The vascular endothelin system in obesity and type 2 diabetes: Pathophysiology and therapeutic implications

Maternal Obesity Modulates Cord Blood Concentrations of Proprotein Convertase Subtilisin/Kexin-type 9 Levels

Context

In utero exposure to maternal obesity or diabetes is considered a pro-inflammatory state.

Objective

To evaluate whether cord blood proprotein convertase subtilisin/kexin-type 9 (PCSK9), which is regulated by inflammation and metabolic derangements, is elevated in neonates born to overweight, obese, or diabetic mothers.

Methods

A retrospective study in full-term neonates born between 2010 and 2023, at Brigham and Women's Hospital. There were 116 neonates included in our study, of which 74 (64%) were born to overweight/obese mothers and 42 (36%) were born to nonoverweight/nonobese mothers.

Results

Neonates born to overweight/obese mothers had significantly higher cord blood concentrations of PCSK9 compared with neonates born to nonoverweight/nonobese group (323 [253-442] ng/mL compared with 270 [244-382] ng/mL, P = .041). We found no significant difference in cord blood concentrations of PCSK9 between neonates of diabetic mothers compared with neonates of nondiabetic mothers. In multivariate linear regression analysis, higher cord plasma PCSK9 concentration was significantly associated with maternal overweight/obesity status (b = 50.12; 95% CI, 4.02-96.22; P = .033), after adjusting for gestational age, birth weight, male sex, and intrauterine growth restriction.

Conclusion

Neonates born to mothers with overweight/obesity have higher cord blood PCSK9 concentrations compared with the nonoverweight/nonobese group, and higher cord blood PCSK9 concentrations were significantly associated with maternal overweight/obesity status, after adjusting for perinatal factors. Larger longitudinal studies are needed to examine the role of PCSK9 in the development of metabolic syndrome in high-risk neonates born to overweight, obese, or diabetic mothers.

Chronic remote ischemic conditioning treatment in patients with chronic stable angina (EARLY-MYO-CSA): a randomized, controlled proof-of-concept trial

BACKGROUND

Chronic remote ischemic conditioning (CRIC) has been shown to improve myocardial ischemia in experimental animal studies; however, its effectiveness in patients with chronic stable angina (CSA) has not been investigated. We conducted a proof-of-concept study to investigate the efficacy and safety of a six-month CRIC treatment in patients with CSA.

METHODS

The EARLY-MYO-CSA trial was a prospective, randomized, controlled trial evaluating the CRIC treatment in patients with CSA with persistent angina pectoris despite receiving ≥ 3-month guideline-recommended optimal medical therapy. The CRIC and control groups received CRIC (at 200 mmHg) or sham CRIC (at 60 mmHg) intervention for 6 months, respectively. The primary endpoint was the 6-month change of myocardial flow reserve (MFR) on single-photon emission computed tomography. The secondary endpoints were changes in rest and stress myocardial blood flow (MBF), angina severity according to the Canadian Cardiovascular Society (CCS) classification, the Seattle Angina Questionnaire (SAQ), and a 6-min walk test (6-MWT).

RESULTS

Among 220 randomized CSA patients, 208 (105 in the CRIC group, and 103 in the control group) completed the treatment and endpoint assessments. The mean change in MFR was significantly greater in the CRIC group than in the control group (0.27 ± 0.38 vs. - 0.04 ± 0.25; P < 0.001). MFR increased from 1.33 ± 0.48 at baseline to 1.61 ± 0.53 (P < 0.001) in the CRIC group; however, a similar increase was not seen in the control group (1.35 ± 0.45 at baseline and 1.31 ± 0.44 at follow-up, P = 0.757). CRIC treatment, when compared with controls, demonstrated improvements in angina symptoms assessed by CCS classification (60.0% vs. 14.6%, P < 0.001), all SAQ dimensions scores (P < 0.001), and 6-MWT distances (440 [400-523] vs. 420 [330-475] m, P = 0.016). The incidence of major adverse cardiovascular events was similar between the groups.

CONCLUSIONS

CSA patients benefit from 6-month CRIC treatment with improvements in MFR, angina symptoms, and exercise performance. This treatment is well-tolerated and can be recommended for symptom relief in this clinical population.

TRIAL REGISTRATION

[chictr.org.cn], identifier [ChiCTR2000038649].

Increased endothelin-1 levels in coronary artery disease with diabetes mellitus in an Indonesian population

Diabetes mellitus (DM) increases risk of coronary artery disease (CAD). Endothelin-1 (ET-1) is a potential biomarker of endothelial dysfunction. This study aimed to evaluate ET-1 level in CAD patients and its relationship with DM. The cross-sectional design included subjects with angiographically proven CAD and controls among Indonesian. DM was defined by medical history and anti-diabetics use. Serum ET-1 level was measured in both subject groups. We recruited 305 subjects, 183 CAD patients and 122 controls. CAD subjects had higher percentage of males, DM, hypertension, dyslipidemia, smoking, family history of cardiovascular disease, and obesity. ET-1 level was significantly higher in CAD than in controls (2.44 ± 1.49 pg/mL vs. 1.76 ± 0.83 pg/mL; p < 0.001). Increased ET-1 level was significantly associated with DM and dyslipidemia. The highest ET-1 level was observed in CAD with DM, followed by CAD non-DM (2.79 ± 1.63 pg/mL vs. 2.29 ± 1.40 pg/mL; p = 0.023). Among controls, ET-1 level was the lowest in non-DM subjects. Female CAD had higher proportion of DM; however, ET-1 level was similar to male CAD with DM. In conclusion, an increased ET-1 level was significantly associated with DM in patients with CAD. Further research should investigate the potential role of ET-1 receptor antagonists in the secondary prevention of CAD with DM.

Single-cell transcriptomic profiling unveils dysregulation of cardiac progenitor cells and cardiomyocytes in a mouse model of maternal hyperglycemia

Congenital heart disease (CHD) is the most prevalent birth defect, often linked to genetic variations, environmental exposures, or combination of both. Epidemiological studies reveal that maternal pregestational diabetes is associated with ~5-fold higher risk of CHD in the offspring; however, the causal mechanisms affecting cardiac gene-regulatory-network (GRN) during early embryonic development remain poorly understood. In this study, we utilize an established murine model of pregestational diabetes to uncover the transcriptional responses in key cell-types of the developing heart exposed to maternal hyperglycemia (matHG). Here we show that matHG elicits diverse cellular responses in E9.5 and E11.5 embryonic hearts compared to non-diabetic hearts by single-cell RNA-sequencing. Through differential-gene-expression and cellular trajectory analyses, we identify perturbations in genes, predominantly affecting Isl1⁺ second heart field progenitors and Tnnt2⁺ cardiomyocytes with matHG. Using cell-fate mapping analysis in Isl1-lineage descendants, we demonstrate that matHG impairs cardiomyocyte differentiation and alters the expression of lineage-specifying cardiac genes. Finally, our work reveals matHG-mediated transcriptional changes in second heart field lineage that elevate CHD risk by perturbing Isl1-GRN during cardiomyocyte differentiation. Gene-environment interaction studies targeting the Isl1-GRN in cardiac progenitor cells will have a broader impact on understanding the mechanisms of matHG-induced risk of CHD associated with diabetic pregnancies.

ScRNA-seq of embryonic heart tissues from a mouse model of maternal hyperglycemia (matHG) provides further insight into how matHG disrupts heart development and perturbs second heart field derived cardiomyocyte differentiation.

Endothelin and the Cardiovascular System: The Long Journey and Where We Are Going

Simple Summary

In this review, we describe the basic functions of endothelin and related molecules, including their receptors and enzymes. Furthermore, we discuss the important role of endothelin in several cardiovascular diseases, the relevant clinical evidence for targeting the endothelin pathway, and the scope of endothelin-targeting treatments in the future. We highlight the present uses of endothelin receptor antagonists and the advancements in the development of future treatment options, thereby providing an overview of endothelin research over the years and its future scope.

Abstract

Endothelin was first discovered more than 30 years ago as a potent vasoconstrictor. In subsequent years, three isoforms, two canonical receptors, and two converting enzymes were identified, and their basic functions were elucidated by numerous preclinical and clinical studies. Over the years, the endothelin system has been found to be critical in the pathogenesis of several cardiovascular diseases, including hypertension, pulmonary arterial hypertension, heart failure, and coronary artery disease. In this review, we summarize the current knowledge on endothelin and its role in cardiovascular diseases. Furthermore, we discuss how endothelin-targeting therapies, such as endothelin receptor antagonists, have been employed to treat cardiovascular diseases with varying degrees of success. Lastly, we provide a glimpse of what could be in store for endothelin-targeting treatment options for cardiovascular diseases in the future.

The Epidemiology and Mechanisms of Lifetime Cardiopulmonary Morbidities Associated With Pre-Pregnancy Obesity and Excessive Gestational Weight Gain

Obesity has reached pandemic proportions in the last few decades. The global increase in obesity has contributed to an increase in the number of pregnant women with pre-pregnancy obesity or with excessive gestational weight gain. Obesity during pregnancy is associated with higher incidence of maternal co-morbidities such as gestational diabetes and hypertension. Both obesity during pregnancy and its associated complications are not only associated with immediate adverse outcomes for the mother and their newborns during the perinatal period but, more importantly, are linked with long-term morbidities in the offsprings. Neonates born to women with obesity are at higher risk for cardiac complications including cardiac malformations, and non-structural cardiac issues such as changes in the microvasculature, e.g., elevated systolic blood pressure, and overt systemic hypertension. Pulmonary diseases associated with maternal obesity include respiratory distress syndrome, asthma during childhood and adolescence, and adulthood diseases, such as chronic obstructive pulmonary disease. Sequelae of short-term complications compound long-term outcomes such as long-term obesity, hypertension later in life, and metabolic complications including insulin resistance and dyslipidemia. Multiple mechanisms have been proposed to explain these adverse outcomes and are related to the emerging knowledge of pathophysiology of obesity in adults. The best investigated ones include the role of obesity-mediated metabolic alterations and systemic inflammation. There is emerging evidence linking metabolic and immune derangements to altered biome, and alteration in epigenetics as one of the intermediary mechanisms underlying the adverse outcomes. These are initiated as part of fetal adaptation to obesity during pregnancy which are compounded by rapid weight gain during infancy and early childhood, a known complication of obesity during pregnancy. This newer evidence points toward the role of specific nutrients and changes in biome that may potentially modify the adverse outcomes observed in the offsprings of women with obesity.

Bioactive Foods and Medicinal Plants for Cardiovascular Complications of Type II Diabetes: Current Clinical Evidence and Future Perspectives

Cardiovascular diseases (CVDs) are the main cause of mortality in type 2 diabetes mellitus (T2DM); however, not all patients are fully satisfied with the current available treatments. Medicinal plants have been globally investigated regarding their effect in CVD, yet the field is far from getting exhausted. The current paper aims to provide an evidence-based review on the clinically evaluated medicinal plants and their main therapeutic targets for the management of CVD in T2DM. Electronic databases including PubMed, Cochrane, Embase, Scopus, and Web of Science were searched from 2000 until November 2019, and related clinical studies were included. Lipid metabolism, glycemic status, systemic inflammation, blood pressure, endothelial function, oxidative stress, and anthropometric parameters are the key points regulated by medicinal plants in T2DM. Anti-inflammatory and antioxidant properties are the two most important mechanisms since inflammation and oxidative stress are the first steps triggering a domino of molecular pathological pathways leading to T2DM and, subsequently, CVD. Polyphenols with potent antioxidant and anti-inflammatory effects, essential oil-derived compounds with vasorelaxant properties, and fibers with demonstrated effects on obesity are the main categories of phytochemicals beneficial for CVD of T2DM. Some medicinal plants such as garlic (Allium sativum) and milk thistle (Silybum marianum) have strong evidences regarding their beneficial effects; however, others have low level of evidence which reveals the need for further clinical studies with larger sample sizes and longer follow-up periods to confirm the safety and efficacy of medicinal plants for the management of CVD in T2DM.

Hyperphosphatemia-Induced Oxidant/Antioxidant Imbalance Impairs Vascular Relaxation and Induces Inflammation and Fibrosis in Old Mice

Aging impairs vascular function, but the mechanisms involved are unknown. The aim of this study was to analyze whether aging-related hyperphosphatemia is implied in this effect by elucidating the role of oxidative stress. C57BL6 mice that were aged 5 months (young) and 24 months (old), receiving a standard (0.6%) or low-phosphate (0.2%) diet, were used. Isolated mesenteric arteries from old mice showed diminished endothelium-dependent vascular relaxation by the down-regulation of NOS3 expression, increased inflammation and increased fibrosis in isolated aortas, compared to those isolated from young mice. In parallel, increased Nox4 expression and reduced Nrf2, Sod2-Mn and Gpx1 were found in the aortas from old mice, resulting in oxidant/antioxidant imbalance. The low-phosphate diet improved vascular function and oxidant/antioxidant balance in old mice. Mechanisms were analyzed in endothelial (EC) and vascular smooth muscle cells (SMCs) treated with the phosphate donor ß-glycerophosphate (BGP). In EC, BGP increased Nox4 expression and ROS production, which reduced NOS3 expression via NFκB. BGP also increased inflammation in EC. In SMC, BGP increased Collagen I and fibronectin expression by priming ROS production and NFκB activity. In conclusion, hyperphosphatemia reduced endothelium-dependent vascular relaxation and increased inflammation and vascular fibrosis through an impairment of oxidant/antioxidant balance in old mice. A low-phosphate diet achieved improvements in the vascular function in old mice.

Gut Dysbiosis and Western Diet in the Pathogenesis of Essential Arterial Hypertension: A Narrative Review

Metabolic syndrome is a cluster of the most dangerous cardiovascular (CV) risk factors including visceral obesity, insulin resistance, hyperglycemia, alterations in lipid metabolism and arterial hypertension (AH). In particular, AH plays a key role in the complications associated with metabolic syndrome. High salt intake is a well-known risk factor for AH and CV diseases. Vasoconstriction, impaired vasodilation, extracellular volume expansion, inflammation, and an increased sympathetic nervous system (SNS) activity are the mechanisms involved in the pathogenesis of AH, induced by Western diet. Gut dysbiosis in AH is associated with reduction of short chain fatty acid-producing bacteria: acetate, butyrate and propionate, which activate different pathways, causing vasoconstriction, impaired vasodilation, salt and water retention and a consequent high blood pressure. Moreover, increased trimethylamine N-oxide and lipopolysaccharides trigger chronic inflammation, which contributes to endothelial dysfunction and target organs damage. Additionally, a high salt-intake diet impacts negatively on gut microbiota composition. A bidirectional neuronal pathway determines the “brain–gut” axis, which, in turn, influences blood pressure levels. Then, we discuss the possible adjuvant novel treatments related to gut microbiota modulation for AH control.

Ketogenic Diet as a Preventive and Supportive Care for COVID-19 Patients

Severe obesity is associated with an increased risk of admission to intensive care units and need for invasive mechanical ventilation in patients with COVID-19. The association of obesity and COVID-19 prognosis may be related to many different factors, such as chronic systemic inflammation, the predisposition to severe respiratory conditions and viral infections. The ketogenic diet is an approach that can be extremely effective in reducing body weight and visceral fat in the short term, preserving the lean mass and reducing systemic inflammation. Therefore, it is a precious preventive measure for severely obese people and may be considered as an adjuvant therapy for patients with respiratory compromise.

Vegan Diet Health Benefits in Metabolic Syndrome

Plant-based diets (PBDs) are increasingly consumed by the Italian population and around the world. In particular, among PBDs, the vegan diet is a food pattern characterized by the exclusion of all animal-origin foods. What drives people to adopt this model are mainly ethical, health and environmental reasons. A vegan diet, if well-balanced and varied, can help in achieving and maintaining an optimal state of health. However, this nutritional approach, if not well-balanced, can cause deficiencies in proteins, ω-3 fatty acids, iron, vitamin D and calcium, zinc, iodine and, above all, vitamin B12. Oral food supplements especially fortified foods are recommended in these cases to restore the nutritional deficiencies. A vegan diet generally reduces the risk of developing chronic non-communicable degenerative diseases, such as metabolic syndrome (MetS) and, in addition, requires fewer natural resources for food production than an omnivorous diet. The aim of this review is to analyze the possible impact of the vegan diet on MetS onset and its treatment.

Association of Gut Hormones and Microbiota with Vascular Dysfunction in Obesity

In the past few decades, obesity has reached pandemic proportions. Obesity is among the main risk factors for cardiovascular diseases, since chronic fat accumulation leads to dysfunction in vascular endothelium and to a precocious arterial stiffness. So far, not all the mechanisms linking adipose tissue and vascular reactivity have been explained. Recently, novel findings reported interesting pathological link between endothelial dysfunction with gut hormones and gut microbiota and energy homeostasis. These findings suggest an active role of gut secretome in regulating the mediators of vascular function, such as nitric oxide (NO) and endothelin-1 (ET-1) that need to be further investigated. Moreover, a central role of brain has been suggested as a main player in the regulation of the different factors and hormones beyond these complex mechanisms. The aim of the present review is to discuss the state of the art in this field, by focusing on the processes leading to endothelial dysfunction mediated by obesity and metabolic diseases, such as insulin resistance. The role of perivascular adipose tissue (PVAT), gut hormones, gut microbiota dysbiosis, and the CNS function in controlling satiety have been considered. Further understanding the crosstalk between these complex mechanisms will allow us to better design novel strategies for the prevention of obesity and its complications.

Preoperative Immunonutrition vs. Standard Dietary Advice in Normo-Nourished Patients Undergoing Fast-Track Laparoscopic Colorectal Surgery

Immunonutrition (IN) appears to reduce infective complications and in-hospital length of stay (LOS) after major gastrointestinal surgery, but its use in normo-nourished patients is still controversial. The primary aim of this comparative observational study was to evaluate if pre-operative IN reduces in-hospital stay in patients undergoing laparoscopic colorectal resection for cancer under an enhanced recovery after surgery (ERAS) program. The influence of IN on time to first bowel movements, time to full oral diet tolerance, number and type of complications, reasons of prolonged LOS and readmission rate was evaluated as secondary outcome. Patients undergoing ERAS laparoscopic colorectal resection between December 2016 and December 2019 were reviewed. Patients who have received preoperative IN (group A) were compared to those receiving standard dietary advice (group B). Mean in-hospital LOS was significantly shorter in patients receiving preoperative IN than standard dietary advice (4.85 ± 2.25 days vs. 6.06 ± 3.95 days; p < 0.0492). No differences in secondary outcomes were observed. Preoperative IN associated with ERAS protocol in normo-nourished patients undergoing laparoscopic colorectal cancer resection seems to reduce LOS.

Effects of Caloric Restriction Diet on Arterial Hypertension and Endothelial Dysfunction

The most common manifestation of cardiovascular (CV) diseases is the presence of arterial hypertension (AH), which impacts on endothelial dysfunction. CV risk is associated with high values of systolic and diastolic blood pressure and depends on the presence of risk factors, both modifiable and not modifiable, such as overweight, obesity, physical exercise, smoking, age, family history, and gender. The main target organs affected by AH are the heart, brain, vessels, kidneys, and eye retina. AH onset can be counteracted or delayed by adopting a proper diet, characterized by a low saturated fat and sodium intake, a high fruit and vegetable intake, a moderate alcohol consumption, and achieving and maintaining over time the ideal body weight. In this review, we analyzed how a new nutritional approach, named caloric restriction diet (CRD), can provide a significant reduction in blood pressure values and an improvement of the endothelial dysfunction. In fact, CRD is able to counteract aging and delay the onset of CV and neurodegenerative diseases through the reduction of body fat mass, systolic and diastolic values, free radicals production, and oxidative stress. Currently, there are few studies on CRD effects in the long term, and it would be advisable to perform observational studies with longer follow-up.

Potential Beneficial Effects of Extra Virgin Olive Oils Characterized by High Content in Minor Polar Compounds in Nephropathic Patients: A Pilot Study

Extra virgin olive oil (EVOO) is a lipid food, which constitutes a pillar of the Mediterranean diet. A high number of scientific data have demonstrated that it exerts a variety of beneficial effects on human health due to its peculiar chemical composition including fatty acids (98–99%) and other active compounds even if found in a very low percentage (1–2%). Among them, minor polar compounds (MCPs), represented mainly by phenolic compounds, are relevant for their healthy properties, as stated by the European Food Safety Authority’s (EFSA) claims. In this paper, we described the results obtained from a pilot in vivo study, focused for the first time on the evaluation of the possible beneficial effects of two EVOOs on chronic kidney disease (CKD) patients after the consumption of 40 mL per day for 9 weeks. The selected EVOOs, traced in the production chain, and characterized by High-Performance Liquid Chromatography (HPLC-DAD-MS) analysis, resulted rich in MCPs and satisfied the EFSA’s claim for their content of hydroxytyrosol and derivatives. The results obtained by this in vivo study appear to highlight the potential beneficial role in CKD patients of these EVOOs and are promising for future studies.

Endothelin XVI

Although 31 years have passed since the discovery of endothelin, that pioneering report, and the subsequent flood of influential studies elucidating its molecular and clinical details, have since paved the way for thousands of publications. They showed the promise of endothelin and the vast amount of work that remains to be done to fully unleash the potential this peptide possesses, both as a key physiological regulator and as a therapeutic target. Endothelin conferences and their proceedings have served as a host for many of these breakthrough studies, and in keeping with this fine tradition, Endothelin XVI will host novel research articles presented at the Sixteenth International Conference on Endothelin (ET-16) as its proceedings. On September 22-25, 2019, ET-16 was held at Kobe Port Oasis, Kobe, Japan, where numerous important discoveries were presented to the scientific community for the first time, many of which are compiled and published in this special issue. As the Editors of this special issue that comprises in-depth reviews, insightful editorials, and numerous original research articles discussing findings from various biomedical fields, we are extremely proud to present Endothelin XVI. We sincerely hope for the continued growth of this field for the benefit of the patients and the advancement of biomedical science.

Maternal Obesity and Diabetes Mellitus as Risk Factors for Congenital Heart Disease in the Offspring

Congenital heart disease (CHD) is the most common anatomical malformation occurring live‐born infants and an increasing cause of morbidity and mortality across the lifespan and throughout the world. Population‐based observations have long described associations between maternal cardiometabolic disorders and the risk of CHD in the offspring. Here we review the epidemiological evidence and clinical observations relating maternal obesity and diabetes mellitus to the risk of CHD offspring with particular attention to mechanistic models of maternal‐fetal risk transmission and first trimester disturbances of fetal cardiac development. A deeper understanding of maternal risk factors holds the potential to improve both prenatal detection of CHD by identifying at‐risk pregnancies, along with primary prevention of disease by improving preconception and prenatal treatment of at‐risk mothers.

Overproduction of endothelin-1 impairs glucose tolerance but does not promote visceral adipose tissue inflammation or limit metabolic adaptations to exercise

Endothelin-1 (ET-1) is a potent vasoconstrictor and proinflammatory peptide that is upregulated in obesity. Herein, we tested the hypothesis that ET-1 signaling promotes visceral adipose tissue (AT) inflammation and disrupts glucose homeostasis. We also tested if reduced ET-1 is a required mechanism by which exercise ameliorates AT inflammation and improves glycemic control in obesity. We found that 1) diet-induced obesity, AT inflammation, and glycemic dysregulation were not accompanied by significantly increased levels of ET-1 in AT or circulation in wild-type mice and that endothelial overexpression of ET-1 and consequently increased ET-1 levels did not cause AT inflammation yet impaired glucose tolerance; 2) reduced AT inflammation and improved glucose tolerance with voluntary wheel running was not associated with decreased levels of ET-1 in AT or circulation in obese mice nor did endothelial overexpression of ET-1 impede such exercise-induced metabolic adaptations; 3) chronic pharmacological blockade of ET-1 receptors did not suppress AT inflammation in obese mice but improved glucose tolerance; and 4) in a cohort of human subjects with a wide range of body mass indexes, ET-1 levels in AT, or circulation were not correlated with markers of inflammation in AT. In aggregate, we conclude that ET-1 signaling is not implicated in the development of visceral AT inflammation but promotes glucose intolerance, thus representing an important therapeutic target for glycemic dysregulation in conditions characterized by hyperendothelinemia. Furthermore, we show that the salutary effects of exercise on AT and systemic metabolic function are not contingent on the suppression of ET-1 signaling.

Endoplasmic reticulum stress and development of insulin resistance in adipose, skeletal, liver, and foetoplacental tissue in diabesity

Diabesity is an abnormal metabolic condition shown by patients with obesity that develop type 2 diabetes mellitus. Patients with diabesity present with insulin resistance, reduced vascular response to insulin, and vascular endothelial dysfunction. Along with the several well-described mechanisms of insulin resistance, a state of endoplasmic reticulum (ER) stress, where the primary human targets are the adipose tissue, liver, skeletal muscle, and the foetoplacental vasculature, is apparent. ER stress characterises by the activation of the unfolded protein response via three canonical ER stress sensors, i.e., the protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1α (IRE1α), and activating transcription factor 6. Slightly different cell signalling mechanisms preferentially enable in diabesity in the ER stress-associated insulin resistance for adipose tissue (IRE1α/X-box binding protein 1 mRNA splicing/c-jun N-terminal kinase 1 activation), skeletal muscle (tribbles-like protein 3 (TRB3)/proinflammatory cytokines activation), and liver (PERK/activating transcription factor 4/TRB3 activation). There is no information in human subjects with diabesity in the foetoplacental vasculature. However, the available literature shows that pregnant women with pre-pregnancy obesity or overweight that develop gestational diabetes mellitus (GDM) and their newborn show insulin resistance. ER stress is recently reported to be triggered in endothelial cells from the human umbilical vein from mothers with pre-pregnancy obesity. However, whether a different metabolic alteration to obesity in pregnancy or GDM is present in women with pre-pregnancy obesity that develop GDM, is unknown. In this review, we summarised the findings on diabesity-associated mechanisms of insulin resistance with emphasis in the primary targets adipose, skeletal muscle, liver, and foetoplacental tissues. We also give evidence on the possibility of a new GDM-associated metabolic condition triggered in pregnancy by maternal obesity, i.e. gestational diabesity, leading to ER stress-associated insulin resistance in the human foetoplacental vasculature.

PVAT and Its Relation to Brown, Beige, and White Adipose Tissue in Development and Function

Adipose tissue is commonly categorized into three types with distinct functions, phenotypes, and anatomical localizations. White adipose tissue (WAT) is the major energy store; the largest depots of WAT are found in subcutaneous or intravisceral sites. Brown adipose tissue (BAT) is responsible for energy dissipation during cold-exposure (i.e., non-shivering thermogenesis) and is primarily located in the interscapular region. Beige or brite (brown-in-white) adipose tissue can be found interspersed in WAT and can attain a brown-like phenotype. These three types of tissues also have endocrine functions and play major roles in whole body metabolism especially in obesity and its co-morbidities, such as cardiovascular disease. Over the last years, perivascular adipose tissue (PVAT) has emerged as an adipose organ with endocrine and paracrine functions. Pro and anti-inflammatory agents released by PVAT affect vascular health, and are implicated in the inflammatory aspects of atherosclerosis. PVAT shares several of the defining characteristics of brown adipose tissue, including its cellular morphology and expression of thermogenic genes characteristic for brown adipocytes. However, PVATs from different vessels are phenotypically different, and significant developmental differences exist between PVAT and other adipose tissues. Whether PVAT represents classical BAT, beige adipose tissue, or WAT with changing characteristics, is unclear. In this review, we summarize the current knowledge on how PVAT relates to other types of adipose tissue, both in terms of functionality, developmental origins, and its role in obesity-related cardiovascular disease and inflammation.

Oral inflammation and infection, and chronic medical diseases: implications for the elderly

Oral diseases, such as caries and periodontitis, not only have local effects on the dentition and on tooth-supporting tissues but also may impact a number of systemic conditions. Emerging evidence suggests that poor oral health influences the initiation and/or progression of diseases such as atherosclerosis (with sequelae including myocardial infarction and stoke), diabetes mellitus and neurodegenerative diseases (such as Alzheimer's disease, rheumatoid arthritis and others). Aspiration of oropharyngeal (including periodontal) bacteria causes pneumonia, especially in hospitalized patients and the elderly, and may influence the course of chronic obstructive pulmonary disease. This article addresses several pertinent aspects related to the medical implications of periodontal disease in the elderly. There is moderate evidence that improved oral hygiene may help prevent aspiration pneumonia in high-risk patients. For other medical conditions, because of the absence of well-designed randomized clinical trials in elderly patients, no specific guidance can be provided regarding oral hygiene or periodontal interventions that enhance the medical management of older adults.

Arterial ageing: from endothelial dysfunction to vascular calcification

Complex structural and functional changes occur in the arterial system with advancing age. The aged artery is characterized by changes in microRNA expression patterns, autophagy, smooth muscle cell migration and proliferation, and arterial calcification with progressively increased mechanical vessel rigidity and stiffness. With age the vascular smooth muscle cells modify their phenotype from contractile to 'synthetic' determining the development of intimal thickening as early as the second decade of life as an adaptive response to forces acting on the arterial wall. The increased permeability observed in intimal thickening could represent the substrate on which low-level atherosclerotic stimuli can promote the development of advanced atherosclerotic lesions. In elderly patients the atherosclerotic plaques tend to be larger with increased vascular stenosis. In these plaques there is a progressive accumulation of both lipids and collagen and a decrease of inflammation. Similarly the plaques from elderly patients show more calcification as compared with those from younger patients. The coronary artery calcium score is a well-established marker of adverse cardiovascular outcomes. The presence of diffuse calcification in a severely stenotic segment probably induces changes in mechanical properties and shear stress of the arterial wall favouring the rupture of a vulnerable lesion in a less stenotic adjacent segment. Oxidative stress and inflammation appear to be the two primary pathological mechanisms of ageing-related endothelial dysfunction even in the absence of clinical disease. Arterial ageing is no longer considered an inexorable process. Only a better understanding of the link between ageing and vascular dysfunction can lead to significant advances in both preventative and therapeutic treatments with the aim that in the future vascular ageing may be halted or even reversed.

Macro- and microvascular endothelial dysfunction in diabetes

Endothelial cells, as well as their major products nitric oxide (NO) and prostacyclin, play a key role in the regulation of vascular homeostasis. Diabetes mellitus is an important risk factor for cardiovascular disease. Diabetes-induced endothelial dysfunction is a critical and initiating factor in the genesis of diabetic vascular complications. The present review focuses on both large blood vessels and the microvasculature. The endothelial dysfunction in diabetic macrovascular complications is characterized by reduced NO bioavailability, poorly compensated for by increased production of prostacyclin and/or endothelium-dependent hyperpolarizations, and increased production or action of endothelium-derived vasoconstrictors. The endothelial dysfunction of microvascular complications is primarily characterized by decreased release of NO, enhanced oxidative stress, increased production of inflammatory factors, abnormal angiogenesis, and impaired endothelial repair. In addition, non-coding RNAs (microRNAs) have emerged as participating in numerous cellular processes. Thus, this reviews pays special attention to microRNAs and their modulatory role in diabetes-induced vascular dysfunction. Some therapeutic strategies for preventing and restoring diabetic endothelial dysfunction are also highlighted.

Levels of metabolic markers in drug-naive prediabetic and type 2 diabetic patients

AIMS

Type 2 diabetes mellitus (T2DM) and prediabetes (pre-DM) are associated with changes in levels of metabolic markers. The main aim of this study is to compare the levels of omentin, irisin, endothelin-1, nesfatin, hepatocyte growth factor (HGF), fibroblast growth factor, and oxytocin (OXT) between normoglycemic and pre-DM/T2DM obese Jordanian patients.

METHODS

One hundred and ninety-eight adult Jordanian subjects were recruited. Demographic data and clinical parameters were collected. The serum levels of biomarkers were measured by enzymatic assay procedure.

RESULTS

Compared to normoglycemic (95 subjects), pre-DM/T2DM (103 subjects) displayed higher HGF (ng/ml) = 78.8 (71.4-104) versus 55.9 (45.3-66.6), p < 0.0001; and nesfatin (ng/ml) = 0.5 (0.4-0.7) versus 0.2 (0.1-0.4), p < 0.0001; betatrophin (ng/ml) = 1.2 (0.8-1.6) versus 0.22 (0.15-0.41), p < 0.0001. On the other hand, they had lower levels of omentin (ng/ml) = 2.1 (0.9-3.3) versus 3.6 (2.0-6.4), p < 0.0001, irisin (ng/ml) = 113.7 (88.9-142.9) versus 132.6 (110.7-147.8), p < 0.0001; and oxytocin (pg/ml) = 1077.9 (667.3-1506.0) versus 2180.1 (1464.5-2795.6), p < 0.0001; respectively. In comparison, FGF-21 (ng/ml) = 0.3 (0.2-0.5) versus 0.2 (0.1-0.4), and endothelin (pg/ml) = 2.7 (1.3-5.2) versus 2.8 (1.6-5.6) did not differ between the two groups (p > 0.05).

CONCLUSIONS

In the present study, patients with pre-DM and T2DM have higher serum levels of metabolic HGF, nesfatin, and betatrophin and lower levels of omentin, irisin, and OXT. Future longitudinal and interventional studies are required to confirm the utility of these markers as novel progression or therapeutic targets in the pharmacotherapy of diabetes.

Effects of equivalent sympathetic activation during hypoglycemia on endothelial function and pro-atherothrombotic balance in healthy individuals and obese standard treated type 2 diabetes

OBJECTIVE

Recent studies in type 2 diabetes have reported an association between hypoglycemia and severe cardiovascular adverse events, which are relatively increased in standard versus intensively treated individuals. The aim of this study was to determine the effects of equivalent sympathetic nervous system (SNS) activity during moderate hypoglycemia on in-vivo endothelial function, pro-inflammatory, pro-atherothrombotic, and pro-coagulant responses in healthy and standard treated type 2 diabetes individuals.

RESEARCH DESIGN AND METHODS

Eleven type 2 diabetes and 16 healthy individuals participated in single 2day studies. Day 1 involved a 2h hyperinsulinemic/euglycemic clamp and day 2, a 2h hyperinsulinemic/hypoglycemic clamp of 3.2±1mmol/L in type 2 diabetes and (2.9±0.1mmol/L) in healthy individuals.

RESULTS

ICAM-1, VCAM-1, P-selectin, PAI-1, VEGF and endothelin-1 (ET-1) fell during hyperinsulinemic euglycemia but increased during hypoglycemia in type 2 diabetes and healthy individuals. Epinephrine and norepinephrine levels were equivalent during hypoglycemia in type 2 DM and healthy individuals. However, despite similar SNS drive but milder and hypoglycemia there were greater ICAM-1, VCAM-1, PAI-1, VEGF and ET-1 responses in the type 2 diabetes group. Endogenous and exogenous nitric oxide mediated arterial vasodilation were also impaired only during hypoglycemia in type 2 diabetes.

CONCLUSION

We conclude that, milder hypoglycemia but equivalent SNS activation results in more diffuse endothelial dysfunction and a greater pro-inflammatory, pro-atherothrombotic and pro-coagulant state in standard treated type 2 diabetes as compared to healthy individuals.

Obesity and kidney disease: Beyond the hyperfiltration

In industrialized countries, overweight and obesity account for approximately 13.8% and 24.9% of the kidney disease observed in men and women, respectively. Moreover, obesity-associated glomerulopathy is now considered as "an emerging epidemic." Kidney function can be negatively impacted by obesity through several mechanisms, either direct or indirect. While it is well established that obesity represents the leading risk factor for type 2 diabetes and hypertension, awareness that obesity is associated with direct kidney damage independently of hypertension and diabetes is still not widespread. In this paper we will discuss the emerging role of adipose tissue, particularly in the visceral depot, in obesity-induced chronic kidney damage.

Vasodilator responses and endothelin-dependent vasoconstriction in metabolically healthy obesity and the metabolic syndrome

Patients with metabolically healthy obesity (MHO) do not present the cluster of metabolic abnormalities that define the metabolic syndrome (MetS). Whether MHO is associated with lower impairment of vasoreactivity than the MetS is unknown. For this purpose, forearm blood flow (FBF) responses were measured by strain-gauge plethysmography during the intra-arterial infusion of acetylcholine (ACh), sodium nitroprusside (SNP), and/or the selective endothelin type A (ETA) receptor blocker BQ-123 in 119 obese individuals with MHO (n = 34) or with the MetS (n = 85) and in healthy lean controls (n = 56). ACh and SNP caused a significant vasodilation in both obese and lean participants (all P < 0.001). However, the response to both agents was significantly lower in the obese than in the control group (both P < 0.001). Among the obese participants, the reactivity to ACh was higher in MHO than in MetS patients, whereas the responsiveness to SNP was equally impaired in both groups (P = 0.45). Infusion of BQ-123 significantly increased FBF in obese patients (P < 0001), but not in the lean participants; hence, FBF following ETA receptor blockade was higher in both obese groups than in controls (both P < 0.001). FBF response to BQ-123 was significantly higher in patients with the MetS than in those with MHO (P = 0.007). In conclusion, patients with MHO have abnormal vascular reactivity, although their endothelial dysfunction is less pronounced than in patients with the MetS. These findings indicate that obesity is associated with vascular damage independent of those metabolic abnormalities underlying the MetS.

Renal blood perfusion in GK rats using targeted contrast enhanced ultrasonography

OBJECTIVE

To explore application of targeted contrast enhanced ultrasonography in diagnosis of early stage vascular endothelial injury and diabetic nephropathy.

METHODS

Targeted SonoVue-TM microbubble was prepared by attaching anti-TM monoclonal antibody to the surface of ordinary microbubble SonoVue by biotin - avidin bridge method and ultrasonic instrument was used to evaluate the developing situation of targeted microbubble in vitro. Twenty 12-week-old male GK rats and 20 Wistar rats were enrolled in this study, and were randomly divided into targeted angiography group and ordinary angiography group. Targeted microbubbles SonoVue-TM or general microbubble SonoVue were rapidly injected to the rats via tail vein; the developing situation of the two contrast agents in rats kidneys was dynamically observed. Time-intensity curve was used to analyze rat kidney perfusion characteristics in different groups.

RESULTS

Targeted ultrasound microbubble SonoVue-TM was successfully constructed, and it could be used to develop an external image. Targeted microbubbles SonoVue-TM enabled clear development of experimental rat kidney. Time-intensity curve shapes of rat kidney of the two groups showed as single apex with steep ascending and slowly descending branch. Compared with the control group, the rising slope of the GK rat renal cortex, medulla in targeted angiography group increased (P < 0.05); the peak intensity of medulla increased (P < 0.05), and the total area under the curve of medulla increased (P < 0.05). Compared with control group, the ascending branch of the GK rat in renal cortex, medulla in ordinary angiography group increased (P < 0.05). The peak intensity of the curve increased (P < 0.05), and the total area under the curve increased (P < 0.05). Compared with the ordinary angiography group, the peak of GK rat medulla curve in targeted angiography group intensity increased (P < 0.05), and the total area under the curve increased (P < 0.05).

CONCLUSIONS

Targeted microbubbles SonoVue-TM can make a clear development of experimental rat kidney, its stable performance meet the requirement of ultrasonic observation time limit, and it can reflect early changes of blood perfusion in GK rat kindey.

Effects of rosuvastatin combined with fasudil therapy on rabbits with dyslipidemia

BACKGROUND

Present study was conducted to investigate the effects of rosuvastatin combined with fasudil on rabbits with dyslipidemia.

METHODS

Dyslipidemia model of rabbits were produced by prescribing atherogenic diet for 2 weeks. Thereafter, 40 rabbits with dyslipidemia were randomly and evenly divided into four groups as follow: untreated group (orally prescribed 3 ml of normal saline), rosuvastatin group (orally prescribed 3 mg/kg body weight daily, dissolved in 3 ml of normal saline), fasudil group (intravenously prescribed 0.5 mg/kg body weight daily, dissolved in 3 ml of normal saline), and combined group (the same doses of rosuvastatin and fasudil as aforementioned). At baseline, 2 weeks of dyslipidemia establishment and 2 weeks of medical therapy, fasting venous blood was drawn for laboratory examination.

RESULTS

After 2 weeks' atherogenic diet treatment, lipid disorders and impaired fasting glucose were observed. Systemic inflammation and oxidation were also promoted as revealed by increased serum levels of high sensitive C-reactive protein (Hs-CRP) and malondialdehyde (MDA). Notably, endothelial function has been impaired significantly as reflected by decreased nitric oxide (NO) production and increased serum asymmetric dimethylarginine (ADMA) level. RhoA associated kinase (ROCK) activity was also profoundly enhanced (P < 0.05). Inter-group comparisons showed that when compared to untreated group, modest improvements of endothelial function, inflammation and oxidation were observed in rosuvastatin and fasudil groups (P > 0.05). These benefits were improved more prominently in combined group (P < 0.05). Intra-group comparisons also showed that when compared to 2 weeks of dyslipidemia, slight improvement of endothelial function, inflammation and oxidation in rosuvastatin and fasudil groups were observed (P > 0.05). The improvements were more prominent in the combined groups (P < 0.05).

CONCLUSION

Rosuvastatin combined with fasudil conferred synergistic effects on endothelium-protection and inflammation- and oxidation-amelioration in the setting of early stage of dyslipidemia.

Impact of maternal obesity on fetal programming of cardiovascular disease

The in utero environment is a key determinant of long-term health outcomes; poor maternal metabolic state and placental insufficiency are strongly associated with these long-term health risks. Human epidemiological studies link maternal obesity and offspring cardiovascular disease in later life, but mechanistic studies in animal models are limited. Here, we review the literature pertaining to maternal consequences of obesity during pregnancy and the subsequent impact on fetal cardiovascular development.

Polymorphisms in endothelin system genes, arsenic levels and obesity risk

BACKGROUND/OBJECTIVES

Obesity has been linked to morbidity and mortality through increased risk for many chronic diseases. Endothelin (EDN) system has been related to endothelial function but it can be involved in lipid metabolism regulation: Receptor type A (EDNRA) activates lipolysis in adipocytes, the two endothelin receptors mediate arsenic-stimulated adipocyte dysfunction, and endothelin system can regulate adiposity by modulating adiponectin activity in different situations and, therefore, influence obesity development. The aim of the present study was to analyze if single nucleotide polymorphisms (SNPs) in the EDN system could be associated with human obesity.

SUBJECTS/METHODS

We analyzed two samples of general-population-based studies from two different regions of Spain: the VALCAR Study, 468 subjects from the area of Valencia, and the Hortega Study, 1502 subjects from the area of Valladolid. Eighteen SNPs throughout five genes were analyzed using SNPlex.

RESULTS

We found associations for two polymorphisms of the EDNRB gene which codifies for EDN receptor type B. Genotypes AG and AA of the rs5351 were associated with a lower risk for obesity in the VALCAR sample (p=0.048, OR=0.63) and in the Hortega sample (p=0.001, OR=0.62). Moreover, in the rs3759475 polymorphism, genotypes CT and TT were also associated with lower risk for obesity in the Hortega sample (p=0.0037, OR=0.66) and in the VALCAR sample we found the same tendency (p=0.12, OR=0.70). Furthermore, upon studying the pooled population, we found a stronger association with obesity (p=0.0001, OR=0.61 and p=0.0008, OR=0.66 for rs5351 and rs3759475, respectively). Regarding plasma arsenic levels, we have found a positive association for the two SNPs studied with obesity risk in individuals with higher arsenic levels in plasma: rs5351 (p=0.0054, OR=0.51) and rs3759475 (p=0.009, OR=0.53).

CONCLUSIONS

Our results support the hypothesis that polymorphisms of the EDNRB gene may influence the susceptibility to obesity and can interact with plasma arsenic levels.

Endothelin XIII

Twenty-five years ago, a groundbreaking paper from Tsukuba University in Japan was published, identifying the sequence of the endothelin gene and peptide (Nature 332, 411-415, 1988). This work opened the way for the discovery of the endothelin receptors and the development of orally active endothelin receptor antagonists (ERAs). Today, ERAs are part of medical therapy of patients around the world for the treatment of pulmonary arterial hypertension. Since the discovery of endothelin, about 1000 papers per year have been published, with more than 27,000 articles available today. Many important and break-through findings presented in the endothelin conferences have been published in the conferences' proceedings. Endothelin XIII is the proceedings of the Thirteenth International Conference on Endothelin, held at Tokyo Campus of Tsukuba University, Japan, in September 2013. At the conference, the 25th anniversary of endothelin's discovery was celebrated and articles produced from data presented at the conference are compiled in this Special Issue of Life Sciences. Endothelin XIII includes more than fifty articles, including review articles by experts in the field and numerous original research articles. As the Editors of this special issue, we are proud to present Endothelin XIII and wish the field continued growth for the benefit of patients and for the advancement of biomedical science.