Aminoglycoside-mediated partial suppression of MECP2 nonsense mutations responsible for Rett syndrome in vitro

Rett syndrome is a pediatric neurological condition that affects primarily girls. Approximately 30% of Rett syndrome cases arise from point mutations that introduce a premature stop codon into the MECP2 gene. Several studies have now shown that certain aminoglycosides can facilitate read-through of some types of nonsense mutations in a context-dependent manner and allow the generation of a full-length protein. It remains mostly unclear whether different nonsense mutations of MECP2 will be responsive to aminoglycoside treatment. In this study, we tested whether the common premature terminating mutations of MECP2 seen in Rett syndrome cases can be partially suppressed by aminoglycoside administration. Our results show that aminoglycosides allow different mutant forms of MECP2 to be overcome in transiently transfected HEK293 cells, but with differing levels of efficiency. In addition, we also show that aminoglycosides increased the prevalence of full-length MeCP2 protein in a dose-dependent manner in a lymphocyte cell line derived from a Rett syndrome girl with the R255X mutation. This study helps to establish the "proof of principle" that some nonsense mutations causing Rett syndrome can be at least partially suppressed by drug treatment.