Plasma Concentrations Of Proinflammatory Cytokines Research Articles

Metabolic Activation and Inflammation Reactions Involved in Carbamazepine-Induced Liver Injury

Drug-induced liver injury is a major safety concern in drug development and clinical pharmacotherapy; however, advances in the understanding of the mechanisms of drug-induced liver injury are hampered by the lack of animal models. Carbamazepine (CBZ) is a widely used antiepileptic agent. Although the drug is generally well tolerated, only a small number of patients prescribed CBZ develop severe hepatitis. In the present study, we developed a mouse model of CBZ-induced liver injury and elucidated the mechanisms accounting for the hepatotoxicity of CBZ. Male BALB/c mice were orally administered CBZ for 5 days. The plasma levels of alanine aminotransferase and aspartate aminotransferase were prominently increased, and severe liver damage was observed via histological evaluation. The analysis of the plasma concentration of CBZ and its metabolites demonstrated that 3-hydroxy CBZ may be relevant in CBZ-induced liver injury. The hepatic glutathione levels were significantly decreased, and oxidative stress markers were significantly altered. Mechanistic investigations found that hepatic mRNA levels of toll-like receptor 4, receptor for advanced glycation end products, and their ligands were significantly increased. Moreover, the plasma concentrations of proinflammatory cytokines were also increased. Prostaglandin E(1) administration ameliorated the hepatic injury caused by CBZ. In conclusion, metabolic activation followed by the stimulation of immune responses was demonstrated to be involved in CBZ-induced liver injury in mice.

The impact of hyaluronan on monocyte Toll-like receptor expression in term infant cord blood

To explore the possible effects of hyaluronan, an endogenous mediator of inflammation, on monocyte surface expression of Toll-like receptors 2 and 4 in human umbilical cord blood ex vivo, and in a model mimicking Gram-negative neonatal sepsis. Term infant cord blood was obtained after elective caesarean sections, n = 15. Both unstimulated and lipopolysaccharide-stimulated (10 ng/mL) blood was incubated with 500 μg/mL high- or low-molecular-weight hyaluronan for 6 h. Expression of Toll-like receptors 2 and 4 on monocytes was measured using flow cytometry, and plasma concentrations of proinflammatory cytokines and matrix metalloproteinase 9 were analysed. RESULTS (MEAN ± SEM): We found a significant decrease in Toll-like receptor 4 expression in the presence of high-molecular-weight hyaluronan (HMW HA) in unstimulated blood (median fluorescence intensity 141 ± 7.3 vs. 163 ± 9.8, p = 0.019). There were no significant changes in Toll-like receptor 2 expression. Levels of cytokines and matrix metalloproteinase 9 increased in the presence of both forms of hyaluronan. Our results confirm that hyaluronan affects the neonatal immune response. The biological significance of these findings requires further clarification. More studies are needed to validate the possible down-modulation of Toll-like receptor 4 exerted by HMW HA.

Bacterial Translocation Is Reduced by a Specific Nutritional Combination in Mice with Chemotherapy-Induced Neutropenia

AbstractImmune function is compromised in many cancer patients, leading to an increased risk of (infectious) complications.Chemotherapy-induced neutropenia is a common cause of treatment-induced immune suppression. In the present study,the effect of a specific nutritional combination (SNC) on bacterial translocation was studied in a model of chemotherapy induced neutropenia in C3H/HeN mice colonized with Pseudomonas aeruginosa PAO-1. Dietary intervention started after stable colonization with P. aeruginosa to compare the SNC containing high protein, L-leucine, fish oil, and specific oligosaccharides to an isoenergetic control diet. After 3 wk, the mice were treated with cyclophosphamide to induce neutropenia. This rendered the mice susceptible to Pseudomonas translocation, which was quantified 5 d later. Intervention with the SNC resulted in a reduced incidence and intensity of bacterial translocation to the liver (P , 0.05) and a similar trend in the lungs (P ≤ 0.057). In addition, the SNC reduced the fecal pH (P < 0.05) and decreased P. aeruginosa counts in fecal samples (P < 0.05). Moreover, plasma concentrations of proinflammatory cytokines were correlated with the reduced bacterial translocation to the liver (r > 0.78; P < 0.001). In conclusion, dietary intervention with the SNC significantly reduced the incidence and severity of P. aeruginosa translocation in a mouse model of chemotherapy-induced immune suppression.Several mechanisms might have played a role, including the modulation of the intestinal microbiota, an improved gut barrier function, immune function, and a reduced inflammatory state. These results suggest an opportunity to develop newapplications in cancer patients, with the aim to reduce infectious and other complications.

Hormonal, hypothalamic and striatal responses to reduced body weight gain are attenuated in anorectic rats bearing small tumors

Lack of compensatory or even reduced food intake is frequently observed in weight-losing cancer patients and contributes to increased morbidity and mortality. Our previous work has shown increased transcription factor expression in the hypothalamus and ventral striatum of anorectic rats bearing small tumors. mRNA expression of molecules known to be involved in pathways regulating appetite in these structures was therefore assessed in this study. Given that pain, pro-inflammatory cytokines and metabolic hormones can modify food intake, spinal cord cellular activation patterns and plasma concentrations of cytokines and hormones were also studied. Morris hepatoma 7777 cells injected subcutaneously in Buffalo rats provoked a 10% lower body weight and 15% reduction in food intake compared to free-feeding tumor-free animals 4weeks later when the tumor represented 1–2% of body mass. No differences in spinal cord activation patterns or plasma concentration of pro-inflammatory cytokines were observed between groups. However, the changes in plasma ghrelin and leptin concentrations found in food-restricted weight-matched rats in comparison to ad libitum-fed animals did not occur in anorectic tumor-bearing animals. Real-time PCR showed that tumor-bearing rats did not display the increase in hypothalamic agouti-related peptide mRNA observed in food-restricted weight-matched animals. In addition, microarray analysis and real-time PCR revealed increased ventral striatal prostaglandin D synthase expression in food-restricted animals compared to anorectic tumor-bearing rats. These findings indicate that blunted hypothalamic AgRP mRNA expression, probably as a consequence of relatively high leptin and low ghrelin concentrations, and reduced ventral striatal prostaglandin D synthesis play a role in maintaining cancer-associated anorexia.

High Mobility Group Box 1 Levels in On and Off-Pump Cardiac Surgery Patients

High mobility group box 1 (HMGB1), which has properties similar to those of proinflammatory cytokines, is released from activated immune cells and necrotic cells. It is known that cardiopulmonary bypass (CPB) induces systemic inflammation and aortic cross-clamping induces myocardial ischemia. This study was conducted to clarify whether HMGB1 is released in CPB-supported cardiac surgery in comparison to off-pump coronary artery bypass grafting (OPCAB) where CPB is not used.Nineteen adult patients undergoing cardiac surgery involving CPB (CPB group) and 5 OPCAB patients (OPCAB group) were included in this study. Plasma concentrations of proinflammatory cytokines including HMGB1 were measured before, during, and after cardiac surgery. The plasma HMGB1 level was significantly increased at one hour after aortic declamping in the CPB group and at 30 minutes after revascularization in the OPCAB group. The peak HMGB1 level was slightly higher in the CPB group than that in the OPCAB group. These values decreased toward baseline value after surgery in both groups. TNF-α and IL-1β were not detectable throughout the study period in either group. IL-6 and IL-10 increased after aortic declamping in the CPB group and after coronary revascularizations in the OPCAB group.Based on these results, we conclude that the major factor involved in the increase in HMGB1 level might be myocardial ischemia/reperfusion during cardiac surgery. Activation of immune cells, altered tissue perfusion, and pulmonary ischemia and reperfusion could be additional factors that increase the HMGB1 level in CPB-supported cardiac surgery.

Caveolin-1 Deficiency Dampens Toll-Like Receptor 4 Signaling through eNOS Activation

Caveolin-1 (Cav1), the scaffolding protein of caveolae, has been shown to play an important role in host defense and inflammation. However, the underlying molecular basis for these actions remains elusive. Here, using double mutant mice with genetic deletions of Cav1 and NOS3, we show that chronic endothelial nitric oxide synthase (eNOS) activation secondary to loss of Cav1 serves a crucial immunomodulatory function through tyrosine nitration-mediated impairment of interleukin-1 receptor associated kinase (IRAK)4, a signaling component required for nuclear factor-kappaB activation and innate immunity. We observed an eNOS-dependent decrease in the plasma concentration of pro-inflammatory cytokines and marked improvement of survival in Cav1(-/-) mice following lipopolysaccharide challenge. Activation of eNOS secondary to loss of Cav1 resulted in decreased activation of nuclear factor-kappaB in response to lipopolysaccharide challenge, and thereby protected the animals from lipopolysaccharide-induced lung injury. IRAK4 was prominently nitrated in Cav1-deficient endothelial cells, whereas eNOS deletion in Cav1-deficient endothelial cells resulted in marked decrease of IRAK4 nitration and restored the inflammatory response after lipopolysaccharide challenge. Furthermore, in vitro nitration of IRAK4 resulted in impairment of the kinase activity. Thus, eNOS activation secondary to loss of Cav1 signals dampening of the innate immune response to lipopolysaccharide through IRAK4 nitration and the resultant impairment of kinase activity, and consequently mitigates inflammatory lung injury.

Acupuncture Induces a Pro-Inflammatory Immune Response Intensified by a Conditioning-Expectation Effect

Background: In a previous study it has been shown that acupuncture activates the respiratory burst (RB) of neutrophils as measured by the differences to baseline of the mean channel number of fluorescence intensity (mfi) in volunteers. Since this result could have been affected by a placebo effect, a study has been designed that controls for the different facets of placebo mechanisms such as expectancy, suggestibility, and conditioning. Participants and Methods: 60 healthy volunteers were randomized either to acupuncture of the acupoint Large Intestine 11 (LI 11) (groups 1 and 2) or relaxation (group 3) twice a week for 4 weeks. Only acupuncture group 1 and the relaxation group were provided with the additional suggestion that the treatment may strengthen the immune system. Results: The repeated measurement analysis for differences of follow-ups to baseline showed significantly different treatment effects for neutrophils but not for monocytes (unprimed neutrophils: p = 0.004; neutrophils primed with TNF-alpha/FMLP or with FMLP only: p = 0.026 and p = 0.019, respectively) between groups. For both cell types post-hoc Dunnett’s t-tests using the relaxation group as control showed significantly stronger treatment effects for acupuncture group 1. Combining all priming procedures, the average increase in mfi for both cell types was about 30% greater in acupuncture group 1 than in the relaxation group. Plasma concentrations of pro-inflammatory cytokines only increased significantly in the acupuncture groups. Conclusion: Repetitive acupuncture increases the cytotoxicity of leukocytes in healthy volunteers, which might be intensified by a conditioning-expectation effect.

Relation of Soluble Endothelial Protein C Receptor and Cytokines After Allogeneic Hematopoietic Stem Cell Transplantation

The objective of this study was to elucidate the effects of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), interleukin 2 (IL-2), interleukin 6 (IL-6), and interleukin 8 (IL-8) on the expression of soluble endothelial protein C receptor (sEPCR) in the pathogenesis of thrombotic complications after hematopoietic stem cell transplantation (HSCT). The relationship between plasma concentrations of proinflammatory cytokines (TNF-α, IL-1β, IL-2, IL-6, and IL-8) and sEPCR was evaluated in 32 consecutive allogeneic hematopoietic stem cell-transplanted patients prior to conditioning regimen and randomly once between +5 and +30 days after transplantation and compared these results with 20 healthy controls. Soluble endothelial protein C receptor levels did not indicate any significant difference between pre- and posttransplantation period, and sEPCR levels showed a significantly negative correlation between IL-6 and IL-8 (sEPCR and IL-6, r = -.43, P < .01; sEPCR and IL-8, r = -.57, P < .01). There was no correlation between sEPCR levels and TNF-α, IL-1β, or IL-2 (sEPCR and TNF-α, r = -.13, P > .05; sEPCR and IL-1β, r = -.1, P ≥ .05; sEPCR and IL-2, r = -.07, P > .05). Our results suggest that the production of sEPCR was not affected by allogeneic HSCT. Soluble endothelial protein C receptor did not show any positive correlation between these proinflammatory cytokines (TNF-α, IL-1β, IL-2, IL-6, and IL-8), on the contrary a significantly negative correlation was determined between sEPCR and either IL-6 or IL-8. This negative correlation may be a protective mechanism in the pathway of protein C activation.

Effect of Plasma Phospholipid Transfer Protein Deficiency on Lethal Endotoxemia in Mice

Lipopolysaccharides (LPS) are components of Gram-negative bacteria. The cellular response from the host to LPS is mediated through stepwise interactions involving the lipopolysaccharide-binding protein (LBP), CD14, and MD-2, which produces the rearrangement of TLR4. In addition to LBP, the lipid transfer/lipopolysaccharide-binding protein gene family includes the phospholipid transfer protein (PLTP). Here we show that the intravascular redistribution of LPS from the plasma lipoprotein-free fraction toward circulating lipoproteins is delayed in PLTP-deficient mice. In agreement with earlier in vitro studies, which predicted the neutralization of the endotoxic properties of LPS when associated with lipoproteins, significant increases in the plasma concentration of proinflammatory cytokines were found in PLTP-deficient as compared with wild type mice. Similar inflammatory damage occurred in tissues from wild type and PLTP-deficient mice 24 h after one single intraperitoneal injection of LPS but with a more severe accumulation of red blood cells in glomeruli of LPS-injected PLTP-deficient mice. Complementary ex vivo experiments on isolated splenocytes from wild type and PLTP-deficient mice further supported the ability of cell-derived PLTP to prevent LPS-mediated inflammation and cytotoxicity when combined with lipoprotein acceptors. Finally, PLTP deficiency in mice led to a significant increase in LPS-induced mortality. It is concluded that increasing circulating levels of PLTP may constitute a new and promising strategy in preventing endotoxic shock.

Low density lipoprotein from patients with Type 2 diabetes increases expression of monocyte matrix metalloproteinase and ADAM metalloproteinase genes

AimsType 2 diabetes is characterised by increased plasma concentrations of pro-inflammatory cytokines [such as tumour necrosis factor – alpha; TNF-α] and soluble forms of adhesion molecules involved in leukocyte – endothelial interactions. These molecules are synthesised as transmembrane proteins and the plasma soluble forms are generated by ectodomain cleavage from the cell surface by members of the ADAM [adisintegrin and metalloproteinase] proteinase family. We hypothesised that plasma low density lipoprotein [LDL] from subjects with Type 2 diabetes would influence in vitro monocytic ADAM and matrix metalloproteinase [MMP] gene expression differently compared to control LDL.MethodsWe examined relative mRNA expression by real time PCR in a monocytic cell line [THP-1] cultured for 4, 8 and 24 hrs with human plasma LDL derived from subjects with [n = 5] or without [n = 4] Type 2 diabetes. Gene expression for MMP-1 and 9, and ADAM – 8, 15, 17 and 28 was studied.ResultsType 2 diabetes LDL significantly increased gene expression of MMP – 1 [p < 0.01] MMP – 9 [p < 0.001], and ADAM 17 [p < 0.05], – 28 [p < 0.01] and – 15 [p < 0.01] compared to control LDL. Type 2 diabetes LDL had disparate effects on inhibitors of MMP.ConclusionThese data suggest that Type 2 diabetes LDL could lead to increased adhesion molecule and TNF alpha cell surface shedding, and vascular plaque instability, by promoting increased expression of ADAM and MMP genes.

Normal-weight obese syndrome: early inflammation?

Background: In obese subjects, the adipose mass represents an important source of proinflammatory cytokines. We have identified a new syndrome—the normal-weight obese (NWO) syndrome—in women with normal weight and body mass index but whose fat mass is >30% of their total body weight and whose risk of developing obesity-related diseases is likely increased.Objective: The aim of the present study was to verify the hypothesis that NWO women are characterized by early inflammation, related to body fat mass, and that their plasma proinflammatory cytokine concentrations are greater than those of nonobese women.Design: Twenty NWO, 20 preobese-obese, and 20 healthy (nonobese), age-matched white Italian women were studied. Anthropometric variables and plasma concentrations of proinflammatory cytokines and cardiovascular disease (CVD) risk factors were measured and compared between groups.Results: Plasma values and body-composition measures were significantly different between the preobese-obese and nonobese women. No significant differences in body weight, laboratory values, or CVD risk factors were found between the NWO and nonobese groups. Compared with concentrations in the NWO women, plasma concentrations of interleukin (IL)-1α, IL-1β, IL-6, IL-8, and TNF-α were significantly lower in the nonobese group and were significantly greater in the preobese-obese group. IL-6 and TNF-α concentrations were related to fat mass distribution in the NWO women.Conclusions: The proinflammatory cytokines could be regarded as significant prognostic indicators of the risk of obesity, CVD, and the metabolic syndrome in NWO women.

Cardiotrophin-1 induces interleukin-6 synthesis in human umbilical vein endothelial cells

In patients with chronic heart failure (CHF) increased plasma concentrations of proinflammatory cytokines are found. For example, the plasma interleukin-6 (IL-6) concentration correlates with disease severity. Beside IL-6 cardiotrophin-1 (CT-1), a member of the IL-6 superfamily, is also increased in CHF. We examined whether CT-1 is able to induce IL-6 in human umbilical vein endothelial cells (HUVEC) and characterised the underlying pathway. IL-6 mRNA was determined by real-time PCR and by RT-PCR in HUVEC which were stimulated with different CT-1 concentrations and for different time periods. IL-6 concentration in the supernatant was determined by ELISA. For the pathway determination following inhibitors were used: piceatannol (signal transducer and activation of transcription (STAT)3 phosphorylation), wortmannin (phosphatiylinositol 3-kinase (PI3K)), SB203580 (p38 mitogen-activated protein kinase (MAPK)), AG490 (Janus kinase (JAK)2), PD98059 (mitogen-activated protein kinase kinase (MEK) 1/2), parthenolide (nuclear factor κB) and cycloheximide (protein biosynthesis). CT-1 caused a concentration- and time-dependent increase in IL-6 mRNA in HUVEC with a maximal induction seen after 6 h (2-fold compared to control) with 100 ng/ml CT-1. In the supernatant of HUVEC a concentration- and time-dependent increase of IL-6 protein was found. A maximum effect with 100 ng/ml CT-1 was found after 24 h (11-fold compared to control). AG490, SB203580, piceatannol, parthenolide and cycloheximide inhibit CT-1 induced IL-6 mRNA and protein expression whereas wortmannin and PD98059 did not inhibit IL-6 expression. CT-1 induced both IL-6 mRNA and protein in a concentration- and time-dependent manner in HUVEC. The underlying pathway includes activation of JAK2, STAT3, p38 and NFκB. CT-1 induced IL-6 expression and requires protein synthesis and IL-6 is not stored intracellularly. We speculate that in CHF CT-1 might be in part responsible for increased IL-6 plasma concentrations. Modulation of the CT-1 pathway may be a further strategy in CHF treatment.

Effects of Preoperative Statin Therapy on Cytokines after Cardiac Surgery

In addition to their lipid-lowering action, it has been demonstrated that statins can exert direct anti-inflammatory effects. We investigated the effect of preoperative statin therapy on systemic inflammatory markers and myocardial NF-kappaB inhibitor IkappaB-alpha after cardiac surgery. Thirty-six patients undergoing elective coronary artery bypass grafting with cardiopulmonary bypass (CPB) with cardioplegia were divided into two groups (statin group, n = 18; control group, n = 18). Plasma concentrations of pro-inflammatory cytokines (tumor necrosis factor alpha [TNFalpha], interleukin [IL]-6, IL-8) and anti-inflammatory IL-10 were measured before and 1, 4, 10, and 24 hours (h) after CPB. Phosphorylated IkappaB-alpha/total IkappaB-alpha ratio was assessed before and after CPB in right atrial biopsies. Baseline and operative data did not differ between groups. Statin therapy was associated with lower preoperative low-density lipoprotein levels compared to control (73+/-6 vs. 92+/-6 mg/dL; P=0.03). Release of IL-6 was attenuated in the statin group at 4 h (2270+/-599 vs. 5120+/-656 pg/ml; P<0.01) and 10 h (1295+/-445 vs. 3116+/-487 pg/ml; P<0.05) compared to the control group. IL-10 increased after surgery in both groups (P<0.05), but was higher in the statin group at 1 h (66+/-15 vs. 26+/-16 pg/mL; P<0.01). Phosphorylated IkappaB-alpha/total IkappaB-alpha ratio before CPB did not differ between groups, but was elevated after CPB in both groups (P<0.05), indicating enhanced degradation of IkappaB-alpha. Statin therapy had no effect on TNFalpha and IL-8. Preoperative statin therapy attenuates the release of pro-inflammatory IL-6 and up-regulates anti-inflammatory IL-10 after cardiac surgery with cardioplegia, but fails to inhibit phosphorylation of myocardial IkappaB-alpha.

Effect of 2 anesthetic techniques on the postoperative proinflammatory and anti-inflammatory cytokine response and cellular immune function to minor surgery

Study Objective The aim of this study was to investigate the influence of 2 established anesthetic techniques: total intravenous anesthesia and balanced inhalation anesthesia (BAL) on the perioperative-induced changes of peripheral blood mononuclear cells (PBMCs), changes in lymphocyte subsets, and the balance of proinflammatory and anti-inflammatory cytokines. Design This is a prospective, randomized, clinical comparison study. Settings This study was set at a university hospital. Patients This study involved 50 patients with American Society of Anesthesiologists physical status I who were scheduled for elective minimal invasive partial diskectomy. Interventions There was no intervention involved in this study. Measurements Changes in differential counts, lymphocyte subsets, and proliferation rates were determined before surgery and in the early postoperative period. Plasma concentrations of proinflammatory cytokines (IL-2, IL-6, IL-12, interferon γ) and anti-inflammatory cytokines (IL-10, IL-1RA, transforming growth factor β), and plasma concentrations of cortisol, epinephrine, and norepinephrine were measured before, during, and after surgery. Main Results Absolute number of CD3 +, CD4 +, and CD8 +, and expression of HLA-DR and activation marker CD25 +, CD26 +, and CD69 + decreased more in response to surgery after BAL. Changes in distribution of T-lymphocyte cells seem to be in part related to severe postoperative pain. Plasma concentration of IL-6 significantly increased during and after surgery with BAL without relation to pain. Conclusion Anesthetic management may have varying influences on the postoperative immune response. Surgery-induced inflammatory response and alteration in cell-mediated immunity seem to be more pronounced after BAL. These effects were attributed to the enhanced stress response after BAL.

168 Early Patterns of Cytokine Response in Preterm Infants and Neuro-Cognitive Outcome at 2 Years of Age

Background: In a cohort study of preterm infants increased plasma concentrations of proinflammatory cytokines were associated with premature rupture of membranes, arterial hypotension and cerebral damage.Objective: To evaluate in a follow-up if early postnatal levels of cytokines in preterm infants predict neuro-cognitive outcome at 2 years of age.Methods: A prospective cohort study of 71 surviving infants <32 gestational weeks. Plasma concentrations of proinflammatory (TNF-alfa, IL-1beta, IFN-gamma, IL-2, IL-6, IL-8, IL-12) and modulatory (IL-4, IL-10) cytokines were analyzed in umbilical cord and at 6, 24 and 72 h age. Intraventricular hemorrhage (IVH) and white matter brain damage (WMD) was assessed with ultrasound. Neuro-cognitive outcome at 24 months corrected age was evaluated using Bayley Scales of Infant Development (Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI)) and a standardized neurological examination (Neurological Optimality Score (NOS)).Results: 64 infants (mean gestational age (GA) 27.1 wks) were assessed at 24 (0.5) months (mean, SD). NOS correlated with both MDI and PDI (r=0.60 p<0.001 and r=0.70 p<0.001 respectively). GA correlated with MDI, PDI and NOS (r=0.34 p=0.006, r=0.42 p=0.001 and r=0.40, p=0.001 respectively). Male gender had lower NOS (p=0.03). Cord levels of the proinflammatory cytokineTNF-alfa were inversely correlated with PDI (r=-0.33 p=0.014) and levels of the modulatory cytokine IL-10 at 24 h correlated positively with PDI and NOS (r=0.42 p=0.001 and r=0.32, p=0.015 respectively) after adjustment for GA and gender. Infants with IVH grade III/IV or WMD (n=8) had lower median (range) MDI and NOS, 74 (50–106) and 63 (36–76), respectively, as compared to infants without brain injury (n=56): 88 (50–116) and 71 (58–78), respectively. Differences remained after adjustment for GA, gender and parental education.Conclusion: An early inflammatory response in preterm infants is associated with perinatal brain injury and might be prognostic for adverse neuro-cognitive outcome at 2 years of age.

Acute stress response in calorie-restricted rats to lipopolysaccharide-induced inflammation

Calorie restriction (CR) reduces morbidity and mortality in a wide range of organisms, possibly through the stress response machinery. We analyzed the acute phase response of CR rats to lipopolysaccharide (LPS)-induced inflammatory challenge. Six-month-old male F344 rats, fed ad libitum (AL) or a 30% calorie-restricted diet from 6 weeks of age, received an intravenous LPS injection and were then sacrificed between 0 and 8 h. CR attenuated liver injury without reduction in the plasma concentrations of proinflammatory cytokines or nitric oxide (NO). Western blotting analysis of liver tissue demonstrated that CR did not affect the degradation of cytoplasmic I-κB and subsequent nuclear translocation of NF-κB, a key transcription factor after inflammatory challenge. We also analyzed the liver gene expression profiles at 0, 1 and 4 h with DNA arrays and cluster analysis. Compared with the AL group, CR upregulated the expression of several genes for inflammatory mediators or their related molecules at 0 h, but not at 1 or 4 h. CR downregulated genes for energy or xenobiotic metabolism and stress response proteins at 0 h. At 1 h, the relatively downregulated genes by CR were those for proteases and the ubiquitin-proteasome pathway. The present results suggest that CR attenuates liver injury without suppression of the proinflammatory response, and that the protective effect emerges from constitutively, rather than inductively, expressed gene products.

Effect of continuous hemofiltration on hemodynamics, lung inflammation and pulmonary edema in a canine model of acute lung injury.

This study examined whether continuous hemofiltration favorably affects cardiopulmonary variables, lung inflammation, and lung fluid balance in a canine model of oleic acid induced acute lung injury. Eleven pentobarbital-anesthetized dogs were randomly divided into a control (mechanical ventilation, MV) group (n=6) and a MV plus hemofiltration (HF) group (n=5). All animals received an intravenous injection of oleic acid (0.09 ml/kg) to induce acute lung injury. Continuous arterial-venous hemofiltration (blood flow 100 ml/min, ultrafiltration rate at 50-65 ml kg(-1) h(-1)) was started after establishment of oleic acid induced acute lung injury and continued for 4 h. Hemodynamics, lung mechanics, gas exchange, lung fluid balance, lung histology, and the level of plasma cytokines were assessed. After 240 min of HF treatment there was a significant increase in cardiac output, reduction in pulmonary arterial pressure, and improvement in both oxygenation and lung mechanics. Also, in the HF group the lung wet-to-dry weight ratio was significantly reduced. Histologically, HF reduced edema and inflammatory cell infiltration in the lung. There was also a significantly greater decrease in plasma IL-6 and IL-8 levels in the HF group than in group receiving MV alone. In a canine model of acute lung injury continuous HF improved cardiopulmonary function, reduced pulmonary edema, decreased lung permeability and inflammation, and decreased the plasma concentration of proinflammatory cytokines.

Plasma levels of TNF-α and IL-6 are inversely related to cytochrome P450-dependent drug metabolism in patients with congestive heart failure

Background: Cytochrome P450 (CYP) enzymes are important mediators of drug metabolism, and activity of these enzymes is a major determinant of the duration and intensity of drug effect. Circulating plasma concentrations of pro-inflammatory cytokines (e.g., tumor necrosis factor [TNF]-α and interleukin [IL]-6) are elevated in patients with heart failure and these cytokines have been shown to down-regulate CYP enzyme activity. The purpose of this study was to evaluate the relationship between plasma cytokine concentrations and CYP enzyme activities in patients with heart failure. Methods and Results: Sixteen patients with congestive heart failure (New York Heart Association classes II-IV) received a metabolic probe cocktail consisting of caffeine, mephenytoin, dextromethorphan, and chlorzoxazone to assess the activities of the CYP enzymes 1A2, 2C19, 2D6, and 2E1. Blood and urine samples were collected for drug and metabolite determinations by high-performance liquid chromatography (HPLC); cytokine concentrations were measured by enzyme-linked immunosorbent assay (ELISA). We found a striking inverse relationship between both TNF-α and IL-6 plasma concentrations and the activity of CYP2C19; metabolism of caffeine (CYP1A2) also had a negative association with IL-6 plasma concentrations. Conclusions: Cytokine-mediated decreases in drug metabolism may contribute to observed variability in drug response and augment the risk of adverse drug effects in CHF patients.

Effects of intravenous anesthetics on interleukin (IL)-6 and IL-10 production by lipopolysaccharide-stimulated mononuclear cells from healthy volunteers.

Surgical trauma has been shown to augment the plasma concentrations of proinflammatory cytokines, which are important mediators of host defense mechanisms and the systemic inflammatory response syndrome (SIRS). Recently, it has been shown that certain kinds of surgery provoke not only a proinflammatory response (SIRS) but also a concurrent anti-inflammatory response. The aim of this study was therefore to examine the effects of intravenous anesthetics on the synthesis of interleukin (IL)-6 (a proinflammatory cytokine) and IL-10 (an anti-inflammatory cytokine) by lipopolysaccharide (LPS)-stimulated mononuclear cells from healthy volunteers. Peripheral blood mononuclear cells (PBMCs) from 17 healthy volunteers, separated by centrifugation on a Ficoll-Hypaque gradient, were washed and suspended in RPMI containing 10% heat-inactivated fetal calf serum (FCS). After adding RPMI-FCS containing various concentrations of intravenous anesthetics (propofol, thiopental, ketamine and midazolam), the PBMCs were incubated overnight in the presence of a submaximal concentration of LPS. The supernatants were collected and their IL-6 and IL-10 contents were assayed using enzyme-linked immunosorbent assay kits. Propofol inhibited both IL-6 and IL-10 production at 0.5 microg/mL, 5 microg/mL and 50 microg/mL. Conversely, thiopental induced IL-10 production at 2 microg/mL and 20 microg/mL. Propofol appears to inhibit both IL-6 and IL-10 production by LPS-stimulated PBMCs in vitro. Further study is required to clarify the mechanism of the suppressive effect of propofol.

Anti-TNF treatment of baboons with sepsis reduces TNF-alpha, IL-6 and IL-8, but not the degree of complement activation.

The activation of complement and the release of TNF-alpha, IL-6 and IL-8 are important pathogenic factors behind organ dysfunction in sepsis. The aim of this study was to determine whether infusion of anti-TNF antibodies alters complement activation and plasma concentrations of pro-inflammatory cytokines at high doses of Escherichia coli. Six baboons received intravenously 2 x 10(9) live E. coli bacteria per kg body weight (group 1), in addition five received pretreatment with 1 mg per kg body weight anti-TNF antibodies (group 2), and seven received 5 x 10(8) live E. coli bacteria per kg body weight (group 3). Two hours after the start of infusion of the bacteria, plasma concentrations of C3 activation products, C5a and the terminal SC5b-9 complement complex were increased in groups 1 and 2 (P < 0.05), but there was no significant difference between the groups. At 2 h the levels of TNF-alpha, IL-6 and IL-8 were lower in group 2 compared with group 1 (P<0.05). In group 2 compared with group 1 the TNF-alpha concentrations were, however, higher at 4, 8 and 24 h. The explanation for this phenomenon is probably that TNF-alpha binds to the anti-TNF antibody complex and is released slowly after it has been bound. The study showed that infusion of anti-TNF antibodies reduced the concentrations of TNF-alpha, IL-6 and IL-8, without any detectable influence on complement activation.