LMNA基因R527C纯合突变儿童早老症干细胞功能异常及分子机理研究

儿童早老症（HGPS）是一种罕见但致死的遗传病，90%以上HGPS患者是由于LMNA基因G608G同义突变引起早老蛋白的产生和堆积所致。本团队近期发现中国家系的三位HGPS患者其LMNA携带新型c.1579C>T（R527C）纯合突变，而携带杂合突变的父母表型正常。为探索该新型突变的致病机制，本申请人已对三位HGPS患者的PBMC进行了单细胞RNA测序，并重编程获得了患者的诱导多能性干细胞（中国HGPS-iPSC），并将使用基因编辑对该突变进行校正，获得与病人遗传背景相同但突变校正的HGPSmc-iPSC。最终比较由HGPSmc-iPSC、HGPS-iPSC和正常iPSC分化产生的三种间充质干细胞的增殖和凋亡等代谢过程，辅以RNA测序、CRISPR/Cas9文库筛选以及关键基因和信号通路分析。本项目可为新型HGPS的致病机制探索和药物筛选提供工具，也为衰老和抗衰老的研究提供新的思路。

Hutchinson Gilford Progeria syndrome (HGPS) is a rare but lethal genetic disorder. More than 90% of HGPS patients are caused by the production and accumulation of progerin induced by the silent G608G mutation in the LMNA gene. We recently found that three HGPS patients in Chinese families carry a novel homozygous mutation c.1579C>T (R527C) in the LMNA gene, while the phenotypes of parents carrying the heterozygous mutation are normal. In order to investigate the disease mechanism of this novel mutation, we have performed single-cell RNA sequencing on the PBMCs of these three Chinese HGPS patients carrying the R527C mutation, and generated induced pluripotent stem cells (Chinese HGPS-iPSC) from these three patients by somatic cell reprogramming, and will use the CRISPR-mediated gene editing to accurately correct the mutation, and obtain the mutation corrected Chinese HGPSmc-iPSC with the same genetic background as the patients. Eventually, the cellular metabolic processes such as cell proliferation and apoptosis will be compared in three different mesenchymal stem cell lines derived from Chinese HGPSmc-iPSC, Chinese HGPS-iPSC and normal iPSC, complemented by genome-wide RNA sequencing, CRISPR/Cas9 library screening and identification of key genes and signaling pathways. This project is expected to provide tools for exploring the pathogenic mechanism and drug screening of this new HGPS, and also provide new ideas for aging and anti-aging research.