Role of neutrophil granulocytes after stroke: mechanisms of brain entry, neutrophil-induced disturbed brain recovery and remodeling

• Applicants: Professor Dr. Matthias Gunzer; Professor Dr. Dirk M. Hermann
• Subject Area: Molecular and Cellular Neurology and Neuropathology ; Immunology
• Term: from 2017 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 389030878

• Final Report Year: 2025

Final Report Abstract

Ischemic stroke is one of the most common causes of death and severe disability in Western countries. Polymorphonuclear neutrophil granulocytes (PMN) play a central role in this process. These immune cells invade the damaged brain tissue at an early stage and have a significant influence on the course of the disease. We were able to show that the integrin very late antigen-4 (VLA4) is crucial for the penetration of PMN across the blood-brain barrier. In the brain, they are partly phagocytized by microglia, which can also have protective effects. However, until now there was no model to investigate how PMNs behave without VLA-4 or how exactly they cause neuronal damage. We have therefore developed a new mouse model that for the first time allows targeted genetic manipulation and fluorescent labeling of PMN in vivo. We were thus pursuing four questions: 1. How do PMN influence microvascular processes such as perfusion, remodeling and angiogenesis (work package 1)? 2. How do they alter neuronal structures and their vitality? What role does microglia play in this process (work-package 2)? 3. What is the function of neutrophil extracellular traps (NETs) in brain damage? What is the effect of their inhibition (work package 3)? 4. How do the molecular signatures of infiltrating PMNs differ from those in the periphery? Can new therapeutic target structures be derived from this (work package 4)? To answer these questions, we used modern methods such as two-photon and light sheet microscopy on optically clarified brains, mass spectrometry and innovative animal models. The aim was to gain a new understanding of PMN-mediated effects in stroke - as a basis for urgently needed new therapeutic approaches.

Publications

• Implications of polymorphonuclear neutrophils for ischemic stroke and intracerebral hemorrhage: Predictive value, pathophysiological consequences and utility as therapeutic target. Journal of Neuroimmunology, 321, 138-143.
  Hermann, Dirk M.; Kleinschnitz, Christoph & Gunzer, Matthias
  
• Contribution of polymorphonuclear neutrophils in the blood periphery to ischemic brain injury. Neurology Neuroimmunology & Neuroinflammation, 6(4).
  Hermann, Dirk M. & Gunzer, Matthias
  
• Polymorphonuclear Neutrophils Play a Decisive Role for Brain Injury and Neurological Recovery Poststroke. Stroke, 50(3).
  Hermann, Dirk M. & Gunzer, Matthias
  
• Homozygous Smpd1 deficiency aggravates brain ischemia/ reperfusion injury by mechanisms involving polymorphonuclear neutrophils, whereas heterozygous Smpd1 deficiency protects against mild focal cerebral ischemia. Basic Research in Cardiology, 115(6).
  Hagemann, Nina; Mohamud Yusuf, Ayan; Martiny, Carlotta; Zhang, Xiaoni; Kleinschnitz, Christoph; Gunzer, Matthias; Kolesnick, Richard; Gulbins, Erich & Hermann, Dirk M.
  
• Mesenchymal Stromal Cell–Derived Small Extracellular Vesicles Induce Ischemic Neuroprotection by Modulating Leukocytes and Specifically Neutrophils. Stroke, 51(6), 1825-1834.
  Wang, Chen; Börger, Verena; Sardari, Maryam; Murke, Florian; Skuljec, Jelena; Pul, Refik; Hagemann, Nina; Dzyubenko, Egor; Dittrich, Robin; Gregorius, Jonas; Hasenberg, Mike; Kleinschnitz, Christoph; Popa-Wagner, Aurel; Doeppner, Thorsten R.; Gunzer, Matthias; Giebel, Bernd & Hermann, Dirk M.
  
• Imaging innate immunity*. Immunological Reviews, 306(1), 293-303.
  Grüneboom, Anika; Aust, Oliver; Cibir, Zülal; Weber, Flora; Hermann, Dirk M. & Gunzer, Matthias
  
• Neutrophil dynamics, plasticity and function in acute neurodegeneration following neonatal hypoxia–ischemia. Brain, Behavior, and Immunity, 92, 232-242.
  Mülling, Kerstin; Fischer, Alexa Josephine; Siakaeva, Elena; Richter, Mathis; Bordbari, Sharareh; Spyra, Ilona; Köster, Christian; Hermann, Dirk M.; Gunzer, Matthias; Felderhoff-Müser, Ursula; Bendix, Ivo; Jablonska, Jadwiga & Herz, Josephine
  
• Platelet endothelial cell adhesion molecule-1 is a gatekeeper of neutrophil transendothelial migration in ischemic stroke. Brain, Behavior, and Immunity, 93, 277-287.
  Winneberger, Jack; Schöls, Sebastian; Lessmann, Katrin; Rández-Garbayo, Javier; Bauer, Alexander T.; Mohamud Yusuf, Ayan; Hermann, Dirk M.; Gunzer, Matthias; Schneider, Stefan W.; Fiehler, Jens; Gerloff, Christian; Gelderblom, Mathias; Ludewig, Peter & Magnus, Tim
  
• Ischemic stroke and concomitant gastrointestinal complications- a fatal combination for patient recovery. Frontiers in Immunology, 13.
  Tuz, Ali A.; Hasenberg, Anja; Hermann, Dirk M.; Gunzer, Matthias & Singh, Vikramjeet
  
• Postischemic Neuroprotection Associated With Anti-Inflammatory Effects by Mesenchymal Stromal Cell-Derived Small Extracellular Vesicles in Aged Mice. Stroke, 53(1).
  Wang, Chen; Börger, Verena; Mohamud Yusuf, Ayan; Tertel, Tobias; Stambouli, Oumaima; Murke, Florian; Freund, Nico; Kleinschnitz, Christoph; Herz, Josephine; Gunzer, Matthias; Popa-Wagner, Aurel; Doeppner, Thorsten R.; Giebel, Bernd & Hermann, Dirk M.
  
• Roles of Polymorphonuclear Neutrophils in Ischemic Brain Injury and Post-Ischemic Brain Remodeling. Frontiers in Immunology, 12.
  Mohamud Yusuf, Ayan; Hagemann, Nina; Ludewig, Peter; Gunzer, Matthias & Hermann, Dirk M.
  
• Neural precursor cell delivery induces acute post-ischemic cerebroprotection, but fails to promote long-term stroke recovery in hyperlipidemic mice due to mechanisms that include pro-inflammatory responses associated with brain hemorrhages. Journal of Neuroinflammation, 20(1).
  Yin, Dongpei; Wang, Chen; Qi, Yachao; Wang, Ya-Chao; Hagemann, Nina; Mohamud Yusuf, Ayan; Dzyubenko, Egor; Kaltwasser, Britta; Tertel, Tobias; Giebel, Bernd; Gunzer, Matthias; Popa-Wagner, Aurel; Doeppner, Thorsten R. & Hermann, Dirk M.
  
• Rapid and fully automated blood vasculature analysis in 3D light-sheet image volumes of different organs. Cell Reports Methods, 3(3), 100436.
  Spangenberg, Philippa; Hagemann, Nina; Squire, Anthony; Förster, Nils; Krauß, Sascha D.; Qi, Yachao; Mohamud Yusuf, Ayan; Wang, Jing; Grüneboom, Anika; Kowitz, Lennart; Korste, Sebastian; Totzeck, Matthias; Cibir, Zülal; Tuz, Ali Ata; Singh, Vikramjeet; Siemes, Devon; Struensee, Laura; Engel, Daniel R.; Ludewig, Peter ... & Mosig, Axel
  
• Arterial specification precedes microvascular restitution in the peri-infarct cortex that is driven by small microvessels. Journal of Cerebral Blood Flow & Metabolism, 45(1), 171-186.
  Hagemann, Nina; Qi, Yachao; Mohamud Yusuf, Ayan; Li, AnRan; Zhang, Xiaoni; Spangenberg, Philippa; Squire, Anthony; Doeppner, Thorsten R.; Jin, Fengyan; Zhao, Shuo; Chen, Jianxu; Mosig, Axel; Gunzer, Matthias & Hermann, Dirk M.
  
• Delayed DNase-I Administration but Not Gasdermin-D Inhibition Induces Hemorrhagic Transformation After Transient Focal Cerebral Ischemia in Mice. Stroke, 55(11).
  Yin, Dongpei; Wang, Chen; Singh, Vikramjeet; Tuz, Ali Ata; Doeppner, Thorsten R.; Gunzer, Matthias & Hermann, Dirk M.
  
• Microvascular Network Remodeling in the Ischemic Mouse Brain Defined by Light Sheet Microscopy. Arteriosclerosis, Thrombosis, and Vascular Biology, 44(4), 915-929.
  Hagemann, Nina; Qi, Yachao; Mohamud Yusuf, Ayan; Li, AnRan; Squire, Anthony; Tertel, Tobias; Giebel, Bernd; Ludewig, Peter; Spangenberg, Philippa; Chen, Jianxu; Mosig, Axel; Gunzer, Matthias & Hermann, Dirk M.
  
• Proteomic Characterization of 1000 Human and Murine Neutrophils Freshly Isolated From Blood and Sites of Sterile Inflammation. Molecular & Cellular Proteomics, 23(11), 100858.
  Ghosh, Susmita; Tuz, Ali Ata; Stenzel, Martin; Singh, Vikramjeet; Richter, Mathis; Soehnlein, Oliver; Lange, Emanuel; Heyer, Robert; Cibir, Zülal; Beer, Alexander; Jung, Marcel; Nagel, Dennis; Hermann, Dirk M.; Hasenberg, Anja; Grüneboom, Anika; Sickmann, Albert & Gunzer, Matthias
  
• Stroke and myocardial infarction induce neutrophil extracellular trap release disrupting lymphoid organ structure and immunoglobulin secretion. Nature Cardiovascular Research, 3(5), 525-540.
  Tuz, Ali A.; Ghosh, Susmita; Karsch, Laura; Ttoouli, Dimitris; Sata, Sai P.; Ulusoy, Özgür; Kraus, Andreas; Hoerenbaum, Nils; Wolf, Jan-Niklas; Lohmann, Sabrina; Zwirnlein, Franziska; Kaygusuz, Viola; Lakovic, Vivian; Tummes, Hannah-Lea; Beer, Alexander; Gallert, Markus; Thiebes, Stephanie; Qefalia, Altea; Cibir, Zülal ... & Singh, Vikramjeet
  
• Hypercholesterolemia triggers innate immune imbalance and transforms brain infarcts after ischemic stroke. Frontiers in Immunology, 15.
  Tuz, Ali Ata; Hoerenbaum, Nils; Ulusoy, Özgür; Ahmadi, Adel; Gerlach, Alana; Beer, Alexander; Kraus, Andreas; Hasenberg, Anja; Hagemann, Nina; Hermann, Dirk M.; Gunzer, Matthias & Singh, Vikramjeet