title: Chloramphenicol enhances IDUA activity on fibroblasts from mucopolysaccharidosis I patients.
abstract: Mucopolysaccharidosis I (MPS I) is a genetic disorder caused by mutations on α-L-iduronidase (IDUA) gene, leading to low or null enzyme activity. As nonsense mutations are present in about two thirds of the patients, stop codon read through (SCRT) is a potential alternative to achieve enhanced enzyme activity. This mechanism suppresses premature stop codon mutations allowing the protein to be fully translated. Chloramphenicol is a peptidyl transferase inhibitor able to induce readthrough and is efficient in cross the blood brain barrier. In this work, fibroblasts from MPS I patients (p.W402X/p.W402X; p.R89W/p.W402X and p.Q70X/c.1739-1g > t) were treated with chloramphenicol, which resulted in 100-fold increase on IDUA activity on compound heterozygous fibroblasts. cDNA sequencing showed that only the alleles without the nonsense mutation were being amplified, even after treatment, leading us to suggest that the nonsense alleles were targeted to nonsense-mediated mRNA decay and that chloramphenicol acts through a mechanism other than SCRT.
authors.affiliation: Gene Therapy Center, Experimental Research Center, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
authors.forename: Fabiana Quoos
authors.initials: FQ
authors.lastname: Mayer
authors.forename: Osvaldo Alfonso
authors.initials: OA
authors.lastname: Artigalás
authors.forename: Valeska Lizzi
authors.initials: VL
authors.lastname: Lagranha
authors.forename: Guilherme
authors.initials: G
authors.lastname: Baldo
authors.forename: Ida Vanessa
authors.initials: IV
authors.lastname: Schwartz
authors.forename: Ursula
authors.initials: U
authors.lastname: Matte
authors.forename: Roberto
authors.initials: R
authors.lastname: Giugliani
mesh_terms: D002478:Cells, Cultured; D002701:Chloramphenicol / Q000494:pharmacology*; D018389:Codon, Nonsense; D018388:Codon, Terminator; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D007068:Iduronidase / Q000235:genetics / Q000378:metabolism*; D008059:Mucopolysaccharidosis I / Q000378:metabolism*; D010458:Peptidyl Transferases / Q000037:antagonists & inhibitors*; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D018389:Codon, Nonsense; D018388:Codon, Terminator; D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D002701:Chloramphenicol; D010458:Peptidyl Transferases; D007068:Iduronidase