title: Endocardial Brg1 represses ADAMTS1 to maintain the microenvironment for myocardial morphogenesis.
abstract: Developing myocardial cells respond to signals from the endocardial layer to form a network of trabeculae that characterize the ventricles of the vertebrate heart. Abnormal myocardial trabeculation results in specific cardiomyopathies in humans and yet trabecular development is poorly understood. We show that trabeculation requires Brg1, a chromatin remodeling protein, to repress ADAMTS1 expression in the endocardium that overlies the developing trabeculae. Repression of ADAMTS1, a secreted matrix metalloproteinase, allows the establishment of an extracellular environment in the cardiac jelly that supports trabecular growth. Later during embryogenesis, ADAMTS1 expression initiates in the endocardium to degrade the cardiac jelly and prevent excessive trabeculation. Thus, the composition of cardiac jelly essential for myocardial morphogenesis is dynamically controlled by ADAMTS1 and its chromatin-based transcriptional regulation. Modification of the intervening microenvironment provides a mechanism by which chromatin regulation within one tissue layer coordinates the morphogenesis of an adjacent layer.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Kryn
authors.initials: K
authors.lastname: Stankunas
authors.forename: Calvin T
authors.initials: CT
authors.lastname: Hang
authors.forename: Zhi-Yang
authors.initials: ZY
authors.lastname: Tsun
authors.forename: Hanying
authors.initials: H
authors.lastname: Chen
authors.forename: Nathan V
authors.initials: NV
authors.lastname: Lee
authors.forename: Jiang I
authors.initials: JI
authors.lastname: Wu
authors.forename: Ching
authors.initials: C
authors.lastname: Shang
authors.forename: J Henri
authors.initials: JH
authors.lastname: Bayle
authors.forename: Weinian
authors.initials: W
authors.lastname: Shou
authors.forename: M Luisa
authors.initials: ML
authors.lastname: Iruela-Arispe
authors.forename: Ching-Pin
authors.initials: CP
authors.lastname: Chang
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism*; D000071097:ADAMTS1 Protein; D000818:Animals; D002460:Cell Line; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D004699:Endocardium / Q000378:metabolism*; D004727:Endothelium / Q000166:cytology / Q000378:metabolism; D004920:Erythropoiesis; D005109:Extracellular Matrix / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006321:Heart / Q000196:embryology*; D006352:Heart Ventricles / Q000196:embryology; D006801:Humans; D051379:Mice; D009024:Morphogenesis; D018919:Neovascularization, Physiologic; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015017:Yolk Sac / Q000098:blood supply
chemical_list: D009687:Nuclear Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; D014157:Transcription Factors; D051722:ADAM Proteins; D000071097:ADAMTS1 Protein; C486323:Adamts1 protein, mouse; C513194:Smarca4 protein, mouse; D004265:DNA Helicases