Inhibition of AMP-activated Protein Kinase α (AMPKα) by Doxorubicin Accentuates Genotoxic Stress and Cell Death in Mouse Embryonic Fibroblasts and Cardiomyocytes

Matrix metalloproteinase-9 (MMP-9) plays a critical role in tissue remodeling under both physiological and pathological conditions. Although MMP-9 expression is low in most cells and is tightly controlled, the mechanism of its regulation is poorly understood. We utilized mouse embryonic fibroblasts (MEFs) that were nullizygous for the catalytic α subunit of AMP-activated protein kinase (AMPK), which is a key regulator of energy homeostasis, to identify AMPK as a suppressor of MMP-9 expression. Total AMPKα deletion significantly elevated MMP-9 expression compared with wild-type (WT) MEFs, whereas single knock-out of the isoforms AMPKα1 and AMPKα2 caused minimal change in the level of MMP-9 expression. The suppressive role of AMPK on MMP-9 expression was mediated through both its activity and presence. The AMPK activators 5-amino-4-imidazole carboxamide riboside and A769662 suppressed MMP-9 expression in WT MEFs, and AMPK inhibition by the overexpression of dominant negative (DN) AMPKα elevated MMP-9 expression. However, in AMPKα−/− MEFs transduced with DN AMPKα, MMP-9 expression was suppressed. AMPKα−/− MEFs showed increased phosphorylation of IκBα, expression of IκBα mRNA, nuclear localization of nuclear factor-κB (NF-κB), and DNA-binding activity of NF-κB compared with WT. Consistently, selective NF-κB inhibitors BMS345541 and SM7368 decreased MMP-9 expression in AMPKα−/− MEFs. Overall, our results suggest that both AMPKα isoforms suppress MMP-9 expression and that both the activity and presence of AMPKα contribute to its function as a regulator of MMP-9 expression by inhibiting the NF-κB pathway.

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Faculty Opinions recommendation of AMP-activated protein kinase confers protection against TNF-{alpha}-induced cardiac cell death.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1163979.624627 ◽

2009 ◽

Author(s):

Michael Irwin ◽

Zhengyuan Xia

Keyword(s):

Cell Death ◽

Protein Kinase ◽

Tnf Alpha ◽

Cardiac Cell ◽

Amp Activated Protein Kinase

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Abstract 337: Activation of Myocardial AMP-activated Protein Kinase by Metformin Prevents Progression of Heart Failure in Dogs; Involvement of eNOS Activation

Circulation ◽

10.1161/circ.118.suppl_18.s_286-c ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Hideyuki Sasaki ◽

Hiroshi Asanuma ◽

Masashi Fujita ◽

Hiroyuki Takahama ◽

Masanori Asakura ◽

...

Keyword(s):

Oxidative Stress ◽

Nitric Oxide ◽

Heart Failure ◽

Cell Death ◽

Protein Kinase ◽

Left Ventricular ◽

Vehicle Group ◽

Mrna Levels ◽

Compound C ◽

Amp Activated Protein Kinase

Background; Several studies have shown that metformin activates AMP-activated protein kinase (AMPK), which mediates potent cardioprotection against ischemia-reperfusion injury. AMPK is also activated in experimental failing myocardium, suggesting that activation of AMPK is beneficial for the pathophysiology of heart failure. We investigated whether metformin prevents oxidative stress-induced cell death in rat cardiomyocytes and attenuates the progression of heart failure in dogs. Methods and Results; The treatment with metformin (10 μmol/L) protected the rat cultured cardiomyocytes against cell death due to H 2 O 2 exposure (50 μmol/L) as indicated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), TUNEL staining, and flow cytometry. These effects were blunted by an AMPK inhibitor, compound-C (20 μmol/L), suggesting that the activation of AMPK decreased the extent of apoptosis-induced cell death due to H 2 O 2 exposure. Continuous rapid ventricular pacing (230/min for 4 weeks) in dogs caused heart failure and the treatment with metformin (100 mg/kg/day PO, n=8) decreased left ventricular (LV) end-diastolic dimension (32.8±0.4 vs. 36.5±1.0 mm, p< 0.01) and pressure (11.8±1.1 vs. 22±0.9 mmHg, p< 0.01), and increased LV fractional shortening (18.6±1.8 vs. 9.6±0.7 %, p< 0.01) along with enhanced phosphorylation of AMPK and the decreased the number of TUNEL-positive cells of the LV myocardium compared with the vehicle group (n=8). Interestingly, metformin increased the protein and mRNA levels of endothelial nitric oxide synthase of the LV myocardium and plasma nitric oxide levels. Metformin improved the plasma insulin resistance without increased myocardial GLUT-4 translocation. Furthermore, the subcutaneous administration of AICAR (50 mg/kg/every other day), another AMPK activator mediated the equivalent effects to metformin, strengthening the pivotal role of AMPK in reduction of apoptosis and prevention of heart failure. Conclusions; Activation of myocardial AMPK attenuated the oxidative stress-induced cardiomyocyte apoptosis and prevented the progression of heart failure in dogs, along with eNOS activation. Thus, metformin or AICAR may be applicable as a novel therapy for heart failure.

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Cell Death and Survival Pathways Involving ATM Protein Kinase

Genes ◽

10.3390/genes12101581 ◽

2021 ◽

Vol 12 (10) ◽

pp. 1581

Author(s):

Toshihiko Aki ◽

Koichi Uemura

Keyword(s):

Cell Death ◽

Protein Kinase ◽

Genotoxic Stress ◽

Short Review ◽

Research Progress ◽

Cellular Protection ◽

Cellular Survival ◽

Cell Death Pathways ◽

Wide Range ◽

Atm Protein

Cell death is the ultimate form of cellular dysfunction, and is induced by a wide range of stresses including genotoxic stresses. During genotoxic stress, two opposite cellular reactions, cellular protection through DNA repair and elimination of damaged cells by the induction of cell death, can occur in both separate and simultaneous manners. ATM (ataxia telangiectasia mutated) kinase (hereafter referred to as ATM) is a protein kinase that plays central roles in the induction of cell death during genotoxic stresses. It has long been considered that ATM mediates DNA damage-induced cell death through inducing apoptosis. However, recent research progress in cell death modality is now revealing ATM-dependent cell death pathways that consist of not only apoptosis but also necroptosis, ferroptosis, and dysfunction of autophagy, a cellular survival mechanism. In this short review, we intend to provide a brief outline of cell death mechanisms in which ATM is involved, with emphasis on pathways other than apoptosis.

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The imidazoline compound RX871024 promotes insulinoma cell death independent of AMP-activated protein kinase inhibition

Investigational New Drugs ◽

10.1007/s10637-016-0362-7 ◽

2016 ◽

Vol 34 (4) ◽

pp. 522-529 ◽

Cited By ~ 3

Author(s):

Irina I. Zaitseva ◽

Sergei V. Zaitsev ◽

Per-Olof Berggren

Keyword(s):

Cell Death ◽

Protein Kinase ◽

Kinase Inhibition ◽

Insulinoma Cell ◽

Protein Kinase Inhibition ◽

Amp Activated Protein Kinase

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Activating AMP-activated protein kinase by an α1 selective activator compound 13 attenuates dexamethasone-induced osteoblast cell death

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2016.02.036 ◽

2016 ◽

Vol 471 (4) ◽

pp. 545-552 ◽

Cited By ~ 41

Author(s):

Shiguang Guo ◽

Li Mao ◽

Feng Ji ◽

Shouguo Wang ◽

Yue Xie ◽

...

Keyword(s):

Cell Death ◽

Protein Kinase ◽

Osteoblast Cell ◽

Amp Activated Protein Kinase

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Caspase3-deficient cells require fibronectin for protection against autophagy-dependent death

10.1101/2021.01.27.428460 ◽

2021 ◽

Author(s):

David B. Weir ◽

Lawrence H. Boise

Keyword(s):

Cell Death ◽

Survival Advantage ◽

Deficient Mouse ◽

Wild Type ◽

Mouse Embryonic Fibroblasts ◽

Embryonic Fibroblasts ◽

Serum Withdrawal ◽

Presence And Absence ◽

Induced Apoptosis

ABSTRACTCaspases are required for execution of apoptosis. However, in their absence, signals that typically induce apoptosis can still result in cell death. Our laboratory previously demonstrated that Casp3-deficient mouse embryonic fibroblasts (MEFs) have increased fibronectin (FN) secretion, and an adhesion-dependent survival advantage compared to wild type (WT) MEFs. Here, we show that FN is required for survival of Casp3-deficient MEFs following serum withdrawal. Furthermore, when FN is silenced, serum withdrawal-induced death is caspase-independent. However, procaspase-7 is cleaved, suggesting that MOMP is taking place. Indeed, in the absence of FN, cytochrome c release is increased following serum withdrawal in Casp3-deficient MEFs. Yet death does not correspond to cytochrome c release in Casp3-deficient MEFs. This is true both in the presence and absence of FN. Additionally, caspase-independent death is inhibited by Bcl-XL overexpression. These findings suggest that Bcl-XL is not inhibiting death through regulation of Bax/Bak insertion into the mitochondria, but through a different mechanism. One such possibility is autophagy and induction of autophagy is associated with caspase-independent death in Casp3-deficient cells. Importantly, when ATG5 is ablated in Casp3-deficient cells, autophagy is blocked and death is largely inhibited. Taken together, our data indicate that Casp3-deficient cells incapable of undergoing canonical serum withdrawal-induced apoptosis, are protected from autophagy-dependent death by FN-mediated adhesion.

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