Cardiac Overexpression of S100A6 Attenuates Cardiomyocyte Apoptosis and Reduces Infarct Size After Myocardial Ischemia-Reperfusion.

Background: Cardiomyocyte-specific transgenic mice overexpressing S100A6, a member of the family of EF-hand calcium-binding proteins, develop less cardiac hypertrophy, interstitial fibrosis, and myocyte apoptosis after permanent coronary ligation, findings that support S100A6 as a potential therapeutic target after acute myocardial infarction. Our purpose was to investigate S100A6 gene therapy for acute myocardial ischemia-reperfusion.

Methods And Results: We first performed in vitro studies to examine the effects of S100A6 overexpression and knockdown in rat neonatal cardiomyocytes.

Novel regulatory role of neuropilin-1 in endothelial-to-mesenchymal transition and fibrosis in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an intense fibrotic reaction termed tumor desmoplasia, which is in part responsible for its aggressiveness. Endothelial cells have been shown to display cellular plasticity in the form of endothelial-to-mesenchymal transition (EndMT) that serves as an important source of fibroblasts in pathological disorders, including cancer. Angiogenic co-receptor, neuropilin-1 (NRP- 1) actively binds TGFβ1, the primary mediator of EndMT and is involved in oncogenic processes like epithelial-to-mesenchymal transition (EMT).

Prospect of ultrasound-mediated gene delivery in cardiovascular applications.

Introduction: The field of regenerative medicine has evolved over the years, investigating gene and stem/progenitor cell therapies to help address the increasing burden of cardiovascular disease (CVD). While the lack of success of gene therapy in clinical trials has dampened enthusiasm, the search continues for a successful and translatable gene therapy strategy for CVD. Ultrasound-mediated gene delivery (UMGD) is a non-invasive technique for gene delivery that utilizes gene-bearing carrier microbubbles and high power ultrasound to facilitate transfection in vivo.

Therapeutic Angiogenesis by Ultrasound-Mediated MicroRNA-126-3p Delivery.

Objective: MicroRNAs are involved in many critical functions, including angiogenesis. Ultrasound-targeted microbubble destruction (UTMD) is a noninvasive technique for targeted vascular transfection of plasmid DNA and may be well suited for proangiogenic microRNA delivery. We aimed to investigate UTMD of miR-126-3p for therapeutic angiogenesis in chronic ischemia.

Early outgrowth pro-angiogenic cell number and function do not correlate with left ventricular structure and function in conventional hemodialysis patients: a cross-sectional study.

Background: Left ventricular hypertrophy (LVH) is commonly found in chronic dialysis (CD) recipients, and is associated with impaired microvascular cardiac perfusion and heart failure. In response to LVH and cardiac ischemia, early outgrowth pro-angiogenic cellS(EPCs) mobilize from the bone marrow to facilitate angiogenesis and endothelial repair. In the general population, EPC number and function correlate inversely with cardiovascular risk.

Perlecan heparan sulfate proteoglycan is a critical determinant of angiogenesis in response to mouse hind-limb ischemia.

Background: Perlecan is a heparan sulfate proteoglycan (HSPG) constituent of the extracellular matrix with roles in cell growth, differentiation, and angiogenesis. The role of the HS side chains in regulating in vivo angiogenesis after hind-limb ischemia is unknown.

Methods: Heparan sulfate (HS)-deficient perlecan (Hspg2(Δ3/Δ3)) mice (n = 35), containing normal perlecan core protein but deficient in HS side chains, and wild-type (n = 33) littermates underwent surgical induction of hind-limb ischemia.

A modified portfolio diet complements medical management to reduce cardiovascular risk factors in diabetic patients with coronary artery disease.

Background & Aims: Secondary prevention can improve outcomes in high risk patients. This study investigated the magnitude of cardiovascular risk reduction associated with consumption of a modified portfolio diet in parallel with medical management.

Design: 30 patients with type II diabetes, 6 weeks post bypass surgery received dietary counseling on a Modified Portfolio Diet (MPD) (low fat, 8 g/1000 kcal viscous fibres, 17 g/1000 kcal soy protein and 22 g/1000 kcal almonds).

Circulating angiogenic cell dysfunction in patients with hereditary hemorrhagic telangiectasia.

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder. Circulating angiogenic cells (CACs) play an important role in vascular repair and regeneration. This study was designed to examine the function of CACs derived from patients with HHT.

Survivin gene therapy attenuates left ventricular systolic dysfunction in doxorubicin cardiomyopathy by reducing apoptosis and fibrosis.

Aims: The aim of this study was to investigate anti-apoptotic gene therapy using ultrasound-mediated plasmid delivery of survivin, an inhibitor of apoptosis protein, to prevent apoptosis and to attenuate left ventricular (LV) systolic dysfunction in a model of heart failure induced by doxorubicin.

Methods And Results: Effect of survivin transduction was investigated in vitro in rat cardiomyoblasts. After survivin transduction, survivin protein was detected in cell culture supernate confirming secretion of extracellular survivin.

Optimization of Ultrasound-mediated Anti-angiogenic Cancer Gene Therapy.

Ultrasound-targeted microbubble destruction (UTMD) can be used to deliver silencing gene therapy to tumors. We hypothesized that UTMD would be effective in suppressing angiogenesis within tumors, and that modulation of the ultrasound pulsing intervals (PI) during UTMD would affect the magnitude of target knockdown. We performed UTMD of vascular endothelial growth factor receptor-2 (VEGFR2) short hairpin (sh)RNA plasmid in an heterotopic mammary adenocarcinoma model in rats, evaluating PIs of 2, 5, 10, and 20 seconds.

Ultrasound-mediated vascular gene transfection by cavitation of endothelial-targeted cationic microbubbles.

Objectives: Ultrasound-mediated gene delivery can be amplified by acoustic disruption of microbubble carriers that undergo cavitation. We hypothesized that endothelial targeting of microbubbles bearing cDNA is feasible and, through optimizing proximity to the vessel wall, increases the efficacy of gene transfection.

Background: Contrast ultrasound-mediated gene delivery is a promising approach for site-specific gene therapy, although there are concerns with the reproducibility of this technique and the safety when using high-power ultrasound.

A direct comparison of endothelial progenitor cell dysfunction in rat metabolic syndrome and diabetes.

Objectives: Diabetes mellitus (DM) is associated with impairment of endothelial progenitor cells (EPCs), but the effects of metabolic syndrome (MS) on EPCs have been less well characterized. We hypothesized that in the presence of MS, the number and functionality of EPCs would be markedly reduced, and would be similar to DM.

Methods: Mononuclear cells were isolated from the bone-marrow (BM) and peripheral blood of lean Zucker, obese Zucker, a model of MS, and Zucker diabetic fatty rats.

Sustained improvement in perfusion and flow reserve after temporally separated delivery of vascular endothelial growth factor and angiopoietin-1 plasmid deoxyribonucleic acid.

Objectives: The aim of this study was to compare temporally separated vascular endothelial growth factor (VEGF) and angiopoietin (Ang)-1 delivery with concomitant delivery or single VEGF delivery, for therapeutic angiogenesis in chronic ischemia.

Background: Single gene delivery of VEGF results in immature neovessels that ultimately regress. Endogenously, VEGF acts early to initiate angiogenesis, whereas Ang-1 acts later to induce vessel maturation.

Fluorescent microangiography is a novel and widely applicable technique for delineating the renal microvasculature.

Rarefaction of the renal microvasculature correlates with declining kidney function. However, current technologies commonly used for its evaluation are limited by their reliance on endothelial cell antigen expression and assessment in two dimensions. We set out to establish a widely applicable and unbiased optical sectioning method to enable three dimensional imaging and reconstruction of the renal microvessels based on their luminal filling.

Nocturnal hemodialysis is associated with restoration of early-outgrowth endothelial progenitor-like cell function.

Background And Objectives: Angiogenesis is a key response to tissue ischemia that may be impaired by uremia. Although early-outgrowth endothelial progenitor-like cells promote angiogenesis in the setting of normal renal function, cells from uremic patients are dysfunctional. When compared with conventional hemodialysis, it was hypothesized that nocturnal hemodialysis would improve the in vivo angiogenic activity of these cells in a well described model of ischemic vascular disease.

Contrast ultrasound and targeted microbubbles: diagnostic and therapeutic applications for angiogenesis.

Angiogenesis represents the formation of new capillaries from existing vasculature, and as such plays a critical role in the response to ischemia in the setting of chronic coronary artery and peripheral vascular disease. Recent technological advances in non-invasive imaging modalities now allow the molecular imaging of angiogenesis. One such technique is contrast-enhanced ultrasound using microbubbles targeted against molecular markers of the angiogenic process.

Vascular gene transfer of SDF-1 promotes endothelial progenitor cell engraftment and enhances angiogenesis in ischemic muscle.

Gene therapy approaches to enhance endothelial progenitor cell (EPC) homing may augment cell engraftment to ischemic tissue and lead to a greater therapeutic response. Therefore, we assessed the effects of ultrasound-mediated (UM) transfection of the chemokine stromal cell-derived factor-1 (SDF-1) on homing and engraftment of intravenously administered EPCs and the subsequent angiogenic response in chronically ischemic skeletal muscle. Bone marrow-derived EPCs were isolated from donor Fisher 344 rats, cultured and labeled in preparation for injection into recipient animals via a jugular vein.

Culture-modified bone marrow cells attenuate cardiac and renal injury in a chronic kidney disease rat model via a novel antifibrotic mechanism.

Background: Most forms of chronic kidney disease are characterized by progressive renal and cardiac fibrosis leading to dysfunction. Preliminary evidence suggests that various bone marrow-derived cell populations have antifibrotic effects. In exploring the therapeutic potential of bone marrow derived cells in chronic cardio-renal disease, we examined the anti-fibrotic effects of bone marrow-derived culture modified cells (CMCs) and stromal cells (SCs).

Comparison of gene delivery techniques for therapeutic angiogenesis ultrasound-mediated destruction of carrier microbubbles versus direct intramuscular injection.

Objectives: This study was designed to compare the efficacy of angiogenic gene delivery by ultrasound-mediated (UM) destruction of intravenous carrier microbubbles to direct intramuscular (IM) injections.

Background: Current trials of gene therapy for angiogenesis remain limited by suboptimal, invasive delivery techniques.

Methods: Hind-limb ischemia was produced by iliac artery ligation in 99 rats.

Molecular imaging of endothelial progenitor cell engraftment using contrast-enhanced ultrasound and targeted microbubbles.

Aims: Imaging methods to track the fate of progenitor cells after their delivery would be useful in assessing the efficacy of cell-based therapies. We hypothesized that contrast-enhanced ultrasound (CEU) using microbubbles targeted to a genetically engineered cell-surface marker on endothelial progenitor cells (EPCs) would allow the targeted imaging of vascular engraftment.

Methods And Results: Rodent bone marrow-derived EPCs were isolated, cultured, and transfected to express the marker protein, H-2Kk, on the cell surface.

The (Pro)renin receptor: site-specific and functional linkage to the vacuolar H+-ATPase in the kidney.

The (pro)renin receptor ([P]RR) is a transmembrane protein that binds both renin and prorenin with high affinity, increasing the catalytic cleavage of angiotensinogen and signaling intracellularly through mitogen-activated protein kinase activation. Although initially reported as having no homology with any known membrane protein, other studies have suggested that the (P)RR is an accessory protein, named ATP6ap2, that associates with the vacuolar H(+)-ATPase, a key mediator of final urinary acidification. Using in situ hybridization, immunohistochemistry, and electron microscopy, together with serial sections stained with nephron segment-specific markers, we found that (P)RR mRNA and protein were predominantly expressed in collecting ducts and in the distal nephron.

Acceleration of diabetic wound healing by an angiopoietin peptide mimetic.

Angiopathies are one of the leading underlying causes of morbidity in diabetic patients. Poorly managed blood glucose levels contribute to vascular defects that manifest themselves in numerous different clinical conditions, including diabetic retinopathy, nephropathy, peripheral artery disease, and compromised wound healing. The angiopoietin family (Angs 1-4) has been shown to play a critical role in the growth and maintenance of vasculature.

Therapeutic arteriogenesis by ultrasound-mediated VEGF165 plasmid gene delivery to chronically ischemic skeletal muscle.

Current methods of gene delivery for therapeutic angiogenesis are invasive, requiring either intraarterial or intramuscular administration. A noninvasive method of gene delivery has been developed using ultrasound-mediated destruction of intravenously administered DNA-bearing carrier microbubbles during their microcirculatory transit. Here we show that chronic ischemia could be markedly improved by ultrasound-mediated destruction of microbubbles bearing vascular endothelial growth factor-165 (VEGF(165)) plasmid DNA.

Low-energy gamma-emitting stents inhibit intimal hyperplasia with minimal "edge effects" in a pig coronary artery model.

Purpose: The objective of this study was to determine the effects of different doses of gamma-emitting radioactive stents on intimal hyperplasia in a porcine coronary stent model at 28 days.

Methods: Sixty-four bare stents and those coated with palladium-103 [activities of 0 (control), 0.5, 1.

Nitroglycerin attenuates human endothelial progenitor cell differentiation, function, and survival.

Endothelial progenitor cells (EPCs) participate in angiogenesis and the response to chronic ischemia. Risk factors and cardiovascular disease attenuate EPC number, function, and survival. Continuous therapy with nitroglycerin (glyceryl trinitrate; GTN) is associated with increased vascular oxidative stress, leading to nitrate tolerance and endothelial dysfunction.