title: Differential changes in TGF-β/BMP signaling pathway in the right ventricular myocardium of newborns with hypoplastic left heart syndrome.
abstract: BACKGROUND
  Hypoplastic left heart syndrome (HLHS) is characterized by underdevelopment of the left ventricle (LV) and increased biomechanical stress on the right ventricle (RV) from single ventricle physiology. Despite the clinical significance, the signaling pathways active during RV remodeling and disease progression are not known. To address this, we examined differential changes in expression of genes associated with transforming growth factor-beta (TGF-beta)/bone morphogenetic protein (BMP) signaling in RV tissue isolated from HLHS patients relative to RV and LV tissue from control subjects.
  
  
  RESULTS
  Quantitative real-time polymerase chain reaction was used to detect changes in expression of 84 genes involved in TGF-beta/BMP-mediated cardiac development, cell growth, and differentiation in RV tissue collected from 6 neonates with HLHS undergoing stage 1 Norwood procedure (age, 1-7 days; mean, 4 days) and RV and LV tissue obtained from 5 infants with noncardiac pathology (age range, 1-135 days: mean, 85 days) that served as controls. Analysis of gene expression profiles between control-LV and control-RV revealed significant depression of TGF-beta/BMP signaling in RV compared with LV. Of the 84 genes analyzed, 38 were differentially expressed between HLHS-RV and control-RV, whereas only 22 compared with control-LV. Significant changes were observed in: tissue remodeling genes including Activin receptor type IIA (ACVR2A) (+2.13) and Activin receptor-like kinase 1 (ACVRL1) (+2.22); and cell survival, growth, and differentiation genes including CDC25A (+2.18), p21 (-3.64), p15 (+2.15), BMP5 (+4.58), BMP3 (+2.16), GDF3 (+8.59), NODAL (+2.32), and BMP binding endothelial regulator (BMPER) (+4.58). The most significant changes common to HLHS-RV versus control-RV and control-LV sample groups is observed for Anti müllerian hormone receptor 2 (AMHR2) (+18.79 control-RV, +3.38 control-LV), and the BMP antagonist Inhibin alpha (INHA) (+11.47 control-RV, +5.73 control-LV).
  
  
  CONCLUSIONS
  Although this descriptive study does not allow cause-effect inferences, our results suggest changes in cardiac development pathways and upregulation of genes associated with cell growth and differentiation in the neonatal RV of children with HLHS. These molecular profiles are more closely related to those observed in the normal LV rather than normal RV at similar maturational age. This work provides the basis for future mechanistic studies to elucidate the molecular mechanisms regulating RV remodeling in HLHS.
authors.affiliation: Division of Cardiothoracic Surgery, University of Miami Miller School of Medicine and Holtz Children's Hospital, Miami, FL, USA. mricci@med.miami.edu
authors.forename: Marco
authors.initials: M
authors.lastname: Ricci
authors.forename: Bhagyalaxmi
authors.initials: B
authors.lastname: Mohapatra
authors.forename: Arnel
authors.initials: A
authors.lastname: Urbiztondo
authors.forename: Rhea J
authors.initials: RJ
authors.lastname: Birusingh
authors.forename: Micaela
authors.initials: M
authors.lastname: Morgado
authors.forename: Maria M
authors.initials: MM
authors.lastname: Rodriguez
authors.forename: Joy
authors.initials: J
authors.lastname: Lincoln
authors.forename: Matteo
authors.initials: M
authors.lastname: Vatta
mesh_terms: D019485:Bone Morphogenetic Proteins / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D006352:Heart Ventricles / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D015398:Signal Transduction / Q000502:physiology*; D016212:Transforming Growth Factor beta / Q000502:physiology*
chemical_list: D019485:Bone Morphogenetic Proteins; D016212:Transforming Growth Factor beta