In recognition of outstanding contributions to neuroscience, the “Researcher of the Month” jury at the Medical University of Vienna has awarded the November 2025 distinction to Dr. Daniel Bormann for his publication in the high-impact journal Nature Communications (impact factor 15.7), entitled “Single-nucleus RNA sequencing reveals glial cell type-specific responses to ischemic stroke in male rodents” (1).
This multidisciplinary investigation emerged from Dr. Bormann’s doctoral research within the Applied Immunology Laboratory under Univ.-Prof. PD. Dr. Hendrik-Jan Ankersmit at the Department of Thoracic Surgery and the group led by Assoc. Prof. Dr. Michael Mildner at the Department of Dermatology. The project benefited from an international, cross-disciplinary collaboration involving the Division of Neuropathology and Neurochemistry (NPNC) at the Department of Neurology (groups of Univ.-Prof. PD. Dr. Romana Höftberger and Dr. Simon Hametner PhD), the Institute of Neurobiochemistry at the Medical University of Innsbruck (group of Ao.-Prof. Dr. Gabriele Baier-Bitterlich), the VASCage Centre on Clinical Stroke Research and the Department of Neurology (Univ.-Prof. Dr. Stefan Kiechl and Assoz. Prof. Priv.-Doz. Dr. Michael Knoflach), as well as the Experimental Stroke Research Platform at the Blood and Brain Institute of the Université de Caen Normandie (group of Ass. Prof. Dr. Cyrille Orset). Funding support was provided by Aposcience AG through a public-private partnership with the Medical University of Vienna, the Austrian Research Promotion Agency (grants #852748 and #862068), and the Vienna Business Agency (grant #2343727).
Mapping Infarct-Specific Cellular Populations via Single-Cell Resolution
Ischemic strokes remain a leading cause of mortality and long-term disability, arising from vascular occlusion that induces critical oxygen and nutrient deprivation, culminating in irreversible cerebral infarction. Despite extensive efforts, therapeutic strategies to enhance neural tissue regeneration post-infarct are limited, partly due to incomplete knowledge of the intricate cellular dynamics in the injured brain.
Glial cells, including astrocytes and oligodendrocytes, constitute the predominant non-neuronal component of the central nervous system. Prior evidence has established that astrocytes proliferate rapidly and aggregate around the infarct core following cerebral ischemia, though the underlying molecular pathways remain incompletely elucidated. The responses of oligodendrocytes to infarction are even less characterized. In this study, researchers employed two validated rodent models of cerebral infarction to profile gene expression across diverse brain cell populations during the acute phase using single-nucleus RNA sequencing. This approach revealed multiple heterogeneous glial and immune cell subsets that selectively accumulate in the peri-infarct zone.
Notably, oligodendrocyte precursor cells (OPCs) were observed to proliferate 48 hours post-infarct and localize to the infarct border, akin to reactive astrocytes. The transcriptional signatures of these infarct-associated OPCs exhibited substantial overlap with those of reactive astrocytes, including upregulation of genes involved in extracellular matrix remodeling within the damaged cerebral tissue. Comparable transcriptional convergences were identified between mature oligodendrocytes and astrocytes in the infarcted regions.
Resident microglia and infiltrating macrophages also concentrate around the infarct site. Through bioinformatic analyses and immunohistochemical validation, the study implicated these immune cells in secreting osteopontin, a signaling molecule that engages the glycoprotein receptor CD44 on glial cells. CD44 expression was markedly elevated in reactive astrocytes and OPCs within the ischemic tissue. Osteopontin-CD44 interactions are known to promote cell migration across various lineages, and in vitro assays confirmed that osteopontin enhances OPC motility. These findings suggest that microglia and macrophages coordinate glial accumulation at the infarct periphery via the osteopontin-CD44 axis. Delineating such immuno-glial crosstalk advances comprehension of cerebral wound healing post-stroke and may inform novel therapeutic targets.
Scientific Trajectory
Dr. Bormann initiated his research career during his psychology studies in the social psychology group led by Univ.-Prof. Dr. Tobias Greitemeyer at the Institute of Psychology, University of Innsbruck (2).
In the third semester of his medical studies, he continued investigations in the group of Assoc. Prof. PD. Dr. Francisco J. Monje Quiroga at the Division of Neurophysiology and Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, where he completed his diploma thesis. His work during this period focused primarily on the influence of methylxanthines on ictogenesis in the hippocampus (3) and the involvement of the miRNA-132/212 cluster in hippocampal responses to oxygen-glucose deprivation (4). Upon thesis completion, he was admitted to the MD-PhD Excellence Program at the Medical University of Vienna. His doctoral training occurred at the Applied Immunology Laboratory of the Department of Thoracic Surgery (directed by Univ.-Prof. PD. Dr. Hendrik-Jan Ankersmit) and the group of Assoc. Prof. Dr. Michael Mildner at the Department of Dermatology. Throughout his PhD, he examined cerebral cellular reactions to inflammatory stimuli (5) and ischemia (1), emphasizing the molecular diversity of reactive glial and immune cells in the brain and their interactions. For contributions arising from his doctoral work, Dr. Bormann received the Theodor Billroth Prize from the Vienna Medical Academy in 2024.
Biographical Overview
Dr. Daniel Bormann completed a bachelor’s degree in psychology from 2011 to 2014. Following a study period at the Institute of Psychology, University of Freiburg, he transitioned to human medicine at the Medical University of Vienna in 2015 and joined the MD-PhD Excellence Program in 2019. He graduated from medical school in 2021 and conducted research until 2024 at the Applied Immunology Laboratory of the Department of Thoracic Surgery (led by Univ.-Prof. PD. Dr. Hendrik-Jan Ankersmit), the group of Assoc. Prof. Dr. Michael Mildner at the Department of Dermatology, and the Division of Neuropathology and Neurochemistry (NPNC) at the Department of Neurology. Since 2024, he has served as a resident physician at the Department of Neurology.
Selected Publications
- RNA sequencing reveals glial cell type-specific responses to ischemic stroke in male rodents. Nature Communications. 2024;15(1):6232.
- Bormann D, Greitemeyer T. Immersed in Virtual Worlds and Minds: Effects of In-Game Storytelling on Immersion, Need Satisfaction, and Affective Theory of Mind. Social Psychological and Personality Science. 2015;6(6):646-52.
- Cicvaric A, Bulat T, Bormann D, Yang J, Auer B, Milenkovic I, et al. Sustained consumption of cocoa-based dark chocolate enhances seizure-like events in the mouse hippocampus. Food Funct. 2018;9(3):1532-44.
- Bormann D, Stojanovic T, Cicvaric A, Schuld GJ, Cabatic M, Ankersmit HJ, et al. miRNA-132/212 Gene-Deletion Aggravates the Effect of Oxygen-Glucose Deprivation on Synaptic Functions in the Female Mouse Hippocampus. Cells. 2021;10(7).
- Bormann D, Copic D, Klas K, Direder M, Riedl CJ, Testa G, et al. Exploring the heterogeneous transcriptional response of the CNS to systemic LPS and Poly(I:C). Neurobiol Dis. 2023;188:106339.
Contact Information
Dr. Daniel Bormann, BSc, PhD
Medical University of Vienna
Department of Neurology
Währinger Gürtel 18-20
1090 Vienna
Telephone: +43 (0)1 40400-31170
Email: daniel.bormann@meduniwien.ac.at
