title: Ca²⁺ disorder caused by rapid electrical field stimulation can be modulated by CaMKIIδ expression in primary rat atrial myocytes.
abstract: Abnormalities in intracellular Ca(2+) handing are believed to contribute to arrhythmogenesis during atrial fibrillation (AF). Ca(2+)/calmodulin-dependent protein kinaseII δ (CaMKIIδ) overexpression was detected in atrial myocytes from patients and animal models with persistent AF. In the present study, we found that rapid electrical field stimulation applied to primary atrial myocytes altered the CaMKIIδ activity, not expression level, resulting in Ca(2+) disorder. By lentivirus mediated delivery of CaMKIIδ gene or siRNA into atrial myocytes, cells with different CaMKIIδ expression were generated. Changes of CaMKIIδ expression altered the sarcoplasmic reticulum (SR) Ca(2+) release and L-type Ca(2+) channels current (I(Ca)) in both steady and electrical stimulating state. These results revealed the important role of CaMKIIδ in Ca(2+) disorder caused by electrical field stimulation. It also provided a potential method to improve Ca(2+) disorder in AF by modulating CaMKIIδ expression level.
authors.affiliation: Department of Cardiology, Southwest Hospital, Third Military Medical University, Chong Qing 400038, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Qin
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Xiang
authors.initials: X
authors.lastname: Ding
authors.forename: Shifei
authors.initials: S
authors.lastname: Tong
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Song
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002128:Calcium Metabolism Disorders / Q000378:metabolism*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000096:biosynthesis*; D002478:Cells, Cultured; D004558:Electric Stimulation; D006325:Heart Atria / Q000166:cytology*; D032383:Myocytes, Cardiac / Q000378:metabolism*; D051381:Rats; D012519:Sarcoplasmic Reticulum / Q000378:metabolism
chemical_list: D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D002118:Calcium