Department of Drug Discovery Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan.
Department of Drug Discovery Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan; Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan.
Cell Chem Biol. 2020 Dec 17;27(12):1472-1482.e6. doi: 10.1016/j.chembiol.2020.08.013. Epub 2020 Sep 8.
Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that compromise its chloride channel activity. Here, we present a therapeutic strategy to ameliorate RNA splicing deficiency of CFTR with a small molecule. The 3,849 + 10 kb C>T is the most common splicing mutation in CF, creating a pseudo exon with premature stop codon. We reveal that the 3,849 + 10 kb C>T-induced CFTR pseudo exon is regulated by phosphorylation of serine/arginine-rich splicing factors, and their functional inhibition by a CDC-like kinase inhibitor restores normal splicing of CFTR. Subsequent screening of our focused chemical library identified CaNDY as a rectifier of the aberrant splicing. CaNDY treatment restored normal splicing of CFTR with the 3,849 + 10 kb C>T in CF patient cells and functional CFTR protein expression in the CF model cells. Our findings open the door for mechanism-based personalized medicine for pseudo-exon-type genetic diseases.
囊性纤维化（CF）是由囊性纤维化跨膜电导调节因子（CFTR）基因突变引起的，该基因突变损害了其氯离子通道活性。在这里，我们提出了一种用小分子改善 CFTR 剪接缺陷的治疗策略。3,849 + 10 kb C>T 是 CF 中最常见的剪接突变，产生具有提前终止密码子的假外显子。我们揭示 3,849 + 10 kb C>T 诱导的 CFTR 假外显子受丝氨酸/精氨酸丰富剪接因子磷酸化的调节，其功能抑制通过 CDC 样激酶抑制剂恢复 CFTR 的正常剪接。随后对我们的靶向化学文库进行筛选，确定 CaNDY 是纠正异常剪接的调节剂。CaNDY 治疗恢复了 CF 患者细胞中 3,849 + 10 kb C>T 的 CFTR 正常剪接和 CF 模型细胞中功能性 CFTR 蛋白表达。我们的发现为基于机制的假外显子型遗传病的个体化医学开辟了道路。
