Secretion of oncostatin M by neutrophils in RA

May 26, 2004

Arthritis Rheum. 2004 May;50(5):1430-6.

Secretion of oncostatin M by neutrophils in rheumatoid arthritis.

Cross A, SW, Bucknall RC, Moots RJ.

Academic Rheumatology Unit, University of Liverpool, University Hospital

Aintree, Longmoor Lane, Liverpool L9 7AL, UK.

OBJECTIVE: Neutrophils are known to express and release a large number

of proinflammatory cytokines when they are stimulated by inflammatory

stimuli. The objective of this study was to determine whether

neutrophils express oncostatin M (OSM), a member of the interleukin-6

family of cytokines that has been implicated in the pathogenesis of

inflammatory joint disease. METHODS: Neutrophils were isolated from the

blood of healthy volunteer donors and from the blood and synovial fluid

of patients with rheumatoid arthritis (RA). OSM levels were measured in

cell extracts and in culture supernatants by Western blotting. Total RNA

was isolated from control and granulocyte-macrophage colony-stimulating

factor (GM-CSF)-treated neutrophils, and OSM messenger RNA levels were

quantified by hybridization of a radiolabeled probe. RESULTS: GM-CSF

stimulated a rapid and transient expression and release of OSM from

blood neutrophils, which was more rapid than the expression and release

from blood monocytes. A 28-kd protein was identified in cell extracts,

but an additional 25-kd isoform was detected in culture supernatants.

Synovial fluid neutrophils could not be stimulated to express OSM, but

this cytokine was detected in cell-free supernatants at various levels.

CONCLUSION: Blood neutrophils can be stimulated to express and rapidly

release large quantities of OSM. We propose that this important cytokine

is released from neutrophils as they infiltrate rheumatoid joints and,

thus, contribute to the complex cytokine network that characterizes RA.

PMID: 15146412

I'll tell you where to go!

Mayo Clinic in Rochester

s Hopkins Medicine

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