NLRC3 promotes host resistance against Pseudomonas aeruginosa-induced keratitis by promoting the degradation of IRAK1

Int J Mol Med. 2017 Sep;40(3):898-906. doi: 10.3892/ijmm.2017.3077. Epub 2017 Jul 20.

Abstract

Pseudomonas aeruginosa (PA)-induced keratitis is one of the most common and destructive bacterial diseases. The pathogenesis of PA infections is closely associated with excessive inflammatory responses. Nucleotide oligomerization domain (NOD)-like receptor (NLR) family with caspase activation and recruitment domain (CARD) containing 3 (NLRC3) protein has been implicated as a negative regulator of inflammation and antiviral response, but the role of NLRC3 in PA-induced keratitis has not been described. In the present study, we investigated the effects of NLRC3 in PA-induced keratitis and explored the underlying mechanism. We found that the expression of NLRC3 was decreased in mouse corneas and macrophages after PA infection. Overexpr-ession of NLRC3 significantly attenuated disease progression, inhibited the activation of nuclear factor-κB signaling and decreased the production of pro-inflammatory cytokines after PA infection. Furthermore, overexpression of NLRC3 promoted K48-linked polyubiquitination and degradation of interleukin-1 receptor-associated kinase 1 (IRAK1). Taken together, we demonstrated that NLRC3 has an anti-inflammatory effect on PA-induced keratitis, which may provide an improved understanding of host resistance to PA infection.

MeSH terms

  • Animals
  • Humans
  • Intercellular Signaling Peptides and Proteins / genetics
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Interleukin-1 Receptor-Associated Kinases / genetics
  • Interleukin-1 Receptor-Associated Kinases / metabolism*
  • Keratitis / genetics
  • Keratitis / metabolism*
  • Keratitis / microbiology
  • Keratitis / pathology
  • Mice
  • Proteolysis*
  • Pseudomonas Infections / genetics
  • Pseudomonas Infections / metabolism*
  • Pseudomonas aeruginosa*
  • RAW 264.7 Cells
  • THP-1 Cells
  • Ubiquitination / genetics

Substances

  • Intercellular Signaling Peptides and Proteins
  • NLRC3 protein, human
  • NLRC3 protein, mouse
  • IRAK1 protein, human
  • Interleukin-1 Receptor-Associated Kinases
  • Irak1 protein, mouse