To characterize the expression of programmed cell death 5 (PDCD5) in normal and osteoarthritic human cartilage.
Articular cartilage specimens were obtained from 20 patients with osteoarthritis and 10 with femoral neck (normal cartilage) at the time of arthroplasty. Expression of PDCD5 was detected by flow cytometry, immunofluorescence, RT-PCR and immunohistochemical analysis.
PDCD5 expression in osteoarthritis cartilage was significantly higher than in normal cartilage especially in the nucleus. PDCD5-positive chondrocytes were mainly observed in the superficial and deep zone of osteoarthritis tissue sections, and in contrast, in the superficial and middle regions of normal controls.
Since apoptotic chondrocyte death occurs more frequently in osteoarthritis compared to normal cartilage and PDCD5 is an apoptosis related protein, the different expression patterns of PDCD5 in osteoarthritis and normal cartilage suggest that it might be involved in the pathogenesis of osteoarthritis.