血管活性肠肽抑制实验性类风湿性关节炎的研究

类风湿性关节炎是一种自身抗原未明的慢性自身免疫病,以多关节的慢性炎症及渐进性骨和软骨的破坏为主要特征。胶原诱导的关节炎因其临床表现、病理组织学改变以及免疫学表现等方面与类风湿性关节炎的相似性而成为理想的动物模型。在成功建立了胶原诱导的大鼠关节炎模型(CIA)的基础上采用了血管活性肠肽(VIP)注射,研究其干预关节炎发生的效果。结果显示:使用血管活性肠肽组的大鼠CIA发病率和严重程度明显降低,关节肿胀以及骨和软骨的破坏减轻,大鼠血清中抗胶原抗体水平显著降低,大鼠T淋巴细胞对胶原的增殖反应也显著降低。提示VIP可能通过减轻对胶原的免疫应答而抑制关节炎症状,具有可能的临床应用价值。     

Artocarpus: A review of its traditional uses,phytochemistry and pharmacology

The genus Artocarpus (Moraceae) comprises about 50 species of evergreen and deciduous trees. Economically, the genus is of appreciable importance as a source of edible fruit, yield fairly good timber and is widely used in folk medicines. The aim of the present review is to present comprehensive information of the chemical constituents, biological and pharmacological research on Artocarpus which will be presented and critically evaluated. The close connection between traditional and modern sources for ethnopharmacological uses of Artocarpus species, especially for treatment against inflammation, malarial fever, diarrhoea, diabetes and tapeworm infection. Artocarpus species are rich in phenolic compounds including flavonoids, stilbenoids, arylbenzofurons and Jacalin, a lectin. The extracts and metabolites of Artocarpus particularly those from leaves, bark, stem and fruit possess several useful bioactive compounds and recently additional data are available on exploitation of these compounds in the various biological activities including antibacterial, antitubercular, antiviral, antifungal, antiplatelet, antiarthritic, tyrosinase inhibitory and cytotoxicity. Several pharmacological studies of the natural products from Artocarpus have conclusively established their mode of action in treatment of various diseases and other health benefits. Jacalin, a lectin present in seeds of this plant has a wide range of activities. Strong interdisciplinary programmes that incorporate conventional and new technologies will be critical for the future development of Artocarpus as a promising source of medicinal products. In the present review, attempts on the important findings have been made on identification; synthesis and bioactivity of metabolites present in Artocarpus which have been highlighted along with the current trends in research on Artocarpus.     

A novel antagonist of the prostaglandin E2 EP4 receptor inhibits Th1 differentiation and Th17 expansion and is orally active in arthritis models

Background and purpose:

Rheumatoid arthritis (RA) is an autoimmune disorder involving subsets of activated T cells, in particular T helper (Th) 1 and Th17 cells, which infiltrate and damage tissues and induce inflammation. Prostaglandin E₂ (PGE₂) enhances the Th17 response, exacerbates collagen-induced arthritis (CIA) and promotes inflammatory pain. The current study investigated whether selective antagonism of the PGE₂ EP₄ receptor would suppress Th1/Th17 cell development and inflammatory arthritis in animal models of RA.

Experimental approach:

Effects of PGE₂ and a novel EP₄ receptor antagonist ER-819762 on Th1 differentiation, interleukin-23 (IL-23) production by dendritic cells (DCs), and Th17 development were assessed in vitro. The effect of ER-819762 was evaluated in CIA and glucose-6-phosphate isomerase (GPI)-induced arthritis models. In addition, the effects of ER-819762 on pain were evaluated in a model of chronic inflammatory pain induced by complete Freund''s adjuvant (CFA) in the rat.

Key results:

Stimulation of the EP₄ receptor enhanced Th1 differentiation via phosphatidylinositol 3 kinase signalling, selectively promoted Th17 cell expansion, and induced IL-23 secretion by activated DCs, effects suppressed by ER-819762 or anti-PGE₂ antibody. Oral administration of ER-19762 suppressed Th1 and Th17 cytokine production, suppressed disease in collagen- and GPI-induced arthritis in mice, and suppressed CFA-induced inflammatory pain in rats.

Conclusion and implications:

PGE₂ stimulates EP₄ receptors to promote Th1 differentiation and Th17 expansion and is critically involved in development of arthritis in two animal models. Selective suppression of EP₄ receptor signalling may have therapeutic value in RA both by modifying inflammatory arthritis and by relieving pain.     

丙酮酸乙酯对胶原诱导性关节炎大鼠的治疗作用

目的探讨丙酮酸乙酯（EP）在胶原诱导关节炎（CIA）大鼠模型中的治疗作用和安全性。方法利用牛Ⅱ型胶原建立Wistar大鼠CIA模型,随机分为CIA对照组和EP干预组,并设立正常对照组。每周观察各组大鼠的一般情况变化,并对双后足进行关节炎指数（AI）评分及测量后足容积;在实验第42、63天分别对各组大鼠的右后足进行放射学及病理学观察。结果 CIA对照组大鼠与正常对照组大鼠比较,有脱毛、精神萎靡,摄食及其他活动减少;EP干预组大鼠精神食欲尚可。体重变化,与正常对照组大鼠比较,CIA对照组大鼠从造模第28天开始,体重增加缓慢;EP干预组从造模第35天开始体重增加程度也有所下降,差异均有统计学意义（P〈0.05）;从造模第56天开始EP干预组体重增加明显,与正常组比较差异无统计学意义（P〉0.05）。关节炎症,EP干预组大鼠造模第28、42、63天AI值分别为3.83±0.71、3.42±0.79、1.50±0.54,明显低于同期CIA对照组AI值4.58±1.08、5.17±1.19、3.67±0.81,差异均有统计学意义（P〈0.05）。足肿胀度,EP干预组大鼠足肿胀度在造模第42、63天分别为（1.58±0.11）、（1.51±0.09）ml,低于CIA对照组足肿胀度（1.97±0.10）、（1.81±0.10）ml,差异均有统计学意义（P〈0.05）。影象学表现,CIA对照组X线示关节间隙消失,严重的可出现骨质破坏、融合;与CIA对照组相比,EP干预组仅可见部分关节有关节间隙模糊、骨质疏松,很少见关节破坏融合。病理学表现,CIA对照组滑膜肥厚,大量炎性细胞浸润,并有骨结构破坏;与CIA对照组相比,EP干预组滑膜细胞增生不明显,有少量炎性细胞浸润,关节软骨和骨组织破坏不明显。EP干预过程中未见明显不良反应。结论 EP能改善CIA大鼠关节炎症状、放射学及滑膜组织病理变化,起到抑制炎症的作用,且安全性好。     

Role of TLR ligands in epicutaneously induced contrasuppression

Our previous work showed that epicutaneous (EC) immunization in mice with protein antigen (Ag) induced an Ag-independent unresponsiveness mediated by suppressor CD4⁺8⁺ T cells (Ts), which inhibited contact hypersensitivity (CS). Simultaneous EC immunization with Ag and various Toll-like receptor (TLR) ligands reversed skin-induced suppression. Our present study shows that this process activates Ag-specific T contrasuppressor (Tcs) cells and leads to the protection of CS effector T cells from suppression. Epicutaneous immunization with Ag and the TLR4 ligand lipopolysaccharide (LPS) led to a significant increase in IFN-γ production by lymph node and spleen cells. Ag and TLR ligands, like LPS, CpG or lipoteichoic acid did not need to be applied concomitantly to the skin. An identical contrasuppressive effect was observed when the Ag and TLR ligands were deposited on distant skin areas, suggesting that both the generation of Ts and Tcs are independent. To corroborate this finding, we used a model system that uses macrophages (Mf) as Ag-presenting cells. Mf labeled in vitro with Ag (Mf-Ag) induced, upon intravenous (iv) administration, an unresponsiveness reaction that was mediated by Ts cells. When treated simultaneously with LPS-treated Mf (Mf-Ag-LPS), a TLRligand could induce CS. Both the Ag and the LPS signal could be uncoupled i.e., Mf-Ag and Mf-LPS given at separate time points (with an 1 h interval between injections) induced immunity.We also found that LPS-treated Mf also produced significant amounts of IL-12, a cytokine that has well-known anti-tolerogenic properties. Our experiments suggest that reversal of EC-induced suppression by TLR-ligands may be a potential tool to increase the immunogenicity of weakly immunogenic antigens.     

Genetic heterogeneity in rheumatoid arthritis mouse models induced by extrinsic and intrinsic factors

A cumulative effect of the susceptibility genes with polymorphic alleles may be responsible for rheumatoid arthritis (RA). The objective of this study was to clarify whether susceptibility to RA is under the control of common allelic loci between two different RA models induced by extrinsic and intrinsic factors, collagen‐induced arthritis (CIA) in DBA/1 mice and arthritis in MRL/Mp (MRL) mice associated with the Fas deficient mutant gene, Fas^lpr, respectively. CIA was examined in mice of parental DBA/1 and MRL, (MRL × DBA/1) F1 and (MRL × DBA/1) F2 progenies. In genome‐wide screening of the severity in the F2 using microsatellite markers, significant linkage was observed on chromosomes 5 and 17 at map position of D5Mit259 and H‐2, respectively, associated with DBA/1 alleles, while there was no loci associated with arthritis of MRL‐Fas^lpr mice previously identified. In a quantitative trait locus (QTL) analysis, the locus on chromosome 5 showed the highest peak at map position 35 cM (LOD score 6.0). This study may indicate that the arthritis induced by extrinsic and intrinsic factors is under the control of a different combination of susceptibility genes with common and different alleles, possibly simulating the genetic heterogeneity of RA.     

胶原诱导性关节炎大鼠滑膜组织中磷酸化p38与JNK通路及痹肿消汤的影响***★

背景：有研究报道滑膜细胞信号传导异常是类风湿关节炎发病的重要机制之一。 目的：观察胶原诱导性关节炎大鼠中丝裂原活化蛋白激酶通路中磷酸化p38和磷酸化JNK的活化及痹肿消汤的影响。 方法：将72只SD大鼠随机分为正常组、模型组、痹肿消汤组。模型组及痹肿消汤组大鼠足趾注射胶原蛋白乳剂制备胶原诱导性关节炎模型大鼠，10 d后加强免疫，初次免疫后第14天开始给痹肿消汤组大鼠每天痹肿消汤灌胃，模型组蒸馏水灌胃，正常组自由饮水。 结果与结论：Western blot 检测结果显示，胶原诱导性关节炎大鼠中磷酸化p38及JNK的表达较正常组显著增高(P < 0.05)。与模型组相比，痹肿消汤组能下调磷酸化p38及JNK蛋白的表达(P < 0.05)。说明痹肿消汤可抑制类风湿关节炎中磷酸化p38及JNK的高表达。     

Adoptive transfer of all-trans-retinal-induced regulatory T cells ameliorates experimental autoimmune arthritis in an interferon-gamma knockout model

Maintaining an appropriate balance between subsets of CD4⁺ helper T cells and T regulatory cells (Tregs) is a critical process in immune homeostasis and a protective mechanism against autoimmunity and inflammation. To identify the role of vitamin A-related compounds, we investigated the regulation of interleukin (IL)-17-producing helper T cells (Th17 cells) and Tregs treated with all-trans-retinal (retinal). CD4⁺T cells or total cells from the spleens of C57BL/6 mice were stimulated under Treg-polarizing (anti-CD3/CD28 and TGF-β) or Th17-polarizing (anti-CD3/CD28, TGF-β, and IL-6) conditions in the presence or absence of retinal. To analyze their suppressive abilities, retinal-induced Tregs or TGF-β-induced Tregs were co-cultured with responder T cells. Collagen-induced arthritis (CIA) was established in interferon (IFN)-γ knockout mice. On day 13, retinal-induced Tregs were adoptively transferred to mice with established CIA after second immunizations. Compared with TGF-β-induced Treg cells, retinal-induced Tregs showed increased Foxp3 expression and mediated stronger suppressive activity. Under Th17-polarizing conditions, retinal inhibited the production of IL-17 and increased the expression of Foxp3.Retinal-induced Tregs showed therapeutic effects in IFN-γ knockout CIA mice. Thus, we demonstrated that retinal reciprocally regulates Foxp3⁺ Tregs and Th17 cells. These findings suggest that retinal, a vitamin A metabolite, can regulate the balance between pro- and anti-inflammatory immunity. A better understanding of the manipulation of Foxp3 and Tregs may enable the application of this tremendous therapeutic potential in various autoimmune diseases.     

Methyl salicylate lactoside inhibits inflammatory response of fibroblast-like synoviocytes and joint destruction in collagen-induced arthritis in mice

BACKGROUND AND PURPOSE

Methyl salicylate 2-O-β-d-lactoside (MSL), whose chemical structure is similar to that of salicylic acid, is a natural product derivative isolated from a traditional Chinese herb. The aim of this study was to investigate the therapeutic effect of MSL in mice with collagen-induced arthritis (CIA) and explore its underlying mechanism.

EXPERIMENTAL APPROACH

The anti-arthritic effects of MSL were evaluated on human rheumatoid fibroblast-like synoviocytes (FLS) in vitro and CIA in mice in vivo by obtaining clinical scores, measuring hind paw thickness and inflammatory cytokine levels, radiographic evaluations and histopathological assessments.

KEY RESULTS

Treatment with MSL after the onset of arthritis significantly prevented the progression and development of rheumatoid arthritis (RA) in CIA mice without megascopic gastric mucosa damage. In addition, MSL inhibited the production of pro-inflammatory mediators, the phosphorylation and translocation of NF-κB, and cell proliferation induced by TNF-α in FLS. MSL non-selectively inhibited the activity of COX in vitro, but was a more potent inhibitor of COX-2 than COX-1. MSL also inhibited the phosphorylation of inhibitor of NF-κB kinase, IκBα and p65, thus blocking the nuclear translocation of NF-κB in TNF-α-stimulated FLS.

CONCLUSION AND IMPLICATIONS

MSL exerts therapeutic effects on CIA mice, suppressing the inflammatory response and joint destruction by non-selectively inhibiting the activity of COX and suppressing activation of the NF-κB signalling pathway, but without damaging the gastric mucosa. Therefore, MSL has great potential to be developed into a novel therapeutic agent for the treatment of RA.