Delta-9-tetrahydrocannabinol accumulation, metabolism and cell-type-specific adverse effects in aggregating brain cell cultures.

Despite the widespread use of Cannabis as recreational drug or as medicine, little is known about its toxicity. The accumulation, metabolism and toxicity of THC were analyzed 10 days after a single treatment, and after repeated exposures during 10 days. Mixed-cell aggregate cultures of fetal rat telencephalon were used as in vitro model, as well as aggregates enriched either in neurons or in glial cells. It was found that THC accumulated preferentially in neurons, and that glia-neuron interactions decreased THC accumulation. The quantification of 11-OH-THC and of THC-COOH showed that brain aggregates were capable of THC metabolism. No cell-type difference was found for the metabolite 11-OH-THC, whereas the THC-COOH content was higher in mixed-cell cultures. No cell death was found at THC concentrations of 2 microM in single treatment and of 1 microM and 2 microM in repeated treatments. Neurons, and particularly GABAergic neurons, were most sensitive to THC. Only the GABAergic marker was affected after the single treatment, whereas the GABAergic, cholinergic and astrocytic markers were decreased after the repeated treatments. JWH 015, a CB2 receptor agonist, showed effects similar to THC, whereas ACEA, a CB1 receptor agonist, had no effect. The expression of the cytokine IL-6 was upregulated 48 h after the single treatment with 5 microM of THC or JWH 015, whereas the expression of TNF-alpha remained unchanged. These results suggest that the adverse effects of THC were related either to THC accumulation or to cannabinoid receptor activation and associated with IL-6 upregulation.

TNF-alpha blockers in inflammatory bowel diseases: practical consensus recommendations and a user's guide.

More than seventy years after their initial characterisation, the aetiology of inflammatory bowel diseases remains elusive. A recent review evaluating the incidence trends of the last 25 years concluded that an increasing incidence has been observed almost worldwide. A north-south gradient is still found in Europe. Genetic associations are variably reproduced worldwide and indicate a strong impact of environmental factors. Tumour necrosis factor alpha (TNF-alpha) has been shown to play a critical role in the pathogenesis of inflammatory bowel disease (IBD). TNF-alpha blockers are biological agents that specifically target this key cytokine in the inflammatory process and have become a mainstay in the therapy of inflammatory bowel diseases. This paper reviews the necessary investigations before using such agents, the use of such agents in pregnancy and lactation, the role of co-immunosuppression, how to monitor efficacy and safety, dose-adaptation, and the decision as to when to switch to another TNF-alpha blocker. Finally it gives recommendations for special situations. Currently there are three TNF-alpha blockers available for clinical use in IBD in Switzerland: infliximab (Remicade), adalimumab (Humira) and certolizumab pegol (Cimzia). Infliximab is a chimeric monoclonal antibody composed of a human IgG1 constant region and a murine variable region and is administered intravenously. Adalimumab is a humanised monoclonal antibody, with both human IgG1 constant and variable regions. Certolizumab pegol is a pegylated, humanised monoclonal anti-TNF fragment antigen binding fragment. Both adalimumab and certolizumab pegol are administered by subcutaneous injection. The efficacy and safety of TNF-alpha blockers in Crohn's disease has been reviewed. The authors conclude that the three above-mentioned agents are effective in luminal Crohn's disease. In fistulizing Crohn's disease, TNF-alpha blockers other than infliximab require additional investigation.

CXCR4-activated astrocyte glutamate release via TNFalpha: amplification by microglia triggers neurotoxicity.

Astrocytes actively participate in synaptic integration by releasing transmitter (glutamate) via a calcium-regulated, exocytosis-like process. Here we show that this process follows activation of the receptor CXCR4 by the chemokine stromal cell-derived factor 1 (SDF-1). An extraordinary feature of the ensuing signaling cascade is the rapid extracellular release of tumor necrosis factor-alpha (TNFalpha). Autocrine/paracrine TNFalpha-dependent signaling leading to prostaglandin (PG) formation not only controls glutamate release and astrocyte communication, but also causes their derangement when activated microglia cooperate to dramatically enhance release of the cytokine in response to CXCR4 stimulation. We demonstrate that altered glial communication has direct neuropathological consequences and that agents interfering with CXCR4-dependent astrocyte-microglia signaling prevent neuronal apoptosis induced by the HIV-1 coat glycoprotein, gp120IIIB. Our results identify a new pathway for glia-glia and glia-neuron communication that is relevant to both normal brain function and neurodegenerative diseases.

Decreased production of TNF-alpha by lymph node cells indicates experimental autoimmune encephalomyelitis remission in Lewis rats

Experimental autoimmune encephalomyelitis (EAE) is mediated by CD4+ Th1 cells that mainly secrete IFN-γ and TNF-α, important cytokines in the pathophysiology of the disease. Spontaneous remission is, in part, attributed to the down regulation of IFN-γ and TNF-α by TGF-β. In the current paper, we compared weight, histopathology and immunological parameters during the acute and recovery phases of EAE to establish the best biomarker for clinical remission. Female Lewis rats were immunised with myelin basic protein (MBP) emulsified with complete Freund's adjuvant. Animals were evaluated daily for clinical score and weight prior to euthanisation. All immunised animals developed the expected characteristics of EAE during the acute phase, including significant weight loss and high clinical scores. Disease remission was associated with a significant reduction in clinical scores, although immunised rats did not regain their initial weight values. Brain inflammatory infiltrates were higher during the acute phase. During the remission phase, anti-myelin antibody levels increased, whereas TNF-α and IFN-γ production by lymph node cells cultured with MBP or concanavalin A, respectively, decreased. The most significant difference observed between the acute and recovery phases was in the induction of TNF-α levels in MBP-stimulated cultures. Therefore, the in vitro production of this cytokine could be used as a biomarker for EAE remission.

High Prevalence of Systemic Autoimmune Diseases in Patients with Meniere's Disease

BACKGROUND. Autoimmunity appears to be associated with the pathophysiology of Meniere's disease (MD), an inner ear disorder characterized by episodes of vertigo associated with hearing loss and tinnitus. However, the prevalence of autoimmune diseases (AD) in patients with MD has not been studied in individuals with uni or bilateral sensorineural hearing loss (SNHL). METHODS AND FINDINGS. We estimated the prevalence of AD in 690 outpatients with MD with uni or bilateral SNHL from otoneurology clinics at six tertiary referral hospitals by using clinica criteria and an immune panel (lymphocyte populations, antinuclear antibodies, C3, C4 and proinflammatory cytokines TNFα, INFγ). The observed prevalence of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and ankylosing spondylitis (AS) was higher than expected for the general population (1.39 for RA, 0.87 for SLE and 0.70 for AS, respectively). Systemic AD were more frequently observed in patients with MD and diagnostic criteria for migraine than cases with MD and tension-type headache (p = 0.007). There were clinical differences between patients with uni or bilateral SNHL, but no differences were found in the immune profile. Multiple linear regression showed that changes in lymphocytes subpopulations were associated with hearing loss and persistence of vertigo, suggesting a role for the immune response in MD. CONCLUSIONS. Despite some limitations, MD displays an elevated prevalence of systemic AD such as RA, SLE and AS. This finding, which suggests an autoimmune background in a subset of patients with MD, has important implications for the treatment of MD.

Assay for high glucose-mediated islet cell sensitization to apoptosis induced by streptozotocin and cytokines

Pancreatic beta-cell apoptosis is known to participate in the beta-cell destruction process that occurs in diabetes. It has been described that high glucose level induces a hyperfunctional status which could provoke apoptosis. This phenomenon is known as glucotoxicity and has been proposed that it can play a role in type 1 diabetes mellitus pathogenesis. In this study we develop an experimental design to sensitize pancreatic islet cells by high glucose to streptozotocin (STZ) and proinflammatory cytokines [interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma]-induced apoptosis. This method is appropriate for subsequent quantification of apoptotic islet cells stained with Tdt-mediated dUTP Nick-End Labeling (TUNEL) and protein expression assays by Western Blotting (WB).

Inflammatory Markers and Incident Heart Failure Risk in Older Adults: The Health, Aging, and Body Composition Study

Background: Inflammation is associated with heart failure (HF) risk factors and also directly affects myocardial function. However, the association between inflammation and HF risk in older adults has not been adequately evaluated. Methods: The association of baseline serum concentrations of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF- ), and C-reactive protein (CRP) with incident HF was assessed with Cox proportional hazards models among 2610 older persons without prevalent HF enrolled in the Health, Aging, and Body Composition (Health ABC) Study (age, 73.6±2.9 years; 48.3% men; 59.6% white). Results: Median (interquartile range) baseline concentrations of IL-6, TNF- , and CRP were 1.80 (1.23, 2.76) pg/mL, 3.14 (2.41, 4.06) pg/mL, and 1.64 (0.99, 3.04) µg/mL, respectively. On follow-up (median, 9.4 years), 311 participants (11.9%) developed HF. In models controlling for clinical predictors of HF and incident coronary heart disease, doubling of IL-6, TNF- , and CRP concentrations was associated with 34% (95% CI, 18 -52%; P<.001), 33% (95% CI, 9 - 63%; P=.006), and 13% (95% CI, 3-24%; P=.01) increase in HF risk, respectively. In models including all 3 markers, IL-6 and TNF- , but not CRP, remained significant. Findings were similar across sex and race. Post-HF ejection fraction (EF) was available in 239 (76.8%) cases. When only cases with preserved EF were considered (n=105), IL-6 (HR per doubling, 1.57; 95% CI, 1.28 -1.94; P<.001), TNF- (HR per doubling, 1.59; 95% CI, 1.12-2.26; P=.01), and CRP (HR per doubling, 1.23; 95% CI, 1.05-1.44; P=.01) were all associated with HF risk in adjusted models. In contrast, when only cases with reduced EF (n=134) were considered, only IL-6 attained marginal significance in adjusted models (HR per doubling, 1.20; 95% CI, 0.99 -1.46; P=.06). Participants with 2 or 3 markers above median had pronounced HF risk in adjusted models (HR, 1.66; 95% CI, 1.12-2.46; P=.01; and HR, 1.76; 95% CI, 1.16 -2.65; P=.007, respectively). Addition of IL-6 to the clinical Health ABC HF model improved discrimination (C index from 0.717 to 0.734; P=.001) and fit (decreased Bayes information criterion by 17.8; P<.001). Conclusions: Inflammatory markers are associated with HF risk among older adults and may improve HF risk stratification.

Polymorphisms IL10-819 and TLR-2 are potentially associated with sepsis in Brazilian patients

Genetic variation in immune response is probably involved in the progression of sepsis and mortality in septic patients. However, findings in the literature are sometimes conflicting or their significance is uncertain. Thus, we investigated the possible association between 12 polymorphisms located in the interleukin-6 (IL6), IL10, TLR-2, Toll-like receptor-4 (TLR-4), tumor necrosis factor-α and tumor necrosis factor-β (lymphotoxin α - LTA) genes and sepsis. Critically ill patients classified with sepsis, severe sepsis and septic shock and 207 healthy volunteers were analyzed and genotyped. Seven of the nine polymorphisms showed similar distributions in allele frequencies between patients and controls. Interestingly, our data suggest that the IL10-819 and TLR-2 polymorphisms may be potential predictors of sepsis.

BAFF and the regulation of B cell survival.

The TNF family member BAFF is a fundamental survival factor for B cells. BAFF binds to three receptors, only one of which, BAFF-R, does not cross-react with the BAFF-related ligand APRIL. The survival function of BAFF on B cells is mediated mainly by BAFF-R and is particularly effective in transitional B cells. BAFF depletion leads to a considerable decrease in mature B cells, without apparent effect on B cell genesis. Consistently, BAFF overexpression results in an expanded B cell compartment and autoimmunity in mice. Elevated amounts of BAFF can be found in the serum of patients suffering from autoimmune diseases. The BAFF system is a promising target for the treatment of autoimmune diseases.

Improved prediction of coronary heart disease with markers of atherosclerosis and of inflammation in older adults?

Background: Several markers of atherosclerosis and of inflammation have been shown to predict coronary heart disease (CHD) individually. However, the utility of markers of atherosclerosis and of inflammation on prediction of CHD over traditional risk factors has not been well established, especially in the elderly. Methods: We studied 2202 men and women, aged 70-79, without baseline cardiovascular disease over 6-year follow-up to assess the risk of incident CHD associated with baseline noninvasive measures of atherosclerosis (ankle-arm index [AAI], aortic pulse wave velocity [aPWV]) and inflammatory markers (interleukin-6 [IL-6], C-reactive protein [CRP], tumor necrosis factor-a [TNF-a]). CHD events were studied as either nonfatal myocardial infarction or coronary death ("hard" events), and "hard" events plus hospitalization for angina, or the need for coronary-revascularization procedures (total CHD events). Results: During the 6-year follow-up, 283 participants had CHD events (including 136 "hard" events). IL-6, TNF-a and AAI independently predicted CHD events above Framingham Risk Score (FRS) with hazard ratios [HR] for the highest as compared with the lowest quartile for IL-6 of 1.95 (95%CI: 1.38-2.75, p for trend <0.001), TNF-a of 1.45 (95%CI: 1.04-2.02, p for trend 0.03), of 1.66 (95%CI: 1.19-2.31) for AAI 0.9, as compared to AAI 1.01-1.30. CRP and aPWV were not independently associated with CHD events. Results were similar for "hard" CHD events. Addition of IL-6 and AAI to traditional cardiovascular risk factors yielded the greatest improvement in the prediction of CHD; C-index for "hard"/total CHD events increased from 0.62/0.62 for traditional risk factors to 0.64/0.64 for IL-6 addition, 0.65/0.63 for AAI, and 0.66/0.64 for IL-6 combined with AAI. Being in the highest quartile of IL-6 combined with an AAI 0.90 or >1.40 yielded an HR of 2.51 (1.50-4.19) and 4.55 (1.65-12.50) above FRS, respectively. With use of CHD risk categories, risk prediction at 5 years was more accurate in models that included IL-6, AAI or both, with 8.0, 8.3 and 12.1% correctly reclassified, respectively. Conclusions: Among older adults, markers of atherosclerosis and of inflammation, particularly IL-6 and AAI, are independently associated with CHD. However, these markers only modestly improve cardiovascular risk prediction beyond traditional risk factors.

Decreased STAMP2 expression in association with visceral adipose tissue dysfunction.

CONTEXT Six-transmembrane protein of prostate 2 (STAMP2) is a counter-regulator of inflammation and insulin resistance according to findings in mice. However, there have been contradictory reports in humans. OBJECTIVE We aimed to explore STAMP2 in association with inflammatory and metabolic status of human obesity. DESIGN, PATIENTS, AND METHODS STAMP2 gene expression was analyzed in adipose tissue samples (171 visceral and 67 sc depots) and during human preadipocyte differentiation. Human adipocytes were treated with macrophage-conditioned medium, TNF-α, and rosiglitazone. RESULTS In visceral adipose tissue, STAMP2 gene expression was significantly decreased in obese subjects, mainly in obese subjects with type 2 diabetes. STAMP2 gene expression and protein were significantly and inversely associated with obesity phenotype measures (body mass index, waist, hip, and fat mass) and obesity-associated metabolic disturbances (systolic blood pressure and fasting glucose). In addition, STAMP2 gene expression was positively associated with lipogenic (FASN, ACC1, SREBP1, THRSP14, TRα, and TRα1), CAV1, IRS1, GLUT4, and CD206 gene expression. In sc adipose tissue, STAMP2 gene expression was not associated with metabolic parameters. In both fat depots, STAMP2 gene expression in stromovascular cells was significantly higher than in mature adipocytes. STAMP2 gene expression was significantly increased during the differentiation process in parallel to adipogenic genes, being increased in preadipocytes derived from lean subjects. Macrophage-conditioned medium (25%) and TNF-α (100 ng/ml) administration increased whereas rosiglitazone (2 μM) decreased significantly STAMP2 gene expression in human differentiated adipocytes. CONCLUSIONS Decreased STAMP2 expression (mRNA and protein) might reflect visceral adipose dysfunction in subjects with obesity and type 2 diabetes.

Conditional deletion of ferritin h in mice reduces B and T lymphocyte populations.

The immune system and iron availability are intimately linked as appropriate iron supply is needed for cell proliferation, while excess iron, as observed in hemochromatosis, may reduce subsets of lymphocytes. We have tested the effects of a ferritin H gene deletion on lymphocytes. Mx-Cre mediated conditional deletion of ferritin H in bone marrow reduced the number of mature B cells and peripheral T cells in all lymphoid organs. FACS analysis showed an increase in the labile iron pool, enhanced reactive oxygen species formation and mitochondrial depolarization. The findings were confirmed by a B-cell specific deletion using Fth(lox/lox) ; CD19-Cre mice. Mature B cells were strongly under-represented in bone marrow and spleen of the deleted mice, whereas pre-B and immature B cells were not affected. Bone marrow B cells showed increased proliferation as judged by the number of cells in S and G2/M phase as well as BrdU incorporation. Upon in vitro culture with B-cell activating factor of the tumor necrosis factor family (BAFF), ferritin H-deleted spleen B cells showed lower survival rates than wild type cells. This was partially reversed with iron-chelator deferiprone. The loss of T cells was also confirmed by a T cell-specific deletion in Fth(lox/lox) ;CD4-Cre mice. Our data show that ferritin H is required for B and T cell survival by actively reducing the labile iron pool. They further suggest that natural B and T cell maturation is influenced by intracellular iron levels and possibly deregulated in iron excess or deprivation.

Soluble inflammatory markers as predictors of virological response in patients with chronic hepatitis C virus infection treated with interferon-α plus ribavirin

The host immune response plays an important role in viral clearance in patients who are chronically infected with hepatitis C virus (HCV) and are treated with interferon and ribavirin. Activation of the immune system involves the release of pro and anti-inflammatory molecules that can be measured in plasma samples. The present study aimed to evaluate the association between pretreatment plasma levels of chemokines and soluble tumor necrosis factor receptors (sTNF-R) and the virological response in treated patients with chronic hepatitis C infection. Forty-one chronically-infected HCV patients that were being treated with interferon-α (IFN-α) plus ribavirin were included in the study. Socio-demographic, clinical and laboratory data were collected and pretreatment plasma levels of chemokine CCL2, CCL3, CCL11, CCL24, chemokine CXCL9, CXCL10, sTNF-R1 and sTNF-R2 were measured. The virological response was assessed at treatment week 12, at the end of treatment and 24 weeks after treatment. Pretreatment CXCL10 levels were significantly higher in patients without an early virological response (EVR) or sustained virological response (SVR) compared to responders [512.9 pg/mL vs. 179.1 pg/mL (p = 0.011) and 289.9 pg/mL vs. 142.7 pg/mL (p = 0.045), respectively]. The accuracy of CXCL10 as a predictor of the absence of EVR and SVR was 0.79 [confidence interval (CI) 95%: 0.59-0.99] and 0.69 (CI 95%: 0.51-0.87), respectively. Pretreatment plasma levels of the other soluble inflammatory markers evaluated were not associated with a treatment response. Pretreatment CXCL10 levels were predictive of both EVR and SVR to IFN-α and ribavirin and may be useful in the evaluation of candidates for therapy.

A high corticosterone/DHEA-s ratio in young rats infected with Trypanosoma cruzi is associated with increased susceptibility

We have previously established that young male rats are more susceptible to the effects of Trypanosoma cruzi infection than adult rats. To explore underlying age-associated differences in disease outcome, we simultaneously assessed hormone levels and cytokine release throughout the acute infection period in young and adult rats infected with T. cruzi. Young rats were inoculated with 1 x 10(6) and adult rats with 7 x 10(6) blood trypomastigotes, according to their relative body weight. At zero, seven, 14, 21 and 28 days after infection, blood was collected for the determination of gonadal and adrenal hormones, tumor necrosis factor α (TNF-α), interleukin (IL)-10 and specific IgM and IgG subtypes. Young animals displayed significantly higher parasitaemia values and an endocrine pattern that was characterised by elevated values in corticosterone (CT) and the CT/dehydroepiandrosterone-sulfate ratio, which favours immunosuppression and susceptibility. In contrast, adult male rats were able to restrict the parasite burden, which likely resulted from increased IgG antibody synthesis and oestradiol levels. Adult rats also showed a reduced TNF-α/IL-10 ratio and less tissue damage. We conclude that young animals exhibited increased vulnerability to T. cruzi infection compared with adults and this is associated with an unsuitable immunoendocrine milieu.

Analysis of the expression of toll-like receptors 2 and 4 and cytokine production during experimental Leishmania chagasi infection

Toll-like receptors (TLRs) recognise pathogen-derived molecules and influence immunity to control parasite infections. This study aimed to evaluate the mRNA expression of TLRs 2 and 4, the expression and production of the cytokines interleukin (IL)-12, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-17, IL-10 and transforming growth factor (TGF)-β and the production of nitric oxide (NO) in the spleen of mice infected with Leishmania chagasi. It also aimed to evaluate any correlations between mRNA expression TLR2 and 4 and cytokines and NO production. Infection resulted in increased TLR2-4, IL-17, TNF-α and TGF-β mRNA expression during early infection, with decreased expression during late infection correlating with parasite load. IFN-γ and IL-12 mRNA expression decreased at the peak of parasitism. IL-10 mRNA expression increased throughout the entire time period analysed. Although TGF-β, TNF-α and IL-17 were highly produced during the initial phase of infection, IFN-γ and IL-12 exhibited high production during the final phase of infection. IL-10 and NO showed increased production throughout the evaluated time period. In the acute phase of infection, there was a positive correlation between TLR2-4, TNF-α, IL-17, NO, IL-10 and TGF-β expression and parasite load. During the chronic phase of infection, there was a positive correlation between TLR2-4, TNF-α, IL-17 and TGF-β expression and parasite load. Our data suggest that infection by L. chagasi resulted in modulation of TLRs 2 and 4 and cytokines.