Expression of heme oxygenase-1 and regulation by cytokines in human osteoarthritic chondrocytes

Heme oxygenase-1 (HO-1) is implicated in the protection against tissue injury. We investigated the expression of this protein in cartilage sections and chondrocytes obtained from osteoarthritic patients. HO-I was immunodetected in preparations from cartilage and also in chondrocytes cultured in the absence of stimulation. We found that HO-I can be modulated by cytokines since the pro-inflammatory cytokines interleukin (IL)-1beta, IL-17 and tumour necrosis factor-alpha (TNF-alpha) down-regulated this protein, whereas the anti-inflammatory cytokine IL-10 exerted the opposite effect. Our results suggest a role for HO-1 as part of protective mechanisms against tissue injury in human cartilage. (C) 2003 Elsevier Inc. All rights reserved.