title: Identification of miR-34 regulatory networks in settings of disease and antimiR-therapy: Implications for treating cardiac pathology and other diseases.
abstract: Expression of the miR-34 family (miR-34a, -34b, -34c) is elevated in settings of heart disease, and inhibition with antimiR-34a/antimiR-34 has emerged as a promising therapeutic strategy. Under chronic cardiac disease settings, targeting the entire miR-34 family is more effective than targeting miR-34a alone. The identification of transcription factor (TF)-miRNA regulatory networks has added complexity to understanding the therapeutic potential of miRNA-based therapies. Here, we sought to determine whether antimiR-34 targets secondary miRNAs via TFs which could contribute to antimiR-34-mediated protection. Using miRNA-Seq we identified differentially regulated miRNAs in hearts from mice with cardiac pathology due to transverse aortic constriction (TAC), and focused on miRNAs which were also regulated by antimiR-34. Two clusters of stress-responsive miRNAs were classified as "pathological" and "cardioprotective," respectively. Using ChIPBase we identified 45 TF binding sites on the promoters of "pathological" and "cardioprotective" miRNAs, and 5 represented direct targets of miR-34, with the capacity to regulate other miRNAs. Knockdown studies in a cardiomyoblast cell line demonstrated that expression of 2 "pathological" miRNAs (let-7e, miR-31) was regulated by one of the identified TFs. Furthermore, by qPCR we confirmed that expression of let-7e and miR-31 was lower in hearts from antimiR-34 treated TAC mice; this may explain why targeting the entire miR-34 family is more effective than targeting miR-34a alone. Finally, we showed that Acsl4 (a common target of miR-34, let-7e and miR-31) was increased in hearts from TAC antimiR-34 treated mice. In summary, antimiR-34 regulates the expression of other miRNAs and this has implications for drug development.
authors.affiliation: a Cardiac Hypertrophy Laboratory , Baker IDI Heart and Diabetes Institute , Melbourne , Australia.
authors.forename: Jenny Y Y
authors.initials: JYY
authors.lastname: Ooi
authors.affiliation: a Cardiac Hypertrophy Laboratory , Baker IDI Heart and Diabetes Institute , Melbourne , Australia.
authors.forename: Bianca C
authors.initials: BC
authors.lastname: Bernardo
authors.affiliation: a Cardiac Hypertrophy Laboratory , Baker IDI Heart and Diabetes Institute , Melbourne , Australia.
authors.forename: Saloni
authors.initials: S
authors.lastname: Singla
authors.affiliation: a Cardiac Hypertrophy Laboratory , Baker IDI Heart and Diabetes Institute , Melbourne , Australia.
authors.forename: Natalie L
authors.initials: NL
authors.lastname: Patterson
authors.affiliation: b Asbestos Diseases Research Institute , Sydney , Australia.|c School of Medical Sciences , University of New South Wales , Sydney , Australia.
authors.forename: Ruby C Y
authors.initials: RCY
authors.lastname: Lin
authors.affiliation: a Cardiac Hypertrophy Laboratory , Baker IDI Heart and Diabetes Institute , Melbourne , Australia.|d Monash University , Clayton , Australia.
authors.forename: Julie R
authors.initials: JR
authors.lastname: McMullen
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000818:Animals; D006332:Cardiomegaly / Q000378:metabolism / Q000628:therapy*; D002460:Cell Line; D003066:Coenzyme A Ligases / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D053263:Gene Regulatory Networks; D006333:Heart Failure / Q000378:metabolism / Q000628:therapy*; D006352:Heart Ventricles / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D035683:MicroRNAs / Q000032:analysis / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000737:chemistry / Q000378:metabolism; D010919:Placebos; D017423:Sequence Analysis, RNA; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: C551848:MIRN34a microRNA, mouse; D035683:MicroRNAs; D010919:Placebos; D014157:Transcription Factors; C581020:Acsl4 protein, mouse; D003066:Coenzyme A Ligases
keywords: Heart disease; miR-Seq; miRNA networks; microRNA; therapy