Silencing of triggering receptor expressed on myeloid cells-2 enhances the inflammatory responses of alveolar macrophages to lipopolysaccharide

Gao,Xiaoling; Dong,Yanting; Liu,Zhuola; Niu,Bo

doi:10.3892/mmr.2013.1268

March 2013 Volume 7 Issue 3

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March 2013 Volume 7 Issue 3

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Article

Silencing of triggering receptor expressed on myeloid cells-2 enhances the inflammatory responses of alveolar macrophages to lipopolysaccharide

Authors:
- Xiaoling Gao
- Yanting Dong
- Zhuola Liu
- Bo Niu
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Affiliations: Department of Respiratory, The Second Hospital of Shanxi Medical University, Taiyuan 030001, P.R. China, Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, P.R. China
Pages: 921-926
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Published online on: January 10, 2013

https://doi.org/10.3892/mmr.2013.1268
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Abstract

Triggering receptor expressed on myeloid cells-2 (TREM-2) has been shown to attenuate inflammatory responses in various cell lines including bone marrow-derived macrophages, hepatic macrophages, osteoclasts and dendritic cells. However, its effects on alveolar macrophages remain unknown. Lentivirus-mediated RNA interference (RNAi) is a post-transcriptional gene silencing method, which is capable of degrading target genes specifically and efficiently. In this study, we silenced TREM-2 in murine alveolar macrophages by using lentivirus-mediated short hairpin RNA (shRNA) and evaluated the effects of TREM-2 silencing on expression of toll-like receptor-4 (TLR-4), tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) in response to lipopolysaccharide (LPS). Alveolar macrophages were transfected with shRNA targeting TREM-2 by use of lentivirus vector, non-sense shRNA as a negative control or empty lentivirus vector as a blank control. Silencing of TREM-2 was assessed by real‑time fluorescence quantitative PCR and flow cytometry. Following LPS stimulation, the levels of TLR-4, TNF-α and IL-10 expressed in alveolar macrophages were measured by real-time PCR, flow cytometry or ELISA. TREM-2 expression on alveolar macrophages was downregulated significantly by lentivirus-mediated shRNA treatment at the transcriptional and translational levels. However, alveolar macrophages that received non-sense shRNA or empty lentivirus vectors showed no effects on TREM-2 expression. Silencing of TREM-2 enhanced expression of TLR-4, as well as TNF-α and IL-10, by alveolar macrophages following LPS stimulation. These results indicate a significant effect of TREM-2 on attenuating the LPS-induced inflammatory response of murine alveolar macrophages, which may be dependent on TLR-4.

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Journals

International Journal of Molecular Medicine

International Journal of Oncology

Molecular Medicine Reports

Oncology Reports

Experimental and Therapeutic Medicine

Oncology Letters

Biomedical Reports

Molecular and Clinical Oncology

World Academy of Sciences Journal

International Journal of Functional Nutrition

International Journal of Epigenetics

Medicine International

Silencing of triggering receptor expressed on myeloid cells-2 enhances the inflammatory responses of alveolar macrophages to lipopolysaccharide

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