Refine
Has Fulltext
- yes (266)
Year of publication
Document Type
- Journal article (156)
- Doctoral Thesis (96)
- Complete part of issue (10)
- Conference Proceeding (3)
- Preprint (1)
Language
- English (148)
- German (115)
- Multiple languages (3)
Keywords
- multiple sclerosis (11)
- Endothel (9)
- Multiple Sklerose (9)
- EAE (8)
- B cells (7)
- Habichtskraut (7)
- Geobotanik (6)
- MS (6)
- Pemphigus (6)
- Pflanzengeographie (6)
- SGLT1 (6)
- expression (6)
- inflammation (6)
- Angiogenese (5)
- Glutamattransporter (5)
- Ratte (5)
- Bavaria (4)
- Biologie (4)
- Blut-Hirn-Schranke (4)
- CEACAM1 (4)
- ELISPOT (4)
- Geobotanik ; Pflanzengeographie (4)
- Kation (4)
- NPY (4)
- OCT (4)
- RS1 (4)
- Stammzelle (4)
- Zelladhäsion (4)
- cell adhesion (4)
- distribution (4)
- endothelium (4)
- experimental autoimmune encephalomyelitis (4)
- induced pluripotent stem cells (4)
- microglia (4)
- mouse (4)
- oligodendrocytes (4)
- 5-HT1A (3)
- 5-HT2C (3)
- Adventitia (3)
- Asteraceae (3)
- Bayern (3)
- Brombeere (3)
- CNS (3)
- Cadherine (3)
- Desmosom (3)
- Germany (3)
- Glukose (3)
- Hieracium (3)
- Immunhistochemie (3)
- Keratinozyten (3)
- Kerntransport (3)
- Korbblütler (3)
- NLS (3)
- Niere (3)
- Ranunculus auricomus (3)
- Regulation (3)
- Rubus (3)
- Schleswig-Holstein (3)
- Tumor (3)
- VE-Cadherin (3)
- blood vessel (3)
- brain (3)
- cardiomyocytes (3)
- glucose (3)
- glutamate transporters (3)
- inhibition (3)
- ischemia (3)
- mRNA (3)
- macrophages (3)
- mice (3)
- neurodegeneration (3)
- new species (3)
- pemphigus (3)
- rOCT1 (3)
- rat (3)
- regulation (3)
- relapse (3)
- 18F-FDG (2)
- Aktin (2)
- Autoimmunität (2)
- B-Zelle (2)
- Brain-derived neurotrophic factor (2)
- Brustkrebs (2)
- Cadherin (2)
- Carrier-Proteine (2)
- Coexpression (2)
- Desmoglein (2)
- Desmogleine (2)
- Durchflusscytometrie (2)
- EAAC1 (2)
- Elektronenmikroskopie (2)
- Endothelbarriere (2)
- Entzündung (2)
- Evolution (2)
- Experimentelle autoimmune Enzephalomyelitis (2)
- FGFR1 (2)
- FTY720 (2)
- Ficaria calthifolia (2)
- Ficaria verna (2)
- Fingolimod (2)
- Franconia (2)
- Franken (2)
- GLAST (2)
- GLT1 (2)
- GLUT2 (2)
- Glucose (2)
- Glucosetransportproteine (2)
- Herz (2)
- Immuncytochemie (2)
- Inhibition (2)
- Kanadaptin (2)
- Karyotyp (2)
- Kationentransporter (2)
- Maus (2)
- Multiple sclerosis (2)
- Mutationsanalyse (2)
- Myokarditis (2)
- Occludin (2)
- Organic cation transporter (2)
- Organische Kationentransporter (2)
- PET (2)
- Pflanzen (2)
- Progerie (2)
- Retina (2)
- Scherstress (2)
- Stofftransport <Biologie> (2)
- Stressfasern (2)
- Stroma (2)
- Systematik (2)
- TGFβ signaling (2)
- Trifolium micranthum (2)
- Unterfranken (2)
- Vegetation (2)
- Vorkommen (2)
- Vorläuferzelle (2)
- Zellkern (2)
- actin (2)
- adherens junction (2)
- aging (2)
- amygdala (2)
- anatomy (2)
- angiogenesis (2)
- animal models (2)
- bariatric surgery (2)
- biomedical applications (2)
- blood brain barrier (2)
- calcium (2)
- cell culture (2)
- central nervous system (2)
- cerebellum (2)
- desmosome (2)
- diabetes (2)
- diabetic nephropathy (2)
- diabetic retinopathy (2)
- differential expression (2)
- electron microscopy (2)
- emphysema (2)
- extracellular matrix (2)
- fatty acid (2)
- glucocorticoid receptor (2)
- heart (2)
- hiPSC-CM (2)
- human induced pluripotent stem cells (2)
- immunohistochemistry (2)
- in situ hybridization (2)
- in vitro (2)
- kidney (2)
- lectotype (2)
- lesions (2)
- medical research (2)
- mitochondria (2)
- mucoepidermoid carcinoma (2)
- myocarditis (2)
- neural (2)
- neuroinflammation (2)
- neuroprotection (2)
- neurotrophins (2)
- new subspecies (2)
- nucleus (2)
- olfactory epithelium (2)
- olfaktorisches Epithel (2)
- organoid (2)
- organoids (2)
- oxidative stress (2)
- parotid gland (2)
- peroxisomes (2)
- photon-counting (2)
- pleomorphic adenoma (2)
- positron emission tomography (2)
- predictive value (2)
- progeria (2)
- regeneration (2)
- remyelination (2)
- retina (2)
- retinitis pigmentosa (2)
- secretion (2)
- serotonergic system (2)
- shear stress (2)
- stem cell therapy (2)
- stroke (2)
- stroma (2)
- tracer (2)
- transgenic mice (2)
- triple in situ hybridization (2)
- ultrastructure (2)
- vasculogenesis (2)
- vegetation (2)
- --- (1)
- 2C-values (1)
- A549 cell line (1)
- ADHD (1)
- AMD (1)
- ARF (1)
- ATF6 (1)
- AZD4547 (1)
- Acetylcholin (1)
- Actin (1)
- Aderhaut (1)
- Adherens-Junction (1)
- Adhärens-/ Occludensjunktionen (1)
- Adhärenskontakte (1)
- Adipositas (1)
- Agamospermy (1)
- Akt (1)
- Alemtuzumab (1)
- Alzheimers disease (1)
- Aminosäuren (1)
- Amrum (1)
- Amygdala (1)
- Amyotrophic-lateral-sclerosis (1)
- Angst (1)
- Anti-CD52-Antikörper (1)
- Antigen CD44 (1)
- Anxiety (1)
- Aortenringassay (1)
- Apomixis (1)
- Armplexusverletzung (1)
- Art (1)
- Arteriosklerose (1)
- Aryl Hydrocarbon Hydroxylase (1)
- Asymmetrie (1)
- Atemwege (1)
- Atherosklerose (1)
- Atlantischer Wildkohl (1)
- Atlas (1)
- Autoantikörper (1)
- Autoimmundermatose (1)
- Autoimmunerkrankung (1)
- Autoimmunity (1)
- Axis (1)
- Axon degeneration (1)
- Axon growth (1)
- Axonal transport (1)
- B-Lymphozyt (1)
- B-Zell-Aggregat (1)
- B-Zellen (1)
- BDNF (1)
- BRP (1)
- BSTA (1)
- Basal Ganglia (1)
- Basalganglien (1)
- Basiocciput (1)
- Basiokziput (1)
- Baumart (1)
- Bayerische Alpen (1)
- Bayern (Nord) (1)
- Benzo(a)pyrene (1)
- Berlin (1)
- Bindestelle (1)
- Biodiversität (1)
- Biomechanical properties (1)
- Biomechanische Eigenschaften (1)
- Bioprozessmethode (1)
- Boden (1)
- Bombesin ; Bombesin receptor ; Chromosomal localization (1)
- Botanische Nomenklatur (1)
- Brain (1)
- Brassica oleracea (1)
- Brillantgrün (1)
- Brombeerart (1)
- Bruchpilot (1)
- CD4 T cells (1)
- CD44 (1)
- CD52 (1)
- CDC42 (1)
- CMV (1)
- CNTF (1)
- COPD (1)
- COS cell expression (1)
- CPFE (1)
- CRISPR/Cas-Methode (1)
- CXCL12-abundant reticular (CAR)-cells (1)
- Calcium (1)
- Cancellous bone (1)
- Cancer models (1)
- Cancer therapeutic resistance (1)
- Carcinogen (1)
- Cardiac Angiogenesis Assay (1)
- Caryophyllaceae (1)
- Cas9 (1)
- Cationentransporter (1)
- Cell reprogramming (1)
- Cell therapy (1)
- Cell-cell communication (1)
- Cells (1)
- Cerastium brachypetalum (1)
- Cerastium tenoreanum (1)
- ChAT (1)
- ChT1 (1)
- Chamaesyce (1)
- Charakterisierung (1)
- Chimären (1)
- Chinin (1)
- Chirurgie (1)
- Choroidea (1)
- Ciliary neurotrophic factor (1)
- Coiled coil (1)
- Coiled-Coile (1)
- Cone-beam computed tomography (1)
- Connexin (1)
- Copaxone® (1)
- Corpus amygdaloideum (1)
- Cortico-striatal projection neurons (1)
- Corticosteroide (1)
- CreERT2 (1)
- Cx3cr1 (1)
- Cyclo-AMP (1)
- Cycloheximide (1)
- Cytokeratin (1)
- Cytologie (1)
- Cytomatrix der aktiven Zone (1)
- Cytoskeleton (1)
- DAMGO (1)
- DNA (1)
- DNA methylation (1)
- DNA weight (1)
- DNA-Binding (1)
- DSG2 (1)
- Darmresorption (1)
- Darmwandnervensystem (1)
- Dens axis (1)
- Developmental biology (1)
- Dexamethason (1)
- Dieldrin (1)
- Drosophilia (1)
- Dsg3-Depletion (1)
- Dsg3-depletion (1)
- Dünndarm (1)
- EBV (1)
- ECM (1)
- ECV304 (1)
- EEOS (1)
- ER stress (1)
- ER-Stress (1)
- ERK (1)
- Echinina (1)
- Elbow (1)
- Elbow joint (1)
- Electron microscopy (1)
- Ellenberg indicator value for light (1)
- Ellenberg indicator values ; Mixed mountain forest ; Niche model ; Phytosociological databank (1)
- Embryonic stem cell (1)
- Endocytose (1)
- Endoplasmic-Reticulum Stress (1)
- Endothelbarriere Rho-GTPasen (1)
- Endothelial barrier functions (1)
- Endothelzelle (1)
- Endothelzelllinie (1)
- Enterisches Nervensystem (1)
- Entwicklung (1)
- Enzyme (1)
- Enzyme-Linked Immunospot assay (ELISPOT) (1)
- Epac (1)
- Epidermal papillae (1)
- Epidermis (1)
- Epithel (1)
- Exosom <Vesikel> (1)
- Exosomes (1)
- Experimental autoimmune encephalomyelitis (1)
- Experimentelle Autoimmune Enzephalomyelitis (1)
- Experimentelle autoimmune Encephalomyelitis (1)
- Experimentelle autoimmune Enzepahlomyelitis (1)
- Expressionsmessungen (1)
- Extracellular Vesicles (1)
- FGF (1)
- FGF/FGFR signalling (1)
- FGFR (1)
- FGFR signaling (1)
- FHA domain (1)
- FHA-Domäne (1)
- Festuco-Brometea (1)
- Fettsucht (1)
- Fibroblastenwachstumsfaktor (1)
- Ficaria ambigua (1)
- G-protein-coupled receptor (1)
- GLT1a (1)
- GLT1v (1)
- GLUT1 (1)
- GLUT3 (1)
- GLUT4 (1)
- GLUT5 (1)
- Garchinger Heide (1)
- Gefäßwand (1)
- Gefäßwand residente Stammzellen (1)
- Gefäßwand-residente Stamm- und Vorläuferzellen (1)
- Gefäßwand-residente Stammzellen (1)
- Gehirn (1)
- Genexpression (1)
- Genom (1)
- Genome Editing (1)
- Gentianaviolett (1)
- Geruch (1)
- Geruchssystem (1)
- Geschmacksrezeptor (1)
- Glucocorticoid-responsives Element (1)
- Glucocorticosteroide (1)
- Glucocorticosteroidrezeptor (1)
- Glukokortikoide (1)
- Glukosetransporter -1 (1)
- Glutamat (1)
- Glutamate transporters (1)
- Glutamatergic synapses (1)
- Gold-Hahnenfuß (1)
- Guinea-pig uterus (1)
- Gustducin (1)
- HCMV infection (1)
- Hahnenfuß (1)
- Hematopoietic Stem (1)
- Heme-regulated inhibitor (1)
- Herzinfarkt (1)
- Herzmuskelzelle (1)
- Hieracium auriculoides (1)
- Hieracium cymosum (1)
- Hieracium echioides (1)
- Hieracium lachenalii subsp. litocretaceum (1)
- Hieracium maculatum (1)
- Hieracium subrigidum (1)
- Hieracium swantevitii (1)
- Hippocampus (1)
- Hirnendothelzellen (1)
- Hitzeschockprotein (1)
- Homologieklonierung (1)
- Hornkraut (1)
- Hueter interval (1)
- Human Muse Cells (1)
- Hypertonie (1)
- II type-2 receptor (1)
- IL-6 (1)
- IL6 (1)
- Immun-Checkpoint (1)
- Immune tolerance (1)
- Immunozyt (1)
- Immunsystem (1)
- Immunzytochemie (1)
- In-situ-Hybridisierung (1)
- Induction (1)
- Induzierte pluripotente Stammzelle (1)
- Inflammation (1)
- Intermediate filaments (1)
- Ionentransport (1)
- Ischämie (1)
- Ischämie-Reperfusions-Schaden (1)
- KATP channel (1)
- Kapillararchitektur (1)
- Kapillare (1)
- Kapillarwand-assoziierte Zellen (1)
- Kardioonkologie (1)
- Kationentransporter 1 der Ratte (1)
- Keimzellentwicklung (1)
- Kern (1)
- Kernproteine (1)
- Kettenblume (1)
- Kidney (1)
- Klee (1)
- Kleinhirn (1)
- Knockout <Molekulargenetik> (1)
- Kohl (1)
- Kollagen (1)
- Kollageninhibition (1)
- Kombinationstherapie (1)
- Konfokale Mikroskopie (1)
- Konformationsänderungen (1)
- Koronararterie (1)
- Kraft-Frequenz-Beziehung (1)
- Kuhblume (1)
- Küstenschutz (1)
- L cells (1)
- L-typ Calciumkanal Antagonist (1)
- LINGO-1 (1)
- LPS (1)
- Lacking neurofilaments (1)
- Lamin (1)
- Lamin A (1)
- Lamine (1)
- Langhaariges Habichtskraut (1)
- Latrophilin (1)
- Lectotypus (1)
- Lokalisierung (1)
- Lower Francony (1)
- Luftröhre (1)
- Luftröhrenschleimhaut (1)
- Lymphoide Neogenese (1)
- Lysyl-Oxidase (1)
- Löwenzahn <Taraxacum> (1)
- MAP kinase pathway (1)
- MK801 (1)
- MNV type 3 (1)
- MP4 (1)
- MP4-EAE (1)
- Mactel 2 (1)
- Makrophagen (1)
- Mamma-Karzinom (1)
- Medium spiny neurons (1)
- Meiose (1)
- Membrantransport (1)
- Messenger-RNAs (1)
- Microtubules (1)
- Microvesicles (1)
- Migration (1)
- Mikroglia (1)
- Minoxidil (1)
- Missense mutation (1)
- Mitomycin C (1)
- Molekularbiologie (1)
- Molekulargenetik (1)
- Monosaccharid-abhängig (1)
- Morphology (1)
- Morphotype (1)
- Motoneuron disease (1)
- Motor learning (1)
- Motorisches Lernen (1)
- Mouse model (1)
- Multidetector computed tomography (1)
- Musculus und Ligamentum pterygospinosus (1)
- Muskel (1)
- Mutation (1)
- Mutationanalysis (1)
- Mycobacterium tuberculosis (1)
- Myokard (1)
- Myokardinfarkt (1)
- N-Myc (1)
- NES (1)
- NF-kappa-B (1)
- NMDA-Antagonist (1)
- NMDA-Rezeptor (1)
- NMDAR (1)
- Na+-DGlucosekotransporter (1)
- Na+-glucosecotransporter (1)
- Nachtkerze <Gattung> (1)
- Nanog protein (1)
- Natrium-abhängigen Glukosetransporter-1 (1)
- Nelkengewächse (1)
- Neophyten <Botanik> (1)
- Nervenregeneration (1)
- Nervenwurzelausriss (1)
- Nervenwurzelreplantation (1)
- Nervenzelle (1)
- Nervus Opticus (1)
- Netherlands (1)
- Netzhaut (1)
- Neural Differentiation (1)
- Neurodegeneration (1)
- Neuroendokrine Zellen (1)
- Neurofilament (1)
- Neuropeptid Y (1)
- Neuroregeneration (1)
- Neurotropher Faktor (1)
- Neurotrophic factors (1)
- Niche model (1)
- Nimodipin (1)
- Nomen novum (1)
- Nordtirol (1)
- Northern Bavaria (1)
- Nuclear Import (1)
- OCT1 (1)
- ODC (1)
- OXPHOS (1)
- Oberflächenexpression (1)
- Oct4 (1)
- Oenothera (1)
- Oenothera stucchii (1)
- Okulodentodigitale Dysplasie (1)
- Olfactory system (1)
- Olfaktion (1)
- Olfaktorisches System (1)
- Ontogenese (1)
- Oozyte (1)
- Organic cation transporters (1)
- Organischer Kationentransporter (1)
- Organoid (1)
- Ornithindecarboxylase (1)
- Osteoarthritis (1)
- Osteoarthrose (1)
- PCDHGC3 (1)
- PD-1/PD-L1 (1)
- PDGF (1)
- PDGF- Scherstress- Endothelzellen (1)
- PDGF- sherstress- endothelial cells (1)
- PIK3R1 (1)
- PKB/Akt phosphorylation (1)
- PKC (1)
- PP2A (1)
- PSP (1)
- Parenchym (1)
- Parkinson Krankheit (1)
- Parkinson's disease (1)
- Parkinson’s disease (1)
- Perizyt (1)
- Permeabilität (1)
- Peyer's patches (1)
- Phedimus middendorffianus, var. diffusus (1)
- Phedimus spurius subsp. oppositifolius (1)
- Phenobarbitone (1)
- Phosphorylation (1)
- Phytosociological database (1)
- Pilosella macranthela (1)
- Pilosella ottonis (1)
- Plasma-membrane (1)
- Plasmamembran (1)
- Plasmamembrane (1)
- Plastizität (1)
- Plexus brachialis (1)
- Pluripotency (1)
- Progenitor (1)
- Progeria infantilum (1)
- Progressive motor neuronopathy (1)
- Prostatakarzinom (1)
- Proteasom (1)
- Protein kinase B (1)
- Protein transduction (1)
- Proteinkinase C (1)
- Proteinkinase CK2 (1)
- Pruno-Rubion sprengelii (1)
- Prunus (1)
- Präkonditionierung (1)
- Quality-control (1)
- Quinine (1)
- RAP (1)
- RNA sequencing (1)
- RNA-sequencing (1)
- RNS (1)
- ROS (1)
- Rac (1)
- Rac 1 (1)
- Rac1 (1)
- Ranunculus (1)
- Ranunculus puberulus (1)
- Ranunculus sarntheinianus (1)
- Ranunculus suborbicularis (1)
- Ranunculus vertumnalis (1)
- Rats (1)
- Regeneration niche (1)
- Regulation of SGLT1 (1)
- Regulation von SGLT1 (1)
- Regulatorprotein (1)
- Regulatory T cells (1)
- Regulierung (1)
- Relapsing-remitting MS (1)
- Restriktive Dermopathie (1)
- Retinsäure (1)
- Rhamno-Prunetea (1)
- Rho (1)
- Rho A (1)
- Rho GTPase (1)
- Rho GTPases (1)
- Rho-GTPasen (1)
- Rho-Proteine (1)
- Rictor-mTOR complex (1)
- Rosaceae (1)
- Rosengewächse (1)
- Rubella virus (1)
- Rubus L. sectio Corylifolii (1)
- Rubus boreofrisicus (1)
- Rubus phylloglotta (1)
- Rubus pseudoglotta (1)
- Rubus section (1)
- Rubus viridilucidus (1)
- Rv3034c (1)
- SAP47 gene (1)
- SARS-CoV-2 (1)
- SEMA3A (1)
- SH group (1)
- SH-Gruppen (1)
- SLC22 (1)
- SLC2A3 (1)
- SP-fixation (1)
- SR protein kinase (1)
- SR-Protein Kinase (1)
- SSRE (1)
- Sammelrohr (1)
- Scanning electron microscopy (1)
- Schlaganfall (1)
- Schwann cells (1)
- Sea dikes (1)
- Sedum oppositifolium (1)
- Seedeich (1)
- Sekretion (1)
- Sektion Corylifolii (1)
- Senescence (1)
- Serin-Threonin-Kinase (1)
- Serotonerge Nervenzelle (1)
- Signaltransduktion (1)
- Signalwege (1)
- Signalübertragung (1)
- Skleroproteine (1)
- Sodium dependent glucose transporter-1 (1)
- Species novum (1)
- Spinal Muscular-arthropy (1)
- Standortfaktor <Botanik> (1)
- Stat3 (1)
- Stathmin (1)
- Stem cells (1)
- Stress (1)
- Stressprotein (1)
- Striatum (1)
- Sturkturprotein (1)
- Substance P receptor (1)
- Substrataffinität (1)
- Substratspezifität (1)
- Switzerland (1)
- Syap1 localization (1)
- Synaptic plasticity (1)
- Synaptinemal-Komplex (1)
- Synaptonemalkomplex (1)
- Systematics (1)
- T cell assay (1)
- T cells (1)
- T-Zellen (1)
- T-cadherin (1)
- T1R1 (1)
- T1R2 (1)
- TGF-beta (1)
- TGF-β1 (1)
- TLO (1)
- TNF-α (1)
- TOC (Condylus occipitale tertius) (1)
- TOC (third occipital condyle) (1)
- TTS (1)
- Taraxacum (1)
- Taraxacum cimae-gallinae spec. nov. (1)
- Taraxacum sect. Borealia (1)
- Targeted therapies (1)
- Taste receptor (1)
- Taxane (1)
- Taxanes (1)
- Taxonomie (1)
- Tertiär lymphatische Organe (1)
- Tertiär lymphatisches Organ (1)
- Thüringen (1)
- Tiermodell (1)
- Tight junction (1)
- Titin (1)
- Trachea (1)
- Transcription factor NRF1 (1)
- Transgenic mice (1)
- Translation Initiation (1)
- Transport (1)
- Transporter (1)
- Transporters (1)
- Trifolium dubium (1)
- Trifolium ornithopodioides (1)
- Triple in situ hybridization (1)
- TrkB (1)
- Tumorimmunumgebung (1)
- Tumour angiogenesis (1)
- UBA (1)
- Ubiquitin (1)
- Ultrastruktur (1)
- Unterart (1)
- VAChT (1)
- VE cadherin (1)
- VE-cadherin (1)
- VEGF (1)
- VPP mouse model (1)
- VW-SCs (1)
- Varikositäten (1)
- Vaskularisation (1)
- Vaskularisierung (1)
- Verbreitung (1)
- Verteilung (1)
- Vesikel (1)
- Viability (1)
- W355 (1)
- W359 (1)
- WNT signaling (1)
- Weißtanne (1)
- X-ray computed (1)
- XBP1 (1)
- Xenopus laevis (1)
- Y-gastric bypass (1)
- Zell-Adhäsionsmolekül (1)
- Zellkommunikation (1)
- Zellkontakt (1)
- Zellkontakte (1)
- Zellkontaktproteine (1)
- Zellkultur (1)
- Zellskelett (1)
- Zellzyklus (1)
- Zuckeraufnahme (1)
- Zytokeratine (1)
- Zytoskelett (1)
- aB-Crystallin (1)
- aB-crystallin (1)
- aPC (1)
- abdominal imaging (1)
- acceptance (1)
- acetylcholine (1)
- acetyltransferase (1)
- acinic cell carcinoma (1)
- activation (1)
- adenocarcinoma (1)
- adenoid cystic carcinoma (ACC) (1)
- adherens tight junctions (1)
- adhesion GPCR (1)
- adhesion molecule-1 (1)
- adipose tissue (1)
- adipose-derived stromal cells (1)
- adventitia (1)
- age-related macular degeneration (1)
- age-related macular degeneration (AMD) (1)
- agricultural landscape (1)
- aktive Zone (1)
- alpha-B-Crystallin (1)
- alpine Taraxaca (1)
- anatomical landmark (1)
- angiotensin II (1)
- antibodies (1)
- anti‐aging (1)
- anxiety (1)
- aorta ring (1)
- aortic adventitia (1)
- apoptosis (1)
- assembloid (1)
- astrocytoma (1)
- asymmetry (1)
- atherosclerosis (1)
- atrial natriuretic peptide (1)
- autoimmunity (1)
- axonal damage (1)
- axonal degeneration (1)
- axonal injury (1)
- axons (1)
- beta-aminopropionitrile (1)
- bile duct (1)
- biliary glycoprotein CD66A (1)
- biliopancreatic diversion (1)
- biodiversity (1)
- biomedicine (1)
- bioprinting (1)
- bioprocessing (1)
- blood coagulation (1)
- blood pressure (1)
- blood-brain barrier (1)
- blood-brain barrier (BBB) model (1)
- blood-brain-barrier (1)
- body weight (1)
- bone marrow-derived monocytes (1)
- brain capillary endothelial cells (1)
- brain endothelial cell line (1)
- brain-retina axis (1)
- breast cancer (1)
- breast cancer cells (1)
- breast cancer model (1)
- brilliant green (1)
- brush cell (1)
- brush cells (1)
- c-Myc (1)
- cAMP (1)
- cable-clamp implants (1)
- cadherin-13 (CDH13) (1)
- cadherins (1)
- calcareous grassland (1)
- calcitonin gene-related peptide (1)
- calcium channel antagonists (1)
- calodon (1)
- cancellous bone (1)
- cancer (1)
- cancer therapy (1)
- carcinoembryonic anitgen family (1)
- cardiac hyperthrophy (1)
- catalase (1)
- cation transporter (1)
- caveolin-1 (1)
- cell adhesion proteins (1)
- cell biology (1)
- cell cycle (1)
- cell penetrating peptides (1)
- cells (1)
- cellular internalization (1)
- cerebEND (1)
- cerebellar granule cells (1)
- cerebral microvasculature (1)
- characterisation (1)
- chemistry (1)
- chemotherapy (CH) (1)
- chimeras (1)
- cholinergic (1)
- choroidal neovascularization (CNV) (1)
- chromatin (1)
- chronic kidney disease (1)
- chronic viral infection (1)
- ciliary neurotrophic factor (CNTF) (1)
- classification (1)
- climate (1)
- coexpression (1)
- coiled-coil (1)
- confluence (1)
- contacts (1)
- contextual anxiety (1)
- contractility (1)
- convolution kernel (1)
- cortical pathology (1)
- corticosterone (1)
- cotransporter SGLT1 (1)
- cytokine secretion kinetics (1)
- cytokines (1)
- cytomegalovirus (1)
- cytotopes (1)
- dCIRL (1)
- dandelion (1)
- degeneration (1)
- demyelination (1)
- dendric cells (1)
- desmosomal cadherins (1)
- desmosomes (1)
- determination key (1)
- development (1)
- developmental biology (1)
- dexamethasone (1)
- diabetes mellitus (1)
- diagnostic markers (1)
- dilated cardiomyopathy with ataxia (1)
- direct anterior approach (1)
- disability (1)
- disease (1)
- distinction (1)
- distribution range (1)
- diversity (1)
- dorsal raphe (1)
- dovitinib (1)
- drug transport (1)
- duodenal jejunal bypass (1)
- early neural precursors (1)
- ecology (1)
- editorial (1)
- elispot (1)
- embryonic stem cells (1)
- endocytosis (1)
- endotelium (1)
- endothelial barrier (1)
- endothelial cell infection (1)
- enteroendocrine cells (1)
- enzyme-linked immunoassays (1)
- epithelial cells (1)
- epithelial salivary gland (1)
- euchaetium (1)
- ex-arable field (1)
- exhaustion (1)
- exocytosis (1)
- exocytotic pathway (1)
- experimentelle autoimmune Enzephalomyelitis (1)
- expression messurements (1)
- extinction (1)
- extracellular loop (1)
- extracellular matrix disorganisation (1)
- extrazelluläre Schleife (1)
- extrusion of hiMPC-containing bioinks alginate + collagen type I (1)
- factor XII (1)
- factor binding profiles (1)
- fallax (1)
- false tongue-leaf blackberry (1)
- fear conditioning (1)
- fentanyl (1)
- ferroptosis (1)
- fibroblastenwachstumsfaktor-rezeptor (1)
- fingolimod (1)
- flora (1)
- food intake (1)
- force frequency relationship (1)
- fracture (1)
- fructose intolerance (1)
- frühe neurale Vorläufer (1)
- functional characterization (1)
- gall bladder (1)
- gene expression (1)
- gene locus (1)
- genetics (1)
- genome (1)
- genome size (1)
- gentian violett (1)
- germ cell development (1)
- glioblastoma multiforme (1)
- glioma (1)
- glucagon like peptide-1 (1)
- glucagon-like peptide-1 (GLP-1) (1)
- glucocorticoid-response element (1)
- glucokinase (1)
- glucose transporter (1)
- glucose-galactose malabsorption (1)
- glucosetransporter (1)
- glut1 (1)
- glutamate (1)
- glutamate transporter (1)
- growth-factor (1)
- gut bacteria (1)
- gut hormones (1)
- hACE2 (1)
- hcv infection (1)
- heart failure (1)
- heart-brain axis (1)
- heat shock protein (1)
- hematopoietic (1)
- hematopoietic stem cells (1)
- high contrast (1)
- hip replacement (1)
- hippocampus (1)
- histone H1 (1)
- homebox genes (1)
- homeodomain transcription factors (1)
- homology cloning (1)
- human (1)
- human cytomegalovirus (HCMV) (1)
- human endothelial cells (1)
- human iPSC-derived mesodermal cells (hiMPCs) (1)
- human induced pluripotent stem cells (hiPSCs)human induced pluripotent stem cells (hiPSCs) (1)
- human neurons (1)
- human osteosarcoma xenografts (1)
- human primary cells (1)
- humanen induzierte pluripotente Stammzellen (1)
- hyaluronic acid (1)
- hydrostatischer Druck (1)
- hypertonic solution (1)
- hypoxia (1)
- hypoxia inducible factor 1 (1)
- iconography (1)
- immuncytochemistry (1)
- immune response (1)
- immunofluorescence (1)
- immunosenescence (1)
- immunotherapy (1)
- in situ Hybridisierung (1)
- in-situ hybridization (1)
- induced neural stem cells (1)
- inflammatory diseases (1)
- influenza virus ; virion RNA segments ; oligonucleotide mapping ; gene reassortment (1)
- innate immunity (1)
- insulin signaling (1)
- integrin α5β1 (1)
- integrin αvβ3 (1)
- interferon beta-1a (1)
- interleukin-1β (1)
- internalization (1)
- intestinal glucose (1)
- intestine (1)
- intraoperative radiotherapy (1)
- ischemia reperfusion injury (1)
- ischemic stroke (1)
- isosteviol sodium (STVNA) (1)
- kAE1 (1)
- kanadaptin (1)
- karyotypes (1)
- keratinocytes (1)
- l-type calcium channel antagonist (1)
- lamin A (1)
- leukemia inhibitory factor (1)
- lipids (1)
- localisation (1)
- lung (1)
- lung fibrosis (1)
- lymphogene Metastasenbildung (1)
- macular neovascularization (1)
- management (1)
- markers (1)
- mechanotransduction (1)
- megakaryocytes (1)
- meiosis (1)
- membrane transport (1)
- membrane vesicles (1)
- memory cells (1)
- meninges (1)
- mesenchymal stem cells (1)
- mesenchymal stromal cells (1)
- mesodermal (1)
- mesodermal organoid (1)
- metabolism (1)
- metabotropic signalling (1)
- microRNA (1)
- microvascular complications (1)
- microvasculature (1)
- microvessel permeability (1)
- migration (1)
- minimally-invasive (1)
- model (1)
- molecular biology (1)
- monocytes (1)
- monosaccharide-dependent (1)
- morphotypes (1)
- mouse model (1)
- mouse models (1)
- mucociliary clearance (1)
- multilayered vessel wall with intimate, media and adventitia (1)
- multipotent fetal neural stem cells (fNSCs) (1)
- muscle (1)
- mutagenesis (1)
- mutation analysis (1)
- mutational analysis (1)
- mutationen (1)
- mutations (1)
- myelin (1)
- myeloid (1)
- myeloid cells (1)
- myocardial infarction (1)
- myocardium (1)
- natural history (1)
- neonatales Pemphigus-Maus-Modell (1)
- neotype (1)
- nerve fibers (1)
- nerve regneration (1)
- nerve root avulsion (1)
- nervous system (1)
- neue Brombeerart (1)
- neural crest (1)
- neural organoid (1)
- neurites varicosities (1)
- neuro-/photoreceptor degeneration (1)
- neurodevelopment (1)
- neuroendocrine cells (1)
- neuroepithelial progenitors (1)
- neuroepitheliale Vorläufer (1)
- neurogenic (1)
- neuroimmunology (1)
- neuropeptide Y (1)
- neuroprotective pathways (1)
- neuroregeneration (1)
- neurotrophe Faktoren (1)
- neurotrophic facors (1)
- neurotrophic factors (1)
- neurovascular unit in vitro (1)
- new Rubus species (1)
- new name (1)
- nicotinic acetylcholine receptors (1)
- nonneuronal acetylcholine (1)
- nuclear export (1)
- nuclear export signal (1)
- nuclear localization sequence (1)
- nuclear localization signal (1)
- nuclear transport (1)
- obesity (1)
- occurrence (1)
- olfaction (1)
- olfactory system (1)
- ontogenesis (1)
- oocyte (1)
- open-access database (1)
- optic nerve (1)
- organic (1)
- organic cation transporter (1)
- organic cations (1)
- organische Kationen (1)
- organischer (1)
- p27(KIP1) (1)
- pancreatic cancer (1)
- parenchyma (1)
- pathology (1)
- pemphigus vulgaris (1)
- penetratin (1)
- perforator (1)
- peripheral nerve (1)
- peripheral nervous system (1)
- peroxisome (1)
- persistant infection (1)
- personalized treatment (1)
- phenotype (1)
- phosphatidylinositol (1)
- phosphocholine (1)
- plasma membrane (1)
- podocytes (1)
- polyamines (1)
- preclinical research (1)
- preconditioning (1)
- prefrontal cortex (1)
- probe level data (1)
- progenitor (1)
- progenitor cells (1)
- progenitors (1)
- proliferation (1)
- proteasome (1)
- protein (1)
- protein conformational changes (1)
- protein phosphorylation (1)
- protein synthesis (1)
- proximal tubule (1)
- proximaler Tubulus (1)
- psychiatric disorders (1)
- psychology (1)
- pterygoalar bars (1)
- pterygospinous complex (1)
- pterygospinous muscle or ligament (1)
- pterygospinöse Strukturen (1)
- pterygospinöser Komplex (1)
- pubic symphysis (1)
- pulmonary hypertension (1)
- rOCT (1)
- rOCT2 (1)
- radial glia (1)
- radiation (1)
- radiotherapy (1)
- rat heart (1)
- reactive oxygen species (1)
- recurrence (1)
- regulatory protein (1)
- renAE1 (1)
- reorganization (1)
- reprogramming (1)
- resident CD34-positive cells (1)
- restrictive dermopathy (1)
- retinal angiomatous proliferation (1)
- retinoic acid (1)
- rhizotomy (1)
- rho GTPases (1)
- salivary (1)
- salivary gland (1)
- salivary gland tumors (1)
- sasculature (1)
- scale-up (1)
- scanning electron micrographs (1)
- self-renewal (1)
- sensory ganglia (1)
- sensory neuron (1)
- sensory physiology (1)
- sepsis (1)
- serial block face EM (1)
- serielle Rasterelektronenmikroskopie (1)
- series Discolores (1)
- series Vestiti (1)
- serotonerges System (1)
- serotonin (1)
- sglt1 (1)
- shear stress fibers (1)
- signal transmission (1)
- signature (1)
- single‐cell RNA‐seq (1)
- small intestine (1)
- sodium channels (1)
- soil nutrients (1)
- solid tumors (1)
- spectral shaping (1)
- spheroids (1)
- spinal cord (1)
- stem cells (1)
- stress (1)
- stress fibers (1)
- stress protein (1)
- structural protein (1)
- substrate affinity (1)
- sugar uptake (1)
- suppressor cells (1)
- suspension culture (1)
- synapse (1)
- synaptic active zone cytomatrix (1)
- synaptic vesicles (1)
- synaptonemal complex (1)
- taste (1)
- taste receptor cells (1)
- taxonomy (1)
- teratocarcinoma cells (1)
- teratokarzinome Zellen (1)
- thrombin (1)
- tight junction (1)
- tin prefiltration (1)
- titin (1)
- tomography (1)
- topsoil removal (1)
- traffiking (1)
- trans-Stimulation (1)
- trans-stimulation (1)
- transcapillary pressure gradient (1)
- transcription-3 (STAT3) (1)
- transinteraction (1)
- transmission electron microscopy (1)
- transport (1)
- transporter (1)
- transporter regulator (1)
- trial (1)
- tube formation (1)
- tuft cells (1)
- tumor (1)
- tumor microenvironment (1)
- tumor spheroids (1)
- tumor-vessel wall-interface model (1)
- tumorigenic properties (1)
- tumors (1)
- ubiquitin (1)
- ultra-low-dose CT (1)
- unfolded protein response (1)
- urinary calculi (1)
- vagus nerve stimulation (1)
- vascular biofabrication (1)
- vascular network and hierarchical organized vessels (1)
- vascular normalization (1)
- vascular wall stem and progenitor cells (1)
- vascularization (1)
- vascularization model (1)
- vasculature (1)
- ventral root replantation (1)
- vesicular acetylcholine transporter (1)
- vessel wall resident stem cells (1)
- viability (1)
- white matter (1)
- xerostomia (1)
- zerebelläre Körnerzellen (1)
- zerebrale Mikrovaskulatur (1)
- µ-Opioid receptor (1)
- Ökologie (1)
- Österreich (1)
- β-Aminopropionitril (1)
Institute
- Institut für Anatomie und Zellbiologie (266) (remove)
Sonstige beteiligte Institutionen
- Department of Biomedical Imaging, National Cerebral and Cardiovascular Research Center, Suita, Japan (2)
- Division of Medical Technology and Science, Department of Medical Physics and Engineering, Course of Health Science, Osaka University Graduate School of Medicine, Suita Japan (2)
- Institut for Molecular Biology and CMBI, Department of Genomics, Stem Cell Biology and Regenerative Medicine, Leopold-Franzens-University Innsbruck, Innsbruck, Austria (2)
- Johns Hopkins School of Medicine, The Russell H Morgan Department of Radiology and Radiological Science, Baltimore, MD, USA (2)
- Naturalis Biodiversity Centre (2)
- Johns Hopkins School of Medicine (1)
- Johns Hopkins School of Medicine, Baltimore, MD, U.S. (1)
Salivary gland tumors are a rare tumor entity within malignant tumors of all tissues. The most common are malignant mucoepidermoid carcinoma, adenoid cystic carcinoma, and acinic cell carcinoma. Pleomorphic adenoma is the most recurrent form of benign salivary gland tumor. Due to their low incidence rates and complex histological patterns, they are difficult to diagnose accurately. Malignant tumors of the salivary glands are challenging in terms of differentiation because of their variability in histochemistry and translocations. Therefore, the primary goal of the study was to review the current literature to identify the recent developments in histochemical diagnostics and translocations for differentiating salivary gland tumors.
Background
Elbow imaging is challenging with conventional multidetector computed tomography (MDCT), while cone-beam CT (CBCT) provides superior options. We compared intra-individually CBCT versus MDCT image quality in cadaveric elbows.
Methods
A twin robotic x-ray system with new CBCT mode and a high-resolution clinical MDCT were compared in 16 cadaveric elbows. Both systems were operated with a dedicated low-dose (LD) protocol (equivalent volume CT dose index [CTDI\(_{vol(16 cm)}\)] = 3.3 mGy) and a regular clinical scan dose (RD) protocol (CTDI\(_{vol(16 cm)}\) = 13.8 mGy). Image quality was evaluated by two radiologists (R1 and R2) on a seven-point Likert scale, and estimation of signal intensity in cancellous bone was conducted. Wilcoxon signed-rank tests and intraclass correlation coefficient (ICC) statistics were used.
Results
The CBCT prototype provided superior subjective image quality compared to MDCT scans (for RD, p ≤ 0.004; for LD, p ≤ 0.001). Image quality was rated very good or excellent in 100% of the cases by both readers for RD CBCT, 100% (R1) and 93.8% (R2) for LD CBCT, 62.6% and 43.8% for RD MDCT, and 0.0% and 0.0% for LD MDCT. Single-measure ICC was 0.95 (95% confidence interval 0.91–0.97; p < 0.001). Software-based assessment supported subjective findings with less “undecided” pixels in CBCT than dose-equivalent MDCT (p < 0.001). No significant difference was found between LD CBCT and RD MDCT.
Conclusions
In cadaveric elbow studies, the tested cone-beam CT prototype delivered superior image quality compared to high-end multidetector CT and showed a potential for considerable dose reduction.
Blood vessel organoids are an important in vitro model to understand the underlying mechanisms of human blood vessel development and for toxicity testing or high throughput drug screening. Here we present a novel, cost-effective, and easy to manufacture vascular organoid model. To engineer the organoids, a defined number of human induced pluripotent stem cells are seeded in non-adhesive agarose coated wells of a 96-well plate and directed towards a lateral plate mesoderm fate by activation of Wnt and BMP4 signaling. We observe the formation of a circular layer of angioblasts around days 5–6. Induced by VEGF application, CD31\(^+\) vascular endothelial cells appear within this vasculogenic zone at approximately day 7 of organoid culture. These cells arrange to form a primitive vascular plexus from which angiogenic sprouting is observed after 10 days of culture. The differentiation outcome is highly reproducible, and the size of organoids is scalable depending on the number of starting cells. We observe that the initial vascular ring forms at the interface between two cell populations. The inner cellular compartment can be distinguished from the outer by the expression of GATA6, a marker of lateral plate mesoderm. Finally, 14-days-old organoids were transplanted on the chorioallantois membrane of chicken embryos resulting in a functional connection of the human vascular network to the chicken circulation. Perfusion of the vessels leads to vessel wall maturation and remodeling as indicated by the formation of a continuous layer of smooth muscle actin expressing cells enwrapping the endothelium. In summary, our organoid model recapitulates human vasculogenesis, angiogenesis as well as vessel wall maturation and therefore represents an easy and cost-effective tool to study all steps of blood vessel development and maturation directly in the human setting without animal experimentation.
During stroke the blood–brain barrier (BBB) is damaged which can result in vasogenic brain edema and inflammation. The reduced blood supply leads to decreased delivery of oxygen and glucose to affected areas of the brain. Oxygen and glucose deprivation (OGD) can cause upregulation of glucose uptake of brain endothelial cells. In this letter, we investigated the influence of MK801, a non-competitive inhibitor of the NMDA-receptor, on the regulation of the glucose uptake and of the main glucose transporters glut1 and sglt1 in murine BBB cell line cerebEND during OGD. mRNA expression of glut1 was upregulated 68.7- fold after 6 h OGD, which was significantly reduced by 10 μM MK801 to 28.9-fold. Sglt1 mRNA expression decreased during OGD which was further reduced by MK801. Glucose uptake was significantly increased up to 907% after 6 h OGD and was still higher (210%) after the 20 h reoxygenation phase compared to normoxia. Ten micromolar MK801 during OGD was able to reduce upregulated glucose uptake after OGD and reoxygenation significantly. Presence of several NMDAR subunits was proven on the mRNA level in cerebEND cells. Furthermore, it was shown that NMDAR subunit NR1 was upregulated during OGD and that this was inhibitable by MK801. In conclusion, the addition of MK801 during the OGD phase reduced significantly the glucose uptake after the subsequent reoxygenation phase in brain endothelial cells.
Aging is an independent risk factor for cardiovascular diseases and therefore of particular interest for the prevention of cardiovascular events. However, the mechanisms underlying vascular aging are not well understood. Since carcinoembryonic antigen‐related cell adhesion molecule 1 (CEACAM1) is crucially involved in vascular homeostasis, we sought to identify the role of CEACAM1 in vascular aging. Using human internal thoracic artery and murine aorta, we show that CEACAM1 is upregulated in the course of vascular aging. Further analyses demonstrated that TNF‐α is CEACAM1‐dependently upregulated in the aging vasculature. Vice versa, TNF‐α induces CEACAM1 expression. This results in a feed‐forward loop in the aging vasculature that maintains a chronic pro‐inflammatory milieu. Furthermore, we demonstrate that age‐associated vascular alterations, that is, increased oxidative stress and vascular fibrosis, due to increased medial collagen deposition crucially depend on the presence of CEACAM1. Additionally, age‐dependent upregulation of vascular CEACAM1 expression contributes to endothelial barrier impairment, putatively via increased VEGF/VEGFR‐2 signaling. Consequently, aging‐related upregulation of vascular CEACAM1 expression results in endothelial dysfunction that may promote atherosclerotic plaque formation in the presence of additional risk factors. Our data suggest that CEACAM1 might represent an attractive target in order to delay physiological aging and therefore the transition to vascular disorders such as atherosclerosis.
Der vordere kraniozervikale Übergang wurde an 99 Kopf-Hals-Präparaten aus dem Präpariersaal mittels MRT, CT und Sägeschnitten untersucht. Weiterhin wurden 110 Schädel, 56 Atlas- und 33 Axispräparate vermessen. Es fand sich in 70% der Präparate das Vorliegen einer Osteoarthrose (Ostheoarthritis) der Art. atlanto-axialis mediana; diese Erkrankung war durch die Bildung von maximalen Osteophyten, Vergrößerung der Gelenkflächen, Verlängerung der Gelenkhöhle und Verminderung des Abstandes zum Hinterhauptsbein charakterisiert. In drei Fällen hatten sich sehr große (giant), nach kranial gerichteten Osteophyten mit knöchernen Kontaktzonen zum Basiokziput gebildet. Die Kontaktzonen waren - wie sich feingeweblich zeigte – echte, erworbene, akzessorische, atlanto-okzipitale Gelenke in der Medianebene. In 11 Fällen lagen - wie die MRT- und CT- Schnittbilder zeigten – Reste des Proatlas bzw. der hypochondralen Spange vor: 3 mal als Condylus occipitalis tertius und knöchernen Kontaktzonen zu Atlas bzw. Axis und 7 mal als freie, überknorpelte Ossikel. Auch hier kann - wie die histologische Kontrolle zeigte – bei den Kontaktzonen von echten, allerdings angeborenen akzessorischen (atlantookzipitalen und odonto-okzipitalen) Gelenken in der Medianebene gesprochen werden. Der Casus mit Vorkommen eines Condylus occipitalis tertius und gleichzeitiger Bildung eines Osteophyten der Densspitze, die zusammen eine knöcherne Kontaktzone und akzessorische Gelenkkammern ausgebildet hatten, kann als „gemischter“ Fall bezeichnet werden.
Barley stripe mosaic virus (BSMV) RNA which was previously reported to contain poly(A) sequences (Agranovsky et al., 1978) can be specifically esterified with tyrosine in vitro in the presence of an aminoacyl-tRNA synthetase fraction from wheat embryos. All the three RNA components of the BSMV strain with a three-component genome (Norwich) and both RNA components of a two-component strain (Russian) can be tyrosylated. The poly(A)-containing (bound to oligo(dT)-cellulose) and poly(A)-deficient(not bound to oligo(dT)-cellulose) fractions of BSMV RNA display a similar amino acidaccepting ability. The nucleotide sequence which accepts tyrosine is coupled with the intact genomic polyadenylated BSMV RNA. The viral RNA isolated after sucrose density gradient centrifugation under drastic denaturing conditions retains its aminoacylating activity, which suggests that this activity is not due to the presence in a BSMV RNA preparation of a tyrosine tRNA associated with BSMV RNA. Inhibition of aminoacylation of the 3’-oxidized (treated with sodium metaperiodate) BSMV RNA suggests that the tyrosine-accepting structure is localized at the 3’ terminus of BSMV RNA molecules. It is shown that segments of different lengths obtained upon random fragmentation can be tyrosylated. The 3’-terminal (tyrosine-accepting) poly(A)+ segments can be isolated. The shortest segments of viral RNA capable of being aminoacylated [i.e., containing both tRNA-like structure and poly(A)] consists of approximately 150-200 nucleotides. The analysis of the oligonucleotides derived from individual BSMV RNA components labeled with 32P at the 3’ end revealed two types of 3’-terminal sequences different from poly(A). It is suggested that a poly(A) sequence is intercalated between a 3’-terminal tyrosineaccepting structure and the 5’-terminal portion of poly(A)+ BSMV RNA.
Background:
Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) for which several new treatment options were recently introduced. Among them is the monoclonal anti-CD52 antibody alemtuzumab that depletes mainly B cells and T cells in the immune periphery. Considering the ongoing controversy about the involvement of B cells and in particular the formation of B cell aggregates in the brains of progressive MS patients, an in-depth understanding of the effects of anti-CD52 antibody treatment on the B cell compartment in the CNS itself is desirable.
Methods:
We used myelin basic protein (MBP)-proteolipid protein (PLP)-induced experimental autoimmune encephalomyelitis (EAE) in C57BL/6 (B6) mice as B cell-dependent model of MS. Mice were treated intraperitoneally either at the peak of EAE or at 60 days after onset with 200 μg murine anti-CD52 vs. IgG2a isotype control antibody for five consecutive days. Disease was subsequently monitored for 10 days. The antigen-specific B cell/antibody response was measured by ELISPOT and ELISA. Effects on CNS infiltration and B cell aggregation were determined by immunohistochemistry. Neurodegeneration was evaluated by Luxol Fast Blue, SMI-32, and Olig2/APC staining as well as by electron microscopy and phosphorylated heavy neurofilament serum ELISA.
Results:
Treatment with anti-CD52 antibody attenuated EAE only when administered at the peak of disease. While there was no effect on the production of MP4-specific IgG, the treatment almost completely depleted CNS infiltrates and B cell aggregates even when given as late as 60 days after onset. On the ultrastructural level, we observed significantly less axonal damage in the spinal cord and cerebellum in chronic EAE after anti-CD52 treatment.
Conclusion:
Anti-CD52 treatment abrogated B cell infiltration and disrupted existing B cell aggregates in the CNS.
In enterocytes, protein RS1 (RSC1A1) mediates an increase of glucose absorption after ingestion of glucose-rich food via upregulation of Na+-D-glucose cotransporter SGLT1 in the brush-border membrane (BBM). Whereas RS1 decelerates the exocytotic pathway of vesicles containing SGLT1 at low glucose levels between meals, RS1-mediated deceleration is relieved after ingestion of glucose-rich food. Regulation of SGLT1 is mediated by RS1 domain RS1-Reg, in which Gln-Ser-Pro (QSP) is effective. In contrast to QSP and RS1-Reg, Gln-Glu-Pro (QEP) and RS1-Reg with a serine to glutamate exchange in the QSP motif downregulate the abundance of SGLT1 in the BBM at high intracellular glucose concentrations by about 50%. We investigated whether oral application of QEP improves diabetes in db/db mice and affects the induction of diabetes in New Zealand obese (NZO) mice under glucolipotoxic conditions. After 6-day administration of drinking water containing 5 mM QEP to db/db mice, fasting glucose was decreased, increase of blood glucose in the oral glucose tolerance test was blunted, and insulin sensitivity was increased. When QEP was added for several days to a high fat/high carbohydrate diet that induced diabetes in NZO mice, the increase of random plasma glucose was prevented, accompanied by lower plasma insulin levels. QEP is considered a lead compound for development of new antidiabetic drugs with more rapid cellular uptake. In contrast to SGLT1 inhibitors, QEP-based drugs may be applied in combination with insulin for the treatment of type 1 and type 2 diabetes, decreasing the required insulin amount, and thereby may reduce the risk of hypoglycemia.
Aims
Cardiac atrial natriuretic peptide (ANP) participates in the maintenance of arterial blood pressure and intravascular volume homeostasis. The hypovolaemic effects of ANP result from coordinated actions in the kidney and systemic microcirculation. Hence, ANP, via its guanylyl cyclase-A (GC-A) receptor and intracellular cyclic GMP as second messenger, stimulates endothelial albumin permeability. Ultimately, this leads to a shift of plasma fluid into interstitial pools. Here we studied the role of caveolae-mediated transendothelial albumin transport in the hyperpermeability effects of ANP.
Methods and results
Intravital microscopy studies of the mouse cremaster microcirculation showed that ANP stimulates the extravasation of fluorescent albumin from post-capillary venules and causes arteriolar vasodilatation. The hyperpermeability effect was prevented in mice with conditional, endothelial deletion of GC-A (EC GC-A KO) or with deleted caveolin-1 (cav-1), the caveolae scaffold protein. In contrast, the vasodilating effect was preserved. Concomitantly, the acute hypovolaemic action of ANP was abolished in EC GC-A KO and Cav-1−/− mice. In cultured microvascular rat fat pad and mouse lung endothelial cells, ANP stimulated uptake and transendothelial transport of fluorescent albumin without altering endothelial electrical resistance. The stimulatory effect on albumin uptake was prevented in GC-A- or cav-1-deficient pulmonary endothelia. Finally, preparation of caveolin-enriched lipid rafts from mouse lung and western blotting showed that GC-A and cGMP-dependent protein kinase I partly co-localize with Cav-1 in caveolae microdomains.
Conclusion
ANP enhances transendothelial caveolae-mediated albumin transport via its GC-A receptor. This ANP-mediated cross-talk between the heart and the microcirculation is critically involved in the regulation of intravascular volume.
Background: Dendritic cells (DCs) rendered suppressive by treatment with mitomycin C and loaded with the autoantigen myelin basic protein demonstrated earlier their ability to prevent experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis (MS). This provides an approach for prophylactic vaccination against autoimmune diseases. For clinical application such DCs are difficult to generate and autoantigens hold the risk of exacerbating the disease.
Methods: We replaced DCs by peripheral mononuclear cells and myelin autoantigens by glatiramer acetate (Copaxone ®), a drug approved for the treatment of MS. Spleen cells were loaded with Copaxone®, incubated with mitomycin C (MICCop) and injected into mice after the first bout of relapsing-remitting EAE. Immunosuppression mediated by MICCop was investigated in vivo by daily assessment of clinical signs of paralysis and in in vitro restimulation assays of peripheral immune cells. Cytokine profiling was performed by enzyme-linked immunosorbent assay (ELISA). Migration of MICCop cells after injection was examined by biodistribution analysis of 111Indium-labelled MICCop. The number and inhibitory activity of CD4+CD25+FoxP3+ regulatory T cells were analysed by histology, flow cytometry and in vitro mixed lymphocyte cultures. In order to assess the specificity of MICCop-induced suppression, treated EAE mice were challenged with the control protein ovalbumin. Humoral and cellular immune responses were then determined by ELISA and in vitro antigen restimulation assay.
Results: MICCop cells were able to inhibit the harmful autoreactive T-cell response and prevented mice from further relapses without affecting general immune responses. Administered MICCop migrated to various organs leading to an increased infiltration of the spleen and the central nervous system with CD4+CD25+FoxP3+ cells displaying a suppressive cytokine profile and inhibiting T-cell responses.
Conclusion: We describe a clinically applicable cell therapeutic approach for controlling relapses in autoimmune encephalomyelitis by specifically silencing the deleterious autoimmune response.
Die Stabiltät und Integrität der Epidermis beruht zu einem großen Teil auf der intakten Funktion der Desmosomen. Diese fleckförmigen Zellkontakte vermitteln extrazellulär die Haftung zwischen den Keratinozyten durch Desmocadherine und sind intrazellulär über Adaptorproteine im Intermediärfilamentsystem des Zellskeletts verankert. Diese Funktion ist bei der Autoimmunerkrankung Pemphigus gestört, die zu intraepidermaler Blasenbildung durch Akantholyse der Keratinozyten führt. Pemphigus vulgaris (PV) und Pemphigus foliaceus (PF) stellen die beiden Hauptvarianten dar, wobei PV durch Autoantikörper gegen die Desmocadherine Desmoglein (Dsg) 3 und oftmals zusätzlich gegen Dsg 1, PF durch Autoantikörper nur gegen Dsg 1 gekennzeichnet ist. Rho-GTPasen sind zelluläre Regulatorproteine, die das Aktinzytoskelett und verschiedene Zellkontakte beeinflussen. Die vorliegende Arbeit beschäftigte sich mit dem Einfluss von Rho-GTPasen bei der Regulation von desmosomal vermittelter Adhäsion. In einem zweiten Teil wurde die Beteiligung von Rho-GTPasen bei den Pemphigusvarianten PV und PF näher charakterisiert. Für den ersten Abschnitt wurden bakterielle Toxine verwendet, die spezifisch Rho GTPasen aktivieren bzw. inhibieren, während für den zweiten Teil IgG-Fraktionen von PV- und PF-Patienten in Kombination mit aktivierenden Toxinen zur Anwendung kamen. Eine Inhibition der drei Hauptvertreter der Rho-GTPasen in kultivierten Keratinozyten und humaner Epidermis führte zu einer Rarefizierung des Aktinfilamentsystems, zu Verlust von membranständig lokalisiertem Dsg 1 und 3 und zu Zelldissoziation sowie zu verminderter Dsg 1 und 3-vermittelter Haftung von Mikroperlen auf der Oberfläche von Keratinozyten. Die Aktivierung der GTPasen resultierte in vermehrter linearisierter Darstellbarkeit von Aktin und Dsg 3 an den Zellgrenzen und einer verstärkten Dsg-vermittelten Haftung. Pemphigus-IgG führten ebenfalls zu Zelldissoziation und Verlust von Dsg-Immunreaktivität in Keratinozytenkulturen, zu Spaltbildung in humaner Epidermis und zum Verlust der durch Dsg 1 und Dsg 3 vermittelten Adhäsion. Dies ging einher mit einer vermehrten Menge an nicht am Zytoskelett verankerten Dsg 3 und wurde durch eine p38MAPK-abhängige Verminderung der Aktivität von Rho A moduliert. Die Aktivierung von Rho A verhinderte die Ausbildung der Pemphigus-induzierten Effekte nahezu vollständig. Zusammenfassend regulieren Rho-GTPasen die desmosomale Haftung in Keratinozyten. Die Daten zeigen weiterhin, dass Pemphigus-IgG durch eine Inhibition von Rho A diese Regulation beeinträchtigt, was zu Schwächung der Zytoskelettverankerung von Desmogleinen und zu Haftungsverlust und Spaltbildung führt. Somit ist Rho A ein wichtiger Faktor der Pemphigus-Pathogenese und stellt einen Erfolg versprechenden Ansatzpunkt zur Entwicklung neuer Therapieoptionen dar.
Die vorliegende Arbeit hatte zum Ziel, neuroendokrine Zellen in den Atemwegen bei Mäusen zu untersuchen, welche Kontakt zu sensorischen Nervenfasern ausbilden. In vorangegangenen Versuchen konnte bereits die Menge des ausgeschütteten CGRPs nach Stimulation mit Bitterstoffen bestimmt werden. Die Methode zur Messung der Freisetzung von CGRP aus verschiedenen Organen wurde von Prof. Reeh und seiner Arbeitsgruppe etabliert. Ziel der vorliegenden Arbeit war es, zu untersuchen, woher das ausgeschüttete CGRP kommt und ob die Stimulation von Bürstenzellen mit Bitterstoffen zur Ausschüttung von CGRP aus den neuroendokrinen Zellen führt. Anhand der elektronenmikroskopischen Auswertung und der dreidimensionalen Rekonstruktion konnte gezeigt werden, dass es Kontakt zwischen den neuroendokrinen Zellen im Epithel der Trachea und sensorischen Nervenfasern gibt. Die immunhistochemischen Versuche zeigten, dass es nach Stimulation mit Denatonium höchstwahrscheinlich zur Ausschüttung von CGRP durch die intraepithelialen Fasern gekommen ist. Diese Annahme spiegelt sich in der veränderten Morphologie sowie der geringeren Quantität der intraepithelialen Fasern nach Stimulation mit Denatonium deutlich wider. Dass es weder bei der Anzahl der neuroendokrinen Zellen, noch bei der Erscheinung und Anzahl der extraepithelialen Fasern nach Denatoniumstimulation zu einer Veränderung gekommen ist, unterstützt diese Annahme ebenfalls. Im Hinblick auf die durchgeführten Versuche mit den TRPM5-gendefizienten Mäusen zeigte sich, dass die Stimulation mit Denatonium keine Auswirkungen auf die Anzahl der neuroendokrinen Zellen hatte. Dieses Ergebnis unterstützt die Erkenntnisse der vorangegangenen Untersuchungen, welche gezeigt haben, dass das CGRP nicht von den neuroendokrinen Zellen ausgeschüttet wurde. Des Weiteren lässt das Ergebnis darauf schließen, dass die Ausschüttung von CGRP nicht abhängig von der Anwesenheit von Bürstenzellen ist. Insgesamt zeigen die Untersuchungen, dass es nach Stimulation mit Bittersubstanzen zu einer CGRP-Ausschüttung durch die intraepithelialen Fasern gekommen ist. Interessant wäre es weiterhin zu klären, welche Effekte diese Ausschüttung bewirkt und welche Bedeutung der Freisetzung von Substanz P in diesem Zusammenhang zukommt.
1994 wurde von Gründemann et al. der erste organische Kationentransporter, der rOCT1 beschrieben. Es wurden bereits einige Aminosäuren identifiziert, die bei der Bindung kationischer Substanzen beteiligt sind. Hierbei handelt es sich um Phenylalanin 160 der zweiten Transmembrandomäne, Tryptophan 218, Tyrosin 222 und Threonin 226 der vierten Transmembrandomäne, um Arginin 440, Leucin 447, Glutamin 448 der zehnten und um Aspartat 475 der elften Transmembrandomäne. Hintergrund der Versuche dieser Arbeit war das im Jahre 2005 von Sturm et al. identifizierte Cystein 451. Es liegt zwischen der zehnten und elften Transmembrandomäne. Cystein 451 ist wahrscheinlich auf Grund seiner Lage im Strukturmodell nicht direkt an der Bindung von Substraten beteiligt. Es wird vermutet, dass die Mutation des Cysteins 451 die Positionen von Aminosäuren in der Bindungsstelle verändert. Daher wurden die Mutante C451M, die Doppelmutanten L447F/C451M, L447Y/C451M und die Dreifachmutante Y222F/L447F/C451M mittels Tracer-Fluxexperimenten hinsichtlich der Hemmung der Tetraethylammonium-Aufnahme durch Kortikosteron und durch Tetrabutylammonium untersucht. Die Mutation C451M steigert verglichen mit dem rOCT1-Wildtyp die Affinität für Kortikosteron, jedoch sinkt bei dieser Mutante die TBuA-Affinität. Man nimmt nun aufgrund dieser Mutageneseversuche und den bereits zuvor generierten Modellen des rOCT1 an, dass aufgrund seiner Lage Cystein 451 nicht direkt an der Bindung von Substraten beteiligt ist, sondern einen indirekten Effekt auf die Substratbindungsregion des Transporters ausübt. Weiterhin wurde festgestellt, dass die Mutanten L447Y/C451M und L447F/C451M gegensätzliche Affinitäten für TBuA und Kotikosteron haben. Tauscht man das Leucin an Position 447 gegen ein Tyrosin aus, so wird der Transporter weniger affin für Kortikosteron, jedoch steigt die TBuA-Affinität. Tauscht man das Leucin gegen ein Phenylalanin aus, verhält es sich gegensätzlich. Die Position 222 scheint weder an der TBuA-Bindung, noch an der Bindung von Kortikosteron maßgeblich beteiligt zu sein.
Eine Reihe mehrtägiger Suchexkur-sionen / Transekte in verschiedene Regionen Bayerns in den Jahren 2011 bis 2014 waren der Gattung Taraxacum gewidmet. Unter den gesammelten und beobachteten Arten ist Taraxacum broddesonii (sect. Ruderalia / Taraxacum) neu für Deutschland. Neu für Bayern sind Taraxacum fusciflorum, marklundii, spiculatum (sect. Hamata) und Taraxacum acroglossum, atroviride, clarum, floccosum, freticola, glossodon, hemicyclum, homoschistum, infuscatum, intumescens, lacinulatum, leucopodum, lundense, ottonis, pallidipes, praestabile, pseudoretroflexum, pulverulentum, saxonicum, sellandii, sundbergii, uncidentatum, uniforme, violaceinervosum (sect. Ruderalia / Taraxacum). Taraxacum lojoënse wird als ältester und korrekter Name für T. lippertianum und T. matricium und wahrscheinlich auch für T. ampelophytum und T. debrayi angesehen. Seltenere Arten sind abgebildet.
Multiple sclerosis (MS) is the most prevalent neurological disease of the central nervous system (CNS) in young adults and is characterized by inflammation, demyelination and axonal pathology that result in multiple neurological and cognitive deficits. The focus of MS research remains on modulating the immune response, but common therapeutic strategies are only effective in slowing down disease progression and attenuating the symptoms; they cannot cure the disease. Developing an option to prevent neurodegeneration early on would be a valuable addition to the current standard of care for MS. Based on our results we suggest that application of nimodipine could be an effective way to target both neuroinflammation and neurodegeneration. We performed detailed analyses of neurodegeneration in experimental autoimmune encephalomyelitis (EAE), an animal model of MS, and in in vitro experiments regarding the effect of the clinically well-established L-type calcium channel antagonist nimodipine. Nimodipine treatment attenuated the course of EAE and spinal cord histopathology. Furthermore, it promoted remyelination. The latter could be due to the protective effect on oligodendrocytes and oligodendrocyte precursor cells (OPCs) we observed in response to nimodipine treatment. To our surprise, we detected calcium channel-independent effects on microglia, resulting in apoptosis. These effects were cell type-specific and independent of microglia polarization. Apoptosis was accompanied by decreased levels of nitric oxide (NO) and inducible NO synthase (iNOS) in cell culture as well as decreased iNOS expression and reactive oxygen species (ROS) activity in EAE. Overall, application of nimodipine seems to generate a favorable environment for regenerative processes and could therefore be a novel treatment option for MS, combining immunomodulatory effects while promoting neuroregeneration.
Bindung der extrazellulären Domäne von N-Cadherin an den Fibroblastenwachstumsfaktor-Rezeptor FGFR-1
(2008)
N-Cadherin, ein Mitglied der klassischen Cadherin Familie vermittelt durch homophile Bindungen der extrazellulären Domänen (EZD) zwischen benachbarten Zellen Zell-Zell-Kontakte. Im Nervensystem kontrolliert es zahlreiche Aufgaben wie beispielsweise die Ausbildung von Synapsen, die synaptische Plastizität, das Auswachsen von Axonen und deren richtungsgezielte Orientierung. In Untersuchungen zum Axonwachstum von cerebellären Körnerzellen konnte von Doherty et al. (1995, 1996) gezeigt werden, dass die isolierte EZDI-V von N-Cadherin über den FGFR-1 (Fibroblastenwachstumsfaktor-Rezeptor-1) ein richtungsvermitteltes Auswachsen von Axonen verursacht. Basierend auf diesen Beobachtungen wurde ein Bindungsmodell erstellt (Doherty et al., 1996). Dieses geht davon aus, dass zwischen transdimeren N-Cadherin-Molekülen, über die Aminosäuren IDPVNGQ der EZD Wechselwirkungen mit den Aminosäuren HAV der EZD von FGFR-1 auftreten (siehe hierzu Abb. 17). Der dadurch dimerisierte FGFR-1 bewirkt innerhalb der Nervenzelle eine intrazelluläre Signaltransduktion, die in einem zielgerichteten Axonwachstum resultiert. Das Ziel der vorliegenden Arbeit war, dieses Bindungsmodell näher zu untersuchen. Ausgehend von den für N-Cadherin und FGFR-1 kodierenden cDNAs und entsprechenden Vektorsystemen wurden in CHO-Zellen stabile Zelllinien erstellt. Das zugrundeliegende Expressionssystem führte zu einem Ausschleusen der für die Experimente notwendigen Fc-Fusionsproteine in den Kulturüberstand. Eine daran anschließende auf Protein A basierende Affinitätschromatographie des Kulturüberstandes ermöglichte die Isolierung und Anreicherung der Fc-Fusionsproteine. Desweiteren wurden Expressionsvektoren verwendet, die für subzelluläre Lokalisationsuntersuchungen verwendet wurden. Zu Beginn der Bindungsstudien wurde Untersuchungen zum Axonwachstum cerebellärer Körnerzellen durchgeführt. Diese dienten zum einen der Überprüfung der von Doherty und Walsh (1996) durchgeführten Experimente zum Längenwachstum cerebellärer Körnerzellen in Gegenwart ausgewählter Zelladhäsionsmoleküle (NCAM, L1 und N-Cadherin), zum anderen dienten sie der Überprüfung der Funktionalität der FGFR-1-und N-Cadherin-spezifischen Peptide (HAV und IDPVNGQ). Wie zu erwarten wurde durch Zugabe von N-Cadherin EZDI-V ein Axonlängenwachstum festgestellt, dass durch Zugabe der HAV- und IDPVNGQ-Peptide inhibiert wurde. Für den Auschluß der Wirkung von Fremdproteinen wurden in der vorliegenden Arbeit direkte Bindungsstudien durchgeführt. Hierzu wurden sowohl ELISA- als auch in Dot-Blot-Experimente durchgeführt. Diese ergaben eine Wechselwirkung der EZD von FGFR-1 und N-Cadherin. Eine von DsRed-FGFR-1 abhängige Lokalisation von GFP-N-Cadherin in CHO-Zellen deutete ebenfalls auf eine Interaktion hin. Nähere Bindungsstudien zeigten, dass die Bindungsmotive IDPVNGQ und HAV für eine Wechselwirkung der FGFR-1- und N-Cadherin-spezifischen EZDs bedeutungslos sind. Auch an der Laserpinzette durchgeführte Untersuchungen ergaben, das Wechselwirkungen zwischen N-Cadherin (auf Mikroperlen immobilisiert) und PC12-Zellen in Gegenwart der inhibierenden IDPVNGQ- und HAV-Peptide nicht verhindert werden konnten. Zusammenfasssend ist es gelungen zum ersten Mal eine direkte Wechselwirkung zwischen N-Cadherin und FGFR-1 nachzuweisen. Allerdings konnte in Kompetitionsexperimenten eine Bedeutung der postulierten Bindungsmotive nicht bestätigt werden.
Biofabrication, including printing technologies, has emerged as a powerful approach to the design of disease models, such as in cancer research. In breast cancer, adipose tissue has been acknowledged as an important part of the tumor microenvironment favoring tumor progression. Therefore, in this study, a 3D-printed breast cancer model for facilitating investigations into cancer cell-adipocyte interaction was developed. First, we focused on the printability of human adipose-derived stromal cell (ASC) spheroids in an extrusion-based bioprinting setup and the adipogenic differentiation within printed spheroids into adipose microtissues. The printing process was optimized in terms of spheroid viability and homogeneous spheroid distribution in a hyaluronic acid-based bioink. Adipogenic differentiation after printing was demonstrated by lipid accumulation, expression of adipogenic marker genes, and an adipogenic ECM profile. Subsequently, a breast cancer cell (MDA-MB-231) compartment was printed onto the adipose tissue constructs. After nine days of co-culture, we observed a cancer cell-induced reduction of the lipid content and a remodeling of the ECM within the adipose tissues, with increased fibronectin, collagen I and collagen VI expression. Together, our data demonstrate that 3D-printed breast cancer-adipose tissue models can recapitulate important aspects of the complex cell–cell and cell–matrix interplay within the tumor-stroma microenvironment
A recombinant plasmid was constructed containing the gene for bovine growth hormone joinea with the regulatory region and the region coding the signal sequence of the Escherichia coli alkaline phosphatase gene. In conditions of phosphorus starvation, which c~s derepression of alkaline phosphatase, expression was shown of the gene for bovine growth hormone, in addition to partial processing and secretion of protein into periplasm.
Aberrant immune responses represent the underlying cause of central nervous system (CNS) autoimmunity, including multiple sclerosis (MS). Recent evidence implicated the crosstalk between coagulation and immunity in CNS autoimmunity. Here we identify coagulation factor XII (FXII), the initiator of the intrinsic coagulation cascade and the kallikrein–kinin system, as a specific immune cell modulator. High levels of FXII activity are present in the plasma of MS patients during relapse. Deficiency or pharmacologic blockade of FXII renders mice less susceptible to experimental autoimmune encephalomyelitis (a model of MS) and is accompanied by reduced numbers of interleukin-17A-producing T cells. Immune activation by FXII is mediated by dendritic cells in a CD87-dependent manner and involves alterations in intracellular cyclic AMP formation. Our study demonstrates that a member of the plasmatic coagulation cascade is a key mediator of autoimmunity. FXII inhibition may provide a strategy to combat MS and other immune-related disorders.
Pathological angiogenesis promotes tumor growth, metastasis, and atherosclerotic plaque rupture. Macrophages are key players in these processes. However, whether these macrophages differentiate from bone marrow-derived monocytes or from local vascular wall-resident stem and progenitor cells (VW-SCs) is an unresolved issue of angiogenesis. To answer this question, we analyzed vascular sprouting and alterations in aortic cell populations in mouse aortic ring assays (ARA). ARA culture leads to the generation of large numbers of macrophages, especially within the aortic adventitia. Using immunohistochemical fate-mapping and genetic in vivo-labeling approaches we show that 60% of these macrophages differentiate from bone marrow-independent Ly6c\(^{+}\)/Sca-1\(^{+}\) adventitial progenitor cells. Analysis of the NCX\(^{−/-}\) mouse model that genetically lacks embryonic circulation and yolk sac perfusion indicates that at least some of those progenitor cells arise yolk sac-independent. Macrophages represent the main source of VEGF in ARA that vice versa promotes the generation of additional macrophages thereby creating a pro-angiogenetic feedforward loop. Additionally, macrophage-derived VEGF activates CD34\(^{+}\) progenitor cells within the adventitial vasculogenic zone to differentiate into CD31\(^{+}\) endothelial cells. Consequently, depletion of macrophages and VEGFR2 antagonism drastically reduce vascular sprouting activity in ARA. In summary, we show that angiogenic activation induces differentiation of macrophages from bone marrow-derived as well as from bone marrow-independent VW-SCs. The latter ones are at least partially yolk sac-independent, too. Those VW-SC-derived macrophages critically contribute to angiogenesis, making them an attractive target to interfere with pathological angiogenesis in cancer and atherosclerosis as well as with regenerative angiogenesis in ischemic cardiovascular disorders.
Although the bone marrow contains most hematopoietic activity during adulthood, hematopoietic stem and progenitor cells can be recovered from various extramedullary sites. Cells with hematopoietic progenitor properties have even been reported in the adult brain under steady‐state conditions, but their nature and localization remain insufficiently defined. Here, we describe a heterogeneous population of myeloid progenitors in the leptomeninges of adult C57BL/6 mice. This cell pool included common myeloid, granulocyte/macrophage, and megakaryocyte/erythrocyte progenitors. Accordingly, it gave rise to all major myelo‐erythroid lineages in clonogenic culture assays. Brain‐associated progenitors persisted after tissue perfusion and were partially inaccessible to intravenous antibodies, suggesting their localization behind continuous blood vessel endothelium such as the blood‐arachnoid barrier. Flt3\(^{Cre}\) lineage tracing and bone marrow transplantation showed that the precursors were derived from adult hematopoietic stem cells and were most likely continuously replaced via cell trafficking. Importantly, their occurrence was tied to the immunologic state of the central nervous system (CNS) and was diminished in the context of neuroinflammation and ischemic stroke. Our findings confirm the presence of myeloid progenitors at the meningeal border of the brain and lay the foundation to unravel their possible functions in CNS surveillance and local immune cell production.
Background: During early prenatal stages of brain development, serotonin (5-HT)-specific neurons migrate through somal translocation to form the raphe nuclei and subsequently begin to project to their target regions. The rostral cluster of cells, comprising the median and dorsal raphe (DR), innervates anterior regions of the brain, including the prefrontal cortex. Differential analysis of the mouse 5-HT system transcriptome identified enrichment of cell adhesion molecules in 5-HT neurons of the DR. One of these molecules, cadherin-13 (Cdh13) has been shown to play a role in cell migration, axon pathfinding, and synaptogenesis. This study aimed to investigate the contribution of Cdh13 to the development of the murine brain 5-HT system.
Methods: For detection of Cdh13 and components of the 5-HT system at different embryonic developmental stages of the mouse brain, we employed immunofluorescence protocols and imaging techniques, including epifluorescence, confocal and structured illumination microscopy. The consequence of CDH13 loss-of-function mutations on brain 5-HT system development was explored in a mouse model of Cdh13 deficiency.
Results: Our data show that in murine embryonic brain Cdh13 is strongly expressed on 5-HT specific neurons of the DR and in radial glial cells (RGCs), which are critically involved in regulation of neuronal migration. We observed that 5-HT neurons are intertwined with these RGCs, suggesting that these neurons undergo RGC-guided migration. Cdh13 is present at points of intersection between these two cell types. Compared to wildtype controls, Cdh13-deficient mice display increased cell densities in the DR at embryonic stages E13.5, E17.5, and adulthood, and higher serotonergic innervation of the prefrontal cortex at E17.5.
Conclusion: Our findings provide evidence for a role of CDH13 in the development of the serotonergic system in early embryonic stages. Specifically, we indicate that Cdh13 deficiency affects the cell density of the developing DR and the posterior innervation of the prefrontal cortex (PFC), and therefore might be involved in the migration, axonal outgrowth and terminal target finding of DR 5-HT neurons. Dysregulation of CDH13 expression may thus contribute to alterations in this system of neurotransmission, impacting cognitive function, which is frequently impaired in neurodevelopmental disorders including attention-deficit/hyperactivity and autism spectrum disorders.
Introduction
B cells are attracting increasing attention in the pathogenesis of multiple sclerosis (MS). B cell-targeted therapies with monoclonal antibodies or plasmapheresis have been shown to be successful in a subset of patients. Here, patients with either relapsing-remitting (n = 24) or secondary progressive (n = 6) MS presenting with an acute clinical relapse were screened for their B cell reactivity to brain antigens and were re-tested three to nine months later. Enzyme-linked immunospot technique (ELISPOT) was used to identify brain-reactive B cells in peripheral blood mononuclear cells (PBMC) directly ex vivo and after 96 h of polyclonal stimulation. Clinical severity of symptoms was determined using the Expanded Disability Status Scale (EDSS).
Results
Nine patients displayed B cells in the blood producing brain-specific antibodies directly ex vivo. Six patients were classified as B cell positive donors only after polyclonal B cell stimulation. In 15 patients a B cell response to brain antigens was absent. Based on the autoreactive B cell response we categorized MS relapses into three different patterns. Patients who displayed brain-reactive B cell responses both directly ex vivo and after polyclonal stimulation (pattern I) were significantly younger than patients in whom only memory B cell responses were detectable or entirely absent (patterns II and III; p = 0.003). In one patient a conversion to a positive B cell response as measured directly ex vivo and subsequently also after polyclonal stimulation was associated with the development of a clinical relapse. The evaluation of the predictive value of a brain antigen-specific B cell response showed that seven of eight patients (87.5%) with a pattern I response encountered a clinical relapse during the observation period of 10 months, compared to two of five patients (40%) with a pattern II and three of 14 patients (21.4%) with a pattern III response (p = 0.0005; hazard ratio 6.08 (95% confidence interval 1.87-19.77).
Conclusions
Our data indicate actively ongoing B cell-mediated immunity against brain antigens in a subset of MS patients that may be causative of clinical relapses and provide new diagnostic and therapeutic options for a subset of patients.
INTRODUCTION:
B cells are attracting increasing attention in the pathogenesis of multiple sclerosis (MS). B cell-targeted therapies with monoclonal antibodies or plasmapheresis have been shown to be successful in a subset of patients. Here, patients with either relapsing-remitting (n = 24) or secondary progressive (n = 6) MS presenting with an acute clinical relapse were screened for their B cell reactivity to brain antigens and were re-tested three to nine months later. Enzyme-linked immunospot technique (ELISPOT) was used to identify brain-reactive B cells in peripheral blood mononuclear cells (PBMC) directly ex vivo and after 96 h of polyclonal stimulation. Clinical severity of symptoms was determined using the Expanded Disability Status Scale (EDSS).
RESULTS:
Nine patients displayed B cells in the blood producing brain-specific antibodies directly ex vivo. Six patients were classified as B cell positive donors only after polyclonal B cell stimulation. In 15 patients a B cell response to brain antigens was absent. Based on the autoreactive B cell response we categorized MS relapses into three different patterns. Patients who displayed brain-reactive B cell responses both directly ex vivo and after polyclonal stimulation (pattern I) were significantly younger than patients in whom only memory B cell responses were detectable or entirely absent (patterns II and III; p = 0.003). In one patient a conversion to a positive B cell response as measured directly ex vivo and subsequently also after polyclonal stimulation was associated with the development of a clinical relapse. The evaluation of the predictive value of a brain antigen-specific B cell response showed that seven of eight patients (87.5%) with a pattern I response encountered a clinical relapse during the observation period of 10 months, compared to two of five patients (40%) with a pattern II and three of 14 patients (21.4%) with a pattern III response (p = 0.0005; hazard ratio 6.08 (95% confidence interval 1.87-19.77).
CONCLUSIONS:
Our data indicate actively ongoing B cell-mediated immunity against brain antigens in a subset of MS patients that may be causative of clinical relapses and provide new diagnostic and therapeutic options for a subset of patients.
B cell aggregates in the central nervous system (CNS) have been associated with rapid disease progression in patients with multiple sclerosis (MS). Here we demonstrate a key role of carcinoembryogenic antigen-related cell adhesion molecule1 (CEACAM1) in B cell aggregate formation in MS patients and a B cell-dependent mouse model of MS. CEACAM1 expression was increased on peripheral blood B cells and CEACAM1\(^+\) B cells were present in brain infiltrates of MS patients. Administration of the anti-CEACAM1 antibody T84.1 was efficient in blocking aggregation of B cells derived from MS patients. Along these lines, application of the monoclonal anti-CEACAM1 antibody mCC1 was able to inhibit CNS B cell aggregate formation and significantly attenuated established MS-like disease in mice in the absence of any adverse effects. CEACAM1 was co-expressed with the regulator molecule T cell immunoglobulin and mucin domain −3 (TIM-3) on B cells, a novel molecule that has recently been described to induce anergy in T cells. Interestingly, elevated coexpression on B cells coincided with an autoreactive T helper cell phenotype in MS patients. Overall, these data identify CEACAM1 as a clinically highly interesting target in MS pathogenesis and open new therapeutic avenues for the treatment of the disease.
Cell-permeant recombinant Nanog protein promotes pluripotency by inhibiting endodermal specification
(2014)
A comprehensive understanding of the functional network of transcription factors establishing and maintaining pluripotency is key for the development of biomedical applications of stem cells. Nanog plays an important role in early development and is essential to induce natural pluripotency in embryonic stem cells (ESCs). Inducible gain-of-function systems allowing a precise control over time and dosage of Nanog activity would be highly desirable to study its vital role in the establishment and maintenance of pluripotency at molecular level. Here we engineered a recombinant cell permeable version of Nanog by fusing it with the cell penetrating peptide TAT. Nanog-TAT can be readily expressed in and purified from E. coli and binds to a consensus Nanog DNA sequence. At cellular level it enhances proliferation and self-renewal of ESCs in the absence of leukemia inhibitory factor (LIF). Nanog-TAT together with LIF acts synergistically as judged by enhanced clonogenicity and activation of an Oct4-promoter-driven GFP reporter gene. Furthermore Nanog-TAT, in the absence of LIF, promotes pluripotency by inhibiting endodermal specification in a Stat3-independent manner. Our results demonstrate that Nanog protein transduction is an attractive tool allowing control over dose and time of addition to the cells for studying the molecular control of pluripotency without genetic manipulation.
BACKGROUND:
Oct4 is a transcription factor that plays a major role for the preservation of the pluripotent state in embryonic stem cells as well as for efficient reprogramming of somatic cells to induced pluripotent stem cells (iPSC) or other progenitors. Protein-based reprogramming methods mainly rely on the addition of a fused cell penetrating peptide. This study describes that Oct4 inherently carries a protein transduction domain, which can translocate into human and mouse cells.
RESULTS:
A 16 amino acid peptide representing the third helix of the human Oct4 homeodomain, referred to as Oct4 protein transduction domain (Oct4-PTD), can internalize in mammalian cells upon conjugation to a fluorescence moiety thereby acting as a cell penetrating peptide (CPP). The cellular distribution of Oct4-PTD shows diffuse cytosolic and nuclear staining, whereas penetratin is strictly localized to a punctuate pattern in the cytoplasm. By using a Cre/loxP-based reporter system, we show that this peptide also drives translocation of a functionally active Oct4-PTD-Cre-fusion protein. We further provide evidence for translocation of full length Oct4 into human and mouse cell lines without the addition of any kind of cationic fusion tag. Finally, physico-chemical properties of the novel CPP are characterized, showing that in contrast to penetratin a helical structure of Oct4-PTD is only observed if the FITC label is present on the N-terminus of the peptide.
CONCLUSIONS:
Oct4 is a key transcription factor in stem cell research and cellular reprogramming. Since it has been shown that recombinant Oct4 fused to a cationic fusion tag can drive generation of iPSCs, our finding might contribute to further development of protein-based methods to generate iPSCs. Moreover, our data support the idea that transcription factors might be part of an alternative paracrine signalling pathway, where the proteins are transferred to neighbouring cells thereby actively changing the behaviour of the recipient cell.
Most humans become infected with human cytomegalovirus (HCMV). Typically, the immune system controls the infection, but the virus persists and can reactivate in states of immunodeficiency. While substantial information is available on the contribution of CD8 T cells and antibodies to anti-HCMV immunity, studies of the T\(_{H}\)1, T\(_{H}\)2, and T\(_{H}\)17 subsets have been limited by the low frequency of HCMV-specific CD4 T cells in peripheral blood mononuclear cell (PBMC). Using the enzyme-linked Immunospot\(^{®}\) assay (ELISPOT) that excels in low frequency measurements, we have established these in a sizable cohort of healthy HCMV controllers. Cytokine recall responses were seen in all seropositive donors. Specifically, interferon (IFN)-\({\gamma}\) and/or interleukin (IL)-17 were seen in isolation or with IL-4 in all test subjects. IL-4 recall did not occur in isolation. While the ratios of T\(_{H}\)1, T\(_{H}\)2, and T\(_{H}\)17 cells exhibited substantial variations between different individuals these ratios and the frequencies were relatively stable when tested in samples drawn up to five years apart. IFN-\({\gamma}\) and IL-2 co-expressing polyfunctional cells were seen in most subjects. Around half of the HCMV-specific CD4 cells were in a reversible state of exhaustion. The data provided here established the T\(_{H}\)1, T\(_{H}\)2, and T\(_{H}\)17 characteristic of the CD4 cells that convey immune protection for successful immune surveillance against which reactivity can be compared when the immune surveillance of HCMV fails.
Prolongierte Ischämieperioden des Herzens führen zu struktureller Schädigung der Kardiomyozyten, d.h. einer Desorganisation und Zerstörung des kontraktilen und plasmalemmalen Zytoskeletts, welche sich final durch Verlust an Kontraktilität und Ruptur der Plasmamembran manifestieren. Stressproteine können an die Komponenten des Zytoskelettes binden und durch Konformationsschutz der ischämischen Schädigung entgegenwirken. In vorangegangenen Untersuchungen wurde gezeigt, dass es unter Ischämie zu einer Translokation des konstitutiv in hoher Konzentration vorkommenden kardialen Stressproteins aB-Crystallin vom Zytosol an die Myofibrillen kommt. Dabei führen bereits kurzdauernde Ischämieperioden zu einer kompletten Umverteilung von aB-Crystallin in die Z/I-Region des Sarkomers. Es war das Ziel dieser Arbeit, diese Bindung von aB-Crystallin an Strukturproteine im Z/I-Banden Bereich näher zu charakterisieren und aB-Crystallin ultrastrukturell zu lokalisieren. Durch Immunogoldmarkierung konnte aB-Crystallin ultrastrukturell im Herzen unter globaler Ischämie in einer Linie parallel zur Z-Scheibe etwa in der Mitte der halben I-Bande lokalisiert werden. Diese Zone entspricht dem Bereich, der als N-Linie bezeichnet wird. In der Frage der in vivo-Bindungspartner von aB-Crystallin waren daher in erster Linie Komponenten der I-Bande, d.h. Aktin und Titin in Betracht zu ziehen. Z-Scheiben Proteine wie a-Actinin treten dagegen in den Hintergrund. Um Anhaltspunkte über die Bindungsstärke des Stressproteins aB-Crystallin an kardiale Myofibrillen unter Ischämie zu erhalten, wurden ischämische Myofibrillen aus dem Rattenherz mit hochmolaren Salzlösungen und chaotropen Substanzen behandelt. Dabei konnte eine sehr hohe Bindungsaffinität von aB-Crystallin an die Myofibrillen festgestellt werden. Die myofibrilläre Bindung zeigte sich resistent gegenüber 1M KCl, 1M NaSCN und 2M Harnstoff, erst 2M NaSCN und 4M Harnstoff, die eine Zerstörung der myofibrillären Integrität bewirken, vermögen die aB-Crystallin-Bindung zu lösen. Aktin dagegen ließ sich bereits durch 0,5M NaSCN-Lösung von den Myofibrillen extrahieren, Bedingungen, unter denen aB-Crystallin noch fest an die Myofibrillen gebunden blieb. Aktin scheidet somit als in vivo-Bindungspartner von aB-Crystallin aus. Dieses Ergebnis immunhistochemischer Untersuchungen konnte auch mit biochemischer Methodik (Immunreplikanalyse) verifiziert werden. Titin zeigte sich wie aB-Crystallin resistent gegenüber den meisten der oben aufgeführten Salzlösungen. Eine deutliche Extraktion von Titin aus den Myofibrillen konnte erst durch Behandlung mit 2M NaSCN sowie 4M Harnstofflösung beobachtet werden, das Extraktionsverhalten entsprach somit dem von aB-Crystallin. Einen Hinweis auf eine Assoziation von aB-Crystallin mit Titin lieferte der Nachweis von aB-Crystallin in isolierten Titinfraktionen aus ischämischen Herzen. Der direkte Beweis für eine aB-Crystallin-Titin-Interaktion konnte im Rahmen dieser Arbeit jedoch nicht erbracht werden. Bindungsstudien, die zwischen ausgewählten nativen, in vitro translatierten Titindomänen und aus der Linse isoliertem aB-Crystallin durchgeführt wurden, waren negativ. Dies ist möglicherweise dadurch bedingt, dass aB-Crystallin erst unter Ischämie mit Titin interagiert und in vitro Kofaktoren benötigt werden. Durch eine Bindung an I-Banden Abschnitte des Titinmoleküls könnte aB-Crystallin eine kardioprotektive Funktion erfüllen, indem es unter Ischämie stabilisierend auf das Filamentsystem einwirkt.
Eine familiäre Myopathie und Kardiomyopathie, der eine Missense-Mutation des alpha-B-Crystallin-Gens zugrunde liegt, weist auf eine wichtige Bedeutung des Stressproteins alpha-B-Crystallin im Herzen hin. Die chaperone-ähnlichen Eigenschaften von alpha-B-Crystallin und die unter kardialer Ischämie zu beobachtende schnelle Translokation vom Zytosol an das elastische Titin-Filamentsystem lassen eine protektive Rolle von alpha-B-Crystallin unter Stressbedingungen vermuten. Ziel der vorliegenden Arbeit war es, eine eventuelle kardioprotektive Funktion von alphaB-Crystallin durch die Charakterisierung alpha-B-Crystallin gendeletierter Mäuse nachzuweisen. Wir etablierten hierfür ein Versuchssystem zur Untersuchung der Kontraktilität isolierter Papillarmuskeln im Organbad. Im Rahmen des Aufbaus unseres Versuchssystems untersuchten wir zunächst den Einfluss der Ca2+-Konzentration, der Temperatur und der Kontraktionsbedingungen (Auxotonie vs. Isometrie) auf die Kraft-Frequenz-Beziehung von murinem Myokard. Wir konnten zeigen, dass die Kraft-Frequenz-Beziehung von Myokardpräparaten der Maus von den genannten Versuchsbedingungen abhängig ist. Bei niedrigen Ca2+-Konzentrationen und Temperaturen ([Ca2+] = 1,0 mM, Temp. = 27 °C) ist sie positiv, flacht bei zunehmender Ca2+-Konzentration und Temperatur ab und ist für [Ca2+] = 5,0 mM, Temp. = 37 °C negativ. Auxotone Kontraktionsbedingungen führen im Vergleich zu isometrischen bei gleichen Ca2+-Konzentrationen und Temperaturen zu einem flacheren Verlauf der Kraft-Frequenz-Beziehung. Unter annähernd physiologischen Bedingungen verläuft die Kraft-Frequenz-Beziehung des Mäuse-Myokards flach bis leicht positiv. Im Gegensatz zum Menschen scheinen somit bei der Maus für eine Steigerung des Herz-Zeit-Volumens andere Mechanismen als eine positive Kraft-Frequenz-Beziehung von Bedeutung zu sein. Hierbei ist insbesondere der Frank-Starling-Mechanismus und die sympathoadrenerge Innervation des Herzens zu erwähnen. Zur Charakterisierung der kardialen Funktion von alphaB-Crystallin untersuchten wir die Kontraktilität isolierter Papillarmuskeln von Wildtyp- und alpha-B-Crystallin gendeletierten Mäusen unter simulierter Ischämie (Glucose- und Sauerstoffentzug) und Reperfusion im Organbad. Unter Kontrollbedingungen zeigten sich zwischen wt- und alpha-B-/- Muskeln keine Unterschiede in der Zuckungskraft, der Geschwindigkeit der Kraftentwicklung und der Relaxationszeit. Die während der 20-minütigen simulierten Ischämie entwickelte Kontraktur setzte jedoch bei den alpha-B-/- Muskeln signifikant früher ein und verlief signifikant stärker als bei wt-Muskeln. Nach einer 60-minütigen Reperfusionsphase blieb die Kontraktur der alpha-B-/- Muskeln im Vergleich zu wt-Muskeln signifikant erhöht. Bezüglich Zuckungskraft, Geschwindigkeit der Kraftentwicklung und Relaxationszeit zeigten sich weder während noch nach simulierter Ischämie deutliche Unterschiede zwischen den Muskeln beider Mäusestämme. Diese Ergebnisse lassen darauf schließen, dass das Fehlen von alpha-B-Crystallin am Gesamtherz nicht zu einer Störung der systolischen Herzfunktion, sondern zu einer eingeschränkten myokardialen Relaxationsfähigkeit unter Ischämie und Reperfusion führen würde. Da alpha-B-Crystallin unter kardialer Ischämie an das elastische Titin-Filamentsystem bindet, könnten die elastischen Eigenschaften des Myokards unter Ischämie durch einen Mangel an alpha-B-Crystallin derart beeinträchtigt werden, dass es zu einer höheren Rigidität der Muskulatur kommt. Eine Funktion von alpha-B-Crystallin im Herzen ist somit möglicherweise die Aufrechterhaltung der elastischen Eigenschaften des Myokards unter kardialer Ischämie und Reperfusion.
Die Blut-Hirn-Schranke reguliert den Transport von Molekülen aus dem Blut in das Gehirn und aus dem Hirngewebe in das Blut. Die Grundlage dieser für den Erhalt der Homöostase im Gehirn wichtigen Schranke bilden zwischen Endothelzellen der Gehirnkapillaren (BCECs) entwickelte, besonders dichte Zonulae Occludentes (Tight Junctions). Viele Krankheiten, zum Beispiel die Multiple Sklerose, gehen mit einer Dysfunktion der BBB einher, die molekularen Grundlagen verschiedener Störungen und damit die Therapiemöglichkeiten sind bisher jedoch oftmals noch unbekannt. Ein grundlegendes Problem der Forschung an der BBB war bislang das Fehlen eines geeigneten immortalisierten in vitro-Modelles zum Verständnis der Differenzierung und Regulierung der Schrankenfunktion. Es gelang nun erstmals, aus murinen BCECs ein solches in vitro-Modell der BBB zu entwickeln, welches wichtige Charakteristika der BBB in vivo aufweist. Zu den Eigenschaften der BBB in vivo zählen allgemein ein hoher transendothelialer elektrischer Widerstand (TER) von bis zu 2000  x cm², die Expression der TJ-Proteine Occludin, Claudin-1, Claudin-3 und Claudin-5 sowie eine geringe Rate transzellulärer Transportvorgänge. Die Entwicklung einer immortalisierten Zelllinie als in vitro-Modell der BBB beinhaltete das Bereitstellen einer möglichst natürlichen Umgebung für die Endothelzellen. Durch Zugabe von Wachstums- und Differenzierungsfaktoren sowie Serumreduktion im Differenzierungsmedium konnte eine dichte Schrankenfunktion induziert werden, welche sich anhand von TER-Messungen nachweisen ließ. Mittels immuncytochemischen und molekularbiologischen Methoden wurde außerdem die Expression verschiedener TJ-Proteine in den immortalisierten BCECs gezeigt. Die Permeabilität der BBB wird durch eine Reihe von Faktoren beeinflusst. So war zu erkennen, dass Glucocorticoide und Insulin die Barrierenfunktion der BBB induzieren und die Zugabe dieser Faktoren die in vitro-Kultivierung von BCECs ermöglicht, ohne dass diese dabei für die BBB in vivo wesentliche Charakteristika verlieren. Diese Ergebnisse stimmen überein mit anderen Studien, denenzufolge für die Induktion und Aufrechterhaltung komplexer Tight Junctions bei kultivierten Endothelzellen Glucocorticoide förderlich sind. Auch klinisch wird dieser Einfluss von Glucocorticoiden bereits genutzt: so konnten im Falle der Multiplen Sklerose Therapieerfolge durch die Gabe von Corticosteroiden erzielt werden.
Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) ist ein multifunktionales Zell-Zell Adhäsionsprotein, das in eine Vielzahl an zellulären Prozessen involviert ist, wie zum Beispiel der Differenzierung von Geweben, der Tumorsuppression, Metastasierung, Angiogenese und Apoptose. Außerdem hat es modulierende Eigenschaften auf die angeborene und erworbene Immunantwort. In der vorliegenden Arbeit charakterisierte ich initial die Lokalisation und die CEACAM1-exprimierenden Zelltypen im Auge und bestimmte quantitativ die Expression von Ceacam1 in der Retina und Choroidea zu unterschiedlichen Zeitpunkten.
Es zeigte sich hierbei, dass Ceacam1 zu allen untersuchten Zeitpunkten, sowohl während der Entwicklung als auch im adulten retinalen und choroidalen Gewebe nachweisbar war. Mittels Immunhistochemie konnte die Expression von CEACAM1 im Corneaepithel, den Gefäßen der Iris und des Ziliarkörpers, im nicht-pigmentierten Epithel des Ziliarkörpers, sowie in den retinalen und choroidalen Gefäßen nachgewiesen werden. Durch Doppelfärbung mit Kollagen IV konnte die endotheliale Expression von CEACAM1 in den Endothelzellen der Gefäße bestätigt werden.
Im zweiten Teil meiner Arbeit untersuchte ich die Funktion von CEACAM1 im Auge und verglich dazu wildtypische Retinae mit Cc1-/--Retinae. Es zeigten sich keine offensichtlichen morphologischen Veränderungen der retinalen Schichten und die anschließend durchgeführten morphometrischen Analysen der Schichtdicken der retinalen Neurone zeigte keine Anzeichen einer Neurodegeneration. Allerdings waren in Cc1-/--Retinae kleine Zysten und IBA1 positive, phagozytisch aktive Zellen im subneuroretinalen Raum, also dem Bereich zwischen RPE und den Außensegmenten der Photorezeptoren zu erkennen. Die anschließend durchgeführten Expressionsanalysen immunmodulierender Faktoren und von Mitgliedern des TGF-β-Signalwegs in retinalen und choroidealen Proben wildtypischer und Cc1-/--Mäusen zeigten keine veränderte Expression für Iba1, Ccl2 sowie Tnf-α. Jedoch konnten signifikant erhöhte Werte für TGF-β1 in der Gruppe der 2-4 als auch der Gruppe der 9 Monate alten Cc1-/--Retinae im Vergleich zu wildtypischen Retinae nachgewiesen werden. Basierend auf den Daten der vorliegenden Arbeit kann geschlussfolgert werden, dass die Deletion von CEACAM1 unter physiologischen Bedingungen die Struktur der Retina und Choroidea nicht offensichtlich beeinflusst. Allerdings führt die Deletion zu erhöhten Tgfβ1 Spiegeln in der Retina und zur Aktivierung und Akkumulation von IBA1 positiven Zellen im subneuroretinalen Raum.
The mouse gastro-intestinal and biliary tract mucosal epithelia harbor choline acetyltransferase (ChAT)-positive brush cells with taste cell-like traits. With the aid of two transgenic mouse lines that express green fluorescent protein (EGFP) under the control of the ChAT promoter (EGFP\(^{ChAT}\)) and by using in situ hybridization and immunohistochemistry we found that EGFP\(^{ChAT}\) cells were clustered in the epithelium lining the gastric groove. EGFP\(^{ChAT}\) cells were numerous in the gall bladder and bile duct, and found scattered as solitary cells along the small and large intestine. While all EGFP\(^{ChAT}\) cells were also ChAT-positive, expression of the high-affinity choline transporter (ChT1) was never detected. Except for the proximal colon, EGFP\(^{ChAT}\) cells also lacked detectable expression of the vesicular acetylcholine transporter (VAChT). EGFP\(^{ChAT}\) cells were found to be separate from enteroendocrine cells, however they were all immunoreactive for cytokeratin 18 (CK18), transient receptor potential melastatin-like subtype 5 channel (TRPM5), and for cyclooxygenases 1 (COX1) and 2 (COX2). The ex vivo stimulation of colonic EGFP\(^{ChAT}\) cells with the bitter substance denatonium resulted in a strong increase in intracellular calcium, while in other epithelial cells such an increase was significantly weaker and also timely delayed. Subsequent stimulation with cycloheximide was ineffective in both cell populations. Given their chemical coding and chemosensory properties, EGFP\(^{ChAT}\) brush cells thus may have integrative functions and participate in induction of protective reflexes and inflammatory events by utilizing ACh and prostaglandins for paracrine signaling.
Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and encompasses chronic bronchitis and emphysema. It has been shown that vascular wall remodeling and pulmonary hypertension (PH) can occur not only in patients with COPD but also in smokers with normal lung function, suggesting a causal role for vascular alterations in the development of emphysema. Mechanistically, abnormalities in the vasculature, such as inflammation, endothelial dysfunction, imbalances in cellular apoptosis/proliferation, and increased oxidative/nitrosative stress promote development of PH, cor pulmonale, and most probably pulmonary emphysema. Hypoxemia in the pulmonary chamber modulates the activation of key transcription factors and signaling cascades, which propagates inflammation and infiltration of neutrophils, resulting in vascular remodeling. Endothelial progenitor cells have angiogenesis capabilities, resulting in transdifferentiation of the smooth muscle cells via aberrant activation of several cytokines, growth factors, and chemokines. The vascular endothelium influences the balance between vaso-constriction and -dilation in the heart. Targeting key players affecting the vasculature might help in the development of new treatment strategies for both PH and COPD. The present review aims to summarize current knowledge about vascular alterations and production of reactive oxygen species in COPD. The present review emphasizes on the importance of the vasculature for the usually parenchyma-focused view of the pathobiology of COPD.
Das olfaktorische System ist aufgrund seiner lebenslangen regenerativen Kapazität, seines Reichtums an neurotrophen Faktoren und der relativ guten Zugänglichkeit für Manipulationen ein attraktiver Gegenstand neurobiologischer Forschung. In der vorliegenden Arbeit wurde die Lokalisation und mögliche Funktion des ziliären neurotrophen Faktors (CNTF) in der primären Geruchsbahn mit Hilfe immunhistochemischer Methoden untersucht. Es konnte gezeigt werden, dass die CNTF-Ir bei Ratten und Mäusen in den olfaktorischen Gliazellen (Ensheathingzellen) lokalisiert ist. Elektronenmikroskopische Aufnahmen belegten ein zytoplasmatisches und nukleäres Vorkommen der CNTF-Ir innerhalb der EC. Ein neues und überraschendes Ergebnis der Arbeit ist, dass CNTF in individuellen olfaktorischen Neuronen vorkommt. Bislang wurde CNTF lediglich in Gliazellen des zentralen und peripheren Nervensystems nachgewiesen. Die weitere Charakterisierung der epithelialen CNTF-ir Neurone kennzeichnete diese als reife olfaktorische Nervenzellen. Die CNTF-Ir war mit dem olfaktorischen Markerprotein (OMP) kolokalisiert, einem Marker ausschließlich reifer ON und wies keine Kolokalisation mit dem Growth associated protein 43 (GAP-43) auf, dessen Expression unreife Riechsinneszellen kennzeichnet. CNTF könnte einerseits an lebenslang fortwährenden De- und/oder Regenerationsvorgängen des olfaktorischen Epithels beteiligt sein. Die Exposition der Riechschleimhaut gegenüber infektiösen, physikalischen und chemischen Noxen bedingt den ständigen Verlust olfaktorischer Neurone und deren lebenslange Regeneration aus neuronalen Vorläuferzellen im olfaktorischen Epithel. Die Zellkerne CNTF-ir ON wiesen in der Mehrzahl keine degenerativen Veränderungen wie Kondensierung und Fragmentierung auf, wie es bei geschädigten und untergehenden Zellen beobachtet wird. Im olfaktorischen Epithel zeigte sich des weiteren keine neuronale Kolokalisation von CNTF mit der aktivierten Caspase-3, einem Exekutorenzym der Apoptose, wie man es bei apoptotisch degenerierenden Neuronen findet. Nach Läsionen des olfaktorischen Epithels von Mäusen, die nekrotische Zelluntergänge auslösen, konnte kein gesteigertes Vorkommen von CNTF-ir ON gezeigt werden. Eine Einbindung von CNTF in die Mechanismen neuronaler Degeneration erscheint nach den Ergebnissen verschiedener Experimente wenig wahrscheinlich. Eine zweite Erklärung für das individuelle neuronale Auftreten der CNTF-Ir bot die Annahme, dass CNTF mit der Expression olfaktorischer Rezeptorproteine vergesellschaftet sein könnte. Dreidimensionale Rekonstruktionen von Paaren von BO bei Ratten und Mäusen zeigte, dass die Axone CNTF-ir ON in Glomeruli olfactorii projizierten, die bilateralsymmetrisch in beiden BO eines Tieres lokalisiert waren. Diese Symmetrie findet man ebenfalls bei den Projektionen der ON, die das gleiche olfaktorische Rezeptorprotein exprimieren. Die Lokalisation der CNTF-ir innervierten Glomeruli war interindividuell ähnlich, ihre Anzahl wies jedoch erhebliche Unterschiede auf. Dieses Phänomen lässt sich mit Befunden vergleichen, die im Rahmen von olfaktorischen Aktivitätsstudien bei Mäusen und Ratten erhoben wurden. Dabei beobachtete man eine Erhöhung der Anzahl aktivierter Glomeruli mit steigenden Geruchsstoffkonzentrationen. Auffallend war eine deutliche Übereinstimmung des Verteilungsmusters der CNTF-ir Glomeruli mit dem in der Literatur dargestellten Verteilungsmuster von Glomeruli, die durch Uringerüche aktiviert werden. Die räumliche Rekonstruktion der BO und die Darstellung der Position der CNTF-ir innervierten Glomeruli legt demnach eine neue mögliche Funktion von CNTF im olfaktorischen System nah: dessen Einbindung in Phänomene der Aktivität olfaktorischer Nervenzellen und plastischer Prozesse, die an der ersten Synapse der Geruchsbahn stattfinden. In der vorliegenden Arbeit konnte durch die Anwendung von klassischen Methoden der anatomisch-histologischen Forschung die Lokalisation von CNTF in der primären Geruchsbahn geklärt werden. Die Befunde führten zu weiteren Hypothesen hinsichtlich seiner funktionellen Einbindung in die olfaktorische Informationsverarbeitung, denen in zukünftigen Studien nachgegangen werden wird.
Combined pulmonary fibrosis and emphysema (CPFE) is a recently recognized syndrome that, as its name indicates, involves the existence of both interstitial lung fibrosis and emphysema in one individual, and is often accompanied by pulmonary hypertension. This debilitating, progressive condition is most often encountered in males with an extensive smoking history, and is presented by dyspnea, preserved lung volumes, and contrastingly impaired gas exchange capacity. The diagnosis of the disease is based on computed tomography imaging, demonstrating the coexistence of emphysema and interstitial fibrosis in the lungs, which might be of various types and extents, in different areas of the lung and several relative positions to each other. CPFE bears high mortality and to date, specific and efficient treatment options do not exist. In this review, we will summarize current knowledge about the clinical attributes and manifestations of CPFE. Moreover, we will focus on pathophysiological and pathohistological lung phenomena and suspected etiological factors of this disease. Finally, since there is a paucity of preclinical research performed for this particular lung pathology, we will review existing animal studies and provide suggestions for the development of additional in vivo models of CPFE syndrome.
Structural peculiarities of the S'-end segments of genomic RNA were studied in F potato virus (F-PV) and white clover mosaic virus (WCMV). The methods of affinity chromatography on oligo(dT) cellulose and oligonucleotide mapping revealed a prolonged (up to 210 nucleotides) polyadenyl sequence at the 3'-end of F-PV RNA. A polyadenyl sequence is missing at the 3'end of WCMV RNA. A study of the translation products of WCMV and F-PV RNAs in a oe11-free protein-synthesizing system derived from rabbit reticulocytes showed that polypeptides electrophoretically comigrating with a structural protein of either virus were synthesized alongside high-molecular-weight polypeptides (M\(_r\)\(\approx\) 180-150 kdaltons).
Contribution of adventitia-derived stem and progenitor cells to new vessel formation in tumors
(2021)
Blocking tumor vascularization has not yet come to fruition to the extent it was hoped for, as angiogenesis inhibitors have shown only partial success in the clinic. We hypothesized that under- appreciated vascular wall-resident stem and progenitor cells (VW-SPCs) might be involved in tumor vascularization and influence effectiveness of anti-angiogenic therapy. Indeed, in patient samples, we observed that vascular adventitia-resident CD34\(^+\) VW-SPCs are recruited to tumors in situ from co-opted vessels. To elucidate this in detail, we established an ex vivo model using concomitant embedding of multi-cellular tumor spheroids (MCTS) and mouse aortic rings (ARs) into collagen
gels, similar to the so-called aortic ring assay (ARA). Moreover, ARA was modified by removing the ARs’ adventitia that harbors VW-SPCs. Thus, this model enabled distinguishing the contribution of VW-SPCs from that of mature endothelial cells (ECs) to new vessel formation. Our results show that the formation of capillary-like sprouts is considerably delayed, and their number and network formation were significantly reduced by removing the adventitia. Substituting iPSC-derived neural spheroids for MCTS resulted in distinct sprouting patterns that were also strongly influenced by the
presence or absence of VW-SPCs, also underlying the involvement of these cells in non-pathological vascularization. Our data suggest that more comprehensive approaches are needed in order to block all of the mechanisms contributing to tumor vascularization.
Ongoing research to fight cancer, one of the dominant diseases of the 21st century has led to big progress especially when it comes to understanding the tumor growth and metastasis. This includes the discovery of the molecular mechanisms of tumor vascularization, which is critically required for establishment of tumor metastasis.
Formation of new blood vessels is the first step in tumor vascularization. Therefore, understanding the molecular and cellular basis of tumor vascularization attracted a significant effort studying in biomedical research. The blood vessels for supplying tumor can be formed by sprouting from pre-existing vessels, a process called angiogenesis, or by vasculogenesis, that is de novo formation of blood vessels from not fully differentiated progenitor cell populations. Vasculogenic endothelial progenitor cells (EPCs) can either be activated from populations in the bone marrow reaching the pathological region via the circulation or they can be recruited from local reservoirs. Neovessel formation influences tumor progression, hence therapeutic response model systems of angiogenesis/vasculogenesis are necessary to study the underlying mechanisms. Although, initially the research in this area focused more on angiogenesis, it is now well understood that both angiogenesis and postnatal vasculogenesis contribute to neovessel formation in adult under both most pathological as well as physiological conditions. Studies in the last two decades demonstrate that in addition to the intimal layer of fully differentiated mature endothelial cells (ECs) and various smaller supplying vessels (vasa vasorum) that can serve as a source for new vessels by angiogenesis, especially the adventitia of large and medium size blood vessels harbors various vascular wall-resident stem and progenitor cells (VW-SPCs) populations that serve as a source for new vessels by postnatal vasculogenesis. However, little is known about the potential role of VW-SPCs in tumor vascularization.
To this end, the present work started first to establish a modified aortic ring assay (ARA) using mouse aorta in order to study the contribution of vascular adventitia-resident VW-SPCs to neovascularization in general and in presence of tumor cells. ARA is already established an ex vivo model for neovascularization allows to study the morphogenetic events of complex new vessel formation that includes all layers of mature blood vessels, a significant advantage over the assays that employ monolayer endothelial cell cultures. Moreover, in contrast to assays employing endothelial cells monocultures, both angiogenic and vasculogenic events take place during new vessel formation in ARA although the exact contribution of these two processes to new vessel formation cannot be easily distinguished in conventional ARA. Thus, in this study, a modified protocol for the ARA (mdARA) was established by either removing or keeping the aortic adventitia in place. The mdARA allows to distinguish the role of VW-SPCs from those of other aortic layers. The present data show that angiogenic sprouting from mature aortic endothelium was markedly delayed when the adventitial layer was removed. Furthermore, the network between the capillary-like sprouts was significantly reduced in absence of aortic adventitia. Moreover, the stabilization of new sprouts by assembling the NG2+ pericyte-like cells that enwrapped the endothelial sprouts from the outside was improved when the adventitial layer remained in place.
Next, mimicking the tumor-vessel adventitia-interaction, multicellular tumor spheroids (MCTS) and aortic rings (ARs) with or without adventitia of C57BL/6-Tg (UBC-GFP) mice were confronted within the collagen gel and cultured ex vivo. This 3D model enabled analysis of the mobilization, migration and capillary-like sprouts formation by VW-SPCs within tumor-vessel wall-interface in comparison to tumor-free side of the ARs. Interestingly, while MCTS preferred the uptake of single vascular adventitia-derived cells, neural spheroids were directly penetrated by capillary-like structures that were sprouted from the aortic adventitia. In summary, the model established in this work allows to study new vessel formation by both postnatal vasculogenesis and angiogenesis under same conditions. It can be applied in various mouse models including reporter mouse models, e.g. Cxcr1 CreER+/mTmG+/- mice, in which GFP-marked macrophages of the vessel wall were directly observed as they mobilized from their niche and migrated into collagen gel. Another benefit of the model is that it can be used for testing different factors such as small molecules, growth factors, cytokines, and drugs with both pro- and anti-angiogenic/vasculogenic effects.
BACKGROUND:
The etiology of multiple sclerosis (MS) has remained unclear, but a causative contribution of factors outside the central nervous system (CNS) is conceivable. It was recently suggested that gut bacteria trigger the activation of CNS-reactive T cells and the development of demyelinative disease.
METHODS:
C57BL/6 (B6) mice were kept either under specific pathogen free or conventional housing conditions, immunized with the myelin basic protein (MBP)-proteolipid protein (PLP) fusion protein MP4 and the development of EAE was clinically monitored. The germinal center size of the Peyer's patches was determined by immunohistochemistry in addition to the level of total IgG secretion which was assessed by ELISPOT. ELISPOT assays were also used to measure MP4-specific T cell and B cell responses in the Peyer's patches and the spleen. Ear swelling assays were performed to determine the extent of delayed-type hypersensitivity reactions in specific pathogen free and conventionally housed mice.
RESULTS:
In B6 mice that were actively immunized with MP4 and kept under conventional housing conditions clinical disease was significantly attenuated compared to specific pathogen free mice. Conventionally housed mice displayed increased levels of IgG secretion in the Peyer's patches, while the germinal center formation in the gut and the MP4-specific TH17 response in the spleen were diminished after immunization. Accordingly, these mice displayed an attenuated delayed type hypersensitivity (DTH) reaction in ear swelling assays.
CONCLUSIONS:
The data corroborate the notion that housing conditions play a substantial role in the induction of murine EAE and suggest that the presence of gut bacteria might be associated with a decreased immune response to antigens of lower affinity. This concept could be of importance for MS and calls for caution when considering the therapeutic approach to treat patients with antibiotics."
Arrhythmogenic cardiomyopathy (ACM) is characterized by fibro-fatty replacement of the myocardium, heart failure and life-threatening ventricular arrhythmias. Causal mutations were identified in genes encoding for proteins of the desmosomes, predominantly plakophilin-2 (PKP2) and desmoglein-2 (DSG2). We generated gene-edited knock-out iPSC lines for PKP2 (JMUi001-A-2) and DSG2 (JMUi001-A-3) using the CRISPR/Cas9 system in a healthy control iPSC background (JMUi001A). Stem cell-like morphology, robust expression of pluripotency markers, embryoid body formation and normal karyotypes confirmed the generation of high quality iPSCs to provide a novel isogenic human in vitro model system mimicking ACM when differentiated into cardiomyocytes.
Megakaryocytes (MKs) release platelets into the lumen of bone marrow (BM) sinusoids while remaining to reside within the BM. The morphogenetic events of this complex process are still not fully understood. We combined confocal laser scanning microscopy with transmission and serial block-face scanning electron microscopy followed by 3D-reconstruction on mouse BM tissue sections. These analyses revealed that MKs in close vicinity to BM sinusoid (BMS) wall first induce the lateral retraction of CXCL12-abundant reticular (CAR) cells (CAR), followed by basal lamina (BL) degradation enabling direct MK-sinusoidal endothelial cells (SECs) interaction. Subsequently, an endothelial engulfment starts that contains a large MK protrusion. Then, MK protrusions penetrate the SEC, transmigrate into the BMS lumen and form proplatelets that are in direct contact to the SEC surface. Furthermore, such processes are induced on several sites, as observed by 3D reconstructions. Our data demonstrate that MKs in interaction with CAR-cells actively induce BMS wall alterations, including CAR-cell retraction, BL degradation, and SEC engulfment containing a large MK protrusion. This results in SEC penetration enabling the migration of MK protrusion into the BMS lumen where proplatelets that are adherent to the luminal SEC surface are formed and contribute to platelet release into the blood circulation.
Voltage-gated calcium channels (VGCCs) are widely distributed within the central nervous system (CNS) and presumed to play an important role in the pathophysiology of a broad spectrum of CNS disorders including Alzheimer’s and Parkinson’s disease as well as multiple sclerosis. Several calcium channel blockers have been in clinical practice for many years so that their toxicity and side effects are well studied. However, these drugs are primarily used for the treatment of cardiovascular diseases and most if not all effects on brain functions are secondary to peripheral effects on blood pressure and circulation. While the use of calcium channel antagonists for the treatment of CNS diseases therefore still heavily depends on the development of novel strategies to specifically target different channels and channel subunits, this review is meant to provide an impulse to further emphasize the importance of future research towards this goal.
Bei der Multiplen Sklerose (MS) handelt es sich um eine Autoimmunerkrankung des zentralen Nervensystems (ZNS). Abhängig von der betroffenen ZNS-Region kann es zu vielfältigen Symptomen kommen. Neben neurologischen Symptomen verursacht durch ZNS-Läsionen leidet ein Großteil der MS-Patienten auch unter gastrointestinalen Funktionsstörungen. Diese gastrointestinalen Symptome wurden bisher eher auf Läsionen im Rückenmark zurückgeführt und nicht direkt in Verbindung mit der autoimmunen Ätiologie der Erkrankung gebracht.
In dieser Studie wurde das enterische Nervensystem (ENS) in einem B-Zell- und Antikörper-abhängigen Mausmodell der MS untersucht. Dafür wurde der Autoimmunprozess durch Immunisierung mit MP4, einem Fusionsprotein aus dem Myelin-Basischen-Protein (MBP) und dem Proteolipid-Protein (PLP), ausgelöst. Das ZNS und ENS wurden in den unterschiedlichen Erkrankungsstadien immunhistochemisch und elektronenmikroskopisch analysiert. Neben der Immunpathologie des ZNS konnte dabei eine Degeneration des ENS schon vor dem Einsetzen der ersten neurologischen Defizite nachgewiesen werden. Die ENS-Pathologie war antikörper-mediiert und ging einher mit einer verringerten gastrointestinalen Motilität sowie mit einer Gliose und Neurodegeneration des ENS.
Mithilfe von Immunpräzipitation und Massenspektrometrie konnten im ENS vier mögliche Zielstrukturen des Autoimmunprozesses identifiziert werden, was auf sog. epitope spreading hindeutet. Auch im Plasma von MS-Patienten konnten Antikörper gegen drei dieser Antigene nachgewiesen werden. Des Weiteren zeigten sich in Kolon-Resektaten von MS-Patienten erste Ansätze einer Neurodegeneration und Gliose des ENS.
In dieser Studie wurde zum ersten Mal ein direkter Zusammenhang zwischen der Autoimmunreaktion gegen das ZNS und einer simultanen Reaktion gegen das ENS gezeigt. Dies kann einen Paradigmenwechsel im Verständnis der Immunpathogenese der MS anstoßen und neue therapeutische und diagnostische Ansätze initiieren.
Transforming growth factor β (TGFβ) signaling has manifold functions such as regulation of cell growth, differentiation, migration, and apoptosis. Moreover, there is increasing evidence that it also acts in a neuroprotective manner. We recently showed that TGFβ receptor type 2 (Tgfbr2) is upregulated in retinal neurons and Müller cells during retinal degeneration. In this study we investigated if this upregulation of TGFβ signaling would have functional consequences in protecting retinal neurons. To this end, we analyzed the impact of TGFβ signaling on photoreceptor viability using mice with cell type-specific deletion of Tgfbr2 in retinal neurons and Müller cells (Tgfbr2\(_{ΔOC}\)) in combination with a genetic model of photoreceptor degeneration (VPP). We examined retinal morphology and the degree of photoreceptor degeneration, as well as alterations of the retinal transcriptome. In summary, retinal morphology was not altered due to TGFβ signaling deficiency. In contrast, VPP-induced photoreceptor degeneration was drastically exacerbated in double mutant mice (Tgfbr2\(_{ΔOC}\); VPP) by induction of pro-apoptotic genes and dysregulation of the MAP kinase pathway. Therefore, TGFβ signaling in retinal neurons and Müller cells exhibits a neuroprotective effect and might pose promising therapeutic options to attenuate photoreceptor degeneration in humans.
Hintergrund - Die Multiple Sklerose (MS) ist bis heute eine nur teilweise verstandene Autoimmunerkrankung des zentralen Nervensystems (ZNS). Das Tiermodell der experimentellen autoimmunen Enzephalomyelitis (EAE) ermöglicht die Erforschung von Teilaspekten der Pathogenese der MS und kann zur Etablierung von Therapeutika herangezogen werden. Die MP4-abhängige EAE ermöglicht als Mausmodell die gezielte Erforschung der Rolle der B-Zelle als Akteur in der Pathogenese der MS. Diese Dissertation untersuchte den Effekt des S1P1-Rezeptor-Modulators FTY720 (Fingolimod) auf die Immunantwort der autoreaktiven B-Zellen in der Peripherie sowie im ZNS.
Methoden - MP4-immunisierte Mäuse erhielten 50 Tage nach dem EAE-Krankheitsbeginn oral appliziertes FTY720 über einen Zeitraum von 30 Tagen. Die Tiere wurden nach dem Auftreten der Krankheitssymptome täglich klinisch evaluiert. Die MP4-spezifische B-Zell-Immunantwort und die MP4-spezifische humorale Immunreaktion wurden mittels ELISPOT und ELISA ausgewertet. Die Verteilung der T- und B-Zell-Anteile im peripheren Blut der Mäuse sowie die Aufteilung der B-Zell-Subsets in der Milz wurden mittels Durchflusszytometrie quantifiziert. Mittels Immunhistochemie wurden die B- und T-Zell-Ansammlungen im ZNS der Mäuse hinsichtlich ihrer Entwicklung in tertiär lymphatische Organe (TLOs) untersucht.
Ergebnisse - In diesem Versuchsaufbau zeigte FTY720 keine signifikante Verbesserung des klinischen Krankheitsverlaufes der Tiere. Der Anteil von T-Zellen im peripheren Blut der Mäuse war unter der Therapie mit FTY720 signifikant reduziert, während die Anzahl an B-Zellen nicht-signifikant beeinflusst wurde. Bei der Untersuchung der B-Zell-Subtypen in der Milz fiel zunächst ein erhöhter Anteil an B220+-B-Zellen auf, während die Verteilung der weiteren Subsets nicht-signifikant verändert war. Unter der Therapie mit FTY720 zeigte sich keine Reduktion bereits etablierter B-Zell-Aggregate im ZNS, allerdings ist eine inhibierte Entwicklung in TLOs zu diskutieren.
Zusammenfassung - Diese Arbeit impliziert unterschiedliche Effekte von FTY720 auf die B-Zellen in einem B-Zell-abhängigen chronischen Mausmodell der MS.
In dieser Dissertation wurden murine Aorta-Explantate im experimentellen Ansatz des "Aortic Ring Assay" über elf Tage kultiviert, erstmalig die Differenzierung zu F4/80(+)-Makrophagen gezeigt und eine nahezu vollständige Depletion dieser Zellen durch Clodronat-Liposomen bewirkt. Diese Adventitia-generierten Makrophagen wurden als die Hauptquelle des lokal gebildeten VEGF nachgewiesen. Die daraus resultierende Depletion des parakrin wirkenden VEGF resultierte in einer teilweisen Konservierung der CD34(+) „Vaskulogenen Zone“ der aortalen Adventitia. Zu der Bestätigung dieser Ergebnisse wurde experimentell über den VEGF-Rezeptor-Blocker E7080 in das VEGF-VEGFR-2 System eingegriffen. Die Versuchsansätze mit diesem Rezeptorblocker resultierten in einem ähnlichen Ergebnis wie die Versuche unter Makrophagen-Depletion.
Die MP4-induzierte experimentelle autoimmune Encephalomyelitis (EAE) erlaubt eine fokussierte Betrachtung von B-Zellen, die eine wichtige Rolle bei der Pathogenese der Multiplen Sklerose (MS) spielen. Es konnte zum Beispiel gezeigt werden, dass das Vorhandensein von B-Zell-Aggregaten im zentralen Nervensystem (ZNS) von MS-Patienten mit einem aggravierten Krankheitsverlauf assoziiert war. Diese Follikel könnten dabei als ektope lymphatische Strukturen den Immunprozess aktiv gestalten und somit ein therapeutisches Ziel darstellen. In der vorliegenden Studie wurde der Effekt des Sphingosin-1-Phosphat-Rezeptor-Modulators Fingolimod (FTY720) auf die autoreaktive B-Zell-Antwort und speziell die Bildung von B-Zell-Aggregaten im Kleinhirn der MP4-EAE-Mäuse untersucht.