Faria T N, Deb S, Kwok S C, Talamantes F, Soares M J
Department of Physiology, University of Kansas Medical Center, Kansas City 66103.
Dev Biol. 1990 Oct;141(2):279-91. doi: 10.1016/0012-1606(90)90384-u.
The purpose of this investigation was to identify the cellular origin, and the temporal and regional characteristics of placental lactogen-I (PL-I) and placental lactogen-II (PL-II) expression during placental development in the rat. PL-I and PL-II mRNA expression were assessed by Northern blot analysis and in situ hybridization. PL-I and PL-II protein expression were determined by Western blot and immunocytochemical analyses. PL-I mRNA was first detected by in situ hybridization at Day 6 of gestation in mural trophoblast giant cells and a day later, PL-I protein was first detected by immunocytochemistry. PL-I immunostaining extended to the polar trophoblast giant cells as gestation advanced. Polar trophoblast giant cell staining for PL-I was not as intense as the mural trophoblast giant cell staining. Northern and Western blot analyses confirmed the asymmetric distribution of PL-I expression. PL-I mRNA migrated as a 1-kb species and PL-I protein migrated as 30- and 36-40-kDa forms. PL-I expression abruptly declined at Day 12, and by Day 13, PL-I was not detectable. PL-II protein was first detectable at Day 11 of gestation and was localized to trophoblast giant cells. PL-II mRNA could be detected at Day 10 of gestation. Northern and Western blot analyses indicated that PL-II expression significantly increased as gestation advanced and that PL-II expression was asymmetrically distributed similar to PL-I. PL-II mRNA migrated as a 1-kb species and PL-II protein migrated as a 25-kDa species. Blastocysts recovered on Day 4 of gestation initially showed no detectable expression of PL-I or PL-II; however, after 2 days of culture PL-I protein expression was detectable. Biochemical characteristics of PL-I synthesized and secreted by blastocyst outgrowths were similar to PL-I synthesized and secreted by Day 10 placental explants. In summary, (1) PL-I and PL-II are produced by trophoblast giant cells of the developing placenta, (2) PL-I and PL-II exhibit distinct temporal and regional patterns of expression during placental morphogenesis, and (3) PL-I expression by blastocyst outgrowths can be induced in vitro, whereas a more complex array of signals appears necessary for induction of PL-II expression.
本研究的目的是确定大鼠胎盘发育过程中胎盘催乳素-I（PL-I）和胎盘催乳素-II（PL-II）表达的细胞起源、时间和区域特征。通过Northern印迹分析和原位杂交评估PL-I和PL-II mRNA表达。通过蛋白质印迹和免疫细胞化学分析确定PL-I和PL-II蛋白表达。妊娠第6天，在壁滋养层巨细胞中首次通过原位杂交检测到PL-I mRNA，一天后，通过免疫细胞化学首次检测到PL-I蛋白。随着妊娠进展，PL-I免疫染色扩展到极滋养层巨细胞。PL-I在极滋养层巨细胞中的染色不如在壁滋养层巨细胞中强烈。Northern和蛋白质印迹分析证实了PL-I表达的不对称分布。PL-I mRNA迁移为1 kb的条带，PL-I蛋白迁移为30 kDa和36 - 40 kDa的形式。PL-I表达在第12天突然下降，到第13天，PL-I无法检测到。PL-II蛋白在妊娠第11天首次可检测到，定位于滋养层巨细胞。PL-II mRNA在妊娠第10天可检测到。Northern和蛋白质印迹分析表明，随着妊娠进展，PL-II表达显著增加，且PL-II表达与PL-I类似呈不对称分布。PL-II mRNA迁移为1 kb的条带，PL-II蛋白迁移为25 kDa的条带。妊娠第4天回收的囊胚最初未检测到PL-I或PL-II的表达；然而，培养2天后可检测到PL-I蛋白表达。囊胚外植体合成和分泌的PL-I的生化特性与第10天胎盘外植体合成和分泌的PL-I相似。总之，（1）PL-I和PL-II由发育中胎盘的滋养层巨细胞产生，（2）PL-I和PL-II在胎盘形态发生过程中表现出不同的时间和区域表达模式，（3）囊胚外植体的PL-I表达可在体外诱导，而诱导PL-II表达似乎需要更复杂的信号组合。
