Sharkey A M, Jokhi P P, King A, Loke Y W, Brown K D, Smith S K
Department of Obstetrics and Gynaecology, University of Cambridge, Rosie Maternity Hospital, UK.
Cytokine. 1994 Mar;6(2):195-205. doi: 10.1016/1043-4666(94)90042-6.
Kit ligand, or stem cell factor, is a recently identified growth factor, which binds to and activates the c-kit proto-oncogene, and which has been shown to act synergistically with other haematopoietic growth factors in the bone marrow. We have previously shown that several isoforms of kit ligand, which arise due to alternative splicing, are expressed in human placenta. In order to elucidate the role of c-kit and its ligand during human placental development we have investigated the expression of c-kit and kit ligand in human first trimester and term placenta as well as in pregnant and non-pregnant endometrium, by immunocytochemistry and flow cytometric analysis. In non-pregnant endometrium no expression of kit ligand was seen. By contrast, in first trimester decidua, kit ligand was strongly expressed by the arterial media of maternal blood vessels. Kit ligand was also expressed throughout pregnancy by invasive fetal extravillous trophoblast, and by fetal fibroblasts within the placental villi. c-kit was found to be expressed on Hofbauer cells within the chorionic villi, and by decidual macrophages at all stages in pregnancy. c-kit was also detected on the small CD56dim subset of uterine large granular lymphocytes which form the major leukocyte population in human first trimester decidua. Our results suggest that kit ligand may be involved in the regulation of fetal macrophages, and in particular in signalling between invading extravillous trophoblast which expresses kit ligand, and maternal leukocytes bearing the c-kit receptor.
kit配体，即干细胞因子，是一种最近发现的生长因子，它能结合并激活c-kit原癌基因，且已证明在骨髓中能与其他造血生长因子协同发挥作用。我们之前已经表明，由于选择性剪接而产生的kit配体的几种异构体在人胎盘中表达。为了阐明c-kit及其配体在人胎盘发育过程中的作用，我们通过免疫细胞化学和流式细胞术分析，研究了c-kit和kit配体在人孕早期和足月胎盘以及妊娠和非妊娠子宫内膜中的表达。在非妊娠子宫内膜中未观察到kit配体的表达。相比之下，在孕早期蜕膜中，母体血管的动脉中层强烈表达kit配体。在整个妊娠期间，侵袭性胎儿绒毛外滋养层以及胎盘绒毛内的胎儿成纤维细胞也表达kit配体。发现c-kit在绒毛膜绒毛内的霍夫鲍尔细胞上表达，并且在妊娠各阶段的蜕膜巨噬细胞上也有表达。在构成人孕早期蜕膜主要白细胞群体的子宫大颗粒淋巴细胞的小CD56dim亚群上也检测到了c-kit。我们的结果表明，kit配体可能参与胎儿巨噬细胞的调节，特别是在表达kit配体的侵袭性绒毛外滋养层与携带c-kit受体的母体白细胞之间的信号传导中。
