Elucidating the Impact of Secretome Derived from Mesenchymal Stem Cell and Uterine Epithelial Cells During <i>In Vitro</i> Blastocyst Production in Buffalo

Abstract

One challenge that needs to be addressed in animal embryo production is to create the appropriate in vitro culture to improve the blastocyst rate and produce high-quality embryos. Buffalo Mesenchymal Stem Cells (MSCs) were derived from Wharton’s jelly and expanded in vitro. Conditioned media (secretome) was collected from well-characterized WJMSCs at 3rd passage. Similarly, buffalo Uterine Epithelial Cells (UECs) were derived from nongravid uteri and expanded in vitro. The secretome was collected from a well-characterized first passage UECs monolayer primed with steroid hormones (progesterone 3.14ng/ml and estradiol-17β 5 31pg/ml). Culture media was replaced with non-serum media, and the media was collected after 72h. Day 4 IVF-derived embryos were cultured in three groups: in regular mSOF media (Group I), mSOF replaced with 50% CM derived from MSCs (Group II), and mSOF replaced with 50% CM from steroid-treated UECs (Group III). Blastocyst rates were evaluated on day 09 post IVF. The blastocyst rate in group II was significantly higher (p < 0.05) than the control group, which was further enhanced in group III. In vitro co-culture of embryos with the secretome derived from mesenchymal stem cells or steroid-treated UECs improved the blastocyst rate. UECs and their secretions are essential to establish uterine receptivity and to mimic the internal in vivo environment.