Increased levels of both Th1 and Th2 cytokines in subjects with metabolic syndrome (CURES-103)

Osteomyelitis is associated with increased anti-inflammatory response and immune exhaustion

Introduction

Osteomyelitis (OMS) is a bone infection causing bone pain and severe complications. A balanced immune response is critical to eradicate infection without harming the host, yet pathogens manipulate immunity to establish a chronic infection. Understanding OMS-driven inflammation is essential for disease management, but comprehensive data on immune profiles and immune cell activation during OMS are lacking.

Methods

Using high-dimensional flow cytometry, we investigated the detailed innate and adaptive systemic immune cell populations in OMS and age- and sex-matched controls.

Results

Our study revealed that OMS is associated with increased levels of immune regulatory cells, namely T regulatory cells, B regulatory cells, and T follicular regulatory cells. In addition, the expression of immune activation markers HLA-DR and CD86 was decreased in OMS, while the expression of immune exhaustion markers TIM-3, PD-1, PD-L1, and VISTA was increased. Members of the T follicular helper (Tfh) cell family as well as classical and typical memory B cells were significantly increased in OMS individuals. We also found a strong correlation between memory B cells and Tfh cells.

Discussion

We conclude that OMS skews the host immune system towards the immunomodulatory arm and that the Tfh memory B cell axis is evident in OMS. Therefore, immune-directed therapies may be a promising alternative for eradication and recurrence of infection in OMS, particularly in individuals and areas where antibiotic resistance is a major concern.

Plant stanol consumption increases anti-COVID-19 antibody responses, independent of changes in serum cholesterol concentrations: a randomized controlled trial

BACKGROUND

People with overweight/obesity generally have impaired immune responses, resulting among others in increased risk of severe complaints and hospitalization after infections with severe acute respiratory syndrome coronavirus 2 (COVID-19), as well as decreased antibody production after vaccinations. Plant stanol ester previously increased the combined IgM/IgG antibody titers toward a hepatitis A vaccination in patients with allergic asthma, but the underlying mechanism is unknown.

OBJECTIVES

We evaluated whether plant stanol ester consumption improved the immune response in subjects with overweight/obesity after a COVID-19 vaccination.

METHODS

A double-blind, randomized, placebo-controlled trial was performed. Thirty-two subjects with overweight/obesity consumed products with added plant stanols (4 g/d; provided as plant stanol ester) or control ≥2 wk before receiving their COVID-19 vaccination until 4 wk after vaccination. Antibody titers were analyzed weekly and statistically analyzed using mixed models. Serum metabolic markers and cytokine profiles were also analyzed.

RESULTS

IgM concentrations against the COVID-19 Spike protein were increased in the plant stanol ester group compared with the control group, with the largest difference observed 2 wk after vaccination [31.2 (0.43, 62.1) BAU/mL, or +139%; Group × Time: P = 0.031]. Subjects that produced very low IgM antibodies produced, as expected, hardly any IgG antibodies. In those with IgG seroconversion, IgG Spike concentrations were also increased in the plant stanol ester group compared with the control group [71.3 (2.51, 140.1) BAU/mL; Group P = 0.043]. Stimulated cytokine concentrations decreased in the plant stanol ester group compared with the control group in all 3 cytokine domains (that is, proinflammatory, T helper [Th1]/Th17, and Th2/regulatory T cells). Between-group differences in serum LDL cholesterol or other metabolic markers were not observed.

CONCLUSIONS

Consuming plant stanols (4 g/d) affects immune responses to COVID-19 vaccinations, translating into increased serum anti-COVID-19 IgM concentrations in subjects with overweight/obesity. Only in IgG seroconverted subjects, serum anti-COVID-19 IgG concentrations also increase. These effects are independent of reductions in LDL cholesterol. These results suggest that this high-risk group for COVID-19 complications could benefit from plant stanol consumption. This trial was registered at clinicaltrials.gov as NCT04844346.

Low-grade inflammation is associated with a heterogeneous lipoprotein subclass profile in an apparently healthy population sample

BACKGROUND AND AIMS

Prevention measures for cardiovascular diseases (CVD) have shifted their focus from lipoproteins to the immune system. However, low-grade inflammation and dyslipidemia are tightly entangled. The objective of this study was to assess the relations between a broad panel of inflammatory biomarkers and lipoprotein subclass parameters.

METHODS

We utilized data from the population-based Study of Health in Pomerania (SHIP-TREND, n = 403). Plasma concentrations of 37 inflammatory markers were measured by a bead-based assay. Furthermore, we employed nuclear magnetic resonance spectroscopy to measure total cholesterol, total triglycerides, total phospholipids as well as the fractional concentrations of cholesterol, triglycerides, phospholipids, ApoA1, ApoA2 and ApoB in all major lipoprotein subclasses. Associations between inflammatory biomarkers and lipoprotein subclasses were analyzed by adjusted linear regression models.

RESULTS

APRIL, BAFF, TWEAK, sCD30, Pentraxin-3, sTNFR1, sTNFR2, Osteocalcin, Chitinase 3-like 1, IFN-alpha2, IFN-gamma, IL-11, IL-12p40, IL-29, IL-32, IL-35, TSLP, MMP1 and MMP2 were related with lipoprotein subclass components, forming two distinct clusters. APRIL had inverse relations to HDL-C (total and subclasses) and HDL Apo-A1 and Apo-A2 content. MMP-2 was inversely related to VLDL-C (total and subclasses), IDL-C as well as LDL5/6-C and VLDL-TG, IDL-TG, total triglycerides as well as LDL5/5-TG and HDL4-TG. Additionally, we identified a cluster of cytokines linked to the Th1-immune response, which were associated with an atherogenic lipoprotein profile.

CONCLUSION

Our findings expand the existing knowledge of inflammation-lipoprotein interactions, many of which are suggested to be involved in the pathogeneses of chronic non-communicable diseases. The results of our study support the use of immunomodulatory substances for the treatment and possibly prevention of CVD.

The metabolic effects of APOL1 in humans

Harboring apolipoprotein L1 (APOL1) variants coded by the G1 or G2 alleles of the APOL1 gene increases the risk for collapsing glomerulopathy, focal segmental glomerulosclerosis, albuminuria, chronic kidney disease, and accelerated kidney function decline towards end-stage kidney disease. However, most subjects carrying APOL1 variants do not develop the kidney phenotype unless a second clinical condition adds to the genotype, indicating that modifying factors modulate the genotype-phenotype correlation. Subjects with an APOL1 high-risk genotype are more likely to develop essential hypertension or obesity, suggesting that carriers of APOL1 risk variants experience more pronounced insulin resistance compared to noncarriers. Likewise, arterionephrosclerosis (the pathological correlate of hypertension-associated nephropathy) and glomerulomegaly take place among carriers of APOL1 risk variants, and these pathological changes are also present in conditions associated with insulin resistance, such as essential hypertension, aging, and diabetes. Insulin resistance may contribute to the clinical features associated with the APOL1 high-risk genotype. Unlike carriers of wild-type APOL1, bearers of APOL1 variants show impaired formation of lipid droplets, which may contribute to inducing insulin resistance. Nascent lipid droplets normally detach from the endoplasmic reticulum into the cytoplasm, although the proteins that enable this process remain to be fully defined. Wild-type APOL1 is located in the lipid droplet, whereas mutated APOL1 remains sited at the endoplasmic reticulum, suggesting that normal APOL1 may participate in lipid droplet biogenesis. The defective formation of lipid droplets is associated with insulin resistance, which in turn may modulate the clinical phenotype present in carriers of APOL1 risk variants.

A Narrative Review Discussing Vasectomy-Related Impact upon the Status of Oxidative Stress and Inflammation Biomarkers and Semen Microbiota

Background: Male contraceptive approaches besides tubal sterilization involve vasectomy and represent the method of choice among midlife men in developing countries thanks to many advantages. However, the subsidiary consequences of this intervention are insufficiently explored since the involved mechanisms may offer insight into a much more complex picture. Methods: Thus, in this manuscript, we aimed to reunite all available data by searching three separate academic database(s) (PubMed, Web of Knowledge, and Scopus) published in the past two decades by covering the interval 2000–2023 and using a predefined set of keywords and strings involving “oxidative stress” (OS), “inflammation”, and “semen microbiota” in combination with “humans”, “rats”, and “mice”. Results: By following all evidence that fits in the pre-, post-, and vasectomy reversal (VR) stages, we identified a total of n = 210 studies from which only n = 21 were finally included following two procedures of eligibility evaluation. Conclusions: The topic surrounding this intricate landscape has created debate since the current evidence is contradictory, limited, or does not exist. Starting from this consideration, we argue that further research is mandatory to decipher how a vasectomy might disturb homeostasis.

Th1/Th2 Balance in Young Subjects: Relationship with Cytokine Levels and Metabolic Profile

Purpose

We aim to identify Th1 and Th2 cell clusters in young subjects, including their clinical and metabolic characteristics and the Th1/Th2 balance.

Patients and Methods

A total of 100 participants were included. The frequencies of Th1 and Th2 cells in peripheral blood were determined by flow cytometry. Serum C-reactive protein was measured using a turbidimetric assay, and insulin levels were quantified with an enzyme-linked immunosorbent assay. Circulating cytokine levels were analyzed using a multiplex system.

Results

A cluster analysis was performed to determine the Th1/Th2 balance in a group of young people, and 3 clusters were formed with the following characteristics: 1) subjects with a higher prevalence of hyperglycemia (38%), dyslipidemia (38–75%), and insulin resistance (50%), as well as a higher percentage of Th1 cells and Th1/Th2 ratio, including elevated IFN-ɣ levels; 2) subjects with a lower prevalence of hyperglycemia (23%) and insulin resistance (15.4%), but a higher prevalence of dyslipidemia (8–85%) with a predominance of Th2 cells, and lower Th1/Th2 ratio; 3) subjects with a lower prevalence of hyperglycemia (6%), insulin resistance (41%), and dyslipidemia (10–63%), as well as a balance of Th1 and Th2 cells and lower Th1/Th2 ratio, including low IFN-ɣ levels. Positive correlations between Th1 cells with IFN-γ, IL-12, and IL-1β and between Th2 cells with IFN-γ, IL-2, and IL-4 were found (p < 0.05). A significant increase in Th1 cells was observed in the presence of hyperglycemia and high LDL-C levels, as well as increased Th2 cells in the absence of abdominal obesity and high blood pressure, including low HDL-C levels. The Th1/Th2 ratio was higher in the group with high cardiometabolic risk (p = 0.03).

Conclusion

Th1/Th2 balance is related to metabolic abnormalities that may occur in young population, and thus the timely identification of different phenotypes may help predict an increased cardiometabolic risk.

Th1/Th2 cytokines profile in overweight/obese young adults and their correlation with airways inflammation

Objectives

Methods

Results

Conclusion

Inflammation Parameters Associated with Metabolic Disorders: Relationship Between Diet and Microbiota

The metabolic syndrome (MetS) includes numerous interrelated clinical, anthropometric, biochemical, and metabolic components and has become a public health problem due to its impact on morbimortality. Inflammation is a central mechanism underlying the etiology and clinical manifestations of MetS, contributing to its related pathological outcomes. Dietary patterns have been associated with the promotion of the diversity of microbiota in the digestive tract. Recently, research has focused on the importance of microbiota changes associated with MetS and inflammation. Other studies have been performed to understand the impact of prebiotics, probiotics, and synbiotics as allies on diet, inflammation, and MetS parameters. This review analyses the correlation between metabolic disorders, inflammation parameters, gut microbiota, and how diet has been involved as treatment of MetS and the modulation of inflammation and microbiota.

COVID-19 and Progesterone: Part 2. Unraveling High Severity, Immunity Patterns, Immunity grading, Progesterone and its potential clinical use

Severely ill COVID–19 (Corona Virus Disease of 2019) patients have a hyperinflammatory condition with a high concentration of pro-inflammatory cytokines termed the cytokine storm. This milieu is reported to cause acute lung injury, oxygen deprivation, multiorgan damage, critical illness, and often death. Post SARS–CoV–2 (Severe Acute Respiratory Syndrome Coronavirus 2) infection, the fight between the invading virus and the host's immune system would either terminate in recovery, with eradication of the infection and regulation of the immune system; or there would be a continuation of immune attacks even after the virus has been cleared, leading to immune dysregulation and disease. This outcome is chiefly dependent on two factors: (1) the patient's immune response, and (2) sufficiency plus efficiency of the regulator(s). Concerning the first, the present research introduces a framework based on different types of immune responses to SARS–CoV–2 along with known disease examples, and how this relates to varying clinical outcomes and treatment needs for COVID–19 patients. About the second factor of ‘regulator(s)’, part 1 of the manuscript described in depth the regulatory role of progesterone in COVID–19. The present study investigates five immunity patterns and the status of the regulatory hormone progesterone with respect to the two established demographic risk factors for COVID–19 high-severity: male sex, and old age. The study evaluates the status of progesterone as a credible determinant of immune regulation and dysregulation. It duly relates the immunity patterns to clinical outcomes and evinces indications for clinical use of progesterone in COVID–19. It proposes a clear answer to the question: "why are males and old patients most likely to have critical illness due to COVID–19?" The study highlights clinical domains for the use of progesterone in COVID–19. Part 2 of this research introduces the concept of immunity patterns and immunity grading. These concepts herewith provided for the clinical course of COVID–19 also apply to other hyperinflammatory conditions. Possible clinical applications of progesterone to treat critically ill COVID–19 patients will open an avenue for hormonal treatments of infections and other immune-related diseases.

Effector Memory CD8+ and CD4+ T Cell Immunity Associated with Metabolic Syndrome in Obese Children

PURPOSE

We investigated the association of effector memory (EM) CD8⁺ T cell and CD4⁺ T cell immunity with metabolic syndrome (MS).

METHODS

Surface and intracellular staining of peripheral blood mononuclear cells was performed. Anti-interleukin-7 receptor-alpha (IL-7Rα) and CX3CR1 antibodies were used to stain the subsets of EM CD8⁺ T cells, while anti-interferon-gamma (IFN-γ), interleukin-17 (IL-17), and forkhead box P3 (FOXP3) antibodies were used for CD4⁺ T cell subsets.

RESULTS

Of the 47 obese children, 11 were female. Children with MS had significantly higher levels of serum insulin (34.8±13.8 vs. 16.4±6.3 μU/mL, p<0.001) and homeostasis model assessment of insulin resistance (8.9±4.1 vs. 3.9±1.5, p<0.001) than children without MS. Children with MS revealed significantly higher frequencies of IL-7Rα^low CD8⁺ T cells (60.1 ±19.1% vs. 48.4±11.5%, p=0.047) and IL-7Rα^lowCX3CR1⁺ CD8⁺ T cells (53.8±20.1% vs. 41.5 ±11.9%, p=0.036) than children without MS. As the serum triglyceride levels increased, the frequency of IL-7Rα^lowCX3CR1⁺ and IL-7Rα^highCX3CR1^- CD8⁺ T cells increased and decreased, respectively (r=0.335, p=0.014 and r=-0.350, p=0.010, respectively), in 47 children. However, no CD4⁺ T cell subset parameters were significantly different between children with and without MS.

CONCLUSION

In obese children with MS, the changes in immunity due to changes in EM CD8⁺ T cells might be related to the morbidity of obesity.

Roles of inflammation in intrinsic pathophysiology and antipsychotic drug-induced metabolic disturbances of schizophrenia

Schizophrenia is a debilitating psychiatric illness that remains poorly understood. While the bulk of symptomatology has classically been associated with disrupted brain functioning, accumulating evidence demonstrates that schizophrenia is characterized by systemic inflammation and disturbances in metabolism. Indeed, metabolic disease is a major determinant of the high mortality rate associated with schizophrenia. Antipsychotic drugs (APDs) have revolutionized management of psychosis, making it possible to rapidly control psychotic symptoms. This has ultimately reduced relapse rates of psychotic episodes and improved overall quality of life for people with schizophrenia. However, long-term APD use has also been associated with significant metabolic disturbances including weight gain, dysglycemia, and worsening of the underlying cardiometabolic disease intrinsic to schizophrenia. While the mechanisms for these intrinsic and medication-induced metabolic effects remain unclear, inflammation appears to play a key role. Here, we review the evidence for roles of inflammatory mechanisms in the disease features of schizophrenia and how these mechanisms interact with APD treatment. We also discuss the effects of common inflammatory mediators on metabolic disease. Then, we review the evidence of intrinsic and APD-mediated effects on systemic inflammation in schizophrenia. Finally, we speculate about possible treatment strategies. Developing an improved understanding of inflammatory processes in schizophrenia may therefore introduce new, more effective options for treating not only schizophrenia but also primary metabolic disorders.

Circulating levels of IL-33 are elevated by obesity and positively correlated with metabolic disorders in Chinese adults

BACKGROUND

Interleukin-33 (IL-33) plays a pivotal role in regulating innate immune response and metabolic homeostasis. However, whether its circulating level is correlated with obesity and metabolic disorders in humans remains largely unknown. We aimed to address this gap by determining IL-33 serum level and its downstream type 2 inflammatory cytokines interleukin-5 (IL-5) and interleukin-13 (IL-13) in overweight/obese population, and analyzing the specific associations between IL-33 and obesity metabolic phenotypes.

METHODS

217 subjects were enrolled and divided into three groups: healthy control (HC) subjects, metabolically healthy overweight/obese (MHOO) subjects and metabolically unhealthy overweight/obese (MUOO) subjects. Circulating levels of IL-33, IL-5 and IL-13 were measured using ELISA analyses. Multivariate regression analyses were further performed to determine the independent association between IL-33 and obesity metabolic phenotypes.

RESULTS

Circulating levels of IL-33 were significantly elevated in subjects of MUOO group compared with HC group and MHOO group, while no significant difference was observed between the latter two groups in IL-33 levels. Consistent with this, serum levels of IL-5/13 were higher in the MUOO group compared with HC and MHOO groups. After adjusted for all confounders, MUOO phenotype was significantly associated with increased IL-33 serum levels (OR = 1.70; 95% CI 1.09-2.64; p = 0.019). With the MHOO group as the reference population, higher circulating level of IL-33 was also positively associated with MUOO phenotype after adjusting for confounders (OR = 1.50; 95% CI 1.20-1.88; p = 2.91E-4). However, there was no significant association between MHOO phenotype and IL-33 levels (p = 0.942). Trend analysis further confirmed the positive correlation between MUOO phenotype and IL-33 level (p for trend = 0.019). Additionally, IL-33 was significantly and positively correlated with diastolic blood pressure (DBP), total cholesterol (TC), alanine aminotransferase (ALT), aspartate aminotransferase (AST), white blood cell (WBC), neutrophil and IL-5 only in MUOO group, while inversely correlated with high density lipoprotein cholesterol (HDL-C) in MHOO subjects.

CONCLUSION

Circulating levels of IL-33 were significantly elevated in overweight/obese Chinese adults with metabolic disorders. Increased levels of IL-33 were positively associated with metabolically unhealthy overweight/obese phenotype and several metabolic syndrome risk factors.

The Antimicrobial Activity of Origanum vulgare L. Correlated with the Gastrointestinal Perturbation in Patients with Metabolic Syndrome

(1) The metabolic syndrome (MS) promotes acute and chronic infections, due to the pro-inflammatory condition given by TNFα and IL6 or by affecting the microbiota. MS is also correlated with insulin resistance, causing inflammation and infections throughout the organism. (2) The purpose of this study was to track the effect of using the essential oil of Origanum vulgare L. (EOO) as an antibacterial treatment, compared to allopathic treatment with antibiotics in MS patients. A group of 106 people with MS was divided into four subgroups: L1-staphylococcal infection group, L2-Escherichia coli infection group, L3-streptococcal infection group with EOO treatment, and CG-control group without infection or treatment. (3) EOO is responsible for the antibacterial effect, and reduced minor uncomplicated infections. After a 10-day treatment, intestinal side effects were absent, improving the phase angle. (4) The results suggest that EOO may exhibit an antibacterial effect, similar to the antibiotic treatment, without promoting MS-specific dysbiosis, and it also improves the phase angle in patients, which is used as an index of health and cellular function.

Association between Dyslipidemia and Chronic Rhinosinusitis in a Korean Population

This study aims to assess the relationship between chronic rhinosinusitis (CRS) and dyslipidemia in a Korean population. The population aged 40 years or over was selected from the Korean National Health Insurance Service-National Health Screening Cohort. CRS was defined if patients were treated ≥2 times with ICD-10 code (J32) and underwent head and neck computed tomography. Patients with CRS were classified as having nasal polyps (J33) or not. Dyslipidemia was defined if participants with the ICD-10 code (E78) were treated ≥2 times from 2002 to 2015. A total of 6163 patients with CRS were matched with 24,652 controls (1:4 ratio) for sex, age, income, and residence. The adjusted odds ratios (aORs) of a previous dyslipidemia in patients with CRS were analyzed by conditional logistic regression analysis, adjusted for confounding factors. The prevalence of dyslipidemia was significantly higher in participants with CRS (26.1%) than in the controls (20.6%) (p < 0.001). There was a significant positive association between CRS with/without nasal polyps and dyslipidemia (aOR = 1.36, 95%CI = 1.26–1.47, p < 0.001). The association between CRS and dyslipidemia was stronger for CRS without nasal polyps (aOR = 1.42, 95% CI = 1.28–1.57, p < 0.001) than for CRS with nasal polyps (aOR = 1.31, 95% CI = 1.17–1.47, p < 0.001). All age and sex subgroups exhibited consistent results. A personal history of dyslipidemia was associated with risk of CRS regardless of total cholesterol and the use of statins.

Factors Influencing Total Serum IgE in Adults: The Role of Obesity and Related Metabolic Disorders

BACKGROUND AND AIM

Few reports have investigated the association between metabolic abnormalities (obesity and related metabolic syndrome) and total serum IgE concentrations.

METHODS

This cross-sectional study included a random sample of 1,516 adult individuals (44.7% men, aged 18-91 years, median 52 years) from a single municipality in Spain. Serum IgE was measured in the ADVIA Centaur system. Atopy was defined by the presence of positive skin prick tests to a panel of common aeroallergens in the area. Body mass index and data related to the definition of metabolic syndrome were obtained from all participants. Alcohol consumption, smoking, and regular physical exercise were assessed by a questionnaire.

RESULTS

Atopy (present in 21.9% of 1,514 evaluable individuals) was the strongest factor determining serum IgE concentrations. Male sex and heavy alcohol drinking were independently associated with higher IgE concentrations, particularly in the non-atopic individuals. Body mass index was positively associated with IgE concentrations, independent of potential confounders, although the effect was only evident among non-atopic individuals. In that group, median IgE concentrations in normal-weight and obese individuals were 15 and 24 kU/L, respectively (p < 0.001); likewise, obesity was associated with high (>100 kU/L) IgE concentrations after adjusting for potential confounders (odds ratio: 1.79, 95% confidence interval: 1.26-2.56, p = 0.001). The presence of metabolic syndrome and its components, particularly abdominal obesity and hyperglycaemia, was also positively and independently associated with higher IgE concentrations in non-atopic individuals.

CONCLUSIONS

Obesity and metabolic syndrome components are associated with high total serum IgE concentrations, particularly in non-atopic individuals.

Cytokines and the immune response in obesity-related disorders

The increasing prevalence of obesity and the associated morbidity and mortality are important public health problems globally. There is an important relationship between an unhealthy lifestyle and increased serum inflammatory cytokines. Adipocytes secrete several pro-inflammatory cytokines involved in the recruitment and activation of macrophages resulting in chronic low-grade inflammation. Increased cytokines in obese individual are related to the progression of several disorders including cardiovascular disease, hypertension, and insulin resistance. In present review we have summarized the crucial roles of cytokines and their inflammatory functions in obesity-related immune disorders.

Cardiovascular diseases and metabolic abnormalities associated with obesity: What is the role of inflammatory responses? A systematic review

INTRODUCTION

Obesity is a chronic disease responsible for a high morbidity and mortality rate, with an increasing worldwide prevalence. Obesity is associated with immune responses characterized by chronic systemic inflammation. This article focuses on the mechanisms that explain the proposed link between obesity-associated diseases and inflammation. Also, it describes the role of inflammatory molecules in obesity-associated metabolic abnormalities.

METHODS

More than 200 articles were selected and consulted by an online English search using various electronic search databases. Predefined key-words for the pathogenesis of obesity-induced inflammation and associated diseases, as well as the role of various inflammatory molecules, were used.

RESULTS

We have summarized the data of the articles consulted in this research and we have found that obesity is associated with a low-grade inflammation resulting from the change of adipose tissue (AT). The AT produces a variety of inflammatory molecules called adipocytokines that are involved in the onset of systemic low-grade inflammation which is the link between obesity and associated-chronic abnormalities; such as insulin resistance, metabolic syndrome, cardiovascular disease (CVD), hypertension, diabetes, and some cancers. Also, we have searched all the inflammatory molecules involved in this pathogenesis and we have briefly described the role of 16 of them which are the most related to obesity-associated inflammation. The results have shown that there are inflammatory molecules that have a positive relationship with the pathogenesis of obesity-related diseases and others have a negative relationship with this pathogenesis.

CONCLUSION

Inflammation plays a crucial role in the development of various metabolic-abnormalities related to obesity. In this regard, the management of obesity may help reduce the risk of cardiovascular disease and other metabolic complications by inhibiting inflammatory mechanisms.

Dietary β-Cryptoxanthin Inhibits High-Refined Carbohydrate Diet-Induced Fatty Liver via Differential Protective Mechanisms Depending on Carotenoid Cleavage Enzymes in Male Mice

BACKGROUND

β-Cryptoxanthin (BCX), a provitamin A carotenoid shown to protect against nonalcoholic fatty liver disease (NAFLD), can be cleaved by β-carotene-15,15'-oxygenase (BCO1) to generate vitamin A, and by β-carotene-9',10'-oxygenase (BCO2) to produce bioactive apo-carotenoids. BCO1/BCO2 polymorphisms have been associated with variations in plasma carotenoid amounts in both humans and animals.

OBJECTIVES

We investigated whether BCX feeding inhibits high refined-carbohydrate diet (HRCD)-induced NAFLD, dependent or independent of BCO1/BCO2.

METHODS

Six-week-old male wild-type (WT) and BCO1-/-/BCO2-/- double knockout (DKO) mice were randomly fed HRCD (66.5% of energy from carbohydrate) with or without BCX (10 mg/kg diet) for 24 wk. Pathological and biochemical variables were analyzed in the liver and mesenteric adipose tissues (MATs). Data were analyzed by 2-factor ANOVA.

RESULTS

Compared to their respective HRCD controls, BCX reduced hepatic steatosis severity by 33‒43% and hepatic total cholesterol by 43‒70% in both WT and DKO mice (P < 0.01). Hepatic concentrations of BCX, but not retinol and retinyl palmitate, were 33-fold higher in DKO mice than in WT mice (P < 0.001). BCX feeding increased the hepatic fatty acid oxidation protein peroxisome proliferator-activated receptor-α, and the cholesterol efflux gene ATP-binding cassette transporter5, and suppressed the lipogenesis gene acetyl-CoA carboxylase 1 (Acc1) in the MAT of WT mice but not DKO mice (P < 0.05). BCX feeding decreased the hepatic lipogenesis proteins ACC and stearoyl-CoA desaturase-1 (3-fold and 5-fold) and the cholesterol synthesis genes 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase and HMG-CoA synthase 1 (2.7-fold and 1.8-fold) and increased the cholesterol catabolism gene cholesterol 7α-hydroxylase (1.9-fold) in the DKO but not WT mice (P < 0.05). BCX feeding increased hepatic protein sirtuin1 (2.5-fold) and AMP-activated protein kinase (9-fold) and decreased hepatic farnesoid X receptor protein (80%) and the inflammatory cytokine gene Il6 (6-fold) in the MAT of DKO mice but not WT mice (P < 0.05).

CONCLUSION

BCX feeding mitigates HRCD-induced NAFLD in both WT and DKO mice through different mechanisms in the liver-MAT axis, depending on the presence or absence of BCO1/BCO2.

Association between Type 2 Diabetes, Obesity and Key Immunological Components of IgE-mediated Inflammation

BACKGROUND

Changes in lifestyle and obesity in recent decades have brought about a dramatic increase in type 2 diabetes mellitus (DM2) and allergic diseases. Clinical and epidemiological studies associate obesity with epidemics of allergic diseases. The link between obesity and DM2 with immunological components of IgE-mediated allergic inflammation is not yet conclusively established.

AIM

To examine the key immunological components of IgE-mediated allergic inflammation in patients with DM2 and their relationship with glycemic control and anthropometric indicators.

MATERIALS AND METHODS

Fifty-five patients with DM2 and 32 healthy controls with normal weight and body mass index (BMI) of 18-24.9 kg/m2 were included in the study. Th2-cytokine profile (serum levels of IL-4 and IL-5, pg/ml) and total serum IgE IU/ml were assessed in all participants in the study using ELISA. In patients with DM2, levels of glycated hemoglobin (HbA1c%) in the blood were also measured.

RESULTS

Serum levels of IL-4 and IL-5 are significantly higher in patients with DM2 compared to the control group. Serum levels of IL-4 and IL-5 positively correlated with BMI as well as serum levels of IL-4 with waist circumference. Total serum IgE positively correlated with HbA1c.

CONCLUSION

Obesity and poor glycemic control in patients with DM2 affect key immunological components of IgE-mediated allergic inflammation and possibly alter the immune response to allergens and antigens.

The effect of short-term intensive insulin therapy on circulating T cell subpopulations in patients with newly diagnosed type 2 diabetes mellitus

AIMS

To evaluate the effect of short-term intensive insulin therapy on circulating T cell subpopulations in patients with newly diagnosed type 2 diabetes mellitus (T2DM).

METHODS

A total of 113 patients with T2DM and 28 normal subjects were enrolled. Demographic parameters and biochemical markers were collected at baseline, and flow cytometry was applied to determine the proportion of T cell subpopulations in participants. Then the patients underwent continuous subcutaneous insulin injection (CSII) treatment with euglycemia for 2 weeks, and the T cell subpopulations were measured again after CSII treatment.

RESULTS

Compared with normal subjects, the proportion of Th1 cells and the ratio of Th1/Th2 increased, the proportion of Treg cells decreased in patients with T2DM (p < 0.05 for all). The ratio of Th1/Th2 was positively correlated with glycosylated hemoglobin A1c (HbA1c) and negatively correlated with high density lipoprotein cholesterol (HDL-C). Furthermore, there were negative associations between the proportion of Treg cells and fasting plasma glucose, HbA1c, triglyceride, low density lipoprotein cholesterol, and positive association between the proportion of Treg cells and HDL-C. After CSII treatment, the proportion of Th1 cells and the ratio of Th1/Th2 decreased (p < 0.05 for both), the proportion of Treg cells increased in patients with T2DM (p < 0.05).

CONCLUSIONS

Short-term intensive insulin therapy could modulate circulating T cell subpopulations in patients with T2DM, which might alleviate inflammatory responses caused by hyperglycemia. This study was registered with ChiCTR-OPN-17010405.

Inflammation in human adipose tissues-Shades of gray, rather than white and brown

Chronic inflammation in adipose tissues has been associated with obesity and metabolic syndrome over the years. Various studies using animal models have contributed to our knowledge on the pro- and anti- inflammatory mediators that regulate obesity. Analyses of cytokine profiles in humans have not revealed a clear scenario. Likewise, treatments targeting inflammation to control obesity and insulin resistance has not yielded promising results. In this review we summarize the data available in human obesity and discuss the possible reasons that could explain the difficulties in treating obesity and insulin resistance by targeting pro-inflammatory cytokines.

Inflammatory Cytokine Profiles in Visceral and Subcutaneous Adipose Tissues of Obese Patients Undergoing Bariatric Surgery Reveal Lack of Correlation With Obesity or Diabetes

Population studies have linked insulin resistance to systemic low-grade chronic inflammation and have reported elevated levels of inflammatory cytokines such as TNFα, IL-1β and IL-6, individually or in certain combinations, in adipose tissues or in the serum. We undertook this comprehensive study to simultaneously evaluate the expression of several pro-inflammatory and anti-inflammatory cytokines in serum and in the visceral and subcutaneous adipose tissues from obese patients undergoing bariatric surgery. We observed that several inflammatory cytokines implicated in obesity-associated inflammation showed no significant difference in protein or gene expression between obese patients with or without diabetes and control groups. IL1B gene expression was significantly elevated in the visceral adipose tissues of obese patients, but did not correlate with their diabetes status. Despite the significant increase in IL1B expression in the obese group, a significant proportion of obese patients did not express TNFA, IL1B or IL6 in visceral adipose tissues. Certain inflammatory cytokines showed correlation with the chemokine CCL2 and VEGF-A in visceral adipose tissues. Our findings suggest that the inflammatory cytokine profile in metabolic syndrome is more complex than what is currently perceived and that chronic inflammation in obese patients likely results from incremental contribution from different cytokines and possibly other inflammatory mediators from within and outside the adipose tissues. It is possible that this obesity associated chronic inflammation is not predicted by a single mediator, but rather includes a large spectrum of possible profiles.

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Visceral and subcutaneous adipose tissues do not express similar pattern of cytokines.

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VAT and SAT tissues from 30% of the obese patients do not express TNFA, IL6 or IL1B.

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Protein levels and gene expression do not necessarily correlate in VAT or SAT.

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The expression pattern of inflammatory mediators may present a larger spectrum than predicted from animal models.

Obesity, type 2 diabetes and cardiometabolic diseases are associated with a low-grade chronic inflammation. Various inflammatory mediators have been shown to mediate this inflammation. In this study we analyzed the expression of many of these inflammatory mediators in the visceral and subcutaneous adipose tissues obtained from patients undergoing bariatric surgery. Our results suggest that the profile of inflammatory mediators expressed in adipose tissue is diverse and varies from one patient to another.

Metabolic syndrome and the skin: a more than superficial association. Reviewing the association between skin diseases and metabolic syndrome and a clinical decision algorithm for high risk patients

There is ongoing scientific interest regarding comorbidities associated with the metabolic syndrome (MeTS). MeTS comprises a combination of parameters that predispose individuals to the development of type 2 diabetes and cardiovascular disease (CVD). Three or more of the following criteria are necessary: fasting glucose > 110 mg/dl (5.6 mmol/l), hypertriglyceridemia > 150 mg/dl (1.7 mmol/l), HDL levels < 40 mg/dl (men)/< 50 mg/dl (women), blood pressure > 130/85 mmHg, waist circumference (values for Mediterranean populations > 94 cm (men)/> 89 cm (women). In this review we attempted to summarize relevant data by searching dermatological literature regarding associations between various skin conditions and MeTS. A multitude of studies was retrieved and a further goal of the present article is to present plausible mechanistic connections. The severity of skin conditions like psoriasis has been linked with MeTS. Parameters of MeTS like insulin resistance are present in patients with early onset androgenic alopecia, hidradenitis suppurativa acne and rosacea. Since MeTS can lead to CVD and type 2 diabetes early detection of patients would be very important. Also therapeutic intervention on MeTS could lead to improvement on the severity of skin conditions. This reciprocal relationship between skin diseases and MeTS in our opinion holds great interest for further investigation.

Serum Levels of Interleukin-13 Increase in Subjects with Insulin Resistance but Do Not Correlate with Markers of Low-Grade Systemic Inflammation

Experimental evidence in mice suggests a role for interleukin- (IL-) 13 in insulin resistance and low-grade systemic inflammation. However, IL-13 serum levels have not been assessed in subjects with insulin resistance, and associations of IL-13 with parameters of low-grade systemic inflammation are still unknown. Our main goal was to examine the systemic levels of IL-13 in patients with insulin resistance, while also studying the relationship of IL-13 with anthropometric, metabolic, and low-grade systemic inflammatory markers. Ninety-two participants were included in the study and divided into insulin-resistant patients and noninsulin-resistant controls. Blood levels of IL-13, glucose, insulin, triglycerides, cholesterol, tumor necrosis factor-alpha (TNF-α), IL-10, proinflammatory (Mon-CD11c⁺CD206^-), and anti-inflammatory (Mon-CD11c^-CD206⁺) monocytes, as well as anthropometric parameters, were measured in all volunteers. Insulin-resistant patients showed 2.5-fold higher serum levels of IL-13 than controls (P < 0.0001) and significantly increased values of TNF-α and Mon-CD11c⁺CD206^-, with concomitant reductions in IL-10 and Mon-CD11c^-CD206⁺. Increased IL-13 was extraordinarily well associated with hyperglycemia (r = 0.7362) and hypertriglyceridemia (r = 0.7632) but unexpectedly exhibited no significant correlations with TNF-α (r = 0.2907), IL-10 (r = -0.3882), Mon-CD11c⁺CD206^- (r = 0.2745) or Mon-CD11c^-CD206⁺ (r = -0.3237). This study demonstrates that IL-13 serum levels are elevated in patients with insulin resistance without showing correlation with parameters of low-grade systemic inflammation.

Cell Type-Specific Immunomodulation Induced by Helminthes: Effect on Metainflammation, Insulin Resistance and Type-2 Diabetes

Recent epidemiological studies have documented an inverse relationship between the decreasing prevalence of helminth infections and the increasing prevalence of metabolic diseases ("metabolic hygiene hypothesis"). Chronic inflammation leading to insulin resistance (IR) has now been identified as a major etiological factor for a variety of metabolic diseases other than obesity and Type-2 diabetes (metainflammation). One way by which helminth infections such as filariasis can modulate IR is by inducing a chronic, nonspecific, low-grade, immune suppression mediated by modified T-helper 2 (Th2) response (induction of both Th2 and regulatory T cells) which can in turn suppress the proinflammatory responses and promote insulin sensitivity (IS). This article provides evidence on how the cross talk between the innate and adaptive arms of the immune responses can modulate IR/sensitivity. The cross talk between innate (macrophages, dendritic cells, natural killer cells, natural killer T cells, myeloid derived suppressor cells, innate lymphoid cells, basophils, eosinophils, and neutrophils) and adaptive (helper T [CD4⁺] cells, cytotoxic T [CD8⁺] cells and B cells) immune cells forms two opposing circuits, one associated with IR and the other associated with IS under the conditions of metabolic syndrome and helminth-mediated immunomodulation, respectively.

Genetics and the metabolic syndrome

Originally coined as "syndrome X" in 1988 by Gerald Reaven (1928), the metabolic syndrome (MetS) encompasses a constellation of risk factors, the coincidence of which amounts to an increased cardiovascular and diabetic risk. Rising numbers of dermatoses are being recognized as cutaneous markers of MetS. Dermatologists should look beyond treating the cutaneous condition and quantify the associated increase in cardiovascular risk. The original dermatosis associated with obesity was acanthosis nigricans-described in 1889 by Paul Gerson Unna (1850-1929) and Sigmund Pollitzer (1859-1937). Over the last 20 years, clear associations between psoriasis, hidradenitis suppurativa, and MetS have also emerged. Several studies have shown synergistic improvement in the cutaneous pathology after treatment of components of MetS. This suggests common causalities and is a burgeoning area of research. We review the available evidence about the genetics underlying psoriasis, hidradenitis suppurativa, and acanthosis nigricans. Despite the strong clinical associations, the underlying genetic basis for a link to MetS remains unclear.

Serum adipocytokine profile and metabolic syndrome in young adult female dermatomyositis patients

OBJECTIVES:

To analyse the frequency of metabolic syndrome in young adult female dermatomyositis patients and its possible association with clinical and laboratory dermatomyositis-related features and serum adipocytokines.

METHOD:

This cross-sectional study included 35 dermatomyositis patients and 48 healthy controls. Metabolic syndrome was defined according to the 2009 Joint Interim Statement.

RESULTS:

Patient age was comparable in the dermatomyositis and control groups, and the median disease duration was 1.0 year. An increased prevalence of metabolic syndrome was detected in the dermatomyositis group (34.3% vs. 6.3%; p=0.001). In addition, increased serum adiponectin and resistin levels were noted in contrast to lower leptin levels. In dermatomyositis patients, adipocytokine levels were correlated with the levels of total cholesterol, low-density cholesterol, triglycerides and muscle enzymes. A comparison of dermatomyositis patients with (n=12) and without (n=23) syndrome metabolic revealed that adipocytokine levels were also correlated with age, and that dermatomyositis patients with metabolic syndrome tended to have more disease activity despite similar adipocytokine levels.

CONCLUSIONS:

Metabolic syndrome is highly prevalent in young adult female dermatomyositis patients and is related to age and disease activity. Moreover, increased serum adiponectin and resistin levels were detected in dermatomyositis patients, but lower serum leptin levels were observed.

A study of TNF-α, TGF-β, IL-10, IL-6, and IFN-γ gene polymorphisms in patients with depression

In the last decade it was found that functional polymorphisms in the promoter and/or coding regions of regulatory genes are likely to pre-determine the phenotype manifestation of a certain cytokine profile, and thus could be used as disease-associated markers. Having in mind the hypothesis of impaired cytokine regulation in depressive disorder, as well as the diverse population-dependent results for cytokine polymorphisms, we investigated the relation between the cytokine gene polymorphisms of key pro- and anti-inflammatory cytokines (TNF-α, TGF-β, IL-10, IL-6, IFN-γ) and susceptibility as well as clinical course of depression in Bulgarians. The study included 80 patients with depression (50 women and 30 men) and 50 healthy controls. Simultaneous analysis of eight polymorphic positions in the cytokine genes listed was performed by PCR-SSP method. The results revealed significant predominance of TGF-β TT (+869) genotype (previously described as predicting low expression activity of TGF-β) in patients (41.3%) compared to healthy subjects (21.2%) (p=0.05, OR=2.62). Furthermore T/T G/C combined genotype (+869, +915) in the same gene was negatively associated with disease recurrence. Additionally we found that certain IL-10 genotypes associated with low gene expression seemed to shape moderate disease manifestation. In conclusion our results mainly demonstrated prevalence of a low-expression TGF-β1 profile in the patients. Thus, although in an indirect way, we supported the hypothesis of impaired immunosuppression by means of Th3 regulation in major depressive disorders.

Metainflammation in Diabetic Coronary Artery Disease: Emerging Role of Innate and Adaptive Immune Responses

Globally, noncommunicable chronic diseases such as Type-2 Diabetes Mellitus (T2DM) and Coronary Artery Disease (CAD) are posing a major threat to the world. T2DM is known to potentiate CAD which had led to the coining of a new clinical entity named diabetic CAD (DM-CAD), leading to excessive morbidity and mortality. The synergistic interaction between these two comorbidities is through sterile inflammation which is now being addressed as metabolic inflammation or metainflammation, which plays a pivotal role during both early and late stages of T2DM and also serves as a link between T2DM and CAD. This review summarises the current concepts on the role played by both innate and adaptive immune responses in setting up metainflammation in DM-CAD. More specifically, the role played by innate pattern recognition receptors (PRRs) like Toll-like receptors (TLRs), NOD1-like receptors (NLRs), Rig-1-like receptors (RLRs), and C-type lectin like receptors (CLRs) and metabolic endotoxemia in fuelling metainflammation in DM-CAD would be discussed. Further, the role played by adaptive immune cells (Th1, Th2, Th17, and Th9 cells) in fuelling metainflammation in DM-CAD will also be discussed.

Modulation of IL-27 in adipocytes during inflammatory stress

OBJECTIVE

While it is well established that adipose tissue-derived inflammation plays an important role in the pathogenic mechanisms linking obesity with metabolic dysfunction, the inflammatory mediators involved have not been fully elucidated. Here, we explored IL-12 family cytokines with a focus on IL-27 during obesity-induced inflammation in mice and cultured adipocytes (ADs) following exposure to inflammatory stimuli.

METHODS

Relative mRNA abundance of IL-12 cytokines was assessed by reverse transcription polymerase chain reaction (RT-PCR) in genetically obese B6-ob/ob mice as well as C57BL/6J mice fed a high-fat diet and in ADs following exposure to inflammatory stimuli. Protein secretion of cytokines into culture media was assessed by ELISA, and the biological outcome of IL-27 stimulation was assessed by RT-PCR and immunoblotting.

RESULTS

Heterodimeric subunits constituting IL-27 were significantly induced in obese mice. While all IL-12 genes were markedly induced by inflammatory stress in cultured ADs, IL-27 protein was the only cytokine secreted into culture media in response to inflammatory stress. Cultured ADs also responded to IL-27 stimulation with divergent outcomes that were dependent on the inflammatory milieu of target cells.

CONCLUSIONS

These findings support the premise of autocrine/paracrine mechanisms involving IL-27 in ADs under conditions of inflammatory stress that may link obesity with inflammatory diseases.

Class II transactivator (CIITA) mediates transcriptional repression of pdk4 gene by interacting with hypermethylated in cancer 1 (HIC1)

Increased accumulation and/or impaired utilization of fatty acid in extra-adipose tissues are implicated in the pathogenesis of insulin resistance and type 2 diabetes. Pyruvate dehydrogenase kinase 4 (Pdk4) is a key enzyme involved in fatty oxidation and energy expenditure, and its expression can be repressed by pro-inflammatory stimuli. Previously, we have shown that class II transactivator (CIITA) mediates the adverse effect of interferon gamma (IFN-γ) in skeletal muscle cells by cooperating with hypermethylated in cancer 1 (HIC1) to repress silent information regulator 1 (SIRT1) transcription. Building upon this finding, we report here that CIITA interacted with HIC1 via the GTP-binding domain (GBD) while HIC1 interacted with CIITA via the BTB/POZ domain. The GBD domain was required for CIITA to repress SIRT1 transcription probably acting as a bridge for CIITA to bind to HIC1 and consequently to bind to the SIRT1 promoter. IFN-γ stimulation, CIITA over-expression, or HIC1 over-expression repressed Pdk4 promoter activity while silencing either CIITA or HIC1 normalized Pdk4 expression in the presence of IFN-γ. An increase in SIRT1 expression or activity partially rescued Pdk4 expression in the presence of CIITA, but SIRT1 inhibition abrogated Pdk4 normalization even in the absence of CIITA. Taken together, our data have identified a HIC1-CIITA-SIRT1 axis that regulates Pdk4 transcription in response to IFN-γ stimulation.

Inflammatory cytokines in general and central obesity and modulating effects of physical activity

Context

Chronic systemic inflammation in obesity originates from local immune responses in visceral adipose tissue. However, assessment of a broad range of inflammation-mediating cytokines and their relationship to physical activity and adipometrics has scarcely been reported to date.

Objective

To characterize the profile of a broad range of pro- and anti-inflammatory cytokines and the impact of physical activity and energy expenditure in individuals with general obesity, central obesity, and non-obese subjects.

Design, Setting, and Participants

A cross-sectional study comprising 117 obese patients (body mass index (BMI) ≥ 30) and 83 non-obese community-based volunteers.

Main Outcomes Measures

Serum levels of interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12, IL-13, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon (IFN)-γ and tumor necrosis factor (TNF)-α were measured. Physical activity and energy expenditure (MET) were assessed with actigraphy. Adipometrics comprised BMI, weight, abdominal-, waist- and hip-circumference, waist to hip ratio (WHR), and waist-to-height-ratio (WHtR).

Results

General obesity was associated with significantly elevated levels of IL-5, IL-10, IL-12, IL-13, IFN-γ and TNF-α, central obesity with significantly elevated IL-5, IL-10, IL-12, IL-13 and IFN-γ-levels. In participants with general obesity, levels of IL-4, IL-10 and IL-13 were significantly elevated in participants with low physical activity, even when controlled for BMI which was negatively associated with physical acitivity. Cytokines significantly correlated with adipometrics, particularly in obese participants.

Conclusions

Results confirm up-regulation of certain pro- and anti-inflammatory cytokines in obesity. In obese subjects, physical activity may lower levels and thus reduce pro-inflammatory effects of cytokines that may link obesity, insulin resistance and diabetes.

Neuronal T-cell autoreactivity is amplified in overweight children with new-onset insulin-requiring diabetes

OBJECTIVE

Disease-associated T-cell autoreactivities are seen in most type 1 diabetic patients and are thought to emerge before islet autoantibodies, but host factors that impact autoimmune elements remain uncertain. We assessed if adiposity and measures of insulin sensitivity impact T- and B-cell autoimmunity in children with insulin-requiring diabetes.

RESEARCH DESIGN AND METHODS

Insulin-requiring children and adolescents diagnosed between January 2004 and June 2008 were studied (n = 261): age 9.7 ± 4 years, 92% white, and 60% male. T-cell responses to 10 diabetes-associated antigens, β-cell autoantibodies (GADA, IA-2A, IAA, and ICA), BMI z score (BMIz), and waist percentile were measured at onset and 3 months later.

RESULTS

All but one subject had either T- or B-cell autoimmunity. Diabetes-associated T-cell autoreactivities were found in 92% of subjects. Higher amplitude T-cell autoreactivities to neuronal diabetes-associated autoantigens were seen in those with the highest BMIz quintile, BMI ≥85th percentile (P < 0.05), and waist circumference ≥85th percentile (P < 0.05). There were no relationships between the number of T-cell reactivities or T-cell diversity with adiposity measures or autoantibody number or type. Patients with positive T-cell reactivities but without autoantibodies had the highest BMIz (P = 0.006).

CONCLUSIONS

Our observations link obesity and diabetes-related autoimmunity, suggesting an amplification of neuronal T-cell autoimmunity associated with adiposity and/or insulin resistance, with obesity-related inflammation possibly enhancing islet autoimmunity.

Chromatin decondensation and T cell hyperresponsiveness in diabetes-associated hyperglycemia

Diabetes is linked to increased inflammation and susceptibility to certain infectious diseases including tuberculosis (TB). We previously reported that aerosol TB in mice with chronic (≥ 12 wk) hyperglycemia features increased bacterial load, overproduction of several cytokines, and increased immune pathology compared with normoglycemic controls. A similar phenotype exists in human patients with diabetes with TB. The mechanisms of increased T cell activation in diabetes are unknown. In the current study, we tested the hypothesis that hyperglycemia modifies the intrinsic responsiveness of naive T cells to TCR stimulation. Purified T cells from chronically hyperglycemic (HG) mice produced higher levels of Th1, Th2, and Th17 cytokines and proliferated more than T cells from normoglycemic controls after anti-CD3e or Ag stimulation. In this way, naive T cells from HG mice resembled Ag-experienced cells, although CD44 expression was not increased. Chromatin decondensation, another characteristic of Ag-experienced T cells, was increased in naive T cells from HG mice. That phenotype depended on expression of the receptor for advanced glycation end products and could be reversed by inhibiting p38 MAPK. Chromatin decondensation and hyperresponsiveness to TCR stimulation persisted following transfer of T cells from HG mice into normoglycemic mice. We propose that chronic hyperglycemia causes receptor for advanced glycation end products-mediated epigenetic modification of naive T cells leading to p38 MAPK-dependent chromatin decondensation. This preactivation state facilitates transcription factor access to DNA, increasing cytokine production and proliferation following TCR stimulation. This mechanism may contribute to pathological inflammation associated with diabetes and might offer a novel therapeutic target.

Endogenous oils derived from human adipocytes are potent adjuvants that promote IL-1α-dependent inflammation

Obesity is characterized by chronic inflammation associated with neutrophil and M1 macrophage infiltration into white adipose tissue. However, the mechanisms underlying this process remain largely unknown. Based on the ability of oil-based adjuvants to induce immune responses, we hypothesized that endogenous oils derived from necrotic adipocytes may function as an immunological "danger signal." Here we show that endogenous oils of human origin are potent adjuvants, enhancing antibody responses to a level comparable to Freund's incomplete adjuvant. The endogenous oils were capable of promoting interleukin (IL)-1α-dependent recruitment of neutrophils and M1-like macrophages, while simultaneously diminishing M2-like macrophages. We found that endogenous oils from subcutaneous and omental adipocytes, and from healthy and unhealthy obese individuals, promoted comparable inflammatory responses. Furthermore, we also confirmed that white adipocytes in visceral fat of metabolically unhealthy obese (MUO) individuals are significantly larger than those in metabolically healthy obese individuals. Since adipocyte size is positively correlated with adipocyte death, we propose that endogenous oils have a higher propensity to be released from hypertrophied visceral fat in MUO individuals and that this is the key factor in driving inflammation. In summary, this study shows that adipocytes contain a potent oil adjuvant which drives IL-1α-dependent proinflammatory responses in vivo.

Attenuated adipose tissue and skeletal muscle inflammation in obese mice with combined CD4+ and CD8+ T cell deficiency

OBJECTIVES

High-fat diet (HFD) feeding in mice is characterized by accumulation of αβ T cells in adipose tissue. However, the contribution of αβ T cells to obesity-induced inflammation of skeletal muscle, a major organ of glucose uptake, is unknown. This study was undertaken to evaluate the effect of αβ T cells on insulin sensitivity and inflammatory state of skeletal muscle and adipose tissue in obesity. Furthermore, we investigated whether CD4+IFNγ+ (TH1) cells are involved in skeletal muscle and adipose tissue metabolic dysfunction that accompanies obesity.

METHODS

Mice lacking αβ T cells (T cell receptor beta chain-deficient [TCRb-/-] mice) were fed HFD for 12 weeks. Obesity-induced skeletal muscle and adipose tissue inflammation was assessed by flow cytometry and quantitative RT-PCR. To investigate the effect of TH1 cells on skeletal muscle and adipose tissue inflammation and metabolic functions, we injected 5×10(5) TH1 cells or PBS weekly over 12 weeks into HFD-fed TCRb-/- mice. We also cultured C2C12 myofibers and 3T3-L1 adipocytes with TH1-conditioned medium.

RESULTS

We showed that similar to adipose tissue, skeletal muscle of obese mice have higher αβ T cell content, including TH1 cells. TCRb-/- mice were protected against obesity-induced hyperglycemia and insulin resistance. We also demonstrated suppressed macrophage infiltration and reduced inflammatory cytokine expression in skeletal muscle and adipose tissue of TCRb-/- mice on HFD compared to wild-type obese controls. Adoptive transfer of TH1 cells into HFD-fed TCRb-/- mice resulted in increased skeletal muscle and adipose tissue inflammation and impaired glucose metabolism. TH1 cells directly impaired functions of C2C12 myotubes and 3T3-L1 adipocytes in vitro.

CONCLUSIONS

We conclude that reduced adipose tissue and skeletal muscle inflammation in obese TCRb-/- mice is partially attributable to the absence of TH1 cells. Our results suggest an important role of TH1 cells in regulating inflammation and insulin resistance in obesity.

Increased Th1 and suppressed Th2 serum cytokine levels in subjects with diabetic coronary artery disease

Background

The role played by T helper cytokines under chronic, low grade inflammation as seen in type-2 Diabetes Mellitus (T2DM) and Coronary Artery Disease (CAD) co-morbidity is less well studied. In the present study, we measured the serum levels of both Th1 and Th2 cytokines and correlated it with clinical risk factors for T2DM (Insulin Resistance (IR), Glycated haemoglobin (HbA1c)) and CAD (C-Reactive Protein (CRP), Intima Media Thickness (IMT) and Augmentation index (AGI)) in T2DM subjects with/without CAD.

Methodology

The study subjects were recruited from Chennai Urban Rural Epidemiology Study (CURES). Serum cytokine profile was determined by multiplex cytokine assay in Control (n = 61), T2DM (n = 60), CAD (n = 23) and T2DM-CAD (n = 21) subjects.

Results

T2DM subjects showed a mixed Th1-Th2 profile. CAD subjects presented a Th1 profile with modest Th2 suppression while T2DM-CAD subjects showed enhanced Th1 profile with strong suppression of Th2 cytokines. Both Th1 and Th2 cytokines showed a positive correlation with FPG, HbA1c, hsCRP, IMT and AGI. Logistic regression analysis revealed a significant association of IL-12 (OR = 9.3; 95% CI = 3.2-70.7; p = 0.016), IFN-γ (OR = 2.8; 95% CI = 2.7-2.9, p = 0.010), IL-4 (OR = 2.7; 95% CI 2.7-2.7, p = 0.010), IL-5 (OR = 1.1; 95% CI = 1.0-1.4; p = 0.003) and IL-13 (OR = 2; 95% CI = 1.7-2.6; p = 0.017) with T2DM-CAD.

Conclusion

In conclusion, from the present study it appears that transition from T2DM or CAD to T2DM-CAD co-morbidity is associated with strong down regulation of Th2 cytokines and enhancement of Th1 responses.

Skeletal muscle nitric oxide (NO) synthases and NO-signaling in "diabesity"--what about the relevance of exercise training interventions?

Type 2 diabetes mellitus associated with obesity, or "diabesity", coincides with an altered nitric oxide (NO) metabolism in skeletal muscle. Three isoforms of nitric oxide synthase (NOS) exist in human skeletal muscle tissue. Both neuronal nitric oxide synthase (nNOS) and endothelial nitric oxide synthase (eNOS) are constitutively expressed under physiological conditions, producing low levels of NO, while the inducible nitric oxide synthase (iNOS) is strongly up-regulated only under pathophysiological conditions, excessively increasing NO concentrations. Due to chronic inflammation, overweight/obese type 2 diabetic patients exhibit up-regulated protein contents of iNOS and concomitant elevated amounts of NO in skeletal muscle. Low muscular NO levels are important for attaining an adequate cellular redox state--thereby maintaining metabolic integrity--while high NO levels are believed to destroy cellular components and to disturb metabolic processes, e.g., through strongly augmented posttranslational protein S-nitrosylation. Physical training with submaximal intensity has been shown to attenuate inflammatory profiles and iNOS protein contents in the long term. The present review summarizes signaling pathways which induce iNOS up-regulation under pathophysiological conditions and describes molecular mechanisms by which high NO concentrations are likely to contribute to triggering skeletal muscle insulin resistance and to reducing mitochondrial capacity during the development and progression of type 2 diabetes. Based on this information, it discusses the beneficial effects of regular physical exercise on the altered NO metabolism in the skeletal muscle of overweight/obese type 2 diabetic subjects, thus unearthing new perspectives on training strategies for this particular patient group.

TNF-alpha -308G>A polymorphism is associated with suicide attempts in major depressive disorder

BACKGROUND

Despite the substantial role of the cytokine network in depression and suicide, few studies have investigated the role of genetic polymorphisms of pro- and anti-inflammatory cytokines in suicide in major depressive disorder (MDD). The aim of this study was to investigate whether tumor necrosis factor-alpha (TNF-alpha) -308G>A, interferon-gamma (IFN-gamma) +874A>T, and interleukin-10 (IL-10) -1082A>G are associated with increased risk for suicide attempts in MDD.

METHODS

Among patients with MDD, 204 patients who had attempted suicide and 97 control patients who had not attempted suicide were recruited. A chi-square test was used to identify a possible risk genotype or allele type for suicide. A subsequent multivariate logistic regression analysis was conducted to investigate the influence of a risk genotype or allele type adjusted for other environmental factors. The lethality of the suicide attempt was also tested between genotype and allele types among suicidal patients with MDD.

RESULTS

The GG genotype of the TNF-alpha -308G>A polymorphism was found to significantly increase risk for suicide attempt (adjusted OR=2.630, 95% CI=1.206 to 5.734). IFN-gamma +874A>T and IL-10 -1082A>G were not associated with risk for suicide. Lethality of the suicide attempt was not associated with any of the three cytokine genotypes or allele types.

LIMITATIONS

Limitations include a relatively small sample size and a cross-sectional design.

CONCLUSIONS

TNF-alpha -308G>A polymorphism is an independent risk factor for suicide attempts in MDD. Future studies should clarify the neural mechanisms by which the GG genotype of TNF-alpha -308G>A influences suicide in MDD.

Serum IL-12 is increased in Mexican obese subjects and associated with low-grade inflammation and obesity-related parameters

Interleukin-(IL-) 12 has been recently suggested to participate during development of insulin resistance in obese mice. Nevertheless, serum IL-12 levels have not been accurately determined in overweight and obese humans. We thus studied serum concentrations of IL-12 in Mexican adult individuals, examining their relationship with low-grade inflammation and obesity-related parameters. A total of 147 healthy individuals, 43 normal weight, 61 overweight, and 43 obese subjects participated in the study. Circulating levels of IL-12, tumor necrosis factor-alpha (TNF-α), leptin, insulin, glucose, total cholesterol, and triglyceride were measured after overnight fasting in all of the study subjects. Waist circumference and body fat percentage were recorded for all the participants. Serum IL-12 was significantly higher in overweight and obese individuals than in normal weight controls. Besides being strongly related with body mass index (r = 0.5154), serum IL-12 exhibited a significant relationship with abdominal obesity (r = 0.4481), body fat percentage (r = 0.5625), serum glucose (r = 0.3158), triglyceride (r = 0.3714), and TNF-α (r = 0.4717). Thus, serum levels of IL-12 are increased in overweight and obese individuals and show a strong relationship with markers of low-grade inflammation and obesity in the Mexican adult population. Further research is needed to understand the role of IL-12 in developing obesity-associated alterations in humans.

The benefits of restraint: a pivotal role for IL-13 in hepatic glucose homeostasis

In response to feeding, insulin promotes the uptake of sugar in peripheral tissues and suppresses the production of sugar, a process called gluconeogenesis, in the liver. Recent research has shown that chronic inflammation promotes insulin resistance, and in turn, chronically high glucose levels can drive inflammation. In this issue of the JCI, Stanya et al. investigate the connection between inflammation and glucose homeostasis by analyzing the effect of the antiinflammatory cytokine IL-13. Their results suggest that IL-13 plays an unexpected role in the regulation of glucose homeostasis by modulating gluconeogenesis and may be a useful therapeutic target for treatment of diabetes and metabolic syndrome.

Adaptive immunity in obesity and insulin resistance

Obesity is the hallmark of the metabolic syndrome and predisposes patients to the development of major chronic metabolic diseases including type 2 diabetes mellitus. Adipose tissue expansion in obesity is characterized by increasing infiltration of proinflammatory immune cells into adipose tissue causing chronic, low-grade inflammation. Phenotypic switching of macrophages is an important mechanism of adipose tissue inflammation, and there is involvement of cells from the adaptive immune system in this process. T-cell phenotype changes and recruitment of B cells and T cells precedes macrophage infiltration. Cytokines and chemokines produced by immune cells influence localized and systemic inflammation, which is a pathogenic link between obesity and insulin resistance. Antigens absorbed from the gut might contribute to T-cell activation and recruitment into visceral adipose tissue in obesity. This Review summarizes, in the context of obesity, the evidence for infiltration of adipose tissue by cells of the adaptive immune system, how adaptive system cells affect innate cell populations and the influence of adaptive immune cells on the development of insulin resistance.

Manipulating molecular switches in brown adipocytes and their precursors: a therapeutic potential

Brown adipocytes constitute a metabolically active tissue responsible for non-shivering thermogenesis and the depletion of excess calories. Differentiation of brown fat adipocytes de novo or stimulation of pre-existing brown adipocytes within white adipose depots could provide a novel method for reducing the obesity and alleviating the consequences of type II diabetes worldwide. In this review, we addressed several molecular mechanisms involved in the control of brown fat activity, namely, the β₃-adrenergic stimulation of thermogenesis during exposure to cold or by catecholamines; the augmentation of thyroid function; the modulation of peroxisome proliferator-activated receptor gamma (PPARγ), transcription factors of the C/EBP family, and the PPARγ co-activator PRDM16; the COX-2-driven expression of UCP1; the stimulation of the vanilloid subfamily receptor TRPV1 by capsaicin and monoacylglycerols; the effects of BMP7 or its analogs; the cannabinoid receptor antagonists and melanogenesis modulating agents. Manipulating one or more of these pathways may provide a solution to the problem of harnessing brown fat's thermogenic potential. However, a better understanding of their interplay and other homeostatic mechanisms is required for the development of novel therapies for millions of obese and/or diabetic individuals.