Elevated circulating vaspin levels were decreased by rosiglitazone therapy in T2DM patients with poor glycemic control on metformin alone

The Role of Anti-Inflammatory Adipokines in Cardiometabolic Disorders: Moving beyond Adiponectin

The global burden of obesity has multiplied owing to its rapidly growing prevalence and obesity-related morbidity and mortality. In addition to the classic role of depositing extra energy, adipose tissue actively interferes with the metabolic balance by means of secreting bioactive compounds called adipokines. While most adipokines give rise to inflammatory conditions, the others with anti-inflammatory properties have been the novel focus of attention for the amelioration of cardiometabolic complications. This review compiles the current evidence on the roles of anti-inflammatory adipokines, namely, adiponectin, vaspin, the C1q/TNF-related protein (CTRP) family, secreted frizzled-related protein 5 (SFRP5), and omentin-1 on cardiometabolic health. Further investigations on the mechanism of action and prospective human trials may pave the way to their clinical application as innovative biomarkers and therapeutic targets for cardiovascular and metabolic disorders.

Physical activity and adipokine levels in individuals with type 2 diabetes: A literature review and practical applications

We review the effects of acute and long-term physical activity on adipokine levels in individuals with type 2 diabetes (T2D). Three electronic databases were searched. Studies made in animal models were excluded, while studies based on participants with and without T2D, and also studies with type 1 diabetes were included. Of the 2,450 citations, 63 trials, including randomised control trials, cross-sectional and longitudinal studies, met our inclusion criteria. Seventy and five percent of studies reported the effects of physical activity on tumor necrosis factor-alpha (TNFα), interleukin 6 (IL-6), adiponectin, visfatin, omentin-1, and leptin levels. There are no robust results due to variations in exercise modality, intensity, duration, and also differences in cohort characteristics in the literature. Only four studies described the effects of an acute session of physical activity on adipokine levels. Overall, physical activity improves diabetes status by regulating adipokine levels. However, long-term aerobic + resistance training combined with dietary modifications is likely to be a more effective strategy for improving adipokines profiles in patients with type 2 diabetes.

Serine protease inhibitors and human wellbeing interplay: new insights for old friends

Serine Protease Inhibitors (Serpins) control tightly regulated physiological processes and their dysfunction is associated to various diseases. Thus, increasing interest is given to these proteins as new therapeutic targets. Several studies provided functional and structural data about human serpins. By comparison, only little knowledge regarding bacterial serpins exists. Through the emergence of metagenomic studies, many bacterial serpins were identified from numerous ecological niches including the human gut microbiota. The origin, distribution and function of these proteins remain to be established. In this report, we shed light on the key role of human and bacterial serpins in health and disease. Moreover, we analyze their function, phylogeny and ecological distribution. This review highlights the potential use of bacterial serpins to set out new therapeutic approaches.

Molecular Mechanisms of Vaspin Action - From Adipose Tissue to Skin and Bone, from Blood Vessels to the Brain

Visceral adipose tissue-derived serine protease inhibitor (vaspin) or SERPINA12 according to the serpin nomenclature was identified together with other genes and gene products that were specifically expressed or overexpressed in the intra-abdominal or visceral adipose tissue (AT) of the Otsuka Long-Evans Tokushima fatty rat. These rats spontaneously develop visceral obesity, insulin resistance, hyperinsulinemia and -glycemia, as well as hypertension and thus represent a well suited animal model of obesity and related metabolic disorders such as type 2 diabetes.The follow-up study reporting the cloning, expression and functional characterization of vaspin suggested the great and promising potential of this molecule to counteract obesity induced insulin resistance and inflammation and has since initiated over 300 publications, clinical and experimental, that have contributed to uncover the multifaceted functions and molecular mechanisms of vaspin action not only in the adipose, but in many different cells, tissues and organs. This review will give an update on mechanistic and structural aspects of vaspin with a focus on its serpin function, the physiology and regulation of vaspin expression, and will summarize the latest on vaspin function in various tissues such as the different adipose tissue depots as well as the vasculature, skin, bone and the brain.

Glypican-4 is increased in human subjects with impaired glucose tolerance and decreased in patients with newly diagnosed type 2 diabetes

CONTEXT

Glypican-4 (GPC-4) has been identified as a novel adipokine capable of enhancing insulin signaling. A significant association between circulating GPC-4 levels and nonalcoholic fatty liver disease and cardiometabolic risk factors has been found in women.

OBJECTIVE

The aim of the present study was to investigate the relationship between GPC-4 and insulin resistance in cross-sectional and interventional studies.

PATIENTS AND DESIGN

We measured circulating GPC-4 (determined with ELISA) in subjects with NGT, IGT, and nT2DM. Euglycemic-hyperinsulinemic clamps were performed in healthy and T2DM subjects. Real-time RT-PCR and Western blotting were used to assess mRNA and protein expression of GPC-4.

RESULTS

Circulating GPC-4 levels were significantly higher in IGT subjects and lower in nT2DM subjects compared to controls. Circulating GPC-4 was positively correlated with BMI, WHR, HOMA-IS, and FAT%, while it was inversely correlated with FBG and HbA1c. Excluding diabetic subjects, increasing GPC-4 levels were associated with HOMA-IR and M values. Significantly lower GPC-4 mRNA and protein levels were found in muscle and fat of nT2DM patients, compared to controls. GPC-4 levels were significantly increased upon an oral glucose intake. The secretion of GPC-4 exhibited a characteristic diurnal rhythm in humans, with a major rise occurring between afternoon and midnight.

CONCLUSIONS

Circulating GPC-4 is elevated in prediabetic subjects and is reduced in nT2DM patients. The elevated GPC-4 appears to be associated with insulin resistance and obesity in IGT subjects.

Higher vaspin levels in subjects with obesity and type 2 diabetes mellitus: a meta-analysis

AIMS

Visceral adipose tissue-derived serpin (vaspin) was identified as a new adipocytokine. Many studies reported vaspin concentrations in obese subjects and type 2 diabetes mellitus (T2DM) patients. However, large variation in levels of vaspin seen in different studies may be attributable to differences of sample size. The aim of this study is to establish an accurate confidence interval of vaspin levels in obese subjects and T2DM patients using a large-scale meta-analysis.

METHODS

Publications of the association between vaspin and obesity and T2DM in the databases of Medline, PubMed and EMBase were collected. The keywords included "vaspin" and "visceral adipose tissue-derived serpin". Review manager 5.0 was used to process the data.

RESULTS

For the analysis of obesity, 6 studies with 1826 participants were included in our meta-analysis; the level of vaspin was 0.52ng/ml [95% confidence interval (CI)](0.10-0.93, P=0.02) higher in obese subjects than that in non-obese healthy controls. Eleven studies with 1570 patients were included for the analysis of T2DM; the level of vaspin was 0.36ng/ml [95%CI] (0.23-0.49, P<0.00001) higher compared with that in healthy controls.

CONCLUSIONS

Significantly higher levels of serum vaspin were observed in obese subjects and T2DM patients.

Association of serum vaspin and adiponectin levels with renal function in patients with or without type 2 diabetes mellitus

Vaspin and adiponectin are two adipocytokines with antidiabetic effects. Some studies reported that levels of adiponectin and vaspin were correlated with decreased glomerular filtration rate (FGR) and increased albuminuria. We therefore evaluated the vaspin and adiponectin levels in renal insufficiency (RI) patients with or without T2DM. Serum vaspin, adiponectin levels were measured in 416 subjects with or without T2DM. Analysis was made between groups divided by these subjects presence or absence of RI. We found that serum adiponectin level was significantly higher in nondiabetic patients with RI than in nondiabetic subjects without RI; however, there were no statistical differences between the diabetic patients with RI and without RI. In all the subjects, the serum adiponectin level was also higher in 50 individuals with RI than that in 366 subjects without RI. The serum vaspin levels showed no significant differences between the diabetic patients or nondiabetics subjects with RI and without RI. Contrary to adiponectin, the serum vaspin level was lower in 169 patients with T2DM than in 247 individuals without T2DM. Our data suggested that both of T2DM and renal insufficiency were correlated with the serum level of adiponectin. However, the serum vaspin levels showed no significant difference between the individuals with renal insufficiency and without renal insufficiency.

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.