Increase of TNFα-stimulated osteoarthritic chondrocytes apoptosis and decrease of matrix metalloproteinases 9 by NF-κB inhibition

Biomed Environ Sci. 2013 Apr;26(4):277-83. doi: 10.3967/0895-3988.2013.04.006.

Abstract

Objective: To investigate the in vitro effect of caffeic acid phenethyl ester (CAPE), a NF-κB inhibitor, on the apoptosis of osteoarthritic (OA) chondrocytes and on the regulation of the gelatinases matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9).

Methods: Annexin V-FITC/propidium iodide (PI) labeling and western blotting were used to observe and determine the apoptosis in TNFα-stimulated primary cultured osteoarthritic chondrocytes. Also, gelatin zymography was applied to examine MMP-2 and MMP-9 activities in supernatants.

Results: It was confirmed by both flow cytometry and western blotting that chondrocytes from OA patients have an apoptotic background. Use of CAPE in combination with 10 ng/mL of TNFα for 24 h facilitated the apoptosis. MMP-9 in the supernatant could be autoactivated (from proMMP-9 to active MMP-9), and the physiologic calcium concentration (2.5 mmol/L) could delay the autoactivation of MMP-9. The activities of MMP-2 and MMP-9 in the fresh supernatant increased significantly in response to stimulation by 10 ng/mL of TNFα for 24 h. The stimulatory effect of TNFα just on proMMP-9 was counteracted significantly by CAPE.

Conclusion: NF-κB could prevent chondrocytes apoptosis though its activation was attributed to the increase of proMMP-9 activity induced by TNFα (a pro-apoptotic factor). Therefore, therapeutic NF-κB inhibitor was a 'double-edged swords' to the apoptosis of chondrocytes and the secretion of MMP-9.

Keywords: Apoptosis; Chondrocytes; Gelatinase; NF-κB; Tumor necrosis factor α.

MeSH terms

  • Aged
  • Apoptosis / drug effects*
  • Caffeic Acids / pharmacology*
  • Caffeic Acids / therapeutic use
  • Calcium / physiology
  • Cells, Cultured
  • Chondrocytes / drug effects*
  • Chondrocytes / enzymology
  • Chondrocytes / metabolism
  • Drug Evaluation, Preclinical
  • Female
  • Humans
  • Matrix Metalloproteinase 2 / metabolism
  • Matrix Metalloproteinase 9 / metabolism*
  • Middle Aged
  • NF-kappa B / antagonists & inhibitors*
  • Osteoarthritis / drug therapy
  • Osteoarthritis / enzymology
  • Phenylethyl Alcohol / analogs & derivatives*
  • Phenylethyl Alcohol / pharmacology
  • Phenylethyl Alcohol / therapeutic use
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • Caffeic Acids
  • NF-kappa B
  • Tumor Necrosis Factor-alpha
  • MMP2 protein, human
  • Matrix Metalloproteinase 2
  • MMP9 protein, human
  • Matrix Metalloproteinase 9
  • caffeic acid phenethyl ester
  • Phenylethyl Alcohol
  • Calcium