RESUMO
Background: Systemic lupus erythematosus (SLE) is a chronic, multi phenotypic, autoimmune inflammatory disease and renal involvement significantly worsens its prognosis. Apoptosis dysregulation plays a key pathogenic role. Survivin, a protein from the apoptosis inhibitors family, has been considered a promising strategy in cancer therapy and evaluated as one of the regulatory pathways in the scenario of immune-mediated disorders. Objective: This study aims to explore survivin behaviour in SLE patients with lupus nephritis (LN), assessing its potential as a therapeutic and prognostic biomarker. Methods: 297 SLE patients were classified based on the American College of Rheumatology (ACR) 1997 criteria, from 2000 to 2015. In a cross-sectional study, the serum level of survivin was measured by an ELISA test and compared between 200 SLE individuals and healthy controls. In a longitudinal cohort, 97 patients with active LN had the concentration of survinin measured, before and after treatment with cyclophosphamide pulse therapy. Results: The serum concentration of survivin was significantly lower in the SLE group than in healthy controls, regardless of concomitant NL or disease activity. The longitudinal evaluation revealed a significant reduction in survivin serum level after treatment. However, survivin rates were not able to discriminate groups that achieved remission from those that maintained nephritis activity. Conclusion: Our study suggests that survivin levels in SLE patients are lower than in the general population. Even so, its use as a biomarker in SLE seems limited, not reflecting disease activity or response to LN treatment, as in other contexts.
RESUMO
This study evaluated the role of macrophage migration inhibitory factor in inflammation caused by monosodium urate crystals. The concentration of macrophage migration inhibitory factor was increased in synovial fluid of patients with acute gout, and there was a positive correlation between intra-articular macrophage migration inhibitory factor and IL-1ß concentrations. In mice, the injection of monosodium urate crystals into the knee joint increased the levels of macrophage migration inhibitory factor in macrophages and in inflamed tissue. The injection of recombinant macrophage migration inhibitory factor into the joint of mice reproduced the inflammatory response observed in acute gout, including histologic changes, the recruitment of neutrophils, and increased levels of IL-1ß and CXCL1. Importantly, the accumulation of neutrophils and the amount IL-1ß in the joints were reduced in macrophage migration inhibitory factor-deficient mice when injected with monosodium urate crystals. We observed a similar effect when we blocked macrophage migration inhibitory factor with (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid or anti-macrophage migration inhibitory factor. In addition, the blockade of IL-1R and CXCR2 reduced recombinant macrophage migration inhibitory factor-induced neutrophil recruitment. Mechanistically, recombinant macrophage migration inhibitory factor is important for the synthesis of il1ß mRNA in vivo and in isolated macrophages. Altogether, macrophage migration inhibitory factor promotes neutrophil accumulation and is important for IL-1ß production, which are 2 crucial events contributing to the pathogenesis of acute gout.
