Effects of lipopolysaccharide on beta-catenin, aromatase, and estrogen production in bovine granulosa cells in vivo and in vitro.

Diseases resulting from Gram-negative bacterial infection can induce an immune response by releasing a lipopolysaccharide (LPS) endotoxin that may lead to impaired fertility in cows. To evaluate the effects of LPS on follicular dynamics in a subacute inflammatory disease state, 14 Angus heifers (BW = 413 kg±14) were blocked by weight and assigned to vehicle (n = 7) or LPS treated (n = 7) groups. Heifers received subcutaneous injections of saline (CON) or 2.

BEEF SPECIES-RUMINANT NUTRITION CACTUS BEEF SYMPOSIUM: Maternal immune modulation prior to embryo arrival in the uterus is important for establishment of pregnancy in cattle1.

In 1953, Sir Peter Medawar first recognized the allogeneic properties of a developing conceptus and rationalized that an "immune-tolerant" physiological state must exist during pregnancy. Early theories speculated that the conceptus evaded the maternal immune system completely, but 40 yr after Medawar's observations, Wegmann proposed that the maternal immune system shifts the cytokine profile away from inflammatory cytokine production when an embryo is present. The economic consequences and production losses of subfertile animals have been well documented in studies evaluating calving distribution.

ASAS-SSR Triennial Reproduction Symposium: Looking Back and Moving Forward-How Reproductive Physiology has Evolved: WNTs role in bovine folliculogenesis and estrogen production.

Appreciation of mechanisms that affect steroidogenesis is critical to identifying compromising signals that may decrease reproductive efficiency. Follicle maturation and steroidogenesis requires coordinated actions from the pituitary gonadotropins and local ovarian signaling molecules. β-Catenin (CTNNB1), the lynchpin molecule of canonical wingless-type mouse mammary tumor virus integration site (WNT) signaling, is required for maximal gonadotropin stimulation of steroid production from granulosa (GC) and luteal cells.