RESEARCH - Overexpression of OPN in rheumatoid synovial mononuclear cells is associated with joint inflammation, not with genetic polymorphism

[Guest guest]

J Rheumatol. 2005 Mar;32(3):410-6.

Overexpression of osteopontin in rheumatoid synovial mononuclear cells is

associated with joint inflammation, not with genetic polymorphism.

Xu G, Sun W, He D, Wang L, Zheng W, Nie H, Ni L, Zhang D, Li N, Zhang J.

Health Science Center, Shanghai Institutes for Biological Sciences,

Shanghai, China.

OBJECTIVE: Osteopontin (OPN) is thought to play an important role in

rheumatoid synovitis. We investigated the expression of OPN in rheumatoid

synovial fluid mononuclear cells (SFMC) and its potential association with

genetic polymorphism of the OPN gene and joint inflammation in rheumatoid

arthritis (RA). METHODS: 1. The expression of OPN mRNA in peripheral blood

mononuclear cells (PBMC) and SFMC of patients with RA was analyzed

quantitatively by real-time polymerase chain reaction (PCR). Results were

analyzed in paired PBMC and SFMC and control PBMC. 2. Six single nuclear

acid polymorphisms of the OPN gene were genotyped in a cohort of 192 Chinese

patients with RA and controls (n = 288) by restriction fragment length

polymorphism PCR or direct DNA sequencing. 3. SF derived from RA patients

was examined for the stimulating effect on mRNA expression of the OPN gene

in PBMC. RESULTS: The expression of OPN gene was significantly increased in

SFMC and, to a lesser degree, in PBMC of patients with RA compared to

control PBMC (p < 0.01). However, the prevalence of OPN genotype and allele

frequencies at the selected positions did not differ significantly between

RA patients and the control group (p > 0.05). Further characterization

indicated that SF known to contain a variety of proinflammatory factors

significantly stimulated mRNA expression of OPN in PBMC obtained from RA

patients or healthy controls.

CONCLUSION: Overexpression of OPN mRNA in SFMC is associated with

proinflammatory factors produced in inflamed joints, but not with OPN

genetic polymorphisms. OPN gene polymorphisms do not correlate with

susceptibility to RA.

PMID: 15742430

Not an MD

I'll tell you where to go!

Mayo Clinic in Rochester

http://www.mayoclinic.org/rochester

s Hopkins Medicine

http://www.hopkinsmedicine.org