Aldosterone signaling through transient receptor potential melastatin 7 cation channel (TRPM7) and its α-kinase domain

We demonstrated a role for the Mg2 + transporter TRPM7, a bifunctional protein with channel and α-kinase domains, in aldosterone signaling. Molecular mechanisms underlying this are elusive. Here we investigated the function of TRPM7 and its α-kinase domain on Mg2 + and pro-inflammatory signaling by aldosterone. Kidney cells (HEK-293) expressing wild-type human TRPM7 (WThTRPM7) or constructs in which the α-kinase domain was deleted (ΔKinase) or rendered inactive with a point mutation in the ATP binding site of the α-kinase domain (K1648R) were studied. Aldosterone rapidly increased [Mg2 +]i and stimulated NADPH oxidase-derived generation of reactive oxygen species (ROS) in WT hTRPM7 and TRPM7 kinase dead mutant cells. Translocation of annexin-1 and calpain-II and spectrin cleavage (calpain target) were increased by aldosterone in WT hTRPM7 cells but not in α-kinase-deficient cells. Aldosterone stimulated phosphorylation of MAP kinases and increased expression of pro-inflammatory mediators ICAM-1, Cox-2 and PAI-1 in Δkinase and K1648R cells, effects that were inhibited by eplerenone (mineralocorticoid receptor (MR) blocker). 2-APB, a TRPM7 channel inhibitor, abrogated aldosterone-induced Mg2 + responses in WT hTRPM7 and mutant cells. In 2-APB-treated ΔKinase and K1648R cells, aldosterone-stimulated inflammatory responses were unchanged. These data indicate that aldosterone stimulates Mg2 + influx and ROS production in a TRPM7-sensitive, kinase-insensitive manner, whereas activation of annexin-1 requires the TRPM7 kinase domain. Moreover TRPM7 α-kinase modulates inflammatory signaling by aldosterone in a TRPM7 channel/Mg2 +-independent manner. Our findings identify novel mechanisms for non-genomic actions of aldosterone involving differential signaling through MR-activated TRPM7 channel and α-kinase

Anti‐atherosclerotic effect of the angiotensin 1–7 mimetic AVE0991 is mediated by inhibition of perivascular and plaque inflammation in early atherosclerosis

Background and Purpose: Inflammation plays a key role in atherosclerosis. A protective role of angiotensin-(1-7) in vascular pathologies opened a possibility for therapeutic use of small molecule non-peptide Ang-(1-7) mimetics, such as AVE0991. The mechanisms of these vaso-protective effects of a Mas receptor agonist, AVE0991, remain unclear. Experimental approach: We investigated the effects of AVE0991 on the spontaneous atherosclerosis in ApoE-/- mice, in the context of vascular inflammation and plaque stability. Key Results: AVE0991 has significant anti-atherosclerotic properties in ApoE-/- mice and increases plaque stability, by reducing plaque macrophage content, without effects on collagen. Using descending aorta of chow fed ApoE-/- mice, before significant atherosclerotic plaque develops, we gained insight to early events in atherosclerosis. Interestingly, perivascular adipose tissue (pVAT) and adventitial infiltration with macrophages and T cells precedes atherosclerotic plaque or the impairment of endothelium-dependent NO bioavailability as a measure of endothelial function. AVE0991 inhibited perivascular inflammation, through the reduction of chemokine expression in pVAT, as well as through direct actions on monocytes/macrophages inhibiting their activation, characterized by IL-1β, TNF-α, MCP-1 and CXCL10 and differentiation to M1 phenotype. Pre-treatment with AVE0991 inhibited migration of THP-1 monocytes towards supernatants of activated adipocytes (SW872). Mas receptors were expressed in pVAT and in THP-1 cells in vitro and anti-inflammatory effects of AVE0991 were partially Mas dependent. Conclusions & implications: Selective Mas receptor agonist AVE0991 possesses anti-atherosclerotic and anti-inflammatory properties, affecting monocyte/macrophage differentiation and recruitment to perivascular space at early stages of atherosclerosis in ApoE-/- mice

Report of the International Society of Hypertension (ISH) Hypertension Teaching Seminar organized by the ISH Africa Regional Advisory Group: Maputo, Mozambique, 2016

The International Society of Hypertension (ISH), in fulfilment of its mission of promoting hypertension control and prevention and also of advancing knowledge globally, organizes hypertension teaching seminars or ‘summer schools’ worldwide through the ISH Regional Advisory Groups. In Africa, seven of such seminars have been organized. This is a report of the eighth seminar held in Maputo, Mozambique, April, 2016. The seminar was attended by over 65 participants from 11 African countries. The Faculty consisted of 11 international hypertension experts. The eighth African hypertension seminar was a great success as confirmed by a pre- and post-test questionnaire

Examining the relationship between semiquantitative methods analysing concentration-time and enhancement-time curves from dynamic-contrast enhanced magnetic resonance imaging and cerebrovascular dysfunction in small vessel disease

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can be used to examine the distribution of an intravenous contrast agent within the brain. Computational methods have been devised to analyse the contrast uptake/washout over time as reflections of cerebrovascular dysfunction. However, there have been few direct comparisons of their relative strengths and weaknesses. In this paper, we compare five semiquantitative methods comprising the slope and area under the enhancement-time curve, the slope and area under the concentration-time curve ( SlopeCon and AUCCon ), and changes in the power spectrum over time. We studied them in cerebrospinal fluid, normal tissues, stroke lesions, and white matter hyperintensities (WMH) using DCE-MRI scans from a cohort of patients with small vessel disease (SVD) who presented mild stroke. The total SVD score was associated with AUCCon in WMH ( p0.05 ) and WMH burden ( p>0.05 ). Our results show the potential of different measures extracted from concentration-time curves extracted from the same DCE examination to demonstrate cerebrovascular dysfunction better than those extracted from enhancement-time curves

Cardiotoxicity and myocardial hypoperfusion associated with anti‐vascular endothelial growth factor therapies: prospective cardiac magnetic resonance imaging in patients with cancer

No abstract available

A four-dimensional computational model of dynamic contrast-enhanced magnetic resonance imaging measurement of subtle blood-brain barrier leakage

Dynamic contrast-enhanced MRI (DCE-MRI) is increasingly used to quantify and map the spatial distribution of blood-brain barrier (BBB) leakage in neurodegenerative disease, including cerebral small vessel disease and dementia. However, the subtle nature of leakage and resulting small signal changes make quantification challenging. While simplified one-dimensional simulations have probed the impact of noise, scanner drift, and model assumptions, the impact of spatio-temporal effects such as gross motion, k-space sampling and motion artefacts on parametric leakage maps has been overlooked. Moreover, evidence on which to base the design of imaging protocols is lacking due to practical difficulties and the lack of a reference method. To address these problems, we present an open-source computational model of the DCE-MRI acquisition process for generating four dimensional Digital Reference Objects (DROs), using a high-resolution brain atlas and incorporating realistic patient motion, extra-cerebral signals, noise and k-space sampling. Simulations using the DROs demonstrated a dominant influence of spatio-temporal effects on both the visual appearance of parameter maps and on measured tissue leakage rates. The computational model permits greater understanding of the sensitivity and limitations of subtle BBB leakage measurement and provides a non-invasive means of testing and optimising imaging protocols for future studies

2022 ESC guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: developed by the task force for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death of the European Society of Cardiology (ESC) endorsed by the Association for European Paediatric and Congenital Cardiology (A

Cardiolog

Vascular Remodeling in Health and Disease

The term vascular remodeling is commonly used to define the structural changes in blood vessel geometry that occur in response to long-term physiologic alterations in blood flow or in response to vessel wall injury brought about by trauma or underlying cardiovascular diseases.1, 2, 3, 4 The process of remodeling, which begins as an adaptive response to long-term hemodynamic alterations such as elevated shear stress or increased intravascular pressure, may eventually become maladaptive, leading to impaired vascular function. The vascular endothelium, owing to its location lining the lumen of blood vessels, plays a pivotal role in regulation of all aspects of vascular function and homeostasis.5 Thus, not surprisingly, endothelial dysfunction has been recognized as the harbinger of all major cardiovascular diseases such as hypertension, atherosclerosis, and diabetes.6, 7, 8 The endothelium elaborates a variety of substances that influence vascular tone and protect the vessel wall against inflammatory cell adhesion, thrombus formation, and vascular cell proliferation.8, 9, 10 Among the primary biologic mediators emanating from the endothelium is nitric oxide (NO) and the arachidonic acid metabolite prostacyclin [prostaglandin I2 (PGI2)], which exert powerful vasodilatory, antiadhesive, and antiproliferative effects in the vessel wall