Adipokines: the missing link between insulin resistance and obesity

Immunometabolic Signatures of Circulating Monocytes in Humans With Obesity and Insulin Resistance

Obesity is associated with chronic inflammation and metabolic complications, including insulin resistance (IR). Immune cells drive inflammation through the rewiring of intracellular metabolism. However, the impact of obesity-related IR on the metabolism and functionality of circulating immune cells, like monocytes, remains poorly understood. To increase insight into the interindividual variation of immunometabolic signatures among individuals and their role in the development of IR, we assessed systemic and tissue-specific IR and circulating immune markers, and we characterized metabolic signatures and cytokine secretion of circulating monocytes from 194 individuals with a BMI ≥25 kg/m2. Monocyte metabolic signatures were defined using extracellular acidification rates (ECARs) to estimate glycolysis and oxygen consumption rates (OCRs) for oxidative metabolism. Although monocyte metabolic signatures and function based on cytokine secretion varied greatly among study participants, they were strongly associated with each other. The ECAR-to-OCR ratio, representing the balance between glycolysis and oxidative metabolism, was negatively associated with fasting insulin levels, systemic IR, and liver-specific IR. These results indicate that monocytes from individuals with IR were relatively more dependent on oxidative metabolism, whereas monocytes from more insulin-sensitive individuals were more dependent on glycolysis. Additionally, circulating CXCL11 was negatively associated with the degree of systemic IR and positively with the ECAR-to-OCR ratio in monocytes, suggesting that individuals with high IR and a monocyte metabolic dependence on oxidative metabolism also have lower levels of circulating CXCL11. Our findings suggest that monocyte metabolism is related to obesity-associated IR progression and deepen insights into the interplay between innate immune cell metabolism and IR development in humans.

ARTICLE HIGHLIGHTS

Effects of an environmentally relevant mixture of organochlorine pesticide compounds on adipogenesis and adipocyte function in an immortalized human adipocyte model

Exposure to persistent organic pollutants (POPs), including organochlorine (OC) pesticide POPs, has been associated with the increased prevalence of obesity and type 2 diabetes. However, the underlying mechanisms through which exposure to these compounds may promote obesity and metabolic dysfunction remain an area of active investigation. To this end, the concentration dependent effects of an environmentally relevant mixture of OC pesticide POPs on adipocyte function was explored utilizing a translationally relevant immortalized human subcutaneous preadipocyte/adipocyte model. Briefly, immortalized human preadipocytes/adipocytes were exposed to a mixture of dichlorodiphenyldichloroethylene (DDE), trans-nonachlor, and oxychlordane (DTO) then key indices of preadipocyte/adipocyte function were assessed. Exposure to DTO did not alter adipogenesis. However, in mature adipocytes, exposure to DTO slightly increased fatty acid uptake whereas isoproterenol stimulated lipolysis, basal and insulin stimulated glucose uptake, mitochondrial membrane potential, and cellular ATP levels were all significantly decreased. DTO significantly increased Staphylococcus aureus infection induced increases in expression of pro-inflammatory cytokines IL-6, IL-1β, and Mcp-1 as well as the adipokine resistin. Taken together, the present data demonstrated exposure to an environmentally relevant mixture of OC pesticide compounds can alter mature adipocyte function in a translationally relevant human adipocyte model which further supports the adipose tissue as an effector site of OC pesticide POPs action.

Overnutrition, Hyperinsulinemia and Ectopic Fat: It Is Time for A Paradigm Shift in the Management of Type 2 Diabetes

The worldwide incidence of prediabetes/type 2 has continued to rise the last 40 years. In the same period, the mean daily energy intake has increased, and the quality of food has significantly changed. The chronic exposure of pancreatic β-cells to calorie excess (excessive energy intake) and food additives may increase pancreatic insulin secretion, decrease insulin pulses and/or reduce hepatic insulin clearance, thereby causing chronic hyperinsulinemia and peripheral insulin resistance. Chronic calorie excess and hyperinsulinemia may promote lipogenesis, inhibit lipolysis and increase lipid storage in adipocytes. In addition, calorie excess and hyperinsulinemia can induce insulin resistance and contribute to progressive and excessive ectopic fat accumulation in the liver and pancreas by the conversion of excess calories into fat. The personal fat threshold hypothesis proposes that in susceptible individuals, excessive ectopic fat accumulation may eventually lead to hepatic insulin receptor resistance, the loss of pancreatic insulin secretion, hyperglycemia and the development of frank type 2 diabetes. Thus, type 2 diabetes seems (partly) to be caused by hyperinsulinemia-induced excess ectopic fat accumulation in the liver and pancreas. Increasing evidence further shows that interventions (hypocaloric diet and/or bariatric surgery), which remove ectopic fat in the liver and pancreas by introducing a negative energy balance, can normalize insulin secretion and glucose tolerance and induce the sustained biochemical remission of type 2 diabetes. This pathophysiological insight may have major implications and may cause a paradigm shift in the management of type 2 diabetes: avoiding/reducing ectopic fat accumulation in the liver and pancreas may both be essential to prevent and cure type 2 diabetes.

Discriminating insulin resistance in middle-aged nondiabetic women using machine learning approaches

Objective

We employed machine learning algorithms to discriminate insulin resistance (IR) in middle-aged nondiabetic women.

Methods

The data was from the National Health and Nutrition Examination Survey (2007-2018). The study subjects were 2084 nondiabetic women aged 45-64. The analysis included 48 predictors. We randomly divided the data into training (n = 1667) and testing (n = 417) datasets. Four machine learning techniques were employed to discriminate IR: extreme gradient boosting (XGBoosting), random forest (RF), gradient boosting machine (GBM), and decision tree (DT). The area under the curve (AUC) of receiver operating characteristic (ROC), accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F1 score were compared as performance metrics to select the optimal technique.

Results

The XGBoosting algorithm achieved a relatively high AUC of 0.93 in the training dataset and 0.86 in the testing dataset to discriminate IR using 48 predictors and was followed by the RF, GBM, and DT models. After selecting the top five predictors to build models, the XGBoost algorithm with the AUC of 0.90 (training dataset) and 0.86 (testing dataset) remained the optimal prediction model. The SHapley Additive exPlanations (SHAP) values revealed the associations between the five predictors and IR, namely BMI (strongly positive impact on IR), fasting glucose (strongly positive), HDL-C (medium negative), triglycerides (medium positive), and glycohemoglobin (medium positive). The threshold values for identifying IR were 29 kg/m2, 100 mg/dL, 54.5 mg/dL, 89 mg/dL, and 5.6% for BMI, glucose, HDL-C, triglycerides, and glycohemoglobin, respectively.

Conclusion

The XGBoosting algorithm demonstrated superior performance metrics for discriminating IR in middle-aged nondiabetic women, with BMI, glucose, HDL-C, glycohemoglobin, and triglycerides as the top five predictors.

Effects of high-intensity interval exercise on arterial stiffness in individuals at risk for cardiovascular disease: a meta-analysis

Objective

The purpose of this meta-analysis was to investigate the effect of high-intensity interval training (HIIT) on arterial stiffness (AS) and vascular function in persons at high risk of cardiovascular disease (CVD).

Methods

We conducted a comprehensive search of randomized controlled trials (RCTs) published in electronic databases (PubMed, Web of Science, Cochrane, Embase, and Ebsco) since their inception through October 2023 to evaluate the effect of HIIT on AS and vascular function in persons at high risk for CVD. The weighted mean difference (WMD) and 95% confidence intervals (95% CI) were calculated, and heterogeneity was assessed using the I2 test.

Results

This study included 661 participants from 16 studies. HIIT significantly reduced pulse wave velocity (PWV) in persons at high risk for CVD [weighted mean difference (WMD), -0.62; 95% CI, -0.86--0.38; P < 0.00001]. Subgroup analysis showed that the PWV improvement effect was better when the HIIT program was performed 2-3 times per week and the duration was controlled within 40 min [2-3 times, -0.67; 95% CI, -0.93--0.41; P < 0.00001; time of duration, ≤40 min, -0.66; 95% CI, -0.91--0.41; P < 0.00001]. HIIT significantly reduced systolic blood pressure (SBP, -5.43; 95% CI, -8.82--2.04; P = 0.002), diastolic blood pressure (DPB, -2.96; 95% CI, -4.88--1.04; P = 0.002), and resting heart rate (RHR, -4.35; 95% CI, -7.04--1.66; P = 0.002), but had no significant effect on augmentation index (AIX, -2.14; 95% CI, -6.77-2.50; P = 0.37).

Conclusion

HIIT can improve PWV in high-risk individuals with CVD and reduce SBP, DBP, and RHR, but has no significant effect on AIX. HIIT can effectively improve AS and vascular function and can be recommended as an effective method to improve AS in high-risk persons with CVD.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42023471593.

Insulinemic potential of lifestyle is associated with depression and anxiety in adults: A large community-based study

BACKGROUND

We aimed to investigate the association between an empirical lifestyle index for hyperinsulinemia (ELIH), empirical lifestyle index for insulin resistance (ELIR), and depression and anxiety in an adult Iranian population.

METHODS

In this cross-sectional study, a total of 6450 participants, aged 35-65 years were recruited as part of the MASHAD cohort study. Dietary intakes were assessed using a validated food frequency questionnaire (FFQ). Depression and anxiety were screened using Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI). ELIH and ELIR were calculated using dietary intake, body mass index, and physical activity information. Multivariable ordinal logistic regression models were applied to determine the association between ELIH, ELIR, and depression and anxiety severity.

RESULTS

In a fully adjusted model, participants with the highest ELIH quartile had a higher odds of more severe depression and anxiety compared to those in the lowest category (OR = 1.44; 95 % CI = 1.22-1.71 and OR = 1.62; 95 % CI = 1.37-1.25, respectively). Participants with the highest ELIR had higher odds of more severe depression and anxiety compared to those in the lowest category (OR = 1.22; 95 % CI = 1.04-1.43 and OR = 1.21; 95 % CI = 1.03-1.42, respectively).

LIMITATIONS

The assessment of dietary intake and mental health by questionnaires may increases the rate of misclassification. Due to the study's cross-sectional nature, causal relationships cannot be established.

CONCLUSION

There was a significant positive association between the hyperinsulinemia and insulin resistance potential of lifestyle and severity of depression and anxiety among Iranian adults.

Mechanisms and risk factors of metabolic syndrome in children and adolescents

Metabolic syndrome (MetS) is a complex disorder characterized by abdominal obesity, elevated blood pressure, hyperlipidemia, and elevated fasting blood glucose levels. The diagnostic criteria for MetS in adults are well-established, but there is currently no consensus on the definition in children and adolescents. The etiology of MetS is believed to involve a complex interplay between genetic predisposition and environmental factors. While genetic predisposition explains only a small part of MetS pathogenesis, modifiable environmental risk factors play a significant role. Factors such as maternal weight during pregnancy, children's lifestyle, sedentariness, high-fat diet, fructose and branched-chain amino acid consumption, vitamin D deficiency, and sleep disturbances contribute to the development of MetS. Early identification and treatment of MetS in children and adolescents is crucial to prevent the development of chronic diseases later in life. In this review we discuss the latest research on factors contributing to the pathogenesis of MetS in children, focusing on non-modifiable and modifiable risk factors, including genetics, dysbiosis and chronic low-grade inflammation.

Exploring oxidative stress, immunological and metabolic biomarkers in dairy cows with postpartum pyometra

Pyometra is a prevalent and severe infectious disease that affects the reproductive systems of cattle worldwide. This study's main goal was to investigate the biomarkers for oxidative stress (OS), adiponectin, leptin and neopterin (NPT) in cows suffering from postpartum pyometra. The study also aimed to determine which bacteria were most commonly implicated in the development of the disease. A total of 74 cows with pyometra were examined and compared to a control group of healthy cows (n = 20). In comparison to the healthy control and post-treatment groups, the pyometra group showed higher mean values of leptin, adiponectin and malondialdehyde (MDA). In contrast, the glutathione (GSH) and superoxide dismutase (SOD) mean values were lower in the pyometra group as compared to the post-treatment and control groups. NPT levels in the post-treatment groups were lower than those in cows with pyometra but comparable to the healthy control group (p > .05). When compared to the other biomarkers, NPT, leptin and adiponectin showed higher sensitivity and specificity in identifying pyometra cases (AUC ≥0.99). The predominant bacterial isolates from the ptomtra-affected cows consisted of Escherichia coli (N = 29; 39.2%), Arcanobacterium pyogenes (N = 27; 36.5%) and Fusobacterium necrophorum (N = 13; 17.6%). Mixed infection was determined in nine samples (12.2%). Conclusively, OS, adiponectin, leptin and NPT play crucial roles in comprehending the development of postpartum pyometra in cows and have the potential to serve as biomarkers for the disease.

Adipose tissue as a therapeutic target for vascular damage in Alzheimer's disease

Adipose tissue has recently been recognized as an important endocrine organ that plays a crucial role in energy metabolism and in the immune response in many metabolic tissues. With this regard, emerging evidence indicates that an important crosstalk exists between the adipose tissue and the brain. However, the contribution of adipose tissue to the development of age-related diseases, including Alzheimer's disease, remains poorly defined. New studies suggest that the adipose tissue modulates brain function through a range of endogenous biologically active factors known as adipokines, which can cross the blood-brain barrier to reach the target areas in the brain or to regulate the function of the blood-brain barrier. In this review, we discuss the effects of several adipokines on the physiology of the blood-brain barrier, their contribution to the development of Alzheimer's disease and their therapeutic potential. LINKED ARTICLES: This article is part of a themed issue From Alzheimer's Disease to Vascular Dementia: Different Roads Leading to Cognitive Decline. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.6/issuetoc.

Association between systemic immune-inflammation index and insulin resistance and mortality

The role of inflammation in disease promotion is significant, yet the precise association between a newly identified inflammatory biomarker and insulin resistance (IR) and mortality remains uncertain. We aim to explore the potential correlation between systemic immune-inflammation index (SII) and these factors. We used data from 2011 to 2016 of National Health and Nutrition Examination Survey, and multivariate logistic regression and restricted cubic spline were employed. Subgroup and interaction analysis were conducted to recognize the consistency of the results. The association between SII and mortality was described by survival analysis. 6734 participants were enrolled, of whom 49.3% (3318) exhibited IR and 7.02% experienced mortality. Multivariate logistic regression revealed that individuals in the highest quartile (Q4) of SII had a significantly increased risk of IR compared to those in the lowest quartile (Q1). We then identified a linear association between SII and IR with an inflection point of 407, but may be influenced by gender. Similarly, compared to Q1, people whose SII at Q4 showed a higher all-cause and cardiovascular mortality. It showed a significant association between SII and both all-cause and cardiovascular mortality, but the results need to be interpreted with caution.

Role of Perturbated Hemostasis in MASLD and Its Correlation with Adipokines

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) continues to rise, making it one of the most prevalent chronic liver disorders. MASLD encompasses a range of liver pathologies, from simple steatosis to metabolic dysfunction-associated steatohepatitis (MASH) with inflammation, hepatocyte damage, and fibrosis. Interestingly, the liver exhibits close intercommunication with fatty tissue. In fact, adipose tissue could contribute to the etiology and advancement of MASLD, acting as an endocrine organ that releases several hormones and cytokines, with the adipokines assuming a pivotal role. The levels of adipokines in the blood are altered in people with MASLD, and recent research has shed light on the crucial role played by adipokines in regulating energy expenditure, inflammation, and fibrosis in MASLD. However, MASLD disease is a multifaceted condition that affects various aspects of health beyond liver function, including its impact on hemostasis. The alterations in coagulation mechanisms and endothelial and platelet functions may play a role in the increased vulnerability and severity of MASLD. Therefore, more attention is being given to imbalanced adipokines as causative agents in causing disturbances in hemostasis in MASLD. Metabolic inflammation and hepatic injury are fundamental components of MASLD, and the interrelation between these biological components and the hemostasis pathway is delineated by reciprocal influences, as well as the induction of alterations. Adipokines have the potential to serve as the shared elements within this complex interrelationship. The objective of this review is to thoroughly examine the existing scientific knowledge on the impairment of hemostasis in MASLD and its connection with adipokines, with the aim of enhancing our comprehension of the disease.

Metabolome analysis reveals that cyclic adenosine diphosphate ribose contributes to the regulation of differentiation in mice adipocyte

Adipocytes play a key role in energy storage and homeostasis. Although the role of transcription factors in adipocyte differentiation is known, the effect of endogenous metabolites of low molecular weight remains unclear. Here, we analyzed time-dependent changes in the levels of these metabolites throughout adipocyte differentiation, using metabolome analysis, and demonstrated that there is a positive correlation between cyclic adenosine diphosphate ribose (cADPR) and Pparγ mRNA expression used as a marker of differentiation. We also found that the treatment of C3H10T1/2 adipocytes with cADPR increased the mRNA expression of those marker genes and the accumulation of triglycerides. Furthermore, inhibition of ryanodine receptors (RyR), which are activated by cADPR, caused a significant reduction in mRNA expression levels of the marker genes and triglyceride accumulation in adipocytes. Our findings show that cADPR accelerates adipocytic differentiation via RyR pathway.

Sensitivity of the Neuroendocrine Stress Axis in Metabolic Diseases

Metabolic diseases are prevalent in modern society and have reached pandemic proportions. Metabolic diseases have systemic effects on the body and can lead to changes in the neuroendocrine stress axis, the critical regulator of the body's stress response. These changes may be attributed to rising insulin levels and the release of adipokines and inflammatory cytokines by adipose tissue, which affect hormone production by the neuroendocrine stress axis. Chronic stress due to inflammation may exacerbate these effects. The increased sensitivity of the neuroendocrine stress axis may be responsible for the development of metabolic syndrome, providing a possible explanation for the high prevalence of severe comorbidities such as heart disease and stroke associated with metabolic disease. In this review, we address current knowledge of the neuroendocrine stress axis in response to metabolic disease and discuss its role in developing metabolic syndrome.

The promising roles of medicinal plants and bioactive compounds on hepatic lipid metabolism in the treatment of non-alcoholic fatty liver disease in animal models: molecular targets

Imbalance in hepatic lipid metabolism can lead to an abnormal triglycerides deposition in the hepatocytes which can cause non-alcoholic fatty liver disease (NAFLD). Four main mechanisms responsible for regulating hepatic lipid metabolism are fatty acid uptake, de novo lipogenesis, lipolysis and fatty acid oxidation. Controlling the expression of transcription factors at molecular level plays a crucial role in NAFLD management. This paper reviews various medicinal plants and their bioactive compounds emphasising mechanisms involved in hepatic lipid metabolism, other important NAFLD pathological features, and their promising roles in managing NAFLD through regulating key transcription factors. Although there are many medicinal plants popularly investigated for NAFLD treatment, there is still little information and scientific evidence available and there has been no research on clinical trials scrutinised on this matter. This review also aims to provide molecular information of medicinal plants in NALFD treatment that might have potentials for future scientifically controlled studies.

Sociodemographic, Behavioural, and Health Factors Associated with Sedentary Behaviour in Community-Dwelling Older Adults: A Nationwide Cross-Sectional Study

Few studies have focused on factors associated with sedentary behaviour among older Asian adults. This study aimed to identify factors independently associated with prolonged sedentary times in Korean older adults. We included 8273 community-dwelling older adults aged ≥65 years who participated in the Korean National Health and Nutrition Examination Survey. Self-reported sedentary times were assessed via the Global Physical Activity Questionnaire, and sedentary times of ≥420 min/day were considered 'long'. Complex-sample multivariable-adjusted logistic regression analyses were conducted to investigate the factors associated with long sedentary times. Among the participants, 4610 (55.72%) had long sedentary times that were associated with advanced age (odds ratio [OR], 2.49; 95% confidence interval [CI], 2.05-3.01), female sex (OR, 1.32; 95% CI, 1.11-1.57), unemployment (OR, 1.23; 95% CI, 1.09-1.38), living alone (OR, 1.24; 95% CI, 1.08-1.43), urban residence (OR, 1.35; 95% CI, 1.14-1.61), and insufficient aerobic exercise (OR, 1.80; 95% CI, 1.60-2.02). Among health factors, obesity (OR, 1.27; 95% CI, 1.12-1.45), diabetes (OR, 1.17; 95% CI, 1.04-1.32), cardiovascular diseases (OR, 1.30; 95% CI, 1.11-1.52), and arthritis (OR, 1.26; 95% CI, 1.11-1.43) had positive associations with long sedentary times. A tailored approach that considered various sociodemographic, behavioural, and health factors is needed to reduce sedentary behaviour in this population.

State of art on the mechanisms of laparoscopic sleeve gastrectomy in treating type 2 diabetes mellitus

Obesity and type-2 diabetes mellitus (T2DM) are metabolic disorders. Obesity increases the risk of T2DM, and as obesity is becoming increasingly common, more individuals suffer from T2DM, which poses a considerable burden on health systems. Traditionally, pharmaceutical therapy together with lifestyle changes is used to treat obesity and T2DM to decrease the incidence of comorbidities and all-cause mortality and to increase life expectancy. Bariatric surgery is increasingly replacing other forms of treatment of morbid obesity, especially in patients with refractory obesity, owing to its many benefits including good long-term outcomes and almost no weight regain. The bariatric surgery options have markedly changed recently, and laparoscopic sleeve gastrectomy (LSG) is gradually gaining popularity. LSG has become an effective and safe treatment for type-2 diabetes and morbid obesity, with a high cost-benefit ratio. Here, we review the me-chanism associated with LSG treatment of T2DM, and we discuss clinical studies and animal experiments with regard to gastrointestinal hormones, gut microbiota, bile acids, and adipokines to clarify current treatment modalities for patients with obesity and T2DM.

Hormonal regulation of visfatin and adiponectin system in quail muscle cells

Visfatin and adiponectin are two adipokines known to regulate energy homeostasis and stress response within different peripheral tissues. Their role and regulation in highly metabolically active tissue such as the muscle is of particular interest. As modern poultry exhibit insulin resistance, obesity, and hyperglycemia along with a lack of insight into the regulation of these avian adipokines, we undertook the present work to determine the regulation of visfatin and adiponectin system by cytokines and obesity-related hormones in a relevant in vitro model of avian muscle, quail muscle (QM7) cells. Cells were treated with pro-inflammatory cytokine IL-6 (5 and 10 ng/mL) and TNFα (5 and 10 ng/mL), as well as leptin (10 and 100 ng/mL) and both orexin-A and orexin-B (ORX-A/B) (5 and 10 ng/mL). Results showed significant increases in visfatin mRNA abundance under both cytokines (IL-6 and TNFα), and down regulation with ORX-B treatment. Adiponectin expression was also upregulated by pro-inflammatory cytokines (IL-6 and TNFα), but down regulated by leptin, ORX-A, and ORXB. High doses of IL-6 and TNFα up regulated the expression of adiponectin receptors AdipoR1 and AdipoR2, respectively. Leptin and orexin treatments also down regulated both AdipoR1 and AdipoR2 expression. Taken together, this is the first report showing a direct response of visfatin and the adiponectin system to pro-inflammatory and obesity-related hormones in avian muscle cells.

Recent progress of biocompatible carbon dots in hypoxia-related fields

Almost all eukaryotes need oxygen to maintain regular physiological activities. When the organism is under hypoxic situation for a persistent or periodic, it will induce irreversible physiological disorders and even pathological results. Hypoxia is closely related to the pathogenesis of metabolic diseases, cancer, chronic heart disease and kidney disease, myocardial ischemia, as well as reproductive diseases like preeclampsia and endometriosis. Therefore, monitoring and treatment of hypoxia have important implications for the pathophysiology of human-related diseases. Carbon dots (CDs) are emerging nanomaterials developed after 2004 with excellent performance, and have broad application potential in variousdomains likeoptical, biomedicine, energy. Advanced hypoxia therapeutics should be integrated with monitoring and treatment, and CDs with excellent performance are good potential options when sensing is combined with various therapeutic methods. Some researchers have also begun to carry out research in related fields and achieved some results. This article aims to clarify the various applications of CDs in hypoxia-related fields in recent years, including hypoxia sensing and hypoxia tumor theranostics. Finally, the possible challenges and prospects for the application of CDs in hypoxia-related fields are discussed.

Decreased adiponectin/leptin ratio relates to insulin resistance in adults with obesity

Adipose tissue dysfunction is a key mechanism that leads to adiposity-based chronic disease. This study aimed to investigate the reliability of the adiponectin/leptin ratio (AdipoQ/Lep) as an adipose tissue and metabolic function biomarker in adults with obesity, without diabetes. Data were collected from a clinical trial conducted in 28 adults with obesity (mean body mass index: 35.4 ± 3.7 kg/m²) (NCT02169778). With the use of a forward stepwise multiple linear regression model to explore the relationship between AdipoQ/Lep and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), it was observed that 48.6% of HOMA-IR variance was explained by triacylglycerols, AdipoQ/Lep, and waist-to-hip ratio (P < 0.001), AdipoQ/Lep being the strongest independent predictor (Beta = -0.449, P < 0.001). A lower AdipoQ/Lep was correlated with higher body mass index (R_s = -0.490, P < 0.001), body fat mass (R_s = -0.486, P < 0.001), waist-to-height ratio (R_s = -0.290, P = 0.037), and plasma resistin (R_s = -0.365, P = 0.009). These data highlight the central role of adipocyte dysfunction in the pathogenesis of insulin resistance and emphasize that AdipoQ/Lep may be a promising early marker of insulin resistance development in adults with obesity.NEW & NOTEWORTHY Adiponectin/leptin ratio, triacylglycerols, and waist-to-hip ratio explained almost half of HOMA-IR variance in the context of obesity. This study provides evidence to support adipose tissue dysfunction as a central feature of the pathophysiology of obesity and insulin resistance. Early identification of individuals at higher risk of developing metabolic complications through adipose tissue dysfunction assessment and the staging of obesity and its transient phenotypes can contribute to improve therapeutic decision-making.

Preeclampsia and Obesity-The Preventive Role of Exercise

Obesity is now recognized as a worldwide epidemic. An inadequate diet and reduced physical activity are acknowledged as the leading causes of excess body weight. Despite growing evidence that obesity is a risk factor for unsuccessful pregnancies, almost half of all women who become pregnant today are overweight or obese. Common complications of pregnancy in this group of women are preeclampsia and gestational hypertension. These conditions are also observed more frequently in women with excessive weight gain during pregnancy. Preeclampsia is one of the most serious pregnancy complications with an unpredictable course, which in its most severe forms, threatens the life and health of the mother and her baby. The early identification of the risk factors for preeclampsia development, including obesity, allows for the implementation of prophylaxis and a reduction in maternal and fetal complications risk. Additionally, preeclampsia and obesity are the recognized risk factors for developing cardiovascular disease in later life, so prophylaxis and treating obesity are paramount for their prevention. Thus, a proper diet and physical activity might play an essential role in the prophylaxis of preeclampsia in this group of women. Limiting weight gain during pregnancy and modifying the metabolic risk factors with regular physical exercise creates favorable metabolic conditions for pregnancy development and benefits the elements of the pathogenetic sequence for preeclampsia development. In addition, it is inexpensive, readily available and, in the absence of contraindications to its performance, safe for the mother and fetus. However, for this form of prevention to be effective, it should be applied early in pregnancy and, for overweight and obese women, proposed as an essential part of planning pregnancy. This paper aims to present the mechanisms of the development of hypertension in pregnancy in obese women and the importance of exercise in its prevention.

Energy metabolism and frailty: The potential role of exercise-induced myokines - A narrative review

Frailty is a complex condition that emerges from dysregulation in multiple physiological systems. Increasing evidence suggests the potential role of age-related energy dysregulation as a key driver of frailty. Exercise is considered the most efficacious intervention to prevent and even ameliorate frailty as it up-tunes and improves the function of several related systems. However, the mechanisms and molecules responsible for these intersystem benefits are not fully understood. The skeletal muscle is considered a secretory organ with endocrine functions that can produce and secrete exercise-related molecules such as myokines. These molecules are cytokines and other peptides released by muscle fibers in response to acute and/or chronic exercise. The available evidence supports that several myokines can elicit autocrine, paracrine, or endocrine effects, partly mediating inter-organ crosstalk and also having a critical role in improving cardiovascular, metabolic, immune, and neurological health. This review describes the current evidence about the potential link between energy metabolism dysregulation and frailty and provides a theoretical framework for the potential role of myokines (via exercise) in counteracting frailty. It also summarizes the physiological role of selected myokines and their response to different acute and chronic exercise protocols in older adults.

The effect of high-intensity interval training on serum and adipose tissues vaspin levels in rats fed a high-fat high-sucrose diet

BACKGROUND

Vaspin is an adipocytokine with insulin-sensitizing and anti-inflammatory traits.

OBJECTIVES

The purpose of this study was to evaluate the effect of high-intensity interval training (HIIT) on serum, visceral and subcutaneous adipose tissue vaspin levels in rats exposed to a diet high in fat and sugar (HFS).

MATERIALS AND METHODS

Thirty-two male Wistar rats were randomly divided into HFS and standard diet (SD) groups. After 12 weeks, each group was divided into sedentary and HIIT groups. HIIT program was performed 3 times/week for 8 weeks. Retroperitoneal adipose tissue, inguinal adipose tissue and serum were collected to analyze vaspin levels. Also, serum glucose and insulin levels, insulin resistance index (HOMA-IR) and retroperitoneal and inguinal fat weights were measured.

RESULTS

HFS significantly increased weight gain, weight of inguinal (p=0.001) and retroperitoneal fat depots (p<0.001), serum glucose levels (p<0.001) and HOMA-IR (p<0.001). The HIIT was able to decline weight gain and fat mass (p<0.05) but did not affect inguinal and retroperitoneal fat depots' vaspin levels. Eight weeks' HIIT significantly increased serum vaspin (p=0.002) and decreased insulin (p=0.001) levels only in rats fed with SD.

CONCLUSIONS

Although the HIIT program can cause significantly reducing effects on weight gain and fat depots' weights, it does not effect on circulating and fat depots' vaspin levels in rats fed an HFS.

Short-Chain Fatty Acids in Gut-Heart Axis: Their Role in the Pathology of Heart Failure

Heart failure (HF) is a syndrome with global clinical and socioeconomic burden worldwide owing to its poor prognosis. Accumulating evidence has implicated the possible contribution of gut microbiota-derived metabolites, short-chain fatty acids (SCFAs), on the pathology of a variety of diseases. The changes of SCFA concentration were reported to be observed in various cardiovascular diseases including HF in experimental animals and humans. HF causes hypoperfusion and/or congestion in the gut, which may lead to lowered production of SCFAs, possibly through the pathological changes of the gut microenvironment including microbiota composition. Recent studies suggest that SCFAs may play a significant role in the pathology of HF, possibly through an agonistic effect on G-protein-coupled receptors, histone deacetylases (HDACs) inhibition, restoration of mitochondrial function, amelioration of cardiac inflammatory response, its utilization as an energy source, and remote effect attributable to a protective effect on the other organs. Collectively, in the pathology of HF, SCFAs might play a significant role as a key mediator in the gut-heart axis. However, these possible mechanisms have not been entirely clarified and need further investigation.

Role of visfatin in obesity-induced insulin resistance

The growing worldwide burden of insulin resistance (IR) emphasizes the importance of early identification for improved management. Obesity, particularly visceral obesity, has been a key contributing factor in the development of IR. The obesity-associated chronic inflammatory state contributes to the development of obesity-related comorbidities, including IR. Adipocytokines, which are released by adipose tissue, have been investigated as possible indicators of IR. Visfatin was one of the adipocytokines that attracted attention due to its insulin-mimetic activity. It is released from a variety of sources, including visceral fat and macrophages, and it influences glucose metabolism and increases inflammation. The relationship between visfatin and IR in obesity is debatable. As a result, the purpose of this review was to better understand the role of visfatin in glucose homeostasis and to review the literature on the association between visfatin levels and IR, cardiovascular diseases, and renal diseases in obesity.

OBEZİTENİN DOLAŞIMDAKİ GALANİN VE VASPİN DÜZEYLERİ İLE İLİŞKİSİ

Objective: Our aim was to compare vaspin and galanin in obese and normal weight individuals, to reveal whether these parameters are related to obesity and other related parameters. Material and Methods: Forty patients with obesity and 40 control subjects were included in the study. Biochemical parameters were recorded from patient’s files. Galanin and vaspin levels were studied by ELISA method, obtained as a result of centrifugation of these blood samples. Results: The groups were similar to each other in terms of gender and age (p>0.05). Galanine levels were higher in the group with obesity compared to the control group (p0.05). Glucose, insulin, triglyceride and LDL-C levels were statistically significantly higher in the patient group than in the control group (p0.05). A statistically significant positive correlation was found with galanin and glucose, insulin, and BMI, respectively (p

Modulation of endoplasmic reticulum stress via sulforaphane-mediated AMPK upregulation against nonalcoholic fatty liver disease in rats

Nonalcoholic fatty liver disease (NAFLD) is a major health concern. Endoplasmic reticulum (ER) stress, inflammation, and metabolic dysfunctions may be targeted to prevent the progress of nonalcoholic fatty liver disease. Sulforaphane (SFN), a sulfur-containing compound that is abundant in broccoli florets, seeds, and sprouts, has been reported to have beneficial effects on attenuating metabolic diseases. In light of this, the present study was designed to elucidate the mechanisms by which SFN ameliorated ER stress, inflammation, lipid metabolism, and insulin resistance - induced by a high-fat diet and ionizing radiation (IR) in rats. In our study, the rats were randomly divided into five groups: control, HFD, HFD + SFN, HFD + IR, and HFD + IR + SFN groups. After the last administration of SFN, liver and blood samples were taken. As a result, the lipid profile, liver enzymes, glucose, insulin, IL-1β, adipokines (leptin and resistin), and PI3K/AKT protein levels, as well as the mRNA gene expression of ER stress markers (IRE-1, sXBP-1, PERK, ATF4, and CHOP), fatty acid synthase (FAS), peroxisome proliferator-activated receptor-α (PPAR-α). Interestingly, SFN treatment modulated the levels of proinflammatory cytokine including IL-1β, metabolic indices (lipid profile, glucose, insulin, and adipokines), and ER stress markers in HFD and HFD + IR groups. SFN also increases the expression of PPAR-α and AMPK genes in the livers of HFD and HFD + IR groups. Meanwhile, the gene expression of FAS and CHOP was significantly attenuated in the SFN-treated groups. Our results clearly show that SFN inhibits liver toxicity induced by HFD and IR by ameliorating the ER stress events in the liver tissue through the upregulation of AMPK and PPAR-α accompanied by downregulation of FAS and CHOP gene expression.

The genetic interactions between non-alcoholic fatty liver disease and cardiovascular diseases

The ongoing debate on whether non-alcoholic fatty liver disease (NAFLD) is an active contributor or an innocent bystander in the development of cardiovascular disease (CVD) has sparked interests in understanding the common mediators between the two biologically distinct entities. This comprehensive review identifies and curates genetic studies of NAFLD overlapping with CVD, and describes the colinear as well as opposing correlations between genetic associations for the two diseases. Here, CVD described in relation to NAFLD are coronary artery disease, cardiomyopathy and atrial fibrillation. Unique findings of this review included certain NAFLD susceptibility genes that possessed cardioprotective properties. Moreover, the complex interactions of genetic and environmental risk factors shed light on the disparity in genetic influence on NAFLD and its incident CVD. This serves to unravel NAFLD-mediated pathways in order to reduce CVD events, and helps identify targeted treatment strategies, develop polygenic risk scores to improve risk prediction and personalise disease prevention.

The Association of lncRNA and mRNA Changes in Adipose Tissue with Improved Insulin Resistance in Type 2 Obese Diabetes Mellitus Rats after Roux-en-Y Gastric Bypass

Objective

Roux-en-Y gastric bypass (RYGB) has shown good effects in improving obesity and type II diabetes mellitus (T2DM), but the underlying mechanisms remain unclear. This study explored the changes of related lncRNAs, mRNAs, and signaling pathways in white adipose tissue of T2DM rats after RYGB based on RNA-Seq sequencing, with the aim to provide a theoretical basis for RYGB treatment.

Methods

T2DM rat models were established by continuous feeding with a high-fat diet and injection of streptozotocin (STZ), after which they underwent RYGB or sham surgery. After the surgery, their body weight was measured weekly. Their fasting blood glucose (FBG) and fasting serum insulin (FSI) were also measured. A homeostasis model assessment of insulin resistance (HOMA-IR) was calculated at weeks 0, 8, and 12. Besides, white adipose tissue of T2DM rats was collected for RNA-Seq sequencing and validated by qRT-PCR. A series of bioinformatics analyses, such as differential expression genes (DEGs) screening, was performed. GO and KEGG functional enrichment analysis and protein-protein interaction (PPI) network construction were conducted based on the sequencing data.

Results

RYGB surgery could significantly inhibit the weight growth rate and decrease the FBG, FSI, and HOMA-IR of T2DM rats. Bioinformatics analysis of RNA sequencing (RNA-Seq) results revealed that 87 DE- lncRNAs (49 upregulated and 38 downregulated) and 1,824 DEGs (896 upregulated and 928 downregulated) were present in between the RYGB group and Sham group. GO and KEGG analysis showed that the target genes of DEGs and differentially expressed lncRNAs (DE-lncRNAs) were mainly associated with amino acid metabolism, fatty acid metabolism, channel activity, and other processes. In addition, the PPI network diagram also displayed that genes such as Fasn, Grin3a, and Nog could be key genes playing a role after RYGB. qRT-PCR showed that the expression level of Grin3a in the RYGB group was significantly increased compared with the Sham group, while the expression of Fasn and Nog was significantly decreased, which was consistent with the sequencing results.

Conclusion

Using RNA-Seq sequencing, this study revealed the changes of related lncRNAs, mRNAs, and signaling pathways in the white adipose tissue of T2DM rats after RYGB and identified Fasn, Grin3a, and Nog as potential key genes to function after RYGB.

Methanolic fruit extract of Myrica nagi protects the hypothalamus and attenuates inflammation associated with gold thioglucose- and high-fat diet-induced obesity via various adipokines

BACKGROUND

Myrica nagi is popular in unani and ayurveda. Chemical constituents like myricetin isolated from its fruit has been shown to exert beneficial effects against cardiovascular disease, cancer, inflammatory conditions, and metabolic disorders.

OBJECTIVES

This study aimed to elucidate the anti-obesity effect of the methanolic extract of M. nagi (MEMN) using in vivo animal models of obesity induced by gold thioglucose or a high-fat diet.

MATERIALS AND METHODS

The obese mice were treated or untreated with MEMN for 8 weeks. Thereafter, feed intake, Lee index, and body mass index (BMI); biochemical parameters such as lipid profile, liver enzymes and specific biomarkers of obesity, including insulin, leptin, adiponectin, free fatty acids (FFA), monocyte chemoattractant protein (MCP)-1, and resistin, were recorded. The weight and histopathology of organs and fat tissue were examined to validate the effectiveness of the extract.

RESULTS

MEMN administration at various doses significantly reduced the induced weight gain, feed intake, BMI, and Lee index. Adipose tissue decreased as the MEMN dose increased. MEMN attenuated liver enzyme activity, decreased lipid, leptin, MCP-1, resistin, and FFA levels, and increased adiponectin levels. It also increased protection of liver cells and decreased accumulation of mesenteric fat.

CONCLUSIONS

MEMN supplementation decreased weight and improved obesity serum/plasma lipid biomarker, insulin, leptin, adiponectin, MCP-1, and resistin levels. The weight-reducing activity of MEMN may be mediated by decreased gastrointestinal fat absorption and modulation of inflammation associated signaling pathways, leading to reduced adipose inflammation associated with energy expenditure.

Contribution of organokines in the development of NAFLD/NASH associated hepatocellular carcinoma

Globally the incidence of hepatocellular carcinoma (HCC) is on an upsurge. Evidence is accumulating that liver disorders like nonalcoholic fatty liver disease (NAFLD) and its more progressive form nonalcoholic steatohepatitis (NASH) are associated with increased risk of developing HCC. NAFLD has a prevalence of about 25% and 50%-90% in obese population. With the growing burden of obesity epidemic worldwide, HCC presents a major healthcare burden. While cirrhosis is one of the major risk factors of HCC, available literature suggests that NAFLD/NASH associated HCC also develops in minimum or noncirrhotic livers. Therefore, there is an urgent need to understand the pathogenesis and risk factors associated with NAFLD and NASH related HCC that would help in early diagnosis and favorable prognosis of HCC secondary to NAFLD. Adipokines, hepatokines and myokines are factors secreted by adipocytes, hepatocytes and myocytes, respectively, playing essential roles in cellular homeostasis, energy balance and metabolism with autocrine, paracrine and endocrine effects. In this review, we endeavor to focus on the role of these organokines in the pathogenesis of NAFLD/NASH and its progression to HCC to augment the understanding of the factors stimulating hepatocytes to acquire a malignant phenotype. This shall aid in the development of novel therapeutic strategies and tools for early diagnosis of NAFLD/NASH and HCC.

A Meta-analysis of ADIPOQ rs2241766 polymorphism association with type 2 diabetes

Objective

There is extensive research on the association between polymorphisms in the adiponectin gene (ADIPOQ) and type 2 diabetes (T2D). The present meta-analytic study explored the association between ADIPOQ rs2241766 polymorphisms and T2D.

Metolds

Articles were collected by searching Google Scholar, Scopus, and PubMed electronic databases until 2021. They were searched using a systematic search of original and sensitive English keywords and their equivalent keywords based on the keywords "type 2 diabetes", "ADIPOQ", and "rs2241766". The article selection criteria were based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram.

Results

The results revealed that there was no bias in this study. Some studies, such as Joshaghani et al. (odds ratio [OR] = 2.18), Hussain et al. (OR = 2.12), Momin (OR = 4.45), and Amal et al. (OR = 1.84), showed an increasing effect of ADIPOQ rs266729 polymorphism on T2D with 95% CI (P ˂ 0.01), while some have shown no significant association between them.

Conclusion

The results of this meta-analytic study showed the relationship between ADIPOQ and rs2241766. Also, it was found that Rs2241766 polymorphism and allele increase the risk, and rs2241766 increases the risk of developing T2D (OR = 1.29).

Trends in insulin resistance: insights into mechanisms and therapeutic strategy

The centenary of insulin discovery represents an important opportunity to transform diabetes from a fatal diagnosis into a medically manageable chronic condition. Insulin is a key peptide hormone and mediates the systemic glucose metabolism in different tissues. Insulin resistance (IR) is a disordered biological response for insulin stimulation through the disruption of different molecular pathways in target tissues. Acquired conditions and genetic factors have been implicated in IR. Recent genetic and biochemical studies suggest that the dysregulated metabolic mediators released by adipose tissue including adipokines, cytokines, chemokines, excess lipids and toxic lipid metabolites promote IR in other tissues. IR is associated with several groups of abnormal syndromes that include obesity, diabetes, metabolic dysfunction-associated fatty liver disease (MAFLD), cardiovascular disease, polycystic ovary syndrome (PCOS), and other abnormalities. Although no medication is specifically approved to treat IR, we summarized the lifestyle changes and pharmacological medications that have been used as efficient intervention to improve insulin sensitivity. Ultimately, the systematic discussion of complex mechanism will help to identify potential new targets and treat the closely associated metabolic syndrome of IR.

Hyperinsulinemia Associated Depression

Hyperinsulinemia promotes fat accumulation, causing obesity. Being an inflammatory state, obesity can induce further inflammation and is a risk factor for HPA (hypothalamic pituitary axis) dysregulation through hypercortisolism-related hyperglycemia. In another hypothesis, the sympathetic nervous system (SNS) plays a significant role in the regulation of hormone secretion from the pancreas such as an increase in catecholamines and glucagon as well as a decrease in plasma insulin levels, a disruption on SNS activity increases insulin levels, and induces glycogenolysis in the liver and lipolysis in adipose tissue during hypoglycemia. Hyperglycemia-hyperinsulinemia exacerbates inflammation and increases the oxidative stress along with regulating the levels of norepinephrine in the brain sympathetic system. Increased inflammatory cytokines have also been shown to disrupt neurotransmitter metabolism and synaptic plasticity which play a role in the development of depression via inhibiting serotonin, dopamine, melatonin, and glutamate signaling. An increased level of plasma insulin over time in the absence of exercising causes accumulation of lipid droplets in hepatocytes and striated muscles thus preventing the movement of glucose transporters shown to result in an increase in insulin resistance due to obesity and further culminates into depression. Further hyperinsulinemia-hyperglycemia condition arising due to exogenous insulin supplementation for diabetes management may also lead to physiological hyperinsulinemia associated depression. Triple therapy with SSRI, bupropion, and cognitive behavioral therapy aids in improving glycemic control, lowering fasting blood glucose, decreasing the chances of relapse, as well as decreasing cortisol levels to improve cognition and the underlying depression. Restoring the gut microbiota has also been shown to restore insulin sensitivity and reduce anxiety and depression symptoms in patients.

Adipose tissue aging: mechanisms and therapeutic implications

Adipose tissue, which is the crucial energy reservoir and endocrine organ for the maintenance of systemic glucose, lipid, and energy homeostasis, undergoes significant changes during aging. These changes cause physiological declines and age-related disease in the elderly population. Here, we review the age-related changes in adipose tissue at multiple levels and highlight the underlying mechanisms regulating the aging process. We also discuss the pathogenic pathways of age-related fat dysfunctions and their systemic negative consequences, such as dyslipidemia, chronic general inflammation, insulin resistance, and type 2 diabetes (T2D). Age-related changes in adipose tissue involve redistribution of deposits and composition, in parallel with the functional decline of adipocyte progenitors and accumulation of senescent cells. Multiple pathogenic pathways induce defective adipogenesis, inflammation, aberrant adipocytokine production, and insulin resistance, leading to adipose tissue dysfunction. Changes in gene expression and extracellular signaling molecules regulate the aging process of adipose tissue through various pathways. In addition, adipose tissue aging impacts other organs that are infiltrated by lipids, which leads to systemic inflammation, metabolic system disruption, and aging process acceleration. Moreover, studies have indicated that adipose aging is an early onset event in aging and a potential target to extend lifespan. Together, we suggest that adipose tissue plays a key role in the aging process and is a therapeutic target for the treatment of age-related disease, which deserves further study to advance relevant knowledge.

Serum uric acid and risk of prehypertension: a dose-response meta-analysis of 17 observational studies of approximately 79 thousand participants

BACKGROUND

Studies examining the association between levels of serum uric acid (SUA) and risk of prehypertension still remained controversial conclusions. Also, a quantitative assessment of the dose-response association between them has not been reported. We aimed to quantitatively evaluate risk of prehypertension with levels of SUA based on observational study.

METHODS

We searched the PubMed, Embase, and Web of Science databases up to December 3, 2019 for relevant studies. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random-effects models. The possible linear or non-linear SUA-prehypertension association was modelled by restricted cubic splines.

RESULTS

We included 17 articles (17 studies) with a total of 79,358 participants and 34,591 cases of prehypertension. Compared with lowest levels of SUA, risk of prehypertension increased 46% (RR 1.46, 95% CI 1.28-1.66) for highest levels of SUA. For per 1 mg/dL increment in levels of SUA, risk of prehypertension increased by 12% (RR 1.12, 95% CI 1.08-1.17). Also, we found evidence of a linear SUA-prehypertension association (P_{non-linearity}=.368).

CONCLUSION

Elevated levels of SUA may be associated with increased risk of prehypertension. Present findings provide the evidence that lowering levels of SUA should be suggested in order to reduce the risk of prehypertension. More longitudinal and intervention studies are needed to clarify the optimal protective levels and whether reducing levels of SUA could prevent or control prehypertension and the progression of prehypertension to hypertension.

Sirt3 Pharmacologically Promotes Insulin Sensitivity through PI3/AKT/mTOR and Their Downstream Pathway in Adipocytes

Sirtuin-3 (Sirt3) is a major mitochondrial deacetylase enzyme that regulates multiple metabolic pathways, and its expression is decreased in diabetes type 1 and type 2 diabetes. This study aimed to elucidate Sirt3′s molecular mechanism in regulating insulin sensitivity in adipocytes that can contribute to the effort of targeting Sirt3 for the treatment of obesity and type 2 diabetes. We found that the Sirt3 activator honokiol (HNK) induced adipogenesis compared to the control, in contrast to Sirt3 inhibitor, 3-TYP. Accordingly, HNK increased expression of adipocyte gene markers, gene-involved lipolysis and glucose transport (GLUT4), while 3-TYP reduced expression of those genes. Interestingly, 3-TYP caused an increase in gene expression of adipocyte-specific cytokines including IL6, resistin, and TNF-α. However, changes in adipocyte-specific cytokines in HNK treated cells were not significant. In addition, HNK stimulated insulin pathway by promoting insulin receptor beta (IRβ) and PI3K/AKT/mTOR pathways, resulting in an increase in phosphorylation of the forkhead family FoxO1/FoxO3a/FoxO4 and glycogen synthase kinase-3 (GSK-3β), opposing 3-TYP. In line with these findings, HNK increased free fatty acid and glucose uptake, contrary to 3-TYP. In conclusion, Sirt3 activator-HNK induced adipogenesis and lipolysis reduced adipocytes specific cytokines. Intriguingly, HNK activated insulin signaling pathway and increased free fatty acid as well as glucose uptake and transport, in sharp contrast to 3-TYP. These results indicate that, via insulin signaling regulation, Sirt3 activation by HNK improves insulin resistance, while Sirt3 inhibition by 3-TYP might precipitate insulin resistance.

The NLRP3 inflammasome activation in subcutaneous, epicardial and pericardial adipose tissue in patients with coronary heart disease undergoing coronary by-pass surgery

Background and aims

Epicardial and pericardial adipose tissue (EAT and PAT) associate with atherosclerosis, however, discussed to have different inflammatory properties. We examined the NLRP3 inflammasome related pathway, playing a pivotal role in atherosclerosis, in EAT, PAT and subcutaneous AT (SAT), their relationship to cell types and anthropometric measures in patients undergoing coronary artery bypass grafting.

Methods

Biopsies from EAT, PAT and SAT were collected from 52 patients with coronary heart disease (CHD) (median body weight 85.0 kg) and 22 controls. RNA was extracted and expression of interleukin (IL)-1β, IL-18, NLRP3, Caspase-1, toll-like receptor 4 (TLR4), IL-6, IL-6 receptor and gp130 were analyzed by RT-PCR.

Results

Limited differences in any genes between CHD patients and controls. IL-18 and IL-6 were 4-fold higher expressed in EAT versus PAT (p < 0.01, both) and SAT (p < 0.001, both), whereas caspase-1, IL-6R and gp130 were higher expressed in SAT compared to the other compartments (all p = 0.06-<0.001). Significant correlations between SAT and PAT gene expressions (r = 0.358-0.579, all p ≤ 0.01). Especially NLRP3 and TLR4 associated with the expression of macrophages in all compartments (all p < 0.001). In EAT IL-18 correlated inversely with the expression of macrophages and T-cells. In SAT and PAT most of the mediators associated with body weight.

Conclusions

Higher expression of IL-18 and IL-6 was observed in EAT in our non-obese CHD patients, not related to inflammatory cells. The NLRP3 inflammasome activation in SAT that mirrored PAT, both related to anthropometrics, suggest that SAT samples, being easily available, to a certain degree, represent adipose tissue inflammation in general.

Low level of adiponectin predicts the development of Nonalcoholic fatty liver disease: is it irrespective to visceral adiposity index, visceral adipose tissue thickness and other obesity indices?

We aimed to study the correlation of adiponectin level with insulin resistance (IR), carotid intima-media thickness (cIMT), and various obesity indices especially visceral adipose tissue (VAT) thickness, and visceral adiposity index (VAI), in patients with NAFLD (n = 41), T2D (n = 22), NAFLD + T2D (n = 41), and healthy subjects (n = 20). Results showed the median level of adiponectin in patients with NAFLD (2.97 μg/mL) and ones with NAFLD + T2D (3.21 μg/mL) is significantly lower rather than in controls (4.39 μg/mL). Moreover, VAI is the only predictor for adiponectin concentration in the combination of patient groups and also in all participants independent of IR and other obesity indices. Adiponectin level had also a positive correlation with cIMT and IR in NAFLD patients. Interestingly, lower level of adiponectin was associated with the presence of T2D, NAFLD, and NAFLD + T2D independent of IR and obesity indices. Collectively, it seems that VAI reflecting visceral adipose tissue function is a possible predictor of adiponectin level.

Synbiotic goat milk kefir improves health status in rats fed a high-fat and high-fructose diet

Background and Aim:

Kefir, a natural probiotic containing bacteria and yeast, is a fermented milk product, whereas glucomannan from porang tuber (Amorphophallus oncophyllus) is prebiotic in vivo. Simvastatin is a potent lipid-lowering statin that can be utilized for pharmacological therapy in obesity. This study aimed to determine the effect of goat milk kefir supplemented with porang glucomannan (synbiotic kefir) and goat milk kefir without glucomannan (probiotic kefir) on blood glucose, hemoglobin A1c (HbA1c), free fatty acids (FFAs), tumor necrosis factor-alpha (TNF-α), gene expression of peroxisome proliferator-activated receptor gamma (PPARg), and insulin-producing cells in rats fed a high-fat and high-fructose (HFHF) diet.

Materials and Methods:

Male Sprague-Dawley rats were divided into five dietary groups: (1) Normal control, (2) rats fed HFHF, (3) rats fed HFHF+probiotic kefir, (4) rats fed HFHF+synbiotic kefir, and (5) rats fed HFHF+simvastatin. All of these treatments were administered for 4 weeks.

Results:

There were no significant differences in plasma glucose levels in HFHF diet-fed rats before and after treatment. However, plasma HbA1c and TNF-α decreased, and FFAs were inhibited in rats after treatment with synbiotic kefir. Synbiotic kefir decreased the gene expression of PPARγ2 in HFHF diet-fed rats but did not affect the total number of islets of Langerhans and insulin-producing cells.

Conclusion:

Synbiotic kefir improved the health of rats fed an HFHF diet by decreasing HbA1c, TNF-α, and PPARγ2 gene expression and preventing an increase in FFAs.

Inflammation as A Precursor of Atherothrombosis, Diabetes and Early Vascular Aging

Vascular disease was for a long time considered a disease of the old age, but it is becoming increasingly clear that a cumulus of factors can cause early vascular aging (EVA). Inflammation plays a key role in vascular stiffening and also in other pathologies that induce vascular damage. There is a known and confirmed connection between inflammation and atherosclerosis. However, it has taken a long time to prove the beneficial effects of anti-inflammatory drugs on cardiovascular events. Diabetes can be both a product of inflammation and a cofactor implicated in the progression of vascular disease. When diabetes and inflammation are accompanied by obesity, this ominous trifecta leads to an increased incidence of atherothrombotic events. Research into earlier stages of vascular disease, and documentation of vulnerability to premature vascular disease, might be the key to success in preventing clinical events. Modulation of inflammation, combined with strict control of classical cardiovascular risk factors, seems to be the winning recipe. Identification of population subsets with a successful vascular aging (supernormal vascular aging-SUPERNOVA) pattern could also bring forth novel therapeutic interventions.

Linking Physical Activity to Breast Cancer: Text Mining Results and a Protocol for Systematically Reviewing Three Potential Mechanistic Pathways

Epidemiologic research suggests that physical activity is associated with a reduced risk of breast cancer, but the causal nature of this link is not clear. Investigating mechanistic pathways can provide evidence of biological plausibility and improve causal inference. This project will examine three putative pathways (sex steroid hormones, insulin signaling, and inflammation) in a series of two-stage systematic reviews. Stage 1 used Text Mining for Mechanism Prioritisation (TeMMPo) to identify and prioritize relevant biological intermediates. Stage 2 will systematically review the findings from studies of (i) physical activity and intermediates and (ii) intermediates and breast cancer. Ovid MEDLINE, EMBASE, and SPORTDiscus will be searched using a combination of subject headings and free-text terms. Human intervention and prospective, observational studies will be eligible for inclusion. Meta-analysis will be performed where possible. Risk of bias will be assessed using the Cochrane Collaboration tool, or the ROBINS-I or ROBINS-E tool, depending on study type. Strength of evidence will be assessed using the GRADE system. In addition to synthesizing the mechanistic evidence that links physical activity with breast cancer risk, this project may also identify priority areas for future research and help inform the design and implementation of physical activity interventions.See related reviews by Swain et al., p. 16 and Drummond et al., p. 28.

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.

Exenatide improves hepatocyte insulin resistance induced by different regional adipose tissue

Obesity is resulted from energy surplus and is characterized by abnormal adipose tissue accumulation and/or distribution. Adipokines secreted by different regional adipose tissue can induce changes in key proteins of the insulin signaling pathway in hepatocytes and result in impaired hepatic glucose metabolism. This study aimed to investigate whether exenatide affects key proteins of IRS2/PI3K/Akt2 signaling pathway in hepatocytes altered by the different regional fat depots. Six non-obese patients without endocrine diseases were selected as the research subjects. Their subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT)were co-cultured with HepG2 cells in the transwell chamber. In the presence or absence of exenatide, adipokines content in the supernatant of each experimental group was detected by ELISA. In addition, HepG2 cells in each co-culture group with and without insulin were collected, and the expression of key proteins IRS2, p-IRS2(S731), PI3K-p85, Akt2, and p-Akt2(S473) was detected by western blotting (WB). The results showed that the adipokines IL-8, MCP-1, VEGF, and sTNFR2 in the supernatant of HepG2 cells induced by different regional adipose tissue were significantly higher than those in the HepG2 group, and VAT released more adipokines than SAT. Furthermore, these adipokines were significantly inhibited by exenatide. Importantly, the different regional fat depot affects the IRS2/PI3K/Akt2 insulin signaling pathway of hepatocytes. Exenatide can up-regulate the expression of hepatocyte proteins IRS2, PI3K-p85, p-Akt2(S731) inhibited by adipose tissue, and down-regulate the expression of hepatocyte proteins p-IRS2(S731) promoted by adipose tissue. The effect of VAT on the expression of these key proteins in hepatocytes is more significant than that of SAT. But there was no statistical difference in the expression of Akt2 protein among each experimental group, suggesting that exenatide has no influence on the expression of Akt2 protein in hepatocytes. In conclusion, exenatide may improve hepatic insulin resistance (IR) by inhibiting adipokines and regulating the expression of key proteins in the IRS2/PI3K/Akt2 pathway.

Association of Mammary Gland Disease With Metabolic Syndrome Factors in Japanese Women—Case-Control Study Based on Health Screening Results

Background:

The association of obesity with breast cancer is clear. Although body mass index (BMI) is used as an indicator of obesity, its accuracy remains questionable. Although, there factors for diagnosing metabolic syndrome are caused by obesity, the association with breast cancer has not been clarified.

Methods:

Women who underwent breast cancer screening with mammography and measurements of metabolic syndrome factors, including waist circumference, blood glucose, triglycerides, HDL (high-density lipoprotein) cholesterol levels, and systolic and diastolic pressure, twice within a 2-year period were enrolled (n = 314), with a final sample size of 256. To determine the presence of mammary gland disease, 2 expert physicians interpreted radiogram findings, with category 3 or higher shown by mammography considered to indicate an abnormality.

Results and Conclusions:

Waist circumference at the initial measurement was marginally significant as a risk factor for onset of mammary gland disease (odds ratio [OR] = 1.036, P = .045) and thus was concluded to be a risk factor for disease onset. Although not significant, a 2-year increase in systolic and diastolic blood pressure has been presumed to be risk factors (systolic: OR = 1.020, P = .085, diastolic: OR = 1.040, P = .065), while high levels of HDL cholesterol have been presumed to protect against the disease (OR = 0.982, P = .064). Based on these results, waist circumference and blood pressure are speculated to be related to development of mammary gland disease.

Spexin ameliorates skeletal muscle insulin resistance through activation of GAL2 receptor

Skeletal muscle is a principal tissue involved in energy expenditure and glucose metabolism. Although the results of our and other studies show that spexin could decrease food intake and obesity, the specific metabolic effect of spexin on glucose metabolism of skeletal muscle is still unclear. The aim of this study is to investigate whether spexin might mitigate obesity-induced insulin resistance in skeletal muscles and to explore its underlying mechanisms. The high fat diet-fed mice were treated with 50 μg/kg/d spexin for 21 consecutive days, and the differentiated myotubes of L6 were treated with spexin (200, 400, 800 nM) in the absence or presence of M871 (800 nM) for 12 h respectively. Besides, the galanin type 2 (GAL2) receptor knockdown myotubes were treated with 800 nM spexin for 12 h in this study. The present findings showed that spexin reversed hyperglycemia and glucose intolerance as well as insulin intolerance and insulin resistance in the mice fed with high fat diet. Furthermore, spexin markedly augmented the peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) expression and deacetylation, and further triggered glucose transporter 4 (GLUT4) expression and trafficking in myotubes through p38 mitogen-activated protein kinase (P38MAPK) and protein kinase B (AKT) activation. More importantly, the elevation of glucose consumption related genes by spexin were abolished by GAL2 receptor antagonist or silencing of GAL2 receptor in myotubes. In conclusion, our findings provide a novel insight that spexin can protect against insulin resistance and increase glucose consumption in skeletal muscles mainly through activation of GAL2/GLUT4 signal pathway. Spexin might therefore be a novel therapeutic target for hyperglycemia and insulin resistance in clinic.

Exercise Training Combined with Calanus Oil Supplementation Improves the Central Cardiodynamic Function in Older Women

The aim of this study was to investigate the possible beneficial effects of exercise training (ET) with omega-3/Calanus oil supplementation on cardiorespiratory and adiposity parameters in elderly women. Fifty-five women (BMI: 19–37 kg/m², 62–80 years old) were recruited and randomly assigned to the 4 month intervention with ET and omega-3 supplementation (Calanus oil, ET-Calanus) or ET and the placebo (sunflower oil; ET-Placebo). The body composition was determined by dual-energy X-ray absorptiometry (DXA), and cardiorespiratory parameters were measured using spiroergometry and PhysioFlow hemodynamic testing. Both interventions resulted in an increased lean mass whereas the fat mass was reduced in the leg and trunk as well as the android and gynoid regions. The content of trunk fat (in percent of the total fat) was lower and the content of the leg fat was higher in the ET-Calanus group compared with the ET-Placebo. Although both interventions resulted in similar improvements in cardiorespiratory fitness (VO_2max), it was explained by an increased peripheral oxygen extraction (a-vO₂diff) alone in the ET-Placebo group whereas increased values of both a-vO₂diff and maximal cardiac output (CO_max) were observed in the ET-Calanus group. Changes in CO_max were associated with changes in systemic vascular resistance, circulating free fatty acids, and the omega-3 index. In conclusion, Calanus oil supplementation during a 4 month ET intervention in elderly women improved the cardiorespiratory function, which was due to combined central and peripheral cardiodynamic mechanisms.

Hepatoprotective Effect of Bee Bread in Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) Rats: Impact on Oxidative Stress and Inflammation

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a pathological accumulation of hepatic lipid closely linked with many metabolic disorders, oxidative stress and inflammation. We aimed to evaluate the hepatoprotective effect of bee bread on oxidative stress and inflammatory parameters in MAFLD rats. Twenty-eight male Sprague-Dawley rats were assigned into four groups (n = 7/group): normal control (NC), high-fat diet (HFD), bee bread (HFD + Bb, HFD + 0.5 g/kg/day bee bread) and orlistat (HFD + Or, HFD + 10 mg/kg/day orlistat) groups. After 12 weeks, the HFD group demonstrated significantly higher body weight gain, serum levels of lipids (TG, TC, LDL), liver enzymes (AST, ALT, ALP) and adiponectin, liver lipids (TG, TC) and insulin resistance (HOMA-IR). Furthermore, the HFD group showed significantly decreased antioxidant enzyme activities (GPx, GST, GR, SOD, CAT) and GSH level, and increased liver oxidative stress (TBARS, NO), translocation of Nrf2 to the nucleus, Keap1 expression and inflammation (TNF-α, NF-κβ, MCP-1) together with histopathological alterations (steatosis, hepatocyte hypertrophy, inflammatory cell infiltration, collagen deposition), which indicated the presence of non-alcoholic steatohepatitis (NASH) and fibrosis. Bee bread significantly attenuated all these changes exerted by HFD feeding. In conclusion, our results suggest that bee bread might have antioxidant, anti-inflammatory, anti-steatotic and anti-fibrotic effects that are beneficial in protecting liver progression towards NASH and fibrosis.

Transcriptomic analysis of MA-10 tumor Leydig cells treated with adipose derived hormones adiponectin and resistin

Obesity contributes to a decrease in testosterone production in men. Indeed, adipose tissue produces several hormones, including adiponectin and resistin, and these may influence the activity of signaling pathways responsible for regulating the expression of genes related to steroidogenesis. In this study, we wanted to identify which genes are directly regulated by these hormones using the MA-10 tumor Leydig cell model. To do this, we treated these cells with adiponectin or resistin, followed by RNA extraction and RNA-Seq transcriptome analysis. Interestingly, genes upregulated by the globular form of adiponectin (gACRP30) were associated to steroid hormones biosynthesis, whereas resistin had no effect on the transcriptome of MA-10 Leydig cells. Moreover, the expression of the Star gene, encoding the steroidogenic acute regulatory protein, was increased in response to treatments with 0.5 mM 8Br-cAMP. Such stimulation was further increased by adiponectin, resulting in increased progesterone production. However, resistin had no effect on steroid production from MA-10 tumor Leydig cells under the treatment conditions investigated. Thus, our data suggest that a direct regulation of steroidogenic genes' expressions in Leydig cells by adipose derived hormones involves cooperation between the cAMP/PKA pathway and adiponectin, but not resistin, to activate Star expression and improve progesterone synthesis.