Veratridine Induces Vasorelaxation in Mouse Cecocolic Mesenteric Arteries.

The vegetal alkaloid toxin veratridine (VTD) is a selective voltage-gated Na (Na) channel activator, widely used as a pharmacological tool in vascular physiology. We have previously shown that Na channels, expressed in arteries, contribute to vascular tone in mouse mesenteric arteries (MAs). Here, we aimed to better characterize the mechanisms of action of VTD using mouse cecocolic arteries (CAs), a model of resistance artery.

Adaptive remodeling of rat adrenomedullary stimulus-secretion coupling in a chronic hypertensive environment.

Chronic elevated blood pressure impinges on the functioning of multiple organs and therefore harms body homeostasis. Elucidating the protective mechanisms whereby the organism copes with sustained or repetitive blood pressure rises is therefore a topical challenge. Here we address this issue in the adrenal medulla, the master neuroendocrine tissue involved in the secretion of catecholamines, influential hormones in blood pressure regulation.

Mechanical stress and anionic lipids synergistically stabilize an atypical structure of the angiotensin II type 1 receptor (AT1).

Environmental factors, including mechanical stress and surrounding lipids, can influence the response of GPCRs, such as the mechanosensitive angiotensin II type 1 receptor (AT1). To investigate the impact of these factors on AT1 activation, we developed a steered molecular dynamics simulations protocol based on quaternion formalism. In this protocol, a pulling force was applied to the N-terminus of transmembrane helix 6 (TM6) to induce the TM6 opening characteristic of activation.

Reduced microvascular flow-mediated dilation in Syrian hamsters lacking δ-sarcoglycan is caused by increased oxidative stress.

δ-Sarcoglycan mutation reduces mechanotransduction and induces dilated cardiomyopathy with aging. We hypothesized that in young hamsters with δ-sarcoglycan mutation, which do not show cardiomyopathy, flow mechanotransduction might be affected in resistance arteries as the control of local blood flow. Flow-mediated dilation (FMD) was measured in isolated mesenteric resistance arteries, using 3-mo-old hamsters carrying a mutation in the δ-sarcoglycan gene (CH-147) and their control littermates.

[Estrogen receptors and vascular aging].

After years of studying cardiovascular diseases (CVD) in men due to their higher incidence compared to women, attention is now being paid to female CVD and their pathophysiology. Even though premenopausal women have a lower incidence of CVD, this disparity progressively diminishes after menopause, highlighting the key role of sex hormones. Many preclinical and fundamental studies have demonstrated protective effects of estrogens on arterial endothelium, suggesting that hormone therapy could improve cardiovascular health in menopausal women.

Zonation and ligand and dose dependence of sphingosine 1-phosphate receptor-1 signalling in blood and lymphatic vasculature.

Aims: Circulating levels of sphingosine 1-phosphate (S1P), an HDL-associated ligand for the endothelial cell (EC) protective S1P receptor-1 (S1PR1), are reduced in disease states associated with endothelial dysfunction. Yet, as S1PR1 has high affinity for S1P and can be activated by ligand-independent mechanisms and EC autonomous S1P production, it is unclear if relative reductions in circulating S1P can cause endothelial dysfunction. It is also unclear how EC S1PR1 insufficiency, whether induced by deficiency in circulating ligand or by S1PR1-directed immunosuppressive therapy, affects different vascular subsets.

L-Wnk1 Deletion in Smooth Muscle Cells Causes Aortitis and Inflammatory Shift.

Background: The long isoform of the Wnk1 (with-no-lysine [K] kinase 1) is a ubiquitous serine/threonine kinase, but its role in vascular smooth muscle cells (VSMCs) pathophysiology remains unknown.

Methods: AngII (angiotensin II) was infused in to induce experimental aortic aneurysm. Mice carrying an allele were cross-bred with mice carrying a floxed allele to specifically investigate the functional role of Wnk1 in VSMCs.

Ketogenic diet enhances the anti-cancer effects of PD-L1 blockade in renal cell carcinoma.

Introduction: Clear cell renal cell carcinoma (ccRCC) is characterized by a predominant metabolic reprogramming triggering energy production by anaerobic glycolysis at the expense of oxydative phosphorylation. Ketogenic diet (KD), which consists of high fat and low carbohydrate intake, could bring required energy substrates to healthy cells while depriving tumor cells of glucose. Our objective was to evaluate the effect of KD on renal cancer cell tumor metabolism and growth proliferation.

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.

Kynurenic Acid: A Novel Player in Cardioprotection against Myocardial Ischemia/Reperfusion Injuries.

Background: Myocardial infarction is one of the leading causes of mortality worldwide; hence, there is an urgent need to discover novel cardioprotective strategies. Kynurenic acid (KYNA), a metabolite of the kynurenine pathway, has been previously reported to have cardioprotective effects. However, the mechanisms by which KYNA may be protective are still unclear.

NTPDase1/CD39 Ectonucleotidase Is Necessary for Normal Arterial Diameter Adaptation to Flow.

NTPDase1/CD39, the major vascular ectonucleotidase, exerts thrombo-immunoregulatory function by controlling endothelial P2 receptor activation. Despite the well-described release of ATP from endothelial cells, few data are available regarding the potential role of CD39 as a regulator of arterial diameter. We thus investigated the contribution of CD39 in short-term diameter adaptation and long-term arterial remodeling in response to flow using male mice.

Autophagy protein 5 controls flow-dependent endothelial functions.

Dysregulated autophagy is associated with cardiovascular and metabolic diseases, where impaired flow-mediated endothelial cell responses promote cardiovascular risk. The mechanism by which the autophagy machinery regulates endothelial functions is complex. We applied multi-omics approaches and in vitro and in vivo functional assays to decipher the diverse roles of autophagy in endothelial cells.

Tetrodotoxin Decreases the Contractility of Mesenteric Arteries, Revealing the Contribution of Voltage-Gated Na Channels in Vascular Tone Regulation.

Tetrodotoxin (TTX) poisoning through the consumption of contaminated fish leads to lethal symptoms, including severe hypotension. This TTX-induced hypotension is likely due to the downfall of peripheral arterial resistance through direct or indirect effects on adrenergic signaling. TTX is a high-affinity blocker of voltage-gated Na (Na) channels.

Homology Modeling in the Twilight Zone: Improved Accuracy by Sequence Space Analysis.

The analysis of the relationship between sequence and structure similarities during the evolution of a protein family has revealed a limit of sequence divergence for which structural conservation can be confidently assumed and homology modeling is reliable. Below this limit, the twilight zone corresponds to sequence divergence for which homology modeling becomes increasingly difficult and requires specific methods. Either with conventional threading methods or with recent deep learning methods, such as AlphaFold, the challenge relies on the identification of a template that shares not only a common ancestor (homology) but also a conserved structure with the query.

Loss of function of the maternal membrane oestrogen receptor ERα alters expansion of trophoblast cells and impacts mouse fertility.

The binding of 17β-oestradiol to oestrogen receptor alpha (ERα) plays a crucial role in the control of reproduction, acting through both nuclear and membrane-initiated signalling. To study the physiological role of membrane ERα in the reproductive system, we used the C451A-ERα mouse model with selective loss of function of membrane ERα. Despite C451A-ERα mice being described as sterile, daily weighing and ultrasound imaging revealed that homozygous females do become pregnant, allowing the investigation of the role of ERα during pregnancy for the first time.

Placental protein 13 dilation of pregnant rat uterine vein is endothelium dependent and involves nitric oxide/calcium activated potassium channels signals.

Introduction: Accumulating evidence demonstrates the importance of the galectin protein Placental Protein 13 (PP13) in predicting Preeclampsia (PE), a gestational disorder that has no cure and is associated with a compromised uterine vascular adaptation to pregnancy. Uterine vasculature undergoes significant remodeling (growth in length and in circumference) during normal pregnancy to accommodate the increased blood volume to the feto-placental unit. The aim of this study was to demonstrate the role of PP13 on the uterine veins (UVs).

Estrogen Receptor and Vascular Aging.

Cardiovascular diseases remain an age-related pathology in both men and women. These pathologies are 3-fold more frequent in men than in women before menopause, although this difference progressively decreases after menopause. The vasculoprotective role of estrogens are well established before menopause, but the consequences of their abrupt decline on the cardiovascular risk at menopause remain debated.

Screening an In-House Isoquinoline Alkaloids Library for New Blockers of Voltage-Gated Na Channels Using Voltage Sensor Fluorescent Probes: Hits and Biases.

Voltage-gated Na (Na) channels are significant therapeutic targets for the treatment of cardiac and neurological disorders, thus promoting the search for novel Na channel ligands. With the objective of discovering new blockers of Na channel ligands, we screened an In-House vegetal alkaloid library using fluorescence cell-based assays. We screened 62 isoquinoline alkaloids (IA) for their ability to decrease the FRET signal of voltage sensor probes (VSP), which were induced by the activation of Na channels with batrachotoxin (BTX) in GH3b6 cells.

Metabolomic Profiling of Angiotensin-II-Induced Abdominal Aortic Aneurysm in Ldlr Mice Points to Alteration of Nitric Oxide, Lipid, and Energy Metabolisms.

Aneurysm is the second-most common disease affecting the aorta worldwide after atherosclerosis. While several clinical metabolomic studies have been reported, no study has reported deep metabolomic phenotyping in experimental animal models of aortic aneurysm. We performed a targeted metabolomics study on the blood and aortas of an experimental mice model of aortic aneurysm generated by high-cholesterol diet and angiotensin II in Ldlr mice.

Altered Mitochondrial Opa1-Related Fusion in Mouse Promotes Endothelial Cell Dysfunction and Atherosclerosis.

Flow (shear stress)-mediated dilation (FMD) of resistance arteries is a rapid endothelial response involved in tissue perfusion. FMD is reduced early in cardiovascular diseases, generating a major risk factor for atherosclerosis. As alteration of mitochondrial fusion reduces endothelial cells' (ECs) sprouting and angiogenesis, we investigated its role in ECs responses to flow.

Modulating the immune response to reduce hypertension-associated cardiovascular damage.

Cardiovascular diseases are a leading cause of mortality and disability worldwide. Hypertension, a major risk factor for these diseases, remains difficult to treat despite numerous drugs being available. In this issue of the JCI, Failer et al.