TUMOUR NECROSIS FACTOR: IMPLICATIONS FOR SURGICAL PATIENTS

Flame retardants, hexabromocyclododecane (HCBD) and tetrabromobisphenol a (TBBPA), alter secretion of tumor necrosis factor alpha (TNFα) from human immune cells

Hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) are flame retardants, used in a variety of applications, which contaminate the environment and are found in human blood. HBCD and TBBPA have been shown to alter the tumor killing function of natural killer (NK) lymphocytes and the secretion of the inflammatory cytokines interferon gamma (IFNγ) and interleukin 1 beta (IL-1β). The current study examined the effects of HBCD and TBBPA on secretion of the critical pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) from human immune cells. Preparations of human immune cells that ranged in complexity were studied to determine if the effects of the compounds were consistent as the composition of the cell preparation became more heterogeneous. Cell preparations studied were: NK cells, monocyte-depleted (MD) peripheral blood mononuclear cells (PBMCs), and PBMCs. Exposure of NK cells to higher concentrations of HBCD (5 and 2.5 µM) caused decreased secretion of TNFα. However, when the cell preparation contained T lymphocytes (MD-PBMCs and PBMCs) these same concentrations of HBCD increased TNFα secretion as did nearly all other concentrations. This suggests that HBCD's ability to increase TNFα secretion from immune cells was dependent on the presence of T lymphocytes. In contrast, exposures to TBBPA decreased the secretion of TNFα from all immune cell preparations regardless of the composition of the cell preparation. Further, HBCD-induced increases in TNFα secretion utilized the p38 MARK pathway. Thus, both HBCD and TBBPA may have the capacity to disrupt the inflammatory response with HBCD having the potential to cause chronic inflammation.

Association between tumor necrosis factor-alpha G-308A polymorphism and dental peri-implant disease risk: A meta-analysis

BACKGROUND

Tumor necrosis factor-alpha (TNF-α) is a potent immune-inflammatory mediator involved in the regulation of bone resorption. The single nucleotide polymorphism G-308A in the TNF-α gene increases the level of this cytokine. This phenomenon is also related to several diseases. Although the association between TNF-α (G-308A) polymorphism and dental peri-implant disease has been investigated, results have remained controversial. Hence, we performed this meta-analysis to provide a comprehensive and systematic conclusion on this topic.

METHODS

We performed a systematic literature search in PubMed, Embase, ISI Web of Science, Cochrane Library, and Chinese National Knowledge Infrastructure until July 2015. A fixed-effect model was established to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs). The calculated values were then used to assess the strength of the association between the TNF-α (G-308A) polymorphism and the dental peri-implant disease risk. The heterogeneity between included studies was evaluated with Cochran Q and I statistics. Interstudy publication bias was investigated with a funnel plot.

RESULTS

Six eligible studies were included in this meta-analysis. The pooled ORs did not reveal a significant relationship between the TNF-α (G-308A) polymorphism and the disease susceptibility. Subgroup analyses in terms of ethnicity and disease type yielded similar results.

CONCLUSION

Our meta-analysis revealed that TNF-α (G-308A) polymorphism was not significantly associated with the risk of dental peri-implant disease. However, further studies with large sample sizes should be performed to verify these results.

A systematic review of the influence of anti-TNF on infection rates in patients with rheumatoid arthritis

OBJECTIVE

The present article aims to provide a systematic review of the influence of antitumor necrosis factor (TNF) on infection rates in patients with rheumatoid arthritis (RA).

METHOD

Medline was searched to obtain quality control information on infection rates in RA patients treated with anti-TNF.

RESULTS

A high proportion of RA patients are now established users of anti-TNF agents. Data from national registries in European countries of patients with RA treated with anti-TNF suggest that biological therapies are closely linked to sepsis. Although previous studies reported a higher risk of infections, there are now emerging data with longer duration of follow-up that suggested an adjusted hazard risk of 1.2. Elderly patients and those with longstanding disease may have a higher rate of serious infections compared to their counterparts who were younger with early disease. There are now emerging data to suggest that anti-TNF therapy is associated with the development of neutropenia shortly after the commencement of treatment. The biologic registries found that RA patients treated with monoclonal antibodies are at increased risk of tuberculosis (TB) compared to those on TNF receptor blockers. This risk of infection needs to be weighed against the established benefits of TNF blockers.

CONCLUSION

Current evidence suggests that anti-TNF treatment in RA is closely linked to infection. Patients need to be aware of the risk of infection together with the established benefits of TNF blockers in order to give informed consent for treatment.

Atrial natriuretic peptide alleviates cardiovascular and metabolic disorders in a rat endotoxemia model: a possible role for its anti-inflammatory properties

BACKGROUND

Atrial natriuretic peptide (ANP) plays important roles in the regulation of cardiovascular and renal homeostasis. Furthermore, several studies have shown that ANP may have anti-inflammatory activities. We hypothesized that ANP may alleviate cardiovascular and/or metabolic disorders in rats with lipopolysaccharide (LPS)-induced endotoxemia.

METHODS

In rats anesthetized with pentobarbital, LPS was injected and ANP was continuously infused at 0.15 µg/kg/min. Mean arterial pressure and pulse rate were monitored hourly, and arterial blood gases were analyzed before LPS injection and at 1, 4, and 6 hours after LPS injection. The expression in the rat left ventricle of mRNAs encoding nitric oxide synthase 2 and 3 (iNOS, eNOS), heme oxygenase 1 and 2 (HO-1, 2), tumor necrosis factor α (TNFα), and interleukin (IL)-1β was measured with the real-time reverse transcriptase-polymerase chain reaction.

RESULTS

LPS increased the expression of TNFα, IL-1β, iNOS, and HO-1, which was inhibited by infusion of ANP. Furthermore, the LPS-induced decrease in mean arterial pressure was attenuated, and the acid-base imbalance caused by increased lactate production was improved 6 hours after the administration of ANP.

CONCLUSIONS

Our results suggest that continuous infusion of ANP counteracts the cardiovascular and metabolic disorders associated with endotoxemia, possibly via anti-inflammatory mechanisms.

Beneficial Effects of Chlorella-11 Peptide on Blocking LPS-Induced Macrophage Activation and Alleviating Thermal Injury-Induced Inflammation in Rats

Chlorella possesses various remarkable biological activities. One component, Val-Glu-Cys-Tyr-Gly-Pro-Asn-Arg-Pro-Gln-Phe ( Chlorella-11 peptide) was found to be able to suppress LPS-induced NO production and inflammation. However, the molecular mechanism behind these findings and the consistency between in vitro and in vivo data have not been investigated. LPS-activated RAW 264.7 macrophages were used to study in vitro molecular anti-inflammatory effects of Chlorella-11 peptide. After activation, NO production and the expression of iNOS and NF-κB proteins as well as iNOS mRNA were measured using Griess colorimetric assay, Western blotting and RT-PCR, respectively. Alterations in PGE2 and TNF-α contents were also monitored by ELISA. For in vivo studies, thermal injury Wistar rats were used and inflammatory indications e.g. serum malondialdehyde (MDA), TNF-α levels and skin erythema were evaluated 48 h after injury implementation. In vitro results showed that Chlorella-11 peptide produced a dose- and time-dependent inhibition on NO production. The effective inhibition could remain for at least 6 h after LPS activation. It was also found that the expression of LPS-induced iNOS mRNA, iNOS and NF-κB proteins were diminished by the peptide treatment. Concurrently, the levels on TNF-α and PGE2 production after LPS activation were also inhibited. These findings are in agreement with the in vivo data that animal serum MDA and TNF-α levels and skin erythema in rats were considerably reduced compared to the control group (saline-treated). The significance of this study sheds light on the effectiveness of Chlorella-11 peptide in preventing inflammation progression in vitro and in vivo and its potential for clinical applications.

Perioperative genomic profiles using structure-specific oligonucleotide probes

OBJECTIVES

Many complications in the perioperative interval are associated with genetic susceptibilities that may be unknown in advance of surgery and anesthesia, including drug toxicity and inefficacy, thrombosis, prolonged neuromuscular blockade, organ failure and sepsis. The aims of this study were to design and validate the first genetic testing platform and panel designed for use in perioperative care, to establish allele frequencies in a target population, and to determine the number of mutant alleles per patient undergoing surgery. DESIGN/SETTING/PARTICIPANTS AND METHODS: One hundred fifty patients at Marshfield Clinic, Marshfield, Wisconsin, 100 patients at the Medical College of Wisconsin Zablocki Veteran's Administration Medical Center, Milwaukee, Wisconsin, and 200 patients at the University of Wisconsin Hospitals and Clinics, Madison, Wisconsin undergoing surgery and anesthesia were tested for 48 polymorphisms in 22 genes including ABC, BChE, ACE, CYP2C9, CYP2C19, CYP2D6, CYP3A4, CYP3A5, beta2AR, TPMT, F2, F5, F7, MTHFR, TNFalpha, TNFbeta, CCR5, ApoE, HBB, MYH7, ABO and Gender (PRKY, PFKFB1). Using structure-specific cleavage of oligonucleotide probes (Invader, Third Wave Technologies, Inc., Madison, WI), 96-well plates were configured so that each well contained reagents for detection of both the wild type and mutant alleles at each locus.

RESULTS

There were 21,600 genotypes confirmed in duplicate. After withdrawal of polymorphisms in non-pathogenic genes (i.e., the ABO blood group and gender-specific alleles), 376 of 450 patients were found to be homozygous for mutant alleles at one or more loci. Modes of two mutant homozygous loci and 10 mutant alleles in aggregate (i.e., the sum of homozygous and heterozygous mutant polymorphisms) were observed per patient.

CONCLUSIONS

Significant genetic heterogeneity that may not be accounted for by taking a family medical history, or by obtaining routine laboratory test results, is present in most patients presenting for surgery and may be detected using a newly developed genotyping platform.

Characterization of the inflammatory response during acute and post-acute phases after severe burn

Severe burn causes a pronounced hypermetabolic response characterized by catabolism and extensive protein wasting. We recently found that this hypermetabolic state is driven by a severe inflammatory response. We characterized in detail the kinetics of serum levels of a panel of cytokines in a rat model, which may serve as reference for the development of therapeutic interventions applicable to humans. Male Sprague-Dawley rats (n = 8) received a full-thickness burn of 60% total body surface area. Serum was harvested 1, 3, 6, 12, 24, 48, 96, and 168 h after burn. Eight serum cytokines commonly used to assess the inflammatory response in humans, such as IL-1beta, IL-6, IL-10, TNF, vascular endothelial growth factor, and monocyte chemotactic protein 1, and the rat-specific cytokines cytokine-induced neutrophil chemoattractant (CINC) 1, CINC-2, and CINC-3 were measured by enzyme-linked immunosorbent assay technique and were compared with controls (n = 4). Statistical analysis was conducted using the t test, with P < 0.05 considered as significantly different. Thermal injury resulted in significantly increased serum levels of IL-1beta, IL-6, IL-10, monocyte chemotactic protein 1, CINC-1, CINC-2, and CINC-3 when compared with the concentrations detected in nonburned rats (P < 0.05). Serum levels of TNF-alpha and vascular endothelial growth factor in burned rats were not found to be significantly different to controls. Burn causes a profound inflammatory response in rats. Specific cytokines known to increase in humans postburn such as IL-1 beta, IL-6, IL-10, MCP-1, and IL-8 (CINC-1, CINC-2, and CINC-3 in the rat) were also observed in our rat burn model, which now allows us to study new anti-inflammatory treatment options.

Genetic polymorphisms and the risk of infection following esophagectomy. positive association with TNF-alpha gene -308 genotype

OBJECTIVE

To examine the association of single nucleotide polymorphisms (SNPs) in inflammation-related genes in the development of infections following esophagectomy.

SUMMARY BACKGROUND DATA

Genetic polymorphisms for immunoregulatory cytokines may explain individual variation in response to trauma. Esophagectomy is associated with a high risk of postoperative infection and sepsis, and this study explored a number of SNPs in cytokine genes and their relationship to postoperative infection.

METHODS

: In a prospective analysis of 197 patients with esophageal cancer undergoing resection, 55 developed postoperative infections. DNA was extracted and genotyping was performed for polymorphisms in genes encoding TNF-alpha, IL-1beta, IL-1 receptor antagonist, IL-10, and Toll-like receptor 4 (TLR-4) using Taqman chemistry and PCR/RFLP. In a blinded analysis, the cohort with infections was compared with the no complication cohort (n = 114) and a cohort that had noninfective complications (n = 28).

RESULTS

No differences in polymorphisms for IL-1beta, IL-1 RN, IL-10, and TLR-4 genes were observed across groups. The frequency of TNF-alpha -308 GG homozygotes was significantly (P = 0.021) higher in the postoperative infection group. The G allele was significantly higher in the postoperative infection group compared with the no complication group (P = 0.017) and other complication group (P = 0.013). By multivariate analysis, this polymorphism as well as age and body mass index were predictors of infection.

CONCLUSION

The TNF-alpha -308A allele has been shown to be associated with higher circulating levels of TNF-alpha and the -308 G allele is a comparative low secretor allele. We propose that the polymorphism in the promotor region of TNF-alpha gene may lead to altered expression and a possible suboptimal activity of TNF-alpha in persons with GG genotypes, and these data suggest a link with infection following major surgery.