Small extracellular vesicles obtained from hypoxic mesenchymal stromal cells have unique characteristics that promote cerebral angiogenesis, brain remodeling and neurological recovery after focal cerebral ischemia in mice

• Published in: Basic research in cardiology Vol. 116; no. 1; p. 40
• Main Authors: Gregorius, Jonas, Wang, Chen, Stambouli, Oumaima, Hussner, Tanja, Qi, Yachao, Tertel, Tobias, Börger, Verena, Mohamud Yusuf, Ayan, Hagemann, Nina, Yin, Dongpei, Dittrich, Robin, Mouloud, Yanis, Mairinger, Fabian D., Magraoui, Fouzi El, Popa-Wagner, Aurel, Kleinschnitz, Christoph, Doeppner, Thorsten R., Gunzer, Matthias, Meyer, Helmut E., Giebel, Bernd, Hermann, Dirk M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-12-2021; Springer Nature B.V
• Subjects: Actin; Adhesion; Angiogenesis; Angiogenic Proteins - genetics; Angiogenic Proteins - metabolism; Animals; Atrophy; Brain; Brain - blood supply; Cardiology; Cell Hypoxia; Cell Movement; Cell Proliferation; Cells, Cultured; Cerebral blood flow; Cytoskeleton; Degeneration; Disease Models, Animal; Endothelial cells; Endothelial Cells - metabolism; Extracellular matrix; Extracellular vesicles; Extracellular Vesicles - metabolism; Extracellular Vesicles - transplantation; Humans; Hypoxia; Infarction, Middle Cerebral Artery - metabolism; Infarction, Middle Cerebral Artery - physiopathology; Infarction, Middle Cerebral Artery - surgery; Ischemia; Leukocyte migration; Leukocytes; Leukocytes (neutrophilic); Leukocytes (polymorphonuclear); Light sheets; Male; Medicine; Medicine & Public Health; Mesenchymal stem cells; Mesenchymal Stem Cells - metabolism; Mesenchyme; Metabolic pathways; Mice; Mice, Inbred C57BL; MicroRNAs - genetics; MicroRNAs - metabolism; Microvasculature; Microvessels - metabolism; Microvessels - physiopathology; Neovascularization, Physiologic; Neurodegeneration; Neurons - metabolism; Neurons - pathology; Occlusion; Original Contribution; Preconditioning; Proteins; Receptors; Recovery; Recovery of Function; Signal Transduction; Stromal cells; Time Factors; Vascular Remodeling; Vesicles; Neuronal survival; Microvascular network characteristics; Tube formation; Microvascular remodeling; Polymorphonuclear neutrophil; Endothelial migration
• ISSN: 0300-8428; 1435-1803
• DOI: 10.1007/s00395-021-00881-9

Obtained from the right cell-type, mesenchymal stromal cell (MSC)-derived small extracellular vesicles (sEVs) promote stroke recovery. Within this process, microvascular remodeling plays a central role. Herein, we evaluated the effects of MSC-sEVs on the proliferation, migration, and tube formation of human cerebral microvascular endothelial cells (hCMEC/D3) in vitro and on post-ischemic angiogenesis, brain remodeling and neurological recovery after middle cerebral artery occlusion (MCAO) in mice. In vitro, sEVs obtained from hypoxic (1% O
2
), but not ‘normoxic’ (21% O
2
) MSCs dose-dependently promoted endothelial proliferation, migration, and tube formation and increased post-ischemic endothelial survival. sEVs from hypoxic MSCs regulated a distinct set of miRNAs in hCMEC/D3 cells previously linked to angiogenesis, three being upregulated (miR-126-3p, miR-140-5p, let-7c-5p) and three downregulated (miR-186-5p, miR-370-3p, miR-409-3p). LC/MS–MS revealed 52 proteins differentially abundant in sEVs from hypoxic and ‘normoxic’ MSCs. 19 proteins were enriched (among them proteins involved in extracellular matrix–receptor interaction, focal adhesion, leukocyte transendothelial migration, protein digestion, and absorption), and 33 proteins reduced (among them proteins associated with metabolic pathways, extracellular matrix–receptor interaction, focal adhesion, and actin cytoskeleton) in hypoxic MSC-sEVs. Post-MCAO, sEVs from hypoxic MSCs increased microvascular length and branching point density in previously ischemic tissue assessed by 3D light sheet microscopy over up to 56 days, reduced delayed neuronal degeneration and brain atrophy, and enhanced neurological recovery. sEV-induced angiogenesis in vivo depended on the presence of polymorphonuclear neutrophils. In neutrophil-depleted mice, MSC-sEVs did not influence microvascular remodeling. sEVs from hypoxic MSCs have distinct angiogenic properties. Hypoxic preconditioning enhances the restorative effects of MSC-sEVs.