title: Comparable calcium handling of human iPSC-derived cardiomyocytes generated by multiple laboratories.
abstract: Cardiomyocytes (CMs) derived from human induced pluripotent stem cells (hiPSCs) are being increasingly used to model human heart diseases. hiPSC-CMs generated by earlier aggregation-based methods (i.e., embryoid body) often lack functional sarcoplasmic reticulum (SR) Ca stores characteristic of mature mammalian CMs. Newer monolayer-based cardiac differentiation methods (i.e., Matrigel sandwich or small molecule-based differentiation) produce hiPSC-CMs of high purity and yield, but their Ca handling has not been comprehensively investigated. Here, we studied Ca handling and cytosolic Ca buffering properties of hiPSC-CMs generated independently from multiple hiPSC lines at Stanford University, Vanderbilt University and University of Wisconsin-Madison. hiPSC-CMs were cryopreserved at each university. Frozen aliquots were shipped, recovered from cryopreservation, plated at low density and compared 3-5days after plating with acutely-isolated adult rabbit and mouse ventricular CMs. Although hiPSC-CM cell volume was significantly smaller, cell capacitance to cell volume ratio and cytoplasmic Ca buffering were not different from rabbit-CMs. hiPSC-CMs from all three laboratories exhibited robust L-type Ca currents, twitch Ca transients and caffeine-releasable SR Ca stores comparable to adult CMs. Ca transport by sarcoendoplasmic reticulum Ca ATPase (SERCA) and Na/Ca exchanger (NCX) was similar in all hiPSC-CM lines, but slower compared to rabbit-CMs. However, the relative contribution of SERCA and NCX to Ca transport of hiPSC-CMs was comparable to rabbit-CMs. Ca handling maturity of hiPSC-CMs increased from 15 to 21days post-induction. We conclude that hiPSC-CMs generated independently from multiple iPSC lines using monolayer-based methods can be reproducibly recovered from cryopreservation and exhibit comparable and functional SR Ca handling.
authors.affiliation: Division of Clinical Pharmacology, Oates Institute for Experimental Therapeutics, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors.forename: Hyun Seok
authors.initials: HS
authors.lastname: Hwang
authors.affiliation: Division of Clinical Pharmacology, Oates Institute for Experimental Therapeutics, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors.forename: Dmytro O
authors.initials: DO
authors.lastname: Kryshtal
authors.affiliation: Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors.forename: T K
authors.initials: TK
authors.lastname: Feaster
authors.affiliation: Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Verónica
authors.initials: V
authors.lastname: Sánchez-Freire
authors.affiliation: Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, WI, USA.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, WI, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Kamp
authors.affiliation: Division of Cardiovascular Medicine, Vanderbilt University School of Medicine, Nashville, TN USA; Research Medicine, Veterans Affairs TVHS, Nasvhille, TN USA.
authors.forename: Charles C
authors.initials: CC
authors.lastname: Hong
authors.affiliation: Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Wu
authors.affiliation: Division of Clinical Pharmacology, Oates Institute for Experimental Therapeutics, Vanderbilt University School of Medicine, Nashville, TN, USA. Electronic address: bjorn.knollmann@vanderbilt.edu.
authors.forename: Björn C
authors.initials: BC
authors.lastname: Knollmann
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D002454:Cell Differentiation; D002478:Cells, Cultured; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000502:physiology*; D051379:Mice; D009200:Myocardial Contraction; D032383:Myocytes, Cardiac / Q000378:metabolism*; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000378:metabolism
chemical_list: D002118:Calcium