Dynamic compression counteracts IL-1beta induced iNOS and COX-2 activity by human chondrocytes cultured in agarose constructs

Biorheology. 2006;43(3,4):413-29.

Abstract

*NO and PGE2 are inflammatory mediators derived from the inducible iNOS and COX enzymes and are potentially important pharmacological targets in OA. Both mechanical loading and IL-1beta will influence the release of *NO and PGE2. Accordingly, the current study examines the effect of dynamic compression on *NO and PGE2 release by human chondrocytes cultured in agarose constructs in the presence and absence of selective iNOS and COX-2 inhibitors. The current data demonstrate that IL-1beta induced nitrite and PGE2 release and inhibited [3H]-thymidine and 35SO4 incorporation. Inhibitor experiments indicate that 1400W and NS-398 either partially reversed or abolished IL-1beta induced nitrite and PGE2 release. IL-1beta induced inhibition of cell proliferation and proteoglycan synthesis was partially reversed with 1400W but was not influenced by NS-398. For the dynamic loading experiments, 1400W and NS-398 either reduced or abolished the compression-induced inhibition of *NO and PGE2 release in the presence of IL-1beta. The IL-1beta induced inhibition of cell proliferation was not influenced by 1400W or NS-398 whereas strain-induced stimulation of proteoglycan synthesis in the presence of IL-1beta was enhanced by 1400W. The data obtained using human chondrocytes demonstrate that IL-1beta induced *NO and PGE2 release via an iNOS-driven-COX-2 inter-dependent pathway. This response could be reversed by dynamic compression. These data indicate interactions exist between the NOS and COX pathways, a finding which will provide new insights in the development of pharmacological or biophysical treatments for cartilage disorders such as OA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Cartilage, Articular / cytology
  • Cartilage, Articular / drug effects
  • Cartilage, Articular / enzymology
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Chondrocytes / drug effects
  • Chondrocytes / enzymology*
  • Chondrocytes / metabolism
  • Cyclooxygenase 2 / metabolism*
  • Cyclooxygenase 2 Inhibitors / pharmacology
  • Dinoprostone / metabolism
  • Dose-Response Relationship, Drug
  • Enzyme Inhibitors / pharmacology
  • Humans
  • Interleukin-1 / antagonists & inhibitors
  • Interleukin-1 / pharmacology*
  • Mechanotransduction, Cellular / physiology*
  • Middle Aged
  • Nitric Oxide Synthase Type II / antagonists & inhibitors
  • Nitric Oxide Synthase Type II / metabolism*
  • Nitrites / metabolism
  • Sepharose
  • Stress, Mechanical
  • Sulfates / metabolism

Substances

  • Cyclooxygenase 2 Inhibitors
  • Enzyme Inhibitors
  • Interleukin-1
  • Nitrites
  • Sulfates
  • Sepharose
  • Nitric Oxide Synthase Type II
  • Cyclooxygenase 2
  • Dinoprostone