Madison Reporter

A new study has shown that a gene therapy approach to enhance placental function is safe in monkeys. This research could potentially improve birthweights of human babies and reduce complications associated with early births and developmental difficulties.

Placental insufficiency in humans restricts fetal growth, often resulting in premature delivery and extended neonatal intensive care. Jenna Schmidt, a scientist at the University of Wisconsin–Madison, highlights the importance of the placenta: “The placenta, although transient and typically discarded after pregnancy, is an organ that is so critical to ensuring healthy babies.” Currently, there is no treatment for placental insufficiency.

Risk factors for this condition include high blood pressure, preeclampsia, diabetes, and smoking. However, many cases have no identifiable cause. Schmidt collaborates with Helen Jones from the University of Florida on improving outcomes for pregnancies affected by placental insufficiency.

Jones's lab developed nanoparticles carrying DNA encoding IGF-1, a protein crucial for normal placental development. In pregnancies with fetal growth restriction, lower levels of IGF-1 contribute to smaller birthweights and increased risks of adult diseases.

The nanoparticles were injected into pregnant monkeys' placentas at the Wisconsin National Primate Research Center. The DNA was successfully absorbed and expressed without harming the animals or their fetuses within 24 hours. These findings were published in Molecular Human Reproduction.

“Our studies so far in mice and guinea pig models of placental insufficiency are very encouraging,” says Jones. Her work is supported by the National Institutes of Health’s Eunice Kennedy Shriver National Institute for Child Health and Development. The recent pilot study showed no adverse effects in non-human primate pregnancies.

“This was the first study to test this treatment in macaques and it worked,” Schmidt notes. The transgene expression persisted up to 10 days post-treatment without maternal immune reactions.

Future research will extend therapy through late pregnancy stages in rhesus macaques to assess impacts on mothers and fetuses through birth.

Schmidt states their aim: “Our goal is to improve placental function, extend pregnancies, and see more healthy babies and adults.”

This research received support from the Wisconsin National Primate Research Center Pilot Awards Program via NIH grants P51OD011106 and R01HD113327.