Adipose Tissue as an Endocrine Organ: An Update on Pro-inflammatory and Anti-inflammatory Microenvironment

Association of adipocytokines with lipid and glycemic profiles in women with normal weight obesity

BACKGROUND

Individuals with normal weight obesity (NWO) are predisposed to having cardiometabolic disorders. This study aims to investigate the circulating levels of vaspin, leptin and their association with glycemic and lipid profiles in women with NWO.

METHODS

Forty women with body mass index (BMI) = 18.5-24.9 kg/m2 and fat mass (FM) ≥ 30% were assigned in the NWO group. Thirty age-matched women with identical BMI range, and FM < 30% (normal weight non-obese; NWNO) were considered as a control group. In addition to anthropometric measurements, glycemic and lipid profiles and circulating levels of leptin and vaspin were measured.

RESULTS

The mean ± standard deviation (SD) age of participants was 28.76 ± 4.76 years in the NWO group and 29.23 ± 4.50 years in the control group. The NWO group had the higher mean serum levels of insulin (9.02 ± 4.75 vs. 6.24 ± 2.51, P = 0.009), leptin (17.31 ± 8.10 vs. 9.94 ± 4.30, P < 0.001) and homeostatic model assessment of insulin resistance (HOMA-IR) (33.77 ± 20.71 vs. 23.48 ± 10.03, P = 0.009) compared to the NWNO group. The serum level of vaspin was higher in the NWO group compared to the control group (34.82 pg/ml vs. 27.72 pg/ml, respectively, P = 0.12). In NWO group, the serum levels of leptin had positive correlation with FBS (r = 0.45, P = 0.02), insulin (r = 0.51, P = 0.008), and HOMA-IR (r = 0.46, P = 0.02) and vaspin concentration was associated with insulin (r = 0.36, P = 0.02) and HOMA-IR (r = 0.30, P = 0.06), positively.

CONCLUSION

It is concluded that the concentration of insulin and HOMA-IR index were significantly higher in women with NWO compared to NWNO. Higher concentrations of leptin and vaspin in the NWO group were associated with glycemic profile.

Cardiovascular Risk Factors and Differential Transcriptomic Profile of the Subcutaneous and Visceral Adipose Tissue and Their Resident Stem Cells

Background: The increase in the incidence of obesity and obesity-related cardiovascular risk factors (CVRFs) over the last decades has brought attention on adipose tissue (AT) pathobiology. The expansion of AT is associated with the development of new vasculature needed to perfuse the tissue; however, not all fat depots have the same ability to induce angiogenesis that requires recruitment of their own endothelial cells. In this study we have investigated the effect of different CVRFs, on the angiogenic capacity of the subcutaneous (SAT) and visceral (VAT) adipose tissue and on the function of their mesenchymal cell reservoir. Methods: A transcriptomic approach was used to compare the different angiogenic and inflammatory profiles of the subcutaneous and visceral fat depots from individuals with obesity, as well as their resident stem cells (ASCs). Influence of other risk factors on fat composition was also measured. Finally, the microvesicles (MVs) released by ASCs were isolated and their regenerative potential analyzed by molecular and cellular methodologies. Results: Obesity decreases the angiogenic capacity of AT. There are differences between SAT and VAT; from the 21 angiogenic-related genes analyzed, only three were decreased in SAT compared with those decreased in VAT. ASCs isolated from both fat depots showed significant differences; there was a significant up-regulation of the VEGF-pathway on visceral derived ASCs. ASCs release MVs that stimulate endothelial cell migration and angiogenic capacity. Conclusions: In patients with obesity, SAT expresses a greater number of angiogenic molecules than VAT, independent of the presence of other CVRFs.

Metabolic and clinical responses to Bunium Persicum (black caraway) supplementation in overweight and obese patients with type 2 diabetes: a double-blind, randomized placebo-controlled clinical trial

Background

Diabetes mellitus is the most common metabolic disorder worldwide. We aimed to determine the metabolic and clinical responses to Bunium Persicum (Black Caraway) supplementation in overweight and obese patients with T2DM.

Methods

Participant recruitment took place in the diabetic clinic of Bu-Ali hospital in Zahedan. Due to the eligibility criteria, 60 participants were randomly placed into two groups, namely placebo (n = 30) and BP (n = 30). The supplementation was considered one 1000 mg capsule 2 times /day BP by meals (lunch and dinner) for 8 weeks. Physical activity levels, dietary intakes, anthropometric measurements [weight, height, and waist circumference], glycemic indices [fasting blood glucose (FBG) and insulin (FBI)], blood lipids [triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), and low-density lipoprotein cholesterol (LDL-c)], and serum nesfatin-1 level were determined. Homeostasis model assessment-insulin resistance (HOMA-IR), Quantitative insulin sensitivity checks index (QUICKI), and Body Mass Index (BMI) were computed.

Results

In comparison with placebo, BP significantly decreased FBG, HOMA-IR, and BMI (P <  0.05). The differences in the FBI, QUICKI, TG, TC, LDL, HDL, WC, and Nesfatin-1 were not significant (P > 0.05).

Conclusion

BP supplementation improved serum glucose indices and BMI among overweight and obese T2DM patients. Further trials are needed to confirm results.

Trial registration

Iranian Registry of Clinical Trials (IRCT), IRCT20181207041876N1, Registered 18/01/2019, https://irct.ir/trial/35752

The Adipokines in Cancer Cachexia

Cachexia is a devastating pathology induced by several kinds of diseases, including cancer. The hallmark of cancer cachexia is an extended weight loss mainly due to skeletal muscle wasting and fat storage depletion from adipose tissue. The latter exerts key functions for the health of the whole organism, also through the secretion of several adipokines. These hormones induce a plethora of effects in target tissues, ranging from metabolic to differentiating ones. Conversely, the decrease of the circulating level of several adipokines positively correlates with insulin resistance, metabolic syndrome, diabetes, and cardiovascular disease. A lot of findings suggest that cancer cachexia is associated with changed secretion of adipokines by adipose tissue. In agreement, cachectic patients show often altered circulating levels of adipokines. This review reported the findings of adipokines (leptin, adiponectin, resistin, apelin, and visfatin) in cancer cachexia, highlighting that to study in-depth the involvement of these hormones in this pathology could lead to the development of new therapeutic strategies.

Pathophysiological roles of chronic low-grade inflammation mediators in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common hormonal imbalance disease in reproductive-aged women. Its basic characteristics are ovulatory dysfunction and ovarian overproduction of androgens that lead to severe symptoms such as insulin resistance, hirsutism, infertility, and acne. Notwithstanding the disease burden, its underlying mechanisms remain unknown, and no causal therapeutic exists. In recent years, further studies showed that inflammation processes are involved in ovulation and play a key role in ovarian follicular dynamics. Visceral adipose tissue can cause inflammatory response and maintenance of the inflammation state in adipocytes by augmented production of inflammatory cytokines, monocyte chemoattractant proteins, and recruitment of the immune cell. Therefore, the PCOS can be related to a low-grade inflammation state and inflammatory markers. Investigating the inflammatory processes and mediators that contribute to the commencement and development of PCOS can be a critical step for better understanding the pathophysiology of the disease and its treatment through inhibition or control of related pathways. In the present review, we discuss the pathophysiological roles of chronic low-grade inflammation mediators including inflammasome-related cytokines, interleukin-1β (IL-1β), and IL-18 in PCOS development.

Thirty-two weeks of randomized interdisciplinary therapy or combined physical training promote similar improvements in anthropometric and biochemical parameters of obese women

BACKGROUND

Obesity is a multicausal illness that generates large expenses to health systems and also for the families of obese individuals. It is important to note that obesity disrupts all systems, generating metabolic consequences that may be irreversible. Interdisciplinary therapy is recommended as the primary method for treating obesity. However, the cost of interdisciplinary treatment can be high due to the need for various professionals, from different areas of expertise. This study compares the effects of 32 weeks of physical training combined with interdisciplinary therapy on anthropometric and biochemical parameters in obese women.

METHODS

Seventy-six subjects were randomized into two groups: Group Physical Exercise (EXE) and Group Interdisciplinary Treatment (INTER), being evaluated in the initial moment and after 32 weeks. 30 subjects completed the intervention and were evaluated (EXE: N.=13; INTER: N.=17).

RESULTS

Psychobiological and biochemical variables were measured. EXE and INTER were similar before treatment and both showed significantly improvements in anthropometric and biochemical parameters after interventions, without difference between groups.

CONCLUSIONS

The results confirmed the relevant role of physical training or the interdisciplinary therapy on metabolic profile of obese women. We realized that physical training can be incorporated into public or private health systems as an alternative strategy for obesity control, especially in locations that do not have the possibility of offering a complete interdisciplinary therapy.

Examination of ex-vivo viability of human adipose tissue slice culture

Obesity is associated with significantly higher mortality rates, and excess adipose tissue is involved in respective pathologies. Here we established a human adipose tissue slice cultures (HATSC) model ex vivo. HATSC match the in vivo cell composition of human adipose tissue with, among others, mature adipocytes, mesenchymal stem cells as well as stroma tissue and immune cells. This is a new method, optimized for live imaging, to study adipose tissue and cell-based mechanisms of obesity in particular. HATSC survival was tested by means of conventional and immunofluorescence histological techniques, functional analyses and live imaging. Surgery-derived tissue was cut with a tissue chopper in 500 μm sections and transferred onto membranes building an air-liquid interface. HATSC were cultured in six-well plates filled with Dulbecco’s Modified Eagle’s Medium (DMEM), insulin, transferrin, and selenium, both with and without serum. After 0, 1, 7 and 14 days in vitro, slices were fixated and analyzed by morphology and Perilipin A for tissue viability. Immunofluorescent staining against IBA1, CD68 and Ki67 was performed to determine macrophage survival and proliferation. These experiments showed preservation of adipose tissue as well as survival and proliferation of monocytes and stroma tissue for at least 14 days in vitro even in the absence of serum. The physiological capabilities of adipocytes were functionally tested by insulin stimulation and measurement of Phospho-Akt on day 7 and 14 in vitro. Viability was further confirmed by live imaging using Calcein-AM (viable cells) and propidium iodide (apoptosis/necrosis). In conclusion, HATSC have been successfully established by preserving the monovacuolar form of adipocytes and surrounding macrophages and connective tissue. This model allows further analysis of mature human adipose tissue biology ex vivo.

Adipokines and Obesity. Potential Link to Metabolic Disorders and Chronic Complications

The World Health Organization (WHO) has recognized obesity as one of the top ten threats to human health. It is estimated that the number of obese and overweight people worldwide exceeds the number of those who are undernourished. Obesity is not only a state of abnormally increased adipose tissue in the body, but also of increased release of biologically active adipokines. Adipokines released into the circulating blood, due to their specific receptors on the surface of target cells, act as classic hormones affecting the metabolism of tissues and organs. What is more, adipokines and cytokines may decrease the insulin sensitivity of tissues and induce inflammation and development of chronic complications. Certainly, it can be stated that in an era of a global obesity pandemic, adipokines may gain more and more importance as regards their use in the diagnostic evaluation and treatment of diseases. An extensive search for materials on the role of white, brown and perivascular fatty tissue and obesity-related metabolic and chronic complications was conducted online using PubMed, the Cochrane database and Embase.

Role of inflammatory mediators (TNF-α, IL-6, CRP), biochemical and hematological parameters in type 2 diabetes mellitus patients of Kashmir, India

Background: Type II Diabetes mellitus (T2DM) is a multifactorial disease and a leading cause of premature deaths. Inflammatory cytokines are reported that they have potential to enhance insulin resistance and hence T2DM. Assessment of immunological profile in T2DM patients of Kashmir valley is unclear. So, detection of cytokines is relevant to determine the extent and direction of immune responses. The current research was taken to study the role of inflammatory mediators in T2DM along with insulin sensitivity, biochemical and hematological parameters in mountainous valley of Kashmiri population. Methods: A total of 340 subjects were selected in this study among them 160 were T2DM cases and 180 were healthy controls. Serum expression of inflammatory mediators (TNF-α and IL-6 ) were quantified by ELISA technique, WBC count was measured on Sysmax (Germany) hematology analyzer, biochemical and Immunoassay parameters were done on Abbott c4000 (USA) and Abbott C1000 (USA) fully automatic analyzer. Data was analyzed using statistical 'software SPSS 16.1' (Chicago, IL). For all assessments, p<0.05 were considered statistically significant. Results: The expressions of candidate cytokines (TNF-α, IL-6, CRP, and WBC) were highly significant (p<0.001) in T2DM. Among inflammatory mediators, TNF-α shows a positive correlation (p<0.001) with glycemic profile and insulin sensitivity in T2DM cases in comparison with healthy normal. Biochemical (fasting sugar, HbA1c, insulin resistance, lipid profile) and anthropometric (BMI) parameters were highly significant (p<0.001) in T2DM cases as compared to non-diabetic normal. Conclusion: Low grade inflammation and up regulation of inflammatory mediators has been purported to play a significant role in pathogenesis of T2DM. Our findings confirm that positive correlation of TNF-α and IL-6 with T2DM and insulin sensitivity. These can act as early prediction biomarkers of T2DM. Further studies on wider range of pro and anti- inflammatory cytokines i.e. mediators, in association with other biochemical, immunoassay and hematological parameters are needed to help clinicians manage and treat T2DM effectively.

The Role of Secretory Activity Molecules of Visceral Adipocytes in Abdominal Obesity in the Development of Cardiovascular Disease: A Review

Adipose tissue is considered one of the endocrine organs in the body because of its ability to synthesize and release a large number of hormones, cytokines, and growth and vasoactive factors that influence a variety of physiological and pathophysiological processes, such as vascular tone, inflammation, vascular smooth muscle cell migration, endothelial function, and vascular redox state. Moreover, genetic factors substantially contribute to the risk of obesity. Research into the biochemical effects of molecules secreted by visceral adipocytes as well as their molecular genetic characteristics is actively conducted around the world mostly in relation to pathologies of the cardiovascular system, metabolic syndrome, and diabetes mellitus. Adipokines could be developed into biomarkers for diagnosis, prognosis, and therapeutic targets in different diseases. This review describes the relevance of secretory activity molecules of visceral adipocytes in cardiovascular disease associated abdominal obesity.

SOD3 Is Secreted by Adipocytes and Mitigates High-Fat Diet-Induced Obesity, Inflammation, and Insulin Resistance

Aims: To study the expression and regulatory role of SOD3 in adipocytes and adipose tissue. Results: SOD3 expression was determined in various tissues of adult C57BL/6J mice, human adipose tissue and epididymal adipose tissue, subcutaneous adipose tissue and brown adipose tissue of high-fat diet (HFD)-induced obese mice. SOD3 expression and release were evaluated in adipocytes differentiated from primary human preadipocytes and murine bone marrow-derived mesenchymal stem cells (BM-MSCs). The regulatory role for SOD3 was determined by SOD3 lentivirus knockdown in human adipocytes and global sod3 knockout (KO) mice. SOD3 was expressed at high levels in white adipose tissue, and adipocytes were the main cells expressing SOD3 in adipose tissue. SOD3 expression was significantly elevated in adipose tissue of HFD-fed mice. Moreover, SOD3 expression and release were markedly increased in differentiated human adipocytes and adipocytes differentiated from mouse BM-MSCs compared with undifferentiated cells. In addition, SOD3 silencing in human adipocytes increased expression of genes involved in lipid metabolic pathways such as PPARγ and SREBP1c and promoted the accumulation of triglycerides. Finally, global sod3 KO mice were more obese and insulin resistant with enlarged adipose tissue and increased triglyceride accumulation. Innovation: Our data showed that SOD3 is secreted from adipocytes and regulates lipid metabolism in adipose tissue. This important discovery may open up new avenues of research for the cytoprotective role of SOD3 in obesity and its associated metabolic disorders. Conclusion: SOD3 is a protective factor secreted by adipocytes in response to HFD-induced obesity and regulates adipose tissue lipid metabolism.

High-fat diet increases labial groove formation in maxillary incisors and is related to aging in C57BL/6 mice

OBJECTIVES

The aim of this study was to explore the relationship between the consumption of a high-fat diet and aging-dependent formation of maxillary incisor grooves in C57BL/6 mice, and to identify putative maxillary incisor groove-related genes.

METHODS

We fed 2-month-old and 16-month-old C57BL/6 mice on either a chow diet or a high-fat diet for three months and observed changes in maxillary incisor grooves. We examined tissue sections of the maxillary incisors with grooves and carried out transcriptome analysis of the apical tissue fragments of maxillary incisors with/without grooves.

RESULTS

Consumption of a high-fat diet for three months resulted in significant increases in both body weight and the number of incisor grooves. Both the number and frequency of incisor grooves increased in an age-dependent manner from 26 to 28 months, during which time an additional groove appeared. There was abnormal differentiation and apoptosis of ameloblasts on the labial surface at the grooves of the maxillary incisors. Transcriptome analysis identified 23 genes as being specific to 24-month-old mice; these included several genes related to apoptosis and cell differentiation.

CONCLUSIONS

The study findings indicate that, in C57BL/6 mice, consumption of a high-fat diet increases labial groove formation in maxillary incisors, which is related to aging of the tissue stem cells in the apical root end of the teeth.

Intra-Abdominal Fat Adipocyte Hypertrophy through a Progressive Alteration of Lipolysis and Lipogenesis in Metabolic Syndrome Rats

This study evaluates the progressive participation of enzymes involved in lipolysis and lipogenesis, leading to adipocyte hypertrophy in a metabolic syndrome (MS) rat model caused by chronic consumption of 30% sucrose in drinking water. A total of 70 male Wistar rats were divided into two groups: C and MS. Each of these groups were then subdivided into five groups which were sacrificed as paired groups every month from the beginning of the treatment until 5 months. The intra-abdominal fat was dissected, and the adipocytes were extracted. Lipoprotein lipase (LPL), hormone-sensitive lipase (HSL), protein kinases A (PKA), and perilipin A expressions were determined. The LPL and HSL activities were evaluated by spectrophotometry. Histological staining was performed in adipose tissue. Significant increases were observed in blood pressure, HOMA-IR, leptin, triglycerides, insulin, intra-abdominal fat, and number of fat cells per field (p = 0.001) and in advanced glycosylation products, adipocyte area, LPL, HSL activities and/or expression (p ≤ 0.01) in the MS groups progressively from the third month onward. Lipogenesis and lipolysis were increased by LPL activity and HSL activity and/or expression. This was associated with hyperinsulinemia and release of non-esterified fatty acids causing a positive feedback loop that contributes to the development of adipocyte hypertrophy.

Inflammatory markers in children and adolescents with type 2 diabetes mellitus

This review examines the potential relationship between serum inflammation markers and type 2 diabetes mellitus (T2DM). Inflammation markers have been proposed as prognostic markers for the development of T2DM and its complications. Furthermore, modulation of the inflammatory process may offer future treatment strategies for T2DM. This review focuses on children and adolescents because there is usually little, if any, complications associated with other disease processes, use of medications, or active tobacco smoking. Furthermore, β-cell failure in young age cannot be solely explained by aging and exhaustion of β-cells due to insulin resistance. Pediatric studies have demonstrated that pro-inflammatory cytokines TNF-α, IL-6, IL-1β, IFNγ, PEDF, and fetuin A were increased in insulin resistance, while the anti-inflammatory cytokines adiponectin and omentin were decreased. Furthermore, TNF-α, fetuin A, FGF-21 were altered in obese children with T2DM suggesting a direct involvement in β-cell failure. Future studies focusing on children and adolescents may facilitate our understanding of T2DM as an inflammatory disease process.

Proportional correlates of adipolin and cathepsin S in metabolic syndrome patients with and without prediabetes

BACKGROUND

Adipolin and cathepsin S are intricately involved in pathophysiology of metabolic syndrome (MetS) and prediabetes (PreDM).

AIMS & METHODS

This cross-sectional study aimed to compare and correlate between these metabolic biomarkers as well as between them and adiposity, atherogenicity and hematological indices in MetS patients. Our cross-sectional study involved recruiting 29 normoglycemic MetS, 30 newly diagnosed drug naïve PreDM-MetS patients versus 29 lean, healthy and normoglycemic controls.

RESULTS

Adipolin and cathepsin S plasma levels were significantly higher in both MetS (normoglycemic and PreDM) groups vs. healthy controls. Evidently proportional adipolin-cathepsin S association was markedly signified in 59 MetS participants (normoglycemic and PreDM). Distinctively unlike adipolin, inverse cathepsin S-diastolic blood pressure (DBP) but direct cathepsin S-monocyte count and its monocyte -to- lymphocyte ratio cross-correlated were marked. Notably unlike cathepsin S, adipolin was positively associated with each of FPG, A1C and TG, visceral adiposity index, lipid accumulation product and atherogenic index of plsama in the MetS pool of participants (N = 59).

CONCLUSIONS

Given the intergroup discrepancies in adiposity, atherogenicity indices and their correlations (as well as hematological indices) with biomarkers; this cross-sectional study cannot rule out either biomarker as an associative predictor or as a surrogate indicator and putative prognostic tool for the prediction/prevention and treatment of metabolism dysregularities.

Adipose Tissue-Derived Signatures for Obesity and Type 2 Diabetes: Adipokines, Batokines and MicroRNAs

: Obesity is one of the main risk factors for type 2 diabetes mellitus (T2DM). It is closely related to metabolic disturbances in the adipose tissue that primarily functions as a fat reservoir. For this reason, adipose tissue is considered as the primary site for initiation and aggravation of obesity and T2DM. As a key endocrine organ, the adipose tissue communicates with other organs, such as the brain, liver, muscle, and pancreas, for the maintenance of energy homeostasis. Two different types of adipose tissues-the white adipose tissue (WAT) and brown adipose tissue (BAT)-secrete bioactive peptides and proteins, known as "adipokines" and "batokines," respectively. Some of them have beneficial anti-inflammatory effects, while others have harmful inflammatory effects. Recently, "exosomal microRNAs (miRNAs)" were identified as novel adipokines, as adipose tissue-derived exosomal miRNAs can affect other organs. In the present review, we discuss the role of adipose-derived secretory factors-adipokines, batokines, and exosomal miRNA-in obesity and T2DM. It will provide new insights into the pathophysiological mechanisms involved in disturbances of adipose-derived factors and will support the development of adipose-derived factors as potential therapeutic targets for obesity and T2DM.

Early-Stage Alzheimer's Disease Is Associated with Simultaneous Systemic and Central Nervous System Dysregulation of Insulin-Linked Metabolic Pathways

BACKGROUND

Brain insulin resistance is a well-recognized abnormality in Alzheimer's disease (AD) and the likely mediator of impaired glucose utilization that emerges early and progresses with disease severity. Moreover, the rates of mild cognitive impairment (MCI) or AD are significantly greater in people with diabetes mellitus or obesity.

OBJECTIVE

This study was designed to determine whether systemic and central nervous system (CNS) insulin resistant disease states emerge together and thus may be integrally related.

METHODS

Insulin-related molecules were measured in paired human serum and cerebrospinal fluid (CSF) samples from 19 with MCI or early AD, and 21 controls using a multiplex ELISA platform.

RESULTS

In MCI/AD, both the CSF and serum samples had significantly elevated mean levels of C-peptide and an incretin, and reduced expression of Visfatin, whereas only CSF showed significant reductions in insulin and leptin and only serum had increased glucagon, PAI-1, and ghrelin. Although the overall CSF and serum responses reflected insulin resistance together with insulin deficiency, the specific alterations measured in CSF and serum were different.

CONCLUSION

In MCI and early-stage AD, CNS and systemic insulin-related metabolic dysfunctions, including insulin resistance, occur simultaneously, suggesting that they are integrally related and possibly mediated similar pathogenic factors.

Visceral fat is associated with elevation of serum alanine aminotransferase and gamma glutamyltransferase in middle-aged Chinese adults

BACKGROUND : Elevation of hepatic enzymes is associated with insulin resistance, dyslipidaemia and obesity. However, the factors behind elevation of liver enzymes remain unclear. The aim of this study was to compare the role of abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in relation with serum alanine aminotransferase (ALT) and gamma glutamyltransferase (GGT) in middle-aged Chinese adults. METHODS : We performed a cross-sectional study on 959 adults aged 40-65 without hepatitis. VAT and SAT were measured at the level of L4-L5 by MRI. Pearson correlation and linear regression were performed to assess the association of VAT/SAT with serum ALT and GGT. Logistic regression was used to evaluate the association of VAT and SAT with high ALT (≥40 U/L) and high GGT (≥35 U/L). RESULTS: VAT had higher correlation coefficient r with ALT and GGT than SAT. VAT, but not SAT, was associated with ALT (males: β=0.15, p=0.01; females: β=0.17, p=0.02) and GGT (males: β=0.39, p<0.0001) in linear regression. VAT remained to be associated with GGT in males (β=0.33, p=0.0001) when was further adjusted. Logistic regression showed that VAT was associated with elevated GGT (OR=2.218, p=0.043) in males but not in females and no such association was observed for SAT. CONCLUSIONS: Increased VAT, but not SAT, was associated with elevation of hepatic enzymes including ALT and GGT. Moreover, VAT was associated with elevated GGT independent of insulin resistance and subcutaneous fat in males.

Visceral fat and insulin resistance - what we know?

One of the most significant challenges of current medicine is the increasing prevalence of obesity worldwide that is accompanied by a wide range of chronic health complications and increased mortality. White adipose tissue actively contributes to metabolic regulation by production of a variety of hormones and cytokines, commonly referred to as adipokines. The spectrum and quantity of adipokines produced by the adipose tissue of obese patients is directly or indirectly involved in much obesity-related pathology (type 2 diabetes mellitus, cardiovascular disease, inflammatory response). One of the underlying mechanisms linking obesity, diabetes, and cardiovascular complications is subclinical inflammation, primarily arising in visceral adipose tissue. Adipocyte size, number and polarization of lymphocytes and infiltrated macrophages are closely related to metabolic and obesity-related diseases. The storage capacity of hypertrophic adipocytes in obese patients is limited. This results in chronic energy overload and leads to increased apoptosis of adipocytes that in turn stimulates the infiltration of visceral adipose tissue by immune cells, in particular macrophages. These cells produce many proinflammatory factors; while the overall production of anti-inflammatory cytokines and adipokines is decreased. The constant release of proinflammatory factors into the circulation then contributes to a subclinical systemic inflammation, which is directly linked to the metabolic and cardiovascular complications of obesity.

Inflammation Markers in Type 2 Diabetes and the Metabolic Syndrome in the Pediatric Population

PURPOSE OF REVIEW

Chronic inflammation, adipokines, and hepatokines have been identified as basis of insulin resistance and β cell failure in animal models. We present our current knowledge concerning the potential relationship between these cytokines, inflammation, metabolic syndrome (MetS), and type 2 diabetes mellitus (T2DM) in the pediatric population.

RECENT FINDINGS

Pro-inflammatory cytokines related to insulin resistance and MetS in children are tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-1β, interferon gamma, pigment epithelium-derived factor, chemerin, vaspin, and fetuin A. Anti-inflammatory cytokines associated with insulin resistance and MetS in children are leptin, adiponectin, omentin, fibroblast growth factor (FGF)-21, osteocalcin, and irisin. These anti-inflammatory cytokines are decreased (adiponectin, omentin, and osteocalcin) or increased (leptin, FGF-21, and irisin) in obesity suggesting a resistance state. TNF-α, fetuin A, and FGF-21 are altered in obese children with T2DM suggesting an involvement in β cell failure. These cytokines, adipokines, and hepatokines may be able to predict development of MetS and T2DM and have a potential therapeutic target ameliorating insulin resistance.

Akkermansia muciniphila can reduce the damage of gluco/lipotoxicity, oxidative stress and inflammation, and normalize intestine microbiota in streptozotocin-induced diabetic rats

This study aimed to investigate how Akkermansia muciniphila can implicate type 2 diabetes mellitus and the mechanisms underlying the effects A. muciniphila on type 2 diabetes mellitus. Normal and streptozotocin-induced diabetic Sprague-Dawley rats were orally administered with A. muciniphila and solvent. After 4 weeks of treatment, diabetic rats orally administered with live or pasteurized A. muciniphila exhibited significant increase in the blood concentration of high-density lipoprotein, and decrease in the hepatic glycogen, serum plasminogen activator inhibitor-1, tumor necrosis factor-α, lipopolysaccharide, malondialdehyde and total glucagon-like peptide-1. Moreover, diabetic rats orally administered with A. muciniphila showed significantly increased species alpha diversity and gene function in gut microbes. These results indicated that A. muciniphila can improve liver function, reduce gluco/lipotoxicity, alleviate oxidative stress, suppress inflammation and normalize intestine microbiota of the host animal, thereby ameliorating type 2 diabetes mellitus. Akkermansia muciniphila might be considered as one of the ideal new probiotics used in the management of type 2 diabetes mellitus in future.

Omentin-1 and NAMPT serum concentrations are higher and CK-18 levels are lower in children and adolescents with type 1 diabetes when compared to healthy age, sex and BMI matched controls

Background Adipokines were shown to affect glucose homeostasis and β-cell function in patients with pancreatic dysfunction which is associated with changes in the adipose tissue secretory profile. However, information about adipokines associated with β-cell dysfunction is lacking in pediatric patients with type 1 diabetes. Methods (1) We compared serum concentrations of nicotinamide phosphoribosyltransferase (NAMPT), omentin-1 and caspase-cleaved cytokeratin 18 fragment M30 (CK-18) in pediatric type 1 diabetes patients (n=245) and healthy age, sex and body mass index standard deviation score (BMI-SDS) matched controls (n=243). (2) We investigated the influence of insulin treatment on serum concentrations of NAMPT, omentin-1 and CK-18 in groups of patients with type 1 diabetes stratified according to the duration of their disease: at onset (n=50), ≥6 months and <5 years (n=185), ≥5 and <10 years (n=98), and ≥10 years (n=52). Results Patients at onset compared with healthy controls demonstrated no significant differences in NAMPT levels (p=0.129), whereas omentin-1 levels were elevated (p<0.001) and CK-18 levels were lowered (p=0.034). In contrast, NAMPT and omentin-1 were elevated and CK-18 serum levels were lower in longstanding patients compared to healthy controls (p<0.001). NAMPT serum levels did not change significantly during the duration of type 1 diabetes (p=0.546). At onset, omentin-1 and CK-18 levels were higher than in any group of longstanding type 1 diabetes (p<0.025). Conclusions Altered serum levels of NAMPT, omentin-1 and CK-18 in pediatric type 1 diabetes patients indicate metabolic changes caused by adipose tissue dysregulation which do not normalize during insulin therapy.

Circulating PGRN Levels Are Increased but Not Associated with Insulin Sensitivity or β-Cell Function in Chinese Obese Children

Progranulin (PGRN), a novel peptide that has recently emerged as an important regulatory adipokine, is relevant to energy homeostasis and obesity in animals and adult humans. Little is known about its roles in children. The aim of the current study was to determine the potential role of PGRN and explore its relationship to various obesity-related markers in obese children. This was a cross-sectional study composed of 77 children (43 obese and 34 healthy, age 8.68 ± 0.28 and 8.46 ± 0.45 years, resp.). The PGRN levels were significantly higher in obese children (102.44 ± 4.18 ng/mL) comparing to controls (69.32 ± 5.49 ng/mL) (P < 0.05). Moreover, the PGRN levels were positively correlated with triglyceride (TG), total cholesterol (TC), IL-6, systolic blood pressure (SBP), and diastolic blood pressure (DBP) in obese children after adjusted for BMI and age. However, there was no correlation of serum PGRN levels with OGTT-derived dynamic parameters, HOMA-IR, or HOMA-β in obese children. The results suggest that serum PGRN levels are significantly higher in obese children in China and correlate significantly with obesity-related markers. Increased PGRN levels may be involved in the pathological mechanism of childhood obesity.

Adipokine interactions promote the pathogenesis of systemic lupus erythematosus

BACKGROUND

Adipokines are chemical mediators released from adipose tissue involved in regulation of appetite, insulin sensitivity, immune system and inflammatory responses. Adipokines contributes to low grade inflammatory response in autoimmune disease like Systemic Lupus Erythematosus (SLE) but the pathophysiology is yet not clear. The aim of this study is to understand role of adipokine interactions in SLE disease pathogenesis.

METHODS

Sixty newly diagnosed treatment naïve SLE patients fulfilling the ACR criteria and forty age-sex matched healthy subjects were enrolled in thiscase-control study. Disease activity in SLE patients was evaluated using SELENA-SLEDAI. Array of adipokines, C1q circulating immune complexes (C1q-CIC), anti-C1q, anti-ribososmal P0 (anti-RibP0) and anti-mitochondrial antibodies (AMA) levels were detected by ELISA. Antinuclear antibodies (ANA) and anti-dsDNA autoantibodieswere detected by Indirect Immunofluorescence (IIF), while antigen specificities were detected by Immunoassay blot. Serum levels of C3 and C4 complement factors were assessed by nephlometer.

RESULTS

Statistically significant elevation in progranulin, adipsin and resistin levels was seen among SLE patients when compared to healthy controls (p < 0.0001). Leptin and omentin levels were significantly reduced in SLE patients (p < 0.0001). There was no statistically significant difference in serum adiponectin, chemerin and visfatin levels when these two groups were compared (p > 0.05). Adiponectin, adipsin and resistin levels were elevated in SLE patients with renal manifestations (p < 0.05). Reduced leptin levels were significantly associated with presence of renal manifestations (p < 0.05). Adiponectin levels positively correlated with disease activity (r = 0.294, p = 0.027) whereas negatively correlated with C3 levels (r = -0.439, p = 0.0007). A positive correlation was observed between hypocomplementemia and leptin levels (p < 0.05). Leptin levels were negatively correlated with disease activity, anti-dsDNA, C1q-CIC and anti-C1q levels (p < 0.05). A significant positive correlation was observed between progranulin levels and anti-ribosomal P0 antibodies (r = 0.499, p < 0.0001).

CONCLUSION

Adipokines levels and associated clinical manifestations suggest involvement of adipokines in disease pathogenesis of SLE. SLE disease activity and complement components may suggest regulatory effect of adipokines (adiponectin and leptin) on disease pathogenesis. Further studies on adipokines in SLE patients with renal manifestations may propose them as prognostic markers in renal damage.

TRIAL REGISTRATION

NA.

Adipose tissue dysfunction in cancer cachexia

Cancer cachexia is a complex disorder that is driven by inflammation and metabolic imbalances, resulting in extreme weight loss. Adipose tissue, a main player in cancer cachexia, is an essential metabolic and secretory organ consisting of both white adipose tissue (WAT) and brown adipose tissue. Its secretory products, including adipokines and cytokines, affect a wide variety of central and peripheral organs, such as the skeletal muscle, brain, pancreas, and liver. Therefore, a combination of metabolic alterations, and systemic inflammation dysregulation of both anti-inflammatory and proinflammatory modulators contribute toward adipose tissue wasting in cancer cachexia. Growing evidence suggests that, during cancer cachexia, WAT undergoes a browning process, resulting in increased lipid mobilization and energy expenditure. In this review, we have summarized the characteristics of cancer cachexia and WAT browning. Furthermore, this review describes how adipose tissue becomes inflamed in cancer, shedding light on the combinatorial action of multiple secreted macromolecules, cytokines, hormones, and tumor mediators on adipose tissue dysfunction. We also highlight the inflammatory responses, energy utilization defects, and molecular mechanisms underlying the WAT dysfunction and browning in cancer cachexia. Further, the actual mechanisms behind the loss of adipose tissue are unknown, but have been attributed to increased adipocyte lipolysis, systemic inflammation, and apoptosis or reduced lipogenesis. The understanding of adipose tissue dysfunction in cancer cachexia will hopefully promote the development of new therapeutic approaches to prevent or treat this wasting syndrome.

Obesity, osteoarthritis and genetic risk: The rs182052 polymorphism in the ADIPOQ gene is potentially associated with risk of knee osteoarthritis

Objectives

Given the function of adiponectin (ADIPOQ) on the inflammatory condition of obesity and osteoarthritis (OA), we hypothesized that the ADIPOQ gene might be a candidate gene for a marker of susceptibility to OA.

Methods

We systematically screened three tagging polymorphisms (rs182052, rs2082940 and rs6773957) in the ADIPOQ gene, and evaluated the association between the genetic variants and OA risk in a case-controlled study that included 196 OA patients and 442 controls in a northern Chinese population. Genotyping was performed using the Sequenom MassARRAY iPLEX platform.

Results

The single nucleotide polymorphism (SNP) rs182052 was found to be potentially associated with knee OA risk (additive model: odds ratio = 1.38; 95% confidence interval 1.07 to 1.76; p = 0.012). Furthermore, a non-significant association was observed for rs182052 and body mass index with regard to OA risk in interaction analyses (p = 0.063). Similarly, no significant interaction was detected for rs182052 and age with regard to OA risk (p = 0.614).

Conclusion

These findings suggest that the SNP rs182052 in the ADIPOQ gene may potentially modify individual susceptibility to knee OA in the Chinese population. Further studies are warranted to investigate our findings in more depth.

Cite this article: L. Jiang, X. Zhu, J. Rong, B. Xing, S. Wang, A. Liu, M. Chu, G. Huang. Obesity, osteoarthritis and genetic risk: The rs182052 polymorphism in the ADIPOQ gene is potentially associated with risk of knee osteoarthritis. Bone Joint Res 2018;7:494–500. DOI: 10.1302/2046-3758.77.BJR-2017-0274.R1.

Metformin Mitigates Fibrosis and Glucose Intolerance Induced by Doxorubicin in Subcutaneous Adipose Tissue

Doxorubicin (DX) is a chemotherapeutic drug that is used in clinical practice that promotes deleterious side effects in non-tumor tissues such as adipose tissue. We showed that DX leads to extensive damage in adipose tissue via a disruption in 5′-adenosine monophosphate-activated protein kinase (AMPK) and PPAR-gamma signaling. Thus, we investigated whether co-treatment with the biguanide drug metformin (MET) could prevent the side effects of DX through the activation of AMPK in adipose tissue. The goal of the present study was to verify the effects of DX and adjuvant MET treatment in subcutaneous adipose tissue (SAT) and to determine whether MET could protect against chemotherapy-induced side effects. C57/BL6 mice received DX hydrochloride (2.5 mg/kg) intraperitoneally 2 times per week for 2 weeks (DX), concomitantly or not, with MET administration (300 mg/kg oral daily) (DX + MET). The control group (CTRL) was pair-fed according to the food consumption of the DX group. After euthanasia, adipose tissue fat pads were collected, and SAT was extracted so that adipocytes could be isolated. Glucose uptake was then measured, and histological, gene, and protein analyses were performed. One-way analysis of variance was also performed, and significance was set to 5%. DX reduced retroperitoneal fat mass and epididymal pads and decreased glycemia. In cultured primary subcutaneous adipocytes, mice in the DX group had lower glucose uptake when stimulated with insulin compared with mice in the CTRL group. Adipocytes in the DX group exhibited a reduced area, perimeter, and diameter; decreased adiponectin secretion; and decreased fatty acid synthase gene expression. SAT from MET-treated mice also showed a reduction in collagen deposition. Treatment with MET prevented fibrosis and restored glucose uptake in SAT after insulin stimulation, yet the drug was unable to prevent other side effects of DX such as tissue loss and inflammatory response.

Comparative omics and feeding manipulations in chicken indicate a shift of the endocrine role of visceral fat towards reproduction

Background

The mammalian adipose tissue plays a central role in energy-balance control, whereas the avian visceral fat hardly expresses leptin, the key adipokine in mammals. Therefore, to assess the endocrine role of adipose tissue in birds, we compared the transcriptome and proteome between two metabolically different types of chickens, broilers and layers, bred towards efficient meat and egg production, respectively.

Results

Broilers and layer hens, grown up to sexual maturation under free-feeding conditions, differed 4.0-fold in weight and 1.6-fold in ovarian-follicle counts, yet the relative accumulation of visceral fat was comparable. RNA-seq and mass-spectrometry (MS) analyses of visceral fat revealed differentially expressed genes between broilers and layers, 1106 at the mRNA level (FDR ≤ 0.05), and 203 at the protein level (P ≤ 0.05). In broilers, Ingenuity Pathway Analysis revealed activation of the PTEN-pathway, and in layers increased response to external signals. The expression pattern of genes encoding fat-secreted proteins in broilers and layers was characterized in the RNA-seq and MS data, as well as by qPCR on visceral fat under free feeding and 24 h-feed deprivation. This characterization was expanded using available RNA-seq data of tissues from red junglefowl, and of visceral fat from broilers of different types. These comparisons revealed expression of new adipokines and secreted proteins (LCAT, LECT2, SERPINE2, SFTP1, ZP1, ZP3, APOV1, VTG1 and VTG2) at the mRNA and/or protein levels, with dynamic gene expression patterns in the selected chicken lines (except for ZP1; FDR/P ≤ 0.05) and feed deprivation (NAMPT, SFTPA1 and ZP3) (P ≤ 0.05). In contrast, some of the most prominent adipokines in mammals, leptin, TNF, IFNG, and IL6 were expressed at a low level (FPKM/RPKM< 1) and did not show differential mRNA expression neither between broiler and layer lines nor between fed vs. feed-deprived chickens.

Conclusions

Our study revealed that RNA and protein expression in visceral fat changes with selective breeding, suggesting endocrine roles of visceral fat in the selected phenotypes. In comparison to gene expression in visceral fat of mammals, our findings points to a more direct cross talk of the chicken visceral fat with the reproductive system and lower involvement in the regulation of appetite, inflammation and insulin resistance.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4675-0) contains supplementary material, which is available to authorized users.

Insulin resistance adipocyte-derived exosomes aggravate atherosclerosis by increasing vasa vasorum angiogenesis in diabetic ApoE-/- mice

BACKGROUND

Vasa vasorum (VV) angiogenesis is increased in type 2 diabetes mellitus (T2DM) and may promote atherosclerotic plaque rupture. We sought to determine whether insulin resistance adipocyte-derived exosomes (IRADEs) played a major role in modulating VV angiogenesis and the mechanisms involved.

METHODS

The characterization of IRADEs was performed by electron microscopy, NTA (Nanoparticle Tracking Analysis) and western blot. The cellular effects of IRADEs on angiogenesis were explored in human umbilical vein endothelial cells (HUVECs) and murine aortic endothelial cells (MAECs) in vitro. The roles of IRADEs in angiogenesis were demonstrated with aortic ring and matrigel plug assays ex vivo and the plaque burden, plaque stability and angiogenesis-related protein expression in vivo were evaluated by ultrasonography, immunohistochemistry and western blot.

RESULTS

The IRADEs had a cup-shaped morphology, could be taken up by HUVECs and atherosclerotic plaques, and promoted tube formation by shh in vitro. In the aortic ring and matrigel plug assays, angiogenesis was significantly increased in the IRADEs group. Exogenously administered shh-containing IRADEs increased VV angiogenesis, the plaque burden, the vulnerability index and the expression of angiogenesis-related factors, whereas these effects were attenuated by silencing shh in IRADEs.

CONCLUSIONS

In conclusion, IRADEs promote plaque burden and plaque vulnerability partly by inducing VV angiogenesis, which occurs partly through shh. Accordingly, the application of IRADEs may serve as a novel therapeutic approach to treat diabetic atherosclerosis.

Purple sweet potato color attenuates high fat-induced neuroinflammation in mouse brain by inhibiting MAPK and NF-κB activation

Purple sweet potato color (PSPC) is a natural anthocyanin pigment that is derived from purple sweet potato storage roots. PSPC possesses a variety of biological activities, including antioxidant, anti‑inflammatory and neuroprotective effects; however, the detailed effects of PSPC on high‑fat diet (HFD)‑induced neuroinflammation remain to be determined. The aim of the present study was to investigate whether PSPC has a protective role in HFD‑associated neuroinflammation in the mouse brain and to provide novel insight into the mechanisms of the action. C57BL 6J mice were maintained on a normal diet (10 kcal% fat), a HFD (60 kcal% fat), a HFD with PSPC (700 mg/kg/day) or PSPC alone, which was administrated over 20 weeks. Open field and step‑through tests were used to evaluate the effects of HFD and PSPC on mouse behavior and memory function. Western blotting and ELISA analyses were used to assess the expression of inflammatory cytokines and the activation of mitogen‑activated protein kinase and nuclear factor‑κB (NF‑κB). The results demonstrated that PSPC treatment was able to significantly improve the HFD‑induced impairment of mouse behavior and memory function, and suppressed the increase in body weight, fat content, hyperlipemia and the level of endotoxin. PSPC treatment also markedly decreased the expression of cyclooxygenase‑2, inducible nitric oxide synthase, tumor necrosis factor‑α, interleukin (IL)‑1β and IL‑6, and increased the level of IL‑10 in the HFD‑treated mouse brain. In addition, PSPC inhibited the HFD‑induced phosphorylation of extracellular signal‑regulated kinase (ERK), c‑Jun N‑terminal kinase (JNK) and p38, and the activation of NF‑κB. These findings indicated that PSPC treatment may alleviate HFD‑induced neuroinflammation in the mouse brain by inhibiting ERK, JNK, p38 and NF-κB activation.

Effect of Roux-en-Y Bariatric Surgery on Lipoproteins, Insulin Resistance, and Systemic and Vascular Inflammation in Obesity and Diabetes

Purpose

Obesity is a major modifiable risk factor for cardiovascular disease. Bariatric surgery is considered to be the most effective treatment option for weight reduction in obese patients with and without type 2 diabetes (T2DM).

Objective

To evaluate changes in lipoproteins, insulin resistance, mediators of systemic and vascular inflammation, and endothelial dysfunction following Roux-en-Y bariatric surgery in obese patients with and without diabetes.

Materials and methods

Lipoproteins, insulin resistance, mediators of systemic and vascular inflammation, and endothelial dysfunction were measured in 37 obese patients with (n = 17) and without (n = 20) T2DM, before and 6 and 12 months after Roux-en-Y bariatric surgery. Two way between subject ANOVA was carried out to study the interaction between independent variables (time since surgery and presence of diabetes) and all dependent variables.

Results

There was a significant effect of time since surgery on (large effect size) weight, body mass index (BMI), waist circumference, triglycerides (TG), small-dense LDL apolipoprotein B (sdLDL ApoB), HOMA-IR, CRP, MCP-1, ICAM-1, E-selectin, P-selectin, leptin, and adiponectin. BMI and waist circumference had the largest impact of time since surgery. The effect of time since surgery was noticed mostly in the first 6 months. Absence of diabetes led to a significantly greater reduction in total cholesterol, low-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol although the effect size was small to medium. There was a greater reduction in TG and HOMA-IR in patients with diabetes with a small effect size. No patients were lost to follow up.

Conclusion

Lipoproteins, insulin resistance, mediators of systemic and vascular inflammation, and endothelial dysfunction improve mostly 6 months after bariatric surgery in obese patients with and without diabetes.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier: NCT02169518. https://clinicaltrials.gov/ct2/show/NCT02169518?term=paraoxonase&cntry1=EU%3AGB&rank=1.

The Role of Body Adiposity Index in Determining Body Fat Percentage in Colombian Adults with Overweight or Obesity

The aim of this study is to investigate the accuracy of body adiposity index (BAI) as a convenient tool for assessing body fat percentage (BF%) in a sample of adults with overweight/obesity using bioelectrical impedance analysis (BIA). The study population was composed of 96 volunteers (60% female, mean age 40.6 ± 7.5 years old). Anthropometric characteristics (body mass index, height, waist-to-height ratio, hip and waist circumference), socioeconomic status, and diet were assessed, and BF% was measured by BIA-BF% and by BAI-BF%. Pearson’s correlation coefficient was used to evaluate the correlation between BAI-BF% and BF% assessed by BIA-BF%, while controlling for potential confounders. The concordance between the BF% measured by both methods was obtained with a paired sample t-test, Lin’s concordance correlation coefficient, and Bland-Altman plot analysis. Overall, the correlation between BF% obtained by BIA-BF% and estimated by BAI-BF% was r = 0.885, p < 0.001, after adjusting for potential confounders (age, socioeconomic status, and diet). Lin’s concordance correlation coefficient was moderate in both sexes. In the men, the paired t-test showed a significant mean difference in BF% between the methods (−5.6 (95% CI −6.4 to −4.8); p < 0.001). In the women, these differences were (−3.6 (95% CI −4.7 to −2.5); p < 0.001). Overall, the bias of the BAI-BF% was −4.8 ± 3.2 BF%; p < 0.001), indicating that the BAI-BF% method significantly underestimated the BF% in comparison with the reference method. In adults with overweight/obesity, the BAI presents low agreement with BF% measured by BIA-BF%; therefore, we conclude that BIA-BF% is not accurate in either sex when body fat percentage levels are low or high. Further studies are necessary to confirm our findings in different ethnic groups.

The Effects of Exercise on Abdominal Fat and Liver Enzymes in Pediatric Obesity: A Systematic Review and Meta-Analysis

BACKGROUND

Despite the prevalence of obesity and the multiple position stands promoting exercise for the treatment of obesity and hepatic function, a meta-analytic approach has not previously been used to examine the effects in the pediatric population. The aim of the study was to determine the effectiveness of exercise interventions on abdominal fat, liver enzymes, and intrahepatic fat in overweight and obese youth.

MATERIALS AND METHODS

A computerized search was made using three databases. The analysis was restricted to studies that examined the effect of supervised exercise interventions on abdominal fat (visceral and subcutaneous fat), liver enzymes (alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase), and intrahepatic fat. Fourteen clinical trials (1231 youths) were eligible for inclusion in this systematic review and meta-analysis. Standardized mean difference [SMD] and 95% confidence intervals (CIs) were calculated.

RESULTS

Exercise was associated with a significant reduction in visceral (SMD = -0.661; 95% CI, -0.976 to -0.346; p < 0.001), subcutaneous (SMD = -0.352; 95% CI, -0.517 to -0.186; p < 0.001) and intrahepatic fat (SMD = -0.802; 95% CI, -1.124 to -0.480; p < 0.001), as well as gamma-glutamyl transferase (SMD = -0.726; 95% CI, -1.203 to -0.249; p < 0.001), but did not alter any other liver enzyme. Subgroup analysis recommends exercise programs that involve aerobic exercise longer than three sessions per week.

CONCLUSIONS

This meta-analysis supports current recommendation for physical exercise, mainly aerobic, as an effective intervention for nonalcoholic fatty liver disease progression by targeting hepatic lipid composition, visceral and subcutaneous adipose tissue. Systematic review registration: PROSPERO CRD42016042163.

Elevated C-reactive protein, interleukin 6, tumor necrosis factor alpha and glycemic load associated with type 2 diabetes mellitus in rural Thais: a cross-sectional study

BACKGROUND

The elevated levels of inflammatory markers, including C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), and interleukin 6 (IL6) are supposed to be associated with type 2 diabetes mellitus (T2DM). Frequent high glycemic load (GL) consumption, central obesity, and a lack of physical activity are considered to be T2DM risk factors. This study aimed to determine the difference of these inflammatory markers as well as GL in individuals with versus those without T2DM in rural Thais.

METHODS

A total of 296 participants aged 35-66 living in Sung Noen District, Nakhon Ratchasima Province, Thailand, were recruited. Blood was collected to evaluate blood glucose levels, lipid profiles, and inflammatory markers. A Semi-food frequency questionnaire was utilized to assess GL followed by socioeconomic and anthropometric assessment. Statistical analysis was subsequently performed.

RESULTS

Elevated CRP and IL6 levels were associated with increased risk of developing T2DM [OR (95% CI): 7.51 (2.11, 26.74) and 4.95 (1.28, 19.11)], respectively. There was a trend towards increased risk of T2DM with elevated TNF-α levels [OR (95% CI): 1.56 (0.39, 6.14)]. GL correlated significantly with fasting blood glucose (r = 0.289, P = 0.016), suggesting that it is involved in T2DM in this study group.

CONCLUSION

In this study, CRP, IL6, and TNF-α associated with T2DM. Our findings suggested that these inflammatory markers, especially CRP, may initiate T2DM.

Global transcriptome analysis identifies differentially expressed genes related to lipid metabolism in Wagyu and Holstein cattle

Fat deposition of beef cattle varies between breeds. However, the regulation mechanism is still not elucidated completely at molecular level. In the present study, we comparatively analyzed transcriptome of subcutaneous adipose tissue between Wagyu and Holstein cattle with a significant difference in fat deposition to identify key genes associated with fat metabolism and adipogenesis by high-throughput RNA-seq technology. A total of 59,149,852 and 69,947,982 high quality reads were generated, respectively. With further analysis, 662 differentially expressed genes were identified. Gene Ontology and KEGG pathway analysis revealed that many differentially expressed genes were enriched in several biological processes and pathways relevant to adipogenesis and lipid metabolism, in which PPAR and fatty acid metabolism signaling pathways with related genes such as PPARγ, PLIN2 and ELOVL6 et al. play a critical role. Protein-protein interaction network analysis showed EGR1, FOS, SERPINE1, AGT, MMP2 may have great impact on adipocyte differentiation and adipogenesis. Moreover, potential alternative splicing events and single nucleotide polymorphisms (SNPs) were also identified. In summary, we comprehensively analyzed and discussed the transcriptome of subcutaneous adipose tissue of Wagyu and Holstein cattle, which might provide a theoretical basis for better understanding molecular mechanism of fat metabolism and deposition in beef cattle.

Comparison of Three Adiposity Indexes and Cutoff Values to Predict Metabolic Syndrome Among University Students

PURPOSE

Obesity and high body fat are related to diabetes and metabolic syndrome (MetS) in all ethnic groups. Based on the International Diabetes Federation (IDF) definition of MetS, the aim of the present study was to compare body adiposity indexes (BAIs) and to assess their various cutoff values for the prediction of MetS in university students from Colombia.

METHODS

A cross-sectional study was conducted on 886 volunteers (51.9% woman; age mean 21.4 years). Anthropometric characteristics (height, weight, waist circumference [WC], and hip circumference [HC]) were measured, and body composition was assessed by bioelectrical impedance analysis. MetS was defined as including ≥3 of the metabolic abnormalities (WC, high-density lipoprotein cholesterol [HDL-C], triglycerides, fasting glucose, and systolic and diastolic blood pressure [BP]) in the definition provided by the IDF. The BAIs (i.e., BAI-HC [BAI], BAI-WC [BAI-w], and [BAI-p]) were calculated from formulas taking into account, height, weight, and WC, and for the visceral adiposity indexes, a formula, including WC, HDL-C, and triglycerides, was used.

RESULTS

The overall prevalence of MetS was 5.9%, higher in men than in women. The most prevalent components were low HDL-C, high triglyceride levels, WC, and BP levels. The receiver operating characteristic curves analysis showed that BAI, BAI-w, and BAI-p could be useful tools to predict MetS in this population.

CONCLUSION

For women, the optimal MetS threshold was found to be 30.34 (area under curve [AUC] = 0.720-0.863), 19.10 (AUC = 0.799-0.925), and 29.68 (AUC = 0.779-0.901), for BAI, BAI-w, and BAI-p, respectively. For men, the optimal MetS threshold was found to be 27.83 (AUC = 0.726-0.873), 21.48 (AUC = 0.755-0.906), and 26.18 (AUC = 0.766-0.894), for BAI, BAI-w, and BAI-p, respectively. The three indexes can be useful tools to predict MetS according to the IDF criteria in university students from Colombia. Data on larger samples are needed.

The influence of different calorie restriction protocols on serum pro-inflammatory cytokines, adipokines and IGF-I levels in female C57BL6 mice: short term and long term diet effects

Calorie restriction (CR) is an effective intervention to prevent chronic diseases including cancer. Although many factors, i.e., sex hormones, IGF-I and mTOR have been studied in response to CR, the molecular mechanisms of CR remain to be identified. Our objective was to determine the short and long-term effects of different CR protocols on pro-inflammatory cytokines. Our hypothesis was that Intermittent CR (ICR) would result in greater inhibition of pro-inflammatory serum cytokines compared to Chronic CR (CCR) as we previously found ICR to be more protective in the prevention of mammary tumor development. From ten weeks of age female C57BL6 mice were maintained on either ad libitum (AL) fed, ICR or CCR protocols (overall CR of ~75% of AL) for up to 74 weeks of age. Blood samples were collected for measurements of serum interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), adiponectin, leptin, IGF-I and insulin at specified ages. For ICR mice samples were collected following 3 weeks of restriction (ICR-R) and after one week of refeeding (ICR-RF). In general, both modes of CR significantly reduced serum IL-6, TNF-α, IGF-I and leptin levels compared to AL with IL-6 levels 24 and 3.5 fold and TNF-α levels t 11 and 1.5 fold lower in ICR and CCR groups, respectively at study termination. There was a trend for adiponectin and insulin to be highest in ICR-RF mice. Body weights were positively correlated with IL-6, TNF-α, insulin and leptin but negatively correlated with adiponectin-to-leptin ratio. Moreover, there was a positive correlation between IL-6 and TNF-α. Beneficial effects of ICR may function through pro-inflammatory cytokine pathways.

The fat and the bad: Mature adipocytes, key actors in tumor progression and resistance

Growing evidence has raised the important roles of adipocytes as an active player in the tumor microenvironment. In many tumors adipocytes are in close contact with cancer cells. They secrete various factors that can mediate local and systemic effects. The adipocyte-cancer cell crosstalk leads to phenotypical and functional changes of both cell types, which can further enhance tumor progression. Moreover, obesity, which is associated with an increase in adipose mass and an alteration of adipose tissue, has been established as a risk factor for cancer incidence and cancer-related mortality. In this review, we summarize the mechanisms of the adipocyte-cancer cell crosstalk in both obese and lean conditions as well as its impact on cancer cell growth, local invasion, metastatic spread and resistance to treatments. Better characterization of cancer-associated adipocytes and the key molecular events in the adipocyte-cancer cell crosstalk will provide insights into tumor biology and suggest efficient therapeutic opportunities.

Sarcopenic obesity or obese sarcopenia: A cross talk between age-associated adipose tissue and skeletal muscle inflammation as a main mechanism of the pathogenesis

Sarcopenia, an age-associated decline in skeletal muscle mass coupled with functional deterioration, may be exacerbated by obesity leading to higher disability, frailty, morbidity and mortality rates. In the combination of sarcopenia and obesity, the state called sarcopenic obesity (SOB), some key age- and obesity-mediated factors and pathways may aggravate sarcopenia. This review will analyze the mechanisms underlying the pathogenesis of SOB. In obese adipose tissue (AT), adipocytes undergo hypertrophy, hyperplasia and activation resulted in accumulation of pro-inflammatory macrophages and other immune cells as well as dysregulated production of various adipokines that together with senescent cells and the immune cell-released cytokines and chemokines create a local pro-inflammatory status. In addition, obese AT is characterized by excessive production and disturbed capacity to store lipids, which accumulate ectopically in skeletal muscle. These intramuscular lipids and their derivatives induce mitochondrial dysfunction characterized by impaired β-oxidation capacity and increased reactive oxygen species formation providing lipotoxic environment and insulin resistance as well as enhanced secretion of some pro-inflammatory myokines capable of inducing muscle dysfunction by auto/paracrine manner. In turn, by endocrine manner, these myokines may exacerbate AT inflammation and also support chronic low grade systemic inflammation (inflammaging), overall establishing a detrimental vicious circle maintaining AT and skeletal muscle inflammation, thus triggering and supporting SOB development. Under these circumstances, we believe that AT inflammation dominates over skeletal muscle inflammation. Thus, in essence, it redirects the vector of processes from "sarcopenia→obesity" to "obesity→sarcopenia". We therefore propose that this condition be defined as "obese sarcopenia", to reflect the direction of the pathological pathway.

Comparison of Antidiabetic Medications during the Treatment of Atherosclerosis in T2DM Patients

Type 2 diabetes is often associated with arterial atherosclerosis in large blood vessels. We set out to elucidate whether commonly used antidiabetic drugs metformin, sitagliptin, and pioglitazone will reduce atherosclerosis in T2DM patients. We enrolled 176 individuals with type 2 diabetes, which were divided into four treatment groups according to different oral drugs: metformin alone, sitagliptin alone, pioglitazone alone, or combination of metformin and sitagliptin. We assessed changes in glycometabolism, lipid metabolism, cytokine released, and carotid artery intima-media thickness as the readout for improvement in atherosclerosis. HbA1c levels were significantly decreased in all treatment groups (p < 0.05), and FBG levels were also decreased in metformin and combined groups (p < 0.05). In addition, we found IL-6 levels significantly decreased in all treatment groups (p < 0.05). Treatment with pioglitazone showed a significant increase in BMI, HDL, and ADPN levels (p < 0.05). We also observed a significant decrease in NHDL levels in the combined treatment group (p < 0.05). Our data revealed that in addition to hypoglycemic properties of metformin, sitagliptin, and pioglitazone, these drugs also have the potential to promote an anti-inflammatory response. Therefore, combination therapy may be more beneficial for reducing atherosclerosis in patients with type 2 diabetes. The clinical trial is registered with ChiCTR-ORC-17010835.

Saturated fatty acids induce development of both metabolic syndrome and osteoarthritis in rats

The predominant saturated fatty acids (SFA) in human diets are lauric acid (LA, C12:0), myristic acid (MA, C14:0), palmitic acid (PA, C16:0) and stearic acid (SA, C18:0). The aim of this study was to investigate whether diets containing individual SFA together with excess simple carbohydrates induce osteoarthritis (OA)-like changes in knee joints and signs of metabolic syndrome in rats. Rats were given either a corn starch diet or a diet composed of simple carbohydrates together with 20% LA, MA, PA, SA or beef tallow for 16 weeks. Rats fed beef tallow, SA, MA or PA diets developed signs of metabolic syndrome, and also exhibited cartilage degradation and subchondral bone changes similar to OA. In contrast, replacement of beef tallow with LA decreased signs of metabolic syndrome together with decreased cartilage degradation. Furthermore, PA and SA but not LA increased release of matrix sulphated proteoglycans in cultures of bovine cartilage explants or human chondrocytes. In conclusion, we have shown that longer-chain dietary SFA in rats induce both metabolic syndrome and OA-like knee changes. Thus, diets containing SFA are strongly relevant to the development or prevention of both OA and metabolic syndrome.

Bone Marrow Adipose Tissue Deficiency Increases Disuse-Induced Bone Loss in Male Mice

Bone marrow adipose tissue (MAT) is negatively associated with bone mass. Since osteoblasts and adipocytes are derived from the same precursor cells, adipocyte differentiation may occur at the expense of osteoblast differentiation. We used MAT-deficient Kit^W/W−v (MAT-) mice to determine if absence of MAT reduced bone loss in hindlimb-unloaded (HU) mice. Male MAT- and wild-type (WT) mice were randomly assigned to a baseline, control or HU group (n = 10 mice/group) within each genotype and HU groups unloaded for 2 weeks. Femurs were evaluated using micro-computed tomography, histomorphometry and targeted gene profiling. MAT- mice had a greater reduction in bone volume fraction after HU than did WT mice. HU MAT- mice had elevated cancellous bone formation and resorption compared to other treatment groups as well as a unique profile of differentially expressed genes. Adoptive transfer of WT bone marrow-derived hematopoietic stem cells reconstituted c-kit but not MAT in Kit^W/W−v mice. The MAT- WT → Kit^W/W−v mice lost cancellous bone following 2 weeks of HU. In summary, results from this study suggest that MAT deficiency was not protective, and was associated with exaggerated disuse-induced cancellous bone loss.

11β-Hydroxysteroid Dehydrogenase Type 1 in Obese Subjects With Type 2 Diabetes Mellitus

Obesity is one of the most significant contributors to the development of type 2 diabetes mellitus. Tissue-specific glucocorticoids regulated by 11β-hydroxysteroid dehydrogenase enzyme (11β-HSD) type 1 are involved in central obesity and obesity-related comorbidities. Moderate downregulation of 11β-HSD1 can attenuate insulin insensitivity and the impairment of glucose-stimulated insulin secretion. Some of the beneficial effects of 11β-HSD1 inhibition may be mediated, at least in part, through inactivation of tissue-specific glucocorticoid action related to insulin signaling mechanisms, alleviation of abnormal cytokine profile and the improvement of β-cell function. Thus, 11β-HSD1 is a promising target for the treatment and prevention of type 2 diabetes mellitus with obesity.