Novel microvascular endothelial model utilizing a collagen vitrigel membrane and its advantages for predicting histamine-induced microvascular hyperpermeability.

The evaluation of microvascular permeability is crucial for drug development. Nonetheless, there are few reliable test methods in vitro due to the lack of vascular endothelial models suitable for quantitative analyses. The purpose of this study is to construct a novel microvascular endothelial model with the high endothelial barrier function and sensitivity to physiological stimuli utilizing a collagen vitrigel membrane (CVM) composed of high-density collagen fibrils. Human microvascular endothelial cells (HMVECs) were cultured for 6 days in a CVM chamber with or without human dermal fibroblasts (HDFs) cocultured on the reverse surface of the CVM. The endothelial barrier function was evaluated by measurement of transendothelial electrical resistance (TEER) and macromolecular permeation. The TEER value of a monolayer of HMVECs cultured on the CVM was 15-20 Ω･cm2 during the culture period while it reached over 60 Ω･cm2 by coculturing with HDFs. The TEER value was decreased from 5.7 to 3.4 Ω･cm2 by 100 μM histamine in the monolayer model and from 50 to 32 Ω･cm2 by 1 nM histamine in the coculture model, respectively. Interestingly, the permeability coefficient of the compound with a molecular weight of not 376 and 40,000 but 4000 was selectively increased in the histamine-treated coculture model. HMVECs cocultured with HDFs via a CVM formed the tight endothelial barrier and showed high responsivity to histamine. The model might be useful for exploring molecules that modulate microvascular permeability and pass through the microvascular endothelial barrier.