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Objectives:The viral gene transfer of interleukin 1 receptor antagonist (IL1ra) and interleukin 10 (IL10) into rheumatoid arthritis (RA) synovial fibroblasts (RASFs) has shown protective effects on cartilage destruction in the severe combined immunodeficiency (SCID) mouse model of RA. Nevertheless, side effects of viral transduction are possible and a number of cytokines or cytokine inhibitors are not available encoded in viral vehicles. As the production of viruses coding for bioactive proteins is cost and time intensive, we established an in vivo long-term release model using osmotic minipumps in the SCID mouse model for RA.Methods:Isolated RASFs were cultured for four passages and coimplanted together with human cartilage and an Alzet osmotic miniature pump model 2004, containing 200 μl of IL10 and IL1ra for 40 days in SCID mice. Implants were removed after 40 days and evaluated histologically. The actual rates of IL10 and IL1ra in murine serum were measured by ELISA.Results:Release of IL10 and IL1ra by the pumps was effective as both could be measured in significant amounts in the serum of the mice. IL10 and IL1ra release showed protective effects towards the coimplanted cartilage, similar to the adenovirally IL10/IL1ra-transduced RASFs. The mean (SD) invasion scores for the implants with the osmotic pumps were: invasion 0.7 (0.5), degradation 0.5 (0.3) (all parameters significant vs controls, pConclusions:The results demonstrate that the combination of osmotic pumps with the SCID mouse model for RA can be used as approach for application and evaluation of cartilage-protective molecules. Furthermore, the effect of cartilage-protective cytokines is independent of the type of application.

Ulcerative colitis is a multifactorial disease, with immunological, genetic, and environmental factors playing an important role in its pathogenesis. Here we investigated the consequences of exposure to chronic psychosocial stress on the severity of a dextran sulfate sodium (DSS)-induced colitis in male C57BL/6 mice. Chronic stress was induced by repeated exposure to social defeat (SD, 2 h) and overcrowding (OC, 24 h) during 19 consecutive days. SD/OC mice showed a diminished body weight gain, thymus-atrophy, and adrenal hypertrophy, but similar light-phase plasma corticosterone concentrations, compared with unstressed mice. In contrast, the rise in dark-phase corticosterone concentration was significantly attenuated in SD/OC mice, whereas plasma ACTH concentrations and hypothalamic CRH mRNA expression did not differ between stressed and nonstressed groups. Additionally, adrenal cells from SD/OC mice showed a decreased in vitro response to ACTH stimulation. Subsequent treatment with 1% DSS for 7 d resulted in a more severe intestinal inflammation in SD/OC mice, as reflected by an increase in body weight loss, histological damage scores, and secretion of IL-6, TNFalpha, and interferon-gamma from mesenteric lymph node cells and by decreased colon length. The impaired health status of stressed mice was also reflected by a significantly lower survival rate after termination of the DSS treatment. In conclusion, the present findings demonstrate that chronic intermittent exposure to a psychosocial stressor before the induction of acute DSS-colitis results in adrenal insufficiency, increases in the severity of the acute inflammation, and impairs the healing phase.

Molecular imaging is a rapidly emerging field in biomedical research, aiming at the visualization, characterization and quantification of molecular and cellular processes non-invasively within intact living organisms. To sense biological processes such as gene expression, angiogenesis, apoptosis or cell trafficking in vivo, imaging reporter agents that interact specifically with molecular targets and appropriate imaging systems are currently under development. In rheumatoid arthritis, these novel tools will be used to evaluate physiological and pathophysiological processes, to facilitate diagnosis and monitor therapeutic regimens, to enable reliable prognosis and to support the development of new therapies. In this review, we summarize the basic principles of molecular imaging, such as the development of molecular imaging agents, the actual capabilities of different imaging modalities and the most recent advances in molecular imaging, demonstrating the potential of this technology. With regard to their applicability in rheumatic diseases, we discuss potential molecular targets, current experimental approaches and the future prospects for molecular imaging in rheumatoid arthritis.