Innate immunity modulates adipokines in humans

Genetically determined circulating resistin concentrations and risk of colorectal cancer: a two-sample Mendelian randomization study

PURPOSE

Resistin, a novel pro-inflammatory protein implicated in inflammatory processes, has been suggested to play a role in colorectal development. However, evidence from observational studies has been inconsistent. Mendelian randomization may be a complementary method to examine this association.

METHODS

We conducted a two-sample Mendelian randomization to estimate the association between genetically determined circulating resistin concentrations and risk of colorectal cancer (CRC). Protein quantitative trait loci (pQTLs) from the SCALLOP consortium were used as instrumental variables (IVs) for resistin. CRC genetic summary data was obtained from GECCO/CORECT/CCFR (the Genetics and Epidemiology of Colorectal Cancer Consortium, Colorectal Cancer Transdisciplinary Study, and Colon Cancer Family Registry), and FinnGen (Finland Biobank). The inverse variance weighted method (IVW) was applied in the main analysis, and other robust methods were used as sensitivity analyses. Estimates for the association from the two data sources were then pooled using a meta-analysis approach.

RESULTS

Thirteen pQTLs were identified as IVs explaining together 7.80% of interindividual variation in circulating resistin concentrations. Based on MR analyses, genetically determined circulating resistin concentrations were not associated with incident CRC (pooled-IVW-OR per standard deviation of resistin, 1.01; 95% CI 0.96, 1.06; p = 0.67. Restricting the analyses to using IVs within or proximal to the resistin-encoding gene (cis-IVs), or to IVs located elsewhere in the genome (trans-IVs) provided similar results. The association was not altered when stratified by sex or CRC subsites.

CONCLUSIONS

We found no evidence of a relationship between genetically determined circulating resistin concentrations and risk of CRC.

Masoprocol: a promising candidate for targeting insulin resistance by inhibiting resistin with optimal druglikeness Potentials: an in silico approach

Resistin is a cysteine-rich secretory hormone that induces resistance to insulin, and its elevated expression is correlated with the onset of diabetes and several related metabolic disorders. Resistin performs its inhibitory role by connecting three identical subunits through Cys22-based disulfide linkages. The necessity to inhibit the formation of resistin trimer is one of the essential means to prevent the aggravation of diabetes mellitus type 2, obesity, and atherosclerosis. This study was conducted to screen the clinically approved drugs to find the most potent one to inhibit resistin with the best pharmacokinetics and drug-likeness properties. A total of 4654 clinically approved drugs were docked against the Cys22 residue of resistin. The top ten drugs with the highest high-precision (XP) docking scores were selected. Ioversol and masoprocol showed the highest XP docking and Molecular Mechanics-Generalized Born Surface Area (MMGBSA) scores, respectively, with double hydrogen bonding with the targeted Cys22. Molecular dynamics (MD) simulations showed that the masoprocol-resistin complex exhibited lower root mean square deviation (RMSD), radius of gyration, and root mean square fluctuation (RMSF) values than those observed in the ioversol-resistin complex. Both drugs induced drastic conformational changes in resistin monomer interactions. However, ioversol did not prove satisfying drug-likeness properties, while masoprocol showed the most favourable pharmacokinetic and drug-likeness properties. This study has demonstrated that masoprocol offers a novel inhibitory effect on resistin with the highest ligand affinity, making it a promising drug for combating insulin resistance.Communicated by Ramaswamy H. Sarma.

P38 MAPK pathway regulates the expression of resistin in porcine alveolar macrophages via Ets2 during Haemophilus parasuis stimulation

Haemophilus parasuis is a widespread bacterial pathogen causing acute systemic inflammation and leading to the sudden death of piglets. Resistin, a multifunctional peptide hormone previously demonstrated to influence the inflammation in porcine, was extremely increased in H. parasuis-infected tissues. However, the mechanism of resistin expression regulation in porcine, especially during pathogen infection, remains unclear. In the present study, we explored for the first time the transcription factor and signaling pathway mediating the expression of pig resistin during H. parasuis stimulation. We found that H. parasuis induced the expression of pig resistin in a time- and dose-dependent manner via the transcription factor Ets2 in porcine alveolar macrophages during H. parasuis stimulation. Moreover, the expression of Ets2 was mediated by the activation of the p38 MAPK pathway induced by H. parasuis, thus promoting resistin production. These results revealed a novel view of the molecular mechanism of pig resistin production during acute inflammation induced by pathogenic bacteria.

Measurement of Plasma Resistin Concentrations in Horses with Metabolic and Inflammatory Disorders

Simple Summary

Obesity and its associated complications, such as metabolic syndrome, are an increasing problem in both humans and horses in the developed world. Adipose tissue is a key endocrine organ that communicates with other organs by multiple endocrine substances called adipokines. There is evidence to suggest that adipokines may contribute to the regulation of biological processes, such as metabolism, immunity, and inflammation. The aim of this study was to investigate the usefulness of one of these adipokines in horses, resistin, and its relationship with insulin dysregulation (ID) and inflammation. Seventy-two horses, included in one of the four following groups, were studied: healthy controls, horses with inflammatory conditions, horses with mild, and horses with severe ID. Plasma resistin concentrations were significantly different between groups, and the highest values were recorded in the inflammatory and severe ID groups. The lack of correlation of resistin with basal insulin concentration and the significant correlation of resistin with the inflammatory marker serum amyloid A suggest that, as is the case in humans, plasma resistin concentrations in horses are predominantly related to inflammatory conditions and not to ID.

Abstract

Obesity and its associated complications, such as metabolic syndrome, are an increasing problem in both humans and horses in the developed world. The expression patterns of resistin differ considerably between species. In rodents, resistin is expressed by adipocytes and is related to obesity and ID. In humans, resistin is predominantly produced by inflammatory cells, and resistin concentrations do not reflect the degree of obesity, although they may predict cardiovascular outcomes. The aim of this study was to investigate the usefulness of resistin and its relationship with ID and selected indicators of inflammation in horses. Seventy-two horses, included in one of the four following groups, were studied: healthy controls (C, n = 14), horses with inflammatory conditions (I, n = 21), horses with mild ID (ID1, n = 18), and horses with severe ID (ID2, n = 19). Plasma resistin concentrations were significantly different between groups and the higher values were recorded in the I and ID2 groups (C: 2.38 ± 1.69 ng/mL; I: 6.85 ± 8.38 ng/mL; ID1: 2.41 ± 2.70 ng/mL; ID2: 4.49 ± 3.08 ng/mL). Plasma resistin was not correlated with basal insulin concentrations. A significant (r = 0.336, p = 0.002) correlation was found between resistin and serum amyloid A. Our results show that, as is the case in humans, plasma resistin concentrations in horses are predominantly related to inflammatory conditions and not to ID. Horses with severe ID showed an elevation in resistin that may be secondary to the inflammatory status associated with metabolic syndrome.

Plasma adipocytokines distinguish tuberculous lymphadenitis from pulmonary tuberculosis

Adipocytokines are the major secretory products of adipose tissue and potential markers of metabolism and inflammation. However, their association in host immune response against tuberculous lymphadenitis (TBL) disease is not known. Thus, we measured the systemic levels of adipocytokines in TBL (n = 44) and compared to pulmonary tuberculosis (PTB, n = 44) and healthy control (HC, n = 44) individuals. We also examined the pre and post-treatment adipocytokine levels in TBL individuals upon completion of standard anti-tuberculosis treatment (ATT). The receiver operating characteristics (ROC) were performed between TBL, PTB and HCs to find the potential discriminatory markers. Finally, principal component (PCA) analysis was performed to reveal the expression patterns of adipocytokines among study groups. Our results demonstrate that TBL is associated with significantly higher systemic levels of adipocytokines (except resistin) when compared with PTB and significantly lower levels when compared with HC (except adiponectin) individuals. Upon completion of ATT, the systemic levels of adiponectin and resistin were significantly decreased when compared to pre-treatment levels. Upon ROC analysis, all the three adipocytokines discriminated TBL from PTB but not with HCs, respectively. Similarly, adipocytokines were differentially clustered in TBL in comparison to PTB in PCA analysis. Therefore, adipocytokines are a distinguishing feature in TBL compared to PTB individuals.

Cardiovascular disease in systemic lupus erythematosus

There is a well-known increased risk for cardiovascular disease that contributes to morbidity and mortality in systemic lupus erythematosus (SLE). Major adverse cardiovascular events and subclinical atherosclerosis are both increased in this patient population. While traditional cardiac risk factors do contribute to the increased risk that is seen, lupus disease-related factors, medications, and genetic factors also impact the overall risk. SLE-specific inflammation, including oxidized lipids, cytokines, and altered immune cell subtypes all are likely to play a role in the pathogenesis of atherosclerotic plaques. Research is ongoing to identify biomarkers that can help clinicians to predict which SLE patients are at the greatest risk for cardiovascular disease (CVD). While SLE-specific treatment regimens for the prevention of cardiovascular events have not been identified, current strategies include minimization of traditional cardiac risk factors and lowering of overall lupus disease activity.

Is resistin the master link between inflammation and inflammation-related chronic diseases?

Resistin has been firstly discovered in mice and was identified as an adipose tissue-secreted hormone or adipokine linking obesity and insulin resistance. In humans, resistin has been characterized as a hormone expressed and secreted by Immune cells especially by macrophages, and was linked to many inflammatory responses including inflammation of adipose tissue due to macrophages' infiltration. Human and mouse resistin display sequence and structural similarities and also dissimilarities that could explain their different expression pattern. In mice, strong pieces of evidence clearly associated high resistin plasma levels to obesity and insulin resistance suggesting that resistin could play an important role in the onset and progression of obesity and insulin resistance via resistin-induced inflammation. In humans, the link between resistin and obesity/insulin resistance is still a matter of debate and needs more epidemiological studies. Also, resistin has been linked to other chronic diseases such as cardiovascular diseases and cancers where resistin has been proposed in many studies as a biological marker.

Connection between Periodontitis-Induced Low-Grade Endotoxemia and Systemic Diseases: Neutrophils as Protagonists and Targets

Periodontitis is considered a promoter of many systemic diseases, but the signaling pathways of this interconnection remain elusive. Recently, it became evident that certain microbial challenges promote a heightened response of myeloid cell populations to subsequent infections either with the same or other pathogens. This phenomenon involves changes in the cell epigenetic and transcription, and is referred to as ''trained immunity''. It acts via modulation of hematopoietic stem and progenitor cells (HSPCs). A main modulation driver is the sustained, persistent low-level transmission of lipopolysaccharide from the periodontal pocket into the peripheral blood. Subsequently, the neutrophil phenotype changes and neutrophils become hyper-responsive and prone to boosted formation of neutrophil extracellular traps (NET). Cytotoxic neutrophil proteases and histones are responsible for ulcer formations on the pocket epithelium, which foster bacteremia and endoxemia. The latter promote systemic low-grade inflammation (SLGI), a precondition for many systemic diseases and some of them, e.g., atherosclerosis, diabetes etc., can be triggered by SLGI alone. Either reverting the polarized neutrophils back to the homeostatic state or attenuation of neutrophil hyper-responsiveness in periodontitis might be an approach to diminish or even to prevent systemic diseases.

Anti-inflammatory and antidiabetic effects of grape-derived stilbene concentrate in the experimental metabolic syndrome

AIMS

This study aimed to investigate the carbohydrate and lipid dynamics, associated inflammation markers and the effectiveness of a grape-derived stilbene concentrate (GDSC) treatment in experimental metabolic syndrome (MetS).

METHODS

The study was carried out on 40 male 12-weeks of age Wistar rats. The MetS was induced using the fructose model (feeding with 60%-solid fructose diet for 24 weeks). Rats with induced MetS were treated with polyphenolic GDSC, which was obtained by water-alcohol extraction of Vitis vinifera grapevine (Ressfood LLC, Russia).

RESULTS

The experimentally induced MetS development leads to classic MetS signs, including abdominal obesity, hyperglycemia, high lipid levels and heart damage. The expression of glucose transporter type 4 (GLUT4) and peroxisome proliferator-activated receptor-γ (PPAR-γ) had greater dynamics than biochemical measurements. The development of the associated inflammatory reactions was confirmed by the increased level of Toll-like receptor type 4 (TLR4) and C-reactive protein (CRP) compared to control levels. The use of the GDSC had positive dynamics in carbohydrate and lipid levels, inflammatory marker, also prevented associated inflammation and heart damage.

Chronic inflammation, cardiometabolic diseases and effects of treatment: Psoriasis as a human model

Chronic inflammation in humans is associated with accelerated development of cardiometabolic diseases such as myocardial infarction, stroke, and diabetes. Strong evidence from animal models and human interventional trials including CANTOS (The Canakinumab Anti-inflammatory Thrombosis Outcome Study) suggests that targeting residual systemic inflammation in humans may impart a benefit in reducing cardiometabolic diseases. Diseases associated with heightened immune-activation and systemic inflammation including psoriasis, rheumatoid arthritis, systemic lupus erythematosus, and human immunodeficiency virus infection are associated with upwards of two to seven-fold risk of future adverse cardiac events even when adjusted for traditional risk factors. Over the past decade, psoriasis has been utilized as a human model to study inflammatory-induced cardiometabolic dysfunction and to better understand residual risk due to inflammation. The high prevalence and early onset of cardiovascular disease in psoriasis enhances the likelihood of discovering novel pathways in vascular disease progression when followed over time. Furthermore, the United States Food and Drug Administration approved treatments for psoriasis include cytokine inhibitors (anti-tumor necrosis factor, anti-interleukin 17, anti-interleukin 12/23) which while treating the skin disease provide a unique opportunity to characterize how treating the inflammatory pathways may impact atherosclerosis. Herein, we provide a review of chronic inflammation, cardiometabolic disease associations, and treatment effects with a focus on psoriasis as a human model of study.

Age-Dependent Changes of Adipokine and Cytokine Secretion From Rat Adipose Tissue by Endogenous and Exogenous Toll-Like Receptor Agonists

White adipose tissue but recently also brown adipose tissue have emerged as endocrine organs. Age-associated obesity is accompanied by prolonged and elevated lipopolysaccharide (LPS)-induced sickness symptoms and increased cytokine and adipokine levels in the circulation partially originating from adipose tissue. In the present study, ex vivo fat explants were used to investigate how the exogenous pathogen-associated molecular pattern (PAMP) LPS or the endogenous danger-associated molecular patterns (DAMPs) high mobility group box-1 protein (HMGB1) and biglycan modulate the release of cytokines and adipokines/batokines and, thus, could influence systemic and/or local inflammation. The response of adipose tissue (epididymal, retroperitoneal, subcutaneous, and brown) was compared between young lean and old obese rats (2 vs. 24 months old). LPS induced a strong interleukin (IL)-6 and tumor necrosis factor (TNF) alpha release into the supernatant of all adipose tissue types investigated. HMGB1 (subcutaneous) and biglycan (retroperitoneal) led to an increased release of IL-6 and TNFalpha (HMGB1) and decreased visfatin and adiponectin (biglycan) secretion from epididymal adipose tissue (young rats). Visfatin was also decreased by HMGB1 in retroperitoneal adipose tissue of old rats. We found significantly higher leptin (all fat pads) and adiponectin (subcutaneous) levels in supernatants of adipose tissue from old compared to young rats, whereas visfatin secretion showed the opposite. The expression of the biglycan receptor Toll-like receptor (TLR) 2 as well as the LPS and HMGB1 receptors TLR4 and receptor for advanced glycation end products (RAGE) were reduced with age (TLR4/RAGE) and by stimulation with their ligands (subcutaneous). Overall, we revealed that adipokines/adipose-tissue released cytokines show some modulation of their release caused by mediators of septic (batokines) and sterile inflammation with potential implication for acute and chronic disease. Moreover, aging may increase or decrease the release of fat-derived mediators. These data show that DAMPS and LPS locally modulate cytokine secretion while only DAMPS but not LPS can locally alter adipokine secretion during inflammation.

Nondigestible Carbohydrates Affect Metabolic Health and Gut Microbiota in Overweight Adults after Weight Loss

BACKGROUND

The composition of diets consumed following weight loss (WL) can have a significant impact on satiety and metabolic health.

OBJECTIVE

This study was designed to test the effects of including a nondigestible carbohydrate to achieve weight maintenance (WM) following a period of WL.

METHODS

Nineteen volunteers [11 females and 8 males, aged 20-62 y; BMI (kg/m2): 27-42] consumed a 3-d maintenance diet (15%:30%:55%), followed by a 21-d WL diet (WL; 30%:30%:40%), followed by 2 randomized 10-d WM diets (20%:30%:50% of energy from protein:fat:carbohydrate) containing either resistant starch type 3 (RS-WM; 22 or 26 g/d for females and males, respectively) or no RS (C-WM) in a within-subject crossover design without washout periods. The primary outcome, WM after WL, was analyzed by body weight. Secondary outcomes of fecal microbiota composition and microbial metabolite concentrations and gut hormones were analyzed in fecal samples and blood plasma, respectively. All outcomes were assessed at the end of each dietary period.

RESULTS

Body weight was similar after the RS-WM and C-WM diets (90.7 and 90.8 kg, respectively), with no difference in subjectively rated appetite. During the WL diet period plasma ghrelin increased by 36% (P < 0.001), glucose-dependent insulinotropic polypeptide (GIP) decreased by 33% (P < 0.001), and insulin decreased by 46% (P < 0.001), but no significant differences were observed during the RS-WM and C-WM diet periods. Fasting blood glucose was lower after the RS-WM diet (5.59 ± 0.31 mmol/L) than after the C-WM diet [5.75 ± 0.49 mmol/L; P = 0.015; standard error of the difference between the means (SED): 0.09]. Dietary treatments influenced the fecal microbiota composition (R2 = 0.054, P = 0.031) but not diversity.

CONCLUSIONS

The metabolic benefits, for overweight adults, from WL were maintained through a subsequent WM diet with higher total carbohydrate intake. Inclusion of resistant starch in the WM diet altered gut microbiota composition positively and resulted in lower fasting glucose compared with the control, with no apparent change in appetite. This trial was registered at clinicaltrials.gov as NCT01724411.

Effects of Coenzyme Q10 Supplementation on Serum Adiponectin Levels: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background:

Adiponectin, a well-known adipokine plays a number of regulatory actions in human body metabolism. Decreased levels of adiponectin have been reported in type 2 diabetes mellitus, cardiovascular diseases, metabolic syndrome and hypertension. Coenzyme Q10 (Co Q10) is a fat-soluble antioxidant substance which has been reported to be effective in several metabolic disturbances such as insulin resistance and inflammation.

Objective:

Present systematic review and meta-analysis were performed to assess the effects of CoQ10 supplementation on adiponectin serum level.

Methods:

A comprehensive search was performed in electronic databases including EMBASE, Google scholar, and PubMed up to January 2018. A meta-analysis of eligible studies was performed using random effects model to estimate pooled effect size of CoQ10 supplementation on adiponectin.

Results:

A total of 209 subjects were recruited from 5 eligible studies. Meta-analysis did not suggest any significant effect of CoQ10 supplementation on adiponectin serum level (0.240 mg/dl, 95%CI: -0.216, 0.696, P= 0.303), without significant heterogeneity between included studies (I2= 40.9%, p= 0.149).

Conclusion:

Although present meta-analysis did not indicate any significant effects of CoQ10 supplementation on serum adiponectin levels but future long-term dose-response trials are needed before any firm conclusion.

The role of adiponectin in placentation and preeclampsia

Preeclampsia is not fully understood; and few biomarkers, therapeutic targets, and therapeutic agents for its management have been identified. Original investigative findings suggest that abnormal placentation triggers preeclampsia and leads to hypertension, proteinuria, endothelial dysfunction, and inflammation, which are characteristics of the disease. Because of the regulatory roles that it plays in several metabolic processes, adiponectin has become a cytokine of interest in metabolic medicine. In this review, we have discussed the role of adiponectin in trophoblast proliferation, trophoblast differentiation, trophoblast invasion of the decidua, and decidual angiogenesis, which are the major phases of placentation. Also, we have highlighted the physiological profile of adiponectin in the course of normal pregnancy. Moreover, we have discussed the involvement of adiponectin in hypertension, endothelial dysfunction, inflammation, and proteinuria. Furthermore, we have summarized the reported relationship between the maternal serum adiponectin level and preeclampsia. The available evidence indicates that adiponectin level physiologically falls as pregnancy advances, regulates placentation, and exhibits protective effects against the symptoms of preeclampsia and that while hyperadiponectinemia is evident in normal-weight preeclamptic women, hypoadiponectinemia is evident in overweight and obese preeclamptic women. Therefore, the clinical use of adiponectin as a biomarker, therapeutic target, or therapeutic agent against the disease looks promising and should be considered.

Evaluation of serum cancer antigen 125, resistin, leptin, homocysteine, and total antioxidant capacity in rat model of endometriosis treated with Curcumin

Endometriosis is one of the most common reproductive diseases of women, with some important biochemical changes in the serum. Curcumin was reported to have anti-endometriosis, anti-inflammatory and antioxidant activity. This study explores the changes of serum levels of Cancer Antigen 125 (CA125), leptin, resistin, homocysteine, and total antioxidant capacity (TAC) in a rat model of endometriosis and the effect of curcumin treatment on these factors. Fifty female Sprague-Dawley rats (220-250 gr body weight) were randomly divided into control (received 0.3 mL of the vehicle), sham(stress of surgery + 0.3 mL of the vehicle) and three endometriosis groups as danazol treatment (7.2 mg/kg BW, IP), curcumin treatment (48 mg/kg BW, IP) and test (received 0.3 mL of the vehicle). Endometriosis was induced by surgically auto-transplantation of uterine tissue to the abdominal wall and intestinal mesentery. The animals were treated for 4 weeks. On the last day, the blood sample was collected by heart puncture, and the above-mentioned factors were measured in the sera. Leptin in the curcumin treatment group was markedly higher than all of the studied groups, except the danazol group, while there were no significant differences between other groups (P < 0.05). Level of resistin in endometriosis groups did not show significant differences with the control group (P < 0.05). There was no significant difference in the serum levels of homocysteine and CA 125 between all of the studied groups (P > 0.05). The serum levels of TAC in the control group were significantly higher than all of the studied groups (P < 0.05). Curcumin could prevent the growth of endometriosis, while there was no significant alteration on measured factors in the serum of rat with induced endometriosis. Hence follow up of these parameters in serum may not be a proper indicator to evaluate the status of endometriosis in the rat model.

Deficiency of Soluble Epoxide Hydrolase Protects Cardiac Function Impaired by LPS-Induced Acute Inflammation

Lipopolysaccharide (LPS) is a bacterial wall endotoxin producing many pathophysiological conditions including myocardial inflammation leading to cardiotoxicity. Linoleic acid (18:2n6, LA) is an essential n-6 PUFA which is converted to arachidonic acid (20:4n6, AA) by desaturation and elongation via enzyme systems within the body. Biological transformation of PUFA through CYP-mediated hydroxylation, epoxidation, and allylic oxidation produces lipid mediators, which may be subsequently hydrolyzed to corresponding diol metabolites by soluble epoxide hydrolase (sEH). In the current study, we investigate whether inhibition of sEH, which alters the PUFA metabolite profile, can influence LPS induced cardiotoxicity and mitochondrial function. Our data demonstrate that deletion of soluble epoxide hydrolase provides protective effects against LPS-induced cardiotoxicity by maintaining mitochondrial function. There was a marked alteration in the cardiac metabolite profile with notable increases in sEH-derived vicinal diols, 9,10- and 12,13-dihydroxyoctadecenoic acid (DiHOME) in WT hearts following LPS administration, which was absent in sEH null mice. We found that DiHOMEs triggered pronounced mitochondrial structural abnormalities, which also contributed to the development of extensive mitochondrial dysfunction in cardiac cells. Accumulation of DiHOMEs may represent an intermediate mechanism through which LPS-induced acute inflammation triggers deleterious alterations in the myocardium in vivo and cardiac cells in vitro. This study reveals novel research exploring the contribution of DiHOMEs in the progression of adverse inflammatory responses toward cardiac function in vitro and in vivo.

Bi-directional drug-microbiome interactions of anti-diabetics

Type 2 diabetes (T2D) has become a global epidemic. Although several drugs are available to manage T2D, problems associated with person-to-person variability in drug efficacy and potential side-effects remain unresolved. Owing to the emerging role of the gut microbiome in obesity and T2D, the interaction between gut microbes and anti-diabetic drugs and its influence on drugs' functions remains of immediate research interest. On one hand, drugs can manipulate gut microbiome composition and metabolic capacity. Conversely, the metabolic activities of the microbiome and its metabolites can also influence drug metabolism and effects. Hence, understanding this bi-directional drug-microbiome interaction and how it influences the clinical outcomes of antidiabetic drugs can pave the way to develop next-generation strategies to ameliorate diabetes. This review presents evidences demonstrating the putative interactions between anti-diabetic drugs and the gut microbiome, and discusses the potential of microbiome modulators to manipulate drug-microbiome interactions and the drug metabolism.

Adipokines in critical illness: A review of the evidence and knowledge gaps

Adipose tissue products or adipokines play a major role in chronic endocrine and metabolic disorders; however, little is known about critical conditions. In this article, the experimental and clinical evidence of alterations of adipokines, adiponectin, leptin, resistin, visfatin, asymmetric dimethylarginine (ADMA), and ghrelin in critical illness, their potential metabolic, diagnostic, and prognostic value, and the gaps in the field have been reviewed. The results showed considerable changes in the concentration of the adipokines; while the impact of adipokines on metabolic disorders such as insulin resistance and inflammation has not been well documented in critically ill patients. There is no consensus about the circulatory and functional changes of leptin and adiponectin. However, it seems that lower concentrations of adiponectin at admission with gradual consequent increase might be a useful pattern in determining better outcomes of critical illness. Some evidence has suggested the adverse effects of elevated resistin concentration, potential prognostic importance of visfatin, and therapeutic value of ghrelin. High ADMA levels and low arginine:ADMA ratio were also proposed as predictors of ICU mortality and morbidities. However, there is no consensus on these findings. Although primary data indicated the role of adipokines in critical illness, further studies are required to clarify whether the reason of these changes is pathophysiological or compensatory. The relationship of pathophysiological background, disease severity, baseline nutritional status and nutrition support during hospitalization, and variations in body fat percentage and distribution with adipokines, as well as the potential prognostic or therapeutic role of these peptides should be further investigated in critically ill patients.

Real-time monitoring of IL-6 and IL-10 reporter expression for anti-inflammation activity in live RAW 264.7 cells

In previous study, we suggested that the interleukin (IL)-6 and IL-10 could serve as a good biomarker for anti-inflammation that related to chronic inflammatory disease. Recently, we are finding new anti-inflammation compounds from natural products by screening of IL-6 and IL-10 levels. Although, we could measure IL-6 and IL-10 levels by several methods. However, all methods could not measure continuous kinetic of IL-6 and IL-10 levels. Most methods have multiple steps and take a long time. Therefore, there is no a suitable method for screening. To this end, we established IL-6 and IL-10 promoter assay which can monitor with reference gene as Glyceraldehyde 3-phosphate dehydrogenase (gapdh) promoter in living single cell. It could determine IL-6 and IL-10 levels continuously in real-time within two steps. We evaluated IL-6 and IL-10 reporter expression in LPS-induced RAW 264.7 cells with well-known anti-inflammatory compounds such as quercetin, xanthones, β-D-glucan and dexamethasone. As the results, the expression of IL-6 and IL-10 reporters were strongly induced by LPS. The expression of IL-6 reporter was inhibited by all anti-inflammation compounds in LPS-induced RAW 264.7 cells. The expression of IL-10 reporter was inhibited by quercetin, xanthones and dexamethasone in LPS-induced RAW 264.7 cells. While, expression of IL-10 reporter was induced by β-D-glucan. These results indicated that this assay could use for determination of IL-6 and IL-10 reporter expression in LPS-induced RAW 264.7 cells for anti-inflammation activity. Moreover, the results showed that natural compounds have an effect on the time course of IL-6 and IL-10 expressions. Therefore, real-time monitoring has a merit for natural compounds screening. We suggested that this assay could serve as a compound screening assay for anti-inflammation activity.

Endotoxinemia contributes to steatosis, insulin resistance and atherosclerosis in chronic hepatitis C: the role of pro-inflammatory cytokines and oxidative stress

PURPOSE

Endotoxin is a component of the outer membrane of gram-negative bacteria that live in the intestine. Endotoxinemia is reported in non-alcoholic fatty liver disease and in cirrhotic patients, causing various biological and clinical effects in the host. It is not known whether endotoxinemia occurs in chronic hepatitis C patients (CHC), therefore we evaluated the occurrence of endotoxinemia and its effect on inflammation, liver damage, insulin resistance (IR) and atherosclerosis.

METHODS

Consecutive CHC patients assessed by liver biopsy were enrolled. Endotoxinemia was evaluated by LAL test. IR was estimated by HOMA-IR. Serum TNF-α, IL-8, adiponectin and MCP-1 were measured with ELISA tests. Oxidative stress was estimated by circulating IgG against malondialdehyde adducts with human serum albumin (MDA-HAS). Carotid atherosclerosis was assessed by ultrasonography.

RESULTS

Endotoxinemia was found in 60% of the 126 patients enrolled. A serum level-dependent association between endotoxinemia, steatosis (p < 0.001) and HOMA-IR (p < 0.006) was observed. Patients with endotoxinemia showed significant increase in TNF-α and IL8 levels. TNF-α correlated with steatosis (p <  0.001) and HOMA-IR (p < 0.03), whereas IL8 correlated with steatosis (p =  <0.001), TNF-α (p < 0.04) and atherosclerosis (p < 0.01). The highest levels of endotoxinemia were associated with oxidative stress and a higher prevalence of carotid atherosclerosis. Multivariate logistic regression analysis showed that the independent factors associated with endotoxinemia were hepatic steatosis, HOMA-IR, IL8 and MDA-HAS.

CONCLUSIONS

Endotoxinemia occurs with high frequency in CHC patients and contributes to the development of hepatic steatosis, IR and atherosclerosis through increased pro-inflammatory cytokines and oxidative stress. Anti-endotoxin treatment could be of clinical relevance.

[Adiponectin: an endogenous molecule with anti-inflammatory and antidepressant properties?]

Adiponectin (ApN) is a hormone produced by adipose tissue, yet the plasma level of ApN is decreased in overweight and obese people, as well as in people with diabetes. In the periphery, this decrease in circulating levels of ApN induces the establishment of a chronic low-grade inflammatory state and is involved in the development of insulin resistance and atheromas. Conversely, "favorable" living conditions, weight loss and regular physical exercise increase ApN blood concentration. Some forms of ApN can reach the brain parenchyma through the cerebrospinal fluid. In the brain, the increase in ApN exerts powerful antidepressant and anxiolytic effects, in particular by fighting against neuroinflammation.

Potential Immunological Links Between Psoriasis and Cardiovascular Disease

Preclinical and clinical research provide strong evidence that chronic, systemic inflammation plays a key role in development and progression of atherosclerosis. Indeed, chronic inflammatory diseases, such as psoriasis, are associated with accelerated atherosclerosis and increased risk of cardiovascular events. Contemporary research has demonstrated plausible mechanistic links between immune cell dysfunction and cardiometabolic disease in psoriasis. In this review, we describe the role of potential common immunological mechanisms underlying both psoriasis and atherogenesis. We primarily discuss innate and adaptive immune cell subsets and their contributions to psoriatic disease and cardiovascular morbidity. Emerging efforts should focus on understanding the interplay among immune cells, adipose tissue, and various biomarkers of immune dysfunction to provide direction for future targeted therapy.

Interindividual variability in gut microbiota and host response to dietary interventions

Dysbiosis is linked to human disease; therefore, gut microbiota modulation strategies provide an attractive means of correcting microbial imbalance to enhance human health. Because diet has a major influence on the composition, diversity, and metabolic capacity of the gut microbiota, numerous dietary intervention studies have been conducted to manipulate the gut microbiota to improve host outcomes and reduce disease risk. Emerging evidence suggests that interindividual variability in gut microbiota and host responsiveness exists, making it difficult to predict gut microbiota and host response to a given dietary intervention. This may, in turn, have implications on the consistency of results among studies and the perceived success or true efficacy of a dietary intervention in eliciting beneficial changes to the gut microbiota and human health.

Interactions of Gut Microbiota, Endotoxemia, Immune Function, and Diet in Exertional Heatstroke

Exertional heatstroke (EHS) is a medical emergency that cannot be predicted, requires immediate whole-body cooling to reduce elevated internal body temperature, and is influenced by numerous host and environmental factors. Widely accepted predisposing factors (PDF) include prolonged or intense exercise, lack of heat acclimatization, sleep deprivation, dehydration, diet, alcohol abuse, drug use, chronic inflammation, febrile illness, older age, and nonsteroidal anti-inflammatory drug use. The present review links these factors to the human intestinal microbiota (IM) and diet, which previously have not been appreciated as PDF. This review also describes plausible mechanisms by which these PDF lead to EHS: endotoxemia resulting from elevated plasma lipopolysaccharide (i.e., a structural component of the outer membrane of Gram-negative bacteria) and tissue injury from oxygen free radicals. We propose that recognizing the lifestyle and host factors which are influenced by intestine-microbial interactions, and modifying habitual dietary patterns to alter the IM ecosystem, will encourage efficient immune function, optimize the intestinal epithelial barrier, and reduce EHS morbidity and mortality.

Serum progranulin levels in relation to insulin resistance in childhood obesity

BACKGROUND

Progranulin is an adipokine that is involved in the inflammatory response, glucose metabolism, insulin resistance, and may therefore be involved in chronic subclinical inflammation associated with the pathogenesis of childhood obesity. We aimed to investigate the association of circulating progranulin levels with metabolic parameters in children and to assess the importance of progranulin as a biomarker for metabolic diseases.

METHODS

A total of 150 children were consecutively recruited from the Pediatric Nutrition Clinics at King Abdulaziz University Hospital in Jeddah, Saudi Arabia. Children were classified into four groups based on quartile for serum progranulin. Anthropometric variables were measured in all study subjects. Fasting blood samples were collected for measurement of blood glucose, insulin and lipid profile.

RESULTS

Children within the upper quartile for serum progranulin concentration were heavier, more insulin resistant and had higher concentrations of serum total cholesterol, triglycerides, insulin and high sensitivity C reactive protein compared to those in the lower quartile. On correlation analysis, serum progranulin concentrations were significantly related to general and central adiposity, metabolic parameters, markers of inflammation and insulin resistance. Stepwise multiple regression showed that 26.6% of the variability in serum progranulin could be explained by measures of adiposity.

CONCLUSIONS

The increased serum progranulin concentrations were closely related to measures of adiposity, metabolic parameters, inflammatory marker and insulin resistance indices, suggesting that progranulin may be an excellent biomarker for obesity in childhood.

Resistin as a Prooxidant Factor and Predictor of Endothelium Damage in Patients with Mild Acute Pancreatitis Exposed to Tobacco Smoke Xenobiotics

Objectives

The study was aimed to assess the influence of tobacco smoke exposure on the intensity of inflammation measured by IL-6, α₁-antitripsin (AAT) and α₁-acid glycoprotein (AGP) concentrations, and Cd level and oxidative stress intensity measured by advanced oxidation protein product (AOPP) concentration in the blood of healthy subjects and AP patients during hospitalization. Endothelin-1 (ET-1) and resistin concentrations, markers of endothelium injury, were determined.

Results

An increased IL-6 concentration in healthy smokers compared to nonsmokers and AP patients compared to controls was shown. An increased AAT and AGP concentrations during hospitalization of AP patients were noted, in both smokers (AAT, AGP) and nonsmokers (AAT). In comparison to control groups, in AP patients, a 2-fold increased resistin concentration correlating with ET-1 concentration and decreased albumin concentration accompanied by increased AOPP concentration were demonstrated. AOPP concentration was higher in smokers with AP compared to nonsmokers and gradually enhanced during their hospitalization.

Conclusions

Tobacco smoke exposure can have a proinflammatory effect in both healthy subjects and AP patients. Increased resistin concentration in AP patients negatively correlating with albumin concentration has prooxidative effect on this protein resulting in enhanced AOPP level. Increased resistin concentration can intensify AAT and AGP production during AP.

Airway and serum adipokines after allergen and diesel exposure in a controlled human crossover study of atopic adults

Adipokines are mediators released from adipose tissue. These proteins are regarded as active elements of systemic and pulmonary inflammation, whose dysregulation can alter an individual's risk of developing allergic lung diseases. Despite this knowledge, adipokine responses to inhaled stimuli are poorly understood. We sought to measure serum and lung adiponectin, leptin, and resistin in an atopic adult study population following exposure to allergen and diesel exhaust (DE). Two types of lung samples including bronchoalveolar lavage (BAL) and bronchial wash (BW), and a time course of serum samples, were collected from the 18 subjects who participated in the randomized, double-blinded controlled human study. The two crossover exposure triads in this study were inhaled DE and filtered air each followed by instilled allergen or saline. Serum and lung adipokine responses to these exposures were quantified using enzyme-linked immunosorbent assay. Allergen significantly increased adiponectin and leptin in BAL, and adiponectin in the BW 48 hours after exposure. Serum leptin and resistin responses were not differentially affected by exposure, but varied over time. Coexposure with DE and allergen revealed significant correlations between the adiponectin/leptin ratio and FEV₁ changes and airway responsiveness measures. Changes in lung and serum adipokines in response to allergen exposure were identified in the context of a controlled exposure study. Coexposure identified a potentially protective role of adiponectin in the lung. This response was not observed in those with baseline airway hyper-responsiveness, or after allergen exposure alone. The clinical relevance of this potentially adaptive adipokine pattern warrants further study.

Novel adipokines: methodological utility in human obesity research

BACKGROUND

Adipokines could pose a link between adiposity, systemic inflammation and metabolic disease risk. However, it is unclear whether representative biomarkers are methodologically suitable for use in human obesity research.

METHODS

We assessed the intra-individual reproducibility of selected adipokines in a sample of 207, apparently healthy, participants with available biosample collections over a 4-month period. Concentrations of the following adipokines were measured at each sampling time point: fatty-acid binding protein-4 (FABP-4), lipocalin-2, monocyte chemoattractant protein 1 (MCP-1), procalcitonin, progranulin, vaspin and visfatin/Nampt. We calculated intraclass correlation coefficients (ICC) and examined Bland-Altman plots.

RESULTS

The analyses suggested an overall good to excellent biomarker reproducibility over 4 months: FABP-4: ICC=0.73 (95% confidence interval: 0.65, 0.78), lipocalin-2: 0.64 (0.55, 0.71), MCP-1: 0.85 (0.81; 0.89), procalcitonin: 0.78 (0.72, 0.83), progranulin: 0.59 (0.50, 0.68) and vaspin: 0.86 (0.82, 0.89). A good agreement of the repeated measurements was further supported by the Bland-Altman plots. No substantial differences in biomarker performance according to adiposity status could be observed. Reliability of visfatin/Nampt could not be assessed due to a high number of measurements below the lower limit of detection.

CONCLUSION

Results suggest that single measurements of the evaluated adipokines could be used in population-based studies aimed to assess links between obesity, inflammation and metabolic diseases.

Expression of Calgranulin Genes S100A8, S100A9 and S100A12 Is Modulated by n-3 PUFA during Inflammation in Adipose Tissue and Mononuclear Cells

Calgranulin genes (S100A8, S100A9 and S100A12) play key immune response roles in inflammatory disorders, including cardiovascular disease. Long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) may have systemic and adipose tissue-specific anti-inflammatory and cardio-protective action. Interactions between calgranulins and the unsaturated fatty acid arachidonic acid (AA) have been reported, yet little is known about the relationship between calgranulins and the LC n-3 PUFA eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). We explored tissue-specific action of calgranulins in the setting of evoked endotoxemia and n-3 PUFA supplementation. Expression of calgranulins in adipose tissue in vivo was assessed by RNA sequencing (RNASeq) before and after n-3 PUFA supplementation and evoked endotoxemia in the fenofibrate and omega-3 fatty acid modulation of endotoxemia (FFAME) Study. Subjects received n-3 PUFA (n = 8; 3600mg/day EPA/DHA) or matched placebo (n = 6) for 6–8 weeks, before completing an endotoxin challenge (LPS 0.6 ng/kg). Calgranulin genes were up-regulated post-LPS, with greater increase in n-3 PUFA (S100A8 15-fold, p = 0.003; S100A9 7-fold, p = 0.003; S100A12 28-fold, p = 0.01) compared to placebo (S100A8 2-fold, p = 0.01; S100A9 1.4-fold, p = 0.4; S100A12 5-fold, p = 0.06). In an independent evoked endotoxemia study, calgranulin gene expression correlated with the systemic inflammatory response. Through in vivo and in vitro interrogation we highlight differential responses in adipocytes and mononuclear cells during inflammation, with n-3 PUFA leading to increased calgranulin expression in adipose, but decreased expression in circulating cells. In conclusion, we present a novel relationship between n-3 PUFA anti-inflammatory action in vivo and cell-specific modulation of calgranulin expression during innate immune activation.

Human Intestinal Barrier Function in Health and Disease

The gastrointestinal tract consists of an enormous surface area that is optimized to efficiently absorb nutrients, water, and electrolytes from food. At the same time, it needs to provide a tight barrier against the ingress of harmful substances, and protect against a reaction to omnipresent harmless compounds. A dysfunctional intestinal barrier is associated with various diseases and disorders. In this review, the role of intestinal permeability in common disorders such as infections with intestinal pathogens, inflammatory bowel disease, irritable bowel syndrome, obesity, celiac disease, non-celiac gluten sensitivity, and food allergies will be discussed. In addition, the effect of the frequently prescribed drugs proton pump inhibitors and non-steroidal anti-inflammatory drugs on intestinal permeability, as well as commonly used methods to assess barrier function will be reviewed.

The Link Between Inflammatory Disorders and Coronary Heart Disease: a Look at Recent Studies and Novel Drugs in Development

Inflammation is a critical component in the development of coronary heart disease (CHD), specifically in the process of atherogenesis. Human translational and preclinical studies have demonstrated that inflammation contributes to the development, sustainment, and progression of atherosclerosis, and epidemiological studies demonstrate that human diseases associated with increased systemic inflammation increase the risk of CHD-related events. Therefore, over the last decade, multiple clinical studies were designed to target the inflammatory cascade in order to reduce the risk of CHD and to identify which populations may benefit from these preventative treatment strategies. This review briefly summarizes inflammation as a risk factor in atherosclerosis, human disease states associated with accelerated atherosclerosis, and current treatment strategies for CHD targeting the inflammatory cascade.

Low expression of the GILZ may contribute to adipose inflammation and altered adipokine production in human obesity

The glucocorticoid-induced leucine zipper (GILZ), a primary target of glucocorticoids, is expressed in human adipocytes, but its importance in adipocyte function is unknown. Because TNFα is increased in obese adipose tissue and antagonizes a number of glucocorticoid actions, we investigated the interplay of these pathways. GILZ knockdown increased and GILZ overexpression decreased interleukin-6 (IL-6) and leptin mRNA and protein secretion. GILZ knockdown increased the magnitude of the glucocorticoid effect on leptin secretion, but did not affect the glucocorticoid suppression of IL-6. Although GILZ silencing decreased adiponectin mRNA levels, it did not affect the amount of adiponectin secreted. GILZ negatively modulated pro-inflammatory signaling pathways, blocking basal and TNFα-stimulated (1 h) p65 nuclear factor κB nuclear translocation and transcriptional activity by binding to p65 in the cytoplasm. GILZ silencing increased basal ERK1/2 and JNK phosphorylation, and decreased MAPK phosphatase-1 protein levels. Longer term TNFα (4 h or 24 h) treatment decreased GILZ expression in human adipocytes. Furthermore, adipose tissue GILZ mRNA levels were reduced in proportion to the degree of obesity and expression of inflammatory markers. Overall, these results suggest that GILZ antagonizes the pro-inflammatory effects of TNFα in human adipocytes, and its downregulation in obesity may contribute to adipose inflammation and dysregulated adipokine production, and thereby systemic metabolism.

Cytokine expression in the visceral adipose tissue after laparoscopic and conventional surgery in a rodent model

Background

Laparoscopic Surgery has become a worldwide standard procedure for a variety of indications. This has been attributed to a milder postoperative inflammatory response by the innate immune system potentially mediated through immune mediators released by the visceral adipose tissue (VAT). However, an in vivo experimental evidence is lacking and is the issue of our present study.

Methods

Male Wistar rats (N = 24) underwent standardized surgical procedures of conventional cecum resection (CCR), conventional sham operation, laparoscopic cecum resection (LCR), or laparoscopic sham operation. Cytokine expression of leptin, resistin, and IL-6 was analyzed in VAT before and after resection by quantitative RT-PCR.

Results

Postoperative leptin gene expression was reduced in the CCR and LCR groups, while expression was not significantly affected in both sham groups compared to the preoperative levels. In contrast, IL-6 expression was not affected in the LCR group, but was significantly elevated in the CCR cohort. The IL-6 expression was significantly higher in CCR compared to LCR. Resistin expression levels did not differ between all groups.

Conclusions

Our study underlines the role of immunological involvement of VAT in the postoperative phase. Low leptin levels seem to act as a stimulator for energy uptake in order to cope with postoperative stress. A lower IL-6 expression in the LCR compared to the CCR group may indicate a weaker inflammatory activity potentially adding to the clinical benefits observed in patients undergoing LS.

Analysis of the correlation between serum resistin and the variability of erythropoietin responsiveness in patients with chronic kidney disease

Chronic kidney disease (CKD) is commonly accompanied by inflammation and anemia; however, the pathogenesis of CKD is unclear. Expression of resistin, a cysteine-rich secretory plasma protein, is correlated with the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and lipoprotein-associated phospholipase A2, indicating that resistin may be involved in inflammatory events. In addition, inflammation inhibits the activity of erythropoietin (EPO) and, thus, erythropoiesis. The aim of the present study was to analyze the correlation between serum resistin and the variability of EPO responsiveness in CKD patients. The levels of serum creatinine (SCr), C-reactive protein (CRP), total cholesterol, triglycerides, IL-6 and serum resistin were measured in the samples obtained from 138 CKD patients and healthy control subjects. The levels of serum resistin in the CKD groups with and without hemodialysis were significantly higher than those observed in the normal control group (P<0.01) and the levels of serum resistin in the hemodialysis CKD group were higher than those observed in the CKD group without dialysis (P<0.01). The levels of serum resistin in patients in the randomly selected CKD group (with hemodialysis) were positively correlated with the duration of dialysis and the levels of SCr and CRP (P<0.05), however, were negatively correlated with the estimated glomerular filtration rate. The EPO resistance index (ERI) was identified to be associated with body mass index and the levels of CRP and resistin; furthermore, EPO reactivity was correlated with the level of resistin and ERI. The levels of serum resistin were correlated with the variability in EPO responsiveness that was observed in the CKD patients. Therefore, the measurement of serum resistin may aid with understanding the mechanisms, clinical diagnosis and treatment of CKD.

Lipopolysaccharide induces a downregulation of adiponectin receptors in-vitro and in-vivo

Background. Adipose tissue contributes to the inflammatory response through production of cytokines, recruitment of macrophages and modulation of the adiponectin system. Previous studies have identified a down-regulation of adiponectin in pathologies characterised by acute (sepsis and endotoxaemia) and chronic inflammation (obesity and type-II diabetes mellitus). In this study, we investigated the hypothesis that LPS would reduce adiponectin receptor expression in a murine model of endotoxaemia and in adipoocyte and myocyte cell cultures.

Methods. 25 mg/kg LPS was injected intra-peritoneally into C57BL/6J mice, equivalent volumes of normal saline were used in control animals. Mice were killed at 4 or 24 h post injection and tissues harvested. Murine adipocytes (3T3-L1) and myocytes (C2C12) were grown in standard culture, treated with LPS (0.1 µg/ml–10 µg/ml) and harvested at 4 and 24 h. RNA was extracted and qPCR was conducted according to standard protocols and relative expression was calculated.

Results. After LPS treatment there was a significant reduction after 4 h in gene expression of adipo R1 in muscle and peri-renal fat and of adipo R2 in liver, peri-renal fat and abdominal wall subcutaneous fat. After 24 h, significant reductions were limited to muscle. Cell culture extracts showed varied changes with reduction in adiponectin and adipo R2 gene expression only in adipocytes.

Conclusions. LPS reduced adiponectin receptor gene expression in several tissues including adipocytes. This reflects a down-regulation of this anti-inflammatory and insulin-sensitising pathway in response to LPS. The trend towards base line after 24 h in tissue depots may reflect counter-regulatory mechanisms. Adiponectin receptor regulation differs in the tissues investigated.

Activation of innate immunity modulates insulin sensitivity, glucose effectiveness and pancreatic β-cell function in both African ancestry and European ancestry healthy humans

OBJECTIVE

Insulin resistance is a risk factor for type 2 diabetes, and is associated with inflammatory cardiometabolic disease. Given differences between African ancestry (AA) and European ancestry (EA) in the epidemiology of type 2 diabetes as well as in response to inflammatory stress, we investigated potential race differences in glucose homeostasis responses during experimental endotoxemia in humans.

METHODS

Healthy volunteers (age 18-45 years, BMI 18-30 kg/m(2), 47% female, African-ancestry (AA, n=42) and European-ancestry (EA, n=106)) were recruited as part of the Genetics of Evoked Responses to Niacin and Endotoxemia (GENE) Study. Subjects underwent an inpatient endotoxin challenge (1 ng/kg LPS) and two frequently-sampled intravenous glucose tolerance tests (FSIGTT). Insulin and glucose values obtained during FSIGTT pre- and 24-hours post-LPS were analyzed using the minimal model.

RESULTS

FSIGTT derived insulin sensitivity index (SI), disposition index (DI) and glucose effectiveness (SG) decreased significantly following LPS (p<0.0001) while the acute insulin response to glucose (AIR(g)) increased (p<0.0001). Although expected race differences were observed in glucose homeostasis parameters at baseline prior to LPS e.g., lower SI (2.5 vs. 4.1 μU/L/min, p<0.0001) but higher AIR(g) (median 848 vs. 290 μU/L/min, p<0.0001) in AA vs. EA, the changes in glucose homeostasis responses to LPS were directionally and proportionally consistent across race e.g., SI median -35% in EA and -29% in AA and AIR(g) median +17% in EA and +26% in AA.

CONCLUSION

Both EA and AA samples modulated glucose and insulin homeostasis similarly during endotoxemia.

IMPLICATIONS

Race differences in response to environmental inflammatory stress are unlikely to be a substantial contributor to the observed difference in diabetes incidence and complications between EA and AA.

Acute Systemic Inflammation is Unlikely to Affect Adiponectin and Leptin Synthesis in Humans

Adipose tissue (AT), classically thought to be merely an energy store, has been shown to produce inflammatory and metabolically active cytokines. Recently, adiponectin and leptin, adipokines primarily synthesized by adipocytes, have attracted considerable attention because inflammation has been suggested to modulate adipokine levels. However, the regulation of adiponectin and leptin is complex and the knowledge about their synthesis within the early onset of inflammation is poorly understood. The aim of this study was to investigate if the synthesis of adiponectin and leptin is affected during the early phase of an acute systemic inflammation. Eighteen healthy subjects were allocated to vaccination against Salmonella typhi or to a control group, and adiponectin and leptin concentrations measured in plasma during 24 h. Nine patients, without markers of inflammation, undergoing open heart surgery were investigated before and after the operation by analysis of plasma levels and AT gene expression of adiponectin and leptin. Plasma interleukin (IL)-6 concentrations were measured in both cohorts. Plasma levels of IL-6 were doubled after vaccination and increased 30-fold after open heart surgery. Plasma levels of adiponectin and leptin were unchanged after vaccination whereas adiponectin and leptin tended to decrease after surgery. The gene expression of adiponectin and leptin was unaltered in omental and subcutaneous AT after surgery. Despite the use of two models of stimulated in vivo systemic inflammation, we found no evidence of an early regulation of adiponectin and leptin synthesis, indicating that these two adipokines are not key elements in an acute systemic inflammation in humans.

Human experimental endotoxemia in modeling the pathophysiology, genomics, and therapeutics of innate immunity in complex cardiometabolic diseases

Inflammation is a fundamental feature of several complex cardiometabolic diseases. Indeed, obesity, insulin resistance, metabolic dyslipidemia, and atherosclerosis are all closely linked inflammatory states. Increasing evidence suggests that the infectious, biome-related, or endogenous activation of the innate immune system may contribute to the development of metabolic syndrome and cardiovascular disease. Here, we describe the human experimental endotoxemia model for the specific study of innate immunity in understanding further the pathogenesis of cardiometabolic disease. In a controlled, experimental setting, administration of an intravenous bolus of purified Escherichia coli endotoxin activates innate immunity in healthy human volunteers. During endotoxemia, changes emerge in glucose metabolism, lipoprotein composition, and lipoprotein functions that closely resemble those observed chronically in inflammatory cardiovascular disease risk states. In this review, we describe the transient systemic inflammation and specific metabolic consequences that develop during human endotoxemia. Such a model provides a controlled induction of systemic inflammation, eliminates confounding, undermines reverse causation, and possesses unique potential as a starting point for genomic screening and testing of novel therapeutics for treatment of the inflammatory underpinning of cardiometabolic disease.

Integrative genomics identifies 7p11.2 as a novel locus for fever and clinical stress response in humans

Fever predicts clinical outcomes in sepsis, trauma and during cardiovascular stress, yet the genetic determinants are poorly understood. We used an integrative genomics approach to identify novel genomic determinants of the febrile response to experimental endotoxemia. We highlight multiple integrated lines of evidence establishing the clinical relevance of this novel fever locus. Through genome-wide association study (GWAS) of evoked endotoxemia (lipopolysaccharide (LPS) 1 ng/kg IV) in healthy subjects of European ancestry we discovered a locus on chr7p11.2 significantly associated with the peak febrile response to LPS (top single nucleotide polymorphism (SNP) rs7805622, P = 2.4 × 10(-12)), as well as with temperature fluctuation over time. We replicated this association in a smaller independent LPS study (rs7805622, P = 0.03). In clinical translation, this locus was also associated with temperature and mortality in critically ill patients with trauma or severe sepsis. The top GWAS SNPs are not located within protein-coding genes, but have significant cis-expression quantitative trait loci (eQTL) associations with expression of a cluster of genes ∼400 kb upstream, several of which (SUMF2, CCT6A, GBAS) are regulated by LPS in vivo in blood cells. LPS- and cold-treatment of adipose stromal cells in vitro suggest genotype-specific modulation of eQTL candidate genes (PSPH). Several eQTL genes were up-regulated in brown and white adipose following cold exposure in mice, highlighting a potential role in thermogenesis. Thus, through genomic interrogation of experimental endotoxemia, we identified and replicated a novel fever locus on chr7p11.2 that modulates clinical responses in trauma and sepsis, and highlight integrated in vivo and in vitro evidence for possible novel cis candidate genes conserved across human and mouse.

Resistin is not an appropriate biochemical marker to predict severity of acute pancreatitis: A case-controlled study

AIM: To assess levels of serum resistin upon hospital admission as a predictor of acute pancreatitis (AP) severity.

METHODS: AP is both a common and serious disease, with severe cases resulting in a high mortality rate. Several predictive inflammatory markers have been used clinically to assess severity. This prospective study collected data from 102 patients who were diagnosed with an initial acute biliary pancreatitis between March 2010 and February 2013. Measurements of body mass index (BMI) and waist circumference (WC) were obtained and serum resistin levels were analyzed at the time of hospital admission using enzyme-linked immunosorbent assay. Additionally, resistin levels were measured from a control group after matching gender, BMI and age.

RESULTS: A total of 102 patients (60 females and 42 males) were diagnosed with acute gallstone-induced pancreatitis. The mean age was 45 years, and mean BMI value was 30.5 kg/m² (Obese, class I). Twenty-two patients (21.6%) had severe AP, while eighty-eight patients had mild pancreatitis (78.4%). Our results showed that BMI significantly correlated with pancreatitis severity (P = 0.007). Serum resistin did not correlate with BMI, weight or WC. Furthermore, serum resistin was significantly higher in patients with AP compared to control subjects (P < 0.0001). The mean resistin values upon admission were 17.5 ng/mL in the severe acute biliary pancreatitis group and 16.82 ng/mL in the mild AP group (P = 0.188), indicating that resistin is not an appropriate predictive marker of clinical severity.

CONCLUSION: We demonstrate that obesity is a risk factor for developing severe AP. Further, although there is a correlation between serum resistin levels and AP at the time of hospital admission, resistin does not adequately serve as a predictive marker of clinical severity.

Psoriasis is associated with decreased plasma adiponectin levels independently of cardiometabolic risk factors

BACKGROUND

Psoriasis is an inflammatory skin disease that may be associated with an adverse cardiometabolic profile including modulated plasma adiponectin and leptin levels. Whether these levels are independent of cardiometabolic risk factors, which are also prevalent in psoriasis, is not known.

METHODS

A consecutive sample of 122 participants with varying degrees of psoriasis severity, and a random sample of 134 participants without psoriasis, were recruited for this case-control study. Cardiometabolic risk factors including traditional cardiovascular risk factors, waist circumference, insulin resistance, and total plasma adiponectin and leptin were measured. Total plasma adiponectin and leptin levels were compared in unadjusted and adjusted analyses by psoriasis status.

RESULTS

Participants with psoriasis had mostly mild disease and were mainly on topical therapies, but still had a more adverse cardiometabolic profile compared with those without psoriasis. Furthermore, plasma adiponectin levels were significantly lower in participants with psoriasis than those without {7.13 μg/mL [interquartile range (IQR) 4.9-11.3) vs. 14.5 μg/mL (IQR 8.4-24.1); P < 0.001]}. Plasma leptin (ng/mL) levels were higher in the psoriasis group but this did not reach statistical significance [11.3 (IQR 6.4-21.8) vs. 9.8 (IQR 4.9-20.5); P = 0.07]. In multivariable modelling, plasma adiponectin levels were still negatively associated with psoriasis status after adjusting for waist size (% difference = -41.2%, P < 0.001), insulin resistance (% difference = -39.5%, P < 0.001), and both waist size and insulin resistance (% difference = -38.5%, P < 0.001).

CONCLUSIONS

Plasma levels of adiponectin were lower in psoriasis, and this relationship persisted after adjusting for cardiometabolic risk factors known to decrease adiponectin levels. These findings suggest that inflammation present in psoriasis may be associated with adipose tissue dysfunction; however, direct studies of adipose tissue are needed to confirm this.

Pathogenesis and treatment of atherosclerosis in lupus

The prevalence of atherosclerosis (ATH) is higher in patients with systemic lupus erythematosus (SLE) and occurs at an earlier age. The lupus-related factors that account for this increased risk are likely numerous and related to the factors described in this article. Identifying of at-risk subjects and increasing the understanding of pathogenesis of ATH in SLE is critical for improving the quality of care and improving mortality in this vulnerable population.