The effects of estrogen and progesterone on prostaglandins and integrin beta 3 (β 3) subunit expression in primary cultures of bovine endometrial cells

In cattle, endometrial expression of integrin α vβ 3 is reduced on day 16 of the estrous cycle, coinciding with the critical period during which the decision is made to initiate luteolysis or continue with pregnancy. The objective of these experiments was to examine the relationship between estrogen and progesterone treatments, endometrial integrin α vβ 3 expression, and prostaglandin F 2α (PGF 2α) and E 2 (PGE 2) production. Epithelial and stromal cells from intercaruncular (ICAR) and caruncular (CAR) bovine endometrium were treated with 17β-estradiol (0.1 and 1.0 nM) and/or progesterone (1.0 and 10 nM) in a manner designed to mimic the steroid fluctuations of the estrous cycle. All cell types expressed estrogen receptor and progesterone receptor mRNA and protein. Intercaruncular stromal cells were the most responsive to steroidal regulation. Estrogen suppressed expression of integrin subunit β 3 mRNA in ICAR stromal cells ( P≤0.05). Progesterone and estrogen+progesterone treated cells did not differ in β 3 expression from controls ( P≥0.05). Steroid treatment did not affect PGF 2α production in any cell type ( P≥0.05), however, estrogen decreased PGE 2 production in all cells except CAR stroma ( P≤0.05). The results indicate that in bovine endometrium expression of integrin α vβ 3 and production of PGE 2 is influenced by estrogen.