title: Angiotensin II does not influence expression of sarcoplasmic reticulum Ca2 + ATPase in atrial myocytes.
abstract: BACKGROUND
  The sarcoplasmic reticulum Ca(2+) ATPase (SERCA) is essential for the regulation of the intracellular calcium level in cardiomyocytes. Previous studies have found that angiotensin II (Ang II) decreased SERCA2 gene expression in ventricular myocytes. Alteration of SERCA activity is important in the mechanism of atrial fibrillation. The present study was undertaken to examine Ang II effects on atrial myocytes.
  
  
  METHODS
  An approximately 1.75-kb promoter region of SERCA2 gene was cloned with the pGL3 luciferase vector. The direct effects of Ang II on SERCA2 gene expression in HL-1 atrial myocytes were examined by promoter activity assay, followed by Western blot analysis for protein levels and quantitative real-time reverse transcription polymerase chain reaction for mRNA amounts.
  
  
  RESULTS
  Ang II did not increase the promoter activity of the 1,754-bp promoter-receptor construct of the SERCA2 gene. The levels of SERCA2 protein and mRNA were also unchanged at different time points after Ang II treatment.
  
  
  CONCLUSIONS
  Although Ang II had prominent effects on SERCA2 in ventricular myocytes, it did not alter SERCA2 gene expression and protein levels in atrial myocytes. We provide a model for further investigation of the regulation of SERCA2 gene expression in atrial myocytes.
authors.affiliation: Department of Internal Medicine, National Taiwan University College of Medicine and Hospital Yun-Lin Branch, Yun-Lin, Taiwan.
authors.forename: Cho-Kai
authors.initials: CK
authors.lastname: Wu
authors.forename: Chuen-Den
authors.initials: CD
authors.lastname: Tseng
authors.forename: Yin-Tsen
authors.initials: YT
authors.lastname: Huang
authors.forename: Chia-Shan
authors.initials: CS
authors.lastname: Hsieh
authors.forename: Wei-Shan
authors.initials: WS
authors.lastname: Tsai
authors.forename: Jiunn-Lee
authors.initials: JL
authors.lastname: Lin
authors.forename: Fu-Tien
authors.initials: FT
authors.lastname: Chiang
authors.forename: Chia-Ti
authors.initials: CT
authors.lastname: Tsai
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001665:Binding Sites; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006325:Heart Atria / Q000166:cytology*; D051379:Mice; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000235:genetics* / Q000378:metabolism*; D014162:Transfection
chemical_list: D012333:RNA, Messenger; D000804:Angiotensin II; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases