The CO-releasing molecule CORM-2 is a novel regulator of the inflammatory process in osteoarthritic chondrocytes.
OBJECTIVE
Previous work has shown that the CO-releasing molecule CORM-2 protects against cartilage degradation. The aim of this study was to examine whether CORM-2 can control the production of inflammatory mediators in osteoarthritic chondrocytes and determine the mechanisms involved.


METHODS
Primary cultures of chondrocytes from OA patients were stimulated with IL-1beta. The production of reactive oxygen species, nitrite, PGE(2), TNF-alpha and IL-1 receptor antagonist (IL-1Ra) were measured in the presence or absence of CORM-2. The expression of nitric oxide synthase-2 (NOS-2), cyclo-oxygenase-2 (COX-2) and microsomal PG E synthase-1 (mPGES-1) was followed by western blot and real-time PCR. Activation of nuclear factor-kappaB (NF-kappaB) and hypoxia inducible factor-1alpha (HIF-1alpha), and phosphorylation of NF-kappaB inhibitory protein alpha (IkappaBalpha) were determined by ELISA.


RESULTS
CORM-2 decreased the production of oxidative stress, nitrite and PGE(2). In addition, CORM-2 inhibited IL-1beta-induced TNF-alpha but enhanced IL-1Ra production. Treatment of chondrocytes with CORM-2 strongly down-regulated NOS-2 and mPGES-1 protein expression, whereas COX-2 was reduced to a lesser extent. These changes were accompanied by a significant decrease in mRNA expression for NOS-2 and mPGES-1. CORM-2 showed a concentration-dependent inhibition of DNA-binding activity for p65 NF-kappaB and HIF-1alpha. IkappaBalpha phosphorylation was also reduced by CORM-2 treatment.


CONCLUSIONS
These data have opened new mechanisms of action for CORM-2, raising the prospect that CO-releasing molecules are an interesting strategy for the development of new treatments in articular conditions.
Guillén
M I
MI
Department of Pharmacology, University of Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjasot, Valencia, Spain.
Megías
J
J
Clérigues
V
V
Gomar
F
F
Alcaraz
M J
MJ
D000368:Aged; D000369:Aged, 80 and over; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects* / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000378:metabolism; D015232:Dinoprostone / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D053590:Interleukin 1 Receptor Antagonist Protein / Q000096:biosynthesis; D053583:Interleukin-1beta / Q000502:physiology; D019746:Intramolecular Oxidoreductases / Q000378:metabolism; D008297:Male; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D009942:Organometallic Compounds / Q000494:pharmacology*; D010003:Osteoarthritis / Q000378:metabolism / Q000473:pathology*; D000071876:Prostaglandin-E Synthases; D017382:Reactive Oxygen Species / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D053590:Interleukin 1 Receptor Antagonist Protein; D053583:Interleukin-1beta; D016328:NF-kappa B; D009942:Organometallic Compounds; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; C447082:tricarbonyldichlororuthenium (II) dimer; D009569:Nitric Oxide; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D019746:Intramolecular Oxidoreductases; C000605862:PTGES protein, human; D000071876:Prostaglandin-E Synthases; D015232:Dinoprostone