Interferon-gamma, a Th1 cytokine, regulates fat inflammation: a role for adaptive immunity in obesity

The Phlorotannin-Rich Fraction of Ecklonia cava Extract Attenuated the Expressions of the Markers Related with Inflammation and Leptin Resistance in Adipose Tissue

Obesity is associated with systemic chronic inflammation, and it induces central leptin resistance which blocks the appetite-suppressing effect of leptin and leptin resistance in adipocytes. In the present study, we evaluated the effects of Ecklonia cava extract (ECE), which contained rich phlorotannins, on inflammation and leptin resistance in the adipose tissue of a diet-induced obese model. Effects of ECE on fat deposition, inflammation, M1/M2 macrophage, and T-cell infiltrations were investigated, and leptin resistance and SOCS3 were also measured in adipose tissue. Furthermore, ECE attenuated the expression of inflammation-related receptors such as TLR4 and RAGE and leptin resistance by reducing SOCS3 expression, increasing expression of leptin receptor in adipose tissue, and increasing lipolysis. ECE showed antiadiposity and anti-inflammatory effects, attenuated leptin resistance, and increased lipolysis in the diet-induced obese model. This study shows that ECE is a suitable dietary supplement candidate for the prevention or treatment of obesity or obesity-associated diseases, especially inflammation-related diseases.

Leveraging cell-specific differentially methylated regions to identify leukocyte infiltration in adipose tissue

Obesity is understood to be an inflammatory condition characterized in part by changes in resident immune cell populations in adipose tissue. However, much of this knowledge has been obtained through experimental animal models. Epigenetic mechanisms, such as DNA methylation may be useful tools for characterizing the changes in immune cell populations in human subjects. In this study, we introduce a simple and intuitive method for assessing cellular infiltration by blood into other heterogeneous, admixed tissues such as adipose tissue, and apply this approach in a large human cohort study. Associations between higher leukocyte infiltration, measured by evaluating a distance measure between the methylation signatures of leukocytes and adipose tissue, and increasing body mass index (BMI) or android fat mass (AFM) were identified and validated in independent replication samples for CD4 (pBMI  = 0.009, pAFM  = 0.020), monocytes (pBMI  = 0.001, pAFM  = 4.3 × 10-4 ), and dendritic cells (pBMI  = 0.571, pAFM  = 0.012). Patterns of depletion with increasing adiposity were observed for plasma B (pBMI  = 0.430, pAFM  = 0.004) and immature B (pBMI  = 0.022, pAFM  = 0.042) cells. CD4, dendritic, monocytes, immature B, and plasma B cells may be important agents in the inflammatory process. Finally, the method used to assess leukocyte infiltration in this study is straightforwardly extended to other cell types and tissues in which infiltration might be of interest.

The influence of the TNFα rs1800629 polymorphism on some inflammatory biomarkers in 45-60-year-old women with metabolic syndrome

Introduction: There are reports that the TNFα gene (rs1800629) can be involved in the pathogenesis of metabolic syndrome through an increased production of pro-inflammatory cytokines. Therefore, we have decided to search for the relationship between the TNFα gene polymorphisms and serum levels of proinflammatory cytokines (IL-1α, IL-1β, IL-6, TNFα, IFNγ) and CRP in women with metabolic syndrome.

Material and methods: The study sample consisted of 416 women aged 45-60 years, including 118 with metabolic syndrome. The participants were surveyed and subjected to anthropometric, biochemical and genetic analysis.

Results: We noticed that in the group meeting the criteria for metabolic syndrome, the G/G genotype of the TNFα gene was related to higher IL-6 levels than in the remainder group. The carriers of the A/G genotype in the metabolic syndrome group had significantly higher levels of IFNγ than those in the group without this syndrome. CRP was significantly higher in the group with metabolic syndrome, irrespective of the women’s genotypes.

Conclusions: The upregulation of IFNγ and IL-6 and CRP suggests that autoinflammatory process may play a significant role in the pathogenesis of metabolic syndrome. However, a direct relationship between the TNFα gene polymorphisms and inflammatory biomarkers analyzed in our study was not confirmed.

Immunity and Inflammation in Atherosclerosis

There is now overwhelming experimental and clinical evidence that atherosclerosis is a chronic inflammatory disease. Lessons from genome-wide association studies, advanced in vivo imaging techniques, transgenic lineage tracing mice, and clinical interventional studies have shown that both innate and adaptive immune mechanisms can accelerate or curb atherosclerosis. Here, we summarize and discuss the pathogenesis of atherosclerosis with a focus on adaptive immunity. We discuss some limitations of animal models and the need for models that are tailored to better translate to human atherosclerosis and ultimately progress in prevention and treatment.

cAMP-MicroRNA-203-IFNγ network regulates subcutaneous white fat browning and glucose tolerance

OBJECTIVE

Brown and beige adipocytes in humans and rodents are specialized to burn lipids for heat generation as a natural defense against cold and obesity, which is advantageous to metabolic homeostasis. MicroRNAs as another regulatory layer to regulate metabolic homeostasis attracted a lot of attentions. Our previous work revealed microRNA (miR)-203 as a brown adipocyte-enriched microRNA involved in brown adipocytes development. However, the potential role of miR-203 in adipose tissue metabolic homeostasis has not been determined in vivo. In this study, we investigate the potential role of miR-203 in subcutaneous white adipose tissue (sub-WAT) browning and metabolic homeostasis.

METHODS

We investigated the relationship between miR-203 and energy homeostasis in adipose tissue from cold exposed, high fat diet (HFD) fed, ob/ob and db/db mice. The functions of miR-203 on sub-WAT browning were validated through miR-203 knockdown or overexpression. The miR-203 targeted signal pathway was screened by RNAseq analysis. Luciferase report assay, western blot, and qPCR were performed to establish the miR-203 related upstream and downstream signal pathway in vivo and in vitro. The functions of miR-203 on obesity and metabolic homeostasis were validated through GTT/ITT and western blot on high fat diet-induced obesity in C57 mice. ELISA was used to determine the concentration of IFN-γ. Flow cytometry analysis was performed to determine the infiltration of macrophages in adipose tissue.

RESULTS

MiR-203 expression positively correlates with energy expenditure, and overexpression of miR-203 could enhance sub-WAT browning in normal diet (ND) condition. Mechanistically, the expression of miR-203 is activated by cAMP-dependent C/EBPβ up-regulation. Subsequently, miR-203 inhibits IFN-γ signal pathway activation by directly targeting Lyn, which is an activator of Jak1-Stat1. Moreover, the forced expression of miR-203 could improve insulin sensitivity and resist high fat diet-induced obesity by inhibiting IFN-γ.

CONCLUSIONS

MicroRNA-203 (miR-203) promotes white adipose tissue browning in cold exposed mice and improves glucose tolerance in HFD fed mice by repressing IFN-γ. Since miR-203 is activated by cAMP-dependent C/EBPβ up-regulation and directly represses IFN-γ signal pathway, we declare that miR-203 acts as a messenger between cAMP signal pathway and IFN-γ signal pathway.

Proteomics approach to identify serum biomarkers associated with the progression of diabetes in Korean patients with abdominal obesity

Type 2 diabetes is a metabolic disease with a group of metabolic derangements and inflammatory reactants in the serum. Despite the substantial public health implications, markers of diabetes progression with abdominal obesity are still needed to facilitate early detection and treatment. In this study, we performed a proteomic approach to identify differential target proteins underlying diabetes progression in patients with abdominal obesity. Proteomic differences were investigated in the serum of controls and patients with prediabetes or diabetes with or without abdominal obesity by 2-DE combined with MALDI-TOF-MS. Proteomics data were validated by western blot analyses and major protein-protein interactions were assessed using a network analysis with String database. Among 245 matched protein spots, 36 exhibited marked differences in normal patients with abdominal obesity, prediabetes, and diabetes compared to levels in normal patients without abdominal obesity. Seven (Alpha-1-antichymotrypsin, Alpha-1-antitrypsin, Apolipoprotein A-I, haptoglobin, retinol-binding protein 4, transthyretin, and zinc-alpha2-glycoprotein) of these spots exhibited significant differences between normal and prediabetes/diabetes patients. After a network analysis, functional annotation using Gene Ontology indicated that most of the identified proteins were involved in lipid transport, lipid localization, and the regulation of serum lipoprotein particle levels. Our results indicated that variation in the levels of these identified protein biomarkers has been reported in normal, prediabetes and diabetic Assessment of the levels of these biomarkers may contribute to the development of biomarkers for not only early diagnosis but also in prognosis of diabetes mellitus type 2.

Obesity-induced inflammation and insulin resistance: A mini-review on T-cells

Excessive lipid accumulation in an obese state is linked with activation and release of detrimental cytokines and chemokines that promote metabolic dysregulation. In fact, emerging experimental evidence shows that abnormal modulation of T-cells in an obese state correlates with the development and progression of insulin resistance. Importantly, the evolving concept linking insulin resistance with impaired immunological mechanisms such as T-cell responses provides new prospects for understanding the role of inflammation in moderating metabolic complications.

Inflammation in atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease is a leading cause of death and morbidity globally. Over the past several years, arterial inflammation has been implicated in the pathophysiology of athero-thrombosis, substantially confirming what pathologist Rudolf Virchow had observed in the 19th century. Lipid lowering, lifestyle changes, and modification of other risk factors have reduced cardiovascular complications of athero-thrombosis, but a substantial residual risk remains. In view of the pathogenic role of inflammation in athero-thrombosis, directly targeting inflammation has emerged as an additional potential therapeutic option; and some early promising results have been suggested by the Canakinumab Anti-inflammatory Thrombosis Outcome Study (CANTOS), in which canakinumab, a fully human monoclonal antibody targeting the pro-inflammatory and pro-atherogenic cytokine interleukin 1 beta, was shown to reduce cardiovascular events.

Pitavastatin Exerts Potent Anti-Inflammatory and Immunomodulatory Effects via the Suppression of AP-1 Signal Transduction in Human T Cells

Statins inhibiting 3-hydroxy-3-methylglutaryl-CoA reductase are the standard treatment for hypercholesterolemia in atherosclerotic cardiovascular disease (ASCVD), mediated by inflammatory reactions within vessel walls. Several studies highlighted the pleiotropic effects of statins beyond their lipid-lowering properties. However, few studies investigated the effects of statins on T cell activation. This study evaluated the immunomodulatory capacities of three common statins, pitavastatin, atorvastatin, and rosuvastatin, in activated human T cells. The enzyme-linked immunosorbent assay (ELISA) and quantitative real time polymerase chain reaction (qRT-PCR) results demonstrated stronger inhibitory effects of pitavastatin on the cytokine production of T cells activated by phorbol 12-myristate 13-acetate (PMA) plus ionomycin, including interleukin (IL)-2, interferon (IFN)-γ, IL-6, and tumor necrosis factor α (TNF-α). Molecular investigations revealed that pitavastatin reduced both activating protein-1 (AP-1) DNA binding and transcriptional activities. Further exploration showed the selectively inhibitory effect of pitavastatin on the signaling pathways of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK), but not c-Jun N-terminal kinase (JNK). Our findings suggested that pitavastatin might provide additional benefits for treating hypercholesterolemia and ASCVD through its potent immunomodulatory effects on the suppression of ERK/p38/AP-1 signaling in human T cells.

Single-Cell RNA Sequencing of Visceral Adipose Tissue Leukocytes Reveals that Caloric Restriction Following Obesity Promotes the Accumulation of a Distinct Macrophage Population with Features of Phagocytic Cells

Obesity can lead to type 2 diabetes and is an epidemic. A major contributor to its adverse effects is inflammation of the visceral adipose tissue (VAT). Life-long caloric restriction (CR), in contrast, results in extended lifespan, enhanced glucose tolerance/insulin sensitivity, and other favorable phenotypes. The effects of CR following obesity are incompletely established, but studies show multiple benefits. Many leukocyte types, macrophages predominantly, reside in VAT in homeostatic and pathological states. CR following obesity transiently increases VAT macrophage content prior to resolution of inflammation and obesity, suggesting that macrophage content and phenotype play critical roles. Here, we examined the heterogeneity of VAT leukocytes and the effects of obesity and CR. In general, our single-cell RNA-sequencing data demonstrate that macrophages are the most abundant and diverse subpopulation of leukocytes in VAT. Obesity induced significant transcriptional changes in all 15 leukocyte subpopulations, with many genes showing coordinated changes in expression across the leukocyte subpopulations. Additionally, obese VAT displayed expansion of one major macrophage subpopulation, which, in silico, was enriched in lipid binding and metabolic processes. This subpopulation returned from dominance in obesity to lean proportions after only 2 weeks of CR, although the pattern of gene expression overall remained similar. Surprisingly, CR VAT is dominated by a different macrophage subpopulation, which is absent in lean conditions. This subpopulation is enriched in genes related to phagocytosis and we postulate that its function includes clearance of dead cells, as well as excess lipids, contributing to limiting VAT inflammation and restoration of the homeostatic state.

Type 2 diabetes is associated with the accumulation of senescent T cells

Type 2 diabetes is a global health priority, given that it is driven, in part, by an ageing population, the role of immune senescence has been overlooked. This is surprising, as the functional impairments of senescent T cells show strong similarities to patients with hyperglycaemia. Immune senescence is typified by alterations in T cell memory, such as the accumulation of highly differentiated end‐stage memory T cells, as well as a constitutive low‐grade inflammation, which drives further immune differentiation. We show here in a preliminary study that people living with type 2 diabetes have a higher circulating volume of senescent T cells accompanied with a higher level of systemic inflammation. This inflammatory environment drives the expression of a unique array of chemokine receptors on senescent T cells, most notably C‐X‐C motif chemokine receptor type 2. However, this increased expression of migratory markers does not translate to improved extravasation owing to a lack of glucose uptake by the T cells. Our results therefore demonstrate that the presence of senescent T cells has a detrimental impact on immune function during type 2 diabetes.

Schistosoma japonicum Soluble Egg Antigen Protects Against Type 2 Diabetes in Lepr db/db Mice by Enhancing Regulatory T Cells and Th2 Cytokines

Type 2 diabetes is a metabolic disorder characterized by persistently elevated glucose levels. There is no effective treatment strategy for this condition, and it poses a massive economic burden globally. Schistosoma soluble egg antigen (SEA)-induced immunomodulatory mechanisms have been reported in the treatment of autoimmune disease. This study aimed to determine the ability of Schistosoma japonicum SEA to protect against type 2 diabetes in Lepr^db/db mice and understand the associated mechanisms. The mice were divided into four groups: C57BL/6 (the normal group), SEA (C57BL/6 mice treated with SEA), Lepr^db/db, and SEA and Lepr^db/db co-treatment groups. The mice in the SEA and co-treatment groups were injected with 50 μg of SEA (twice a week for 6 weeks), and the same volume of PBS was used as control. Blood glucose, insulin, and HOMA-IR levels were measured in all mice, which were sacrificed 6 weeks after the last SEA administration. Flow cytometry was used to detect the percentages of regulatory T cells in splenocytes. ELISA was used to detect the levels of IFN-γ, IL-2, IL-4, and IL-5 in cell culture supernatants. Compared with the mice in the Lepr^db/db group, the mice in the SEA + Lepr^db/db group exhibited significantly reduced insulin resistance, as evidenced by the enhancement of wound healing. The frequency of spleen regulatory T cells increased significantly after SEA administration; meanwhile, the secretion of IL-4 and IL-5 in spleen cells was elevated. These results indicate that SEA can reduce insulin resistance and provide new targets for the treatment of type 2 diabetes. The potential mechanisms might be associated with increases in regulatory T cells and Th2 cytokines in Lepr^db/db mice, which warrants further investigation.

Cactus pear (Opuntia ficus-indica) juice fermented with autochthonous Lactobacillus plantarum S-811

The present study aimed at investigating the lactic fermentation of cactus pear (Opuntia ficus-indica) fruit juice with the autochthonous and potentially probiotic strain Lactobacillus plantarum S-811. L. plantarum S-811 was able to quickly acidify the juice with a decrease in the pH from 5.5 to 3.7 and a production of 5.06 g l-1 of lactic acid. Fermentation of cactus pear juice led to conservation of its health-promoting properties and it markedly promoted antioxidant mechanisms in yeast cells, showing in a Saccharomyces cerevisiae model a protective effect of up to 11 times against H2O2 (4 mM), compared to yeasts not supplemented with the fermented juice. Administration of fermented juice to obese mice caused a significant decrease in the body weight gain and ameliorated the insulin resistance, hyperglycemia, and hyperlipemia that characterize obesity. These results reveal the potential of the cactus pear juice fermented with L. plantarum S-811 as a functional beverage for the prevention of obesity and related pathologies.

[Immunity and inflammation in atherosclerosis]

There is now overwhelming experimental and clinical evidence that arteriosclerosis is a chronic inflammatory disease. Lessons learned from genome-wide association studies, advanced in vivo imaging techniques, transgenic lineage tracing mice models and clinical interventional studies have shown that both innate and adaptive immune mechanisms can accelerate or curb arteriosclerosis. This article summarizes and discusses the pathogenesis of arteriosclerosis with a focus on the role of the adaptive immune system. Some limitations of animal models are discussed and the need for models that are tailored to better translate to human atherosclerosis and ultimately progress in prevention and treatment are emphasized.

T-cell senescence contributes to abnormal glucose homeostasis in humans and mice

Chronic inflammation is a driving force for the development of metabolic disease including diabetes and obesity. However, the functional characteristics of T-cell senescence in the abnormal glucose homeostasis are not fully understood. We studied the patients visiting a hospital for routine health check-ups, who were divided into two groups: normal controls and people with prediabetes. Gene expression profiling of peripheral blood mononuclear cells from normal controls and patients with type 2 diabetes was undertaken using microarray analysis. We also investigated the immunometabolic characteristics of peripheral and hepatic senescent T cells in the normal subjects and patients with prediabetes. Moreover, murine senescent T cells were tested functionally in the liver of normal or mice with metabolic deterioration caused by diet-induced obesity. Human senescent (CD28^-CD57⁺) CD8⁺ T cells are increased in the development of diabetes and proinflammatory cytokines and cytotoxic molecules are highly expressed in senescent T cells from patients with prediabetes. Moreover, we demonstrate that patients with prediabetes have higher concentrations of reactive oxygen species (ROS) in their senescent CD8⁺ T cells via enhancing capacity to use glycolysis. These functional properties of senescent CD8⁺ T cells contribute to the impairment of hepatic insulin sensitivity in humans. Furthermore, we found an increase of hepatic senescent T cells in mouse models of aging and diet-induced obesity. Adoptive transfer of senescent CD8⁺ T cells also led to a significant deterioration in systemic abnormal glucose homeostasis, which is improved by ROS scavengers in mice. This study defines a new clinically relevant concept of T-cell senescence-mediated inflammatory responses in the pathophysiology of abnormal glucose homeostasis. We also found that T-cell senescence is associated with systemic inflammation and alters hepatic glucose homeostasis. The rational modulation of T-cell senescence would be a promising avenue for the treatment or prevention of diabetes.

Searching for the Role of the IFNγ rs2430561 Polymorphism in Inducible Inflammation: Contribution to Metabolic Syndrome in 45 to 60-Year-Old Women

Metabolic syndrome (MetS) is a cluster of conditions, increasing the risk of developing diseases that can lead to premature death. Interferon γ-inducible (the production of which is dependent on the IFNγ rs2430561 polymorphism) tryptophan-kynurenine inflammatory cascade helps to understand the increased association between inflammatory process and MetS, which is why we seek the relationship between the IFNγ gene polymorphisms and serum levels of markers of interferon-gamma (IFNγ)-inducible inflammatory cascade. The study sample consisted of 416 women, including 118 (28.4%) with MetS. The research procedure involved interview, anthropometric measurements, and blood collection. Kynurenine levels were significantly higher in the group of women with MetS. In the group with MetS, the A/T genotype of the IFNγ gene was accompanied by higher kynurenine levels. A direct relationship between the IFNγ gene polymorphisms and the rest of the markers of IFNγ-inducible inflammatory cascade was not confirmed with regard to MetS in 45 to 60-year-old women. A disparity in the kynurenine level, as well as the relationship between the presence of the A/T genotype of the IFNγ gene and a higher level of kynurenine in the group of women with MetS, may indicate an association between inflammation, metabolic disorders and tryptophan-kynurenine inflammatory cascade.

The influence of high-fat, high-sugar diet and bariatric surgery on HSP70 and HSP90 plasma and liver concentrations in diet-induced obese rats

Metabolic surgery ameliorates insulin resistance and is associated with long-term, effective weight loss, but the mechanisms involved remain unknown. Here, the duodenal-jejunal omega switch (DJOS) surgery in combination with high-fat, high-carbohydrate diet was performed on diet obese rats and joint effects of bariatric surgery and different dietary patterns on heat shock protein 70 (HSP70) and HSP90 plasma and liver concentrations were measured. We found that plasma and liver levels of HSP70 were lower after DJOS surgery in comparison to the control in the groups of animals kept on control diet (CD) and high-fat, high-sugar diet (HFS) but the postoperative change of the diet led to the increase in HSP70 in plasma and liver concentration in DJOS-operated animals. A high-calorie meal, rich in carbohydrates and fats, significantly increased circulating levels of HSP90, reducing the normalising effect of DJOS. The HFS diet applied during all stages of the experiment led to the higher levels of liver HSP90 concentration. The combination of CD and DJOS surgery was the most efficient in the lowering of the HSP90 liver concentration. The normalisation of circulating levels and liver concentrations of HSP70 and HSP90 may be achieved in a combination of DJOS procedure with a proper dietary plan.

The Differential Roles of T Cells in Non-alcoholic Fatty Liver Disease and Obesity

Non-alcoholic fatty liver disease (NAFLD) constitutes a spectrum of disease states characterized by hepatic steatosis and is closely associated to obesity and the metabolic syndrome. In non-alcoholic steatohepatitis (NASH), additionally, inflammatory changes and hepatocellular damage are present, representing a more severe condition, for which the treatment is an unmet medical need. Pathophysiologically, the immune system is one of the main drivers of NAFLD progression and other obesity-related comorbidities, and both the innate and adaptive immune system are involved. T cells form the cellular component of the adaptive immune system and consist of multiple differentially active subsets, i.e., T helper (Th) cells, regulatory T (Treg) cells, and cytotoxic T (Tc) cells, as well as several innate T-cell subsets. This review focuses on the role of these T-cell subsets in the pathogenesis of NAFLD, as well as the association with obesity and type 2 diabetes mellitus, reviewing the available evidence from both animal and human studies. Briefly, Th1, Th2, Th17, and Th22 cells seem to have an attenuating effect on adiposity. Th2, Th22, and Treg cells seem to decrease insulin resistance, whereas Th1, Th17, and Tc cells have an aggravating effect. Concerning NAFLD, both Th22 and Treg cells appear to have an overall tempering effect, whereas Th17 and Tc cells seem to induce more liver damage and fibrosis progression. The evidence regarding the role of the innate T-cell subsets is more controversial and warrants further exploration.

An update on immune dysregulation in obesity-related insulin resistance

Obesity is associated with chronic low-grade inflammation of the adipose tissue (AT) that might develop into systemic inflammation, insulin resistance (IR) and an increased risk of type 2 diabetes mellitus (T2DM) in severe obese rodents and humans. In the lean state, small normal adipocytes and AT macrophages interact with each other to maintain metabolic homeostasis but during obesity, enlarged adipocytes secrete inflammatory mediators and express immune receptors to recruit immune cells and aggravate the inflammation. The better understanding of the obesity-related inflammatory milieu and the sequential events leading to IR could be helpful in designing new preventive and therapeutic strategies. The present review will discuss the cellular and molecular abnormalities participating in the pathogenesis of obesity in obese individuals as well as high-fat diet (HFD)-fed mice, a mouse model of obesity.

Inflammation, infection and atherosclerosis

Atherosclerotic cardiovascular disease is a leading cause of death in much of the world. Adoption of a healthy lifestyle and cholesterol lowering are the key measures used to prevent major complications of atherosclerosis. Recent data have identified a critical role for inflammation mediated through activation of both innate and adaptive immune pathways in the pathophysiology of atherosclerosis opening up opportunities for development of anti-inflammatory interventions that could supplement risk factor modification and lipid lowering as an approach to further reducing the burden of atherosclerotic cardiovascular disease.

Serum Neopterin Concentration and Impaired Glucose Metabolism: Relationship With β-Cell Function and Insulin Resistance

Aim: The purpose of this study was to measure the serum neopterin according to glucose metabolism and to evaluate neopterin as a predictor of type 2 diabetes (T2D) in a hospital-based cohort. Methods: A 75-g oral glucose tolerance test (OGTT) was performed by people who visited the outpatient clinic in Seoul National University Bundang Hospital for suspected abnormal glucose tolerance or a strong family history of T2D. Neopterin was measured using an enzyme-link immunosorbent assay with baseline samples from the OGTT. Results: Neopterin was measured in 184 participants. Indices related to glucose metabolism, such as the HOMA-IR, disposition index, etc. were calculated based on the results of the OGTT. The classifications for the 184 participants were: 24 (13%) had NGT, 89 (48.4%) prediabetes, and 60 (38.6%) T2D. Neopterin increased with deterioration of glucose metabolism (0.55 ± 0.25 vs. 0.58 ± 0.27 vs. 0.67 ± 0.27 ng/ml, p = 0.041; NGT, prediabetes, and T2D, respectively). Neopterin also correlated with fasting plasma glucose, 30-min and 120-min glucose of OGTT and HbA1c (r = 0.251, 0.259, 0.184, and 0.270, all p < 0.05). The HOMA-IR and disposition index correlated with neopterin (r = 0.291 and -0.170, respectively, both p < 0.05). When combined with C-peptide level, neopterin was as powerful as HOMA-IR in predicting future T2D. Conclusion: Serum neopterin appears to be related to impaired insulin secretion and insulin resistance in the development of T2D. Further investigation of the relationship between neopterin and glucose metabolism would be helpful to understand the pathophysiology for the development of T2D.

Adipose Tissue is Enriched for Activated and Late-Differentiated CD8+ T Cells and Shows Distinct CD8+ Receptor Usage, Compared With Blood in HIV-Infected Persons

BACKGROUND

Adverse viral and medication effects on adipose tissue contribute to the development of metabolic disease in HIV-infected persons, but T cells also have a central role modulating local inflammation and adipocyte function. We sought to characterize potentially proinflammatory T-cell populations in adipose tissue among persons on long-term antiretroviral therapy and assess whether adipose tissue CD8 T cells represent an expanded, oligoclonal population.

METHODS

We recruited 10 HIV-infected, non-diabetic, overweight or obese adults on efavirenz, tenofovir, and emtricitabine for >4 years with consistent viral suppression. We collected fasting blood and subcutaneous abdominal adipose tissue to measure the percentage of CD4 and CD8 T cells expressing activation, exhaustion, late differentiation/senescence, and memory surface markers. We performed T-cell receptor (TCR) sequencing on sorted CD8 cells. We compared the proportion of each T-cell subset and the TCR repertoire diversity, in blood versus adipose tissue.

RESULTS

Adipose tissue had a higher percentage of CD3CD8 T cells compared with blood (61.0% vs. 51.7%, P < 0.01) and was enriched for both activated CD8HLA-DR T cells (5.5% vs. 0.9%, P < 0.01) and late-differentiated CD8CD57 T cells (37.4% vs. 22.7%, P < 0.01). Adipose tissue CD8 T cells displayed distinct TCRβ V and J gene usage, and the Shannon Entropy index, a measure of overall TCRβ repertoire diversity, was lower compared with blood (4.39 vs. 4.46; P = 0.05).

CONCLUSIONS

Adipose tissue is enriched for activated and late-differentiated CD8 T cells with distinct TCR usage. These cells may contribute to tissue inflammation and impaired adipocyte fitness in HIV-infected persons.

T Cells in Adipose Tissue: Critical Players in Immunometabolism

Adipose tissue performs immunoregulatory functions in addition to fat storage. Various T cells in different fat depots either help maintain metabolic homeostasis under healthy conditions or contribute to metabolic disorders in pathological conditions such as obesity, diabetes, cardiovascular diseases, or even cancer. These T cells play critical roles in immunometabolism, which refers to the intersection of immunity and metabolism. Numerous studies have examined the presence and changes of different T cell subsets, including helper T cells, regulatory T cells, cytotoxic T cells, and natural killer T cells, in adipose depots in health and diseases. In this review, we will discuss the adipose tissue niches that influence the patterns and functions of T cell subsets and in turn the impact of these T cells on cell- or body-based immunometabolism accounting for health and obesity.

Inflammation, Immunity, and Infection in Atherothrombosis: JACC Review Topic of the Week

Observations on human and experimental atherosclerosis, biomarker studies, and now a large-scale clinical trial support the operation of immune and inflammatory pathways in this disease. The factors that incite innate and adaptive immune responses implicated in atherogenesis and in lesion complication include traditional risk factors such as protein and lipid components of native and modified low-density lipoprotein, angiotensin II, smoking, visceral adipose tissue, and dysmetabolism. Infectious processes and products of the endogenous microbiome might also modulate atherosclerosis and its complications either directly, or indirectly by eliciting local and systemic responses that potentiate disease expression. Trials with antibiotics have not reduced recurrent cardiovascular events, nor have vaccination strategies yet achieved clinical translation. However, anti-inflammatory interventions such as anticytokine therapy and colchicine have begun to show efficacy in this regard. Thus, inflammatory and immune mechanisms can link traditional and emerging risk factors to atherosclerosis, and offer novel avenues for therapeutic intervention.

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.

Regulation, Communication, and Functional Roles of Adipose Tissue-Resident CD4+ T Cells in the Control of Metabolic Homeostasis

Evidence accumulated over the past few years has documented a critical role for adipose tissue (AT)-resident immune cells in the regulation of local and systemic metabolic homeostasis. In the lean state, visceral adipose tissue (VAT) is predominated by anti-inflammatory T-helper 2 (Th2) and regulatory T (Treg) cell subsets. As obesity progresses, the population of Th2 and Treg cells decreases while that of the T-helper 1 (Th1) and T-helper 17 (Th17) cells increases, leading to augmented inflammation and insulin resistance. Notably, recent studies also suggest a potential role of CD4⁺ T cells in the control of thermogenesis and energy homeostasis. In this review, we have summarized recent advances in understanding the characteristics and functional roles of AT CD4⁺ T cell subsets during obesity and energy expenditure. We have also discussed new findings on the crosstalk between CD4⁺ T cells and local antigen-presenting cells (APCs) including adipocytes, macrophages, and dendritic cells (DCs) to regulate AT function and metabolic homeostasis. Finally, we have highlighted the therapeutic potential of targeting CD4⁺ T cells as an effective strategy for the treatment of obesity and its associated metabolic diseases.

Insight into the development of obesity: functional alterations of adipose-derived mesenchymal stem cells

Obesity is associated with a variety of disorders including cardiovascular diseases, diabetes mellitus and cancer. Obesity changes the composition and structure of adipose tissue, linked to pro-inflammatory environment, endocrine/metabolic dysfunction, insulin resistance and oxidative stress. Adipose-derived mesenchymal stem cells (ASCs) have multiple functions like cell renewal, spontaneous repair and homeostasis in adipose tissue. In this review article, we have summarized the recent data highlighting that ASCs in obesity are defective in various functionalities and properties including differentiation, angiogenesis, motility, multipotent state, metabolism and immunomodulation. Inflammatory milieu, hypoxia and abnormal metabolites in obese tissue are crucial for impairing the functions of ASCs. Further work is required to explore the precise molecular mechanisms underlying its alterations and impairments. Based on these data, we suggest that deregulated ASCs, possibly also other mesenchymal stem cells, are important in promoting the development of obesity. Restoration of ASCs/mesenchymal stem cells might be an additional strategy to combat obesity and its associated diseases.

Obesity and Insulin Resistance Promote Atherosclerosis through an IFNγ-Regulated Macrophage Protein Network

Type 2 diabetes (T2D) is associated with increased risk for atherosclerosis; however, the mechanisms underlying this relationship are poorly understood. Macrophages, which are activated in T2D and causatively linked to atherogenesis, are an attractive mechanistic link. Here, we use proteomics to show that diet-induced obesity and insulin resistance (obesity/IR) modulate a pro-atherogenic "macrophage-sterol-responsive-network" (MSRN), which, in turn, predisposes macrophages to cholesterol accumulation. We identify IFNγ as the mediator of obesity/IR-induced MSRN dysregulation and increased macrophage cholesterol accumulation and show that obesity/IR primes T cells to increase IFNγ production. Accordingly, myeloid cell-specific deletion of the IFNγ receptor (Ifngr1-/-) restores MSRN proteins, attenuates macrophage cholesterol accumulation and atherogenesis, and uncouples the strong relationship between hyperinsulinemia and aortic root lesion size in hypercholesterolemic Ldlr-/- mice with obesity/IR, but does not affect these parameters in Ldlr-/- mice without obesity/IR. Collectively, our findings identify an IFNγ-macrophage pathway as a mechanistic link between obesity/IR and accelerated atherogenesis.

Microenvironment of Immune Cells Within the Visceral Adipose Tissue Sensu Lato vs. Epicardial Adipose Tissue: What Do We Know?

The chronic low-grade inflammation of the visceral adipose tissue is now fully established as one of the main contributors to metabolic disorders such as insulin resistance, subsequently leading to metabolic syndrome and other associated cardiometabolic pathologies. The orchestration of immune response and the "ratio of responsibility" of different immune cell populations have been studied extensively over the last few years within the visceral adipose tissue in general sense (sensu lato). However, it is essential to clearly distinguish different types of visceral fat distribution. Visceral adipose tissue is not only the classical omental or epididymal depot, but includes also specific type of fat in the close vicinity to the myocardium-the epicardial adipose tissue. Disruption of this type of fat during obesity was found to have a unique and direct influence over the cardiovascular disease development. Therefore, epicardial adipose tissue and other types of visceral adipose tissue depots should be studied separately. The purpose of this review is to explore the present knowledge about the morphology and dynamics of individual populations of immune cells within the visceral adipose tissue sensu lato in comparison to the knowledge regarding the epicardial adipose tissue specifically.

Effect of Low-Selenium/High-Fat Diet on Pig Peripheral Blood Lymphocytes: Perspectives from Selenoproteins, Heat Shock Proteins, and Cytokines

The aim of the present study was to clarify the effect of low selenium (Se)/high fat on the mRNA expression of selenoproteins, heat shock proteins (HSPs) and cytokines in pig peripheral blood lymphocytes. Forty crossbred boar piglets with healthy lean body weights of 10 kg were randomly divided into four treatment groups (group C, group L-Se, group H-fat, and group L-Se-H-fat) (n = 10/group) and fed with the corresponding diet for 16 weeks. The pig peripheral blood lymphocytes were extracted, and the mRNA expression of selenoproteins, HSPs, and cytokines was measured. Most mRNA levels for selenoproteins decreased in group L-Se, group H-fat, and group L-Se-H-fat, except Gpx1, Gpx2, Selt, and Selm, which were elevated in group H-fat. At the same time, low-Se/high-fat diet increased the expression of HSPs (HSP40, HSP60, HSP70, and HSP90) and inflammatory cytokines (IL-1α, IL-1β, IL-6, IL-8, IL-9, iNOS, COX-2, NF-κB, and TNF-α) in group L-Se, group H-fat, and group L-Se-H-fat, and genes in group L-Se-H-fat showed greater increases. Also, low-Se/high-fat diet inhibits the expression of TGF-β1 and IFN-γ. In summary, a low-Se/high-fat diet can cause relevant selenoprotein expression changes and promote the expression of pro-inflammatory factors and HSPs, and low Se enhances the expression of HSPs and inflammation factors induced by high fat. This information is helpful for understanding the effects of low-Se and high-fat diet on pig peripheral blood lymphocytes.

Mast cells participate in chronic low-grade inflammation within adipose tissue

Obesity is reckoned as one of the civilization diseases, posing a considerable global health issue. Evidence points towards a contribution of multitude immune cell populations in obesity pathomechanism and the development of chronic low-grade inflammation in the expanded adipose tissue. Notably, adipose tissue is a reservoir of mast cells which number in individuals with obesity particularly increased. Some of them tend to degranulation what generate secretion of strong pro-inflammatory and regulatory mediators, as well as cytokines/chemokines. Several lines of evidence suggest that mast cells are strictly associated with pro-inflammatory status in adipose tissue by their indirect impact on immune cell attraction and activation. Furthermore, mast cells affect adipose tissue remodelling and fibrosis by adipocyte differentiation, fibroblast proliferation and enhancing extracellular matrix proteins expression. This review will summarize current knowledge on mast cell features and their role in the development of chronic low-grade inflammation within adipose tissue.

Chrysanthemum indicum L. ethanol extract reduces high-fat diet-induced obesity in mice

The present study was undertaken to investigate the mechanism behind the anti-obesity effect of the 50% ethanol extract of Chrysanthemum indicum L. flowers (CIEE) in a mouse model of high-fat diet (HFD)-induced obesity. Male C57BL/6J mice (six mice in each group) were administered CIEE (8, 40 and 200 mg/kg) for 6 weeks while being fed with a HFD. Garcinia cambogia (GC) was used as the positive control and was administered in the same manner as CIEE. Results demonstrated that oral administration of CIEE significantly reduced body weight, epididymal white adipose tissue (EWAT), liver weight and serum levels of total cholesterol and triglyceride (P<0.05). In addition, CIEE reduced serum leptin and increased adiponectin levels. CIEE significantly downregulated peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein-α and fatty acid synthase expression levels in EWAT, and upregulated the protein expression of PPARα in liver tissue of HFD-fed obese mice (P<0.05). These results suggested that Chrysanthemum indicum L. flowers may be a potentially effective therapeutic agent for obesity and its associated complications.

Rainbow trout (Oncorhynchus mykiss) adipose tissue undergoes major changes in immune gene expression following bacterial infection or stimulation with pro-inflammatory molecules

In mammals, visceral adipose is increasingly seen as playing an important role in immune function with numerous pro-inflammatory, anti-inflammatory and immune-modulating proteins and peptides being identified in adipocytes. Adipose is also now known as a tissue that has an important role in the regulation of peritoneal immune responses. Despite this, only lately has consideration been given to visceral adipose as an important immune tissue in fish, especially in the context of intraperitoneal vaccination. The present study demonstrates that fish visceral adipose is capable of expressing a large range of immune molecules in response to stimulation with a live bacterium (A. salmonicida), a bacterial PAMP (Y. ruckeri flagellin), and the pro-inflammatory cytokines IL-1β, TNF-α3 and IFN-γ. Following infection and stimulation with flagellin and IL-1β a large upregulation of pro-inflammatory and antimicrobial molecules was seen, with a high degree of overlap. TNF-α treatment affected relatively few genes and the effects were more modest. IFN-γ had the smallest impact on adipose but IFN-γ inducible genes showed some of the largest effects. Overall, it is clear that adipose tissue should be considered an active immune site in fish, capable of participating in and influencing immune responses.

Obesity associated disease risk: the role of inherent differences and location of adipose depots

Obesity and associated metabolic co-morbidities are a worldwide public health problem. Negative health outcomes associated with obesity, however, do not arise from excessive adiposity alone. Rather, deleterious outcomes of adipose tissue accumulation are a result of how adipocytes are distributed to individual regions in the body. Due to our increased understanding of the dynamic relationship that exists between specific adipose depots and disease risk, an accurate characterization of total body adiposity as well as location is required to properly evaluate a population's disease risk. Specifically, distinctive tissue depots within the body include the lower body, upper body and abdominal (deep and superficial) subcutaneous regions, as well as visceral (mesenteric and omental) regions. Upper body and visceral adipose tissues are highly associated with metabolic dysfunction and chronic disease development, whereas lower body gluteofemoral subcutaneous adipose tissue imparts protection against diet-induced metabolic derangement. Each adipose depot functions distinctly as an endocrine organ hence it has a different level of impact on health outcomes. Effluent from adipose tissue can modulate the functions of other tissues, whilst receiving differential communication from the rest of the body via central nervous system innervation, metabolites and other signaling molecules. More so, adipose depots contain a diverse reservoir of tissue-resident immune cells that play an integral part in both maintaining tissue homeostasis, as well as propagating metabolically-induced inflammation. Overall, the conceptualization of obesity and associated risks needs updating to reflect the complexities of obesity. We review adipose tissue characteristics that are linked to deleterious or beneficial adipose tissue distributions.

Adipocyte CD1d determines adipose inflammation and insulin resistance in obesity

Obesity-induced adipose tissue inflammation is regulated by various immune cells for innate and adaptive immunity. Among adipose tissue immune cells, it has been proposed that invariant Natural Killer T (iNKT) cells play crucial roles in anti-inflammatory responses in obesity. iNKT cells recognize 'lipid' antigens loaded on CD1d of antigen presenting cells and modulate immune responses by secreting Th1 or Th2 type cytokines depending on species of lipid antigens, antigen presenting cell types, and environmental cytokine milieu. However, the regulatory mechanisms of antigen presenting cells for adipose iNKT cell stimulation have not been clearly elucidated. Recently, we have reported that CD1d expressing adipocytes could act as an antigen presenting cell for adipose iNKT cells by characterization of adipocyte-specific CD1d knockout (CD1d^ADKO) mice. Upon high-fat diet (HFD) feeding, CD1d^ADKO mice aggravated adipose tissue inflammation and insulin resistance compared with CD1d^f/f mice. In this commentary, we provide the additional data of adipocyte CD1d-dependent regulation of adipose iNKT cell responses as well as systemic insulin sensitivity. In addition, we discuss how the interaction between adipocytes and iNKT cells would be regulated with the progression of obesity.

Adipose tissue macrophages and their polarization in health and obesity

Adipose tissue is a special tissue environment due to its high lipid content. Adipose tissue macrophages (ATMs) help maintain adipose tissue homeostasis in steady state by clearing dead adipocytes. However, adipose tissue changes drastically during obesity, resulting in a state of chronic low grade inflammation and a shift in the adipose immune landscape. In this review we will discuss how these changes influence the polarization of ATMs.

Parallels in Immunometabolic Adipose Tissue Dysfunction with Ageing and Obesity

Ageing, like obesity, is often associated with alterations in metabolic and inflammatory processes resulting in morbidity from diseases characterised by poor metabolic control, insulin insensitivity, and inflammation. Ageing populations also exhibit a decline in immune competence referred to as immunosenescence, which contributes to, or might be driven by chronic, low-grade inflammation termed "inflammageing". In recent years, animal and human studies have started to uncover a role for immune cells within the stromal fraction of adipose tissue in driving the health complications that come with obesity, but relatively little work has been conducted in the context of immunometabolic adipose function in ageing. It is now clear that aberrant immune function within adipose tissue in obesity-including an accumulation of pro-inflammatory immune cell populations-plays a major role in the development of systemic chronic, low-grade inflammation, and limiting the function of adipocytes leading to an impaired fat handling capacity. As a consequence, these changes increase the chance of multiorgan dysfunction and disease onset. Considering the important role of the immune system in obesity-associated metabolic and inflammatory diseases, it is critically important to further understand the interplay between immunological processes and adipose tissue function, establishing whether this interaction contributes to age-associated immunometabolic dysfunction and inflammation. Therefore, the aim of this article is to summarise how the interaction between adipose tissue and the immune system changes with ageing, likely contributing to the age-associated increase in inflammatory activity and loss of metabolic control. To understand the potential mechanisms involved, parallels will be drawn to the current knowledge derived from investigations in obesity. We also highlight gaps in research and propose potential future directions based on the current evidence.

Schistosoma Infection and Schistosoma-Derived Products Modulate the Immune Responses Associated with Protection against Type 2 Diabetes

Studies on parasite-induced immunoregulatory mechanisms could contribute to the development of new therapies for inflammatory diseases such as type 2 diabetes (T2D), which is a chronic inflammatory disease characterized by persistent elevated glucose levels due to insulin resistance. The association between previous Schistosoma infection and T2D has been confirmed—Schistosoma infection and Schistosoma-derived products modulate the immune system, including innate and acquired immune responses, contributing to T2D disease control. Schistosoma infections and Schistosoma-derived molecules affect the immune cell composition in adipose tissue, dampening inflammation and improving glucose tolerance. This protective role includes the polarization of immune cells to alternatively activated macrophages, dendritic cells, eosinophils, and group 2 innate lymphoid cells. Furthermore, Schistosoma infection and Schistosoma products are effective for the treatment of T2D, as they increase the number of type 2 helper T cells (Th2) and regulatory T cells (Tregs) and decrease type 1 helper T cells (Th1) and type 17 helper T cells (Th17) cells. Thus, our aim was to comprehensively review the mechanism through which Schistosoma infection and Schistosoma products modulate the immune response against T2D.

IDO chronic immune activation and tryptophan metabolic pathway: A potential pathophysiological link between depression and obesity

Obesity and depression are among the most pressing health problems in the contemporary world. Obesity and depression share a bidirectional relationship, whereby each condition increases the risk of the other. By inference, shared pathways may underpin the comorbidity between obesity and depression. Activation of cell-mediated immunity (CMI) is a key factor in the pathophysiology of depression. CMI cytokines, including IFN-γ, TNFα and IL-1β, induce the catabolism of tryptophan (TRY) by stimulating indoleamine 2,3-dioxygenase (IDO) resulting in the synthesis of kynurenine (KYN) and other tryptophan catabolites (TRYCATs). In the CNS, TRYCATs have been related to oxidative damage, inflammation, mitochondrial dysfunction, cytotoxicity, excitotoxicity, neurotoxicity and lowered neuroplasticity. The pathophysiology of obesity is also associated with a state of aberrant inflammation that activates aryl hydrocarbon receptor (AHR), a pathway involved in the detection of intracellular or environmental changes as well as with increases in the production of TRYCATs, being KYN an agonists of AHR. Both AHR and TRYCATS are involved in obesity and related metabolic disorders. These changes in the TRYCAT pathway may contribute to the onset of neuropsychiatric symptoms in obesity. This paper reviews the role of immune activation, IDO stimulation and increased TRYCAT production in the pathophysiology of depression and obesity. Here we suggest that increased synthesis of detrimental TRYCATs is implicated in comorbid obesity and depression and is a new drug target to treat both diseases.

Interactions Between the Neuroendocrine System and T Lymphocytes in Diabetes

It is well established that there is a fine-tuned bidirectional communication between the immune and neuroendocrine tissues in maintaining homeostasis. Several types of immune cells, hormones, and neurotransmitters of different chemical nature are involved as communicators between organs. Apart of being key players of the adaptive arm of the immune system, it has been recently described that T lymphocytes are involved in the modulation of metabolism of several tissues in health and disease. Diabetes may result mainly from lack of insulin production (type 1 diabetes) or insufficient insulin and insulin resistance (type 2 diabetes), both influenced by genetic and environmental components. Herein, we discuss accumulating data regarding the role of the adaptive arm of the immune system in the pathogenesis of diabetes; including the action of several hormones and neurotransmitters influencing on central and peripheral T lymphocytes development and maturation, particularly under the metabolic burden triggered by diabetes. In addition, we comment on the role of T-effector lymphocytes in adipose and liver tissues during diabetes, which together enhances pancreatic β-cell stress aggravating the disease.

The Dark Side of IFN-γ: Its Role in Promoting Cancer Immunoevasion

Interferon-γ (IFN-γ) is a pleiotropic cytokine that has long been praised as an important effector molecule of anti-tumor immunity, capable of suppressing tumor growth through various mechanisms. On the contrary to such a bright side of IFN-γ, it has also been involved in promoting an outgrowth of tumor cells with immunoevasive phenotype suggesting an existence of a dark "tumor-promoting" side effect of IFN-γ. In this review, we will summarize this multi-functional role of IFN-γ in tumor context, how it promotes changes in tumor phenotype towards increased fitness for growth in immunocompetent host. Furthermore, we summarize how IFN-γ is involved in homeostatic or cancer-triggered mechanisms to establish an immunosuppressive tumor microenvironment.

Polyphenols and their effects on diabetes management: A review

Background: Type 2 diabetes is a growing public health problem and is associated with increased morbidity and mortality. The worldwide prevalence of type 2 diabetes is rising. Polyphenols, such as flavonoids, phenolic acid, and stilbens, are a large and heterogeneous group of phytochemicals in plant-based foods. In this review, we aimed at assessing the studies on polyphenols and diabetes management. Methods: A literature search in the PubMed, EMBASE, Scopus, and ISI Web of Science databases was conducted to identify relevant studies published from 1986 to Jan 2017. Results: Several animal models and a limited number of human studies have revealed that polyphenols decrease hyperglycemia and improve acute insulin secretion and insulin sensitivity. The possible mechanisms include decrease in glucose absorption in the intestine, inhibition of carbohydrates digestion, stimulation of insulin secretion, modulation of glucose release from the liver, activation of insulin receptors and glucose uptake in insulin-sensitive tissues, modulation of intracellular signaling pathways, and gene expression. Conclusion: Growing evidence indicates that various dietary polyphenols may influence blood glucose at different levels and may also help control and prevent diabetes complication. However, we still need more clinical trials to determine the effects of polyphenols- rich foods, their effective dose, and mechanisms of their effects in managing diabetes.

Immune response of bovine sourced cross-linked collagen sponge for hemostasis

A comprehensive immunogenicity scheme is proposed to examine immune response of bovine sourced hemostasis collagen sponge to establish foundation for further researches and decrease the incidence of adverse reaction in clinical trials. Compared with negative control group without any implant, spleen and lymph nodes morphology show no apparent swelling in mice with different doses of collagen sponge implants. Immune cells population, especially lymph nodes cells population, is practically coincident with organs. However, splenic cells display slight proliferation in early phase following collagen sponge implantation. Splenic cells apoptosis also demonstrates no significant difference among all groups. T lymphocytes subsets, CD4/CD8 cells ratio, in spleen and lymph nodes are practically normal. Splenic cells Ki67 + proportions do not exhibit significant difference between collagen sponge groups and negative control group. Humoral response is determined by detection of IgG and IgM concentration in serum, not exhibiting remarkable increase with collagen sponge implantation, compared to the drastic increase in positive control group with bovine tendon implantation. Local analysis around implants by hematoxylin-eosin staining discovers slight cell infiltration around collagen sponge. Tumour necrosis factor-α immunostaining indicates slight inflammation in early phase following collagen sponge implantation, but interferon-γ immunostaining is negligible even in positive control group. Collagen sponge, especially in high dose, may have evoked benign immune response in BALB/c mice, but this response is transient. The present evaluation scheme for immune response is integrated and comprehensive, suitable for various biomaterials.

Alterations in systemic levels of Th1, Th2, and Th17 cytokines in overweight adolescents and obese mice

BACKGROUND

Obesity represents a major problem for patients and health care systems in most industrialized countries. A chronic inflammatory state in obese individuals leads to disease conditions associated with activation of cellular immune mechanisms. Here, we sought to investigate the role of Th1-, Th2-, and Th17-related cytokines in overweight adolescents and mice on a high-fat diet.

METHODS

Plasma samples were obtained from 79 male adolescents aged 13-17 years. Thirty-seven of them had a body mass index (BMI) above the 90th age-specific percentile. Th1, Th2, and Th17 cytokines were measured using Bio-Plex multiplex technology (Bio-Rad, Hercules, USA). In an experimental approach, mice were fed with high-fat (HFD) or normal chow for 15 weeks.

RESULTS

Interleukin (IL)-17 concentrations were significantly decreased in overweight adolescents compared to lean controls [99.8 ± 7.3 pg/mL standard error of the mean (SEM) vs 146.6 ± 11.5 pg/mL SEM P = .001]. Levels of IL-17 correlated significantly with anthropometrical parameters of obesity. A concordant response was found in mice consuming a HFD for 15 weeks compared to controls (861 ± 165 pg/mL SEM vs 1575 ± 187 pg/ml SEM, P = .0183). However, a biphasic response was evident for most Th1, Th2, and Th17 cytokines as levels initially increased within the first 5 weeks on HFD and showed a decline afterwards.

CONCLUSIONS

In contrast to previous studies showing elevated levels of IL-17 in obese adults, we found a decreasing trend in overweight adolescents. This difference could possibly be related to the fact that disease conditions associated with obesity such as hypertension, vascular pathologies, diabetes, and a triggering of the Th1/Th17 axis were not yet present in overweight teenagers.

Integrated Immunomodulatory Mechanisms through which Long-Chain n-3 Polyunsaturated Fatty Acids Attenuate Obese Adipose Tissue Dysfunction

Obesity is a global health concern with rising prevalence that increases the risk of developing other chronic diseases. A causal link connecting overnutrition, the development of obesity and obesity-associated co-morbidities is visceral adipose tissue (AT) dysfunction, characterized by changes in the cellularity of various immune cell populations, altered production of inflammatory adipokines that sustain a chronic state of low-grade inflammation and, ultimately, dysregulated AT metabolic function. Therefore, dietary intervention strategies aimed to halt the progression of obese AT dysfunction through any of the aforementioned processes represent an important active area of research. In this connection, fish oil-derived dietary long-chain n-3 polyunsaturated fatty acids (PUFA) in the form of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been demonstrated to attenuate obese AT dysfunction through multiple mechanisms, ultimately affecting AT immune cellularity and function, adipokine production, and metabolic signaling pathways, all of which will be discussed herein.

Deep RNA Sequencing Uncovers a Repertoire of Human Macrophage Long Intergenic Noncoding RNAs Modulated by Macrophage Activation and Associated With Cardiometabolic Diseases

Background

Sustained and dysfunctional macrophage activation promotes inflammatory cardiometabolic disorders, but the role of long intergenic noncoding RNA (lincRNA) in human macrophage activation and cardiometabolic disorders is poorly defined. Through transcriptomics, bioinformatics, and selective functional studies, we sought to elucidate the lincRNA landscape of human macrophages.

Methods and Results

We used deep RNA sequencing to assemble the lincRNA transcriptome of human monocyte‐derived macrophages at rest and following stimulation with lipopolysaccharide and IFN‐γ (interferon γ) for M1 activation and IL‐4 (interleukin 4) for M2 activation. Through de novo assembly, we identified 2766 macrophage lincRNAs, including 861 that were previously unannotated. The majority (≈85%) was nonsyntenic or was syntenic but not annotated as expressed in mouse. Many macrophage lincRNAs demonstrated tissue‐enriched transcription patterns (21.5%) and enhancer‐like chromatin signatures (60.9%). Macrophage activation, particularly to the M1 phenotype, markedly altered the lincRNA expression profiles, revealing 96 lincRNAs differentially expressed, suggesting potential roles in regulating macrophage inflammatory functions. A subset of lincRNAs overlapped genomewide association study loci for cardiometabolic disorders. MacORIS (macrophage‐enriched obesity‐associated lincRNA serving as a repressor of IFN‐γ signaling), a macrophage‐enriched lincRNA not expressed in mouse macrophages, harbors variants associated with central obesity. Knockdown of MacORIS, which is located in the cytoplasm, enhanced IFN‐γ–induced JAK2 (Janus kinase 2) and STAT1 (signal transducer and activator of transcription 1) phosphorylation in THP‐1 macrophages, suggesting a potential role as a repressor of IFN‐γ signaling. Induced pluripotent stem cell–derived macrophages recapitulated the lincRNA transcriptome of human monocyte‐derived macrophages and provided a high‐fidelity model with which to study lincRNAs in human macrophage biology, particularly those not conserved in mouse.

Conclusions

High‐resolution transcriptomics identified lincRNAs that form part of the coordinated response during macrophage activation, including specific macrophage lincRNAs associated with human cardiometabolic disorders that modulate macrophage inflammatory functions.

Mouse adenovirus type 1 infection of adipose tissue

Human adenovirus (HAdV) type 36 seropositivity has been linked to obesity in humans. That link is supported by a small number of studies using HAdV-36 infection of animals that are not natural hosts for HAdVs. In this study, we infected mice with mouse adenovirus type 1 (MAV-1), a mouse pathogen, to determine whether MAV-1 infected adipose tissue and was associated with adipose tissue inflammation and obesity. We detected MAV-1 in adipose tissue during acute MAV-1 infection, but we did not detect virus-induced increases in adipose tissue cytokine expression or histological evidence of adipose tissue inflammation during acute infection. MAV-1 did not persist in adipose tissue at later times, and we did not detect long-term adipose inflammation, increased adipose tissue mass, or body weight in infected mice. Our data indicate that MAV-1 is not associated with obesity in infected mice.

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.