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.

Evidence for operation of nicotinic and muscarinic acetylcholine receptor-dependent survival pathways in human coronary artery endothelial cells

“…Our observation that nicotine-induced phosphorylation of JAK2 and STAT3 are inhibited by a-bungarotoxin, represent the first evidence to date indicating activation of the JAK2/STAT3 axis downstream a7-nAChRs in human coronary endothelial cells. Unlike our findings in HCAECs, recent work showed that nicotine treatment of human umbilical vein and dermal microvascular endothelial cells inhibits JAK2/STAT3 [Chatterjee et al, 2009]. Rather than contradictory, these findings likely reflect heterogeneity of endothelial cells derived from different vascular beds in regards to their responsiveness to cholinergic stimulation.…”

Acetylcholine Inhibits LPS-Induced MMP-9 Production and Cell Migration via the a7 nAChR-JAK2/STAT3 Pathway in RAW264.7 Cells

“…The anti-inflammatory activity of ACh involves JAK2/STAT3 signaling [36,37]. Previous studies have demonstrated that nicotine acted on macrophages via the recruitment of JAK2 to the α7 nAChR and activation of JAK2, thereby initiating the anti-inflammatory STAT3 signaling cascade [36].…”

Asymmetric dimethyl arginine induces pulmonary vascular dysfunction via activation of signal transducer and activator of transcription 3 and stabilization of hypoxia-inducible factor 1-alpha

“…Although the activation or stabilization of transcription factors STAT3 (signal transducer and activator of transcription 3) and HIF-1α (hypoxia-inducible factor 1-alpha) has been demonstrated to play a crucial role in PH pathology [1,[37][38][39], as far as we know there exists no information concerning the effect of ADMA. Interestingly, STAT3 and HIF-1α were shown to be responsible for regulation of cell survival and proliferation, angiogenesis, as well as for inflammatory processes, associated with production of different types of inflammatory-derived mediators described above [37][38][39][40][41][42][43][44][45][46].…”