运用CRISPR/Cas9编辑SMN2基因点突变和JNK3抑制剂对SMA患者iPSC诱导的运动神经元细胞凋亡分化的影响和协同作用研究

Spinal muscular atrophy (SMA) is an autosomal recessive hereditary disease characterized by degeneration of motor neurons, which is the most lethal disease among children. SMA is caused by homozygous deletion of exon 7 of SMN1 gene located at 5q13. SMN2 gene is a high homologous gene of SMN1. A single C to T transiton of exon 7 of SMN2 disrupts an exon splicing enhancer and creats an exon splicing silencer element, therefore encodes a truncated SMN protein. No effective treatment is available for this disease. Gene editing from SMN2 to SMN1 is an important strategy to promote the expression of SMN protein. JNK3-induced signaling pathway is involved in apoptosis of motor neurons. The present study will combine CRISPR/Cas9 and inhibitor of JNK3 to treat SMA-derived iPSC from amniotic fluid and evaluate the biologic function and involved signaling pathway.

脊髓性肌肉萎缩症(SMA)是以脊髓前角运动神经元退行性病变为特征的常染色体隐性遗传病，是儿童期常见的致死性遗传病。位于5q13处的运动神经元存活基因(SMN1)外显子7纯合缺失是主要病因，与SMN1高度同源的拷贝-SMN2基因，两者序列几乎一致，主要差异为第7外显子第6个碱基分别为C/T，引起剪接异常导致SMN2不能有效表达SMN蛋白。该病目前无有效的治疗方法，基因编辑SMN2基因转变为类SMN1基因，提高SMN1基因转录表达量是治疗该病的重要策略；已发现JNK3信号通路参与SMA发病中的运动神经元凋亡。本研究拟建立SMA疾病人羊水来源的多潜能干细胞(hAF-iPSC)，采用CRISPR系统对hAF-iPS细胞SMN2基因第7外显子第6个碱基进行T>C的碱基纠正后，联合应用JNK3抑制剂对诱导分化为运动神经元细胞的凋亡分化和相关信号通路进行研究，以为今后多基因联合治疗提供理论依据。