scholarly journals mTOR‐mediated calcium transients affect cardiac function in ex vivo ischemia–reperfusion injury

2021 ◽  
Vol 9 (6) ◽  
Author(s):  
Briana K. Shimada ◽  
Naaiko Yorichika ◽  
Jason K. Higa ◽  
Yuichi Baba ◽  
Motoi Kobayashi ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ex Vivo ◽  
Ischemia Reperfusion ◽  
Calcium Transients

Abstract 428: Pharmacologic and Activated Fibroblast-specific Gβγ-GRK2 Inhibition is Protective Following Ischemia Reperfusion Injury

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Joshua G Travers ◽  
Fadia A Kamal ◽  
Michelle L Nieman ◽  
Michelle A Sargent ◽  
Jeffery D Molkentin ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Function ◽  
Reperfusion Injury ◽  
G Protein ◽  
Knockout Mice ◽  
Ischemia Reperfusion Injury ◽  
Interstitial Fibrosis ◽  
Myocardial Dysfunction ◽  
Ischemia Reperfusion ◽  
Ventricular Compliance

Heart failure is a devastating disease characterized by chamber remodeling, interstitial fibrosis and reduced ventricular compliance. Cardiac fibroblasts are responsible for extracellular matrix homeostasis, however upon injury or pathologic stimulation, these cells transform to a myofibroblast phenotype and play a fundamental role in myocardial fibrosis and remodeling. Chronic sympathetic overstimulation induces excess signaling through G protein βγ subunits and ultimately the pathologic activation of G protein-coupled receptor kinase 2 (GRK2). We hypothesized that Gβγ-GRK2 inhibition plays an important role in the cardiac fibroblast to attenuate pathologic myofibroblast activation and cardiac remodeling. To investigate this hypothesis, mice were subjected to ischemia/reperfusion (I/R) injury and treated with the small molecule Gβγ-GRK2 inhibitor gallein. While animals receiving vehicle demonstrated a reduction in overall cardiac function as measured by echocardiography, mice treated with gallein exhibited nearly complete preservation of cardiac function and reduced fibrotic scar formation. We next sought to establish the cell specificity of this compound by treating inducible cardiomyocyte- and activated fibroblast-specific GRK2 knockout mice post-I/R. Although we observed modest restoration in cardiac function in cardiomyocyte-specific GRK2 null mice, treatment of these mice with gallein resulted in further protection against myocardial dysfunction following injury, suggesting a functional role in other cardiac cell types, including fibroblasts. Activated fibroblast-specific GRK2 knockout mice were also subjected to ischemia/reperfusion injury; these animals displayed preserved myocardial function and reduced collagen deposition compared to littermate controls following injury. Furthermore, systemic Gβγ-GRK2 inhibition by gallein did not appear to confer further protection over activated fibroblast-specific GRK2 ablation alone. In summary, these findings suggest a potential therapeutic role for Gβγ-GRK2 inhibition in limiting pathologic myofibroblast activation, interstitial fibrosis and heart failure progression.

scholarly journals Effects of CXCR4 Gene Transfer on Cardiac Function After Ischemia-Reperfusion Injury

2010 ◽  
Vol 176 (4) ◽  
pp. 1705-1715 ◽  
Author(s):  
Jiqiu Chen ◽  
Elie Chemaly ◽  
Lifan Liang ◽  
Changwon Kho ◽  
Ahyoung Lee ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Cardiac Function ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion

scholarly journals Selective β 2 -Adrenoreceptor Stimulation Attenuates Myocardial Cell Death and Preserves Cardiac Function After Ischemia–Reperfusion Injury

2012 ◽  
Vol 32 (8) ◽  
pp. 1865-1874 ◽  
Author(s):  
Shashi Bhushan ◽  
Kazuhisa Kondo ◽  
Benjamin L. Predmore ◽  
Maxim Zlatopolsky ◽  
Adrienne L. King ◽  
...  
Keyword(s):  
Cell Death ◽  
Cardiac Function ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Myocardial Cell

scholarly journals Ex vivo carbon monoxide prevents cytochrome P450 degradation and ischemia/reperfusion injury of kidney grafts

2008 ◽  
Vol 74 (8) ◽  
pp. 1009-1016 ◽  
Author(s):  
Atsunori Nakao ◽  
Gaetano Faleo ◽  
Hiroko Shimizu ◽  
Kiichi Nakahira ◽  
Junichi Kohmoto ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Cytochrome P450 ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ex Vivo ◽  
Ischemia Reperfusion

scholarly journals Therapeutic Inhibition of Acid Sensing Ion Channel 1a Recovers Heart Function After Ischemia-Reperfusion Injury

Circulation ◽  
2021 ◽  
Author(s):  
Meredith A. Redd ◽  
Sarah E. Scheuer ◽  
Natalie J. Saez ◽  
Yusuke Yoshikawa ◽  
Han Sheng Chiu ◽  
...  
Keyword(s):  
Ion Channel ◽  
Reperfusion Injury ◽  
Electromechanical Coupling ◽  
Ischemia Reperfusion Injury ◽  
Ex Vivo ◽  
Heart Function ◽  
Ischemia Reperfusion ◽  
Genetic Ablation ◽  
Organ Level

Background: Ischemia-reperfusion injury (IRI) is one of the major risk factors implicated in morbidity and mortality associated with cardiovascular disease. During cardiac ischemia, the build-up of acidic metabolites results in decreased intracellular and extracellular pH that can reach as low as 6.0-6.5. The resulting tissue acidosis exacerbates ischemic injury and significantly impacts cardiac function. Methods: We used genetic and pharmacological methods to investigate the role of acid sensing ion channel 1a (ASIC1a) in cardiac IRI at the cellular and whole organ level. Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) as well as ex vivo and in vivo models of IRI were used to test the efficacy of ASIC1a inhibitors as pre- and post-conditioning therapeutic agents. Results: Analysis of human complex trait genetics indicate that variants in the ASIC1 genetic locus are significantly associated with cardiac and cerebrovascular ischemic injuries. Using hiPSC-CMs in vitro and murine ex vivo heart models, we demonstrate that genetic ablation of ASIC1a improves cardiomyocyte viability after acute IRI. Therapeutic blockade of ASIC1a using specific and potent pharmacological inhibitors recapitulates this cardioprotective effect. We used an in vivo model of myocardial infarction (MI) and two models of ex vivo donor heart procurement and storage as clinical models to show that ASIC1a inhibition improves post-IRI cardiac viability. Use of ASIC1a inhibitors as pre- or post-conditioning agents provided equivalent cardioprotection to benchmark drugs, including the sodium-hydrogen exchange inhibitor zoniporide. At the cellular and whole organ level, we show that acute exposure to ASIC1a inhibitors has no impact on cardiac ion channels regulating baseline electromechanical coupling and physiological performance. Conclusions: Collectively, our data provide compelling evidence for a novel pharmacological strategy involving ASIC1a blockade as a cardioprotective therapy to improve the viability of hearts subjected to IRI.

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