Establishment and characterization of spinal cord microvascular endothelial cell lines

Abstract

Objectives The blood-spinal cord barrier (BSCB) has been recognized as one of the barrier organs in the central nervous system. Unlike the blood-brain barrier (BBB), the function of the BSCB still remains to be fully understood, partly because of the lack of a good in vitro BSCB model. In the present study, we established a microvascular endothelial cell line derived from a rat spinal cord and characterized this new model. Methods A conditionally immortalized cell line, termed rBSCB-1, was established by introducing the temperature-sensitive SV40 large T-antigen gene into primary microvascular endothelial cells isolated from a rat spinal cord. We examined whether this model retains barrier-specific properties. Results The rBSCB-1 expressed several basic endothelial cell markers and the large T-antigen, and showed temperature-dependent cell growth and barrier function. They also expressed tight junction molecules including claudin-1, 3, 5, 12, occludin, zonula occludens (ZO)-1 and barrier-specific transporters. The rBSCB-1 showed low paracellular permeability to 4 kDa dextran and high transport activity of P-glycoprotein. In addition, the treatment with astrocytic factors increased the barrier properties of rBSCB-1, including their expression levels of tight junctional molecules. Conclusion The rBSCB-1 cells are the first conditionally immortalized endothelial cell line derived from the BSCB that have been fully characterized as barrier-forming cells. This cell line should be a useful tool to understand the BSCB disruption involved in many neurological disorders including multiple sclerosis and spinal cord injury. © 2013 Japanese Society for Neuroimmunology.