Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC, Canada.
Placenta. 2010 Mar;31(3):213-21. doi: 10.1016/j.placenta.2009.12.011. Epub 2010 Jan 18.
Extravillous cytotrophoblast (EVT) migration, invasion and endovascular differentiation are regulated by a variety of growth factors, cytokines and adhesion molecules. Decidual natural killer cells (dNK) and their secreted cytokines probably modulate these processes. In this study, we used dNK-derived conditioned medium (dNK-CM) to investigate whether or not (i) dNK-CM was able to enhance capillary tube and network formation of an EVT cell line, HTR8/SVneo, on Matrigel, (ii) PI3K/AKT pathway and p38 MAPK pathway activation were involved, and (iii) HTR8/SVneo surface ICAM-1 played a role in the process of HTR8/SVneo endovascular differentiation. The results demonstrated that HTR8/SVneo constitutively form 'vascular' tubes and networks after culture on Matrigel. dNK-CM enhanced and maintained tube and network formation, acquiring an endothelium-like angiogenic morphology followed by increased VEGF-C production. HTR8/SVneo cell expression level of VE-cadherin, PECAM-1, VCAM-1 and alphavbeta3 was unaltered by dNK-CM, whereas ICAM-1 expression level was increased. Anti-human ICAM-1 blocking antibody inhibited HTR8/SVneo migration and partially reversed dNK-CM-mediated enhancement of HTR8/SVneo tube and network formation. PI3K/AKT and p38 MAPK pathways were activated in dNK-CM-mediated enhancement of HTR8/SVneo tube and network formation. The PI3K/AKT and p38 MAPK pathway inhibitors (LY294002 and SB202190, respectively) decreased dNK-CM-stimulated ICAM-1 induction, HTR8/SVneo migration, and reversed tube and network formation. The results suggest that dNK cell-secreted growth factors and cytokines participate in the regulation of HTR8/SVneo endothelium-like tube formation. Adhesion molecules, particularly ICAM-1, expressed on EVT may participate in the process. To our knowledge, this is the first report of a role for ICAM-1 in EVT angiogenesis, as previously reported for endothelial cells.
滋养细胞外绒毛 (EVT) 的迁移、浸润和血管内分化受多种生长因子、细胞因子和黏附分子的调控。蜕膜自然杀伤细胞 (dNK) 及其分泌的细胞因子可能调节这些过程。在这项研究中，我们使用 dNK 衍生的条件培养基 (dNK-CM) 来研究 dNK-CM 是否能够：(i) 增强 EVT 细胞系 HTR8/SVneo 在 Matrigel 上的毛细血管管和网络形成；(ii) 是否涉及 PI3K/AKT 通路和 p38 MAPK 通路的激活；(iii) HTR8/SVneo 表面的 ICAM-1 是否在 HTR8/SVneo 血管内分化过程中发挥作用。结果表明，HTR8/SVneo 在 Matrigel 上培养后可自发形成“血管”管和网络。dNK-CM 增强并维持管和网络的形成，获得类似内皮的血管生成形态，随后 VEGF-C 的产生增加。dNK-CM 不改变 HTR8/SVneo 细胞 VE-钙黏蛋白、PECAM-1、VCAM-1 和 alphavbeta3 的表达水平，但增加 ICAM-1 的表达水平。抗人 ICAM-1 阻断抗体抑制 HTR8/SVneo 的迁移，并部分逆转 dNK-CM 介导的 HTR8/SVneo 管和网络形成的增强。PI3K/AKT 和 p38 MAPK 通路在 dNK-CM 介导的 HTR8/SVneo 管和网络形成的增强中被激活。PI3K/AKT 和 p38 MAPK 通路抑制剂（分别为 LY294002 和 SB202190）降低了 dNK-CM 刺激的 ICAM-1 诱导、HTR8/SVneo 的迁移，并逆转了管和网络的形成。结果表明，dNK 细胞分泌的生长因子和细胞因子参与了 HTR8/SVneo 内皮样管形成的调节。黏附分子，特别是 EVT 上表达的 ICAM-1，可能参与这一过程。据我们所知，这是首次报道 ICAM-1 在 EVT 血管生成中的作用，此前已在血管内皮细胞中报道过。
