Interleukin-10 modulates pro-apoptotic effects of TNF-alpha in human articular chondrocytes in vitro

Cytokine. 2007 Dec;40(3):226-34. doi: 10.1016/j.cyto.2007.10.002. Epub 2007 Nov 19.

Abstract

The aim of this study is to determine if there is an antagonistic effect between tumour necrosis factor (TNF)-alpha and the immunoregulatory interleukin (IL)-10 on chondrocytes survival. Serum-starved primary human articular chondrocytes were stimulated with either 10 ng/ml recombinant TNF-alpha, IL-10 or a combination of both (at 10 ng/ml each). Chondrocyte apoptosis was determined by measuring caspase-3/7, -8 and -9 activities using caspase assays. Mitochondrial apoptotic inducer bax, and the suppressor bcl-2 were evaluated using western blotting at 48 h. Results indicated that TNF-alpha increased caspase activities and resulted in a significant (p = 0.001) increase in bax/bcl-2 ratio. Stimulation with IL-10 did not alter caspase activities, while co-treatment with IL-10 and TNF-alpha inhibited TNF-alpha induced caspase activities and significantly (p > 0.004) impaired bax/bcl-2 ratio. At 24 h, mRNA levels for collagen type II, TNF-alpha and IL-10 were determined using real-time RT-PCR. Stimulation with TNF-alpha or TNF-alpha and IL-10 significantly inhibited collagen type II and increased IL-10 and TNF-alpha mRNA expression. IL-10 modulated the pro-apoptotic capacity of TNF-alpha in chondrocytes as shown by the decrease in caspase activities and bax/bcl-2 ratio compared to TNF-alpha stimulated chondrocytes, suggesting a mostly antagonistic interplay of IL-10 and TNF-alpha on mitochondrial apoptotic pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Apoptosis / drug effects*
  • Apoptosis / immunology
  • Cartilage, Articular / cytology
  • Cartilage, Articular / immunology*
  • Cartilage, Articular / metabolism
  • Caspases / immunology
  • Caspases / metabolism
  • Cell Survival / drug effects
  • Cell Survival / immunology
  • Cells, Cultured
  • Chondrocytes / cytology
  • Chondrocytes / immunology*
  • Chondrocytes / metabolism
  • Collagen Type II / biosynthesis
  • Collagen Type II / immunology
  • Drug Antagonism
  • Female
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation / immunology
  • Humans
  • Interleukin-10 / antagonists & inhibitors
  • Interleukin-10 / immunology
  • Interleukin-10 / metabolism
  • Interleukin-10 / pharmacology*
  • Male
  • Middle Aged
  • Mitochondria / immunology
  • Mitochondria / metabolism
  • Recombinant Proteins / antagonists & inhibitors
  • Recombinant Proteins / immunology
  • Recombinant Proteins / metabolism
  • Recombinant Proteins / pharmacology
  • Time Factors
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors
  • Tumor Necrosis Factor-alpha / biosynthesis
  • Tumor Necrosis Factor-alpha / immunology
  • Tumor Necrosis Factor-alpha / pharmacology*
  • bcl-2-Associated X Protein / immunology
  • bcl-2-Associated X Protein / metabolism

Substances

  • BAX protein, human
  • Collagen Type II
  • IL10 protein, human
  • Recombinant Proteins
  • Tumor Necrosis Factor-alpha
  • bcl-2-Associated X Protein
  • Interleukin-10
  • Caspases