Rett综合征(RTT),严重的X连锁神经发育障碍,主要由甲基CpG结合蛋白2基因(MECP2)的突变引起。超过35%的RTT患者在MECP2中携带无义突变,使其成为无义抑制疗法的合适候选疾病。在我们之前的研究中,发现庆大霉素以适度的效率诱导MECP2无义突变的读取。鉴于最近发现的连读增强剂,CDX化合物,我们在此评估了CDX5-1,CDX5-288和CDX6-180对携带四种最常见的MECP2无义突变的转染HeLa细胞系中庆大霉素介导的连读效率的增强作用.我们表明,所有三种CDX化合物都增强了庆大霉素介导的读入,并增加了表达R168X的细胞中全长MeCP2蛋白的水平。R255X,R270X,和R294X无义突变。在所有三种CDX化合物中,CDX5-288是最有效的增强剂,可以使用减少剂量的庆大霉素,从而减轻毒性。此外,我们成功地证明了通过组合治疗的Mecp2R255X/Y小鼠成纤维细胞中全长Mecp2蛋白表达的上调。一起来看,研究结果表明,这种组合方法对一部分RTT患者进行无义抑制治疗的可行性。
Rett syndrome (RTT), a severe X-linked neurodevelopmental disorder, is primarily caused by mutations in the methyl CpG binding protein 2 gene (MECP2). Over 35% RTT patients carry nonsense mutation in MECP2, making it a suitable candidate disease for nonsense suppression therapy. In our previous study, gentamicin was found to induce
readthrough of MECP2 nonsense mutations with modest efficiency. Given the recent discovery of
readthrough enhancers, CDX compounds, we herein evaluated the potentiation effect of CDX5-1, CDX5-288, and CDX6-180 on gentamicin-mediated
readthrough efficiency in transfected HeLa cell lines bearing the four most common MECP2 nonsense mutations. We showed that all three CDX compounds potentiated gentamicin-mediated
readthrough and increased full-length MeCP2 protein levels in cells expressing the R168X, R255X, R270X, and R294X nonsense mutations. Among all three CDX compounds, CDX5-288 was the most potent enhancer and enabled the use of reduced doses of gentamicin, thus mitigating the toxicity. Furthermore, we successfully demonstrated the upregulation of full-length Mecp2 protein expression in fibroblasts derived from Mecp2R255X/Y mice through combinatorial treatment. Taken together, findings demonstrate the feasibility of this combinatorial approach to nonsense suppression therapy for a subset of RTT patients.