Extracellular Vesicles Derived from Neural Progenitor Cells\u2013\u2013a Preclinical Evaluation for Stroke Treatment in Mice

X Zheng,C Lenz,D M Hermann,W.-H Zimmermann,M Bähr,Thorsten R Doeppner,E Kilic,M S Weber,H Urlaub,Y Kuang,K Hein,L Zhang,W Moebius,V Venkataramani,M P Zafeiriou,F Jin

doi:10.1007/s12975-020-00814-z

Abstract

Stem cells such as mesenchymal stem cells (MSCs) enhance neurological recovery in preclinical stroke models by secreting extracellular vesicles (EVs). Since previous reports have focused on the application of MSC-EVs only, the role of the most suitable host cell for EV enrichment and preclinical stroke treatment remains elusive. The present study aimed to evaluate the therapeutic potential of EVs derived from neural progenitor cells (NPCs) following experimental stroke. Using the PEG technique, EVs were enriched and characterized by electron microscopy, proteomics, rt-PCR, nanosight tracking analysis, and Western blotting. Different dosages of NPC-EVs displaying a characteristic profile in size, shape, cargo protein, and non-coding RNA contents were incubated in the presence of cerebral organoids exposed to oxygen-glucose deprivation (OGD), significantly reducing cell injury when compared with control organoids. Systemic administration of NPC-EVs in male C57BL6 mice following experimental ischemia enhanced neurological recovery and neuroregeneration for as long as 3 months. Interestingly, the therapeutic impact of such NPC-EVs was found to be not inferior to MSC-EVs. Flow cytometric analyses of blood and brain samples 7 days post-stroke demonstrated increased blood concentrations of B and T lymphocytes after NPC-EV delivery, without affecting cerebral cell counts. Likewise, a biodistribution analysis after systemic delivery of NPC-EVs revealed the majority of NPC-EVs to be found in extracranial organs such as the liver and the lung. This proof-of-concept study supports the idea of EVs being a general concept of stem cell–induced neuroprotection under stroke conditions, where EVs contribute to reverting the peripheral post-stroke immunosuppression.

Highlights

The systemic transplantation of stem cells such as mesenchymal stem cells (MSCs) and neural progenitor cells (NPCs) promotes neurological recovery, angiogenesis, and neurogenesis in animal models of cerebral ischemia [1,2,3,4,5,6,7]
Western blot analysis for selected extracellular vesicles (EVs) biomarkers revealed that CD63, TSG101, TAPA1, and Alix were present in NPC-EVs obtained from both polyethylene glycol (PEG) enrichment and ultracentrifugation only (Fig. 1a, b)
nanoparticle tracking analysis (NTA) revealed the distribution of NPC-EVs to be in the range of 30 to 300 nm, which is typical of exosomes and microvesicles alike (Fig. 1c)

Summary

Introduction

The systemic transplantation of stem cells such as mesenchymal stem cells (MSCs) and neural progenitor cells (NPCs) promotes neurological recovery, angiogenesis, and neurogenesis in animal models of cerebral ischemia [1,2,3,4,5,6,7]. Bilayer structured vesicles, termed extracellular vesicles (EVs), secreted from eukaryotic cells, including MSCs, have been found to be critical players in the aforementioned process. These EVs have been detected in conditioned medium derived from stem cells [17, 18], further supporting the idea that EVs are biological mediators of stem cell–induced actions under conditions of cerebral ischemia

Methods

Results

Conclusion