谢通路基因变异的小鼠模型，评估其I型胶原代谢、骨密度、骨微结构及骨生物力学等表型信息，证实I型胶原代谢通路分子标志物在骨质疏松早期诊治中的应用价值。本研究对于骨质疏松症的精准诊疗，具有重要的研究意义和实用价值。

骨质疏松症是以骨强度下降、骨折危险性升高为特征的全身性骨骼疾病。目前我国骨质疏松症患病人数已高居世界首位，但疾病的遗传调控机制和精准治疗策略，亟待探索。I型胶原蛋白占骨有机质的90%以上，构成骨骼基本结构框架，对骨结构完整性和生物力学性能至关重要，而骨质疏松领域对I型胶原遗传与代谢异常的研究十分匮乏。本课题锚定科学问题：骨骼中重要的I 型胶原蛋白代谢通路多种候选基因具有多态性，其与骨质疏松症表型及骨折风险是否密切相关？本研究构建骨质疏松患者的大型研究队列，获得临床数据库和生物样本库，采用自主构建的二代靶向测序技术，对I型胶原代谢通路的多种候选基因进行高通量测序，明确I型胶原代谢通路基因多态性与骨质疏松患者的骨骼表型的相关性，表明I型胶原代谢通路的基因均与骨密度、骨折风险息息相关，是骨质疏松症的重要候选基因；本课题还对绝经后和男性骨质疏松症的药物治疗进行了前瞻性研究，为疾病的治疗提供了新的选择；另外，课题锚定I型胶原代谢通路基因突变所致的骨质疏松性骨折的天然疾病模型——成骨不全症展开深入研究，建立了我国最大样本的成骨不全症研究队列，采用二代靶向测序技术，分析患者的致病基因型与表型、精准治疗、疾病转归的相关性；并采用CRISPR/Cas9基因编辑系统，创新性构建了I型胶原代谢通路PLS3基因突变的骨质疏松症大鼠模型，大鼠具有皮质骨变薄、生物力学性能明显下降的特点，成功复制了母系遗传的骨质疏松患者的疾病表型。本研究内容丰富，临床与基础研究相结合，使得我们对I型胶原代谢通路候选基因变异与骨质疏松症的关系获得了深入的认识，有助于提高骨质疏松症和成骨不全症等疾病基于候选基因遗传变异的精准诊断与治疗水平。本课题发表SCI论文17篇，其中Q1区论文5篇，制定疾病诊疗指南2部，获授权发明专利一项，获得省部级奖励2项，培养青年研究人才11人，圆满完成研究任务。