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Exposure to hydrogen peroxide induces oxidation and activation of AMP-activated protein kinase.

ABSTRACT: Although metabolic conditions associated with an increased AMP/ATP ratio are primary factors in the activation of 5'-adenosine monophosphate-activated protein kinase (AMPK), a number of recent studies have shown that increased intracellular levels of reactive oxygen species can stimulate AMPK activity, even without a decrease in cellular levels of ATP. We found that exposure of recombinant AMPK??? complex or HEK 293 cells to H(2)O(2) was associated with increased kinase activity and also resulted in oxidative modification of AMPK, including S-glutathionylation of the AMPK? and AMPK? subunits. In experiments using C-terminal truncation mutants of AMPK? (amino acids 1-312), we found that mutation of cysteine 299 to alanine diminished the ability of H(2)O(2) to induce kinase activation, and mutation of cysteine 304 to alanine totally abrogated the enhancing effect of H(2)O(2) on kinase activity. Similar to the results obtained with H(2)O(2)-treated HEK 293 cells, activation and S-glutathionylation of the AMPK? subunit were present in the lungs of acatalasemic mice or mice treated with the catalase inhibitor aminotriazole, conditions in which intracellular steady state levels of H(2)O(2) are increased. These results demonstrate that physiologically relevant concentrations of H(2)O(2) can activate AMPK through oxidative modification of the AMPK? subunit. The present findings also imply that AMPK activation, in addition to being a response to alterations in intracellular metabolic pathways, is directly influenced by cellular redox status.

SUBMITTER: Zmijewski JW

PROVIDER: S-EPMC2963401 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature

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Exposure to hydrogen peroxide induces oxidation and activation of AMP-activated protein kinase.

Zmijewski Jaroslaw W JW Banerjee Sami S Bae Hongbeom H Friggeri Arnaud A Lazarowski Eduardo R ER Abraham Edward E

The Journal of biological chemistry 20100820 43

Although metabolic conditions associated with an increased AMP/ATP ratio are primary factors in the activation of 5'-adenosine monophosphate-activated protein kinase (AMPK), a number of recent studies have shown that increased intracellular levels of reactive oxygen species can stimulate AMPK activity, even without a decrease in cellular levels of ATP. We found that exposure of recombinant AMPKαβγ complex or HEK 293 cells to H(2)O(2) was associated with increased kinase activity and also resulte ...[more]

PMID: 20729205

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Project description:BACKGROUND & AIMS:Glycogen synthase kinase 3? (Gsk3? [Gsk3b]) is a ubiquitously expressed kinase with distinctive functions in different types of cells. Although its roles in regulating innate immune activation and ischaemia and reperfusion injuries (IRIs) have been well documented, the underlying mechanisms remain ambiguous, in part because of the lack of cell-specific tools in vivo. METHODS:We created a myeloid-specific Gsk3b knockout (KO) strain to study the function of Gsk3? in macrophages in a murine liver partial warm ischaemia model. RESULTS:Compared with controls, myeloid Gsk3b KO mice were protected from IRI, with diminished proinflammatory but enhanced anti-inflammatory immune responses in livers. In bone marrow-derived macrophages, Gsk3? deficiency resulted in an early reduction of Tnf gene transcription but sustained increase of Il10 gene transcription on Toll-like receptor 4 stimulation in vitro. These effects were associated with enhanced AMP-activated protein kinase (AMPK) activation, which led to an accelerated and higher level of induction of the novel innate immune negative regulator small heterodimer partner (SHP [Nr0b2]). The regulatory function of Gsk3? on AMPK activation and SHP induction was confirmed in wild-type bone marrow-derived macrophages with a Gsk3 inhibitor. Furthermore, we found that this immune regulatory mechanism was independent of Gsk3? Ser9 phosphorylation and the phosphoinositide 3-kinase-Akt signalling pathway. In vivo, myeloid Gsk3? deficiency facilitated SHP upregulation by ischaemia-reperfusion in liver macrophages. Treatment of Gsk3b KO mice with either AMPK inhibitor or SHP small interfering RNA before the onset of liver ischaemia restored liver proinflammatory immune activation and IRI in these otherwise protected hosts. Additionally, pharmacological activation of AMPK protected wild-type mice from liver IRI, with reduced proinflammatory immune activation. Inhibition of the AMPK-SHP pathway by liver ischaemia was demonstrated in tumour resection patients. CONCLUSIONS:Gsk3? promotes innate proinflammatory immune activation by restraining AMPK activation. LAY SUMMARY:Glycogen synthase kinase 3? promotes macrophage inflammatory activation by inhibiting the immune regulatory signalling of AMP-activated protein kinase and the induction of small heterodimer partner. Therefore, therapeutic targeting of glycogen synthase kinase 3? enhances innate immune regulation and protects liver from ischaemia and reperfusion injury.

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Exposure to hydrogen peroxide induces oxidation and activation of AMP-activated protein kinase.

Publications

Exposure to hydrogen peroxide induces oxidation and activation of AMP-activated protein kinase.

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