Endothelial Cells Exposed to Fluid Shear Stress Support Diffusion Based Maturation of Adult Neural Progenitor Cells
The neural stem cell (NSC) niche is a highly complex cellular and biochemical milieu supporting proliferating NSCs and neural progenitor cells (NPCs) with close apposition to the vasculature, primarily comprised of endothelial cells (ECs). Current in vitro models of the niche incorporate EC-derived factors, but do not reflect the physiologically relevant hemodynamic state of the ECs or the spatial resolution observed between cells within the niche.
In this work, we developed a novel in vitro model of the niche that (1) incorporates ECs cultured with fluid shear stress and (2) fosters paracrine cytokine gradients between ECs and NSCs in a spatiotemporal configuration mimicking the cytoarchitecture of the subventricular niche. A modified cone and plate viscometer was used to generate a shear stress of 10 dynes cm−2 for ECs cultured on a membrane, while statically cultured NPCs are 10 or 1000 μm below the ECs.
NPCs cultured within 10 μm of dynamic ECs exhibit increased PSA-NCAM+ and OLIG2+ cells compared to progenitors in all other culture regimes and the hemodynamic EC phenotype results in distinct progeny phenotypes. This co-culture regime yields greater release of pro-neurogenic factors, suggesting a potential mechanism for the observed progenitor maturation.
Based on these results, models incorporating ECs exposed to shear stress allow for paracrine signaling gradients and regulate NPC lineage progression with appropriate niche spatial resolution occurring at 10 μm. This model could be used to evaluate cellular or pharmacological interactions within the healthy, diseased, or aged brain.
KeywordsNeural stem cells Vascular niche Shear stress Neurogenesis Endothelial cells
The authors acknowledge both the Stem Cell Biology and Microscopy Research Cores within the Center for Biotechnology and Interdisciplinary Studies at Rensselaer Polytechnic Institute. Funding was provided by the National Institutes of Health (RO1AG041861-ST), the National Science Foundation (CBET-1350240 - GD), and the New York State Department of Health NYSTEM (C026419 - DMT).
Conflict of interest
Courtney Dumont, Jennifer Piselli, Sally Temple, Guohao Dai, and Deanna Thompson declare that they have no conflicts of interest.
No human studies were carried out by the authors for this article. All animal studies were carried out in accordance with the Institutional Animal Care and Use Committee guidelines at Rensselaer Polytechnic Institute.
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