Six proteins could be key to diagnosing early preeclampsia

Preeclampsia is a life-threatening pregnancy complication marked by persistent high blood pressure, which is even more serious when it occurs early in the first trimester. The exact cause of early preeclampsia is unknown and it is difficult to predict, prevent and diagnose. Now in the Journal of Proteome Researchresearchers report six proteins that could be used as targets to diagnose and treat the disease.

The main symptom of preeclampsia is high maternal blood pressure, and severe cases can lead to maternal organ failure, low infant birth weight, or maternal or fetal death. Preeclampsia before 34 weeks of pregnancy poses a higher risk of serious outcomes, especially for the fetus.

But it’s difficult for health care providers to detect this disease before harmful symptoms appear because little is known about its causes. So, Jing Li and colleagues set out to characterize proteins in placental tissue that could offer clues to the cause of early-onset preeclampsia and serve as targets for early detection or treatment.

The researchers collected placental tissue from 30 pregnant women, half with early-onset preeclampsia and half with healthy pregnancies. Li and his colleagues used mass spectrometry to examine molecular fragments from each sample, followed by software to match the fragments to their associated proteins. This process identified 59 proteins present in different amounts (higher or lower) for preeclamptic placental tissue samples compared to healthy placental tissue samples.

The researchers chose 16 of these proteins to target with a different, more sensitive mass spectrometry method that more precisely measured the amounts of each protein. Of these 16 proteins, six were present in statistically different amounts across the tissue sample groups:

• Preeclamptic placental tissue had higher levels of monocarboxylate transporter 4, ERO1-like protein alpha, and pappalysin-2. These proteins participate in protein synthesis and the regulation of growth hormones.
• Preeclamptic placental tissue had lower levels of desmin, caldesmon, and keratin 18. These proteins play a key role in cardiovascular complications, such as cardiac enlargement; blood flow in placental muscle cells; estrogen signaling and cellular health of the uterine lining.

Overall, the results suggest that cardiovascular complications or the estrogen cycle may be linked to the development of early-onset preeclampsia. The team says more research is needed, but the identification of these six proteins is a promising first step toward improved detection and treatment of this potentially deadly disease.