Inhibitory effects of anti-inflammatory drugs on type II collagen induced arthritis in rats

Effect of electroacupuncture at ST36 on the cerebral metabolic kinetics of rheumatoid arthritis rats

Electroacupuncture (EA) has been shown to enhance the recovery of symptoms in rheumatoid arthritis (RA); however, the underlying mechanism remains unclear. Both the pathogenesis of RA and the therapeutic effects of EA are closely associated with the metabolic activity of the brain. In this study, we investigated the effect of EA at the "Zusanli" acupoint (ST36) on a rat model of collagen-induced rheumatoid arthritis (CIA). The results demonstrated that EA effectively alleviated joint swelling, synovial hyperplasia, cartilage erosion, and bone destruction in CIA rats. Additionally, the metabolic kinetics study revealed a significant increase in the 13C enrichment of GABA2 and Glu4 in the midbrain of CIA rats treated with EA. Correlation network analysis showed that changes in Gln4 levels in the hippocampus were strongly associated with the severity of rheumatoid arthritis. Immunofluorescence staining of c-Fos in the midbrain's periaqueductal gray matter (PAG) and hippocampus demonstrated increased c-Fos expression in these regions following EA treatment. These findings suggest that GABAergic and glutamatergic neurons in the midbrain, along with astrocytes in the hippocampus, may play vital roles in the beneficial effects of EA on RA. Furthermore, the PAG and hippocampus brain regions hold potential as critical targets for future RA treatments. Overall, this study provides valuable insights into the specific mechanism of EA in treating RA by elucidating the perspective of cerebral metabolism.

Old and new therapeutics for Rheumatoid Arthritis: in vivo models and drug development

Development of novel drugs for treatment of chronic inflammatory diseases is to a large extent dependent on the availability of good experimental in vivo models in order to perform preclinical tests of new drugs and for the identification of novel drug targets. Here, we review a number of existing rodent models for Rheumatoid Arthritis in the context of how these models have been utilized for developing established therapy in Rheumatoid Arthritis and, furthermore, the present use of animal models for studies of novel drug candidates. We have studied the literature in the field for the use of in vivo models during development of anti-rheumatic drugs; from Methotrexate to various antibody treatments, to novel drugs that are, or have recently been, in clinical trials. For novel drugs, we have explored websites for clinical trials. Although a single Rheumatoid Arthritis in vivo model cannot mirror the complexity of disease development, there exist a number of good animal models for Rheumatoid Arthritis, each defining some parts in disease development, which are useful for studies of drug response. We find that many of the established drugs were not tested in in vivo models before being used in the clinic, but rather animal models have been subsequently used to find mechanisms for efficacy. Finally, we report a number of novel drugs, tested in preclinical in vivo models, presently in clinical trials.

Resolution-associated molecular patterns (RAMP): RAMParts defending immunological homeostasis?

The resolution of inflammation is central to the maintenance of good health and immune homeostasis. Recently, several intracellular stress proteins have been described as having extracellular properties that are anti-inflammatory or favour the resolution of inflammation. We propose that these molecules should be defined as resolution-associated molecular patterns (RAMPs). RAMPs are released at times of cellular stress and help to counterbalance the inflammatory effects of pathogen-associated (PAMPs) and damage-associated (DAMPs) molecular patterns. We propose that heat shock protein 10 (HSP10), αB-crystallin (αBC), HSP27 and binding immunoglobulin protein (BiP) should be considered founding members of the RAMP family. A greater understanding of RAMP biology may herald the development of novel immunotherapies.

Quantification of rebound edema after steroid treatment

OBJECTIVE

Return of edema after abrupt discontinuation of steroid treatment has never been studied or quantified. The purpose of this study was to measure the effect of abrupt cessation and tapering doses of steroids on tissue water content (TWC) in a rat skin flap model.

DESIGN

A randomized controlled animal trial was designed to study the effects of discontinuation of steroid on skin flap edema. The animals were assigned to a control group (C), a steroid group (S), an abrupt steroid cessation (SC) group, or a tapering steroid (ST) group.

MAIN OUTCOME MEASURES

In each group the skin flaps were biopsied at 30 and 36 hours. TWC was determined by a biopsy-drying technique.

RESULTS

A significant difference (P = 0.05) was found between the C and S groups and between the SC and S groups at both 30 and 36 hours, with the C group having the highest TWC. No significant difference was noted between the SC and C groups. The ST group had significantly less edema than the C group and similar TWC to that of the S group.

CONCLUSION

Edema rebounded in the skin flaps after abrupt cessation of steroids (SC was not different from C), presumably because of destabilization of inflammatory mediators. The rebound effect was not observed in the ST group. The control of rebound edema by a tapering steroid protocol may be important in skin flap survival and may have implications for the management of airway edema.

Novel DMARDs on the basis of a new concept of dual cytokine regulation, TNF-alpha suppression and IL-10 augmentation

A series of arylpiperazine derivatives was synthesized to obtain agents showing apparent therapeutic effects in a chronic inflammatory animal model, starting from a lead possessing potent dual cytokine regulatory activity in vivo. We found a pyrimidylpiperazine derivative 17c showing the dual regulatory activity and an excellent therapeutic effect in an adjuvant-induced arthritis model.

Effect of acetylsalicylic acid and dexamethasone on antibody production in adjuvant arthritis

The production of antibodies to IgG and type II collagen occurs in a similar fashion in human rheumatoid arthritis and adjuvant arthritis. In this study, the effect of dexamethasone (DXT) and acetylsalicylic acid (ASA) on antibody synthesis was analysed. Daily treatment with DXT (0.3 mg/kg per day p.o.) or with ASA (200 mg/kg per day p.o.) from day 14 to day 56 after arthritis induction inhibited both the synthesis of antibodies to IgG and type II collagen and also the humoral immune response to the mycobacteria that induced the disease. The immunosuppressive response was similar for both drugs: DXT, which is known to suppress the immune response, and ASA, a classical anti-inflammatory agent.

Effects of gold sodium thiomalate, cyclosporin A, cyclophosphamide, and placebo on collagen-induced arthritis in rats

The prophylactic and therapeutic effects of gold sodium thiomalate, cyclosporin A, cyclophosphamide, and placebo on collagen-induced arthritis (CIA) were evaluated in DA rats. Prophylactic treatment with cyclosporin A and cyclophosphamide suppressed the arthritis incidence, clinical inflammation, destructive bone changes, and development of anti-collagen antibody in DA rats subsequently injected with porcine type-II collagen. Therapeutic treatment with cyclosporin A and cyclophosphamide had a definite suppression on established CIA when started 21 days after the initial collagen injection, but the suppression was less marked than that of prophylactic treatment. Gold had no impact on CIA in DA rats when administered either prophylactically or therapeutically.

Interleukin 1 mediated acceleration of type II collagen-induced arthritis: effects of anti-inflammatory or anti-arthritic drugs

We previously demonstrated that treatments with rIL-1 beta accelerated the onset and progression of CIA in mice. In the present study, it was observed that IL-1 also enhanced the development of CIA in rats. Like the mouse model, maximal incidence (80-100%) of arthritis occurred within 7 days after the first treatment with IL-1 in rats. Thus, the acceleration of CIA by IL-1 (IL-1 CIA) may be an improved model for the rapid screening of anti-inflammatory and/or anti-arthritic drugs. As a first step to determining the utility of the IL-1 CIA model as a drug screen, we examined the ability of various known anti-inflammatory and anti-arthritic drugs to modify the IL-1 mediated enhancement of CIA in both rats and mice. The results of these studies showed that when analyzed in the IL-1 CIA model, rats and mice exhibited differences in their responses to several of these drugs. For example, dexamethasone, cyclophosphamide, azathioprine, various non-steroidal anti-inflammatory drugs (NSAIDs) as well as methotrexate were found active in the IL-1 CIA of rats. By contrast, the NSAIDs were found to be less effective in suppressing the IL-1 accelerated disease in mice. In both rats and mice, cyclosporine A and several disease modifying anti-arthritic drugs failed to the prevent the development of CIA that was potentiated by IL-1. Thus, in the IL-1 CIA model NSAIDs appeared to be less active in mice than rats. In conclusion, because of the shorter latent period required for the development of arthritis in the IL-1 treated animals, the IL-1 accelerated CIA model in both mice and rats may be useful for screening anti-inflammatory or anti-arthritic compounds.