TY - JOUR
T1 - Adenosine 59-monophosphate-activated protein kinase regulates IL-10-mediated anti-inflammatory signaling pathways in macrophages
AU - Zhu, Yanfang Peipei
AU - Brown, Jonathan R.
AU - Sag, Duygu
AU - Zhang, Lihua
AU - Suttles, Jill
N1 - Publisher Copyright:
Copyright © 2015 by The American Association of Immunologists, Inc.
PY - 2015/1/15
Y1 - 2015/1/15
N2 - AMP-activated protein kinase (AMPK) is a conserved serine/threonine kinase with a critical function in the regulation of metabolic pathways in eukaryotic cells. Recently, AMPK has been shown to play an additional role as a regulator of inflammatory activity in leukocytes. Treatment of macrophages with chemical AMPK activators, or forced expression of a constitutively active form of AMPK, results in polarization to an anti-inflammatory phenotype. In addition, we reported previously that stimulation of macrophages with anti-inflammatory cytokines such as IL-10, IL-4, and TGF-β results in rapid activation of AMPK, suggesting that AMPK contributes to the suppressive function of these cytokines. In this study, we investigated the role of AMPK in IL-10- induced gene expression and anti-inflammatory function. IL-10-stimulated wild-type macrophages displayed rapid activation of PI3K and its downstream targets Akt and mammalian target of rapamycin complex (mTORC1), an effect that was not seen in macrophages generated from AMPKa1-deficient mice. AMPK activation was not impacted by treatment with either the PI3K inhibitor LY294002 or the JAK inhibitor CP-690550, suggesting that IL-10-mediated activation of AMPK is independent of PI3K and JAK activity. IL-10 induced phosphorylation of both Tyr705 and Ser727 residues of STAT3 in an AMPKα1-dependent manner, and these phosphorylation events were blocked by inhibition of Ca2+/calmodulin-dependent protein kinase kinase β, an upstream activator of AMPK, and by the mTORC1 inhibitor rapamycin, respectively. The impaired STAT3 phosphorylation in response to IL-10 observed in AMPKa1-deficient macrophages was accompanied by reduced suppressor of cytokine signaling 3 expression and an inadequacy of IL-10 to suppress LPS-induced proinflammatory cytokine production. Overall, our data demonstrate that AMPKa1 is required for IL-10 activation of the PI3K/Akt/mTORC1 and STAT3-mediated anti-inflammatory pathways regulating macrophage functional polarization.
AB - AMP-activated protein kinase (AMPK) is a conserved serine/threonine kinase with a critical function in the regulation of metabolic pathways in eukaryotic cells. Recently, AMPK has been shown to play an additional role as a regulator of inflammatory activity in leukocytes. Treatment of macrophages with chemical AMPK activators, or forced expression of a constitutively active form of AMPK, results in polarization to an anti-inflammatory phenotype. In addition, we reported previously that stimulation of macrophages with anti-inflammatory cytokines such as IL-10, IL-4, and TGF-β results in rapid activation of AMPK, suggesting that AMPK contributes to the suppressive function of these cytokines. In this study, we investigated the role of AMPK in IL-10- induced gene expression and anti-inflammatory function. IL-10-stimulated wild-type macrophages displayed rapid activation of PI3K and its downstream targets Akt and mammalian target of rapamycin complex (mTORC1), an effect that was not seen in macrophages generated from AMPKa1-deficient mice. AMPK activation was not impacted by treatment with either the PI3K inhibitor LY294002 or the JAK inhibitor CP-690550, suggesting that IL-10-mediated activation of AMPK is independent of PI3K and JAK activity. IL-10 induced phosphorylation of both Tyr705 and Ser727 residues of STAT3 in an AMPKα1-dependent manner, and these phosphorylation events were blocked by inhibition of Ca2+/calmodulin-dependent protein kinase kinase β, an upstream activator of AMPK, and by the mTORC1 inhibitor rapamycin, respectively. The impaired STAT3 phosphorylation in response to IL-10 observed in AMPKa1-deficient macrophages was accompanied by reduced suppressor of cytokine signaling 3 expression and an inadequacy of IL-10 to suppress LPS-induced proinflammatory cytokine production. Overall, our data demonstrate that AMPKa1 is required for IL-10 activation of the PI3K/Akt/mTORC1 and STAT3-mediated anti-inflammatory pathways regulating macrophage functional polarization.
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U2 - 10.4049/jimmunol.1401024
DO - 10.4049/jimmunol.1401024
M3 - Article
C2 - 25512602
AN - SCOPUS:84920466745
SN - 0022-1767
VL - 194
SP - 584
EP - 594
JO - Journal of Immunology
JF - Journal of Immunology
IS - 2
ER -