Stained blood vessels in the mouse placenta. Mice without the gene Inf2 had significantly less blood vessels in their placentas than healthy mice. Image provided by Lamm et al. (CC BY 4.0)

In utero

The INF2 gene is necessary for the placenta to develop properly.

The placenta is an organ that develops with the baby during pregnancy and links the baby with his or her mother. This connection allows mom and baby to communicate throughout the pregnancy to share nutrition and growth signals, and to coordinate their immune systems. Abnormal placental growth can have lasting, harmful effects on the health of the mother and baby.

Specialized cells in the placenta called trophoblasts help the embryo implant into the mother’s womb and direct the flow of nutrient- and oxygen-rich blood from the mother to the baby. If trophoblasts do not penetrate deeply enough into the womb, the mother will be at risk for developing a life-threating condition called preeclampsia, which occurs when her blood pressure becomes dangerously high. The only treatment is to deliver the baby. Her baby will also be at risk of poor growth and premature delivery. Scientists still do not know exactly how the trophoblasts invade the womb and what goes wrong that causes placental abnormalities.

Now, Lamm et al. show that losing a gene called Inverted Formin 2, or Inf2 for short, which helps cells to form structures, causes placental abnormalities and preeclampsia symptoms in mice. In the experiments, trophoblasts in mice without Inf2 were unable to invade the womb properly. The Inf2-lacking mice had fewer blood vessels feeding the placenta. These mice developed high blood pressure late in pregnancy, which returned to normal after their babies were born and the placentas expelled. During pregnancy, the placentas of Inf2-lacking mice were less efficient in transporting nutrients and gases, and their fetuses grew slowly and showed signs of distress.

This suggests that the INF2 gene is necessary for the placenta to develop properly. Learning more about what can go wrong as the placenta forms might help physicians predict or prevent preeclampsia, fetal growth problems, and other placental abnormalities. More studies could determine if treatments targeting INF2 would improve the development of the placenta, protect mothers from preeclampsia, and prevent conditions that slow down the babies’ growth.

To find out more

Read the eLife research paper on which this eLife digest is based:

Inverted formin 2 regulates intracellular trafficking, placentation, and pregnancy outcome

eLife is an open-access journal that publishes outstanding research in the life sciences and biomedicine.

This text was reused under the terms of a Creative Commons Attribution 4.0 International License.