Placental Protein Levels Offer Insights into Early-Onset Preeclampsia

A potentially fatal pregnancy complication, preeclampsia is characterized by persistently elevated blood pressure, which is exacerbated when it develops early in the first trimester. Predicting, preventing, and diagnosing early-onset preeclampsia is challenging, and its precise cause is unknown.

Researchers have now reported on six proteins that may be targeted for the diagnosis and treatment of the illness in the ACS Journal of Proteome Research.

High maternal blood pressure is the primary sign of preeclampsia, and severe cases can result in low birth weight, maternal organ failure, or fetal or maternal mortality. There is an increased risk of serious consequences, particularly for the fetus, if preeclampsia develops before 34 weeks of pregnancy.

However, because little is known about its causes, it is challenging for medical professionals to identify this disorder before dangerous symptoms manifest. Therefore, Jing Li and associates set out to identify proteins in placenta tissue that could be targeted for early detection or treatment and provide hints regarding the etiology of early-onset preeclampsia.

The researchers collected placenta tissue from around 30 pregnant women, half with early-onset preeclampsia and the other half with healthy pregnancies. Li and associates screened each sample for molecular fragments using mass spectrometry and then utilized software to match the fragments to the proteins they were connected with.

In comparison to healthy placenta tissue samples, the procedure identified 59 proteins that were present in preeclamptic placenta tissue samples in varying levels (either higher or lower). To more accurately detect the levels of each protein, the researchers selected 16 of these proteins to target using a new, more sensitive mass spectrometry approach. Six of these 16 proteins varied statistically in their levels among the tissue sample groups:

• Pappalysin-2, ERO1-like protein alpha, and monocarboxylate transporter 4 were all more abundant in preeclamptic placenta tissue. These proteins play a role in growth hormone regulation and protein synthesis.
• Desmin, caldesmon, and keratine 18 were all less abundant in preeclamptic placenta tissue. These proteins are important for blood flow in placental muscle cells, uterine lining cell health, estrogen signaling, and cardiovascular problems such as an enlarged heart.

Overall, the findings point to the possibility that early-onset preeclampsia may be caused by the estrogen cycle or cardiovascular issues. Finding these six proteins is a promising first step toward better identification and treatment of this potentially fatal illness, but the team warns further research is required.