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Interactions of TLR4 and PPARγ, Dependent on AMPK Signalling Pathway Contribute to Anti-Inflammatory Effects of Vaccariae Hypaphorine in Endothelial Cells

Interactions of TLR4 and PPARγ, Dependent on AMPK Signalling Pathway Contribute to Anti-Inflammatory Effects of Vaccariae Hypaphorine in Endothelial Cells

Authors :
Haijian Sun
Xuexue Zhu
Wei Lin
Yuetao Zhou
Weiwei Cai
Liying Qiu
Source :
Cellular Physiology and Biochemistry, Vol 42, Iss 3, Pp 1227-1239 (2017)
Publication Year :
2017
Publisher :
Cell Physiol Biochem Press GmbH & Co KG, 2017.

Abstract

Background /Aims: Accumulating evidence indicates that endothelial inflammation is one of the critical determinants in pathogenesis of atherosclerotic cardiovascular disease. Our previous studies had demonstrated that Vaccariae prevented high glucose or oxidative stress-triggered endothelial dysfunction in vitro. Very little is known about the potential effects of hypaphorine from Vaccariae seed on inflammatory response in endothelial cells. Methods: In the present study, we evaluated the anti-inflammatory effects of Vaccariae hypaphorine (VH) on lipopolysaccharide (LPS)-challenged endothelial EA.hy926 cells. The inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), monocyte chemoattractant protein 1 (MCP-1) and vascular cellular adhesion molecule-1 (VCAM-1) were measured by real-time PCR (RT-PCR). The expressions of adenosine monophosphate-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), toll-like receptor 4 (TLR4), peroxisome proliferator-activated receptor γ (PPARγ) were detected by Western blotting or immunofluorescence. Results: We showed that LPS stimulated the expressions of TNF-α, IL-1β, MCP-1, VCAM-1 and TLR4, but attenuated the phosphorylation of AMPK and ACC as well as PPARγ protein levels, which were reversed by VH pretreatment. Moreover, we observed that LPS-upregulated TLR4 protein expressions were inhibited by PPARγ agonist pioglitazone, and the downregulated PPARγ expressions in response to LPS were partially restored by knockdown of TLR4. The negative regulation loop between TLR4 and PPARγ response to LPS was modulated by AMPK agonist AICAR (5-Aminoimidazole-4-carboxamide riboside or acadesine) or A769662. Conclusions: Taken together, our results suggested that VH ameliorated LPS-induced inflammatory cytokines production in endothelial cells via inhibition of TLR4 and activation of PPARγ, dependent on AMPK signalling pathway.

Details

Language :
English
ISSN :
10158987 and 14219778
Volume :
42
Issue :
3
Database :
Directory of Open Access Journals
Journal :
Cellular Physiology and Biochemistry
Publication Type :
Academic Journal
Accession number :
edsdoj.8810a73d7a524f3f9b11c6973e473fd2
Document Type :
article
Full Text :
https://doi.org/10.1159/000478920