Meeting Abstract
Endometrial cells lining the uterus are critical for pregnancy success. These cells support implantation and early placental development. In humans, the sex steroids estradiol(E2) and progesterone(P4) modulate endometrial cells by stimulating proliferation, altering cell function, and directing cells to form glands in the uterine lining in preparation for blastocyst implantation. However, the pattern of sex steroid production across the reproductive cycle varies in other animals. For example, in humans estradiol remains elevated above baseline after ovulation, whereas estradiol in the domestic cat drops to baseline (<20 pg/mL). We are interested in whether sex steroids regulate feline endometrial cell growth and organization. We cultured isolated endometrial cells in a 3D in vitro system and treated them with E2 and P4 at concentrations corresponding to different periods in the estrous cycle. We also treated cells with E2 or P4 alone to determine whether these steroid hormones act independently. From images of the treated cells, we quantified morphological changes in cell growth. Steroid hormone treatment decreased the size of 3D structures formed in vitro (AOV, P < 0.001; Tukey’s HSD: P < 1.6e-5). However, progesterone alone increased the number of 3D structures relative to the estradiol treatment (AOV, P < 0.05; Tukey’s HSD: P < 0.003). Analysis of mixed steroid treatments are on-going; however, our findings thus far suggest that feline endometrial cells respond to sex steroids in similar ways to humans. We are using quantitative PCR to measure the expression of genes related to endometrial tissue function, which will further validate that cell organizational changes reflect functional shifts that occur in response to steroids.
