Enhancing AMPK activation during ischemia protects the diabetic heart against reperfusion injury

Paiva, Marta; Rutter-Locher, Zoe; Gonçalves, Lino; Providência, Luí­s A.; Davidson, Sean M.; Yellon, Derek M.; Mocanu, Mihaela M.

doi:10.1152/ajpheart.00707.2010

Cited by 110 publications

(76 citation statements)

References 57 publications

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“…An upregulation of uncoupling protein 2 is another transcriptional effect of AMPK (23). AMPK also reduces the impact of ROS production on mitochondrial function by avoiding permeability transition pore opening (32) or by promoting mitochondrial biosynthesis through proliferatoractivated receptor-␥ coactivator-1␣. AMPK also inhibits ROSinduced mitochondrial fission and collapse of the mitochondrial membrane potential (7).…”

Section: Discussionmentioning

confidence: 99%

AMPK activation by glucagon-like peptide-1 prevents NADPH oxidase activation induced by hyperglycemia in adult cardiomyocytes

Balteau¹,

Steenbergen²,

Timmermans³

et al. 2014

American Journal of Physiology-Heart and Circulatory Physiology

101

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Exposure of cardiomyocytes to high glucose concentrations (HG) stimulates reactive oxygen species (ROS) production by NADPH oxidase (NOX2). NOX2 activation is triggered by enhanced glucose transport through a sodium-glucose cotransporter (SGLT) but not by a stimulation of glucose metabolism. The aim of this work was to identify potential therapeutic approaches to counteract this glucotoxicity. In cultured adult rat cardiomyocytes incubated with 21 mM glucose (HG), AMP-activated protein kinase (AMPK) activation by A769662 or phenformin nearly suppressed ROS production. Interestingly, glucagon-like peptide 1 (GLP-1), a new antidiabetic drug, concomitantly induced AMPK activation and prevented the HG-mediated ROS production (maximal effect at 100 nM). α2-AMPK, the major isoform expressed in cardiomyocytes (but not α1-AMPK), was activated in response to GLP-1. Anti-ROS properties of AMPK activators were not related to changes in glucose uptake or glycolysis. Using in situ proximity ligation assay, we demonstrated that AMPK activation prevented the HG-induced p47phox translocation to caveolae, whatever the AMPK activators used. NOX2 activation by either α-methyl-d-glucopyranoside, a glucose analog transported through SGLT, or angiotensin II was also counteracted by GLP-1. The crucial role of AMPK in limiting HG-mediated NOX2 activation was demonstrated by overexpressing a constitutively active form of α2-AMPK using adenoviral infection. This overexpression prevented NOX2 activation in response to HG, whereas GLP-1 lost its protective action in α2-AMPK-deficient mouse cardiomyocytes. Under HG, the GLP-1/AMPK pathway inhibited PKC-β2 phosphorylation, a key element mediating p47phox translocation. In conclusion, GLP-1 induces α2-AMPK activation and blocks HG-induced p47phox translocation to the plasma membrane, thereby preventing glucotoxicity.

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Section: Discussionmentioning

confidence: 99%

AMPK activation by glucagon-like peptide-1 prevents NADPH oxidase activation induced by hyperglycemia in adult cardiomyocytes

Balteau¹,

Steenbergen²,

Timmermans³

et al. 2014

American Journal of Physiology-Heart and Circulatory Physiology

101

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“…Indeed, AMPK activation has been associated to the reduction in ROS production during myocardial ischemia (23). Second, it has been proposed recently that A-769662/AMPK also protect the ischemic heart by inhibiting mitochondrial permeability transition pore opening (28).…”

Section: Discussionmentioning

confidence: 99%

A-769662 potentiates the effect of other AMP-activated protein kinase activators on cardiac glucose uptake

Timmermans

Balteau

Gélinas

et al. 2014

American Journal of Physiology-Heart and Circulatory Physiology

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AMP-activated protein kinase (AMPK), a key cellular sensor of energy, regulates metabolic homeostasis and plays a protective role in the ischemic or diabetic heart. Stimulation of cardiac glucose uptake contributes to this AMPK-mediated protection. The small-molecule AMPK activator A-769662, which binds and directly activates AMPK, has recently been characterized. A-769662-dependent AMPK activation protects the heart against an ischemia-reperfusion episode but is unable to stimulate skeletal muscle glucose uptake. Here, we tried to reconcile these conflicting findings by investigating the impact of A-769662 on cardiac AMPK signaling and glucose uptake. We showed that A-769662 promoted AMPK activation, resulting in the phosphorylation of several downstream targets, but was incapable of stimulating glucose uptake in cultured cardiomyocytes and the perfused heart. The lack of glucose uptake stimulation can be explained by A-769662's narrow specificity, since it selectively activates cardiac AMPK heterotrimeric complexes containing α2/β1-subunits, the others being presumably required for this metabolic outcome. However, when combined with classical AMPK activators, such as metformin, phenformin, oligomycin, or hypoxia, which impact AMPK heterotrimers more broadly via elevation of cellular AMP levels, A-769662 induced more profound AMPK phosphorylation and subsequent glucose uptake stimulation. The synergistic effect of A-769662 under such ischemia-mimetic conditions protected cardiomyocytes against ROS production and cell death. In conclusion, despite the fact that A-769662 activates AMPK, it alone does not significantly stimulate glucose uptake. However, strikingly, its ability of potentiating the action on other AMPK activators makes it a potentially useful participant in the protective role of AMPK in the heart.

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“…Moreover, as said above, glucose metabolism during myocardial ischemia appears to be affected by impairment of AMPK in the heart (51,53). Therefore, it has been proposed that modulation of AMPK activity in the diabetic heart may overcome the increased susceptibility to I/R injury (263).…”

Section: Cardioprotection In Msmentioning

confidence: 96%

Mitochondrial Pathways, Permeability Transition Pore, and Redox Signaling in Cardioprotection: Therapeutic Implications

Penna

Perrelli²,

Pagliaro³

2013

Antioxidants & Redox Signaling

145

133

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Reperfusion therapy is the indispensable treatment of acute myocardial infarction (AMI) and must be applied as soon as possible to attenuate the ischemic insult. However, reperfusion is responsible for additional myocardial damage likely involving opening of the mitochondrial permeability transition pore (mPTP). A great part of reperfusion injury occurs during the first minute of reperfusion. The prolonged opening of mPTP is considered one of the endpoints of the cascade to myocardial damage, causing loss of cardiomyocyte function and viability. Opening of mPTP and the consequent oxidative stress due to reactive oxygen and nitrogen species (ROS/RNS) are considered among the major mechanisms of mitochondrial and myocardial dysfunction. Kinases and mitochondrial components constitute an intricate network of signaling molecules and mitochondrial proteins, which interact in response to stressors. Cardioprotective pathways are activated by stimuli such as preconditioning and postconditioning (PostC), obtained with brief intermittent ischemia or with pharmacological agents, which drastically reduce the lethal ischemia/reperfusion injury. The protective pathways converging on mitochondria may preserve their function. Protection involves kinases, adenosine triphosphate-dependent potassium channels, ROS signaling, and the mPTP modulation. Some clinical studies using ischemic PostC during angioplasty support its protective effects, and an interesting alternative is pharmacological PostC. In fact, the mPTP desensitizer, cyclosporine A, has been shown to induce appreciable protections in AMI patients. Several factors and comorbidities that might interfere with cardioprotective signaling are considered. Hence, treatments adapted to the characteristics of the patient (i.e., phenotype oriented) might be feasible in the future. Antioxid. Redox Signal. 00, 000-000.

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Enhancing AMPK activation during ischemia protects the diabetic heart against reperfusion injury

Cited by 110 publications

References 57 publications

AMPK activation by glucagon-like peptide-1 prevents NADPH oxidase activation induced by hyperglycemia in adult cardiomyocytes

AMPK activation by glucagon-like peptide-1 prevents NADPH oxidase activation induced by hyperglycemia in adult cardiomyocytes

A-769662 potentiates the effect of other AMP-activated protein kinase activators on cardiac glucose uptake

Mitochondrial Pathways, Permeability Transition Pore, and Redox Signaling in Cardioprotection: Therapeutic Implications

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