Angiotensin II does not influence expression of sarcoplasmic reticulum Ca2+ ATPase in atrial myocytes

作者：Wu Cho Kai; Tseng Chuen Den^*; Huang Yin Tsen; Hsieh Chia Shan; Tsai Wei Shan; Lin Jiunn Lee; Chiang Fu Tien; Tsai Chia Ti

来源：Journal of the Renin-Angiotensin-Aldosterone System, 2009, 10(3): 121-126.

DOI：10.1177/1470320309342732

• angiotensin II
• HL-1 cardiomyocytes
• promoter
• sarcoplasmic reticulum Ca2+ ATPase
• transcriptional regulation

Introduction. The sarcoplasmic reticulum Ca2+ ATPase (SERCA) is essential for the regulation of the intracellular calcium level in cardiomyocytes. Previous studies have found that angiotensin 11 (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 11 effects on atrial myocytes.
Materials and methods. An approximate to 1.75-kb promoter region of SERCA2 gene was cloned with the pGL3 luciferase vector. The direct effects of Ang 11 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 11 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 11 treatment.
Conclusions. Although Ang 11 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.

• 出版日期2009-9