Layer II of placental syncytiotrophoblasts expresses MDR1 and BCRP at the apical membrane in rodents.
The purpose of this study is to clarify the subcellular localizations of multidrug resistance protein 1 (MDR1)/ABCB1 and breast cancer resistance protein (BCRP)/ABCG2 in the rodent placental SynT bilayer, i.e., a maternal-facing (SynT-I) layer and a fetal-facing (SynT-II) layer. In double immunofluorescence staining, the signals of MDR1 and BCRP appeared midway between the signals of glucose transporter 1 on the apical membrane of SynT-I and the basal plasma membrane of SynT-II, and mostly overlapped with signals of connexin 26, which forms gap junctions between SynT-I and SynT-II. In detail, median intensities (pixels) of the MDR1 and BCRP signals were significantly closer to the fetal circulation as compared to the location of connexin 26 signals. In double in situ hybridization studies, the signals of Mdr1b mRNA mostly overlapped with those of Syncytin-B, a SynT-II marker. In conclusion, MDR1 and BCRP are expressed on apical membranes of the rodent placental SynT-II layer.
Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.
Tomoya
T
Akashi
Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.
Tomohiro
T
Nishimura
Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.
Yoshiya
Y
Takaki
Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.
Masaya
M
Takahashi
Department of Pediatrics, Division of Neonatology and Developmental Biology, Neonatal Research Center, David School of Medicine, University of California Los Angeles, 10833 Le Conte Ave., MDCC-22-402, Los Angeles, CA, 90095-1752, United States.
Bo-Chul
BC
Shin
Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan. Electronic address: tomi-ms@pha.keio.ac.jp.
Masatoshi
M
Tomi
Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.
Emi
E
Nakashima
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism*; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2 / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D005260:Female; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010920:Placenta / Q000166:cytology / Q000378:metabolism*; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D014327:Trophoblasts / Q000378:metabolism*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; C501412:Abcg2 protein, mouse; D012333:RNA, Messenger
BCRP; MDR1; Placental barrier; Rodent; Syncytiotrophoblast; Transporter