scholarly journals AdipoRon, the first orally active adiponectin receptor activator, attenuates postischemic myocardial apoptosis through both AMPK-mediated and AMPK-independent signalings

2015 ◽  
Vol 309 (3) ◽  
pp. E275-E282 ◽  
Author(s):  
Yanqing Zhang ◽  
Jianli Zhao ◽  
Rui Li ◽  
Wayne Bond Lau ◽  
Yue-Xing Yuan ◽  
...  
Keyword(s):  
Apoptotic Cell ◽  
Ischemia Reperfusion ◽  
Cardiac Injury ◽  
Cardiovascular Complications ◽  
Dominant Negative ◽  
Tunel Staining ◽  
Dna Ladder ◽  
Receptor Activator ◽  
Myocardial Ischemia Reperfusion ◽  
Orally Active

Adiponectin (APN) is a cardioprotective molecule. Its reduction in diabetes exacerbates myocardial ischemia/reperfusion (MI/R) injury. Although APN administration in animals attenuates MI/R injury, multiple factors limit its clinical application. The current study investigated whether AdipoRon, the first orally active molecule that binds APN receptors, may protect the heart against MI/R injury, and if so, to delineate the involved mechanisms. Wild-type (WT), APN knockout (APN-KO), and cardiomyocyte specific-AMPK dominant negative (AMPK-DN) mice were treated with vehicle or AdipoRon (50 mg/kg, 10 min prior to MI) and subjected to MI/R (30 min/3–24 h). Compared with vehicle, oral administration of AdipoRon to WT mice significantly improved cardiac function and attenuated postischemic cardiomyocyte apoptosis, determined by DNA ladder formation, TUNEL staining, and caspase-3 activation (all P < 0.01). MI/R-induced apoptotic cell death was significantly enhanced in mice deficient in either APN (APN-KO) or AMPK (AMPK-DN). In APN-KO mice, AdipoRon attenuated MI/R injury to the same degree as observed in WT mice. In AMPK-DN mice, AdipoRon's antiapoptotic action was partially inhibited but not lost. Finally, AdipoRon significantly attenuated postischemic oxidative stress, as evidenced by reduced NADPH oxidase expression and superoxide production. Collectively, these results demonstrate for the first time that AdipoRon, an orally active APN receptor activator, effectively attenuated postischemic cardiac injury, supporting APN receptor agonists as a promising novel therapeutic approach treating cardiovascular complications caused by obesity-related disorders such as type 2 diabetes.

Abstract 114: AdipoRon, the First Orally Active Adiponectin Receptor Activator, Attenuates Post-ischemic Myocardial Apoptosis via AMPK Activation and Oxidative Stress Reduction

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Yajing Wang ◽  
Wayne Lau ◽  
Yuanhui Du ◽  
Erhe Gao ◽  
Walter Koch ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Apoptotic Cell ◽  
Ischemia Reperfusion ◽  
Cardiac Injury ◽  
Regulatory Function ◽  
Tunel Staining ◽  
Ampk Activation ◽  
Dna Ladder ◽  
Receptor Activator ◽  
Orally Active

Adiponectin (APN) is a cardioprotective molecule. Its reduction in diabetes exacerbates myocardial ischemia/reperfusion (MI/R) injury. Although APN administration in animals attenuates MI/R injury, multiple factors limit its clinical application. The current study investigated whether AdipoRon, the first orally active molecule that binds APN receptors, may protect the heart against MI/R injury, and if so, to delineate the involved mechanisms. Wild type (WT) or gene manipulated mice were treated with vehicle or AdipoRon (50 mg/kg, 10 minutes prior to MI) and subjected to MI/R (30 minutes/3-24 hours). Oral administration of AdipoRon to WT mice significantly improved cardiac function (P<0.01) and reduced infarct size (P<0.01). At cellular level, AdipoRon attenuated post-ischemic cardiomyocyte apoptosis determined by DNA ladder formation, TUNEL staining, and caspase-3 activation (P<0.01). MI/R-induced apoptotic cell death was significantly enhanced in APN deficient mice (APNKO), and AdipoRon attenuated MI/R injury to the same degree observed in WT mice, indicating the pathological exageration caused by APN deficience can be rescured by a small molecule APN receptor activator. Cardiomyocyte-specific inhibition of AMPK (AMPK-DN), the most significant molecule mediating APN’s metabolic regulatory function, also increased post-ischemic apoptosis. Interestingly, AdipoRon’s anti-apoptotic action was partially inhibited, but not lost in AMPK-DN mice, indicating the anti-apoptotic effect of AdipoRon cannot be completely atributed to AMPK activation. AdipoRon significantly attenuated post-ischemic oxidative stress in an AMPK-independent fashion, as evidenced by reduced NADPH oxidase expression and superoxide production in both WT and AMPK-DN mice. Collectively, these results demonstrate for the first time that AdipoRon, an orally active APN receptor activator, effectively attenuated post-ischemic cardiac injury, supporting APN receptor agonists as a promising novel therapeutic approach treating cardiovascular complications caused by obesity-related disorders such as type 2 diabetes.

Abstract 13879: Ischemic Postconditioning Confers Cardioprotection through Adiponectin-dependent Mitochondrial STAT3 Activation in Mice

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Haobo Li ◽  
Michael G Irwin ◽  
Zhengyuan Xia
Keyword(s):  
Cell Injury ◽  
Troponin I ◽  
Ischemia Reperfusion Injury ◽  
Apoptotic Cell ◽  
Ischemia Reperfusion ◽  
Cardiac Injury ◽  
Systolic Pressure ◽  
Gene Knockdown ◽  
Area At Risk ◽  
In Cells

Introduction: Signal transducer and activator of transcription 3 (STAT3) plays a key role in postconditioning (IPo) mediated protection against myocardial ischemia reperfusion injury, but the mechanism by which IPo activates STAT3 is unknown. Adiponectin (APN), a protein with anti-ischemic properties, activates STAT3. We hypothesized that IPo activates mitochondrial STAT3 (MitoSTAT3) via APN signaling. Methods and Results: Wild type (WT) and APN knockout (KO) mice were either sham operated or subjected to 30 min of coronary artery occlusion followed by 2 hours of reperfusion with or without IPo (3 cycles of 10 seconds reperfusion and 10 seconds reocclusion; n=8/group). At the end of reperfusion, KO mice exhibited more severe myocardial injury evidenced as increased infarct size (% of area at risk) 49.2±2.0 vs WT 39.4±3.5, P <0.01; plasma troponin I (ng/ml): KO 72.8±7.6 vs WT 45.7±4.0, P <0.01; worse cardiac function (lower dP/dt max and end-systolic pressure-volume relation, P <0.05); more severely impaired mitochondrial function (reductions in complex IV and complex V protein expression) and more severe reduction of MitoSTAT3 phosphorylation (activation) at site Ser727, P <0.01. IPo significantly attenuated post-ischemic cardiac injury and dysfunction with a concomitant increase in phosphorylated MitoSTAT3 and attenuation of mitochondrial dysfunction in WT (all P <0.05) but not in KO mice. In cultured cardiac H9C2 cells, hypoxic postconditioning (HPo, 3 cycles of 5 min hypoxia and 5 min reoxygenation) significantly attenuated hypoxia/reoxygenation (HR, 3 hours hypoxia/3 hours reoxygenation) induced cell injury (increased apoptotic cell death as % of HR): HR 100.2±0.4 vs HPo 78.2±4.8, P <0.05) and reduced mitochondrial transmembrane potential (% total cells, HR 37.2±4.9 vs HPo 23.5±3.7, P <0.01). APN, adiponectin receptor 1 (AdipoR1), or STAT3 gene knockdown but not AdipoR2 gene knockdown, respectively, abolished HPo cellular protection (all P <0.05 vs. HPo). APN supplementation (10μg/ml) restored HPo protection in cells with APN knockdown but not in cells with AdipoR1or STAT3 gene knockdown. Conclusion: Adiponectin and AdipoR1 signaling are required for IPo to activate myocardial mitochondrial STAT3 to confer cardioprotection.

scholarly journals The Antioxidant, Anti-Inflammatory and Anti-Apoptotic Activities of the Bauhinia Championii Flavone are Connected with Protection Against Myocardial Ischemia/Reperfusion Injury

2016 ◽  
Vol 38 (4) ◽  
pp. 1365-1375 ◽  
Author(s):  
Jie Jian ◽  
Feifei Xuan ◽  
Feizhang Qin ◽  
Renbin Huang
Keyword(s):  
Myocardial Ischemia ◽  
Caspase 3 ◽  
Ischemia Reperfusion Injury ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Enzyme Linked Immunosorbent Assay ◽  
Tunel Staining ◽  
Myocardial Infarct Size ◽  
Myocardial Ischemia Reperfusion

Background/Aims: Previous studies have demonstrated that Bauhinia championii flavone (BCF) exhibits anti-oxidative, anti-hypoxic and anti-stress properties. This study was designed to investigate whether BCF has a cardioprotective effect against myocardial ischemia/reperfusion (I/R) injuries in rats and to shed light on its possible mechanism. Methods: The model of I/R was established by ligating the left anterior descending coronary artery for 30 min, then reperfusing for 180 min. Hemodynamic changes were continuously monitored. The content of malondialdehyde (MDA) as well as the lactate dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were assessed. The release of interleukin-6 (IL-6) was measured by enzyme-linked immunosorbent assay (ELISA). Apoptosis of cardiomyocytes was determined by caspase-3 activity and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The expression of TLR4, NF-κBp65, Bcl-2 and Bax were detected by western blotting. Results: Pretreatment with BCF significantly reduced the serum levels of LDH, MDA and IL-6, but increased the activities of SOD and GSH-Px. It also attenuated myocardial infarct size, reduced the apoptosis rate and preserved cardiac function. Furthermore, BCF inhibited caspase-3 activity and the expression of TLR4, phosphorylated NF-κBp65 and Bax, but enhanced the expression of Bcl-2. Conclusion: These results provide substantial evidence that BCF exerts a protective effect on myocardial I/R injury, which may be attributed to attenuating lipid peroxidation, the inflammatory response and apoptosis.

scholarly journals The Blockade of Transmembrane Cl- Flux Mitigates I/R-Induced Heart Injury via the Inhibition of Calpain Activity

2015 ◽  
Vol 35 (6) ◽  
pp. 2121-2134 ◽  
Author(s):  
Jian-Ying Zhang ◽  
Feng Wu ◽  
Xiao-Ming Gu ◽  
Zhen-Xiao Jin ◽  
Ling-Heng Kong ◽  
...  
Keyword(s):  
Myocardial Injury ◽  
Caspase 3 ◽  
Ischemia Reperfusion ◽  
Cardiac Injury ◽  
Calpain Activity ◽  
Rat Hearts ◽  
Marked Decline ◽  
Heart Injury ◽  
Myocardial Ischemia Reperfusion ◽  
Injury Area

Aims: The aim of this study was to determine whether calpain is involved in Cl- -induced myocardial ischemia/reperfusion (I/R) injury. Methods: Isolated rat hearts were subjected to either 45 min of global no-flow ischemia followed by reperfusion or successive perfusion with Ca2+ -free KH solution for 3 min and normal KH solution for 30 min, also known as Ca2+ paradox. Results: The hearts in the I/R group exhibited increases in myocardial injury area, LDH release, caspase 3 activity and apoptotic indices and a marked decline in cardiac performance. As was the case regarding the effects of MDL 28170, an inhibitor of calpain, treatment with 5 µM NPPB, 5 µM DIDS and low Cl- significantly attenuated cardiac injury. Moreover, each of the treatments significantly protected against Ca2+ overload-induced injury in the setting of Ca2+ paradox. The Western blot and immunofluorescence data revealed that there was an increase in the percentages of calpain membrane-positive cells and the numbers of fragments resulting from the calpain-mediated proteolysis of α-fodrin in both the I/R and the Ca2+ paradox, indicating that the activation of calpain occurred. More importantly, these effects were mitigated by the blockade of transmembrane Cl- flux, as was accomplished via MDL 28170. Conclusion: Our results provide evidence that the blockade of transmembrane Cl- flux mitigates I/R-induced cardiac injury via the inhibition of calpain activity. They also indicate that intracellular Ca2+ overload regulates calpain activation in the setting of Cl- -induced injury.

Astragaloside attenuates cardiotoxicity effects of Doxorubicin by inhibiting TLR4/NF-кB signaling pathway

2017 ◽  
Vol 5 (1) ◽  
pp. 78-92
Author(s):  
Najah R. Hadi ◽  
Fadhil G. Al-Amran
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Myocardial Ischemia ◽  
Protective Effect ◽  
Ischemia Reperfusion ◽  
Cardiac Injury ◽  
Ischemic Tissue ◽  
Tnf Α ◽  
Myocardial Ischemia Reperfusion ◽  
Significant Protective Effect

Myocardial Ischemia-Reperfusion (I/R) injury refers to myocardial, vascular or electrophysiological dysfunction of heart induced by the restoration of blood flow to previously ischemic tissue. In this study, we investigated the effects of Telmisartan in I/R injury and apoptosis. Mice are subjected to 30 min ischemia followed by 120 min reperfusion through ligation of descending coronary artery (LAD). Mice treated with Telmisartan (0.5mg/kg, via IP injection) significantly attenuated I/R-induced increases of myocardial TNF-α, IL-1β, IL-6 and markedly increased myocardial Bcl-2 protein expression. Furthermore, Telmisartan significant protective effect against myocardial I/R injury. These results demonstrated that Telmisartan reduces inflammatory reaction associated with I/R injury induced by LAD ligation in addition to its reduction for cardiac injury and apoptosis induced by ischemia reperfusion.

scholarly journals Proteomic mapping of proteins released during necrosis and apoptosis from cultured neonatal cardiac myocytes

2014 ◽  
Vol 306 (7) ◽  
pp. C639-C647 ◽  
Author(s):  
Kurt D. Marshall ◽  
Michelle A. Edwards ◽  
Maike Krenz ◽  
J. Wade Davis ◽  
Christopher P. Baines
Keyword(s):  
Cell Death ◽  
Cardiac Myocytes ◽  
Cardiac Myocyte ◽  
Ischemia Reperfusion Injury ◽  
Apoptotic Cell ◽  
Ischemia Reperfusion ◽  
Cardiac Injury ◽  
High Mobility ◽  
Neonatal Rat ◽  
Protein Markers

Cardiac injury induces myocyte apoptosis and necrosis, resulting in the secretion and/or release of intracellular proteins. Currently, myocardial injury can be detected by analysis of a limited number of biomarkers in blood or coronary artery perfusate. However, the complete proteomic signature of protein release from necrotic cardiac myocytes is unknown. Therefore, we undertook a proteomic-based study of proteins released from cultured neonatal rat cardiac myocytes in response to H2O2 (necrosis) or staurosporine (apoptosis) to identify novel specific markers of cardiac myocyte cell death. Necrosis and apoptosis resulted in the identification of 147 and 79 proteins, respectively. Necrosis resulted in a relative increase in the amount of many proteins including the classical necrotic markers lactate dehydrogenase (LDH), high-mobility group B1 (HMGB1), myoglobin, enolase, and 14-3-3 proteins. Additionally, we identified several novel markers of necrosis including HSP90, α-actinin, and Trim72, many of which were elevated over control levels earlier than classical markers of necrotic injury. In contrast, the majority of identified proteins remained at low levels during apoptotic cell death, resulting in no candidate markers for apoptosis being identified. Blotting for a selection of these proteins confirmed their release during necrosis but not apoptosis. We were able to confirm the presence of classical necrotic markers in the extracellular milieu of necrotic myocytes. We also were able to identify novel markers of necrotic cell death with relatively early release profiles compared with classical protein markers of necrosis. These results have implications for the discovery of novel biomarkers of necrotic myocyte injury, especially in the context of ischemia-reperfusion injury.

Cardioprotective Effects of Saponins from Rhizoma Panacis Majoris on Myocardial Ischemia/Reperfusion Injury via Scavenging Excessive Reactive Oxygen Species

2014 ◽  
Vol 934 ◽  
pp. 165-172
Author(s):  
Cai Hong Bai ◽  
Hai Bo He ◽  
Fan Cheng ◽  
Jun Zhi Wang ◽  
Xiao Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Activity ◽  
Myocardial Ischemia ◽  
Infarct Size ◽  
Apoptotic Cell ◽  
Ischemia Reperfusion ◽  
Radical Scavenging ◽  
Protective Effects ◽  
Cardioprotective Effects ◽  
Myocardial Ischemia Reperfusion

Saponins from Rhizoma Panacis Majoris (SRPM), the bioactive component inRhizoma Panacis Majoris, were reported to possess protective effects on myocardial injury, but the underlying mechanisms remain poorly understood. This study was performed to investigate the protective effects and possible mechanism of SRPM on myocardial ischemia/reperfusion (I/R) injury in vivo. Cardioprotective effects of SPRM in I/R rats was evaluated by hemodynamic, infarct size, biochemical values, histopathological observations, antioxidative relative gene expressions; And the antioxidant activity of SPRM was studied using DPPH scavenging and β-carotene/linoleic acid tests. In the study, we found that SRPM possessed significant free radical-scavenging activity and considerable antioxidant activity, and significantly improved cardiac function, serum biochemical index and antioxidation level, decreased infarct size, reversed the down-regulated mRNA expressions of the SOD1, SOD2, SOD3 in I/R rats. The studies demonstrated that oxidative stress caused the overgeneration and accumulation of ROS, which was central of myocardial I/R injury. SPRM exerted beneficially cardioprotective effects on myocardial I/R injury, mainly scavenging oxidative stress-triggered overgeneration and accumulation of ROS, alleviating myocardial I/R injury and apoptotic cell death.

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