Pulmonary fibroblasts-secreted CXCL10 polarizes alveolar macrophages under pro-inflammatory stimuli

Cheng-Fang Tsai; Jia-Hong Chen; Wei-Lan Yeh

doi:10.1016/j.taap.2019.114698

Pulmonary fibroblasts-secreted CXCL10 polarizes alveolar macrophages under pro-inflammatory stimuli

Toxicol Appl Pharmacol. 2019 Oct 1:380:114698. doi: 10.1016/j.taap.2019.114698. Epub 2019 Aug 5.

Authors

Cheng-Fang Tsai¹, Jia-Hong Chen², Wei-Lan Yeh³

Affiliations

¹ Department of Biotechnology, Asia University, No.500 Lioufeng Road, Taichung 41354, Taiwan.
² Department of General Surgery, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung 42743, Taiwan.
³ Institute of New Drug Development, China Medical University, No.91 Hsueh-Shih Road, Taichung 40402, Taiwan. Electronic address: wlyeh@mail.cmu.edu.tw.

PMID: 31394157
DOI: 10.1016/j.taap.2019.114698

Abstract

Background: During acute lung injury, lung fibroblasts produce chemokines that assist the activation and migration of resident macrophages. The interactions between pulmonary fibroblasts and alveolar macrophages demonstrate the early event in the recruitment of immune cells, and the production of chemokines appear to be central mediators of the initiation and progression of inflammatory responses. In this study, the aim was to investigate the signaling pathway leading to CXCL10 secretion and the effects of CXCL10 released by activated fibroblasts on regulating macrophage polarization in a pro-inflammatory microenvironment.

Methods: The expression of chemokines CCL2, CCL5, CXCL10, and CXCL12, and the phosphorylation of signaling molecules STAT3, FAK, GSK3αβ and PKCδ were investigated by real time-PCR, ELISA, or Western blot on TNFα- or IL-1β-activated MRC-5 pulmonary fibroblasts. By collecting conditioned medium from TNFα-activated fibroblasts, the expression of iNOS and arginase I on MH-S alveolar macrophages were examined by real-time PCR. Surface markers CD86 and CD206 expressions on alveolar macrophages were also evaluated by flow cytometry.

Results: We found that CXCL10 production was significantly elevated on MRC-5 fibroblasts under TNFα- or IL-1β treatment. In addition, we revealed that TNFα and IL-1β initiated phosphorylation of STAT3, FAK, GSK3αβ and PKCδ signaling cascade, leading to the elevation of CXCL10 expression. Moreover, conditioned medium collected from TNFα-activated MRC-5 fibroblasts increased iNOS and CD86 expressions and decreased arginase I and CD206 expressions on MH-S alveolar macrophages, and neutralization of CXCL10 abolished these observed phenomena.

Conclusion: These results suggest that CXCL10 is crucial in activated fibroblasts-promoted M1 phenotype polarization of alveolar macrophages. In this regard, targeting fibroblasts-released CXCL10 may be promising as anti-inflammatory therapy against acute lung injury.

Keywords: Alveolar Macrophage; CXCL10; Inflammation; Polarization; Pulmonary Fibroblast.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cell Line
Cytokines / physiology*
Fibroblasts / physiology*
Humans
Lung / cytology*
Macrophages, Alveolar / physiology*
Signal Transduction

Substances

Cytokines