RESUMO
Aim To establish in vitro blood-brain barrier (BBB) model with characteristics of simulation of in vivo BBB by primi-tive co-culture of brain-microvessel endothelial cells (BMECs) with brain-microvessel pericytes (BMPC)and astrocytes (AS). Methods BMECs,BMPC and AS from SD rats were primitively isolated,purified and cultured,and then primitive culture cells were identified by cellular morphological and immunocytochemi-cal staining methods.Five types of in vitro BBB models were es-tablished by using Millicell culture insert (pore diameter 0.4μm)and their barrier functions were evaluated by detection of transendothelial electrical resistance (TEER),permeability of sodium fluorescent (Na-FLU ),expression of alkaline phospha-tase (AKP)and γ-glutamyl transpeptidase (γ-GT1 ),and simi-larity of permeation amount for positive drugs in vitro and in vivo BBB conditions.Results Primitive culture of BMECs presented typical pebbles-like structure,BMPC presented larger soma with branching property,AS presented slender synapse and shallower cytoplasm.Moreover,immunocytochemical staining results iden-tified primitive cells were targeted cells.TEER value for co-cul-ture of BMECs,BMPC and AS reached (478 ±25 )Ω· cm2 , permeability coefficients (Papp )value of Na-FLU was [(8.23 ± 0.78) ×10 -6 ]cm·s-1 ,expression of AKP and γ-GT1 were (6.90 ±0.27 )King unit · g-1 Pro and (4.39 ±0.32 )μg · g-1 Pro respectively.Moreover,good correlation could be found in Papp for positive controls in vitro and in vivo BBB models (R2=0.92).Conclusion The established in vitro BBB model by using primitive co-culture of BMECs with BMPC and AS posses-ses in vivo BBB properties in cell morphology,structures and barrier functions,and can be used as a powerful tool for studying physiology,pathology of BBB and screening candidate com-pounds.
RESUMO
Aim To establish a highly purified,active and prac-tical extract and primitive culture method for rat brain microvas-cular endothelial cells ( BMECs) for providing materials for con-struction in vitro blood-brain barrier ( BBB) model. Methods Cerebral cortex of 1-2 week SD rats was collected,and successive digestion with typeⅡcollagenase and collagenase/dispase, sieve filtration and then twice gradient centrifugation in 20% BSA and 44% Percoll condition were used to obtain brain microvascular section. After that brain microvascular section was seeded in cul-ture bottle and then primarily cultured. Inverted microscope and factor-VIII relative antigen immunostaining methods were used for cellular morphological observation and identification. Results BMECs climbed out the vessel segment and proliferated with ad-herence after 2 h in vitro culture,and they became typical peb-bles structure after further 3-4 d culture. Morever, factor-VIII relative antigen immunostaining identified that expression for the endothelial cells was positive,cytoplasm was brown and positive cells account for more than 99%. Conclusion Rat BMECs with high purity could be extracted and cultured by using the above methods,and it has great potential for construction in vitro BBB model and in depth studies on biological characteristics and func-tions of BMECs.