Embryonic stem cell-derived endothelial cells engraft into the ischemic hindlimb and restore perfusion.

Objective: We examined the effect of delivery modality on the survival, localization, and functional effects of exogenously administered embryonic stem cells (ESCs) or endothelial cells derived from them (ESC-ECs) in the ischemic hindlimb.

Methods And Results: Murine ESCs or ESC-ECs were stably transduced with a construct for bioluminescence imaging (BLI) and fluorescent detection. In a syngeneic murine model of limb ischemia, ESCs or ESC-ECs were delivered by intramuscular (IM), intrafemoral artery (IA), or intrafemoral vein injections (n=5 in each group).

Relationship of asymmetric dimethylarginine and homocysteine to vascular aging in systemic lupus erythematosus patients.

Objective: Systemic lupus erythematosus (SLE) is independently associated with accelerated atherosclerosis and premature arterial stiffening. Asymmetric dimethylarginine (ADMA) and homocysteine are mechanistically interrelated mediators of endothelial dysfunction and correlates of atherosclerosis in the general population. The aim of this study was to assess the relationship of ADMA and homocysteine to subclinical vascular disease in patients with SLE.

Role of nitric oxide signaling in endothelial differentiation of embryonic stem cells.

Signaling pathways that govern embryonic stem cell (ESCs) differentiation are not well characterized. Nitric oxide (NO) is a potent vasodilator that modulates other signaling pathways in part by activating soluble guanylyl cyclase (sGC) to produce cyclic guanosine monophosphate (cGMP). Because of its importance in endothelial cell (EC) growth in the adult, we hypothesized that NO may play a critical role in EC development.

Noise in biological circuits.

Noise biology focuses on the sources, processing, and biological consequences of the inherent stochastic fluctuations in molecular transitions or interactions that control cellular behavior. These fluctuations are especially pronounced in small systems where the magnitudes of the fluctuations approach or exceed the mean value of the molecular population. Noise biology is an essential component of nanomedicine where the communication of information is across a boundary that separates small synthetic and biological systems that are bound by their size to reside in environments of large fluctuations.

Overexpression of dimethylarginine dimethylaminohydrolase protects against cerebral vascular effects of hyperhomocysteinemia.

Rationale: Hyperhomocysteinemia is a cardiovascular risk factor that is associated with elevation of the nitric oxide synthase inhibitor asymmetrical dimethylarginine (ADMA).

Objective: Using mice transgenic for overexpression of the ADMA-hydrolyzing enzyme dimethylarginine dimethylaminohydrolase-1 (DDAH1), we tested the hypothesis that overexpression of DDAH1 protects from adverse structural and functional changes in cerebral arterioles in hyperhomocysteinemia.

Methods And Results: Hyperhomocysteinemia was induced in DDAH1 transgenic (DDAH1 Tg) mice and wild-type littermates using a high methionine/low folate (HM/LF) diet.

Chronic exposure to nicotine impairs cholinergic angiogenesis.

Cholinergic angiogenesis is mediated by an endothelial nicotinic acetylcholine receptor (EC nAChR). Short-term administration of nicotine stimulates angiogenesis via EC nAChRs.The long-term effects of nicotine upon cholinergic angiogenesis are unknown.

nAChRs mediate human embryonic stem cell-derived endothelial cells: proliferation, apoptosis, and angiogenesis.

Background: Many patients with ischemic heart disease have cardiovascular risk factors such as cigarette smoking. We tested the effect of nicotine (a key component of cigarette smoking) on the therapeutic effects of human embryonic stem cell-derived endothelial cells (hESC-ECs).

Methods And Results: To induce endothelial cell differentiation, undifferentiated hESCs (H9 line) underwent 4-day floating EB formation and 8-day outgrowth differentiation in EGM-2 media.

Cell-free production of transducible transcription factors for nuclear reprogramming.

Ectopic expression of a defined set of transcription factors chosen from Oct3/4, Sox2, c-Myc, Klf4, Nanog, and Lin28 can directly reprogram somatic cells to pluripotency. These reprogrammed cells are referred to as induced pluripotent stem cells (iPSCs). To date, iPSCs have been successfully generated using lentiviruses, retroviruses, adenoviruses, plasmids, transposons, and recombinant proteins.

Extensive characterization of the human DDAH1 transgenic mice.

Purpose Of The Research: Overexpression of the human dimethylarginine dimethylaminohydrolase type 1 (hDDAH1) gene was reported to have beneficial cardiovascular effects in mice. To date, it is unclear whether these effects are related to enhanced metabolic clearance of asymmetric dimethylarginine (ADMA) and l-N(G)-mono-methyl-l-arginine (l-NMMA) or increased DDAH1 expression and activity in cardiovascular tissues of hDDAH1 transgenic mice.

Principal Results: DDAH activity (DDAH1+DDAH2) was found to be markedly increased in aortic and heart tissues but unaltered in liver and kidney tissues of hDDAH1 transgenic as compared to wild-type (WT) mice.

Hypercholesterolemia impairs exercise capacity in mice.

We previously reported an attenuation of both exercise hyperemia and measures of aerobic capacity in hypercholesterolemic mice. In this study, we expanded upon the previous findings by examining the temporal and quantitative relationship of hypercholesterolemia to aerobic and anaerobic capacity and by exploring several potential mechanisms of dysfunction. Eight-week-old wild type (n = 123) and apoE knockout (n = 79) C57BL/6J mice were divided into groups with distinct cholesterol levels by feeding with regular or high-fat diets.

Cholinergic modulation of angiogenesis: role of the 7 nicotinic acetylcholine receptor.

Pathological angiogenesis contributes to tobacco-related diseases such as malignancy, atherosclerosis and age-related macular degeneration. Nicotine acts on endothelial nicotinic acetylcholine receptors (nAChRs) to activate endothelial cells and to augment pathological angiogenesis. In the current study, we studied nAChR subunits involved in these actions.

Does improving mood in depressed patients alter factors that may affect cardiovascular disease risk?

To determine if improvement in mood would ameliorate autonomic dysregulation, HPA dysfunction, typical risk factors and C-reactive protein in depressed patients with elevated cardiovascular disease risk (CVD), 48 depressed participants with elevated cardiovascular risk factors were randomized to a cognitive behavioral intervention (CBT) or a waiting list control (WLC) condition. Twenty non-depressed age and risk-matched controls were also recruited. Traditional risk factors (e.

Can mean platelet component be used as an index of platelet activity in stable coronary artery disease?

Acute coronary syndrome is associated with intracoronary thrombosis secondary to platelet activation. Previous groups have investigated platelet activation in both stable and unstable vascular disease. Most measures of platelet activation are not routinely available or easily adaptable to large scale clinical use.

What is the optimal duration of tilt testing for the assessment of patients with suspected postural tachycardia syndrome?

Aims: The aim of this study is to define the optimal duration of tilt testing for the assessment of patients with suspected postural tachycardia syndrome (POTS).

Methods And Results: This was a case-control study. Cases were identified retrospectively from a database of patients referred with orthostatic intolerance (OI).

Endothelial nicotinic acetylcholine receptors and angiogenesis.

Nicotinic acetylcholine receptors (nAChRs) were first described in non-excitable cells just more than a decade ago. The nAChRs on endothelial cells modulate key angiogenic processes, including endothelial cell survival, proliferation, and migration. The receptors may be stimulated by endogenous agonists such as acetylcholine, or exogenous chemicals such as nicotine, to activate physiologic angiogenesis (such as in wound healing) or pathologic angiogenesis (such as retinal neovascularization or tumor angiogenesis).

Embryonic stem cell-derived endothelial cells for treatment of hindlimb ischemia.

Peripheral arterial disease (PAD) results from narrowing of the peripheral arteries that supply oxygenated blood and nutrients to the legs and feet, This pathology causes symptoms such as intermittent claudication (pain with walking), painful ischemic ulcerations, or even limb-threatening gangrene. It is generally believed that the vascular endothelium, a monolayer of endothelial cells that invests the luminal surface of all blood and lymphatic vessels, plays a dominant role in vascular homeostasis and vascular regeneration. As a result, stem cell-based regeneration of the endothelium may be a promising approach for treating PAD.

Murine model of hindlimb ischemia.

In the United States, peripheral arterial disease (PAD) affects about 10 million individuals, and is also prevalent worldwide. Medical therapies for symptomatic relief are limited. Surgical or endovascular interventions are useful for some individuals, but long-term results are often disappointing.

Bone morphogenetic protein 2 induces pulmonary angiogenesis via Wnt-beta-catenin and Wnt-RhoA-Rac1 pathways.

Mutations in bone morphogenetic protein (BMP) receptor II (BMPRII) are associated with pulmonary artery endothelial cell (PAEC) apoptosis and the loss of small vessels seen in idiopathic pulmonary arterial hypertension. Given the low penetrance of BMPRII mutations, abnormalities in other converging signaling pathways may be necessary for disease development. We hypothesized that BMPRII supports normal PAEC function by recruiting Wingless (Wnt) signaling pathways to promote proliferation, survival, and motility.

A review of postural orthostatic tachycardia syndrome.

A 21-year-old female reports an 18-month history of light-headedness on standing. This is often associated with palpitations and a feeling of intense anxiety. She has had two black-outs in the past 12 months.

Two cardiovascular risk factors in one? Homocysteine and its relation to glomerular filtration rate. A meta-analysis of 41 studies with 27,000 participants.

Background: Hyperhomocysteinemia is thought to be an independent risk factor for cardiovascular disease, but the association between renal dysfunction and homocysteine may not have been fully taken into account. We performed a meta-analysis of studies that report correlations between glomerular filtration rate (GFR) and homocysteine plasma levels.

Methods: Using a prespecified research strategy, we identified 41 studies involving 26,617 participants that reported Pearson or Spearman correlation coefficients for the association between 1/GFR and homocysteine.

A biomarker panel for peripheral arterial disease.

Peripheral arterial disease (PAD) is common, but often not diagnosed. A biomarker index would be useful to raise suspicion of PAD, so as to trigger appropriate vascular testing and management. The study comprised 540 individuals: 197 individuals with both coronary artery disease and peripheral arterial disease (CAD + PAD); 81 with CAD only; and 262 with no hemodynamically significant disease (NHSD) of the coronary or peripheral arteries.

Tissue-specific downregulation of dimethylarginine dimethylaminohydrolase in hyperhomocysteinemia.

Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthase, has been proposed to be a mediator of vascular dysfunction during hyperhomocysteinemia. Levels of ADMA are regulated by dimethylarginine dimethylaminohydrolase (DDAH). Using both in vitro and in vivo approaches, we tested the hypothesis that hyperhomocysteinemia causes downregulation of the two genes encoding DDAH (Ddah1 and Ddah2).