Stem cell therapies for ischemic cardiovascular diseases

Myocardial infarction results in loss of cardiac muscle and deficiency in cardiac performance. Likewise, peripheral artery disease can result in critical limb ischemia leading to reduced mobility, non-healing ulcers, gangrene and amputation. Both of these common conditions diminish quality of life and enhance risk of mortality. Successful advances in treatment have led to more people surviving incidences of myocardial infarction or living with peripheral artery disease. However, the current treatments are inadequate in repairing ischemic tissue. Over the last 5 years, a vast number of patents have been submitted concerning the use of stem cells, which correlates with the exponential growth in stem cell publications. Exploiting stem cell therapy offers a real potential in replacing ischemic tissue with functional cells. In this paper, we review recent patents concerning stem cell therapy that have the potential to provide or potentiate novel treatment for ischemic cardiovascular disease. In addition, we evaluate the promise of the inventions by describing some clinical trials that are currently taking place, as well as considering how current research on ischemic cardiovascular disease may change the patent landscape in the future.

Embedded fibre Bragg grating array sensors in aluminium alloy matrix by ultrasonic consolidation

Fibre Bragg Grating (FBG) array sensors have been successfully embedded in aluminium alloy matrix by ultrasonic consolidation (UC) technique. The temperature and loading responses of the embedded FBG arrays have been systematically characterised. The embedded grating sensors exhibit an average temperature sensitivity of ~36pm/°C, which is three times higher than that of normal FBGs, and a loading responsivity of ~0.1nm/kg within the dynamic range from 0kg to 3kg. This initial experiment clearly demonstrates that FBG array sensors can be embedded in metal matrix together with other passive and active fibres to fabricate smart materials to monitor the operation and health of engineering structures.

Development of potent and selective tissue transglutaminase inhibitors:their effect on TG2 function and application in pathological conditions

Potent-selective peptidomimetic inhibitors of tissue transglutaminase (TG2) were developed through a combination of protein-ligand docking and molecular dynamic techniques. Derivatives of these inhibitors were made with the aim of specific TG2 targeting to the intra- and extracellular space. A cell-permeable fluorescently labeled derivative enabled detection of in situ cellular TG2 activity in human umbilical cord endothelial cells and TG2-transduced NIH3T3 cells, which could be enhanced by treatment of cells with ionomycin. Reaction of TG2 with this fluorescent inhibitor in NIH3T3 cells resulted in loss of binding of TG2 to cell surface syndecan-4 and inhibition of translocation of the enzyme into the extracellular matrix, with a parallel reduction in fibronectin deposition. In human umbilical cord endothelial cells, this same fluorescent inhibitor also demonstrated a reduction in fibronectin deposition, cell motility, and cord formation in Matrigel. Use of the same inhibitor in a mouse model of hypertensive nephrosclerosis showed over a 40% reduction in collagen deposition.

Endothelial cell redox regulation of ischemic angiogenesis

The endothelium produces and responds to reactive oxygen and nitrogen species (RONS), providing important redox regulation to the cardiovascular system in physiology and disease. In no other situation are RONS more critical than in the response to tissue ischemia. Here, tissue healing requires growth factor-mediated angiogenesis that is in part dependent on low levels of RONS, which paradoxically must overcome the damaging effects of high levels of RONS generated as a result of ischemia. While generation of endothelial cell RONS in hypoxia/reoxygenation is acknowledged, the mechanism for their role in angiogenesis is still poorly understood. During ischemia, the major low molecular weight thiol glutathione (GSH) reacts with RONS and protein cysteines, producing GSH-protein adducts. Recent data indicate that GSH adducts on certain proteins are essential to growth factor responses in endothelial cells. Genetic deletion of the enzyme glutaredoxin-1, which selectively removes GSH protein adducts, improves, while its overexpression impairs, revascularization of the ischemic hindlimb of mice. Ischemia-induced GSH adducts on specific cysteine residues of several proteins, including p65 NFkB and the sarcoplasmic reticulum calcium ATPase-2 (SERCA2), appear to promote ischemic angiogenesis. Identifying the specific proteins in the redox response to ischemia has provided therapeutic opportunities to improve clinical outcomes of ischemia.

Glutathione adducts induced by ischemia and deletion of glutaredoxin-1 stabilize HIF-1α and improve limb revascularization

Reactive oxygen species (ROS) are increased in ischemic tissues and necessary for revascularization; however, the mechanism remains unclear. Exposure of cysteine residues to ROS in the presence of glutathione (GSH) generates GSH-protein adducts that are specifically reversed by the cytosolic thioltransferase, glutaredoxin-1 (Glrx). Here, we show that a key angiogenic transcriptional factor hypoxia-inducible factor (HIF)-1α is stabilized by GSH adducts, and the genetic deletion of Glrx improves ischemic revascularization. In mouse muscle C2C12 cells, HIF-1α protein levels are increased by increasing GSH adducts with cell-permeable oxidized GSH (GSSG-ethyl ester) or 2-acetylamino-3-[4-(2-acetylamino-2-carboxyethylsulfanyl thiocarbonylamino) phenylthiocarbamoylsulfanyl] propionic acid (2-AAPA), an inhibitor of glutathione reductase. A biotin switch assay shows that GSSG-ester-induced HIF-1α contains reversibly modified thiols, and MS confirms GSH adducts on Cys520 (mouse Cys533). In addition, an HIF-1α Cys520 serine mutant is resistant to 2-AAPA–induced HIF-1α stabilization. Furthermore, Glrx overexpression prevents HIF-1α stabilization, whereas Glrx ablation by siRNA increases HIF-1α protein and expression of downstream angiogenic genes. Blood flow recovery after femoral artery ligation is significantly improved in Glrx KO mice, associated with increased levels of GSH-protein adducts, capillary density, vascular endothelial growth factor (VEGF)-A, and HIF-1α in the ischemic muscles. Therefore, Glrx ablation stabilizes HIF-1α by increasing GSH adducts on Cys520 promoting in vivo HIF-1α stabilization, VEGF-A production, and revascularization in the ischemic muscles

Cell-specific effects of Nox2 on the acute and chronic response to myocardial infarction

BACKGROUND: Increased reactive oxygen species (ROS) production is involved in the process of adverse cardiac remodeling and development of heart failure after myocardial infarction (MI). NADPH oxidase-2 (Nox2) is a major ROS source within the heart and its activity increases after MI. Furthermore, genetic deletion of Nox2 is protective against post-MI cardiac remodeling. Nox2 levels may increase both in cardiomyocytes and endothelial cells and recent studies indicate cell-specific effects of Nox2, but it is not known which of these cell types is important in post-MI remodeling. METHODS AND RESULTS: We have generated transgenic mouse models in which Nox2 expression is targeted either to cardiomyocytes (cardio-Nox2TG) or endothelial cells (endo-Nox2TG). We here studied the response of cardio-Nox2TG mice, endo-Nox2TG mice and matched wild-type littermates (WT) to MI induced by permanent left coronary artery ligation up to 4weeks. Initial infarct size assessed by magnetic resonance imaging (MRI) and cardiac dysfunction were similar among groups. Cardiomyocyte hypertrophy and interstitial fibrosis were augmented in cardio-Nox2TG compared to WT after MI and post-MI survival tended to be worse whereas endo-Nox2TG mice showed no significant difference compared to WT. CONCLUSIONS: These results indicate that cardiomyocyte rather than endothelial cell Nox2 may have the more important role in post-MI remodeling.

TG2: a credible therapeutic target in fibrotic diseasedue to its multifunctional roles

The role of TG2 in fibrosis is reported to be related to two important effects. The first in mediating the deposition and accumulation of the fibrotic extracellular matrix (ECM) via its cross-linking of proteins like fibronectin, collagen I and collagen III; and the second, the activation of latent matrix bound TGFβ1. We report here that the role of TG2 in fibrosis progression can be much more complex. We also report a new family of TG2-specific inhibitors that can not only inhibit protein cross-linking, but also regulate other functions of TG2, thus increasing their potency which can be demonstrated by their effectiveness in inhibiting fibrosis in two different fibrotic in vivo models.

Doing Research with Vulnerable Populations: The Case of Intravenous Drug Users

Article

Les traditions ancestrales, au sein de l'école d'aujourd'hui, chez les Cris de la Baie James : le cas de l'école Wiinibekuu à Waskaganish

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Glutaredoxin-1 Is up-regulated in preeclampsia and increases soluble Flt-1 expression

INTRODUCTION: Preeclampsia is a vascular disorder in pregnancyand is biochemical characterization by high soluble Flt-1 and lowplacenta growth factor as well as an imbalance in redox homeostasis.During conditions of high oxidative stress, cysteine residues on keyproteins are reversibly altered by S-glutathionylation, modifying theirfunction. Glutaredoxin-1 (Glrx) enzymatically catalyzes the removal of S-glutathione adducts, conferring reversible signaling dynamics toproteins with redox-sensitive cysteines. The role of Glrx in preeclampsiais unknown.METHODS: Immunohistochemistry and Western blot analysis for Glrx orglutathione were conducted on human placenta samples collected pre-termfrom early onset preeclamptic patients (n=10) or non-preeclamptic induceddeliveries (n=9). Human endothelial cells were infected with adenovirusencoding Glrx or LacZ prior to the cells being exposed to hypoxia (0.1%O2, 24h) to measure changes in soluble Flt-1 (sFlt-1). Quantitative PCRand ELISA were used to measure sFlt-1 at mRNA and protein level.RESULTS: Immunohistochemical staining for GSH revealed lowerS-glutathionylation adducts in preeclampsia placenta in comparison tocontrols. Glrx expression, which catalyses de-glutathionylation wasenhanced in early onset preeclampsia compared to pre-term controlsamples. In contrast, no change was observed in preeclamptic and IUGRplacentas at full term. In endothelial cells overexpressing Glrx, sFlt-1expression was dramatically enhanced at mRNA (3-fold P<0.05) andprotein level (5 fold P>0.01, n=4) after hypoxia andoverexpressing Glrxin mice enhanced levels of circulating sFlt-1 during in vivo ischemia.CONCLUSIONS: Enhanced Glrx expression in preeclamptic placentain line with an apparent decrease in S-glutathionylation may leavekey proteins susceptible to irreversible oxidation in conditions of highoxidative stress.

Vitamin D, d-dimer, Interferon γ, and sCD14 Levels are Independently Associated with Immune Reconstitution Inflammatory Syndrome: A Prospective, International Study

© 2015.To determine the immunological profile most important for IRIS prediction, we evaluated 20 baseline plasma biomarkers in Acquired Immunodeficiency Syndrome (AIDS) patients initiating antiretroviral therapy (ART). Patients were enrolled in a randomized, placebo-controlled ART initiation trial in South Africa and Mexico to test whether maraviroc could prevent IRIS. Participants were classified prospectively as having IRIS within 6. months of ART initiation. Twenty plasma biomarkers were measured at study enrollment for 267 participants. Biomarkers were tested for predicting IRIS with adjustment for covariates chosen through forward stepwise selection. Sixty-two participants developed IRIS and of these 21 were tuberculosis (TB)-IRIS. Baseline levels of vitamin D and higher d-dimer, interferon gamma (IFNγ), and sCD14 were independently associated with risk of IRIS in multivariate analyses. TB-IRIS cases exhibited a distinct biosignature from IRIS related to other pathogens, with increased levels of C-reactive protein (CRP), sCD14, IFNγ, and lower levels of Hb that could be captured by a composite risk score. Elevated markers of Type 1 T helper (Th1) response, monocyte activation, coagulation and low vitamin D were independently associated with IRIS risk. Interventions that decrease immune activation and increase vitamin D levels warrant further study.

Doing Research with Vulnerable Populations: The Case of Intravenous Drug Users

Article

Les traditions ancestrales, au sein de l'école d'aujourd'hui, chez les Cris de la Baie James : le cas de l'école Wiinibekuu à Waskaganish

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Invited lectures from a spatial orientation symposium in honor of Frederick Guedry, Day 2

This report contains the invited lectures from day 2 of a Spatial Orientation Symposium in honor of the late Dr. Frederick Guedry, held at the Institute of Human and Machine Cognition (IHMC) in Pensacola, Florida in November of 2010. The conference was sponsored by the Coalition Warfare Program of the Office of the Under Secretary of Defense for Acquisition, Technology, and Logistics. It was organized by Drs. Angus Rupert and Ben Lawson (USAARL) and hosted by Drs. Anil Raj and Ken Ford (IHMC). The lectures from day 1 are in Lawson et al., 2014. Day 2 includes lectures by Drs. Scott, Ben Lawson, Angus Rupert, Owen Black, Karen Atkins, Kim Gottshall, Anil Raj, and Måns Magnusson. The lectures focus on the structure, function and reflexes of the vestibular system, orientation perceptions, motion sickness, adaptation, and rehabilitation. This report also features banquet talks given by Drs. Lawson and Rupert, in which they honor Dr. Fred Guedry. Also featured is an interview with Dr. Guedry, conducted by a Navy historian, in which the reader can catch a glimpse into Dr. Guedry's wartime experiences and early days as a researcher.

Sweat Lodges in Iron Age Iberian Peninsula: New Data, Typologies and Interpretations

Three questions on the study of NO Iberian Peninsula sweat lodges are posed. First, the new sauna of Monte Ornedo (Cantabria), the review of the one of Armea (Ourense), and the Cantabrian pedra formosa type are discussed. Second, the known types of sweat lodges are reconsidered underlining the differences between the Cantabrian and the Douro - Minho groups as these differences contribute to a better assessment of the saunas located out of those territories, such as those of Monte Ornedo or Ulaca. Third, a richer record demands a more specific terminology, a larger use of archaeometric analysis and the application of landscape archaeology or art history methodologies. In this way the range of interpretation of the sweat lodges is opened, as an example an essay is proposed that digs on some already known proposals and suggests that the saunas are material metaphors of wombs whose rationale derives from ideologies and ritual practices of Indo-European tradition.