Objective:To investigate the serum level of C-C chemokine ligand 19 (CCL19)and its clinical significance in rheumatoid arthritis.Methods:The serum CCL19 levels in both rheumatoid ar-thritis (RA)patients and health controls were detected by ELISA.The proportion of peripheral blood B cells and memory B cell subsets were also detected in some patients.Then the clinical and laboratory data of the patients were collected.The CCL19 levels in patients with different clinical features were analyzed. And the correlation between the clinical data,laboratory parameters,B cell subsets proportion and serum CCL19 levels were also analyzed.Independent samples t test,paired t test,Pearson and Spearman corre-lation were used for statistical analysis.Results:The levels of CCL19 was higher in the RA patients than the health controls (P <0.05).The serum CCL19 levels were decreased in the RA patients who accep-ted disease-modifying anti-rheumatic drugs (DMARDs)treatment for 6 months (P <0.001 ).Serum CCL19 levels were correlated with the titers of both rheumatoid factor (RF)and anti-cyclic citrullinated peptide (CCP)antibody (r =0.42,P =0.002;r =0.33,P =0.013),but not with erythrocyte sedi-mentation rate (ESR),C-reactive protein (CRP)and disease activity score in 28 joints (DAS28)(P >0.05).The levels of CCL19 were higher in the serum positive (RF and anti-CCP antibody)patients,but there were no differences between low and high disease activity RA,as well as early and non-early RA. There was no correlation between the serum CCL19 levels and the proportion of B cells as well as memory B subsets.All the proportion of peripheral blood CD27 + memory B cell subsets in RA was lower than the healthy controls,including CD27 +IgD +,CD27 +IgD - and CD27 + B cells.Conclusion:The increased serum CCL19 levels in RA patients are associated with the activity of B cells,so CCL19 might predict whether the RA type is a B cell mediated RA,and specify the treatment directions for the rheumatologist.

BACKGROUND:Numerous studies have shown that mechanical stimulation is essential for the lineage-specific differentiation of bone marrow mesenchymal stem cells.However,osteogenic differentiation of bone marrow mesenchymal stem cells on surfaces with different roughnesses under mechanical stretching conditions is unknown. OBJECTIVE:To investigate the effects and action mechanisms of different roughness surfaces of polydimethylsiloxane(PDMS)on osteogenic differentiation of bone marrow mesenchymal stem cells under stretching conditions. METHODS:Three morphologies with different roughnesses(PDMS-120M,PDMS-1000M,and PDMS-10000M)were constructed on PDMS surfaces by means of different grits of sandpaper(120 grits,1 000 grits and 10 000 grits),and PDMS surfaces in contact with air served as a control group.With different amplitudes of 0%,2%,4%,and 6%,osteogenesis-related gene expression of bone marrow mesenchymal stem cells on different PDMS surfaces under static and stretching conditions was detected by RT-qPCR.RT-qPCR and western blot assay were used to detect the expression of SIRT1 gene and protein as well as osteogenesis-related genes and proteins in bone marrow mesenchymal stem cells on different roughness surfaces under 2%stretching conditions.Alkaline phosphatase staining and alizarin red staining were further used to observe the osteogenic differentiation ability of bone marrow mesenchymal stem cells on different PDMS surfaces under 2%stretching conditions. RESULTS AND CONCLUSION:(1)Bone marrow mesenchymal stem cells on the PDMS-1000M surface with a roughness of(13.51±2.11)μm had better osteogenic gene expression under static conditions.(2)Bone marrow mesenchymal stem cells on the PDMS surface in contact with air had better osteogenic differentiation under 4%stretching conditions,while bone marrow mesenchymal stem cells on the PDMS-1000M surface had better osteogenic differentiation under 2%stretching conditions.(3)Bone marrow mesenchymal stem cells on the PDMS-1000M surface with a roughness of(13.51±2.11)μm had better osteogenic differentiation under 2%stretching conditions,which may be related to activation of SIRT1 signaling pathway.