Mutation in RyR2-FKBP Binding site alters Ca 2+ signaling modestly but increases "arrhythmogenesis" in human stem cells derived cardiomyocytes.

Autor: Fernández-Morales JC; Cardiac Signaling Center of MUSC, USC and Clemson, Charleston, SC, 29425 United States of America., Xia Y; Cardiac Signaling Center of MUSC, USC and Clemson, Charleston, SC, 29425 United States of America., Renzo TJ; Cardiac Signaling Center of MUSC, USC and Clemson, Charleston, SC, 29425 United States of America., Zhang XH; Cardiac Signaling Center of MUSC, USC and Clemson, Charleston, SC, 29425 United States of America., Morad M; Cardiac Signaling Center of MUSC, USC and Clemson, Charleston, SC, 29425 United States of America; Department of Pharmacology, Georgetown University Medical Center, Washington, DC, United States of America. Electronic address: moradm@musc.edu.
Jazyk: angličtina
Zdroj: Cell calcium [Cell Calcium] 2022 Jan; Vol. 101, pp. 102500. Date of Electronic Publication: 2021 Nov 08.
DOI: 10.1016/j.ceca.2021.102500
Abstrakt: Aims: To gain insights into FKBP regulation of cardiac ryanodine receptor (RyR2) and Ca 2+ signaling, we introduced the point mutation (N771D-RyR2) corresponding to skeletal muscle mutation (N760D-RyR1) associated with central core disease (CCD) via CRISPR/Cas9 gene-editing in the RyR2 FKBP binding site expressed in human induced pluripotent stem cell-derived cardiomyocytes (hiPSCCMs). Patients inflicted with CCD and other hereditary skeletal muscle diseases often show higher incidence of atrial or ventricular arrhythmias.
Methods and Results: Ca 2+ imaging of voltage-clamped N771D-RyR2 mutant compared to WT hiPSCCMs showed: (1) ∼30% suppressed I Ca with no significant changes in the gating kinetics of I Ca ; (2) 29% lower SR Ca 2+ content and 33% lower RyR2 Ca 2+ leak; (3) higher CICR gain and 30-35% increased efficiency of I Ca -triggered Ca 2± release; (4) higher incidence of aberrant SR Ca 2+ releases, DADs, and Ca 2+ sparks; (5) no change in fractional Ca 2+ -release, action potential morphology, sensitivity to isoproterenol, and sarcomeric FKBP-binding pattern.
Conclusions: The more frequent spontaneous Ca 2+ releases and longer Ca 2+ sparks underlie the increased incidence of DADs and cellular arrhythmogenesis of N771D-RyR2 mutant. The smaller RyR2 Ca 2± leak and SR content result from suppressed I Ca that is compensated by higher CICR gain.
(Copyright © 2021 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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