Visfatin in obese children and adolescents and its association with insulin resistance and metabolic syndrome

Insulin resistance-related circulating predictive markers in the metabolic syndrome: a systematic review in the Iranian population

Background

Specific biomarkers for metabolic syndrome (MetS) may improve diagnostic specificity for clinical information. One of the main pathophysiological mechanisms of MetS is insulin resistance (IR). This systematic review aimed to summarize IR-related biomarkers that predict MetS and have been investigated in Iranian populations.

Methods

An electronic literature search was done using the PubMed and Scopus databases up to June 2022. The risk of bias was assessed for the selected articles using the instrument suggested by the Joanna Briggs Institute (JBI). This systematic review protocol was registered with PROSPERO (registration number CRD42022372415).

Results

Among the reviewed articles, 46 studies investigated the association between IR biomarkers and MetS in the Iranian population. The selected studies were published between 2009 and 2022, with the majority being conducted on adults and seven on children and adolescents. The adult treatment panel III (ATP III) was the most commonly used criteria to define MetS. At least four studies were conducted for each IR biomarker, with LDL-C being the most frequently evaluated biomarker. Some studies have assessed the diagnostic potency of markers using the area under the curve (AUC) with sensitivity, specificity, and an optimal cut-off value. Among the reported values, lipid ratios and the difference between non-HDL-C and LDL-C levels showed the highest AUCs (≥ 0.80) for predicting MetS.

Conclusions

Considering the findings of the reviewed studies, fasting insulin, HOMA-IR, leptin, HbA1c, and visfatin levels were positively associated with MetS, whereas adiponectin and ghrelin levels were negatively correlated with this syndrome. Among the investigated IR biomarkers, the association between adiponectin levels and components of MetS was well established.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01347-6.

Obesity and Oral Health: The Link Between Adipokines and Periodontitis

Periodontitis is a chronic inflammatory disease of the periodontium, or the supportive tissues around the tooth. This disease has been related to different risk factors, such as the presence of plaque and calculus, tobacco smoking, low socioeconomic status, and the immune state of the host. Importantly, the chronic inflammatory environment generated by periodontitis may lead to tooth loss and diverse systemic complications, such as cardiovascular disease, osteoarthritis and metabolic disease. Recent investigations have supported the role of obesity as a risk factor for periodontitis. Furthermore, studies have found obesity to compromise healing after periodontal therapy; however, the mechanisms underlying this association are not well understood. Proteins called 'adipokines' could be the factor linking obesity to periodontitis. Adipokines are bioactive molecules with hormonal properties and a structure similar to cytokines produced by the adipose tissue. Although adipokines have both pro-and anti-inflammatory effects, the shift towards pro-inflammatory actions occurs when the adipose tissue becomes pathological, as observe in the progression of conditions such as obesity or adiposopathy. This article reviews the role of adipokines in the pathophysiology and progression of periodontitis by focusing on their impact on inflammation and the molecular mechanisms through which adipokines contribute to the onset and development of periodontitis.

Association of Visfatin gene polymorphism with obesity related metabolic disorders among Pakistani population: a case control study

In recent years, the global prevalence of obesity and its associated metabolic disorders has reached alarming levels, presenting a significant challenge to public health worldwide. Visfatin, also known as pre-B cell colony-enhancing factor (PBEF) or nicotinamide phosphoribosyltransferase (NAMPT), is an adipokine that has been implicated in various physiological processes, including glucose homeostasis, lipid metabolism, and inflammation. The main objective of this proposed study is to find out the association between visfatin genetic variants and metabolic syndrome. The sample size of the study consisted of 300 blood samples (150 control and 150 cases). This study found that the genotypic frequency of visfatin SNPs, including rs2302559 (OD: 18.222; 95% CI 10.228-32.466; p-value < 0.001) and rs1215113036 (OD: 129.40; 95% CI 44.576-375.693; p-value < 0.001) were significantly associated with metabolic syndrome. Moreover, the frequency of the mutant alleles of both visfatin SNPs was found to be higher in patients with metabolic syndrome as compared to controls. Results of the current study indicate that people with any genetic variation of Visfatin, such as rs2302559 and rs1215113036, are more likely to develop metabolic syndrome. Visfatin genetic variants are linked to an increased risk of metabolic syndrome, implying it's role in disease pathophysiology.

The Role of Adipokines and Myokines in the Pathogenesis of Different Obesity Phenotypes-New Perspectives

Obesity is a characteristic disease of the twenty-first century that is affecting an increasing percentage of society. Obesity expresses itself in different phenotypes: normal-weight obesity (NWO), metabolically obese normal-weight (MONW), metabolically healthy obesity (MHO), and metabolically unhealthy obesity (MUO). A range of pathophysiological mechanisms underlie the occurrence of obesity, including inflammation, oxidative stress, adipokine secretion, and other processes related to the pathophysiology of adipose tissue (AT). Body mass index (BMI) is the key indicator in the diagnosis of obesity; however, in the case of the NWO and MONW phenotypes, the metabolic disturbances are present despite BMI being within the normal range. On the other hand, MHO subjects with elevated BMI values do not present metabolic abnormalities. The MUO phenotype involves both a high BMI value and an abnormal metabolic profile. In this regard, attention has been focused on the variety of molecules produced by AT and their role in the development of obesity. Nesfatin-1, neuregulin 4, myonectin, irisin, and brain-derived neurotrophic factor (BDNF) all seem to have protective effects against obesity. The primary mechanism underlying the action of nesfatin-1 involves an increase in insulin sensitivity and reduced food intake. Neuregulin 4 sup-presses lipogenesis, decreases lipid accumulation, and reduces chronic low-grade inflammation. Myonectin lowers the amount of fatty acids in the bloodstream by increasing their absorption in the liver and AT. Irisin stimulates the browning of white adipose tissue (WAT) and consequently in-creases energy expenditure, additionally regulating glucose metabolism. Another molecule, BDNF, has anorexigenic effects. Decorin protects against the development of hyperglycemia, but may also contribute to proinflammatory processes. Similar effects are shown in the case of visfatin and chemerin, which may predispose to obesity. Visfatin increases adipogenesis, causes cholesterol accumulation in macrophages, and contributes to the development of glucose intolerance. Chemerin induces angiogenesis, which promotes the expansion of AT. This review aims to discuss the role of adipokines and myokines in the pathogenesis of the different obesity phenotypes.

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.

Association of Adiponectin 45T/G (rs2241766) and Visfatin 4689G/T (rs2110385) Gene Polymorphisms with Susceptibility to Obesity

Background

This study aimed to see whether the adiponectin 45T/G (rs2241766) and visfatin 4689G/T (rs2110385) gene polymorphisms in an Iranian population are linked to obesity and/or obesity-related traits in normal and obese individuals.

Methods

230 obese individuals and 169 healthy controls had their genomic DNA taken. The alleles and genotypes of the rs2241766 and rs2110385 polymorphisms were determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique.

Results

Obese individuals had considerably greater frequencies of the G allele and GG genotypes of the rs2241766 polymorphism than healthy controls (35% vs 21%, Probability (P) <0.0001, odds ratios (OR): 1.99, 95% confidence intervals (CI): 1.45-2.75 and 21% vs 7%, P = 0.002, OR: 3.52, 95% CI: 1.81-6.85, respectively). In comparison to healthy controls, obesity patients had substantially lower frequencies of the T allele and TT genotype of the rs2241766 polymorphism (65% vs 79%, P < 0.0001, OR: 0.50, 95% CI: 0.36-0.69 and 51% vs 65%, P = 0.008, OR: 0.58, 95% CI: 0.39-0.87, respectively). Obese individuals had substantially higher frequencies of the G allele and GG genotype in the rs2110385 polymorphism than healthy controls (77% vs 69%, P = 0.01, OR: 1.47, 95% CI: 1.07-2.0 and 61% versus 51%, P = 0.047, OR: 1.5, 95% CI: 1.0-2.2, respectively). When compared to healthy controls, the frequency of the T allele in the rs2110385 polymorphism was considerably lower in obese individuals (23% vs 31%, P = 0.01, OR: 0.68, 95% CI: 0.5-0.93). Furthermore, these single nucleotide polymorphisms (SNPs) were shown to have a strong link to clinical data in obese individuals. In the case of adiponectin, 45T/G (rs2241766) genotypes, serum low-density lipoprotein, waist circumference, and diastolic blood pressure were substantially different among the rs2241766 genotypes (P = 0.007, P = 0.000, and P = 0.011, respectively). In the instance of the visfatin 4689G/T (rs2110385) gene polymorphism, serum triglycerides was substantially different among the rs2110385 genotypes (P = 0.039).

Conclusions

In the Iranian population, our findings revealed a strong link between adiponectin and visfatin gene polymorphisms and obesity and several obesity-related clinical characteristics. These SNPs might be used to identify those who are at risk of becoming obese.

Noninvasive biomarkers in pediatric nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease worldwide among children and adolescents. It encompasses a spectrum of disease, from its mildest form of isolated steatosis, to nonalcoholic steatohepatitis (NASH) to liver fibrosis and cirrhosis, or end-stage liver disease. The early diagnosis of pediatric NAFLD is crucial in preventing disease progression and in improving outcomes. Currently, liver biopsy is the gold standard for diagnosing NAFLD. However, given its invasive nature, there has been significant interest in developing noninvasive methods that can be used as accurate alternatives. Here, we review noninvasive biomarkers in pediatric NAFLD, focusing primarily on the diagnostic accuracy of various biomarkers as measured by their area under the receiver operating characteristic, sensitivity, and specificity. We examine two major approaches to noninvasive biomarkers in children with NAFLD. First, the biological approach that quantifies serological biomarkers. This includes the study of individual circulating molecules as biomarkers as well as the use of composite algorithms derived from combinations of biomarkers. The second is a more physical approach that examines data measured through imaging techniques as noninvasive biomarkers for pediatric NAFLD. Each of these approaches was applied to children with NAFLD, NASH, and NAFLD with fibrosis. Finally, we suggest possible areas for future research based on current gaps in knowledge.

AMP-activated protein kinase is a key regulator of obesity-associated factors

An imbalance between caloric intake and energy expenditure leads to obesity. Obesity is an important risk factor for the development of several metabolic diseases including insulin resistance, metabolic syndrome, type 2 diabetes mellitus, and cardiovascular disease. So, controlling obesity could be effective in the improvement of obesity-related diseases. Various factors are involved in obesity, such as AMP-activated protein kinases (AMPK), silent information regulators, inflammatory mediators, oxidative stress parameters, gastrointestinal hormones, adipokines, angiopoietin-like proteins, and microRNAs. These factors play an important role in obesity by controlling fat metabolism, energy homeostasis, food intake, and insulin sensitivity. AMPK is a heterotrimeric serine/threonine protein kinase known as a fuel-sensing enzyme. The central role of AMPK in obesity makes it an attractive molecule to target obesity and related metabolic diseases. In this review, the critical role of AMPK in obesity and the interplay between AMPK and obesity-associated factors were elaborated.

Role of visfatin in obesity-induced insulin resistance

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

Circulatory Adipokines and Incretins in Adolescent Idiopathic Scoliosis: A Pilot Study

Adolescent idiopathic scoliosis (AIS) is a three-dimensional malformation of the spine of unknown cause that develops between 10 and 18 years old and affects 2-3% of adolescents, mostly girls. It has been reported that girls with AIS have a taller stature, lower body mass index (BMI), and bone mineral density (BMD) than their peers, but the causes remain unexplained. Energy metabolism discrepancies, including alterations in adipokine and incretin circulatory levels, could influence these parameters and contribute to disease pathophysiology. This pilot study aims to compare the anthropometry, BMD, and metabolic profile of 19 AIS girls to 19 age-matched healthy controls. Collected data include participants' fasting metabolic profile, anthropometry (measurements and DXA scan), nutritional intake, and physical activity level. AIS girls (14.8 ± 1.7 years, Cobb angle 27 ± 10°), compared to controls (14.8 ± 2.1 years), were leaner (BMI-for-age z-score ± SD: -0.59 ± 0.81 vs. 0.09 ± 1.11, p = 0.016; fat percentage: 24.4 ± 5.9 vs. 29.2 ± 7.2%, p = 0.036), had lower BMD (total body without head z-score ± SD: -0.6 ± 0.83 vs. 0.23 ± 0.98, p = 0.038; femoral neck z-score: -0.54 ± 1.20 vs. 0.59 ± 1.59, p = 0.043), but their height was similar. AIS girls had higher adiponectin levels [56 (9-287) vs. 32 (7-74) μg/mL, p = 0.005] and lower leptin/adiponectin ratio [0.042 (0.005-0.320) vs. 0.258 (0.024-1.053), p = 0.005]. AIS participants with a Cobb angle superior to 25° had higher resistin levels compared to controls [98.2 (12.8-287.2) vs. 32.1 (6.6-73.8), p = 0.0013]. This pilot study suggests that adipokines are implicated in AIS development and/or progression, but more work is needed to confirm their role in the disease.

Correlation of Serum Visfatin Level in Non-obese Women with Polycystic Ovary Syndrome and Matched Control

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrinopathy affecting reproductive-age women. Visfatin, an adipocytokine, and insulin resistance (IR) marker in diabetes since PCOS and diabetes share insulin resistance as an etiological factor, this study aimed to investigate visfatin as a predictive marker for IR and hyperandrogenemia in non-obese PCOS women and test its correlation to other parameters. A cross-sectional study conducted at the University Hospital recruited 140 women, divided into two groups. Group I (70/140, study group) was PCOS patients' diagnosis based on 2003 Rotterdam criteria and Group II (70/140, healthy controls). Both were aged, and body mass index (BMI) matched. After a detailed history and general examination, the clinical, demographic, biochemical, hormonal, and metabolic parameters were taken for comparison's sake. PCOS patients were subdivided according to the clinical or hormonal evidence of hyperandrogenemia into two groups: those with hyperandrogenemia and those without. Higher serum visfatin was estimated in the PCOS group (4.4 ± 1.7) versus healthy controls (3.1 ± 0.7) ng/mL, P < 0.0001. Significantly higher visfatin was confirmed in hyperandrogenic PCOS versus non-hyperandrogenic PCOS women (5.69 ± 1.1 vs. 2.76 ± 0.51 ng/mL). A strong correlation was found between visfatin versus hemoglobin A1c and free androgen index (FAI); r = 0.784 and 0.624, respectively. BMI and free testosterone scored a modest correlation. BMI centiles' correlation with serum visfatin revealed no significant effect on serum visfatin, P = 0.62. The ROC calculated visfatin cut-off value; 4.34 ng/mL with 51.4% sensitivity and 100% specificity, and a P-value < 0.001 in discriminating PCOS cases. In conclusion, a strong positive correlation of visfatin with insulin resistance, followed by FAI in PCOS cases irrespective of BMI, suggests the intimate relation of visfatin in PCOS pathophysiology among non-obese women. Further research is warranted to explore this association's therapeutic and prognostic value.

Gestational Diabetes Mellitus: The Crosslink among Inflammation, Nitroxidative Stress, Intestinal Microbiota and Alternative Therapies

Gestational diabetes mellitus (GDM) is characterized by a set of metabolic complications arising from adaptive failures to the pregnancy period. Estimates point to a prevalence of 3 to 15% of pregnancies. Its etiology includes intrinsic and extrinsic aspects of the progenitress, which may contribute to the pathophysiogenesis of GDM. Recently, researchers have identified that inflammation, oxidative stress, and the gut microbiota participate in the development of the disease, with potentially harmful effects on the health of the maternal-fetal binomial, in the short and long terms. In this context, alternative therapies were investigated from two perspectives: the modulation of the intestinal microbiota, with probiotics and prebiotics, and the use of natural products with antioxidant and anti-inflammatory properties, which may mitigate the endogenous processes of the GDM, favoring the health of the mother and her offspring, and in a future perspective, alleviating this critical public health problem.

The Roles and Associated Mechanisms of Adipokines in Development of Metabolic Syndrome

Metabolic syndrome is a cluster of metabolic indicators that increase the risk of diabetes and cardiovascular diseases. Visceral obesity and factors derived from altered adipose tissue, adipokines, play critical roles in the development of metabolic syndrome. Although the adipokines leptin and adiponectin improve insulin sensitivity, others contribute to the development of glucose intolerance, including visfatin, fetuin-A, resistin, and plasminogen activator inhibitor-1 (PAI-1). Leptin and adiponectin increase fatty acid oxidation, prevent foam cell formation, and improve lipid metabolism, while visfatin, fetuin-A, PAI-1, and resistin have pro-atherogenic properties. In this review, we briefly summarize the role of various adipokines in the development of metabolic syndrome, focusing on glucose homeostasis and lipid metabolism.

Effects of low-glycemic index diet on plasma adipokines in obese children

BACKGROUND

A low-glycemic index (GI) diet may modulate adipocyte-produced adipokines linking to insulin resistance.

METHODS

The stored plasma samples from the RCT of a low-GI vs. conventional diet in obese children were analyzed for adipokines: leptin, adiponectin, resistin, and visfatin. Their relationships with clinical outcomes were assessed.

RESULTS

Fifty-two participants completed the 6-month intervention trial (mean age: 12.0 ± 2.0 years, 35 boys). Both groups had significantly decreased BMI z-scores from baseline whereas the low-GI group had significant reduction in fasting insulin and HOMA-IR. There were no differences in adipokines between the groups before and after the intervention. However, there was an association between baseline leptin and the change of fat mass index (FMI) but not the insulin resistance in both groups. The higher the baseline leptin was, the lower the changes were for FMI after the intervention.

CONCLUSION

Despite no demonstrable effect of low-GI diet on plasma adipokines, the higher baseline leptin was correlated with lower reduction of fat mass. Leptin resistance may have a detrimental effect on the reduction of adiposity in obese children. Baseline leptin could be a useful predictor of the change in body composition in an obesity intervention trial.

IMPACT

Leptin resistance may have a detrimental effect in reducing the adiposity in obese children. This study is the first of its kind to compare the plasma adipokine concentrations of obese children on low-GI diet and conventional diet. We found that serum leptin was significantly correlated with the reduction of BMI z-score and FMI in both groups. Baseline leptin could be a useful predictor of the change in body composition in an obesity intervention trial.

Angiopoietin-Like Proteins 2 and 3 in Children and Adolescents with Obesity and Their Relationship with Hypertension and Metabolic Syndrome

Background

Angiopoietin-like protein 2 (ANGPTL2) is one of the adipocyte-derived inflammatory factors which connects obesity to insulin resistance. ANGPTL3 has a direct role in regulation of lipid metabolism. The objective of this study was to evaluate ANGPTL2 and ANGPTL3 in childhood obesity and their relationship with metabolic syndrome.

Methods

70 children and adolescents, 35 obese and 35 normal-weight subjects, were enrolled in this research after complete clinical examination and anthropometric evaluations. Serum ANGPTL2 and ANGPTL3 and insulin were measured by enzyme-linked immunosorbent assay (ELISA). Homeostatic model assessment of insulin resistance (HOMA-IR) was calculated and used to estimate insulin resistance (IR). Colorimetric methods were used for the assessment of fasting plasma glucose (FPG), LDL-C, HDL-C, total cholesterol (TC), and triglyceride (TG).

Results

The levels of ANGPTL2 and ANGPTL3 were significantly higher in obese subjects than those in controls, but they did not differ significantly in subjects with or without IR. ANGPTL3 was found to be significantly elevated in obese children with metabolic syndrome (MetS) in comparison with those without MetS. Both of the studied ANGPTLs were positively correlated with BMI, systolic blood pressure (SBP), diastolic blood pressure (DBP), TC, and LDL-C. The correlation between ANGPTL3 and either TC or LDL-C remained significant after adjusting for BMI.

Conclusion

Serum ANGPTL2 and ANGPTL3 were elevated in obesity and associated with blood pressure and indices of metabolic syndrome, suggesting that they might be involved in the advancement of obesity-related hypertension and metabolic syndrome.

Omentin and visfatin in adolescent inpatients with anorexia nervosa; association with symptoms

Anorexia nervosa (AN) is associated with significant weight loss; thus, it is crucial to discern the contribution of hormones produced by adipose tissue. Some of the adipokines have not been sufficiently studied. Therefore, the present study aims to measure serum concentrations of omentin and visfatin, in adolescent inpatients with AN. The correlations between selected adipokines and psychopathological symptoms of AN were also analyzed. Thirty adolescent inpatients with anorexia nervosa and thirty healthy age and height matched girls (CONT) were enrolled in the study. The physical and mental examination, anthropometric and psychometric assessment - Beck Depression Inventory (BDI), Hamilton Depression Rating Scale (HDRS), Eating Attitude Test (EAT-26) and Yale-Brown Obsessive-Compulsive Scale (YBOCS), and blood analysis were performed at two-time points - in the malnourished patients (AN T1) and after partial weight recovery (8.30 ± 3.75 weeks) (AN T2). The omentin concentration was not significantly different from the CONT neither in AN T1 nor AN T2. The visfatin level was altered in AN T1 and did not change after partial weight normalization (AN T2). A positive correlation between visfatin and YBOCS was found in AN T2. Visfatin concentrations were decreased in adolescent inpatients suffering from AN in the acute phase of the disease and did not normalize after partial weight restoration. The studies considering visfatin as a biomarker of the acute phase of AN should be continued. Moreover, the visfatin showed association with the obsessive and compulsive symptoms; thus its participation in non-homeostatic regulation of food intake should be investigated in further studies.

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.

A reusable colorimetric assay based on mixed valence state Ce-MOF@Pt nanoparticles for highly sensitive detection of visfatin

In this work, a colorimetric assay for visfatin detection is described. The mixed valence state Ce-MOF (MVCM) modified by platinum nanoparticles (Pt NPs) is used as a novel catalyst. MVCM exhibits excellent intrinsic peroxidase-like catalytic activity due to the spontaneous recycling of the Ce(III)/Ce(IV) system. Pt NPs serve not only as a carrier of the -NH₂-modified single strand DNA (S1) but also as a synergistic catalyst of MVCM. The capture probe (S2) attached to the streptavidin-modified magnetic beads (Mag-SA) could combine with the aptamer to form the Mag-SA/S2/aptamer complex. When in the presence of the target visfatin, aptamer specifically combines with the visfatin, which induces the release of Mag-SA/S2 from the Mag-SA/S2/aptamer complex. At this time, the MVCM@Pt/S1 complex connects with the released Mag-SA/S2, which quickly catalyzes the 3,3,3',3'-tetramethylbenzidine (TMB), leading to a color change. Under optimal conditions, the absorbance increases linearly when the concentration ranges from 1 ng mL^-1 to 100 ng mL^-1, and the detection limit is as low as 0.11 ng mL^-1. Furthermore, Mag-SA/S2 can be reused at least five times by using the uracil-DNA glycosylase (UDG) and an external magnetic field. The proposed method shows satisfying reproducibility, stability, specificity, and sensitivity, and it was successfully applied to detect visfatin in spiked human serum samples. Thus, it has great potential for clinical research, detection, and catalytic applications.

Inhibition of visfatin/NAMPT affects ovarian proliferation, apoptosis, and steroidogenesis in pre-pubertal mice ovary

Pubertal ovarian function might be dependent on the factors present in the pre-pubertal stages. Visfatin regulates ovarian steroidogenesis in adult. To date, no study has investigated the role of visfatin either in pre-pubertal or pubertal mice ovary. Thus, we investigated the role of visfatin in pre-pubertal mice ovary in relation to steroidogenesis and proliferation and apoptosis in vitro by inhibiting the endogenous visfatin by a specific inhibitor, FK866. Inhibition of visfatin increased the estrogen secretion and also up-regulated the expression of CYP11A1, 17βHSD and CYP19A1 in mice ovary. Furthermore, active caspase3 was up-regulated along with the down-regulation of BAX and BCL2 in the pre-pubertal ovary after visfatin inhibition. The expression of GCNA, PCNA, and BrdU labeling was also decreased by FK866 treatment. These results suggest that visfatin inhibits steroidogenesis, increases proliferation, and suppresses apoptosis in the pre-pubertal mice ovary. So, visfatin is a new regulator of ovary function in pre-pubertal mice.

Visfatin and Rheumatoid Arthritis: Pathogenetic Implications and Clinical Utility

Objective:

Analysis and generalization of data related to visfatin involvement in the pathogenesis of inflammation at various stages of rheumatoid arthritis.

Data Synthesis:

Visfatin is an adipocytokine which has also been identified in non-adipose tissues. It influences directly on the maturation of B cells, which are involved in autoantibody production and T cell activation. Visfatin can promote inflammation via regulation of pro-inflammatory cytokines including TNF, IL-1β and IL-6. The concentration of circulating visfatin in rheumatoid arthritis patients is higher compared to healthy individuals. Several studies suggest that visfatin level is associated with rheumatoid arthritis activity, and its elevation may precede clinical signs of the relapse. In murine collagen-induced arthritis, visfatin levels were also found to be elevated both in inflamed synovial cells and in joint vasculature. Visfatin blockers have been shown to confer fast and long-term attenuation of pathological processes; however, most of their effects are transient. Other factors responsible for hyperactivation of the immune system can participate in this process at a later stage. Treatment of rheumatoid arthritis with a combination of these blockers and inhibitors of other mediators of inflammation can potentially improve treatment outcomes compared to current therapeutic strategies. Recent advances in the treatment of experimental arthritis in mice as well as the application of emerging treatment strategies obtained from oncology for rheumatoid arthritis management could be a source of novel adipokine-mediated anti-rheumatic drugs.

Conclusion:

The ongoing surge of interest in anticytokine therapy makes further study of visfatin highly relevant as it may serve as a base for innovational RA treatment.

Adipocytokines: Are they the Theory of Everything?

INTRODUCTION

Adipose tissue secretes various bioactive peptides/proteins, immune molecules and inflammatory mediators which are known as adipokines or adipocytokines. Adipokines play important roles in the maintenance of energy homeostasis, appetite, glucose and lipid metabolism, insulin sensitivity, angiogenesis, immunity and inflammation. Enormous number of studies from all over the world proved that adipocytokines are involved in the pathogenesis of diseases affecting nearly all body systems, which raises the question whether we can always blame adipocytokines as the triggering factor of every disease that may hit the body.

OBJECTIVE

Our review targeted the role played by adipocytokines in the pathogenesis of different diseases affecting different body systems including diabetes mellitus, kidney diseases, gynecological diseases, rheumatologic disorders, cancers, Alzheimer's, depression, muscle disorders, liver diseases, cardiovascular and lung diseases.

METHODOLOGY

We cited more than 33 recent literature reviews that discussed the role played by adipocytokines in the pathogenesis of different diseases affecting different body systems.

CONCLUSION

More evidence is being discovered to date about the role played by adipocytokines in more diseases and extra research is needed to explore hidden roles played by adipokine imbalance on disease pathogenesis.

The up-regulation of markers of adipose tissue fibrosis by visfatin in pre-adipocytes as well as obese children and adolescents

Adipocytes are surrounded by a three-dimensional network of extracellular matrix (ECM) proteins. Aberrant ECM accumulation and remodeling leads to adipose tissue fibrosis. Visfatin is one of the adipocytokines that is increased in obesity and is implicated in insulin resistance. The objective of this study was to investigate the effect of visfatin on major components of ECM remodeling. In this study, plasma levels of both endotrophin and visfatin in obese children and adolescents were significantly higher than those in control subjects and they showed a positive correlation with each other. Treatment of 3T3-L1 pre-adipocytes with visfatin caused significant up-regulation of Osteopontin (Opn), Collagen type VI (Col6), matrix metalloproteinases MMP-2 and MMP-9. By using inhibitors of major signaling pathways it was shown that visfatin exerted its effect on Col6a3 gene expression through PI3K, JNK, and NF-кB pathways, while induced Opn gene expression via PI3K, JNK, MAPK/ERK, and NOTCH1. Our conclusion is that, the relationship between visfatin, endotrophin and insulin resistance parameters in obesity as well as increased expression of ECM proteins by visfatin suggests adipose tissue fibrosis as a mechanism for devastating effects of visfatin in obesity.

The Impact of Hormonal Imbalances Associated with Obesity on the Incidence of Endometrial Cancer in Postmenopausal Women

Obesity has long been associated with endometrial cancer amongst postmenopausal women; in fact, obese women are more than twice as likely to develop endometrial cancer as women of normal weight. The risk of developing this type of cancer increases with weight gains in adulthood, especially among women who did not use hormonal therapy for menopause. Thus, with an association between menopause, obesity, and endometrial cancer established, it prompts the following question: what specific factors could cause higher risk levels for endometrial cancer in this cohort of women? In this paper, the factor of hormonal changes and imbalances associated with both obesity and menopause will be examined. The hormones that will be discussed are insulin and insulin-like factors, estrogen, and adipokines (specifically adiponectin, visfatin, and leptin).

Can adipokine visfatin be a novel marker of pregnancy-related disorders in women with obesity?

Overweight and obesity have become a dangerous disease requiring multiple interventions, treatment and preventions. In women of reproductive age, obesity is one of the most common medical conditions. Among others, obese state is characterized by low-grade systemic inflammation and enhanced oxidative stress. Increased maternal body mass index might amplify inflammation and reactive oxygen species production, which is associated with unfavourable clinical outcomes that affect both mother and child. Intrauterine growth retardation, preeclampsia, or gestational diabetes mellitus are examples of the hampered maternal and foetoplacental unit interactions. Visfatin is the obesity-related adipokine produced mainly by the visceral adipose tissue. Visfatin affects glucose homeostasis, as well as the regulation of genes related to oxidative stress and inflammatory response. Here, we review visfatin interactions in pregnancy-related disorders linked to obesity. We highlight the possible predictive and prognostic value of visfatin in diagnostic strategies on gravidas with obesity.

Visfatin and SREBP-1c mRNA Expressions and Serum Levels Among Egyptian Women with Polycystic Ovary Syndrome

Background: Obesity and insulin resistance are common features accompanying polycystic ovary syndrome (PCOS). Aim: To analyze the impact of obesity on the expression of the visfatin and sterol regulatory element-binding protein (SREBP)-1c genes among a group of Egyptian women with PCOS, and to assess their suitability as PCOS biomarkers. Subject and methods: Seventy healthy women (control group) (35 nonobese and 35 obese) and 140 women with PCOS (70 nonobese and 70 obese) were enrolled in this study. The visfatin and SREBP-1c genes' expression analyses were performed via real-time polymerase chain reaction. Serum visfatin and SREBP-1c protein levels were measured with ELISA kits. Results: Among PCOS patients, upregulation of visfatin and SREBP-1c expression was observed. We did not identify significant differences between the obese and nonobese PCOS patients nor between obese and non-obese controls. The mRNA expression levels of both genes were significantly positively correlated with their serum protein levels, as well as with fasting serum insulin levels, homeostatic model assessments of insulin resistance (HOMA-IR), luteinizing hormone (LH) ratios, LH/follicular stimulating hormone ratios, total testosterone, and free androgens. We observed significant negative correlations between visfatin and SREBP-1c expression levels and sex hormone binding globulin levels in all studied groups. Receiver operating characteristic curve analyses revealed that combining the visfatin and SREBP-1c expression data increased the sensitivity (95.92%) and specificity (93.2%) for PCOS diagnoses. Conclusion: Upregulation of visfatin and SREBP-1c was observed among PCOS patients. These genes may play a role in the pathogenesis of PCOS independent of obesity. Combined visfatin and SREBP-1c analyses could be used as a noninvasive biomarker for PCOS.

Serum visfatin and vaspin levels in hepatocellular carcinoma (HCC)

Hepatocellular carcinoma (HCC) is the most common liver cancer, accountable for 90% cases. Visfatin and vaspin are adipocytokines with various suggested functions and proven significant correlations between BMI and percentage of body fat. The aim was to assess visfatin and vaspin serum levels in HCC patients and controls, compare their levels in patients with different cancer etiology and grade assessed according to the Barcelona-Clinic Liver Cancer (BCLC) staging system. The additional aim was to analyze relationship between analyzed adipokines and metabolic abnormalities and liver disfunction severity. The study was performed on 69 cirrhotic patients (54 males/15 females) with HCC, aged 59.0 ± 12.1 years, and with BMI 29.0 ± 4.5 kg/m² compared to 20 healthy volunteers. Serum visfatin and vaspin concentrations were significantly increased in HCC patients compared to controls (p = 0.01 and p = 0.02, respectively). Serum vaspin was significantly higher in HCC patients with viral compared to those with non-viral etiology (p = 0.02), with more evident increase in chronic hepatitis C patients (CHC). Serum visfatin levels were significantly higher in patients with higher insulin resistance (p = 0.04) and with platelets count > 100 000/mm³ (p<0.001). Patients with BMI >30 kg/m² had markedly up-regulated vaspin levels (p = 0.04). There was no difference in vaspin and visfatin serum levels with respect to liver dysfunction and BCLC classification. In conclusion, our study revealed serum vaspin and visfatin to be significantly increased in HCC patients independently of cancer etiology compared to controls. Additionally, serum vaspin was elevated in viral disease, especially in CHC. Vaspin up-regulation can be a compensatory mechanism against IR in HCC patients. Serum visfatin and vaspin, although up-regulated, seem not to be associated with cancer grade and cirrhosis severity.

Characterization and Treatment of Inflammation and Insulin Resistance in Obese Adipose Tissue

Adipose tissue is the largest energy storage and protection organ. It is distributed subcutaneously and around the internal organs. It regulates metabolism by storing and releasing fatty acids and secreting adipokines. Excessive nutritional intake results in adipocyte hypertrophy and proliferation, leading to local hypoxia in adipose tissue and changes in the release of adipokines. These lead to recruit of more immune cells into adipose tissue and release of inflammatory signaling factors. Excess free fatty acids and inflammatory factors interfere with intracellular insulin signaling. In this review, we summarize the characteristics of obese adipose tissue and analyze how its inflammation causes insulin resistance. We further discuss the latest clinical research progress on the control of insulin resistance and inflammation resulting from obesity through anti-inflammatory therapy and bariatric surgery. Our review shows that targeted anti-inflammatory therapy is of great significance for obese patients with insulin resistance.

Mechanistic Links Between Obesity, Diabetes, and Blood Pressure: Role of Perivascular Adipose Tissue

Obesity is increasingly prevalent and is associated with substantial cardiovascular risk. Adipose tissue distribution and morphology play a key role in determining the degree of adverse effects, and a key factor in the disease process appears to be the inflammatory cell population in adipose tissue. Healthy adipose tissue secretes a number of vasoactive adipokines and anti-inflammatory cytokines, and changes to this secretory profile will contribute to pathogenesis in obesity. In this review, we discuss the links between adipokine dysregulation and the development of hypertension and diabetes and explore the potential for manipulating adipose tissue morphology and its immune cell population to improve cardiovascular health in obesity.

Hyperlipidemias and Obesity

The organs require oxygen and other types of nutrients (amino acids, sugars, and lipids) to function, the heart consuming large amounts of fatty acids for oxidation and adenosine triphosphate (ATP) generation.

Visfatin Induces Inflammation and Insulin Resistance via the NF-κB and STAT3 Signaling Pathways in Hepatocytes

BACKGROUND

It has been suggested that visfatin, which is an adipocytokine, exhibits proinflammatory properties and is associated with insulin resistance. Insulin resistance and inflammation are the principal pathogeneses of nonalcoholic fatty liver disease (NAFLD), but the relationship, if any, between visfatin and NAFLD remains unclear. Here, we evaluated the effects of visfatin on hepatic inflammation and insulin resistance in HepG2 cells and examined the molecular mechanisms involved.

METHODS

After treatment with visfatin, the inflammatory cytokines IL-6, TNF-α, and IL-1β were assessed by real-time polymerase chain reaction (RT-PCR) and immunocytochemical staining in HepG2 cells. To investigate the effects of visfatin on insulin resistance, we evaluated insulin-signaling pathways, such as IR, IRS-1, GSK, and AKT using immunoblotting. We assessed the intracellular signaling molecules including STAT3, NF-κB, IKK, p38, JNK, and ERK by western blotting. We treated HepG2 cells with both visfatin and either AG490 (a JAK2 inhibitor) or Bay 7082 (an NF-κB inhibitor); we examined proinflammatory cytokine mRNA levels using RT-PCR and insulin signaling using western blotting.

RESULTS

In HepG2 cells, visfatin significantly increased the levels of proinflammatory cytokines, reduced the levels of proteins (e.g., phospho-IR, phospho-IRS-1 (Tyr612), phospho-AKT, and phospho-GSK-3α/β) involved in insulin signaling, and increased IRS-1 S307 phosphorylation compared to controls. Interestingly, visfatin increased the activities of the JAK2/STAT3 and IKK/NF-κB signaling pathways but not those of the JNK, p38, and ERK pathways. Visfatin-induced inflammation and insulin resistance were regulated by JAK2/STAT3 and IKK/NF-κB signaling; together with AG490 or Bay 7082, visfatin significantly reduced mRNA levels of IL-6, TNF-α and IL-1β and rescued insulin signaling.

CONCLUSION

Visfatin induced proinflammatory cytokine production and inhibited insulin signaling via the STAT3 and NF-κB pathways in HepG2 cells.

Elevated 1-hour post-load plasma glucose identifies obese youth with abnormal glucose metabolism and an unfavourable inflammatory profile

CONTEXT

Adults with plasma glucose levels at one hour (1h-GL) ≥8.6 mmol/L during an oral glucose tolerance test (OGTT) are at increased risk for type 2 diabetes mellitus and present an unfavourable cardiometabolic and inflammatory profile, but relevant data on children are scarce.

OBJECTIVE

To investigate if elevated 1h-GL during OGTT in obese children and adolescents is associated with insulin resistance and specific pro-inflammatory biomarkers.

RESEARCH DESIGN AND METHODS

The study group comprised 88 obese children who attended the Outpatient Pediatric Clinic of our Hospital between January and December 2016. Children were divided into two groups according to 1h-GL during an OGTT: group 1 (n = 57) consisted of those with 1h-GL <8.6 mmol/L and group 2 (n = 31) of those with 1h-GL ≥8.6 mmol/L. Arterial blood pressure, body mass index (BMI) and waist circumference (WC) z-scores were measured in all participants. Specific insulin resistance (IR) indices, that is HOMA-IR, Matsuda index and Cederholm insulin sensitivity index (ISI) were calculated. Further, pro-inflammatory biomarkers that have been correlated with obesity complications, namely adiponectin, leptin, visfatin and interleukin (IL)-6 together with lipid levels were measured in all participants. Logistic regression analysis was used.

RESULTS

Children in group 2 had higher insulin (15.5 ± 6.4 vs 10.9 ± 4.8 μU/mL), HOMA-IR (3.41 ± 1.4 vs 2.34 ± 1.05) and lower Matsuda index [4.7 (3.1) vs 18.4 (17) median plus IQR] and Cederholm ISI (38 ± 6 vs 56 ± 11), than children in group 1 (all P < 0.001). They also had higher visfatin (15.4 ± 5.2 vs 10.1 ± 7 ng/mL), and IL-6 [12.5 (6.7) vs 4.8 (4.4) pg/mL], and lower adiponectin (5.9 ± 3.4 vs 11.8 ± 4.7 μg/mL) than children in group 1 (all P < 0.001). Logistic regression showed that these differences between the two groups were independent of age, sex, Tanner stage, BMI and WC z-scores.

CONCLUSIONS

In obese children, 1h-GL ≥8.6 mmol/L during an OGTT is correlated with worsened IR, and an unfavourable metabolic and inflammatory profile. Thus, 1h-GL could be used as an additional marker to identify obese children and adolescents at increased risk of developing obesity complications.

Adipocytokines in Rheumatoid Arthritis: The Hidden Link between Inflammation and Cardiometabolic Comorbidities

Rheumatoid arthritis is a chronic autoimmune disease affecting typically synovial joints and leading to progressive articular damage, disability, and reduced quality of life. Despite better recent therapeutic strategies improving long-term outcomes, RA is associated with a high rate of comorbidities, infections, malignancies, and cardiovascular disease (CVD). Remarkably, some well-known pathogenic proinflammatory mediators in RA, such as interleukin-1β (IL-1β) and tumor necrosis factor (TNF), may play a pivotal role in the development of CVD. Interestingly, different preclinical and clinical studies have suggested that biologic agents commonly used to treat RA patients may be effective in improving CVD. In this context, the contribution of adipocytokines has been suggested. Adipocytokines are pleiotropic molecules, mainly released by white adipose tissue and immune cells. Adipocytokines modulate the function of different tissues and cells, and in addition to energy homeostasis and metabolism, amplify inflammation, immune response, and tissue damage. Adipocytokines may contribute to the proinflammatory state in RA patients and development of bone damage. Furthermore, they could be associated with the occurrence of CVD. In this study, we reviewed available evidence about adipocytokines in RA, because of their involvement in disease activity, associated CVD, and possible biomarkers of prognosis and treatment outcome and because of their potential as a possible new therapeutic target.

THE ASSOCIATION OF PLASMA LEVELS OF miR-34a AND miR-149 WITH OBESITY AND INSULIN RESISTANCE IN OBESE CHILDREN AND ADOLESCENTS

CONTEXT

MicroRNAs (miRNAs) are short noncoding RNAs involved in posttranscriptional regulation of gene expression that influence various cellular functions including glucose and lipid metabolism and adipocyte differentiation.

OBJECTIVE

The aim of this study was to evaluate the levels of miR-34a and miR-149 and their relationship with metabolic parameters in obese children and adolescents.

DESIGN

Seventy children and adolescents were enrolled in the study. Plasma levels of microRNAs were evaluated by real-time PCR using SYBR green and analyzed by ΔCt method. Plasma concentrations of visfatin and insulin were measured by ELISA method. Glucose and lipid profile were determined colorimetrically. HOMA-IR was calculated and used as an index of insulin resistance (IR).

RESULTS

miR-34a was significantly lower in subjects with insulin resistance compared to obese children with normal insulin sensitivity. There was an inverse relationship between miR-34a levels and both insulin and HOMA-IR. On the other hand, miR-149 was significantly correlated with visfatin. There was no significant difference in miR-34a and miR-149 between obese and normal weight subjects.

CONCLUSIONS

miR-34a is associated with insulin and HOMA-IR and thus seems to be involved in IR. miR-149 is inversely associated with visfatin levels which could be indicative of anti-inflammatory effect of this miRNA.

Metabolic syndrome, leptin-insulin resistance and uric acid: a trinomial foe for Algerian city-dweller adolescents' health

Background Adolescence is one of the critical periods where increased risk for long-term obesity-related complications is an important health concern. This highlights the need to perform early diagnostics based on precise biomarkers to decrease the risk of complications in adolescents with obesity. Objective To determine the relationships between serum levels of uric acid (UA), leptin and insulin with metabolic syndrome (MS) components in Algerian adolescents. Subjects Nondiabetic adolescents (n = 204). Methods Blood pressure (BP) and anthropometric measurements were performed using standardized techniques. Blood samples were taken for determination of glycemia, triglyceridemia, uricemia, cholesterolemia, leptinemia and insulinemia. Results The rate of MS among an excess weight group was 17.4% [95% confidence interval (CI)]. Serum levels of UA, leptin and insulin were significantly higher in the excess weight group compared to a normal weight group (279.4 ± 86.05 vs. 204.9 ± 50.34 μmol/L and 25.65 ± 14.01 vs. 4.09 ± 2.60 μg/L, p < 0.001; 24.58 ± 13.85 vs. 13.34 ± 6.41 μIU/L, p < 0.05). Serum levels of UA, leptin and insulin were significantly higher in adolescents with MS compared to those without MS (304.86 ± 111.41 vs. 224.72 ± 77.81 μmol/L, 30.26 ± 12.46 vs. 16.93 ± 14.97 μg/L and 30.91 ± 17.30 vs. 18.71 ± 10.14 μIU/L, p < 0.05, respectively). Significant correlations were found between UA and leptin with waist circumference (r = 0.50 and 0.76), diastolic blood pressure (r = 0.58 and 0.43), triglycerides (r = 0.42 and 0.35) and high-density lipoprotein-cholesterol (r = -0.36 and -0.35). Conclusion Serum levels of UA and leptin may be useful biomarkers for early diagnosis of the risk of MS in our Algerian adolescent population.

Extracellular NAMPT/visfatin causes p53 deacetylation via NAD production and SIRT1 activation in breast cancer cells

Visfatin, which is secreted as an adipokine and cytokine, has been implicated in cancer development and progression. In this study, we investigated the NAD-producing ability of visfatin and its relationship with SIRT1 (silent information regulator 2) and p53 to clarify the role of visfatin in breast cancer. MCF-7 breast cancer cells were cultured and treated with visfatin. SIRT1 activity was assessed by measuring fluorescence intensity from fluoro-substrate peptide. To investigate the effect of visfatin on p53 acetylation, SDS-PAGE followed by western blotting was performed using specific antibodies against p53 and its acetylated form. Total NAD was measured both in cell lysate and the extracellular medium by colorimetric method. Visfatin increased both extracellular and intracellular NAD concentrations. It also induced proliferation of breast cancer cells, an effect that was abolished by inhibition of its enzymatic activity. Visfatin significantly increased SIRT1 activity, accompanied by induction of p53 deacetylation. In conclusion, the results show that extracellular visfatin produces NAD that causes upregulation of SIRT1 activity and p53 deacetylation. These findings explain the relationship between visfatin and breast cancer progression.

Extracellular NAMPT/Visfatin induces proliferation through ERK1/2 and AKT and inhibits apoptosis in breast cancer cells

BACKGROUND

Visfatin is a novel adipokine and proinflammatory cytokine which is implicated in breast cancer progression. The exact proliferative and anti-apoptotic mechanisms of visfatin are still under debate. In this study, the effect of extracellular visfatin on proliferation and apoptosis of breast cancer cells were investigated considering key regulatory molecules in these procedures.

METHODS

BrdU (Bromodeoxyuridine) experiment was used to assess cell proliferation in response to visfatin treatment. Cell viability and apoptosis were assessed using MTT assay and flowcytometry, respectively. Phosphorylation levels of AKT and ERK1/2 as well as survivin levels and Poly ADP ribose polymerase (PARP) cleavage were investigated by western blot analysis.

RESULTS

Visfatin induced proliferation of MCF-7 and MDA-MB-231 cells, an effect that was repressed by using AKT and ERK1/2 inhibitors, indicating involvement of these two signaling pathways in the proliferative effect of visfatin. Similarly, phosphorylation of AKT and ERK1/2 were elevated by visfatin treatment. On the other hand, visfatin improved cell viability and prevented TNF-α-induced apoptosis as well as PARP cleavage. Visfatin also exerted a protective effect on survivin.

CONCLUSION

The results of this study suggest that visfatin induces breast cancer cell proliferation through AKT/PI3K and ERK/MAPK activation and protects against apoptosis in these cells. Thus increased visfatin levels may augment breast cancer development and attenuate treatment efficiency in breast cancer patients.

Recent advances in understanding the role of adipocytokines during non-alcoholic fatty liver disease pathogenesis and their link with hepatokines

Non-alcoholic fatty liver disease (NAFLD) is currently considered the main cause of chronic liver disease worldwide. Mechanisms leading to the development and progression of this disease are topics of great interest for researchers and clinicians. The current multi-hit hypothesis has thrown the crosstalk between liver and adipose tissue into sharp focus. It is well known that adipose tissue produces circulating factors, known as adipocytokines, which exert several effects on liver cells, promoting the onset of NAFLD and its progression to non-alcoholic steatohepatitis in obese subjects. In a similar way, hepatocytes may also respond to obesogenic stimuli by producing and releasing hepatokines into the circulation. Here, the authors provide an overview of recent advances in our understanding of the role of the most relevant adipocytokines and hepatokines in NAFLD pathogenesis, highlighting their possible molecular and functional interactions.

Visfatin serum level and expression in subcutaneous and visceral adipose tissue in prepubertal boys

BACKGROUND

The biological role of visfatin in humans, especially in eutrophic and healthy children, is not understood yet, except for its link to obesity-related disorders in adolescents and adults.

OBJECTIVES

To determine the physiological values of serum visfatin concentrations, and visfatin mRNA expression in subcutaneous (SAT) and visceral adipose tissue (VAT), and to correlate them with anthropometric/metabolic data in prepubertal healthy boys.

METHODS

The study included 59 healthy boys, age 1-10 years, hospitalized for elective surgery, divided according to age into group I (1-3 years old), group II (3-7 years old) and group III (7-10 years old). Anthropometric and biochemical measurements, and the visfatin serum and mRNA level in SAT and VAT were determined in all patients.

RESULTS

Visfatin mRNA expression was higher in SAT compared with VAT in all three studied groups. Highest visfatin mRNA was found in SAT of group III compared with group II (P = 0.030). VAT visfatin mRNA expression negatively correlates with body weight (P = 0.039), waist circumference (P = 0.027) and morning glucose level (P = 0.007).

CONCLUSION

Lack of changes in serum visfatin level despite the changes in visfatin mRNA expression of adipose tissue suggests paracrine effect of visfatin rather than endocrine. Negative correlation of visfatin VAT mRNA expression with anthropometric parameters indicates important role of VAT visfatin in maturation and in glucose metabolism.

From Placenta to Polycystic Ovarian Syndrome: The Role of Adipokines

Adipokines are cytokines produced mainly by adipose tissue, besides many other tissues such as placenta, ovaries, peripheral-blood mononuclear cells, liver, muscle, kidney, heart, and bone marrow. Adipokines play a significant role in the metabolic syndrome and in cardiovascular diseases, have implications in regulating insulin sensitivity and inflammation, and have significant effects on growth and reproductive function. The objective of this review was to analyze the functions known today of adiponectin, leptin, resistin, and visfatin from placenta throughout childhood and adolescence. It is well known now that their serum concentrations during pregnancy and lactation have long-term effects beyond the fetus and newborn. With regard to puberty, adipokines are involved in the regulation of the relationship between nutritional status and normal physiology or disorders of puberty and altered gonadal function, as, for example, premature pubarche and polycystic ovarian syndrome (PCOS). Cytokines are involved in the maturation of oocytes and in the regular progression of puberty and pregnancy.