Expression of Locally Produced Adipokines and Their Receptors during Different Physiological and Reproductive Stages in the Bovine Corpus Luteum

This study aimed to determine the gene expression of different local novel adipokines, such as vaspin, adiponectin, visfatin, and resistin, and their known receptors, namely, heat shock 70 protein 5, adiponectin receptor 1, and adiponectin receptor 2, in the bovine corpus luteum (CL) during different phases of the estrous cycle (on days 1-2, 3-4, 5-7, 8-12, 13-18, >18) and pregnancy (at months 1-2, 3-4, 5-7, >7). The mRNA expression was measured by reverse transcription polymerase chain reaction (RT-qPCR). The mRNA expression levels were normalized to the geometric mean of all three constantly expressed reference genes (cyclophilin A, ubiquitin, ubiquitin C). Our findings suggest that adipokines are expressed and present in all investigated groups, and are specifically up- or downregulated during the estrus cycle and during pregnancy. Vaspin and adiponectin levels were upregulated in the middle and late cycle stages. Resistin was abundant during the CL regression stage and in the first months of pregnancy. The specific expression of adipokine receptors indicates their involvement in the local mechanisms that regulate CL function. Further investigations are required to elucidate the regulative mechanisms underlying the different local effects of adipokines on the ovarian physiology of cows.

The Role of Selected Adipocytokines in Ovarian Cancer and Endometrial Cancer

Due to their multidirectional influence, adipocytokines are currently the subject of numerous intensive studies. Significant impact applies to many processes, both physiological and pathological. Moreover, the role of adipocytokines in carcinogenesis seems particularly interesting and not fully understood. For this reason, ongoing research focuses on the role of these compounds in the network of interactions in the tumor microenvironment. Particular attention should be drawn to cancers that remain challenging for modern gynecological oncology-ovarian and endometrial cancer. This paper presents the role of selected adipocytokines, including leptin, adiponectin, visfatin, resistin, apelin, chemerin, omentin and vaspin in cancer, with a particular focus on ovarian and endometrial cancer, and their potential clinical relevance.

Could Vaspin Be a Potential Diagnostic Marker in Endometrial Cancer?

Obesity and being overweight are risk factors for many types of cancer, including endometrial cancer. Adipose tissue is thought to be an endocrine organ that produces various hormones, including one known as vaspin. Insulin resistance, metabolic syndrome and type 2 diabetes are all associated with higher vaspin levels. A total of 127 patients divided into study (endometrial cancer) and control groups (non-cancerous) participated in this research. Serum vaspin levels were measured for all patients. The analysis was performed while taking into account grading and staging. In order to assess the usefulness of the tested protein as a new diagnostic marker, we used the plotting of a curve (ROC) and the calculation of the AUC curve to characterize the sensitivity and specificity of the parameters tested. We concluded that there were significantly lower vaspin levels in patients with endometrial cancer compared to patients with benign endometrial lesions. Vaspin may be a useful diagnostic marker in separating benign lesions from endometrial cancer.

Evaluation of Tissue Expression of Vaspin and Serum Vaspin Concentration as a Prognostic and Risk Factor in Endometrial Cancer

Adipose tissue is a multifunctional endocrine organ. One of the biologically active substances is vaspin, which is part of the serpin family. The purpose of the following study is to determine the possibility of using vaspin as a prognostic and risk factor in endometrial cancer. The study included 127 patients with abnormal uterine bleeding. To determine the value of adipokine, the study used Kaplan-Meier curves to estimate patients survival. Univariate and multivariate analyses were performed simultaneously using the Cox regression model. Tissue expression of vaspin was assessed in patients from the study group (endometrial cancer) and the control group (non-cancerous). We found that higher levels of vaspin are found in obese people, with lower staging (FIGO I and II), lower grading (G1), no LVSI metastases and no lymph node metastases. Higher serum vaspin levels are an independent protective factor for endometrial cancer. We concluded that endometrial cancer patients with serum vaspin concentrations above the median have longer DFS compared to patients with concentrations below the median. Considering multivariate analysis, vaspin concentrations above the median are independent favourable prognostic factors for endometrial cancer. Tissue expression of vaspin cannot be a histological marker to distinguish between cancer and non-cancerous lesions and between different grading levels.

Role of Distinct Fat Depots in Metabolic Regulation and Pathological Implications

People suffering from obesity and associated metabolic disorders including diabetes are increasing exponentially around the world. Adipose tissue (AT) distribution and alteration in their biochemical properties play a major role in the pathogenesis of these diseases. Emerging evidence suggests that AT heterogeneity and depot-specific physiological changes are vital in the development of insulin resistance in peripheral tissues like muscle and liver. Classically, AT depots are classified into white adipose tissue (WAT) and brown adipose tissue (BAT); WAT is the site of fatty acid storage, while BAT is a dedicated organ of metabolic heat production. The discovery of beige adipocyte clusters in WAT depots indicates AT heterogeneity has a more central role than hither to ascribed. Therefore, we have discussed in detail the current state of understanding on cellular and molecular origin of different AT depots and their relevance toward physiological metabolic homeostasis. A major focus is to highlight the correlation between altered WAT distribution in the body and metabolic pathogenesis in animal models and humans. We have also underscored the disparity in the molecular (including signaling) changes in various WAT tissues during diabetic pathogenesis. Exercise-mediated beneficial alteration in WAT physiology/distribution that protects against metabolic disorders is evolving. Here we have discussed the depot-specific biochemical adjustments induced by different forms of exercise. A detailed understanding of the molecular details of inter-organ crosstalk via substrate utilization/storage and signaling through chemokines provide strategies to target selected WAT depots to pharmacologically mimic the benefits of exercise countering metabolic diseases including diabetes.

Role of vaspin in porcine ovary: effect on signaling pathways and steroid synthesis via GRP78 receptor and protein kinase A†

Vaspin, visceral-adipose-tissue-derived serine protease inhibitor, is involved in the development of obesity, insulin resistance, inflammation, and energy metabolism. Our previous study showed vaspin expression and its regulation in the ovary; however, the role of this adipokine in ovarian cells has never been studied. Here, we studied the in vitro effect of vaspin on various kinase-signaling pathways: mitogen-activated kinase (MAP3/1), serine/threonine kinase (AKT), signal transducer and activator of transcription 3 (STAT3) protein kinase AMP (PRKAA1), protein kinase A (PKA), and on expression of nuclear factor kappa B (NFKB2) as well as on steroid synthesis by porcine ovarian cells. By using western blot, we found that vaspin (1 ng/ml), in a time-dependent manner, increased phosphorylation of MAP3/1, AKT, STAT3, PRKAA1, and PKA, while it decreased the expression of NFKB2. We observed that vaspin, in a dose-dependent manner, increased the basal steroid hormone secretion (progesterone and estradiol), mRNA and protein expression of steroid enzymes using real-time PCR and western blot, respectively, and the mRNA of gonadotropins (FSHR, LHCGR) and steroids (PGR, ESR2) receptors. The stimulatory effect of vaspin on basal steroidogenesis was reversed when ovarian cells were cultured in the presence of a PKA pharmacological inhibitor (KT5720) and when GRP78 receptor was knocked down (siRNA). However, in the presence of insulin-like growth factor type 1 and gonadotropins, vaspin reduced steroidogenesis. Thus, vaspin, by activation of various signaling pathways and stimulation of basal steroid production via GRP78 receptor and PKA, could be a new regulator of porcine ovarian function.

The possible role of endocrine dysfunction of adipose tissue in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is diabetes that is first diagnosed in the second or third trimester of pregnancy in patients who did not have a history of diabetes before pregnancy. Consequences of GDM include increased risk of macrosomia and birth complications in the infant and an increased risk of maternal type 2 diabetes mellitus (T2DM) after pregnancy. There is also a longer-term risk of obesity, T2DM, and cardiovascular diseases in the child. GDM is the result of impaired glucose tolerance due to pancreatic β-cell dysfunction on a background of insulin resistance that physiologically increases during pregnancy. The strongest clinical predictors of GDM are overweight and obesity. The fact that women with GDM are more likely to be overweight or obese suggests that adipose tissue dysfunction may be involved in the pathogenesis of GDM, similarly to T2DM. Adipose tissue is not only involved in energy storage but also functions as an active endocrine organ secreting adipokines (specific hormones and cytokines) with the ability to alter insulin sensitivity. Recent evidence points to a crucial role of numerous adipokines produced by fat in the development of GDM. The following text summarizes the current knowledge about a possible role of selected adipokines in the development of GDM.

The Role of the Interplay Between Autophagy and NLRP3 Inflammasome in Metabolic Disorders

Autophagy is an important and conserved cellular pathway in which cells transmit cytoplasmic contents to lysosomes for degradation. It plays an important role in maintaining the balance of cell composition synthesis, decomposition and reuse, and participates in a variety of physiological and pathological processes. The nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome can induce the maturation and secretion of Interleukin-1 beta (IL-1β) and IL-18 by activating caspase-1. It is involved in many diseases. In recent years, the interplay between autophagy and NLRP3 inflammasome has been reported to contribute to many diseases including metabolic disorders related diseases. In this review, we summarized the recent studies on the interplay between autophagy and NLRP3 inflammasome in metabolic disorders to provide ideas for the relevant basic research in the future.

The Usefulness of Diagnostic Panels Based on Circulating Adipocytokines/Regulatory Peptides, Renal Function Tests, Insulin Resistance Indicators and Lipid-Carbohydrate Metabolism Parameters in Diagnosis and Prognosis of Type 2 Diabetes Mellitus with Obesity

The quantitative analysis of selected regulatory molecules, i.e., adropin, irisin, and vaspin in the plasma of obese patients with newly diagnosed, untreated type 2 diabetes mellitus, and in the same patients after six months of using metformin, in relation to adropinemia, irisinemia and vaspinemia in obese individuals, was performed. The relationship between plasma concentration of the adipocytokines/regulatory peptides and parameters of renal function (albumin/creatinine ratio-ACR, estimated glomerular filtration rate-eGFR), values of insulin resistance indicators (Homeostatic Model Assessment of Insulin Resistance (HOMA-IR2), Homeostatic Model Assessment of Insulin Sensitivity (HOMA-S), Homeostatic Model Assessment of β-cell function (HOMA-B), quantitative insulin sensitivity check index (QUICKI), insulin), and parameters of carbohydrate-lipid metabolism (fasting plasma glucose-FPG, glycated hemoglobin-HbA_1C, estimated glucose disposal rate-eGDR, fasting lipid profile, TG/HDL ratio) in obese type 2 diabetic patients was also investigated. Circulating irisin and vaspin were found significantly different in subjects with metabolically healthy obesity and in type 2 diabetic patients. Significant increases in blood levels of both analyzed adipokines/regulatory peptides were observed in diabetic patients after six months of metformin treatment, as compared to pre-treatment levels. The change in plasma vaspin level in response to metformin therapy was parallel with the improving of insulin resistance/sensitivity parameters. An attempt was made to identify a set of biochemical tests that would vary greatly in obese non-diabetic subjects and obese patients with type 2 diabetes, as well as a set of parameters that are changing in patients with type 2 diabetes under the influence of six months metformin therapy, and thus differentiating patients' metabolic state before and after treatment. For these data analyses, both statistical measures of strength of the relationships of individual parameters, as well as multidimensional methods, including discriminant analysis and multifactorial analysis derived from machine learning methods, were used. Adropin, irisin, and vaspin were found as promising regulatory molecules, which may turn out to be useful indicators in the early detection of T2DM and differentiating the obesity phenotype with normal metabolic profile from T2DM obese patients. Multifactorial discriminant analysis revealed that irisin and vaspin plasma levels contribute clinically relevant information concerning the effectiveness of metformin treatment in T2D patients. Among the sets of variables differentiating with the highest accuracy the metabolic state of patients before and after six-month metformin treatment, were: (1) vaspin, HbA1c, HDL, LDL, TG, insulin, and HOMA-B (ACC = 88 [%]); (2) vaspin, irisin, QUICKI, and eGDR (ACC = 86 [%]); as well as, (3) vaspin, irisin, LDL, HOMA-S, ACR, and eGFR (ACC = 86 [%]).

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

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

Correlation between vaspin and PANSS scores in schizophrenia patients with obesity

OBJECTIVE

Metabolic abnormalities such as diabetes, dyslipidemia, abdominal obesity, metabolic syndrome, and abnormal levels of plasma adipokines have been observed in patients with schizophrenia. This study aimed to investigate the differences and correlations of plasma vaspin levels with metabolic parameters in patients with schizophrenia and to compare with healthy controls.

METHOD

We measured plasma levels of vaspin and metabolic parameters of 100 patients with schizophrenia and 95 healthy controls. Patients with schizophrenia were evaluated with the Positive and Negative Syndrome Scale (PANSS) and The Global Assessment of Functioning.

RESULTS

Mean levels of body mass index, waist circumference, triglyceride, and low-density lipoprotein cholesterol of the patients were statistically higher than those of the healthy controls (p = 0.002, p < 0.001, p = 0.03, and p = 0.002, respectively). Plasma levels of vaspin were 0.96 ± 0.73 ng/ml in patients with schizophrenia and 0.29 ± 0.15 ng/ml in the healthy controls (p < 0.001). Plasma vaspin levels were statistically higher in patients with schizophrenia than healthy controls both in groups with and without metabolic syndrome and obesity (p < 0.001). Plasma vaspin levels showed a positive correlation with triglyceride in patients with schizophrenia (r = 0.26, p = 0.007). There were positive correlations between vaspin and PANSS scores in schizophrenia patients with obesity (PANSS Positive: r = 0.42, p = 0.01; PANSS Negative: r = 0.42, p = 0.01; PANSS General: r = 0.43, p = 0.01; PANSS Total: r = 0.47, p = 0.006).

CONCLUSIONS

Our study showed a significant relationship and positive correlation between vaspin and PANSS scores in schizophrenia patients with obesity. Vaspin may play an important role in the metabolic processes of patients with schizophrenia.

Flutamide Alters the Expression of Chemerin, Apelin, and Vaspin and Their Respective Receptors in the Testes of Adult Rats

Adipokines influence energy metabolism and have effects on male reproduction, including spermatogenesis and/or Sertoli cell maturation; however, the relationship between these active proteins and androgens in testicular cells is limited. Here, we studied the impact of short-term exposure to flutamide (an anti-androgen that blocks androgen receptors) on the expression of chemerin, apelin, vaspin and their receptors (CCRL2, CMKLR1, GPR1, APLNR, GRP78, respectively) in adult rat testes. Moreover, the levels of expression of lipid metabolism-modulating proteins (PLIN1, perilipin1; TSPO, translocator protein) and intercellular adherens junction proteins (nectin-2 and afadin) were determined in testicular cells. Plasma levels of adipokines, testosterone and cholesterol were also evaluated. Gene expression techniques used included the quantitative real-time polymerase chain reaction (qRT-PCR), Western blot (WB) and immunohistochemistry (IHC). The androgen-mediated effects observed post-flutamide treatment were found at the gonadal level as chemerin, apelin, and vaspin gene expression alterations at mRNA and protein levels were detected, whereas the cellular targets for these adipokines were recognised by localisation of respective receptors in testicular cells. Plasma concentrations of all adipokines were unchanged, whereas plasma cholesterol content and testosterone level increased after flutamide exposure. Differential distribution of adipokine receptors indicates potential para- or autocrine action of the adipokines within the rat testes. Additionally, changes in the expression of PLIN1 and TSPO, involved in the initial step of testosterone synthesis in Leydig cells, suggest that testicular cells represent a target of flutamide action. Increase in the gene expression of PLIN1 and TSPO and higher total plasma cholesterol content indicates enhanced availability of cholesterol in Leydig cells as a result of androgen-mediated effects of flutamide. Alterations in adherens junction protein expression in the testis confirm the flutamide efficacy in disruption of androgen signalling and presumably lead to impaired para- and autocrine communication, important for proper functioning of adipokines.

Remodeling adipose tissue inflammasome for type 2 diabetes mellitus treatment: Current perspective and translational strategies

Obesity-associated type 2 diabetes mellitus (T2DM) is characterized by low-grade chronic systemic inflammation that arises primarily from the white adipose tissue. The interplay between various adipose tissue-derived chemokines drives insulin resistance in T2DM and has therefore become a subject of rigorous investigation. The adipocytokines strongly associated with glucose homeostasis include tumor necrosis factor-α, various interleukins, monocyte chemoattractant protein-1, adiponectin, and leptin, among others. Remodeling the adipose tissue inflammasome in obesity-associated T2DM is likely to treat the underlying cause of the disease and bring significant therapeutic benefit. Various strategies have been adopted or are being investigated to modulate the serum/tissue levels of pro- and anti-inflammatory adipocytokines to improve glucose homeostasis in T2DM. These include use of small molecule agonists/inhibitors, mimetics, antibodies, gene therapy, and other novel formulations. Here, we discuss adipocytokines that are strongly associated with insulin activity and therapies that are under investigation for modulation of their levels in the treatment of T2DM.

Insight into adipokines to optimize therapeutic effects of stem cell for tissue regeneration

Stem cell therapy is considered as a promising regenerative medicine for repairing and treating damaged tissues and/or preventing various diseases. But there are still some obstacles such as low cell migration, poor stem cell engraftment and decreased cell survival that need to be overcome before transplantation. Therefore, a large body of studies has focused on improving the efficiency of stem cell therapy. For instance, preconditioning of stem cells has emerged as an effective strategy to reinforce therapeutic efficacy. Adipokines are signaling molecules, secreted by adipose tissue, which regulate a variety of biological processes in adipose tissue and other organs including the brain, liver, and muscle. In this review article, we shed light on the biological effects of some adipokines including apelin, oncostatin M, omentin-1 and vaspin on stem cell therapy and the most recent preclinical advances in our understanding of how these functions ameliorate stem cell therapy outcome.

VASPIN, ADIPONECTIN AND LEPTIN LEVELS IN TYPE 1 DIABETIC RATS INDUCED BY STREPTOZOTOCIN

Background

Adiponectin, vaspin and leptin are only a few of these numerous adipocytokines. Little is known about the behavior of adipocytokines and how adipose tissue metabolism is affected in this Type 1 DM model. In this study we investigated the serum levels of adiponectin, leptin, vaspin in streptozotocin(STZ) induced diabetic rats.

Material and methods

Twelve Spraque Dawley albino rats were included in the study. The animals were divided into two groups. The first group was diabetic (D) (n: 6) and 60mg / kg STZ was administered intraperitoneally (i.p.) to these rats. The second group was the non-diabetic control (ND) group (n: 6). All the animals were euthanized by cervical dislocation. Quantification of vaspin, Adiponectin, leptin in serum was performed using the ELISA kit.

Results

Adiponectin, vaspin levels of diabetic group were found to be statistically lower than of control group (p<0.05). Leptin levels were significantly higher in the diabetic group (P<0.05).

Conclusion

There is a need for new researches that can explain the relationship between Vaspin, Leptin and Adiponectin and Type 1 diabetes. New studies in this area will open new horizons for the identification of new biomarkers in the diagnosis and treatment of Type 1 diabetes.

In Vitro Effects of Vaspin on Porcine Granulosa Cell Proliferation, Cell Cycle Progression, and Apoptosis by Activation of GRP78 Receptor and Several Kinase Signaling Pathways Including MAP3/1, AKT, and STAT3

Vaspin, a visceral adipose tissue-derived serine protease inhibitor, is expressed in the porcine ovary; it induces the activation of various kinases and steroidogenesis. The aim of this study was to examine the effect of vaspin on granulosa (Gc) proliferation, cell cycle regulation, and apoptosis. Porcine Gc was incubated with vaspin (0.01-10 ng/mL) for 24 to 72 h, proliferation was measured using alamarBlue assay, cell cycle progression was assessed using flow cytometry, and cyclin (D, E, and A) protein expression was measured using immunoblotting. Apoptosis was assessed by measuring caspase activity using Caspase-glo 3/7 assay. Furthermore, histone-associated DNA fragments levels were measured using a cell-death detection ELISA; BAX (bcl-2-like protein 4), BCL2 (B-cell lymphoma 2), caspases (-3, -8, and -9), p53 mRNA, and protein expression were assessed using real time PCR and immunoblotting. We found that vaspin significantly enhanced Gc proliferation and cell cycle progression into the S and G2/M phases and decreased apoptosis. We observed that siRNA silencing of the glucose-regulated protein (GRP78) receptor and pharmacological inhibitors of mitogen-activated kinase (MAP3/1/ERK1/2), Janus kinase (STAT3) and protein kinase B (AKT) blocked the ability of vaspin cell proliferation and enhanced caspase-3/7 activities. These results suggest that vaspin via mitogenic effect on porcine Gc acts as a new regulator of ovarian growth, development, or folliculogenesis.

Association of vaspin rs2236242 gene variants with type 2 diabetes and obesity in a Chinese population: A prospective, single-center study

AIM

Vaspin is an adipokine separated from visceral fat tissues of obese diabetic rats. This study was to investigate the association between vaspin rs2236242 gene polymorphism and type 2 diabetes mellitus (T2DM) or obesity in a Chinese population.

MATERIALS AND METHODS

T2DM patients and nondiabetic controls were recruited from Qingpu Branch of Zhongshan Hospital Affiliated to Fudan University (Shanghai, China) from May 1, 2015 to June 30, 2017. Clinicopathologic characteristics were recorded and their blood samples were collected. Serum vaspin levels were detected by enzyme-linked immunosorbent assay and vaspin rs2236242 genotypes by tetra-amplification refractory mutation system-polymerase chain reaction.

RESULTS

Two hundred and ninety-nine patients with T2DM and 311 controls were recruited at last. The vaspin genotypes of diabetic patients were distinct from nondiabetic controls (χ ²  = 54.611, p < 0.0001). Genotyping revealed that T2DM patients have a greater prevalence of A allele compared with controls (61.9% vs. 42.1%, p < 0.0001). A allele was associated with an increased risk of T2DM (odds ratio = 2.23, 95% confidence interval = 1.773-2.804, p < 0.0001) compared with T allele. The genotype distribution did not differ among nondiabetic subjects with or without obesity. The serum vaspin levels were higher in T2DM patients and obese controls than the nonobese controls, however, the rs2236242 was not found to be significantly related to serum vaspin levels.

CONCLUSIONS

Our findings showed the association between vaspin rs2236242 gene variants with obesity and T2DM in a Chinese population. People with rs2236242 A allele had a 2.23-fold increased risk of T2DM. These findings suggest that vaspin rs2236242 may serve as a potential diagnostic and/or therapeutic targets for T2DM.

Is there a relationship between serum vaspin levels and insulin resistance in chronic renal failure?

Objective

Chronic kidney disease (CKD) patients have insulin secretion disorders and resistance to insulin effects, that is responsible for the development of cardiovascular events. Vaspin is an adipocytokine that regulates glucose and lipid metabolism. We aimed to determine the serum vaspin levels and its relationship with insulin resistance in CKD patients.

Methods

In the study groups, serum vaspin levels, anthropometric parameters and routine blood tests were measured. The serum vaspin levels were examined by the enzyme-linked immunosorbent assay (ELISA) and insulin resistance was determined by the homeostasis model assessment of insulin resistance (HOMA-IR) formula.

Results

The serum vaspin, HOMA-IR index and insulin levels were observed significantly high in the CKD group in comparison with the control group. No correlation was found between the serum vaspin level and the anthropometric and metabolic values. The serum vaspin level was positively correlated with the fasting plasma glucose and age but without statistical significance.

Conclusion

Insulin resistance and hyperinsulinemia contribute to the development of cardiovascular complications in CKD. We consider that the increase in the serum vaspin level is a consequence of the reduced renal excretion in the CKD and increases in response to insulin resistance.

Adipocytokine Regulation and Antiangiogenic Activity Underlie the Molecular Mechanisms of Therapeutic Effects of Phyllanthus niruri against Non-Alcoholic Fatty Liver Disease

The growth of adipose tissues is considered angiogenesis-dependent during non-alcoholic fatty liver disease (NAFLD). We have recently reported that our standardized 50% methanolic extract (ME) of Phyllanthus niruri (50% ME of P. niruri) has alleviated NAFLD in Sprague⁻Dawley rats. This study aimed to assess the molecular mechanisms of action, and to further evaluate the antiangiogenic effect of this extract. NAFLD was induced by eight weeks of high-fat diet, and treatment was applied for four weeks. Antiangiogenic activity was assessed by aortic ring assay and by in vitro tests. Our findings demonstrated that the therapeutic effects of 50% ME among NAFLD rats, were associated with a significant increase in serum adiponectin, reduction in the serum levels of RBP4, vaspin, progranulin, TNF-α, IL-6, and significant downregulation of the hepatic gene expression of PPARγ, SLC10A2, and Collα1. Concomitantly, 50% ME of P. niruri has exhibited a potent antiangiogenic activity on ring assay, cell migration, vascular endothelial growth factor (VEGF), and tube formation, without any cytotoxic effect. Together, our findings revealed that the protective effects of P. niruri against NAFLD might be attributed to its antiangiogenic effect, as well as to the regulation of adipocytokines and reducing the expression of adipogenic genes.

THE EFFECTS OF VARIOUS DOSES OF PREDNISOLONE ADMINISTRATION ON SERUM VASPIN LEVELS IN RATS

AIM

The aim of this study was to investigate the dose-dependent effects of prednisolone administration on serum vaspin levels and correlate this with changes in the BMI and lipogenesis in rats.

MATERIALS AND METHODS

Twenty-four albino Wistar male rats weighing between 190-240 g were divided into four groups, three experimental (5 mg/kg, 10 mg/kg, and 20 mg/kg prednisolone) and one control. The prednisolone groups were given once-daily doses for 30 days, orally. In addition, the rats were weighed, and their height and waist circumferences were measured once a week. At the end of 30 days, vaspin and glucose levels were measured from blood samples.

RESULTS

In the prednisolone groups, the vaspin levels significantly increased when compared with the control group. The control group has a serum vaspin level of 155 ± 20.99 pg/mL and this level has been increased by prednisolone administration in a dose dependent manner. In the prednisolone groups, especially the 10 mg/kg and 20 mg/kg groups, the glucose levels increased in a dose dependent fashion.

CONCLUSION

Prednisolone administration significantly increased serum glucose and vaspin levels in a dose dependent manner, indicating that the increase in the serum vaspin levels could be related to the increase in the serum glucose concentration. Vaspin can be a molecule that is released in response to increased glucose and can be a rebound defense mechanism to modulate the blood glucose concentration. We suggest vaspin as a potential target for the treatment and diagnosis of diabetes mellitus and other metabolic disorders.

Study of salivary and serum vaspin and total antioxidants in anorexia nervosa

OBJECTIVES

Patients with anorexia nervosa (AN) are primarily at high risk of multiple somatic complications, including oral diseases. In recent years, a number of new molecules that may play a potentially important role in AN progress and prognosis have been identified in saliva, but their exact roles are still poorly understood. Two such group of substances are antioxidants and vaspin. The purpose of this observational, cross-sectional study was to measure both the salivary and serum total antioxidant status (TAS), and vaspin (VASP) concentrations of patients with AN in comparison to an average population.

MATERIAL AND METHODS

Ninety subjects participated (30 patients with AN, 60 matched healthy control subjects). A clinical examination was made, and blood and salivary samples were taken during the acute stage of AN (BMI < 15 kg/m²) in the first week of hospitalization. Enzyme immunoassay (ELISA) suitable for measuring VASP and colorimetric assay for TAS were used.

RESULTS

Anorexic patients had significant reductions in salivary flow, TAS, and an elevation in VASP levels in their saliva and serum. Significant correlations between TAS, VASP, salivary flow, and nutritional status were detected.

CONCLUSION

Determination of TAS and VASP in combined biological material confirmed that saliva might be a reliable non-invasive source of information for potent nutritional biomarkers.

CLINICAL RELEVANCE

Our findings suggest that VASP cannot be excluded, as its increased concentration in saliva is an adaptive mechanism in reduced TAS, one resulting from diminished salivary secretion. It is therefore worth conducting further research aimed at recognizing the role of TAS and VASP in the saliva of underweight patients.

The Association Between Serum Vaspin and Omentin-1 Levels in Obese Children with Metabolic Syndrome

BACKGROUND AND AIM

Excess visceral fat accumulation results in altered release of adipokines. The aim of this study was to examine the relationship between new adipokines (omentin-1 and vaspin), insulin resistance, and serum inflammatory markers in obese subjects with metabolic syndrome (MS).

PATIENTS AND METHODS

The study included a total of 121 obese children (79 females and 42 males, aged 12-17 years old). The obese subjects were divided into two groups based on the presence or absence of MS criteria (MS group and non-MS group). Serum omentin-1, vaspin, and high-sensitivity C-reactive protein (CRP) were measured in addition to the other glucose metabolism parameters.

RESULTS

MS was diagnosed in 45 obese children and 76 children did not meet the MS criteria. Serum omentin-1 (289.5 ± 51.9 ng/mL vs. 268.2 ± 60 ng/mL, P = 0.03) levels were significantly lower in the MS group compared to the non-MS group. Serum vaspin levels (1058.3 ± 118 pg/mL vs. 1178.6 ± 158 pg/mL, P = 0.02) were higher in the MS group than the non-MS group. CRP levels correlated well with both the adipokines (r = -0.236, P = 0.04 for omentin-1 and r = 0.296, P = 0.008 for vaspin), although these adipokines did not show statistically significant correlations with fasting glucose-insulin levels, homeostasis model assessment of insulin resistance, and 2 hr postload glucose level.

CONCLUSIONS

Higher vaspin and lower omentin-1 levels were determined in obese MS children compared to non-MS children and these adipokines were significantly correlated with high CRP values. These data support the view that adipokines in MS children contribute to increased inflammation markers before abnormal glucose metabolism.

Effects of vaspin on pancreatic β cell secretion via PI3K/Akt and NF-κB signaling pathways

Vaspin (visceral adipose tissue-derived serine protease inhibitor) is a recently discovered adipokine that has been implicated in diabetes mellitus and other metabolic disorders. However, the effects of vaspin on pancreatic β cell function and related mechanisms are not fully understood. Thus, the present study was performed to investigate the effects of vaspin on pancreatic β cell function and the potential underlying mechanisms. Both in vitro (rat insulinoma cells, INS-1) and in vivo (high fat diet fed rats) experiments were conducted. The results showed that vaspin significantly increased INS-1 cell secretory function. Potential mechanisms were explored using inhibitors, western blot and real-time PCR techniques. We found that vaspin increased the levels of IRS-2 mRNA and IRS-2 total protein, while decreased the serine phosphorylation level of IRS-2 protein. Moreover, vaspin increased the Akt phosphorylation protein level which was reversed by PI3K inhibitor ly294002. In addition, vaspin increased the phosphorylation levels of mTOR and p70S6K, which was inhibited by rapamycin. Meanwhile, we found that the NF-κB mRNA and protein levels were reduced after vaspin treatment, similar to the effect of NF-κB inhibitor TPCK. Furthermore, vaspin increased the glucose stimulated insulin secretion (GSIS) level, lowered blood glucose level and improved the glucose tolerance and insulin sensitivity of high fat diet fed rats. Hyperglycemic clamp test manifested that vaspin improved islet β cell function. Together, these findings provide a new understanding of the function of vaspin on pancreatic β cell and suggest that it may serve as a potential agent for the prevention and treatment of type 2 diabetes.

Experimental type 2 diabetes induction reduces serum vaspin, but not serum omentin, in Wistar rats

Vaspin and omentin are adipose tissue adipokines that have often been related to obesity and its comorbidities. The aim of this study was to investigate the behaviour of serum omentin and vaspin in models of type 2 diabetes. To do this, Wistar rats (~200 g) were randomly divided into two groups: a non-diabetic group (n = 6) and a diabetic group fed on a high-fat diet (n = 6) and a low dose of streptozotocin (Sigma^® ). All procedures were approved by the Brazilian Ethics Committee. Body weight (BW) and food intake were recorded daily. Tail blood glucose levels were assessed at the end of the diabetes induction period. The insulin tolerance test (ITT) was performed after the diabetes induction period (7 weeks). The serum and tissues (liver, pancreas, and retroperitoneal (RET), epididymal (EPI) and visceral (VIS) white adipose tissues) were immediately removed and weighed. Analyses of levels of insulin, omentin, vaspin, adiponectin and inflammatory cytokines IL-6, IL-8 (CXCL8), TNF-α and C-reactive protein (CRP) in serum were performed using the enzyme-linked immunosorbent assay (ELISA). Our results showed that IL-8 and CRP serum levels in the diabetic group were significantly higher than in the non-diabetic group. Vaspin and adiponectin values were lower for the diabetic group than for the non-diabetic group. Omentin, IL-6 and TNF-α values did not differ between the groups. Our results showed that both the metabolism of the adipose tissue and the secretion of adipokines may be affected in diabetic rats. Omentin showed no difference between the groups, although the vaspin values decreased in the diabetic group.

Impact of age on plasma vaspin concentration in a group of normal Chinese people

PURPOSE

Visceral adipose tissue-derived serine protease inhibitor (vaspin) is an adipocytokine with insulin-sensitizing effects. Accumulating data implied that vaspin represents a compensatory mechanism but it is unknown how vaspin change during ageing. This study was designed to examine the correlation between plasma vaspin and age in a group of normal Chinese people.

METHODS

A total of 191 Chinese volunteers aged 19-80 years were enrolled into four groups based upon age quartiles (19-35, 36-50, 51-65 and 66-80 years). Demographic, anthropometric, metabolic covariates, vaspin and adiponectin were measured. The influence of age on plasma vaspin was analysed using SPSS 13.0.

RESULTS

Vaspin increased with ageing, with mean vaspin levels (ng/mL) of 1.01 ± 2.25, 1.67 ± 2.95, 2.05 ± 3.46 and 2.40 ± 3.06 for those between quartile ages 19-35, 36-50, 51-65 and 66-80 years. When divided into subgroups, vaspin increased with increasing age for both sexes, both insulin resistance and non-insulin resistance subjects and both obese and lean subjects. In univariate analyses, vaspin plasma level positively associated with age (r = 0.215, p = 0.003), adiponectin, insulin, homoeostasis model of assessment for insulin resistance index and waist-hip ratio in the whole population. The correlation between ageing and increasing vaspin remained significant after multivariate adjustments for factors such as sex, body mass index, waist-hip ratio, indices of glucose metabolism, white blood cell, lipid profile and adiponectin. Stepwise multiple regression analysis showed that age contributed 7.6 % on plasma vaspin level.

CONCLUSION

Vaspin level increased with ageing, independent of sex, indices of glucose metabolism, lipid profile and other markers of adiposity.

Serum vaspin concentrations in girls with anorexia nervosa

BACKGROUND

Vaspin (VASP) is a protein detected in pre- and mature adipocytes, the production and secretion of which may be conditioned by nutrition status. VASP may also play a role in the regulation of food intake. Since to date, there are no available studies on serum vaspin concentrations in patients with anorexia nervosa (AN), the aim of our study is to assess serum vaspin concentrations in girls with AN in comparison to healthy subjects and determine its relationship with body weight, body masss index (BMI) and insulin.

METHODS

In this cross-sectional study vaspin serum concentrations were evaluated using a commercially available ELISA kit in 47 Polish girls hospitalized due to restrictive AN and 39 healthy controls (H).

RESULTS

The mean serum concentration of VASP in girls with AN was significantly higher than in the H group. These differences were also noted after adjustment for body masss index-standard deviation score (BMI-SDS), the homeostatic model assessment-insulin resistance (HOMA-IR) index and insulin levels. There were no statistically significant correlations between the serum concentrations of VASP and body mass, BMI, BMI-SDS, insulin and HOMA-IR in the AN or healthy group.

CONCLUSIONS

Serum vaspin levels in lean subjects are regulated in different mechanisms than previously reported in obesity. It should be established if elevated serum vaspin levels in girls with AN may contribute to low food intake in these patients.

The correlation of inflammatory markers and plasma vaspin levels in patients with diabetic nephropathy

Vaspin, a recently identified adipokine, is a visceral adipose tissue-derived serine protease inhibitor that may have insulin sensitizing effect on adipose tissue. Herein, we measured vaspin level in patients with different stages of diabetic nephropathy (DNP), and investigated the correlation of the vaspin level with other inflammatory parameters. 106 adult type 2 diabetic patients with no known chronic inflammatory disease were included and grouped according to the stage of DNP: Albuminuria <30 mg/day and estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73m(2) (Group-1); albuminuria 30-300 mg/day and eGFR >60 mL/min/1.73m(2) (Group-2); albuminuria >300 mL/min and eGFR <60 mL/min/1.73m(2) (Group-3). Demographic, clinical and laboratory data were recorded as well as vaspin, high sensitivity C-reactive protein (hsCRP), interleukin (IL)-1 and tumor necrosis factor (TNF)-α levels. There were 38, 35 and 33 patients in Group 1, 2 and 3, respectively. Groups were similar regarding age and gender. Vaspin level did not differ between groups. When all the groups were considered, vaspin was positively correlated with IL-6 level (r = 0.215, p = 0.041). No correlation of vaspin was found with IL-1, TNF-α and hsCRP levels (p = 0.580, r = 0.054; p = 0.463, r = 0.072; p = 0.812, r = 0.025, respectively). Vaspin levels of the patients with GFR ≥60 mL/min/1.73m(2) was less than that of patients with GFR <60 mL/min/1.73m(2) (p = 0.03). Age and IL-6 were found to be the major determinants of vaspin level with linear regression analysis. In patients with DNP, vaspin level does not change within the early stages of DNP; while it is higher in patients with decreased GFR, which may be related with increasing inflammation regardless of the stage of the kidney disease.

Chenodeoxycholic acid, an endogenous FXR ligand alters adipokines and reverses insulin resistance

Adipose tissue secretes adipokines that regulate insulin sensitivity in adipocytes and other peripheral tissues critical to glucose metabolism. Insulin resistance is associated with severe alterations in adipokines characterized by release of increased pro-inflammatory cytokines and decreased anti-inflammatory cytokines from adipose tissue. The role of Farnesoid X receptor (FXR) activation on adipokines in relation to adipose tissue inflammation and insulin resistance is not completely explored. For the first time, we have evaluated the ability of Chenodeoxycholic acid (CDCA), an endogenous FXR ligand, in restoring the disturbance in adipokine secretion and insulin resistance in palmitate treated 3T3-L1 cells and adipose tissues of High fat diet (HFD) rats. CDCA suppressed several of the tested pro-inflammatory adipokines (TNF-α, MCP-1, IL-6, Chemerin, PAI, RBP4, resistin, vaspin), and enhanced the major anti-inflammatory and insulin sensitizing adipokines (adiponectin, leptin). CDCA suppressed the activation of critical inflammatory regulators such as NF-κB and IKKβ which are activated by palmitate treatment in differentiated cells and HFD in rats. We show the altered adipokines in insulin resistance, its association with inflammatory regulators, and the role of CDCA in amelioration of insulin resistance by modulation of adipokines.

Serum vaspin and adiponectin levels in patients with prolactinoma

BACKGROUND

Studies investigating serum vaspin and adiponectin levels in patients with prolactinoma are inconclusive. The aim of this study was to evaluate serum vaspin and adiponectin levels in patients with prolactinoma and healthy controls.

METHODS

A total of 42 prolactinoma patients (Group 1, 21 patients; Group 2, 21 patients) and 30 healthy controls were enrolled in the study. Group 1 consisted of newly diagnosed patients who were never treated or had not received a dopamine agonist (DA) within 6 months prior to screening. Group 2 consisted of prolactinoma patients who were on DA treatment for at least 6 months at the time of screening. The control group (group 3) consisted of healthy controls.

RESULTS

Patients with prolactinoma had higher homeostasis model assessment of insulin resistance and lower quantitative insulin sensitivity check index values in comparison to healthy controls (p < 0.001 for both). Serum levels of adiponectin and vaspin were also significantly lower in prolactinoma patients when compared to the control group (p < 0.01 and p < 0.001, respectively). Following adjustment for confounding factors, the respective odds ratios for prolactinoma in patients in the lower subgroup compared with those in the higher subgroup for adiponectin and vaspin were 2.733 (0.621-12.035; p > 0.05) and 5.041 (1.191-21.339; p < 0.05).

CONCLUSION

This is the first study to demonstrate the presence of low vaspin levels in patients with prolactinomas. Further studies are needed to help establish the roles of vaspin and adiponectin in prolactinoma patients.

Mediatory effect of circulating vaspin on resting metabolic rate in obese individuals

BACKGROUND/OBJECTIVE

Vaspin is a recently identified adipokine related to obesity and insulin sensitivity. The precise mechanism of vaspin in the body is not well known, and its function in resting metabolic rate (RMR) is even less understood. Therefore, the main aim of this study was to investigate the effect of circulating vaspin on RMR in obese people.

MATERIALS AND METHODS

A total of 222 obese participants were included in the current comparative cross-sectional study. Body composition was measured using body composition analyzer. RMR was measured by means of indirect calorimetry. For the measurement of vaspin serum concentrations, an enzyme-linked immunosorbent assay was used. Dietary intake was assessed using 3-day 24-h dietary recall.

RESULTS

Between low and high circulating vaspin groups, there was significant difference for sex (P = 0.03), fat percent (P = 0.008), RMR per weight (P < 0.001), and RMR per fat free mass (FFM) (P = 0.007). However, there was no statistical difference between the groups in dietary intake after adjustment for energy intake (P > 0.05). Furthermore, individuals with higher level of RMR had higher vaspin concentration. Weight, visceral fat, FFM, and fat mass had significant effect on increasing RMR (P < 0.05) but after adding vaspin as a covariate in the general linear model; visceral fat (P = 0.078) and fat mass (P = 0.339) missed their effectiveness.

CONCLUSION

Circulating vaspin level is higher in women than in men in obese individuals. Moreover, it was found that vaspin had mediator effect between visceral fat and fat mass associations with RMR in obese participants.

The role of vaspin in the development of metabolic and glucose tolerance disorders and atherosclerosis

In recent years, most research efforts have been focused on studying insulin-sensitizing adipokines. One of the most recently discovered adipokines is vaspin, a visceral adipose tissue-derived serine protease inhibitor. Vaspin levels have been found significantly increased in mice with obesity and insulin resistance. It has been assumed that vaspin serves as an insulin sensitizer with anti-inflammatory effects and might act as a compensatory mechanism in response to decreased insulin sensitivity. Most studies in humans have shown a positive correlation between vaspin gene expression and serum levels, and metabolic syndrome parameters. Vaspin gene expression is influenced by age and gender, and the administration of insulin sensitizers enhances it in mice, whereas the use of metformin decreases serum vaspin levels in humans, probably due to different regulatory mechanisms. Presumably vaspin plays local and endocrine role in the development of initial and advanced atherosclerosis in obese subjects and might be used as a predictor of coronary and cerebrovascular disease. It is believed that vaspin could be regarded as a new link between obesity and related metabolic disorders, including glucose intolerance. The entire understanding of vaspin intimate mechanism of action might enable the development of novel etiology-based treatment strategies, targeting metabolic and glucose tolerance disorders.

Highly amplified detection of visceral adipose tissue-derived serpin (vaspin) using a cognate aptamer duo

A cognate aptamer duo for visceral adipose tissue-derived serpin (vaspin) which distinctively bind to two different sites on vaspin with high affinity and specificity were successfully developed by using graphene oxide-based systematic evolution of ligands by exponential enrichment (GO-SELEX), which offers immobilization-free screening of aptamers. The specific and simultaneous bindings of this aptamer duo (V1 and V49 aptamers) to the different sites of vaspin were confirmed by circular dichroism (CD) analysis and both sandwich-type surface plasmon resonance (SPR) and quantum dot labelled fluorescence imaging analysis (V1 aptamer serves as primary capturing aptamer and V49 aptamer as secondary signalling aptamer or vice versa). With this vaspin cognate aptamer duo on SPR platform, the detection of the target vaspin were improved to the limit of detection down to 3.5 ng/ml in buffer and 4.7 ng/ml in human serum samples. This cognate aptamer duo based biosensor could be utilized in the early diagnosis of type-2 diabetes.

Serum Level of the Adipokine “Vaspin” in Relation to Metabolic Parameters: Short – Term Effect of Specific Dietary Therapy

AIM: To investigate the association between the circulating vaspin concentration and both of glucose homeostasis and insulin resistance in metabolic syndrome (MetS) patients, and also to evaluate the metabolic impact of two different dietary therapies on such conditions.MATERIALS AND METHODS:  Fifty eight obese female volunteers suffering from MetS, followed a specially designed dietary therapy consists of a low caloric balanced diet, accompanied by either 30% doum biscuits (group A), or whole wheat biscuits (group B) for four weeks (phase 1). During the next four weeks, they were continued on the hypocaloric diet alone (phase 2).RESULTS: The health effects of two dietary therapies were more prominent in improving the biochemical markers of the MetS than in the body weight reduction. The lower levels of serum vaspin were significantly increased at the end of the 1st phase in both groups especially group (A). Sustained negative correlations were detected between vaspin level and both of C-peptide and insulin resistance expressed as modified homeostatic model assessment (M.HOMA).CONCLUSION: The effect of the dietary supplements may play a role in alleviating the impact of the components of the MetS and may also sustain the level of the vaspin in the sensitization of the C-peptide in order to attain glucose homeostasis.

Association of vaspin with metabolic syndrome: the pivotal role of insulin resistance

BACKGROUND

Previous studies evaluating the relationship between serum vaspin concentrations and metabolic syndrome (MetS) have yielded contrasting results. Additionally, contribution of general and abdominal obesity, chronic inflammation, and insulin resistance to this relationship remains unknown.

METHODS

In a cross-sectional setting, we investigated the association between vaspin and MetS in 145 subjects ranging from normoglycemia to type 2 diabetes. Vaspin concentrations were measured using enzyme-linked immunosorbent assay.

RESULTS

Women had 29% higher vaspin concentrations compared with men. Subjects with MetS (51% of all participants) had higher vaspin concentrations (P=0.019 in women and P<0.001 in men). In logistic regression, vaspin significantly predicted raised fasting plasma glucose (P<0.001), and raised triglycerides (P<0.001) after controlling for age in both sexes. Moreover, vaspin was the significant predictor for reduced high-density lipoprotein cholesterol and raised waist circumference in women and men, respectively. Considering MetS as a whole, vaspin predicted MetS even after adjustment for age, medications, diabetes, total cholesterol, and waist circumference in both sexes (odds ratio [OR], 3.88; 95% confidence interval [CI], 1.36 to 11.05; P=0.011 for women; OR, 3.16; 95% CI, 1.28 to 7.78; P=0.012 for men). However, this relationship rendered nonsignificant after introducing homeostasis model assessment of insulin resistance (HOMA-IR) in women (P=0.089) and high-sensitivity C-reactive protein (P=0.073) or HOMA-IR in men (P=0.095).

CONCLUSION

Vaspin is associated with some but not all components of MetS. Vaspin is a predictor of MetS as a single entity, independent of obesity. This relationship is largely ascribed to the effects of insulin resistance and chronic inflammation.

Fenofibrate increases serum vaspin by upregulating its expression in adipose tissue

Fenofibrate is a peroxisome proliferator-activated receptor-α that has been clinically used to treat dyslipidemia and insulin resistance. To better understand the molecular mechanisms underlying fenofibrate action, we investigated whether fenofibrate affects serum levels of vaspin, an adipocytokine that has recently been shown to link obesity and insulin resistance. Fenofibrate treatment significantly increased serum vaspin levels of dyslipidemic patients, which correlated with reduced body weight and increased insulin sensitivity. To elucidate the biochemical mechanisms of fenofibrate action, we investigated the effect of fenofibrate on vaspin mRNA and protein expressions in obese rats. Fenofibrate greatly increased vaspin mRNA and protein levels in visceral adipose tissue consisting of retroperitoneal, mesenteric, and periepididymal adipose tissue but not in the subcutaneous adipose tissue, which correlated with increased serum vaspin levels and increased insulin sensitivity in obese rats. Consistent with a direct effect on vaspin expression, fenofibrate treatment significantly increased the mRNA and protein expression levels of vaspin in 3T3-L1 adipocytes. Together, our results demonstrate for the first time that fenofibrate upregulates vaspin expression in dyslipidemic human subjects and suggest that upregulation of vaspin expression in adipocytes may provide a mechanism by which fenofibrate improves insulin sensitivity in dyslipidemic patients.

Vaspin inhibited proinflammatory cytokine induced activation of nuclear factor-kappa B and its downstream molecules in human endothelial EA.hy926 cells

AIMS

In this study, we investigated the effects of visceral adipose tissue-derived serpin (vaspin), a newly discovered adipocytokine, on nuclear factor-kappa B (NF-κB) and its downstream molecules in proinflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukine-1 (IL-1), stimulated human endothelial EA.hy926 cells to elucidate the role of vaspin in the inflammatory states of endothelium.

METHODS

A NF-κB luciferase reporter system was constructed and stably transfected into human endothelial cell line EA.hy926. Following transfection, EA.hy926 cells were pretreated with various concentrations of vaspin (0-320 ng/ml) before TNF-α and IL-1 stimulation. The transcription activity of NF-κB was determined using luciferase reporter assay. Expression levels of NF-κB downstream inflammatory cytokines, TNF-α, IL-1 and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA). Expressions of adhesion molecules and chemokines, intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemotactic protein-1 (MCP-1) were determined by quantitative real-time PCR (RT-PCR) and western blot in mRNA and protein levels, respectively.

RESULTS

Results showed that vaspin inhibited TNF-α and IL-1 mediated activation of NF-κB and its downstream molecules in a concentration-dependent manner (P<0.05).

CONCLUSIONS

We conclude that vaspin protected endothelial cells from proinflammatory cytokines induced inflammation by inhibition of NF-κB and its downstream molecules.

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.

Investigation of vaspin level in patients with acute ischemic stroke

BACKGROUND

Cerebrovascular event is a clinical condition characterized by symptoms and findings pertaining to loss of focal cerebral function because of the vascular causes. Atherosclerosis has a forefront role in the pathogenesis of stroke. Inflammation has an important place in the formation of atherogenesis and atherosclerosis. Visceral adipose tissue-derived serpin (vaspin) is a new adipokine, which is identified recently, associated with obesity and diabetes and also has a proinflammatory characteristic. This study was intended to investigate the relation between vaspin and stroke and stroke and other risk factors.

METHODS

A total of 50 patients with stroke, as 28 men (56%) and 22 women (44%), and a total of 50 healthy individuals, as 25 men (50%) and 25 women (50%), were enrolled in the study. Blood samples were taken in the acute period (first 48 hours) in the patient group, and serum vaspin levels were measured. Vaspin level was also measured in the control group. The association of vaspin with the lipid parameters, gender, and the severity of internal carotid artery (ICA) stenosis in the patient group was evaluated. Stenotic plaques in ICA were classified as normal, mild (stenosis under 50%), moderate (stenosis 50%-69%), severe (stenosis 70%-99% to preocclusion), and occlusion.

RESULTS

No statistically significant difference was found between 2 groups in terms of age and gender (P > .05). Vaspin levels were found to be significantly higher in the patient group (164.73 ± 153.76 ng/mL) compared with the control group (116.21 ± 34.60 ng/mL) (P < .05). However, no relation was established between vaspin level and the severity of ICA stenosis.

CONCLUSIONS

Vaspin levels have been shown to increase in acute ischemic stroke patients. The increased vaspin levels may vary depending on several factors in acute period of ischemic stroke.

[Adipokines in healthy and obese children]

The worldwide increase in the prevalence of obesity in children and adolescents during the last decades, as well as the mounting evidence indicating that obesity is associated with an increased incidence of comorbidities and the risk of premature death, resulting in a high economic impact, has stimulated obesity focused research. These studies have highlighted the prominent endocrine activity of adipose tissue, which is exerted through the synthesis and secretion of a wide variety of peptides and cytokines, called adipokines. This review presents a summary of the current knowledge and most relevant studies of adipokine dynamics and actions in children, focusing on the control of energy homeostasis, metabolic regulation (particularly carbohydrate metabolism), and inflammation. The particularities of adipose secretion and actions in healthy children, from birth to adolescence, and the modifications induced by early onset obesity are highlighted.

Adipokines in childhood obesity

The worldwide increase in the prevalence of obesity in children and adolescents during the past decades, in addition to mounting evidence indicating that obesity is associated with an increased incidence of comorbidities and the risk of premature death, resulting in a high economical impact, has stimulated obesity-focused research. These studies have highlightened the prominent endocrine activity of adipose tissue, which is exerted through the synthesis and secretion of a wide variety of peptides and cytokines, called adipokines. In the present review, we have summarized the current knowledge and most relevant studies of adipokine dynamics and actions in children, focusing on the control of energy homeostasis, metabolic regulation (particularly, carbohydrate metabolism), and inflammation. The particularities of adipose secretion and actions in healthy children, from birth to adolescence, and the modifications induced by early-onset obesity are highlighted.

Effects of bariatric surgery on adipokine-induced inflammation and insulin resistance

Over a third of the US population is obese and at high risk for developing type 2 diabetes, insulin resistance, and other metabolic disorders. Obesity is considered a chronic low-grade inflammatory condition that is primarily attributed to expansion and inflammation of adipose tissues. Indeed, adipocytes produce and secrete numerous proinflammatory and anti-inflammatory cytokines known as adipokines. When the balance of these adipokines is shifted toward higher production of proinflammatory factors, local inflammation within adipose tissues and subsequently systemic inflammation occur. These adipokines including leptin, visfatin, resistin, apelin, vaspin, and retinol binding protein-4 can regulate inflammatory responses and contribute to the pathogenesis of diabetes. These effects are mediated by key inflammatory signaling molecules including activated serine kinases such as c-Jun N-terminal kinase and serine kinases inhibitor κB kinase and insulin signaling molecules including insulin receptor substrates, protein kinase B (PKB, also known as Akt), and nuclear factor kappa B. Bariatric surgery can decrease body weight and improve insulin resistance in morbidly obese subjects. However, despite reports suggesting reduced inflammation and weight-independent effects of bariatric surgery on glucose metabolism, mechanisms behind such improvements are not yet well understood. This review article focuses on some of these novel adipokines and discusses their changes after bariatric surgery and their relationship to insulin resistance, fat mass, inflammation, and glucose homeostasis.

Association of vaspin gene polymorphisms with coronary artery disease in Chinese population and function study

BACKGROUND

Visceral adipose tissue-derived serine protease inhibitor (vaspin) is a recently identified adipokine. Studies suggest it is involved in many diseases such as obesity, diabetes and coronary artery disease (CAD). This study is to investigate the association of single nucleotide polymorphisms (SNPs) in vaspin with CAD and its potential mechanisms.

METHODS

A total of 1570 consecutive patients undergoing coronary angiography were enrolled and the genotypes were determined by TaqMan allelic discrimination. Serum vaspin concentrations and mRNA expression levels were determined by ELISA and RT-PCR, respectively. Reporter gene assay was performed to investigate the effect of polymorphism on vaspin promoter function.

RESULTS

After multivariate analysis, allele A of rs2236242 was found as an independent determinant of CAD (OR=1.32, p=0.004). Rs35262691 in vaspin promoter was associated with serum vaspin concentration and mRNA expression in peripheral blood mononuclear cells (PBMC) though no association had been found with CAD. Reporter gene assay further confirmed that CC genotype of rs35262691 had 2.1±0.4-fold higher activities than TT genotype in facilitating gene expression.

CONCLUSIONS

Our results show that the variants of vaspin gene are associated with serum vaspin levels and risk for CAD in Chinese population.

Vaspin--a link of obesity and psoriasis?

Psoriasis is an inflammatory skin disease often associated with obesity. The anti-inflammatory adipokine vaspin, a suggested serine proteinase inhibitor of the serpin family, is discussed as a new link between inflammation and obesity. Here, we demonstrate that - different from healthy controls - vaspin serum levels in patients with psoriasis were body mass index independent. Moreover, we could identify keratinocytes as the major source of vaspin in skin. Vaspin expression in lesional psoriatic skin was reduced compared with uninvolved skin as shown by immunohistochemistry and RT-PCR. In aggregate, we report on the cellular source of vaspin in skin and its expression in psoriasis.

Vaspin plasma concentrations and mRNA expressions in patients with stable and unstable angina pectoris

BACKGROUND

Vaspin was a recently identified adipokine, playing a protective role in many metabolic diseases. The present study aimed to investigate the association between vaspin plasma level and stable angina pectoris (SAP) and unstable angina pectoris (UAP).

METHODS

A total of 88 patients with angiographically-proved coronary artery disease (CAD) (SAP 47, UAP 41) and 103 control subjects without cardiovascular diseases were enrolled in this study. Circulating vaspin, mRNA expression of vaspin in peripheral blood mononuclear cells (PBMC), clinical parameters, lipid profile and high-sensitivity C-reactive protein (hsCRP) were assayed. The severity of CAD was also assessed according to the number of vessels diseased.

RESULTS

There are significant differences in circulating vaspin levels and mRNA levels of PBMC between SAP and UAP groups (SAP 0.91±0.95 ng/mL and UAP 0.43±0.38 ng/mL, p<0.01 in circulating vaspin level; SAP 1.19±0.85 and UAP 0.82±0.56, p<0.05 in mRNA level of PBMC). An inverse correlation between the number of diseased vessels and plasma vaspin concentration was observed (r=-0.350, p<0.01) in the CAD group. Construction of receiver operating characteristic curves confirmed that vaspin plasma concentrations significantly differentiated CAD patients (area under the curve=0.684, p<0.001), as well as UAP (area under the curve=0.640, p<0.05).

CONCLUSION

Decreased vaspin plasma levels and mRNA levels in PBMC were observed in patients with UAP. Low vaspin concentrations correlate with CAD severity. The findings suggested that vaspin could serve as a novel biomarker of CAD as well as UAP.

Leptin, adiponectin and other adipokines in gestational diabetes mellitus and pre-eclampsia

Proteins secreted from adipocytes - so-called adipokines - influence metabolic and vascular function. Recent data suggest that various adipokines are dysregulated in gestational diabetes mellitus (GDM) and pre-eclampsia (PE) and might be of pathophysiological and prognostic significance in these complications of pregnancy. This review gives an overview on the regulation and pathophysiology of leptin and adiponectin in GDM and PE. Furthermore, data on novel adipokines including resistin, visfatin, retinol-binding protein 4 and vaspin are summarized.

The pathophysiology of HIV-/HAART-related metabolic syndrome leading to cardiovascular disorders: the emerging role of adipokines

Individuals infected with human immunodeficiency virus (HIV) frequently demonstrate metabolic syndrome (MS) associated with increased incidence of cardiovascular disorders. Characteristics of HIV infection, such as immunodeficiency, viral load, and duration of the disease, in addition to the highly active antiretroviral therapy (HAART) have been suggested to induce MS in these patients. It is well documented that MS involves a number of traditional cardiovascular risk factors, like glucose, lipids, and arterial blood pressure abnormalities, leading to extensive atherogenic arterial wall changes. Nevertheless, the above traditional cardiovascular risk factors merely explain the exacerbated cardiovascular risk in MS. Nowadays, the adipose-tissue derivatives, known as adipokines, have been suggested to contribute to chronic inflammation and the MS-related cardiovascular disease. In view of a novel understanding on how adipokines affect the pathogenesis of HIV/HAART-related MS and cardiovascular complications, this paper focuses on the interaction of the metabolic pathways and the potential cardiovascular consequences. Based on the current literature, we suggest adipokines to have a role in the pathogenesis of the HIV/HAART-related MS. It is crucial to understand the pathophysiology of the HIV/HAART-related MS and apply therapeutic strategies in order to reduce cardiovascular risk in HIV patients.