Calcium Regulation on the Atrial Regional Difference of Collagen Production Activity in Atrial Fibrogenesis

Biomedicines

Yao-Chang Chen¹  Yung-Hsin Yeh²  Yung-Kuo Lin³  Yi-Jen Chen³  Cheng-Chih Chung³  Yu-Hsun Kao⁴ 

[1] Department of Biomedical Engineering, National Defense Medical Center, Taipei 11490, Taiwan;Division of Cardiology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan;Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan;Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan;

关键词: fibroblasts;    heart failure;    left atrium;    right atrium;    Ca²⁺;    CaMKII;   

DOI  :  10.3390/biomedicines9060686

来源: DOAJ

【 摘 要 】

Background: Atrial fibrosis plays an important role in the genesis of heart failure and atrial fibrillation. The left atrium (LA) exhibits a higher level of fibrosis than the right atrium (RA) in heart failure and atrial arrhythmia. However, the mechanism for the high fibrogenic potential of the LA fibroblasts remains unclear. Calcium (Ca²⁺) signaling contributes to the pro-fibrotic activities of fibroblasts. This study investigated whether differences in Ca²⁺ homeostasis contribute to differential fibrogenesis in LA and RA fibroblasts. Methods: Ca²⁺ imaging, a patch clamp assay and Western blotting were performed in isolated rat LA and RA fibroblasts. Results: The LA fibroblasts exhibited a higher Ca²⁺ entry and gadolinium-sensitive current compared with the RA fibroblasts. The LA fibroblasts exhibited greater pro-collagen type I, type III, phosphorylated Ca²⁺/calmodulin-dependent protein kinase II (CaMKII), phosphorylated phospholipase C (PLC), stromal interaction molecule 1 (STIM1) and transient receptor potential canonical (TRPC) 3 protein expression compared with RA fibroblasts. In the presence of 1 mmol/L ethylene glycol tetra-acetic acid (EGTA, Ca²⁺ chelator), the LA fibroblasts had similar pro-collagen type I, type III and phosphorylated CaMKII expression compared with RA fibroblasts. Moreover, in the presence of KN93 (a CaMKII inhibitor, 10 μmol/L), the LA fibroblasts had similar pro-collagen type I and type III compared with RA fibroblasts. Conclusion: The discrepancy of phosphorylated PLC signaling and gadolinium-sensitive Ca²⁺ channels in LA and RA fibroblasts induces different levels of Ca²⁺ influx, phosphorylated CaMKII expression and collagen production.

【 授权许可】

Unknown