Increased Plasma Levels Of IL-6 Research Articles

Effect of 2-methoxyestradiol on mammary tumor initiation and progression.

The anti-cancer agent 2-methoxyestradiol (2-ME) has been shown to have anti-proliferative and anti-angiogenic properties. Previously, the effect of 2-ME on early- and late-stage breast cancer (BC) was investigated in vivo using a transgenic mouse model (FVB/N-Tg(MMTV-PyVT)) of spontaneous mammary carcinoma. Anti-tumor effects were observed in late-stage BC with no effect on early-stage BC. Given the contrasting results obtained from the different BC stages, we have now investigated the effect of 2-ME when administered before the appearance of palpable tumors. Each mouse received 100 mg/kg 2-ME on day 30 after birth, twice per week for 28 days, while control mice received vehicle only. Animals were terminated on day 59. Lung and mammary tissue were obtained for immunohistochemical analysis of CD163 and CD3 expression, and histological examination was performed to analyze tumor necrosis. Additionally, blood samples were collected to measure plasma cytokine levels. 2-ME increased tumor mass when compared to the untreated animals (p = .0139). The pro-tumorigenic activity of 2-ME was accompanied by lower CD3+ T-cell numbers in the tumor microenvironment (TME) and high levels of the pro-inflammatory cytokine interleukin (IL)-1β. Conversely, 2-ME-treatment resulted in fewer CD163+ cells detectable in the TME, increased levels of tumor necrosis, increased IL-10 plasma levels, and low IL-6 and IL-27 plasma levels. Taken together, these findings suggest that 2-ME promotes early-stage BC development.

Effects of a single phosphate-enriched test meal on inflammasome activity and postprandial inflammatory markers in healthy subjects.

The consumption of highly processed food is often associated with a high intake of inorganic phosphate. Hyperphosphatemia is accompanied by an inflammatory status in patients with chronic kidney disease. However, the immune response to high phosphorus intake in healthy individuals is largely unknown. Therefore, the aim of the present study was to evaluate the effect of a single phosphate-enriched meal on inflammasome activity and plasma levels of inflammatory markers. The analysis included 28 participants who received a single dose of either 700mg phosphorus or a placebo with a test meal. At baseline, 4 and 8h post-meal, plasma interleukin (IL)-6, IL-1β, IL-10, c-reactive protein (CRP), soluble IL-6 receptor (sIL-6R) and glycoprotein 130 (sgp130) levels were determined. At baseline and 4h post-meal, peripheral blood mononuclear cells were isolated to assess inflammasome activity. Subsequently, the effect of phosphate with or without glucose on IL-6 and IL-1β gene expression and secretion in U937 monocytes was examined. While both groups showed a marked postprandial increase in IL-6 plasma levels, neither plasma levels of IL-6, IL-1β, CRP, IL-10, sIL-6R, and sgp130 nor inflammasome activity were affected by phosphate compared to placebo. In U937 cells, there was also no effect of phosphate on IL-6 expression, but the addition of glucose increased it. Phosphate, however, reduced the IL-1β secretion of these cells. Postprandial inflammatory markers were not affected by dietary phosphate. However, IL-6 plasma levels were markedly increased post-meal, which appears to be a metabolic rather than a pro-inflammatory phenomenon. ClinicalTrials.gov, NCT03771924, date of registration: 11th December 2018, retrospectively registered.

Neuro-PASC is characterized by enhanced CD4+ and diminished CD8+ T cell responses to SARS-CoV-2 Nucleocapsid protein.

Many people with long COVID symptoms suffer from debilitating neurologic post-acute sequelae of SARS-CoV-2 infection (Neuro-PASC). Although symptoms of Neuro-PASC are widely documented, it is still unclear whether PASC symptoms impact virus-specific immune responses. Therefore, we examined T cell and antibody responses to SARS-CoV-2 Nucleocapsid protein to identify activation signatures distinguishing Neuro-PASC patients from healthy COVID convalescents. We report that Neuro-PASC patients exhibit distinct immunological signatures composed of elevated CD4+ T cell responses and diminished CD8+ memory T cell activation toward the C-terminal region of SARS-CoV-2 Nucleocapsid protein when examined both functionally and using TCR sequencing. CD8+ T cell production of IL-6 correlated with increased plasma IL-6 levels as well as heightened severity of neurologic symptoms, including pain. Elevated plasma immunoregulatory and reduced pro-inflammatory and antiviral response signatures were evident in Neuro-PASC patients compared with COVID convalescent controls without lasting symptoms, correlating with worse neurocognitive dysfunction. We conclude that these data provide new insight into the impact of virus-specific cellular immunity on the pathogenesis of long COVID and pave the way for the rational design of predictive biomarkers and therapeutic interventions.

Intra-individual state-dependent comparison of plasma mitochondrial DNA copy number and IL-6 levels in patients with bipolar disorder

BackgroundPatients with bipolar disorder (BD) have increased plasma IL-6 levels, which are higher in depressed BD (dBD) than remitted BD (rBD). However, the mechanism that differentiates the cytokine levels between dBD and rBD is not understood. First, we determined whether brain-derived mtDNA can be detected in plasma using neuron-specific mutant Polg1 transgenic (Tg) mice. Second, we investigated whether the plasma circulating cell-free mitochondrial DNA (ccf-mtDNA) differentiate the cytokine levels between dBD and rBD. MethodsMouse plasma ccf-mtDNA levels were measured using real-time PCR targeting two regions of the mtDNA (CO1 and d-loop) in Tg mice and non-Tg littermates. Human plasma ccf-mtDNA levels were measured using real-time PCR targeting two regions of the mtDNA (ND1 and ND4) and IL-6 levels were evaluated in 10 patients in different states (depressed and remitted) of BD in a longitudinal manner and 10 healthy controls. ResultsThe mouse plasma CO1/D-loop ratio was significantly lower in Tg than non-Tg mice (P = 0.0029). Human plasma ccf-mtDNA copy number, ND4/ND1 ratio, and IL-6 levels were not significantly different between dBD and rBD. Human plasma ccf-mtDNA levels showed a nominal significant correlation with delusional symptoms (P = 0.033, ρ = 0.68). LimitationsA larger sample size is required to generalize the results and to determine whether plasma ccf-mtDNA is associated with systemic inflammation. ConclusionsTg mice revealed that brain-derived mtDNA could be present in peripheral blood. The present findings did not coincide with our hypothesis that plasma ccf-mtDNA differentiates the cytokine levels between dBD and rBD.

Effects of high fat diets and supplemental tart cherry and fish oil on obesity and type 2 diabetes in male and female C57BL/6J and TALLYHO/Jng mice

Obesogenic and diabetogenic high fat (HF) diets can influence genetic factors in disease development with sexual dimorphic responses. We investigated potential protective effects of tart cherry (TC), fish oil (FO) and TC+FO supplementation in TALLYHO/Jng (TH) and C57BL/6J (B6) mice fed HF diets. Male and female TH and B6 mice were weaned onto five different diets; low fat (LF), HF, and HF supplemented with TC, FO, or TC+FO and maintained. For both males and females on LF, TH mice were heavier and fatter than B6, which was accentuated by HF in males, but not in females. TH males, but not others, developed severe glucose intolerance and hyperglycemia on HF, with reduced mRNA levels of Adipoq and Esr1 in adipose tissue. Considering energy balance, locomotor activity was lower in TH mice than B6 for both sexes without diet effects, except B6 females where HF decreased it. Compared to LF, HF decreased energy expenditure, RER, and food intake (in grams) for both sexes without strain differences. In all mice, but B6 males, HF increased plasma IL6 levels compared to LF. No preventive effects of TC, FO or TC+FO were noted for HF-induced obesity or energy imbalance, but FO alleviated glucose intolerance in TH males. Further, TC and FO decreased plasma IL6 levels, especially in females, without additive or synergistic effects of these two. Collectively, obesogenic and diabetogenic impacts of HF diets differed depending on the genetic predisposition. Moreover, sexually dimorphic effects of dietary supplementation were observed for glucose metabolism and inflammatory markers.

IL-6 Reduces Mitochondrial Replication, and IL-6 Receptors Reduce Chronic Inflammation in NAFLD and Type 2 Diabetes.

Interleukin (IL)-6 family cytokines act through a receptor complex with gp130 subunits. IL-6 is a pleiotropic cytokine that regulates inflammation and liver regeneration. Mitochondria are the first to respond to stress and adapt their dynamics in conditions of damage. In this regard, the study aimed to investigate the role of the IL-6 cytokine family (sIL-6Ra, gp130/sIL-6Rb, and IL-11) in the regulation of mitochondrial dynamics in the liver in obese patients and to assess the contribution of these cytokines to the pathogenesis of type 2 diabetes mellitus (T2DM). We studied 134 obese patients with and without T2DM and 41 healthy donors. We found that increasing the concentration of sIL-6Ra and gp130/sIL-6Rb protected against carbohydrate disorders in obese patients and prevented non-alcoholic fatty liver disease (NAFLD) progression in obese patients. An increase in plasma IL-6 levels is associated with decreased, mitochondrial transcription factor A (TFAM) protein production in liver biopsies in obese patients with and without T2DM. Replication, transcription, and division processes in liver biopsy were reduced in patients with T2DM. Inflammatory processes stimulate liver cell apoptosis in obese patients with T2DM. The increase in IL-11 levels is associated with decreased pro-apoptotic Bcl-2-associated X protein (BAX) protein production in obese patients with and without T2DM.

Pseudomonas aeruginosa virulence proteins pseudolysin and protease IV impede cutaneous wound healing

AbstractThe intricate biological process of cutaneous wound healing is achieved through precise and highly programmed events. Dermal fibroblasts and keratinocytes play a significant role in the process of reepithelialization during wound healing. Pathogenic bacteria such as Pseudomonas aeruginosa (P. aeruginosa) may delay the proliferative phase of wound repair by secreting their proteins leading to delayed or impaired wound healing. We have analyzed three virulent strains of P. aeruginosa isolated from the wound environment which also differed in their ability to produce biofilms. Mass spectrometric analysis of differentially expressed secreted proteins by three virulent strains of P. aeruginosa revealed peptides from pseudolysin and protease IV expressed from lasB and prpL genes. Pseudolysin and protease IV recombinant proteins were tested for their ability to modulate wound healing in several cell types of wound microenvironment in in vitro and in vivo models. Both pseudolysin and protease IV inhibited migration and survival of fibroblasts, keratinocytes, and endothelial cells. In three dimensional spheroid endothelial models and matrigel assays these proteins impeded sprouting and tube formation. In a mouse model of excision wound, pseudolysin and protease IV treatment showed reduced collagen content, inhibited neovascularization and epithelialization, and delayed wound contraction. Furthermore, pseudolysin and protease IV treatment resulted in a significant increase in plasma IL-6 levels when compared to vehicle control and control, suggesting the induction of a state of prolonged inflammation. Taken together, our data indicate pseudolysin and protease IV secreted from biofilm producing and antibiotic resistant P. aeruginosa in wound microenvironment produce both local and systemic effects that is detrimental to the maintenance of tissue homeostasis. Hence, these proteins may serve as potential therapeutic targets toward better clinical management of wounds.

A Lipid Peroxidation Product, 4-Hydroxy-2-Nonenal, Triggers Intravascular Coagulation and Inflammation through Generation of Tissue Factor-Positive Microvesicles

Tissue factor (TF) is a cellular receptor for the clotting protease factor VIIa (FVIIa), and TF-FVIIa complex initiates activation of the coagulation cascade. TF-FVIIa also influences non-hemostatic functions via direct or indirect cell signaling. Constitutive expression of TF is primarily restricted to the surface of perivascular cells, sequestered from circulating blood clotting factors, to prevent aberrant intravascular clotting. It has been suggested that TF is also present in the blood associated with microvesicles (MVs). These circulating TF, however, do not induce any thrombotic complications as they are either cleared from the system before they could accumulate to a pathological level or lack procoagulant activity. However, various pathological conditions such as sepsis, diabetes, bacterial infection, atherosclerosis, and cancer can increase the levels of circulating TF+ MVs, which can then trigger intravascular coagulation and inflammation. We hypothesized that oxidative stress, a pathological condition, central to most of the diseases mentioned above, plays a role in the generation of TF+ MVs in vivo, which could contribute to intravascular coagulation and inflammation. We recently showed that 4-hydroxy-2-nonenal (HNE), the most abundant and stable unsaturated aldehyde produced by the oxidation of ω-6 polyunsaturated fatty acids, enhances TF activity in monocytic cells and macrophages. However, the role of HNE in activation of intravascular coagulation is unknown. To investigate this, C57Bl/6J wild-type mice were administered with HNE intraperitoneally (10 mg/kg body weight) and generation of TF+ MVs, activation of intravascular coagulation, and inflammation was assessed. HNE administration markedly increased TF activity associated with MVs. Nanoparticle tracking analysis (NTA) showed a 3-fold increase in the number of MVs in the plasma of HNE-treated mice. Measurement of thrombin-antithrombin (TAT) complexes revealed a significant increase in TAT levels in HNE treated mice. Pre-treatment of the mice with anti-murine TF antibody attenuated the HNE-induced increase in TAT levels. Measurement of plasma clotting times showed a significant reduction in HNE treated mice (118.3 ± 10.42 sec) compared to saline treated control mice (> 300 sec). Incubation of plasma with anti-TF antibody reversed the reduction observed in the plasma clotting time of HNE treated mice. Assessment of clotting in the saphenous vein injury bleeding model showed an increased number of clots, and reduced blood loss in HNE-administered mice compared to saline treated mice. Blockade of TF with 1H1 anti-TF antibody negated the HNE-mediated reduction in the clotting time. Next, we investigated whether HNE administration also induces a proinflammatory response in mice. Blood cells analysis showed approximately a 4-fold increase in circulating neutrophils in HNE-treated mice at 6 h following HNE treatment. Immunohistochemistry studies showed a robust infiltration of neutrophils into the lungs. Cytokine analysis of plasma showed a significant increase in IL-6 and CXCL1 levels in HNE-treated mice. Blockade of TF using 1H1 anti-TF antibody significantly reduced the HNE-mediated neutrophil infiltration into the lungs and completely abrogated the increase in plasma IL-6 levels. In additional studies, we attempted to identify the source of TF+ MVs. It is unlikely that they are originated from monocytes or endothelial cells as HNE did not induce TF expression in these cell types. LPS, used as a positive control, showed significant induction of TF on both PBMCs and the endothelium Immunohistochemistry revealed that HNE disrupted endothelial barrier integrity of vessel wall, raising a possibility that TF+ MVs could have come from perivascular cells. In summary, our data indicate that oxidative stress could induce the release of TF+ MVs, and this would contribute to intravascular coagulation and inflammation. Our studies also suggest that TF-positive microvesicles can be a useful therapeutic target in the treatment of thromboinflammatory diseases. Disclosures No relevant conflicts of interest to declare.

Murine Anorectic Response to Deoxynivalenol (Vomitoxin) Is Sex-Dependent.

Deoxynivalenol (DON, vomitoxin), a common trichothecene mycotoxin found in cereal foods, dysregulates immune function and maintenance of energy balance. The purpose of this study was to determine if sex differences are similarly evident in DON’s anorectic responses in mice. A bioassay for feed refusal, previously developed by our lab, was used to compare acute i.p. exposures of 1 and 5 mg/kg bw DON in C57BL6 mice. Greater anorectic responses were seen in male than female mice. Male mice had higher organ and plasma concentrations of DON upon acute exposure than their female counterparts. A significant increase in IL-6 plasma levels was also observed in males while cholecystokinin response was higher in females. When effects of sex on food intake and body weight changes were compared after subchronic dietary exposure to 1, 2.5, and 10 ppm DON, males were found again to be more sensitive. Demonstration of male predilection to DON-induced changes in food intake and weight gain might an important consideration in future risk assessment of DON and other trichothecenes.

Immunoglobulin response to Plasmodium falciparum RESA proteins in uncomplicated and severe malaria.

BackgroundThe three members of the ring-infected erythrocyte surface antigen (RESA) proteins family share high sequence homologies, which impair the detection and assignment to one or another protein of some pathogenic processes inherent to Plasmodium falciparum malaria. The present study was intended to determine if the antibody and inflammatory responses of children living in a malaria-endemic area varied depending on the RESA-1, RESA-2 or RESA-3 proteins and the severity of the disease, two groups of severe and uncomplicated malaria cases being considered.MethodsTwo synthetic peptides representing predicted B cell epitopes were designed per RESA protein, all located outside of the 3′ and 5′ repetition blocks, in order to allow an antibody detection specific of each member of the family. Recombinant rRESA-1B and rRESA-3B proteins were also engineered. Two groups of Beninese children admitted to hospital in 2009 for either uncomplicated or severe malaria were compared for their plasma levels of IgG specifically recognizing each recombinant RESA protein or synthetic peptide, and for their plasma inflammatory cytokine levels (IFN-γ, TNF-α and IL-10), taking into account host and parasite genetic factors.ResultsThe absence of IgG cross-reactivity between rRESA proteins and their protein carrier as well as between each RESA peptide and a non-epitopic RESA control peptide validated the use of the engineered recombinant proteins and peptides for the measurement of plasma IgG. Taking into account age, fever duration and parasitaemia, a multiple logistic regression performed on children clustered according to their antibody responses’ profiles concluded to an increased risk of severe malaria for P2 (representative of RESA-1) responders (P = 0.007). Increased IL-10 plasma levels were found in children harbouring multiclonal P. falciparum infections on the basis of the T1526G resa2 gene polymorphism (P = 0.004).ConclusionsThis study provided novel tools to dissect the seroreactivity against the three members of the RESA protein family and to describe its relation to protection against malaria. It suggested the measurement of plasma antibodies raised against specific peptides to serve as predictive immunologic markers for disease severity. Lastly, it reinforced previous observations linking the T1526G resa2 gene mutation to severe malaria.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-015-0799-8) contains supplementary material, which is available to authorized users.

Angiotensin II-induced endothelial dysfunction is temporally linked with increases in interleukin-6 and vascular macrophage accumulation.

Angiotensin II (Ang II) is associated with vascular hypertrophy, endothelial dysfunction and activation of a number of inflammatory molecules, however the linear events involved in the development of hypertension and endothelial dysfunction produced in response to Ang II are not well defined. The goal of this study was to examine the dose- and temporal-dependent development of endothelial dysfunction in response to Ang II. Blood pressure and responses of carotid arteries were examined in control (C57Bl/6) mice and in mice infused with 50, 100, 200, 400, or 1000 ng/kg/min Ang II for either 14 or 28 Days. Infusion of Ang II was associated with graded and marked increases in systolic blood pressure and plasma Ang II concentrations. While low doses of Ang II (i.e., 50 and 100 ng/kg/min) had little to no effect on blood pressure or endothelial function, high doses of Ang II (e.g., 1000 ng/kg/min) were associated with large increases in arterial pressure and marked impairment of endothelial function. In contrast, intermediate doses of Ang II (200 and 400 ng/kg/min) while initially having no effect on systolic blood pressure were associated with significant increases in pressure over time. Despite increasing blood pressure, 200 ng/kg/min had no effect on endothelial function, whereas 400 ng/kg/min produced modest impairment on Day 14 and marked impairment of endothelial function on Day 28. The degree of endothelial dysfunction produced by 400 and 1000 ng/kg/min Ang II was reflective of parallel increases in plasma IL-6 levels and vascular macrophage content, suggesting that increases in arterial blood pressure precede the development of endothelial dysfunction. These findings are important as they demonstrate that along with increases in arterial pressure that increases in IL-6 and vascular macrophage accumulation correlate with the impairment of endothelial function produced by Ang II.

Evidence for Anti-Inflammatory Effects of Exercise in CKD

CKD is associated with a complex state of immune dysfunction characterized by immune depression, predisposing patients to infections, and immune activation, resulting in inflammation that associates with higher risk of cardiovascular disease. Physical exercise may enhance immune function and exert anti-inflammatory effects, but such effects are unclear in CKD. We investigated the separate effects of acute and regular moderate-intensity aerobic exercise on neutrophil degranulation (elastase release), activation of T lymphocytes (CD69 expression) and monocytes (CD86 and HLA-DR expression), and plasma inflammatory markers (IL-6, IL-10, soluble TNF-receptors, and C-reactive protein) in patients with predialysis CKD. A single 30-minute (acute) bout of walking induced a normal pattern of leukocyte mobilization and had no effect on T-lymphocyte and monocyte activation but improved neutrophil responsiveness to a bacterial challenge in the postexercise period. Furthermore, acute exercise induced a systemic anti-inflammatory environment, evidenced by a marked increase in plasma IL-10 levels (peaked at 1 hour postexercise), that was most likely mediated by increased plasma IL-6 levels (peaked immediately postexercise). Six months of regular walking exercise (30 min/d for 5 times/wk) exerted anti-inflammatory effects (reduction in the ratio of plasma IL-6 to IL-10 levels) and a downregulation of T-lymphocyte and monocyte activation, but it had no effect on circulating immune cell numbers or neutrophil degranulation responses. Renal function, proteinuria, and BP were also unaffected. These findings provide compelling evidence that walking exercise is safe with regard to immune and inflammatory responses and has the potential to be an effective anti-inflammatory therapy in predialysis CKD.

HIV-1 Is Not a Major Driver of Increased Plasma IL-6 Levels in Chronic HIV-1 Disease

Increased plasma IL-6 levels have been associated with HIV-1 disease progression risk, yet the drivers of IL-6 production in HIV-1 infection are not known. This study was designed to explore the relationship between HIV-1 replication and IL-6 induction. Correlations between plasma levels of IL-6 and HIV-1 RNA were examined in 2 clinical studies. To more directly assess the induction of IL-6 by HIV-1, several cell and tissue types that support HIV-1 replication in vivo were infected with HIV-1, and expression of IL-6 was measured. Spearman rank correlations were used to examine the relationship between plasma levels of IL-6 and HIV-1 RNA. Macrophages and colonic and lymph node histocultures were infected with HIV-1 or stimulated with bacterial products, lipopolysaccharide (LPS) or flagellin, and IL-6 levels in supernatant were measured by enzyme-linked immunosorbent assay or multiplex bead assay. In the clinical studies, there was weak or no correlation between plasma levels of IL-6 and HIV-1 RNA, but IL-6 levels were correlated with plasma levels of the LPS coreceptor CD14. Macrophages stimulated with LPS or flagellin showed robust production of IL-6, but there was no increase in IL-6 production after HIV-1 infection. IL-6 expression was not increased in lymph node histocultures obtained from HIV-1-infected subjects nor after productive HIV-1 infection of colonic or lymph node histocultures ex vivo. We find no evidence that HIV-1 replication is an important driver of IL-6 expression in vivo or in in vitro systems.

Effects of Repeated Bouts of Supramaximal Exercise on Plasma Adiponectin, Interleukin-6, and Tumor Necrosis Factor-α Levels in Sedentary Men

The objective of the study was to determine the effects of repeated bouts of supramaximal exercise on plasma adiponectin, interleukin (IL)-6 and tumor necrosis factor (TNF)-α levels in sedentary men. Fourteen healthy, nonsmoking, and sedentary men aged between 18.4 and 21.4 years participated in the study. All the subjects performed 5 Wingate tests (WTs) with 75 g per kilogram body weight load with 2-minute intervals between the tests. Blood samples were collected at preexercise, immediately after, 15 and 60 minutes after the fifth WT. Serum and plasma samples were stored at -80°C until the time of analysis for myoglobin, adiponectin, IL-6, and TNF-α. Plasma adiponectin levels decreased, whereas IL-6 levels increased postexercise compared with that preexercise. The TNF-α levels were not changed with supramaximal exercise. In conclusion, repeated bouts of supramaximal exercise cause an inflammatory response in exercised muscle and increase in plasma IL-6 levels and decrease in adiponectin concentrations.

Mo1879 EGFR in Gastroesophageal Reflux Disease, Barrett's, Esophagus, and Esophageal Adenocarcinoma

Adipose tissue has been shown to produce a number of inflammatory cytokines and may play a role in the development and progression of several inflammatory diseases. Accumulation of intra-abdominal fat correlates more strongly with inflammatory disease states than does total body fat, suggesting depot-specific differences in the inflammatory potential of adipose tissue. In inflammatory bowel disease specifically, recent clinical studies suggest that patients with increased intra-abdominal fat may suffer a more aggressive clinical course. Objective: The purpose of the present study was to evaluate the significance of inflammatory cytokine production by various adipose tissue depots during acute experimental colitis. Methods: Colitis was induced in C57BL mice by addition of 2% dextran sulfate sodium (DSS) to drinking water for 5 days. Mice were sacrificed at Day 3, 7, 14, and 21 following initiation of DSS treatment. Control mice were sacrificed prior to initiation of treatment. Plasma cytokine levels at time of sacrifice were analyzed by multiplex assays. Colonic tissue damage was evaluated histologically by H&E staining. Tissue levels of cytokine mRNAwere compared between the colon, 3 adipose tissue depots (mesenteric, epididymal, and subcutaneous), kidney, and liver by qRT-PCR. Results: Histologic evidence of colitis and significantly increased plasma IL-6 levels were evident by Day 7 and peaked at Day 14. Changes in cytokine expression within the colon occurred earlier, with significant increases in TNF-a, IL-1b, and IL-6 mRNA all evident by Day 3 (P=0.016). Of the cytokines analyzed, IL-6 in the colon exhibited the most profound increase with colitis, with levels at Day 7 increased 230-fold from baseline (P=0.002). Analysis of adipose tissues from this time point revealed that while IL-6 mRNA expression in mesenteric and epididymal adipose tissue was significantly increased compared to controls, 8.6-fold (P=0.016) and 3.8-fold (P=0.004) respectively, no increase in subcutaneous adipose tissue IL-6 mRNA was observed. Multi-tissue analysis at this time point revealed that mesenteric and epididymal adipose tissue expressed significantly more IL-6 mRNA than the kidney or the liver, whose levels of IL-6 did not increase significantly from baseline. Conclusions: This study demonstrates that intra-abdominal adipose tissue is a major source of IL-6 during acute experimental colitis. The time course analysis suggests that intra-abdominal fat may have a significant impact on plasma IL-6 levels. Unlike the mesentery, the epididymal fat pad is not contiguous with the inflamed bowel and does not contain the venous or lymphatic drainage of the affected bowel. This suggests a tissue-specific response by the intra-abdominal adipose tissue, rather than merely a local lymphoid reaction to tissue damage in the colon.

Differential effects of shiitake- and white button mushroom-supplemented diets on hepatic steatosis in C57BL/6 mice

Shiitake mushrooms (SMs) have been used in Asia for treatment and/or prevention of chronic diseases and hypercholesterolemia. Previously, we observed a diet supplemented with 5% SM resulted in a twofold increase in plasma IL-6 levels in DBA arthritic mice. An elevation in plasma IL-6 has also been implicated in the pathogenesis fatty liver disease. Thus, the aim of this study was to investigate the effect of SM supplemented-diet on hepatic steatosis. In study 1, eight-week old female C57BL/6 mice were randomly assigned to the following groups for 6weeks: the AIN-93 diet; 5% SM, and 5% white button mushroom (WBM) supplemented diets (12/group). In study 2, mice were fed either the AIN-93 diet or SM (20/group). After 6weeks, 13 mice fed SM diet were given the AIN93 diet for 8 or 15days. Unlike other groups, all mice fed the SM diet developed fatty liver (mean histopathology score 4.5 vs <1 in the other groups; p<0.001) without fibrosis and inflammation. Fifteen days post withdrawal of SM completely normalized liver histology. To the best of our knowledge, this is the first report that chronic consumption of SM is associated with the development of fatty liver. The mechanism by which SM causes hepatic steatosis warrants further investigation.

Genetic deficiency of Smad3 protects against murine ischemic acute kidney injury

TGF-β1 contributes to chronic kidney disease, at least in part, via Smad3. TGF-β1 is induced in the kidney following acute ischemia, and there is increasing evidence that TGF-β1 may protect against acute kidney injury. As there is a paucity of information regarding the functional significance of Smad3 in acute kidney injury, the present study explored this issue in a murine model of ischemic acute kidney injury in Smad3(+/+) and Smad3(-/-) mice. We demonstrate that, at 24 h after ischemia, Smad3 is significantly induced in Smad3(+/+) mice, whereas Smad3(-/-) mice fail to express this protein in the kidney in either the sham or postischemic groups. Compared with Smad3(+/+) mice, and 24 h following ischemia, Smad3(-/-) mice exhibited greater preservation of renal function as measured by blood urea nitrogen (BUN) and serum creatinine; less histological injury assessed by both semiquantitative and qualitative analyses; markedly suppressed renal expression of IL-6 and endothelin-1 mRNA (but comparable expression of MCP-1, TNF-α, and heme oxygenase-1 mRNA); and no increase in plasma IL-6 levels, the latter increasing approximately sixfold in postischemic Smad3(+/+) mice. We conclude that genetic deficiency of Smad3 confers structural and functional protection against acute ischemic injury to the kidney. We speculate that these effects may be mediated through suppression of IL-6 production. Finally, we suggest that upregulation of Smad3 after an ischemic insult may contribute to the increased risk for chronic kidney disease that occurs after acute renal ischemia.

Expression of C-reactive protein and cyclooxygenase enzyme-2 in clear cell renal cell carcinoma: correlation with pathological parameters in 110 patients

C-reactive protein is produced in response to cytokines such as interleukin (IL)-6. It is known that increased plasma IL-6 levels induce increased hepatic and intratumoral production of C-reactive protein. Cyclooxygenase enzyme-2 is induced by various stimuli, including inflammation and various growth factors. Expression of these two markers has not been well studied in clear cell renal cell carcinoma. The objective of this study is to correlate the expression of C-reactive protein and cyclooxygenase enzyme-2 in clear cell renal cell carcinoma with pathologic parameters. A search of the surgical pathology and consultation files at our institution was performed for nephrectomy specimens with clear cell renal cell carcinoma from 2007 to 2008. Immunohistochemical stains for C-reactive protein and cyclooxygenase enzyme-2 were performed. Staining intensity was graded as 0, 1+, 2+, and 3+. The staining intensity was then correlated with pathologic stage and Fuhrman nuclear grade for each case. A total of 110 cases were identified. Strong expression of C-reactive protein was associated with higher Fuhrman nuclear grade and pathologic stage, and the strength of correlation was statistically significant (p = 0.01 and p = 0.001), respectively. However, cyclooxygenase enzyme-2 expression did not show statistically significant correlation with both pathologic stage and Fuhrman nuclear grade (p = 0.1 and p = 0.15), respectively. To our knowledge, this is the largest study to date correlating the expression of both C-reactive protein and cyclooxygenase enzyme-2 in tissue with pathologic parameters in patients with clear cell renal cell carcinoma, which could have significant prognostic and therapeutic implications.

Thrombopoietin limits IL-6 release but fails to attenuate liver injury in two hepatic stress models

Various pleiotropic substances have been suggested as candidates that directly reduce the severity of liver injury after hepatic ischemia/reperfusion (I/R) and upon acute liver failure (ALF). Herein, we studied whether thrombopoietin (TPO), the main regulator of megakaryopoiesis and thrombopoiesis, showed hepatoprotective effects and might mediate an antiapoptotic function in liver tissue under stress. In livers with ALF or undergoing warm hepatic I/R, injury was quantified by intravital fluorescence microscopy, chemical, and immunohistochemical analysis as well as western immunoblot. Induction of both ALF and I/R injury led to hepatocellular expression of c-mpl, the receptor of TPO. Exogenous application of recombinant TPO in a low (12.5 microg/kg) as well as a high (75 microg/kg) dose, however, did not ameliorate postischemic perfusion and leukocyte endothelial cell interaction, but slightly aggravated transaminase release upon I/R. Similarly, TPO was unable to dampen hepatic microcirculatory deteriorations after the induction of ALF, but caused an increase of leukocyte accumulation and transaminase activity when applied in high dose. Low dose of TPO did not influence the amount of hepatocellular apoptosis, whereas high-dose TPO slightly diminished the activation of caspase 3. Interestingly, exogenous TPO application completely reversed the stress-induced increase of plasma IL-6 levels, suggesting a negative feedback of TPO on IL-6 release. Although the existence of the TPO-receptor on target liver cells TPO plays only a minor role in mediating hepatocyte apoptosis and does not provide protection against hepatic injury, contrasting the efficacy of the related hematopoietic growth factor erythropoietin.

Aspirin, but not propranolol, attenuates the acute stress-induced increase in circulating levels of interleukin-6: A randomized, double-blind, placebo-controlled study

Psychosocial stress might increase the risk of atherothrombotic events by setting off an elevation in circulating levels of the proinflammatory cytokine interleukin (IL)-6. We investigated the effect of aspirin and propranolol on the responsiveness of plasma IL-6 levels to acute psychosocial stress. For 5 days, 64 healthy subjects were randomized, double-blind, to daily oral aspirin 100 mg plus long-acting propranolol 80 mg, aspirin 100 mg plus placebo, long-acting propranolol 80 mg plus placebo, or placebo plus placebo. Thereafter, all subjects underwent the 13-min Trier Social Stress Test, which combines a preparation phase, a job interview, and a mental arithmetic task. Plasma IL-6 levels were measured in blood samples collected immediately pre- and post-stress, and 45 min and 105 min thereafter. The change in IL-6 from pre-stress to 105 min post-stress differed between subjects with aspirin medication and those without ( p = 0.033; η p 2 = 0.059). IL-6 levels increased less from pre-stress to 105 min post-stress ( p < 0.027) and were lower ( p = 0.010) at 105 min post-stress in subjects with aspirin than in subjects without aspirin. The significance of these results was maintained when controlling for gender, age, waist-to-hip ratio, mean arterial blood pressure, and smoking status. Medication with propranolol was not significantly associated with the stress-induced change in IL-6 levels. Also, aspirin and propranolol did not significantly interact in determining the IL-6 stress response. Aspirin but not propranolol attenuated the stress-induced increase in plasma IL-6 levels. This suggests one mechanism by which aspirin treatment might reduce the risk of atherothrombotic events triggered by acute mental stress.