Institute of Physiological Chemistry
Institute of Physiological Chemistry
Schnedl W.J.,General Practice for General Internal Medicine |
Krause R.,Medical University of Graz |
Tafeit E.,Institute of Physiological Chemistry |
Tillich M.,Diagnostikum Sued West |
And 2 more authors.
Nature Reviews Gastroenterology and Hepatology | Year: 2011
Epiploic appendagitis is a rare cause of abdominal pain. Diagnosis of epiploic appendagitis, although infrequent, is easily made with CT or ultrasonography in experienced hands. As reported in the literature, most patients with primary epiploic appendagitis are treated conservatively without surgery, with or without anti-inflammatory drugs. A small number of patients are treated with antibiotics and some patients require surgical intervention to ensure therapeutic success. Symptoms of primary epiploic appendagitis usually resolve with or without treatment within a few days. A correct diagnosis of epiploic appendagitis with imaging procedures enables conservative and successful outpatient management of the condition and avoids unnecessary surgical intervention and associated additional health-care costs. Gastroenterologists and all medical personnel should be aware of this rare disease, which mimics many other intra-abdominal acute and subacute conditions, such as diverticulitis, cholecystitis and appendicitis. This article reviews epiploic appendagitis and includes discussion of clinical findings, pathophysiology, diagnosis and therapeutic possibilities. © 2011 Macmillan Publishers Limited. All rights reserved.
Dehne N.,Goethe University Frankfurt |
Kerkweg U.,Institute of Physiological Chemistry |
Flohe S.B.,Surgical Research |
Brune B.,Goethe University Frankfurt |
Fandrey J.,University of Duisburg - Essen
Shock | Year: 2011
Skeletal muscle damage provokes complex repair mechanisms including recruitment of leukocytes as well as activation of myogenic precursor cells such as satellite cells. To study muscle cell repair mechanisms after muscle fiber damage, we used an in vitro model of scrape-injured myotubes. Exposing vital C2C12 myoblasts and myotubes to cell debris of damaged myotubes revealed mRNA upregulation of adrenomedullin (ADM), insulin-like growth factors 1 and 2, metallopeptidase 9, and monocyte chemoattractant protein11. When cell debris was treated with ultrasound, frozen in liquid nitrogen, or heat inactivated before addition to C2C12 cells, gene expression was drastically reduced or completely absent. Moreover, incubations of myoblasts with debris separated by transwell inserts indicated that direct cell contact is required for gene induction. Incubation with albumin and PolyIC ruled out that ADM induction by cell debris simply results from increased protein or nucleic acid concentrations in the supernatant. Because the genes, which were upregulated by cell debris, are potential target genes of hypoxia-inducible factor (HIF), cells were analyzed for HIF-1α expression. Western blot analysis showed accumulation of the α-subunit upon contact to cell debris. Knockdown of HIF-1α in C2C12 cells proved that activation of HIF-1 in response to cell debris was responsible for upregulating ADM and monocyte chemoattractant protein 1. Furthermore, by incubating cells on gas-permeable culture dishes, we excluded a reduced pericellular pO2 induced by cell debris as the cause for ADM upregulation. Our data suggest that damaged myofibers activate HIF-1 in neighboring myotubes and precursor myoblasts by direct contact, concomitantly upregulating factors necessary for angiogenesis, tissue regeneration, and phagocyte recruitment. Copyright © 2011 by the Shock Society.
Vijayaraj P.,Institute of Physiological Chemistry |
Vijayaraj P.,Beth Israel Deaconess Medical Center |
Kroeger C.,Institute of Physiological Chemistry |
Reuter U.,Institute of Physiological Chemistry |
And 2 more authors.
European Journal of Cell Biology | Year: 2010
Keratin intermediate filament proteins form the major cytoskeleton in all embryonic and adult epithelia. Increasing evidence suggests that keratins, besides their primary cytoskeletal function, can act as scaffolds which locally regulate cell growth and survival in epithelial cells. Many of these functions, however, are not understood in full, owing to keratin redundancy. We have recently created mice which lack all keratins and found that keratins act upstream of mTOR signaling to regulate protein biosynthesis via GLUT localization. Here, we report that keratins are necessary to maintain adhesion between endodermal and mesodermal cell layers of the yolk sac. As a consequence, keratin-/- embryos suffer from reduced yolk sac hematopoiesis and vasculogenesis. Pathway analysis revealed a reduction of the hedgehog target Foxf1 in yolk sac mesoderm of keratin-/- embryos, and subsequent reduction of BMP-4 and P-p38 MAPK. These defects may be caused by the overall reduction in protein biosynthesis and diminished adhesion. Our data show for the first time that keratins are necessary for the differentiation of a non-epithelial cell lineage through a combination of mechanical and signaling mechanisms. © 2010 Elsevier GmbH. All rights reserved.
Buchgraber B.,University of Graz |
Kqiku L.,University of Graz |
Reibnegger G.,Institute of Physiological Chemistry |
Stadtler P.,University of Graz
Collegium Antropologicum | Year: 2013
Saliva buffering test is in need of improvements. This article illustrates the most commonly used saliva buffering capacity tests and its major problems. Starting with Ericsson and his laboratory buffer capacity test and all the way to Kitasako a lot of issues are to release. The aim of this paper is to put saliva buffering tests up to serious discussion.
Hermann M.-R.,Max Planck Institute of Biochemistry |
Jakobson M.,Max Planck Institute of Biochemistry |
Colo G.P.,Max Planck Institute of Biochemistry |
Rognoni E.,Max Planck Institute of Biochemistry |
And 3 more authors.
Journal of Cell Science | Year: 2016
Integrin-mediated activation of small GTPases induces the polymerisation of G-actin into various actin structures and the release of the transcriptional co-activator MRTF from G-actin. Here we report that pan-integrin-null fibroblasts seeded on fibronectin and expressing β1- and/or aV-class integrin contained different G-actin pools, nuclear MRTF-A (also known as MKL1 or MAL) levels and MRTF-A-SRF activities. The nuclear MRTF-A levels and activities were highest in cells expressing both integrin classes, lower in cells expressing β1 integrins and lowest in cells expressing the αV integrins. Quantitative proteomics and transcriptomics analyses linked the differential MRTF-A activities to the expression of the ubiquitin-like modifier interferon-stimulated gene 15 (ISG15), which is known to modify focal adhesion and cytoskeletal proteins. The malignant breast cancer cell line MDA-MB-231 expressed high levels of β1 integrins, ISG15 and ISGylated proteins, which promoted invasive properties, whereas non-invasive MDA-MB-468 and MCF-7 cell lines expressed low levels of β1 integrins, ISG15 and ISGylated proteins. Our findings suggest that integrin-adhesion-induced MRTF-A-SRF activation and ISG15 expression constitute a newly discovered signalling circuit that promotes cell migration and invasion. © 2016. Published by The Company of Biologists Ltd | Journal of Cell Science.
Crnkovic S.,Institute of Molecular Biology and Biochemistry |
Crnkovic S.,University Clinic for Anesthesiology and Intensive Care Medicine |
Riederer M.,Institute of Molecular Biology and Biochemistry |
Lechleitner M.,Institute of Molecular Biology and Biochemistry |
And 8 more authors.
Free Radical Biology and Medicine | Year: 2012
Proliferation of vascular smooth muscle cells is a characteristic of pathological vascular remodeling and represents a significant therapeutic challenge in several cardiovascular diseases. Docosahexaenoic acid (DHA), a member of the n-3 polyunsaturated fatty acids, was shown to inhibit proliferation of numerous cell types, implicating several different mechanisms. In this study we examined the molecular events underlying the inhibitory effects of DHA on proliferation of primary human smooth muscle cells isolated from small pulmonary artery (hPASMCs). DHA concentration-dependently inhibited hPASMC proliferation, induced G1 cell cycle arrest, and decreased cyclin D1 protein expression. DHA activated the unfolded protein response (UPR), evidenced by increased mRNA expression of HSPA5, increased phosphorylation of eukaryotic initiation factor 2α, and splicing of X-box binding protein 1. DHA altered cellular lipid composition and led to increased reactive oxygen species (ROS) production. DHA-induced ROS were dependent on both intracellular Ca 2+ release and entry of extracellular Ca 2+ . Overall cellular ROS and mitochondrial ROS were decreased by RU360, a specific inhibitor of mitochondrial Ca 2+ uptake. DHA-induced mitochondrial dysfunction was evidenced by decreased mitochondrial membrane potential and decreased cellular ATP content. DHA triggered apoptosis as found by increased numbers of cleaved caspase-3- and TUNEL-positive cells. The free radical scavenger Tempol counteracted DHA-induced ROS, cell cycle arrest, induction of UPR, and apoptosis. We conclude that Ca 2+-dependent oxidative stress is the central and initial event responsible for induction of UPR, cell cycle arrest, and apoptosis in DHA-treated hPASMCs. © 2012 Elsevier Inc. All rights reserved.
PubMed | TU Munich, Max Planck Institute of Biochemistry and Institute of Physiological Chemistry
Type: Journal Article | Journal: Journal of cell science | Year: 2016
Integrin-mediated activation of small GTPases induces the polymerisation of G-actin into various actin structures and the release of the transcriptional co-activator MRTF from G-actin. Here we report that pan-integrin-null fibroblasts seeded on fibronectin and expressing 1- and/or V-class integrin contained different G-actin pools, nuclear MRTF-A (also known as MKL1 or MAL) levels and MRTF-A-SRF activities. The nuclear MRTF-A levels and activities were highest in cells expressing both integrin classes, lower in cells expressing 1 integrins and lowest in cells expressing the V integrins. Quantitative proteomics and transcriptomics analyses linked the differential MRTF-A activities to the expression of the ubiquitin-like modifier interferon-stimulated gene 15 (ISG15), which is known to modify focal adhesion and cytoskeletal proteins. The malignant breast cancer cell line MDA-MB-231 expressed high levels of 1 integrins, ISG15 and ISGylated proteins, which promoted invasive properties, whereas non-invasive MDA-MB-468 and MCF-7 cell lines expressed low levels of 1 integrins, ISG15 and ISGylated proteins. Our findings suggest that integrin-adhesion-induced MRTF-A-SRF activation and ISG15 expression constitute a newly discovered signalling circuit that promotes cell migration and invasion.
Stoeckel K.,Institute of Physiological Chemistry |
Nielsen L.H.,Boehringer Ingelheim |
Fuhrmann H.,Institute of Physiological Chemistry |
Bachmann L.,Institute of Physiological Chemistry |
Bachmann L.,German Institute of Animal Nutrition
Acta Veterinaria Scandinavica | Year: 2011
Background: In dogs, increasing the tissue n-3 fatty acid (FA) content is associated with potential benefit in some medical conditions, e.g. atopic dermatitis, cancer or heart disease. Therefore effectively and conveniently increasing tissue n-3 FA levels in dogs is of interest. Incorporation of dietary n-3 FA into cell membranes may be studied by FA analysis of erythrocyte membranes (EM), because of the correlation of its FA composition with the FA composition of other cells. Aim of the study was to determine whether an n-3 FA additive added to a control diet is as effective in increasing EM n-3 FA content as feeding an n-3 FA enriched diet. Furthermore the time course of the incorporation of dietary n-3 FA into canine EM was investigated.Methods: Thirty dogs were randomly divided into three dietary groups with ten dogs per group. CONT got a dry dog food diet which did not contain EPA or DHA. FO got a dry dog food diet with a high EPA and DHA content. ADD got the CONT diet combined with an n-3 FA additive rich in DHA and EPA. After a feeding period of 12 weeks the additive was discontinued in ADD and these dogs were fed CONT diet for another four weeks to observe washout effects. Erythrocyte lipids were extracted from venous blood samples and their FA composition was determined by gas chromatography. The Mann-Whitney-U-test was used to detect significant differences between the different groups and time points.Results: After one week the proportions of n-3 FA, DHA and EPA were already significantly increased in ADD and FO, apparently reaching a plateau within eight weeks. In our study DHA and not EPA was preferably incorporated into the EM. After discontinuing the administration of the additive in ADD, the n-3 FA values declined slowly without reaching baseline levels within four weeks.Conclusions: In dogs, an increase of dietary n-3 FA content leads to a rapid inclusion of n-3 FA into EM, regardless of whether the n-3 FA are offered as an enriched diet or as a normal diet supplemented with an n-3 FA additive. © 2011 Stoeckel et al; licensee BioMed Central Ltd.
Beindorff N.,German Primate Center |
Einspanier A.,German Primate Center |
Einspanier A.,Institute of Physiological Chemistry
Reproduction | Year: 2010
In early pregnant primates, relaxin (RLX) is highly upregulated within the corpus luteum (CL), suggesting that RLX may have an important role in the implantation of the blastocyst. Therefore, the aim of the present study was to investigate the local effects of RLX and gonadotrophins on the maintenance of the CL using an in vitro microdialysis system. CLs of common marmoset monkeys were collected by luteectomy during different stages of the luteal phase and early pregnancy. Each CL was perfused with either Ringer's solution alone or Ringer's solution supplemented with either porcine RLX (250, 500 and 1000 ng/ml) or gonadotrophins (50 IU/ml). Application of RLX provoked a significant luteal response of progesterone (P4) and oestradiol (E2) secretions during the mid-luteal phase (500 ng/ml: P4 54±42%, E2 24±11%; 1000 ng/ml: E2 16±13%), and especially during the late luteal phase (250 ng/ml: P4 53±10%; 500 ng/ml: P4 44±15%; 1000 ng/ml: P4 62±15%, E2 18±7%). The effects of RLX on steroid secretion were irrespective of the RLX dosages. While treatment with human chorionic gonadotrophin did not affect luteal steroid or RLX secretion, the application of FSH resulted in a significant increase in the secretion of both P4 (20±8%) and E2 (37±28%), and a prominent rise in RLX during early pregnancy. In conclusion, our results demonstrate that RLX and FSH have a luteotrophic function in the marmoset monkeys; moreover, FSH has a function beyond its traditional role just as a follicle-stimulating hormone. © 2010 Society for Reproduction and Fertility.
Hoyer F.F.,University of Bonn |
Steinmetz M.,University of Bonn |
Zimmer S.,University of Bonn |
Becker A.,University of Bonn |
And 4 more authors.
Journal of Molecular and Cellular Cardiology | Year: 2011
Low-dose oral tetrahydrocannabinol (THC) reduces progression of atherosclerosis in mice. THC activates central cannabinoid-1 receptors (CB1) with subsequent psychoactive effects as well as peripheral cannabinoid-2 receptors (CB2). In order to dissect the underlying mechanisms, we performed experiments under selective CB2 stimulation as well as after genetic disruption of the CB2 receptor. Atherosclerosis prone apolipoprotein E-deficient mice were crossed with cannabinoid receptor-2 deficient mice to obtain ApoE -/- CB2 -/- double knockout mice. After 8. weeks of a high-cholesterol diet, immunohistochemical stainings of the aortic root revealed that vascular leukocyte infiltration in atherosclerotic plaques was accelerated in ApoE -/- CB2 -/- mice compared with ApoE -/- mice. This was accompanied by increased release of reactive oxygen species as measured using L012-enhanced chemiluminescence, and by decreased endothelial function as assessed in isolated aortic rings in organ chamber experiments. ApoE -/- mice treated with the selective CB2 agonist JWH 133 during a high-cholesterol diet showed decreased atherosclerotic lesion formation, improved endothelial function and reduced levels of reactive oxygen species. To assess whether CB2 expression in circulating cells influences atherosclerosis, irradiated ApoE -/- mice were repopulated with bone marrow-derived cells from ApoE -/- and ApoE -/- CB2 -/- mice and were fed a high-cholesterol diet for 8. weeks. CB2 deficiency in bone marrow-derived cells increased leukocyte infiltration into the vessel wall, but had no impact on plaque formation. Cell culture experiments revealed that CB2 activation diminishes ROS generation in vascular cells. Selective CB2 receptor stimulation modulates atherogenesis via impact on both circulating proinflammatory and vascular cells. © 2011 Elsevier Ltd.