angiogenin and Arthritis--Rheumatoid

Rheumatoid arthritis (RA) is the most common inflammatory arthritis and is a major cause of disability. The nuclear factor-kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway has been reported to be involved in the pathogenesis of RA with unclear mechanisms. Therefore, this study aims to explore the effect of NF-κB pathway on proliferation, apoptosis, and angiogenesis of human fibroblast-like synovial cells (HFLS) in RA.. Normal HFLS and RA-HFLS were selected as the normal and control groups, respectively. RA-HFLS were treated by BAY11-7082 (an inhibitor of NF-κB) in different concentrations, namely 2.5 μmol/L BAY11-7082, 5 μmol/LBAY11-7082 and 10 μmol/L BAY11-7082. MTT assay was employed to detect cell proliferation. Cell apoptosis was determined by flow cytometry at 24, 48, and 72 hours after culture. Western blot analysis was employed to detect the expressions of NF-κB, angiogenesis-related factors (VEGF, Ang1, and Ang2).. Initially, we found that BAY11-7082 inhibited NF-κB expression in a concentration-dependent manner. According to the findings of MTT assay and flow cytometry, we understood that RA-HFLS treated by BAY11-7082 (an inhibitor of NF-κB), the inhibition of NF-κB pathway, suppressed RA-HFLS proliferation and induced RA-HFLS apoptosis in a concentration and time-dependent manner. Furthermore, RA-HFLS treated by BAY11-7082 presented decreased VEGF, Ang1 and Ang2 expressions in a concentration-dependent manner.. The study concluded that inhibition of NF-κB pathway induced cell apoptosis and suppressed proliferation and angiogenesis of RA-HFLS, which could serve as a novel target in the treatment of RA.

Topics: Apoptosis; Arthritis, Rheumatoid; Cell Proliferation; Cells, Cultured; Humans; Myofibroblasts; Neovascularization, Pathologic; NF-kappa B; Nitriles; Ribonuclease, Pancreatic; Signal Transduction; Sulfones; Synoviocytes; Vascular Endothelial Growth Factor A; Vesicular Transport Proteins

To evaluate an association between synovial Doppler flow and serum levels of vascular endothelial growth factor (VEGF), angiogenin and TIMP-2 in patients with rheumatoid arthritis during anti-inflammatory treatment with glucocorticoids and TNF-α inhibitors.. Inflamed wrists of 15 patients with rheumatoid arthritis (RA) were examined by two independent ultrasound investigators prior to and at days 3, 7, 14 and 42 after the initiation of treatment with glucocorticoids in therapy-naïve patients or after the beginning of a therapy with a TNF-α inhibitor in patients with DMARD failure. Quantitative three-dimensional power Doppler ultrasonographic assessment of synovial vascularization was compared at each visit with serum levels of VEGF, angiogenin and TIMP-2.. In the glucocorticoid group, synovial Doppler signals decreased significantly at day 3 (-44%; P=0.003) in comparison to a delayed decrease in the TNF-α inhibitor group after 6 weeks (-46%; P=0.001). A significant reduction of serum VEGF levels could be determined with a delay of 1 week after the decrease of Doppler activity but no correlation was found between both parameters (rho: P=0.7; r=-0.03). Angiogenin concentrations decreased in the TNF group and increased in the GC group. Levels of TIMP-2 did not change significantly in both groups.. The decrease of serum VEGF levels under treatment with glucocorticoids or TNF-α inhibitors followed the reduction of the intra-articular synovial Doppler flow. This result supports the idea that the reduction of synovial perfusion due to anti-inflammatory treatment is not regulated by systemic VEGF, but that the inflamed joints are the source for circulating VEGF.

Topics: Aged; Anti-Inflammatory Agents; Arthritis, Rheumatoid; Drug Monitoring; Female; Glucocorticoids; Humans; Male; Middle Aged; Ribonuclease, Pancreatic; Synovial Membrane; Tissue Inhibitor of Metalloproteinase-2; Tumor Necrosis Factor-alpha; Ultrasonography, Doppler; Vascular Endothelial Growth Factor A; Wrist Joint

Angiogenesis is a key process in the pathogenesis of inflammatory arthritis. Angiogenin is one of the most potent inducers of neovascularization in experimental models in vivo. To look for evidence that angiogenin is involved in inflammatory joint disease, we examined plasma and synovial fluid (SF) samples from rheumatology patients and synovial fibroblast cell culture supernatants. Angiogenin levels were determined by radioimmunoassay and ELISA. Plasma angiogenin concentrations ranged from 96 to 478 ng/ml, with no significant difference between patients and normal controls. In SF, angiogenin concentrations were significantly higher in patients with acute or chronic synovitis (rheumatoid arthritis (RA): median, 104 ng/ml; range 13-748, n = 14; crystal-induced arthritis (CIA): median, 149 ng/ml; range, 37-616, n = 14, and other chronic inflammatory arthritis: median, 42 ng/ml; range, 15-205; n = 9) than in the 18 patients with osteoarthritis (OA) (median, 20 ng/ml; range 8-116) (P < 0.0001, anova). Angiogenin levels in SF from RA patients in remission with secondary OA were similar to those achieved in primary OA, and decreased in parallel with the resolution of acute gout. Angiogenin protein was released by cultured synovial fibroblasts from OA and RA patients, and reached 1.18 ng/106 cells/day. These data suggest that angiogenin may mediate local inflammation in arthritis via effects on angiogenesis and leucocyte regulation.

Topics: Analysis of Variance; Arthritis; Arthritis, Infectious; Arthritis, Psoriatic; Arthritis, Rheumatoid; Case-Control Studies; Cells, Cultured; Culture Media, Conditioned; Fibroblasts; Humans; Leukocytes, Mononuclear; Osteoarthritis; Ribonuclease, Pancreatic; Statistics, Nonparametric; Synovial Fluid

Angiogenesis is an integral component of the vasculoproliferative phase of rheumatoid arthritis (RA). We examined the distribution of two angiogenic factors, basic fibroblast growth factor (bFGF) and angiogenin (ANG) in arthritic diseases. We used an enzyme-linked immunosorbent assay and immunohistochemical analysis to determine the levels of bFGF and ANG in synovial fluid (SF) and their distribution in synovial tissue (ST), respectively. Most SF contained little or no detectable bFGF ( < 5 pg/ml). ANG in RA SF was 248.7 +/- 17.4 ng/ml, which did not differ significantly from levels found in osteoarthritis (OA; 305.9 +/- 23.1 ng/ml). Synovial lining cells, macrophages, endothelial cells, and vascular smooth muscle cells were immunopositive for bFGF and ANG; however, their expression was not up-regulated in RA ST compared to ST from OA and normal subjects. Though bFGF and ANG are present in the joints of patients with arthritic diseases, they are not up-regulated in RA. These results suggest that not all angiogenic mediators are up-regulated in RA compared to normal subjects and subjects with other arthritic diseases. It may be that some of these mediators, like ANG, play a role in the physiology of normal synovium.

Topics: Angiogenesis Inducing Agents; Arthritis; Arthritis, Rheumatoid; Cells, Cultured; Enzyme-Linked Immunosorbent Assay; Fibroblast Growth Factor 2; Fibroblasts; Humans; Immunohistochemistry; Osteoarthritis; Protein Biosynthesis; Proteins; Ribonuclease, Pancreatic; Synovial Fluid; Synovial Membrane; Up-Regulation