Jackson D, Linzer D I
Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston, Illinois 60208, USA.
Endocrinology. 1997 Jan;138(1):149-55. doi: 10.1210/endo.138.1.4828.
Proliferin (PLF), a member of the PRL/GH family secreted by the placenta, can be detected in both the maternal and fetal compartments. We now show that PLF immunoreactivity can be detected in association with the yolk sac, consistent with the transport of PLF across this structure into the amniotic fluid. Furthermore, PLF is transported across the extraembryonic membranes in isolated conceptuses that are placed in culture, and specific binding sites for PLF are detected in these embryos. The major binding sites for PLF in the cultured conceptus correspond to sites at which endogenous PLF localizes in the fetus, including developing vertebral and vascular structures. Similar binding patterns were also detected for PLF that was incubated with fetal sections. Competition and comparative binding studies indicate that the insulin-like growth factor II/mannose 6-phosphate receptor is involved in PLF binding to specific cells in the fetus. These results suggest that in addition to the effects of PLF in the placenta on neovascularization and in the maternal uterus on cell proliferation, PLF may also act at specific sites in the developing fetus.
增殖蛋白（PLF）是胎盘分泌的催乳素/生长激素（PRL/GH）家族的成员，在母体和胎儿体内均可检测到。我们现在发现，与卵黄囊相关可检测到PLF免疫反应性，这与PLF通过该结构转运到羊水中一致。此外，在培养的分离胚胎中，PLF可穿过胚外膜，并且在这些胚胎中检测到PLF的特异性结合位点。培养的胚胎中PLF的主要结合位点与内源性PLF在胎儿中定位的位点相对应，包括发育中的椎骨和血管结构。在用胎儿切片孵育的PLF中也检测到类似的结合模式。竞争和比较结合研究表明，胰岛素样生长因子II/甘露糖6-磷酸受体参与PLF与胎儿特定细胞的结合。这些结果表明，除了PLF在胎盘对新血管形成的作用以及在母体子宫对细胞增殖的作用外，PLF还可能在发育中的胎儿的特定部位起作用。
