Metabolic syndrome, insulin resistance, and roles of inflammation--mechanisms and therapeutic targets

Association of metabolic syndrome and sarcopenia with all-cause and cardiovascular mortality: a prospective cohort study based on the NHANES

Background

Metabolic syndrome (MetS) and sarcopenia (SP) have emerged as significant public health concerns in contemporary societies, characterized by shared pathophysiological mechanisms and interrelatedness, leading to profound health implications. In this prospective cohort study conducted within a US population, we aimed to examine the influence of MetS and SP on all-cause and cardiovascular mortality.

Methods

This study analyzed data from the National Health and Nutrition Examination Survey (NHANES) III for the years 1999-2006 and 2011-2018, and death outcomes were ascertained by linkage to National Death Index (NDI) records through December 31, 2019. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for all-cause and cardiovascular mortality. In addition, subgroup and sensitivity analyses were conducted to test the robustness of the results.

Results

Over a median follow-up period of 13.3 years (95% CI: 12.8-13.8), 1714 deaths were observed. The groups characterized by MetS-/SP+, MetS+/SP-, and MetS+/SP+ exhibited higher all-cause mortality rates in comparison to the MetS-/SP- group, with the MetS+/SP+ group (HR 1.76, 95% CI: 1.37-2.25) displaying the highest all-cause mortality. Increased cardiovascular mortality was observed in the MetS+/SP- (HR 1.84, 95% CI: 1.24-2.72), and MetS+/SP+ groups (HR 2.39, 95% CI: 1.32-4.35) compared to the MetS-/SP- group, whereas it was not statistically significant in the MetS-/SP+ group. However, among males and individuals aged < 60, the presence of both MetS and SP (MetS+/SP+ group) was found to be significantly associated with a higher risk of all-cause and cardiovascular mortality.

Conclusion

The coexistence of MetS and SP increased the risk of all-cause and cardiovascular mortality, particularly in males and in nonelderly populations. Individuals with either MetS or SP may require more careful management to prevent the development of other diseases and thereby reduce mortality.

Modification of incident cancer risk with changes in metabolic syndrome status: A prospective cohort study in Taiwan

PURPOSE

We aimed to investigate the effect of altered metabolic syndrome (MetS) status on cancer risk.

METHODS

From 2002 through 2008 of the Taiwan MJ cohort, there were 111,616 adults who had repeated MetS measurements performed 3.3 years apart and were followed up for cancer incidence over 11.8 years. Cancer was confirmed based on histopathological reports.

RESULTS

Participants were categorized as MetS-free (n = 80,409; no MetS at the first or last health screening), MetS-developed (n = 9833; MetS absence at the first screening and presence at the last screening), MetS-recovered (n = 8958; MetS presence at the first screening and absence at the last screening), and MetS-persisted (n = 12,416; MetS presence at the first and last screenings). We used the Fine-Gray sub-distribution method, with death as competing risk, to determine the association between MetS changes and incident cancer risk. During 1320,796 person-years of follow-up, 5862 individuals developed cancer. The incidence rate of cancer per 1000 person-years was 3.89 in the MetS-free, 5.26 in MetS-developed, 4.61 in MetS-recovered, and 7.33 in MetS-persisted groups (P < .001). Compared with the MetS-free group, MetS-persisted individuals had a higher risk of incident cancer.

CONCLUSIONS

Persistent MetS was found to be associated with a high risk of incident cancer.

miR-335-3p improves type II diabetes mellitus by IGF-1 regulating macrophage polarization

Previous studies have found that miR-335 is highly expressed in type II diabetes mellitus (T2DM) models and is related to insulin secretion, but there are few studies on the regulatory effects of miR-335-3p on insulin resistance and macrophage polarization in T2DM patients. This study aims to explore the effects of miR-335-3p on insulin resistance and macrophage polarization in T2DM patients. Blood glucose (insulin tolerance tests, glucose tolerance tests) and body weight of the T2DM model were measured; macrophages from adipose tissue were isolated and cultured, and the number of macrophages was detected by F4/80 immunofluorescence assay; the Real-time quantitative polymerase chain reaction (qPCR) assay and Western blot assay were used to detect the miR-335-3p expression levels, insulin-like growth factor 1 (IGF-1), M1-polarizing genes (inducible nitric oxide synthase [iNOS] and TNF-α) as well as M2-polarizing genes (IL-10 and ARG-1). The targeting link between miR-335-3p and IGF-1 was confirmed using bioinformatics and dual luciferase assay. The results showed that miR-335-3p expression level in adipose tissue of the T2DM model was significantly decreased, and the mice's body weight and blood glucose levels dropped considerably, miR-335-3p inhibited the number of macrophages, inhibiting the iNOS and TNF-α relative mRNA expression levels, and up-regulated the IL-10 and ARG-1 relative mRNA expression levels, miR-335-3p negatively regulated target gene IGF-1, IGF-1 significantly increased the iNOS and TNF-α mRNA and protein expression levels, decreasing the IL-10 and ARG-1 mRNA and protein expression levels, indicating that miR-335-3p could affect the T2DM process by regulating macrophage polarization via IGF-1.

The Metabolic Syndrome, a Human Disease

This review focuses on the question of metabolic syndrome (MS) being a complex, but essentially monophyletic, galaxy of associated diseases/disorders, or just a syndrome of related but rather independent pathologies. The human nature of MS (its exceptionality in Nature and its close interdependence with human action and evolution) is presented and discussed. The text also describes the close interdependence of its components, with special emphasis on the description of their interrelations (including their syndromic development and recruitment), as well as their consequences upon energy handling and partition. The main theories on MS's origin and development are presented in relation to hepatic steatosis, type 2 diabetes, and obesity, but encompass most of the MS components described so far. The differential effects of sex and its biological consequences are considered under the light of human social needs and evolution, which are also directly related to MS epidemiology, severity, and relations with senescence. The triggering and maintenance factors of MS are discussed, with especial emphasis on inflammation, a complex process affecting different levels of organization and which is a critical element for MS development. Inflammation is also related to the operation of connective tissue (including the adipose organ) and the widely studied and acknowledged influence of diet. The role of diet composition, including the transcendence of the anaplerotic maintenance of the Krebs cycle from dietary amino acid supply (and its timing), is developed in the context of testosterone and β-estradiol control of the insulin-glycaemia hepatic core system of carbohydrate-triacylglycerol energy handling. The high probability of MS acting as a unique complex biological control system (essentially monophyletic) is presented, together with additional perspectives/considerations on the treatment of this 'very' human disease.

Recent research progress on metabolic syndrome and risk of Parkinson's disease

Parkinson's disease (PD) is one of the most widespread neurodegenerative diseases. PD is associated with progressive loss of substantia nigra dopaminergic neurons, including various motor symptoms (e.g., bradykinesia, rigidity, and resting tremor), as well as non-motor symptoms (e.g., cognitive impairment, constipation, fatigue, sleep disturbance, and depression). PD involves multiple biological processes, including mitochondrial or lysosomal dysfunction, oxidative stress, insulin resistance, and neuroinflammation. Metabolic syndrome (MetS), a collection of numerous connected cerebral cardiovascular conditions, is a common and growing public health problem associated with many chronic diseases worldwide. MetS components include central/abdominal obesity, systemic hypertension, diabetes, and atherogenic dyslipidemia. MetS and PD share multiple pathophysiological processes, including insulin resistance, oxidative stress, and chronic inflammation. In recent years, MetS has been linked to an increased risk of PD, according to studies; however, the specific mechanism remains unclear. Researchers also found that some related metabolic therapies are potential therapeutic strategies to prevent and improve PD. This article reviews the epidemiological relationship between components of MetS and the risk of PD and discusses the potentially relevant mechanisms and recent progress of MetS as a risk factor for PD. Furthermore, we conclude that MetS-related therapies are beneficial for the prevention and treatment of PD.

Differential Roles of Interleukin-6 in Severe Acute Respiratory Syndrome-Coronavirus-2 Infection and Cardiometabolic Diseases

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection can lead to a cytokine storm, unleashed in part by pyroptosis of virus-infected macrophages and monocytes. Interleukin-6 (IL-6) has emerged as a key participant in this ominous complication of COVID-19. IL-6 antagonists have improved outcomes in patients with COVID-19 in some, but not all, studies. IL-6 signaling involves at least 3 distinct pathways, including classic-signaling, trans-signaling, and trans-presentation depending on the localization of IL-6 receptor and its binding partner glycoprotein gp130. IL-6 has become a therapeutic target in COVID-19, cardiovascular diseases, and other inflammatory conditions. However, the efficacy of inhibition of IL-6 signaling in metabolic diseases, such as obesity and diabetes, may depend in part on cell type-dependent actions of IL-6 in controlling lipid metabolism, glucose uptake, and insulin sensitivity owing to complexities that remain to be elucidated. The present review sought to summarize and discuss the current understanding of how and whether targeting IL-6 signaling ameliorates outcomes following SARS-CoV-2 infection and associated clinical complications, focusing predominantly on metabolic and cardiovascular diseases.

Elevation in white blood cell count and development of hyper LDL cholesterolemia

To investigate the relationship between white blood cell (WBC) count and incidence of hyper-low-density lipoprotein (LDL) cholesterolemia in a population-based longitudinal study. This is a retrospective study using data of annual health check-ups for residents of Iki City, Japan. A total of 3312 residents (≥ 30 years) without hyper-LDL cholesterolemia at baseline were included in this analysis. Primary outcome was incidence of hyper-LDL cholesterolemia (LDL cholesterol levels ≥ 3.62 mmol/L and/or use of lipid lowering drugs). During follow-up (average 4.6 years), 698 participants development of hyper-LDL cholesterolemia (incidence 46.8 per 1000 person-years). Higher incidence of hyper-LDL cholesterolemia was observed among participants with higher leukocyte count (1st quartile group: 38.5, 2nd quartile group: 47.7, 3rd quartile group: 47.3, and 4th quartile group: 52.4 per 1,000 person-years, P = 0.012 for trend). Statistically significant relation was observed even after adjustment for age, gender, smoking, alcohol intake, leisure-time exercise, obesity, hypertension and diabetes: hazard ratio 1.24 (95% confidence interval 0.99 to 1.54) for 2nd quartile group, 1.29 (1.03-1.62) for 3rd quartile group and 1.39 (1.10-1.75) for 4th quartile group, compared with 1st quartile group (P for trend = 0.006). Increased WBC count was related to incidence of hyper-LDL cholesterolemia in general Japanese population.

Epidermal Growth Factor Receptor in Hepatic Endothelial Cells Suppresses MCP-1-Dependent Monocyte Recruitment in Diabetes

Insulin resistance is a compromised response to insulin in target tissues such as liver. Emerging evidence shows that vascular endothelial cells (ECs) are critical in mediating glucose metabolism. However, how liver ECs can regulate inflammation in the setting of insulin resistance is still unknown. Using genome-wide transcriptome analysis of ECs isolated from diabetic mice, we found enrichment of the genes involved in epidermal growth factor receptor (Egfr) signaling. In line with this, hepatic sinusoidal ECs in diabetic mice had elevated levels of Egfr expression. Interestingly, we found an increased number of hepatic myeloid cells, especially macrophages, and systemic glucose intolerance in Cdh5Cre/+Egfrfl/fl mice lacking Egfr in ECs compared with littermate control mice with type II diabetes. Egfr deficiency upregulated the expression of MCP-1 in hepatic sinusoidal ECs. This resulted in augmented monocyte recruitment and macrophage differentiation in Cdh5Cre/+Egfrfl/fl mice compared with littermate control mice as determined by a mouse model of parabiosis. Finally, MCP-1 neutralization and hepatic macrophage depletion in Cdh5Cre/+Egfrfl/fl mice resulted in a reduced number of hepatic macrophages and ameliorated glucose intolerance compared with the control groups. Collectively, these results demonstrate a protective endothelial Egfr signaling in reducing monocyte-mediated hepatic inflammation and glucose intolerance in type II diabetic mice.

Effect of propolis on mood, quality of life, and metabolic profiles in subjects with metabolic syndrome: a randomized clinical trial

Metabolic syndrome (MeS) is a common multifaceted disorder. Plants contain antioxidant bioactive compounds, which are beneficial to improve the health condition of patients with MeS. Propolis is a hive natural product that is composed of various constituent. We aimed to assess the effects of Iranian propolis as a natural and safe agent on indicators of MeS, quality of life and mood status in individuals with MeS. In total, 66 interested eligible patients recruited to the present study. Participants were randomly assigned to consume a tablet at dose of 250 mg of propolis extract, twice daily for 12 weeks or placebo. Propolis supplementation could lead to a significant reduction in waist circumference (WC), increase in physical functioning, general health and the overall score of SF-36 compared with placebo group (P-value < 0.05). However, no significant differences were observed regarding other anthropometric indices and biochemical parameters between two groups (P-value > 0.05). The current study indicated that propolis can be effective in decreasing WC and improving physical health and quality of life, while had no significant effects on other components of MeS among subjects with this syndrome. Clinical trials registration Iran Registry of Clinical Trials.ir IRCT20121216011763N49, registration date 23/12/2020.

The Synergistic Action of Metformin and Glycyrrhiza uralensis Fischer Extract Alleviates Metabolic Disorders in Mice with Diet-Induced Obesity

Metformin, an antidiabetic drug, and Glycyrrhiza uralensis Fischer (GU), an oriental medicinal herb, have been reported to exert anti-obesity effects. This study investigated the synergistic action of metformin and GU in improving diet-induced obesity. Mice were fed a normal diet, a high-fat diet (HFD), or HFD + 0.015% GU water extract for 8 weeks. The HFD and GU groups were then randomly divided into two groups and fed the following diets for the next 8 weeks: HFD with 50 mg/kg metformin (HFDM) and GU with 50 mg/kg metformin (GUM). GUM prevented hepatic steatosis and adiposity by suppressing expression of mRNAs and enzyme activities related to lipogenesis in the liver and upregulating the expression of adipocyte mRNAs associated with fatty acid oxidation and lipolysis, and as a result, improved dyslipidemia. Moreover, GUM improved glucose homeostasis by inducing glucose uptake in tissues and upregulating mRNA expressions associated with glycolysis in the liver and muscle through AMP-activated protein kinase activation. GUM also improved inflammation by increasing antioxidant activity in the liver and erythrocytes and decreasing inflammatory cytokine productions. Here, we demonstrate that GU and metformin exert synergistic action in the prevention of obesity and its complications.

Machine learning of plasma metabolome identifies biomarker panels for metabolic syndrome: findings from the China Suboptimal Health Cohort

BACKGROUND

Metabolic syndrome (MetS) has been proposed as a clinically identifiable high-risk state for the prediction and prevention of cardiovascular diseases and type 2 diabetes mellitus. As a promising "omics" technology, metabolomics provides an innovative strategy to gain a deeper understanding of the pathophysiology of MetS. The study aimed to systematically investigate the metabolic alterations in MetS and identify biomarker panels for the identification of MetS using machine learning methods.

METHODS

Nuclear magnetic resonance-based untargeted metabolomics analysis was performed on 1011 plasma samples (205 MetS patients and 806 healthy controls). Univariate and multivariate analyses were applied to identify metabolic biomarkers for MetS. Metabolic pathway enrichment analysis was performed to reveal the disturbed metabolic pathways related to MetS. Four machine learning algorithms, including support vector machine (SVM), random forest (RF), k-nearest neighbor (KNN), and logistic regression were used to build diagnostic models for MetS.

RESULTS

Thirteen significantly differential metabolites were identified and pathway enrichment revealed that arginine, proline, and glutathione metabolism are disturbed metabolic pathways related to MetS. The protein-metabolite-disease interaction network identified 38 proteins and 23 diseases are associated with 10 MetS-related metabolites. The areas under the receiver operating characteristic curve of the SVM, RF, KNN, and logistic regression models based on metabolic biomarkers were 0.887, 0.993, 0.914, and 0.755, respectively.

CONCLUSIONS

The plasma metabolome provides a promising resource of biomarkers for the predictive diagnosis and targeted prevention of MetS. Alterations in amino acid metabolism play significant roles in the pathophysiology of MetS. The biomarker panels and metabolic pathways could be used as preventive targets in dealing with cardiometabolic diseases related to MetS.

Angiotensin II and human obesity. A narrative review of the pathogenesis

Angiotensin II (Ang II) is a hormone and the main effector of the renin-angiotensin system (RAS). This peptide has crucial pathophysiologi-cal effects on hypertension, cardiac hypertrophy, endothelial proliferation, in-flammation and tissue remodelling through G protein-coupled receptors. The pro-inflammatory role of Ang II has been reported in various inflammatory pro-cesses. Obesity is linked to a chronic inflammatory process which in turn is the cause of some of its morbidities. Ang II is related to the comorbidities related to the comorbidities of obesity, which include alterations in the heart, kid-ney, hypertension and coagulation. In this regard, activation of AT1 receptors by Ang II can induce an inflammatory process mediated by the transcription factor NF-kB, triggering inflammation in various systems that are related to the comorbidities observed in obesity. The aim of this review was to highlight the pro-inflammatory effects of Ang II and the alterations induced by this hor-mone in various organs and systems in obesity. The search was done since 1990 through Medline, EMBASE and PubMed, using the keywords: angiotensin II; an-giotensin II, obesity; angiotensin II, kidney, obesity; angiotensin II, coagulation, obesity; angiotensin II, inflammation, obesity; angiotensin II, adipose tissue, obesity; angiotensin II, hypertension, obesity; angiotensin II, insulin resistance, obesity; angiotensin II, adiponectin, leptin, obesity; angiotensin II, COVID-19, obesity. Angiotensin II through its interaction with its AT1 receptor, can induce alterations in diverse systems that are related to the comorbidities observed in obesity. Therapeutic strategies to decrease the production and action of Ang II could improve the clinical conditions in individuals with obesity.

Associations between heart rate variability and maximal fat oxidation in two different cohorts of healthy sedentary adults

BACKGROUND AND AIMS

Resting heart rate variability (HRV) and maximal fat oxidation (MFO) during exercise are both considered as a noninvasive biomarkers for early detection of cardiovascular risk factors. Thus, this study aimed to analyze the relationship between resting HRV parameters and MFO during exercise, and the intensity of exercise that elicit MFO (Fat_max) in healthy sedentary adults.

METHODS AND RESULTS

A total of 103 healthy young adults (22.2 ± 2.3 years old, 67% female; from the ACTIBATE cohort) and 67 healthy middle-aged adults (53.1 ± 5.0 years old, 52% female; from the FIT-AGEING cohort) were included in this cross-sectional study. HRV was assessed using a Polar RS800CX heart rate monitor, while MFO and Fat_max were determined during a graded exercise treadmill test using indirect calorimetry. No significant associations were observed for healthy young adults (standardized β coefficients ranged from -0.063 to 0.094, and all P ≥ 0.347) and for middle-aged adults (standardized β coefficients ranged from -0.234 to 0.090, and all P ≥ 0.056). Nevertheless, only a weak association was observed between one HRV parameter in time-domain (the percentage of R-R intervals that shows a difference higher than 50 ms [pNN50]) and MFO in the cohort of middle-aged adults (β coefficient = -0.279, and P = 0.033).

CONCLUSION

The results of this study suggest that resting HRV parameters are not associated with MFO and Fat_max during exercise in two independent cohorts of healthy sedentary young and middle-aged adults, respectively.

Extracellular vesicles and particles impact the systemic landscape of cancer

Intercellular cross talk between cancer cells and stromal and immune cells is essential for tumor progression and metastasis. Extracellular vesicles and particles (EVPs) are a heterogeneous class of secreted messengers that carry bioactive molecules and that have been shown to be crucial for this cell-cell communication. Here, we highlight the multifaceted roles of EVPs in cancer. Functionally, transfer of EVP cargo between cells influences tumor cell growth and invasion, alters immune cell composition and function, and contributes to stromal cell activation. These EVP-mediated changes impact local tumor progression, foster cultivation of pre-metastatic niches at distant organ-specific sites, and mediate systemic effects of cancer. Furthermore, we discuss how exploiting the highly selective enrichment of molecules within EVPs has profound implications for advancing diagnostic and prognostic biomarker development and for improving therapy delivery in cancer patients. Altogether, these investigations into the role of EVPs in cancer have led to discoveries that hold great promise for improving cancer patient care and outcome.

Effect of HEAT therapy in patiEnts with type 2 Diabetes mellitus (HEATED): protocol for a randomised controlled trial

INTRODUCTION

The burden of type 2 diabetes mellitus (T2DM) is increasing worldwide. Heat therapy has been found effective in improving glycaemic control. However, to date, there is a lack of randomised controlled studies investigating the efficacy of heat therapy in T2DM. Therefore, we aim to investigate whether heat therapy with natural thermal mineral water can improve glycaemic control in patients with T2DM.

METHODS AND ANALYSIS

The HEAT therapy in patiEnts with type 2 Diabetes mellitus (HEATED) Study is a single-centre, two-arm randomised controlled trial being conducted at Harkány Thermal Rehabilitation Centre in Hungary. Patients with T2DM will be randomly assigned to group A (bath sessions in 38°C natural thermal mineral water) and group B (baths in thermoneutral water (30°C-32°C)). Both groups will complete a maximum of 5 weekly visits, averaging 50-60 visits over the 12-week study. Each session will last 30 min, with a physical check-up before the bath. At baseline, patients' T2DM status will be investigated thoroughly. Possible microvascular and macrovascular complications of T2DM will be assessed with physical and laboratory examinations. The short form-36 questionnaire will assess the quality of life. Patients will also be evaluated at weeks 4, 8 and 12. The primary endpoint will be the change of glycated haemoglobin from baseline to week 12. An estimated 65 patients will be enrolled per group, with a sample size re-estimation at the enrolment of 50% of the calculated sample size.

ETHICS AND DISSEMINATION

The study has been approved by the Scientific and Research Ethics Committee of the Hungarian Medical Research Council (818-2/2022/EÜIG). Written informed consent is required from all participants. We will disseminate our results to the medical community and will publish our results in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, NCT05237219.

Brown adipose tissue-derived MaR2 contributes to cold-induced resolution of inflammation

Obesity induces chronic inflammation resulting in insulin resistance and metabolic disorders. Cold exposure can improve insulin sensitivity in humans and rodents, but the mechanisms have not been fully elucidated. Here, we find that cold resolves obesity-induced inflammation and insulin resistance and improves glucose tolerance in diet-induced obese mice. The beneficial effects of cold exposure on improving obesity-induced inflammation and insulin resistance depend on brown adipose tissue (BAT) and liver. Using targeted liquid chromatography with tandem mass spectrometry, we discovered that cold and β3-adrenergic stimulation promote BAT to produce maresin 2 (MaR2), a member of the specialized pro-resolving mediators of bioactive lipids that play a role in the resolution of inflammation. Notably, MaR2 reduces inflammation in obesity in part by targeting macrophages in the liver. Thus, BAT-derived MaR2 could contribute to the beneficial effects of BAT activation in resolving obesity-induced inflammation and may inform therapeutic approaches to combat obesity and its complications.

Defects of Nutrient Signaling and Autophagy in Neurodegeneration

Neurons are post-mitotic cells that allocate huge amounts of energy to the synthesis of new organelles and molecules, neurotransmission and to the maintenance of redox homeostasis. In neurons, autophagy is not only crucial to ensure organelle renewal but it is also essential to balance nutritional needs through the mobilization of internal energy stores. A delicate crosstalk between the pathways that sense nutritional status of the cell and the autophagic processes to recycle organelles and macronutrients is fundamental to guarantee the proper functioning of the neuron in times of energy scarcity. This review provides a detailed overview of the pathways and processes involved in the balance of cellular energy mediated by autophagy, which when defective, precipitate the neurodegenerative cascade of Parkinson’s disease, frontotemporal dementia, amyotrophic lateral sclerosis or Alzheimer’s disease.

Obesogenic and diabetic effects of CD44 in mice are sexually dimorphic and dependent on genetic background

Introduction

CD44 is a candidate gene for obesity and diabetes development and may be a critical mediator of a systemic inflammation associated with obesity and diabetes.

Methods

We investigated the relationship of CD44 with obesity in CD44-deficient mice challenged with a high-fat diet.

Results

In mice fed a diet high in fat, cholesterol, and sucrose for 12 weeks fat mass accumulation was reduced in CD44-deficient mice bred onto both a C57BL/6J and the naturally TLR deficient C3H/HeJ background. Reduced fat mass could not be attributed to lower food intake or an increase in energy expenditure as measured by indirect calorimetry. However, we observed a 40–60% lower mRNA expression of the inflammation markers, F4/80, CD11b, TNF-α, and CD14, in adipose tissue of CD44-deficient mice on the C57BL/6J background but not the C3H/HeJ background, perhaps indicating that alternative factors may be affecting adiposity in this model. Measures of hepatic steatosis and insulin sensitivity were improved in CD44-deficient mice on a C57BL/6J but not in the C3H/HeJ mice. These results were highly sexually dimorphic as there were no detectable effects of CD44 inactivation in female mice on a C57BL/6 J or C3H/HeJ background.

Conclusion

CD44 was associated with adiposity, liver fat, and glucose in male mice. However, the effects of CD44 on obesity may be independent of TLR4 signaling.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13293-022-00426-2.

Interleukin 6 in diabetes, chronic kidney disease and cardiovascular disease: mechanisms and therapeutic perspectives

INTRODUCTION

Diabetes, chronic kidney disease (CKD) and cardiovascular disease (CVD) are cardiometabolic diseases that remain amongst the leading causes of morbidity and premature mortality. Here, we review the current understanding of how anti-inflammatory intervention via inhibition of the pro-inflammatory but pleiotropic cytokine interleukin (IL) 6 may benefit patients with these or related diseases or complications.

AREAS COVERED

Based on a PubMed literature search, this review integrates and contextualizes evidence regarding the clinical utility of anti-IL-6 intervention in the treatment of cardiometabolic diseases, as well as of the associated condition non-alcoholic hepatosteatosis.

EXPERT OPINION

Evidence implicates the pro-inflammatory effects of IL-6 in the pathophysiology of diabetes, CKD and CVD. Thus, targeting the IL-6 pathway holds a therapeutic potential in these cardiometabolic disorders. However, because IL-6 has multiple homeostatic roles, antagonizing this cytokine may be associated with side effects such as increased risk of infection as seen with other anti-inflammatory drugs. Additional studies are required to establish the benefit-risk profile of anti-IL-6 intervention in the cardiometabolic diseases, whilst also considering alternative interventions such as lifestyle changes. IL-6 is also elevated in NASH, but the clinical usefulness of targeting IL-6 in this hepatic disorder remains largely unexplored.

Sarcopenia Is Associated with Metabolic Syndrome in Korean Adults Aged over 50 Years: A Cross-Sectional Study

This study assessed the association between sarcopenia and metabolic syndrome in Korean adults aged over 50 years. The study obtained data from the Korea National Health and Nutrition Examination Survey (KNHANES, 2008–2011), a cross-sectional and nationally representative survey conducted by the Korean Centers for Disease Control and Prevention. Among the 8363 participants included in this study, the prevalence rate of sarcopenia according to metabolic syndrome was stratified by sex. Crude odds ratios not adjusted for any variables were 1.827 (1.496–2.231) in males, 2.189 (1.818–2.635) in females, and 2.209 (1.766–2.331) in total participants compared with non-sarcopenia. Model 3, which was adjusted for all variables that could affect sarcopenia and metabolic syndrome, showed significant increases in the odds ratios, to 1.957 (1.587–2.413) in males, 1.779 (1.478–2.141) in females, and 1.822 (1.586–2.095) for total participants. The results suggest that the association between sarcopenia and metabolic syndrome is significant in Korean adults.

Impact of Metabolic Risk Factors on COVID-19 Clinical Outcomes: An Extensive Review

BACKGROUND

Cardiovascular (CV) risk factors, particularly cardiometabolic, seem to be associated with heightened severity and increased morbimortality in patients infected with the novel Coronavirus disease-2019 (COVID-19).

METHODS

A thorough scoping review was conducted to elucidate and summarize the latest evidence for the effects of adverse cardiac metabolic profiles on the severity, morbidity, and prognosis of COVID-19 infection.

RESULTS

The pathophysiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is complex, being characterized by viral-induced immune dysregulation and hypercytokinemia, particularly in patients with critical disease, evolving with profound endothelial dysfunction, systemic inflammation, and prothrombotic state. Moreover, cardiovascular comorbidities such as diabetes are the most prevalent amongst individuals requiring hospitalization, raising concerns towards the clinical evolution and prognosis of these patients. The chronic proinflammatory state observed in patients with cardiovascular risk factors may contribute to the immune dysregulation mediated by SARS-CoV-2, favoring more adverse clinical outcomes and increased severity. Cardiometabolism is defined as a combination of interrelated risk factors and metabolic dysfunctions such as dyslipidemia, insulin resistance, impaired glucose tolerance, and central adiposity, which increase the likelihood of vascular events, being imperative to specifically analyze its clinical association with COVID-19 outcomes.

CONCLUSION

DM and obesity appears to be important risk factors for severe COVID-19. The chronic proinflammatory state observed in patients with excess visceral adipose tissue (VAT) possibly augments COVID-19 immune hyperactivity leading to more adverse clinical outcomes in these patients.

OUP accepted manuscript

Type 2 diabetes is a complex, systemic disease affected by both genetic and environmental factors. Previous research has identified genetic variants associated with type 2 diabetes risk; however, gene regulatory changes underlying progression to metabolic dysfunction are still largely unknown. We investigated RNA expression changes that occur during diabetes progression using a two-stage approach. In our discovery stage, we compared changes in gene expression using two longitudinally collected blood samples from subjects whose fasting blood glucose transitioned to a level consistent with type 2 diabetes diagnosis between the time points against those who did not with a novel analytical network approach. Our network methodology identified 17 networks, one of which was significantly associated with transition status. This 822-gene network harbors many genes novel to the type 2 diabetes literature but is also significantly enriched for genes previously associated with type 2 diabetes. In the validation stage, we queried associations of genetically determined expression with diabetes-related traits in a large biobank with linked electronic health records. We observed a significant enrichment of genes in our identified network whose genetically determined expression is associated with type 2 diabetes and other metabolic traits and validated 31 genes that are not near previously reported type 2 diabetes loci. Finally, we provide additional functional support, which suggests that the genes in this network are regulated by enhancers that operate in human pancreatic islet cells. We present an innovative and systematic approach that identified and validated key gene expression changes associated with type 2 diabetes transition status and demonstrated their translational relevance in a large clinical resource.

Linagliptin in Combination With Metformin Ameliorates Diabetic Osteoporosis Through Modulating BMP-2 and Sclerostin in the High-Fat Diet Fed C57BL/6 Mice

BACKGROUND

Diabetic osteoporosis is a poorly managed serious skeletal complication, characterized by high fracture risk, increased bone resorption, reduced bone formation, and disrupted bone architecture. There is a need to investigate drugs that can improve bone health along with managing glycemic control. DPP-4 inhibitors and metformin have proven benefits in improving bone health. Here, we investigated the effects of linagliptin, a DPP inhibitor, and metformin alone and in combination to treat diabetic osteoporosis in high-fat-fed mice.

METHODS

C57BL/6 mice were kept on the high-fat diet (HFD) for 22 weeks to induce diabetic osteoporosis. Linagliptin (10mg/Kg), metformin (150mg/Kg), and their combination were orally administered to the diabetic mice from the 18^th-22^nd week. Femur and tibial bone microarchitecture together with bone mineral density (BMD) were evaluated using µCT and histopathological changes were assessed. Further, bone turnover biomarkers namely bone morphogenetic protein-2 (BMP-2), sclerostin, tartrate-resistant acid phosphatase (TRAP), osteocalcin, alkaline phosphatase (ALP), calcium, and pro-inflammatory cytokines were assessed. Additionally, metabolic parameters including body weight, fasting blood glucose (FBG), glucose & insulin tolerance, lipids profile, and leptin were measured.

RESULTS

HFD feeding resulted in impaired bone microarchitecture, reduced BMD, distorted bone histology, and altered bone turnover biomarkers as indicated by the significant reduction in bone ALP, BMP-2, osteocalcin, and an increase in sclerostin, TRAP, and serum calcium. Interestingly, treatment with linagliptin and its combination with metformin significantly reverted the impaired bone architecture, BMD, and positively modulated bone turnover biomarkers, while metformin alone did not exhibit any significant improvement. Further, HFD induced diabetes and metabolic abnormalities (including an increase in body weight, FBG, impaired glucose and insulin tolerance, leptin, triglycerides, cholesterol), and pro-inflammatory cytokines (TNF-alpha and IL-1β) were successfully reversed by treatment with linagliptin, metformin, and their combination.

CONCLUSION

Linagliptin and its combination with metformin successfully ameliorated diabetic osteoporosis in HFD-fed mice possibly through modulation of BMP-2 and sclerostin. The study provides the first evidence for the possible use of linagliptin and metformin combination for managing diabetic osteoporosis.

On the Immunometabolic Role of NF-κB in Adipocytes

Two decades of research have established that Nuclear Factor-κB (NF-κB) signaling plays a critical role in reprogramming the fat cell transcriptome towards inflammation in response to overnutrition and metabolic stress. Several groups have suggested that inhibition of NF-κB signaling could have metabolic benefits for obesity-associated adipose tissue inflammation. However, two significant problems arise with this approach. The first is how to deliver general NF-κB inhibitors into adipocytes without allowing these compounds to disrupt normal functioning in cells of the immune system. The second issue is that general inhibition of canonical NF-κB signaling in adipocytes will likely lead to a massive increase in adipocyte apoptosis under conditions of metabolic stress, leading full circle into a secondary inflammation (However, this problem may not be true for non-canonical NF-κB signaling.). This review will focus on the research that has examined canonical and non-canonical NF-κB signaling in adipocytes, focusing on genetic studies that examine loss-of-function of NF-κB specifically in fat cells. Although the development of general inhibitors of canonical NF-κB signaling seems unlikely to succeed in alleviating adipose tissue inflammation in humans, the door remains open for more targeted therapeutics. In principle, these would include compounds that interrogate NF-κB DNA binding, protein-protein interactions, or post-translational modifications that partition NF-κB activity towards some genes and away from others in adipocytes. I also discuss the possibility for inhibitors of non-canonical NF-κB signaling to realize success in mitigating fat cell dysfunction in obesity. To plant the seeds for such approaches, much biochemical “digging” in adipocytes remains; this includes identifying—in an unbiased manner–NF-κB direct and indirect targets, genomic DNA binding sites for all five NF-κB subunits, NF-κB protein-protein interactions, and post-translational modifications of NF-κB in fat cells.

Green tea aqueous extract (GTAE) prevents high-fat diet-induced obesity by activating fat browning

Adipose browning leads to increased energy expenditure and reduced adiposity and has, therefore, become an attractive therapeutic strategy for obesity. In this study, we elucidated the effect of green tea aqueous extract (GTAE) on the browning of inguinal white adipose tissue (Ing-WAT) and brown adipose tissue (BAT) in high-fat diet (HFD)-fed mice. The main phytochemical components identified in GTAE through high-performance liquid chromatography (HPLC) included (-)-gallocatechin, (-)-epigallocatechin, (-)-catechin, (-)-epigallocatechin-3-gallate, caffeine, (-)-epicatechin, (-)-gallocatechin gallate, and (-)-epicatechin-3-gallate. Daily supplementation with 1% GTAE for 12 weeks markedly reduced bodyweight gain, systemic inflammation, oxidative stress, and improved insulin resistance. Additionally, histological analysis revealed that dietary supplementation with 1% GTAE reversed HFD-induced adipocyte size and hepatic steatosis. These effects were associated with activation of browning in the Ing-WAT and BAT, which mediate systemic metabolic dysfunction in HFD-fed mice. Taken together, our data support the use of GTAE, a natural product, for the attenuation of obesity through the activation of fat browning.

Resolvin D1 reduces inflammation in co-cultures of primary human macrophages and adipocytes by triggering macrophages

Obesity leads to chronic inflammation of the adipose tissue which is tightly associated with the metabolic syndrome, type 2 diabetes and cardiovascular disease. Inflammation of the adipose tissue is mainly characterized by the presence of crown-like structures composed of inflammatory macrophages in the neighborhood of adipocytes. Resolvin D1 (RvD1), a potent anti-inflammatory and pro-resolving lipid mediator derived from the omega-3 fatty acid docosahexaenoic acid, has been shown to reduce the inflammatory tone of adipose tissue in animal models but the underlying mechanism is not clear. We investigated the effect of RvD1 on the inflammatory state of a human co-culture system of adipocytes and macrophages. For this, human mesenchymal stem cells were differentiated into mature adipocytes and overlaid with human primary macrophages. In this co-culture, 10-500 nM RvD1 dose-dependently reduced the secretion of the pro-inflammatory cytokine IL-6 (-21%) and its soluble receptor IL-6Rα (-22%), of the chemokine MCP-1 (-13%), and of the adipokine leptin (-22%). Similarly, we observed a reduction in secretion of the soluble receptor IL-6Rα (-20%), and TNF-α (-11%) when macrophages alone were treated with RvD1, while no change of cytokine secretion was observed when adipocytes were treated with RvD1. We conclude that RvD1 polarizes macrophages to an anti-inflammatory phenotype, which in turn modulates inflammation in adipocytes.

Hemogram-based decision tree for predicting the metabolic syndrome and cardiovascular diseases in the elderly

BACKGROUND

This study aimed to build a hemogram-based decision tree to evaluate the association between current probability of metabolic syndrome (MetS) and prediction of future hypertension, type 2 diabetes and cardiovascular diseases (CVD) risk.

METHODS

A total of 40 395 elder participants (≥60 years) were enrolled in a standard health examination program in Taiwan from January 1999 to December 2014. A decision tree classification of the presence or absence of MetS at baseline, using age, sex and hemogram (white blood cell, hemoglobin and platelet) as independent variables, was conducted for the randomly assigned training (70%) and validation (30%) groups. Participants without MetS at baseline (n = 25 643) were followed up to observe whether they developed MetS, hypertension, type 2 diabetes or CVD in the future.

RESULTS

Modest accuracy of the decision tree in the training and validation groups with area under the curves of 0.653 and 0.652, respectively, indicated an acceptable generalizability of results. The predicted probability of baseline MetS was obtained from decision tree analysis. Participants without MetS at baseline were categorized into three equally sized groups according to the predicted probability. Participants in the third tertile had significantly higher risks of future MetS (hazard ratio 1.40, 95% confidence interval 1.25-1.58); type 2 diabetes (1.46, 1.17-1.83); hypertension (1.14, 1.01-1.28); and CVD (1.21, 1.01-1.44), compared with those in the first tertile.

CONCLUSIONS

Execution of hemogram-based decision tree analysis can assist in early identification and prompt management of elderly patients at a high risk of future hypertension, type 2 diabetes and CVD.

Genetic Deficiency of TRAF5 Promotes Adipose Tissue Inflammation and Aggravates Diet-Induced Obesity in Mice

Objective: The accumulation of inflammatory leukocytes is a prerequisite of adipose tissue inflammation during cardiometabolic disease. We previously reported that a genetic deficiency of the intracellular signaling adaptor TRAF5 (TNF [tumor necrosis factor] receptor-associated factor 5) accelerates atherosclerosis in mice by increasing inflammatory cell recruitment. Here, we tested the hypothesis that an impairment of TRAF5 signaling modulates adipose tissue inflammation and its metabolic complications in a model of diet-induced obesity in mice. Approach and Results: To induce diet-induced obesity and adipose tissue inflammation, wild-type or Traf5-/- mice consumed a high-fat diet for 18 weeks. Traf5-/- mice showed an increased weight gain, impaired insulin tolerance, and increased fasting blood glucose. Weight of livers and peripheral fat pads was increased in Traf5-/- mice, whereas lean tissue weight and growth were not affected. Flow cytometry of the stromal vascular fraction of visceral adipose tissue from Traf5-/- mice revealed an increase in cytotoxic T cells, CD11c+ macrophages, and increased gene expression of proinflammatory cytokines and chemokines. At the level of cell types, expression of TNF[alpha], MIP (macrophage inflammatory protein)-1[alpha], MCP (monocyte chemoattractant protein)-1, and RANTES (regulated on activation, normal T-cell expressed and secreted) was significantly upregulated in Traf5-deficient adipocytes but not in Traf5-deficient leukocytes from visceral adipose tissue. Finally, Traf5 expression was lower in adipocytes from obese patients and mice and recovered in adipose tissue of obese patients one year after bariatric surgery. Conclusions: We show that a genetic deficiency of TRAF5 in mice aggravates diet-induced obesity and its metabolic derangements by a proinflammatory response in adipocytes. Our data indicate that TRAF5 may promote anti-inflammatory and obesity-preventing signaling events in adipose tissue.

Adipose Tissue Macrophages Modulate Obesity-Associated β Cell Adaptations through Secreted miRNA-Containing Extracellular Vesicles

Obesity induces an adaptive expansion of β cell mass and insulin secretion abnormality. Expansion of adipose tissue macrophages (ATMs) is a hallmark of obesity. Here, we assessed a novel role of ATMs in mediating obesity-induced β cell adaptation through the release of miRNA-containing extracellular vesicles (EVs). In both in vivo and in vitro experiments, we show that ATM EVs derived from obese mice notably suppress insulin secretion and enhance β cell proliferation. We also observed similar phenotypes from human islets after obese ATM EV treatment. Importantly, depletion of miRNAs blunts the effects of obese ATM EVs, as evidenced by minimal effects of obese DicerKO ATM EVs on β cell responses. miR-155 is a highly enriched miRNA within obese ATM EVs and miR-155 overexpressed in β cells impairs insulin secretion and enhances β cell proliferation. In contrast, knockout of miR-155 attenuates the regulation of obese ATM EVs on β cell responses. We further demonstrate that the miR-155-Mafb axis plays a critical role in controlling β cell responses. These studies show a novel mechanism by which ATM-derived EVs act as endocrine vehicles delivering miRNAs and subsequently mediating obesity-associated β cell adaptation and dysfunction.

Hepatocyte-derived exosomes from early onset obese mice promote insulin sensitivity through miR-3075

In chronic obesity, hepatocytes become insulin resistant and exert important effects on systemic metabolism. Here we show that in early onset obesity (4 weeks high-fat diet), hepatocytes secrete exosomes that enhance insulin sensitivity both in vitro and in vivo. These beneficial effects were due to exosomal microRNA miR-3075, which is enriched in these hepatocyte exosomes. FA2H is a direct target of miR-3075 and small interfering RNA depletion of FA2H in adipocytes, myocytes and primary hepatocytes leads to increased insulin sensitivity. In chronic obesity (16-18 weeks of a high-fat diet), hepatocyte exosomes promote a state of insulin resistance. These chronic obese hepatocyte exosomes do not directly cause impaired insulin signalling in vitro but do promote proinflammatory activation of macrophages. Taken together, these studies show that in early onset obesity, hepatocytes produce exosomes that express high levels of the insulin-sensitizing miR-3075. In chronic obesity, this compensatory effect is lost and hepatocyte-derived exosomes from chronic obese mice promote insulin resistance.

Multifactorial Basis and Therapeutic Strategies in Metabolism-Related Diseases

Throughout the 20th and 21st centuries, the incidence of non-communicable diseases (NCDs), also known as chronic diseases, has been increasing worldwide. Changes in dietary and physical activity patterns, along with genetic conditions, are the main factors that modulate the metabolism of individuals, leading to the development of NCDs. Obesity, diabetes, metabolic associated fatty liver disease (MAFLD), and cardiovascular diseases (CVDs) are classified in this group of chronic diseases. Therefore, understanding the underlying molecular mechanisms of these diseases leads us to develop more accurate and effective treatments to reduce or mitigate their prevalence in the population. Given the global relevance of NCDs and ongoing research progress, this article reviews the current understanding about NCDs and their related risk factors, with a focus on obesity, diabetes, MAFLD, and CVDs, summarizing the knowledge about their pathophysiology and highlighting the currently available and emerging therapeutic strategies, especially pharmacological interventions. All of these diseases play an important role in the contamination by the SARS-CoV-2 virus, as well as in the progression and severity of the symptoms of the coronavirus disease 2019 (COVID-19). Therefore, we briefly explore the relationship between NCDs and COVID-19.

Effects of non-surgical treatment of chronic periodontitis on insulin resistance and glucose tolerance in subjects without diabetes (PARODIA 2 study)

This study aimed to assess the effects of non-surgical periodontal treatment (NSPT) of chronic periodontitis on insulin sensitivity, glucose tolerance, and serum C reactive protein (CRP) level in individuals without diabetes. Twenty individuals without diabetes with chronic periodontitis underwent NSPT, which consisted of complete scaling, polishing, root planing, and irrigation of the periodontal pockets with a 10% povidone-iodine solution. Periodontal indices (plaque index, gingival bleeding index, pocket depth, and clinical attachment loss), insulin sensitivity using the Short Insulin Tolerance Test index (KITT), glucose tolerance derived from oral glucose tolerance test, and serum CRP level were measured before and 3 months after the intervention. This study was carried out at the National Obesity Center of Yaoundé Central Hospital, Cameroon. After 3 months, we observed significant improvement in periodontal parameters (all p<0.001) and insulin sensitivity (3.72 (2.99-4.17) %/min before treatment vs 4.04 (3.67-4.78) %/min after treatment, p=0.001) and significant decrease in serum CRP level (2.35 (1.46-4.18) mg/L before vs 1.53 (1.03-2.12) mg/L after, p=0.033). There was a trend toward improvement in glucose tolerance, although not statistically significant after the intervention. This study suggests that NSPT of chronic periodontitis in individuals without diabetes is associated with increased insulin sensitivity and decreased serum CRP levels.Trial registration number NCT02830113.

Metabolic Syndrome: the Influence of Adipokines on the L-Arginine-NO Synthase-Nitric Oxide Signaling Pathway

Metabolic syndrome includes the following symptoms: obesity, hyperlipidemia, hypertension, insulin resistance, and cardiovascular disease. The purpose of this review is to elucidate the role of adipokines in the regulation of the L-arginine-NO-synthas-NO signaling pathway in the pathogenesis of metabolic syndrome. The main questions raised in the review are: how adipokine secretion changes, how the level of their receptors is regulated, and which signaling pathways are involved in the transmission of adipokine signals when coupled to the L-arginine-NO-synthase-NO signaling cascade. Adipokines are peptide hormones that transmit a signal from adipose tissue to targets in the brain, blood vessels, liver, pancreas, muscles, and other tissues. Some adipokines have anti-inflammatory and insulin-sensitive effects: adiponectin, omentin, adipolin, chemerin, progranulin. Others have the negative inflammatory effect in the development ofmetabolic syndrome: visfatin, vaspin, apelin. Adipokines primarily regulate the expression and activity of endothelial NO-synthase. They either activate an enzyme involving 5-AMP protein kinase or Akt kinase, increasing its activity and synthesis of NO in the tissues of healthy patients: adiponectin, adipolin, omentin, or inhibit the activity of eNOS, which leads to a decrease in NO-synthase and suppression of mRNA bioavailability: vaspin, visfatin, apelin in metabolic syndrome, and a decrease in its activity leads to dissociation and endothelial dysfunction. It should be noted that the bioavailability of NO formed by NO-synthase is affected at many levels, including: the expression ofNO-synthase mRNA and its protein; the concentration of L-arginine; the level of cofactors of the reaction; and to detect the maximum activity of endothelial NO-synthase, dimerization of the enzyme is required, posttranslational modifications are important, in particular, phosphorylation of endothelial NO-synthase by serine 1177 with the participation of 5-AMP protein kinase, Akt kinase and other kinases. It should be noted that the participation of adiponectin, omentin, and kemerin in the regulation of the L-arginine-NO-synthase-NO cascade in metabolic syndrom opens up certain opportunities for the development of new approaches for the correction of disorders observed in this disease. The review analyzes the results of research searching in PubMed databases, starting from 2001 and up to 2020 using keywords and adipokine names, more than half of the references of the last 5 years. 

The relationship between brain-derived neurotrophic factor and metabolic syndrome in patients with chronic schizophrenia: A systematic review

BACKGROUND & AIMS

Schizophrenia is a serious long-term disorder in which the metabolic complications and abnormalities of the brain-derived neurotrophic factor (BDNF) can be found. In this study, we conducted a systematic review of the relationship between BDNF, metabolic syndrome (MetS) and its components in schizophrenic patients.

METHODS

Data were collected mainly from PubMed, Google Scholar, Scopus, and ProQuest databases. The keywords related to the BDNF, MetS, schizophrenia were searched. Two reviewers independently screened 1061 abstracts. And eventually, a total of 7 studies (6 observational and 1 interventional) was included in the systematic reviews.

RESULTS

Four of the 7 study ascertained statistically significant inverse relationship between serum BDNF levels and MetS in schizophrenic patients. While in the other two studies, there was no inverse relationship. In the last selected study, the researchers found a weak association between the Val66Met polymorphism in BDNF Gene and clozapine-induced MetS.

CONCLUSION

Although this relationship could not be determined but BDNF levels appear to be reduced in schizophrenic patients with MetS and factors such as sex and antipsychotic class differentiation, sampling and methodology and episodes of illness could play a role in the results and outcomes.

Naofucong Ameliorates High Glucose Induced Hippocampal Neuron Injury Through Suppressing P2X7/NLRP1/Caspase-1 Pathway

P2X7/NLRP1/caspase-1 mediated neuronal injury plays an important role in diabetic cognitive impairment and eventually inflammatory cascade reaction. Chinese herbal compound Naofucong has been mainly used to treat cognitive disorders in Traditional Chinese Medicine The present study aimed to investigate whether its neuroprotective effects might be related to the inhibition of P2X7R/NLRP1/caspase-1 mediated neuronal injury or not. In this study, high glucose-induced HT22 hippocampal neurons were used to determine Naofucong-containing serum neuronal protective effects. Lentiviruses knock out of TXNIP and P2X7R was used to determine that protective effects of Naofucong was related to inflammatory response and P2X7/NLRP1/caspase-1 mediated neuronal injury. NAC was also used to inhibit oxidative stress, so as to determine that oxidative stress is an important starting factor for neuronal injury of HT22 cells cultured with high glucose. Naofucong decreased apoptosis, IL-1β and IL-18 levels in high glucose-induced HT22 hippocampal neuron cells. Naofucong suppressed NLRP1/caspase-1 mediated neuronal injury, and P2X7 was involved in process. HT22 cells cultured in high glucose had an internal environment with elevated oxidative stress, which could promote neuronal injury. The current study demonstrated that Naofucong could significantly improve high glucose-induced HT22 hippocampal neuron injury, which might be related to suppress P2X7R/NLRP1/caspase-1 pathway, which provides novel evidence to support the future clinical use of Naofucong.

MiR-690, an exosomal-derived miRNA from M2-polarized macrophages, improves insulin sensitivity in obese mice

Insulin resistance is a major pathophysiologic defect in type 2 diabetes and obesity, while anti-inflammatory M2-like macrophages are important in maintaining normal metabolic homeostasis. Here, we show that M2 polarized bone marrow-derived macrophages (BMDMs) secrete miRNA-containing exosomes (Exos), which improve glucose tolerance and insulin sensitivity when given to obese mice. Depletion of their miRNA cargo blocks the ability of M2 BMDM Exos to enhance insulin sensitivity. We found that miR-690 is highly expressed in M2 BMDM Exos and functions as an insulin sensitizer both in vivo and in vitro. Expressing an miR-690 mimic in miRNA-depleted BMDMs generates Exos that recapitulate the effects of M2 BMDM Exos on metabolic phenotypes. Nadk is a bona fide target mRNA of miR-690, and Nadk plays a role in modulating macrophage inflammation and insulin signaling. Taken together, these data suggest miR-690 could be a new therapeutic insulin-sensitizing agent for metabolic disease.

Clusterin and Its Role in Insulin Resistance and the Cardiometabolic Syndrome

The cardiometabolic syndrome involves a clustering of metabolic and cardiovascular factors which increase the risk of patients developing both Type 2 Diabetes Mellitus and cardio/cerebrovascular disease. Although the mechanistic underpinnings of this link remain uncertain, key factors include insulin resistance, excess visceral adiposity, atherogenic dyslipidemia, and endothelial dysfunction. Of these, a state of resistance to insulin action in overweight/obese patients appears to be central to the pathophysiologic process. Given the increasing prevalence of obesity-related Type 2 Diabetes, coupled with the fact that cardiovascular disease is the number one cause of mortality in this patient population, a more thorough understanding of the cardiometabolic syndrome and potential options to mitigate its risk is imperative. Inherent in the pathogenesis of insulin resistance is an underlying state of chronic inflammation, at least partly in response to excess adiposity. Within obese adipose tissue, an immunomodulatory shift occurs, involving a preponderance of pro-inflammatory immune cells and cytokines/adipokines, along with antigen presentation by adipocytes. Therefore, various adipokines differentially expressed by obese adipocytes may have a significant effect on cardiometabolism. Clusterin is a molecular chaperone that is widely produced by many tissues throughout the body, but is also preferentially overexpressed by obese compared lean adipocytes and relates strongly to multiple components of the cardiometabolic syndrome. Herein, we summarize the known and potential roles of circulating and adipocyte-specific clusterin in cardiometabolism and discuss potential further investigations to determine if clusterin is a viable target to attenuate both metabolic and cardiovascular disease.

Rice Bran Oil Attenuates Chronic Inflammation by Inducing M2 Macrophage Switching in High-Fat Diet-Fed Obese Mice

Macrophages are involved in all inflammatory processes from killing pathogens to repairing damaged tissue. In the obese state, macrophages infiltrate into enlarged adipose tissue and polarize into pro-inflammatory M1 macrophages, resulting in chronic low-grade inflammation due to the secretion of inflammatory mediators. Rice bran oil (RBO) is an edible oil containing tocopherols, tocotrienols, and γ-oryzanol. Previous research in normal diet-fed mice suggested that RBO mitigates inflammatory responses by modulating mitochondrial respiration of macrophages. Therefore, we investigated if RBO had an anti-inflammatory effect in diet-induced obese mice by assessing the expression of inflammatory markers in epididymal white adipose tissue (eWAT) and polarization of bone marrow-derived macrophages (BMDMs). Rice bran oil exerted a local anti-inflammatory effect in white adipose tissue by suppressing the production of inflammatory mediators and upregulating transcription of anti-inflammatory genes. Rice bran oil also promoted anti-inflammatory M2 macrophage polarization in BMDMs thereby affecting systemic inflammation. Overall, our in vivo and ex vivo results highlight the potential of RBO as a dietary mediator that can ameliorate obesity-induced chronic low-grade inflammation by mediating the expression of inflammation-related factors and macrophage polarization.

Effect of qualitative and quantitative nutritional plan on gene expression in obese patients in secondary prevention for cardiovascular disease

BACKGROUND & AIMS

Diet is a modifiable risk factor, which may influence the gene expression and the concentration of inflammatory biomarkers related to obesity and atherosclerosis. In this substudy from Brazilian Cardioprotective Nutritional (BALANCE) Program, we hypothesized that a nutritional intervention based on the usual Brazilian diet modulates the expression of genes involved with atherosclerosis and inflammatory biomarkers in male patients, in the secondary prevention for cardiovascular disease.

METHODS

Six male patients, aged 45 years or older, obese, were selected to follow a qualitative-quantitative food plan for 6 months. Glycemia, insulinemia, lipid profile, plasma concentration of inflammatory biomarkers (interleukin (IL) -1β), IL-6, IL-8, IL-10, IL-12, tumor necrosis factor alpha, C-reactive protein and adiponectin, and expression of 84 atherosclerosis-related genes in total peripheral blood cells, were measured.

RESULTS

After nutritional intervention, the participants reduced weight (p < 0.04), waist circumference (p < 0.04), Homeostasis Model Assessment index for insulin resistance (p = 0.046) and overall leukocyte count (p = 0.046) and neutrophils (p = 0.028). There was no significant modification in the plasma concentration of the inflammatory biomarkers, however, there was a significant increase in the expression of Apo A1 (p = 0.011), ELN (p = 0.017) and IL4 (p = 0.037) genes.

CONCLUSIONS

The BALANCE Program, the qualitative-quantitative food plan composed of Brazilian usual foods, did not reduce the concentration of inflammatory biomarkers, but increased in total peripheral blood cells the expression of genes involved in reducing the risk of cardiometabolic in obese patients, in secondary prevention for cardiovascular disease. The clinical trial is registered at https://clinicaltrials.gov/ and the unique identifier is NCT01620398.

Influence of irisin on diet-induced metabolic syndrome in experimental rat model

OBJECTIVE

To evaluate the influence of irisin on the experimental paradigm of non-alcoholic fatty liver (NAFL) as a part of MetS cluster.

METHODS

Forty male albino rats were divided into four groups; normal control, standard diet + irisin, high carbohydrate and fat diet (HCHF), and HCHF + irisin. After the experimental period, levels of fasting blood sugar (FBS), insulin, lipid profile, kidney functions, salusin-alpha (Sal-α), adropin, and retinol-binding protein-4 (RBP-4) were evaluated. Peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1α) expression in skeletal muscle was evaluated by quantitative real-time PCR. Aorta, liver, pancreas, and skeletal muscle tissue samples were prepared for histopathological examination.

RESULTS

Rats administrated HCHF showed elevated levels of FBS, lipid profile, kidney functions, RBP-4, and downregulation of PGC-1α expression along with a decline in levels of insulin, Sal-α, and adropin while administration of irisin significantly attenuated these levels.

CONCLUSIONS

Irisin as based therapy could emerge as a new line of treatment against MetS and its related diseases.

Improvement of obesity-associated disorders by a small-molecule drug targeting mitochondria of adipose tissue macrophages

Pro-inflammatory activation of adipose tissue macrophages (ATMs) is causally linked to obesity and obesity-associated disorders. A number of studies have demonstrated the crucial role of mitochondrial metabolism in macrophage activation. However, there is a lack of pharmaceutical agents to target the mitochondrial metabolism of ATMs for the treatment of obesity-related diseases. Here, we characterize a near-infrared fluorophore (IR-61) that preferentially accumulates in the mitochondria of ATMs and has a therapeutic effect on diet-induced obesity as well as obesity-associated insulin resistance and fatty liver. IR-61 inhibits the classical activation of ATMs by increasing mitochondrial complex levels and oxidative phosphorylation via the ROS/Akt/Acly pathway. Taken together, our findings indicate that specific enhancement of ATMs oxidative phosphorylation improves chronic inflammation and obesity-related disorders. IR-61 might be an anti-inflammatory agent useful for the treatment of obesity-related diseases by targeting the mitochondria of ATMs.

Adipose tissue macrophages are central to controlling inflammation in the context of obesity. Here the authors present a new infrared dye (IR-61) that accumulates in the mitochondria of these cells resulting in anti-inflammatory effects that counter obesity-associated pathology in mice.

The Associations of Perceived and Oxidative Stress with Hypertension in a Cohort of Police Officers

PURPOSE

Associations between perceived stress and oxidative stress marker and metabolic syndrome (MetS) components were investigated in a cohort of police officers.

METHODS

Cross-sectional data from a cohort of non-diabetic subjects (n=233; 19F), median [interquartile range] age 50 [37-44] years, were analysed. MetS was construed in line with International Diabetes Federation (IDF) criteria and perceived stress with Cohen's 10-item Perceived Stress Scale. Plasma oxidative stress marker (free 8-iso-prostaglandin F_2α; 8-iso-PGF_2α), presence of coronary plaque, carotid artery intima-media thickness (cIMT), and physical activity level were also determined.

RESULTS

Obesity was established in 100 (42.92%), hypertension in 111 (47.64), whereas MetS was identified in 104 (44.63%) of the study subjects. A significant difference (p=0.003) in plasma 8-iso-PGF_2α level, depending on the MetS components status, was noted. The associations of perceived stress with plasma 8-iso-PGF_2α level and the select study variables were gender-specific. In multivariate analysis (adjusted for age and current smoking), positive associations of plasma 8-iso-PGF_2α levels with PSS score (B=0.108, 95% CI [0.008, 0.209], p=0.03) and systolic blood pressure (B=0.029, 95% CI [0.003, 0.057], p=0.02) in men only were established. Both the perceived stress (OR 1.101, 95% CI [1.001-1.202], p=0.03) and plasma 8-iso-PGF_2α levels (OR 1.223, 95% CI [1.046-1.432], p=0.01) impacted the prevalence of hypertension. Out of the MetS components, the effect of waist circumference (OR=1.138, 95% CI [1.064-1.218], p=0.0001) and glucose (B=2.696, 95% CI [1.081-6.725], p=0.03) were also encountered. No such associations were noted in women, though, neither in univariate nor in multivariate analyses. The prevalence of coronary plaque (0.001), obesity (p<0.001), hypertension (p<0.001) and median cIMT value (p=0.005), as well as leisure-time (p=0.04) and total walking physical activity (p=0.03), differed significantly between the subgroups stratified by MetS components status.

CONCLUSION

Both the perceived and oxidative stress were found instrumental in promoting hypertension in a cohort of police officers under study, whereas all study outcomes were conclusively gender-related.

Cardiometabolic Risk Factors for COVID-19 Susceptibility and Severity: A Mendelian Randomization Analysis

IMPORTANCE

Early epidemiological studies report associations of diverse cardiometabolic conditions especially body mass index (BMI), with COVID-19 susceptibility and severity, but causality has not been established. Identifying causal risk factors is critical to inform preventive strategies aimed at modifying disease risk.

OBJECTIVE

We sought to evaluate the causal associations of cardiometabolic conditions with COVID-19 susceptibility and severity.

DESIGN

Two-sample Mendelian Randomization (MR) Study.

SETTING

Population-based cohorts that contributed to the genome-wide association study (GWAS) meta-analysis by the COVID-19 Host Genetics Initiative.

PARTICIPANTS

Patients hospitalized with COVID-19 diagnosed by RNA PCR, serologic testing, or clinician diagnosis. Population controls defined as anyone who was not a case in the cohorts. Exposures: Selected genetic variants associated with 17 cardiometabolic diseases, including diabetes, coronary artery disease, stroke, chronic kidney disease, and BMI, at p<5 x 10-8 from published largescale GWAS.

MAIN OUTCOMES

We performed an inverse-variance weighted averages of variant-specific causal estimates for susceptibility, defined as people who tested positive for COVID-19 vs. population controls, and severity, defined as patients hospitalized with COVID-19 vs. population controls, and repeated the analysis for BMI using effect estimates from UKBB. To estimate direct and indirect causal effects of BMI through obesity-related cardiometabolic diseases, we performed pairwise multivariable MR. We used p<0.05/17 exposure/2 outcomes=0.0015 to declare statistical significance.

RESULTS

Genetically increased BMI was causally associated with testing positive for COVID-19 [6,696 cases / 1,073,072 controls; p=6.7 x 10-4, odds ratio and 95% confidence interval 1.08 (1.03, 1.13) per kg/m2] and a higher risk of COVID-19 hospitalization [3,199 cases/897,488 controls; p=8.7 x 10-4, 1.12 (1.04, 1.21) per kg/m2]. In the multivariable MR, the direct effect of BMI was abolished upon conditioning on the effect on type 2 diabetes but persisted when conditioning on the effects on coronary artery disease, stroke, chronic kidney disease, and c-reactive protein. No other cardiometabolic exposures tested were associated with a higher risk of poorer COVID-19 outcomes.

CONCLUSIONS AND RELEVANCE

Genetic evidence supports BMI as a causal risk factor for COVID-19 susceptibility and severity. This relationship may be mediated via type 2 diabetes. Obesity may have amplified the disease burden of the COVID-19 pandemic either single-handedly or through its metabolic consequences.

Metabolic Syndrome and Parkinson's Disease Incidence: A Nationwide Study Using Propensity Score Matching

Background: Metabolic syndrome (MetS) and Parkinson's disease (PD) share common pathophysiological mechanisms. This study aimed to investigate the influence of MetS on PD incidence. Materials and Methods: A propensity score-matched cohort study was conducted using the National Health Insurance Service-National Health Screening Cohort (NHIS-HealS) data (2002-2015) from the Korean National Health Insurance Service. Individuals with MetS were identified from those who underwent a health checkup in 2009-2010 and were 1:1 matched to individuals without MetS (non-MetS) using the propensity score method. Among 314,737 eligible individuals, 85,530 MetS and non-MetS pairs were selected. Results: During a mean follow-up of 7.23 years, 819 (0.48%) PD cases occurred. Individuals with MetS exhibited 1.23 times greater PD incidence (95% confidence interval [CI], 1.06-1.43; P = 0.006). The risk of PD increased with the number of MetS components, with the presence of five MetS components altogether doubling the incidence of PD (odds ratio [OR], 2.00; 95% CI, 1.30-3.04; P = 0.001). High blood pressure, low high-density lipoprotein cholesterol, and high fasting blood glucose increased PD incidence by 1.34 times (95% CI, 1.15-1.58; P < 0.001), 1.31 times (95% CI, 1.13-1.52; P < 0.001), and 1.20 times (95% CI, 1.04-1.38; P = 0.013), respectively. Elevated waist circumference was not associated with PD incidence (OR, 1.11; 95% CI, 0.96-1.28; P = 0.176). High triglycerides exerted a protective effect against PD incidence especially in men (OR, 0.66; 95% CI, 0.54-0.81; P < 0.001). Conclusions: MetS may be a risk factor for PD incidence, and individual components of MetS exert different effects depending on sex.

NLRP3 sparks the Greek fire in the war against lipid-related diseases

In recent years, the obesity rate worldwide has reached epidemic proportions and contributed to the growing prevalence of lipid-related diseases. A strong link between inflammation and metabolism is becoming increasingly evident. Compelling evidence has indicated the activation of the nucleotide-binding and oligomerization domain-like receptor, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome, a cytoplasmic complex containing multiple proteins, in a variety of lipid-related diseases including obesity, atherosclerosis, liver diseases, and type 2 diabetes. Recent studies have further clarified the regulatory mechanisms and the optional therapeutic agents that target NLRP3 inflammasomes. In this study, we review the recent progress in the research on NLRP3 inflammasomes and discuss their implications for a better understanding of inflammation in lipid-related disease and the prospects of targeting the NLRP3 inflammasome for therapeutic intervention.

Mitochondrial Dysfunction and Insulin Resistance in Pubertal Youth Living with Perinatally Acquired HIV

Mitochondrial dysfunction (MD) is linked to cardiometabolic complications, such as obesity and insulin resistance (IR), the frequencies of which are higher in adults living with HIV infection and receiving combination antiretroviral therapies (ARV). ARV-treated youth living with perinatally acquired HIV infection (YLPHIV) may be especially susceptible to IR due to long-term exposure to both factors. Medical histories, fasting blood chemistry panels, and mitochondrial function in banked peripheral blood mononuclear cells (PBMCs) were assessed in eligible YLPHIV from the Pediatric HIV/AIDS Cohort Study (PHACS)/Adolescent Master Protocol (AMP) Mitochondrial Determinants Component cohort, stratified by Homeostatic Model Assessment of IR (HOMA-IR) score: case (score ≥4, n = 39) or control (score <4, n = 105). PBMCs were sources for mitochondrial (mt) DNA copies/cell; mtRNA transcript levels of oxidative phosphorylation (OXPHOS) subunits NADH dehydrogenases 1 and 6, and cytochrome B; and enzymatic activities of OXPHOS Complexes I (CI) and IV (CIV). Logistic regression models were fit to estimate the odds of IR case diagnosis, adjusted for sex, race/ethnicity, body mass index (BMI) z-score, and Tanner stage. IR cases were similar to controls by age, sex, and race/ethnicity. Cases had higher median levels of peak HIV viral load, lactate, pyruvate, triglycerides, and BMI z-scores. OXPHOS CI enzymatic activity was lower in cases (log₁₀ 1.62 vs. 1.70) and inversely correlated with HOMA-IR score (r = -0.157, p = .061), but did not associate with IR in adjusted models. Fully adjusted models indicated associations of nadir CD4% [odds ratio (OR) = 0.95, 95% confidence intervals (CIs) = 0.90-1.00] or peak HIV load (OR = 3.48, 95% CIs = 1.70-10.79) with IR. IR in YLPHIV was strongly associated with morphometrics, but early virologic and immunologic factors may also influence MD.

Obesity and insulin resistance in children

PURPOSE OF REVIEW

It is well known that obesity represents the main modifiable risk factor for insulin resistance in children and adolescents; obesity-induced insulin resistance in children is the most important risk factor for developing cardiovascular diseases and type 2 diabetes in adulthood. The mechanisms through which obesity causes insulin resistance are complex and not completely known to date.

RECENT FINDINGS

In children, global adiposity is the main factor determining insulin resistance. Excessive fatty acids play a determinant role in the pathogenesis of insulin resistance in obese children, inducing an increased production of acetyl-CoA in the liver and enhancing inflammation in adipose tissue. The aetiology of insulin resistance in polycystic ovary syndrome is multifactorial and still debated.

SUMMARY

The aim of this review is to present an updated frame and new insights of the numerous pathways involved in the development of insulin resistance in obese patients, focusing on the peculiarities of children and adolescents. Improving the knowledge of mechanisms through which obesity leads to insulin resistance is fundamental in order to recommend particular follow-up and possible treatment to specific categories of obese children and adolescents.

Association between faecal haemoglobin concentration and the risk of cardiovascular diseases among Taiwanese adults in a community-based screening cohort

OBJECTIVES

The role of faecal haemoglobin as a colorectal cancer screening tool has been demonstrated. However, the association between the faecal haemoglobin concentration and the risk of cardiovascular disease events and deaths is still unclear.

DESIGN

Cohort study design.

SETTING

Population-based organised integrated service screening in Keelung City, Taiwan PARTICIPANTS: A total of 33 355 healthy individuals aged over 40 years who were free of cardiovascular disease at study entry were followed up.

MAIN OUTCOMES AND MEASURES

Newly diagnosed cardiovascular disease events and deaths.

RESULTS

After a median follow-up of 2.39 years, a total of 2768 participants developed cardiovascular events, and after a median follow-up of 8.43 years, 317 cases of cardiovascular deaths occurred. The risk of cardiovascular disease increased with baseline faecal haemoglobin in a dose-response manner, yielding a significant elevated risk of cardiovascular disease in parallel with the incremental concentration of faecal haemoglobin (adjusted HRs=1.04, 1.10, 1.40 and 1.23 for faecal haemoglobin concentrations of 1-19, 20-49, 50-99 and ≥100 ng/mL, trend test, p<0.0001, as compared with the reference group with undetectable faecal haemoglobin concentrations). A similar pattern was observed for the risk of cardiovascular disease deaths. In addition, the faecal haemoglobin improved the prediction performance of the model for the risk of cardiovascular diseases; the integrated discrimination improvement was 0.3% (p<0.001) for cardiovascular events and 0.1% (p=0.020) for cardiovascular deaths.

CONCLUSIONS

Our data support that faecal haemoglobin concentrations may be associated with the risk of cardiovascular diseases. The biological mechanisms underlying the role of faecal haemoglobin as health outcomes should be investigated.

Association Between Serum Retinol and α-Tocopherol Levels and Metabolic Syndrome in Korean General Population: Analysis of Population-based Nationally Representative Data

This study aimed to evaluate the association between serum retinol and α-tocopherol levels and metabolic syndrome (MetS) using data from the Korea National Health and Nutrition Examination Survey. Of the 24,269 individuals, 5885 adults (2672 men and 3213 women) were included. The prevalence of MetS and its components according to quartiles of serum retinol and α-tocopherol levels was calculated. Multivariate linear regression model was used to calculate the number of metabolic components according to serum vitamin levels. The association between serum vitamin levels and MetS with its components was assessed using multivariate logistic regression model. The prevalence of MetS was highest in Q4 and lowest in Q1 for both vitamins, regardless of sex. A dose-dependent association between serum retinol and α-tocopherol levels and MetS was observed. After adjustment for covariates, the odds ratio (OR) for MetS in Q4 compared to Q1 was 2.351 (95% CI: 1.748-3.163, Ptrend < 0.001) in the retinol group and 2.559 (95% CI: 1.953-3.353, Ptrend < 0.001) in α-tocopherol group. Among metabolic components, hypertriglyceridemia, high fasting glucose, and high blood pressure was positively associated with serum retinol and α-tocopherol levels. In conclusion, high serum retinol and α-tocopherol levels were associated with increased risk of MetS.