Porcinechoroid plexus epithelial cells in culture: Regulation of barrier properties and transport processes

Abstract

The epithelial cells of the choroid plexus are the structural basis of the blood‐cerebrospinal fluid (CSF)‐barrier. Here we summarise our recent efforts to culture those cells mainly on permeable supports in vitro. Isolated from porcine brains, we report a simple protocol for the primary culture using cytosine arabinoside as an additive that is cytotoxic for other cells except the plexus epithelial cells. Enhanced barrier properties are obtained by withdrawal of serum from the culture medium after confluency is reached. Cells improve their polarity, permeability for hydrophilic substrates is lowered, electrical resistance is increased tenfold, and a pH‐gradient is built up across the cell monolayer. Polarised secretion of proteins and most importantly fluid secretion into the apical filter compartment was attained and proven to be dependent on the Na+,K+‐ATPase activity. Active transport processes (penicillin G, riboflavin, myo‐inositol, ascorbic acid) were studied and clearly showed the involvement of the organic anion transporter. The permeability of the barrier was found to be regulated by cyclic adenosine monophosphate (cAMP). Moreover, we report that cell proliferation and differentiation is controlled by components of the extracellular matrix. The present culture model could now be used as an in vitro system to quantify drug transport across the blood‐CSF‐barrier. Microsc. Res. Tech. 52:137–152, 2001. © 2001 Wiley‐Liss, Inc.

Culture models to study leukocyte trafficking across the choroid plexus

“…In the case of the endothelium at the BBB , these cells are interconnected by a dense network of TJs and they exhibit a low pinocytotic activity concomitant with the absence of fenestrae [4]. Properties of these cellular barriers are a high transendothelial or transepithelial electrical resistance (TEER) as well as a low permeability for macromolecules [5]. …”

“…An important factor for investigating this disease is the development of suitable in vitro systems mimicking the above-mentioned barriers. Whereas human models of the BBB employing immortalized cell lines have been developed [17-19], in vitro systems mimicking the BCSFB are limited to animal models, including rat cell lines and primary porcine choroid plexus epithelial cells (PCPEC) [5,20-23] (an extensive recent review covering BCSFB in vitro models is provided by Strazielle and Ghersi-Egea [24]).…”

“…This can be clearly demonstrated by an increase in transepithelial resistance (TEER) values and a decrease in macromolecular permeability [5]. We have used this culture system for the first time to study the pathogenesis of bacterial meningitis, and ideally use S. suis as a relevant pathogen causing disease in pigs and humans.…”

Transmigration of Trypanosoma brucei across an in vitro blood-cerebrospinal fluid barrier

“…Medium was changed every second day until the filters reached an impedance of 300 Ω (100 Ω cm 2 ). Then, medium was changed to serum-free DMEM:F12, since cultivation in serum-free medium causes formation of a higher TEER by choroid plexus epithelial cells in vitro ( Haselbach et al., 2001 ; Schwerk et al., 2012 ). Once the filter reached an impedance of 600 Ω (200 Ω cm 2 ) it was used for experiments.…”

Culture Model for Non-human Primate Choroid Plexus

“…Several rodent models of the choroid plexus exist, including immortalized rat Z310 and TR-CSFB, as well as primary mouse models (Kläs et al, 2010; Menheniott et al, 2010; Monnot and Zheng, 2013; Barkho and Monuki, 2015). Porcine choroid plexus epithelial cell lines have been used to study bacterial and drug infection of the brain (Haselbach et al, 2001; Angelow et al, 2004; Schwerk et al, 2011). However, the murine models have reported difficulty in proliferation in culture, the immortalized rat cultures have altered tight junction proteins compared to primary rat cultures, and none of the models is useful for studies of HIV infection (Angelow et al, 2004; Abel, 2009; Barkho and Monuki, 2015; Beck et al, 2017).…”