1. Academic Validation
  2. Macrophage Inflammatory Protein-2 in High Mobility Group Box 1 Secretion of Macrophage Cells Exposed to Lipopolysaccharide

Macrophage Inflammatory Protein-2 in High Mobility Group Box 1 Secretion of Macrophage Cells Exposed to Lipopolysaccharide

  • Cell Physiol Biochem. 2017;42(3):913-928. doi: 10.1159/000478646.
Qin Chaochao 1 Guohua Lou 1 Ying Yang 1 Yanning Liu 1 Ying Hu 1 Zheng Min 1 Ping Chen 1 Jiliang He 2 Zhi Chen 1
Affiliations

Affiliations

  • 1 State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.
  • 2 Department of Environmental Medicine, School of Public Health, Zhejiang University, Hangzhou, China.
Abstract

Background/aims: Macrophage inflammatory protein-2 (MIP-2), a type of leukocyte chemokine, is primarily produced by macrophages, and levels increase significantly in early inflammation. However, the precise biological functions and mechanisms of MIP-2 in the development of inflammation remain unclear. The purposes of the present study were to investigate the role of MIP-2 in inflammation induced by lipopolysaccharide (LPS) in vitro and to determine the possibility of blocking the high mobility group box 1 (HMGB1) signalling pathway via MIP-2 inhibition.

Methods: Macrophage cells (RAW264.7, U937 and THP-1 cells) were divided into control and treatments groups. Expression levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α), HMGB1, chemokine (C-C motif) ligand-2 (Ccl-2), Toll-like receptor-4 (TLR-4), inducible nitric oxide synthase (iNOS), phosphorylated MAPKs (p38, ERKs, JNKs), PI3K/Akts, JAKs/STAT3, IκB, and cytoplasmic and nuclear NF-κB p65 in RAW264.7 cells were detected by qRT-PCR, enzyme-linked immunosorbent assay (ELISA) or western blot assays.

Results: mip-2 siRNA and an anti-MIP-2 antibody significantly reduced the expression levels of Ccl-2, TLR-4, iNOS, IL-6, IL-1β, HMGB1, and TNF-α in RAW264.7 cells exposed to LPS (P<0.01). Additionally, mRNA expression levels of HMGB1 and TLR-4 in cells treated with LPS+mip-2 siRNA were significantly lower than those in cells treated with LPS alone (P<0.01 or P<0.05). The MIP-2 antibody significantly suppressed activation of p38-MAPK, p-STAT3, and p-Akts and translocation of NF-κB p65 from the cytoplasm to the nucleus in RAW264.7 exposed to LPS (P<0.01 or P<0.05).

Conclusion: mip-2 siRNA and the MIP-2 antibody can reduce the inflammatory effects induced by LPS in macrophage cells. The mechanisms may occur through down-regulation of p38-MAPK, STAT3 and Akts phosphorylation and translocation of NF-κB p65. MIP-2 plays an important role in inflammation induced by LPS.

Keywords

Acute inflammation; HMGB1; Macrophage inflammatory protein-2; Macrophages.

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