IL-36α: a novel cytokine involved in the catabolic and inflammatory response in chondrocytes

Sci Rep. 2015 Nov 12:5:16674. doi: 10.1038/srep16674.

Abstract

Recent studies confer to IL-36α pro-inflammatory properties. However, little is known about the expression and function of IL-36α in cartilage. This study sought to analyze the expression of IL-36α in healthy and OA cartilage. Next, we determined the effects of recombinant IL-36α on catabolism and inflammation in chondrocytes. For completeness, part of the signaling pathway elicited by IL-36α was also explored. IL-36α expression was evaluated by immunohistochemistry and RT-qPCR. Expression of MMP-13, NOS2 and COX-2 was also determined in OA articular chondrocytes treated with recombinant IL-36α. IκB-α and P-p38 was explored by western blot. We observed a low constitutive expression of IL-36α in healthy human chondrocytes. However, OA chondrocytes likely expressed more IL-36α than healthy chondrocytes. In addition, immune cells infiltrated into the joint and PBMCs express higher levels of IL-36α in comparison to chondrocytes. OA chondrocytes, treated with IL-36α, showed significant increase in the expression of MMP-13, NOS2 and COX-2. Finally, IL-36α stimulated cells showed NFκB and p38 MAPK activated pathways. IL-36α acts as a pro-inflammatory cytokine at cartilage level, by increasing the expression of markers of inflammation and cartilage catabolism. Like other members of IL-1 family, IL-36α acts through the activation of NFκB and p38 MAPK pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers
  • Case-Control Studies
  • Cells, Cultured
  • Chondrocytes / metabolism*
  • Cyclooxygenase 2 / metabolism
  • Gene Expression
  • Humans
  • Inflammation / genetics*
  • Inflammation / metabolism*
  • Interleukin-1 / genetics*
  • Interleukin-1 / metabolism*
  • Interleukin-1beta / metabolism
  • Matrix Metalloproteinase 13 / metabolism
  • Models, Biological
  • NF-kappa B / metabolism
  • Nitric Oxide Synthase Type II / metabolism
  • Osteoarthritis / genetics
  • Osteoarthritis / metabolism
  • Signal Transduction
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Biomarkers
  • IL36A protein, human
  • Interleukin-1
  • Interleukin-1beta
  • NF-kappa B
  • Nitric Oxide Synthase Type II
  • Cyclooxygenase 2
  • p38 Mitogen-Activated Protein Kinases
  • Matrix Metalloproteinase 13