Electrophysiology of human cardiac atrial and ventricular telocytes. Issue 2 (February 2014)

• Record Type: Journal Article
• Authors: Sheng, Jingwei; Shim, Winston; Lu, Jun; Lim, Sze Yun; Ong, Boon Hean; Lim, Tien Siang; Liew, Reginald; Chua, Yeow Leng; Wong, Philip
• Is Part Of: Journal of cellular and molecular medicine. Volume 18:Issue 2(2014)
• Page Start: 355
• Page End: 362
• Publication Date: 2014-02
• Subjects: Cytology; Medicine; Molecular Biology; Cytologie -- Périodiques; Médecine -- Périodiques; Biologie moléculaire -- Périodiques; Cytology -- Periodicals; Medicine -- Periodicals; Molecular biology -- Periodicals; 611.01805
• DOI: 10.1111/jcmm.12240
• Languages: English
• ISSNs: 1582-1838

Abstract

<abstract abstract-type="main" id="jcmm12240-abs-0001"> <title>Abstract</title> <p>Telocytes (TCs) with exceptionally long cellular processes of telopodes have been described in human epicardium to act as structural supporting cells in the heart. We examined myocardial chamber‐specific TCs identified in atrial and ventricular fibroblast culture using immunocytochemistry and studied their electrophysiological property by whole‐cell patch clamp. Atrial and ventricular TCs with extended telopodes and alternating podoms and podomers that expressed CD34, c‐Kit and PDGFR‐β were identified. These cells expressed large conductance Ca<sup>2+</sup>‐activated K<sup>+</sup> current (BK<sub>Ca</sub>) and inwardly rectifying K<sup>+</sup> current (IK<sub>ir</sub>), but not transient outward K<sup>+</sup> current (I<sub>to</sub>) and ATP‐sensitive potassium current (K<sub>ATP</sub>). The active channels were functionally competent with demonstrated modulatory response to H<sub>2</sub>S and transforming growth factor (TGF)‐β1 whereby H<sub>2</sub>S significantly inhibited the stimulatory effect of TGF‐β1 on current density of both BK<sub>Ca</sub> and IK<sub>ir</sub>. Furthermore, H<sub>2</sub>S attenuated TGF‐β1‐stimulated KCa1.1/Kv1.1 (encode BK<sub>Ca</sub>) and Kir2.1 (encode IK<sub>ir</sub>) expression in TCs. Our results show that functionally competent K<sup>+</sup> channels are present in human atrial and ventricular TCs and their modulation may have significant implications in myocardial physiopathology.</p> </abstract>