Hypoadiponectinemia is associated with impaired endothelium-dependent vasodilation

Exploring the Link Between Metabolic Syndrome and Cellulite

Metabolic syndrome (MetS) encompasses a cluster of metabolic abnormalities, including insulin resistance, hypertension, abdominal obesity, and dyslipidemia, increasing cardiovascular disease and type 2 diabetes risks. Cellulite, a cosmetic condition marked by dimpled skin, predominantly affects women and shares risk factors with MetS, such as obesity and hormonal imbalances. This review examines the potential link between MetS and cellulite, focusing on shared pathophysiological pathways and implications for clinical practice and future research. Common factors such as inflammation, hormonal changes, and adipose tissue dysfunction are explored. The review highlights the importance of longitudinal studies to track cellulite progression in MetS patients, biomarker identification for early detection, intervention trials to assess therapeutic efficacy, mechanistic studies to elucidate underlying pathways and the impact of comorbidities on cellulite development. Understanding these relationships can enhance prevention, diagnosis, and treatment strategies for both MetS and cellulite, addressing significant public health and cosmetic concerns.

The Long-Term Effect of Maternal Obesity on the Cardiovascular Health of the Offspring-Systematic Review

Maternal obesity may affect offspring's cardiovascular health. Our literature search using PubMed, Web of Sciences included original English research and Google Scholar articles published over the past ten years, culminating in 96 articles in this topic. A mother's obesity during pregnancy has a negative impact on the cardiovascular risk for their offspring. Dependence was observed in relation to hypertension, coronary artery disease, stroke, and heart failure. The adverse impact of an abnormal diet in pregnant mice on heart hypertrophy was observed, and was also confirmed in human research. Pregnant women with obesity were at greater risk of having a child with innate heart disease than pregnant women with normal mass. To conclude: mother's obesity has a negative impact on the long-term cardiovascular consequences for their offspring, increasing their risk of high blood pressure, coronary heart disease, stroke and heart failure. It also increases the probability of heart hypertrophy and innate heart defects.

Serum adiponectin level is positively associated with vascular reactivity index by digital thermal monitoring in patients with coronary artery disease

Objectives

Adiponectin has anti-inflammatory and antiatherogenic effects and is important in the pathogenesis of cardiovascular diseases. In this cross-sectional study, our objective was to study the potential correlation between serum adiponectin levels and endothelial function in participants with coronary artery disease (CAD).

Materials and Methods

We collected serum specimens from 125 fasting participants with CAD. The endothelial function was measured using the vascular reactivity index (VRI) determined by digital thermal monitoring, and VRI values of >2.0, 1.0-1.9, and <1.0 indicated good, intermediate, and poor vascular reactivity, respectively. A commercially available enzyme immunoassay kit was used to measure serum adiponectin levels.

Results

The cohort included 55, 57, and 13 patients with good, intermediate, and poor vascular reactivity, respectively. Poor vascular reactivity was shown to be associated with older age, higher levels of serum total cholesterol, low-density lipoprotein cholesterol (LDL-C), C-reactive protein, and lower levels of serum albumin and adiponectin. The linear regression analysis with multivariable forward stepwise approach revealed that age (β = -0.232), serum LDL-C (β = -0.264), and serum adiponectin (β = 0.574) were correlated with the VRI in CAD patients significantly.

Conclusion

Fasting serum adiponectin levels were associated with good endothelial function determined using the VRI in patients with CAD.

Obesity Contributes to Transformation of Myometrial Stem-Cell Niche to Leiomyoma via Inducing Oxidative Stress, DNA Damage, Proliferation, and Extracellular Matrix Deposition

Leiomyomas (fibroids) are monoclonal tumors in which myometrial stem cells (MSCs) turn tumorigenic after mutation, abnormal methylation, or aberrant signaling. Several factors contribute to metabolic dysfunction in obesity, including abnormal cellular proliferation, oxidative stress, and DNA damage. The present study aims to determine how adipocytes and adipocyte-secreted factors affect changes in MSCs in a manner that promotes the growth of uterine leiomyomas. Myometrial stem cells were isolated from the uteri of patients by fluorescence-activated cell sorting (FACS) using CD44/Stro1 antibodies. Enzyme-linked immunosorbent assay (ELISA), Western blot, and immunocytochemistry assays were performed on human adipocytes (SW872) co-cultured with MSCs and treated with leptin or adiponectin to examine the effects of proliferation, extracellular matrix (ECM) deposition, oxidative damage, and DNA damage. Co-culture with SW872 increased MSC proliferation compared to MSC culture alone, according to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) results. The expressions of PCNA and COL1A increased significantly with SW872 co-culture. In addition, the expression of these markers was increased after leptin treatment and decreased after adiponectin treatment in MSCs. The Wnt/β-catenin and TGF-β/SMAD signaling pathways promote proliferation and ECM deposition in uterine leiomyomas. The expression of Wnt4, β-catenin, TGFβ3, and pSMAD2/3 of MSCs was increased when co-cultured with adipocytes. We found that the co-culture of MSCs with adipocytes resulted in increased NOX4 expression, reactive oxygen species production, and γ-H2AX expression. Leptin acts by binding to its receptor (LEP-R), leading to signal transduction, resulting in the transcription of genes involved in cellular proliferation, angiogenesis, and glycolysis. In MSCs, co-culture with adipocytes increased the expression of LEP-R, pSTAT3/STAT3, and pERK1/2/ERK/12. Based on the above results, we suggest that obesity may mediate MSC initiation of tumorigenesis, resulting in leiomyomas.

The Association between Serum Adiponectin Levels and Endothelial Function in Non-Dialysis-Dependent Chronic Kidney Disease Patients

Adiponectin is the richest human circulating adipokine with anti-inflammatory, antioxidant, and insulin-sensitizing effects. We evaluated the association between serum adiponectin levels and endothelial function in chronic kidney disease (CKD) patients, obtaining fasting blood samples from 130 non-dialysis CKD subjects. We measured the endothelial function-represented by the vascular reactivity index (VRI)-via non-invasive digital thermal monitoring, and serum adiponectin concentrations by enzyme immunoassay kits. A total of 22 (16.9%), 39 (30.0%), and 69 (53.1%) patients had poor (VRI < 1.0), intermediate (1.0 ≤ VRI < 2.0), and good (VRI ≥ 2.0) vascular reactivity. Elevated serum blood urea nitrogen (BUN) level was negatively correlated with VRI values, but serum adiponectin and estimated glomerular filtration rate were positively associated with VRI values by univariate linear regression analysis. After applying multivariate stepwise linear regression analysis adjustment, the significantly positive association of adiponectin (p < 0.001), and the significantly negative association of log-BUN (p = 0.021) with VRI values in CKD subjects remained. In an animal study using in vitro blood-vessel myography, treatment with adiponectin enhancing acetylcholine-mediated vasorelaxation in 5/6 nephrectomy CKD mice. Our study results indicated that adiponectin concentration was positively associated with VRI values and modulated endothelial function in non-dialysis CKD patients.

Effect of the interaction between the visceral-to-subcutaneous fat ratio and aldosterone on cardiac function in patients with primary aldosteronism

Primary aldosteronism is the most frequent secondary hypertensive disease and is characterized by an elevated risk for cardiovascular disease. The current standard treatments are adrenalectomy and/or administration of mineralocorticoid receptor blockers, both of which are effective at ameliorating hypertension via intervention for hyperaldosteronism. However, both of these approaches have side effects and contraindications, and mineralocorticoid receptor blockers also have limited preventive efficacy against cardiovascular events. Recently, in vitro experiments have shown that aldosterone regulation is closely related to abdominal fat accumulation and that there is crosstalk between aldosterone and visceral fat tissue accumulation. We previously reported that this interaction was clinically significant in renal dysfunction; however, its effects on the heart remain unclear. Here, we analyzed data from 49 patients with primary aldosteronism and 29 patients with essential hypertension to examine the potential effect of the interaction between the ratio of visceral-to-subcutaneous fat tissue volume and the plasma aldosterone concentration on echocardiographic indices, including the tissue Doppler-derived E/e' ratio. A significant interaction was found in patients with primary aldosteronism (p < 0.05), indicating that patients with the combination of a high plasma aldosterone concentration and high visceral-to-subcutaneous fat ratio show an increased E/e' ratio, which is a well-known risk factor for future cardiovascular events. Our results confirm the clinical importance of the interaction between aldosterone and abdominal fat tissue, suggesting that an improvement in the visceral-to-subcutaneous fat ratio may be synergistically and complementarily effective in reducing the elevated risk of cardiovascular disease in patients with primary aldosteronism when combined with conventional therapies for reducing aldosterone activity. A significant effect of the interaction between plasma aldosterone concentration and the visceral-to-subcutaneous fat ratio on the tissue Doppler-derived E/e' ratio in patients with primary aldosteronism.

Adipose Tissue Paracrine-, Autocrine-, and Matrix-Dependent Signaling during the Development and Progression of Obesity

Obesity is an ever-increasing phenomenon, with 42% of Americans being considered obese (BMI ≥ 30) and 9.2% being considered morbidly obese (BMI ≥ 40) as of 2016. With obesity being characterized by an abundance of adipose tissue expansion, abnormal tissue remodeling is a typical consequence. Importantly, this pathological tissue expansion is associated with many alterations in the cellular populations and phenotypes within the tissue, lending to cellular, paracrine, mechanical, and metabolic alterations that have local and systemic effects, including diabetes and cardiovascular disease. In particular, vascular dynamics shift during the progression of obesity, providing signaling cues that drive metabolic dysfunction. In this review, paracrine-, autocrine-, and matrix-dependent signaling between adipocytes and endothelial cells is discussed in the context of the development and progression of obesity and its consequential diseases, including adipose fibrosis, diabetes, and cardiovascular disease.

Increased epicardial adipose tissue thickness correlates with endothelial dysfunction in spondyloarthritis

INTRODUCTION

We aimed to investigate the relationship between epicardial adipose tissue (EAT) thickness, flow-mediated dilation (FMD), and carotid intima-media thickness (cIMT) in spondyloarthritis (SpA) patients compared to healthy controls.

METHODS

We performed a cross-sectional study including SpA patients aged ≤ 50 years without traditional cardiovascular risk factors and healthy controls matched for age and gender. Baseline characteristics, laboratory data, and SpA-related parameters were recorded. All participants underwent ultrasound examination with measurement of EAT thickness, FMD, and cIMT by both an experienced cardiologist and radiologist blinded to clinical data. The relationships between the ultrasound measurements were analyzed using Spearman's correlation coefficient and Person correlation.

RESULTS

The study included 94 subjects (47 SpA and 47 healthy controls). The sex-ratio was 2.35; the median age of patients was 36 years (IQR: 28-46), and the median disease duration was 11 years (IQR: 5-16). Compared to the control group, SpA patients had significantly higher values of EAT thickness (p = 0.001) and cIMT (p < 0.0001). FMD values were significantly lower in SpA patients compared to controls (p = 0.008). The univariate analysis detected a significant negative association between EAT thickness and FMD (p = 0.026; r =  - 0.325), and between left cIMT and FMD (p = 0.027; r =  - 0.322). No association was found between EAT thickness and cIMT.

CONCLUSION

EAT thickness, FMD, and cIMT were significantly impaired in SpA patients compared with healthy controls supporting evidence of accelerated atherosclerosis in SpA. EAT thickness was correlated to endothelial dysfunction suggesting the role of EAT in predicting the early reversible stages of atherosclerosis. Key Points • Spondyloarthritis is associated with impaired subclinical atherosclerosis markers accurately increased epicardial fat and carotid intima-media thickness and endothelial dysfunction. • Increased epicardial fat thickness is correlated with impaired endothelial function in spondyloarthritis patients.

A Potential Interplay between HDLs and Adiponectin in Promoting Endothelial Dysfunction in Obesity

Obesity is an epidemic public health problem that has progressively worsened in recent decades and is associated with low-grade chronic inflammation (LGCI) in metabolic tissues and an increased risk of several diseases. In particular, LGCI alters metabolism and increases cardiovascular risk by impairing endothelial function and altering the functions of adiponectin and high-density lipoproteins (HDLs). Adiponectin is an adipokine involved in regulating energy metabolism and body composition. Serum adiponectin levels are reduced in obese individuals and negatively correlate with chronic sub-clinical inflammatory markers. HDLs are a heterogeneous and complex class of lipoproteins that can be dysfunctional in obesity. Adiponectin and HDLs are strictly interdependent, and the maintenance of their interplay is essential for vascular function. Since such a complex network of interactions is still overlooked in clinical settings, this review aims to highlight the mechanisms involved in the impairment of the HDLs/adiponectin axis in obese patients to predict the risk of cardiovascular diseases and activate preventive countermeasures. Here, we provide a narrative review of the role of LGCI in altering HDLs, adiponectin and endothelial functions in obesity to encourage new studies about their synergic effects on cardiovascular health and disease.

Decreased Adiponectin Levels in Early Pregnancy Are Associated with High Risk of Prematurity for African American Women

The relationship of low maternal serum adiponectin levels with preterm delivery among a multi-ethnic group has not been extensively investigated. We examined ethnic differences in cytokine/adipokine profiles and whether they contribute to several adverse pregnancy outcomes, particularly preterm delivery. Data and samples were from a large prospective observational cohort (n = 1776) of young, generally healthy pregnant women (African American 36.4%, Hispanic 48.0%, Caucasian 15.6%). Serum cytokine/adipokine concentrations were measured at entry (mean gestational age of 16.83 weeks) using the Liminex xMap Technology. Multivariable analyses were performed. A significant difference in adiponectin level was observed among ethnic groups. African Americans had a decreased adiponectin and increased resistin levels compared to Hispanics and Caucasians (p < 0.05 to p < 0.0001 for each). Decreased adiponectin (lowest quartile) was positively associated with preterm delivery independent of usual risk factors (adjusted odds ratio (AOR) 1.46, 95% confidence interval (CI) 1.05, 2.04 for all preterm and AOR 1.84, 95% CI 1.07, 3.17 for early preterm births). The results were unchanged when women with preeclampsia were excluded. Similar results were observed in African Americans. Decreased adiponectin levels were not related to preterm birth in either Hispanics or Caucasians. Lower adiponectin levels were also significantly associated with an increased risk of developing gestational diabetes (AOR 1.72, 95% CI 1.05, 2.84) and preeclampsia (AOR 1.45, 95% CI 1.00, 2.14) in the whole cohort and in Caucasians. We did not find any consistent relationships between the other markers with outcome variables. Dysregulation in maternal adiponectin at early gestation is associated with an increased risk of preterm delivery. An ethnic difference in adiponectin levels may contribute to a higher preterm delivery rate in African American women.

Vascular endothelial adiponectin signaling across the life span

Cardiovascular disease risk increases with age regardless of sex. Some of this risk is attributable to alterations in natural hormones throughout the life span. The quintessential example of this being the dramatic increase in cardiovascular disease following the transition to menopause. Plasma levels of adiponectin, a "cardioprotective" adipokine released primarily by adipose tissue and regulated by hormones, also fluctuate throughout one's life. Plasma adiponectin levels increase with age in both men and women, with higher levels in both pre- and postmenopausal women compared with men. Younger cohorts seem to confer cardioprotective benefits from increased adiponectin levels yet elevated levels in the elderly and those with existing heart disease are associated with poor cardiovascular outcomes. Here, we review the most recent data regarding adiponectin signaling in the vasculature, highlight the differences observed between the sexes, and shed light on the apparent paradox regarding increased cardiovascular disease risk despite rising plasma adiponectin levels over time.

Positive Association of Serum Adiponectin Level With the Vascular Reactivity Index in Kidney Transplant Patients

OBJECTIVES

Adiponectin has an important role in obesity, insulin resistance, and cardiovascular disease. We investigated the association between serum adiponectin levels and endothelial function in kidney transplant patients.

MATERIALS AND METHODS

Fasting blood samples were obtained from 70 kidney transplant patients. The vascular reactivity index was measured with a digital thermal monitoring test. Serum adiponectin levels were measured with a commercially available enzyme immunoassay kit. A vascular reactivity index <1.0 was defined as poor, 1.0 or greater but less than 2.0 was intermediate, and 2.0 or greater was good.

RESULTS

The results showed that 10 kidney transplant patients (13.3%) were categorized with a vascular reactivity index of poor, 25 (35.7%) were intermediate, and 35 (50%) were good. Increased waist circumference (P = .037), increased serum alkaline phosphatase (P = .026), and lower serum adiponectin (P = .001) were associated with poor vascular reactivity index. Advanced age (r = -0.300; P = .012), waist circumference (r = -0.372; P = .002), serum alkaline phosphatase (r = -0.323; P = .006), and logarithmically transformed serum triglycerides (r = -0.317; P = .007) were negatively correlated with the vascular reactivity index, whereas serum adiponectin (r = 0.332; P = .005) was positively correlated with the vascular reactivity index. Multi variable forward stepwise linear regression analysis showed that waist circumference, serum alkaline phosphatase, and serum adiponectin were significantly and independently associated with the vascular reactivity index.

CONCLUSIONS

Fasting serum adiponectin levels were positively associated with the vascular reactivity index and negatively associated with endothelial function in kidney transplant patients.

Gut permeability is associated with hypertension and measures of obesity but not with Endothelial Dysfunction in South African youth

Background

Though gut permeability has shown to be associated with measures of obesity and hypertension, its relationship with endothelial dysfunction, an early predictor for cardiovascular diseases remains unknown.

Objective

This study assessed the relationship between hypertension, measures of obesity, gut permeability and endothelial dysfunction.

Methods

A cross-sectional quantitative study which enrolled 151 South African youths was conducted. Anthropometric and blood pressure measurements were performed. Zonulin, a marker for gut permeability; adiponectin, an anti-inflammatory molecule, as well as asymmetric dimethylarginine (ADMA) and Nitric oxide (NO) which are markers for endothelialfunction were assayed.

Results

Approximately eighteen percent (17.88%) of the participants were hypertensive while 40.4% were pre-hypertensive. Adiponectin significantly increased in hypertensive subjects and negatively correlated (p<0.05) with measures of obesity but was not associated with gut permeability and endothelial dysfunction. Increased body mass index (BMI) and visceral fat (VF) predicted reduced adiponectin (inflammation). Zonulin was significantly higher (p<0.05) in hypertensive subjects and positively associated (p<0.05) with systolic blood pressure (SBP) in females. A positive relationship (p<0.05) was observed between zonulin and measurements of obesity. Moreover, zonulin negatively associated (p<0.05) with ADMA but positively associated (p<0.05) with NO in males. Increased VF and waist circumference predicted gut permeability.

Conclusion

Gut permeability was associated with hypertension and measures of obesity but not with markers of endothelial dysfunction in a South African youth population.

Plasma Adiponectin and Blood Pressure Progression in African Americans: The Jackson Heart Study

BACKGROUND

Little is known on the association of plasma adiponectin with blood pressure (BP) changes in African Americans (AAs). We evaluated the associations between plasma adiponectin and BP progression among AAs.

METHODS

We analyzed data from 1,184 participants without hypertension at baseline (2000-2004) with ≥1 follow-up visits in the Jackson Heart Study. We used robust Poisson regression to generate risk ratios (RRs) for BP progression (an increase by ≥1 BP stage) and incident hypertension.

RESULTS

Over a median of 7 years, 71% progressed to higher BP stage and 65% developed hypertension. We found evidence of interaction by sex (P-interaction = 0.088). Compared with those in the lowest quartile (Q1), male participants in the highest adiponectin quartile (Q4) had reduced risks of BP progression (RR 0.76 [95% confidence interval, CI, 0.60-0.96]) and incident hypertension (RR 0.74 [95% CI 0.56-0.97]). After accounting for body mass index, this relation persisted among obese men (RR for the highest [vs. lowest] adiponectin quartile: 0.59 [95% CI 0.36-0.97] for incident hypertension, and 0.69 [95% CI 0.45-1.06] for BP progression). Among women, adiponectin was not associated with BP outcomes (RR [95% CI] for Q4 vs. Q1: 1.03 [0.86-1.23] and 1.01 [0.83-1.23] for BP progression and incident hypertension, respectively). Our findings were consistent across both the American College of Cardiology (ACC)/American Heart Association (AHA) and Seventh Joint National Committee (JNC-7) BP categories.

CONCLUSIONS

In a large, community-based sample of AAs, higher adiponectin concentrations were associated with lower risks of BP progression and incident hypertension in men, but no significant association was observed in women.

All-trans-retinoic acid ameliorates atherosclerosis, promotes perivascular adipose tissue browning, and increases adiponectin production in Apo-E mice

All-trans-retinoic acid (atRA), an active metabolite of vitamin A, exerts a potential role in the prevention of cardiovascular diseases. It has been shown that atRA ameliorates atherosclerosis while the exact mechanism underlying this protection remains unknown. This study investigated the influence of atRA on insulin resistance (IR), atherosclerosis, and the process of perivascular adipose tissue (PVAT) browning. Moreover, syntheses of adiponectin, adipokine with anti-atherogenic effects, and tumor necrosis factor-alpha (TNF-α), a pro-inflammatory cytokine, were determined in PVAT. Apolipoprotein E-deficient mice (Apo-E) and control C57BL/6J wild-type mice were treated with atRA (5 mg/kg/day) or vehicle (corn oil) by plastic feeding tubes for 8 weeks. Long-term atRA treatment in Apo-E mice did not affect insulin resistance. AtRa administration ameliorated atherosclerosis, induced PVAT browning, and increased adiponectin production in PVAT in Apo-E mice. Furthermore, atRA increased nitric oxide (NO) level but did not affect adiponectin concentration in the aorta of Apo-E mice. These results indicate that atRA ameliorates atherosclerosis in Apo-E mice. We also observed the browning of PVAT. Besides, atRA increased the synthesis of adiponectin in PVAT and augmented NO level in the aorta in ApoE mice.

From diabetes to renal aging: the therapeutic potential of adiponectin

Nowadays, the complications related to diabetes, such as nephropathy, cardiovascular problems, and aging, are highly being considered. Renal cell aging is affected by various mechanisms of inflammation, oxidative stress, and basement membrane thickening, which are significant causes of renal dysfunction in diabetes. Due to recent studies, adiponectin plays a key role in diabetes-related kidney diseases as a fat-derived hormone. In diabetes, reduced adiponectin levels are associated to renal cell aging. Oxidative stress and related signaling pathways are the main routes in which adiponectin may be effective to decline diabetes-associated aging. Therefore, adiponectin signaling in target tissues becomes one of the research areas of interest in metabolism and clinical medicine. Studies on adiponectin signaling will increase our understanding of adiponectin role in diabetes-linked diseases as well as shortening life span conditions which may guide the design of antidiabetic and anti-aging drugs.

Association of the ratio of visceral-to-subcutaneous fat volume with renal function among patients with primary aldosteronism

Patients with primary aldosteronism have a higher risk of chronic kidney disease. Visceral fat tissue is hypothesized to stimulate the adrenal glands to overproduce aldosterone, and aldosterone promotes visceral fat tissue to produce inflammatory cytokines. However, it is unclear whether the volume of accumulated visceral fat tissue is associated with renal impairment among patients with hyperaldosteronism. We conducted a single-center cross-sectional study to assess the association between the estimated glomerular filtration rate and the ratio of the visceral-to-subcutaneous fat volume calculated by computed tomography. One hundred eighty patients with primary aldosteronism were enrolled. The mean ± SD age was 52.7 ± 11.0 years, and 60.0% were women. The ratio of visceral-to-subcutaneous fat volume was highly correlated with the estimated glomerular filtration rate (r = 0.49, p < 0.001). In multiple linear regression models, the ratio of visceral-to-subcutaneous fat tissue volume was significantly associated with the estimated glomerular filtration rate (estimates: -4.56 mL/min/1.73 m² per 1-SD), and there was an interaction effect between the plasma aldosterone concentration and the ratio of visceral-to-subcutaneous fat volume (p < 0.05). The group with a higher plasma aldosterone concentration exhibited a steeper decline in eGFR than the lower plasma aldosterone concentration group when the ratio increased. The ratio of visceral-to-subcutaneous fat tissue volume was an independent risk factor for renal dysfunction. This association increased in the presence of a high plasma aldosterone concentration. Clinicians should pay attention to the ratio of visceral-to-subcutaneous fat tissue volume and encourage primary aldosteronism patients to improve their lifestyle in addition to treating renin-aldosterone activity.

Dietary berries, insulin resistance and type 2 diabetes: an overview of human feeding trials

Dietary berries are a rich source of several nutrients and phytochemicals and in recent years, accumulating evidence suggests they can reduce risks of several chronic diseases, including type 2 diabetes (T2D). The objective of this review is to summarize and discuss the role of dietary berries (taken as fresh, frozen, or other processed forms) on insulin resistance and biomarkers of T2D in human feeding studies. Reported feeding trials involve different berries taken in different forms, and consequently differences in nutritional or polyphenol composition must be considered in their interpretation. Commonly consumed berries, especially cranberries, blueberries, raspberries and strawberries, ameliorate postprandial hyperglycemia and hyperinsulinemia in overweight or obese adults with insulin resistance, and in adults with the metabolic syndrome (MetS). In non-acute long-term studies, these berries either alone, or in combination with other functional foods or dietary interventions, can improve glycemic and lipid profiles, blood pressure and surrogate markers of atherosclerosis. Studies specifically in people with T2D are few, and more knowledge is needed. Nevertheless, existing evidence, although sparse, suggests that berries have an emerging role in dietary strategies for the prevention of diabetes and its complications in adults. Despite the beneficial effects of berries on diabetes prevention and management, they must be consumed as part of a healthy and balanced diet.

Physiological role of adiponectin in different tissues: a review

Adiponectin is the most important adipokine secreted by the adipose tissue. It carries out an important role in setting up the metabolism and improving the function of various organs. Adiponectin in the kidneys prevents degradation of the renal arteries, reduces protein excretion, and improves filtration. This role is accomplished by regulating anabolic pathways and reducing oxidative stress in the renal tissue. This hormone in the liver prevents the accumulation of fat and free radicals that cause damage to liver cells and tissue. This adipokine, by preventing inflammatory processes, oxidative stress, obesity and insulin resistance, improves vascular function and prevents the development of atherosclerosis. It seems that adiponectin can also be a therapeutic target for many metabolic diseases. This study aims to clarify the adipose tissue discharge. Here, the diverse physiological actions of adiponectin were reviewed to provide an overview of its therapeutic potential in different metabolic disorders.

The Role of Adiponectin in Maintaining Metabolic Homeostasis

BACKGROUND

Adiponectin is an adipocyte-derived cytokine closely associated with obesity, altered body adipose tissue distribution, insulin resistance, and cardiovascular diseases.

INTRODUCTION

Evidence from animal and human studies demonstrate that adiponectin plays an important role in the regulation of glucose and lipid metabolism. Adiponectin increases insulin sensitivity and improves systemic lipid metabolism. Although research efforts on adiponectin mostly aim towards its endocrine functions, this adipocyte-derived molecule also has profound autocrine and paracrine functions.

CONCLUSION

In this review, our aim is to discuss the role of adiponectin in maintaining metabolic homeostasis and its association with cardiovascular health. The proper identification of these roles is of great importance, which has the potential to identify a wealth of novel targets for the treatment of diabetes and related cardio-metabolic diseases.

Effect of vitamin D supplementation on endothelial function - An updated systematic review with meta-analysis and meta-regression

BACKGROUND AND AIMS

Atherogenesis and endothelial dysfunction contribute to cardiovascular risk and vitamin D has been implemented in endothelial repair. This systematic review, meta-analysis and meta-regression aims to establish the effect of vitamin D supplementation on endothelial function.

METHODS AND RESULTS

To conduct the systematic review we searched the Cochrane Library of Controlled Trials, PubMed, ProQuest and EMBASE for randomized controlled trials that investigated the effects of vitamin D supplementation on flow-mediated dilation (FMD%), pulse wave velocity (PWV), and central augmentation index (AIx). Meta-analysis was based on a random effects model and inverse-variance methods to calculate either mean difference (MD) or standardized mean difference (SMD) as effects sizes. This was followed by meta-regression investigating the effect of baseline vitamin D concentrations, vitamin D dosing and study duration. Risk of bias was assessed using the JADAD scale and funnel plots. We identified 1056 studies of which 26 studies met inclusion criteria for quantitative analysis. Forty-two percent of the 2808 participants had either deficient or insufficient levels of vitamin D. FMD% (MD 1.17% (95% CI -0.20, 2.54), p = 0.095), PWV (SMD -0.09 m/s (95% CI -0.24, 0.07), p = 0.275) and AIx (SMD 0.05% (95% CI -0.1, 0.19), p = 0.52) showed no improvement with vitamin D supplementation. Sub-analysis and meta-regression revealed a tendency for AIx and FMD% to increase as weekly vitamin doses increased; no other significant relationships were identified.

CONCLUSIONS

Vitamin D supplementation showed no improvement in endothelial function. More evidence is required before recommendations for management of endothelial dysfunction can be made.

The role of adiponectin in placentation and preeclampsia

Preeclampsia is not fully understood; and few biomarkers, therapeutic targets, and therapeutic agents for its management have been identified. Original investigative findings suggest that abnormal placentation triggers preeclampsia and leads to hypertension, proteinuria, endothelial dysfunction, and inflammation, which are characteristics of the disease. Because of the regulatory roles that it plays in several metabolic processes, adiponectin has become a cytokine of interest in metabolic medicine. In this review, we have discussed the role of adiponectin in trophoblast proliferation, trophoblast differentiation, trophoblast invasion of the decidua, and decidual angiogenesis, which are the major phases of placentation. Also, we have highlighted the physiological profile of adiponectin in the course of normal pregnancy. Moreover, we have discussed the involvement of adiponectin in hypertension, endothelial dysfunction, inflammation, and proteinuria. Furthermore, we have summarized the reported relationship between the maternal serum adiponectin level and preeclampsia. The available evidence indicates that adiponectin level physiologically falls as pregnancy advances, regulates placentation, and exhibits protective effects against the symptoms of preeclampsia and that while hyperadiponectinemia is evident in normal-weight preeclamptic women, hypoadiponectinemia is evident in overweight and obese preeclamptic women. Therefore, the clinical use of adiponectin as a biomarker, therapeutic target, or therapeutic agent against the disease looks promising and should be considered.

Atorvastatin suppresses vascular hypersensitivity and remodeling induced by transient adventitial administration of lipopolysaccharide in rats

Background

The phenotypic transition of vascular smooth muscle cells (VSMCs) from a contractile to a proliferative state markedly affects the pathophysiology of cardiovascular diseases. The adventitial inflammation can promote neointimal formation and vascular remodeling. We used direct administration of lipopolysaccharide (LPS) into the periphery of the carotid artery to investigate the influence of transient adventitial inflammation on vascular remodeling and its potential mechanism.

Methods

Male 15-week-old Wistar rats were randomly assigned to four groups with six rats in each group. The rats of groups I and II were administered distilled water, and group III and IV were treated with fasudil and atorvastatin respectively. All treatments were given daily for 11 days. On day 8, the adventitia in group I was injected with 5 µL sterile saline, and the group II-IV were injected with 5 µL sterilized LPS. The carotid blood flow and femoral blood pressure were measured in vivo, and the thickness of vascular intima and middle layer was measured in vitro. Serum interleukin-6 (IL-6) and tumor necrosis factor α (TNFα) were determined using enzyme-linked immunosorbent assay (ELISA) assay. And the Rho-associated coiled-coil-containing protein kinase 2 (ROCK2), myosin phosphatase target subunit 1 (MYPT1), myosin light chain (MLC), myocardin, SM-α actin or glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were detected by western blot. The comparisons were made by one-way analysis of variance with Bonferroni's post hoc test. A value of P<0.05 was considered to represent a statistically significant difference.

Results

Transient adventitial inflammation induced by LPS caused no obvious change in basal blood flow, but did lead to vascular hypersensitivity to serotonin. Morphological examinations revealed that the medial layer was the only domain affected, and showed VSMC proliferation and rearrangement. LPS increased serum IL-6 and TNFα contents, ROCK2 expression and activity, and caused changes in the expression levels of some stereotypical VSMC genes. Similar to the Rho-kinase inhibitor fasudil, atorvastatin completely restored the morphological alterations, even increased blood flow.

Conclusions

Our study confirms the beneficial effect of atorvastatin on the vascular system in terms of morphology and function.

Pulmonary Hypertension and Obesity: Focus on Adiponectin

Pulmonary hypertension is an umbrella term including many different disorders causing an increase of the mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg. Recent data revealed a strong association between obesity and pulmonary hypertension. Adiponectin is a protein synthetized by the adipose tissue with pleiotropic effects on inflammation and cell proliferation, with a potential protective role on the pulmonary vasculature. Both in vivo and in vitro studies documented that adiponectin is an endogenous modulator of NO production and interferes with AMP-activated protein kinase (AMPK) activation, mammalian target of rapamycin (mTOR), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κβ) signaling preventing endothelial dysfunction and proliferation. Furthermore, adiponectin ameliorates insulin resistance by mediating the biological effects of peroxisome proliferator-activated receptor-gamma (PPARγ). Therefore, adiponectin modulation emerged as a theoretical target for the treatment of pulmonary hypertension, currently under investigation. Recently, consistent data showed that hypoglycemic agents targeting PPARγ as well as renin–angiotensin system inhibitors and mineralocorticoid receptor blockers may influence pulmonary hemodynamics in different models of pulmonary hypertension.

Intracranial atherosclerotic disease

Intracranial atherosclerosis (ICAS) is a progressive pathological process that causes progressive stenosis and cerebral hypoperfusion and is a major cause of stroke occurrence and recurrence around the world. Multiple factors contribute to the development of ICAS. Angiography imaging techniques can improve the diagnosis of and the selection of appropriate treatment regimens for ICAS. Neither aggressive medication nor endovascular interventions can eradicate stroke recurrence in patients with ICAS. Non-pharmacological therapies such as remote ischemic conditioning and hypothermia are emerging. Comprehensive therapy with medication in combination with endovascular intervention and/or non-pharmacological treatment may be a potential strategy for ICAS treatment in the future. We summarized the epidemiology, pathophysiological mechanisms, risk factors, biomarkers, imaging and management of ICAS.

Serum cardiovascular risk biomarkers in pre-pubertal obese children

BACKGROUND

Childhood obesity is associated with premature cardiovascular complications. However, little is known about the effect of a family-based behavioural intervention on the relationship between arterial function, blood pressure and biomarkers in pre-pubertal children with obesity.

DESIGN

This was a single centre randomized controlled trial (RCT) including 74 children randomized to a 6-month behavioural intervention to treat obesity. In 48 children (13 controls and 35 interventions), we assessed: serum level of cytokine (CCL2), adiponectin, and neutrophil product (MMP-8), as well as carotid intima-media thickness, flow-mediated dilation (FMD), nitroglycerin-mediated dilation; arterial stiffness (incremental elastic modulus, Einc), pulse wave velocity (PWV), resting and 24-hour blood pressure (BP).

RESULTS

At baseline, resting systolic BP was positively associated with MMP-8 levels which was significantly higher in children with hypertension (P = 0.033). Biochemical markers were not related to endothelial function at baseline, but they globally increased after 6 months in the intervention group. The significant increase of CCL2 levels in the intervention group was associated with a decrease in diastolic BP. Furthermore, adiponectin change was positively related to a change in FMD and negatively to change in Einc and PWV.

CONCLUSIONS

The usefulness of serum biomarkers for the detection of cardiovascular diseases is not well established in children. In our population, MMP-8 concentration was higher in hypertensive children. Furthermore, behavioural interventions resulted in a paradoxical increase in some biomarkers in children, with potentially beneficial effects detected with CCL2 changes. Caution should be taken when using nonspecific serum biomarkers for the clinical monitoring of children with obesity.

Effect ofBifidobacterium lactisHN019 on inflammatory markers and oxidative stress in subjects with and without the metabolic syndrome

Beneficial effects of probiotics have been reported on body weight, lipid and carbohydrate metabolism, inflammatory state and oxidative stress in healthy subjects and in many metabolic and inflammatory diseases. The aim of this study was to evaluate the effects ofBifidobacterium lactisHN019 on inflammatory state and nitro-oxidative stress in patients with and without the metabolic syndrome (MetS). The usual diets of the thirty-three subjects were supplemented with probiotic milk for 90 d. Inflammatory markers and oxidative measurements were performed. In relation to the baseline values, subjects in both groups showed a decrease in homocysteine (P=0·02 andP=0·03, respectively), hydroperoxides (P=0·02 andP=0·01, respectively) and IL-6 levels (P=0·02). Increases in adiponectin (P=0·04) and nitric oxide metabolites (NOx,P=0·001) levels were only seen in the group with the MetS in relation to the baseline values, whereas only the individuals without the MetS had increases in total radical-trapping antioxidant parameter levels (P=0·002). In conclusion,B. lactisHN019 have several beneficial effects on inflammatory and oxidative biomarkers in healthy subjects and the MetS patients. Patients with the MetS showed a specific improvement in adiponectin and NOx levels, whereas a specific favourable effect was shown in the antioxidant defenses in healthy subjects. If the results obtained in the present study are confirmed, supplementation of fermented milk with probiotics in healthy subjects and patients with the MetS must be further discussed.

Cellulite: a cosmetic or systemic issue? Contemporary views on the etiopathogenesis of cellulite

Cellulite (also known as gynoid lipodystrophy or orange peel syndrome) is one of the most common lipodystrophy syndromes, which affects millions of post-adolescent women. Cellulite is manifested by topographic disorders of subcutaneous tissue such as nodules, edema, and abnormal fibrosis. It is located mainly on the pelvic area, especially on the buttocks. Its pathogenesis is complexed and unclear. There are several theories about its pathophysiology. Hormonal disorders, endothelial dysfunction and genetic predispositions are taken under consideration.

Adiponectin as a potential therapeutic target for the treatment of restenosis

Restenosis is a pathologic re-narrowing of a coronary artery lesion after mechanical injury. Its pathophysiological mechanisms have not been fully elucidated at present, but are thought to include inflammation, vascular smooth muscle cell (VSMC) proliferation, and matrix remodeling, beginning with insufficient endothelium healing. Restenosis presents with angina symptoms or acute coronary syndromes and lead to a revascularization, either with coronary artery bypass or repeat percutaneous coronary intervention. Some studies have reported that hypoadiponectinemia has been an independent risk factor for the onset of acute coronary syndromes and restenosis. Accumulating evidence shows that low concentrations of adiponectin may be involved in impairing endothelium functions, inflammation, and VSMC proliferation that lead to restenosis. Preclinical studies have proven that adiponectin promotes endothelium healing, effectively inhibits inflammation, and maintains contractile phenotypes of VSMCs, indicating that it may be developed as a new therapeutic target for the treatment of restenosis.

The Potential Role of Fibroblast Growth Factor 21 in Lipid Metabolism and Hypertension

Fibroblast growth factor (FGF) 21 belongs to the FGF superfamily that is involved in cell proliferation and differentiation, neural development, angiogenesis, and metabolism. FGF21 requires β-Klotho as a co-receptor. Tissues involved in metabolism such as the liver, adipose tissues, skeletal muscle, and pancreas express FGF21. Starvation increases hepatic expression of FGF21, which then acts centrally to increase hepatic gluconeogenesis. FGF21 also increases fatty acid oxidation. This may be relevant in cold exposure, when expression of FGF21 is induced. Chronic treatment with recombinant FGF21 reduces serum and hepatic triglyceride levels and ameliorates fatty liver in obese mice, through the suppression of the lipogenic gene, Srebp-1. FGF21 reduces hepatic cholesterol production by inhibiting Srebp-2, a transactivator of proprotein convertase subtilisin/kexin type 9 (PCSK9). LY2045319, an FGF21 analog, reduces LDL-C and triglycerides and increases HDL-C in obese human subjects with type 2 diabetes. FGF21 does not seem to lower blood pressure acutely. In rats fed with high-fructose water to induce mild hypertension, 4-week treatment with recombinant FGF21 led to normalization of systolic blood pressure and improved serum lipid profile. FGF receptors and β-Klotho are expressed on the nucleus tractus solitarii and nodose ganglion in the baroreflex afferent pathway. Moreover, FGF21 acts on the hypothalamus to release corticosterone and induces in adipocytes the production of adiponectin, an adipokine with antihypertensive activities. Therefore, FGF21 may decrease blood pressure indirectly, through its actions in the liver, brain, and adipose tissues.

Vascular Alterations in a Murine Model of Acute Graft-Versus-Host Disease Are Associated with Decreased Serum Levels of Adiponectin and an Increased Activity and Vascular Expression of Indoleamine 2,3-Dioxygenase

Graft-versus-host disease (GVHD) is the limiting complication after bone marrow transplantation (BMT), and its pathophysiology seems to be highly influenced by vascular factors. Our study aimed at elucidating possible mechanisms involved in vascular GVHD. For this purpose, we used a fully MHC-mismatched model of BALB/c mice conditioned according to two different intensity protocols with total body irradiation and transplantation of allogeneic (C57BL/6) or syngeneic bone marrow cells and splenocytes. Mesenteric resistance arteries were studied in a pressurized myograph. We also quantified the expression of indoleamine 2,3-dioxygenase (IDO), endothelial (eNOS), and inducible NO synthase (iNOS), as well as several pro- and anti-inflammatory cytokines. We measured the serum levels of tryptophan (trp) and kynurenine (kyn), the kyn/trp ratio (KTR) as a marker of IDO activity, and adiponectin (APN). The myographic study showed a correlation of GVHD severity after allogeneic BMT with functional vessel alterations that started with increased vessel stress and ended in eccentric vessel remodeling, increased vessel strain, and endothelial dysfunction. These alterations were accompanied by increasing IDO activity and decreasing APN levels in the serum of allogeneic animals. The mRNA expression showed significantly elevated IDO, decreased eNOS, and elevation of most studied pro- and anti-inflammatory cytokines. Our study provides further data supporting the importance of vessel alterations in GVHD and is the first to show an association of vascular GVHD with hypoadiponectinemia and an increased activity and vascular expression of IDO. Whether there is also a causative involvement of these two factors in the development of GVHD needs to be further investigated.

Relationships between adiponectin levels, the metabolic syndrome, and type 2 diabetes: a literature review

Elevated hepatic glucose production, impaired insulin secretion, and insulin resistance - abnormalities of glucose metabolism typically found in subjects with obesity - are major factors underlying the pathogenesis of type 2 diabetes (DM2) and the metabolic syndrome (MS). Adiponectin is a major regulator of glucose and lipid homeostasis via its insulin-sensitizing properties, and lower levels seems to be associated with the development of DM2 and MS. The purpose of this review is to clarify the mechanisms whereby adiponectin relates to the development of DM2 and MS and the association between polymorphisms of the adiponectin gene, circulating levels of the hormone, and its relationships with DM2. In addition, the impact of dietary lipids in the circulating levels of adiponectin will be addressed. According to the literature, circulating adiponectin levels seem to decrease as the number of MS components increases. Lower adiponectin concentrations are associated with higher intra-abdominal fat content. Therefore, adiponectin could link intra-abdominal fat with insulin resistance and development of MS. Therapeutic strategies that target the MS and its components, such as lifestyle modification through physical activity and weight loss, have been shown to increase adiponectin concentrations. Possible roles of diets containing either low or high amounts of fat, or different types of fat, have been analyzed in several studies, with heterogeneous results. Supplementation with n-3 PUFA modestly increases adiponectin levels, whereas conjugated linoleic acid supplementation appears to reduce concentrations when compared with unsaturated fatty acid supplementation used as an active placebo.

Adipokines at the crossroad between obesity and cardiovascular disease

Obesity, and especially excessive visceral adipose tissue accumulation, is considered as a low-grade inflammatory state that is responsible for adipocyte dysfunction and associated metabolic disorders. Adipose tissue displays endocrine functions by releasing pro- or antiinflammatory bioactive molecules named adipokines. An altered expression of these molecules, provoked by obesity or adipocyte dysregulation, contributes to major metabolic diseases such as insulin resistance and type 2 diabetes mellitus that are important risk factors for cardiovascular disease. However, obesity is also characterised by the expansion of perivascular adipose tissue that acts locally via diffusion of adipokines into the vascular wall. Local inflammation within blood vessels induced by adipokines contributes to the onset of endothelial dysfunction, atherosclerosis and thrombosis, but also to vascular remodelling and hypertension. A fast expansion of obesity is expected in the near future, which will rapidly increase the incidence of these cardiovascular diseases. The focus of this review is to summarise the link between metabolic and cardiovascular disease and discuss current treatment approaches, limitations and future perspectives for more targeted therapies.

Ascending aortic diameter and metabolic syndrome in Korean men

This study aimed to evaluate the association of ascending aortic diameter (AAD) measured by low-dose chest CT (LDCT) and metabolic syndrome (MS) in Korean men. AAD was measured with LDCT in 1046 healthy Korean men (mean age 50.7±9.7 years, range 28 to 69 years) participating in medical health check-up in a university health promotion center. AAD was defined as the longest length measured from the left main coronary ostium to the level of the right pulmonary artery in the axial plane in LDCT. The association between AAD and MS was examined using logistic regression. The mean of AAD was significantly higher in cases with MS (37.2±4.2 mm) compared with those without MS (35.1±4.3 mm) (p<0.001). Logistic regression with AAD showed that ORs and 95% CI of MS in Q2 (1.72, 95% CI 1.23 to 2.53), Q3 (2.59, 95% CI 1.85 to 5.81) and Q4 (4.71, 95% CI 1.63 to 8.79) were significantly higher compared with Q1 (the lowest quartile). In variable (age, body surface area, total cholesterol, alanine aminotransferase, gamma-glutamyl transferase, smoking, alcohol intake and exercise) adjusted multiple linear regression analysis, Q4 (the highest quartile of AAD) was significantly associated with MS compared with Q1 (OR 4.52, 95% CI 1.67 to 9.87). In conclusion, AAD measured by LDCT is significantly associated with the prevalence of MS in Korean men.

Sex differences in the regulation of porcine coronary artery tone by perivascular adipose tissue: a role of adiponectin?

BACKGROUND AND PURPOSE

As there is sexual dimorphism in the regulation of vascular tone, the aim of this present study was to determine whether there are sex differences in perivascular adipose tissue (PVAT)-mediated regulation of the porcine coronary artery (PCA) tone.

EXPERIMENTAL APPROACH

Isometric tension recording system was used to record changes in tone in PCAs. Western blot analysis was performed to examine the expression of adiponectin in PVAT and adiponectin receptors and adiponectin binding protein (APPL1) in PCA. The level of adiponectin released from PVAT was measured using elisa.

KEY RESULTS

In the presence of adherent PVAT, contractions to the thromboxane mimetic U46619 and endothelin-1 were significantly reduced in PCAs from females, but not males. In PCAs pre-contracted with U46619, re-addition of PVAT caused relaxation in PCAs from females, but not males. This relaxant response in females was attenuated by combined inhibition of NOS (with L-NAME) and COX (with indomethacin). Pre-incubation with an anti-adiponectin antibody abolished the relaxant effects of PVAT. The adiponectin receptor agonist (adipoRon) produced a greater relaxation in PCAs from females compared with males. However, there was no difference in either the expression or release of adiponectin from PVAT between sexes. Similarly, there was no difference in the expression of adiponectin receptors or the adiponectin receptor adaptor protein APPL1 in PCAs.

CONCLUSION AND IMPLICATIONS

These findings demonstrate a clear sex difference in the regulation of coronary arterial tone in response to adiponectin receptor stimulation, which may underlie the anticontractile effects of PVAT in females.

Adiponectin improves endothelial function in mesenteric arteries of rats fed a high-fat diet: role of perivascular adipose tissue

BACKGROUND AND PURPOSE

Adiponectin, the most abundant peptide secreted by adipocytes, is involved in the regulation of energy metabolism and vascular physiology. Here, we have investigated the effects of exogenous administration of adiponectin on metabolism, vascular reactivity and perivascular adipose tissue (PVAT) of mesenteric arteries in Wistar rats fed a high-fat diet.

EXPERIMENTAL APPROACH

The effects of adiponectin on NO-dependent and independent vasorelaxation were investigated in isolated mesenteric arteries from 12-month-old male Wistar rats (W12m) fed a high-fat diet (HFD) for 4 months and compared with those from age-matched rats given a control diet. Adiponectin ((96 μg·day^-1 ) was administered by continuous infusion with a minipump, implanted subcutaneously, for 28 days.

KEY RESULTS

Chronic adiponectin treatment reduced body weight, total cholesterol, free fatty acids, fasting glucose and area under the curve of intraperitoneal glucose tolerance test, compared with HFD rats. It also normalized NO-dependent vasorelaxation increasing endothelial NO synthase (eNOS) phosphorylation in mesenteric arteries of HFD rats. In PVAT from aged (W12m) and HFD rats there was increased expression of chemokines and pro-inflammatory adipokines, the latter being important contributors to endothelial dysfunction. Infusion of adiponectin reduced these changes.

CONCLUSIONS AND IMPLICATIONS

Adiponectin normalized endothelial cell function by a mechanism that involved increased eNOS phoshorylation and decreased PVAT inflammation. Detailed characterization of the adiponectin signalling pathway in the vasculature and perivascular fat is likely to provide novel approaches to the management of atherosclerosis and metabolic disease.

LINKED ARTICLES

This article is part of a themed section on Molecular Mechanisms Regulating Perivascular Adipose Tissue - Potential Pharmacological Targets? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.20/issuetoc.

Retinol-binding protein 7 is an endothelium-specific PPAR cofactor mediating an antioxidant response through adiponectin

Impaired PPARγ activity in endothelial cells causes oxidative stress and endothelial dysfunction which causes a predisposition to hypertension, but the identity of key PPARγ target genes that protect the endothelium remain unclear. Retinol-binding protein 7 (RBP7) is a PPARγ target gene that is essentially endothelium specific. Whereas RBP7-deficient mice exhibit normal endothelial function at baseline, they exhibit severe endothelial dysfunction in response to cardiovascular stressors, including high-fat diet and subpressor angiotensin II. Endothelial dysfunction was not due to differences in weight gain, impaired glucose homeostasis, or hepatosteatosis, but occurred through an oxidative stress-dependent mechanism which can be rescued by scavengers of superoxide. RNA sequencing revealed that RBP7 was required to mediate induction of a subset of PPARγ target genes by rosiglitazone in the endothelium including adiponectin. Adiponectin was selectively induced in the endothelium of control mice by high-fat diet and rosiglitazone, whereas RBP7 deficiency abolished this induction. Adiponectin inhibition caused endothelial dysfunction in control vessels, whereas adiponectin treatment of RBP7-deficient vessels improved endothelium-dependent relaxation and reduced oxidative stress. We conclude that RBP7 is required to mediate the protective effects of PPARγ in the endothelium through adiponectin, and RBP7 is an endothelium-specific PPARγ target and regulator of PPARγ activity.

Endothelial dysfunction and vascular disease - a 30th anniversary update

The endothelium can evoke relaxations of the underlying vascular smooth muscle, by releasing vasodilator substances. The best-characterized endothelium-derived relaxing factor (EDRF) is nitric oxide (NO) which activates soluble guanylyl cyclase in the vascular smooth muscle cells, with the production of cyclic guanosine monophosphate (cGMP) initiating relaxation. The endothelial cells also evoke hyperpolarization of the cell membrane of vascular smooth muscle (endothelium-dependent hyperpolarizations, EDH-mediated responses). As regards the latter, hydrogen peroxide (H₂ O₂ ) now appears to play a dominant role. Endothelium-dependent relaxations involve both pertussis toxin-sensitive G_i (e.g. responses to α₂ -adrenergic agonists, serotonin, and thrombin) and pertussis toxin-insensitive G_q (e.g. adenosine diphosphate and bradykinin) coupling proteins. New stimulators (e.g. insulin, adiponectin) of the release of EDRFs have emerged. In recent years, evidence has also accumulated, confirming that the release of NO by the endothelial cell can chronically be upregulated (e.g. by oestrogens, exercise and dietary factors) and downregulated (e.g. oxidative stress, smoking, pollution and oxidized low-density lipoproteins) and that it is reduced with ageing and in the course of vascular disease (e.g. diabetes and hypertension). Arteries covered with regenerated endothelium (e.g. following angioplasty) selectively lose the pertussis toxin-sensitive pathway for NO release which favours vasospasm, thrombosis, penetration of macrophages, cellular growth and the inflammatory reaction leading to atherosclerosis. In addition to the release of NO (and EDH, in particular those due to H₂ O₂ ), endothelial cells also can evoke contraction of the underlying vascular smooth muscle cells by releasing endothelium-derived contracting factors. Recent evidence confirms that most endothelium-dependent acute increases in contractile force are due to the formation of vasoconstrictor prostanoids (endoperoxides and prostacyclin) which activate TP receptors of the vascular smooth muscle cells and that prostacyclin plays a key role in such responses. Endothelium-dependent contractions are exacerbated when the production of nitric oxide is impaired (e.g. by oxidative stress, ageing, spontaneous hypertension and diabetes). They contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive and diabetic patients. In addition, recent data confirm that the release of endothelin-1 can contribute to endothelial dysfunction and that the peptide appears to be an important contributor to vascular dysfunction. Finally, it has become clear that nitric oxide itself, under certain conditions (e.g. hypoxia), can cause biased activation of soluble guanylyl cyclase leading to the production of cyclic inosine monophosphate (cIMP) rather than cGMP and hence causes contraction rather than relaxation of the underlying vascular smooth muscle.

Prognostic value of adiponectin in coronary artery disease: Role of diabetes and left ventricular systolic dysfunction

OBJECTIVES

Adiponectin (AD) promotes insulin sensitivity and has anti-atherogenic properties. However, the role of AD on clinical outcomes in coronary artery disease (CAD) is controversial. We analyzed whether AD was an independent predictor of all-cause mortality and hospitalization in patients with CAD.

METHOD

We prospectively enrolled 138 patients with stable CAD, with or without type 2 diabetes and with or without left ventricular dysfunction. A telephone follow-up was conducted to register long term outcomes. Sensitivity/specificity ratio for AD was investigated with ROC analysis and the independent role of AD on outcome was evaluated with Cox regression model of analysis. The survival rate was represented by Kaplan Meyer curves.

RESULTS

Of 138 patients, 61 had type 2 diabetes and 71 left ventricular systolic dysfunction (EF<40%). Median time of follow-up was 1384days; mortality rate was 18.8% (26 deaths) and hospitalization rate was 47.1% (65 events). Mean concentration of AD was 9.87±7.53ng/ml; the analysis of the ROC curve identified an AD cut-off level of 13.2ng/ml (AUC 0.779; p<0.0001). Patients with AD >13.2ng/ml had a significantly higher risk of death (HR=6.50; 95% CI: 2.40-17.70), but not of cardiovascular hospitalization (HR=0.87; 95% CI: 0.31-2.44). AD predictivity remained significant also in patients with type 2 diabetes and with left ventricular systolic dysfunction.

CONCLUSION

In stable CAD, an AD value of >13.2ng/ml independently predicts a 6-fold increased risk of all-cause mortality.

The effects of telmisartan and amlodipine on metabolic parameters and blood pressure in type 2 diabetic, hypertensive patients

Introduction. Hypertension in type 2 diabetes represents a strong risk factor for cardiovascular events. Either calcium channel blockers or angiotensin receptor blockers (ARBs) may reduce insulin resistance. One of the ARBs, telmisartan (Telm) acting as a PPARγ agonist, significantly reduces HbA1C levels.The aim of this study was the comparison of the effects on glycaemic control of amlodipine (Aml) and Telm in hypertensive type 2 diabetic patients.

Materials and methods. Forty diabetic hypertensive subjects were assigned to two groups. Group A: rosiglitazone (RSG) 4 mg + Telm 80 mg; Group B: RSG 4 mg + Aml 10 mg. All the patients were already treated with metformin, but not with antihypertensive drugs.

Results. After four months treatment, both groups showed a significant reduction of mean blood pressure (Group A: - 13.5%; Group B: - 13.3%) and a positive influence on glycaemic control and insulin resistance. Lower values of glucose, HbA1C, HOMA index and higher adiponectin levels were observed in Group A compared to Group B.

Conclusions. In type 2 diabetic hypertensive patients, the association of Telm 80 mg and RSG 4 mg seems to display a metabolic advantage compared to Aml 10 mg.The simultaneous beneficial effects on blood pressure and insulin sensitivity may confer make Telm particularly suitable in the treatment of the metabolic syndrome.

The effects of paternal high-fat diet exposure on offspring metabolism with epigenetic changes in the mouse adiponectin and leptin gene promoters

Recent studies have demonstrated that epigenetic changes resulting from malnutrition might play important roles in transgenerational links with metabolic diseases. Previously, we observed that exposure to a high-fat diet (HFD) in utero caused a metabolic syndrome-like phenomenon through epigenetic modifications of the adiponectin and leptin genes that persisted for multiple generations. Recent etiological studies indicated that paternal BMI had effects on offspring BMI that were independent of but additive to maternal BMI effects. Thus, we examined whether paternal HFD-induced obesity affected the metabolic status of offspring through epigenetic changes in the adiponectin and leptin genes. Additionally, we investigated whether a normal diet during subsequent generations abolished the epigenetic changes associated with paternal HFD exposure before conception. We observed the effects of paternal HFD exposure before conception over multiple generations on offspring metabolic traits, including weight and fat gain, glucose intolerance, hypertriglyceridemia, abnormal adipocytokine levels, hypertension, and adiponectin and leptin gene expression and epigenetic changes. Normal diet consumption by male offspring during the subsequent generation following paternal HFD exposure diminished whereas consumption for two generations completely abolished the effect of paternal HFD exposure on metabolic traits and adipocytokine promoter epigenetic changes in the offspring. The effects of paternal HFD exposure on offspring were relatively weaker than those following HFD exposure in utero. However, paternal HFD exposure had an additive metabolic effect for two generations, suggesting that both paternal and maternal nutrition might affect offspring metabolism through epigenetic modifications of adipocytokine genes for multiple generations.

An update on the role of adipokines in arterial stiffness and hypertension

Adipokines are hormones produced by adipocytes and have been involved in multiple pathologic pathways, including inflammatory and cardiovascular complications in essential hypertension. Arterial stiffness is a frequent vascular complication that represents increased cardiovascular risk in hypertensive patients. Adipokines, such as adiponectin, leptin and resistin, might be implicated in hypertension, as well as in vascular alterations associated with this condition. Arterial stiffness has proven to be a predictor of cardiovascular events. Obesity and target-organ damage such as arterial stiffness are features associated with hypertension. This review aims to update the association between adipokines and arterial stiffness in essential and resistant hypertension (RHTN).

Serum Adiponectin Level as a Predictor of Subclinical Cushing's Syndrome in Patients with Adrenal Incidentaloma

Subclinical Cushing's syndrome (SCS) is a condition of slight but chronic cortisol excess in patients with adrenal incidentaloma (AI) without typical signs and symptoms of Cushing's syndrome. Adiponectin has potent roles in modulating energy balance and metabolic homeostasis and acts in opposition to glucocorticoids. This study aimed to evaluate adiponectin level in SCS and nonfunctional AI (NAI) patients and its relation with metabolic parameters. Patients with AI (n = 40) and metabolically healthy controls (n = 30) were included. In AI patients and controls, detailed medical history assessment, physical examinations, anthropometric measurements, and laboratory measurements were performed. Age, body mass index, waist circumference, and lipid profiles were significantly higher and waist-to-hip ratio and adiponectin level were significantly lower in the AI patients than in the controls. The midnight cortisol and urinary free cortisol levels were significantly higher in the SCS patients (n = 8) than in the NAI patients (n = 32). Adiponectin level of the SCS group was significantly lower than those of the NAI and control groups. The sensitivity and specificity for an adiponectin level of ≤13.00 ng/mL in predicting the presence of SCS were 87.5% and 77.4%, respectively. In conclusion, adiponectin is valuable in predicting the presence of SCS in AI patients.

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.

Effects of Olive Oil on Markers of Inflammation and Endothelial Function-A Systematic Review and Meta-Analysis

The aim of the present systematic review was to synthesize data from randomized controlled trials investigating the effects of olive oil on markers of inflammation or endothelial function. Literature search in electronic databases Cochrane Trial Register, EMBASE, and MEDLINE was performed. Thirty studies enrolling 3106 participants fulfilled the selection criteria. Pooled effects of different interventions were assessed as mean difference using a random effects model. Olive oil interventions (with daily consumption ranging approximately between 1 mg and 50 mg) resulted in a significantly more pronounced decrease in C-reactive protein (mean difference: −0.64 mg/L, (95% confidence interval (CI) −0.96 to −0.31), p < 0.0001, n = 15 trials) and interleukin-6 (mean difference: −0.29 (95% CI −0.7 to −0.02), p < 0.04, n = 7 trials) as compared to controls, respectively. Values of flow-mediated dilatation (given as absolute percentage) were significantly more increased in individuals subjected to olive oil interventions (mean difference: 0.76% (95% CI 0.27 to 1.24), p < 0.002, n = 8 trials). These results provide evidence that olive oil might exert beneficial effects on endothelial function as well as markers of inflammation and endothelial function, thus representing a key ingredient contributing to the cardiovascular-protective effects of a Mediterranean diet. However, due to the heterogeneous study designs (e.g., olive oil given as a supplement or as part of dietary pattern, variations in control diets), a conservative interpretation of the results is necessary.

AdipoRon, the first orally active adiponectin receptor activator, attenuates postischemic myocardial apoptosis through both AMPK-mediated and AMPK-independent signalings

Adiponectin (APN) is a cardioprotective molecule. Its reduction in diabetes exacerbates myocardial ischemia/reperfusion (MI/R) injury. Although APN administration in animals attenuates MI/R injury, multiple factors limit its clinical application. The current study investigated whether AdipoRon, the first orally active molecule that binds APN receptors, may protect the heart against MI/R injury, and if so, to delineate the involved mechanisms. Wild-type (WT), APN knockout (APN-KO), and cardiomyocyte specific-AMPK dominant negative (AMPK-DN) mice were treated with vehicle or AdipoRon (50 mg/kg, 10 min prior to MI) and subjected to MI/R (30 min/3-24 h). Compared with vehicle, oral administration of AdipoRon to WT mice significantly improved cardiac function and attenuated postischemic cardiomyocyte apoptosis, determined by DNA ladder formation, TUNEL staining, and caspase-3 activation (all P < 0.01). MI/R-induced apoptotic cell death was significantly enhanced in mice deficient in either APN (APN-KO) or AMPK (AMPK-DN). In APN-KO mice, AdipoRon attenuated MI/R injury to the same degree as observed in WT mice. In AMPK-DN mice, AdipoRon's antiapoptotic action was partially inhibited but not lost. Finally, AdipoRon significantly attenuated postischemic oxidative stress, as evidenced by reduced NADPH oxidase expression and superoxide production. Collectively, these results demonstrate for the first time that AdipoRon, an orally active APN receptor activator, effectively attenuated postischemic cardiac injury, supporting APN receptor agonists as a promising novel therapeutic approach treating cardiovascular complications caused by obesity-related disorders such as type 2 diabetes.

The Effects of High-Fat Diet Exposure In Utero on the Obesogenic and Diabetogenic Traits Through Epigenetic Changes in Adiponectin and Leptin Gene Expression for Multiple Generations in Female Mice

Recent studies demonstrate that epigenetic changes under malnutrition in utero might play important roles in transgenerational links with metabolic diseases. We have previously shown that exposure to a high-fat diet (HFD) in utero may cause a metabolic syndrome-like phenomenon through epigenetic modifications of Adiponectin and Leptin genes. Because an association of obesity between mother and offspring endured in multiple generations, we examined whether HFD exposure in utero might affect the metabolic status of female offspring through multigenerational epigenetic changes of Adiponectin and Leptin genes and whether a normal diet in utero for multiple generations might abolish such epigenetic changes after exposure to a HFD in utero using ICR mice. We observed that the effect of maternal HFD on offspring over multiple generations in metabolic syndrome-like phenomenon such as weight and fat mass gain, glucose intolerance, hypertriglyceridemia, abnormal adiponectin and leptin levels, and hypertension, were accumulated with expression and epigenetic changes in Adiponectin and Leptin genes. A normal diet in utero in the subsequent generations after HFD exposure in utero diminished, and a normal diet in utero for 3 generations completely abolished, the effect of HFD in utero on weight and fat mass gain, insulin resistance, serum triglyceride, adiponectin, and leptin levels, with epigenetic changes of Adiponectin and Leptin genes. Exposure to a HFD in utero might affect glucose and lipid metabolism of female offspring through epigenetic modifications to Adiponectin and Leptin genes for multiple generations. Obesogenic and diabetogenic traits were abolished after a maternal normal diet for 3 generations.