Heat shock protein 70 membrane expression on fibroblast-like synovial cells derived from synovial tissue of patients with rheumatoid and juvenile idiopathic arthritis

OBJECTIVE: To screen fibroblast-like synovial cells derived from synovial tissue of rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA) patients for the membrane expression of the heat shock protein Hsp70. METHODS: We performed flow cytometric (fluorescence-activated cell sorting, or FACS) analysis on fibroblast-like synovial cells of 15 RA patients and three JIA patients to investigate Hsp70 membrane expression. Skin fibroblasts derived from the operation wound (n = 4) and peripheral blood mononuclear cells (PBMC) of seven RA and three JIA patients were also tested. Peripheral blood lymphocytes (PBL) and skin fibroblasts of 10 healthy individuals were used as negative controls. RESULTS: A significantly higher percentage of Hsp70 membrane expression was found on fibroblast-like synovial cells derived from arthritis-affected joints in RA patients (mean 47.7%) when compared with autologous skin fibroblasts (mean 9.5%, p < 0.001) and control skin fibroblasts (mean 5.6%, p < 0.001) or autologous PBL (mean CD45/Hsp70-positive 10.4%, p < 0.001) and control PBL (mean CD45/Hsp70-positive 7.7%, p < 0.001). A high percentage of Hsp70 membrane expression was also observed on fibroblast-like synovial cells derived from three patients with JIA (mean 35.2%) when compared with autologous PBL (mean CD45/Hsp70-positive 10.4%). Synovial cells derived from non-affected joints in a patient with RA who underwent synovectomy for trauma showed low expression of Hsp70 (10.9%). CONCLUSION: Fibroblast-like synovial cells derived from patients with severe course of RA and JIA are strongly positive for membrane-expressed Hsp70.     

Receptor expression in synovial fluid neutrophils from patients with rheumatoid arthritis.

OBJECTIVES--The aim of this study was to determine if neutrophils isolated from the blood and synovial fluid of patients with rheumatoid arthritis had patterns of receptor expression resembling those of blood neutrophils from controls which had been activated and primed in vitro. METHODS--Fluorescence activated cell sorting was used to measure receptor expression in paired blood and synovial fluid neutrophils from patients and in control neutrophils exposed to phorbol myristate acetate and granulocyte-macrophage colony stimulating factor. RESULTS--There was no significant difference in the patterns of receptor expression in blood neutrophils from patients and healthy controls, but neutrophils in the synovial fluid had been primed and activated within the joint. About 50% of rheumatoid synovial fluid neutrophil samples expressed Fc gamma RI, a high affinity receptor for monomeric IgG, which is only expressed in neutrophils exposed to cytokines. CONCLUSIONS--Synovial fluid neutrophils are activated and primed within the inflamed joint and hence their ability to respond to activating factors such as immune complexes will be modulated. As the expression of Fc gamma RI requires active biosynthesis, this work indicates that selective gene activation occurs when neutrophils are recruited into rheumatoid joints.     

分泌卷曲相关蛋白4结构特征及其对脂质代谢的作用

分泌卷曲相关蛋白4(SFRP4)是Wnt信号通路的抑制因子,在人类个体发育过程中发挥重要作用。同时,SFRP4基因表达和蛋白分泌异常导致机体发生病理变化。本文介绍了SFRP4基因和蛋白的结构特征、组织分布以及胚胎发育过程中的表达变化。临床研究发现,糖尿病患者血清中SFRP4蛋白水平显著升高,其与胰岛素分泌呈负相关。作为Wnt信号通路的抑制因子,SFRP4在调控脂肪形成、糖代谢以及胰岛素抵抗等生理和病理生理过程中扮演着重要角色。近年来,SFRP4在肥胖、脂质代谢紊乱以及糖尿病发生中的病理作用引起了广泛关注,并取得了重要进展。对其进一步系统深入的研究,不仅可以揭示肥胖、脂质代谢紊乱和糖尿病发生的新机制,也有望发现临床药物治疗新靶点。     

Synovial vascular patterns and angiogenic factors expression in synovial tissue and serum of patients with rheumatoid arthritis

OBJECTIVE: To determine whether subgroups of rheumatoid arthritis (RA) patients classified according to their synovial vascular pattern have a different expression of angiogenic mediators or exhibit distinct clinical or biological characteristics. METHODS: Arthroscopies were performed in 27 patients with RA and synovial samples were obtained. Vascular morphology was classified in three patterns: straight (S), tortuous (T) and mixed (M). Immunostaining was performed with anti-vascular endothelial growth factor (anti-VEGF), anti-vascular endothelial growth factor receptor (VEGFR)-1, anti-VEGFR-2, anti-IL-8 and anti-TGF-beta, and measured by digital image analysis. Serum levels of VEGF, TGF-beta and IL-8, and clinical, radiographic and serological data were also analysed. RESULTS: Eleven (41%) patients had the S pattern, nine (33%) the M pattern and seven (26%) the T pattern. The S and M groups had a higher prevalence of rheumatoid factor positivity and erosive disease, and higher levels of markers of systemic inflammation compared with the T group. Synovial expression of VEGF was higher in the S and T groups compared with the M group, whereas TGF-beta was higher in the T compared with the S and M groups. Distinct synovial distribution of VEGF and TGF-beta between groups was also observed. CONCLUSIONS: This preliminary study suggests that RA patients with the S and M patterns share different clinical, biological and serological characteristics compared with those with the T pattern, which may constitute a group with less severe disease. Differences in the intensity and distribution of synovial expression of VEGF and TGF-beta observed between groups could have pathophysiological relevance. However, larger, prospective multicentre studies would be need to determine the clinical relevance of vascular patterns in RA.     

类风湿关节炎患者滑膜树突状细胞的研究

目的　探讨滑膜树突状细胞在类风湿关节炎 (RA)中的作用。方法　采用免疫组织化学方法观察 2 5例RA滑膜中HLA DR抗原阳性表达细胞、S 10 0阳性CD1a阳性的树突状细胞(DC)的多少和分布情况。结果　 2 3例RA滑膜细胞HLA DR表达阳性 ,19例S 10 0表达阳性 ,16例CD1a表达阳性 ,其阳性例数的百分率均高于对照组。RA滑膜中HLA DR、S 10 0和CD1a标记阳性细胞数均明显高于对照组 ,其差异有非常显著意义 (P <0 0 1)。结论　RA滑膜中DC和被激活的DC及HLA DR阳性细胞的存在和增多可能在RA病变局部递呈自身抗原的过程中起重要的作用 ,是RA自身免疫异常的重要的始发因素     

High in vivo expression of interleukin-17 receptor in synovial endothelial cells and chondrocytes from arthritis patients

OBJECTIVE: To evaluate the presence of interleukin-17 (IL-17) and the expression of IL-17 receptor (IL-17R) in joint tissues from subjects with different arthritides. METHODS: Immunohistochemistry was used on frozen synovial and cartilage biopsies to identify cells expressing IL-17 and IL-17R. RESULTS: IL-17 staining was present only in synovial biopsies of rheumatoid arthritis (RA) (seven out of nine cases). IL-17R was expressed by all synovial biopsies evaluated except for three cases of post-traumatic arthritis (PTA). Vascular endothelial cells mainly expressed IL-17R. The percentage of IL-17R(+) vessels was the highest in RA synovium and the lowest in PTA. Chondrocytes from all types of arthritides were negative for IL-17 staining, but expressed IL-17R; the highest percentage of positive chondrocytes was found in seronegative spondylarthritis and the lowest in RA. CONCLUSIONS: IL-17-positive cells are found exclusively in RA. On the other hand, synovial endothelial cells and chondrocytes expressing IL-17R are found in the majority of patients with different types of arthritis. This finding suggests a role for a second ligand for IL-17R, which could be either a different cytokine or a different isoform of IL-17.     

Differential metabolism of 25-hydroxyvitamin D3 by cultured synovial fluid macrophages and fibroblast-like cells from patients with arthritis.

Differential metabolism of 25-hydroxyvitamin D3 (25(OH)D3) has been shown for macrophages and fibroblast-like cells (possibly synoviocytes) cultured for two to 50 days after isolation from the synovial fluid of 12 patients with various forms of inflammatory arthritis. Macrophages synthesised the active metabolite of vitamin D3, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), the synthesis of which was increased by bacterial lipopolysaccharide, a known macrophage activating factor. In contrast, fibroblast-like cells formed 24, 25-dihydroxyvitamin D3 (24,25(OH)2D3), synthesis of which was stimulated by 1,25(OH)2D3 and inhibited by lipopolysaccharide. The synthesis of 1,25(OH)2D3 and 24,25(OH)2D3 by macrophages and fibroblast-like cells respectively was inhibited by ketoconazole, indicating that both hydroxylases are dependent on cytochrome P-450. Mean (SEM) synovial fluid and serum 25(OH)D3 concentrations were 16.7 (1.7) and 22.2 (2.6) ng/ml and those of 1,25(OH)2D3 were 29.4 (4.8) and 43.3 (4.0) pg/ml respectively. In most cases concentrations were lower in synovial fluid than in paired serum samples, but in two patients 1,25(OH)2D3 concentrations were greater in synovial fluid than in serum, suggesting local synthesis within the affected joints.     

Trisomy 7 in synovial fluid cells of patients with rheumatoid arthritis

Objective Recent studies revealed trisomy 7 as a chromosomal abnormality in non-neoplastic disorders such as rheumatoid arthritis (RA). In the present study, we investigated the presence of trisomy 7 in the synovial fluid cells of patients with RA using fluorescence in situ hybridisation (FISH) analysis.Methods Synovial fluid from 15 patients with RA was collected from knee joints. The control group consisted of seven patients with traumatic synovial effusion in their knee joints. The arthrocenteses were performed under aseptic conditions. Dual-colour FISH analysis was performed using chromosome-7-specific LSI D7S522 (7q31) and chromosome-5-specific LSI EGR1 (5q31)/D5S721 (5p15.2) probes on the slides prepared from synovial fluid of RA patients and controls.Results The slides of our cases were analysed using two different DNA probes. When the slides hybridised with chromosome-5-specific probes were analysed, no trisomic or monosomic cells were revealed in both patients and controls. However, in eight of 15 patients, trisomy 7 occurred in variable percentages of cells (23% to 48%) of synovial fluid. No monosomic 7 cells were detected in these specimens. All control cases were disomic for chromosome 7.Conclusion The results of the present investigation suggest that trisomy 7 may play a role in the pathogenesis of synovial hyperproliferation in RA.     

Aberrant responsiveness to RANTES in synovial fluid T cells from patients with rheumatoid arthritis

OBJECTIVE: To study expression and function of the chemokine receptor CCR5 in synovial fluid (SF) T cells from patients with rheumatoid arthritis (RA). METHODS: Expression of CCR5 was studied by flow cytometry and immunoblotting. The chemotactic response of T cells to chemokines was studied in cell migration assay. Tyrosine phosphorylation of Crk-associated substrate lymphocyte-type (CasL) was evaluated in immunoprecipitation and immunoblotting. RESULTS: SF T cells showed an increase in the population of CCR5, CXCR4, and CD45RO positive cells and exhibited an increase in chemotactic activity, which was not augmented with RANTES but stromal cell-derived factor-1alpha. Tyrosine phosphorylation per CasL molecule was markedly enhanced in SF T cells. In H9 cells, tyrosine phosphorylation of not only focal adhesion kinase but also CasL was induced after treatment with RANTES. Downmodulation of CCR5 by RANTES was decreased and recycling of CCR5 was accelerated in SF T cells when compared with peripheral blood (PB) T cells. When CD45RO positive PB T cells were cultured with interleukin 2, blunted responsiveness to RANTES-induced chemotaxis was reproduced as well as spontaneous chemotaxis, increased expression of CCR5, and aberrant receptor dynamics, after RANTES stimulation as observed in SF T cells. CONCLUSION: Synovial fluid T cells highly positive for CCR5 show aberrant characteristics; resistant to RANTES in terms of migration, but responsive in terms of dynamics of CCR5.