Vaspin can not inhibit TNF-alpha-induced inflammation of human umbilical vein endothelial cells

Associations between Vaspin Levels and Coronary Artery Disease

The relationship between serum vaspin levels and metabolic or coronary artery disease is currently of interest for researchers. Although adipokine concentrations have been shown to be increased significantly in atherosclerotic lesions, the role adipokines in the atherosclerotic process remains to be elucidated. Vaspin is a new biological marker associated with obesity and impaired insulin sensitivity. Plasma vaspin concentration has been shown to correlate with the severity of coronary artery disease. Vascular inflammation triggered by vaspin inhibits atherogenesis by suppressing macrophage foam cell formation and vascular smooth muscle cell migration and proliferation. Vaspin also contributes to plaque stabilization by increasing collagen content and reducing the intraplaque macrophage to vascular smooth muscle cell ratio. The therapeutic goal concerning vaspin is to fight atherosclerosis and related diseases, as well as to maintain vascular health.

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.

Insights into the molecular mechanisms of diabetes-induced endothelial dysfunction: focus on oxidative stress and endothelial progenitor cells

Diabetes mellitus is a heterogeneous, multifactorial, chronic disease characterized by hyperglycemia owing to insulin insufficiency and insulin resistance (IR). Recent epidemiological studies showed that the diabetes epidemic affects 382 million people worldwide in 2013, and this figure is expected to be 600 million people by 2035. Diabetes is associated with microvascular and macrovascular complications resulting in accelerated endothelial dysfunction (ED), atherosclerosis, and cardiovascular disease (CVD). Unfortunately, the complex pathophysiology of diabetic cardiovascular damage is not fully understood. Therefore, there is a clear need to better understand the molecular pathophysiology of ED in diabetes, and consequently, better treatment options and novel efficacious therapies could be identified. In the light of recent extensive research, we re-investigate the association between diabetes-associated metabolic disturbances (IR, subclinical inflammation, dyslipidemia, hyperglycemia, dysregulated production of adipokines, defective incretin and gut hormones production/action, and oxidative stress) and ED, focusing on oxidative stress and endothelial progenitor cells (EPCs). In addition, we re-emphasize that oxidative stress is the final common pathway that transduces signals from other conditions-either directly or indirectly-leading to ED and CVD.

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.

Angiogenesis and liver fibrosis

Recent data indicate that hepatic angiogenesis, regardless of the etiology, takes place in chronic liver diseases (CLDs) that are characterized by inflammation and progressive fibrosis. Because anti-angiogenic therapy has been found to be efficient in the prevention of fibrosis in experimental models of CLDs, it is suggested that blocking angiogenesis could be a promising therapeutic option in patients with advanced fibrosis. Consequently, efforts are being directed to revealing the mechanisms involved in angiogenesis during the progression of liver fibrosis. Literature evidences indicate that hepatic angiogenesis and fibrosis are closely related in both clinical and experimental conditions. Hypoxia is a major inducer of angiogenesis together with inflammation and hepatic stellate cells. These profibrogenic cells stand at the intersection between inflammation, angiogenesis and fibrosis and play also a pivotal role in angiogenesis. This review mainly focuses to give a clear view on the relevant features that communicate angiogenesis with progression of fibrosis in CLDs towards the-end point of cirrhosis that may be translated into future therapies. The pathogenesis of hepatic angiogenesis associated with portal hypertension, viral hepatitis, non-alcoholic fatty liver disease and alcoholic liver disease are also discussed to emphasize the various mechanisms involved in angiogenesis during liver fibrogenesis.

Vaspin (serpinA12) in obesity, insulin resistance, and inflammation

While genome-wide association studies as well as candidate gene studies have revealed a great deal of insight into the contribution of genetics to obesity development and susceptibility, advances in adipose tissue research have substantially changed the understanding of adipose tissue function. Its perception has changed from passive lipid storage tissue to active endocrine organ regulating and modulating whole-body energy homeostasis and metabolism and inflammatory and immune responses by secreting a multitude of bioactive molecules, termed adipokines. The expression of human vaspin (serpinA12) is positively correlated to body mass index and insulin sensitivity and increases glucose tolerance in vivo, suggesting a compensatory role in response to diminished insulin signaling in obesity. Recently, considerable insight has been gained into vaspin structure, function, and specific target tissue-dependent effects, and several lines of evidence suggest vaspin as a promising candidate for drug development for the treatment of obesity-related insulin resistance and inflammation. These will be summarized in this review with a focus on molecular mechanisms and pathways.

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.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Vaspin attenuates RANKL-induced osteoclast formation in RAW264.7 cells

Visceral adipose tissue-derived serine protease inhibitor (vaspin), an adipokine that was recently identified in a rat model of type 2 diabetes, has been suggested to have an insulin-sensitizing effect. In this study, we investigated whether vaspin inhibits receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis using two types of osteoclast precursors: RAW264.7 cells and bone marrow cells (BMCs). Vaspin inhibited RANKL-induced osteoclastogenesis in RAW264.7 cells and BMCs. Interestingly, vaspin also inhibited the RANKL-induced expression of nuclear factor of activated T cells c1 (NFATc1) in RAW264.7 cells and BMCs. Furthermore, it inhibited the RANKL-induced upregulation of matrix metalloproteinase-9 and cathepsin K in RAW264.7 cells. Thus, we suggest that vaspin downregulates osteoclastogenesis in part by inhibiting expression of the transcription factor NFATc1.

Vaspin attenuates high glucose-induced vascular smooth muscle cells proliferation and chemokinesis by inhibiting the MAPK, PI3K/Akt, and NF-κB signaling pathways

BACKGROUND

Vaspin has insulin-sensitizing effects, as well as additional beneficial effects on metabolic diseases. However, little is known about the direct effects of vaspin on vascular complications mediated by diabetes. The objective of this study is to determine the efficacy and mechanism of vaspin on hyperglycemia-induced vascular smooth muscle cells (VSMCs) proliferation, chemokinesis and cell signaling.

METHODS

Rat VSMCs proliferation was determined with 5-ethynyl-2'-deoxyuridine cell proliferation assays, chemokinesis was monitored with scratch assays, and reactive oxygen species (ROS) production was assessed using H2DCFDA and SOD-inhibited reduction of ferricytochrome c assay. Luciferase activity is assayed using a Dual Luciferase Reporter Assay System. Cell signaling is assessed by immunoblotting.

RESULTS

Vaspin significantly inhibited VSMCs proliferation and chemokinesis, as well as ROS generation and NADPH oxidase activity, induced by high glucose (HG) treatment. Compared with HG, vaspin significantly decreased VSMCs proliferation by 40 ± 8% at 100 ng/ml. Vaspin also decreased ROS production by 16 ± 8% at 100 ng/ml and 30 ± 8% at 300 ng/ml (all P < 0.01). Vaspin significantly abolished HG-induced phosphorylation of oxidase subunits p47phox, Akt, p38, and JNK1/2 without affecting their total levels, and attenuated HG-induced phosphorylation of insulin receptor and its downstream IRS-1 and IRS-2. For downstream targets, NF-κB activity and IκBα phosphorylation were both enhanced significantly after HG stimulation, and these effects were inhibited by vaspin. Vaspin also significantly abolished HG-induced PCNA and cyclin D1 expression.

CONCLUSIONS

Vaspin inhibits HG-induced VSMCs proliferation and chemokinesis by preventing ROS activation and MAPK, PI3K/Akt, and NF-κB signaling.

Adipokines and the cardiovascular system: mechanisms mediating health and disease

This review focuses on the role of adipokines in the maintenance of a healthy cardiovascular system, and the mechanisms by which these factors mediate the development of cardiovascular disease in obesity. Adipocytes are the major cell type comprising the adipose tissue. These cells secrete numerous factors, termed adipokines, into the blood, including adiponectin, leptin, resistin, chemerin, omentin, vaspin, and visfatin. Adipose tissue is a highly vascularised endocrine organ, and different adipose depots have distinct adipokine secretion profiles, which are altered with obesity. The ability of many adipokines to stimulate angiogenesis is crucial for adipose tissue expansion; however, excessive blood vessel growth is deleterious. As well, some adipokines induce inflammation, which promotes cardiovascular disease progression. We discuss how these 7 aforementioned adipokines act upon the various cardiovascular cell types (endothelial progenitor cells, endothelial cells, vascular smooth muscle cells, pericytes, cardiomyocytes, and cardiac fibroblasts), the direct effects of these actions, and their overall impact on the cardiovascular system. These were chosen, as these adipokines are secreted predominantly from adipocytes and have known effects on cardiovascular cells.

Angiogenesis: a phenomenon which aggravates chronic liver disease progression

It has become increasingly clear that angiogenesis occurring during chronic wound healing and fibrogenesis provides a key contribution to disease progression and complications. The association of fibrogenesis and angiogenesis should be regarded as crucial in the modern evaluation of liver disease progression and in the search for therapeutic targets. Physiological hepatic angiogenesis occurs during liver regeneration, contributing to the formation of new functional sinusoids. Pathological angiogenesis in liver is characterized by intrahepatic vascular remodeling with capillarization of the sinusoids and development of intrahepatic shunts, which lead to increased hepatic resistance and decreased effective hepatocyte perfusion. The problem of angiogenesis in chronic hepatitis C and nonalcoholic fatty liver disease has not been fully resolved. This manuscript briefly describes pathogenesis of new blood vessel formation in chronic hepatitis and potential role of angiogenesis in disease progression.

Circulating vaspin levels and epicardial adipose tissue thickness are associated with impaired coronary flow reserve in patients with nonalcoholic fatty liver disease

BACKGROUND

Patients with nonalcoholic fatty liver disease (NAFLD) have a reduced coronary flow reserve (CFR) and an increased risk of cardiovascular disease. The fat cells that surround coronary arteries may play a central and underrecognized role in development of cardiovascular disease through the systemic secretion of adipokines. We therefore evaluated the relation of epicardial fat thickness, serum levels of epicardial fat-related adipokines (chemerin and vaspin), and CFR in patients with NAFLD.

METHODS

We investigated 54 patients with biopsy-proven NAFLD and 56 age- and sex-matched controls. CFR and epicardial fat thickness (EFT) were measured by transthoracic echocardiography. Serum levels of chemerin and vaspin were measured by ELISA.

RESULTS

EFT was significantly higher (0.64 ± 0.13 vs. 0.54 ± 0.10 cm, P<0.001) and CFR significantly lower (2.11 ± 0.45 vs. 2.52 ± 0.62, P < 0.001) in patients with NAFLD than in controls. Serum levels of vaspin and chemerin were both significantly increased in patients with NAFLD compared with controls. Stepwise regression analysis showed that EFT (β=-0.53, t=-3.7, P<0.001), serum vaspin levels (β=-0.30, t=-2.5, P=0.014), and liver fibrosis (β=-0.31, t=-2.11, P=0.041), in the order they entered into the model, were independent predictors of CFR in NAFLD patients.

CONCLUSION

Our data suggest the presence of a complex interplay between EFT, serum vaspin, and liver histology in promoting an impaired hyperemic stimulation of coronary blood flow in patients with NAFLD.