Methylprednisolone inhibits IFN-gamma and IL-17 expression and production by cells infiltrating central nervous system in experimental autoimmune encephalomyelitis.

BACKGROUND: Glucocorticoids have been shown to be effective in the treatment of autoimmune diseases of the CNS such as multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). However, the mechanisms and the site of glucocorticoids' actions are still not completely defined. The aim of this study was to investigate the in vivo effect of the synthetic glucocorticoid methylprednisolone (MP) on the expression and production of proinflammatory cytokines interferon (IFN)-gamma and interleukin (IL)-17 by cells infiltrating CNS tissue. METHODS: Experimental autoimmune encephalomyelitis was induced in Dark Agouti (DA) rats by immunization with rat spinal cord homogenate mixed with adjuvants. Commencing on the day when the first EAE signs appeared, DA rats were injected daily for 3 days with MP and/or RU486, an antagonist of glucocorticoid receptor. Cytokine production and gene expression in CNS-infiltrating cells and lymph node cells were measured using ELISA and real time PCR, respectively. RESULTS: Treatment of rats with MP ameliorated EAE, and the animals recovered without relapses. Further, MP inhibited IFN-gamma and IL-17 expression and production in cells isolated from the CNS of DA rats with EAE after the last injection of MP. The observed effect of MP in vivo treatment was not mediated through depletion of CD4+ T cells among CNS infiltrating cells, or through induction of their apoptosis within the CNS. Finally, the glucocorticoid receptor-antagonist RU486 prevented the inhibitory effect of MP on IFN-gamma and IL-17 production both in vitro and in vivo, thus indicating that the observed effects of MP were mediated through glucocorticoid receptor-dependent mechanisms. CONCLUSION: Taken together, these results demonstrate that amelioration of EAE by exogenous glucocorticoids might be, at least partly, ascribed to the limitation of effector cell functions in the target tissue.

Transforming growth factor-beta 1 in Balkan endemic nephropathy.

BACKGROUND/AIM: The aim of this study was to compare plasma and urine transforming growth factor-beta1 (TGF-beta1) levels in patients with different stages of Balkan endemic nephropathy (BEN) with those in patients with primary glomerulonephritis (GN) and healthy controls. METHODS: The study involved 47 patients with BEN (30 with manifest BEN and 17 in the early stage of BEN), 12 patients with GN and 10 healthy controls. Plasma and urine TGF-beta1 was assayed by enzyme-linked immunosorbent assay. RESULTS: The median plasma TGF-beta1 levels differed nonsignificantly between the groups (4,908-6,442 pg/ml), but individual plasma TGF-beta1 levels in BEN patients exhibited the highest dispersion. Median urinary TGF-beta1 excretion (pg/mg creatinine) was significantly higher in patient groups (manifest BEN: 203, early-stage BEN: 341, GN: 775) than in healthy controls (42). No correlation was found between plasma and urine TGF-beta1 levels or between plasma TGF-beta1 levels and creatinine clearance for any of the examined groups. CONCLUSION: Plasma TGF-beta1 levels in BEN patients extended over the widest range, but no significant differences were found between the median values for the groups. Median urinary TGF-beta1 excretion was significantly higher in patients with BEN and GN than in healthy controls.

Methylprednisolone inhibits interleukin-17 and interferon-gamma expression by both naive and primed T cells.

BACKGROUND: Interleukin-17 (IL-17)-producing cells are increasingly considered to be the major pathogenic population in various autoimmune disorders. The effects of glucocorticoids, widely used as therapeutics for inflammatory and autoimmune disorders, on IL-17 generation have not been thoroughly investigated so far. Therefore, we have explored the influence of methylprednisolone (MP) on IL-17 expression in rat lymphocytes, and compared it to the effect of the drug on interferon (IFN)-gamma. RESULTS: Production of IL-17 in mitogen-stimulated lymph node cells (LNC) from non-treated rats, as well as in myelin basic protein (MBP)-stimulated draining LNC from rats immunized with spinal cord homogenate and complete Freund's adjuvant was significantly reduced by MP. The reduction was dose-dependent, sustained through the follow-up period of 48 hours, and was not achieved through anti-proliferative effect. Additionally, MP inhibited IL-17 production in purified T cells as well, but to less extent than in LNC. In its influence on IL-17 production MP inhibited Ror-gammaT transcription factor expression, as well as Jun phosphorylation, but not ERK or p38 activation in mitogen-stimulated LNC. Importantly, MP collaborated with IFN-gamma in inhibiting IL-17 generation in LNC. CONCLUSION: The observed difference in the effect of MP on IL-17 and IFN-gamma could be important for the understanding of the variability in the efficiency of glucocorticoids in the treatment of autoimmune diseases.

Kinetics of IFN-gamma and IL-17 expression and production in active experimental autoimmune encephalomyelitis in Dark Agouti rats.

Interferon-gamma (IFN-gamma) and interleukin-17 (IL-17) have been involved in the pathogenesis of experimental autoimmune encephalomyelitis (EAE). We have carried out a follow-up study of the expression and production of these cytokines, as well as of cells expressing these cytokines during the course of active EAE in Dark Agouti (DA) rats. As a result, IL-17, but not IFN-gamma expression and production had the peak value in draining lymph nodes (DLN) during the induction phase of the disease, and in spinal cords (SC) at the onset of clinical signs of the disease, and then declined toward the resolution of the disease. Also, a significant proportion of IFN-gamma/IL-17 double-positive cells was observed in SC of DA rats in active EAE. Importantly, the highest proportion of IL-17 single positive and double-positive cells, but not of IFN-gamma single positive cells, was observed at the onset of the disease. The observed difference in the kinetics of IFN-gamma and IL-17 expression during active EAE in DA rats suggests different roles these cytokines might have in the pathogenesis of the disease.

Dry olive leaf extract ameliorates experimental autoimmune encephalomyelitis.

BACKGROUND & AIMS: Experimental autoimmune encephalomyelitis (EAE) is an animal model of CNS inflammatory and demyelinating disease multiple sclerosis. Mediterranean diet, rich in olive products is associated with lower incidence of multiple sclerosis in South European population. Therefore, the influence of dry olive leaf extract (DOLE) on EAE course was investigated. METHODS: Spinal cord homogenate and complete Freund's adjuvant were used for the induction of EAE in Dark Agouti rats. DOLE was applied intragastrically once per day, starting from the day of the immunization. Real time PCR and ELISA were used for the determination of IFN-gamma and IL-17 gene expression and production, respectively. RESULTS: DOLE reduced various parameters of EAE severity in DA rats, including cumulative disease index, maximal clinical score and disease duration. Also, DOLE decreased cellularity of the draining lymph nodes and production of IFN-gamma and IL-17 by the cells infiltrating spinal cord of EAE rats. CONCLUSIONS: The results presented in this paper strongly suggest that DOLE-enriched diet has a beneficial effect in EAE in rats. Further studies in humans are required in order to investigate if DOLE could be a useful supplementary dietetic for the patients suffering from multiple sclerosis and other neuroinflammatory disorders.

Strain difference in susceptibility to experimental autoimmune encephalomyelitis in rats correlates with T(H)1 and T(H)17-inducing cytokine profiles.

Albino Oxford (AO) rats are resistant to induction of experimental autoimmune encephalomyelitis (EAE), in contrast to susceptible Dark Agouti (DA) rats. We have previously shown that draining lymph node cells (DLNC) obtained from immunized DA rats before the onset of the clinical disease produced more interferon (IFN)-gamma and interleukin (IL)-17 (signature cytokines of T(H)1 and T(H)17 responses, respectively) compared to DLNC from AO rats. In this study, we extend our analysis to entire induction phase of EAE with the emphasis on the T(H)1 and T(H)17-inducing cytokines. As a result, we show that throughout the inductive phase of the disease DLNC of DA rats, not only expressed higher levels of IFN-gamma and IL-17, but also of T(H)1-inducing cytokine-IL-12. As for T(H)17-inducing cytokines, DLNC of DA rats expressed more mRNA for p19, specific subunit of IL-23, but the expression of transforming growth factor (TGF)-beta in both strains was similar. Interestingly, the analysis of IL-6 expression revealed striking difference: while all DA DLNC were positive for IL-6 mRNA, cells from none of AO rats expressed detectable levels of mRNA for this cytokine. Taken together, our data suggest that the differential regulation of production of T(H)1 and T(H)17 cytokines, and IL-6 in particular, during the induction phase of disease could be responsible for the discrepancy in susceptibility to EAE between these two rat strains.

[Morphometric variability of precuneus in relation to gender and the hemisphere of human brain]. / Morfometrijska varijabilnost prekuneusa u odnosu na pol i hemisferu mozga covenka.

Precuneus, a quadrangular gyms of the medial surface of the human parietal lobe, is bound by three primary brain sulci and by superior hemispheric border. Precise encephalometric data about precuneus are important in the studies of brain lateralization, sex dimorphism, and brain functions in general. In this study, total and visible (exstrasulcal) surface area of the precuneus were measured on 50 brains of the adult persons (31 male, and 29 female), together with the investigation of its relationship to the side (left/right) and gender (sex dimorphism). The average total surface area of the precuneus was 16.07 cm2 on the right (males 16.44 cm2, females 15.27 cm2), and 15.44 cm2 on the left (males 15.67 cm2, females 14.62 cm2). The average visible (extrasulcal) surface area of cortex of precuneus was 9.97 cm2 on the left (males 10.75 cm2, females 8.91 cm2), and 9.38 cm2 on the right (males 10.25 cm2, females 8.19 cm2). Exstrasulcal surface area of the left precuneus was larger, by 0.59 cm on the average, which was not statistically significant. Total surface area of precuneus of males was significantly larger on the right (16.44 cm2) (p<0.01) than on the left (15.67 cm2). In females it was also larger on the right (15.27 cm2) than on the left (14.62 cm2), but with no statistical significance. Visible (exstrasulcal) surface area of both, (left and right precuneus of males), was highly significantly larger in comparison with the females (p<0.001). The obtained results and other facts suggested that sex dimorphism of human brain, including precuneus, was present, but not always easily observable, studied or proven in all the details.