title: Ca²+-regulatory proteins in cardiomyocytes from the right ventricle in children with congenital heart disease.
abstract: BACKGROUND
  Hypoxia and hypertrophy are the most frequent pathophysiological consequence of congenital heart disease (CHD) which can induce the alteration of Ca2+-regulatory proteins and inhibit cardiac contractility. Few studies have been performed to examine Ca2+-regulatory proteins in human cardiomyocytes from the hypertrophic right ventricle with or without hypoxia.
  
  
  METHODS
  Right ventricle tissues were collected from children with tetralogy of Fallot [n = 25, hypoxia and hypertrophy group (HH group)], pulmonary stenosis [n = 25, hypertrophy group (H group)], or small isolated ventricular septal defect [n = 25, control group (C group)] during open-heart surgery. Paraffin sections of tissues were stained with 3,3'-dioctadecyloxacarbocyanine perchlorate to measure cardiomyocyte size. Expression levels of Ca2+-regulatory proteins [sarcoplasmic reticulum Ca2+-ATPase (SERCA2a), ryanodine receptor (RyR2), sodiumcalcium exchanger (NCX), sarcolipin (SLN) and phospholamban (PLN)] were analysed by means of real-time PCR, western blot, or immunofluorescence. Additionally, phosphorylation level of RyR and PLN and activity of protein phosphatase (PP1) were evaluated using western blot.
  
  
  RESULTS
  Mild cardiomyocyte hypertrophy of the right ventricle in H and HH groups was confirmed by comparing cardiomyocyte size. A significant reduction of SERCA2a in mRNA (P<0.01) was observed in the HH group compared with the C group. The level of Ser16-phosphorylated PLN was down-regulated (P<0.01) and PP1 was increased (P<0.01) in the HH group compared to that in the C group.
  
  
  CONCLUSIONS
  The decreased SERCA2a mRNA may be a biomarker of the pathological process in the early stage of cyanotic CHD with the hypertrophic right ventricle. A combination of hypoxia and hypertrophy can induce the adverse effect of PLN-Ser16 dephosphorylation. Increased PP1 could result in the decreased PLN-Ser16 and inhibition of PP1 is a potential therapeutic target for heart dysfunction in pediatrics.
authors.affiliation: State Key Laboratory of Cardiovascular Medicine, Cardiovascular Institute & Fuwai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: Yihe
authors.initials: Y
authors.lastname: Wu
authors.forename: Wei
authors.initials: W
authors.lastname: Feng
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Shoujun
authors.initials: S
authors.lastname: Li
authors.forename: De
authors.initials: D
authors.lastname: Wang
authors.forename: Xiangbin
authors.initials: X
authors.lastname: Pan
authors.forename: Shengshou
authors.initials: S
authors.lastname: Hu
mesh_terms: D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D048429:Cell Size; D002675:Child, Preschool; D003710:Demography; D005260:Female; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D006330:Heart Defects, Congenital / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D006352:Heart Ventricles / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008297:Male; D032383:Myocytes, Cardiac / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*; D010766:Phosphorylation; D054645:Protein Phosphatase 1 / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D002135:Calcium-Binding Proteins; D012333:RNA, Messenger; D054645:Protein Phosphatase 1; D002118:Calcium