Abstract 12156: Loss of Thiol on C674 SERCA2 Leads to Ca2 + Mishandling With Hypertrophy in Right Ventricular Exposed to Hypoxia
| Autor: | Kazuki Kagami, Kei Ito, Hirotaka Yada, Yusuke Yumita, Midori Iwashita, Ishinoda Yuki, Takumi Toya, Takayuki Namba, Yukinori Ikegami, Risako Yasuda, Nobuyuki Masaki, Yasuo Ido, Yuji Nagatomo, Takeshi Adachi |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Circulation. 144 |
| ISSN: | 1524-4539 0009-7322 |
| DOI: | 10.1161/circ.144.suppl_1.12156 |
| Popis: | Introduction: Right ventricular (RV) dysfunction is the strongest predictor of mortality in pulmonary artery hypertension (PAH). Reactive oxygen species in heart failure cause irreversible oxidation of sarcoplasmic reticulum (SR) Ca 2+ -ATPase2 (SERCA2) C674, which results in SERCA2 dysfunction and intracellular Ca 2+ overload. However, the contribution of the loss of the thiol on C674 SERCA2 and RV failure in PAH remains unclear. Hypothesis: The loss of the thiol on C674 SERCA2 contributes to the RV dysfunction in PAH. Methods & Results: We employed the SERCA2 C674S heterozygote knock-in (SKI) mice, in which C674 is replaced by serine, mimics oxidative modification of SERCA2 by loss of the specific thiol. Wild-type mice (WT) and SKI were exposed to either normoxia (Nx) or chronic hypoxia (Hx) for four weeks. Hypoxia elevated RV systolic pressure (WT-Nx: 21.4mmHg vs. WT-Hx: 37.0mmHg, P2+ transient measurement of isolated myocytes with Fluo-4, SKI prolonged the time to 50% of cytosolic Ca 2+ extrusion (T50) and lower the peak Ca 2+ transient amplitude (F/F0) than WT under Nx. Prolonged T50 and lowered peak F/F0 were observed in WT-Hx, both of which additionally progressed in SKI-Hx. Conclusions: Hypoxia impaired SR Ca 2+ homeostasis in RV. SKI additionally impaired SR Ca 2+ homeostasis with the progression of RV hypertrophy. The loss of the thiol on C674 SERCA2 contributed to the pathogenesis of RV failure in PAH. |
| Databáze: | OpenAIRE |
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