The Effect of Adipocyte-Secreted Factors in Activating Focal Adhesion Kinase-Mediated Cell Signaling Pathway towards Metastasis in Breast Cancer Cells

Obesity-associated perturbations in the normal secretion of adipocytokines from white adipocytes can drive the metastatic progression of cancer. However, the association between obesity-induced changes in secretory factors of white adipocytes and subsequent transactivation of the downstream effector proteins impacting metastasis in breast cancer cells remains unclear. Focal adhesion kinase, a cytoplasmic signal transducer, regulates the biological phenomenon of metastasis by activating downstream targets such as beta-catenin and MMP9. Thus, the possible role of phosphorylated FAK in potentiating cancer cell migration was investigated. To elucidate this potential relationship, MCF7 (ER+), MDA-MB-231 (Triple Negative) breast cancer cells, and MCF-10A non-tumorigenic breast cells were exposed to in vitro murine adipocyte-conditioned medium derived from 3T3-L1 MBX cells differentiated to obesity with fatty acid supplementation. Our results show that the conditioned medium derived from these obese adipocytes enhanced motility and invasiveness of breast cancer cells. Importantly, no such changes were observed in the non-tumorigenic breast cells. Our results also show that increased FAK autophosphorylation was followed by increased expression of beta-catenin and MMP9 in the breast cancer cells when exposed to obese adipocyte-conditioned medium, but not in the MCF10A cells. These results indicate that adipocyte-derived secretory factors induced FAK activation through phosphorylation. This in turn increased breast cancer cell migration and invasion by activating its downstream effector proteins beta-catenin and MMP9.

Extracellular nicotinamide phosphoribosyltransferase: role in disease pathophysiology and as a biomarker

Nicotinamide phosphoribosyltransferase (NAMPT) plays a central role in mammalian cell metabolism by contributing to nicotinamide adenine dinucleotide biosynthesis. However, NAMPT activity is not limited to the intracellular compartment, as once secreted, the protein accomplishes diverse functions in the extracellular space. Extracellular NAMPT (eNAMPT, also called visfatin or pre-B-cell colony enhancing factor) has been shown to possess adipocytokine, pro-inflammatory, and pro-angiogenic activities. Numerous studies have reported the association between elevated levels of circulating eNAMPT and various inflammatory and metabolic disorders such as obesity, diabetes, atherosclerosis, arthritis, inflammatory bowel disease, lung injury and cancer. In this review, we summarize the current state of knowledge on eNAMPT biology, proposed roles in disease pathogenesis, and its potential as a disease biomarker. We also briefly discuss the emerging therapeutic approaches for eNAMPT inhibition.

Characterizing 3T3-L1 MBX Adipocyte Cell Differentiation Maintained with Fatty Acids as an In Vitro Model to Study the Effects of Obesity

The increasing prevalence of obesity has prompted intensive research into understanding its role in pathogenesis and designing appropriate treatments. To determine the signals generated from the interaction of fat cells with a target organ, a reliable white adipocyte model in vitro is needed. Differentiated fibroblasts are the most extensively studied using in vitro cell models of white adipocytes. However, it can be argued that differentiated fibroblasts minimally recapitulate the consequences of obesity. Here, we describe 3T3-L1 MBX cells as a culture model for studying obese adipocytes and their effects. Differentiation of 3T3-L1 MBX cells was at first optimized and then maintained in the presence of fatty acids cocktail combination to induce the obese condition. Lipid accumulation and adipokine secretion profiles were analyzed. Results showed that fatty acid-maintained, differentiated 3T3-L1 MBX cells had significantly greater accumulation of lipids and significant changes in the adipokine secretions in comparison to differentiated 3T3-L1 MBX cells maintained in medium without fatty acids. To elucidate the molecular changes associated with adipogenesis and lipid accumulation profile of 3T3-L1 MBX cells, we have also explored the expression of some of the regulatory proteins related to the development and maintenance of adipocytes from the preadipocyte lineage.

Human Omentin-1 Administration Ameliorates Hypertensive Complications without Affecting Hypertension in Spontaneously Hypertensive Rats

Hypertension is one of the major risk factors for cardiovascular diseases and is caused by various abnormalities including the contractility of blood vessels. Spontaneously hypertensive rats (SHR), whose systemic blood pressure increases with aging, are a frequently used animal model for investigating essential hypertension and related complications in humans due to the damage of several organs. Human omentin-1 is an adipocytokine consisting of 313 amino acids. Serum omentin-1 levels decreased in hypertensive patients compared with normotensive controls. Furthermore, omentin-1 knockout mice showed elevated blood pressure and impaired endothelial vasodilation. Taken together, we hypothesized that adipocytokine, human omentin-1 may improve the hypertension and its complications including heart and renal failure in the aged SHR (65-68-weeks-old). SHR were subcutaneously administered with human omentin-1 (18 μg/kg/day, 2 weeks). Human omentin-1 had no effect on body weight, heart rate, and systolic blood pressure in SHR. The measurement of isometric contraction revealed that human omentin-1 had no influence on the enhanced vasocontractile or impaired vasodilator responses in the isolated thoracic aorta from SHR. On the other hand, human omentin-1 tended to improve left ventricular diastolic failure and renal failure in SHR. In summary, human omentin-1 tended to improve hypertensive complications (heart and renal failure), while it had no influence on the severe hypertension in the aged SHR. The further study of human omentin-1 may lead to the development of therapeutic agents for hypertensive complications.

First-Trimester Maternal Serum Adiponectin/Leptin Ratio in Pre-Eclampsia and Fetal Growth

The serum adiponectin/leptin ratio (A/L ratio) is a surrogate marker of insulin sensitivity. Pre-eclampsia (PE) is associated with maternal metabolic syndrome and occasionally impaired fetal growth. We assessed whether the A/L ratio in first-trimester maternal serum was associated with PE and/or birth weight. Adiponectin and leptin were quantitated in first-trimester blood samples (gestational week 10+3−13+6) from 126 women who later developed PE with proteinuria (98 mild PE; 21 severe PE; 7 HELLP syndrome), and 297 controls, recruited from the Copenhagen First-Trimester Screening Study. The A/L ratio was reduced in PE pregnancies, median 0.17 (IQR: 0.12−0.27) compared with controls, median 0.32 (IQR: 0.19−0.62) (p < 0.001). A multiple logistic regression showed that PE was negatively associated with log A/L ratio independent of maternal BMI (odds ratio = 0.315, 95% CI = 0.191 to 0.519). Adiponectin (AUC = 0.632) and PAPP-A (AUC = 0.605) were negatively associated with PE, and leptin (AUC = 0.712) was positively associated with PE. However, the A/L ratio was a better predictor of PE (AUC = 0.737), albeit not clinically relevant as a single marker. No significant association was found between A/L ratio and clinical severity of pre-eclampsia or preterm birth. PE was associated with a significantly lower relative birth weight (p < 0.001). A significant negative correlation was found between relative birth weight and A/L ratio in controls (β = −0.165, p < 0.05) but not in PE pregnancies), independent of maternal BMI. After correction for maternal BMI, leptin was significantly associated with relative birth weight (β = 2.98, p < 0.05), while adiponectin was not significantly associated. Our findings suggest that an impairment of the A/L ratio (as seen in metabolic syndrome) in the first trimester is characteristic of PE, while aberrant fetal growth in PE is not dependent on insulin sensitivity, but rather on leptin-associated pathways.

Impact of combined chronic exposure to low-dose bisphenol A and fructose on serum adipocytokines and the energy target metabolome in white adipose tissue

Background: Adipose tissue is a dynamic endocrine organ that plays a key role in regulating metabolic homeostasis. Previous studies confirmed that bisphenol A (BPA) or fructose can interfere with the function of adipose tissue. Nonetheless, knowledge on how exposure to BPA and fructose impacts energy metabolism in adipose tissue remains limited.Purpose: To determine impact of combined chronic exposure to low-dose bisphenol A and fructose on serum adipocytokines and the energy target metabolome in white adipose tissue.Method: 57 energy metabolic intermediates in adipose tissue and 7 adipocytokines in serum from Sprague Dawley rats were examined after combined exposure to two levels of BPA (lower dose: 0.25, and higher dose: 25 μg/kg every other day) and 5% fructose for 6 months.Results: combined exposure to lower-dose BPA and fructose significantly increased omentin-1, pyruvic acid, adenosine triphosphate (ATP), adenosine monophosphate (AMP), inosine monophosphate (IMP), inosine, and l-lactate; however, these parameters were not significantly affected by higher-dose BPA combined with fructose. Interestingly, the level of succinate (an intermediate of the citric acid cycle) increased dose-dependently in adipose tissue, and the level of apelin 13 (a versatile adipocytokine) decreased dose-dependently in serum after combined exposure to BPA and fructose. Phosphoenolpyruvic acid, phenyl-lactate, and ornithine were significantly correlated with asprosin, omentin-1, apelin, apelin 13, and adiponectin, while l-tyrosine was significantly correlated with irisin and a-FABP under combined exposure to BPA and fructose.Conclusions: these findings indicated that lower-dose BPA combined with fructose could amplify the impact on glycolysis, energy storage, and purine nucleotide biosynthesis in adipose tissue, and adipocytokines, such as omentin-1 and apelin 13, may be related to metabolic interference induced by BPA and fructose exposure.

Transcriptome analysis of adipocytokines and their-related LncRNAs in lung adenocarcinoma revealing the association with prognosis, immune infiltration, and metabolic characteristics

Lung adenocarcinoma (LUAD) is amongst the major contributors to cancer-related deaths on a global scale. Adipocytokines and long non-coding RNAs (lncRNAs) are indispensable participants in cancer. We performed a pan-cancer analysis of the mRNA expression, single nucleotide variation, copy number variation, and prognostic value of adipocytokines. LUAD samples were obtained from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Simultaneously, train, internal and external cohorts were grouped. After a stepwise screening of optimized genes through least absolute shrinkage and selection operator regression analysis, random forest algorithm,, and Cox regression analysis, an adipocytokine-related prognostic signature (ARPS) with superior performance compared with four additional well-established signatures for survival prediction was constructed. After determination of risk levels, the discrepancy of immune microenvironment, immune checkpoint gene expression, immune subtypes, and immune response in low- and high-risk cohorts were explored through multiple bioinformatics methods. Abnormal pathways underlying high- and low-risk subgroups were identified through gene set enrichment analysis (GSEA). Immune-and metabolism-related pathways that were correlated with risk score were selected through single sample GSEA. Finally, a nomogram with satisfied predictive survival probability was plotted. In summary, this study offers meaningful information for clinical treatment and scientific investigation.

Can EAT be an INOCA goalkeeper

Ischemia with non-obstructive coronary artery (INOCA) is a blind spot of coronary artery disease (CAD). Such patients are often reassured but offered no specific care, that lead to a heightened risk of adverse cerebrovascular disease (CVD) outcomes. Epicardial adipose tissue (EAT) is proven to correlate independently with CAD and its severity, but it is unknown whether EAT is a specific and sensitive indicator of INOCA. This review focuses on the INOCA epidemiology and related factors, as well as the association between EAT.

Prognostic Observational Analysis of BMI, Leptin, and Adiponectin in Children With Acute Lymphocytic Leukemia Undergoing Remission-Induction Chemotherapy

BACKGROUND

The survival rate of children and adolescents with acute lymphoblastic leukemia (ALL) has progressively improved. However, ALL survivors often have adverse effects after treatment, such as an increased risk of obesity. Obesity has been associated with reduced survival.

OBJECTIVE

We investigated the relationship between obesity, adipocytokine levels, and ALL short-term outcomes.

METHODS

Weight and height were measured, and body mass index (BMI) was calculated at patient diagnosis and discharge. Leptin and Adiponectin levels and Minimal Residual Disease (MRD) were measured before therapy, at days 19 of remission-induction therapy, and at the end of remission-induction therapy (days 46). The relationship between BMI, adipocytokine levels, and MRD was then determined.

RESULTS

Compared to the normal BMI group, children with an abnormal increase in BMI had an increase in MRD at day 19 and 46 (P = 0.04 and P = 0.008), and showed a positive correlation (P = 0.014). In addition, we found a positive correlation between weight, hip circumference at diagnosis and at day 19, and MRD at day 46. Both BMI and fat concentric distribution affected the outcome of ALL children. A higher BMI was also associated with a significant increase in Leptin levels at diagnosis. Leptin resistance should be considered in ALL children with high BMI.

CONCLUSION

BMI affects the outcome of ALL patients. Early interventions such as regular weight, height monitoring, and dietary assessments should be preferably initiated during remission-induction chemotherapy.

A System-Level Mechanism of Anmyungambi Decoction for Obesity: A Network Pharmacological Approach

Obesity is a low-grade systemic inflammatory disease involving adipocytokines. As though Anmyungambi decoction (AMGB) showed significant improvement on obesity in a clinical trial, the molecular mechanism of AMGB in obesity remains unknown. Therefore, we explored the potential mechanisms of action of AMGB on obesity through network pharmacological approaches. We revealed that targets of AMGB are significantly associated with obesity-related and adipocyte-elevated genes. Evodiamine, berberine, genipin, palmitic acid, genistein, and quercetin were shown to regulate adipocytokine signaling pathway proteins which mainly involved tumor necrosis factor receptor 1, leptin receptor. In terms of the regulatory pathway of lipolysis in adipocytes, norephedrine, pseudoephedrine, quercetin, and limonin were shown to affect adrenergic receptor-beta, protein kinase A, etc. We also found that AMGB has the potentials to enhance the insulin signaling pathway thereby preventing type II diabetes mellitus. Additionally, AMGB was discovered to be able to control not only insulin-related proteins but also inflammatory mediators and apoptotic regulators and caspases, hence reducing hepatocyte injury in nonalcoholic fatty liver disease. Our findings help develop a better understanding of how AMGB controls obesity.

Chemokine-like Receptor 1 in Brain of Spontaneously Hypertensive Rats Mediates Systemic Hypertension

Adipocytokine chemerin is a biologically active molecule secreted from adipose tissue. Chemerin elicits a variety of functions via chemokine-like receptor 1 (CMKLR1). The cardiovascular center in brain that regulates blood pressure (BP) is involved in pathophysiology of systemic hypertension. Thus, we explored the roles of brain chemerin/CMKLR1 on regulation of BP in spontaneously hypertensive rats (SHR). For this aim, we examined effects of intracerebroventricular (i.c.v.) injection of CMKLR1 small interfering (si)RNA on both systemic BP as measured by tail cuff system and protein expression in paraventricular nucleus (PVN) of SHR as determined by Western blotting. We also examined both central and peripheral protein expression of chemerin by Western blotting. Systolic BP of SHR but not normotensive Wistar Kyoto rats (WKY) was decreased by CMKLR1 siRNA. The decrease of BP by CMKLR1 siRNA persisted for 3 days. Protein expression of CMKLR1 in PVN of SHR tended to be increased compared with WKY, which was suppressed by CMKLR1 siRNA. Protein expression of chemerin in brain, peripheral plasma, and adipose tissue was not different between WKY and SHR. In summary, we for the first time revealed that the increased protein expression of CMKLR1 in PVN is at least partly responsible for systemic hypertension in SHR.

Reduced tissue and serum resistin expression as a clinical marker for esophageal squamous cell carcinoma

Esophageal cancer is one of the most common malignancies and leading cause of cancer-associated mortality worldwide. However, the molecular mechanisms underlying esophageal cancer progression and the development of clinical tools for effective diagnosis remain unclear. Resistin, which was originally identified as an adipose tissue-secretory factor, has been associated with obesity-related diseases, including certain types of cancer. Thus, the present study aimed to investigate the expression levels of resistin in tissue and serum specimens from patients with esophageal squamous cell carcinoma (ESCC) to determine the potential biological effects of resistin on ESCC cells. The results demonstrated that both tissue and serum resistin levels were significantly lower in patients with ESCC compared with healthy controls. In addition, resistin expression was positively associated with the body mass index of patients with ESCC. In vitro studies revealed that resistin inhibited the migratory ability of ESCC cells, while having no effect on ESCC cell proliferation. Taken together, these results suggest that resistin may have the potential to be developed into a clinical marker for ESCC. However, further studies are required to investigate resistin receptor expression and determine the potential involvement of resistin-associated biological pathways, which may provide insight for future development of targeted therapies for resistin-mediated ESCC.

Elevated Nesfatin-1 Level in Synovium and Synovial Fluid is Associated with Pro-Inflammatory Cytokines in Patients with Rheumatoid Arthritis

Background

Adipocytokines have been proven to be involved in the progression of autoimmune diseases, including rheumatoid arthritis (RA). Nesfatin-1, a newly discovered adipokine, has recently been reported to possess potent anti-inflammatory, antiapoptotic, and antioxidative properties. However, its role in RA has not yet been reported. Therefore, this study aimed to determine nesfatin-1 levels in the synovium and synovial fluid (SF) of patients with RA and examine their correlation with clinical manifestations and proinflammatory cytokine levels.

Methods

Synovium and SF samples were collected from patients with RA and non-RA patients during joint surgery. Immunohistochemistry was used to measure nesfatin-1 protein expression in the synovium. Enzyme-linked immunosorbent assay was used to measure nesfatin-1, interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) levels in the synovium and SF. Pearson correlation analysis was used to evaluate the correlations between nesfatin-1 levels, RA clinical features, and proinflammatory cytokines. The diagnostic value of synovium nesfatin-1 for RA was assessed using receiver operating characteristic (ROC) curve analysis.

Results

The results showed that nesfatin-1, IL-1β, and TNF-α levels in the synovium were significantly higher in patients with RA than in controls, with age and body mass index as covariates. Moreover, the results of Pearson correlation analysis showed that nesfatin-1 levels were positively correlated with IL-1β and TNF-α levels in the synovium of patients with RA. Furthermore, there was a positive relationship between synovium nesfatin-1 levels and rheumatoid factor in patients with RA. Additionally, the results of the ROC curve analysis revealed an area under the curve of 0.733 with 77.5% sensitivity and 60.0% specificity for synovium nesfatin-1 in discriminating patients with RA from controls.

Conclusion

These findings suggest that increased nesfatin-1 levels in the synovium may be associated with proinflammatory cytokines and RA severity.

Obesity and Breast Cancer: A Paradoxical and Controversial Relationship Influenced by Menopausal Status

Breast cancer is the most common tumor in women worldwide, and an increasing public health concern. Knowledge of both protective and negative risk factors is essential for a better understanding of this heterogenous disease. We undertook a review of the recent literature and evaluated the relationship between obesity mediators and breast cancer development depending on menopausal status. Excess weight is now pandemic and has replaced tobacco as the main lifestyle-related risk factor for premature death. Although the prevalence of obesity/overweight has increased globally over the last 50 years, the potential harm attributable to excess fat has generally been underestimated. The relationship between overweight/obesity, breast cancer and overall risk appears to be highly dependent on menopausal status. Thus, obesity increases the risk of breast cancer in postmenopausal women but, conversely, it appears to be protective in premenopausal women. We evaluate the role of different clinical factors potentially involved in this seemingly contradictory relationship, including estrogen, mammogram density, adipokines, insulin-signaling pathway activation, and inflammatory status. A key focus of this review is to better understand the impact of body mass index and menopausal status on these clinical factors and, hence, provide some clarity into the inter-relationships involved in this controversial issue.

Validation of Antiobesity Effects of Black Soybean Seed Coat Powder Suitable as a Food Material: Comparisons with Conventional Yellow Soybean Seed Coat Powder

In this study, we fed obese model mice black soybean seed coat powder (BSCP) and evaluated the antiobesity effects. As a control, normal yellow soybean seed coat powder (YSCP) was used. C57BL/6J, a high-fat diet-induced obesity model mouse, was fed a high-fat diet containing BSCP or YSCP (20% fat) to induce obesity. The results showed that in the BSCP group, it caused significant suppression of body weight gain and suppression of white adipose tissue weight compared with the YSCP group. Moreover, it significantly decreased serum leptin levels, which correlated with visceral fat mass, and increased antidiabetic adipocytokine and adiponectin levels. Therefore, this suggests the pigmented components contained in BSCP have an antiobesity effect in obese model mice. It is suggested that this material, which can be prepared without extraction with an organic solvent and is suitable for use as a food material, could be a functional food material with a practicable antiobesity effect.

Visfatin: An emerging adipocytokine bridging the gap in the evolution of cardiovascular diseases

Visfatin/nicotinamide phosphoribosyltransferase (NAMPT) is an adipokine expressed predominately in visceral fat tissues. High circulating levels of visfatin/NAMPT have been implicated in vascular remodeling, vascular inflammation, and atherosclerosis, all of which pose increased risks of cardiovascular events. In this context, increased levels of visfatin have been correlated with several upregulated pro-inflammatory mediators, such as IL-1, IL-1Ra, IL-6, IL-8, and TNF-α. Furthermore, visfatin is associated with leukocyte recruitment by endothelial cells and the production of adhesion molecules such as vascular cell adhesion molecule 1, intercellular cell adhesion molecule 1, and E-selectin, which are well known to mediate the progression of atherosclerosis. Moreover, diverse angiogenic factors have been found to mediate visfatin-induced angiogenesis. These include matrix metalloproteinases, vascular endothelial growth factor, monocyte chemoattractant protein 1, and fibroblast growth factor 2. This review aims to provide a comprehensive overview of the pro-inflammatory and angiogenic actions of visfatin, with a focus on the pertinent signaling pathways whose dysregulation contributes to the pathogenesis of atherosclerosis. Most importantly, some hypotheses regarding the integration of the aforementioned factors with the plausible atherogenic effect of visfatin are put forth for consideration in future studies. The pharmacotherapeutic potential of modulating visfatin's roles could be important in the management of cardiovascular disease, which continues to be the leading cause of death worldwide.

Bone Marrow Adipocytes, Adipocytokines, and Breast Cancer Cells: Novel Implications in Bone Metastasis of Breast Cancer

Accumulating discoveries highlight the importance of interaction between marrow stromal cells and cancer cells for bone metastasis. Bone is the most common metastatic site of breast cancer and bone marrow adipocytes (BMAs) are the most abundant component of the bone marrow microenvironment. BMAs are unique in their origin and location, and recently they are found to serve as an endocrine organ that secretes adipokines, cytokines, chemokines, and growth factors. It is reasonable to speculate that BMAs contribute to the modification of bone metastatic microenvironment and affecting metastatic breast cancer cells in the bone marrow. Indeed, BMAs may participate in bone metastasis of breast cancer through regulation of recruitment, invasion, survival, colonization, proliferation, angiogenesis, and immune modulation by their production of various adipocytokines. In this review, we provide an overview of research progress, focusing on adipocytokines secreted by BMAs and their potential roles for bone metastasis of breast cancer, and investigating the mechanisms mediating the interaction between BMAs and metastatic breast cancer cells. Based on current findings, BMAs may function as a pivotal modulator of bone metastasis of breast cancer, therefore targeting BMAs combined with conventional treatment programs might present a promising therapeutic option.

Sex dimorphism in the associations of gestational diabetes with cord blood adiponectin and retinol-binding protein 4

INTRODUCTION

Gestational diabetes (GD) is associated with impaired insulin sensitivity in newborns. Adiponectin and retinol-binding protein 4 (RBP-4) are involved in regulating insulin sensitivity. Females are more likely to develop diabetes at young ages than males. We tested the hypothesis that GD may affect RBP-4 and adiponectin levels in early life, and there may be sex-dimorphic associations.

RESEARCH DESIGN AND METHODS

In a nested case-control study of 153 matched pairs of neonates of mothers with GD and euglycemic pregnancies in the Shanghai Birth Cohort, we evaluated cord plasma leptin, high molecular weight (HMW) and total adiponectin and RBP-4 concentrations.

RESULTS

Comparing GD versus euglycemic pregnancies adjusted for maternal and neonatal characteristics in female newborns, cord plasma total adiponectin (mean±SD: 30.8±14.3 vs 37.1±16.1 µg/mL, p=0.048) and HMW adiponectin (14.6±7.7 vs 19.3±8.3 µg/mL, p=0.004) concentrations were lower, while RBP-4 concentrations were higher (21.7±5.4 vs 20.0±4.8 µg/mL, p=0.007). In contrast, there were no differences in male newborns (all p>0.2). RBP-4 concentrations were higher in female versus male newborns (21.7±5.4 vs 18.8±4.5 µg/mL, p<0.001) in GD pregnancies only. HMW adiponectin concentrations were significantly higher in female versus male newborns in euglycemic pregnancies only (19.3±8.3 vs 16.1±7.4 µg/mL, p=0.014).

CONCLUSIONS

GD was associated with lower cord plasma HMW adiponectin and higher RBP-4 concentrations in female newborns only. The study is the first to reveal a sex-dimorphic early life impact of GD on metabolic health biomarkers in the offspring. GD may alter the normal presence (HMW adiponectin) or absence (RBP-4) of sex dimorphism in some insulin sensitivity regulation-relevant adipokines in early life.

Effects of Secretome from Fat Tissues on Ion Currents of Cardiomyocyte Modulated by Sodium-Glucose Transporter 2 Inhibitor

Sodium-glucose transporter 2 (SGLT2) inhibitors were shown to decrease mortality from cardiovascular diseases in the EMPA-REG trial. However, the effects of empagliflozin (EMPA) for cardiac arrhythmia are not yet clarified. A total of 20 C57BL/6J mice were divided into four groups: (1) The control group were fed standard chow, (2) the metabolic syndrome (MS) group were fed a high-fat diet, (3) the empagliflozin (EMPA) group were fed a high-fat diet and empagliflozin 10 mg/kg daily, and (4) the glibenclamide (GLI) group were fed a high-fat diet and glibenclamide 0.6 mg/kg daily. All mice were sacrificed after 16 weeks of feeding. H9c2 cells were treated with adipocytokines from the pericardial and peripheral fat from the study groups. The delayed-rectifier potassium current (I_K) and L-type calcium channel current (I_Ca,L) were measured by the whole-cell patch clamp techniques. Adipocytokines from the peripheral and pericardial fat tissues of mice with MS could decrease the I_K and increase the I_Ca,L of cardiomyocytes. After treating adipocytokines from pericardial fat, the I_K in the EMPA and GLI groups were significantly higher than that in the MS group. The I_K of the EMPA group was also significantly higher than the GLI group. The I_Ca,L of the EMPA and GLI groups were significantly decreased overload compared with that of the MS group. However, there was no significant difference of I_K and I_Ca,L among study groups after treating adipocytokines from peripheral fat. Adipocytokines from pericardial fat but not peripheral fat tissues after EMPA therapy attenuated the effects of I_K decreasing and I_Ca,L increasing in the MS cardiomyocytes, which may contribute to anti-arrhythmic mechanisms of sodium-glucose transporter 2 (SGLT2) inhibitors.

Adipocytokine expression, platelet-to-lymphocyte ratio and TGF-1/Smad signaling activity in diabetic patients complicated with pulmonary infection

OBJECTIVE

To investigate adipocytokine expression levels, platelet-to-lymphocyte ratio (PLR) and transforming growth factor (TGF)-β1/Smad signaling activity in diabetic patients with pulmonary infection.

METHODS

Eighty-two type 2 diabetic patients with pulmonary infection were included in the observation group and 75 patients with simple type 2 diabetes were recruited into the control group. The fasting blood glucose (FBG), glycated hemoglobin (HbA1c), and PLR in the two groups were compared. Complement-C1q/tumor necrosis factor related protein 3 (CTRP-3), complement-C1q/tumor necrosis factor related protein 9 (CTRP-9), leptin, adiponectin, and TGF-β1/Smad signaling pathway activity in peripheral blood mononuclear cells (PBMCs) was detected.

RESULTS

Compared with patients in the control group, patients in the observation group presented with increased levels of FGB, HbA1c, and leptin, an increase in the PLR, and decreased serum CTRP-3, CTRP-9, and adiponectin levels. TGF-β1, p-Smad2, and p-Smad3 protein expression levels were up-regulated in PBMCs from patients in the observation group compared with the control group.

CONCLUSIONS

These results show that in type 2 diabetic patients with pulmonary infection, adipocytokine expression is altered, PLR is disturbed, and the TGF-β1/Smad signaling pathways in PBMCs are significantly activated.

High level of visfatin and the activation of Akt and ERK1/2 signaling pathways are associated with endometrium malignant transformation in polycystic ovary syndrome

This study aimed to assess the clinicopathological significance of serum levels and endometrium tissue expression of visfatin in polycystic ovary syndrome (PCOS) patients. A total of 80 PCOS patients and 80 matching controls were included in this study. We analyzed the relationship between the expression of visfatin in endometrium and clinicopathological characteristics in PCOS patients. The correlation between the expression of visfatin and p-Akt, Akt, p-ERK1/2, and ERK1/2 in PCOS tissues was evaluated as well. Visfatin expression in PCOS endometrial tissues were significantly higher than those in controls (p = .001). The expression of phosphorylation of Akt and ERK1/2 were significantly higher in PCOS endometrium tissues compared to controls (p < .05). Moreover, a high expression of tissue visfatin in PCOS tissues was positively correlated with the expression of p-Akt (p = .015), and p-ERK1/2 (p = .013). Western blotting revealed that protein expression of visfatin in PCOS patients with endometrial hyperplasia and cancer was higher than that in patients with normal endometrium tissues, and the difference was statistically significant (p = .027). The expression of p-Akt (p = .018) and p-ERK1/2 (p = .035) in PCOS patients with endometrial hyperplasia and cancer was significantly higher than that in patients with normal endometrium tissues. Visfatin may be a potential biomarker for endometrial malignant transformation in PCOS patients.

Hyperbaric oxygen activates visfatin expression and angiogenesis via angiotensin II and JNK pathway in hypoxic human coronary artery endothelial cells

Visfatin is an adipocytokine with important roles in endothelial angiogenesis. Hyperbaric oxygen (HBO) has been widely used to treat various medical illness with enhanced angiogenesis. The molecular effects of HBO on visfatin under hypoxia are poorly understood. This study aimed to investigate the effect of HBO on visfatin in hypoxic human coronary arterial endothelial cells (HCAECs). HCAECs under chemical hypoxia (antimycin A, 0.01 mmol/L) were exposed to HBO (2.5 atmosphere absolute; ATA) for 2‐4 hours. Western blot, real‐time polymerase chain reaction, electrophoretic mobility shift assay, luciferase promoter activity, migration and tube formation assay, and in vitro glucose uptake were measured. Visfatin protein expression increased in hypoxic HCAECs with earlier angiotensin II (AngII) secretion and c‐Jun N‐terminal kinase (JNK) phosphorylation, which could be effectively suppressed by the JNK inhibitor (SP600125), AngII antibody or AngII receptor blocker (losartan). In hypoxic HCAECs, HBO further induced earlier expression of visfatin and AngII. Hypoxia significantly increased DNA‐protein binding activity of hypoxia‐inducible factor‐1α (HIF‐1α) and visfatin. Hypoxia, hypoxia with HBO and exogenous addition of AngII also increased promoter transcription to visfatin; SP600125 and losartan blocked this activity. In HCAECs, glucose uptake, migration and tube formation were increased in the presence of hypoxia with HBO, but were inhibited by visfatin small interfering RNA, SP600125 and losartan. In conclusion, HBO activates visfatin expression and angiogenesis in hypoxic HCAECs, an effect mediated by AngII, mainly through the JNK pathway.

Autocrine action of adipokine omentin-1 in the SW480 colon cancer cell line

Omentin-1, a 34-kDa protein, has been demonstrated to be associated with colorectal cancer (CRC). Epidemiological and clinical studies have indicated that the levels of circulating omentin-1 are significantly increased in patients with CRC, but the cause of the high omentin-1 levels and whether CRC cells express this adipokine have not been determined. In the present study, human colorectal carcinoma and para-carcinoma tissues were collected from 24 patients with CRC. In addition, SW480 and HCT116 colon cancer cells were cultured in vitro. The expression and localization of omentin-1 protein in human CRC and para-carcinoma tissues were determined by immunohistochemistry. The mRNA and protein expression levels of omentin-1 in human CRC and para-carcinoma tissues were detected by reverse transcription-quantitative PCR (RT-qPCR) and western blotting, respectively. In addition, omentin-1 mRNA expression levels in SW480 and HCT116 cell lines were detected by RT-qPCR. Since SW480 cells exhibited higher omentin-1 mRNA levels compared with those of HCT116 cells, SW480 cells were selected for further experiments. The expression of omentin-1 protein in the supernatant and lysate of SW480 cells obtained at 6, 12, 24 and 48 h was determined by ELISA. The immunohistochemistry results demonstrated that the positive expression of omentin-1 protein was mainly located in the cytoplasm of cancer cells in human CRC tissues. The mRNA and protein expression levels of omentin-1 in the CRC tissues were higher compared with those in para-carcinoma tissues. The expression levels of omentin-1 were detected in the cell lysate and supernatant of SW480 cells; the expression level of omentin-1 protein in the cell lysate was higher compared with that in the supernatant. These results indicated that SW480 cells secret and express the adipokine omentin-1 endogenously. Omentin-1 may serve its potential carcinogenetic role in CRC through endocrine, autocrine and paracrine pathways.

Pulmonary Hypertension and Obesity: Focus on Adiponectin

Pulmonary hypertension is an umbrella term including many different disorders causing an increase of the mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg. Recent data revealed a strong association between obesity and pulmonary hypertension. Adiponectin is a protein synthetized by the adipose tissue with pleiotropic effects on inflammation and cell proliferation, with a potential protective role on the pulmonary vasculature. Both in vivo and in vitro studies documented that adiponectin is an endogenous modulator of NO production and interferes with AMP-activated protein kinase (AMPK) activation, mammalian target of rapamycin (mTOR), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κβ) signaling preventing endothelial dysfunction and proliferation. Furthermore, adiponectin ameliorates insulin resistance by mediating the biological effects of peroxisome proliferator-activated receptor-gamma (PPARγ). Therefore, adiponectin modulation emerged as a theoretical target for the treatment of pulmonary hypertension, currently under investigation. Recently, consistent data showed that hypoglycemic agents targeting PPARγ as well as renin–angiotensin system inhibitors and mineralocorticoid receptor blockers may influence pulmonary hemodynamics in different models of pulmonary hypertension.

The effect of isotretinoin on insulin resistance and adipocytokine levels in acne vulgaris patients

Background/aim

Recent data draw attention to the effect of body composition, insulin resistance, and adipocytokines to acne vulgaris (AV) development. The aim of this study was to assess the association of AV with insulin resistance and adipocytokine levels and to evaluate the effect of isotretinoin on insulin resistance and adipocytokine levels.

Materials and methods

In 29 AV patients and 29 healthy volunteers, body mass index (BMI) and body fat mass (BFM), lipid, adiponectin, leptin, resistin, retinol binding protein-4 (RBP4), and insulin levels were measured and insulin resistance was assessed by HOMA-IR index in serum samples taken twice from patients before and after isotretinoin treatment.

Results

In AV patients, pretreatment HOMA-IR and adipocytokine levels were not found to correlate with disease severity. With five months of isotretinoin treatment, higher HOMA-IR values ​​were found (P = 0.028). Isotretinoin therapy maintained lower mean resistin levels (P = 0.016), higher mean RBP4 levels (P = 0.040), but not affected the mean adiponectin and leptin levels (P = 0.113, P = 0.125, respectively).

Conclusions

All data suggests that five months of isotretinoin therapy in AV patients causes insulin resistance and the increase in insulin resistance is not dependent on age, BMI, BFM, and lipid levels of these patients.

Plasma fibroblast growth factor 21 levels increase with ectopic fat accumulation and its receptor levels are decreased in the visceral fat of patients with type 2 diabetes

BACKGROUND

Fibroblast growth factor 21 (FGF21) is a novel metabolic regulator that has beneficial effects on glucose and lipid metabolism. However, plasma FGF21 levels are paradoxically increased in type 2 diabetes mellitus (T2DM) and obesity, suggesting resistance to this ligand. FGF21 acts mainly on adipose tissue and ectopic fat accumulation is a typical feature in metabolic deterioration such as diabetes, metabolic syndrome, and cardiovascular disease.

OBJECTIVE

To investigate the relationship between FGF21 resistance and ectopic fat accumulation.

RESEARCH DESIGN AND METHODS

Subjects who underwent 64-slice multidetector CT (MDCT) were enrolled (n=190). Plasma FGF21 levels and MDCT data of ectopic fats at various sites were analyzed. Human visceral and subcutaneous fat tissues from abdominal and coronary artery bypass surgery were obtained. FGF21 receptor expression and postreceptor signaling in different fat deposits of both control and T2DM subjects were analyzed.

RESULTS

Plasma FGF21 levels were significantly associated with body mass index, triglyceride, homeostatic model assessment of insulin resistance, and Matsuda index. Plasma FGF21 levels were significantly higher in patients with T2DM than in the pre-diabetes and normal glucose tolerance groups. The ectopic fat phenotypes (visceral, epicardial, intrahepatic, and intramuscular fat) of T2DM were significantly higher than controls. Plasma FGF21 levels were elevated and exhibited a strong positive correlation with ectopic fat accumulation in T2DM. The expression of genes comprising the FGF21 signaling pathway was also lower in visceral fat than in subcutaneous fat in this disease.

CONCLUSIONS

Human FGF21 resistance in T2DM could result from increases in FGF21-resistant ectopic fat accumulation. Our study provides novel clinical evidence linking FGF21 resistance and T2DM pathogenesis.

Senescence marker activin A is increased in human diabetic kidney disease: association with kidney function and potential implications for therapy

OBJECTIVE

Activin A, an inflammatory mediator implicated in cellular senescence-induced adipose tissue dysfunction and profibrotic kidney injury, may become a new target for the treatment of diabetic kidney disease (DKD) and chronic kidney diseases. We tested the hypothesis that human DKD-related injury leads to upregulation of activin A in blood and urine and in a human kidney cell model. We further hypothesized that circulating activin A parallels kidney injury markers in DKD.

RESEARCH DESIGN AND METHODS

In two adult diabetes cohorts and controls (Minnesota, USA; Galway, Ireland), the relationships between plasma (or urine) activin A, estimated glomerular filtration rate (eGFR) and DKD injury biomarkers were tested with logistic regression and correlation coefficients. Activin A, inflammatory, epithelial-mesenchymal-transition (EMT) and senescence markers were assayed in human kidney (HK-2) cells incubated in high glucose plus transforming growth factor-β1 or albumin.

RESULTS

Plasma activin A levels were elevated in diabetes (n=206) compared with controls (n=76; 418.1 vs 259.3 pg/mL; p<0.001) and correlated inversely with eGFR (r_s=-0.61; p<0.001; diabetes). After eGFR adjustment, only albuminuria (OR 1.56, 95% CI 1.16 to 2.09) and tumor necrosis factor receptor-1 (OR 6.40, 95% CI 1.08 to 38.00) associated with the highest activin tertile. Albuminuria also related to urinary activin (r_s=0.65; p<0.001). Following in vitro HK-2 injury, activin, inflammatory, EMT genes and supernatant activin levels were increased.

CONCLUSIONS

Circulating activin A is increased in human DKD and correlates with reduced kidney function and kidney injury markers. DKD-injured human renal tubule cells develop a profibrotic and inflammatory phenotype with activin A upregulation. These findings underscore the role of inflammation and provide a basis for further exploration of activin A as a diagnostic marker and therapeutic target in DKD.

Dysregulation of insulin levels in Chagas heart disease is associated with altered adipocytokine levels

Metabolic, inflammatory, and autonomic nervous system (ANS) dysfunction are present in patients with heart failure. However, whether these changes are due to left ventricular dysfunction or heart failure etiology is unknown. We evaluated metabolism and inflammatory activity in patients with idiopathic dilated cardiomyopathy (IDC) and Chagas cardiomyopathy (CHG) and their correlation with the ANS. Forty-six patients were divided into 3 groups: IDC, CHG, and control. We evaluated adiponectin, leptin, insulin, interleukin-6, and tumor necrosis factor-alpha. ANS were analyzed by heart rate variability in time and frequency domains on a 24-hour Holter monitor. Levels of glucose, cholesterol, leptin, and adiponectin did not show differences between groups. Insulin levels were lower in CHG group (5.4 ± 3.3 μU/mL) when compared with control (8.0 ± 4.9 μU/mL) and IDC (9.9 ± 5.0 μU/mL) groups (p = 0.007). Insulin was positively associated with LFr/HFr ratio (r = 0.562; p = 0.029) and with the LFr component (r = 0.562; p = 0.029) and negatively associated with adiponectin (r = -0.603; p = 0.017) in CHG group. The addition of an adiponectin unit reduced average insulin by 0.332 μg/mL. Insulin levels were decreased in the CHG group when compared with the IDC group and were associated with ANS indexes and adiponectin levels.

Adipocytokines in Non-functional Adrenal Incidentalomas and Relation with Insulin Resistance Parameters

OBJECTIVE

Adrenal incidentalomas are diagnosed incidentally during radiological screenings and require endocrinological investigations for hormonal activity and malignancy. In certain studies, it has been reported that non-functional incidentalomas can be associated with high adipocytokines levels affecting the insulin resistance just like the adipose tissue with metabolic syndrome. Here, we studied serum adipocytokine levels including leptin, resistin, visfatin, omentin 1 and adiponectin in subjects with non-functional adrenal incidentaloma.

METHODS

Seventy-seven (77) patients (Female 57; Male 20) with non-functional adrenal incidentaloma (NFAI) were enrolled in the study. All patients' past medical history, physical examination including Body Mass Index (BMI) and waist circumference were performed. The patients' demographic, radiologic, hormonal and biochemical parameters were recorded. To compare the parameters, a control group (CG) (n=30) was formed from healthy volunteers. Both groups were matched for age, gender, waist circumference and BMI. Serum adipocytokines including leptin, resistin, visfatin, omentin 1 and adiponectin were measured quantitatively by ELISA. Fasting plasma glucose, insulin, sodium, potassium, cortisol, adrenocorticotropic hormone (ACTH), lipid profiles, and dehidroepiandrostenedion sulphate (DHEAS) were measured.

RESULTS

Mean age of the patients was 52.2±10.4 years. BMI and waist circumference of NFAI patients were 26.2±3.28 kg/m2 and 90.2 ±7.5cm, respectively. The mean age of the control group was 48.0±8.16. BMI and waist circumference values for the control group were 25.3±3.5 kg/m2 and 88.3±9.6 cm, respectively. When both groups were compared for age, gender, BMI and waist circumference were non-significant (p>0.05). Serum fasting insulin, total cholesterol, LDL, triglyceride levels of the NFAI group were significantly higher than CG (p<0.05). The insulin resistance index (HOMAIR) values of the NFAI subjects were found to be higher than CG (2.5±1.37, 1.1±0.3 p=0.00). Resistin level of NFAI group was also found to be higher than CG [286.6 ng/L vs. 197 ng/L; (P=0,00)], respectively. Leptin levels of NFAI were significantly higher than CG [441.1 ng/mL vs. 186.5 ng/mL; (P=0.00)] respectively. Adiponectin levels were significantly reduced in the NFAI group than in the CG [10.7 mg/L vs. 30.8 mg/L; (P=0.00)]. Comparision of visfatin and omentin levels was nonsignificant.

CONCLUSION

In this study on subjects with non-functional adrenal incidentaloma, we found not only significantly decreased serum adiponectin levels but also increased leptin, resistin levels as well as dyslipidemia, hypertension and high insulin resistance index. All of which could affect insulin resistance and cardiovascular risk factors. The underlying mechanisms of these findings are unknown, hence further studies are needed.

Effects of small interfering RNA targeting TLR4 on expressions of adipocytokines in obstructive sleep apnea hyponea syndrome with hypertension in a rat model

We explored the effects of RNA interference-mediated silencing of TLR4 gene on expressions of adipocytokines in obstructive sleep apnea hyponea syndrome (OSAS) with hypertension in a rat model. Systolic blood pressure of caudal artery and physiological changes were observed when establishing rat models of OSAS with hypertension. Mature rat adipocytes were induced from separated and cultured primary rat adipocytes. To transfect rat mature adipocytes, TLR4 siRNA group and negative control (NC) siRNA group were established. Expressions of TLR4 mRNA of adipocytes were examined after silenced by siRNA by quantitative real-time polymerase chain reaction (qRT-PCR). By enzyme-linked immunosorbent assay (ELISA), expressions of inflammatory cytokines, and adipocytokines of adipocytes were detected. Blood pressure in rat caudal artery was higher in the intermittent hypoxia group than that of the blank control group by 29.87 mmHg, and cardiocytes in the former group showed physiological changes, which indicated successful establishment of rat models of OSAS with hypertension. Red particles could be seen in mature rat adipocytes when stained with Oil Red O. Transfection of TLR4 mRNA was significantly suppressed in the TLR4 siRNA group, which didn't happen in the untransfected control group. Rats in the TLR4 siRNA group had significantly reduced expressions of such inflammatory cytokines as interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) and such adipocytokines as visfatin, adiponectin (ADN), and leptin than those in the untransfected control group. RNA interference-mediated silencing of TLR4 gene could regulate occurrence and development of OSAS with hypertension in rats by downregulating expressions of adipocytokines.

Roles of Perivascular Adipose Tissue in the Pathogenesis of Atherosclerosis

Traditionally, it is believed that white adipose tissues serve as energy storage, heat insulation, and mechanical cushion, whereas non-shivering thermogenesis occurs in brown adipose tissue. Recent evidence revealed that adipose tissue secretes many types of cytokines, called as adipocytokines, which modulate glucose metabolism, lipid profile, appetite, fibrinolysis, blood pressure, and inflammation. Most of the arteries are surrounded by perivascular adipose tissue (PVAT). PVAT has been thought to be simply a structurally supportive tissue for vasculature. However, recent studies showed that PVAT influences vasodilation and vasocontraction, suggesting that PVAT regulates vascular tone and diameter. Adipocytokines secreted from PVAT appear to have direct access to the adjacent arterial wall by diffusion or via vasa vasorum. In fact, PVAT around atherosclerotic lesions and mechanically-injured arteries displayed inflammatory cytokine profiles, suggesting that PVAT functions to promote vascular lesion formation. Many clinical studies revealed that increased accumulation of epicardial adipose tissue (EAT), which surrounds coronary arteries, is associated with coronary artery disease. In this review article, we will summarize recent findings about potential roles of PVAT in the pathogenesis of atherosclerosis, particularly focusing on a series of basic and clinical studies from our laboratory.

Chronic transgenerational vitamin B12 deficiency of severe and moderate magnitudes modulates adiposity-probable underlying mechanisms

We have demonstrated previously that severe but not moderate vitamin B12 deficiency altered body composition and induced adiposity in female C57BL/6 mice. This study aims to elucidate the effects of chronic transgenerational dietary vitamin B12 restriction on body composition and various biochemical parameters in the F1 generation offspring of our mouse models of severe and moderate vitamin B12 deficiency established earlier. Female weanling C57BL/6 mice received, ad libitum, for 4 weeks a (i) control diet, (ii) vitamin B12-restricted diet with pectin as dietary fiber (severely deficient diet), or (iii) vitamin B12-restricted diet with cellulose as dietary fiber (moderately deficient diet) and then mated with control males. The offspring of control and severely deficient dams continued on the respective diets of their mothers. Few moderately deficient dams were rehabilitated to control diet from parturition and their pups were weaned to control diet. Also, some offspring born to moderately B12 deficient dams were weaned to control diet, while others continued on the same diet as their mothers. Various parameters were determined in the F1 offspring after 12 and 36 weeks of feeding. The results indicate that both severe and moderate maternal vitamin B12 restrictions were associated with accelerated catch-up growth, increased body fat percentage, visceral adiposity, dyslipidemia, fasting hyperglycemia and insulin resistance in the F1 offspring. Inflammation, increased glucocorticoid and oxidative stress and poor antioxidant defence probably underlie these adverse effects. Rehabilitation from parturition but not weaning was beneficial in delaying the onset of the adverse outcomes in the offspring. © 2016 BioFactors, 43(3):400-414, 2017.

Adipocytokine, progranulin, augments acetylcholine-induced nitric oxide-mediated relaxation through the increases of cGMP production in rat isolated mesenteric artery

AIM

Progranulin (PGRN) is a novel adipocytokine with anti-inflammatory effects in vascular cells. The aim of this study was to clarify the effects of PGRN on reactivity of isolated blood vessel.

METHODS

Isometric contraction of rat isolated superior mesenteric artery was measured.

RESULTS

Pre-treatment with PGRN (10-100 ng mL^-1 , 30 min) had no effect on noradrenaline- or 5-hydroxytriptamine-induced contraction. On the other hand, pre-treatment with PGRN (100 ng mL^-1 ) augmented acetylcholine (ACh; 30 nm)-induced endothelium-dependent relaxation. Pre-treatment with PGRN (100 ng mL^-1 ) augmented ACh (10 μm)-induced nitric oxide (NO)-mediated relaxation in the presence of indomethacin (10 μm), a cyclooxygenase inhibitor, and tetraethyl ammonium (10 mm), a non-selective potassium channel blocker. In contrast, pre-treatment with PGRN (100 ng mL^-1 ) had no effect on ACh-induced endothelium-derived hyperpolarizing factor-mediated relaxation. Pre-treatment with PGRN (100 ng mL^-1 ) had no effect on ACh (10 μm, 1 min)-induced endothelial NO synthase phosphorylation (at Ser1177) as determined by Western blotting. Pre-treatment with PGRN (100 ng mL^-1 ) augmented an NO donor, sodium nitroprusside (SNP; 30 nm-1 μm)- but not a membrane-permeable cGMP analogue, 8-bromo-cGMP-induced relaxation. In the presence of 3-isobutyl-1-methylxanthine (100 μm), a phosphodiesterase inhibitor, pre-treatment with PGRN (100 ng mL^-1 ) increased SNP (30 nm, 5 min)-induced cGMP production as determined by enzyme immunoassay.

CONCLUSION

We for the first time demonstrate that PGRN augments ACh-induced NO-mediated relaxation through the increases of cGMP production in smooth muscle. These results indicate PGRN as a possible pharmacotherapeutic target against cardiovascular diseases including obesity-related hypertension.

Obesity and cancer: the role of adipose tissue and adipo-cytokines-induced chronic inflammation

Adipose tissue in addition to its ability to keep lipids is now recognized as a real organ with both metabolic and endocrine functions. Recent studies demonstrated that in obese animals is established a status of adipocyte hypoxia and in this hypoxic state interaction between adipocytes and stromal vascular cells contribute to tumor development and progression. In several tumors such as breast, colon, liver and prostate, obesity represents a poor predictor of clinical outcomes. Dysfunctional adipose tissue in obesity releases a disturbed profile of adipokines with elevated levels of pro-inflammatory factors and a consequent alteration of key signaling mediators which may be an active local player in establishing the peritumoral environment promoting tumor growth and progression. Therefore, adipose tissue hypoxia might contribute to cancer risk in the obese population. To date the precise mechanisms behind this obesity-cancer link is not yet fully understood. In the light of information provided in this review that aims to identify the key mechanisms underlying the link between obesity and cancer we support that inflammatory state specific of obesity may be important in obesity-cancer link.

Adipocytes play an etiological role in the podocytopathy of high-fat diet-fed rats

Obesity is a risk factor that promotes progressive kidney disease. Studies have shown that an adipocytokine imbalance contributes to impaired renal function in humans and animals, but the underlying interplay between adipocytokines and renal injury remains to be elucidated. We aimed to investigate the mechanisms linking obesity to chronic kidney disease. We assessed renal function in high-fat (HF) diet-fed and normal diet-fed rats, and the effects of preadipocyte- and adipocyte-conditioned medium on cultured podocytes. HF diet-fed and normal diet-fed Sprague Dawley rats were used to analyze the changes in plasma BUN, creatinine, urine protein and renal histology. Additionally, podocytes were incubated with preadipocyte- or adipocyte-conditioned medium to investigate the effects on podocyte morphology and protein expression. In the HF diet group, 24 h urinary protein excretion (357.5 ± 64.2 mg/day vs 115.9 ± 12.4 mg/day, P < 0.05) and the urine protein/creatinine ratio were significantly higher (1.76 ± 0.22 vs 1.09 ± 0.15, P < 0.05), increased kidney weight (3.54 ± 0.04 g vs 3.38 ± 0.04 g, P < 0.05) and the glomerular volume and podocyte effacement increased by electron microscopy. Increased renal expression of desmin and decreased renal expression of CD2AP and nephrin were also seen in the HF diet group (P < 0.05). Furthermore, we found that adipocyte-conditioned medium-treated podocytes showed increased desmin expression and decreased CD2AP and nephrin expression compared with that in preadipocyte-conditioned medium-treated controls (P < 0.05). These findings show that adipocyte-derived factor(s) can modulate renal function. Adipocyte-derived factors play an important role in obesity-related podocytopathy.

Increased Ghrelin Levels and Unchanged Adipocytokine Levels in Major Depressive Disorder

OBJECTIVE

One of the hypotheses of the pathophysiology of major depressive disorder (MDD) proposes that there is a relationship between adipocytokine and ghrelin levels and depression.

METHODS

Patients with major depression with a BMI ≤25 kg/m² between the ages of 11 and 18 years (n = 30) were compared with a healthy control group (n = 30). Both groups were evaluated across a pretreatment period (MD-PT) and an improved period (MD-I). We measured serum leptin, adiponectin, resistin, and ghrelin levels and other parameters related to metabolic syndrome, such as glucose, insulin, insulin resistance (homeostasis model assessment [HOMA]), triglycerides (TG), and total cholesterol (TCHOL).

RESULTS

Leptin, adiponectin, and resistin levels did not differ across groups; however, ghrelin levels were increased in the MD-I group compared with the control and MD-PT groups (p < 0.05). HOMA levels were also higher in the MD-PT group than in the control group (p < 0.05). After treatment, there was no difference in this measurement.

CONCLUSIONS

The relationship between adipocytokines and major depression may be dependent on ghrelin levels as a result of antidepressant treatment and subsequent obesity.

Serum lipocalin-2 levels are positively associated with not only total body fat but also visceral fat area in Chinese men

Serum lipocalin-2 (LCN2) plays an important role in the regulation of the obesity-associated dysmetabolic state and cardiovascular disease. However, relatively little is known about the relationship between serum LCN2 levels and body fat content and distribution. We examined the associations of total body fat content and abdominal fat distribution with serum LCN2 levels in Chinese men.The study was based on a cross-sectional analysis of data for 1203 Chinese men aged 22 to 78 years from the Shanghai Obesity Study. Body fat percentage (fat%) was assessed by bioelectrical impedance analysis, and magnetic resonance imaging was adopted to quantify the visceral fat area (VFA) and subcutaneous fat area (SFA). Serum levels of LCN2 were measured with a standard enzyme-linked immunosorbent assay method.Subjects with a high fat% had higher serum LCN2 levels than those with a normal fat% regardless of their body mass index category (<25 and ≥25 kg/m). The frequency of isolated high VFA was increased with increasing quintiles of serum LCN2 levels (P < 0.001), but the frequency of isolated high SFA did not differ between quintiles of serum LCN2 levels. A trend of increasing VFA was observed with increasing serum LCN2 levels (P < 0.001). Multiple stepwise regression analysis showed that VFA was positively associated with serum LCN2 levels, independent of overall obesity and other confounding factors (standardized β = 0.082, P = 0.008).Serum LCN2 levels are positively correlated with body fat content and independently associated with VFA in Chinese men.

Effect of oncological treatment on serum adipocytokine levels in patients with stage II-III breast cancer

Adipose tissue-derived hormones (adipocytokines), such as adiponectin, leptin, resistin and visfatin, and the pancreatic hormone insulin, have been suggested to play a role in carcinogenesis. we therefore hypothesized that the oncological treatment of breast cancer may alter the serum levels of these adipocytokines and insulin. In this study, we aimed to compare the serum levels of adipocytokines and insulin between the pre- and post-treatment period in patients with breast cancer. In this prospective study, 20 consecutive patients with stage II and III breast cancer underwent breast-conserving surgery or total mastectomy and/or axillary dissection. The patients received adjuvant chemotherapy and radiotherapy, if necessary. Blood samples were obtained during the preoperative period and postoperatively after completion of the adjuvant therapy. There was no statistically significant difference between the pre- and post-treatment levels of visfatin, adiponectin and leptin. However, the serum insulin and resistin levels and insulin resistance were found to be statistically significantly increased following treatment (P<0.05). Post-treatment resistin levels were positively correlated with insulin resistance (r=0.45, P<0.05). Therefore, oncological treatment of stage II and III breast cancer did not affect visfatin, adiponectin and leptin levels, but statistically significantly increased resistin levels and insulin resistance. In addition, the post-treatment resistin levels were positively correlated with insulin resistance, suggesting that resistin may be involved in the development of insulin resistance in breast cancer patients following treatment.

Targeting the ERK signaling pathway as a potential treatment for insulin resistance and type 2 diabetes

Extracellular signal-regulated kinase (ERK) has been implicated in the development of insulin resistance associated with obesity and type 2 diabetes mellitus. We have now examined the potential of pharmacological targeting of the ERK pathway with MEK (ERK kinase) inhibitors (PD184352 and PD0325901) for the treatment of obesity-associated insulin resistance. The effects of PD184352 and PD0325901 on the expression of adipocytokines and lipolysis activity were thus examined in 3T3-L1 adipocytes maintained in long-term culture as a model of adipocyte hypertrophy. Leptin receptor-deficient (db/db) mice and high-fat diet-fed KKAy mice, both of which are models of type 2 diabetes, were also treated orally with PD184352 to examine its effects on the diabetic condition. ERK activity was increased in hypertrophic 3T3-L1 adipocytes as well as in adipose tissue of db/db mice and high-fat diet-fed KKAy mice, and this enhanced ERK signaling was associated with dysregulation of adipocytokine expression and increased lipolysis activity. Specific blockade of the ERK pathway in hypertrophic 3T3-L1 adipocytes by MEK inhibitors ameliorated the dysregulation of adipocytokine expression and suppressed the enhanced lipolysis activity. Furthermore, repeated oral administration of PD184352 normalized hyperglycemia and hyperlipidemia and improved insulin sensitivity and glucose tolerance in the diabetic mice. These results suggest that sustained activation of the ERK pathway in adipocytes is associated with the pathogenesis of type 2 diabetes and that selective blockade of this pathway with MEK inhibitors warrants further study as a promising approach to the treatment of insulin resistance and type 2 diabetes.

Visceral adipose tissue-derived serine protease inhibitor augments acetylcholine-induced relaxation via the inhibition of acetylcholine esterase activity in rat isolated mesenteric artery

AIM

Visceral adipose tissue-derived serine protease inhibitor (vaspin) is an adipocytokine with insulin-sensitizing activity originally identified in visceral adipose tissues of obesity-related type II diabetic rats. We previously showed that vaspin inhibits vascular cell migration and apoptosis as well as inflammatory responses, which are crucial for the development of hypertension. However, little is known about the effects of vaspin on vascular reactivity. The aim of this study was thus to explore the effects of vaspin on contraction and relaxation of isolated blood vessel.

METHODS

After mesenteric arteries were isolated from male Wistar rats, the effects of pretreatment with vaspin (3 ng mL(-1) , 30 min) on concentration-contraction and concentration-relaxation relationships for each agent were examined. The effects of vaspin on acetylcholine (ACh)-induced phosphorylation of endothelial nitric oxide (NO) synthase (eNOS) and ACh esterase (AChE) activity were also examined using Western blotting and colorimetric method respectively.

RESULTS

Vaspin did not affect noradrenaline- or 5-hydroxytryptamine-induced contraction. In contrast, vaspin augmented ACh- but not histamine-, A23187- or carbachol-induced NO-mediated relaxation. Vaspin significantly increased ACh-induced eNOS phosphorylation and inhibited AChE activity.

CONCLUSION

We for the first time demonstrate that vaspin augments the ACh-induced NO-mediated endothelium-dependent relaxation via the inhibition of AChE activity.

Treatment with metformin and a dipeptidyl peptidase-4 inhibitor elevates apelin levels in patients with type 2 diabetes mellitus

BACKGROUND

The objective of this study was to assess the effects of metformin monotherapy or combined treatment with a dipeptidyl peptidase-4 inhibitor (vildagliptin) on apelin levels in patients with type 2 diabetes mellitus.

METHODS

Twenty-five patients with poor glycemic control (glycosylated hemoglobin >6.5% [48 mmol/mol]) taking 1,000 mg of metformin daily and 25 healthy controls matched for age and body mass index were enrolled in this study. Anthropometric parameters, glycemic and lipid profile, insulin resistance (homeostasis model assessment of insulin resistance index), and apelin levels were measured at baseline and at 12-week and 24-week visits.

RESULTS

At baseline, apelin levels were higher in the T2DM patients than in the controls (1.93±1.81 ng/mL versus 6.09±4.90 ng/mL; P<0.05). After 12 weeks, when vildagliptin was added, fasting blood glucose and glycosylated hemoglobin decreased, and apelin levels increased further (from 6.09±4.90 ng/mL to 24.23±12.59 ng/mL; P<0.05). Follow-up at 24 weeks showed no further improvement in the glycemic profile and no further increase in apelin levels.

CONCLUSION

Both metformin and vildagliptin favorably changed glycemic indices and apelin levels. For patients inadequately controlled on a low dose of metformin, addition of vildagliptin may be helpful.

Long-term oral exposure to bisphenol A induces glucose intolerance and insulin resistance

Bisphenol A (BPA) is a widely used endocrine disruptor. Recent epidemiologic results have suggested an association between exposure to BPA and cardiovascular disease, type 2 diabetes, and obesity. We investigated the in vivo effects of long-term oral exposure to BPA on insulin resistance and glucose intolerance. In the present study, 4- to 6-week-old male mice on a high-fat diet (HFD) were treated with 50 μg/kg body weight per day of BPA orally for 12 weeks. Long-term oral exposure to BPA along with an HFD for 12 weeks induced glucose intolerance in growing male mice. Intraperitoneal glucose tolerance tests showed that the mice that received an HFD and BPA exhibited a significantly larger area under the curve than did those that received an HFD only (119.9±16.8 vs. 97.9±18.2 mM/min, P=0.027). Body weight, percentage of white adipose tissue, and percentage of body fat did not differ between the two groups of mice. However, treatment with BPA reduced Akt phosphorylation at position Thr308 and GSK3β phosphorylation at position Ser9 in skeletal muscle. BPA tended to decrease serum adiponectin levels and to increase serum interleukin 6 and tumor necrosis factor α, although these findings were not statistically significant. Treatment with BPA did not induce any detrimental changes in the islet area or morphology or the insulin content of β cells. In conclusion, long-term oral exposure to BPA induced glucose intolerance and insulin resistance in growing mice. Decreased Akt phosphorylation in skeletal muscle by way of altered serum adipocytokine levels might be one mechanism by which BPA induces glucose intolerance.

Increased plasma vaspin concentration in patients with sepsis: an exploratory examination

Introduction

Vaspin (visceral adipose tissue-derived serpin) was first described as an insulin-sensitizing adipose tissue hormone. Recently its anti-inflammatory function has been demonstrated. Since no appropriate data is available yet, we sought to investigate the plasma concentrations of vaspin in sepsis.

Materials and methods

57 patients in intensive care, fulfilling the ACCP/SCCM criteria for sepsis, were prospectively included in our exploratory study. The control group consisted of 48 critically ill patients, receiving intensive care after trauma or major surgery. Patients were matched by age, sex, weight and existence of diabetes before statistical analysis. Blood samples were collected on the day of diagnosis. Vaspin plasma concentrations were measured using a commercially available enzyme-linked immunosorbent assay.

Results

Vaspin concentrations were significantly higher in septic patients compared to the control group (0.3 (0.1-0.4) ng/mL vs. 0.1 (0.0-0.3) ng/mL, respectively; P < 0.001). Vaspin concentration showed weak positive correlation with concentration of C-reactive protein (CRP) (r = 0.31, P = 0.002) as well as with SAPS II (r = 0.34, P = 0.002) and maximum of SOFA (r = 0.39, P < 0.001) scoring systems, as tested for the overall study population.

Conclusion

In the sepsis group, vaspin plasma concentration was about three-fold as high as in the median surgical control group. We demonstrated a weak positive correlation between vaspin and CRP concentration, as well as with two scoring systems commonly used in intensive care settings. Although there seems to be some connection between vaspin and inflammation, its role in human sepsis needs to be evaluated further.

Adiponectin and visfatin may serve as diagnosis markers for metabolic syndrome in Uygur population

OBJECTIVES

This study is to determine if two adipocytokines, adiponectin and visfatin, can be used as diagnosis markers for metabolic syndrome (MS) in Uygur population.

METHODS

Sixty-two MS patients and 41 control individuals with normal body weights were enrolled in this study. Abdominal subcutaneous and omental adipose tissues were collected for determination of biochemical indices. The adipokines serum levels were determined by enzyme-linked immunosorbent assay (ELISA). Blood were collected from the MS patients and the control individuals and extracted proteins and RNAs subjected to western blot analysis and real-time PCR to determine adiponectin and visfatin expression, respectively.

RESULTS

ELISA indicated that the serum adiponectin in the MS group was decreased (0.59 ± 0.21 versus 0.49 ± 0.18) in comparison with the control group (P < 0.05). But the serum visfatin in the MS group were increased (1.07 ± 0.41 versus 1.25 ± 0.32) when compared with the control group (P < 0.05). The western blot revealed decreased adiponectin and increased visfatin expression in the MS patients when compared with the normal controls. Further real-time RT-PCR analysis showed that the adiponectin and visfatin expression are altered via a transcriptional mechanism.

CONCLUSIONS

Adiponectin and visfatin might be used as diagnosis markers of MS in Uygur population.

Vitamin D and Dysfunctional Adipose Tissue in Obesity

Vitamin D deficiency and dysfunctional adipose tissue are involved in the development of cardiometabolic disturbances (eg, hypertension, insulin resistance, type 2 diabetes mellitus, obesity, and dyslipidemia). We evaluated the relation between vitamin D and adipocytokines derived from adipose tissue. We studied 50 obese individuals who were classified into different subgroups according to medians of observed anthropometric parameters (body mass index, body fat percentage, waist circumference, and trunk fat mass). There was a negative correlation between vitamin D level and leptin and resistin (r = -.61, P < .01), while a positive association with adiponectin concentrations was found (r = .7, P < .001). Trend estimation showed that increase in vitamin D level is accompanied by intensive increase in adiponectin concentrations (growth coefficient: 12.13). In conclusion, a positive trend was established between vitamin D and the protective adipocytokine adiponectin. The clinical relevance of this relationship needs to be investigated in larger studies.

Putative role of adipose tissue in growth and metabolism of colon cancer cells

Newly emerging data highlight obesity as an important risk factor for developing certain types of cancer, including colorectal cancer. Although evidence supports a link between the two, the mechanisms responsible for this relationship have not yet been fully elucidated. Hypertrophied and dysfunctional adipose tissue of the obese state is characterized by low-grade inflammation. Adipokines and cytokines secreted from adipocytes, together with the abundant availability of lipids from adipocytes in the tumor microenvironment, promote adhesion, migration, and invasion of tumor cells and support tumor progression and uncontrolled growth. One of the predisposed targets of the deleterious effects exerted by secretions from adipose tissue in obesity is the activities associated with the cellular mitochondria. Mitochondrial oxidative metabolism plays a key role in meeting cells' energetic demands by oxidative phosphorylation (OxPhos). Here we discuss: (a) the dynamic relationship between glycolysis, the tricarboxylic acid cycle, and OxPhos; (b) the evidence for impaired OxPhos (i.e., mitochondrial dysfunction) in colon cancer; (c) the mechanisms by which mitochondrial dysfunction can predispose to cancer. We propose that impaired OxPhos increases susceptibility to colon cancer since OxPhos is sensitive to a large number of factors that are intrinsic to the host (e.g., inflammation). Given that adipocytes are a major source of adipokines and energy for the cancer cell, understanding the mechanisms of metabolic symbiosis between cancer cells and adipocytes should reveal new therapeutic possibilities.

Adipocytokines in obesity and metabolic disease

The current global obesity pandemic is the leading cause for the soaring rates of metabolic diseases, especially diabetes, cardiovascular disease, hypertension, and non-alcoholic hepatosteatosis. Efforts devoted to find cures for obesity and associated disorders in the past two decades have prompted intensive interest in adipocyte biology, and have led to major advances in the mechanistic understanding of adipose tissue as an essential endocrine organ. Adipose tissue secretes an array of hormones (adipokines) that signal key organs to maintain metabolic homeostasis, and their dysfunction has been causally linked to a wide range of metabolic diseases. In addition, obesity induces production of inflammatory cytokines (often referred to together with adipokines as adipocytokines) and infiltration of immune cells into adipose tissue, which creates a state of chronic low-grade inflammation. Metabolic inflammation has been increasingly recognized as a unifying mechanism linking obesity to a broad spectrum of pathological conditions. This review focuses on classic examples of adipocytokines that have helped to form the basis of the endocrine and inflammatory roles of adipose tissue, and it also details a few newly characterized adipocytokines that provide fresh insights into adipose biology. Studies of adipocytokines in clinical settings and their therapeutic potential are also discussed.

Vaspin prevents methylglyoxal-induced apoptosis in human vascular endothelial cells by inhibiting reactive oxygen species generation

AIM

Vaspin (visceral adipose tissue-derived serine protease inhibitor) is a novel adipocytokine found in visceral white adipose tissues of obese type 2 diabetic rats. We have previously shown that vaspin has anti-inflammatory and antimigratory effects in vascular smooth muscle cells. Methylglyoxal (MGO) is an active metabolite of glucose and mediates diabetic vascular complications including endothelial cell (EC) apoptosis. Nonetheless, effects of vaspin on MGO-induced apoptosis of vascular EC remain to be determined. We investigated the effects of vaspin on MGO-induced apoptosis of human umbilical vein ECs (HUVECs).

METHODS

Human umbilical vein ECs were treated with MGO (560 μm, 12 h) in the absence or presence of vaspin (1 ng mL(-1), pre-treatment for 2 h). Cell death was evaluated by a cell counting assay. Apoptosis was determined by a terminal deoxyribonucleotide transferase-mediated deoxyuridine triphosphate nick-end labelling (TUNEL) assay. Cleaved caspase-3 expression was determined by Western blotting. Reactive oxygen species (ROS) generation was fluorometrically measured using 2', 7'-dichlorodihydrofluorescein diacetate. NADPH oxidase (NOX) activity was determined by a lucigenin assay.

RESULTS

Vaspin significantly inhibited MGO-induced HUVEC death. Vaspin significantly attenuated MGO-increased TUNEL-positive ECs. Moreover, vaspin significantly inhibited MGO-induced caspase-3 cleavage. Vaspin significantly inhibited MGO-induced ROS generation as well as NOX activation.

CONCLUSIONS

The present results for the first time demonstrate that vaspin inhibits MGO-induced EC apoptosis by preventing caspase-3 activation via the inhibition of NOX-derived ROS generation.

Adipocytokines in childhood cancer survivors and correlation with metabolic syndrome components

BACKGROUND

Although there are several studies on the prevalence of metabolic syndrome (MetS) in childhood cancer survivors (CCS), the association between MetS components and serum adipocytokine level has not been elucidated.

METHODS

The charts of 49 patients (27 male, 22 female) who had attended the CCS clinic of the Department of Pediatrics, Kyoto University Hospital, between April 2009 and March 2010 were retrospectively reviewed. Median age was 10.7 years, and the median interval since the completion of chemotherapy was 5.1 years. The diagnosis of MetS was made based on the Japanese criteria for either children or adults.

RESULTS

Three (6.1%) of 49 patients fulfilled the criteria for MetS, and 28 (57.1%) had at least one component of MetS. High leptin level was seen in 18 patients (36.7%), and low total adiponectin level was seen in 20 (40.8%). The number of patients with high leptin was correlated with body mass index z-score (>2.0), abdominal circumference/height (≥0.5), diastolic blood pressure and fasting blood sugar. The number of patients with low total adiponectin was correlated with systolic blood pressure and triglyceride. When the patients were divided into three groups based on the number of positive MetS components (0, 1 and 2-4), leptin and adiponectin tended to be higher and lower in the third group, respectively.

CONCLUSIONS

Adipocytokines may play a role in the pathogenesis of MetS occurring in CCS. It is recommended that adipocytokines be evaluated together with MetS components at the CCS follow-up clinics.

Effects of dietary carbohydrate replaced with wild rice (Zizania latifolia (Griseb) Turcz) on insulin resistance in rats fed with a high-fat/cholesterol diet

Wild rice (WR) is a very nutritious grain that has been used to treat diabetes in Chinese medicinal practice. City diet (CD) is based on the diet consumed by Asian area residents in modern society, which is rich in saturated fats, cholesterol and carbohydrates. The present study was aimed at evaluating the effects of replacing white rice and processed wheat starch of CD with WR as the chief source of dietary carbohydrates on insulin resistance in rats fed with a high-fat/cholesterol diet. Except the rats of the low-fat (LF) diet group, the rats of the other three groups, including to high-fat/cholesterol (HFC) diet, CD and WR diet, were fed with high-fat/cholesterol diets for eight weeks. The rats fed with CD exhibited higher weight gain and lower insulin sensitivity compared to the rats consuming a HFC diet. However, WR suppressed high-fat/cholesterol diet-induced insulin resistance. WR decreased liver homogenate triglyceride and free fatty acids levels, raised serum adiponectin concentration and reduced serum lipocalin-2 and visfatin concentrations. In addition, the WR diet potently augmented the relative expressions of adiponectin receptor 2, peroxisome proliferator-activated receptors, alpha and gamma, and abated relative expressions of leptin and lipocalin-2 in the tissues of interest. These findings indicate that WR is effective in ameliorating abnormal glucose metabolism and insulin resistance in rats, even when the diet consumed is high in fat and cholesterol.