Beta-3 adrenergic receptor overexpression reverses aortic stenosis-induced heart failure and restores balanced mitochondrial dynamics.

Aortic stenosis (AS) is associated with left ventricular (LV) hypertrophy and heart failure (HF). There is a lack of therapies able to prevent/revert AS-induced HF. Beta3 adrenergic receptor (β3AR) signaling is beneficial in several forms of HF.

NT3/TrkC Pathway Modulates the Expression of UCP-1 and Adipocyte Size in Human and Rodent Adipose Tissue.

Unlabelled: (NT3), through activation of its tropomyosin-related kinase receptor C (TrkC), modulates neuronal survival and neural stem cell differentiation. It is widely distributed in peripheral tissues (especially vessels and pancreas) and this ubiquitous pattern suggests a role for NT3, outside the nervous system and related to metabolic functions. The presence of the NT3/TrkC pathway in the adipose tissue (AT) has never been investigated.

β2-Adrenoceptors and GRK2 as Potential Biomarkers in Patients With Chronic Pulmonary Regurgitation.

Pulmonary regurgitation (PR) is a frequent complication after repair of congenital heart disease. Three different GRK isoforms (GRK2, GRK5, and GRK3) and two β-adrenoceptors (β1-AR and β2-AR) are present in peripheral blood mononuclear cells (PBMC) and their expression changes as a consequence of the hemodynamic and neurohumoral alterations that occur in some cardiovascular diseases. Therefore, they could be useful as biomarkers in PR.

Dexamethasone Preconditioning in Cardiac Procedures Reduces Decreased Antithrombin Activity and Is Associated to Beneficial Outcomes: Role of Endothelium.

Decreased antithrombin (AT) activity in patients scheduled for cardiovascular surgery under cardiopulmonary bypass (CPB) is related to increased postoperative complications and hospitalization time. Indirect evidence suggests that glucocorticoids mitigate this decreased AT activity. To better understand the beneficial effects of AT we have analyzed: (i) the clinical relevance of acute dexamethasone (DX) administration before cardiac surgery on AT activity, (ii) the modulation by DX of AT expression in human endothelial cells (hECs), (iii) the activity of AT on migration and angiogenesis of hECs, or on angiogenesis of rat aorta.

Activation of α -adrenoceptors desensitizes the rat aorta response to phenylephrine through a neuronal NOS pathway, a mechanism lost with ageing.

Background And Purpose: A NO-mediated desensitization of vasoconstrictor responses evoked by stimulation of α -adrenoceptors has been reported in different vessels. We investigated the involvement of each α -adrenoceptor subtype and constitutive NOS isoforms and the influence of ageing and hypertension on this process.

Experimental Approach: Wistar and spontaneously hypertensive rats (SHR), 16, 32, 52 and 72 weeks-old, were used to evaluate the desensitization process.

Changes in the expression of α-adrenoceptor in peripheral mononuclear cells correlates with blood pressure and plasmatic homocysteine.

Human peripheral mononuclear cells (HPMC) have been suggested as a practical surrogate for myocardial or vascular cells. Present work analyses if changes in the expression of α-adrenoceptors (ARs) in HPMC are related to the hypertensive state and its clinical consequences. Quantitative RT-PCR was employed to evaluate the mRNA levels of the three α-ARs (α, α, α) in HPMC isolated from normotensive and hypertensive patients, and also in tissues from two animal models of hypertension: spontaneously hypertensive rats (SHR) and hypertension induced by chronic treatment with L-NAME.

Methodological Approach to Use Fresh and Cryopreserved Vessels as Tools to Analyze Pharmacological Modulation of the Angiogenic Growth.

The sprouting of new vessels is greatly influenced by the procedure chosen. We sought to optimize the experimental conditions of the angiogenic growth of fresh and cryopreserved vessels cultured in Matrigel with the aim to use this system to analyze the pharmacological modulation of the process. Segments of second-order branches of rat mesenteric resistance arteries, thoracic aorta of rat or mouse, and cryopreserved rat aorta and human femoral arteries were cultured in Matrigel for 7-21 days in different mediums, as well as in the absence of endothelial or adventitia layer.

β2- and β1-Adrenoceptor Expression Exhibits a Common Regulatory Pattern With GRK2 and GRK5 in Human and Animal Models of Cardiovascular Diseases.

To explore if genic expression of β(1)- or β(2)-adrenoceptors (ARs) exhibits a common regulatory pattern with G protein-coupled receptor kinase (GRK) 2, GRK3, or GRK5 expression, we determined messenger RNA levels for these genes in different tissues from human and animal models of cardiovascular disease. We measured genic expression by qRT polymerase chain reaction in the left and right ventricles or peripheral blood mononuclear cells from healthy (n = 21), hypertensive (n = 20), heart failure (n = 24), and heart transplanted patients (n = 17) or in left ventricle, peripheral blood mononuclear cells, and kidney from spontaneously hypertensive rats or L-N-methyl-arginine-induced hypertensive rats and their respective controls (n = 4-5). In diseased versus healthy subjects and rats, parallel changes in messenger RNA levels of GRK2 and β(2)-AR or GRK5 and β(1)-AR were observed in each territory.

Glucocorticoids as modulators of expression and activity of Antithrombin (At): potential clinical relevance.

Introduction: An inverse relationship has been reported between decreased postoperative Antithrombin (AT) plasmatic levels and the incidence of complications. We hypothesized that Nuclear Hormone Receptors could modulate the expression of SERPINC1, encoding AT, through a Hormone Regulatory Element present in its promoter, and thus hormone analogs could be a pharmacological complement in surgical procedures to activate endogenous AT synthesis.

Materials And Methods: The expression of SERPINC1 was analyzed in HepG2 cells by quantitative RT-PCR and Western Blot.

Action of an extract from the seeds of Fraxinus excelsior L. on metabolic disorders in hypertensive and obese animal models.

Nuzhenide and GI3, the principal secoiridoids of an extract obtained from the seeds of Fraxinus excelsior L. (FXE), are believed to be the active compounds responsible for the previously reported hypoglycemic effects of this extract. In this study, the effects of FXE were studied in two animal models which are representative of metabolic disorders: spontaneously hypertensive rats (SHR) and obese Zucker rats.

Myocardial and lymphocytic expression of eNOS and nNOS before and after heart transplantation: relationship to clinical status.

Aims: The present study investigates the expression and clinical relevance of the constitutive NO synthases in heart and peripheral blood mononuclear cells (PBMCs) obtained from heart failure patients.

Main Methods: mRNA and protein levels (qRT-PCR and immunoblot) of eNOS and nNOS were determined in: i) Left ventricle (LV, n=4) and PBMCs (n=10) from healthy donors; ii) LV, right ventricle (RV) and PBMCs of heart failure (HF) patients (n=32); and iii) biopsies and PBMCs of the HF patients after cardiac transplant (n=15).

Key Findings: Expression of constitutive NOS isoforms in heart exhibits wide variability in HF patients, but this variability was not related to aetiology, disease severity, concomitant pathologies or drug regimes.

Differences in the signaling pathways of α(1A)- and α(1B)-adrenoceptors are related to different endosomal targeting.

Aims: To compare the constitutive and agonist-dependent endosomal trafficking of α(1A)- and α(1B)-adrenoceptors (ARs) and to establish if the internalization pattern determines the signaling pathways of each subtype.

Methods: Using CypHer5 technology and VSV-G epitope tagged α(1A)- and α(1B)-ARs stably and transiently expressed in HEK 293 cells, we analyzed by confocal microscopy the constitutive and agonist-induced internalization of each subtype, and the temporal relationship between agonist induced internalization and the increase in intracellular calcium (determined by FLUO-3 flouorescence), or the phosphorylation of ERK1/2 and p38 MAP kinases (determined by Western blot).

Results And Conclusions: Constitutive as well as agonist-induced trafficking of α(1A) and α(1B) ARs maintain two different endosomal pools of receptors: one located close to the plasma membrane and the other deeper into the cytosol.

Different expression of adrenoceptors and GRKs in the human myocardium depends on heart failure etiology and correlates to clinical variables.

Downregulation of β(1)- adrenergic receptors (β(1)-ARs) and increased expression/function of G-protein-coupled receptor kinase 2 (GRK2) have been observed in human heart failure, but changes in expression of other ARs and GRKs have not been established. Another unresolved question is the incidence of these compensatory mechanisms depending on heart failure etiology and treatment. To analyze these questions, we quantified the mRNA/protein expressions of six ARs (α(1A), α(1B), α(1D), β(1), β(2), and β(3)) and three GRKs (GRK2, GRK3, and GRK5) in left (LV) and right ventricle (RV) from four donors, 10 patients with ischemic cardiomyopathy (IC), 14 patients with dilated cardiomyopathy (DC), and 10 patients with nonischemic, nondilated cardiopathies (NINDC).

Myocardial G protein receptor-coupled kinase expression correlates with functional parameters and clinical severity in advanced heart failure.

Background: In heart failure (HF), sympathetic hyperactivation induces deleterious effects in myocardial β-adrenergic signaling, with receptor down-regulation and desensitization mediated by G protein receptor-coupled kinases (GRKs). We hypothesised that changes in GRK isoforms may be associated with clinical status in advanced HF, using the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) scale.

Methods: We included 31 patients with advanced HF undergoing transplantation.

beta-Adrenoceptor and GRK3 expression in human lymphocytes is related to blood pressure and urinary albumin excretion.

Objective: The objective of our work was to analyze if changes in the expression of beta-adrenoceptors (beta-ARs) and G-protein-coupled receptor kinases (GRKs) in human lymphocytes - a practical surrogate for myocardial or vascular cells - are related to the hypertensive state and its clinical consequences.

Methods: Real-time quantitative RT-PCR was employed to evaluate the expression of the three beta-ARs (beta1, beta2, beta3) and three GRKs (GRK2, GRK3, GRK5) in human lymphocytes obtained from both normotensive and hypertensive patients, some of whom had been treated with blockers of the renin-angiotensin system. Office blood pressure, 24-h ambulatory blood pressure, urinary albumin excretion and serum biochemical profile were also recorded.

Myocardial and peripheral lymphocytic transcriptomic dissociation of beta-adrenoceptors and G protein-coupled receptor kinases in heart transplantation.

Background: The genetic expression of adrenergic receptors plays an important pathophysiologic role in heart failure. G protein-coupled receptor kinases (GRKs) desensitize the beta-receptor to catecholaminergic stimulation. It has been suggested that their mRNA expression in peripheral lymphocytes could mirror the changes in their myocardial expression in the failing heart, but this relationship between the myocyte and lymphocyte has not been studied in heart transplantation (HT).

The impact of alpha1-adrenoceptors up-regulation accompanied by the impairment of beta-adrenergic vasodilatation in hypertension.

In human and animal hypertension models, increased activity of G-protein-coupled receptor kinase (GRK) 2 determines a generalized decrease of beta-adrenergic vasodilatation. We analyzed the possibility of differential changes in the expression and functionality of alpha(1A), alpha(1B), alpha(1D), beta(1), beta(2), and beta(3)-ARs also being involved in the process. We combined the quantification of mRNA levels with immunoblotting and functional studies in aortas of young and adult spontaneously hypertensive rats (SHRs) and their controls (Wistar Kyoto).