Throughout the estrous cycle the oviduct epithelium undergoes
dramatic morphological and functional changes. To
elucidate cyclic cellular events and associated regulation
mechanisms of 17beta estradiol (E2) and progesterone (P4), we
mimicked estrous cycle stages in vitro using a culture system of
primary porcine oviduct epithelium cells (POEC). Cells were
polarized in an air/liquid interface and then treated with E2 and
P4 for physiological time periods: In experiment 1, high
concentration of P4 with low concentration of E2 for 10 days
resembled diestrus; in experiment 2, following the previous
diestrus, sequential high E2 with low P4 for 2.5 days represented
estrus. Histomorphometry and electron microscopy showed
cyclic changes in cellular height, cell population, and cilia
density under the influence of hormone stimulation. Transepithelial
electrical resistance was high in simulated diestrus but
reduced in estrus. Thus, E2 and P4 affect cellular polarity,
transformation of ciliated and secretory cells, as well as
electrical conductivity of oviduct epithelium. Simulation of
diestrus led to significant decrease in expression of hormone
receptors (PGR and ESR1) and other epithelial markers (MUC16,
OVGP1, and HSP90B1), while sequential simulated estrus
caused an increase in these markers. The hormonal regulation
of some marker genes was clearly time-dependent. Furthermore,
POEC showed increased sperm-binding capacity in simulated
estrus. In this study, we also present a novel approach based on
the AndroVision software, which can be routinely utilized as a
parameter for ciliary activity, and for the first time, we showed
fluid movement patterns along the epithelium lining in vitro.