MODIFICATIONS OF EXTRACELLULAR MATRIX FEATURES IN THE LEFT AND RIGHT UTERINE HORNS DURING THE EMBRYO PRE-IMPLANTATION PERIOD IN VICUGNA PACOS

DANIELA E BARRAZA; RENATO ZAMPINI; SILVANA APICHELA; JOEL PACHECO; MARTIN E. ARGAÑARAZ

THERIOGENOLOGY

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2020

0093-691X

More than 98% of the pregnancies in South American camelids iscarried out in the left uterine horn (LUH). Hence, embryos originatedfrom right-ovary ovulations have to migrate to the contralateral or leftuterine horn (LUH) to implant and survive. A reason for this uniquepattern of embryo implantation has not been elucidated yet. In general,embryo implantation involves an extensive extracellular matrix (ECM)remodeling within the endometrium, in which collagen and matrixmetalloproteinases (MMPs) play an essential role. Deregulation ofcollagen and MMPs has been related to embryo implantation failure,miscarriage, and infertility. Therefore, we hypothesized that ECMcomponents in camelids could be involved in differential embryoimplantation and consequently the high incidence of left horn gestations.The aim of this study was to describe and compare changes in ECMcomponents in the left and right uterine horn of non-pregnant and 15 daypregnant alpacas. To test this hypothesis, the collagen content wasevaluated by specific staining with Picrosirius Red and using ImageJ1.42q software. Subsequently, gene expression of the following componentsof the MMP pathway was determined: MMP-2, -3, -7, -9, and -14, MMPsubstrates (COL1A2 and COL3A1), MMP inhibitors (TIMP1 and TIMP2), LGMN,an MMP activator, and EMMPRIN, an extracellular matrix metalloproteinaseinducer. Uterine horns of pregnant alpacas exhibited a marked decrease incollagen content. In contrast, transcript expression of COL1A2 and COL3A1was higher in the LUH of pregnant alpacas. Gene expression of MMP-3, -7,-9, -14, LGMN, and EMMPRIN were also higher in the LUH of pregnantanimals, whereas MMP-2 gene expression was higher in the LUH of bothpregnant and non-pregnant alpacas. Expression of TIMP1 and TIMP2increased during pregnancy, with higher values in the LUH. In conclusion,expression of ECM components displayed a specific pattern depending onthe uterine side and the physiological status (pregnant vs non-pregnant)of the animal. The increased expression of ECM transcripts in the leftuterine horn during early pregnancy in alpacas suggests the involvement of these molecules in a highly regulated process leading to theimplantation process.