Thermotaxis of human trophoblastic cells

The objective of this study was to determine whether cultured human trophoblasts migrate in response to changes in oxygen tension or temperature. Human trophoblastic cells distributed homogenously within individual wells of standard culture plates were subjected to oxygen and thermal gradients. The redistribution of cells was determined 90 min to 18 h after these gradients had been established. Trophoblastic cells did not migrate in response to gradients of oxygen or carbon dioxide applied in this manner. In contrast, the cells migrated in response to thermal gradients of less than 1 degree C in the direction of the warmer temperature. The response began within minutes, was reversed by a change in the direction of the thermal gradient, and was inhibited at high cell concentrations. Migration was independent of proliferation or protein synthesis, but required microfilament assembly. The capacity of trophoblasts to migrate in response to small difference of temperature within the physiologic range may contribute to the initiation of placental development before contact with the maternal circulation has been established.