From Blood to Lesioned Brain: An In Vitro Study on Migration Mechanisms of Human Nasal Olfactory Stem Cells

Figure 1

Migration of human olfactory stem cells through the blood-brain barrier (BBB). (a–f) GFP-positive human OE-MSCs were seeded at two densities (120,000 and 500,000 cells per well) on a BBB model, and their diapedesis was observed 24 hours later. Phase contrast (a) and fluorescent (b) photomicrographs displaying globular OE-MSCs adhering on the external surface of the endothelial cell layer and attached OE-MSCs with processes indicating their localization on the membrane and under the BBB. Scale bar: 100 μm. (c) Anti-Claudin 5 antibody identifies endothelial tight junctions (red). (d) Immunostaining reveals openings in the BBB (white dotted lines) and the integration of two OE-MSCs under the BBB. Scale bar: 10 μm. (e, f) Focus on migrating cells. (e) The sequential plane bars (spaced 0.4 μm), on the top and the right, indicate that the migrating cell (green) is located under the Claudin 5-stained endothelial cells (red). (f) Focus on a GFP-positive OE-MSC during transmigration (white arrowhead) and on another one installed under the BBB (white arrow). (g) One day after seeding, BBB permeability was measured by a Lucifer yellow test. The fluorometric measurement of Lucifer yellow indicates that stem cell increases BBB permeability at both cell densities (). .

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