Arrhythmogenic properties of dismantling cadherin-mediated adhesion in murine hearts

• Published in: Journal of biomedical research 2010-07, Vol.24 (4), p.292-300
• Main Authors: Zhu, Hongjun, Wang, Hegui, Zhang, Xiwen, Hou, Xiaofeng, Cao, Kejiang, Zou, Jiangang
• Format: Article
• Language: English
• Subjects: adherence junction; gap junction; N-cadherin; recombinant mouse ami-nopeptidase N; Research Paper; ventricular tachyarrhythmia; 心律失常; 粘附性; 钙粘蛋白; 间隙连接蛋白43
• ISSN: 1674-8301
• DOI: 10.1016/S1674-8301(10)60041-3

Objective： To evaluate the arrhythmogenic effects of dismantling cadherin-mediated adhesion by recombinant mouse aminopeptidase N （rmAPN） in murine hearts. Methods： rmAPN was incubated with cultured neonatal rat cardiomyocytes as well as being infused in adult mice. The cell-cell connections were immunolabelled and observed by laser confocal microscopy. Disruption of the N-terminal of N-cadherin （N-cad） was detected by western blot and quantitative immunofluorescence. The risk of inducible ventricular tachyarrhythmia was evaluated in mice by an electrophysiological study. Results： Disrupted cell-cell contact was observed in cultured neonatal rat cardiomyocytes in response to 30-40 ng/μL rmAPN. Loss of the N-terminal in N-cad and altered distribution of connexin 43 （Cx43） were observed in hearts from rmAPN-infused mice. In addition, a reduction of phosphorylated Cx43 was also detected concomitant with redistribution of Cx43. Electrophysiological studies of rmAPN-infused mice showed prolonged QRS duration and increased inducibility of ventricular tachycardias. Conclusion： Disruption of N-cad by rmAPN contributes to gap junction remodeling and may elicit arrhythmogenic effects. The disorder of adherent junctions by proteolytic enzymes may play an important role in arrhythmogenic mechanisms in correlated diseases.