Spred-2 deficiency exacerbates lipopolysaccharide-induced acute lung inflammation in mice

Yang Xu, Toshihiro Ito, Soichiro Fushimi, Sakuma Takahashi, Junya Itakura, Ryojiro Kimura, Miwa Sato, Megumi Mino, Akihiko Yoshimura, Akihiro Matsukawa

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Background: Acute respiratory distress syndrome (ARDS) is a severe and life-threatening acute lung injury (ALI) that is caused by noxious stimuli and pathogens. ALI is characterized by marked acute inflammation with elevated alveolar cytokine levels. Mitogen-activated protein kinase (MAPK) pathways are involved in cytokine production, but the mechanisms that regulate these pathways remain poorly characterized. Here, we focused on the role of Sprouty-related EVH1-domain-containing protein (Spred)-2, a negative regulator of the Ras-Raf-extracellular signal-regulated kinase (ERK)-MAPK pathway, in lipopolysaccharide (LPS)-induced acute lung inflammation.

Methods: Wild-type (WT) mice and Spred-2 mice were exposed to intratracheal LPS (50 μg in 50 μL PBS) to induce pulmonary inflammation. After LPS-injection, the lungs were harvested to assess leukocyte infiltration, cytokine and chemokine production, ERK-MAPK activation and immunopathology. For ex vivo experiments, alveolar macrophages were harvested from untreated WT and Spred-2mice and stimulated with LPS. In in vitro experiments, specific knock down of Spred-2 by siRNA or overexpression of Spred-2 by transfection with a plasmid encoding the Spred-2 sense sequence was introduced into murine RAW264.7 macrophage cells or MLE-12 lung epithelial cells.

Results: LPS-induced acute lung inflammation was significantly exacerbated in Spred-2 mice compared with WT mice, as indicated by the numbers of infiltrating leukocytes, levels of alveolar TNF-α, CXCL2 and CCL2 in a later phase, and lung pathology. U0126, a selective MEK/ERK inhibitor, reduced the augmented LPS-induced inflammation in Spred-2mice. Specific knock down of Spred-2 augmented LPS-induced cytokine and chemokine responses in RAW264.7 cells and MLE-12 cells, whereas Spred-2 overexpression decreased this response in RAW264.7 cells.

Conclusions: The ERK-MAPK pathway is involved in LPS-induced acute lung inflammation. Spred-2 controls the development of LPS-induced lung inflammation by negatively regulating the ERK-MAPK pathway. Thus, Spred-2 may represent a therapeutic target for the treatment of ALI.

Original languageEnglish
Article number108914
JournalPloS one
Volume9
Issue number10
DOIs
Publication statusPublished - 2014 Oct 2

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)
  • General

Fingerprint Dive into the research topics of 'Spred-2 deficiency exacerbates lipopolysaccharide-induced acute lung inflammation in mice'. Together they form a unique fingerprint.

  • Cite this

    Xu, Y., Ito, T., Fushimi, S., Takahashi, S., Itakura, J., Kimura, R., Sato, M., Mino, M., Yoshimura, A., & Matsukawa, A. (2014). Spred-2 deficiency exacerbates lipopolysaccharide-induced acute lung inflammation in mice. PloS one, 9(10), [108914]. https://doi.org/10.1371/journal.pone.0108914