Abstract
Cell-based therapies are emerging as potential treatments for neurovascular diseases. Human neural stem cell (hNSC) transplantation, for example, has been applied in ischemic stroke, and is now in clinical trials. As neurons are integrated into the neurovascular unit (NVU) in the central nervous system, the neurological outcome is associated with the functions of neurons within a multicellular complex consisting of neurons, astrocytes, vascular endothelial cells and pericytes, as well as an assortment of growth factors and extracellular matrix (ECM) proteins.The primary purpose of this study was to devise a novel model of neurovascular network formation, using hNSCs and human cerebral microvascular endothelial cells (hCMECs). A distinctive neurovascular cytoarchitecture developed as angiogenic morphogenesis of hCMECs was driven by hNSCs, which were differentiating into neurons, astrocytes, and oligodendrocytes. The reciprocal relationships between hNSCs and hCMECs were disentangled by analysing gene expression in sorted endothelial and neural lineage cell populations, in addition to measurements of soluble factors, distribution of ECM components and receptor mapping. Molecular mechanisms previously reported to underlie typical endothelial cell-mural cell interactions were observed here in the hCMEC/hNSC co-culture. Perivascular hNSCs acted synergistically with endothelium, contributing to endothelial morphogenesis and structure stability. Mechanisms underlying differential angiogenic efficiencies between hNSC lines derived from striatum and cortex were further elucidated with functional blockades of specific signalling pathways, using antiangiogenic agents against receptors for growth factors and ECM molecules.
This single EC/NSC co-culture model displays a unique pattern of multi-stage sequential regulation of the stages of angiogenesis through contact-mediated and soluble factors. The temporal and spatial coordination of the expression and distribution of growth factors and ECM molecules contributes to the cytoarchitectural organisation during the development of neurovascular networks. The results shown here will allow for better informed decisions regarding the optimal timing for intervention, cell dose, and the target site of cell transplantation in order to promote neurovascular network integration in vivo, and potentially improve therapeutic outcomes.
| Date of Award | 1 Oct 2014 |
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| Original language | English |
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| Supervisor | Giovanni Mann (Supervisor) & Brenda Williams (Supervisor) |