Immunomodulatory actions of central ghrelin in diet-induced energy imbalance.

We investigated the effects of centrally administered orexigenic hormone ghrelin on energy imbalance-induced inflammation. Rats were subjected for four weeks to three different dietary regimes: normal (standard food), high-fat (standard food with 30% lard) or food-restricted (70%, 50%, 40% and 40% of the expected food intake in 1st, 2nd, 3rd and 4th week, respectively). Compared to normal-weight controls, starved, but not obese rats had significantly higher levels of proinflammatory cytokines (TNF, IL-1ß, IFN-γ) in the blood. When compared to normally fed animals, the hearts of starved and obese animals expressed higher levels of mRNAs encoding proinflammatory mediators (TNF, IL-1ß, IL-6, IFN-γ, IL-17, IL-12, iNOS), while mRNA levels of the anti-inflammatory TGF-ß remained unchanged. Intracerebroventricular (ICV) injection of ghrelin (1 µg/day) for five consecutive days significantly reduced TNF, IL-1ß and IFN-γ levels in the blood of starved rats, as well as TNF, IL-17 and IL-12p40 mRNA expression in the hearts of obese rats. Conversely, ICV ghrelin increased the levels of IFN-γ, IL-17, IL-12p35 and IL-12p40 mRNA in the heart tissue of food-restricted animals. This was associated with an increase of immunosuppressive ACTH/corticosterone production in starved animals and a decrease of the immunostimulatory adipokine leptin both in food-restricted and high-fat groups. Ghrelin activated the energy sensor AMP-activated protein kinase (AMPK) in the hypothalamus and inhibited extracellular signal-regulated kinase (ERK) in the hearts of obese, but not starved rats. Therefore, central ghrelin may play a complex role in energy imbalance-induced inflammation by modulating HPA axis, leptin and AMPK/ERK signaling pathways.

Aloe-emodin inhibits proliferation of adult human keratinocytes in vitro.

Aloe-emodin (AE) is a plant-derived hydroxyanthraquinone with several biological activities. It is present in a variety of skin-conditioning agents containing aloe extracts, but its influence on keratinocyte growth was not examined so far. We investigated the influence of AE on human keratinocyte proliferation and apoptosis in vitro. AE significantly inhibited proliferation of cultivated human keratinocytes at 5 µM concentration, as revealed by incorporation of radioactive thymidine. The antiproliferative effect of AE was accompanied with induction of apoptosis, but not necrosis, as demonstrated by flow cytometric analysis and lactate dehydrogenase release assay. Based on the half maximal inhibitory concentration values, we demonstrated that AE may impair proliferation of keratinocytes at concentrations far below the industry standards for commercial products containing aloe extracts. Therefore, further research of AE effects on the human skin and proper labeling of products are necessary for maximizing benefits from aloe extracts and to avoid undesired responses.

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.

TNF, IL12B, and IFNG Gene Polymorphisms in Serbian Patients with Psoriasis.

BACKGROUND: Psoriasis is a common chronic inflammatory skin disease with a strong genetic basis. Cytokines such as tumor necrosis factor alpha (TNF-α), interleukins (ILs) such are IL-12 and IL-23, and interferon gamma (IFN-γ) are released from various inflammatory and resident cells, and have been implicated in the initiation/maintenance of inflammation. Certain alleles of the aforementioned cytokines may be associated with disease susceptibility/severity. OBJECTIVE: To investigate the association of three common functional gene polymorphisms, namely TNF -308 G/A (rs1800629), IL12B (encoding the p40 subunit of IL-12/23) +1188 A/C (rs3212227), and IFNG +874 T/A (rs2430561) with psoriasis development and severity in Serbian patients. METHODS: We genotyped 130 patients with psoriasis (26 of whom also had psoriatic arthritis) and 259 controls; rs1800629 and rs3212227, and rs2430561, by real-time PCR assay. RESULTS: The TNF GG genotype was detected at a higher frequency in patients with psoriasis compared to control subjects (OR, 1.420; 95% CI, 0.870~2.403) without statistical significance (p=0.191). Lack of the TNF G allele was associated with lower psoriasis severity (p=0.007). The IL12B AC genotype was underrepresented in the patients with psoriatic arthritis compared to healthy subjects (OR, 0.308; 95% CI, 0.090~1.057; p=0.049). The distribution of the rs2430561 allele and genotype frequencies was similar between patients with psoriasis and controls. CONCLUSION: Our study demonstrates an effect of the rs1800629 on psoriasis severity, and a marginal impact of the rs3212227 on susceptibility to psoriatic arthritis. Collectively, our results obtained in a Serbian cohort expand current knowledge regarding individual predisposition to psoriatic disease.

Multiple sclerosis: individualized disease susceptibility and therapy response.

Multiple sclerosis (MS) is a heterogeneous disease in which diverse genetic, pathological and clinical backgrounds lead to variable therapy response. Accordingly, MS care should be tailored to address disease traits unique to each person. At the core of personalized management is the emergence of new knowledge, enabling optimized treatment and disease-modifying therapies. This overview analyzes the promise of genetic and nongenetic biomarkers in advancing decision-making algorithms to assist diagnosis or in predicting the disease course and therapy response in any given MS patient.

Single nucleotide polymorphisms in multiple sclerosis: disease susceptibility and treatment response biomarkers.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system characterized by unpredictable and variable clinical course. Etiology of MS involves both genetic and environmental factors. New technologies identified genetic polymorphisms associated with MS susceptibility among which immunologically relevant genes are significantly overrepresented. Although individual genes contribute only a small part to MS susceptibility, they might be used as biomarkers, thus helping to identify accurate diagnosis, predict clinical disease course and response to therapy. This review focuses on recent progress in research on MS genetics with special emphasis on the possibility to use single nucleotide polymorphism of candidate genes as biomarkers of susceptibility to disease and response to therapy.

Distinctive frequencies of +874T/A IFN-γ gene polymorphism in a healthy Serbian population.

PURPOSE: Single nucleotide polymorphism (SNP) in IFN-γ gene (+874T/A) that determines high (TT), low (AA), and intermediate (TA) responder phenotypes has shown associations with susceptibility to infectious and chronic inflammatory diseases, as well as disease outcome. Therefore, the susceptibility to and outcome of certain diseases can vary in different ethnic populations partially due to the notable differences in frequencies of genotypes and alleles between them. The aim of this study was to determine the distribution of +874T/A genotype and allele frequencies in a healthy Serbian population as a reference for further disease association studies. MATERIALS AND METHODS: Genomic DNA samples from 166 healthy volunteers were evaluated for IFN-γ SNP at position +874 using TaqMan SNP genotyping assay. RESULTS: The frequencies of AA, AT, and TT genotypes were 28.9%, 49.4%, and 21.7%, respectively. The A and T allele frequencies were 53.6% and 46.4%. CONCLUSIONS: Analysis of genotype and allele frequencies for IFN-γ+874T/A SNP in healthy subjects revealed, for the first time, the genetic profile for this polymorphism in a Serbian population resembling most European populations, but differing from some Asian and African ethnic groups.

The preoperative activity of Th1 and Th17 cytokine axes in prediction of sepsis after radical cystectomy.

The aim of the study was to correlate the preoperative activity of Th1 and Th17 cytokine axes with the development of sepsis after radical cystectomy. The study involved twenty patients with the infiltrative transitional cell carcinoma of the urinary bladder without previous radiotherapy/chemotherapy, who underwent open radical cystectomy with urinary diversion. Preoperative plasma concentrations of Th1 cytokines interleukin 12 (IL-12) and interferon gamma (IFN-γ), and Th17 cytokines IL-23 and IL-17, were measured using ELISA. Preoperative expression of mRNA for IL-12p35, IFN-γ, IL-23p19 and IL-17 was quantified by real-time RT-PCR using mRNA extracted from peripheral blood mononuclear cells. Eight patients developed postoperative sepsis, diagnosed within two weeks post-operation as systemic inflammatory response syndrome in the presence of local or systemic infection. The preoperative basal plasma concentrations of Th1 and Th17 cytokines were slightly above the detection limits, with a tendency toward lower concentrations in patients who developed sepsis, but the difference was not significant (p>0.05). The preoperative expression of mRNA encoding IL-12p35 and IL-17 was significantly lower in patients who developed sepsis (p=0.003 and p=0.028, respectively). The similar trend was observed for IL-23p19 and IFN-γ, but the differences did not reach the statistical significance (p=0.051 and p=0.172, respectively). These data suggest that determination of preoperative Th1 and Th17 cytokine mRNA levels might be useful in predicting sepsis development after radical cystectomy.

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.

Expression of Th1 and Th17 cytokines and transcription factors in multiple sclerosis patients: does baseline T-bet mRNA predict the response to interferon-beta treatment?

We studied the effect of one-year interferon (IFN)-beta treatment on the in vivo mRNA expression of IFN-gamma, interleukin (IL)-17, T-bet and RoR-gammat, on peripheral blood mononuclear cells (PBMC) from 36 multiple sclerosis (MS) patients. In the total MS group, IFN-beta induced decrease in mRNA levels of IFN-gamma and T-bet (p<0.0001), while the levels of IL-17 and RoR-gammat remained similar. In both responders and non-responders, IFN-beta induced significant decrease of IFN-gamma (p<0.0001 and p=0.011, respectively), while decrease in T-bet was detected only in responders (p<0.0001). Higher pre-treatment T-bet allowed prediction of the clinical response in the first year (beta=0.601, p=0.036). Our preliminary findings suggest that T-bet expression might be a potential prognostic marker of treatment response to IFN-beta in MS.