Overexpression of Na+-HCO3– cotransporter contributes to the exacerbation of cardiac remodeling in mice with myocardial infarction by increasing intracellular calcium overload

Publication date: Available online 26 November 2019Source: Biochimica et Biophysica Acta (BBA) - Molecular Basis of DiseaseAuthor(s): Zhenhuan Chen, Lu Chen, Kaitong Chen, Hairuo Lin, Mengjia Shen, Lin Chen, Hailin Zhu, Yingqi Zhu, Qiancheng Wang, Fang Xi, Xiaobo Huang, Yuegang Wang, Wangjun Liao, Jianping Bin, Masanori Asakura, Jie Liu, Masafumi Kitakaze, Yulin LiaoAbstractThe role of the cardiac isoform of the electrogenic sodium-bicarbonate ion cotransporter (NBCe1) in cardiac remodeling is not fully understood. The aim of this study was to assess the effects of NBCe1 overexpression on cardiac remodeling induced by myocardial infarction (MI) in mice. We generated NBCe1 transgenic (Tg) mice and NBCe1 overexpressing adult mouse ventricular myocytes (AMVMs) to investigate the role of NBCe1 on post-MI remodeling and calcium kinetics. Tg mice showed a markedly higher mortality rate and larger infarct size after MI. At 6 weeks after MI, the maximum rising rates of left ventricular pressure (dp/dt), contractility index, and the exponential time constant of relaxation (τ) were markedly lower, and there was higher cardiomyocyte apoptosis, in Tg mice compared with WT mice. In cultured AMVMs, overexpression of NBCe1 decreased sarcomere shortening and calcium amplitude. In WT AMVMs, the rates of the rise and decay phase of calcium transients, indicated by the rising time (Tpeak, time to peak) and decay time constant (τd), and the number of apoptotic cells, were increased following ...
Source: Biochimica et Biophysica Acta (BBA) Molecular Basis of Disease - Category: Molecular Biology Source Type: research