Toll-like receptor 9–dependent AMPKa activation occurs via TAK1 and contributes to RhoA/ROCK signaling and actin polymerization in vascular smooth muscle cells

Cameron G. McCarthy, Camilla F. Wenceslau, Safia Ogbi, Theodora Szasz, R Clinton Webb

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Traditionally, Toll-like receptor 9 (TLR9) signals through an MyD88-dependent cascade that results in proinflammatory gene transcription. Recently, it was reported that TLR9 also participates in a stress tolerance signaling cascade in nonimmune cells. In this noncanonical pathway, TLR9 binds to and inhibits sarcoplasmic/endoplasmic reticulum Ca 21 -ATPase 2 (SERCA2), modulating intracellular calcium handling, and subsequently resulting in the activation of 59-AMP–activated protein kinase a (AMPKa). We have previously reported that TLR9 causes increased contraction in isolated arteries; however, the mechanisms underlying this vascular dysfunction need to be further clarified. Therefore, we hypothesized that noncanonical TLR9 signaling was also present in vascular smooth muscle cells (VSMCs) and that it mediates enhanced contractile responses through SERCA2 inhibition. To test these hypotheses, aortic microsomes, aortic VSMCs, and isolated arteries from male Sprague-Dawley rats were incubated with vehicle or TLR9 agonist (ODN2395). Despite clear AMPKa activation after treatment with ODN2395, SERCA2 activity was unaffected. Alternatively, ODN2395 caused the phosphorylation of AMPKa via transforming growth factor b–activated kinase 1 (TAK1), a kinase involved in TLR9 inflammatory signaling. Downstream, we hypothesized that that TLR9 activation of AMPKa may be important in mediating actin cytoskeleton reorganization. ODN2395 significantly increased the filamentous-to-globular actin ratio, as well as indices of RhoA /Rho-associated protein kinase (ROCK) activation, with the latter being prevented by AMPKa inhibition. In conclusion, AMPKa phosphorylation after TLR9 activation in VSMCs appears to be an extension of traditional inflammatory signaling via TAK1, as opposed to SERCA2 inhibition and the noncanonical pathway. Nonetheless, TLR9-AMPKa signaling can mediate VSMC function via RhoA /ROCK activation and actin polymerization.

Original languageEnglish (US)
Pages (from-to)60-71
Number of pages12
JournalJournal of Pharmacology and Experimental Therapeutics
Volume365
Issue number1
DOIs
StatePublished - Apr 1 2018

Fingerprint

Toll-Like Receptor 9
Toll-Like Receptors
Vascular Smooth Muscle
Polymerization
Protein Kinases
Smooth Muscle Myocytes
Actins
Sarcoplasmic Reticulum
Endoplasmic Reticulum
Adenosine Triphosphatases
Phosphotransferases
Arteries
Phosphorylation
rho-Associated Kinases
Transforming Growth Factors
Microsomes
Actin Cytoskeleton
Blood Vessels
Sprague Dawley Rats

ASJC Scopus subject areas

  • Molecular Medicine
  • Pharmacology

Cite this

Toll-like receptor 9–dependent AMPKa activation occurs via TAK1 and contributes to RhoA/ROCK signaling and actin polymerization in vascular smooth muscle cells. / McCarthy, Cameron G.; Wenceslau, Camilla F.; Ogbi, Safia; Szasz, Theodora; Webb, R Clinton.

In: Journal of Pharmacology and Experimental Therapeutics, Vol. 365, No. 1, 01.04.2018, p. 60-71.

Research output: Contribution to journalArticle

@article{0c277e7d56df410e9b9b9fed275eed67,
title = "Toll-like receptor 9–dependent AMPKa activation occurs via TAK1 and contributes to RhoA/ROCK signaling and actin polymerization in vascular smooth muscle cells",
abstract = "Traditionally, Toll-like receptor 9 (TLR9) signals through an MyD88-dependent cascade that results in proinflammatory gene transcription. Recently, it was reported that TLR9 also participates in a stress tolerance signaling cascade in nonimmune cells. In this noncanonical pathway, TLR9 binds to and inhibits sarcoplasmic/endoplasmic reticulum Ca 21 -ATPase 2 (SERCA2), modulating intracellular calcium handling, and subsequently resulting in the activation of 59-AMP–activated protein kinase a (AMPKa). We have previously reported that TLR9 causes increased contraction in isolated arteries; however, the mechanisms underlying this vascular dysfunction need to be further clarified. Therefore, we hypothesized that noncanonical TLR9 signaling was also present in vascular smooth muscle cells (VSMCs) and that it mediates enhanced contractile responses through SERCA2 inhibition. To test these hypotheses, aortic microsomes, aortic VSMCs, and isolated arteries from male Sprague-Dawley rats were incubated with vehicle or TLR9 agonist (ODN2395). Despite clear AMPKa activation after treatment with ODN2395, SERCA2 activity was unaffected. Alternatively, ODN2395 caused the phosphorylation of AMPKa via transforming growth factor b–activated kinase 1 (TAK1), a kinase involved in TLR9 inflammatory signaling. Downstream, we hypothesized that that TLR9 activation of AMPKa may be important in mediating actin cytoskeleton reorganization. ODN2395 significantly increased the filamentous-to-globular actin ratio, as well as indices of RhoA /Rho-associated protein kinase (ROCK) activation, with the latter being prevented by AMPKa inhibition. In conclusion, AMPKa phosphorylation after TLR9 activation in VSMCs appears to be an extension of traditional inflammatory signaling via TAK1, as opposed to SERCA2 inhibition and the noncanonical pathway. Nonetheless, TLR9-AMPKa signaling can mediate VSMC function via RhoA /ROCK activation and actin polymerization.",
author = "McCarthy, {Cameron G.} and Wenceslau, {Camilla F.} and Safia Ogbi and Theodora Szasz and Webb, {R Clinton}",
year = "2018",
month = "4",
day = "1",
doi = "10.1124/jpet.117.245746",
language = "English (US)",
volume = "365",
pages = "60--71",
journal = "The Journal of pharmacology and experimental therapeutics",
issn = "0022-3565",
publisher = "American Society for Pharmacology and Experimental Therapeutics",
number = "1",

}

TY - JOUR

T1 - Toll-like receptor 9–dependent AMPKa activation occurs via TAK1 and contributes to RhoA/ROCK signaling and actin polymerization in vascular smooth muscle cells

AU - McCarthy, Cameron G.

AU - Wenceslau, Camilla F.

AU - Ogbi, Safia

AU - Szasz, Theodora

AU - Webb, R Clinton

PY - 2018/4/1

Y1 - 2018/4/1

N2 - Traditionally, Toll-like receptor 9 (TLR9) signals through an MyD88-dependent cascade that results in proinflammatory gene transcription. Recently, it was reported that TLR9 also participates in a stress tolerance signaling cascade in nonimmune cells. In this noncanonical pathway, TLR9 binds to and inhibits sarcoplasmic/endoplasmic reticulum Ca 21 -ATPase 2 (SERCA2), modulating intracellular calcium handling, and subsequently resulting in the activation of 59-AMP–activated protein kinase a (AMPKa). We have previously reported that TLR9 causes increased contraction in isolated arteries; however, the mechanisms underlying this vascular dysfunction need to be further clarified. Therefore, we hypothesized that noncanonical TLR9 signaling was also present in vascular smooth muscle cells (VSMCs) and that it mediates enhanced contractile responses through SERCA2 inhibition. To test these hypotheses, aortic microsomes, aortic VSMCs, and isolated arteries from male Sprague-Dawley rats were incubated with vehicle or TLR9 agonist (ODN2395). Despite clear AMPKa activation after treatment with ODN2395, SERCA2 activity was unaffected. Alternatively, ODN2395 caused the phosphorylation of AMPKa via transforming growth factor b–activated kinase 1 (TAK1), a kinase involved in TLR9 inflammatory signaling. Downstream, we hypothesized that that TLR9 activation of AMPKa may be important in mediating actin cytoskeleton reorganization. ODN2395 significantly increased the filamentous-to-globular actin ratio, as well as indices of RhoA /Rho-associated protein kinase (ROCK) activation, with the latter being prevented by AMPKa inhibition. In conclusion, AMPKa phosphorylation after TLR9 activation in VSMCs appears to be an extension of traditional inflammatory signaling via TAK1, as opposed to SERCA2 inhibition and the noncanonical pathway. Nonetheless, TLR9-AMPKa signaling can mediate VSMC function via RhoA /ROCK activation and actin polymerization.

AB - Traditionally, Toll-like receptor 9 (TLR9) signals through an MyD88-dependent cascade that results in proinflammatory gene transcription. Recently, it was reported that TLR9 also participates in a stress tolerance signaling cascade in nonimmune cells. In this noncanonical pathway, TLR9 binds to and inhibits sarcoplasmic/endoplasmic reticulum Ca 21 -ATPase 2 (SERCA2), modulating intracellular calcium handling, and subsequently resulting in the activation of 59-AMP–activated protein kinase a (AMPKa). We have previously reported that TLR9 causes increased contraction in isolated arteries; however, the mechanisms underlying this vascular dysfunction need to be further clarified. Therefore, we hypothesized that noncanonical TLR9 signaling was also present in vascular smooth muscle cells (VSMCs) and that it mediates enhanced contractile responses through SERCA2 inhibition. To test these hypotheses, aortic microsomes, aortic VSMCs, and isolated arteries from male Sprague-Dawley rats were incubated with vehicle or TLR9 agonist (ODN2395). Despite clear AMPKa activation after treatment with ODN2395, SERCA2 activity was unaffected. Alternatively, ODN2395 caused the phosphorylation of AMPKa via transforming growth factor b–activated kinase 1 (TAK1), a kinase involved in TLR9 inflammatory signaling. Downstream, we hypothesized that that TLR9 activation of AMPKa may be important in mediating actin cytoskeleton reorganization. ODN2395 significantly increased the filamentous-to-globular actin ratio, as well as indices of RhoA /Rho-associated protein kinase (ROCK) activation, with the latter being prevented by AMPKa inhibition. In conclusion, AMPKa phosphorylation after TLR9 activation in VSMCs appears to be an extension of traditional inflammatory signaling via TAK1, as opposed to SERCA2 inhibition and the noncanonical pathway. Nonetheless, TLR9-AMPKa signaling can mediate VSMC function via RhoA /ROCK activation and actin polymerization.

UR - http://www.scopus.com/inward/record.url?scp=85043282975&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85043282975&partnerID=8YFLogxK

U2 - 10.1124/jpet.117.245746

DO - 10.1124/jpet.117.245746

M3 - Article

VL - 365

SP - 60

EP - 71

JO - The Journal of pharmacology and experimental therapeutics

JF - The Journal of pharmacology and experimental therapeutics

SN - 0022-3565

IS - 1

ER -