COL1A1基因选择性剪接在成骨不全发生中的作用机制研究

成骨不全是一种罕见遗传性疾病，尚无有效治愈方法。该病主要的致病基因是COL1A1，已明确的转录本只有一种。前期我们在研究一成骨不全家系COL1A1基因剪接位点突变对mRNA的影响时，首次在正常人中发现了将47号内含子转录的新型转录本。进一步研究观察到正常人和患者两个转录本的表达比例存在差异；同时在小鼠多个组织中也发现了与人相似的新型转录本。基于以上研究基础我们提出假设：COL1A1基因存在选择性剪接，产生的两种转录本具有时空表达差异性；突变可能导致选择性剪接行为的改变，破坏转录后调控机制，最终引起成骨不全。针对该假设，本项目拟开展以下研究：1.小鼠模型的影像学和生化表型分析；2.COL1A1基因两种转录本的剪接机理；3.COL1A1基因的转录组研究及转录后调控机制研究。本项目对阐明COL1A1基因选择性剪接参与成骨不全发生的分子机制具有重要意义。

Osteogenesis imperfecta is a rare genetic disease, which cannot be cured so far. COL1A1 is the main pathogenic gene and there is only one known transcript. In the previous study about discussing the effect of COL1A1 gene mutation at the splice site on mRNA in a family with osteogenesis imperfecta, we found a new transcript including intron 47 in normal people for the first time. Further study found that there was a difference in the expression ratio of the two transcripts between normal people and patients. Meanwhile, new transcript similar to human was also observed in many tissues of mice. Based on the above research, we hypothesized that alternative splicing in COL1A1 gene is present, and the two transcripts produced show spatial and temporal differences in expression. In addition, the mutation may alter selective splicing behavior, disrupt post-transcriptional regulation mechanisms, which eventually cause osteogenesis imperfecta. In view of this hypothesis, the project will carry out research from the following aspects: 1) imaging and biochemical phenotypic analysis of mouse models; 2) studying the splicing mechanism of the two COL1A1 gene transcripts; 3) studying the transcriptome of the COL1A1 gene and the post-transcriptional regulation mechanism. This project is of great significance to clarify the molecular mechanism of COL1A1 gene alternative splicing in osteogenesis imperfecta.