The biochemical and electrophysiological profiles of amniotic fluid-derived stem cells following Wnt signaling modulation cardiac differentiation

Yen-Wen Liu; Yi-Hsein Fang; Chi-Ting Su; Shiaw-Min Hwang; Ping-Yen Liu; Sheng-Nan Wu

doi:10.1038/s41420-019-0143-0

The biochemical and electrophysiological profiles of amniotic fluid-derived stem cells following Wnt signaling modulation cardiac differentiation

Cell Death Discov. 2019 Jan 28:5:59. doi: 10.1038/s41420-019-0143-0. eCollection 2019.

Authors

Yen-Wen Liu^{1

2}, Yi-Hsein Fang², Chi-Ting Su³, Shiaw-Min Hwang⁴, Ping-Yen Liu^{1

2}, Sheng-Nan Wu^{5

6}

Affiliations

¹ 1Division of Cardiology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, 138 Sheng-Li Rd. North District, Tainan, 70403 Taiwan.
² 2Institute of Clinical Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
³ 3Division of Nephrology, Department of Internal Medicine, National Taiwan University Hospital, Yun-Lin Branch, Yun-Lin, Taiwan.
⁴ 4Bioresource Collection and Research Center, Food Industry Research and Development Institute, Hsinchu, Taiwan.
⁵ 5Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd, East District, Tainan, Taiwan.
⁶ 6Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.

Abstract

Owing to the beneficial properties of amniotic fluid-derived stem cells (AFSCs), including pluripotency and the lack of ethical issues associated with embryonic stem cells (ESCs), they should be a promising cell source for regenerative medicine. However, how to differentiate AFSCs into contracting cardiomyocytes has not been established. In this study, a well-established, direct cardiac differentiation protocol involving the modulation of Wnt signaling was used to differentiate Oct 3/4⁺ AFSCs into cardiomyocytes. By day 14 of cardiomyocyte differentiation, these AFSCs expressed cardiac-specific genes (i.e., cardiac troponin T and myosin light chain 2v) and proteins but could not spontaneously contract. Using the patch-clamp technique, we further characterized the electrophysiological properties of human ESC-derived cardiomyocytes (hESC-CMs) and differentiated AFSCs. We used different configurations to investigate membrane potentials and ion currents in differentiated AFSCs and hESC-CMs. Under cell-attached voltage- or whole-cell current-clamp modes, we recorded spontaneous action currents (ACs) or action potentials (APs) in hESC-CMs but not in differentiated AFSCs. Compared to hESC-CMs, differentiated AFSCs showed significantly diminished activity of both BK_Ca and IK_Ca channels, which might lead to a lack of spontaneous ACs and APs in differentiated AFSCs. These results indicated that this well-established Wnt signaling modulating cardiac differentiation protocol was insufficient to induce the differentiation of functional cardiomyocytes from Oct 3/4⁺ AFSCs. Therefore, AFSC may not be an ideal candidate for cardiomyocyte differentiation.