Expression of SDF-1/CXCR4 axis in bone marrow mesenchymal stem cells derived from rheumatoid arthritis-usual interstitial pneumonia.

OBJECTIVES: To explore the SDF-1/ CXCR4 axis as driving mechanism of bone marrow mesenchymal stem-cells to the injured lung in patients with rheumatoid arthritis associated usual interstitial pneumonia (RA-UIP). METHODS: We evaluated the m-RNA expression of SDF-1 and CXCR4 with real-time PCR in bone marrow mesenchymal stem cells of 7 RA-UIP and 10 RA patients without lung involvement. RESULTS: The axis was not expressed in RA whereas both SDF-1 and CXCR4 were expressed in RA-UIP [1.93 (1.32, 2.00) and 0.008 (0, 0.01)] respectively. CONCLUSIONS: The development of pulmonary fibrosis in RA may be considered as the key event for the migration of stem cells to the injured lung through the SDF-1/CXCR4 axis.