Human fallopian tube epithelium co-culture with murine ovarian follicles reveals crosstalk in the reproductive cycle

Do interactions between human fallopian tube epithelium and murine follicles occur during an artificial reproductive cycle in a co-culture system in vitro? In a co-culture system, human fallopian tissues responded to the menstrual cycle mimetic by changes in morphology and levels of secreted factors, and increasing murine corpus luteum progesterone secretion. The entire fallopian tube epithelium, including ciliated and secretory cells, can be regulated in the reproductive cycle. Currently, there are no in vitro culture models that can monitor fallopian tissues in real time in response to factors produced by the ovary. In addition, there are no reports on the impact of fallopian tissue on ovarian function during the menstrual cycle. Human fallopian tissue (n = 24) was obtained by routine hysterectomies from women (aged 26-50 years, mean age = 43.6) who had not undergone exogenous hormonal treatment for at least 3 months prior to surgery. CD1 female mice were used for ovarian follicle isolation. The human fallopian epithelium layers were either co-cultured with five murine multilayer secondary follicles (150-180 μm follicles, encapsulated in one alginate gel bead) for 15 days or received stepwise steroid hormone additions for 13 days. The fallopian tissue morphology and cilia beating rate, as measured by an Andor Spinning Disk Confocal, were investigated. Oviduct-specific glycoprotein 1 (OVGP1), human insulin-like growth factor 1 (hIGF1), vascular endothelial growth factor A (VEGF-A) and interleukin 8 (IL8) as biological functional markers were measured either by ELISA or western blot to indicate dynamic changes in the fallopian epithelium during the reproductive cycle generated by mouse follicles or by stepwise steroid hormone induction. Three or four patients in each experiment were recruited for replicates. Data were presented as mean ± SD and further analyzed using one-way ANOVA followed by Tukey's multiple comparisons test. The cultured fallopian tube epithelium responded to exogenous steroid hormone stimulation, as demonstrated by enhanced cilia beating rate (~25% increase, P = 0.04) and an increase in OVGP1 secretion (P = 0.02) in response to 1 nM estradiol (E ) treatment when compared with 0.1 nM E . Conversely, 10 nM progesterone plus 1 nM E suppressed cilia beating rate by ~30% (P = 0.008), while OVGP1 secretion was suppressed by 0.1 nM E plus 50 nM progesterone (P = 0.002 versus 1 nM E alone). Human fallopian tube epithelium was co-cultured with m