Expression of Beta-Defensin 131 Promotes an Innate Immune Response in Human Prostate Epithelial Cells

PLoS One. 2015 Dec 9;10(12):e0144776. doi: 10.1371/journal.pone.0144776. eCollection 2015.

Abstract

Previously, using the Illumina HumanHT-12 microarray we found that β-defensin 131 (DEFB131), an antimicrobial peptide, is upregulated in the human prostate epithelial cell line RWPE-1 upon stimulation with lipoteichoic acid (LTA; a gram-positive bacterial component), than that in the untreated RWPE-1 cells. In the current study, we aimed to investigate the role of DEFB131 in RWPE-1 cells during bacterial infection. We examined the intracellular signaling pathways and nuclear responses in RWPE-1 cells that contribute to DEFB131 gene induction upon stimulation with LTA. Chromatin immunoprecipitation was performed to determine whether NF-κB directly binds to the DEFB131 promoter after LTA stimulation in RWPE-1 cells. We found that DEFB131 expression was induced by LTA stimulation through TLR2 and p38MAPK/NF-κB activation, which was evident in the phosphorylation of both p38MAPK and IκBα. We also found that SB203580 and Bay11-7082, inhibitors of p38MAPK and NF-κB, respectively, suppressed LTA-induced DEFB131 expression. The chromatin immunoprecipitation assay showed that NF-κB directly binds to the DEFB131 promoter, suggesting that NF-κB is a direct regulator, and is necessary for LTA-induced DEFB131 expression in RWPE-1 cells. Interestingly, with DEFB131 overexpression in RWPE-1 cells, the accumulation of mRNA and protein secretion of cytokines (IL-1α, IL-1β, IL-6, and IL-12α) and chemokines (CCL20, CCL22, and CXCL8) were significantly enhanced. In addition, DEFB131-transfected RWPE-1 cells markedly induced chemotactic activity in THP-1 monocytes. We concluded that DEFB131 induces cytokine and chemokine upregulation through the TLR2/NF-κB signaling pathway in RWPE-1 cells during bacterial infection and promotes an innate immune response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Infections / immunology*
  • Chemokines / metabolism
  • Cytokines / metabolism
  • Epithelial Cells / metabolism
  • Humans
  • Immunity, Innate*
  • Interleukin-8 / metabolism
  • Lipopolysaccharides
  • Male
  • NF-kappa B / metabolism
  • Nitriles
  • Prostate / metabolism*
  • Signal Transduction
  • Teichoic Acids
  • Up-Regulation
  • beta-Defensins / physiology*
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Chemokines
  • Cytokines
  • Interleukin-8
  • Lipopolysaccharides
  • NF-kappa B
  • Nitriles
  • Teichoic Acids
  • beta-Defensins
  • p38 Mitogen-Activated Protein Kinases

Grant support

This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2013R1A1A2011824). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.