Metabolic and cardiac adaptation to chronic pharmacologic blockade of facilitative glucose transport in murine dilated cardiomyopathy and myocardial ischemia

Abstract GLUT transgenic and knockout mice have provided valuable insight into the role of facilitative glucose transporters (GLUTs) in cardiovascular and metabolic disease, but compensatory physiological changes can hinder interpretation of these models. To determine whether adaptations occur in response to GLUT inhibition in the failing adult heart, we chronically treated TG9 mice, a transgenic model of dilated cardiomyopathy and heart failure, with the GLUT inhibitor ritonavir. Glucose tolerance was significantly improved with chronic treatment and correlated with decreased adipose tissue retinol binding protein 4 (RBP4) and resistin. A modest improvement in lifespan was associated with decreased cardiomyocyte brain natriuretic peptide (BNP) expression, a marker of heart failure severity. GLUT1 and −12 protein expression was significantly increased in left ventricular (LV) myocardium in ritonavir-treated animals. Supporting a switch from fatty acid to glucose utilization in these tissues, fatty acid transporter CD36 and fatty acid transcriptional regulator peroxisome proliferator-activated receptor α (PPARα) mRNA were also decreased in LV and soleus muscle. Chronic ritonavir also increased cardiac output and dV/dt-d in C57Bl/6 mice following ischemia-reperfusion injury. Taken together, these data demonstrate compensatory metabolic adaptation in response to chronic GLUT blockade as a means to evade deleterious changes in the failing heart

Occlusion of retinal capillaries caused by glial cell proliferation in chronic ocular inflammation

The inner blood-retinal barrier is a gliovascular unit in which glial cells surround capillary endothelial cells and regulate retinal capillaries by paracrine interactions. During chronic ocular inflammation, microvascular complications can give rise to vascular proliferative lesions, which compromise visual acuity. This pathologic remodelling caused by proliferating Müller cells determines occlusion of retinal capillaries. The aim of the present study was to identify qualitative and quantitative alterations in the retinal capillaries in patients with post-traumatic chronic ocular inflammation or post-thrombotic vascular glaucoma. Moreover, we investigated the potential role of vascular endothelial growth factor (VEGF) and pro-inflammatory cytokines in retinal inflammation. Our electron microscopy findings demonstrated that during chronic ocular inflammation, thickening of the basement membrane, loss of pericytes and endothelial cells and proliferation of Müller cells occur with irreversible occlusion of retinal capillaries. Angiogenesis takes place as part of a regenerative reaction that results in fibrosis. We believe that VEGF and pro-inflammatory cytokines may be potential therapeutic targets in the treatment of this disease although further studies are required to confirm these findings

Mein Assistent des Verschwindens

In den Jahren 1998 bis 2010 entstanden zahlreiche gemeinsame Projekte der beiden Künstler Elfriede Jelinek und Christoph Schlingensief. Jelinek verfasste für und über den Künstler eine Vielzahl an Texten. Das Textkorpus, das für die Zusammenarbeit und für die Auseinandersetzung der Autorin mit Schlingensief relevant ist, umfasst fünf essayistische Texte (Laß dir raten: Gründe Staaten!, Der Raum im Raum, Interferenzen im E-Werk, Schlingensief, Der Verschwender), sechs Theatertexte (Ich liebe Österreich, Bambiland, Irm sagt:, Margit sagt:, Parsifal: (Laß o Welt o Schreck laß nach!), Tod-krank.Doc), einen Chateintrag (gelb) sowie ein Statement zum Tod von Schlingensief. Jelineks Texte für und über Schlingensief unterscheiden sich formal nicht von ihrem übrigen Werk, nehmen jedoch inhaltlich deutlich auf den Künstler Bezug. Es können vier Ebenen bestimmt werden, die für die Präsenz des Künstlers und seines Werks innerhalb der Texte von Bedeutung sind: die Strategie, Schlingensief als mögliche Sprecherinstanz hörbar zu machen; die Übernahme und Fortschreibung von Motiven; die Reflexion von Schlingensiefs Ästhetik; die Reflexion der Zusammenarbeit. Durch die Textstrategie, Schlingensief als mögliche Stimme hörbar zu machen, wird v.a. in den beiden Theatertexten Parsifal: (Laß o Welt o Schreck laß nach!) und Tod-krank.Doc die Präsenz des Künstlers erzeugt. Mithilfe von Verweisen auf Schlingensiefs Biografie und auf sein Werk wird er vom Leser als mögliche Sprecherinstanz assoziiert. Motivübernahmen und -fortschreibungen sind in allen Texten vorhanden. Die wichtigsten Motive sind das Motiv der Erlösung und das Motiv der Krankheit. Beide wurden von Schlingensief zentral bearbeitet und fanden Eingang in Jelineks Texte. Das Motiv der Krankheit wird von Jelinek im Theatertext Tod-krank.Doc aufgegriffen. Sie assoziiert mit der Krankheit eine Höhle im Körper und entwickelt daraus ihren Text weiter. Das Motiv der Erlösung wird von Jelinek v.a. mit religiösen und antiken Erlösungsmythen verbunden sowie mit der Frage, ob Kunst zur Erlösung führen kann. Jelinek dekonstruiert in ihren Texten jegliche Erlösungsphantasien und negiert die Frage nach der Möglichkeit der Erlösung durch Kunst. In den nach dem Tod entstandenen Texten der Autorin zeigt sich jedoch die Tendenz, Schlingensief als „Kunstheiland“ zu verklären. In den essayistischen Texten reflektiert Jelinek Schlingensiefs Ästhetik. Sie ordnet ihn als bildenden Künstler ein und unterstreicht den Kunstcharakter seiner Arbeiten. Der von Schlingensief entwickelte Animatograph stellt für sie das zentrale Element seiner Arbeiten dar, da Schlingensief damit die Trennung zwischen Publikum und Bühne aufhob. Jelinek stellt besonders in den neuesten essayistischen Texten die Frage nach ihrem eigenen Vorkommen innerhalb der Arbeiten des Künstlers. Einerseits betont sie, dass ihre Person und ihre Texte in den Werken des Künstlers zum Verschwinden gebracht wurden, andererseits hält sie fest, dass Schlingensief ihre Texte transformierte und „auf andre Weise wirksam“ (S) werden ließ. Jelinek löst dieses Spannungsfeld, das sie damit eröffnet, nicht auf, beendet ihren Text Schlingensief jedoch mit einer Formulierung, die die Möglichkeit des Vorhandenseins in den Werken Schlingensiefs nicht ausschließt. Trotz der speziellen Form der Zusammenarbeit muss in Hinblick auf Jelinek und Schlingensief von einem künstlerischen Austausch gesprochen werden, da Jelinek in ihren Texten deutlich auf den Künstler Bezug nimmt und es innerhalb der Arbeiten Berührungspunkte gibt, von denen ausgehend wiederum neue Werke entwickelt wurden

Age and diabetes related changes of the retinal capillaries: an ultrastructural and immunohistochemical study

Normal human aging and diabetes are associated with a gradual decrease of cerebral flow in the brain with changes in vascular architecture. Thickening of the capillary basement membrane and microvascular fibrosis are evident in the central nervous system of elderly and diabetic patients. Current findings assign a primary role to endothelial dysfunction as a cause of basement membrane (BM) thickening, while retinal alterations are considered to be a secondary cause of either ischemia or exudation. The aim of this study was to reveal any initial retinal alterations and variations in the BM of retinal capillaries during diabetes and aging as compared to healthy controls. Moreover, we investigated the potential role of vascular endothelial growth factor (VEGF) and pro-inflammatory cytokines in diabetic retina.Transmission electron microscopy (TEM) was performed on 46 enucleated human eyes with particular attention to alterations of the retinal capillary wall and Müller glial cells. Inflammatory cytokines expression in the retina was investigated by immunohistochemistry.Our electron microscopy findings demonstrated that thickening of the BM begins primarily at the level of the glial side of the retina during aging and diabetes. The Müller cells showed numerous cytoplasmic endosomes and highly electron-dense lysosomes which surrounded the retinal capillaries. Our study is the first to present morphological evidence that Müller cells start to deposit excessive BM material in retinal capillaries during aging and diabetes. Our results confirm the induction of pro-inflammatory cytokines TNF-α and IL-1β within the retina as a result of diabetes.These observations strongly suggest that inflammatory cytokines and changes in the metabolism of Müller glial cells rather than changes in of endothelial cells may play a primary role in the alteration of retinal capillaries BM during aging and diabetes

Expanding the role of 3-O sulfated heparan sulfate in herpes simplex virus type-1 entry

AbstractHeparan sulfate (HS) proteoglycans are commonly exploited by multiple viruses for initial attachment to host cells. Herpes simplex virus-1 (HSV-1) is unique because it can use HS for both attachment and penetration, provided specific binding sites for HSV-1 envelope glycoprotein gD are present. The interaction with gD is mediated by specific HS moieties or 3-O sulfated HS (3-OS HS), which are generated by all but one of the seven isoforms of 3-O sulfotransferases (3-OSTs). Here we demonstrate that several common experimental cell lines express unique sets of 3-OST isoforms. While the isoforms 3-OST-3, -5 and -6 were most commonly expressed, isoforms 3-OST-2 and -4 were undetectable in the cell lines examined. Since most cell lines expressed multiple 3-OST isoforms, we addressed the significance of 3-OS HS in HSV-1 entry by down-regulating 2-O-sulfation, a prerequisite for 3-OS HS formation, by knocking down 2-OST expression by RNA interference (RNAi). 2-OST knockdown was verified by reverse-transcriptase PCR and Western blot analysis, while 3-OS HS knockdown was verified by immunofluorescence. Cells showed a significant decrease in viral entry, suggesting an important role for 3-OS HS. Implicating 3-OS HS further, cells knocked down for 2-OST expression also demonstrated decreased cell–cell fusion when cocultivated with effector cells transfected with HSV-1 glycoproteins. Our findings suggest that 3-OS HS may play an important role in HSV-1 entry into many different cell lines

A quantitative metric for the comparative evaluation of optical clearing protocols for 3D multicellular spheroids

3D multicellular spheroids quickly emerged as in vitro models because they represent the in vivo tumor environment better than standard 2D cell cultures. However, with current microscopy technologies, it is difficult to visualize individual cells in the deeper layers of 3D samples mainly because of limited light penetration and scattering. To overcome this problem several optical clearing methods have been proposed but defining the most appropriate clearing approach is an open issue due to the lack of a gold standard metric. Here, we propose a guideline for 3D light microscopy imaging to achieve single-cell resolution. The guideline includes a validation experiment focusing on five optical clearing protocols. We review and compare seven quality metrics which quantitatively characterize the imaging quality of spheroids. As a test environment, we have created and shared a large 3D dataset including approximately hundred fluorescently stained and optically cleared spheroids. Based on the results we introduce the use of a novel quality metric as a promising method to serve as a gold standard, applicable to compare optical clearing protocols, and decide on the most suitable one for a particular experiment. (C) 2021 The Authors. Published by Elsevier B.V. on behalf of Research Network of Computational and Structural Biotechnology.Peer reviewe