FGF-23 dysregulates calcium homeostasis and electrophysiological properties in HL-1 atrial cells

Yu Hsun Kao, Yao Chang Chen, Yung Kuo Lin, Rong Jie Shiu, Tze Fan Chao, Shih Ann Chen, Yi Jen Chen

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Background: Fibroblast growth factor (FGF)-23 is a key regulator of phosphate homeostasis. Higher FGF-23 levels are correlated with poor outcomes in cardiovascular diseases. FGF-23 can produce cardiac hypertrophy and increase intracellular calcium, which can change cardiac electrical activity. However, it is not clear whether FGF-23 possesses arrhythmogenic potential through calcium dysregulation. Therefore, the purposes of this study were to evaluate the electrophysiological effects of FGF-23 and identify the underlying mechanisms. Methods: Patch clamp, confocal microscope with Fluo-4 fluorescence, and Western blot analyses were used to evaluate the electrophysiological characteristics, calcium homeostasis and calcium regulatory proteins in HL-1 atrial myocytes with and without FGF-23 (10 and 25 ng/mL) incubation for 24 h. Results: FGF-23 (25 ng/mL) increased L-type calcium currents, calcium transient and sarcoplasmic reticulum Ca2+ contents in HL-1 cells. FGF-23 (25 ng/mL)-treated cells (n = 14) had greater incidences (57%, 17% and 15%, P <0·05) of delayed afterdepolarizations than control (n = 12) and FGF-23 (10 ng/mL)-treated cells (n = 13). Compared with control cells, FGF-23 (25 ng/mL)-treated cells (n = 14) exhibited increased phosphorylation of calcium/calmodulin-dependent protein kinase IIδ and phospholamban (PLB) at threonine 17 but had similar phosphorylation extents of PLB at serine 16, total PLB and sarcoplasmic reticulum Ca2+-ATPase protein. Moreover, the FGF receptor inhibitor (PD173074, 10 nM), calmodulin inhibitor (W7, 5 μM) and phospholipase C inhibitor (U73122, 1 μM) attenuated the effects of FGF-23 on calcium/calmodulin-dependent protein kinase II phosphorylation. Conclusions: FGF-23 increases HL-1 cells arrhythmogenesis with calcium dysregulation through modulating calcium-handling proteins.

Original languageEnglish
Pages (from-to)795-801
Number of pages7
JournalEuropean Journal of Clinical Investigation
Volume44
Issue number8
DOIs
Publication statusPublished - 2014

Keywords

  • Atrial arrhythmogenesis
  • Calcium-handling protein
  • Calcium/calmodulin-dependent protein kinase II
  • Fibroblast growth factor-23

ASJC Scopus subject areas

  • Medicine(all)
  • Clinical Biochemistry
  • Biochemistry

Fingerprint Dive into the research topics of 'FGF-23 dysregulates calcium homeostasis and electrophysiological properties in HL-1 atrial cells'. Together they form a unique fingerprint.

  • Cite this