ABSTRACT
Compelling evidence is now available that gentamicin and Geneticin (G418) can induce the mammalian ribosome to suppress disease-causing nonsense mutations and partially restore the expression of functional proteins. However, toxicity and relative lack of efficacy at subtoxic doses limit the use of gentamicin for suppression therapy. Although G418 exhibits the strongest activity, it is very cytotoxic even at low doses. We describe here the first systematic development of the novel aminoglycoside (S)-11 exhibiting similar in vitro and ex vivo activity to that of G418, while its cell toxicity is significantly lower than those of gentamicin and G418. Using a series of biochemical assays, we provide proof of principle that antibacterial activity and toxicity of aminoglycosides can be dissected from their suppression activity. The data further indicate that the increased specificity toward cytoplasmic ribosome correlates with the increased activity and that the decreased specificity toward mitochondrial ribosome confers the lowered cytotoxicity.
Subject(s)
Aminoglycosides/pharmacology , Codon, Nonsense , Cytoplasm/drug effects , Genetic Diseases, Inborn/therapy , Mitochondria/drug effects , Ribosomes/drug effects , Humans , Magnetic Resonance Spectroscopy , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationABSTRACT
New pseudo-di- and pseudo-trisaccharide derivatives of the aminoglycoside drug G418 were designed, synthesized and their ability to readthrough nonsense mutations was examined in both in vitro and ex vivo systems, along with the toxicity tests. Two novel lead structures, NB74 and NB84, exhibiting significantly reduced cell toxicity and superior readthrough efficiency than those of gentamicin, were discovered. The superiority of new leads was demonstrated in six different nonsense DNA-constructs underling the genetic diseases cystic fibrosis, Duchenne muscular dystrophy, Usher syndrome and Hurler syndrome.
