NMSU Animal and Range
Sciences professor examines placenta development, dysfunction
DATE: 04/06/2020
WRITER: Adriana M.
Chavez, 575-646-1957, adchavez@nmsu.edu
CONTACT: Ryan Ashley, 575-646-4135, ryashley@nmsu.edu
Most expectant mothers know that a placenta is something that forms around
fetuses to nourish and protect them. However, what they may not realize is that
a placenta is considered an organ that only appears during pregnancy.
Ryan Ashley, associate professor of animal science in the College of
Agricultural, Consumer and Environmental Sciences, is exploring placental
development and ways of preventing placental dysfunction, which leads to
pregnancy complications in both humans and livestock. He also is researching
the role of a progesterone receptor commonly seen in the development of
cancerous breast tumors, as placental development actually shares several
similarities with how tumors form.
“When we look at some of the key events of what has to happen when the placenta
forms, it’s really interesting how similar it is to how a tumor forms,” Ashley
said.
An interesting aspect of placental development, Ashley said, is how trophoblast
cells undergo a high rate of mitosis, essentially actively dividing and trying
to invade tissue inside a mother’s uterus to attach and begin placental
development. Meanwhile, these trophoblast cells can avoid attacks from the
mother’s immune system.
“If we think about the cells of the embryo, these cells have different genetic
makeups,” Ashley said. “The mom’s genome in her uterus is actually quite
different from the embryo because the embryo’s got half of its DNA from mom and
the other half from dad. So there’s always been this question in the
reproductive field of why the mom’s immune system does not attack that embryo
because, in essence, this would really be a foreign object the immune system
should try to get rid of.”
Ashley’s research aims to help women experience successful pregnancies. To
thoroughly study placenta development in humans, biomedical researchers have
often turned to animals as models. Ashley is relying on sheep, which experience
a similar placental development to humans.
Because Ashley uses animals in his research, he also can explore ways of
helping livestock carry out successful pregnancies and help avoid future health
problems in both humans and animals.
“We now know that the offspring that result from placental dysfunction are at
increased risk for Type 2 diabetes, obesity, stroke and cardiovascular disease.
All of these health problems have some correlation with how well that placenta
formed and functioned in utero,” Ashley said. “That concept, that the placenta
can not only impact the health of mom and baby during the pregnancy but can
also impact that individual later in life, I think really underscores just how
important the placenta is.”
To determine how to maintain placental health, Ashley has referred to cancer
studies to figure out how cells function in the placenta. He has focused on the
CXCR4 receptor, a receptor commonly seen in various types of cancers. He also
has focused on an FDA-approved compound called AMD3100, which acts as an
antagonist to inhibit the CXCR4 receptor’s functions.
“We’re using the same compound to inhibit the receptor in sheep during the time
the placenta is forming to try and determine the role this particular receptor
is playing,” he said. “This receptor is playing pretty important roles in
vascularization, immune cell recruitment, a lot of things that are important in
how the placenta forms.”
Ashley said he hopes his research using sheep helps answer questions both from
a biomedical research side to help women who are struggling with carrying a
successful pregnancy and also from an agricultural side.
“In couples who are struggling to have children, women most often will lose
their pregnancy early in gestation,” he said. “It’s the same thing with
livestock. Cattle, pigs, sheep and goats most often lose their offspring early
in gestation. Pregnancy loss is a major factor affecting the livestock
industry, and thus economic efficiency in livestock meat and milk production.
Placental dysfunction is a frequent source of pregnancy loss in livestock and
humans, but the underlying causes of impaired placental function are not well
characterized. To dually improve animal and human health as well as farm animal
production, it is imperative to elucidate the mechanisms causing impaired
placental development.”
“Any loss there is detrimental to their livelihood, so there’s always that push
for trying to increase reproductive efficiency in livestock.” Shanna
Lodge-Ivey, head of the department of Animal and Range Sciences and Extension
Animal Science and Natural Resources, said.
“Dr. Ashley and his laboratory are doing amazing work in the field of pregnancy
and cancer research. However, the greatest contribution Dr. Ashley makes to
research is the care and dedication he puts forth to student training. He is
training the next generation of scientists,” said Jon Boren, associate dean and
director of the Cooperative Extension Service.
Ashley’s research exemplifies the important nexus between agriculture and human
health.
“Thanks to the great work of Dr. Ashley,” Boren said, “the College of ACES is
addressing significant issues for our agricultural producers and major health
concerns for all New Mexicans.”
