The Cosmc-mediated effects of neutrophil elastase on T antigen expression in BEAS-2B cells

Respir Physiol Neurobiol. 2020 Oct;281:103496. doi: 10.1016/j.resp.2020.103496. Epub 2020 Jul 16.


Mucin 5AC (MUC5AC) is a highly O-glycosylated mucin secreted by human bronchial epithelial cells during pulmonary inflammatory diseases. T antigen, a component of the MUC5AC glycans, is the product of the O-glycosylation transferase T-synthase and its chaperone Cosmc. Since the expression of Cosmc is mediated by signaling pathways and inflammatory factors affecting mucin O-glycosylation, we analyzed the impact of neutrophil elastase (NE)-mediated Cosmc and T antigen expression in BEAS-2B cells derived from human bronchial epithelial cells. The expression of Cosmc and T antigen in human lung tissue was analyzed by immunohistochemistry. Cellular immunohistochemistry and western blot analysis demonstrated elevated expression of T antigen in BEAS-2B cells after NE stimulation. Altered Cosmc expression in BEAS-2B cells after NE stimulation was analyzed by confocal microscopy, western blot analysis and quantitative RT-PCR. To assess the biological implications of Cosmc function for T-synthase activity and T antigen synthesis after NE stimulation, BEAS-2B cells were transfected with shRNA to silence the expression of Cosmc. The changes in signaling pathways were analyzed by western blotting. The expression of Cosmc and T antigen increased in lung tissue exposed to chronic inflammation. The expression of Cosmc and T antigen increased in NE-stimulated BEAS-2B cells. NE induced increases in T antigen expression and T-synthase transferase activity in BEAS-2B cells expressing Cosmc, highlighting the importance of Cosmc in the relationship between NE and T antigen. Cosmc and phosphatidylinositol-3-kinase (PI3K) played important roles in the signaling pathway that stimulated hyperexpression of T antigen.

Keywords: Cosmc; NE; PI3K; T antigen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Viral, Tumor / metabolism*
  • Cell Line
  • Cells, Cultured
  • Humans
  • Inflammation / metabolism*
  • Leukocyte Elastase / metabolism*
  • Molecular Chaperones / metabolism*
  • Mucin 5AC / metabolism*
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Respiratory Mucosa / metabolism*
  • Signal Transduction / physiology*


  • Antigens, Viral, Tumor
  • C1GALT1C1 protein, human
  • MUC5AC protein, human
  • Molecular Chaperones
  • Mucin 5AC
  • ELANE protein, human
  • Leukocyte Elastase