TLR4/MyD88 -mediated CCL2 production by lipopolysaccharide (endotoxin): Implications for metabolic inflammation

被引：68

作者：

Akhter N. ^{[1
]}

Hasan A. ^{[1
]}

Shenouda S. ^{[1
]}

Wilson A. ^{[1
]}

Kochumon S. ^{[1
]}

Ali S. ^{[1
]}

Tuomilehto J. ^{[1
]}

Sindhu S. ^{[1
]}

Ahmad R. ^{[1
]}

机构：

[1] Immunology Unit, Dasman Diabetes Institute (DDI), Al-Soor Street, P.O. Box 1180, Dasman

来源：

Journal of Diabetes & Metabolic Disorders | 2018年 / 17卷 / 1期

关键词：

CCL2 Production; Metabolic Inflammation; TLR4 siRNA; CCL2 Gene Expression; Primary Macrophages;

D O I：

10.1007/s40200-018-0341-y

中图分类号：

学科分类号：

摘要：

Background: Obese human and mice were reported to have higher circularity endotoxin (LPS) levels as compared to their lean counter parts. The current study was aimed to reveal the molecular mechanisms underlying the LPS mediated induction of CCL2 in human monocytes/macrophages. Methods: Human monocytic cell line THP-1, THP-1 cells derived macrophages and primary macrophages were treated with LPS and TNF-α (positive control). CCL2 expression was determined with real-time RT-PCR and ELISA. THP-1-XBlue™ cells, THP-1-XBlue™-defMyD cells, TLR4 neutralization antibody, TLR4 siRNA and inhibitors for NF-kB and MAPK were used to study the signaling pathways. Phosphorylation of NF-kB and c-Jun was analyzed by ELISA. Results: LPS upregulates CCL2 expression at both mRNA (THP-1: 23.40 ±.071 Fold, P < 0.0001; THP-1-derived macrophages: 103 ± 0.56 Fold, < 0.0001; Primary macrophages: 48 ± 1.41 Fold, P < 0.0005) and protein (THP1 monocytes:1048 ± 5.67 pg/ml, P < 0.0001; THP-1-derived macrophages; 2014 ± 2.12, P = 0.0001; Primary macrophages: 859.5 ± 3.54, P < 0.0001) levels in human monocytic cells/macrophages. Neutralization of TLR4 blocked LPS-induced CCL-2 secretion (P < 0.0001). Silencing of TLR4 by siRNA also significantly reduced LPS-induced CCL-2 production. Furthermore, MyD88-Knockout cells treated with LPS did not produce CCL-2. NF-kB and c-Jun phosphorylation was noted in LPS treated cells. Conclusion: Overall, our data reveal that LPS induces CCL-2 in monocytes/macrophages via TLR4/MyD88 signaling which leads to the activation of NF-kB/AP-1 transcription factors. © 2018, Springer International Publishing AG.

引用

页码：77 / 84

页数：7

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