Long noncoding RNA MALAT1 downregulates cardiac transient outward potassium current by regulating miR‐200c/HMGB1 pathway

2018 ◽  
Vol 119 (12) ◽  
pp. 10239-10249 ◽  
Author(s):  
Peng Zhu ◽  
Manli Yang ◽  
Hui Ren ◽  
Guidong Shen ◽  
Jinye Chen ◽  
...  
Keyword(s):  
Long Noncoding Rna ◽  
Potassium Current ◽  
Noncoding Rna ◽  
Transient Outward Potassium Current ◽  
Outward Potassium Current

scholarly journals A transient outward potassium current activator recapitulates the electrocardiographic manifestations of Brugada syndrome

2008 ◽  
Vol 81 (4) ◽  
pp. 686-694 ◽  
Author(s):  
K. Calloe ◽  
J. M. Cordeiro ◽  
J. M. Di Diego ◽  
R. S. Hansen ◽  
M. Grunnet ◽  
...  
Keyword(s):  
Brugada Syndrome ◽  
Potassium Current ◽  
Transient Outward Potassium Current ◽  
Outward Potassium Current

Abstract 16953: Role of the Fast Transient Outward Current Ito,f in Shaping Action Potential Waveforms in Human iPSC-derived Cardiomyocytes

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Scott Marrus ◽  
Steven Springer ◽  
Rita Martinez ◽  
Edward Dranoff ◽  
Rebecca Mellor ◽  
...  
Keyword(s):  
Action Potential ◽  
Potassium Current ◽  
Ventricular Myocytes ◽  
Current Clamp ◽  
Transient Outward Potassium Current ◽  
Fast Transient ◽  
Human Ipsc ◽  
Outward Potassium Current ◽  
Upstroke Velocity

Abnormalities of a key repolarizing cardiac potassium current, the fast transient outward potassium current, I to,f , are associated with both heart failure and congenital arrhythmia syndromes. However, the precise role of I to,f in shaping action potential waveforms remains unclear. This study was designed to define the functional role of the fast transient outward potassium current, I to,f , in shaping action potentials in human iPSC-derived cardiomyocytes (iPSC-CMs). Most iPSC-CMs (29 of 43 cells) demonstrated spontaneous electrical activity, slow upstroke velocity (63±71 V/s), a wide range of action potential durations (APD90 = 860±722 ms) and heterogeneous action potential waveforms. Using dynamic current clamp, a modeled human ventricular inwardly rectifying K + current, I K1 , was introduced into iPSC-CMs, resulting in silencing of spontaneous activity, hyperpolarization of the resting membrane potential (RMP = -90±3 mV), increased peak upstroke velocity (dV/dt = 346±71 V/s) and decreased APD90 (420±211 ms) to values similar to those recorded in isolated adult human ventricular myocytes (RMP = -84±3 mV, dV/dt = 348±101 V/s and APD90 = 468±133 ms, all p>0.05). Importantly, a ventricular-like action potential waveform was observed in 25 of the 26 cells studied following the dynamic clamp addition of I K1 . Using these cells as a model of human ventricular myocytes, further dynamic current clamp experiments introduced a modeled human fast transient outward K + current, I to,f , and revealed that increasing in the amplitude of I to,f results in an increase in the phase 1 notch and a progressive shortening of the action potential duration in iPSC-CMs. Together, the experiments here demonstrate that combining human iPSC-CMs with the power of the dynamic current clamp technique to modulate directly and precisely the “expression” of individual ionic currents provides a novel and quantitative approach to defining the roles of specific ionic conductances in regulating the excitability of human cardiomyocytes.

scholarly journals Regulation of the Transient Outward Potassium Current Itof in Cardiac Hypertrophy by Sphingosine-1-Phosphate Signaling

2010 ◽  
Vol 98 (3) ◽  
pp. 531a-532a
Author(s):  
Brian K. Panama ◽  
Desiree Latour ◽  
Lorrie Kirshenbaum ◽  
Steffen-Sebastian Bolz ◽  
Peter H. Backx
Keyword(s):  
Cardiac Hypertrophy ◽  
Potassium Current ◽  
Transient Outward Potassium Current ◽  
Sphingosine 1 Phosphate ◽  
Outward Potassium Current

scholarly journals Role of the transient outward potassium current in the genesis of early afterdepolarizations in cardiac cells

2012 ◽  
Vol 95 (3) ◽  
pp. 308-316 ◽  
Author(s):  
Zhenghang Zhao ◽  
Yuanfang Xie ◽  
Hairuo Wen ◽  
Dandan Xiao ◽  
Charelle Allen ◽  
...  
Keyword(s):  
Potassium Current ◽  
Cardiac Cells ◽  
Early Afterdepolarizations ◽  
Transient Outward Potassium Current ◽  
Outward Potassium Current
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