Conditionally Immortalized Syncytiotrophoblast Cell Lines as New Tools for Study of the Blood-Placenta Barrier

Abstract

Syncytiotrophoblasts play an essential role in restriction of drug delivery through the blood-placenta barrier (BPB). Conditionally immortalized syncytiotrophoblast cell lines, TR-TBTs, were established at gestational day 18 from pregnant transgenic rats (Tg-rats) harboring the temperature-sensitive SV 40 (ts SV40) large T-antigen. TR-TBTs exhibit temperature-sensitive cell growth due to the expression of SV 40 large T-antigen, and thus the cell growth can be regulated by changing the culture temperature. TR-TBTs exhibit typical properties of syncytiotrophoblast cells, such as syncytium-like morphology, the expression of cytokeratins and hormones, and polarized expression of glucose transporter 1 (GLUT1) and GLUT3. TR-TBTs express in vivo influx and efflux transporters, such as taurine transporter (TauT), betaine/GABA transporter (BGT-1), amino acid transporter 2 (ATA2), organic anion transporting polypeptide 2 (oatp2), organic cation/carnitine transporter (OCTN2), P-glycoprotein (P-gp), and breast cancer resistance protein (BCRP/ABCG2). Moreover, TR-TBTs exhibit taurine, GABA, and DHEA-S uptake activity via TauT, BGT-1, and oatp2, respectively. Therefore, TR-TBTs can be used for the analysis of these functions and would be a good in vitro models for investigating carrier-mediated transport functions at the BPB.

Differential Expression of Ezrin and CLP36 in the Two Layers of Syncytiotrophoblast in Rats

“…We previously reported that the mRNA expression of various transporters and the localization of GLUT1 and GLUT3 in TR-TBTs are comparable to those in rat placenta. 14,15) These data suggested that TR-TBTs may be good model of rat syncytiotrophoblasts for analysis of the localization and the protein expression of transporters and anchoring proteins in blood-placenta barrier.…”

“…Total cellular RNA was prepared from PBS(Ϫ)-washed cells or tissues using an RNeasy Mini Kit (QIAGEN Sciences) according to the manufacturer's instructions. cDNA was synthesized from 1 mg of total RNA using oligo (dT) 15 as a primer, with molony murine leukemia virus (M-MLV) reverse transcriptase (RT) (ReverTraAce, Toyobo Co., Ltd., Osaka, Japan) for TR-TBT cells and Superscript III (Invitrogen) for rat placenta. Real-time PCR analysis was performed using an ABI PRISM 7700 sequence detector system (PE Applied Biosystems, Foster City, CA, U.S.A.) with 2X SYBR Green PCR Master Mix (PE Applied Biosystems) according to the manufacturer's protocol.…”

“…14,15) TR-TBTs express various transporters that are expressed in rat placenta. [16][17][18] In rat placenta, a facilitative glucose transporter (GLUT) 1, is localized on the apical (maternal-blood side) membrane of SynI and the basal membrane of SynII.…”

“…11,14,19) Immunocytochemical studies showed that localization of GLUT1 and GLUT3 in TR-TBT 18d-1 and TR-TBT 18d-2 cells coincide well with those of rat SynI and SynII in vivo, respectively. 14,15) Therefore, we chose to use these cell lines to clarify the mechanism, physiological role and pharmacological significance of the polar distribution of membrane proteins in the syncytiotrophoblast.…”

La hipótesis de Pedersen no es suficiente: Otros nutrientes además de la glucosaexplicarían la macrosomía fetal enpacientes diabéticas gestacionales consobrepeso y buen control glicémico

“…vM = vellosidades en lado materno de la placenta; stB = sinsiciotrofoblasto; ctB = cito-trofoblasto; ecF = endotelio del capilar del lado fetal de la placenta. (detalles en el texto) 26,27,46 . Figura 3. la hipótesis de Pedersen en forma gráfica 19 .…”