Functional analysis of LH/hCG receptor in human placental chorionic villous macrophages

人类性腺和非性腺器官/组织表达LH/CG受体。本研究旨在鉴定人胎盘绒毛膜巨噬细胞LH/CG受体，并阐明其功能。在整个妊娠期，人绒毛组织的巨噬细胞和合体滋养细胞均呈LH/CG受体免疫化学阳性。通过RT-PCR，绒毛巨噬细胞显示表达LH/CG受体的变体类型，其测序显示外显子9的缺失。对于体外实验，单核细胞-巨噬细胞系THP-1在佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）处理后用单独的载体、野生型LH/CG受体和外显子9缺失的LH/CG受体转染。还检查了单独用载体转染的未经PMA处理的THP-1细胞。PMA处理后，THP-1细胞表达第9外显子缺失的LH/CG受体。各组细胞在含完整hCG的培养液中培养后， ...更多信息 在培养基上清液和细胞胞质溶胶中测量β-CF。在非PMA处理的和PMA处理的THP-1细胞中观察到时间依赖性hCG摄取，表明变体受体不直接参与hCG的摄取。PMA处理的细胞hCG降解和β-CF分泌增加，而未处理的细胞则无此变化。在细胞胞液中，PMA处理的细胞中β-CF和hCG浓度的比率（β-CF/hCG）显著高于非PMA处理的细胞;然而，在用外显子9缺失受体转染的PMA处理的细胞和仅用载体转染的细胞之间没有差异。巨噬细胞可表达变异受体，以识别胞浆内hCG并将其转运至溶酶体。在两种PMA处理的细胞中，在用野生型受体转染的细胞中的比率较低。变体受体的表达可以调节hCG的降解，但在其缺乏的巨噬细胞中通过野生型受体的表达而降低。我们的数据表明，在人胎盘绒毛巨噬细胞中表达的LH/CG受体9号外显子缺失在hCG的局部代谢中具有潜在的重要作用。少

Human gonads and non-gonadal organs/tissues express LH/CG receptors. This study aimed to identify the LH/CG receptors and to clarify their function in human placental chorionic villous macrophages. Macrophages as well as syncytiotrophoblasts of human chorionic villous tissues were immunohistochemically positive for LH/CG receptor throughout gestation. By RT-PCR, villous macrophages were shown to express a variant type of LH/CG receptor, the sequencing of which revealed a deletion of exon 9. For experiments in vitro, a monocyte-macrophage cell line, THP-1, was transfected with vector alone, wild-type LH/CG receptor, and exon 9-deleted LH/CG receptor after phorbol 12-myristate 13-acetate (PMA) treatment. Non-PMA-treated THP-1 cells transfected with vector alone were also examined. THP-1 cells expressed exon 9-deleted LH/CG receptor after treatment with PMA. After the cells of the four groups were cultured in medium containing intact hCG, the concentrations of hCG and its b-core fragment … More (β-CF) were measured in the supernatant of the culture medium and in the cell cytosol. Time-dependent hCG uptake was observed in both non-PMA-treated and PMA-treated THP-1 cells, suggesting that the variant receptor is not directly involved in the ingestion of hCG. The degradation of hCG and excretion of β-CF were progressed in PMA-treated cells but not in the un-treated cells. In the cell cytosol, the ratio of β-CF and hCG concentrations (β-CF/hCG) was significantly higher in the PMA-treated cells than in non-PMA-treated cells ; however, it did not differ between the PMA-treated cells transfected with exon 9-deleted receptor and those transfected with vector alone. Macrophages may express the variant receptor in order to recognize the intracytoplasmic hCG and transport it to the lysosome. Among the two PMA-treated cells, the ratio was lower in those transfected with wild-type receptor. The expression of the variant receptor may modulate the degradation of hCG but be reduced by expression of the wild-type receptor in its lacking macrophages. Our data suggest a potentially important role for exon 9-deleted LH/CG receptors expressed in human placental villous macrophages in the local metabolism of hCG. Less