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Updated: Aug 3, 2025
10:53
Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
Published on: July 3, 2013
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KCa3.1 Promotes Proinflammatory Exosome Secretion by Activating AKT/Rab27a in Atrial Myocytes during Rapid Pacing
Dishiwen Liu1,2,3, Huiyu Chen1,2,3, Yuntao Fu1,2,3
1Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China.
Cardiovascular Therapeutics
|April 10, 2023
Summary
The medium-conductance calcium-activated potassium channel (KCa3.1) promotes proinflammatory exosome secretion in atrial myocytes via the AKT/Rab27a pathway. Inhibiting this KCa3.1/AKT/Rab27a pathway reduces atrial fibrillation-induced structural remodeling.
Area of Science:
- Cardiovascular Biology
- Ion Channel Physiology
- Exosome Biology
Background:
- Atrial fibrillation (AF) is associated with electrical remodeling, inflammation, and fibrosis.
- Exosomes play a role in intercellular communication and inflammation.
- The role of KCa3.1 in atrial myocyte exosome secretion remains unclear.
Purpose of the Study:
- To investigate the role of KCa3.1 in the secretion of proinflammatory exosomes by atrial myocytes.
- To elucidate the signaling pathway through which KCa3.1 regulates exosome secretion.
Main Methods:
- Beagles underwent sham, pacing, or pacing+TRAM-34 treatment.
- Electrophysiological parameters and atrial tissue histology were assessed.
- KCa3.1, Rab27a expression, and exosome markers were analyzed using immunohistochemistry and western blotting.
- HL-1 cells were used to examine KCa3.1 signaling pathways.
Main Results:
- Atrial rapid pacing induced electrical remodeling, inflammation, fibrosis, and exosome secretion, which were inhibited by TRAM-34.
- Pacing increased exosome markers and inflammatory factors in HL-1 cells.
- KCa3.1 regulated exosome secretion via the AKT/Rab27a signaling pathway.
- Inhibition of KCa3.1 downstream signaling reduced exosome secretion.
Conclusions:
- KCa3.1 promotes proinflammatory exosome secretion through the AKT/Rab27a signaling pathway.
- Inhibiting the KCa3.1/AKT/Rab27a pathway reduces myocardial structural remodeling in AF.
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