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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. [ABSTRACT FROM AUTHOR]

Abstract: A tracheal epithelial cell line RTEC11 was established from transgenic rats harboring temperature-sensitive simian virus 40 large T-antigen. The cells grew continuously at a permissive temperature of 33°C but not at a non-permissive temperature of 39°C. Morphological and functional investigations demonstrated that the cells were polarized epithelial cells maintaining a regulated permeability barrier function. Interestingly, the expression levels of Muc1 (mucin 1) and Scgb1a1 (uteroglobin), non-ciliated secretory cell markers, and Tubb4 (tubulin beta 4), a ciliated cell marker, were significantly increased under the cell growth-restricted condition. Global gene expression and computational network analyses demonstrated a significant genetic network associated with cellular development and differentiation in cells cultured at the non-permissive temperature. The tracheal epithelial cell line RTEC11 with unique characteristics should be useful as an in vitro model for studies of the physiological functions and gene expression of tracheal epithelial cells. [Copyright &y& Elsevier]

The objective of this study was to establish pure blood–nerve barrier (BNB)-derived peripheral nerve pericyte cell lines and to investigate their unique properties as barrier-forming cells. We isolated peripheral nerve, brain, and lung pericytes from transgenic rats harboring the temperature-sensitive simian virus 40 large T-antigen gene. These cell lines expressed several pericyte markers such as α-smooth muscle actin, NG2, osteopontin, and desmin, whereas they did not express endothelial cell markers such as vWF and PECAM. In addition, these cell lines expressed several tight junction molecules such as occludin, claudin-12, ZO-1, and ZO-2. In particular, the expression of occludin was detected in peripheral nerve and brain pericytes, although it was not detected in lung pericytes by a Western blot analysis. An immunocytochemical analysis confirmed that occludin and ZO-1 were localized at the cell–cell boundaries among the pericytes. Brain and peripheral nerve pericytes also showed significantly higher trans-pericyte electrical resistance values and lower inulin clearances than lung pericytes. We considered that occludin localized at the cell–cell boundaries among the pericytes might mechanically stabilize the microvessels of the BNB and the blood–brain barrier. Furthermore, we also showed that these cell lines expressed many barrier-related transporters. ABCG2, p-gp, MRP-1, and Glut-1 were detected by a Western blot analysis and were observed in the cytoplasm and outer membrane by an immunocytochemical analysis. These transporters on pericytes might facilitate the peripheral nerve-to-blood efflux and blood-to-peripheral nerve influx transport of substrates in cooperation with those on endothelial cells in order to maintain peripheral nerve homeostasis. J. Cell. Physiol. 217: 388–399, 2008. © 2008 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]