PROJECT SUMMARY/ABSTRACT
The placenta plays a crucial role during pregnancy ensuring fetal growth and development. Successful
pregnancy hinges upon placental adaptations to the maternal environment. The human placenta is classified as
hemochorial and is characterized by extensive intrauterine trophoblast cell invasion. During the course of the
gestation, invasive trophoblast cells or extravillous trophoblast, as they are referred to in humans, migrate from
the placenta into the uterine parenchyma where they act to anchor the placenta to the uterus and remodel uterine
spiral arteries. Uterine NK (NK) cells are major immune cell population at the uterine-placental interface. Uterine
NK cell numbers expand at the uterine-placental interface during early gestation. In addition to functioning as
sentinels, they promote uterine vasculature development by secreting proangiogenic factors and initiating
crosstalk with cellular constituents. Invasive trophoblast cells and uterine NK cells contribute to an effective
partnership in modifying the uterine vasculature. Uterine vascular remodeling is central to providing adequate
nutrient flow to the fetus and normal fetal development. Aberrant modification of the uterine vasculature is directly
linked to preeclampsia, early pregnancy loss, intrauterine growth restriction, pre-term birth, and placental
abruption. Placentation in the rat is characterized by contributions of uterine NK cells and invasive trophoblast
cell to uterine spiral artery remodeling, resembling developmental processes evident in human placentation.
Global genome-editing in the rat is an effective tool for investigating a sub-set of candidate genes implicated in
regulating events at the uterine-placental interface. Some genes possess multiple roles in the biology of the
maternal rat, precluding an evaluation of a specific role in uterine NK cells. The generation of a conditional allele
circumvents this issue. In the proposed research, we will develop a rat model for uterine NK cell specific
conditional alleles using Crispr/Cas9 genome editing. We will generate a transgenic rat model expressing Cre
recombinase in uterine NK cells under control of Ncr1 regulatory sequences and validate the Ncr1-Cre driver rat
strain. The proposed experiments will provide valuable new tools for the scientific community to discern roles
for candidate genes in the regulation of the uterine-placental interface, including uterine spiral artery remodeling,
and thus a novel experimental paradigm to explore the etiology of high-risk pregnancies.