Black S, Kadyrov M, Kaufmann P, Ugele B, Emans N, Huppertz B
Department of Anatomy, University Hospital Aachen, Germany.
Cell Death Differ. 2004 Jan;11(1):90-8. doi: 10.1038/sj.cdd.4401307.
Differentiation of human placental villous trophoblast includes syncytial fusion of cytotrophoblast forming syncytiotrophoblast. Early stages of the apoptosis cascade were described to be involved in this differentiation process. We investigated the role of the initiator caspase 8 in syncytial fusion in vitro, cultivating placental villous explants with or without caspase 8 antisense oligonucleotides or peptide inhibitors for up to 120 h. Trophoblast fusion and differentiation were assessed by confocal microscopy, immunohistochemistry and Western blot analysis. Culture with caspase 8 antisense oligonucleotides or peptide inhibitors reduced the fusion of cytotrophoblast with the syncytiotrophoblast, and resulted in multilayered cytotrophoblast. Caspase 8 expression was suppressed by antisense oligonucleotides and caspase 8 activities were reduced by peptide inhibitors. The organic anion-transporter hOAT-4 normally expressed in the cytotrophoblast and transferred into the syncytiotrophoblast by syncytial fusion was retained in the cytotrophoblast due to lack of fusion. We conclude that expression and activity of caspase 8 is a prerequisite for differentiation and syncytial fusion of cytotrophoblast cells.
人胎盘绒毛滋养层细胞的分化包括细胞滋养层细胞的合体融合形成合体滋养层细胞。据描述，凋亡级联反应的早期阶段参与了这一分化过程。我们研究了起始半胱天冬酶8在体外合体融合中的作用，用或不用半胱天冬酶8反义寡核苷酸或肽抑制剂培养胎盘绒毛外植体长达120小时。通过共聚焦显微镜、免疫组织化学和蛋白质印迹分析评估滋养层细胞融合和分化情况。用半胱天冬酶8反义寡核苷酸或肽抑制剂培养可减少细胞滋养层细胞与合体滋养层细胞的融合，并导致细胞滋养层细胞多层化。反义寡核苷酸抑制半胱天冬酶8的表达，肽抑制剂降低半胱天冬酶8的活性。由于缺乏融合，通常在细胞滋养层细胞中表达并通过合体融合转移到合体滋养层细胞中的有机阴离子转运体hOAT-4保留在细胞滋养层细胞中。我们得出结论，半胱天冬酶8的表达和活性是细胞滋养层细胞分化和合体融合的先决条件。
