Elevated plasma endothelin-1 is associated with reduced weight loss post vertical sleeve gastrectomy

Serum Level of Cadherin-P (CDH3) Is a Novel Predictor of Cardiovascular Events Related to Atherosclerosis in a 3-Year Follow-Up Study

Background: Placental cadherin (CDH3) is an adhesion molecule expressed in many malignant tumors. The role of serum CDH3 in atherosclerosis is unclear. Methods: This 3-year follow-up study measured atherosclerosis and serum CDH3 in 218 angiography inpatients. Coronary stenosis was assessed as the Gensini score. The brachiocephalic and femoral plaques were quantified by ultrasound. Microarray serum profiling was conducted in selected samples. CDH3 in the serum was measured using an indirect ELISA. The odds ratio (OR), ROC analysis, and logistic regressions were used to evaluate the associations between CDH3 content, atherosclerotic lesions, and various serum biomarkers. Results: Serum CDH3 was associated with the severity of atherosclerosis and diastolic blood pressure. The levels of CDH3 were able to discriminate patients with total subclinical and hemodynamically significant atherosclerotic lesions in all circulation pools (coronary, brachiocephalic, and femoral). Elevated serum CDH3 appeared to be a risk factor for cardiovascular outcomes after 3-year follow up with OR = 1.81 (95% CI: 1.07-3.72; p = 0.022). Endothelin-1 and NOx were associated with the content of CDH3 in the serum, suggesting the involvement of certain signal transduction pathways that may participate in plaque formation. Conclusions: CDH3 was associated with cardiovascular outcomes adjusted for coronary plaque presence, indicating a role of CDH3 in plaque biology.

The Pathophysiological Associations Between Obesity, NAFLD, and Atherosclerotic Cardiovascular Diseases

Obesity, non-alcoholic fatty liver disease (NAFLD), and atherosclerotic cardiovascular diseases are common and growing public health concerns. Previous epidemiological studies unfolded the robust correlation between obesity, NAFLD, and atherosclerotic cardiovascular diseases. Obesity is a well-known risk factor for NAFLD, and both of them can markedly increase the odds of atherosclerotic cardiovascular diseases. On the other hand, significant weight loss achieved by lifestyle modification, bariatric surgery, or medications, such as semaglutide, can concomitantly improve NAFLD and atherosclerotic cardiovascular diseases. Therefore, certain pathophysiological links are involved in the development of NAFLD in obesity, and atherosclerotic cardiovascular diseases in obesity and NAFLD. Moreover, recent studies indicated that simultaneously targeting several mechanisms by tirzepatide and retatrutide leads to greater weight loss and markedly improves the complications of metabolic syndrome. These findings remind the importance of a mechanistic viewpoint for breaking the association between obesity, NAFLD, and atherosclerotic cardiovascular diseases. In this review article, we mainly focus on shared pathophysiological mechanisms, including insulin resistance, dyslipidemia, GLP1 signaling, inflammation, oxidative stress, mitochondrial dysfunction, gut dysbiosis, renin-angiotensin-aldosterone system (RAAS) overactivity, and endothelial dysfunction. Most of these pathophysiological alterations are primarily initiated by obesity. The development of NAFLD further exacerbates these molecular and cellular alterations, leading to atherosclerotic cardiovascular disease development or progression as the final manifestation of molecular perturbation. A better insight into these mechanisms makes it feasible to develop new multi-target approaches to simultaneously unhinge the deleterious chain of events linking obesity and NAFLD to atherosclerotic cardiovascular diseases.

Endothelin-1 impairs skeletal muscle myogenesis and development via ETB receptors and p38 MAPK signaling pathway

Myopenia is a condition marked by progressive decline of muscle mass and strength and is associated with aging or obesity. It poses the risk of falling, with potential bone fractures, thereby also increasing the burden on family and society. Skeletal muscle wasting is characterized by a reduced number of myoblasts, impaired muscle regeneration and increased muscle atrophy markers (Atrogin-1, MuRF-1). Endothelin-1 (ET-1) is a potent vasoconstrictor peptide. Increased circulating levels of ET-1 is noted with aging and is associated with muscular fibrosis and decline of strength. However, the regulatory mechanism controlling its effect on myogenesis and atrophy remains unknown. In the present study, the effects of ET-1 on myoblast proliferation, differentiation and development were investigated in C2C12 cells and in ET-1-infused mice. The results show that ET-1, acting via ETB receptors, reduced insulin-stimulated cell proliferation, and also reduced MyoD, MyoG and MyHC expression in the differentiation processes of C2C12 myoblasts. ET-1 inhibited myoblast differentiation through ETB receptors and the p38 mitogen-activated protein kinase (MAPK)-dependent pathway. Additionally, ET-1 decreased MyHC expression in differentiated myotubes. Inhibition of proteasome activity by MG132 ameliorated the ET-1-stimulated protein degradation in differentiated C2C12 myotubes. Furthermore, chronic ET-1 infusion caused skeletal muscle atrophy and impaired exercise performance in mice. In conclusion, ET-1 inhibits insulin-induced cell proliferation, impairs myogenesis and induces muscle atrophy via ETB receptors and the p38 MAPK-dependent pathway.

Endothelin receptor antagonism improves glucose tolerance and adipose tissue inflammation in an experimental model of systemic lupus erythematosus

Endothelin-1 (ET-1) is elevated in patients with systemic lupus erythematosus (SLE), an autoimmune disease characterized by high rates of hypertension, renal injury, and cardiovascular disease. SLE is also associated with an increased prevalence of obesity and insulin resistance compared to the general population. In the present study, we tested the hypothesis that elevated ET-1 in SLE contributes to obesity and insulin resistance. For these studies, we used the NZBWF1 mouse model of SLE, which develops obesity and insulin resistance on a normal chow diet. To test this hypothesis, we treated control (NZW) and SLE (NZBWF1) mice with vehicle, atrasentan (ETA receptor antagonist, 10 mg/kg/day), or bosentan (ETA/ETB receptor antagonist, 100 mg/kg/day) for 4 wk. Neither treatment impacted circulating immunoglobulin levels, but treatment with bosentan lowered anti-dsDNA IgG levels, a marker of SLE disease activity. Treatment with atrasentan and bosentan decreased glomerulosclerosis, and atrasentan lowered renal T-cell infiltration. Body weight was lower in SLE mice treated with atrasentan or bosentan. Endothelin receptor antagonism also improved hyperinsulinemia, homeostatic model assessment for insulin resistance, and glucose tolerance in SLE mice. Adipose tissue inflammation was also improved by endothelin receptor blockade. Taken together, these data suggest a potential therapeutic benefit for SLE patients with obesity and insulin resistance.NEW & NOTEWORTHY SLE is an autoimmune disease that is associated with obesity, insulin resistance, and elevated endothelin-1. The present study demonstrated that pharmacological inhibition of endothelin receptors decreased body weight, insulin resistance, and adipose tissue inflammation in a murine model of SLE. The therapeutic potential of endothelin receptor antagonists to treat obesity-related diseases and pathophysiological conditions, such as autoimmune diseases and insulin resistance, has become increasingly clear.

Endothelin antagonism reduces hemoglobin A1c in patients with pulmonary hypertension

Our lab recently reported that the blockade of endothelin-1 (ET-1) receptors attenuates insulin resistance in obese mice; therefore, we hypothesized that patients taking ET-1 receptor antagonists (ERAs) will have improved glycemic control. University of Mississippi Medical Center (2013-2020) electronic health record (EPIC) data were extracted from patients ≥18 years old with a clinical diagnosis of pulmonary hypertension (Food and Drug Administration indication for ERA use) and at least two clinical visits within 2 years. Patients prescribed ERAs (n = 11) were similar in age (61 ± 14 years vs. 60 ± 14 years), body mass index (BMI) (34 ± 8 kg/m ² vs. 35 ± 11 kg/m²), diabetes prevalence (73% vs. 80%, p = 0.59), and follow-up time (209 ± 74 days vs. 283 ± 180 days) compared with patients not taking ERAs (n = 137). There was a small but similar decrease in BMI at follow-up in the ERA (-1.9 ± 3 kg/m²) and control patients (-1.6 ± 5 kg/m²). At follow-up, hemoglobin A1c (HbA1c) significantly decreased -12% ± 11% of baseline in patients taking ERAs, while this did not occur in the control patients (2% ± 20% increase in HbA1c). In the whole population, baseline HbA1c and ERA prescription predicted the fall in HbA1c, while there was no significant association with demographics, diabetes prevalence, and diabetic treatment. These data suggest a potential role of ET-1 in promoting insulin resistance and warrant further investigation into using these drugs for glycemic control.

Dual endothelin receptor antagonism increases resting energy expenditure in people with increased adiposity

Increased adiposity is associated with dysregulation of the endothelin system, both of which increase the risk of cardiovascular disease (CVD). Preclinical data indicate that endothelin dysregulation also reduces resting energy expenditure (REE). The objective was to test the hypothesis that endothelin receptor antagonism will increase REE in people with obesity compared with healthy weight individuals. Using a double blind, placebo-controlled, crossover design, 32 participants [healthy weight (HW): n = 16, BMI: 21.3 ± 2.8 kg/m2, age: 26 ± 7 yr and overweight/obese (OB): n = 16, BMI: 33.5 ± 9.5 kg/m2, age: 31 ± 6 yr] were randomized to receive either 125 mg of bosentan (ETA/B antagonism) or placebo twice per day for 3 days. Breath-by-breath gas exchange data were collected and REE was assessed by indirect calorimetry. Venous blood samples were analyzed for concentrations of endothelin-1 (ET-1). Treatment with bosentan increased plasma ET-1 in both OB and HW groups. Within the OB group, the changes in absolute REE (PLA: -77.6 ± 127.6 vs. BOS: 72.2 ± 146.6 kcal/day; P = 0.046). The change in REE was not different following either treatment in the HW group. Overall, absolute plasma concentrations of ET-1 following treatment with bosentan were significantly associated with kcal/day of fat (r = 0.488, P = 0.005), percentage of fat utilization (r = 0.415, P = 0.020), and inversely associated with the percentage of carbohydrates (r = -0.419, P = 0.019), and respiratory exchange ratio (r = -0.407, P = 0.023). Taken together, these results suggest that modulation of the endothelin system may represent a novel therapeutic approach to increase both resting metabolism and caloric expenditure, and reduce CVD risk in people with increased adiposity.NEW & NOTEWORTHY Findings from our current translational investigation demonstrate that dual endothelin A/B receptor antagonism increases total REE in overweight/obese individuals. These results suggest that modulation of the endothelin system may represent a novel therapeutic target to increase both resting metabolism and caloric expenditure, enhance weight loss, and reduce CVD risk in seemingly healthy individuals with elevated adiposity.

Endothelin receptor antagonism improves glucose handling, dyslipidemia, and adipose tissue inflammation in obese mice

Endothelin-1 (ET-1) is elevated in patients with obesity; however, its contribution to the pathophysiology related to obesity is not fully understood. We hypothesized that high ET-1 levels cause dyslipidemia, inflammation, and insulin resistance within the adipose tissue of obese mice. To test this hypothesis, male C57BL/6J mice were fed either normal diet (NMD) or high-fat diet (HFD) for 8 weeks followed by 2 weeks of treatment with either vehicle, atrasentan (ETA receptor antagonist, 10 mg/kg/day) or bosentan (ETA/ETB receptor antagonist, 100 mg/kg/day). Atrasentan and bosentan lowered circulating non-esterified free fatty acids and triglycerides seen in HFD mice, while atrasentan-treated mice had significantly lower liver triglycerides compared with non-treated HFD mice. ET-1 receptor blockade significantly improved insulin tolerance compared with insulin-resistant HFD mice and lowered expression of genes in epididymal white adipose tissue (eWAT) associated with insulin resistance and inflammation. Flow cytometric analyses of eWAT indicated that HFD mice had significantly higher percentages of both CD4+ and CD8+ T cells compared with NMD mice, which was attenuated by treatment with atrasentan or bosentan. Atrasentan treatment also abolished the decrease in eosinophils seen in HFD mice. Taken together, these data indicate that ETA and ETA/ETB receptor blockade improves peripheral glucose homeostasis, dyslipidemia and liver triglycerides, and also attenuates the pro-inflammatory immune profile in eWAT of mice fed HFD. These data suggest a potential use for ETA and ETA/ETB receptor blockers in the treatment of obesity-associated dyslipidemia and insulin resistance.

Effect of laparoscopic sleeve gastrectomy on vasoactive mediators in obese hypertensive patients: A prospective study

INTRODUCTION

The causal relationship between obesity and high blood pressure is established; however, the detailed pathways for such association are still under research. This work aims to assess the changes in neprilysin, vasoconstrictor and vasodilatory molecules in obese hypertensive patients undergoing laparoscopic sleeve gastrectomy (LSG).

PATIENTS

The present prospective study was done on 59 hypertensive obese patients in whom LGS was performed. Blood pressure, as well as blood samples for neprilysin, angiotensinogen, angiotensin II, renin, endothelin-1 "ET-1", aldosterone, atrial natriuretic peptide "ANP" and B-type natriuretic peptide "BNP", were assessed before and 15 months after surgery. Patients were divided into two groups according to the remission of hypertension (HTN).

RESULTS

After 15 months, remission of hypertension was seen in 42 patients (71%). The declines in the following measurements were significantly higher in patients with remission than those with persistent HTN: aldosterone (p = .029567), angiotensin II (p < .000001), angiotensinogen (p = .000021), neprilysin (p = .000601), renin (p = .000454) and endothelin-1(p = .000030). There was a significantly higher increment in ANP (p = .000002) and a non-significant increment in BNP (p = .081740). Angiotensin II 15 months after LSG and Δ ANP % were significant independent predictors of persistent HTN.

CONCLUSION

In the setting of LSG, aldosterone, angiotensinogen, angiotensin II, renin and neprilysin were significantly lower in patients with remission of HTN after 15 months than those with persistent HTN, and natriuretic peptides were significantly higher. A lower postoperative level of angiotensin II and a larger percentage increment of ANP are independently associated with hypertension remission after LSG.

Endothelin-1 in the pathophysiology of obesity and insulin resistance

The association between plasma endothelin-1 (ET-1) and obesity has been documented for decades, yet the contribution of ET-1 to risk factors associated with obesity is not fully understood. In 1994, one of first papers to document this association also noted a positive correlation between plasma insulin and ET-1, suggesting a potential contribution of ET-1 to the development of insulin resistance. Both endogenous receptors for ET-1, ETA and ETB are present in all insulin-sensitive tissues including adipose, liver and muscle, and ET-1 actions within these tissues suggest that ET-1 may be playing a role in the pathogenesis of insulin resistance. Further, antagonists for ET-1 receptors are clinically approved making these sites attractive therapeutic targets. This review focuses on known mechanisms through which ET-1 affects plasma lipid profiles and insulin signalling in these metabolically important tissues and also identifies gaps in our understanding of ET-1 in obesity-related pathophysiology.

Sleeve gastrectomy ameliorates endothelial function and prevents lung cancer by normalizing endothelin-1 axis in obese and diabetic rats

BACKGROUND

Previous evidence has implied that obesity is an independent risk factor for developing cancer. Being closely related to obesity, type 2 diabetes mellitus provides a suitable environment for the formation and metastasis of tumors through multiple pathways. Although bariatric surgeries are effective in preventing and lowering the risk of various types of cancer, the underlying mechanisms of this effect are not clearly elucidated.

AIM

To uncover the role and effect of sleeve gastrectomy (SG) in preventing lung cancer in obese and diabetic rats.

METHODS

SG was performed on obese and diabetic Wistar rats, and the postoperative transcriptional and translational alterations of the endothelin-1 (ET-1) axis in the lungs were compared to sham-operated obese and diabetic rats and age-matched healthy controls to assess the improvements in endothelial function and risk of developing lung cancer at the postoperative 4^th, 8^th, and 12^th weeks. The risk was also evaluated using nuclear phosphorylation of H2A histone family member X as a marker of DNA damage (double-strand break).

RESULTS

Compared to obese and diabetic sham-operated rats, SG brought a significant reduction to body weight, food intake, and fasting blood glucose while improving oral glucose tolerance and insulin sensitivity. In addition, ameliorated levels of gene and protein expression in the ET-1 axis as well as reduced DNA damage indicated improved endothelial function and a lower risk of developing lung cancer after the surgery.

CONCLUSION

Apart from eliminating metabolic disorders, SG improves endothelial function and plays a protective role in preventing lung cancer via normalized ET-1 axis and reduced DNA damage.