title: RBM20 Regulates Circular RNA Production From the Titin Gene.
abstract: BACKGROUND
  RNA-binding motif protein 20 (RBM20) is essential for normal splicing of many cardiac genes, and loss of RBM20 causes dilated cardiomyopathy. Given its role in splicing, we hypothesized an important role for RBM20 in forming circular RNAs (circRNAs), a novel class of noncoding RNA molecules.
  
  
  OBJECTIVE
  To establish the role of RBM20 in the formation of circRNAs in the heart.
  
  
  RESULTS
  Here, we performed circRNA profiling on ribosomal depleted RNA from human hearts and identified the expression of thousands of circRNAs, with some of them regulated in disease. Interestingly, we identified 80 circRNAs to be expressed from the titin gene, a gene that is known to undergo highly complex alternative splicing. We show that some of these circRNAs are dynamically regulated in dilated cardiomyopathy but not in hypertrophic cardiomyopathy. We generated RBM20-null mice and show that they completely lack these titin circRNAs. In addition, in a cardiac sample from an RBM20 mutation carrier, titin circRNA production was severely altered. Interestingly, the loss of RBM20 caused only a specific subset of titin circRNAs to be lost. These circRNAs originated from the RBM20-regulated I-band region of the titin transcript.
  
  
  CONCLUSIONS
  We show that RBM20 is crucial for the formation of a subset of circRNAs that originate from the I-band of the titin gene. We propose that RBM20, by excluding specific exons from the pre-mRNA, provides the substrate to form this class of RBM20-dependent circRNAs.
authors.affiliation: From the Department of Experimental Cardiology (M.A.F.K., Y.J.R., S.A., M.M.G.v.d.H., I.v.d.M., A.B., E.E.C., Y.M.P.), Department of Clinical Epidemiology, Biostatistics and Bioinformatics (M.A.F.K., S.A.), and Department of Cardiothoracic Surgery (D.R.K.), Academic Medical Center, Amsterdam, The Netherlands; Department of Cardiology, Aarhus University Hospital, Denmark (T.B.R.); and Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands (J.v.d.V.).
authors.forename: Mohsin A F
authors.initials: MA
authors.lastname: Khan
authors.affiliation: From the Department of Experimental Cardiology (M.A.F.K., Y.J.R., S.A., M.M.G.v.d.H., I.v.d.M., A.B., E.E.C., Y.M.P.), Department of Clinical Epidemiology, Biostatistics and Bioinformatics (M.A.F.K., S.A.), and Department of Cardiothoracic Surgery (D.R.K.), Academic Medical Center, Amsterdam, The Netherlands; Department of Cardiology, Aarhus University Hospital, Denmark (T.B.R.); and Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands (J.v.d.V.).
authors.forename: Yolan J
authors.initials: YJ
authors.lastname: Reckman
authors.affiliation: From the Department of Experimental Cardiology (M.A.F.K., Y.J.R., S.A., M.M.G.v.d.H., I.v.d.M., A.B., E.E.C., Y.M.P.), Department of Clinical Epidemiology, Biostatistics and Bioinformatics (M.A.F.K., S.A.), and Department of Cardiothoracic Surgery (D.R.K.), Academic Medical Center, Amsterdam, The Netherlands; Department of Cardiology, Aarhus University Hospital, Denmark (T.B.R.); and Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands (J.v.d.V.).
authors.forename: Simona
authors.initials: S
authors.lastname: Aufiero
authors.affiliation: From the Department of Experimental Cardiology (M.A.F.K., Y.J.R., S.A., M.M.G.v.d.H., I.v.d.M., A.B., E.E.C., Y.M.P.), Department of Clinical Epidemiology, Biostatistics and Bioinformatics (M.A.F.K., S.A.), and Department of Cardiothoracic Surgery (D.R.K.), Academic Medical Center, Amsterdam, The Netherlands; Department of Cardiology, Aarhus University Hospital, Denmark (T.B.R.); and Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands (J.v.d.V.).
authors.forename: Maarten M G
authors.initials: MM
authors.lastname: van den Hoogenhof
authors.affiliation: From the Department of Experimental Cardiology (M.A.F.K., Y.J.R., S.A., M.M.G.v.d.H., I.v.d.M., A.B., E.E.C., Y.M.P.), Department of Clinical Epidemiology, Biostatistics and Bioinformatics (M.A.F.K., S.A.), and Department of Cardiothoracic Surgery (D.R.K.), Academic Medical Center, Amsterdam, The Netherlands; Department of Cardiology, Aarhus University Hospital, Denmark (T.B.R.); and Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands (J.v.d.V.).
authors.forename: Ingeborg
authors.initials: I
authors.lastname: van der Made
authors.affiliation: From the Department of Experimental Cardiology (M.A.F.K., Y.J.R., S.A., M.M.G.v.d.H., I.v.d.M., A.B., E.E.C., Y.M.P.), Department of Clinical Epidemiology, Biostatistics and Bioinformatics (M.A.F.K., S.A.), and Department of Cardiothoracic Surgery (D.R.K.), Academic Medical Center, Amsterdam, The Netherlands; Department of Cardiology, Aarhus University Hospital, Denmark (T.B.R.); and Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands (J.v.d.V.).
authors.forename: Abdelaziz
authors.initials: A
authors.lastname: Beqqali
authors.affiliation: From the Department of Experimental Cardiology (M.A.F.K., Y.J.R., S.A., M.M.G.v.d.H., I.v.d.M., A.B., E.E.C., Y.M.P.), Department of Clinical Epidemiology, Biostatistics and Bioinformatics (M.A.F.K., S.A.), and Department of Cardiothoracic Surgery (D.R.K.), Academic Medical Center, Amsterdam, The Netherlands; Department of Cardiology, Aarhus University Hospital, Denmark (T.B.R.); and Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands (J.v.d.V.).
authors.forename: Dave R
authors.initials: DR
authors.lastname: Koolbergen
authors.affiliation: From the Department of Experimental Cardiology (M.A.F.K., Y.J.R., S.A., M.M.G.v.d.H., I.v.d.M., A.B., E.E.C., Y.M.P.), Department of Clinical Epidemiology, Biostatistics and Bioinformatics (M.A.F.K., S.A.), and Department of Cardiothoracic Surgery (D.R.K.), Academic Medical Center, Amsterdam, The Netherlands; Department of Cardiology, Aarhus University Hospital, Denmark (T.B.R.); and Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands (J.v.d.V.).
authors.forename: Torsten B
authors.initials: TB
authors.lastname: Rasmussen
authors.affiliation: From the Department of Experimental Cardiology (M.A.F.K., Y.J.R., S.A., M.M.G.v.d.H., I.v.d.M., A.B., E.E.C., Y.M.P.), Department of Clinical Epidemiology, Biostatistics and Bioinformatics (M.A.F.K., S.A.), and Department of Cardiothoracic Surgery (D.R.K.), Academic Medical Center, Amsterdam, The Netherlands; Department of Cardiology, Aarhus University Hospital, Denmark (T.B.R.); and Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands (J.v.d.V.).
authors.forename: Jolanda
authors.initials: J
authors.lastname: van der Velden
authors.affiliation: From the Department of Experimental Cardiology (M.A.F.K., Y.J.R., S.A., M.M.G.v.d.H., I.v.d.M., A.B., E.E.C., Y.M.P.), Department of Clinical Epidemiology, Biostatistics and Bioinformatics (M.A.F.K., S.A.), and Department of Cardiothoracic Surgery (D.R.K.), Academic Medical Center, Amsterdam, The Netherlands; Department of Cardiology, Aarhus University Hospital, Denmark (T.B.R.); and Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands (J.v.d.V.). e.e.creemers@amc.uva.nl y.pinto@amc.uva.nl.
authors.forename: Esther E
authors.initials: EE
authors.lastname: Creemers
authors.affiliation: From the Department of Experimental Cardiology (M.A.F.K., Y.J.R., S.A., M.M.G.v.d.H., I.v.d.M., A.B., E.E.C., Y.M.P.), Department of Clinical Epidemiology, Biostatistics and Bioinformatics (M.A.F.K., S.A.), and Department of Cardiothoracic Surgery (D.R.K.), Academic Medical Center, Amsterdam, The Netherlands; Department of Cardiology, Aarhus University Hospital, Denmark (T.B.R.); and Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands (J.v.d.V.). e.e.creemers@amc.uva.nl y.pinto@amc.uva.nl.
authors.forename: Yigal M
authors.initials: YM
authors.lastname: Pinto
mesh_terms: D000328:Adult; D000818:Animals; D001665:Binding Sites / Q000502:physiology; D064211:Connectin / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D006352:Heart Ventricles / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008875:Middle Aged; D012313:RNA / Q000096:biosynthesis* / Q000235:genetics; D000079962:RNA, Circular; D016601:RNA-Binding Proteins / Q000502:physiology*
chemical_list: D064211:Connectin; D000079962:RNA, Circular; D016601:RNA-Binding Proteins; C577285:TTN protein, human; C543725:ribonucleic acid binding motif protein 20, human; D012313:RNA
keywords: alternative splicing; cardiovascular system; dilated cardiomyopathy; hypertrophic cardiomyopathy; mutation