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1.
Mol Immunol ; 171: 66-76, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38795686

ABSTRACT

Chronic inflammation has long been considered the characteristic feature of type II diabetes mellitus (T2DM) Immunopathogenesis. Pro-inflammatory cytokines are considered the central drivers of the inflammatory cascade leading to ß-cell dysfunction and insulin resistance (IR), two major pathologic events contributing to T2DM. Analyzing the cytokine profile of T2DM patients has also introduced interleukin-17 (IL-17) as an upstream regulator of inflammation, regarding its role in inducing the nuclear factor-kappa B (NF-κB) pathway. In diabetic tissues, IL-17 induces the expression of inflammatory cytokines and chemokines. Hence, IL-17 can deteriorate insulin signaling and ß-cell function by activating the JNK pathway and inducing infiltration of neutrophils into pancreatic islets, respectively. Additionally, higher levels of IL-17 expression in patients with diabetic complications compared to non-complicated individuals have also proposed a role for IL-17 in T2DM complications. Here, we highlight the role of IL-17 in the Immunopathogenesis of T2DM and corresponding pathways, recent advances in preclinical and clinical studies targeting IL-17 in T2DM, and corresponding challenges and possible solutions.


Subject(s)
Diabetes Mellitus, Type 2 , Interleukin-17 , Humans , Diabetes Mellitus, Type 2/immunology , Interleukin-17/immunology , Animals , Inflammation/immunology , Insulin-Secreting Cells/immunology , Insulin-Secreting Cells/metabolism , Insulin-Secreting Cells/pathology , Diabetes Complications/immunology , Insulin Resistance/immunology , Signal Transduction/immunology
2.
Immunity ; 57(6): 1289-1305.e9, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38772366

ABSTRACT

Adipose tissue group 2 innate lymphoid cells (ILC2s) help maintain metabolic homeostasis by sustaining type 2 immunity and promoting adipose beiging. Although impairment of the ILC2 compartment contributes to obesity-associated insulin resistance, the underlying mechanisms have not been elucidated. Here, we found that ILC2s in obese mice and humans exhibited impaired liver kinase B1 (LKB1) activation. Genetic ablation of LKB1 disrupted ILC2 mitochondrial metabolism and suppressed ILC2 responses, resulting in exacerbated insulin resistance. Mechanistically, LKB1 deficiency induced aberrant PD-1 expression through activation of NFAT, which in turn enhanced mitophagy by suppressing Bcl-xL expression. Blockade of PD-1 restored the normal functions of ILC2s and reversed obesity-induced insulin resistance in mice. Collectively, these data present the LKB1-PD-1 axis as a promising therapeutic target for the treatment of metabolic disease.


Subject(s)
Adipose Tissue , Homeostasis , Insulin Resistance , Lymphocytes , Mitochondria , Obesity , Programmed Cell Death 1 Receptor , Protein Serine-Threonine Kinases , Animals , Insulin Resistance/immunology , Programmed Cell Death 1 Receptor/metabolism , Mice , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/genetics , Mitochondria/metabolism , Humans , Adipose Tissue/metabolism , Adipose Tissue/immunology , Obesity/immunology , Obesity/metabolism , Lymphocytes/immunology , Lymphocytes/metabolism , AMP-Activated Protein Kinases/metabolism , Mice, Inbred C57BL , Mice, Knockout , Immunity, Innate , Male , Mitophagy/immunology , AMP-Activated Protein Kinase Kinases
3.
Biomolecules ; 14(4)2024 Apr 13.
Article in English | MEDLINE | ID: mdl-38672492

ABSTRACT

Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as the most common liver disease worldwide in recent years. MASLD commonly presents as simple hepatic steatosis, but ~25% of patients develop liver inflammation, progressive fibrosis, liver cirrhosis and related hepatocellular carcinoma. Liver inflammation and the degree of fibrosis are key determinants of the prognosis. The pathophysiology of liver inflammation is incompletely understood and involves diverse factors and specifically innate and adaptive immune responses. More specifically, diverse mediators of innate immunity such as proinflammatory cytokines, adipokines, inflammasomes and various cell types like mononuclear cells, macrophages and natural killer cells are involved in directing the inflammatory process in MASLD. The activation of innate immunity is driven by various factors including excess lipids and lipotoxicity, insulin resistance and molecular patterns derived from gut commensals. Targeting pathways of innate immunity might therefore appear as an attractive therapeutic strategy in the future management of MASLD and possibly its complications.


Subject(s)
Immunity, Innate , Humans , Animals , Fatty Liver/immunology , Inflammasomes/immunology , Inflammasomes/metabolism , Cytokines/metabolism , Cytokines/immunology , Insulin Resistance/immunology , Inflammation/immunology
4.
Int Immunopharmacol ; 133: 112091, 2024 May 30.
Article in English | MEDLINE | ID: mdl-38657500

ABSTRACT

The pathophysiology of hepatic steatosis is thoroughly reviewed in this comprehensive report, with particular attention to the complex interactions between inflammatory pathways, insulin resistance, lipid metabolism, metabolic dysregulation, and immunological responses in the liver including non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), and hepatocellular carcinoma (HCC). The study highlights the role of immune cell regulation in disease progression and explores the potential of immune cell-specific treatments for treating hepatic disorders. The development of liver disorders is significantly influenced by immune cells, including dendritic cells, T cells, and natural killer cells. Clinical investigations show that immune cell-specific treatments can effectively reduce liver fibrosis and inflammation. Future research should focus on finding new immunological targets for therapeutic interventions, as well as addressing the management challenges associated with NAFLD/NASH. Hepatic immune microorganisms also impact liver homeostasis and disorders. Improvements in immune cell regulation and liver transplantation methods give patients hope for better prognoses. Important phases include optimizing the selection of donors for malignancy of the liver, using machine perfusion for organ preservation, and fine-tuning immunosuppressive strategies. For focused treatments in hepatic steatosis, it is imperative to understand the intricate interactions between immune and metabolic variables. Understanding the liver's heterogeneous immune profile, encompassing a range of immune cell subpopulations, is crucial for formulating focused therapeutic interventions. To improve patient care and outcomes in hepatic illnesses, there is an urgent need for further research and innovation. Therefore, to effectively treat hepatic steatosis, it is important to enhance therapeutic techniques and maximize liver transplantation strategies.


Subject(s)
Non-alcoholic Fatty Liver Disease , Humans , Animals , Non-alcoholic Fatty Liver Disease/immunology , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/therapy , Carcinoma, Hepatocellular/immunology , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/therapy , Liver Neoplasms/immunology , Liver Neoplasms/metabolism , Liver Neoplasms/therapy , Liver/immunology , Liver/metabolism , Liver/pathology , Lipid Metabolism , Insulin Resistance/immunology , Fatty Liver/immunology , Fatty Liver/metabolism , Fatty Liver/therapy
5.
Autoimmun Rev ; 23(3): 103502, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38101692

ABSTRACT

Metabolic syndrome poses a great worldwide threat to the health of the patients. Increased visceral adiposity is recognized as the main determinant of the detrimental clinical effects of insulin resistance. Inflammation and immune system activation in the adipose tissue (AT) have a central role in the pathophysiology of metabolic syndrome, but the mechanisms linking increased adiposity to immunity in the AT remain in part elusive. In this review, we support the central role of adipocyte overload and relative adipose failure as key determinants in triggering immune aggression to AT. This provides a mechanistic explanation of the relative metabolic wellness of metabolically normal obese people and the disruption in insulin signaling in metabolically obese lean people.


Subject(s)
Adipocytes , Adipose Tissue , Autoimmunity , Humans , Adipocytes/immunology , Adipocytes/metabolism , Autoimmunity/immunology , Adipose Tissue/immunology , Adipose Tissue/metabolism , Obesity/immunology , Obesity/metabolism , Animals , Metabolic Syndrome/immunology , Metabolic Syndrome/metabolism , Insulin Resistance/immunology , Adiposity/immunology
6.
Eur J Immunol ; 53(2): e2249990, 2023 02.
Article in English | MEDLINE | ID: mdl-36433684

ABSTRACT

Adipose tissue inflammation is a driving factor for the development of obesity-associated metabolic disturbances, and a role of adipose tissue T cells in initiating the pro-inflammatory signaling is emerging. However, data on human adipose tissue T cells in obesity are limited, reflected by the lack of phenotypic markers to define tissue-resident T cell subsets. In this study, we performed a deep characterization of T cells in blood and adipose tissue depots using multicolor flow cytometry and RNA sequencing. We identified distinct subsets of T cells associated with obesity expressing the activation markers, CD26 and CCR5, and obesity-specific genes that are potentially engaged in activating pro-inflammatory pathway, including ceramide signaling, autophagy, and IL-6 signaling. These findings increase our knowledge on the heterogeneity of T cells in adipose tissue and on subsets that may play a role in obesity-related pathogenesis.


Subject(s)
Adipose Tissue , Inflammation , Insulin Resistance , Obesity , T-Lymphocyte Subsets , Humans , Adipose Tissue/immunology , Adipose Tissue/pathology , Autophagy/immunology , Ceramides/immunology , Inflammation/blood , Inflammation/genetics , Inflammation/immunology , Insulin Resistance/genetics , Insulin Resistance/immunology , Obesity/blood , Obesity/genetics , Obesity/immunology , Obesity/pathology , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/pathology
7.
Nat Commun ; 13(1): 5208, 2022 09 05.
Article in English | MEDLINE | ID: mdl-36064857

ABSTRACT

Adipose tissue macrophage (ATM) inflammation is involved with meta-inflammation and pathology of metabolic complications. Here we report that in adipocytes, elevated lactate production, previously regarded as the waste product of glycolysis, serves as a danger signal to promote ATM polarization to an inflammatory state in the context of obesity. Adipocyte-selective deletion of lactate dehydrogenase A (Ldha), the enzyme converting pyruvate to lactate, protects mice from obesity-associated glucose intolerance and insulin resistance, accompanied by a lower percentage of inflammatory ATM and reduced production of pro-inflammatory cytokines such as interleukin 1ß (IL-1ß). Mechanistically, lactate, at its physiological concentration, fosters the activation of inflammatory macrophages by directly binding to the catalytic domain of prolyl hydroxylase domain-containing 2 (PHD2) in a competitive manner with α-ketoglutarate and stabilizes hypoxia inducible factor (HIF-1α). Lactate-induced IL-1ß was abolished in PHD2-deficient macrophages. Human adipose lactate level is positively linked with local inflammatory features and insulin resistance index independent of the body mass index (BMI). Our study shows a critical function of adipocyte-derived lactate in promoting the pro-inflammatory microenvironment in adipose and identifies PHD2 as a direct sensor of lactate, which functions to connect chronic inflammation and energy metabolism.


Subject(s)
Adipocytes , Hypoxia-Inducible Factor-Proline Dioxygenases , Inflammation , Lactate Dehydrogenase 5 , Lactic Acid , Macrophages , Adipocytes/immunology , Adipose Tissue/immunology , Animals , Humans , Hypoxia-Inducible Factor-Proline Dioxygenases/genetics , Hypoxia-Inducible Factor-Proline Dioxygenases/immunology , Inflammation/genetics , Inflammation/immunology , Inflammation/pathology , Insulin Resistance/genetics , Insulin Resistance/immunology , Insulin Resistance/physiology , L-Lactate Dehydrogenase/genetics , L-Lactate Dehydrogenase/immunology , Lactate Dehydrogenase 5/genetics , Lactate Dehydrogenase 5/immunology , Lactic Acid/immunology , Macrophages/immunology , Mice , Obesity/genetics , Obesity/immunology , Obesity/pathology , Procollagen-Proline Dioxygenase/genetics , Procollagen-Proline Dioxygenase/immunology , Prolyl Hydroxylases
8.
J Pak Med Assoc ; 72(4): 696-701, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35614604

ABSTRACT

OBJECTIVE: To determine the correlation of insulin resistance with neutrophil-to-lymphocyte ratio and serum ferritin, and to evaluate whether NLR and serum ferritin can predict insulin resistance in metabolic syndrome. METHODS: The cross-sectional analytical study was conducted at the University of Health Sciences, Lahore, Pakistan, from July 2016 to 2019, and comprised male patients of metabolic syndrome and healthy controls. The correlation involving insulin resistance, serum ferritin and neutrophil-to-lymphocyte ratio was determined. Data was analysed using SPSS 22. RESULTS: Of the 210 subjects, 160(76.2%) were cases with a median age of 45 years (interquartile range: 39-50 years), and 50(23.8%) were controls with a median age of 41 years (interquartile range: 35-50 years). Serum ferritin, alanine aminotransferase, total neutrophil count, lymphocyte count and neutrophil-to-lymphocyte ratio were significantly higher among the cases than the controls (p<0.05). Significant positive correlation of insulin resistance was observed with serum ferritin and neutrophil-to-lymphocyte ratio (p<0.05)) among the cases. Neutrophil-to-lymphocyte ratio significantly predicted insulin resistance among the cases (p<0.05). Conclusion: Neutrophil-to-lymphocyte ratio was fund to be a significant predictor of insulin resistance in metabolic syndrome.


Subject(s)
Insulin Resistance , Metabolic Syndrome , Adult , Cross-Sectional Studies , Ferritins/blood , Humans , Insulin Resistance/immunology , Lymphocyte Count , Lymphocytes , Male , Metabolic Syndrome/diagnosis , Metabolic Syndrome/pathology , Middle Aged , Neutrophils
9.
J Clin Endocrinol Metab ; 107(1): 53-66, 2022 01 01.
Article in English | MEDLINE | ID: mdl-34519830

ABSTRACT

CONTEXT: Circulating adiponectin levels are decreased in pregnant women with obesity or gestational diabetes, and this is believed to contribute to the insulin resistance and increased risk of fetal overgrowth associated with these conditions. However, the molecular mechanisms regulating adiponectin secretion from maternal adipose tissues in pregnancy are poorly understood. OBJECTIVE: We tested the hypothesis that obesity in pregnancy is associated with adipose tissue insulin resistance and increased adiponectin ubiquitination and degradation, caused by inflammation and endoplasmic reticulum (ER) stress. METHODS: Visceral adipose tissues were collected from lean and obese pregnant humans and mice. Total and ubiquitinated adiponectin, and markers of inflammation, ER stress, and insulin resistance were examined in adipose tissues. The role of insulin, inflammation, and ER stress in mediating adiponectin ubiquitination and degradation was examined using 3T3L-1 adipocytes. RESULTS: Obesity in pregnancy is associated with adipose tissue inflammation, ER stress, insulin resistance, increased adiponectin ubiquitination, and decreased total abundance of adiponectin. Adiponectin ubiquitination was increased in visceral fat of obese pregnant women as compared to lean pregnant women. We further observed that insulin prevents, whereas ER stress and inflammation promote, adiponectin ubiquitination and degradation in differentiated 3T3-L1 adipocytes. CONCLUSION: We have identified adiponectin ubiquitination as a key mechanism by which obesity diminishes adiponectin secretion in pregnancy. This information will help us better understand the mechanisms controlling maternal insulin resistance and fetal growth in pregnancy and may provide a foundation for the development of strategies aimed at improving adiponectin production in pregnant women with obesity or gestational diabetes.


Subject(s)
Adiponectin/metabolism , Diabetes, Gestational/metabolism , Insulin/metabolism , Obesity, Maternal/metabolism , 3T3-L1 Cells , Adipocytes/metabolism , Adiponectin/analysis , Adult , Animals , Cohort Studies , Diabetes, Gestational/immunology , Disease Models, Animal , Female , Humans , Infant, Newborn , Insulin Resistance/immunology , Intra-Abdominal Fat/immunology , Intra-Abdominal Fat/pathology , Male , Mice , Obesity, Maternal/immunology , Obesity, Maternal/pathology , Pregnancy , Proteolysis , Ubiquitination/immunology
10.
J Clin Endocrinol Metab ; 107(1): 119-135, 2022 01 01.
Article in English | MEDLINE | ID: mdl-34498048

ABSTRACT

CONTEXT: Disentangling contributions of HIV from antiretroviral therapy (ART) and understanding the effects of different ART on metabolic complications in persons living with HIV (PLHIV) has been challenging. OBJECTIVE: We assessed the effect of untreated HIV infection as well as different antiretroviral therapy (ART) on the metabolome/lipidome. METHODS: Widely targeted plasma metabolomic and lipidomic profiling was performed on HIV-seronegative individuals and people living with HIV (PLHIV) before and after initiating ART (tenofovir/emtricitabine plus atazanavir/ritonavir [ATV/r] or darunavir/ritonavir [DRV/r] or raltegravir [RAL]). Orthogonal partial least squares discriminant analysis was used to assess metabolites/lipid subspecies that discriminated between groups. Graphical lasso estimated group-specific metabolite/lipid subspecies networks associated with the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). Correlations between inflammatory markers and metabolites/lipid subspecies were visualized using heat maps. RESULTS: Of 435 participants, 218 were PLHIV. Compared to HIV-seronegative individuals, ART-naive PLHIV exhibited higher levels of saturated triacylglycerols/triglycerides (TAGs) and 3-hydroxy-kynurenine, lower levels of unsaturated TAGs and N-acetyl-tryptophan, and a sparser and less heterogeneous network of metabolites/lipid subspecies associated with HOMA-IR. PLHIV on RAL vs ATV/r or DRV/r had lower saturated and unsaturated TAGs. Positive correlations were found between medium-long chain acylcarnitines (C14-C6 ACs), palmitate, and HOMA-IR for RAL but not ATV/r or DRV/r. Stronger correlations were seen for TAGs with interleukin 6 and high-sensitivity C-reactive protein after RAL vs ATV/r or DRV/r initiation; these correlations were absent in ART-naive PLHIV. CONCLUSION: Alterations in the metabolome/lipidome suggest increased lipogenesis for ART-naive PLHIV vs HIV-seronegative individuals, increased TAG turnover for RAL vs ATV/r or DRV/r, and increased inflammation associated with this altered metabolome/lipidome after initiating ART. Future studies are needed to understand cardiometabolic consequences of lipogenesis and inflammation in PLHIV.


Subject(s)
Anti-HIV Agents/administration & dosage , HIV Infections/drug therapy , Lipid Metabolism/drug effects , Lipids/blood , Metabolic Syndrome/diagnosis , Adult , Anti-HIV Agents/adverse effects , Cardiometabolic Risk Factors , Case-Control Studies , Clinical Trials, Phase III as Topic , Drug Therapy, Combination/adverse effects , Drug Therapy, Combination/methods , Female , HIV Infections/blood , HIV Infections/immunology , HIV Infections/metabolism , Humans , Inflammation/blood , Inflammation/diagnosis , Inflammation/immunology , Inflammation/metabolism , Insulin Resistance/immunology , Lipidomics , Male , Metabolic Syndrome/blood , Metabolic Syndrome/etiology , Metabolic Syndrome/metabolism , Middle Aged , Multicenter Studies as Topic , Observational Studies as Topic , Prospective Studies , Randomized Controlled Trials as Topic
11.
Signal Transduct Target Ther ; 6(1): 409, 2021 11 30.
Article in English | MEDLINE | ID: mdl-34848693

ABSTRACT

Natural killer (NK) cells have been suggested to be associated with type 2 diabetes by regulating systemic inflammation. However, the mechanism by which NK cells regulate insulin sensitivity remains unknown. This study shows that NK-derived exosomes from lean mice attenuate obesity-induced insulin resistance and inflammation in mice of type 2 diabetes. Moreover, lean NK-derived exosomes enhance insulin sensitivity and relieve inflammation in adipocytes and hepatocytes. MiR-1249-3p, which is significantly upregulated in lean NK-derived exosomes, can be transferred from NK cells to adipocytes and hepatocytes via exosomes. NK-derived exosomal miR-1249-3p dramatically induces cellular insulin sensitivity and relieves inflammation. Mechanistically, exosomal miR-1249-3p directly targets SKOR1 to regulate the formation of ternary complex SMAD6/MYD88/SMURF1, which mediates glucose homeostasis by suppressing the TLR4/NF-κB signaling pathway. This study reveals an emerging role for NK-derived exosomal miR-1249-3p in remission of insulin resistance, and provides a series of potential therapeutic targets in type 2 diabetes.


Subject(s)
Diabetes Mellitus, Experimental/immunology , Diabetes Mellitus, Type 2/immunology , Exosomes/immunology , Insulin Resistance/immunology , Killer Cells, Natural/immunology , MicroRNAs/immunology , Animals , Inflammation/immunology , Male , Mice
12.
OMICS ; 25(12): 770-781, 2021 12.
Article in English | MEDLINE | ID: mdl-34807729

ABSTRACT

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a systemic disease affecting not only the lungs but also multiple organ systems. Clinical studies implicate that SARS-CoV-2 infection causes imbalance of cellular homeostasis and immune response that trigger cytokine storm, oxidative stress, thrombosis, and insulin resistance. Mathematical modeling can offer in-depth understanding of the SARS-CoV-2 infection and illuminate how subcellular mechanisms and feedback loops underpin disease progression and multiorgan failure. We report here a mathematical model of SARS-CoV-2 infection pathway network with cytokine storm, oxidative stress, thrombosis, insulin resistance, and nitric oxide (NO) pathways. The biochemical systems theory model shows autocrine loops with positive feedback enabling excessive immune response, cytokines, transcription factors, and interferons, which can imbalance homeostasis of the system. The simulations suggest that changes in immune response led to uncontrolled release of cytokines and chemokines, including interleukin (IL)-1ß, IL-6, and tumor necrosis factor α (TNFα), and affect insulin, coagulation, and NO signaling pathways. Increased production of NETs (neutrophil extracellular traps), thrombin, PAI-1 (plasminogen activator inhibitor-1), and other procoagulant factors led to thrombosis. By analyzing complex biochemical reactions, this model forecasts the key intermediates, potential biomarkers, and risk factors at different stages of COVID-19. These insights can be useful for drug discovery and development, as well as precision treatment of multiorgan implications of COVID-19 as seen in systems medicine.


Subject(s)
COVID-19/immunology , Cytokine Release Syndrome/immunology , Insulin Resistance/immunology , Nitric Oxide/immunology , Oxidative Stress/immunology , SARS-CoV-2/immunology , Thrombosis/immunology , COVID-19/virology , Cytokine Release Syndrome/virology , Cytokines/immunology , Humans , Models, Theoretical , Signal Transduction/immunology , Thrombosis/virology
13.
Nutrients ; 13(11)2021 Oct 25.
Article in English | MEDLINE | ID: mdl-34836036

ABSTRACT

Studies suggest that time-restricted feeding (TRF) may prevent obesity and its commodities. At present, little is known about how TRF impacts immune cells, and whether such an effect is linked to altered metabolic parameters under condition of a high-fat diet (HFD)-induced obesity. To address these issues, we conducted a study in which we determined whether TRF has therapeutic efficacy against weight gain, adiposity, as well as associated immune cell disturbance found in obese mice. Six-week-old male C57BL/6 mice were fed a low-fat diet (LFD) or HFD ad libitum for six weeks, after which time a subgroup of HFD mice was switched to the 10 h TRF paradigm (HFD-TRF) for additional eight weeks. We found that TRF intervention reduced HFD-induced weight gain. Even with comparable fat mass and mean adipocyte area, the HFD-TRF group had lower mRNA levels of proinflammatory cytokine Tnfα and chemokine Ccl8, along with reduced numbers of adipose tissue macrophages (ATM), CD11c+ ATM, and CD8+ T cell compared to the HFD group, while maintaining CD8+ to CD4+ ratio at levels similar to those in the LFD group. Furthermore, TRF intervention was effective in improving glucose tolerance and reducing HOMA-IR. Taken together, our findings suggest that TRF restores the obesity-induced alteration in immune cell composition, and this effect may in part contribute to health benefits (including insulin sensitivity) of practicing TRF.


Subject(s)
Adipose Tissue/immunology , Fasting/metabolism , Lymphocytes/immunology , Macrophages/immunology , Obesity/prevention & control , Adipose Tissue/cytology , Adiposity/immunology , Animals , Diet, Fat-Restricted , Diet, High-Fat/adverse effects , Disease Models, Animal , Insulin Resistance/immunology , Male , Mice , Mice, Inbred C57BL , Obesity/etiology , Phenotype , Weight Gain/immunology
14.
Sci Rep ; 11(1): 19160, 2021 09 27.
Article in English | MEDLINE | ID: mdl-34580412

ABSTRACT

This study investigated whether oxidative and glycolytic rat skeletal muscles respond differently to a high-fat (HF) sucrose-enriched diet with respect to diacylglycerol (DAG) and ceramides accumulation, protein kinase C (PKC) activation, glucose metabolism, and the expression of inflammatory genes. HF diet (8 weeks) suppressed insulin-stimulated glycogen synthesis and glucose oxidation in soleus (Sol), extensor digitorum longus (EDL) and epitrochlearis (Epit) muscles. However, DAG and ceramides levels increased in Sol and EDL, but not in Epit muscles of HF-fed rats. Additionally, membrane-bound PKC-delta and PKC-theta increased in Sol and EDL, whereas in Epit muscles both PKC isoforms were reduced by HF diet. In Epit muscles, HF diet also increased the expression of tumor necrosis factor-α (TNF-α) receptors (CD40 and FAS), toll-like receptor 4 (TLR4), and nuclear factor kappa light polypeptide gene enhancer in B cells (NF-kB), whereas in Sol and EDL muscles the expression of these inflammatory genes remained unchanged upon HF feeding. In conclusion, HF diet caused DAG and ceramides accumulation, PKC activation, and the induction of inflammatory pathways in a fiber type-specific manner. These findings help explain why oxidative and glycolytic muscles similarly develop insulin resistance, despite major differences in their metabolic characteristics and responsiveness to dietary lipid abundance.


Subject(s)
Glycolysis/immunology , Insulin Resistance/immunology , Muscle, Skeletal/metabolism , Obesity/metabolism , Animals , Ceramides/analysis , Ceramides/metabolism , Diet, High-Fat/adverse effects , Dietary Sucrose/adverse effects , Diglycerides/analysis , Diglycerides/metabolism , Disease Models, Animal , Humans , Inflammation/diagnosis , Inflammation/immunology , Inflammation/metabolism , Insulin/metabolism , Male , Muscle, Skeletal/immunology , Obesity/etiology , Obesity/immunology , Oxidative Stress/immunology , Rats
15.
Nat Immunol ; 22(9): 1175-1185, 2021 09.
Article in English | MEDLINE | ID: mdl-34429546

ABSTRACT

Systematic characterizations of adipose regulatory T (Treg) cell subsets and their phenotypes remain uncommon. Using single-cell ATAC-sequencing and paired single-cell RNA and T cell receptor (TCR) sequencing to map mouse adipose Treg cells, we identified CD73hiST2lo and CD73loST2hi subsets with distinct clonal expansion patterns. Analysis of TCR-sharing data implied a state transition between CD73hiST2lo and CD73loST2hi subsets. Mechanistically, we revealed that insulin signaling occurs through a HIF-1α-Med23-PPAR-γ axis to drive the transition of CD73hiST2lo into a CD73loST2hi adipose Treg cell subset. Treg cells deficient in insulin receptor, HIF-1α or Med23 have decreased PPAR-γ expression that in turn promotes accumulation of CD73hiST2lo adipose Treg cells and physiological adenosine production to activate beige fat biogenesis. We therefore unveiled a developmental trajectory of adipose Treg cells and its dependence on insulin signaling. Our findings have implications for understanding the dynamics of adipose Treg cell subsets in aged and obese contexts.


Subject(s)
Adipose Tissue/immunology , Insulin Resistance/immunology , Insulin/metabolism , Receptor, Insulin/metabolism , T-Lymphocytes, Regulatory/immunology , 5'-Nucleotidase/genetics , 5'-Nucleotidase/metabolism , Adipose Tissue/cytology , Aging/immunology , Animals , Cells, Cultured , High-Throughput Nucleotide Sequencing , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Interleukin-1 Receptor-Like 1 Protein/genetics , Interleukin-1 Receptor-Like 1 Protein/metabolism , Male , Mediator Complex/metabolism , Mice , Mice, Inbred C57BL , Obesity/genetics , Obesity/immunology , PPAR gamma/metabolism , Receptors, Antigen, T-Cell/genetics , Signal Transduction/genetics , Signal Transduction/immunology , T-Lymphocytes, Regulatory/cytology
16.
Int J Mol Sci ; 22(16)2021 Aug 12.
Article in English | MEDLINE | ID: mdl-34445379

ABSTRACT

Chronic inflammation of the adipose tissue (AT) is a critical component of obesity-induced insulin resistance and type 2 diabetes. Adipose tissue immune cells, including AT macrophages (ATMs), AT dendritic cells (ATDCs), and T cells, are dynamically regulated by obesity and participate in obesity-induced inflammation. Among AT resident immune cells, ATDCs are master immune regulators and engage in crosstalk with various immune cells to initiate and regulate immune responses. However, due to confounding markers and lack of animal models, their exact role and contribution to the initiation and maintenance of AT inflammation and insulin resistance have not been clearly elucidated. This paper reviews the current understanding of ATDCs and their role in obesity-induced AT inflammation. We also provide the potential mechanisms by which ATDCs regulate AT inflammation and insulin resistance in obesity. Finally, this review offers perspectives on ways to better dissect the distinct functions and contributions of ATDCs to obesity.


Subject(s)
Adipose Tissue/cytology , Diabetes Mellitus, Type 2/etiology , Insulin Resistance/immunology , Obesity/immunology , Adipose Tissue/immunology , Animals , Antigen Presentation , Dendritic Cells/immunology , Diabetes Mellitus, Type 2/immunology , Humans , Macrophages/immunology , Mice , Mice, Inbred C57BL
17.
Oxid Med Cell Longev ; 2021: 5566053, 2021.
Article in English | MEDLINE | ID: mdl-34326919

ABSTRACT

The Jiang Tang Xiao Ke (JTXK) granule is a classic Chinese herbal formula that has been put into clinical use in the treatment of type 2 diabetes mellitus for decades. However, whether its ability to ameliorate skeletal muscle insulin resistance (IR) is through modulation of the AMPK/SIRT1/PGC-1α signaling pathway remains unknown. Therefore, we aimed to investigate the effects of JTXK granules on IR in skeletal muscle of high-fat diet-induced diabetic mice and C2C12 cells and analyze the underlying mechanisms. In the present study, we showed that JTXK granules attenuated body weight gain, reduced body fat mass, improved body lean mass, and enhanced muscle performance of diabetic mice. JTXK granules also improved glucose metabolism and skeletal muscle insulin sensitivity and partially reversed abnormal serum lipid levels, which might be related to the regulation of the AMPK/SIRT1/PGC-1α pathway, both in skeletal muscle tissue of diabetic mice and in C2C12 cells. Furthermore, drug-containing serum of JTXK granules was capable of enhancing glucose uptake and mitochondrial respiration in C2C12 cells, and AMPKα was proven to be closely involved in this process. Taken together, these results suggest that the JTXK granule ameliorates skeletal muscle IR through activation of the AMPK/SIRT1/PGC-1α signaling pathway, which offers a novel perspective of this formula to combat IR-related metabolic diseases.


Subject(s)
AMP-Activated Protein Kinases/drug effects , Diabetes Mellitus, Experimental/drug therapy , Diet, High-Fat/adverse effects , Drugs, Chinese Herbal/therapeutic use , Insulin Resistance/immunology , Muscle, Skeletal/drug effects , Animals , Drugs, Chinese Herbal/pharmacology , Male , Mice , Signal Transduction
18.
J Ovarian Res ; 14(1): 100, 2021 Jul 31.
Article in English | MEDLINE | ID: mdl-34330312

ABSTRACT

OBJECTIVE: The design of this study was due to the report of the antioxidant properties of Ellagic acid (EA) for its evaluation on the Insulin resistance (IR), oxidative stress and sex hormones levels in women with polycystic ovarian syndrome (PCOS). METHODS: In this randomized, double-blind, placebo-controlled clinical trial, 60 patients were recruited. Patients were randomly allocated consumed a capsule containing 200 mg of EA per day (n = 30) or placebo (n = 30) for 8 weeks. The fasting blood sugar (FBS), insulin, IR, total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), total antioxidant capacity (TAC), Malondialdehyde (MDA), C-reactive protein (CRP), Tumor necrosis factor-alpha (TNF-α), sex hormones and anti-mullerian hormone (AMH) were measured at the beginning and end of the study. RESULT: At the end of the study, the mean of FBS, insulin, IR, TC, TG, LDL, MDA, CRP, TNF-α, total testosterone, prolactin and AMH were significantly decreased in the intervention group compared to the placebo group (P < 0.05). Also, there was a significant increase in the mean of TAC after supplementation with EA (P < 0.05). At the end of the study, no significant changes were observed in the mean of anthropometric factors, physical activity and food intake (P > 0.05). CONCLUSION: EA supplementation can be helpful as a diet supplement in women with PCOS through improvement in insulin resistance. This supplement may be used to reduce metabolic disorders in women. TRIAL REGISTRATION: This study was retrospectively (07-07-2019) registered in the Iranian website ( www.irct.ir ) for registration of clinical trials ( IRCT20141025019669N12 ).


Subject(s)
Ellagic Acid/therapeutic use , Gonadal Steroid Hormones/immunology , Insulin Resistance/immunology , Oxidative Stress/drug effects , Adolescent , Adult , Double-Blind Method , Ellagic Acid/pharmacology , Female , Humans , Middle Aged , Retrospective Studies , Young Adult
19.
Sci Rep ; 11(1): 12314, 2021 06 10.
Article in English | MEDLINE | ID: mdl-34112902

ABSTRACT

We tested the hypothesis that a particular immune activation profile might be correlated with insulin resistance in a general population. By measuring 43 markers of immune, endothelial, and coagulation activation, we have previously shown that five different immune activation profiles may be distinguished in 150 volunteers. One of these profiles, Profile 2, characterized by CD4+ T cell senescence, inflammation, monocyte, B cell, and endothelial activation, presented elevated insulinemia, glycemia, triglyceridemia, and γ-glutamyl transferase, a marker of liver injury, in comparison with other profiles. Our data are compatible with a model in which a particular immune activation profile might favor the development of insulin resistance and metabolic syndrome. In this hypothesis, identification of this profile, that is feasible with only 3 markers with an error rate of 5%, might allow to personalize the screening and prevention of metabolic syndrome-driven morbidities as liver steatosis.


Subject(s)
Inflammation/immunology , Insulin Resistance/immunology , Metabolic Syndrome/immunology , T-Lymphocytes/immunology , gamma-Glutamyltransferase/genetics , Aged , B-Lymphocytes/immunology , Biomarkers/blood , Blood Glucose , CD4-Positive T-Lymphocytes/immunology , Cellular Senescence/genetics , Fatty Liver/genetics , Fatty Liver/immunology , Female , Humans , Inflammation/genetics , Inflammation/pathology , Insulin Resistance/genetics , Male , Metabolic Syndrome/genetics , Metabolic Syndrome/pathology , Middle Aged , Monocytes/immunology , T-Lymphocytes/pathology
20.
Nat Commun ; 12(1): 2598, 2021 05 10.
Article in English | MEDLINE | ID: mdl-33972511

ABSTRACT

The intestinal immune system is an important modulator of glucose homeostasis and obesity-associated insulin resistance. Dietary factors, the intestinal microbiota and their metabolites shape intestinal immunity during obesity. The intestinal immune system in turn affects processes such as intestinal permeability, immune cell trafficking, and intestinal hormone availability, impacting systemic insulin resistance. Understanding these pathways might identify mechanisms underlying treatments for insulin resistance, such as metformin and bariatric surgery, or aid in developing new therapies and vaccination approaches. Here, we highlight evolving concepts centered on intestinal immunity, diet, and the microbiota to provide a working model of obesity-related metabolic disease.


Subject(s)
Gastrointestinal Microbiome/immunology , Metabolic Diseases/immunology , Metabolic Diseases/metabolism , Obesity/metabolism , Animals , B-Lymphocytes/immunology , Cytokines/metabolism , Diet Therapy , Humans , Immune System/cytology , Immune System/metabolism , Inflammation/immunology , Inflammation/metabolism , Insulin Resistance/immunology , Metabolic Diseases/microbiology , Metabolic Diseases/therapy , Obesity/diet therapy , Obesity/immunology , Obesity/therapy , T-Lymphocytes/immunology
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