Intact endothelial autophagy is required to maintain vascular lipid homeostasis.

The physiological role of autophagic flux within the vascular endothelial layer remains poorly understood. Here, we show that in primary endothelial cells, oxidized and native LDL stimulates autophagosome formation. Moreover, by both confocal and electron microscopy, excess native or modified LDL appears to be engulfed within autophagic structures.

Adiponectin limits monocytic microparticle-induced endothelial activation by modulation of the AMPK, Akt and NFκB signaling pathways.

Objective: Monocyte-derived microparticles (mono-MPs) are emerging as critical transducers of inflammatory signals, and have been suggested to link cardiovascular risk factors to vascular injury. Since adiponectin has been proposed to exert multiple anti-inflammatory and vasculoprotective effects, we hypothesized that it might serve to limit the production and/or action of mono-MPs.

Methods: Flow cytometry and western blot studies were conducted on THP-1 cells, THP-1-derived MPs, human umbilical vein endothelial cells (HUVECs), peripheral blood CD14+ monocytes and mice to evaluate the effects of adiponectin on mono-MPs.

Effects of long-term chloroquine administration on the natural history of aortic aneurysms in mice.

Autophagy regulates cellular homeostasis and integrates the cellular pro-survival machinery. We investigated the role of autophagy in the natural history of murine abdominal aortic aneurysms (AAA). ApoE(-/-) mice were implanted with saline- or angiotensin II (Ang-II)-filled miniosmotic pumps then treated with either the autophagy inhibitor chloroquine (CQ; 50 mg·(kg body mass)(-1)·day(-1), by intraperitoneal injection) or saline.

Obesity and atherosclerosis: mechanistic insights.

Obesity is a multifactorial chronic disease characterized by an accumulation of visceral and subcutaneous fat, which leads to a predisposition toward cardiometabolic diseases. A plethora of mechanisms, including abnormalities in lipid metabolism, insulin resistance, inflammation, endothelial dysfunction, adipokine imbalance, and inflammasome activation have been suggested to underlie the relationship between obesity and atherosclerosis. More recent data point toward an emerging role of impaired autophagy and altered gut microbiome homeostasis as potentially contributing factors.

The essential autophagy gene ATG7 modulates organ fibrosis via regulation of endothelial-to-mesenchymal transition.

Pulmonary fibrosis is a progressive disease characterized by fibroblast proliferation and excess deposition of collagen and other extracellular matrix components. Although the origin of fibroblasts is multifactorial, recent data implicate endothelial-to-mesenchymal transition as an important source of fibroblasts. We report herein that loss of the essential autophagy gene ATG7 in endothelial cells (ECs) leads to impaired autophagic flux accompanied by marked changes in EC architecture, loss of endothelial, and gain of mesenchymal markers consistent with endothelial-to-mesenchymal transition.

Pedicled no-touch saphenous vein graft harvest limits vascular smooth muscle cell activation: the PATENT saphenous vein graft study.

Objective: Neointimal hyperplasia secondary to vascular smooth muscle cell (VSMC) activation limits the long-term patency of saphenous vein grafts (SVGs). We compared markers of vascular injury and VSMC activation in SVGs harvested using the pedicled 'no-touch' (NT) vs the conventional (CON) technique.

Methods: Patients undergoing coronary artery bypass surgery were enrolled in the PATENT SVG trial (clinicaltrials.

BRCA1 shields vascular smooth muscle cells from oxidative stress.

Background: Excessive production of reactive oxygen species (ROS), in part via upregulation of DNA damage pathways, is a central mechanism governing pathologic activation of vascular smooth muscle cells (VSMCs). We hypothesized that the breast cancer 1, early onset (BRCA1) gene that is involved in cellular resistance to DNA damage limits ROS production and oxidative stress in VSMCs.

Methods: We evaluated basal and H2O2-stimulated expression of BRCA1 in human aortic smooth muscle cells (HASMCs).

Autophagy gene fingerprint in human ischemia and reperfusion.

Objective: Autophagy is an evolutionary conserved adaptive response that is believed to promote cell survival in response to stressful stimuli via recycling of precursors derived from the degradation of endogenous cellular components. The autophagic molecular machinery is controlled by a large family of autophagy-related genes (ATGs) and downstream regulators. We sought to define the autophagy gene fingerprint associated with human ischemia and reperfusion (IR) injury using an intraoperative model developed by Sellke and colleagues.

Evolving role of microparticles in the pathophysiology of endothelial dysfunction.

Background: Endothelial dysfunction is an early event in the development and progression of a wide range of cardiovascular diseases. Various human studies have identified that measures of endothelial dysfunction may offer prognostic information with respect to vascular events. Microparticles (MPs) are a heterogeneous population of small membrane fragments shed from various cell types.

BRCA1 is a novel target to improve endothelial dysfunction and retard atherosclerosis.

Objective: BRCA1, a tumor suppressor gene implicated in breast and ovarian cancers, exerts multiple effects on DNA repair and affords resistance against cellular stress responses. We hypothesized that BRCA1 limits endothelial cell apoptosis and dysfunction, and via this mechanism attenuates atherosclerosis.

Methods: Loss and gain of function were achieved in cultured endothelial cells by silencing and overexpressing BRCA1, respectively.

Regulating cardiac energy metabolism and bioenergetics by targeting the DNA damage repair protein BRCA1.

Objective: Alterations in cardiac energy and substrate metabolism play a critical role in the development and clinical course of heart failure. We hypothesized that the cardioprotective role of the breast cancer 1, early onset (BRCA1) gene might be mediated in part by alterations in cardiac bioenergetics.

Methods: We generated cardiomyocyte-specific BRCA1 homozygous and heterozygous knockout mice using the Cre-loxP technology and evaluated the key molecules and pathways involved in glucose metabolism, fatty acid metabolism, and mitochondrial bioenergetics.

MicroRNA-145 targeted therapy reduces atherosclerosis.

Background: MicroRNA are essential posttranscriptional modulators of gene expression implicated in various chronic diseases. Because microRNA-145 is highly expressed in vascular smooth muscle cells (VSMC) and regulates VSMC fate and plasticity, we hypothesized that it may be a novel regulator of atherosclerosis and plaque stability.

Methods And Results: Apolipoprotein E knockout mice (ApoE(-/-)) mice were treated with either a microRNA-145 lentivirus under the control of the smooth muscle cell (SMC)-specific promoter SM22α or a SM22α control lentivirus before commencing the Western diet for 12 weeks.

miRNA-141 is a novel regulator of BMP-2-mediated calcification in aortic stenosis.

Objective: Bone morphogenetic protein-2 (BMP-2) is a major regulator of aortic valve calcification. MicroRNAs (miRNAs) are essential post-transcriptional modulators of gene expression and miRNA-141 is a known repressor of BMP-2-mediated osteogenesis. We hypothesized that miRNA-141 is a key regulator of aortic valve calcification.

BRCA1 gene therapy reduces systemic inflammatory response and multiple organ failure and improves survival in experimental sepsis.

Sepsis-related complications and mortality remain a major clinical problem. Increased cell death and unresolved cellular repair have been implicated as key upstream mediators of sepsis-induced organ dysfunction and death. We hypothesised that gene therapy with BRCA1, a critical regulator of DNA damage repair and cell survival, would attenuate the sequelae of sepsis and peritonitis in mice subjected to caecal ligation and perforation (CLP) and thioglycollate stimulation.

BRCA1 is an essential regulator of heart function and survival following myocardial infarction.

The tumour suppressor BRCA1 is mutated in familial breast and ovarian cancer but its role in protecting other tissues from DNA damage has not been explored. Here we show a new role for BRCA1 as a gatekeeper of cardiac function and survival. In mice, loss of BRCA1 in cardiomyocytes results in adverse cardiac remodelling, poor ventricular function and higher mortality in response to ischaemic or genotoxic stress.

BRCA2 protein deficiency exaggerates doxorubicin-induced cardiomyocyte apoptosis and cardiac failure.

The tumor suppressor breast cancer susceptibility gene 2 (BRCA2) plays an important role in the repair of DNA damage, and loss of BRCA2 predisposes carriers to breast and ovarian cancers. Doxorubicin (DOX) remains the cornerstone of chemotherapy in such individuals. However, it is often associated with cardiac failure, which once manifests carries a poor prognosis.

Herceptin, a recombinant humanized anti-ERBB2 monoclonal antibody, induces cardiomyocyte death.

P53 protein levels are elevated by trastuzumab and the biologically similar rat ERBB2/HER2/NEU antibody; and that this coincides with enhanced apoptosis, increased cleaved caspase-3 levels and diminished cardiac function. We also demonstrate that MDM2 may be a regulatory target of anti-ERBB2 thereby implicating the MDM2/p53 axis as a potential molecular component for the undesirable cardiac outcomes noted with trastuzumab. Finally, we show that these MDM2/p53-mediated events are independent of both the ERK1/2 and Akt systems.

Adropin is a novel regulator of endothelial function.

Background: Adropin is a recently identified protein that has been implicated in the maintenance of energy homeostasis and insulin resistance. Because vascular function and insulin sensitivity are closely related, we hypothesized that adropin may also exert direct effects on the endothelium.

Methods And Results: In vitro cell culture models were partnered with an in vivo murine injury model to determine the potential vascular effects of adropin.

Adiponectin primes human monocytes into alternative anti-inflammatory M2 macrophages.

Altered macrophage kinetics is a pivotal mechanism of visceral obesity-induced inflammation and cardiometabolic risk. Because monocytes can differentiate into either proatherogenic M1 macrophages or anti-inflammatory M2 macrophages, approaches that limit M1 while promoting M2 differentiation represent a unique therapeutic strategy. We hypothesized that adiponectin may prime human monocytes toward the M2 phenotype.

Nocturnal haemodialysis is associated with improved vascular smooth muscle cell biology.

Background: Conventional haemodialysis (CHD) is associated with a reduction in vascular smooth muscle cells (VSMCs) proliferation and an increase in apoptosis.

Methods: VSMC proliferation, migration, apoptosis and Runx2 expression were assessed under normal conditions (n = 4) and before and after conversion from CHD to NHD (n = 15).

Results: Compared to normal, CHD is associated with a reduction in VSMC proliferation [0.

Visfatin activates eNOS via Akt and MAP kinases and improves endothelial cell function and angiogenesis in vitro and in vivo: translational implications for atherosclerosis.

Improving endothelial nitric oxide synthase (eNOS) bioactivity and endothelial function is important to limit native, vein graft, and transplant atherosclerosis. Visfatin, a NAD biosynthetic enzyme, regulates the activity of the cellular survival factor, Sirt1. We hypothesized that visfatin may improve eNOS expression, endothelial function, and postnatal angiogenesis.

Angiotensin converting enzyme-2 confers endothelial protection and attenuates atherosclerosis.

The endothelium plays a central role in the maintenance of vascular homeostasis. One of the main effectors of endothelial dysfunction is ANG II, and pharmacological approaches to limit ANG II bioactivity remain the cornerstone of cardiovascular therapeutics. Angiotensin converting enzyme-2 (ACE2) has been identified as a critical negative modulator of ANG II bioactivity, counterbalancing the effects of ACE in determining net tissue ANG II levels; however, the role of ACE2 in the vasculature remains unknown.

Adiponectin deficiency promotes endothelial activation and profoundly exacerbates sepsis-related mortality.

Sepsis is a multifactorial, and often fatal, disorder typically characterized by widespread inflammation and immune activation with resultant endothelial activation. In the present study, we postulated that the adipokine adiponectin serves as a critical modulator of survival and endothelial activation in sepsis. To this aim, we evaluated both loss-of-function (adiponectin gene-deficient mice) and subsequent gain-of-function (recombinant adiponectin reconstitution) strategies in two well-established inflammatory models, cecal ligation perforation (CLP) and thioglyocollate-induced peritonitis.

Impaired endothelial function in C-reactive protein overexpressing mice.

Increasing evidence suggests that the inflammatory biomarker, C-reactive protein (CRP), may play a causal role in the development and progression of atherothrombosis. Since endothelial dysfunction is an early and integral component of atherosclerosis, we hypothesized that endothelial homeostasis would be impaired in CRP-overexpressing CRP transgenic (CRPtg) mice. Male CRPtg and wild-type mice were injected thrice over 2 weeks with vehicle or turpentine to induce the inflammation-sensitive CRP transgene.