title: Specific correction of a splice defect in brain by nutritional supplementation.
abstract: Recent studies emphasize the importance of mRNA splicing in human genetic disease, as 20-30% of all disease-causing mutations are predicted to result in mRNA splicing defects. The plasticity of the mRNA splicing reaction has made these mutations attractive candidates for the development of therapeutics. Familial dysautonomia (FD) is a severe neurodegenerative disorder, and all patients have an intronic IVS20+6T>C splice site mutation in the IKBKAP gene, which results in tissue-specific skipping of exon 20 and a corresponding reduction in ikappaB kinase complex associated protein (IKAP) levels. We created transgenic mouse lines using a human IKBKAP bacterial artificial chromosome (BAC) into which we inserted the IKBKAP splice mutation (FD BAC) and have shown that the transgenic mice exhibit the same tissue-specific aberrant splicing patterns as seen in FD patients. We have previously demonstrated that the plant cytokinin kinetin can significantly improve the production of wild-type IKBKAP transcripts in FD lymphoblast cell lines by improving exon inclusion. In this study, we tested the ability of kinetin to alter IKBKAP splicing in the transgenic mice carrying the FD BAC and show that it corrects IKBKAP splicing in all major tissues assayed, including the brain. The amount of wild-type IKBKAP mRNA and IKAP protein was significantly higher in the kinetin-treated mice. These exciting results prove that treatment of FD, as well as other mechanistically related splicing disorders, with kinetin holds great promise as a potential therapeutic aimed at increasing normal protein levels, which may, in turn, slow disease progression.
authors.affiliation: Center for Human Genetic Research, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, CPZN-5254, Boston, MA 02114, USA.
authors.forename: Ranjit S
authors.initials: RS
authors.lastname: Shetty
authors.forename: Cary S
authors.initials: CS
authors.lastname: Gallagher
authors.forename: Yei-Tsung
authors.initials: YT
authors.lastname: Chen
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Hims
authors.forename: James
authors.initials: J
authors.lastname: Mull
authors.forename: Maire
authors.initials: M
authors.lastname: Leyne
authors.forename: James
authors.initials: J
authors.lastname: Pickel
authors.forename: David
authors.initials: D
authors.lastname: Kwok
authors.forename: Susan A
authors.initials: SA
authors.lastname: Slaugenhaupt
mesh_terms: D017398:Alternative Splicing / Q000187:drug effects*; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D004032:Diet; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D047908:Intracellular Signaling Peptides and Proteins; D007701:Kinetin / Q000008:administration & dosage / Q000494:pharmacology*; D051379:Mice; D008822:Mice, Transgenic; D009474:Neurons / Q000187:drug effects / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; C491968:Ikbkap protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D007701:Kinetin