Spanel-Borowski Katharina, Sass Kristina, Löffler Sabine, Brylla Elke, Sakurai Michiharu, Ricken Albert M
Institute of Anatomy, University of Leipzig, Liebigstrasse 13, D-04103 Leipzig, Germany.
Reproduction. 2007 Oct;134(4):625-34. doi: 10.1530/REP-07-0236.
The tyrosine kinase KIT receptor, the protooncogene CD117, plays a key role in growth and maturation of oocytes and follicles. Relevant data are sparse for the corpus luteum (CL). We first confirmed the presence of KIT mRNA and KIT protein in bovine CL homogenates. We then localized KIT-positive (KIT+) cells in CL sections by immunohistochemistry. At the CL stage of early development, the former theca transforming into capsule/septa showed a strong band-like KIT+ immunoresponse. In addition, CD45+ leukocytes in septa included subpopulations of CD45+/KIT+ and CD14+/KIT+ leukocytes as validated by double immunofluorescence localization. At the early secretory stage, KIT+ cells appeared within the septa/capsule region and in the periphery of the CL parenchyma, there forming a complex network. This was separate from the capillary bed as determined by double staining for CD117 and FVIII-related endothelial cell antigen (FVIIIr). The KIT+ network coincided with cells positive for cytochrome P450 17alpha-hydroxylase, a thecal cell-specific enzyme. The late secretory stage was defined by an advanced manifestation of the KIT+ network in the CL periphery. At the stage of regression, the KIT+ network was absent. The CL of pregnancy expressed high levels of KIT mRNA and KIT protein uniformly throughout pregnancy. The KIT+ immunolocalization revealed small fibroblast-like cells, luteal cells with granules, and clusters of large luteal cells with staining of the cell membrane. We conclude that a majority of KIT+ cells in the bovine CL are primarily theca-derived small luteal cells, and that a minority represent KIT+ leukocytes, in some cases KIT+ monocytes.
酪氨酸激酶KIT受体，即原癌基因CD117，在卵母细胞和卵泡的生长与成熟过程中起关键作用。关于黄体（CL）的相关数据较少。我们首先证实了牛黄体匀浆中存在KIT mRNA和KIT蛋白。然后，我们通过免疫组织化学对黄体切片中的KIT阳性（KIT+）细胞进行定位。在早期发育的黄体阶段，由前卵泡膜转化而来的包膜/中隔呈现出强烈的带状KIT+免疫反应。此外，通过双重免疫荧光定位证实，中隔中的CD45+白细胞包括CD45+/KIT+和CD14+/KIT+白细胞亚群。在早期分泌阶段，KIT+细胞出现在中隔/包膜区域以及黄体实质的周边，在那里形成一个复杂的网络。通过对CD117和FVIII相关内皮细胞抗原（FVIIIr）的双重染色确定，这个网络与毛细血管床是分开的。KIT+网络与细胞色素P450 17α-羟化酶阳性的细胞一致，细胞色素P450 17α-羟化酶是卵泡膜细胞特异性酶。晚期分泌阶段的特征是黄体周边的KIT+网络更为明显。在退化阶段，KIT+网络消失。妊娠黄体在整个妊娠期均高水平表达KIT mRNA和KIT蛋白。KIT+免疫定位显示有小的成纤维细胞样细胞、有颗粒的黄体细胞以及细胞膜染色的大黄体细胞簇。我们得出结论，牛黄体中的大多数KIT+细胞主要是来源于卵泡膜的小黄体细胞，少数代表KIT+白细胞，在某些情况下是KIT+单核细胞。
