title: Involvement of PI3K and ROCK signaling pathways in migration of bone marrow-derived mesenchymal stem cells through human brain microvascular endothelial cell monolayers.
abstract: Bone marrow-derived mesenchymal stem cells (MSC) represent an important and easily available source of stem cells for potential therapeutic use in neurological diseases. The entry of circulating cells into the central nervous system by intravenous administration requires, firstly, the passage of the cells across the blood-brain barrier (BBB). However, little is known of the details of MSC transmigration across the BBB. In the present study, we employed an in vitro BBB model constructed using a human brain microvascular endothelial cell monolayer to study the mechanism underlying MSC transendothelial migration. Transmigration assays, transendothelial electrical resistance (TEER) and horseradish peroxidase (HRP) flux assays showed that MSC could transmigrate through human brain microvascular endothelial cell monolayers by a paracellular pathway. Cell fractionation and immunofluorescence assays confirmed the disruption of tight junctions. Inhibition assays showed that a Rho-kinase (ROCK) inhibitor (Y27632) effectively promoted MSC transendothelial migration; conversely, a PI3K inhibitor (LY294002) blocked MSC transendothelial migration. Interestingly, adenovirus-mediated interference with ROCK in MSC significantly increased MSC transendothelial migration, and overexpression of a PI3K dominant negative mutant in MSC cells could block transendothelial migration. Our findings provide clear evidence that the PI3K and ROCK pathways are involved in MSC migration through human brain microvascular endothelial cell monolayers. The information yielded by this study may be helpful in constructing gene-modified mesenchymal stem cells that are able to penetrate the BBB effectively for cell therapy.
authors.affiliation: Department of Developmental Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health, Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, 92 Bei Er Road, Heping District, Shenyang 110001, China.
authors.forename: Mei-Na
authors.initials: MN
authors.lastname: Lin
authors.forename: De-Shu
authors.initials: DS
authors.lastname: Shang
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.forename: Wen-Gang
authors.initials: WG
authors.lastname: Fang
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Zhao
authors.forename: Liu
authors.initials: L
authors.lastname: Cao
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Chen
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000502:physiology; D004730:Endothelium, Vascular / Q000166:cytology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006735:Horseradish Peroxidase / Q000378:metabolism; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000502:physiology*; D009154:Mutation / Q000502:physiology; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors; D014161:Transduction, Genetic; D057705:Transendothelial and Transepithelial Migration / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D062826:Zonula Occludens-1 Protein / Q000378:metabolism; D054460:rho-Associated Kinases / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D034741:RNA, Small Interfering; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein; D006735:Horseradish Peroxidase; D019869:Phosphatidylinositol 3-Kinases; D054460:rho-Associated Kinases