A platform utilizing Drosophila ovulation for nonhormonal contraceptive screening

Abstract

A significant unmet need for new contraceptive options for both women and men remains due to side-effect profiles, medical concerns, and the inconvenience of many currently available contraceptive products. Unfortunately, the development of novel nonsteroidal female contraceptive medicine has been stalled in the last couple of decades due to the lack of effective screening platforms. Drosophila utilizes conserved signaling pathways for follicle rupture, a final step in ovulation that is essential for female reproduction. Therefore, we explored the potential to use Drosophila as a model to screen compounds that could inhibit follicle rupture and be nonsteroidal contraceptive candidates. Using our ex vivo follicle rupture assay, we screened 1,172 Food and Drug Administration (FDA)–approved drugs and identified six drugs that could inhibit Drosophila follicle rupture in a dose-dependent manner. In addition, we characterized the molecular actions of these drugs in the inhibition of adrenergic signaling and follicle rupture. Furthermore, we validated that three of the four drugs consistently inhibited mouse follicle rupture in vitro and that two of them did not affect progesterone production. Finally, we showed that chlorpromazine, one of the candidate drugs, can significantly inhibit mouse follicle rupture in vivo. Our work suggests that Drosophila ovulation is a valuable platform for identifying lead compounds for nonsteroidal contraceptive development and highlights the potential of these FDA-approved drugs as novel nonsteroidal contraceptive agents.

Anex vivoovulation system enables the discovery of novel ovulatory pathways and nonhormonal contraceptive candidates

“…While LH is the established physiological stimulus that triggers ovulation, the complete molecular events of ovulation remain poorly defined due to limited research models. Many systems have been developed to assess ovulatory processes and contraceptive development including non-mammalian models (41). The method of eIVFG has been successfully used to culture follicles of multiple species (42)(43)(44).…”

The bHLH-PAS transcriptional complex Sim:Tgo plays active roles in late oogenesis to promote follicle maturation and ovulation

“…To knockdown or overexpress genes under the control of the above mentioned Gal4 drivers, the following transgenic lines were used: UAS-sim RNAi (Vienna Drosophila Resource Center - VDRC, stock #26888), UAS-tgo RNAi1 (Bloomington Drosophila Stock Center - BDSC, stock #53351), UAS-tgo RNAi2 (BDSC, stock #26740), UAS-hnt RNAi (VDRC, stock #3788), UAS-hnt EP55 (BDSC, stock #5358), and UAS-EcR DN (BDSC, stock #6872). Isolation and identification of stage-14 follicles for follicle rupture assay were performed using Oamb-RFP (Knapp et al, 2019) or 47A04-Gal4 driving UAS-RFP ( 47A04>RFP ) or UAS-RG6 (47A04>RG6; Jiang et al, 2021). The following protein trap lines were used: Mmp2::GFP (Deady et al, 2015), Sim::GFP (VDRC, stock #318096; (Sarov et al, 2016), and NOX::GFP .…”

Recapitulating folliculogenesis and oogenesis outside the body: encapsulated in vitro follicle growth

“…reproductive toxicity and bioactivity (27,31,45,46), and as a means for nonhormonal contraceptive discovery (38). The following protocol focuses on standard eIVFG methods, but various modifications in culture conditions, alginate composition, and uses for eIVFG are well documented in the literature (2-34, 38, 46-49).…”