The Defective Expression Of Cell Proliferation Signaling Molecules In Peripheral Blood CD34 + Hematopoietic Stem/progenitor Cells From Rheumatoid Arthritis Patients

Objective:To measure the number of peripheral blood CD34⁺hematopoietic stem/progenitor cell (HSC/HPC) in patients with rheumatoid arthritis(RA).To observe whether the expression of Wnt5a,Beta-catenin,NFkB1,NFkB2 and P15^INK4b genes are impaired in hematopoietic stem/progenitor cel(lHSC/HPC)derived from RA.Methods: The percentage of peripheral blood CD34⁺HSC/HPC from 34 RA and l6 normal controls were measured with flow cytometry assay.The clinical date of 24 RA patients and 9 healthy control were collected,Peripheral blood mononuclear cells (PBMCs) derived from 50ml of whole blood were separated by gradient centrifugation and CD34⁺ cells were purified using an MACS magnetic separation device. Total RNA of CD34⁺ cells was extracted and transcripted into cDNA. SYBR Green I dye based real-time quantitative PCR method was used to compare the expression of Wnt5a,β-catenin,NFkB1,NFkB2,P15^INK4b in patients and those in the control,then the correlation with DAS28, erythrocyte sedimentation rate(ESR), C reactive protein(CRP),was analyzed.Results:1) The percentage of CD34⁺ HSC/HPC in RA patients (0.13±0.09)% was lower than that in normal controls[(0.38±0.21)%,P=0.00].2) The levels of Wnt5a andβ-catenin mRNA were [144.86(0.14—252.06)] and (8.87±4.81) respectively in normal controls.In RA patients, Wnt5a mRNA expression was [1.15(0.09—71.52)], lower than that in normal control (P=0.004).β-catenin mRNA expression was (4.96±4.52),lower than that in normal control(P=0.037).3) The expression level of NFkB1 was [2.14(0.68—7.09)] respectively in normal controls. In RA patients, NFkB1 mRNA expression was [6.57(1.08—76.71)], higher than that in normal controls (P=0.013).NFkB2,P15^INK4b mRNA expression were no significant difference between normal controls and RA patients.4) The expression of Wnt5a,β-catenin,NFkB1,NFkB2 and P15^INK4b mRNA with and without methotrexate (MTX) treatment was no significant difference in CD34 ⁺ HSC /HPC RA patients ,and were not correlated with such as DAS28, erythrocyte sedimentation rate(ESR), C reactive protein(CRP),etc.Conclusion :1) The number of CD34⁺ HSC/HPC is reduced ,the proliferative ability of HSC /HPC was impaired in RA patients.2) The expression of Wnt5a andβ-catenin genes in HSC /HPC of RA patients were lower than that from normal controls. Wnt signaling pathways was regulated in HSC /HPC of RA patients may lead to the proliferative ability of HSC /HPC impaired.3) The expression of NFkB1gene in HSC /HPC of RA patients were higher than that from normal controls. The high expression of NFkB1gene may be an important defect in CD34 ⁺ HSC /HPC RA patients.