Detection and identification of factors in the atrium responsible for blood pressure regulation in patients with hypertension

Resection of the left atrial appendage reportedly improves blood pressure in patients with hypertension. This study aimed to validate the transcriptional profiles of atrial genes responsible for blood pressure regulation in patients with hypertension as well as to identify the molecular mechanisms in rat biological systems. RNA sequencing data of left atrial appendages from patients with (n = 6) and without (n = 6) hypertension were subjected to unsupervised principal component analysis (PCA). Reduction of blood pressure was reflected by third and ninth principal components PC3 and PC9, and that eighteen transcripts, including endothelin-1, were revealed by PCA-based pathway analysis. Resection of the left atrial appendage in hypertensive rats improved their blood pressure accompanied by a decrease in serum endothelin-1 concentration. Expression of the endothelin-1 gene in the atrium and atrial appendectomy could play roles in blood pressure regulation in humans and rats.

Endothelin-1-mediated Brainstem Glial Activation Produces Asthmatic Airway Vagal Hypertonia Via Enhanced ATP-P2X4 Receptor Signaling in Sprague-Dawley Rats

The occurrence of major asthma symptoms is largely attributed to airway vagal hypertonia, of which the central mechanisms remain unclear. This study tests the hypotheses that endothelin-1-mediated brainstem glial activation produces asthmatic airway vagal hypertonia via enhanced action of adenosine 5'-triphosphate on neuronal purinergic P2X4 receptors. A rat model of asthma was prepared using ovalbumin. Airway vagal tone was evaluated by the recurrent laryngeal discharge and plethysmographic measurement of pulmonary function. The changes in the brainstem were examined using ELISA, Western blot, luciferin-luciferase, quantitative reverse transcription-polymerase chain reaction, enzyme activity assay and immunofluorescent staining, respectively. The results showed that in the medulla of rats, endothelin receptor type B and P2X4 receptors were primarily expressed in astrocytes and neurons, respectively, and both of which, along with endothelin-1 content, were significantly increased after ovalbumin sensitization. Ovalbumin sensitization significantly increased recurrent laryngeal discharge, which was blocked by acute intracisternal injection of P2X4 receptor antagonist 5-BDBD, knockdown of brainstem P2X4 receptors, and chronic intraperitoneal injection of endothelin receptor type B antagonist BQ788, respectively. Ovalbumin sensitization activated microglia and astrocytes and significantly decreased ecto-5'-nucleotidase activity in the medulla, and all of which, together with the increase of medullary P2X4 receptor expression and decrease of pulmonary function, were reversed by chronic BQ788 treatment. These results demonstrated that in rats, allergic airway challenge activates both microglia and astrocytes in the medulla via enhanced endothelin-1/endothelin receptor type B signaling, which subsequently causes airway vagal hypertonia via augmented adenosine 5'-triphosphate/P2X4 receptor signaling in central neurons of airway vagal reflex.

Experimentally Induced Peripheral Venous Congestion Exacerbates Inflammation, Oxidative Stress, and Neurohormonal and Endothelial Cell Activation in Patients With Systolic Heart Failure

BACKGROUND

Venous congestion (VC) is a hallmark of symptomatic heart failure (HF) requiring hospitalization; however, its role in the pathogenesis of HF progression remains unclear. We investigated whether peripheral VC exacerbates inflammation, oxidative stress and neurohormonal and endothelial cell (EC) activation in patients with HF with reduced ejection fraction (HFrEF).

METHODS AND RESULTS

Two matched groups of patients with HFrEF and with no peripheral VC vs without recent HF hospitalization were studied. We modeled peripheral VC by inflating a cuff around the dominant arm, targeting ∼ 30 mmHg increase in venous pressure (venous stress test [VST]). Blood and ECs were sampled before and after 90 minutes of VST. We studied 44 patients (age 53 ± 12 years, 32% female). Circulating endothelin-1, tumor necrosis factor-α, interleukin-6, isoprostane, angiotensin II (ang-2), angiopoietin-2, vascular cell adhesion molecule-1, and CD146 significantly increased after the VST. Enhanced endothelin-1 and angiopoietin-2 responses to the VST were present in patients with vs without recent hospitalization and were prospectively associated with incident HF-related events; 6698 messenger ribonucleic acid (mRNA probe sets were differentially expressed in ECs after VST.

CONCLUSIONS

Experimental VC exacerbates inflammation, oxidative stress, neurohormonal and EC activation and promotes unfavorable transcriptome remodeling in ECs of patients with HFrEF. A distinct biological sensitivity to VC appears to be associated with high risk for HF progression.

Relationship Between Serum ET-1, HDL-C, and sVCAM-1 and Hearing Loss in Patients with Sudden Deafness

Vascular causes are most commonly associated with sudden sensorineural hearing loss (SSHL). This study was performed to determine the relationship between serum endothelin-1 (ET-1), high-density lipoprotein cholesterol (HDL-C), soluble vascular cell adhesion molecule-1 (sVCAM-1) levels, and the degree of hearing loss in patients with SSHL. Firstly, 60 SSHL patients were admitted to The First Hospital of Shanxi Medical University. In the same period, 60 healthy subjects matching the age and gender of SSHL patients were selected as the control group. Then, serum levels of ET-1, HDL-C, and sVCAM-1 were measured by enzyme-linked immunosorbent assay (ELISA). Next, the relationship between serum levels of ET-1, HDL-C, and sVCAM-1 with clinicopathological factors and their diagnostic and prognostic values were analyzed and evaluated. Serum ET-1 and sVCAM-1 were increased, and HDL-C was decreased in patients with SSHL. Serum ET-1 and sVCAM-1 were higher and HDL-C was lower in patients aged ≥ 45 years, or severe hearing loss patients (P < 0.05). ROC analysis determined that ET-1 (AUC = 0.839), HDL-C (AUC = 0.830), and sVCAM-1 (AUC = 0.865) had excellent diagnostic values. In addition, patients with low levels of ET-1 and sVCAM-1 and high levels of HDL-C had better hearing prognosis (P < 0.05). Abnormal serum ET-1, HDL-C, and sVCAM-1 in patients with SSHL are closely related to age, and degree of hearing loss, and perform diagnostic and prognostic values.

Schizochytrium sp. and lactoferrin supplementation alleviates Escherichia coli K99-induced diarrhea in preweaning dairy calves

Calf diarrhea, a common disease mainly induced by Escherichia coli infection, is one of the main reasons for nonpredator losses. Hence, an effective nonantibacterial approach to prevent calf diarrhea has become an emerging requirement. This study evaluated the microalgae Schizochytrium sp. (SZ) and lactoferrin (LF) as a nutrient intervention approach against E. coli O101:K99-induced preweaning calve diarrhea. Fifty 1-d-old male Holstein calves were randomly divided into 5 groups (n = 10): (1) control, (2) blank (no supplement or challenge), (3) 1 g/d LF, (4) 20 g/d SZ, or (5) 1 g/d LF plus 20 g/d SZ (LFSZ). The experimental period lasted 14 d. On the morning of d 7, calves were challenged with 1 × 1011 cfu of E. coli O101:K99, and rectum feces were collected on 3, 12, 24, and 168 h postchallenge for the control, LF, SZ, and LFSZ groups. The rectal feces of the blank group were collected on d 14. Data were analyzed using the mixed procedure of SAS (version 9.4; SAS Institute Inc.). The E. coli K99 challenge decreased the average daily gain (ADG) and increased feed-to-gain ratio (F:G) and diarrhea frequency (control vs. blank). Compared with the control group, the LFSZ group had a higher ADG and lower F:G, and the LFSZ and SZ groups had lower diarrhea frequency compared with the control group. In addition, the LFSZ and SZ groups have no differences in diarrhea frequency compared with the blank group. Compared with the control group, the blank group had lower serum nitric oxide (NO), endothelin-1, d-lactic acid (D-LA), and lipopolysaccharide (LPS) concentrations, as well as serum IgG, IL-1β, IL-6, IL-10, and TNF-α levels on d 7 and 14. On d 7, compared with the control group, all treatment groups had lower serum NO level, the SZ group had a lower serum D-LA concentration, and the LF and LFSZ groups had lower serum LPS concentration. On d 14, compared with the control group, the fecal microbiota of the blank group had lower Shannon, Simpson, Chao1, and ACE indexes, the LFSZ group had lower Shannon and Simpson indexes, the SZ and LFSZ groups had a higher Chao1 index, and all treatment groups had a higher ACE index. In fecal microbiota, Bifidobacterium and Actinobacteria were negatively associated with IL-10 and d-lactate, while Akkermansia was negatively associated with endothelin-1 and positively correlated with LPS, fecal scores, and d-lactate levels. Our results indicated that LF and SZ supplements could alleviate E. coli O101:K99-induced calf diarrhea individually or in combination. Supplementing 1 g/d LF and 20 g/d SZ could be a potential nutrient intervention approach to prevent bacterial diarrhea in calves.

Gut Microbiota and Biomarkers of Endothelial Dysfunction in Cirrhosis

Our aim was to study the association of endothelial dysfunction biomarkers with cirrhosis manifestations, bacterial translocation, and gut microbiota taxa. The fecal microbiome was assessed using 16S rRNA gene sequencing. Plasma levels of nitrite, big endothelin-1, asymmetric dimethylarginine (ADMA), presepsin, and claudin were measured as biomarkers of endothelial dysfunction, bacterial translocation, and intestinal barrier dysfunction. An echocardiography with simultaneous determination of blood pressure and heart rate was performed to evaluate hemodynamic parameters. Presepsin, claudin 3, nitrite, and ADMA levels were higher in cirrhosis patients than in controls. Elevated nitrite levels were associated with high levels of presepsin and claudin 3, the development of hemodynamic circulation, hypoalbuminemia, grade 2-3 ascites, overt hepatic encephalopathy, high mean pulmonary artery pressure, increased abundance of Proteobacteria and Erysipelatoclostridium, and decreased abundance of Oscillospiraceae, Subdoligranulum, Rikenellaceae, Acidaminococcaceae, Christensenellaceae, and Anaerovoracaceae. Elevated ADMA levels were associated with higher Child-Pugh scores, lower serum sodium levels, hypoalbuminemia, grade 2-3 ascites, milder esophageal varices, overt hepatic encephalopathy, lower mean pulmonary artery pressure, and low abundance of Erysipelotrichia and Erysipelatoclostridiaceae. High big endothelin-1 levels were associated with high levels of presepsin and sodium, low levels of fibrinogen and cholesterol, hypocoagulation, increased Bilophila and Coprobacillus abundances, and decreased Alloprevotella abundance.

Can Endothelin-1 Levels in Patients with Esophageal Variceal Bleeding at Admission Predict Rebleeding Within 5 Days?

BACKGROUND/AIMS

Portal hypertension complicating liver cirrhosis is associated with vascular resistance, possibly due to overexpression of humoral vasoconstrictors, including endothelin. The study aimed to evaluate the efficacy of serum endothelin-1 levels as a noninvasive predictor of early esophageal rebleeding (within 5 days) following endoscopic treatment.

MATERIALS AND METHODS

Of the patients presented to the endoscopy unit at Mansoura University Hospital, 50 patients were chosen for this study on the basis of endoscopically proven acute esophageal variceal bleeding consequent to hepatitis C viral infection complicated by liver cirrhosis and portal hypertension. Routine laboratory parameters and serum endothelin-1 levels were assessed prior to endoscopic treatment. Patients were divided into 2 groups depending on the development of early postendoscopic rebleeding. Group A consisted of 16 patients who developed rebleeding, while group B included 34 patients who did not. Statistical analysis was performed to determine the predictors of rebleeding.

RESULTS

Multivariate logistic regression demonstrated that endothelin-1 level (P < .001) and serum albumin level (P = .04) were independent risk factors for early rebleeding. The most efficient cutoff value for endothelin-1 levels in predicting variceal rebleeding within the 5 days after endoscopic intervention was 65.29, which had an 88.2% specificity, 87.5% sensitivity, 88% accuracy, and area under the curve value of 0.89. In addition, hemoglobin, albumin, and creatinine levels were significantly different between bleeding and nonrebleeding groups (P = .03, P = .014, and P <.001, respectively), as was the duration of hospital stay (P < .001).

CONCLUSION

Serum endothelin-1 levels appear to be a reliable, practical, noninvasive predictor of early variceal rebleeding and related comorbidities such as the severity of kidney affection and duration of hospital stay.

Tonic action of endothelin type B and dopamine D3 receptors in spontaneously hypertensive and deoxycorticosterone acetate-salt hypertensive rats: effects of intrarenally applied selective antagonists

Endothelins and renal dopamine contribute to control of renal function and arterial pressure in health and various forms of experimental hypertension, the action is mediated by tonic activity of specific receptors. We determined the action mediated by endothelin type B and by dopamine D3 receptors (ETB-R, D3-R) in anaesthetized spontaneously hypertensive (SHR) and in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. In rats of both hypertension models infused during 60 min into the interstitium of in situ kidney were either ETB-R antagonist, BQ788 (0.67 mg kg-1 BW h-1) or D3-R antagonist, GR103691 (0.2 mg kg-1 BW h-1). Arterial pressure (MAP), renal artery blood flow (RBF, transonic probe) and renal medullary blood flow (MBF, laser-Doppler) were measured along with sodium, water and total solute excretion (UNaV, V, UosmV). Experiments with ETB-R blockade confirmed their tonic vasodilator action in the whole kidney (RBF) and medulla (MBF) in both hypertension models. In SHR only, the first evidence was provided that ETB-R specifically increases transtubular backflux of non-electrolyte solutes. In DOCA-salt rats ETB-R blockade caused an early decrease in water and salt transport whereas an increase was often reported from many previous studies. The most striking effect of D3-R blockade in SHR was a selective increase in MBF, which strongly suggested tonic vasoconstrictor action of these receptors in the renal medulla; this speaks against prevailing opinion that D3 receptors are virtually inactive in SHR. In our model variant of DOCA-salt rats of D3-R blockade clearly caused a rapid major increase in MAP in parallel with depression of renal haemodynamics.

The Effects of Regulating Increased Blood Glucose Levels on Plasma Endothelin-1 Levels After Severe Head Trauma in Rats

AIM

To examine the effects of regulating increased blood glucose levels on plasma ET-1 levels after severe head trauma in rats.

MATERIAL AND METHODS

Traumatic diffuse brain injury-induced rats were followed for 7 days and were randomly divided into two groups of 36 rats. Pre- and posttraumatic blood glucose and ET-1 levels were measured in group 1 (control). Posttraumatic blood glucose levels were maintained at normal levels using insulin and both blood glucose and ET-1 levels were measured at 2, 6, 12, 24, and 48 h and 7 days posttrauma in group 2. The study excluded animals that died and had skull fractures.

RESULTS

Posttraumatic plasma ET-1 levels (n=36) were significantly higher than baseline values in group 1 (p < 0.05). ET-1 levels in group 2 at the 7-day follow-up after trauma were significantly higher than baseline values (n=36) (p < 0.05). However, the increased ET-1 levels were statistically significantly lower in group 2 than in group 1 (p < 0.05).

CONCLUSION

The increased ET-1 levels were significantly prevented by keeping blood glucose levels within normal limits with insulin after severe head trauma. Thus, secondary injury to cerebral blood flow can be prevented by reducing the occurrence of vasospasm that starts in the early posttraumatic period or by stimulating the release of nitric oxide. Therefore, further studies on the role of ET-1 and insulin in developing secondary injuries after severe head trauma would be beneficial.

Vascular reactivity is altered in the placentas of fetuses with congenital diaphragmatic hernia

INTRODUCTION

Infants with congenital diaphragmatic hernia (CDH) often develop pulmonary hypertension but frequently fail to respond to vasodilator therapy, for instance because of an altered pulmonary vasoreactivity. Investigating such alterations in vivo is impossible. We hypothesised that these alterations are also present in fetoplacental vessels, since both vasculatures are exposed to the same circulating factors (e.g. endothelin-1) and respond similarly to certain stimuli (e.g. hypoxia). As proof-of-concept, we compared fetoplacental vasoreactivity between healthy and CDH-affected placentas.

METHODS

Fetoplacental vascular function of healthy and antenatally diagnosed left-sided CDH fetuses was assessed by wire myography. Placental expression of enzymes and receptors involved in the altered vasoreactive pathways was measured using quantitative PCR.

RESULTS

CDH arteries (n = 6) constricted more strongly to thromboxane A2 agonist U46619 (p < 0.001) and dilated less to bradykinin (p = 0.01) and nitric oxide (NO)-donor sodium nitroprusside (p = 0.04) than healthy arteries (n = 8). Vasodilation to prostacyclin analogue iloprost and adenylate cyclase stimulator forskolin, and vasoconstriction to endothelin-1 were not different between both groups. Angiotensin II did not induce vasoconstriction. Phosphodiesterase inhibitors sildenafil and milrinone did not affect responses to sodium nitroprusside, forskolin, or U46619. The mRNA expression of guanylate cyclase 1 soluble subunit alpha 1 (p = 0.003) and protein kinase cyclic guanine monophosphate (cGMP)-dependent 1 (p = 0.02) were reduced in CDH versus healthy placentas.

DISCUSSION

The identified changes in the thromboxane and NO-cGMP pathways in the fetoplacental vasculature correspond with currently described alterations in the pulmonary vasculature in CDH. Therefore, fetoplacental arteries may provide an opportunity to predict pulmonary therapeutic responses in infants with CDH.

Deficiency of diacylglycerol Kinase ζ promotes Beclin1-mediated autophagy via the mTOR/TFEB signaling pathway: Relevance to maladaptive cardiac hypertrophy

The activation Gq protein-coupled receptors (GPCRs) is a crucial factor contributing to maladaptive cardiac hypertrophy, and dysregulation of autophagy is implicated in its prohypertrophic effects. Previous studies have shown that diacylglycerol kinase zeta (DGKζ) can suppress cardiac hypertrophy by inhibiting the diacylglycerol (DAG)-PKC pathway in response to mechanical strain or growth agonists such as endothelin-1 (ET-1). However, the involvement of DGKζ in autophagy regulation remains poorly understood. In this study, we aimed to investigate the role of DGKζ in autophagy regulation during maladaptive cardiac hypertrophy. We found that Beclin1-mediated autophagy was involved in the development of maladaptive cardiac hypertrophy and dysfunction in response to prohypertrophic challenges of transverse aortic constriction (TAC) or ET-1. Deficiency of DGKζ promoted Beclin1-mediated autophagy, aggravated adverse cardiac remodeling, and cardiac dysfunction, which could be ameliorated by genetic deletion of Beclin1 or TFEB. Mechanistically, the deficiency of DGKζ disrupted the activation of AKT/mTOR signaling, the association between mTOR and TFEB, and favored the nuclear translocation of TFEB from the cytoplasm, leading to enhanced activation of Beclin1-mediated autophagy through ULK1/Beclin1 signaling and TFEB-dependent Beclin1 transcription. Taken together, these results suggest that the mechanisms by which DGKζ alleviates pathological cardiac hypertrophy may involve the regulation of Beclin1-mediated autophagy through the mTOR/TFEB signaling pathway.

Association between endothelin-1, nitric oxide, and Gensini score in chronic coronary syndrome

BACKGROUND

Chronic coronary syndrome (CCS) is a major public health burden; its pathogenesis involves atherosclerosis and endothelial dysfunction. Endothelin-1 (ET-1) and nitric oxide (NO) are vasoactive substances synthesized by endothelial cells that play a crucial role in CCS development. The Gensini score (GS) is used for evaluating CCS severity based on lumen segment changes, stenosis degree, and coronary stenosis site.

METHODS

This prospective study included 71 patients with CCS; we evaluated the relationships between GS and ET-1 and NO serum levels were evaluated in these patients. The GS was calculated for all patients. Serum ET-1 & NO levels among other laboratory parameters were measured.

RESULTS

The high GS group had higher ET-1 and relatively NO expressions in the than the low GS group. GS was positively correlated with ET-1 and negatively correlated with NO, T4, and TSH levels. The results of the multiple linear regression analysis showed that ET-1 had the most significant effect on GS.

CONCLUSIONS

We found a strong association between ET-1, NO, and CCS severity. A combination of ET-1, NO, and GS is an essential predictor of CCS disease severity.

Enhanced external counterpulsation increases coronary flow reserve in coronary microvascular disease

OBJECTIVES

To investigates the outcomes of enhanced external counterpulsation (EECP) among coronary microvascular disease (CMD) patients.

METHODS

Coronary microvascular disease patients were separated into the EECP (n=41) and control cohorts (n=42). Prior to and following the 4-week EECP program, coronary flow reserve (CFR) was recorded using transthoracic Doppler echocardiography. The serum endothelial nitric oxide synthase (eNOS) and endothelin-1 (ET-1) contents were analyzed by ELISA. Quality of life (QoL) was assessed by the Seattle Angina Questionnaire (SAQ) and the Canadian Cardiovascular Society (CCS) angina class.

RESULTS

After four weeks, CFR was substantially enhanced in the EECP versus control cohort (p<0.05). Endothelin-1 was strongly diminished whereas eNOS was considerably upregulated in the EECP cohort. EECP also enhanced patients' SAQ scores and decreased the CCS angina class.

CONCLUSION

Enhanced external counterpulsation may improve CFR and enhance the CMD patient QoL.

Endothelin Receptor Blockade Improves Cerebral Blood Flow-Mediated Dilation in a Mouse Model of Alzheimer's Disease

INTRODUCTION

Cerebral blood flow (CBF) is reduced in patients with Alzheimer's disease (AD). Flow-mediated dilation (FMD), which plays a key role in the regulation of blood flow, is attenuated by endothelin-1. We hypothesized that endothelin receptor blockade may improve CBF in AD.

METHODS

We investigated cerebrovascular reactivity in a mouse model of AD (APP-PS1; 5-6-month-old male subjects). We assessed the in vivo response to normoxic hypercapnia and in vitro FMD in isolated cerebral and mesenteric resistance arteries before and after endothelin receptor blockade (bosentan).

RESULTS

Normoxic hypercapnia increased basilar trunk blood flow velocity (+12.3 ± 2.4%; p = 0.006, n = 6) in wild-type (WT) mice but reduced blood flow in APP-PS1 mice (-11.4 ± 1.2%; p < 0.0001, n = 8). Bosentan (50 mg/kg, acute intraperitoneal injection) restored cerebrovascular reactivity in APP-PS1 mice (+10.2 ± 2.2%; p < 0.0001, n = 8) but had no effect in WT. FMD was reduced in the posterior cerebral artery of APP-PS1 compared to WT and was normalized by bosentan (1 μmol/L, 30 min, or 50 mg/kg/day for 28 days). FMD was similar in the mesenteric artery of APPS-PS1 and WT.

CONCLUSION

APP-PS1 mice exhibited cerebrovascular endothelial dysfunction. Acute and chronic blockade of endothelin receptors restored endothelial vasomotor function, suggesting a promising therapeutic approach to restoring cerebral vasoreactivity in AD.

Bosentan Does Not Affect Renal Resistive Index in Scleroderma/Systemic Sclerosis Patients

INTRODUCTION

If properly evaluated, chronic kidney disease can be found in up to 50% of patients with systemic sclerosis (SSc). The renal resistive index (RRI) is a marker of intrarenal vascular resistance and can predict SSc-associated vasculopathy. This study aimed to determine the impact of bosentan, a nonselective endothelin-1 receptor antagonist, on RRI and kidney function in SSc patients with recurrent digital ulcers.

METHODS

Twenty-one patients (age 57 ± 9 years, 19 females) were recruited in a 16-week prospective open-label uncontrolled study. Standardized procedures were used to measure general clinical and laboratory characteristics, systolic, diastolic, and mean arterial pressure (MAP), pulse pressure (PP), diastolic to systolic blood pressure (D/S) ratio, and urinary endothelin-1 levels. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was used to calculate kidney function as an estimated glomerular filtration rate (eGFR). RRI was measured by Doppler ultrasound as the average of three samplings of intrarenal blood flow in different kidney regions of both kidneys. Patients with secondary causes of kidney disease or kidney diseases associated with albuminuria were excluded.

RESULTS

Bosentan treatment for 16 weeks did not change RRI (0.731 ± 0.049-0.730 ± 0.054, p = 0.925), but increased urine endothelin-1 to creatinine ratio (0.27 ± 0.15-0.49 ± 0.57 pg/mg, p = 0.032) and reduced MAP (123 ± 10-101 ± 11 mm Hg, p < 0.001), PP (76 ± 11-68 ± 10 mm Hg, p = 0.003), D/S ratio (0.563 ± 0.044-0.538 ± 0.031, p = 0.006), and eGFR (92 ± 20-84 ± 24 mL/min/1.73 m2, p = 0.003).

DISCUSSION/CONCLUSION

In conclusion, in patients with SSc complicated by digital ulcers and normal to mildly diminished kidney function, bosentan had no effect on intrarenal hemodynamics, but reduced blood pressure levels and kidney function.

Aprocitentan, a dual endothelin-1 (ET-1) antagonist for treating resistant hypertension: Mechanism of action and therapeutic potential

Hypertension is reaching epidemic proportions worldwide and is a significant public health concern. However, ∼15% of patients with hypertension continue to experience elevated blood pressure, even after taking antihypertensive medications [such as angiotensin II receptor blockers (ARBs), angiotensin-converting enzyme inhibitors (ACEIs), dihydropyridine calcium channel blockers (CCBs) and thiazide diuretics], a condition referred to as resistant hypertension (RH). Within the complex realm of blood pressure regulation and vascular function, endothelin-1 (ET-1), a potent vasoconstrictor, plays a pivotal role. Recent research, particularly a Phase III clinical trial (NCT03541174), has shed light on the potential of aprocitentan, a dual ET-1 receptor antagonist, in significantly lowering blood pressure in individuals with RH. In this review, we summarize the mechanism of action and therapeutic potential of aprocitentan as an innovative approach for treating RH.

ET-traps: Potential therapeutics for preeclampsia

Elevated endothelin-1 (ET-1) has been implicated in several diseases including preeclampsia, where it causes the induction of hypertension, oxidative stress, endoplasmic reticulum stress, microvascular dysfunction and tissue damage in different organs. ET-traps are Fc-fusion proteins with a design based on the physiological receptors of ET-1. This paper discusses the potential use of ET-traps as a therapeutic for preeclampsia. ET-traps potently bind and sequester pathologically elevated ET-1 to significantly reduce different markers of pathology to non-disease levels with no toxicity.

Histopathological Evaluation of Pulmonary Thromboendarterectomy Specimens of Chronic Thromboembolic Pulmonary Hypertension

AIMS

Chronic thromboembolic pulmonary hypertension (CTEPH) is a condition with a poor prognosis in which the pulmonary arteries are occluded by organized thrombi. Pulmonary thromboendarterectomy (PEA) is an effective treatment for CTEPH; however, the literature on its histopathological examination is lacking. This study aimed to investigate the histopathological findings and protein and gene expression in PEA specimens, establish an optimal histopathological evaluation method, and clarify the mechanisms of thrombus organization and disease progression in CTEPH.

METHODS

In total, 50 patients with CTEPH who underwent PEA were analyzed. The patients were categorized according to their clinical data into two groups: good and poor postoperative courses. The relationship between their histopathological findings and the clinical course was examined. Immunohistochemical studies confirmed the expression of oxidants, antioxidants, and smooth muscle cell (SMC) differentiation markers and their changes during the progression of thrombus organization. The mRNA expression analysis of 102 samples from 27 cases included oxidants, antioxidants, and vasoconstrictor endothelin-1.

RESULTS

In the PEA specimens, colander-like lesions (aggregations of recanalized blood vessels with well-differentiated SMCs) were significantly more common in the good postoperative course group than in the poor postoperative course group; analysis of proteins and genes proposed that oxidative and antioxidant mechanisms were involved. In the colander-like lesions, there was an increase in endothelin-1 mRNA and protein expression of endothelin receptor A.

CONCLUSIONS

Colander-like lesions in PEA specimens must be identified. Additionally, SMC differentiation in recanalized vessels and the expression of vasoconstrictors and their receptors may contribute to the progression of CTEPH.

Endothelin mediates sex-differences in acclimation to high salt diet in rats

INTRODUCTION

Current understanding of sodium (Na+) handling is based on studies done primarily in males. Contrary to the gradual increase in high salt (HS) induced natriuresis over 3-5 days in males, female Sprague Dawley (SD) rats have a robust natriuresis after 1 day of HS. Renal endothelin-1 (ET-1) signaling, through ET receptor A and B, is an important natriuretic pathway and was implicated in our previous dietary salt acclimation studies, however, the contribution of ET receptors to sex-differences in acclimation to dietary Na+ challenges has yet to be clarified. We hypothesized that ET receptors mediate the augmented natriuretic capacity of female rats in response to a HS diet.

METHODS

To test our hypothesis, male and female SD rats were implanted with telemeters and randomly assigned to treatment with A-182086, a dual ETA and ETB receptor antagonist, or control. 24-h urine samples were collected and assessed for electrolytes and ET-1. Studies were performed on a normal salt (NS, 0.3% NaCl) diet and after challenging rats with HS (4% NaCl) diet for 1 day.

RESULTS

We found that A-182086 increased blood pressure in male and female SD rats fed either diet. Importantly, A-182086 eliminated sex-differences in natriuresis on NS and HS. In particular, A-182086 promotes HS-induced natriuresis in male rats rather than attenuating the natriuretic capacity of females. Further, the sex-difference in urinary ET-1 excretion in NS-fed rats was eliminated by A-182086.

CONCLUSION

In conclusion, ET receptors are crucial for mediating sex-difference in the natriuretic capacity primarily through their actions in male rats.

The role of hypoxia related hormones responses in acute mountain sickness susceptibility individuals unaccustomed to high altitude

Acute mountain sickness (AMS) is caused by rapid ascent to altitude (>2500 m) and remains a poorly understood pathophysiological condition. Accordingly, we investigated the relationship between acute exposure to high altitude and hypoxia related biochemical proteins. 21 healthy subjects (Female (8) and male (13), Age: 36.7±8.5, BMI: 23.2±3.1) volunteers participated in this project and fasting blood samples were taken before (sea level) and after 1 and 24-h exposure to high altitude (3,550 m). Blood oxygen saturation (SpO2), AMS status (Lake Louise Score) and serum HIF-1, Endothelin-1, VEGF and Orexin-A were measured (via ELISA) at 1, 6 and 24 h after exposure to high altitude. Pre-ascent measurement of hypoxia related proteins (Orexin-A, HIF-1, VEGF and Endothelin-1) where all significantly (<0.05) higher in the AMS-resistant individuals (No-AMS) when compared to AMS susceptible individuals (AMS+). Upon ascent to high altitude, 11 out of 21 volunteers had AMS (10.1±0.6 in AMS+ vs. 0.9±0.6 in No-AMS, P<0.05) and presented with lower resting SpO2 levels (77.7±0.4 vs. 83.5±0.3 respectively, p<0.05). Orexin-A, HIF-1, VEGF and Endothelin-1, significantly increased 24 hrs after exposure to high altitude in both AMS+ and No-AMS. The response of Orexin-A was similar between two groups, also, HIF-1 elevation 24 hrs after exposure to altitude was more in AMS+ (13% vs. 19%), but the increase of VEGF and Endothelin-1, 1 and 24 hrs after exposure to altitude in No-AMS was double that of AMS+. Hypoxia related proteins include Orexin-A, HIF-1, VEGF and Endothelin-1 may play a pathophysiological role in those who are susceptible to AMS.

Biomarkers of sustained systemic inflammation and microvascular dysfunction associated with post-COVID-19 condition symptoms at 24 months after SARS-CoV-2-infection

Introduction

Comprehensive studies investigating sustained hypercoagulability, endothelial function, and/or inflammation in relation to post-COVID-19 (PCC) symptoms with a prolonged follow-up are currently lacking. Therefore, the aim of this single-centre cohort study was to investigate serum biomarkers of coagulation activation, microvascular dysfunction, and inflammation in relation to persisting symptoms two years after acute COVID-19.

Methods

Patients diagnosed with acute SARS-CoV-2 infection between February and June 2020 were recruited. Outcome measures included the CORona Follow-Up (CORFU) questionnaire, which is based on an internationally developed and partially validated basic questionnaire on persistent PCC symptoms. Additionally, plasma biomarkers reflecting coagulation activation, endothelial dysfunction and systemic inflammation were measured.

Results

167 individuals were approached of which 148 (89%) completed the CORFU questionnaire. At 24 months after acute infection, fatigue was the most prevalent PCC symptom (84.5%). Over 50% of the patients experienced symptoms related to breathing, cognition, sleep or mobility; 30.3% still experienced at least one severe or extreme (4 or 5 on a 5-point scale) PCC symptom. Multiple correlations were found between several PCC symptoms and markers of endothelial dysfunction (endothelin-1 and von Willebrand factor) and systemic inflammation (Interleukin-1 Receptor antagonist). No positive correlations were found between PCC symptoms and coagulation complexes.

Discussion

In conclusion, this study shows that at 24 months after acute COVID-19 infection patients experience a high prevalence of PCC symptoms which correlate with inflammatory cytokine IL-1Ra and markers of endothelial dysfunction, especially endothelin-1. Our data may provide a rationale for the selection of treatment strategies for further clinical studies.

Trial registration

This study was performed in collaboration with the CORona Follow-Up (CORFU) study (NCT05240742, https://clinicaltrials.gov/ct2/show/ NCT05240742).

Adipokines and Inflammatory Markers in Acute Myocardial Infarction Patients with and without Obstructive Sleep Apnea: A Comparative Analysis

An association has been suggested between acute myocardial infarction (AMI) and obstructive sleep apnea (OSA). Considering the role of adipose-tissue-derived inflammatory mediators (adipokines) and the shared risk factor of obesity in OSA and AMI, this study aimed to investigate the involvement of adipokines in AMI patients with and without OSA. Serum levels of adipokines and inflammatory mediators were quantified, and home respiratory polygraphy was conducted. A total of 30 AMI patients and 25 controls were included. Patients with AMI exhibited elevated levels of resistin (7.4 vs. 3.7 ng/mL), interleukin-6 (8.8 vs. 1.3 pg/mL), and endothelin-1 (3.31 vs. 1.8 pg/mL). Remarkably, AMI patients with concomitant OSA exhibited higher levels of resistin (7.1 vs. 3.7 ng/mL), interleukin-6 (8.9 vs. 1.3 pg/mL), endothelin-1 (3.2 vs. 1.8 pg/mL), creatin kinase (1430 vs. 377 U/L), creatine kinase-MB (64.6 vs. 9.7 ng/mL), and troponin T (2298 vs. 356 pg/mL) than their non-OSA counterparts. Leptin showed a correlation with OSA severity markers. OSA was associated with greater cardiac damage in AMI patients. Our findings underscore that adipokines alone are not sufficient to discriminate the risk of AMI in the presence of OSA. Further research is necessary to determine the potential mechanisms contributing to exacerbated cardiac damage in patients with both conditions.

Women Have Greater Endothelin-B Receptor Function and Lower Mitochondrial Capacity Compared to Men With Type 1 Diabetes

CONTEXT

Type 1 diabetes (T1D) negatively affects both the endothelin system and muscle oxidative capacity. The endothelin pathway is a critical regulator of microcirculatory function and may exhibit sexual dichotomy by which healthy premenopausal women have greater endothelin-B receptor (ETBR) function compared to men. Moreover, T1D may differentially alter muscle oxidative capacity in men and women; however, whether ETBR function is impaired in women compared to men with T1D and its relationship with muscle oxidative capacity has yet to be explored.

OBJECTIVE

The purpose of this investigation was to determine if ETBR-mediated dilation is impaired in women compared to men with T1D and if this is related to their skeletal muscle oxidative capacity.

METHODS

Men (n = 9; glycated hemoglobin A1c [HbA1c] = 7.8 ± 1.0%) and women (N = 10 women; HbA1c = 8.4 ± 1.3%) with uncomplicated T1D were recruited for this investigation. Near-infrared spectroscopy (NIRS) and intradermal microdialysis (750 nM BQ-123 + ET-1 [10-20-10-8 mol/L]) were used to evaluate skeletal muscle oxidative capacity and assess ETBR-mediated vasodilation, respectively.

RESULTS

Skeletal muscle oxidative capacity was significantly lower (P = .031) in women compared with men with T1D. However, ETBR-mediated dilation induced a significantly greater (P = .012) vasodilatory response in women compared to men with T1D, and the area under the curve was negatively associated with skeletal muscle oxidative capacity (r = -.620; P = .042).

CONCLUSION

Compared to men with uncomplicated T1D, muscle oxidative capacity was lower and ETBR-mediated vasodilation was higher in women with uncomplicated T1D. ETBR-induced vasodilatory capacity was inversely related to skeletal muscle oxidative capacity, suggesting there may be compensatory mechanisms occurring to preserve microvascular blood flow in women with T1D.

Renal Glomerular Expression of WT-1, TGF-β, VEGF, and ET-1 Immunostains in Murine Models of Focal and Segmental Glomerulosclerosis

Primary focal segmental glomerulosclerosis (FSGS) is a type of chronic renal disease that commonly progresses to renal failure as the treatments are not particularly effective. Glomerular podocyte injury and loss are pivotal to the pathogenesis of FSGS. This study aims to explore the glomerular immunohistochemistry stain expression of Wilms tumor-1 (WT-1) (podocyte-specific protein), transforming growth factor beta (TGF-β) (cytokine protein), vascular endothelial growth factor (VEGF) (angiogenic protein), and endothelin-1 (ET-1) (profibrotic growth factor), in rats with adriamycin nephropathy, which represents the murine model of human FSGS. By the end of 8 and 12 weeks, the kidneys of adriamycin-treated rats and control rats were harvested and the histomorphology was studied. Both 8- and 12-week test groups developed proteinuria, and hypoalbuminemia and showed FSGS on hematoxylin and eosin-stained slides. The renal tissue samples were also treated with immunostains for WT-1, TGF-β, VEGF, and ET-1. The glomeruli in all the FSGS kidneys showed loss of WT-1 expression with a concomitant notable increased expression of TGF-β, VEGF, and ET-1 immunostains. These results demonstrate that as FSGS evolves, the WT-1-expressing podocytes are lost and it correlates inversely with the overexpression of TGF-β, VEGF, and ET-1, suggesting that during the pathogenesis of FSGS, podocyte damage triggers the activation of these proteins. The findings in the current study echo the theory hypothesized in world literature that TGF-β, VEGF, and ET-1 play an integral part in the evolution of FSGS. More research is needed to further detail the pathogenic role of these proteins as it may open routes to more targeted and effective treatment modalities.

Tumor necrosis factor-α stimulation endothelial-to-mesenchymal transition during cardiac fibrosis via endothelin-1 signaling

Cardiac fibrosis is an important pathological change after myocardial infarction (MI). High concentration of tumor necrosis factor-α (TNF-α) contributes to cardiac fibrosis, and TNF-α has been demonstrated to be involved in transforming growth factor-β1-induced endothelial-to-mesenchymal transition (EndMT). However, the role and molecular mechanisms of TNF-α during cardiac fibrosis remain largely unexplored. In this study, we demonstrated that TNF-α and endothelin-1 (ET-1) were upregulated in cardiac fibrosis after MI, and genes associated with EndMT were also upregulated. An in vitro model of EndMT demonstrated that TNF-α promoted EndMT by upregulation of vimentin and α-smooth muscle actin, and which strongly increased ET-1 expression. ET-1 promoted TNF-α-induced expression of gene program through phosphorylation levels of SMAD family member 2, while subsequent inhibition of ET-1 almost abolished the effect of TNF-α during the process of EndMT. In summary, these findings demonstrated that ET-1 is involved in the EndMT induced by TNF-α during cardiac fibrosis.

The Association between Vascular Abnormalities and Glaucoma-What Comes First?

Glaucoma is a leading cause of irreversible blindness worldwide. While intraocular pressure (IOP) presents a major risk factor, the underlying pathophysiology still remains largely unclear. The correlation between vascular abnormalities and glaucoma has been deliberated for decades. Evidence for a role played by vascular factors in the pathogenesis of glaucomatous neurodegeneration has already been postulated. In addition, the fact that glaucoma causes both structural and functional changes to retinal blood vessels has been described. This review aims to investigate the published evidence concerning the relationship between vascular abnormalities and glaucoma, and to provide an overview of the "chicken or egg" dilemma in glaucoma. In this study, several biomarkers of glaucoma progression from a vascular perspective, including endothelin-1 (ET-1), nitric oxide, vascular endothelial growth factor (VEGF), and matrix metalloproteinases (MMPs), were identified and subsequently assessed for their potential as pharmacological intervention targets.

Rhinovirus infection induces secretion of endothelin-1 from airway epithelial cells in both in vitro and in vivo models

BACKGROUND

Rhinovirus (RV) infection of airway epithelial cells triggers asthma exacerbations, during which airway smooth muscle (ASM) excessively contracts. Due to ASM contraction, airway epithelial cells become mechanically compressed. We previously reported that compressed human bronchial epithelial (HBE) cells are a source of endothelin-1 (ET-1) that causes ASM contraction. Here, we hypothesized that epithelial sensing of RV by TLR3 and epithelial compression induce ET-1 secretion through a TGF-β receptor (TGFβR)-dependent mechanism.

METHODS

To test this, we used primary HBE cells well-differentiated in air-liquid interface culture and two mouse models (ovalbumin and house dust mite) of allergic airway disease (AAD). HBE cells were infected with RV-A16, treated with a TLR3 agonist (poly(I:C)), or exposed to compression. Thereafter, EDN1 (ET-1 protein-encoding gene) mRNA expression and secreted ET-1 protein were measured. We examined the role of TGFβR in ET-1 secretion using either a pharmacologic inhibitor of TGFβR or recombinant TGF-β1 protein. In the AAD mouse models, allergen-sensitized and allergen-challenged mice were subsequently infected with RV. We then measured ET-1 in bronchoalveolar lavage fluid (BALF) and airway hyperresponsiveness (AHR) following methacholine challenge.

RESULTS

Our data reveal that RV infection induced EDN1 expression and ET-1 secretion in HBE cells, potentially mediated by TLR3. TGFβR activation was partially required for ET-1 secretion, which was induced by RV, poly(I:C), or compression. TGFβR activation alone was sufficient to increase ET-1 secretion. In AAD mouse models, RV induced ET-1 secretion in BALF, which positively correlated with AHR.

CONCLUSIONS

Our data provide evidence that RV infection increased epithelial-cell ET-1 secretion through a TGFβR-dependent mechanism, which contributes to bronchoconstriction during RV-induced asthma exacerbations.

Association of blood pressure variability with Endothelin-1 by menopause status among Black women: findings from the Jackson Heart Study

TO THE EDITOR

Postmenopausal women have a higher risk of hypertension compared with premenopausal women possibly related to increased endothelial dysfunction in the setting of lower levels of circulating estrogen. Using data from 660 women in the Jackson Heart Study (JHS), postmenopausal women had higher daytime, nighttime and 24 h systolic blood pressure variability (BPV) compared with premenopausal women, and higher nighttime systolic BPV was associated with higher endothlin-1 (a marker of endothelial dysfunction) in postmenopausal women (ß = 0.27 [0.05, 0.50], p = 0.019), even after adjustment for possible confounders including age. These findings highlight the relevance of menopause status to blood pressure variability and the potential role of blood pressure variability in the development of high endothelin-1 in postmenopausal women.

Exploring I-FABP, endothelin-1 and L-lactate as biomarkers of acute intestinal necrosis: a case-control study

OBJECTIVE

Acute intestinal necrosis (AIN) is a disease with devastating high mortality. AIN due to obstructed arterial blood flow has a blurred clinical presentation. Timely diagnosis is paramount, and a blood-based biomarker is warranted to increase patient survival. We aimed to assess intestinal fatty acid binding protein (I-FABP) and endothelin-1 as diagnostic biomarkers for AIN. To our knowledge, this is the first study exploring endothelin-1 in AIN patients from a general surgical population.

DESIGN

We conducted a single-centre nested case-control study comparing acutely admitted AIN patients to age- and sex-matched non-AIN patients during 2015-2016. I-FABP and endothelin-1 were analysed using an enzyme-linked immunosorbent assay. L-lactate levels were also measured in all patients. Cut-offs were estimated using receiver operator characteristic curves, and the diagnostic performance was estimated using the area under the receiver operator characteristic curve (AUC).

RESULTS

We identified 43 AIN patients and included 225 matched control patients. Median levels of I-FABP, endothelin-1 and L-lactate were 3550 (IQR: 1746-9235) pg/ml, 3.91 (IQR: 3.33-5.19) pg/ml and 0.92 (IQR: 0.74-1.45) mM in AIN patients and 1731 (IQR: 1124-2848) pg/ml, 2.94 (IQR: 2.32-3.82) pg/ml and 0.85 (IQR: 0.64-1.21) mM in control patients, respectively. The diagnostic performances of endothelin-1 and of I-FABP + endothelin-1 combined were moderate. Endothelin-1 alone revealed an AUC of 0.74 (0.67; 0.82). The sensitivity and specificity of endothelin-1 were 0.81 and 0.64, respectively.

CONCLUSION

I-FABP and endothelin-1 are promising biomarkers for AIN, with moderate diagnostic performance compared with the commonly used biomarker L-lactate.

PREREGISTRATION

ClinicalTrials.gov: NCT05665946.

Effect of Sodium TanshinoneⅡA Sulfonate on Uric Acid, Sicam-1, ET-1 and FMD in Patients with Coronary Heart Disease Complicated with Hyperuricemia

This study was to observe the effect of Sodium TanshinoneⅡA Sulfonate (ST-ⅡAS) on blood uric acid (UA), human Soluble Intercellular Adhesion Molecule-1 (sICAM-1), Endothelin-1 (ET-1) and percentage of brachial artery Flow-Mediated Dilatation (FMD) in individuals with Hyperuricemia Complicated Coronary Heart Disease (HC-CHD). The study's participants were 108 patients with HC-CHD who attended our hospital between January 2020 and June 2022. In the trial, the patients were split into two groups with 54 instances each: the general group and the observation group. The observation group received ST-IIAS therapy, while the general group received standard care. The experiment chose to observe and compare the difference of uric acid, sICAM-1, ET-1, FMD, therapeutic effectiveness and negative effects between the two groups at various times. Results showed that on the 14th day, the observation group's amounts of UA, sICAM-1, and ET-1 were inferior to the general group (P<0.05); On the 7th and 14th days, the observation group's amount of ET-1 was lower than that of the general group (P<0.05); The observation group's FMD of patients on the 14th day was inferior to the general group after treatment (P<0.05); The observation group's overall effective rate was 94.44% higher than the general group's (P<0.05); The observation group experienced fewer negative responses than the general group did (P<0.05). In conclusion, ST-ⅡAS can be used for uric acid, vascular endothelial systolic and diastolic function in patients with HC-CHD, and has better clinical efficacy and lower risk of adverse reactions.

Antihypertensive effects of Pleurospermum lindleyanum aqueous extract in spontaneously hypertensive rats

ETHNOPHARMACOLOGICAL RELEVANCE

Pleurospermum lindleyanum (Lipsky) B. Fedtsch is a perennial herb classified in the Apiaceae family, genus Pleurospermum, chiefly native to the Taxkorgan County, Xinjiang, China. In the Xinjiang Province, it is a well-known ethnic traditional herb, often addressed by its tribal name, Kurumuti. It grows in harsh conditions over 4000 m above sea level, such as the Pamirs plateau. It is rich in flavonoids, coumarins, terpenoids, essential oil, substances that have been widely applied in the prevention and treatment of hypertension, diabetes, coronary heart disease, and cerebral thrombosis by local Tajik residents.

AIMS OF THE STUDY

The present study aimed to evaluate the antihypertensive effects of the Pleurospermum Lindleyanum aqueous extract (PLAE) in spontaneously hypertensive rats (SHRs).

MATERIALS AND METHODS

The Pleurospermum lindleyanum was collected from the Taxkorgan Tajik Autonomous County, Xinjiang, China. The main chemical composition of PLAE was identified using the ultra-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS). SHRs were treated by gavage with PLAE (equivalent to Pleurospermum lindleyanum 5 or 10 g/kg/day) for 6 weeks, using Captopril (10 mg/kg/day) as positive control. The systolic blood pressure (SBP), renal and cardiac morphology, plasma levels of angiotensin-converting enzyme (ACE), aldosterone (ALD), angiotensinⅡ (AngⅡ), superoxide dismutase (SOD), endothelin-1 (ET-1) and nitric oxide (NO) were measured.

RESULTS

A total of 30 compounds were identified in PLAE. PLAE significantly attenuated the SBP of SHRs. The effects began after 3 weeks of administration and then became steady and long-lasting. Its potential mechanisms may be associated with the protective effects on renal and cardiac injury caused by hypertension, the decrease of plasma vasoconstrictors, such as ACE, ALD, AngⅡ, and ET-1 levels, the maintenance of NO/ET balance, the increase in plasma NO levels and SOD activity, thereby reducing oxidative stress.

CONCLUSION

Pleurospermum lindleyanum can be suggested as a novel antihypertensive ethnic traditional herb, which lays the foundation for researching safe and effective antihypertensive herbal medicines.

Inhibiting Cyclin B1-treated Pontine Infarction by Suppressing Proliferation of SPP1+ Microglia

Pontine infarction is the major subtype of brainstem stroke causing severe neurological deficits. The pathophysiology and treatment of pontine infarction was rarely studied. A rat model of acute pontine infarction was established via injection of endothelin-1 in the pons. Single-cell RNA sequencing was applied to detect the cellular response in pontine infarction. Based on this finding, a potential treatment for pontine infarction targeting microglia was verified. Occlusion of penetrating artery caused by endothelin-1 led to pontine infarction. Single-cell RNA sequencing revealed a subtype of activated microglia, SPP1+ microglia, which were different from M1-like or M2-like depolarization. SPP1+ microglia interacted with oligodendrocytes and contributed to the demyelination of nerve tracts. Cyclin B1 regulated the proliferation of SPP1+ microglia. Cucurbitacin E, a cyclin B1 inhibitor, reduced the proliferation of SPP1+ microglia around the injured myelin sheath and alleviated the demyelination. Moreover, cucurbitacin E treatment decreased the ischemic infarction volume and neurological deficits after pontine infarction. SPP1+ microglia contributed to axonal demyelination in the pontine infarction, and inhibition of SPP1+ microglia provided neuroprotection for pontine infarction.

Progressive exercise training improves cardiovascular psychophysiological outcomes in young adult women with a history of adverse childhood experiences

Adverse childhood experiences (ACEs) are early-life psychosocial stressors that are associated with poorer mental health and increased cardiovascular disease (CVD) risk in a dose-dependent manner. We examined the feasibility of an 8-wk combined aerobic and resistance exercise training program to improve systolic (SBP) and diastolic blood pressure (DBP), serum endothelin-1 (ET-1), resilience, hope agency, and hope pathways in young women with ACEs. Forty-two healthy women (21 ± 3 yr) with ≥4 (ACE+; n = 28) or 0 ACEs (ACE-; n = 14) participated in this study. Women with ACEs were randomly assigned to an exercise (ACE+EXT; n = 14) or nonexercise control (ACE+CON; n = 14) group, whereas all ACE- participants were assigned to a nonexercise control (n = 14) group. Hope agency and DBP did not change in any group (P ≥ 0.43), but hope pathways improved only in ACE+EXT (means ± SE change; +1.6 ± 0.74 au, P = 0.032, Hedges' g = 0.53). ET-1 decreased in ACE+EXT only (-0.31 ± 0.15 pg/mL, P = 0.043, g = 0.46). Although the interactions for resilience and SBP did not reach significance (P = 0.05-0.06), forced post hoc analyses indicated that resilience improved (+4.9 ± 1.9 au, P = 0.012, g = 0.64) and SBP tended to improve (-4.0 ± 2.0 mmHg, P = 0.053, g = 0.51) in ACE+EXT only. There were significant associations between changes in hope pathways and SBP (ρ = -0.43, P = 0.023) and ET-1 (ρ = -0.53, P = 0.005), and between changes in SBP and ET-1 (ρ = 0.49; P = 0.012) in the ACE+ group. In summary, structured exercise training reduces serum ET-1 levels, improves positive psychological coping, and may improve SBP in young women with ACEs. The relationships among the changes in hope pathways, SBP, and ET-1 suggest a cardiovascular psychophysiological relationship in young women with ACEs.NEW & NOTEWORTHY This randomized controlled pilot trial shows, for the first time, that 8 wk of structured, progressive exercise training lowers serum endothelin-1 (ET-1) and improves positive psychological coping in young women with significant early-life psychosocial stress. Furthermore, the observed associations among changes in psychological attributes, ET-1, and systolic blood pressure signify a potential interplay between positive psychology and cardiovascular disease risk among women with adverse childhood experiences.

Plasma biomarkers of endothelial function, inflammation and oxidative stress in individuals with non-freezing cold injury

NEW FINDINGS

What is the central question of this study? Are biomarkers of endothelial function, oxidative stress and inflammation altered by non-freezing cold injury (NFCI)? What is the main finding and its importance? Baseline plasma [interleukin-10] and [syndecan-1] were elevated in individuals with NFCI and cold-exposed control participants. Increased [endothelin-1] following thermal challenges might explain, in part, the increased pain/discomfort experienced with NFCI. Mild to moderate chronic NFCI does not appear to be associated with either oxidative stress or a pro-inflammatory state. Baseline [interleukin-10] and [syndecan-1] and post-heating [endothelin-1] are the most promising candidates for diagnosis of NFCI.

ABSTRACT

Plasma biomarkers of inflammation, oxidative stress, endothelial function and damage were examined in 16 individuals with chronic NFCI (NFCI) and matched control participants with (COLD, n = 17) or without (CON, n = 14) previous cold exposure. Venous blood samples were collected at baseline to assess plasma biomarkers of endothelial function (nitrate, nitrite and endothelin-1), inflammation [interleukin-6 (IL-6), interleukin-10 (IL-10), tumour necrosis factor alpha and E-selectin], oxidative stress [protein carbonyl, 4-hydroxy-2-nonenal (4-HNE), superoxide dismutase and nitrotyrosine) and endothelial damage [von Willebrand factor, syndecan-1 and tissue type plasminogen activator (TTPA)]. Immediately after whole-body heating and separately, foot cooling, blood samples were taken for measurement of plasma [nitrate], [nitrite], [endothelin-1], [IL-6], [4-HNE] and [TTPA]. At baseline, [IL-10] and [syndecan-1] were increased in NFCI (P < 0.001 and P = 0.015, respectively) and COLD (P = 0.033 and P = 0.030, respectively) compared with CON participants. The [4-HNE] was elevated in CON compared with both NFCI (P = 0.002) and COLD (P < 0.001). [Endothelin-1] was elevated in NFCI compared with COLD (P < 0.001) post-heating. The [4-HNE] was lower in NFCI compared with CON post-heating (P = 0.032) and lower than both COLD (P = 0.02) and CON (P = 0.015) post-cooling. No between-group differences were seen for the other biomarkers. Mild to moderate chronic NFCI does not appear to be associated with a pro-inflammatory state or oxidative stress. Baseline [IL-10] and [syndecan-1] and post-heating [endothelin-1] are the most promising candidates for diagnosing NFCI, but it is likely that a combination of tests will be required.

Endothelin Receptor Antagonists in Kidney Disease

Endothelin (ET) is found to be increased in kidney disease secondary to hyperglycaemia, hypertension, acidosis, and the presence of insulin or proinflammatory cytokines. In this context, ET, via the endothelin receptor type A (ET_A) activation, causes sustained vasoconstriction of the afferent arterioles that produces deleterious effects such as hyperfiltration, podocyte damage, proteinuria and, eventually, GFR decline. Therefore, endothelin receptor antagonists (ERAs) have been proposed as a therapeutic strategy to reduce proteinuria and slow the progression of kidney disease. Preclinical and clinical evidence has revealed that the administration of ERAs reduces kidney fibrosis, inflammation and proteinuria. Currently, the efficacy of many ERAs to treat kidney disease is being tested in randomized controlled trials; however, some of these, such as avosentan and atrasentan, were not commercialized due to the adverse events related to their use. Therefore, to take advantage of the protective properties of the ERAs, the use of ET_A receptor-specific antagonists and/or combining them with sodium-glucose cotransporter 2 inhibitors (SGLT2i) has been proposed to prevent oedemas, the main ERAs-related deleterious effect. The use of a dual angiotensin-II type 1/endothelin receptor blocker (sparsentan) is also being evaluated to treat kidney disease. Here, we reviewed the main ERAs developed and the preclinical and clinical evidence of their kidney-protective effects. Additionally, we provided an overview of new strategies that have been proposed to integrate ERAs in kidney disease treatment.

Endothelin type A receptor blockade attenuates aorto-caval fistula-induced heart failure in rats with angiotensin II-dependent hypertension

OBJECTIVE

Evaluation of the effect of endothelin type A (ET A ) receptor blockade on the course of volume-overload heart failure in rats with angiotensin II-dependent hypertension.

METHODS

Ren-2 renin transgenic rats (TGR) were used as a model of hypertension. Heart failure was induced by creating an aorto-caval fistula (ACF). Selective ET A receptor blockade was achieved by atrasentan. For comparison, other rat groups received trandolapril, an angiotensin-converting enzyme inhibitor (ACEi). Animals first underwent ACF creation and 2 weeks later the treatment with atrasentan or trandolapril, alone or combined, was applied; the follow-up period was 20 weeks.

RESULTS

Eighteen days after creating ACF, untreated TGR began to die, and none was alive by day 79. Both atrasentan and trandolapril treatment improved the survival rate, ultimately to 56% (18 of 31 animals) and 69% (22 of 32 animals), respectively. Combined ACEi and ET A receptor blockade improved the final survival rate to 52% (17 of 33 animals). The effects of the three treatment regimens on the survival rate did not significantly differ. All three treatment regimens suppressed the development of cardiac hypertrophy and lung congestion, decreased left ventricle (LV) end-diastolic volume and LV end-diastolic pressure, and improved LV systolic contractility in ACF TGR as compared with their untreated counterparts.

CONCLUSION

The treatment with ET A receptor antagonist delays the onset of decompensation of volume-overload heart failure and improves the survival rate in hypertensive TGR with ACF-induced heart failure. However, the addition of ET A receptor blockade did not enhance the beneficial effects beyond those obtained with standard treatment with ACEi alone.

[The effect of antioxidant therapy on some pathogenetic factors of primary open-angle glaucoma]

In patients with glaucoma, one of the main initiating mechanisms that triggers the chain of events is disruption of the universal mechanism for regulating vascular tone due to endothelial dysfunction (ED). The main manifestation of ED is an imbalance of vasoconstrictor and vasodilator endothelial mediators, which inconsistency triggers the mechanisms of adaptive distress leading to the progression of morphological destruction, dyslipidemia, acceleration of atherogenesis, development of hemodynamic and hydrodynamic disorders. The drug Mexidol has a wide range of pharmacological activity and affects the main pathogenetic links of primary open-angle glaucoma (POAG).

PURPOSE

The study analyzes the vascular remodulation, antioxidant and antihypoxic effects of the drug Mexidol in patients with PAOG.

MATERIAL AND METHODS

The study included 78 patients with POAG of the early (n=43) and advanced stage (n=35) with average age of 67.8±1.5 years. The main study group consisted of 47 patients who received Mexidol in addition to local hypotensive treatment; 31 patients comprised the control group. In the comparison groups, the degree of ED was determined by the results of reactive hyperemia test, patients' blood plasma was analyzed for levels of stable nitric oxide metabolite (nitrite NO2-) and endothelin-1 (ET-1). General assessment of oxidative stress was carried out by high-performance liquid chromatography. Functional activity of the retina was studied using an electroretinograph and static computer perimetry performed according to the standard technique.

RESULTS

The following changes are observed in patients of the main group using Mexidol: the index of oscillatory potentials significantly increases, peak latency decreases, perimeter indices show positive trends, vascular endothelial function improves according to reactive hyperemia test, concentration of vasoconstrictor mediator ET-1 in blood plasma decreases and of nitrite (NO2-) increases moderately, the coefficient of bioeffective vasotonic activity decreases, the level of glutathione peroxidase increases (p<0.05 compared to the baseline value), the level of malonyldialdehyde decreases, lipid metabolism improves (reduction in total cholesterol, low-density lipoprotein-cholesterol, triglycerides, decrease in the Atherogenic Index compared to the initial level).

CONCLUSIONS

The drug Mexidol proved to be an effective endothelial protector, a powerful antioxidant and antihypoxant, contributed to deceleration of atherogenesis in patients with POAG.

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.

Effect of Acacia senegal on TGF-β1 and vascular mediators in a rat model of diabetic nephropathy

CONTEXT

Transforming growth factor-β1 (TGF-β1), endothelin-1 and angiotensin II are responsible for extracellular matrix accumulation within the kidney in diabetic nephropathy.

OBJECTIVE

This study evaluated the effect of adding Gum Arabic (GA) and insulin on serum glucose, renal function, TGF-β1, endothelin-1, and angiotensin II in rats with diabetic nephropathy.

METHODS

Sixty male Sprague-Dawley rats were divided into; normal, normal plus GA, diabetic rats (DM), DM plus insulin, DM plus GA, and DM plus insulin plus GA groups. Levels of glucose and creatinine in serum, TGF-β1, angiotensin II, and endothelin-1 in renal homogenate and HbA1c were measured.

RESULTS

Serum creatinine, TGF-β1, angiotensin II, and endothelin-1 were increased in diabetic rats. GA decreased serum glucose, TGF-β1, angiotensin II, endothelin-1, and HbA1c in diabetic rats. GA and insulin decreased serum glucose, creatinine, TGF-β1, angiotensin II, endothelin-1, and HbA1c in diabetic rats.

CONCLUSION

Co-administration of GA with insulin to rats with diabetic nephropathy improved the glycemic state, renal function, TGF-β1, endothelin-1, and angiotensin II.

Hydrogen sulfide and miR21 are suitable biomarkers of hypoxic exposure

Hypoxia is the reduction of alveolar partial pressure of oxygen ([Formula: see text]). Military members and people who practice recreational activities from moderate to high altitudes are at risk for hypoxic exposure. Hypoxemia's signs and symptoms vary from asymptomatic to severe responses, such as excessive hypoxic ventilatory responses and residual neurobehavioral impairment. Therefore, it is essential to identify hypoxia-induced biomarkers to indicate people with exposure to hypoxia. Advances have been made in understanding physiological responses to hypoxia, including elevations in circulating levels of endothelin 1 (ET-1) and microRNA 21 (miR-21) and reduction in circulating levels of hydrogen sulfide (H2S). Although the levels of these factors change upon exposure to hypoxia, it is unclear if these changes are sustained on return to normoxia. We hypothesize that hypoxia-induced ET-1 and miR-21 remain elevated, whereas hypoxia-reduction in H2S sustains after returning to normoxic conditions. To test this hypothesis, we exposed male rats to 6 h of 12% O2 and measured circulating levels of ET-1 and miR-21, pre, during, and posthypoxia. We found that ET-1 plasma levels increased in response to hypoxia but returned to normal levels within 30 min after the restoration of normoxia. miR-21 plasma levels and transdermal H2S emissions decreased in response to hypoxia, remaining decreased on return to normoxia, thus following the biomarker criteria. Therefore, this study supports a unique role for plasma miR21 and transdermal H2S as hypoxia biomarkers that could be used to identify individuals after exposure to hypoxia.

Auraptene, a citrus peel-derived natural product, prevents myocardial infarction-induced heart failure by activating PPARα in rats

BACKGROUND

Auraptene derived from the peel of Citrus hassaku possesses anti-tumor, anti-inflammatory, and neuroprotective activities. Thus, it could be a valuable pharmacological alternative to treat some diseases. However, the therapeutic value of auraptene for heart failure (HF) is unknown.

STUDY DESIGN/METHODS

In cultured cardiomyocytes from neonatal rats, the effect of auraptene on phenylephrine-induced hypertrophic responses and peroxisome proliferator-activated receptor-alpha (PPARα)-dependent gene transcriptions. To investigate whether auraptene prevents the development of heart failure after myocardial infarction (MI) in vivo, Sprague-Dawley rats with moderate MI (fractional shortening < 40%) were randomly assigned for treatment with low- or high-dose auraptene (5 or 50 mg/kg/day, respectively) or vehicle for 6 weeks. The effects of auraptene were evaluated by echocardiography, histological analysis, and the measurement of mRNA levels of hypertrophy, fibrosis, and PPARα-associated genes.

RESULTS

In cultured cardiomyocytes, auraptene repressed phenylephrine-induced hypertrophic responses, such as increases in cell size and activities of atrial natriuretic factor and endothelin-1 promoters. Auraptene induced PPARα-dependent gene activation by enhancing cardiomyocyte peroxisome proliferator-responsive element reporter activity. The inhibition of PPARα abrogated the protective effect of auraptene on phenylephrine-induced hypertrophic responses. In rats with MI, auraptene significantly improved MI-induced systolic dysfunction and increased posterior wall thickness compared to the vehicle. Auraptene treatment also suppressed MI-induced increases in myocardial cell diameter, perivascular fibrosis, and expression of hypertrophy and fibrosis response markers at the mRNA level compared with vehicle treatment. MI-induced decreases in the expression of PPARα-dependent genes were improved by auraptene treatment.

CONCLUSIONS

Auraptene has beneficial effects on MI-induced cardiac hypertrophy and left ventricular systolic dysfunction in rats, at least partly due to PPARα activation. Further clinical studies are required to evaluate the efficacy of auraptene in patients with HF.

Temporal assessment of lesion morphology on radiological images beyond lesion volumes-a proof-of-principle study

OBJECTIVES

To develop a general framework to assess temporal changes in lesion morphology on radiological images beyond volumetric changes and to test whether cocaine abstinence changes coronary plaque structure on serial coronary CT angiography (CTA).

METHODS

Chronic cocaine users with human immunodeficiency virus (HIV) infection were prospectively enrolled to undergo cash-based contingency management to achieve cocaine abstinence. Participants underwent coronary CTA at baseline and 6 and 12 months following recruitment. We segmented all coronary plaques and extracted 1103 radiomic features. We implemented weighted correlation network analysis to derive consensus eigen radiomic features (named as different colors) and used linear mixed models and mediation analysis to assess whether cocaine abstinence affects plaque morphology correcting for clinical variables and plaque volumes and whether serum biomarkers causally mediate these changes. Furthermore, we used Bayesian hidden Markov network changepoint analysis to assess the potential rewiring of the radiomic network.

RESULTS

Sixty-nine PLWH (median age 55 IQR: 52-59 years, 19% female) completed the study, of whom 26 achieved total abstinence. Twenty consensus eigen radiomic features were derived. Cocaine abstinence significantly affected the pink and cyan eigen features (-0.04 CI: [-0.06; -0.02], p = 0.0009; 0.03 CI: [0.001; 0.04], p = 0.0017, respectively). These effects were mediated through changes in endothelin-1 levels. In abstinent individuals, we observed significant rewiring of the latent radiomic signature network.

CONCLUSIONS

Using our proposed framework, we found 1 year of cocaine abstinence to significantly change specific latent coronary plaque morphological features and rewire the latent morphologic network above and beyond changes in plaque volumes and clinical characteristics.

KEY POINTS

• We propose a general methodology to decompose the latent morphology of lesions on radiological images using a radiomics-based systems biology approach. • As a proof-of-principle, we show that 1 year of cocaine abstinence results in significant changes in specific latent coronary plaque morphologic features and rewiring of the latent morphologic network above and beyond changes in plaque volumes and clinical characteristics. • We found endothelin-1 levels to mediate these structural changes providing potential pathological pathways warranting further investigation.

Angiotensin converting enzyme inhibitor potentiates the hypoglycaemic effect of NG-nitro-L-arginine methyl ester (L-NAME) in rats

The inhibition of renin angiotensin system pathway has been largely documented to be effective in the control of cardiovascular events. The present study investigated the effect of angiotensin converting enzyme (ACE) inhibitor on fasting blood glucose level in hypertension induced by the inhibition of nitric oxide synthase (NOS) in male Wistar rats. Hypertension was induced by the inhibition of NOS using a non-selective NOS inhibitor, NG-nitro-L-arginine methyl ester (L-NAME). The blockade of NOS resulted in an increase in blood pressure, ACE, angiotensin II and endothelin-1 levels, and a decrease in fasting blood glucose and nitric oxide (NO) levels. The hypertensive rats treated with ACE inhibitor (ramipril) recorded a decrease in blood pressure, ACE, angiotensin II, endothelin-1, NO and fasting blood glucose levels, and an increase in prostacyclin level. In conclusion, ACE inhibitor potentiated the hypoglycaemic effect of NOS inhibitor and this effect is independent of NO and pancreatic insulin release.

Pulmonary Function Trajectories in People with HIV: Analysis of the Pittsburgh HIV Lung Cohort

Rationale: Human immunodeficiency virus (HIV) infection is associated with chronic lung disease and impaired pulmonary function; however, longitudinal pulmonary function phenotypes in HIV are undefined. Objectives: To identify pulmonary function trajectories, their determinants, and outcomes. Methods: We used data from participants with HIV in the Pittsburgh HIV Lung Cohort with three or more pulmonary function tests between 2007 and 2020. We analyzed post-bronchodilator forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC, and diffusing capacity of the lung for carbon monoxide (DlCO) using group-based trajectory modeling to identify subgroups of individuals whose measurements followed a similar pattern over time. We examined the association between participant characteristics and trajectories using multivariable logistic regression. In exploratory adjusted analyses restricted to individuals with available plasma cytokine data, we investigated the association between 18 individual standardized cytokine concentrations and trajectories. We compared mortality, dyspnea prevalence, respiratory health status, and 6-minute-walk distance between phenotypes. Results: A total of 265 participants contributed 1,606 pulmonary function measurements over a median follow-up of 8.1 years. We identified two trajectories each for FEV1 and FVC: "low baseline, slow decline" and "high baseline, rapid decline." There were three trajectory groups for FEV1/FVC: "rapid decline," "moderate decline," and "slow decline." Finally, we identified two trajectories for DlCO: "baseline low" and "baseline high." The low baseline, slow decline FEV1 and FVC, rapid decline, and moderate decline FEV1/FVC, and baseline low DlCO phenotypes were associated with increased dyspnea prevalence, worse respiratory health status, and decreased 6-minute-walk distance. The baseline low DlCO phenotype was also associated with worse mortality. Current smoking and pack-years of smoking were associated with the adverse FEV1, FEV1/FVC, and DlCO phenotypes. Detectable viremia was the only HIV marker associated with the adverse DlCO phenotype. C-reactive protein and endothelin-1 were associated with the adverse FEV1 and FVC phenotypes, and endothelin-1 trended toward an association with the adverse DlCO phenotype. Conclusions: We identified novel, distinct longitudinal pulmonary function phenotypes with significant differences in characteristics and outcomes. These findings highlight the importance of lung dysfunction over time in people with HIV and should be validated in additional cohorts.

Endothelin A receptors contribute to senescence of brain microvascular endothelial cells

Cellular senescence plays a pivotal role in the aging and progression of neurodegenerative diseases, including vascular cognitive impairment and dementia (VCID). In postmortem brains from individuals with VCID, endothelin-1 (ET-1) levels closely correlate with blood barrier breakdown and cerebral hypoperfusion. Brain microvascular endothelial cells (BMVECs), previously thought to have exclusively endothelin B receptors, also possess endothelin A (ETA) receptors; however, the functional significance of this receptor in BMVECs is not known. We hypothesize that ETA receptors mediate BMVEC senescence. Serum-starved human BMVECs (HBEC5i) were incubated with ET-1 (1 µmol/L) in the presence/absence of ETA receptor antagonist BQ-123 (20 µmol/L). Cells were collected for Western blot and quantitative real-time PCR analyses. Treatment of ET-1 increased protein expression of ETA receptor, while it was prevented by the ETA receptor antagonist. ET-1 increased p21, p16, p53, LIF1 and cyclin D1 protein levels, and β-galactosidase accumulation, which were prevented in the presence of ETA blockade. While there was no change in tight junction proteins, ET-1 decreased adherent junction protein vascular endothelial cadherin (VE-cadherin) levels. In conclusion, ET-1 upregulates ETA receptors in BMVECs in an autocrine manner and triggers the activation of senescence. These in vitro findings need to be further studied in vivo to establish the role of ETA receptors in the progression of endothelial senescence in VCID.

Hydroxychloroquine reduces hypertension and soluble fms-like kinase-1 in a Nω-nitro-l-arginine methyl ester-induced preeclampsia rat model

OBJECTIVE

Hydroxychloroquine, a drug used for malaria and autoimmune diseases reportedly has beneficial effects against preeclampsia in pregnant women with lupus. However, its mechanism against preeclampsia remains unclear. We investigated the effect of hydroxychloroquine on an Nω-nitro-l-arginine methyl ester-induced preeclampsia rat model.

METHODS

Pregnant Sprague-Dawley rats were divided into four groups based on treatment (administered on gestational days 7-18): control, Nω-nitro-l-arginine methyl ester, hydroxychloroquine, and Nω-nitro-l-arginine methyl ester plus hydroxychloroquine. All animals were sacrificed on gestational day 19. We assayed tube formation and determined reactive oxygen species levels using human umbilical vein endothelial cells.

RESULTS

Results showed that hydroxychloroquine significantly lowered mean systolic blood pressure (P  < 0.05) in Nω-nitro-l-arginine methyl ester-treated rats. Hydroxychloroquine did not affect their fetal and placental weights. Hydroxychloroquine mitigated Nω-nitro-l-arginine methyl ester-associated changes in proteinuria (P  < 0.05). It normalized plasma soluble fms-like kinase-1 (P  < 0.05) and endothelin-1 (P  < 0.01) levels. In the tube formation assay, hydroxychloroquine increased the total meshes area (P  < 0.05) and mitigated Nω-nitro-l-arginine methyl ester-induced reactive oxygen species formation (P  < 0.05) in human umbilical vein endothelial cells.

CONCLUSION

We conclude that hydroxychloroquine alleviated hypertension, proteinuria, and normalized soluble fms-like kinase-1 and endothelin-1 levels in our preeclampsia model and that these changes may involve the restoration of endothelial dysfunction; thus, hydroxychloroquine could potentially be used for preventing preeclampsia, even in the absence of lupus.

Novel sedentary cage induced sedentariness in rats: evidence from relevant biomarkers

BACKGROUND

Sedentary behavior or physical inactivity is considered a foremost contributor to the rise in obesity and overweight and a risk factor for several non-communicable diseases. However, its effect on the etiopathogenesis of some diseases is underestimated in both developed and developing countries worldwide. The present study designed a novel sedentary cage with a view to achieving sedentariness in rats, and also investigated the effectiveness of the cage in achieving sedentariness by assessing some markers of cardiometabolic risks in Wistar rats.

METHODS

Adult male Wistar rats were divided into 3 groups of six rats. Rats in Group 1 were the control. The sedentary groups were 4-hr. sedentary and 8-hr. sedentary. The sedentary rats were subjected to restrained movements for 4 and 8 hours daily in the sedentary cage for 3 months. Anthropometric indices, food consumption and blood pressure parameters of the rats were measured. Microalbuminuria and serum glucose, uric acid, albumin, nitric oxide, endothelin-1, insulin, inflammatory markers were also Measured.

RESULTS

Results indicated significant increases in body weight, BMI, Lee index, food consumption, systolic and diastolic pressure and decrease in serum nitric oxide bioavailability in the 8-hr sedentary rats. There were also significant increases in serum glucose, uric acid, endothelin-1, insulin, CRP and microalbuminuria in the 8-hr. sedentary rats in comparison with the control. The interleukin-6 and TNF-α also revealed a significant increase in the 8-hr. sedentary rats compared with the control. However, there was no significant difference in cortisol level across all the groups.

CONCLUSIONS

We concluded that the novel sedentary cage successfully caused sedentariness in the rats as evident by the alteration in the cardiometabolic health in the rats, especially the group that were made sedentary for 8 h.

A common Matrix metalloproteinase 8 promoter haplotype enhances the risk for hypertension via diminished interactions with nuclear factor kappa B

OBJECTIVES

Matrix metalloproteinase 8 (MMP8) has a prominent role in collagen turnover in blood vessels and vascular remodeling. The contribution of regulatory single nucleotide polymorphisms in MMP8 to cardiovascular diseases is unclear. We aimed to delineate the influence of MMP8 promoter variations on hypertension.

METHODS

A case-control study in unrelated individuals ( n  = 2565) was carried out. Resequencing of the MMP8 proximal promoter, linkage disequilibrium analysis, genotyping of variants and regression analyses were performed. MMP8 promoter-reporter constructs were generated and expressed in human vascular endothelial cells under various conditions.

RESULTS

We identified four single nucleotide polymorphisms (SNPs) in the promoter region of MMP8 : -1089A/G (rs17099452), -815G/T (rs17099451), -795C/T (rs11225395), -763A/T (rs35308160); these SNPs form three major haplotypes. Hap3 (viz., GTTT haplotype) carriers showed significant associations with hypertension in two geographically distinct human populations (e.g., Chennai: odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.16-1.86, P  = 2 × 10 -3 ; Chandigarh: OR = 1.85, 95% CI = 1.21-2.81, P  = 4 × 10 -3 ). Hap3 carriers also displayed elevated systolic blood pressure, diastolic blood pressure and mean arterial pressure levels. Hap3 promoter-reporter construct showed lower promoter activity than the wild-type (Hap1) construct. In silico analysis and molecular dynamics studies predicted diminished binding of the transcription factor nuclear factor kappa B (NF-κB) to the functional -815T allele of Hap3 compared to the -815G wild-type allele; this prediction was validated by in-vitro experiments. Hap3 displayed impaired response to tumor necrosis factor-alpha treatment, possibly due to weaker binding of NF-κB. Notably, MMP8 promoter haplotypes were identified as independent predictors of plasma MMP8 and endothelial dysfunction markers (von Willebrand factor and endothelin-1) levels.

CONCLUSION

MMP8 promoter GTTT haplotype has a functional role in reducing MMP8 expression during inflammation via diminished interaction with NF-κB and in enhancing the risk of hypertension.