Establishment of an in vitro blood-brain harrier modal by coculturing brain microvascular endothelial cells and pericytes / 国际脑血管病杂志

ABSTRACT

Objective To establish a stable in vitro model of blood-brain barrier (BBB) simulating in vivo state using the primary-cultured rat brain microvascular endothelial cells (BMVECs) and pericytes.Methods The primary rat BMVECs and pericytes were isolated,purified and cultured.The isolated cells were identified by immunocytochemical staining method.An in vitro model of BBB was constructed using Transwell inserts (pore size 0.4 μm) coculture.Its barrier function was evaluated by the 4-hour leakage test,tight junction protein identification,transendothelial resistance detection,and permeability test.The difference between the cocultured model and simple BMVEC model across the membrane resistance values,and the permeability difference of the small molecule sodium fluorescein (Na-F) were compared.Results Confluent BMVEC monolayers demonstrated a typical cobblestone appearance and the pericytes displayed irregular shape and overlapping growth.Immunodouble labeling technique identification showed that the pericytes positively expressed α-srmooth muscle actin (α-SMA) and neuron-glial antigen 2 (NG2); after the fusion of cocultured model endothelial cells,the surface leakage test became positive; immnocytochemical staining shows that a continuous and dense tight junction formed between the endothelial cells; compared to the BMVEC model,the transendothelial electrical resistance of the cocultured model increased significantly (190.762 ± 10.326 Ω/cm2 vs.96.503 ± 8.012 Ω/cm2; t=- 24.489,P ＜0.01),and the permeability decreased significantly (56.149％ ± 3.572％ of the single endothelial model; t =19.330,P ＜ 0.01 ).Conclusions The primary isolated rat BMVECs and pericytes cocultured the morphology,structure and barrier function of in vitro model have the basic characteristics of BBB,and they have provided a useful tool for the research of BBB.