title: Cholinergic agonists regulate JAK2/STAT3 signaling to suppress endothelial cell activation.
abstract: The cholinergic anti-inflammatory pathway is a physiological mechanism that inhibits cytokine production and minimizes tissue injury during inflammation. Previous investigations revealed that cholinergic stimulation (via cholinergic agonists and vagus nerve stimulation) suppresses endothelial cell activation and leukocyte recruitment. The purpose of this study was to investigate the mechanisms by which cholinergic agonists (e.g., nicotine and GTS-21) regulate endothelial cell activation. Specifically, we examined the effects of cholinergic agonists on IL-6-mediated endothelial cell activation through the JAK2/STAT3 signaling pathway. Treatment of macrovascular human umbilical vein endothelial cells (HUVECs) and microvascular endothelial cells (MVECs) with the cholinergic agonists nicotine and GTS-21 significantly reduced IL-6-mediated monocyte chemoattractant protein-1 (MCP-1) production and ICAM-1 expression which are regulated through the JAK2/STAT3 pathway. We found that treatment of endothelial cells with cholinergic agonists significantly reduced STAT3 activation by phosphorylation and DNA binding. The inhibition of STAT3 phosphorylation was reversed by sodium orthovanadate, an inhibitor of tyrosine phosphatases, as well as by NSC-87877 suggesting a SHP1/2-dependent mechanism. Further investigations showed that cholinergic agonists reduced the phosphorylation of JAK2, an upstream component of the JAK2/STAT3 pathway. Finally, we observed that nicotine and GTS-21 treatment decreased levels of SOCS3 (suppressor of cytokine signaling; a regulator of the inflammatory activity of IL-6) in activated endothelial cells. These data demonstrate that cholinergic agonists suppress IL-6-mediated endothelial cell activation through the JAK2/STAT3 pathway. Our results have significant implications for better understanding the therapeutic potential of cholinergic agonists for treating IL-6 mediated inflammatory conditions.
authors.affiliation: The Center for Immunology and Inflammation, The Feinstein Institute for Medical Research, Manhasset, New York, USA.
authors.forename: Prodyot K
authors.initials: PK
authors.lastname: Chatterjee
authors.forename: Yousef
authors.initials: Y
authors.lastname: Al-Abed
authors.forename: Barbara
authors.initials: B
authors.lastname: Sherry
authors.forename: Christine N
authors.initials: CN
authors.lastname: Metz
mesh_terms: D001597:Benzylidene Compounds / Q000494:pharmacology; D015153:Blotting, Western; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000187:drug effects / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000187:drug effects / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D053614:Janus Kinase 2 / Q000187:drug effects / Q000378:metabolism*; D009538:Nicotine / Q000494:pharmacology; D018722:Nicotinic Agonists / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology; D050796:STAT3 Transcription Factor / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000187:drug effects / Q000378:metabolism
chemical_list: D001597:Benzylidene Compounds; C111835:CCL2 protein, human; D018932:Chemokine CCL2; D015850:Interleukin-6; D018722:Nicotinic Agonists; D011725:Pyridines; C106644:SOCS3 protein, human; D050796:STAT3 Transcription Factor; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D018799:Intercellular Adhesion Molecule-1; D009538:Nicotine; C088936:3-(2,4-dimethoxybenzylidene)anabaseine; D053614:Janus Kinase 2