title: Cardiac glycosides correct aberrant splicing of IKBKAP-encoded mRNA in familial dysautonomia derived cells by suppressing expression of SRSF3.
abstract: The ability to modulate the production of the wild-type transcript in cells bearing the splice-altering familial dysautonomia (FD) causing mutation in the IKBKAP gene prompted a study of the impact of a panel of pharmaceuticals on the splicing of this transcript, which revealed the ability of the cardiac glycoside digoxin to increase the production of the wild-type, exon-20-containing, IKBKAP-encoded transcript and the full-length IκB-kinase-complex-associated protein in FD-derived cells. Characterization of the cis elements and trans factors involved in the digoxin-mediated effect on splicing reveals that this response is dependent on an SRSF3 binding site(s) located in the intron 5' of the alternatively spliced exon and that digoxin mediates its effect by suppressing the level of the SRSF3 protein. Characterization of the digoxin-mediated effect on the RNA splicing process was facilitated by the identification of several RNA splicing events in which digoxin treatment mediates the enhanced inclusion of exonic sequence. Moreover, we demonstrate the ability of digoxin to impact the splicing process in neuronal cells, a cell type profoundly impacted by FD. This study represents the first demonstration that digoxin possesses splice-altering capabilities that are capable of reversing the impact of the FD-causing mutation. These findings support the clinical evaluation of the impact of digoxin on the FD patient population.
authors.affiliation: Laboratory for Familial Dysautonomia Research, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA.
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.forename: Sylvia L
authors.initials: SL
authors.lastname: Anderson
authors.forename: Jinsong
authors.initials: J
authors.lastname: Qiu
authors.forename: Berish Y
authors.initials: BY
authors.lastname: Rubin
mesh_terms: D017398:Alternative Splicing; D001483:Base Sequence; D001665:Binding Sites; D002301:Cardiac Glycosides / Q000494:pharmacology*; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D004077:Digoxin / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical; D004402:Dysautonomia, Familial / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D005091:Exons; D020868:Gene Silencing; D006801:Humans; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D017384:Sequence Deletion; D000068103:Serine-Arginine Splicing Factors; D035602:Transcriptional Elongation Factors; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D002301:Cardiac Glycosides; D002352:Carrier Proteins; C114720:Elp1 protein, human; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C491388:SRSF3 protein, human; C495901:TP53 protein, human; D035602:Transcriptional Elongation Factors; D016159:Tumor Suppressor Protein p53; D000068103:Serine-Arginine Splicing Factors; D004077:Digoxin; D017346:Protein Serine-Threonine Kinases
keywords: SRSF3; alternative splicing; cardiac glycoside; digoxin; familial dysautonomia