Congestive heart failure induces endothelial cell apoptosis: protective role of carvedilol

Endothelial Dysfunction in Heart Failure: What Is Its Role?

The endothelium is a continuous layer of cells that coats the interior walls of arteries, capillaries, and veins. It has an essential regulatory role in hemostatic function, vascular tone, inflammation, and platelet activity. Endothelial dysfunction is characterized by a shift to a proinflammatory and prothrombic state, and it could have a bidirectional relationship with heart failure (HF). Due to neurohormonal activation and shear stress, HFrEF may promote endothelial dysfunction, increase ROS synthesis, and reduce nitric oxide production. Different studies have also shown that endothelium function is damaged in HFpEF because of a systemic inflammatory state. Some clinical trials suggest that drugs that have an effect on endothelial dysfunction in patients with HF or cardiovascular disease may be a therapeutic option. The aim of this review is to highlight the pathogenetic correlation between endothelial dysfunction and heart failure and the related potential therapeutic options.

The potential of herbal drugs to treat heart failure: The roles of Sirt1/AMPK

Heart failure (HF) is a highly morbid syndrome that seriously affects the physical and mental health of patients and generates an enormous socio-economic burden. In addition to cardiac myocyte oxidative stress and apoptosis, which are considered mechanisms for the development of HF, alterations in cardiac energy metabolism and pathological autophagy also contribute to cardiac abnormalities and ultimately HF. Silent information regulator 1 (Sirt1) and adenosine monophosphate-activated protein kinase (AMPK) are nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases and phosphorylated kinases, respectively. They play similar roles in regulating some pathological processes of the heart through regulating targets such as peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), protein 38 mitogen-activated protein kinase (p38 MAPK), peroxisome proliferator-activated receptors (PPARs), and mammalian target of rapamycin (mTOR). We summarized the synergistic effects of Sirt1 and AMPK in the heart, and listed the traditional Chinese medicine (TCM) that exhibit cardioprotective properties by modulating the Sirt1/AMPK pathway, to provide a basis for the development of Sirt1/AMPK activators or inhibitors for the treatment of HF and other cardiovascular diseases (CVDs).

Endothelial Dysfunction and Heart Failure with Preserved Ejection Fraction-An Updated Review of the Literature

Heart failure (HF) is a clinical syndrome consisting of typical symptoms and signs due to structural and/or functional abnormalities of the heart, resulting in elevated intracardiac pressures and/or inadequate cardiac output. The vascular system plays a crucial role in the development and progression of HF regardless of ejection fraction, with endothelial dysfunction (ED) as one of the principal features of HF. The main ED manifestations (i.e., impaired endothelium-dependent vasodilation, increased oxidative stress, chronic inflammation, leukocyte adhesion, and endothelial cell senescence) affect the systemic and pulmonary haemodynamic and the renal and coronary circulation. The present review is aimed to discuss the contribution of ED to HF pathophysiology-in particular, HF with preserved ejection fraction-ED role in HF patients, and the possible effects of pharmacological and non-pharmacological approaches. For this purpose, relevant data from a literature search (PubMed, Scopus, EMBASE, and Medline) were reviewed. As a result, ED, assessed via venous occlusion plethysmography or flow-mediated dilation, was shown to be independently associated with poor outcomes in HF patients (e.g., mortality, cardiovascular events, and hospitalization due to worsening HF). In addition, SGLT2 inhibitors, endothelin antagonists, endothelial nitric oxide synthase cofactors, antioxidants, and exercise training were shown to positively modulate ED in HF. Despite the need for future research to better clarify the role of the vascular endothelium in HF, ED represents an interesting and promising potential therapeutic target.

Impact of blood factors on endothelial cell metabolism and function in two diverse heart failure models

Role of blood-based factors in development and progression of heart failure (HF) is poorly characterized. Blood contains factors released during pathophysiological states that may impact cellular function and provide mechanistic insights to HF management. We tested effects of blood from two distinct HF models on cardiac metabolism and identified possible cellular targets of the effects. Blood plasma was obtained from daunorubicin- and myocardial infarction-induced HF rabbits (Dauno-HF and MI-HF) and their controls (Dauno-Control and MI-Control). Effects of plasma on bioenergetics of myocardial tissue from healthy mice and cellular cardiac components were assessed using high-resolution respirometry and Seahorse flux analyzer. Since endothelial cell respiration was profoundly affected by HF plasma, effects of plasma on endothelial cell barrier function and death were further evaluated. Western-blotting and electron microscopy were performed to evaluate mitochondrial proteins and morphology. Brief exposure to HF plasma decreased cardiac tissue respiration. Endothelial cell respiration was most impacted by exposure to HF plasma. Endothelial cell monolayer integrity was decreased by incubation with Dauno-HF plasma. Apoptosis and necrosis were increased in cells incubated with Dauno-HF plasma for 24 h. Down-regulation of voltage-dependent anion-selective channel (VDAC)-1, translocase of outer membrane 20 (Tom20), and mitochondrial fission factor (MFF) in cells exposed to Dauno-HF plasma and mitochondrial signal transducer and activator of transcription 3 (Stat3) and MFF in cells exposed to MI-HF plasma were observed. Mitochondrial structure was disrupted in cells exposed to HF plasma. These findings indicate that endothelial cells and mitochondrial structure and function may be primary target where HF pathology manifests and accelerates. High-throughput blood-based screening of HF may provide innovative ways to advance disease diagnosis and management.

Carvedilol attenuates brain damage in mice with hepatic encephalopathy

Brain injury is the most common and serious consequence of hepatic encephalopathy (HE), and its pathophysiology is poorly understood. Excessive inflammatory, oxidative and apoptotic responses are the major mechanisms involved in the progression of brain injury induced by HE. Carvedilol is an adrenergic receptor antagonist with pronouncedantioxidant and anti-inflammatory activity. The present study aimed to investigatethe effects and underlying mechanisms of carvedilol on HE-induced brain damage in mice. Experimental model of HE was induced by the injection of thioacetamide (200 mg/kg) for two consecutive days and then mice were treated with carvedilol (10 or 20 mg/kg/day, orally) for 3 days in treatment groups. After the behavioral test, animals were sacrificed and the brain tissues were collected for biochemical, real time PCR and immunohistochemical analysis. The results showed that carvedilol improved locomotor impairment and reduced mortality rate in mice with HE. Carvedilol treatment decreased the brain levels of oxidative stress markers and induced Nrf2/HO-1 pathway. Carvedilol inhibited the activity of nuclear factor kappa B (NF-κB) and the expression of pro-inflammatory cytokines TNF-α, IL1β and IL-6 in the brain tissues. Treatment of mice with carvedilol caused a significant reduction in the brain levels of iNOS/NO, myeloperoxidase (MPO), cyclooxygenase (COX)-2 and chemokine MCP-1 as proinflammatory mediators in HE. Moreover, the ratio of Bcl2/Bax was increased and apoptotic cell death was decreased in the brain of mice treated with carvedilol. In conclusion, carvedilol exerted protective effect against HE-induced brain injury through increasing antioxidant defense mechanisms and inhibitionof inflammatory and apoptotic pathways.

Microparticles in COVID-19 as a link between lung injury extension and thrombosis

Among the distinctive features of coronavirus disease 2019 (COVID-19), numerous reports have stressed the importance of vascular damage associated with coagulopathy onset [1]. Histological analysis of pulmonary vessels in patients with COVID-19 revealed severe endothelial injury associated with intracellular severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus and disrupted endothelial cell membranes together with widespread thrombosis and occlusion of alveolar capillaries. Microparticles (MPs) shed by apoptotic/stimulated cells of various cellular lineages, including platelets, leukocytes, macrophages or endothelial cells, are reliable markers of vascular damage [2] released upon pro-inflammatory conditions and behave as active participants in the early steps of clot formation [3]. Circulating MPs promote procoagulant responses due to the exposure of tissue factor, the physiological activator of the coagulation cascade, and of negatively charged phospholipids, such as phosphatidylserine, required for the assembly of the tenase and prothrombinase coagulation complexes ultimately leading to thrombin generation, through which they can precisely be quantified [4]. MPs carry angiotensin-converting enzyme (ACE)1 and upregulate ACE1 expression in neighbouring endothelial cells [5]. By contrast, exosomes were recently reported to convey ACE2, the cell-entry receptor for SARS-CoV-2 [4], in the vasculature [6]. ACE2 converts angiotensin II (Ang II) into angiotensin 1–7 (Ang 1–7), which by virtue of its actions on the Mas receptor, limits the noxious effects of Ang II. Pioneering data have demonstrated that the renin–angiotensin system has a crucial role in severe acute injury and that ACE2 has a protective role in acute lung injury mediated by SARS-CoV [7]. According to this paradigm, the loss of ACE2 function following binding by SARS-CoV-2 may contribute to unopposed Ang II accumulation that further exacerbates tissue injury and promotes inflammation, MPs release and thrombosis. During SARS-CoV-2 infection, we hypothesised that various factors including inflammatory burden, Ang II, altered shear stress and hypoxic vasoconstriction, could enhance MPs shedding by various cell lineages including the alveolar vascular endothelium and contribute to clot formation.

Procoagulant microparticles are associated with the extent of lung injuries in #COVID19 and pulmonary thrombosishttps://bit.ly/3eX2LPc

Impaired skeletal muscle fatigue resistance during cardiac hypertrophy is prevented by functional overload- or exercise-induced functional capillarity

KEY POINTS

Capillary rarefaction is hypothesized to contribute to impaired exercise tolerance in cardiovascular disease, but it remains a poorly exploited therapeutic target for improving skeletal muscle performance. Using an abdominal aortic coarctation rat model of compensatory cardiac hypertrophy, we determine the efficacy of aerobic exercise for the prevention of, and mechanical overload for, restoration of hindlimb muscle fatigue resistance and microvascular impairment in the early stages of heart disease. Impaired muscle fatigue resistance was found after development of cardiac hypertrophy, but this impairment was prevented by low-intensity aerobic exercise and recovered after mechanical stretch due to muscle overload. Changes in muscle fatigue resistance were closely related to functional (i.e. perfused) microvascular density, independent of arterial blood flow, emphasizing the critical importance of optimal capillary diffusion for skeletal muscle function. Pro-angiogenic therapies are an important tool for improving skeletal muscle function in the incipient stages of heart disease.

ABSTRACT

Microvascular rarefaction may contribute to declining skeletal muscle performance in cardiac and vascular diseases. It remains uncertain to what extent microvascular rarefaction occurs in the earliest stages of these conditions, if impaired blood flow is an aggravating factor and whether angiogenesis restores muscle performance. To investigate this, the effects of aerobic exercise (voluntary wheel running) and functional muscle overload on the performance, femoral blood flow (FBF) and microvascular perfusion of the extensor digitorum longus (EDL) were determined in a chronic rat model of compensatory cardiac hypertrophy (CCH, induced by surgically imposed abdominal aortic coarctation). CCH was associated with hypertension (P = 0.001 vs. Control) and increased relative heart mass (P < 0.001). Immediately upon placing the aortic band (i.e. before development of CCH), post-fatigue test FBF was reduced (P < 0.003), coinciding with attenuated fatigue resistance (P = 0.039) indicating an acute arterial perfusion constraint on muscle performance. While FBF was normalized during CCH in chronic groups (P > 0.05) fatigue resistance remained reduced (P = 0.039) and was associated with reduced (P = 0.009) functional capillarity after development of CCH without intervention, indicating a microvascular limitation to muscle performance. Normalization of functional capillarity after aerobic exercise (P = 0.065) and overload (P = 0.329) in CCH coincided with restoration to control levels of muscle fatigue resistance (P > 0.999), although overload-induced EDL hypertrophy (P = 0.027) and wheel-running velocity and duration (both P < 0.05) were attenuated after aortic banding. These data show that reductions in skeletal muscle performance during CCH can be countered by improving functional capillarity, providing a therapeutic target to improve skeletal muscle function in chronic diseases.

Effect of carvedilol versus propranolol on acute and chronic liver toxicity in rats

Non-selective β-blockers have largely been used for prophylaxis of bleeding from gastroesophageal varices, but their hepatic effects and their influence on the development of varices has yet to be clarified. This study examined whether carvedilol would reduce acute and chronic liver injury in rats in comparison to propranolol. Experiment (1) Investigated the effects of carvedilol (1.2 mg/kg) and propranolol (4.0 mg/kg) administered daily for 7 days by gavage on paracetamol (1500 mg/kg i.p.) -induced acute liver injury in rats. Experiment (2) Investigated the effects of carvedilol (1.2 mg/kg) and propranolol (4.0 mg/kg) by gavage daily for 8 weeks on CCl4 -induced chronic liver injury in rats. Biochemical markers and histopathology of the livers were studied. Liver perfusion studies were carried out on CCl4 treated rats. Experiment (1) Carvedilol significantly improved the functional state of the liver in paracetamol-induced acute toxic hepatitis to a greater extent than propranolol. This was evidenced by a greater reduction in elevated serum levels of ALT and AST, hepatic MDA and TNF-α, attenuation of the paracetamol-induced decrease in GSH, together with improvement in the histological architecture of the liver. Experiment (2) Carvedilol was superior to propranolol against CCl4-induced hepatic injury and fibrogenesis. It suppressed hepatic inflammation, attenuated hepatic oxidative stress, and inhibited HSC activation. Carvedilol also decreased portal perfusion pressure. These results suggest that carvedilol might be a therapeutic anti-fibrogenic candidate against hepatic fibrosis, protecting the liver from acute and chronic toxic injury, in addition to lowering portal pressure.

Precision medicine in distinct heart failure phenotypes: Focus on clinical epigenetics

Heart failure (HF) management is challenging due to high clinical heterogeneity of this disease which makes patients responding differently to evidence-based standard therapy established by the current reductionist approach. Better understanding of the genetic and epigenetic interactions may clarify molecular signatures underlying maladaptive responses in HF, including metabolic shift, myocardial injury, fibrosis, and mitochondrial dysfunction. DNA methylation, histone modifications and micro-RNA (miRNAs) may be major epigenetic players in the pathogenesis of HF. DNA hypermethylation of the kruppel-like factor 15 (KLF15) gene plays a key role in switching the failing heart from oxidative to glycolytic metabolism. Moreover, hypomethylation at H3K9 promoter level of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) genes also leads to reactivation of fetal genes in man. The role of miRNAs has been investigated in HF patients undergoing heart transplantation, for whom miR-10a, miR-155, miR-31, and miR-92 may be putative useful prognostic biomarkers. Recently, higher RNA methylation levels have been observed in ischemic human hearts, opening the era of "epitranscriptome" in the pathogenesis of HF. Currently, hydralazine, statins, apabetalone, and omega-3 polyunsatured fatty acids (PUFA) are being tested in clinical trials to provide epigenetic-driven therapeutic interventions. Moreover, network-oriented analysis could advance current medical practice by focusing on protein-protein interactions (PPIs) perturbing the "cardiac" interactome. In this review, we provide an epigenetic map of maladaptive responses in HF patients. Furthermore, we propose the "EPi-transgeneratIonal network mOdeling for STratificatiOn of heaRt Morbidity" (EPIKO-STORM), a clinical research strategy offering novel opportunities to stratify the natural history of HF.

Differential Response to Heart Rate Reduction by Carvedilol in Heart Failure and Reduced Ejection Fraction Between Sinus Rhythm and Atrial Fibrillation - Insight From J-CHF Study

Background: Heart rate (HR) reduction by β-blocker might not benefit patients with heart failure and reduced ejection fraction (HFrEF) with atrial fibrillation (AF).

Methods and Results: The J-CHF study was a prospective randomized multicenter trial that assigned 360 HFrEF patients to a 2.5 mg/5 mg/20 mg target dose of carvedilol. Carvedilol was uptitrated over 8 weeks and then the dose was fixed. Of 321 patients available for analysis, AF was identified in 65 (20%). Using the median absolute change in HR at 32 weeks (∆HR), the subjects were further divided into group A (∆HR >−6 beats/min) and B (∆HR ≤−6 beats/min). Both in sinus rhythm (SR) and AF, baseline characteristics and achieved carvedilol dose were similar between groups A and B. In SR, the time-dependent change in left ventricular EF (LVEF) and LV end-diastolic dimension (LVEDD) over 56 weeks was more favorable in B compared with A (∆LVEF, P=0.036; ∆LVEDD, P=0.047), and ∆HR was independently associated with ∆LVEF (P=0.040). Group B had a lower rate of the primary endpoint, defined as a composite of death and hospitalization due to cardiovascular causes including acute decompensated HF at 3 years (P=0.002). ∆HR was an independent predictor of the primary endpoint (P=0.01), but this was not observed in AF.

Conclusions: Response to the carvedilol HR reduction might differ in HFrEF between SR and AF.

Is Cardiac Troponin I Valuable to Detect Low-Level Myocardial Damage in Congestive Heart Failure?

Objectives:

Congestive heart failure (CHF) is a heart disease with a growing incidence and prevalence. Creatine kinase-myocardial base (CK-MB) is generally used to determine myocardial damage; however, it is insufficiently sensitive to measure the relatively low level of myocardial damage that typically occurs in heart failure (HF). The use of cardiac troponins, which are far more sensitive and specific, has become common to identify myocardial damage and permits the detection of even minute amounts of damage. The aim of this study was to ascertain whether cardiac troponin I (cTnI) can be used to detect low-level myocardial damage occurring in CHF in real-life conditions.

Methods:

Fifty patients with CHF symptoms (Group I) and 20 patients who were evaluated as normal (Group II) were included in this prospective study. The Framingham criteria were used to diagnose HF. Group I was divided into 3 subgroups according to the New York Heart Association classification of functional capacity: Class II, Group A; Class III, Group B, and Class IV, Group C. On the first day of admission, CK-MB and cTnI levels were measured and assessed quantitatively. The cTnI level was compared between these 3 subgroups and between Groups I and II. Linear regression analysis was performed to investigate the relationship between ejection fraction (EF) and cTnI.

Results

The mean cTnI value was 0.084±0.07 ng/mL in Group I and 0.018±0.012 ng/mL in Group II (p=0.0001). The mean cTnI value was 0.047±0.016 ng/mL, 0.080±0.048 ng/mL, and 0.175± 0.102 ng/mL in Groups A, B, and C, respectively. The difference between the subgroups of Group I was statistically significant. In addition, it was observed that there was a significant difference in the EF (%) value between Groups I and II and between Groups A, B, and C. Linear regression analysis revealed an inverse relationship between EF and cTnI (r: -0.66) (p=0.0001).

Conclusion

As the severity of HF increased, the cTnI serum level also increased. This increase was inversely related to the EF value. These results are consistent with other studies in the literature, suggesting that the cTnI level may be a useful marker in the diagnosis and evaluation of severity of HF.

Structural characterization of centipede oligopeptides and capability detection in human small cell lung carcinoma: inducing apoptosis

Lung cancer is the most frequent cause of cancer deaths in the world, and smoking is considered as one of the major causes. Small cell lung carcinoma (SCLC) represents a highly malignant and particularly aggressive form, with properties of widespread metastases and poor prognosis. Herein, twenty-five Scolopendra subspinipes mutilans L. Koch Oligopeptides (SSMOs) were isolated and their structures were identified, and the anti-proliferative activity against lung cancer cell lines was evaluated. Results showed that SSMO-5 induced the production of reactive oxygen species (ROS) markedly in NCI-H446 cells. Furthermore, SSMO-5 decreased the mitochondrial membrane potential (MMP) and enhanced the mitochondria-related apoptosis. These results demonstrate that in NCI-H446 cells, the apoptotic and cytotoxic effects of SSMO-5 are mediated by the intrinsic mitochondria-mediated apoptotic pathway, which in turn causes the activation of caspases and increases Bax expression, while decreases Bcl-2 and Bcl-xL expressions and regulates the interaction of p53/MDM2. In conclusion, a ROS-mediated mitochondrial pathway plays an important role in the process of SSMO-5-induced apoptosis against SCLC.

SSMO-5 mediated the lung cancer cells apoptosis by activating the caspases and regulating the interaction of p53/MDM2.

Thoracic Aortic Aneurysm Development in Patients with Bicuspid Aortic Valve: What Is the Role of Endothelial Cells?

Bicuspid aortic valve (BAV) is the most common type of congenital cardiac malformation. Patients with a BAV have a predisposition for the development of thoracic aortic aneurysm (TAA). This pathological aortic dilation may result in aortic rupture, which is fatal in most cases. The abnormal aortic morphology of TAAs results from a complex series of events that alter the cellular structure and extracellular matrix (ECM) composition of the aortic wall. Because the major degeneration is located in the media of the aorta, most studies aim to unravel impaired smooth muscle cell (SMC) function in BAV TAA. However, recent studies suggest that endothelial cells play a key role in both the initiation and progression of TAAs by influencing the medial layer. Aortic endothelial cells are activated in BAV mediated TAAs and have a substantial influence on ECM composition and SMC phenotype, by secreting several key growth factors and matrix modulating enzymes. In recent years there have been significant advances in the genetic and molecular understanding of endothelial cells in BAV associated TAAs. In this review, the involvement of the endothelial cells in BAV TAA pathogenesis is discussed. Endothelial cell functioning in vessel homeostasis, flow response and signaling will be highlighted to give an overview of the importance and the under investigated potential of endothelial cells in BAV-associated TAA.

Apoptosis and remodeling in adriamycin-induced cardiomyopathy rat model

Purpose

The mechanism for the pathogenesis of adriamycin (ADR)-induced cardiomyopathy is not yet known. Different hypotheses include the production of free radicals, an interaction between ADR and nuclear components, and a disruption in cardiac-specific gene expression. Apoptosis has also been proposed as being involved in cardiac dysfunction. The purpose of this study was to determine if apoptosis might play a role in ADR-induced cardiomyopathy.

Methods

Male Sprague-Dawley rats were separated into 2 groups: the control group (C group) and the experimental group (ADR 5 mg/wk for 3 weeks through intraperitoneal injections; A group). Echocardiographic images were obtained at week 3. Changes in caspase-3, B-cell leukemia/lymphoma (Bcl)-2, Bcl-2-associated X (Bax), interleukin (IL)-6, tumor necrosis factor-α, brain natriuretic peptide (BNP), troponin I, collagen 1, and collagen 3 protein expression from the left ventricle tissues of C and A group rats were determined by Western blot.

Results

Ascites and heart failure as well as left ventricular hypertrophy were noted in the A group. Ejection fraction and shortening fraction were significantly lower in the A group by echocardiography. The expression of caspase-3, Bax, IL-6, BNP, collagen 1, and collagen 3 were significantly higher in the A group as compared with the C group. Protein expression of Bcl-2 decreased significantly in the A group compared with the C group.

Conclusion

ADR induced an upregulation of caspase-3, Bax, IL-6, and collagen, as well as a depression in Bcl-2. Thus, apoptosis and fibrosis may play an important role in ADR-induced cardiomyopathy.

Oxidized low-density lipoprotein-induced microparticles promote endothelial monocyte adhesion via intercellular adhesion molecule 1

Oxidized low-density lipoprotein (oxLDL) accumulates early in atherosclerotic lesions and plays an important role in the progressive formation of atherosclerotic plaques. Endothelial derived microparticles (EMPs) form a heterogeneous population of <1-μm particles that shed from endothelial membranes upon activation. While EMPs are shown to be involved in atherosclerotic pathophysiology and progression, there is no report regarding the relationship between oxLDL and EMPs. In this study, we aim to determine the influence of oxLDL on endothelial microparticle release and the subsequent regulation of the endothelial activation. EMPs were collected from the medium of human umbilical vein endothelial cells (HUVECs) treated with oxLDL or PBS as control. We find that oxLDL increases the release of EMPs containing intercellular adhesion molecule 1 (ICAM-1) but not vascular cell adhesion molecule 1 (VCAM-1). Confocal microscopy analysis further demonstrates that these EMPs interact with endothelial cells and increase the expression of ICAM-1 in HUVECs. The fact that injecting oxLDL-induced EMPs via the tail vein of ICR mice augments ICAM-1 expression on aortic endothelial cells confirms our results in vivo. Finally, oxLDL-induced EMPs from HUVECs increase the adhesion of monocytes to endothelial cells as determined by the adhesion assay. Our study suggests that oxLDL may augment the release of EMPs harboring increased levels of ICAM-1 that can be transferred to endothelial cells elsewhere. This leads to increased monocyte recruitment in other regions where oxLDL accumulation was initially more limited. EMPs may therefore serve as the mediator that propagates oxLDL-induced endothelial inflammation.

Pulmonary arterial hypertension treatment with carvedilol for heart failure: a randomized controlled trial

BACKGROUND

Right-sided heart failure is the leading cause of death in pulmonary arterial hypertension (PAH). Similar to left heart failure, sympathetic overactivation and β-adrenoreceptor (βAR) abnormalities are found in PAH. Based on successful therapy of left heart failure with β-blockade, the safety and benefits of the nonselective β-blocker/vasodilator carvedilol were evaluated in PAH.

METHODS

PAH Treatment with Carvedilol for Heart Failure (PAHTCH) is a single-center, double-blind, randomized, controlled trial. Following 1-week run-in, 30 participants were randomized to 1 of 3 arms for 24 weeks: placebo, low-fixed-dose, or dose-escalating carvedilol. Outcomes included clinical measures and mechanistic biomarkers.

RESULTS

Decreases in heart rate and blood pressure with carvedilol were well tolerated; heart rate correlated with carvedilol dose. Carvedilol-treated groups had no decrease in exercise capacity measured by 6-minute walk, but had lower heart rates at peak and after exercise, and faster heart rate recovery. Dose-escalating carvedilol was associated with reduction in right ventricular (RV) glycolytic rate and increase in βAR levels. There was no evidence of RV functional deterioration; rather, cardiac output was maintained.

CONCLUSIONS

Carvedilol is likely safe in PAH over 6 months of therapy and has clinical and mechanistic benefits associated with improved outcomes. The data provide support for longer and larger studies to establish guidelines for use of β-blockers in PAH.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01586156FUNDING. This project was supported by NIH R01HL115008 and R01HL60917 and in part by the National Center for Advancing Translational Sciences, UL1TR000439.

Estradiol postconditioning relieves ischemia/reperfusion injury in axial skin flaps of rats, inhibits apoptosis and alters the MKP-1/ERK pathway

Previous studies have suggested that estradiol can reduce the ischemia/reperfusion (I/R) injury in skin flaps. However, the mechanism, particularly the signal pathways involved in this protective effect are not well established. In the current study, an I/R injury model was established in rats to explore the connection between estradiol protection during I/R injury and extracellular signal‑regulated kinase (ERK) signaling. Healthy male Wistar rats were divided into five groups (n=10): Control group (group I), I/R group (group II), saline group (group III), estradiol group (group IV) and inhibitor (PD‑98059) group (group V). The survival rate of the flap was compared between groups, morphological changes were observed by hematoxylin and eosin staining of sections, and terminal deoxynucleotidyl transferase dUTP nick end labeling was performed to identify apoptotic cells and determine the apoptotic index. To further investigate the mechanism, western blot analysis was performed to assess the protein level of ERK1/2, phospho‑ERK1/2, and mitogen‑activated protein kinase phosphatase 1 (MKP‑1). The results of the present study demonstrated that estradiol therapy can reduce I/R injury and decrease the apoptosis index in an axial skin flap model. The inhibitor of the ERK pathway (PD‑98059) partially abolished the effects of estradiol, which involve the phosphatase enzyme MKP‑1. Taken together, the findings of the present study indicate that estradiol may act by reducing the expression of MKP‑1, mediating the expression/activation changes of the ERK pathway and subsequently reduce the level of apoptosis and the I/R injury the axial flap. Estrogen may be used to mitigate the adverse reaction caused by ischemia‑reperfusion injury and effectively improve the survival rate and survival quality of free skin flap and improve patient prognosis.

Methylglyoxal-Induced Endothelial Cell Loss and Inflammation Contribute to the Development of Diabetic Cardiomyopathy

The mechanisms for the development of diabetic cardiomyopathy remain largely unknown. Methylglyoxal (MG) can accumulate and promote inflammation and vascular damage in diabetes. We examined if overexpression of the MG-metabolizing enzyme glyoxalase 1 (GLO1) in macrophages and the vasculature could reduce MG-induced inflammation and prevent ventricular dysfunction in diabetes. Hyperglycemia increased circulating inflammatory markers in wild-type (WT) but not in GLO1-overexpressing mice. Endothelial cell number was reduced in WT-diabetic hearts compared with nondiabetic controls, whereas GLO1 overexpression preserved capillary density. Neuregulin production, endothelial nitric oxide synthase dimerization, and Bcl-2 expression in endothelial cells was maintained in the hearts of GLO1-diabetic mice and corresponded to less myocardial cell death compared with the WT-diabetic group. Lower receptor for advanced glycation end products and tumor necrosis factor-α (TNF-α) levels were also observed in GLO1-diabetic versus WT-diabetic mice. Over a period of 8 weeks of hyperglycemia, GLO1 overexpression delayed and limited the loss of cardiac function. In vitro, MG and TNF-α were shown to synergize in promoting endothelial cell death, which was associated with increased angiopoietin 2 expression and reduced Bcl-2 expression. These results suggest that MG in diabetes increases inflammation, leading to endothelial cell loss. This contributes to the development of diabetic cardiomyopathy and identifies MG-induced endothelial inflammation as a target for therapy.

Serum From Advanced Heart Failure Patients Promotes Angiogenic Sprouting and Affects the Notch Pathway in Human Endothelial Cells

It is unknown whether components present in heart failure (HF) patients' serum provide an angiogenic stimulus. We sought to determine whether serum from HF patients affects angiogenesis and its major modulator, the Notch pathway, in human umbilical vein endothelial cells (HUVECs). In cells treated with serum from healthy subjects or from patients at different HF stage we determined: (1) Sprouting angiogenesis, by measuring cells network (closed tubes) in collagen gel. (2) Protein levels of Notch receptors 1, 2, 4, and ligands Jagged1, Delta-like4. We found a higher number of closed tubes in HUVECs treated with advanced HF patients serum in comparison with cells treated with serum from mild HF patients or controls. Furthermore, as indicated by the reduction of the active form of Notch4 (N4IC) and of Jagged1, advanced HF patients serum inhibited Notch signalling in HUVECs in comparison with mild HF patients' serum and controls. The circulating levels of NT-proBNP (N-terminal of the pro-hormone brain natriuretic peptide), a marker for the detection and evalutation of HF, were positively correlated with the number of closed tubes (r = 0.485) and negatively with Notch4IC and Jagged1 levels in sera-treated cells (r = -0.526 and r = -0.604, respectively). In conclusion, we found that sera from advanced HF patients promote sprouting angiogenesis and dysregulate Notch signaling in HUVECs. Our study provides in vitro evidence of an angiogenic stimulus arising during HF progression and suggests a role for the Notch pathway in it. J. Cell. Physiol. 231: 2700-2710, 2016. © 2016 Wiley Periodicals, Inc.

Mst1 inhibition rescues β1-adrenergic cardiomyopathy by reducing myocyte necrosis and non-myocyte apoptosis rather than myocyte apoptosis

It is generally held that inhibition of mammalian sterile 20-like kinase 1 (Mst1) protects the heart through reducing myocyte apoptosis. We determined whether inhibition with a dominant-negative Mst1 (DN-Mst1) would protect against the cardiomyopathy induced by chronic β1-adrenergic receptor (β1-AR) stimulation by preventing myocyte apoptosis. DN-Mst1 mice were mated with β1-AR transgenic (Tg) mice and followed for 20 months. β1-AR Tg mice developed cardiomyopathy as they aged, as reflected by premature mortality and depressed cardiac function, which were rescued in β1-AR × DN-Mst1 bigenic mice. Surprisingly, myocyte apoptosis did not significantly decrease with Mst1 inhibition. Instead, Mst1 inhibition predominantly reduced non-myocyte apoptosis, e.g., fibroblasts, macrophages, neutrophils and endothelial cells. Fibrosis in the hearts with cardiomyopathy increased fivefold and this increase was nearly abolished in the bigenic mice with Mst1 inhibition. Regression analysis showed no correlation between myocyte apoptosis and cardiac function or myocyte number, whereas the latter two correlated significantly, p < 0.05, with fibrosis, which generally results from necrosis. To examine the role of myocyte necrosis, chronic β-AR stimulation with isoproterenol was induced for 24 h and myocyte necrosis was assessed by 1% Evans blue dye. Compared to WT, DN-Mst1 mice showed significant inhibition, p < 0.05, of myocyte necrosis. We confirmed this result in Mst1-knockout mice, which also showed significant protection, p < 0.05, against myocyte necrosis compared to WT. These data indicate that Mst1 inhibition rescued cardiac fibrosis and myocardial dysfunction in β1-AR cardiomyopathy. However, this did not occur through Mst1 inhibition of myocyte apoptosis but rather by inhibition of cardiomyocyte necrosis and non-myocyte apoptosis, features of Mst1 not considered previously.

Prevention of skin carcinogenesis by the β-blocker carvedilol

The stress-related catecholamine hormones and the α- and β-adrenergic receptors (α- and β-AR) may affect carcinogenesis. The β-AR GRK/β-arrestin biased agonist carvedilol can induce β-AR-mediated transactivation of the EGFR. The initial purpose of this study was to determine whether carvedilol, through activation of EGFR, can promote cancer. Carvedilol failed to promote anchorage-independent growth of JB6 P(+) cells, a skin cell model used to study tumor promotion. However, at nontoxic concentrations, carvedilol dose dependently inhibited EGF-induced malignant transformation of JB6 P(+) cells, suggesting that carvedilol has chemopreventive activity against skin cancer. Such effect was not observed for the β-AR agonist isoproterenol and the β-AR antagonist atenolol. Gene expression, receptor binding, and functional studies indicate that JB6 P(+) cells only express β2-ARs. Carvedilol, but not atenolol, inhibited EGF-mediated activator protein-1 (AP-1) activation. A topical 7,12-dimethylbenz(α)anthracene (DMBA)-induced skin hyperplasia model in SENCAR mice was utilized to determine the in vivo cancer preventative activity of carvedilol. Both topical and oral carvedilol treatment inhibited DMBA-induced epidermal hyperplasia (P < 0.05) and reduced H-ras mutations; topical treatment being the most potent. However, in models of established cancer, carvedilol had modest to no inhibitory effect on tumor growth of human lung cancer A549 cells in vitro and in vivo. In conclusion, these results suggest that the cardiovascular drug carvedilol may be repurposed for skin cancer chemoprevention, but may not be an effective treatment of established tumors. More broadly, this study suggests that β-ARs may serve as a novel target for cancer prevention.

Pressure overload induces IL-18 and IL-18R expression, but markedly suppresses IL-18BP expression in a rabbit model. IL-18 potentiates TNF-α-induced cardiomyocyte death

Recurrent or sustained inflammation plays a causal role in the development and progression of left ventricular hypertrophy (LVH) and its transition to failure. Interleukin (IL)-18 is a potent pro-hypertrophic inflammatory cytokine. We report that induction of pressure overload in the rabbit, by constriction of the descending thoracic aorta induces compensatory hypertrophy at 4weeks (mass/volume ratio: 1.7±0.11) and ventricular dilatation indicative of heart failure at 6weeks (mass/volume ratio: 0.7±0.04). In concordance with this, fractional shortening was preserved at 4weeks, but markedly attenuated at 6weeks. We cloned rabbit IL-18, IL-18Rα, IL-18Rβ, and IL-18 binding protein (IL-18BP) cDNA, and show that pressure overload, while enhancing IL-18 and IL-18R expression in hypertrophied and failing hearts, markedly attenuated the level of expression of the endogenous IL-18 antagonist IL-18BP. Cyclical mechanical stretch (10% cyclic equibiaxial stretch, 1Hz) induced hypertrophy of primary rabbit cardiomyocytes in vitro and enhanced ANP, IL-18, and IL-18Rα expression. Further, treatment with rhIL-18 induced its own expression and that of IL-18Rα via AP-1 activation, and induced cardiomyocyte hypertrophy in part via PI3K/Akt/GATA4 signaling. In contrast, IL-18 potentiated TNF-α-induced cardiomyocyte death, and by itself induced cardiac endothelial cell death. These results demonstrate that pressure overload is associated with enhanced IL-18 and its receptor expression in hypertrophied and failingrabbit hearts. Since IL-18BP expression is markedly inhibited, our results indicate a positive amplification in IL-18 proinflammatory signaling during pressure overload, and suggest IL-18 as a potential therapeutic target in pathological hypertrophy and cardiac failure.

β-Blocker carvedilol protects cardiomyocytes against oxidative stress-induced apoptosis by up-regulating miR-133 expression

Oxidative stress is a causal factor and key promoter of a variety of cardiovascular diseases associated with apoptotic cell death by causing deregulation of related genes. Though carvedilol, a β-adrenergic blocker, has been shown to produce cytoprotective effects against cardiomyocyte apoptosis, the mechanisms are not fully understood. The present study was designed to investigate whether the beneficial effects of carvedilol are related to microRNAs which have emerged as critical players in cardiovascular pathophysiology via post-transcriptional regulation of protein-coding genes. In vivo, we demonstrated that carvedilol ameliorated impaired cardiac function of infarct rats and restored miR-133 expression. In vitro, carvedilol protected cardiomyocytes from H2O2 induced apoptosis detected by TUNEL staining and MTT assays, and increased miR-133 expression in cardiomyocytes. Overexpression of miR-133, a recognized anti-apoptotic miRNA, produced similar effects to carvedilol: reduction of reactive oxygen species (ROS) and malondialdehyde (MDA) content and increment of superoxide dismutase (SOD) activity and glutathione peroxidase (GPx) level, so as to protect cardiomyocytes from apoptosis by downregulating caspase-9 and caspase-3 expression in the presence of H2O2. Transfection with AMO-133 (antisense inhibitor oligodeoxyribonucleotides) alone abolished the beneficial effects of carvedilol. Caspase-9-specific inhibitor z-LEHD-fmk, caspase-3-specific inhibitor z-DEVD-fmk, caspase-9 siRNA and caspase-3 siRNA were used to establish caspase-3 as a downstream target of miR-133. In conclusion, our data indicated that carvedilol protected cardiomyocytes by increasing miR-133 expression and suppressing caspase-9 and subsequent apoptotic pathways.

Carvedilol protects against iron-induced microparticle generation and apoptosis of endothelial cells

BACKGROUND

Increased circulating endothelial microparticles (EMPs) have been shown to associate with endothelial dysfunction. We explored the effect of iron on EMP generation by human umbilical vein endothelial cells (HUVECs) and the potential protective effect of carvedilol.

METHODS

FeCl 3 was added to HUVEC culture. Iron entry into cells was monitored using fluorescent microscopic imaging, while the quantity of EMPs that was released was determined by flow cytometry. The apoptosis of HUVECs was assessed by annexin V/propidium iodide assay and caspase-3 expression. Membrane bleb formation was visualized using electron microscopy. Intracellular production of reactive oxygen species (ROS) was also monitored. The effects of beta-blockers, carvedilol and propranolol on these processes were determined by co-incubation in a dose-dependent manner. Iron entry into HUVECs was not blocked by either beta-blocker. Iron induced the generation of EMPs, the formation of membrane blebs, the apoptosis of HUVECs and the production of ROS, each in a dose-dependent manner. Carvedilol, but not propranolol, ameliorated all of these processes.

RESULTS

Our result indicates that iron induces EMP generation and apoptosis of endothelial cells in association with increased oxidative stress.

CONCLUSION

The protective effects of carvedilol, via its antioxidant effect, may have therapeutic potential in patients with iron overload.

Reducing methylglyoxal as a therapeutic target for diabetic heart disease

Diabetes is a well-known risk factor for the development of cardiovascular diseases. Diabetes affects cardiac tissue through several different, yet interconnected, pathways. Damage to endothelial cells from direct exposure to high blood glucose is a primary cause of deregulated heart function. Toxic by-products of non-enzymatic glycolysis, mainly methylglyoxal, have been shown to contribute to the endothelial cell damage. Methylglyoxal is a precursor for advanced glycation end-products, and, although it is detoxified by the glyoxalase system, this protection mechanism fails in diabetes. Recent work has identified methylglyoxal as a therapeutic target for the prevention of cardiovascular complications in diabetes. A better understanding of the glyoxalase system and the effects of methylglyoxal may lead to more advanced strategies for treating cardiovascular complications associated with diabetes.

Endothelial dysfunction, arterial stiffness, and heart failure

Outcomes for heart failure (HF) patients remain suboptimal. No known therapy improves mortality in acute HF and HF with preserved ejection fraction; the most recent HF trial results have been negative or neutral. Improvement in surrogate markers has not necessarily translated into better outcomes. To translate breakthroughs with potential therapies into clinical benefit, a better understanding of the pathophysiology establishing the foundation of benefit is necessary. Vascular function plays a central role in the development and progression of HF. Endothelial function and nitric oxide availability affect myocardial function, systemic and pulmonary hemodynamics, and coronary and renal circulation. Arterial stiffness modulates ventricular loading conditions and diastolic function, key components of HF with preserved ejection. Endothelial function and arterial stiffness may therefore serve as important physiological targets for new HF therapies and facilitate patient selection for improved application of existing agents.

Microvesicles at the crossroads between infection and cardiovascular diseases

Observational and experimental studies continue to support the association of infection and infection-stimulated inflammation with development of cardiovascular disease (CVD) including atherosclerosis and thrombosis. Microvesicles (MV) are heterogeneous populations of sealed membrane-derived vesicles shed into circulation by activated mammalian cells and/or pathogenic microbes that may represent an interface between bacterial/microbial infection and increased risk of CVD. This review evaluates how MV act to modulate and intersect immunological and inflammatory responses to infection with particular attention to progression of CVD. Although infection-related stimuli provoke release of MV from blood and vascular cells, MV express phosphatidylserine and other procoagulant factors on their surface, which initiate and amplify blood coagulation. In addition, MV mediate cell-cell adhesion, which may stimulate production of pro-inflammatory cytokines in vascular cells, which in turn aggravate progression of CVD and propagate atherothrombosis. MV transfer membrane receptors, RNA and proteins among cells, and present auto-antigens from their cells of origin to proximal or remote target cells. Because MV harbor cell surface proteins and contain cytoplasmic components of the parent cell, they mediate biological messages and play a pivotal role in the crossroad between infection-stimulated inflammation and CVDs.

X-linked inhibitor of apoptosis protein-mediated attenuation of apoptosis, using a novel cardiac-enhanced adeno-associated viral vector

Successful amelioration of cardiac dysfunction and heart failure through gene therapy approaches will require a transgene effective at attenuating myocardial injury, and subsequent remodeling, using an efficient and safe delivery vehicle. Our laboratory has established a well-curated, high-quality repository of human myocardial tissues that we use as a discovery engine to identify putative therapeutic transgene targets, as well as to better understand the molecular basis of human heart failure. By using this rare resource we were able to examine age- and sex-matched left ventricular samples from (1) end-stage failing human hearts and (2) nonfailing human hearts and were able to identify the X-linked inhibitor of apoptosis protein (XIAP) as a novel target for treating cardiac dysfunction. We demonstrate that XIAP is diminished in failing human hearts, indicating that this potent inhibitor of apoptosis may be central in protecting the human heart from cellular injury culminating in heart failure. Efforts to ameliorate heart failure through delivery of XIAP compelled the design of a novel adeno-associated viral (AAV) vector, termed SASTG, that achieves highly efficient transduction in mouse heart and in cultured neonatal rat cardiomyocytes. Increased XIAP expression achieved with the SASTG vector inhibits caspase-3/7 activity in neonatal cardiomyocytes after induction of apoptosis through three common cardiac stresses: protein kinase C-γ inhibition, hypoxia, or β-adrenergic receptor agonist. These studies demonstrate the potential benefit of XIAP to correct heart failure after highly efficient delivery to the heart with the rationally designed SASTG AAV vector.

Circulating CD62E+ microparticles and cardiovascular outcomes

BACKGROUND

Activated endothelial cells release plasma membrane submicron vesicles expressing CD62E (E-selectin) into blood, known as endothelial microparticles (EMPs). We studied whether the levels of endothelial microparticles expressing CD62E(+), CD31(+)/Annexin-V(+), or CD31(+)/CD42(-) predict cardiovascular outcomes in patients with stroke history.

METHODS/PRINCIPAL FINDINGS

Patients with stroke history at least 3 months prior to enrolment were recruited. Peripheral blood EMP levels were measured by flow cytometry. Major cardiovascular events and death were monitored for 36 months. Three hundred patients were enrolled, of which 298 completed the study according to protocol. Major cardiovascular events occurred in 29 patients (9.7%). Nine patients died, five from cardiovascular causes. Cumulative event-free survival rates were lower in patients with high levels of CD62E(+) microparticles. Multivariate Cox regression analysis adjusted for cardiovascular risk factors, medications and stroke etiologic groups showed an association between a high CD62E(+) microparticle level and a risk of major cardiovascular events and hospitalization. Levels of other kinds of EMPs expressing CD31(+)/Annexin-V(+) or CD31(+)/CD42(-) markers were not predictive of cardiovascular outcomes.

CONCLUSION

A high level of CD62E(+) microparticles is associated with cardiovascular events in patients with stroke history, suggesting that the systemic endothelial activation increases the risk for cardiovascular morbidities.

Artist® tablets (carvedilol) for hypertensive patients in Japan: results of a drug use survey

Background: In Japan, when pharmaceutical companies launch a new drug, they are obligated to conduct a post-marketing survey to evaluate the safety and efficacy of the drug in accordance with Good Post-Marketing Surveillance Practice under Article 14.4 (re-examination) of the Pharmaceutical Affairs Law at contracted medical institutions. We report the results of a drug use survey, which we conducted as a post-marketing survey.

Objective: This prospective post-marketing drug use survey was conducted to assess the safety and efficacy of the β-adrenergic receptor antagonist (β-blocker) Artist® Tablets (carvedilol) in patients with hypertension in Japan.

Patients: Patients were carvedilol-naive and had essential hypertension or renal parenchymal hypertension.

Methods: This was a prospective survey conducted over 3 years from October 1993 to September 1996. The standard observation period for the patients was defined as 12 weeks of treatment with carvedilol.

Results: We collected data on 4961 patients at 561 medical institutions who had not been previously treated with carvedilol; 4574 patients were included in the safety analysis and 4422 in the efficacy analysis. The incidence of adverse drug reactions (the proportion of patients with adverse drug reactions) was 4.31% (197 of 4574 patients), which is less than that shown in the pre-approval clinical trial of carvedilol (6.85%[68 of 993]). The most common adverse drug reactions were bradycardia, dizziness, hypotension, headache, and feeling light-headed.

After 12 weeks’ treatment with carvedilol, systolic/diastolic blood pressure (SBP/DBP) was reduced from 168.2 ± 18.6/95.7 ± 11.3mmHg at baseline to 144.3 ± 17.3/83.4 ± 10.8mmHg. Patients were classified according to which antihypertensive drug they had been using when carvedilol treatment was initiated. Coadministered agents were calcium channel blockers (CCBs), angiotensinconverting enzyme inhibitors (ACEIs), diuretics, and a-adrenergic receptor antagonists (α-blockers). At 12 weeks, the change in SBP/DBP in the monotherapy group was −22.7/−12.2mmHg and that of each combination therapy subgroup, CCB, ACEI, diuretic, and b-blocker, was −26.1/−12.7mmHg, −25.4/−11.9mmHg, −26.3/−13.0mmHg, and −24.4/−11.5mmHg, respectively. The achievement rates for target BP (<140/90mmHg) were 29.5% in the monotherapy group, 34.8% in the CCB group, 31.3% in the ACEI group, 31.8% in the diuretic group, and 32.4% in the β-blocker group. There was no significant difference in the achievement of target BP among the four combination therapy subgroups (p = 0.475). These results indicate that carvedilol exerts reasonable BP reduction regardless of whether it is used as monotherapy or in combination therapy, and that the effect is not influenced by the coadministered drug. Moreover, carvedilol was also effective in reducing BP levels in elderly patients (≥65 years) and in patients with diabetes mellitus or renal diseases.

Conclusions: The results of this study reflect the results of clinical trials up to the time of approval and it was confirmed that carvedilol is a highly useful drug in the treatment of hypertension.

Exercise as a nonpharmacologic intervention in patients with heart failure

For patients with heart failure (HF), dyspnea and fatigue resulting in diminished exercise tolerance are among the main factors that contribute to decreased social and physical functioning and quality of life. There has long been evidence to suggest that measures of cardiac function, such as ejection fraction and cardiac output, only poorly correlate with a patient's exercise capacity, indicating the involvement of factors other than those impacting central circulation. The lack of a close correlation between central hemodynamics and exercise tolerance has led to investigations into alterations in the periphery, such as abnormalities in vascular endothelial function, hyperactivation of the sympathetic nervous system, and changes in structure and oxidative capacity of skeletal muscle, which are commonly seen in patients with HF. Over the past 2 decades, numerous clinical trials have demonstrated the beneficial impact of exercise training on skeletal muscle energy metabolism, vascular function, and ventilatory capacity, which correlate with improvements in exercise tolerance, hospitalization rates, and quality of life of patients with HF. In accordance with recent guidelines established by the leading cardiology societies in the United States and Europe, physicians are urged to emphasize exercise training for all clinically stable patients with HF using individualized protocols that feature early mobilization after acute exacerbations of the disease and gradual increases in intensity.

Inflammation and therapy for hypertension

It is currently accepted that hypertension, atherosclerosis, and diabetes are disorders with subtle or overt activation of inflammatory mediators. Therefore, it has become increasingly important to ascertain whether current antihypertensive drug families have proinflammatory or anti-inflammatory actions that modify the outcomes of their hemodynamic effects on blood pressure. We review the current state of knowledge about the effects of the major classes of available antihypertensive agents on inflammation and speculate on the possible contribution of these effects to observations in clinical trials. We suggest that a strategy of drug development specifically addressing inflammation in hypertension may provide increased benefit in terms of target organ damage, and we describe some examples of these promising developments.

Membrane vesicles, current state-of-the-art: emerging role of extracellular vesicles

Release of membrane vesicles, a process conserved in both prokaryotes and eukaryotes, represents an evolutionary link, and suggests essential functions of a dynamic extracellular vesicular compartment (including exosomes, microparticles or microvesicles and apoptotic bodies). Compelling evidence supports the significance of this compartment in a broad range of physiological and pathological processes. However, classification of membrane vesicles, protocols of their isolation and detection, molecular details of vesicular release, clearance and biological functions are still under intense investigation. Here, we give a comprehensive overview of extracellular vesicles. After discussing the technical pitfalls and potential artifacts of the rapidly emerging field, we compare results from meta-analyses of published proteomic studies on membrane vesicles. We also summarize clinical implications of membrane vesicles. Lessons from this compartment challenge current paradigms concerning the mechanisms of intercellular communication and immune regulation. Furthermore, its clinical implementation may open new perspectives in translational medicine both in diagnostics and therapy.

Extracellular heat shock proteins, cellular export vesicles, and the Stress Observation System: a form of communication during injury, infection, and cell damage. It is never known how far a controversial finding will go! Dedicated to Ferruccio Ritossa

Heat shock proteins (hsp) have been found to play a fundamental role in the recovery from multiple stress conditions and to offer protection from subsequent insults. The function of hsp during stress goes beyond their intracellular localization and chaperone role as they have been detected outside cells activating signaling pathways. Extracellular hsp are likely to act as indicators of the stress conditions, priming other cells, particularly of the immune system, to avoid the propagation of the insult. Some extracellular hsp, for instance Hsp70, are associated with export vesicles, displaying a robust activation of macrophages. We have coined the term Stress Observation System (SOS) for the mechanism for sensing extracellular hsp, which we propose is a form of cellular communication during stress conditions. An enigmatic and still poorly understood process is the mechanism for the release of hsp, which do not contain any consensus secretory signal. The export of hsp appears to be a very complex phenomenon encompassing different alternative pathways. Moreover, extracellular hsp may not come in a single flavor, but rather in a variety of physical conditions. This review addresses some of our current knowledge about the release and function of extracellular hsp, in particular those associated with vesicles.

Combined effects of irbesartan and carvedilol on expression of tissue factor and tissue factor pathway inhibitor in rats after myocardial infarction

The objective of this study was to investigate the effects of irbesartan, carvedilol, and irbesartan plus carvedilol on the expression of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) mRNA and protein in rat myocardium after myocardial infarction (MI). MI was induced in male Wistar rats by ligation of the anterior descending branch of the left coronary artery. Irbesartan at 50 mg/kg/day, carvedilol at 1 mg/kg/day, irbesartan plus carvedilol, or placebo was administered intragastrically; expression of TF and TFPI mRNA and protein was determined by RT-PCR and Western blot analysis. The relative left ventricle weights were lower in all three treatment groups than in the placebo group, with the lowest relative weight in the irbesartan plus carvedilol group (P < 0.001). The size of the infarcted area was lower in the carvedilol and the combined groups than in the placebo group (P < 0.001). The levels of expression of TF and TFPI mRNA and protein were lower in the combined group than in the placebo group or the carvedilol group (P < 0.001). Treatment with irbesartan plus carvedilol reduced the expression of TF and TFPI mRNA and protein after MI in rats, and combined treatment with both agents had greater effects than the single agents alone. These findings suggest that the beneficial effects of these drugs may include anticoagulation and that combined therapy with both agents is an option that should be evaluated further.

Over-expression of mitogen-activated protein kinase phosphatase-2 enhances adhesion molecule expression and protects against apoptosis in human endothelial cells

BACKGROUND AND PURPOSE

We assessed the effects of over-expressing the dual-specific phosphatase, mitogen-activated protein (MAP) kinase phosphatase-2 (MKP-2), in human umbilical vein endothelial cells (HUVECs) on inflammatory protein expression and apoptosis, two key features of endothelial dysfunction in disease.

EXPERIMENTAL APPROACHES

We infected HUVECs for 40 h with an adenoviral version of MKP-2 (Adv.MKP-2). Tumour necrosis factor (TNF)-α-stimulated phosphorylation of MAP kinase and protein expression was measured by Western blotting. Cellular apoptosis was assayed by FACS.

KEY RESULTS

Infection with Adv.MKP-2 selectively abolished TNF-α-mediated c-Jun-N-terminal kinase (JNK) activation and had little effect upon extracellular signal-regulated kinase or p38 MAP kinase. Adv.MKP-2 abolished COX-2 expression, while induction of the endothelial cell adhesion molecules, intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM), two NFκB-dependent proteins, was not affected. However, when ICAM and VCAM expression was partly reduced by blockade of the NFκB pathway, Adv.MKP-2 was able to reverse this inhibition. This correlated with enhanced TNF-α-induced loss of the inhibitor of κB (IκB)α loss, a marker of NFκB activation. TNF-α in combination with NFκB blockade also increased HUVEC apoptosis; this was significantly reversed by Adv.MKP-2. Protein markers of cellular damage and apoptosis, H2AX phosphorylation and caspase-3 cleavage, were also reversed by MKP-2 over-expression.

CONCLUSIONS AND IMPLICATIONS

Over-expression of MKP-2 had different effects upon the expression of inflammatory proteins due to a reciprocal effect upon JNK and NFκB signalling, and also prevented TNF-α-mediated endothelial cell death. These properties may make Adv.MKP-2 a potentially useful future therapy in cardiovascular diseases where endothelial dysfunction is a feature.

Innovation in basic science: stem cells and their role in the treatment of paediatric cardiac failure--opportunities and challenges

Heart failure is a leading cause of death worldwide. Current therapies only delay progression of the cardiac disease or replace the diseased heart with cardiac transplantation. Stem cells represent a recently discovered novel approach to the treatment of cardiac failure that may facilitate the replacement of diseased cardiac tissue and subsequently lead to improved cardiac function and cardiac regeneration. A stem cell is defined as a cell with the properties of being clonogenic, self-renewing, and multipotent. In response to intercellular signalling or environmental stimuli, stem cells differentiate into cells derived from any of the three primary germ layers: ectoderm, endoderm, and mesoderm, a powerful advantage for regenerative therapies. Meanwhile, a cardiac progenitor cell is a multipotent cell that can differentiate into cells of any of the cardiac lineages, including endothelial cells and cardiomyocytes. Stem cells can be classified into three categories: (1) adult stem cells, (2) embryonic stem cells, and (3) induced pluripotential cells. Adult stem cells have been identified in numerous organs and tissues in adults, including bone-marrow, skeletal muscle, adipose tissue, and, as was recently discovered, the heart. Embryonic stem cells are derived from the inner cell mass of the blastocyst stage of the developing embryo. Finally through transcriptional reprogramming, somatic cells, such as fibroblasts, can be converted into induced pluripotential cells that resemble embryonic stem cells. Four classes of stem cells that may lead to cardiac regeneration are: (1) Embryonic stem cells, (2) Bone Marrow derived stem cells, (3) Skeletal myoblasts, and (4) Cardiac stem cells and cardiac progenitor cells. Embryonic stem cells are problematic because of several reasons: (1) the formation of teratomas, (2) potential immunologic cellular rejection, (3) low efficiency of their differentiation into cardiomyocytes, typically 1% in culture, and (4) ethical and political issues. As of now, bone marrow derived stem cells have not been proven to differentiate reproducibly and reliably into cardiomyocytes. Skeletal myoblasts have created in vivo myotubes but have not electrically integrated with the myocardium. Cardiac stem cells and cardiac progenitor cells represent one of the most promising types of cellular therapy for children with cardiac failure.