Orphan receptor kinase ROR2 is expressed in the mouse uterus.
OBJECTIVE
Wingless-type mouse mammary tumor virus integration site family, member 5A (WNT5A), is expressed in mouse decidua and is thought to play an important role in decidualization. We examined expression of the receptor for WNT5A, receptor tyrosine kinase-like orphan receptor 2 (ROR2), in the uteri of cycling and pregnant mice.


METHODS
Reverse transcription (RT)-PCR and immunohistochemistry were performed.


RESULTS
RT-PCR revealed that transcripts for Ror2, Wnt3a, Wnt5a and inhibitor of WNT signaling, Dickkopf homolog 1 (Dkk1), were present in the pregnant uterus. Immunohistochemistry revealed that in the virgin uterus, ROR2 is expressed in stromal cells and on the basal side of uterine gland and endometrial epithelial cells. During pregnancy, both the luminal and basal side of uterine gland epithelial cells expressed ROR2, stromal cell expression of ROR2 became more frequent and ROR2 expressing uterine Natural Killer (NK) cells and cells lining the maternal vascular space emerged. Immunofluorescence imaging and flow cytometry revealed that although uterine NK cells expressed ROR2, NK cells of the spleen were ROR2 negative.


CONCLUSIONS
The expression of ROR2 by endometrial epithelial cells may suggest WNT signaling has roles in uterine epithelial cell polarity or implantation. Expression of ROR2 by uterine NK cells may suggest WNT signaling regulates uterine NK cell functions such angiogenesis and regulation of trophoblast migration. In summary, our results show that ROR2 expression by maternal uterine cells is influenced by pregnancy.
Hatta
K
K
Department of Microbiology and Immunology, Queen's University, Kingston, ON K7L 3N6, Canada.
Chen
Z
Z
Carter
A L
AL
Leno-Durán
E
E
Zhang
J
J
Ruiz-Ruiz
C
C
Olivares
E G
EG
MacLeod
R J
RJ
Croy
B A
BA
D000818:Animals; D005260:Female; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics; D007694:Killer Cells, Natural / Q000378:metabolism; D051379:Mice; D011247:Pregnancy; D057050:Receptor Tyrosine Kinase-like Orphan Receptors / Q000096:biosynthesis* / Q000235:genetics; D014599:Uterus / Q000378:metabolism*; D051153:Wnt Proteins / Q000235:genetics; D000071818:Wnt-5a Protein; D060508:Wnt3 Protein; D060509:Wnt3A Protein
C501127:Dkk1 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; D060508:Wnt3 Protein; D060509:Wnt3A Protein; C555511:Wnt3a protein, mouse; C438615:Wnt5a protein, mouse; D057050:Receptor Tyrosine Kinase-like Orphan Receptors; C477010:Ror2 protein, mouse