Measuring visfatin levels in saliva: an alternative approach to gestational diabetes screening

ABSTRACT Objective: Oral glucose tolerance testing (OGTT) is the current recommended approach for the diagnosis of gestational diabetes mellitus (GDM). Visfatin is a type of novel adipokine of interest that mostly participates in glucose metabolism and inflammatory processes. We aim to identify a screening technique for GDM using salivary visfatin levels and to establish this technique's value as a screening method compared to OGTT. Materials and methods: This is a cross-sectional case-control study. The cohort was formed from the saliva samples of pregnant patients in their 24th through 28th weeks of gestation. Patients were divided into two groups depending on their GDM status. OGTT and visfatin test results were compared and subjected to further analysis to establish a cutoff value for visfatin testing. Results: ELISA results indicated a significant difference between patients with GDM compared to patients without GDM; the values were 18.89 ± 9.59 and 12.44 ± 8.75, respectively (p: 0.007). A cutoff value of 10.5 ng/mL can be used to detect GDM with 78% sensitivity and 51% specificity. Conclusion: Salivary visfatin levels were significantly higher in patients with GDM. The existence of a differential in the concentration of visfatin in saliva can be utilized to develop a new screening method for GDM.

Development of a biomarker mortality risk model in acute respiratory distress syndrome.

BACKGROUND: There is a compelling unmet medical need for biomarker-based models to risk-stratify patients with acute respiratory distress syndrome. Effective stratification would optimize participant selection for clinical trial enrollment by focusing on those most likely to benefit from new interventions. Our objective was to develop a prognostic, biomarker-based model for predicting mortality in adult patients with acute respiratory distress syndrome. METHODS: This is a secondary analysis using a cohort of 252 mechanically ventilated subjects with the diagnosis of acute respiratory distress syndrome. Survival to day 7 with both day 0 (first day of presentation) and day 7 sample availability was required. Blood was collected for biomarker measurements at first presentation to the intensive care unit and on the seventh day. Biomarkers included cytokine-chemokines, dual-functioning cytozymes, and vascular injury markers. Logistic regression, latent class analysis, and classification and regression tree analysis were used to identify the plasma biomarkers most predictive of 28-day ARDS mortality. RESULTS: From eight biologically relevant biomarker candidates, six demonstrated an enhanced capacity to predict mortality at day 0. Latent-class analysis identified two biomarker-based phenotypes. Phenotype A exhibited significantly higher plasma levels of angiopoietin-2, macrophage migration inhibitory factor, interleukin-8, interleukin-1 receptor antagonist, interleukin-6, and extracellular nicotinamide phosphoribosyltransferase (eNAMPT) compared to phenotype B. Mortality at 28 days was significantly higher for phenotype A compared to phenotype B (32% vs 19%, p = 0.04). CONCLUSIONS: An adult biomarker-based risk model reliably identifies ARDS subjects at risk of death within 28 days of hospitalization.

The role of visfatin levels in gingival crevicular fluid as a potential biomarker in the relationship between obesity and periodontal disease.

OBJECTIVES: Visfatin is an adipokine that plays an important role in immune functions as a growth factor, enzyme, and pro-inflammatory mediator. We aimed to determine the levels of visfatin, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in gingival crevicular fluid (GCF) in both obese/non-obese patients, with/without generalized chronic periodontitis (GCP). METHODOLOGY: Patients were categorized as obese (O) (n=31) or non-obese (nO) (n=19). Groups were divided into four subgroups according to periodontal conditions: (1) periodontally healthy without obesity (nO-Ctrl); (2) GCP without obesity (nO-CP); (3) periodontally healthy with obesity (O-Ctrl); and (4) GCP with obesity (O-CP). Demographic variables, anthropometric and laboratory data were recorded. Periodontal parameters were measured at baseline and 3rd months after either non-surgical periodontal treatment or calorie -restricted diet therapy. At the same time, GCF samples were taken from patients to analyze TNF-alpha, IL-6,and visfatin levels. RESULTS: Periodontal parameters were significantly higher in the O group than in the nO group (P<0.05). IL-6 levels were higher in the O group than in the nO group (P<0.001). The visfatin levels of the obese patients were reduceddecreased following the treatments (P<0.05). Cholesterol levels were higher in the O group than in the nO groups (P<0.05). IL-6 levels were higher in O-CP and O-Ctrl groups than in the nO-Ctrl group (P<0.05). Compared to the other groups, visfatin levels were significantly higher in the O-CP group but decreased following treatment (P<0.05). CONCLUSIONS: Our findings suggest that visfatin and IL-6 levels in GCF are associated with the pathogenesis of obesity and periodontitis. Within the limits of this study, we considered that there might be an association between the lipid profile and periodontitis on systemically healthy individuals.

Nicotinamide Phosphoribosyl Transferase Is Increased in Osteosarcomas and Chondrosarcomas Compared to Benign Bone and Cartilage.

BACKGROUND/AIM: Primary bone neoplasms include osteosarcomas (OS), chondrosarcomas (CS), and giant cell tumors (GCT). Nicotinamide phosphoribosyl transferase (NAMPT) catalyzes the rate-limiting step of nicotinamide adenine dinucleotide synthesis and is increased in multiple tumor types. In malignancies, NAMPT expression often correlates positively with tumor grade, chemotherapy resistance, and metastatic potential. MATERIALS AND METHODS: Tissue microarray was used to examine NAMPT expression in benign bone and cartilage, GCTs, OS, and different CS grades. RESULTS: For the first time, we showed that NAMPT expression was increased in GCTs and OS compared to benign bone, and in CS compared to benign cartilage. Its expression also increased with higher CS grade. CONCLUSION: Our data indicate that NAMPT plays a role in bone sarcomas and GCTs, and its higher expression may contribute to increased tumor aggressiveness.

Nicotinamide phosphoribosyltransferase expression and clinical outcome of resected stage I/II pancreatic ductal adenocarcinoma.

BACKGROUND: Nicotinamide phosphoribosyltransferase (NAMPT) plays a key role in the biosynthesis of nicotinamide adenine dinucleotide (NAD+), which is a vital cofactor in redox reactions and a substrate for NAD+ consuming enzymes including CD38, PARPs and sirtuins. NAMPT over-expression has been shown in various cancers and its inhibition decreases cancer cell growth, making it an attractive therapeutic target. Here we examine the NAMPT expression in a large cohort of resected stage I/II pancreatic ductal adenocarcinomas (PDAs) and correlate its expression with clinical outcomes and pathologic features. METHODS: A retrospective review of patients with PDAs was conducted at a single institution. Tissue microarrays (TMAs) containing primary PDAs and their metastatic lymph nodes (mLNs) were constructed and stained for NAMPT expression. Each TMA core was evaluated for staining intensity of cancer cells (0 = no staining, 1+ = weak, 2+ = moderate, 3+ = strong) and a mean score was calculated for each case with at least two evaluable cores. NAMPT expression was correlated with clinicopathological variables using chi-squared or Fisher's exact test, and t-tests for categorical and continuous variables, respectively. Survival probabilities were estimated and plotted using the Kaplan-Meier method. Cox proportional hazards regression was used to assess the effects of NAMPT staining values on recurrence-free survival (RFS) and overall survival (OS). This study was conducted under an approved IRB protocol. RESULTS: 173 primary PDAs had at least 2 TMA cores with identifiable cancer cells. The mean IHC score was 0.55 (range: 0 to 2.33). The mean IHC score of mLNs was 0.39 (range: 0-2), which was not significantly different from their primary tumors (mean IHC score = 0.47, P = 0.38). Sixty-four percent (111/173) of PDAs were positive for NAMPT staining. Stage II tumors were more likely to be positive (68% of 151 vs 41% of 22; P = 0.01). Non-obese non-diabetic patients were more likely to have NAMPT+ tumors (43.7% vs. 27.9%, P = 0.04). While RFS and OS were not statistically different between NAMPT+ vs. NAMPT- PDAs, patients with NAMPT- tumors tended to have a longer median OS (26.0 vs. 20.4 months, P = 0.34). CONCLUSION: NAMPT expression was detected in 64% of stage I/II PDAs and up to 72% in non-obese non-diabetic patients. Frequency of NAMPT expression correlated with pathological stage, consistent with published literature regarding its role in cancer progression. While RFS and OS were not statistically significantly different, patients with NAMPT+ PDAs tended to have a shorter survival. Thus, NAMPT inhibition may prove beneficial in clinical trials.

Expression of n-MYC, NAMPT and SIRT1 in Basal Cell Carcinomas and their Cells of Origin.

Deregulated Hedgehog signalling is a driver of basal cell carcinomas. One effector of the Hedgehog pathway is n-MYC. c/n-MYC proteins, NAMPT and DBC1 are linked to SIRT1 in a positive feedback loop that may contribute to tumorigenesis of basal cell carcinoma. In 5 basal cell carcinoma types immunohistochemistry revealed n-MYC, NAMPT and SIRT1 expression. DBC1 was homogenously expressed in all epithelial cells. NAMPT, SIRT1 and c-MYC were expressed in the stratum basale of human and murine skin. In hair follicles NAMPT and SIRT1 were expressed together with c-MYC and n-MYC, except for the matrix, where n-MYC was strongly positive, but c-MYC expression was absent. Therefore, a common pathway connecting n-MYC, NAMPT and SIRT1 may be active in basal cell carcinomas and in their cells of origin. This pathway may contribute to the development of basal cell carcinomas. Targeting factors in the feedback loop may offer novel therapeutic options.

The role of visfatin levels in gingival crevicular fluid as a potential biomarker in the relationship between obesity and periodontal disease

Abstract Objectives Visfatin is an adipokine that plays an important role in immune functions as a growth factor, enzyme, and pro-inflammatory mediator. We aimed to determine the levels of visfatin, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in gingival crevicular fluid (GCF) in both obese/non-obese patients, with/without generalized chronic periodontitis (GCP). Methodology Patients were categorized as obese (O) (n=31) or non-obese (nO) (n=19). Groups were divided into four subgroups according to periodontal conditions: (1) periodontally healthy without obesity (nO-Ctrl); (2) GCP without obesity (nO-CP); (3) periodontally healthy with obesity (O-Ctrl); and (4) GCP with obesity (O-CP). Demographic variables, anthropometric and laboratory data were recorded. Periodontal parameters were measured at baseline and 3rd months after either non-surgical periodontal treatment or calorie -restricted diet therapy. At the same time, GCF samples were taken from patients to analyze TNF-alpha, IL-6,and visfatin levels. Results Periodontal parameters were significantly higher in the O group than in the nO group (P<0.05). IL-6 levels were higher in the O group than in the nO group (P<0.001). The visfatin levels of the obese patients were reduceddecreased following the treatments (P<0.05). Cholesterol levels were higher in the O group than in the nO groups (P<0.05). IL-6 levels were higher in O-CP and O-Ctrl groups than in the nO-Ctrl group (P<0.05). Compared to the other groups, visfatin levels were significantly higher in the O-CP group but decreased following treatment (P<0.05). Conclusions Our findings suggest that visfatin and IL-6 levels in GCF are associated with the pathogenesis of obesity and periodontitis. Within the limits of this study, we considered that there might be an association between the lipid profile and periodontitis on systemically healthy individuals.

Resistin and visfatin concentrations are related to central obesity and inflammation in Brazilian children

Background:The evidence that cardiovascular disease begins in childhood and adolescence, especially in the presence of excess weight, is associated with dysfunction on adipokine pro-inflammatory secretion. These affect glucose metabolism and lead to other complications related to insulin resistance and cardiovascular disease. This study assessed the association of anthropometric and metabolic parameters related to obesity, cardiovascular risk,and insulin resistance with concentrations of resistin and visfatin, in children. Methods: A cross-sectional study was developed with 178 children of 6­10 years old enrolled in public city schools. Anthropometric data, composition body, clinical, and biochemical were measured according to standard procedures. We used multiple regression models by stepwise method to evaluate the associations of resistin and visfatin with variables of interest.RESULTS: In healthy weight children, resistin was associated with LDL cholesterol, visfatin, atherogenic index, andwaist-to-height ratio, whereas in obese children resistin was associated with visfatin and interaction between conicity index and HOMA-AD. Furthermore, in healthy weight children, visfatin was associated to resistin and triceps skinfold thickness and negatively associated to HOMA-AD, while in obese ones visfatin was associated with waist-to-height ratio, atherogenic index, resistin, and interaction between trunk adiposity index and adiponectin and wasnegatively associated with the HOMA-IR index.CONCLUSIONS:Our study shows an association between anthropometric and biochemical variables related tovisceral fat and inflammation. These results suggest the resistin and visfatin as good pro-inflammatory markers. In addition, both adipokines are strongly related to central obesity, in children. In addition, both adipokines are strongly related to central obesity, in children.

Novel bone metabolism-associated hormones: the importance of the pre-analytical phase for understanding their physiological roles.

The endocrine function of bone is now a recognized feature of this tissue. Bone-derived hormones that modulate whole-body homeostasis, are being discovered as for the effects on bone of novel and classic hormones produced by other tissues become known. Often, however, the data regarding these last generation bone-derived or bone-targeting hormones do not give about a clear picture of their physiological roles or concentration ranges. A certain degree of uncertainty could stem from differences in the pre-analytical management of biological samples. The pre-analytical phase comprises a series of decisions and actions (i.e., choice of sample matrix, methods of collection, transportation, treatment and storage) preceding analysis. Errors arising in this phase will inevitably be carried over to the analytical phase where they can reduce the measurement accuracy, ultimately, leading discrepant results. While the pre-analytical phase is all important, in routine laboratory medicine, it is often not given due consideration in research and clinical trials. This is particularly true for novel molecules, such as the hormones regulating the endocrine function of bone. In this review we discuss the importance of the pre-analytical variables affecting the measurement of last generation bone-associated hormones and describe their, often debated and rarely clear physiological roles.

Proteomic analysis of ascending colon biopsies from a paediatric inflammatory bowel disease inception cohort identifies protein biomarkers that differentiate Crohn's disease from UC.

OBJECTIVE: Accurate differentiation between Crohn's disease (CD) and UC is important to ensure early and appropriate therapeutic intervention. We sought to identify proteins that enable differentiation between CD and UC in children with new onset IBD. DESIGN: Mucosal biopsies were obtained from children undergoing baseline diagnostic endoscopy prior to therapeutic interventions. Using a super-stable isotope labeling with amino acids in cell culture (SILAC)-based approach, the proteomes of 99 paediatric control and biopsies of patients with CD and UC were compared. Multivariate analysis of a subset of these (n=50) was applied to identify novel biomarkers, which were validated in a second subset (n=49). RESULTS: In the discovery cohort, a panel of five proteins was sufficient to distinguish control from IBD-affected tissue biopsies with an AUC of 1.0 (95% CI 0.99 to 1.0); a second panel of 12 proteins segregated inflamed CD from UC within an AUC of 0.95 (95% CI 0.86 to 1.0). Application of the two panels to the validation cohort resulted in accurate classification of 95.9% (IBD from control) and 80% (CD from UC) of patients. 116 proteins were identified to have correlation with the severity of disease, four of which were components of the two panels, including visfatin and metallothionein-2. CONCLUSIONS: This study has identified two panels of candidate biomarkers for the diagnosis of IBD and the differentiation of IBD subtypes to guide appropriate therapeutic interventions in paediatric patients.

High-density lipoprotein inhibits ox-LDL-induced adipokine secretion by upregulating SR-BI expression and suppressing ER Stress pathway.

Endoplasmic reticulum stress (ERS) in adipocytes can modulate adipokines secretion. The aim of this study was to explore the protective effect of high-density lipoprotein (HDL) on oxidized low-density lipoprotein (ox-LDL)-induced ERS-C/EBP homologous protein (CHOP) pathway-mediated adipokine secretion. Our results showed that serum adipokines, including visfatin, resistin and TNF-α, correlated inversely with serum HDL cholesterol level in patients with abdominal obesity. In vitro, like ERS inhibitor 4-phenylbutyric acid (PBA), HDL inhibited ox-LDL- or tunicamycin (TM, an ERS inducer)-induced increase in visfatin and resistin secretion. Moreover, HDL inhibited ox-LDL-induced free cholesterol (FC) accumulation in whole cell lysate and in the endoplasmic reticulum. Additionally, like PBA, HDL inhibited ox-LDL- or TM-induced activation of ERS response as assessed by the decreased phosphorylation of protein kinase-like ER kinase and eukaryotic translation initiation factor 2α and reduced nuclear translocation of activating transcription factor 6 as well as the downregulation of Bip and CHOP. Furthermore, HDL increased scavenger receptor class B type I (SR-BI) expression and SR-BI siRNA treatment abolished the inhibitory effects of HDL on ox-LDL-induced FC accumulation and CHOP upregulation. These data indicate that HDL may suppress ox-LDL-induced FC accumulation in adipocytes through upregulation of SR-BI, subsequently preventing ox-LDL-induced ER stress-CHOP pathway-mediated adipocyte inflammation.

Simultaneous Analysis of Major Coenzymes of Cellular Redox Reactions and Energy Using ex Vivo (1)H NMR Spectroscopy.

Coenzymes of cellular redox reactions and cellular energy mediate biochemical reactions fundamental to the functioning of all living cells. Despite their immense interest, no simple method exists to gain insights into their cellular concentrations in a single step. We show that a simple (1)H NMR experiment can simultaneously measure oxidized and reduced forms of nicotinamide adenine dinucleotide (NAD(+) and NADH), oxidized and reduced forms of nicotinamide adenine dinucleotide phosphate (NADP(+) and NADPH), and adenosine triphosphate (ATP) and its precursors, adenosine diphosphate (ADP) and adenosine monophosphate (AMP), using mouse heart, kidney, brain, liver, and skeletal muscle tissue extracts as examples. Combining 1D/2D NMR experiments, chemical shift libraries, and authentic compound data, reliable peak identities for these coenzymes have been established. To assess this methodology, cardiac NADH and NAD(+) ratios/pool sizes were measured using mouse models with a cardiac-specific knockout of the mitochondrial Complex I Ndufs4 gene (cKO) and cardiac-specific overexpression of nicotinamide phosphoribosyltransferase (cNAMPT) as examples. Sensitivity of NAD(+) and NADH to cKO or cNAMPT was observed, as anticipated. Time-dependent investigations showed that the levels of NADH and NADPH diminish by up to ∼50% within 24 h; concomitantly, NAD(+) and NADP(+) increase proportionately; however, degassing the sample and flushing the sample tubes with helium gas halted such changes. The analysis protocol along with the annotated characteristic fingerprints for each coenzyme is provided for easy identification and absolute quantification using a single internal reference for routine use. The ability to visualize the ubiquitous coenzymes fundamental to cellular functions, simultaneously and reliably, offers a new avenue to interrogate the mechanistic details of cellular function in health and disease.

Increased visfatin levels are associated with higher disease activity in anti-Jo-1-positive myositis patients.

OBJECTIVES: The aim of this study was to evaluate serum levels of visfatin in anti-Jo-1-positive myositis patients, its expression in muscle tissue and to investigate potential relationships between visfatin, B-cell activating factor of the TNF family (BAFF), disease activity and anti-Jo-1 autoantibody levels. METHODS: Serum levels of visfatin and BAFF were measured in 38 anti-Jo-1 positive myositis patients and 35 healthy subjects. Disease activity was evaluated by myositis disease activity assessment tool (MYOACT) using visual analogue scales (VAS) and by serum muscle enzymes. Visfatin expression was evaluated by immunohistochemistry in muscle tissue of myositis patients (n=10) and compared with non-inflammatory control muscle tissue samples from patients with myasthenia gravis (n=5). RESULTS: Serum visfatin and BAFF levels were significantly higher in myositis patients compared to healthy subjects and were associated with clinical muscle activity assessed by VAS. Only serum BAFF levels, but not visfatin levels, positively correlated with muscle enzyme concentrations and anti-Jo1 antibody levels. There was a positive correlation between visfatin and BAFF serum levels in myositis patients but a negative correlation was observed in healthy subjects. Visfatin expression was up-regulated in endomysial and perimysial inflammatory infiltrates of muscle tissue from myositis patients. CONCLUSIONS: Up-regulation of visfatin in myositis muscle tissue and an association between increased visfatin levels and muscle disease activity evaluated by MYOACT in anti-Jo-1 positive myositis patients could support possible role of visfatin in the pathogenesis of myositis.

Melatonin reduces obesity and restores adipokine patterns and metabolism in obese (ob/ob) mice.

The increasing incidence of obesity, leading to metabolic complications, is now recognized as a major public health problem. The adipocytes are not merely energy-storing cells, but they play crucial roles in the development of the so-called metabolic syndrome due to the adipocyte-derived bioactive factors such as adipokines, cytokines, and growth factors. The dysregulated production and secretion of adipokines seen in obesity is linked to the pathogenesis of the metabolic disease processes. In this study, we hypothesized that dietary melatonin administration would support an anti-inflammatory response and play an important role in energy metabolism in subcutaneous and visceral adipose tissues of obese mice and so may counteract some of the disruptive effects of obesity. Lean and obese mice (ob/ob) received melatonin or vehicle in drinking water for 8 weeks. Thereafter, they were evaluated for morphologic alteration, inflammatory cell infiltration, and the adipokine patterns in visceral and subcutaneous white fat depots. In obese mice treated with vehicle, we observed a significant increase in fat depots, inflammation, and a dysregulation of the adipokine network. In particular, we measured a significant reduction of adiponectin and an increase of tumor necrosis factor α, resistin, and visfatin in adipose tissue deposits. These changes were partially reversed when melatonin was supplemented to obese mice. Melatonin supplementation by regulating inflammatory infiltration ameliorates obesity-induced adipokine alteration, whereas melatonin administration in lean mice was unaffected. Thus, it is likely that melatonin would be provided in supplement form to control some of the disruptive effects on the basis of obesity pathogenic process.

Expression of Leptin and Visfatin in Gingival Tissues of Chronic Periodontitis With and Without Type 2 Diabetes Mellitus: A Study Using Enzyme-Linked Immunosorbent Assay and Real-Time Polymerase Chain Reaction.

BACKGROUND: The aim of this study is to investigate the protein and gene expression of leptin and visfatin in gingival tissue from patients with chronic periodontitis (CP), patients with CP and type 2 diabetes mellitus (T2DM), and healthy individuals. METHODS: The study includes 50 individuals: 10 healthy individuals, 20 patients with CP, and 20 patients with CP and T2DM. Plaque index, gingival index, probing depth, and clinical attachment loss were measured, and gingival biopsies were obtained. Leptin and visfatin protein expression in gingival tissues was determined using enzyme-linked immunosorbent assay, and messenger RNA (mRNA) expression was measured via real-time polymerase chain reaction. RESULTS: The highest leptin mRNA and protein expression was observed in the control group and was significantly (P ≤0.05) different from the CP and CP+T2DM groups. Gingival tissues from patients with CP and T2DM had a significant increase in visfatin and a decrease in leptin gene and protein expression (P <0.05) compared with both controls and patients with CP. CONCLUSION: Expression of leptin and visfatin in the gingival tissues suggests a possible role for these adipokines in the pathogenesis of CP and T2DM.

Associations between tissue visfatin/nicotinamide, phosphoribosyltransferase (Nampt), retinol binding protein-4, and vaspin concentrations and insulin resistance in morbidly obese subjects.

Visfatin/Nampt, vaspin, and retinol binding protein-4 (RBP-4) play an important role in insulin resistance. The objectives of this study were to measure visfatin/Nampt, vaspin, and RBP-4 concentrations in blood, liver, muscle, subcutaneous, omental, and mesenteric adipose tissues in morbidly obese subjects and investigate their relationship to insulin resistance. Blood and tissue samples were collected from 38 morbidly obese subjects during Roux-en-Y surgery. Insulin resistance biomarkers were measured using standard kits. Visfatin/Nampt, vaspin, and RBP-4 gene expression levels in tissues were measured using real-time PCR. Their protein concentrations in blood and tissues were measured using ELISA kits. Diabetic subjects had significantly higher homeostasis model of assessment-insulin resistance and age and lower blood HDL-cholesterol concentrations than nondiabetic and prediabetic subjects. Diabetic and prediabetic subjects had significantly higher blood concentrations of visfatin/Nampt and vaspin than nondiabetic subjects. Liver RBP-4 concentrations were positively associated with blood glucose concentrations. Blood insulin resistance biomarker levels were positively associated with visfatin/Nampt concentrations in omental adipose tissue and liver, and vaspin concentrations in mesenteric adipose tissue. In conclusion, the correlations of visfatin/Nampt, vaspin, and RBP-4 with insulin resistance are tissue dependent.

Visfatin as a novel mediator released by inflamed human endothelial cells.

BACKGROUND: Visfatin is a multifaceted adipokine whose circulating levels are enhanced in different metabolic diseases. Extracellular visfatin can exert various deleterious effects on vascular cells, including inflammation and proliferation. Limited evidence exists, however, on the capacity of human vascular cells to synthesize and release visfatin by themselves, under basal or pro-inflammatory conditions. METHODS AND RESULTS: Intracellular visfatin was detected by Western blot in non-stimulated human umbilical vein endothelial cells (HUVEC). However, exposing HUVEC for 18 h to a series of pro-inflammatory stimulus, such as interleukin (IL)-1ß (1 to 10 ng/mL), tumor necrosis factor-α (1 to 10 ng/mL) or angiotensin II (10 pmol/L to 1 µmol/L) markedly enhanced intracellular visfatin content. Using IL-1ß (10 ng/mL; 18 h), it was determined that the increase in intracellular visfatin, which was paralleled by enhanced visfatin mRNA levels, relied on a signalling mechanism involving both nuclear factor-κB and poly (ADP ribose) polymerase-1 activation. Moreover, IL-1ß modified the sub-cellular localization of visfatin; while in non-stimulated HUVEC immunoreactive visfatin predominantly showed an intra-nuclear granular pattern, in IL-1ß-inflamed cells an extra-nuclear filamentous staining, co-localising with F-actin fibers and suggesting a secretory pattern, was mainly found. Indeed, IL-1ß promoted visfatin secretion, as determined by both ELISA and immunocytochemistry. CONCLUSIONS: Human endothelial cells synthesize and release visfatin, particularly in response to inflammation. We suggest that the inflamed endothelium can be a source of visfatin, which arises as a local inflammatory mediator and a potential therapeutic target to interfere with vascular inflammation.

Elevated visfatin levels in obese children are related to proinflammatory factors.

BACKGROUND: Obesity and related metabolic diseases are associated with a state of chronic low-grade inflammation,which is characterized by abnormal cytokine production and increased synthesis of proinflammatory proteins.Recent studies have indicated that visfatin is both an adipokine and an inflammatory cytokine. OBJECTIVE: In this study, we assessed the association between serum visfatin concentrations and markers of systemic inflammation [high-sensitivity C-reactive protein (hs-CRP), interleukin 6 (IL-6), and tumor necrosis factor a (TNF-a)] and insulin resistance in Chinese obese children. METHODS: A total of 44 obese Chinese children (23 boys and 21 girls) and 50 age- and gender-matched normal weight children (23 boys and 27 girls) were enrolled in the study. Anthropometric measurements and blood pressure were taken. Fasting levels of visfatin, hs-CRP, IL-6, TNF-a,glucose, insulin, and lipid profile were assayed, and the homeostasis model assessment for insulin resistance was calculated as a marker of insulin resistance. RESULTS: Serum visfatin levels [obese group (OB):7.48±0.39 vs. C: 5.31±0.28, pO.OS); there were no significant differences in visfatin, hs-CRP, IL-6, and TNF-a concentrations between girls and boys. The correlations between visfatin and anthropometric, metabolic parameters,and inflammatory [body mass index (BMI), waist circumference, triglyceride, hs-CRP, IL-6, TNF-a] revealed differences between genders; visfatin correlated with BMI(r=0.247, p=0.029) and IL-6 (r=0.427, p=0.013) in boys only. CONCLUSION: The association of circulating visfatin with anthropometric parameters, metabolic parameters, and inflammatory factors is dependent on gender, although no such correlation was observed between serum visfatin concentration and insulin resistance. Visfatin could bean important inflammatory cytokine representing a low grade inflammatory state in obesity.

Clinical analysis of systemic and adipose tissue levels of selected hormones/adipokines and stromal-derived factor-1.

Recent studies demonstrated that selected hormones/adipokines may be involved into the regulation of bone metabolism and bone marrow-derived hematopoietic stem/progenitor cells (HSPCs) mobilization in humans. Interestingly, in obese individuals significantly higher numbers of spontaneously circulating stem cells are also observed. Therefore in this study we comprehensively examined plasma and AT (subcutaneous and visceral/omental) levels of hormones/adipokines involved in HSPCs mobilization in lean, overweight and obese individuals as well as verified their potential associations with concentrations of HSPCs chemoattractant, stromal-derived factor-1 (SDF-1). Blood and AT samples (35 subcutaneous and 35 omental) were obtained from individuals undergoing elective surgery. Plasma and AT-derived interstitial fluid levels of resistin, visfatin, osteocalcin and SDF-1 were measured using ELISA. In our study obese patients had almost significantly (P<0.06) higher plasma visfatin and resistin levels as well as lower osteocalcin concentrations (P<0.04) than lean individuals. Osteocalcin and resistin concentrations were strongly associated with levels of SDF-1 and metalloproteinases (MMP 2 and 9). AT levels of all examined substances were significantly lower than the corresponding levels in the plasma (in all cases at least P<0.05), and depot-specific differences in the concentrations of these factors were found only in terms of osteocalcin and SDF-1. In addition, subcutaneous and visceral/omental concentrations of osteocalcin and visfatin, but not of resistin, were associated with values of such parameters as age, body mass or adiposity indexes (BMI and BAI, respectively) and/or waist-to-hip ratio (WHR). In summary, our study showed that in obese individuals the biochemical constellation of adipokines/hormones involved in the process of HSPCs mobilization resembles this observed during pharmacological HSPCs mobilization. Moreover, our study offers further indirect translational evidence for existence of a biochemical cross-talk between bone and AT metabolism (so called - bone-fat- axis) in humans.

The influence of intensive physical training on salivary adipokine levels in Elite Rhythmic Gymnasts.

Exercise challenges homeostasis and establishes a new dynamic equilibrium. Elite Rhythmic Gymnasts (RG's) begin exercise at an early age, undergo physical and psychological stress, and adopt negative energy balance to retain a lean physique. The aim of the present study was to evaluate the effect of negative energy balance, acute and chronic exercise on salivary adiponectin, resistin and visfatin levels and their interaction with salivary cortisol, and insulin levels in elite RG's. This study is unique in character, as all variables were assessed on the field of competition. The study included 51 elite RG's participating in "Kalamata 2010 World Cup" in Kalamata, Greece on April 2010. Twenty-seven healthy age-matched girls were used as controls. Anthropometric values were assessed; baseline and post exercise salivary cortisol, insulin, adiponectin, resistin, and visfatin levels were measured. Comparisons regarding hormonal features between RG's and controls were adjusted for BMI and body fat percentage. Salivary adiponectin levels were higher (p<0.05) and visfatin lower (p=0.094) in RG's compared with controls, while no significant changes were observed regarding salivary cortisol, insulin, and resistin levels. In elite RG's acute intensive anaerobic exercise led to increased salivary insulin levels (p<0.001), reduced salivary adiponectin (p<0.001) and visfatin levels (p<0.05), and no changes in salivary resistin levels. Moreover, diurnal variation of salivary cortisol was lost. In elite RG's salivary adiponectin is upregulated and salivary visfatin is downregulated after chronic intensive exercise and negative energy balance, while both salivary adiponectin and visfatin levels are suppressed after short term intensive anaerobic exercise.