Inhibition of late sodium current via PI3K/Akt signaling prevents cellular remodeling in tachypacing-induced HL-1 atrial myocytes
- Authors
- Ko, Tae Hee; Jeong, Daun; Yu, Byeongil; Song, Ji Eun; Le, Qui Anh; Woo, Sun-Hee; Choi, Jong-Il
- Issue Date
- Feb-2023
- Publisher
- Springer Verlag
- Keywords
- Late sodium current; Atrial Fibrillation; Electrical remodeling; Tachypacing; PI3K/Akt signaling
- Citation
- Pflugers Archiv European Journal of Physiology, v.475, no.2, pp 217 - 231
- Pages
- 15
- Indexed
- SCIE
SCOPUS
- Journal Title
- Pflugers Archiv European Journal of Physiology
- Volume
- 475
- Number
- 2
- Start Page
- 217
- End Page
- 231
- URI
- https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/61719
- DOI
- 10.1007/s00424-022-02754-z
- ISSN
- 0031-6768
1432-2013
- Abstract
- An aberrant late sodium current (I-Na,I-Late) caused by a mutation in the cardiac sodium channel (Na(v)1.5) has emerged as a contributor to electrical remodeling that causes susceptibility to atrial fibrillation (AF). Although downregulation of phosphoinositide 3-kinase (PI3K)/Akt signaling is associated with AF, the molecular mechanisms underlying the negative regulation of I-Na,I-Late in AF remain unclear, and potential therapeutic approaches are needed. In this work, we constructed a tachypacing-induced cellular model of AF by exposing HL-1 myocytes to rapid electrical stimulation (1.5 V/cm, 4 ms, 10 Hz) for 6 h. Then, we gathered data using confocal Ca2+ imaging, immunofluorescence, patch-clamp recordings, and immunoblots. The tachypacing cells displayed irregular Ca2+ release, delayed afterdepolarization, prolonged action potential duration, and reduced PI3K/Akt signaling compared with controls. Those detrimental effects were related to increased I-Na,I-Late and were significantly mediated by treatment with the I-Na,I-Late blocker ranolazine. Furthermore, decreased PI3K/Akt signaling via PI3K inhibition increased I-Na,I-Late and subsequent aberrant myocyte excitability, which were abolished by I-Na,I-Late inhibition, suggesting that PI3K/Akt signaling is responsible for regulating pathogenic I-Na,I-Late. These results indicate that PI3K/Akt signaling is critical for regulating I-Na,I-Late and electrical remodeling, supporting the use of PI3K/Akt-mediated I-Na,I-Late as a therapeutic target for AF.
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- Appears in
Collections - 2. Clinical Science > Department of Cardiology > 1. Journal Articles
- 4. Research institute > Cardiovascular Research Institute > 1. Journal Articles
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