title: Loss of H3K4 methylation destabilizes gene expression patterns and physiological functions in adult murine cardiomyocytes.
abstract: Histone H3 lysine 4 (H3K4me) methyltransferases and their cofactors are essential for embryonic development and the establishment of gene expression patterns in a cell-specific and heritable manner. However, the importance of such epigenetic marks in maintaining gene expression in adults and in initiating human disease is unclear. Here, we addressed this question using a mouse model in which we could inducibly ablate PAX interacting (with transcription-activation domain) protein 1 (PTIP), a key component of the H3K4me complex, in cardiac cells. Reducing H3K4me3 marks in differentiated cardiomyocytes was sufficient to alter gene expression profiles. One gene regulated by H3K4me3 was Kv channel-interacting protein 2 (Kcnip2), which regulates a cardiac repolarization current that is downregulated in heart failure and functions in arrhythmogenesis. This regulation led to a decreased sodium current and action potential upstroke velocity and significantly prolonged action potential duration (APD). The prolonged APD augmented intracellular calcium and in vivo systolic heart function. Treatment with isoproterenol and caffeine in this mouse model resulted in the generation of premature ventricular beats, a harbinger of lethal ventricular arrhythmias. These results suggest that the maintenance of H3K4me3 marks is necessary for the stability of a transcriptional program in differentiated cells and point to an essential function for H3K4me3 epigenetic marks in cellular homeostasis.
authors.affiliation: Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA. adamstei@umich.edu
authors.forename: Adam B
authors.initials: AB
authors.lastname: Stein
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Jones
authors.forename: Todd J
authors.initials: TJ
authors.lastname: Herron
authors.forename: Sanjeevkumar R
authors.initials: SR
authors.lastname: Patel
authors.forename: Sharlene M
authors.initials: SM
authors.lastname: Day
authors.forename: Sami F
authors.initials: SF
authors.lastname: Noujaim
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Milstein
authors.forename: Matthew
authors.initials: M
authors.lastname: Klos
authors.forename: Philip B
authors.initials: PB
authors.lastname: Furspan
authors.forename: José
authors.initials: J
authors.lastname: Jalife
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Dressler
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins; D044127:Epigenesis, Genetic; D015870:Gene Expression; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051605:Kv Channel-Interacting Proteins / Q000235:genetics / Q000378:metabolism; D008239:Lysine / Q000378:metabolism*; D008745:Methylation; D051379:Mice; D018345:Mice, Knockout; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism* / Q000502:physiology*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D018879:Ventricular Premature Complexes
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D006657:Histones; C496755:Kcnip2 protein, mouse; D051605:Kv Channel-Interacting Proteins; D009687:Nuclear Proteins; C412792:Paxip1 protein, mouse; D008239:Lysine; D002118:Calcium