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

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

THERIOGENOLOGY

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2020

0093-691X

In South American camelids more than 98% of pregnancies are carried out in the left uterine horn (LUH). Hence, embryos originated from the right-ovary ovulations must migrate to the contralateral uterine horn (LUH) to implant and survive. The causes for this unique pattern of embryo implantation have not yet been clarified. In general, embryo implantation involves an extensive extracellular matrix (ECM) remodeling within the endometrium, in which collagen and matrix metalloproteinases (MMPs) play an essential role. The deregulation of collagen and MMPs has been related to embryo implantation failure, miscarriage, and infertility. Thus, we hypothesized that in camelids ECM components could be involved in the differential embryo implantation and consequently the high incidence of left horn gestations. Therefore, the aim of this study was to describe and compare ECM components changes in the LUH and right uterine horn (RUH) of non-pregnant and 15 days pregnant alpacas. To test this hypothesis, the collagen content was evaluated by the specific staining Picrosirius Red and ImageJ 1.42q software. Then, the gene expression of several components of the MMPs pathway was determined: MMP-2, -3, -7, -9, and -14, MMPs substrates (COL1A2, COL3A1), MMPs inhibitors (TIMP1, TIMP2), MMPs activator (LGMN), and extracellular matrix metalloproteinase inducer (EMMPRIN). Uterine horns of pregnant alpacas exhibited a marked decrease of collagen content. Contrary, COL1A2 and COL3A1 transcript expression were 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 pregnant animals. Whereas, MMP-2 gene expression was higher in the LUH of non-pregnant and pregnant alpacas. TIMP1 and TIMP2 expression surged during pregnancy, especially in the LUH. In conclusion, ECM components expression displayed a specific pattern depending on the uterine side and the female physiological status, non- and pregnant alpacas. The increased expression of ECM transcripts in the left uterine horn in early pregnant alpacas suggests the involvement of these molecules in a highly regulated process conducting to the implantation process.