Heme oxygenase-1 induction modulates microsomal prostaglandin E synthase-1 expression and prostaglandin E(2) production in osteoarthritic chondrocytes.
Pro-inflammatory cytokines such as interleukin-1beta (IL-1beta) may participate in the pathogenesis of cartilage damage in osteoarthritis (OA) through the production of catabolic enzymes and inflammatory mediators. Induction of heme oxygenase-1 (HO-1) has previously been shown to exert anti-inflammatory effects in different cell types. We have investigated whether HO-1 induction may modify chondrocyte viability and the production of relevant mediators such as oxidative stress and prostaglandin E(2) (PGE(2)) elicited by IL-1beta in OA chondrocytes. Chondrocytes were isolated from OA cartilage and used in primary culture. Cells were stimulated with IL-1beta in the absence or presence of the HO-1 inducer cobalt protoporphyrin IX (CoPP). Gene expression was assessed by quantitative real-time PCR, protein levels by ELISA and Western blot, apoptosis by laser scanning cytometry using annexin V-FITC and TUNEL assays, and oxidative stress by LSC with dihydrorhodamine 123. HO-1 induction by CoPP enhanced chondrocyte viability and aggrecan content while inhibiting apoptosis and oxidative stress generation. PGE(2) is produced in OA chondrocytes stimulated by IL-1beta by the coordinated induction of cyclooxygenase-2 and microsomal PGE synthase 1 (mPGES-1). The production of PGE(2) was decreased by HO-1 induction as a result of diminished mPGES-1 protein and mRNA expression. Transfection with HO-1 small interfering RNA counteracted CoPP effects. In addition, the activation of nuclear factor-kappaB and early growth response-1 was significantly reduced by CoPP providing a basis for its anti-inflammatory effects. These results confirm the protective role of HO-1 induction in OA chondrocytes and suggest the potential interest of this strategy in degenerative joint diseases.
Department of Pharmacology, Faculty of Pharmacy, University of Valencia, Valencia, Spain.
Javier
J
Megías
María Isabel
MI
Guillén
Victoria
V
Clérigues
Ana I
AI
Rojo
Antonio
A
Cuadrado
Miguel Angel
MA
Castejón
Francisco
F
Gomar
María José
MJ
Alcaraz
D002470:Cell Survival; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism / Q000473:pathology*; D015232:Dinoprostone / Q000096:biosynthesis*; D051547:Heme Oxygenase-1 / Q000235:genetics*; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000235:genetics*; D008861:Microsomes / Q000201:enzymology / Q000378:metabolism; D010003:Osteoarthritis / Q000473:pathology*; D000071876:Prostaglandin-E Synthases; D015533:Transcriptional Activation
D051547:Heme Oxygenase-1; D019746:Intramolecular Oxidoreductases; C000605862:PTGES protein, human; D000071876:Prostaglandin-E Synthases; D015232:Dinoprostone