Conditioned medium from primary cytotrophoblasts, primary placenta-derived mesenchymal stem cells, or placental tissue promoted HUVECs angiogenesis in vitro

Abstract

Background As a large capillary network, the human placenta plays an important role throughout pregnancy. Placental vascular development is complex and delicate and involves many types of placental cells, such as trophoblasts, and mesenchymal stem cells. There has been no systematic, comparative study on the roles of these two groups of placental cells and the whole placental tissue in the placental angiogenesis. In this study, primary cytotrophoblasts (CTBs) from early-pregnancy and primary human placenta-derived mesenchymal stem cells (hPDMSCs) from different stages of pregnancy were selected as the cell research objects, and full-term placental tissue was selected as the tissue research object to detect the effects of their conditioned medium (CM) on HUVECs angiogenesis.Methods We successfully isolated primary hPDMSCs and CTBs, collected CM from these placental cells and placental tissue, and then evaluated the effects of the CM on a series of angiogenic processes in HUVECs in vitro. Furthermore, we measured the levels of angiogenic factors in the CM of placental cells or tissue by an angiogenesis antibody array.Results The results showed that not only placental cells but also placental tissue, to some extent, promoted HUVECs angiogenesis in vitro by promoting proliferation, adhesion, migration, invasion, and tube formation. We also found that primary placental cells in early pregnancy, whether CTBs or hPDMSCs, played more significant roles than those in middle and full-term pregnancy. The effect of CM from placental tissue was better than that of CM from a single placental cell type. The semiquantitative angiogenesis antibody array showed that, in placental tissue-derived CM, 18 of the 43 angiogenic factors had obvious spots, and the levels of 5 factors (including CXCL-5, GRO, IL-6, IL-8, and MCP-1) were the highest. The levels of these 18 angiogenic factors in placental tissue were higher than those in any single placental cell type.Conclusions CM obtained from placental cells (primary CTBs or hPDMSCs) or placental tissue contained proangiogenic factors and promoted HUVECs angiogenesis in vitro. Therefore, our research is helpful to better understand placental angiogenesis regulation and provides theoretical support for the clinical application of placental components, especially placental tissue-derived CM, in vascular tissue engineering and clinical treatments.