Modulation of calcium-activated potassium channels induces cardiogenesis of pluripotent stem cells and enrichment of pacemaker-like cells.
BACKGROUND
Ion channels are key determinants for the function of excitable cells, but little is known about their role and involvement during cardiac development. Earlier work identified Ca(2+)-activated potassium channels of small and intermediate conductance (SKCas) as important regulators of neural stem cell fate. Here we have investigated their impact on the differentiation of pluripotent cells toward the cardiac lineage.


RESULTS
We have applied the SKCa activator 1-ethyl-2-benzimidazolinone on embryonic stem cells and identified this particular ion channel family as a new critical target involved in the generation of cardiac pacemaker-like cells: SKCa activation led to rapid remodeling of the actin cytoskeleton, inhibition of proliferation, induction of differentiation, and diminished teratoma formation. Time-restricted SKCa activation induced cardiac mesoderm and commitment to the cardiac lineage as shown by gene regulation, protein, and functional electrophysiological studies. In addition, the differentiation into cardiomyocytes was modulated in a qualitative fashion, resulting in a strong enrichment of pacemaker-like cells. This was accompanied by induction of the sino-atrial gene program and in parallel by a loss of the chamber-specific myocardium. In addition, SKCa activity induced activation of the Ras-Mek-Erk signaling cascade, a signaling pathway involved in the 1-ethyl-2-benzimidazolinone-induced effects.


CONCLUSIONS
SKCa activation drives the fate of pluripotent cells toward mesoderm commitment and cardiomyocyte specification, preferentially into nodal-like cardiomyocytes. This provides a novel strategy for the enrichment of cardiomyocytes and in particular, the generation of a specific subtype of cardiomyocytes, pacemaker-like cells, without genetic modification.
Kleger
Alexander
A
Institute for Anatomy and Cell Biology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany.
Seufferlein
Thomas
T
Malan
Daniela
D
Tischendorf
Michael
M
Storch
Alexander
A
Wolheim
Anne
A
Latz
Stephan
S
Protze
Stephanie
S
Porzner
Marc
M
Proepper
Christian
C
Brunner
Cornelia
C
Katz
Sarah-Fee
SF
Varma Pusapati
Ganesh
G
Bullinger
Lars
L
Franz
Wolfgang-Michael
WM
Koehntop
Ralf
R
Giehl
Klaudia
K
Spyrantis
Andreas
A
Wittekindt
Oliver
O
Lin
Qiong
Q
Lin
Quiong
Q
Zenke
Martin
M
Fleischmann
Bernd K
BK
Wartenberg
Maria
M
Wobus
Anna M
AM
Boeckers
Tobias M
TM
Liebau
Stefan
S
D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology; D002120:Calcium Channel Agonists / Q000494:pharmacology; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D049109:Cell Proliferation; D003599:Cytoskeleton / Q000502:physiology; D006329:Heart Conduction System / Q000166:cytology* / Q000502:physiology; D051660:Intermediate-Conductance Calcium-Activated Potassium Channels / Q000235:genetics / Q000502:physiology; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000502:physiology; D048052:Mitogen-Activated Protein Kinase 3 / Q000502:physiology; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000502:physiology; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000502:physiology; D024681:Potassium Channels, Calcium-Activated / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology
D001562:Benzimidazoles; D002120:Calcium Channel Agonists; D051660:Intermediate-Conductance Calcium-Activated Potassium Channels; C496923:KCNN4 protein, human; D024681:Potassium Channels, Calcium-Activated; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; C102635:1-ethyl-2-benzimidazolinone