Cytoskeletal remodelling proteins identified in fetal-maternal interface in pregnant women and rhesus monkeys

The uterus undergoes dramatic remodelling in preparation for embryo implantation and pregnancy establishment. A receptive uterus is pivotal for embryo attachment, implantation and the eventual formation of a hemochorial placenta. We have previously identified by proteomics that tropomyosin alpha-4 chain (TPM4), protein disulfide isomerase A1 (PDIA1) and src substrate cortactin 8 (SRC8) were up regulated in the decidualized stromal cells during the late secretory phase of the menstrual cycle in women. These three proteins are associated with cytoskeletal remodelling. This study determined the localization of these three cytoskeletal proteins in the fetal-maternal interface including the decidual cells in the 1st trimester of pregnancy in women and rhesus monkeys. Immunohistochemical analysis revealed that TPM4, PDIA1 and SRC8 were all expressed by the decidual cells and the wall of the spiral arterioles in pregnant women. Similar expression pattern were also found in the rhesus monkey. In addition, TPM4, PDIA and SRC8 were also localized to the trophoblast cells, further highlighting the importance of these cytoskeletal remodelling proteins in early pregnancy.