Reduced expression of cardiac ryanodine receptor protects against stress-induced ventricular tachyarrhythmia, but increases the susceptibility to cardiac alternans
Por:
Zhong, XW, Vallmitjana, A, Sun, B, Xiao, ZC, Guo, WT, Wei, JH, Ni, MK, Chen, YX, O'Brien, ER, Gillis, AM, Hoshijima, M, Takeshima, H, Hove-Madsen, L, Benitez, R, Belke, D, Chen, SRW
Publicada:
15 ene 2018
Resumen:
Reduced protein expression of the cardiac ryanodine receptor type 2 (RyR2) is thought to affect the susceptibility to stress-induced ventricular tachyarrhythmia (VT) and cardiac alternans, but direct evidence for the role of RyR2 protein expression in VT and cardiac alternans is lacking. Here, we used a mouse model (crr(m1)) that expresses a reduced level of the RyR2 protein to determine the impact of reduced RyR2 protein expression on the susceptibility to VT, cardiac alternans, cardiac hypertrophy, and sudden death. Electrocardiographic analysis revealed that after the injection of relatively high doses of caffeine and epinephrine (agents commonly used for stress test), wild-type (WT) mice displayed long-lasting VTs, whereas the crr(m1) mutant mice exhibited no VTs at all, indicating that the crr(m1) mutant mice are resistant to stress-induced VTs. Intact heart Ca2+ imaging and action potential (AP) recordings showed that the crr(m1) mutant mice are more susceptible to fast-pacing induced Ca2+ alternans and AP duration alternans compared with WT mice. The crr(m1) mutant mice also showed an increased heart-to-body-weight ratio and incidence of sudden death at young ages. Furthermore, the crr(m1) mutant hearts displayed altered Ca2+ transients with increased time-to-peak and decay time (T-50), increased ventricular wall thickness and ventricular cell area compared with WT hearts. These results indicate that reduced RyR2 protein expression suppresses stress-induced VTs, but enhances the susceptibility to cardiac alternans, hypertrophy, and sudden death.
Filiaciones:
Zhong, XW:
Univ Calgary, Libin Cardiovasc Inst Alberta, Dept Physiol & Pharmacol, Calgary, AB T2N 4N1, Canada
Vallmitjana, A:
Univ Politecn Cataluna, Dept Automat Control, ES-08034 Barcelona, Spain
Sun, B:
Univ Calgary, Libin Cardiovasc Inst Alberta, Dept Physiol & Pharmacol, Calgary, AB T2N 4N1, Canada
Xiao, ZC:
Univ Calgary, Libin Cardiovasc Inst Alberta, Dept Physiol & Pharmacol, Calgary, AB T2N 4N1, Canada
Guo, WT:
Univ Calgary, Libin Cardiovasc Inst Alberta, Dept Physiol & Pharmacol, Calgary, AB T2N 4N1, Canada
Wei, JH:
Univ Calgary, Libin Cardiovasc Inst Alberta, Dept Physiol & Pharmacol, Calgary, AB T2N 4N1, Canada
Ni, MK:
Univ Calgary, Libin Cardiovasc Inst Alberta, Dept Physiol & Pharmacol, Calgary, AB T2N 4N1, Canada
Chen, YX:
Univ Calgary, Libin Cardiovasc Inst Alberta, Dept Physiol & Pharmacol, Calgary, AB T2N 4N1, Canada
O'Brien, ER:
Univ Calgary, Libin Cardiovasc Inst Alberta, Dept Physiol & Pharmacol, Calgary, AB T2N 4N1, Canada
Gillis, AM:
Univ Calgary, Libin Cardiovasc Inst Alberta, Dept Physiol & Pharmacol, Calgary, AB T2N 4N1, Canada
Hoshijima, M:
Univ Calif San Diego, Dept Med, San Diego, CA 92093 USA
Univ Calif San Diego, Ctr Res Biol Syst, San Diego, CA 92093 USA
Takeshima, H:
Kyoto Univ, Grad Sch Pharmaceut Sci, Dept Biol Chem, Kyoto 6068501, Japan
Hove-Madsen, L:
Hosp Santa Creu & Sant Pau, CSIC, Biomed Res Inst Barcelona IIBB, Barcelona 08025, Spain
Benitez, R:
Univ Politecn Cataluna, Dept Automat Control, ES-08034 Barcelona, Spain
Belke, D:
Univ Calgary, Libin Cardiovasc Inst Alberta, Dept Physiol & Pharmacol, Calgary, AB T2N 4N1, Canada
Chen, SRW:
Univ Calgary, Libin Cardiovasc Inst Alberta, Dept Physiol & Pharmacol, Calgary, AB T2N 4N1, Canada
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