| Popis: |
Rheumatoid arthritis (RA) is marked by persistent inflammation and joint destruction involving infiltration of osteoclasts. Human osteoclast progenitors (OCPs) are contained among peripheral blood monocytes at low frequency, exhibit chemotaxis and, furthermore, synovial compartment of RA patients highly expresses different chemokines. The aim was to define these chemotactic signals. Mononuclear cells were isolated from peripheral blood of control and RA patients. The phenotype of OCPs (CD3-CD19-CD56-CD11b CD14 ) was determined using flow cytometry for receptors CCR1, CCR2, CCR4, CXCR4, C5AR1. Chemokine ligand concentrations (CCL2, CCL3, CCL4, CCL5, CXCL9, CXCL10) were measured in serum and synovial fluid of RA patients using cytometric bead assay. OCPs were sorted and cultured with M-CSF and RANKL. After two weeks, the cells were stained for TRAP enzyme and mature osteoclasts were counted. Human peripheral blood OCPs similarly expressed chemokine receptors in RA and healthy subjects. However, CCL4 and CXCL10 concentrations were significantly higher in synovial fluid compared to serum levels in RA, while CCL2, CXCL9 and CXCL10 serum levels were higher in RA patients compared to the control group. Cell culture revealed no significant differences in mature osteoclast count between groups. Although OCPs in RA have a differentiation potential similar to controls, levels of several chemokines are upregulated, indicating a possible chemotactic mechanism of OCP migration to affected joints. These results may help to reveal a migration mechanism of OCPs specifically associated with RA in order to develop more efficient therapeutic approaches. |
