Blockade of Wnt/β-Catenin Pathway Aggravated Silica-Induced Lung Inflammation through Tregs Regulation on Th Immune Responses

Mediators Inflamm. 2016:2016:6235614. doi: 10.1155/2016/6235614. Epub 2016 Mar 16.

Abstract

CD4(+) T cells play an important role in regulating silica-induced inflammation and fibrosis. Recent studies showed that Wnt/β-catenin pathway could modulate the function and the differentiation of CD4(+) T cells. Therefore, Wnt/β-catenin pathway may participate in the development and progress of silicosis. To investigate the role of Wnt/β-catenin pathway, we used lentivirus expressing β-catenin shRNA to block the Wnt/β-catenin pathway by intratracheal instillation to the mice model of silicosis. Treatment of lentivirus could significantly aggravate the silica-induced lung inflammation and attenuated the fibrosis at the late stage. By analyzing CD4(+) T cells, we found that blockade of Wnt/β-catenin pathway suppressed regulatory T cells (Tregs). Reciprocally, enhanced Th17 response was responsible for the further accumulation of neutrophils and production of proinflammatory cytokines. In addition, blockade of Wnt/β-catenin pathway delayed the Th1/Th2 polarization by inhibiting Tregs and Th2 response. These results indicated that Wnt/β-catenin pathway could regulate Tregs to modulate Th immune response, which finally altered the pathological character of silicosis. Our study suggested that Wnt/β-catenin pathway might be a potential target to treat the silica-induced inflammation and fibrosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Models, Animal
  • Female
  • Mice
  • Mice, Inbred C57BL
  • Pneumonia / chemically induced*
  • Pneumonia / metabolism*
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / physiology
  • Silicon Dioxide
  • T-Lymphocytes, Regulatory / drug effects
  • T-Lymphocytes, Regulatory / metabolism*
  • Th1 Cells / drug effects
  • Th1 Cells / metabolism
  • Th17 Cells / drug effects
  • Th17 Cells / metabolism
  • Th2 Cells / drug effects
  • Th2 Cells / metabolism
  • Wnt Signaling Pathway / genetics
  • Wnt Signaling Pathway / physiology*
  • beta Catenin / genetics
  • beta Catenin / metabolism*

Substances

  • RNA, Small Interfering
  • beta Catenin
  • Silicon Dioxide