Ezrin immunoexpression in trophoblast cells of the equine placenta

• Published in: Journal of equine veterinary science Vol. 125; p. 104759
• Main Authors: Campos, Isabela Syllos, Batista, Bárbara Paula Dos Santos, Matos, Ana Carina Heil Silva, Leite, Juliana Da Silva, Gomes, Gustavo Mendes, Gomes, Letícia Patrão De Macedo, Pinna, Aline Emerim, Ferreira, Ana Maria Reis
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-06-2023
• ISSN: 0737-0806; 1542-7412
• DOI: 10.1016/j.jevs.2023.104759

Ezrin expression in microcotyledons and trophoblastic cells plays an important role in vascularization and maternal-fetal exchange. Ezrin is a membrane cytoskeletal crosslinker protein that helps regulate several cytoskeletal-related functions, including cell adhesion (Souza.et.al. Research in Veterinary Science.2023. 154: 84-88). Here, we describe the histopathological findings and expression as detected by an ezrin-specific antibody in pregnant and non-pregnant uterine horns of normal equine placentas. Eighteen placentas from embryo recipient mares of the Mangalarga Machador breed were collected at delivery (n=18; age 4-8 years). All placentas were evaluated for macroscopic characteristics. As part of the histopathological evaluation, pregnant and non-pregnant horn samples underwent hematoxylin-eosin staining to grade and compare the arrangement and vascularity of microcotyledons and allantochorions. Silanized slides were immunostained with an ezrin-specific antibody (clone: H-276; rabbit polyclonal-IgG; Santa Cruz; dilution: 1:500μl; LSAB+ Dako, Carpenteria, California, USA). A sample of human breast ductal adenocarcinoma was used as the positive control. For the negative control, the primaryantibody was replaced with a primary antibody isotype. In the microscopic analysis, the microcotyledonary arrangement in the pregnant horn was more intense than in the non-pregnant horn, except for one case. In terms of vascularization, the horns did not differ in the number or intensity of vessels in the microcotyledons and allantochorion. Ezrin antibody expression in placental horns was more intense in the proximal region of the microcotyledons compared with the basal lamina of the allantochorion and was diffused throughout the microcotyledonary network. The pregnant horn showed greater ezrin expression in trophoblasts compared to the non-pregnant horn. The two horn types showed similar color intensity in most samples however, ezrin was expressed mildly in the pregnant horn, while the non-pregnant horn from the same placenta showed moderate to intense ezrin expression. These observations may reflect a way of modulating maternal–fetal exchange, because trophoblast cells have this function. In summary, ezrin was expressed in trophoblast cells located in the microcotyledons of equine placentas, suggesting that this protein may play a role at the maternal–fetal interface.