Acute Inhibition of Inflammation Mediated by Sympathetic Nerves: The Inflammatory Reflex

In this review, we will try to convince the readers that the immune system is controlled by an endogenous neural reflex, termed inflammatory reflex, that inhibits the acute immune response during the course of a systemic immune challenge. We will analyse here the contribution of different sympathetic nerves as possible efferent arms of the inflammatory reflex. We will discuss the evidence that demonstrates that neither the splenic sympathetic nerves nor the hepatic sympathetic nerves are necessary for the endogenous neural reflex inhibition of inflammation. We will discuss the contribution of the adrenal glands to the reflex control of inflammation, noting that the neurally mediated release of catecholamines in the systemic circulation is responsible for the enhancement of the anti-inflammatory cytokine interleukin 10 (IL-10) but not of the inhibition of the pro-inflammatory cytokine tumour necrosis factor α (TNF). We will conclude by reviewing the evidence that demonstrates that the splanchnic anti-inflammatory pathway, composed by preganglionic and postganglionic sympathetic splanchnic fibres with different target organs, including the spleen and the adrenal glands, is the efferent arm of the inflammatory reflex. During the course of a systemic immune challenge, the splanchnic anti-inflammatory pathway is endogenously activated to inhibit the TNF and enhance the IL-10 response, independently, presumably acting on separate populations of leukocytes.

The effects of phytochemicals and herbal bio-active compounds on tumour necrosis factor-α in overweight and obese individuals: a clinical review

Obesity is abnormal fat accumulation in the body which acts as a risk factor for various cardiometabolic states. Adipose tissue in excess can release inflammatory factors, including TNF-α and IL-6, and suppress adiponectin production. TNF-α increases the levels of IL-6 and acute phase reactants such as C-reactive protein. Inflammation has a crucial role in developing and progressing various cardiometabolic diseases and a wide range of obesity-related complications. It has been shown that TNF-α has a significant role in the development of insulin resistance. Recently, a growing body of evidence has focused on herbal medicine, phytochemicals and natural bioactive compounds as inexpensive, relatively easy accessible agents with low adverse effects to reduce inflammatory markers such as TNF-α and simultaneously decrease insulin resistance, glucose intolerance, and dyslipidemia in obesity. The main focus of the current review is to summarize the results of the studies, which assessed the effects of phytochemicals and herbal bio-active compounds on serum TNF-α in subjects with overweight or obesity. This review suggests that herbal medicine have favorable effects on the reduction of TNF-α concentration; however, the results were not uniform for different products. Among the reviewed plants, ginger, ginseng, resveratrol, and flaxseed had more promising effects.

Association of osteoprotegerin gene T950C polymorphism with cardiometabolic risk factors in gestational diabetes mellitus in South Indian Tamilian women

BACKGROUND & AIMS

This study was designed to explore the relevance of Osteoprotegerin (OPG) and its polymorphism in the cardiometabolic risk in gestational diabetes mellitus patients before diet-therapy (GDMA1).

METHODS

South Indian Tamilian pregnant women were screened and 145 were grouped as GDMA1 (n = 73) and normal pregnancy (n = 72). Serum OPG, TNF α, lipid profile, insulin and blood pressure was compared. Genomic DNA was analysed for rs2073617 T950C polymorphism. Chi square test was done to analyze the frequency distribution of alleles. Multiple regression analysis was done to assess the association among cardiometabolic parameters.

RESULTS

TNF α (p < 0.01), Osteoprotegerin (p < 0.01), lipid profile (p < 0.01), atherogenic indices (p < 0.01), systolic and diastolic and blood pressure (<0.001) levels were higher in GDMA1 patients. TNF α (p < 0.01) and osteoprotegerin (p < 0.01) were higher in women with CT allele. Osteoprotegerin was independently contributed by BMI in all GDMA1 cases and diastolic blood pressure (DBP) in CT allele cases. There was significantly higher odd (OR = 3.63) in the distribution of CT genotype among the multiparous women.

CONCLUSIONS

Osteoprotegerin, atherogenic lipid risk factor and inflammation are higher in GDMA1 women. Rise in OPG is contributed by high BMI in GDMA1 women. Higher odds of CT allele distribution in multiparous women suggests that TT allele women are at higher risk of developing GDM in their first pregnancy. Further analysis of T950C polymorphism in a larger cohort is warranted to confirm its role.

Changes in PCSK 9 and apolipoprotein B100 in Niemann-Pick disease after enzyme replacement therapy with olipudase alfa

Background

Enzyme replacement therapy (ERT) with olipudase alfa, a recombinant human acid sphingomyelinase (rhASM), is being developed to treat patients with ASM deficiency (ASMD), commonly known as Niemann–Pick disease (NPD) types A or B. This study assessed the effect of ERT on lipid parameters and inflammatory markers.

Methods

Serum and plasma samples from five adults with NPD type B (NPD-B) who received olipudase alfa ERT for 26 weeks were analysed. We also collected fasting blood samples from fifteen age- and sex-matched participants as reference and comparison group. We measured fasting lipid profile, apolipoproteins B48 and B100 (apoB48 and apoB100), apolipoprotein A1 (apoA1), proprotein convertase subtilisin/klexin type 9 (PCSK9) mass, oxidised low-density lipoprotein (oxLDL), small dense low-density lipoprotein cholesterol (sdLDL-C) and tumour necrosis factor α (TNF-α).

Results

Patients with NPD-B, compared with age and sex matched reference group, had higher triglycerides, PCSK9, apoB48, oxLDL and TNF-α and lower high density lipoprotein cholesterol (HDL-C) and apoA1. Treatment with ERT was associated with improved lipid parameters including total cholesterol, triglycerides, low density lipoprotein cholesterol (LDL-C), sdLDL-C, oxLDL and apoB100. Though there was an increase in apoA1, HDL-C was slightly reduced. TNF-α showed a reduction. ApoB100 decreased in parallel with a decrease in total serum PCSK9 mass after ERT.

Conclusion

This study demonstrated that patients with NPD-B had a proatherogenic lipid profile and higher circulating TNF-α compared to reference group. There was an improvement in dyslipidaemia after olipudase alfa. It was possible that reductions in LDL-C and apoB100 were driven by reductions in TNF-α and PCSK9 following ERT.

Mycobacterium tuberculosis EsxL induces TNF-α secretion through activation of TLR2 dependent MAPK and NF-κB pathways

Mycobacterium tuberculosis (Mtb) employs distinct strategies to circumvent host immune responses during the infection process. Various Mtb cell-wall associated and secretory proteins are known to play a critical role in the orchestration of host innate immune responses through modulation of signaling pathways. Mtb genome encodes for 23 (EsxA-EsxW) proteins belonging to the ESAT-6 like family; however, most of them are functionally unknown. Here, we show that Mtb EsxL induces tumor necrosis factor-alpha (TNF-α) production by activating nuclear translocation of nuclear factor-κB (NF-κB) via interaction with Toll-like Receptor 2 (TLR2). Blocking or silencing of TLR2 abrogated nuclear translocation of NF-kB and TNF-α production. Treatment with recombinant purified EsxL (rEsxL) activated mitogen-activated protein kinase (MAPK) pathway by inducing the phosphorylation of extracellular signal-regulated kinase (ERK) and p38 kinase (p38) pathways. At the same time, inhibition of ERK and p38 down-regulated the expression of TNF-α in rEsxL exposed murine macrophages. Besides TNF-α, EsxL also induced the production of IL-6 proinflammatory cytokine. Taken together, these results suggest that EsxL is able to induce TNF-α secretion via TLR2 through activation of NF-κB and MAPK signaling. This study will help in deducing therapeutic strategies for better control of the disease.

Evaluation of the effect of experimentally induced cartilage defect and intra-articular hyaluronan on synovial fluid biomarkers in intercarpal joints of horses

BACKGROUND

Inflammatory and degenerative activity inside the joint can be studied in vivo by analysis of synovial fluid biomarkers. In addition to pro-inflammatory mediators, several anabolic and anti-inflammatory substances are produced during the disease process. They counteract the catabolic effects of the pro-inflammatory cytokines and thus diminish the cartilage damage. The response of synovial fluid biomarkers after intra-articular hyaluronan injection, alone or in combination with other substances, has been examined only in a few equine studies. The effects of hyaluronan on some pro-inflammatory mediators, such as prostaglandin E₂, have been documented but especially the effects on synovial fluid anti-inflammatory mediators are less studied. In animal models hyaluronan has been demonstrated to reduce pain via protecting nociceptive nerve endings and by blocking pain receptor channels. However, the results obtained for pain-relief of human osteoarthritis are contradictory. The aim of the study was to measure the synovial fluid IL-1ra, PDGF-BB, TGF-β₁ and TNF-α concentrations before and after surgically induced cartilage defect, and following intra-articular hyaluronan injection in horses. Eight Standardbred horses underwent bilateral arthroscopic surgeries of their intercarpal joints under general anaesthesia, and cartilage defect was created on the dorsal edge of the third carpal bone of one randomly selected intercarpal joint of each horse. Five days post-surgery, one randomly selected intercarpal joint was injected intra-articular with 3 mL HA (20 mg/mL).

RESULTS

Operation type had no significant effect on the synovial fluid IL-1ra, PDGF-BB, TGF-β₁ and TNF-α concentrations but compared with baseline, synovial fluid IL-1ra and TNF-α concentrations increased. Intra-articular hyaluronan had no significant effect on the biomarker concentrations but a trend of mild improvement in the clinical signs of intra-articular inflammation was seen.

CONCLUSIONS

Creation of the cartilage defect and sham-operation lead to an increase of synovial fluid IL-1ra and TNF-α concentrations but changes in concentrations of anabolic growth factors TGF-β₁ and PDGF-BB could not be documented 5 days after the arthroscopy. Intra-articular hyaluronan was well tolerated. Further research is needed to document possible treatment effects of intra-articular hyaluronan on the synovial fluid biomarkers of inflammation and cartilage metabolism.

IL-1β/MMP9 activation in primary human vascular smooth muscle-like cells: Exploring the role of TNFα and P2X7

BACKGROUND

Vascular smooth muscle cells exhibit phenotypic plasticity in response to microenvironmental stimuli and contribute to vascular remodelling through mechanisms only partially understood. In atherosclerosis, P2X-purinoceptor7 (P2X7) has been related to interleukin-1β (IL-1β) and metalloproteinase 9 (MMP9). The hypoxia-inducible factor-1alpha (HIF1α) was associated to remodelling. Here the activation of IL-1β and MMP9 was studied in relationship to P2X7 and HIF1α in cells exploited from human carotid plaque and internal mammary artery.

METHODS AND RESULTS

Migrating cells expressed HIF1α-regulated canopy FGF-signalling regulator 2 and CD117, and led to primary cells with SMC-like phenotype (VSMC), P2X7⁺. We investigated in VSMC the effects of hypoxia, of treatment with tumour necrosis factor-α (TNFα) and/or with P2X7 antagonist, A740003. Quantitative RT-PCR showed that hypoxia unaffected IL-1β and down-regulated MMP9 mRNAs, without activating HIF1α. TNFα increased IL-1β mRNA via NLR Family Pyrin Domain-Containing 3, with production of proIL-1β but no rise of mature IL-1β. Zymography demonstrated that A740003 triggered MMP9 secretion from VSMC. Combination of A740003 with TNFα abrogated this effect. Combination was ineffective on IL-1β activation elicited by TNFα, but down-regulated HIF1α mRNA. A740003 induced the intracellular P2X7 aggregation and differently perturbed lysosome and mitochondria network compared to TNFα.

CONCLUSIONS

Cells migration from human arteries leads to partially differentiated VSMC analogous to neointimal cells within atherosclerotic lesions. Down-regulated HIF1α in stimulated VSMC translates in resilience in atherosclerotic lesions. P2X7-independent partial activation of IL-1β elicited by TNFα underlines complexity of the cytokine secretion. Data also supported P2X7 as modulator of MMP9 secretion, important for atherosclerosis progression.

Associations between circulating levels of adipocytokines and abdominal adiposity in patients after acute pancreatitis

Adipocytokines are strongly associated with abdominal adiposity during the course of acute pancreatitis (AP). This study investigated associations between a panel of adipocytokines and abdominal adiposity in AP patients after hospital discharge, as well as the effect of several covariates. Fasting venous blood samples were collected to measure adiponectin, interleukin 6, leptin, monocyte chemoattractant protein 1, tumour necrosis factor α (TNFα), resistin, and retinol-binding protein 4. Waist circumference (WC), waist-hip ratio, and waist-height ratio (WheightR) were used as measures of abdominal adiposity. Generalised linear models were built, adjusting for age, sex, ethnicity, diabetes status, aetiology, duration since admission for AP, recurrence, and severity of AP. A total of 93 patients were studied, on average at 22 months after AP. Interleukin 6, TNFα, and leptin were significantly associated with WC in both the unadjusted and all the three adjusted models. Also, they were significantly associated with WheightR in both the unadjusted and the three adjusted models. Other studied adipocytokines did not show a consistent association or were not significantly associated with the abdominal adiposity indices. The results suggest that excess abdominal adiposity favours pro-inflammatory milieu in AP patients after hospital discharge, independent of diabetes and effect of other covariates.

Expression analysis of the Atlantic bluefin tuna (Thunnus thynnus) pro-inflammatory cytokines, IL-1β, TNFα1 and TNFα2 in response to parasites Pseudocycnus appendiculatus (Copepoda) and Didymosulcus katsuwonicola (Digenea)

Pro-inflammatory cytokines play an important role in teleost defence against numerous types of pathogens, therefore are often used as biomarkers during various infections. In order to evaluate Atlantic bluefin tuna IL-1β, TNFα1 and TNFα2 induction by PAMPs, we quantified their expression during in vitro stimulation of peripheral blood leukocytes by LPS and Poly I:C. Furthermore, their role in acute and chronic parasitic infection was examined during natural infection of Pseudocycnus appendiculatus (Copepoda) and Didymosulcus katsuwonicola (Digenea), as well as during leukocyte exposure to total protein extracts isolated from two parasite species. Induction of ABT IL-1β and TNFα2 by PAMPs and protein extracts from D. katsuwonicola and P. appendiculatus, as well as during natural infection with two parasites, suggests these cytokines play an important role in inflammation, being engaged in controlling parasite infections, in contrast to ABT TNFα1. Cellular innate response to the digenean D. katsuwonicola showed rather chronic character, resulting with parasite encapsulation in connective tissue. Mast cells, eosinophils, goblet cells, and occasional rodlet cells found at the site of infection, along with the induction of TNFα2, suggest the presence of a moderate inflammatory reaction that fails to seriously endanger digenean existence. In contrast, copepod P. appendiculatus, attached to the gill epithelium by clamping, caused direct tissue disruption with undergoing necrotic or apoptotic processes, and extensive proliferation of rodlet and goblet cells. Differential expression patterns of target cytokines in tissue surrounding two parasites and in vitro PBL model suggest that quality and quantity of tuna immune response is conditioned by parasite adaptive mechanisms and pathogenicity.

Treatment modifications in tumour necrosis factor-α (TNF)-based isolated limb perfusion in patients with advanced extremity soft tissue sarcomas

BACKGROUND

Tumour necrosis factor-α (TNF) and melphalan based isolated limb perfusion (TM-ILP) is an attractive treatment option for advanced extremity soft tissue sarcomas (STS). This study reports on a 20-year single centre experience and discusses the evolution and changes in methodology since the introduction of TNF in ILP.

PATIENTS AND METHODS

We performed 306 TM-ILPs in 275 patients with extremity STS. All patients were candidates for amputation or mutilating surgery in order to achieve local control. Clinical response evaluation consisted of clinical examination and magnetic resonance imaging. To evaluate the importance of TNF-dose, treatment results of two periods (1991-2003 high dose (3-4 mg) TNF; 2003-2012 reduced dose (1-2mg) TNF) were compared.

RESULTS

During the study period, more femoral perfusions were done instead of iliac perfusions. Reduction of TNF dose and reduction of total ILP time did not lead to different clinical response rates (70% and 69% for periods 1 and 2 respectively) or different local recurrence rates, but was associated with less local toxicity (23% and 14% for periods 1 and 2 respectively). Hospital stay was significantly reduced during the study period. There was an improved pathological response in the high dose TNF group without consequences for clinical outcome.

CONCLUSION

TM-ILP remains a very effective treatment modality for limb threatening extremity STS. Moreover, reduction of dose and the growing experience in ILP led to less local toxicity and shorter hospital stay.

Lack of association between TNFα rs1800629 polymorphism and schizophrenia risk: a meta-analysis

Evidence has suggested that tumour necrosis factor α (TNFα) may be involved in the aetiology of schizophrenia, but the underlying association between TNFα-308G/A polymorphism (rs1800629) and schizophrenia risk is still ambiguous. This meta-analysis was performed to quantitatively summarise the evidence for such a relationship. Eligible studies were identified by searching PubMed, EMBASE, CNKI (China National Knowledge Infrastructure), CBM (Chinese Biomedical Literature Database) and WANFANG databases within a range of published years from 1990 to July 2012. The odds ratio (OR) corresponding to the 95% confidence interval (CI) was used to assess the different associations. Twenty-one studies with 4340 cases and 5745 controls were included in this meta-analysis. The pooled examination displayed that there was no significant association between TNFα-308G/A polymorphism and susceptibility to schizophrenia overall (OR=1.047, 95% CI=0.876-1.253, P=0.614 for A vs. G), and no difference in Caucasian subgroup (OR=1.041, 95% CI=0.815-1.331, P=0.747) and Asian subgroup (OR=1.057, 95% CI=0.807-1.386, P=0.686). Lack of association was also found in males (OR=0.862, 95% CI=0.413-1.797, P=0.692) and females (OR=0.797, 95% CI=0.579-1.097, P=0.163) with a dominant model. Taken together, this meta-analysis suggests that TNFα-308G/A polymorphism may not be associated with schizophrenia susceptibility.

[Association between inflammatory markers and microbial translocation in patients with human immunodeficiency virus infection taking antiretroviral treatment]

BACKGROUND AND OBJECTIVE

Inflammatory biomarkers are increased in patients with human immunodeficiency virus (HIV) infection. Antiretroviral treatment (ART) improves some parameters but do not normalize them. The aim of this study is to determine those factors (including microbial translocation) associated with higher inflammation in HIV treated patients.

PATIENTS AND METHODS

Transversal observational study.

INCLUSION CRITERIA

HIV patients receiving ART with an HIV viral load (VL)<400 copies/mL. Selection of patients: consecutively between November 2011 and January 2012. Main variable: plasma levels of interleukin 6 (IL-6) and tumour necrosis factor α (TNF-α). Main explanatory variable: microbial translocation markers (16S ribosomal DNA and sCD14). Patients with IL-6 or TNF-α levels above percentile 75 (group 1) were compared with the rest of patients (group 2). Odds ratio (OR) were determined.

RESULTS

Eighty-one patients were included (73% male, median age 45 years, 48% stage C). Twenty-six percent had chronic hepatitis C. Median CD4 cell was 493/mm(3) and 30% had detectable HIV VL. 16S ribosomal DNA was detected in 21% of patients. Factors associated with the higher levels of inflammatory markers were 16S ribosomal DNA (OR 77, P<.0001), sCD14 levels (P<.0001) and history of cardiovascular disease (OR 15, P<.01). In multivariate analysis, associations remained for 16S ribosomal DNA (OR 62, P<.0001) and previous cardiovascular disease (OR 25, P<.01).

CONCLUSIONS

In patients with HIV infection receiving treatment, the higher levels of inflammatory markers are associated with microbial translocation and past cardiovascular events.