Biological Roles of Hydroxysteroid (11-Beta) Dehydrogenase 1 (HSD11B1), HSD11B2, and Glucocorticoid Receptor (NR3C1) in Sheep Conceptus Elongation1

Abstract

In sheep, the elongating conceptus synthesizes and secretes interferon tau (IFNT) as well as prostaglandins (PGs) and cortisol. The enzymes, hydroxysteroid (11-beta) dehydrogenase 1 (HSD11B1) and HSD11B2 interconvert cortisone and cortisol. In sheep, HSD11B1 is expressed and active in the conceptus trophectoderm as well as in the endometrial luminal epithelia; in contrast, HSD11B2 expression is most abundant in conceptus trophectoderm. Cortisol is a biologically active glucocorticoid and ligand for the glucocorticoid receptor (NR3C1 or GR) and mineralocorticoid receptor (NR3C2 or MR). Expression of MR is not detectable in either the ovine endometrium or conceptus during early pregnancy. In tissues that do not express MR, HSD11B2 protects cells from the growth-inhibiting and/or proapoptotic effects of cortisol, particularly during embryonic development. In study one, an in utero loss-of-function analysis of HSD11B1 and HSD11B2 was conducted in the conceptus trophectoderm using morpholino antisense oligonucleotides (MAOs) that inhibit mRNA translation. Elongating, filamentous conceptuses were recovered on Day 14 from ewes infused with control morpholino or HSD11B2 MAO. In contrast, HSD11B1 MAO resulted in severely growth-retarded conceptuses or conceptus fragments with apoptotic trophectoderm. In study two, clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 genome editing was used to determine the role of GR in conceptus elongation and development. Elongating, filamentous-type conceptuses (12-14 cm in length) were recovered from ewes gestating control embryos (n = 7/7) and gestating GR-edited embryos (n = 6/7). These results support the idea that the effects of HSD11B1-derived cortisol on conceptus elongation are indirectly mediated by the endometrium and are not directly mediated through GR in the trophectoderm.

Endometrial luminal epithelial cells sense embryo elongation in the roe deer independent of interferon-tau†

“…The deviation in gene expression in roe deer endometrium versus other species might reflect a time-dependent and/or speciesdependent effect. The cortisone reductase HSD11B1 was higher abundant during elongation in the LE as reported earlier in sheep, where HSD11B1 has been shown to be involved in conceptus elongation [29]. We hypothesize that cortisone metabolism is involved in inducing and/or supporting embryo elongation.…”

NANOG is required to form the epiblast and maintain pluripotency in the bovine embryo

“…Three gRNAs with the fewest predicted off‐targets were selected for further testing. The selected gRNAs ordered within a gBlocks® Gene Fragments (IDT Technologies, San Jose, CA) containing a promoter region for T7 RNA polymerase (Brooks, Burns, & Spencer, ).…”

Prostaglandin‐endoperoxide synthase 2 is not required for preimplantation ovine conceptus development in sheep

“…The amount of IFNT in the uterine flush was determined by a western dot blot analysis using an antibody specific for IFNT raised in rabbits as previously described (Brooks, Burns, & Spencer, ). Protein content of ULF was quantified by Qubit protein assay.…”