Researchers found a link between genes and preeclampsia

Date:
July 14, 2020
Source:
University of Helsinki
Summary:
Researchers have showed that HLA-G gene regulates male-to-female
ratio at birth. The study strengthens earlier findings of the
vulnerability of male fetuses to preeclampsia.



FULL STORY ========================================================================== Preeclampsia is globally a leading cause of illness and deaths among
mothers and their babies. This severe pregnancy disorder occurs in up
to five percent of all pregnancies.


========================================================================== Preeclampsia is characterized by the elevated blood pressure of the
mother, and the baby is often delivered preterm and smaller than usual.

Although preeclampsia is cured by the delivery of the placenta, the
mechanism of the disease has still remained unclear.

"It is necessary for a successful pregnancy that the mother's immune
system does not react too strongly and reject the fetus, even though
half of its genes are from the father and thus foreign," says professor
Juha Kere from Karolinska Institutet, Sweden.

Kere coordinated the research to uncover the role of the HLA-G gene in preeclampsia. This gene protects the placenta against mother's immune
attack.

The results of the study have now been published in EBiomedicine,
a journal published by The Lancet.



==========================================================================
"The study reveals mechanisms of preeclampsia. In addition, we showed for
the first time in any species that there is a gene directly influencing
the balance of boys and girls born," says Dr. Satu Wedenoja, the lead
author of the study, from University of Helsinki and Helsinki University Hospital.

Fewer boys are born from preeclamptic pregnancies The researchers
studied 1.79 million births from the Finnish Birth Registry, a national preeclampsia cohort, and a group of stillborn babies. They found that
fewer boys than girls were born from preeclamptic pregnancies, especially
among babies delivered preterm and smaller than usual for the duration
of pregnancy.

According to the results, certain alternative forms of the HLA-G gene
are connected to the male-to-female ratio at birth, the survival of the fetuses, and preeclampsia.

The researchers pointed out that natural selection works even today on
the HLA- G gene. The oldest forms of the HLA-G gene increase the risk of
fetal death and preeclampsia, but might protect the fetus from infections during pregnancy, such as malaria. In placental samples collected from pre-eclamptic pregnancies, the gene expression of HLA-G was low, but
in contrast, the expression was highly elevated for interferon-alpha-1,
a gene involved in autoimmune disorders and tissue rejection.

"The results show that natural selection works through the fetal HLA-G
gene influencing the pregnancy outcome and its complications. The
results further strengthen earlier findings of the vulnerability of
boys to mother's inflammation, late miscarriages, and preeclampsia,"
says Wedenoja.

Based on the results, the researchers propose that a well-known drug
for autoimmune disorders might be tested to prevent or treat preeclampsia.

"The mother's immune system affects the survival of the fetus. This
generally safe drug can also be used during pregnancy and it modulates
immune reactivity, thus potentially preventing preeclampsia," says
Wedenoja.


========================================================================== Story Source: Materials provided by University_of_Helsinki. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Satu Wedenoja, Masahito Yoshihara, Hindrek Teder, Hannu Sariola,
Mika
Gissler, Shintaro Katayama, Juho Wedenoja, Inka M. Ha"kkinen,
Sini Ezer, Nina Linder, Johan Lundin, Tiina Skoog, Ellika
Sahlin, Erik Iwarsson, Karin Pettersson, Eero Kajantie, Mikael
Mokkonen, Seppo Heinonen, Hannele Laivuori, Kaarel Krjutskov,
Juha Kere. Fetal HLA-G mediated immune tolerance and interferon
response in preeclampsia. EBioMedicine, 2020; 102872 DOI:
10.1016/j.ebiom.2020.102872 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/07/200714101246.htm

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