Isolation and expression profiling of genes upregulated in bone marrow-derived mononuclear cells of rheumatoid arthritis patients

Abstract

We have comprehensively identified the genes whose expressions are augmented in bone marrow-derived mononuclear cells (BMMC) from patients with Rheumatoid Arthritis (RA) as compared with BMMCs from Osteoarthritis (OA) patients, and named them AURA after augmented in RA. Both stepwise subtractive hybridization and microarray analyses were used to identify AURA genes, which were confirmed by northern blot analysis and/or reverse transcription polymerase chain reaction (RT–PCR). We also assessed their expression levels in individual patients by quantitative real-time RT–PCR. Of 103 AURA genes we have identified, the mRNA levels of the following 10 genes, which are somehow related to immune responses, were increased in many of the RA patients: AREG (AURA9), FK506-binding protein 5 (FKBP5 AURA45), C-type lectin superfamily member 9 (CLECSF9 AURA24), tyrosylprotein sulfotransferase 1 (TPST1 AURA52), lymphocyte G0/G1 switch gene (G0S2 AURA8), chemokine receptor 4 (CXCR4 AURA86), nuclear factor-kappa B (NF-kB AURA25) and two genes of unknown function (FLJ11106 AURA1, BC022398 AURA2 and XM 058513 AURA17). Since AREG was most significantly increased in many of the RA patients, we subjected it to further analysis and found that AREG-epidermal growth factor receptor signaling is highly activated in synovial cells isolated from R