Metabolic syndrome and endothelin-1 mediated vasoconstrictor tone in overweight/obese adults

Comparison of the effect of consuming the prepared cakes with acorn flour and wheat flour following a hypocaloric diet on serum levels of leptin, endothelin, inflammatory factors, and oxidative stress parameters in obese and overweight patients with metabolic syndrome: A double-blind clinical trial

Metabolic syndrome (MetS), which is a major consequence of obesity, increases mortality risks. Evidence shows favorable effects of nutritional approaches in the management of MetS. Accordingly, the use of functional foods has increased to enhance weight loss and reduce the risk factors associated with MetS. So, we aimed to investigate the effects of daily consumption of a functional acorn-based cake in conjunction with energy-restricted diet on some complications of patients with MetS. The study included 66 participants who were randomly assigned to either (A) a calorie-restricted diet + functional cake (FC) (n = 33) or (B) a calorie-restricted diet + a placebo cake (PC) (n = 33). Sociodemographic information, anthropometric measurements, dietary intakes, and serum biochemical parameters (inflammatory and oxidative stress markers, leptin, and endothelin) were measured before and after 8 weeks of intervention. Sixty-three participants completed this trial. After adjustment for baseline levels, consumption of FC compared to the PC resulted in a significant decrease in IL-6 (p = .03) and high-sensitivity C-reactive protein (p = .04) levels. No differences were observed between groups with regard to serum malondialdehyde, total antioxidant capacity, endothelin, and leptin levels (p > .05). Acorn-based cake could improve inflammation as an adjunct to an energy-restricted diet in overweight and obese patients with MetS. However, it is not clear whether acorn-based cake can be used to prevent or treat MetS because of indecisive findings regarding its ability to manage oxidative stress and serum hormones.

Endothelin-1 down-regulates nuclear factor erythroid 2-related factor-2 and contributes to perivascular adipose tissue dysfunction in obesity

Perivascular adipose tissue (PVAT) negatively regulates vascular muscle contraction. However, in the context of obesity, the PVAT releases vasoconstrictor substances that detrimentally affect vascular function. A pivotal player in this scenario is the peptide endothelin-1 (ET-1), which induces oxidative stress and disrupts vascular function. The present study postulates that obesity augments ET-1 production in the PVAT, decreases the function of the nuclear factor erythroid 2-related factor-2 (Nrf2) transcription factor, further increasing reactive oxygen species (ROS) generation, culminating in PVAT dysfunction. Male C57BL/6 mice were fed either a standard or a high-fat diet for 16 weeks. Mice were also treated with saline or a daily dose of 100 mg·kg-1 of the ETA and ETB receptor antagonist Bosentan, for 7 days. Vascular function was evaluated in thoracic aortic rings, with and without PVAT. Mechanistic studies utilized PVAT from all groups and cultured WT-1 mouse brown adipocytes. PVAT from obese mice exhibited increased ET-1 production, increased ECE1 and ETA gene expression, loss of the anticontractile effect, as well as increased ROS production, decreased Nrf2 activity, and downregulated expression of Nrf2-targeted antioxidant genes. PVAT of obese mice also exhibited increased expression of Tyr216-phosphorylated-GSK3β and KEAP1, but not BACH1 - negative Nrf2 regulators. Bosentan treatment reversed all these effects. Similarly, ET-1 increased ROS generation and decreased Nrf2 activity in brown adipocytes, events mitigated by BQ123 (ETA receptor antagonist). These findings place ET-1 as a major contributor to PVAT dysfunction in obesity and highlight that pharmacological control of ET-1 effects restores PVAT's cardiovascular protective role.

Endothelin-1 Plasma and Aqueous Humor Levels in Different Types of Glaucoma: A Systematic Review and Meta-Analysis

Background and Objectives: Several studies suggest the complex relationship between Endothelin-1 (ET-1) levels with various types of glaucoma. This systematic review and meta-analysis explore ET-1 levels in plasma and aqueous humor among different types of glaucoma. Materials and Methods: A literature search (PubMed, ScienceDirect, Cochrane Library) was made up to April 2024 (PROSPERO: CRD42023430471). The results were synthesized according to PRISMA Guidelines. Results were presented as standardized mean differences (SMD) with 95% confidence intervals (CI). Results: A total of 2597 subjects (1513 patients with glaucoma vs. 1084 healthy controls) from 23 studies were included in a meta-analysis. Notably, patients with glaucoma reported significantly higher plasma levels of ET-1 compared to controls (SMD: 1.21, 95% CI: 0.59-1.82, p < 0.001). Particularly, plasma ET-1 levels were higher in primary open-angle glaucoma (POAG) (SMD: 0.87, 95% CI: 0.09-1.65, p < 0.05), normal-tension glaucoma (SMD: 0.86, 95% CI: 0.27-1.46, p = 0.05), and angle-closure glaucoma patients (SMD: 1.03, 95% CI: 0.43-1.63, p < 0.001) compared to healthy controls. Moreover, ET-1 aqueous humor levels were significantly higher in patients with glaucoma compared to controls (SMD: 1.60, 95% CI: 1.04-2.15, p < 0.001). In particular, aqueous humor levels were higher in POAG patients (SMD: 2.03 95% CI: 1.00-3.14, p < 0.001), and pseudoexfoliative glaucoma patients (SMD: 2.03, 95% CI: 1.00-3.07, p < 0.001) compared to controls. Conclusions: This meta-analysis indicates that elevated levels of ET-1 plasma and aqueous humor are significantly associated with different types of glaucoma. The pathogenesis of ET-1-related mechanisms may vary across different glaucoma types, indicating that possible therapeutic approaches targeting ET-1 pathways should be tailored to each specific glaucoma type.

Evaluation of Metabolic and Cardiovascular Risk Measured by Laboratory Biomarkers and Cardiopulmonary Exercise Test in Children and Adolescents Recovered from Brain Tumors: The CARMEP Study

In recent decades, the improvement of treatments and the adoption of therapeutic protocols of international cooperation has led to an improvement in the survival of children affected by brain tumors. However, in parallel with the increase in survival, long-term side effects related to treatments have been observed over time, including the activation of chronic inflammatory processes and metabolic alterations, which can facilitate the onset of metabolic syndrome and increased cardiovascular risk. The aim of this study was to find possible statistically significant differences in the serum concentrations of early biomarkers of metabolic syndrome and in the results of cardiopulmonary exercise testing between survivors of childhood brain tumors and healthy controls. This is a prospective and observational study conducted on a group of 14 male patients who survived childhood brain tumors compared with the same number of healthy controls. The concentrations of early metabolic syndrome biomarkers [adiponectin, leptin, TNF-α, IL-1, IL-6, IL-10, endothelin-1, apolipoprotein B, and lipoprotein (a)] were measured and a cardiopulmonary exercise test (CPET) was performed. Results: Childhood brain tumor survivors performed worse on average than controls on the CPET. Furthermore, they showed higher endothelin-1 values than controls (p = 0.025). The CPET results showed an inverse correlation with leptin. The differences found highlight the greater cardiovascular risk of brain tumor survivors, and radiotherapy could be implicated in the genesis of this greater cardiovascular risk.

Supplementation with Two New Standardized Tea Extracts Prevents the Development of Hypertension in Mice with Metabolic Syndrome

Hypertension is considered to be both a cardiovascular disease and a risk factor for other cardiovascular diseases, such as coronary ischemia or stroke. In many cases, hypertension occurs in the context of metabolic syndrome (MetS), a condition in which other circumstances such as abdominal obesity, dyslipidemia, and insulin resistance are also present. The high incidence of MetS makes necessary the search for new strategies, ideally of natural origin and with fewer side effects than conventional pharmacological treatments. Among them, the tea plant is a good candidate, as it contains several bioactive compounds such as caffeine, volatile terpenes, organic acids, and polyphenols with positive biological effects. The aim of this study was to assess whether two new standardized tea extracts, one of white tea (WTE) and the other of black and green tea (CTE), exert beneficial effects on the cardiovascular alterations associated with MetS. For this purpose, male C57/BL6J mice were fed a standard diet (Controls), a diet high in fats and sugars (HFHS), HFHS supplemented with 1.6% WTE, or HFHS supplemented with 1.6% CTE for 20 weeks. The chromatography results showed that CTE is more concentrated on gallic acid, xanthines and flavan-3-ols than WTE. In vivo, supplementation with WTE and CTE prevented the development of MetS-associated hypertension through improved endothelial function. This improvement was associated with a lower expression of proinflammatory and prooxidant markers, and—in the case of CTE supplementation—also with a higher expression of antioxidant enzymes in arterial tissue. In conclusion, supplementation with WTE and CTE prevents the development of hypertension in obese mice; as such, they could be an interesting strategy to prevent the cardiovascular disorders associated with MetS.

Treatment with neurohormonal inhibitors and prognostic outcome in pulmonary arterial hypertension with risk factors for left heart disease

BACKGROUND

Despite major advances in pharmacologic treatment, patients with pulmonary arterial hypertension (PAH) still have a considerably reduced life expectancy. In this context, chronic hyperactivity of the neurohormonal axis has been shown to be detrimental in PAH, thus providing novel insights on the role of neurohormonal blockade as a potential therapeutic target.

AIM

To evaluate the application and prognostic effect of neurohormonal inhibitors (NEUi) in a single-center sample of patients with idiopathic PAH and risk factors for left heart disease.

METHODS

We analyzed data retrospectively collected from our register of right heart catheterizations performed consecutively from January 1, 2005 to October 31, 2018. Patients on beta-blocker, angiotensin-converting enzyme inhibitor, angiotensin receptor blocker or mineralocorticoid receptor antagonist at the time of right heart catheterization were classified as NEUi users and compared to NEUi non-recipients.

RESULTS

Complete data were available for 57 PAH subjects: 27 of those (47.4%) were taking at least one NEUi at the time of right heart catheterization and were compared with the remaining 36 NEUi non-recipients. NEUi users were older and had a higher cardiovascular risk profile compared to non-recipients. Additionally, NEUi non-users had a higher probability of dying during the course of follow-up than NEUi recipients (56.7% vs 25.9%, log-rank P = 0.020).

CONCLUSION

The above data highlighted a subgroup of patients with PAH and comorbidities for left heart disease in which NEUi use has shown to be associated with improved survival. Future prospective studies are needed to identify the most appropriate therapeutic strategies in this subset population.

Elevated circulating amyloid concentrations in obesity and diabetes promote vascular dysfunction

Diabetes, obesity, and Alzheimer’s disease (AD) are associated with vascular complications and impaired nitric oxide (NO) production. Furthermore, increased β-site amyloid precursor protein–cleaving (APP-cleaving) enzyme 1 (BACE1), APP, and β-amyloid (Aβ) are linked with vascular disease development and increased BACE1 and Aβ accompany hyperglycemia and hyperlipidemia. However, the causal relationship between obesity and diabetes, increased Aβ, and vascular dysfunction is unclear. We report that diet-induced obesity (DIO) in mice increased plasma and vascular Aβ42 that correlated with decreased NO bioavailability, endothelial dysfunction, and increased blood pressure. Genetic or pharmacological reduction of BACE1 activity and Aβ42 prevented and reversed, respectively, these outcomes. In contrast, expression of human mutant APP in mice or Aβ42 infusion into control diet–fed mice to mimic obese levels impaired NO production, vascular relaxation, and raised blood pressure. In humans, increased plasma Aβ42 correlated with diabetes and endothelial dysfunction. Mechanistically, higher Aβ42 reduced endothelial NO synthase (eNOS), cyclic GMP (cGMP), and protein kinase G (PKG) activity independently of diet, whereas endothelin-1 was increased by diet and Aβ42. Lowering Aβ42 reversed the DIO deficit in the eNOS/cGMP/PKG pathway and decreased endothelin-1. Our findings suggest that BACE1 inhibitors may have therapeutic value in the treatment of vascular disease associated with diabetes.

Chaiqi decoction ameliorates vascular endothelial injury in metabolic syndrome by upregulating autophagy

OBJECTIVE

The present study aimed to investigate the protective effect of the Chaiqi decoction on vascular endothelial injury in metabolic syndrome and to determine whether the underlying mechanism was associated with autophagy.

METHODS

Chaiqi formula granules were administered to a rat model of metabolic syndrome established by feeding with a high-salt-sugar-fat diet (HSSFD). The drug-containing serum was used in a hyperglycemia cell model established using HUVECs cultured with palmitic acid PA. The influence of the Chaiqi decoction on metabolic syndrome-related vascular endothelial injury and autophagy was investigated. Autophagy flux was assessed in vitro by transfecting cells with GFP-mRFP-LC3 adenoviruses or incubating with DALGreen and DAPRed.

RESULTS

The metabolic syndrome model rats displayed adiposity, hyperglycemia, dyslipidemia, hypertension, thickened intima, deposition of various forms of collagen and lipid droplets, downregulated levels of phosphorylated endothelial nitric oxide synthase and nitric oxide, upregulated expression of endothelin 1, and dysfunctional autophagy. All these abnormalities were ameliorated by administration of the Chaiqi decoction to the metabolic syndrome rats. Furthermore, the Chaiqi-containing serum could upregulate autophagy similarly to rapamycin, in a time-dependent manner.

CONCLUSION

The Chaiqi decoction could ameliorate vascular endothelial injury by improving autophagy in metabolic syndrome.

Chronic Elevation of Endothelin-1 Alone May Not Be Sufficient to Impair Endothelium-Dependent Relaxation

Endothelin-1 (ET-1) is a powerful vasoconstrictor peptide considered to be causally implicated in hypertension and the development of cardiovascular disease. Increased ET-1 is commonly associated with reduced NO bioavailability and impaired vascular function; however, whether chronic elevation of ET-1 directly impairs endothelium-dependent relaxation (EDR) remains elusive. Herein, we report that (1) prolonged ET-1 exposure (ie, 48 hours) of naive mouse aortas or cultured endothelial cells did not impair EDR or reduce eNOS (endothelial NO synthase) activity, respectively (P>0.05); (2) mice with endothelial cell-specific ET-1 overexpression did not exhibit impaired EDR or reduced eNOS activity (P>0.05); (3) chronic (8 weeks) pharmacological blockade of ET-1 receptors in obese/hyperlipidemic mice did not improve aortic EDR or increase eNOS activity (P>0.05); and (4) vascular and plasma ET-1 did not inversely correlate with EDR in resistance arteries isolated from human subjects with a wide range of ET-1 levels (r=0.0037 and r=-0.1258, respectively). Furthermore, we report that prolonged ET-1 exposure downregulated vascular UCP-1 (uncoupling protein-1; P<0.05), which may contribute to the preservation of EDR in conditions characterized by hyperendothelinemia. Collectively, our findings demonstrate that chronic elevation of ET-1 alone may not be sufficient to impair EDR.

Relationship between Resistin, Endothelin-1, and Flow-Mediated Dilation in Patient with and without Metabolic Syndrome

Background:

Resistin is peptides that signal the functional status of adipose tissue to the brain and other target organs. It causes insulin resistance and affects the vascular endothelial dysfunction. However, the function and relation between resistin in endothelin-1 (ET-1), which leads to the endothelial dysfunction in humans are enigmatic.

Materials and Methods:

In a cross-sectional study of 76 participants (38 metabolic syndrome patients and 38 healthy participants), biochemical and clinical parameters, including lipid profile, fasting glucose, resistin, ET-1, C-reactive protein (CRP), flow-mediated dilation (FMD), and hypertension were determined and compared between the two groups.

Results:

Multiple linear regression analysis was performed with age- and sex-adjusted plasma resistin levels, FMD, and ET-1 as the dependent variables. Analysis showed that weight, body mass index, triglycerides (TGs), and ET-1 were statistically significant correlated with serum resistin. FMD has negative significantly correlated with weight (r = −0.491, P = 0.001), waist circumference (r = −0.491, P = 0.001), waist-to-hip ratio (r = −0.0444, P = 0.001), and ET-1 (r = −0.075, P = 0.050), but it has significantly correlated with systolic blood pressure (SBP) (r = 0.290, P = 0.016), diastolic blood pressure (DBP) (r = 0.275, P = 0.023), and high-density lipoprotein cholesterol (HDL-C) (r = −0.266, P = 0.050), and ET-1, but it has significantly correlated with SBP, DBP, and HDL-C. ET-1 is significantly correlated with TGs (r = −0.436, P = 0.006), total cholesterol (r = 0.452, P = 0.004), low-density lipoprotein cholesterol (r = 0.454, r = 0.004), and resistin (r = 0.282, P = 0.050), whereas it has negative significantly correlated with HDL-C (r = 0.346, P = 0.034), FMD (r = −0.075, P = 0.050.

Conclusion:

In this study, results shown plasma ET-1 and resistin are suggested as risk factors for the development of endothelial dysfunction and with further study, it is possible that can diagnose the risk of diabetes and cardiovascular disease in the early stages.

Diet-induced obesity alters the maternal metabolome and early placenta transcriptome and decreases placenta vascularity in the mouse

Maternal obesity is associated with an increased risk of obesity and metabolic disease in offspring. Increasing evidence suggests that the placenta plays an active role in fetal programming. In this study, we used a mouse model of diet-induced obesity to demonstrate that the abnormal metabolic milieu of maternal obesity sets the stage very early in pregnancy by altering the transcriptome of placenta progenitor cells in the preimplantation (trophectoderm [TE]) and early postimplantation (ectoplacental cone [EPC]) placenta precursors, which is associated with later changes in placenta development and function. Sphingolipid metabolism was markedly altered in the plasma of obese dams very early in pregnancy as was expression of genes related to sphingolipid processing in the early placenta. Upregulation of these pathways inhibits angiogenesis and causes endothelial dysfunction. The expression of many other genes related to angiogenesis and vascular development were disrupted in the TE and EPC. Other key changes in the maternal metabolome in obese dams that are likely to influence placenta and fetal development include a marked decrease in myo and chiro-inositol. These early metabolic and gene expression changes may contribute to phenotypic changes in the placenta, as we found that exposure to a high-fat diet decreased placenta microvessel density at both mid and late gestation. This is the first study to demonstrate that maternal obesity alters the transcriptome at the earliest stages of murine placenta development.

TRPM8 downregulation by angiotensin II in vascular smooth muscle cells is involved in hypertension

Angiotensin II (Ang II)-induced injury of vascular smooth muscle cells (VSMCs) serves an important role in hypertension and other cardiovascular disorders. Transient receptor potential melastatin 8 (TRPM8) is a thermally‑regulated Ca2+‑permeable channel that is activated by reduced body temperature. Although several recent studies have revealed the regulatory effect of TRPM8 in vascular tone and hypertension, the precise role of TRPM8 in dysfunction of vascular smooth muscle cells (VSMCs) induced by Ang II remains elusive. In the present study, the possible function of TRPM8 in Ang II‑induced VSMCs malfunction in vivo and in vitro was investigated. In the aortae from rats that had undergone a two‑kidney one‑clip operation, which is a widely‑used renovascular hypertension model, the mRNA and protein levels of TRPM8 were reduced. In addition, exogenous Ang II treatment decreased TRPM8 mRNA and protein expression levels in primary cultures of rat VSMCs. TRPM8 activation by menthol, a pharmacological agonist, in VSMCs, significantly attenuated the Ang II‑induced increase in reactive oxygen species and H2O2 production. In addition, TRPM8 activation reduced the Ang II‑induced upregulation of NADPH oxidase (NOX) 1 and NOX4 in VSMCs. Furthermore, TRPM8 activation relieved the Ang II‑induced activation of ras homolog gene family, member A‑rho associated protein kinase 2 and janus kinase 2 signaling pathways in VSMCs. In conclusion, the results presented in the current study indicated that TRPM8 downregulation by Ang II in VSMCs may be involved in hypertension.

Endothelial vasodilator function in normal-weight adults with metabolic syndrome

Metabolic syndrome (MetS) typically presents with obesity; however, obesity is not a requisite characteristic for MetS classification and related vascular risk. We tested the hypothesis that MetS, independent of excess adiposity, is associated with impaired endothelial vasodilator dysfunction. Thirty-two sedentary, middle-aged adults were studied: 11 normal weight (9 male and 2 female; body mass index (BMI), 24.0 ± 0.3 kg/m2); 11 normal weight with MetS (9 male and 2 female; BMI, 24.7 ± 0.3 kg/m2); and 10 obese without MetS (8 male and 2 female; BMI, 31.4 ± 0.5 kg/m2). MetS was established according to National Cholesterol Education Program Adult Treatment Panel III criteria. Forearm blood flow (FBF) responses to intra-arterial infusions of acetylcholine and sodium nitroprusside were measured via strain-gauge plethysmography. FBF responses to acetylcholine were ∼20% lower (P < 0.05) in the normal-weight subjects with MetS (from 4.0 ± 0.3 to 13.0 ± 1.0 mL/(100 mL tissue·min)) and obese subjects (from 4.8 ± 0.2 to 12.2 ± 1.1 mL/(100 mL tissue·min)) compared with the normal-weight subjects (from 4.6 ± 0.4 to 15.8 ± 0.7 mL/(100 mL tissue·min)). Of note, FBF responses to acetylcholine were similar between the normal-weight adults with MetS and the obese adults. There were no differences among groups in FBF response to sodium nitroprusside. These data indicate that the presence of MetS, independent of obesity, is associated with diminished endothelium-dependent vasodilation. Endothelial vasodilator dysfunction may underlie the increased cardiovascular risk in normal-weight adults with MetS.

Salusins and adropin: New peptides potentially involved in lipid metabolism and atherosclerosis

Dyslipidemia is one of the most potent risk factors for the development of atherosclerosis. The high atherosclerotic risk in dyslipidemic patients is associated with endothelial dysfunction. During the last two decades, novel bioactive peptides have emerged as potential biomarkers of endothelial dysfunction and dyslipidemia-salusins and adropin. Salusin-alpha is likely to prevent atherosclerosis, while salusin-beta may act as a potential proatherogenic factor. Adropin was recently identified as important for energy homeostasis and lipid metabolism. Adropin is closely related to the inhibition of atherosclerosis by up-regulation of the endothelial nitric oxide synthase expression through the vascular endothelial growth factor receptor-2. These peptides represent a novel target to limit diseases characterized by endothelial dysfunction and may form the basis for the development of new therapeutic agents for treating metabolic disorders associated with atherosclerosis.