Klotho modulates electrical activity and calcium homeostasis in pulmonary vein cardiomyocytes via PI3K/Akt signalling

Yuan Hung, Yao Chang Chen, Shih Yu Huang, Yen Yu Lu, Yung Kuo Lin, Yu Hsun Kao, Wei Shiang Lin, Shih Ann Chen, Yi Jen Chen

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Aims: Klotho, a potential antiageing protein has remarkable cardiovascular effects, which is lower in the patients with chronic kidney disease (CKD). Chronic kidney disease increases the risk of atrial fibrillation, majorly triggered by pulmonary vein (PV) arrhythmogenesis. This study investigated whether klotho protein can modulate PV electrical activity and the underlying potential mechanisms. Methods and results: A conventional microelectrode and whole-cell patch clamp were used to investigate the action potentials and ionic currents in isolated rabbit PV tissue preparations and single cardiomyocytes before and after klotho administration. Phosphoinositide 3-kinase (PI3K)/Akt signalling was studied using western blotting. Klotho significantly reduced PV spontaneous beating rates in PV tissue preparations at 1.0 and 3.0 ng/mL (but not at 0.1 and 0.3 ng/mL). In the presence of the Akt inhibitor (10 μM), klotho (1.0 and 3.0 ng/mL) did not change PV electrical activities. Klotho (1.0 ng/mL) significantly decreased the late sodium current (INa-Late) and L-type calcium current (ICa-L), similar to the Akt inhibitor (10 μM). Western blots demonstrated that klotho (1.0 ng/mL)-treated PV cardiomyocytes had less phosphorylation of Akt (Ser473) compared with klotho-untreated cardiomyocytes. Compared with control PVs, klotho at relatively lower concentrations (0.1 and 0.3 ng/mL) significantly reduced beating rates and decreased the amplitudes of delay afterdepolarizations in CKD PVs. Conclusion: Klotho modulated PV electrical activity by inhibiting PI3K/Akt signalling, which may provide a novel insight into CKD-induced arrhythmogenesis.

Original languageEnglish
Pages (from-to)1132-1141
Number of pages10
JournalEuropace
Volume22
Issue number7
DOIs
Publication statusPublished - Jul 1 2020

Keywords

  • Atrial fibrillation
  • Klotho
  • PI3K/Akt
  • Pulmonary vein

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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