The interactions between brain microvascular endothelial cells and mesenchymal stem cells under hypoxic conditions.
The purpose of the present study was to investigate the interactions between brain microvascular endothelial cells (BMEC) and mesenchymal stem cells (MSC) under hypoxic conditions. Primary cultured human bone marrow MSC and rat BMEC were isolated, cultured and identified. Vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) were detected in the conditioned media of BMEC and MSC under normal and hypoxic conditions using ELISA. MSC differentiation was analyzed using flow cytometry and fluorescence immunocytochemistry. Transendothelial electrical resistance (TEER) techniques were employed to measure changes in permeability across the BMEC monolayer. Under hypoxic conditions, the concentration of VEGF and MMP-9 in the conditioned media increased significantly, with greater levels in the MSC than the BMEC media. Primary MSC did not express vWF and Flk-1. MSC were co-cultured with BMEC under hypoxic conditions 5 days later. MSC expressing Flk-1 accounted for 23.64+/-2.50% (n=6, P<0.001) of the total number of cells. Interestingly, some Flk-1 positive cells began to coexpress vWF simultaneously. Under hypoxic conditions, MSC conditioned media significantly enhanced the proliferation and migration of BMEC. In addition, MSC decreased the TEER of the BMEC monolayer (lowest values: 50.5+/-2.6% of the original), which could partially be inhibited by both anti-VEGF antibody and MMP-9 inhibitor. These data indicate that under hypoxic conditions BMEC induce MSC to differentiate into endothelial cells, and MSC enhance the proliferation and migration of BMEC through paracrine functions, while simultaneously increasing the permeability of the BMEC monolayer.
Liu
Kaiming
K
Department of Cardiology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
Chi
Luxiang
L
Guo
Liang
L
Liu
Xianghui
X
Luo
Chunxia
C
Zhang
Shanchun
S
He
Guoxiang
G
D000818:Animals; D019138:Antibodies, Blocking; D001921:Brain / Q000098:blood supply*; D002545:Brain Ischemia / Q000378:metabolism; D002199:Capillary Permeability; D002454:Cell Differentiation; D015687:Cell Hypoxia; D019070:Cell Lineage; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D017077:Culture Media, Conditioned / Q000378:metabolism; D017097:Electric Impedance; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008833:Microcirculation / Q000378:metabolism; D019899:Paracrine Communication / Q000187:drug effects; D011480:Protease Inhibitors / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000276:immunology / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism; D014841:von Willebrand Factor / Q000378:metabolism
D019138:Antibodies, Blocking; D017077:Culture Media, Conditioned; D061965:Matrix Metalloproteinase Inhibitors; D011480:Protease Inhibitors; D042461:Vascular Endothelial Growth Factor A; D014841:von Willebrand Factor; D040301:Vascular Endothelial Growth Factor Receptor-2; D020780:Matrix Metalloproteinase 9