Abstract 1791 Investigation on the impact of sphingolipid disrupting agents on follicle-stimulating hormone receptor function

With over 121 million unintended pregnancies occurring each year worldwide, the study of sexual reproduction hormones is necessary to provide better contraceptive measures. A hormone responsible for sexual reproduction in males and females is follicle-stimulating hormone (FSH). When FSH binds to its receptor (FSHR), signaling cascades are activated, resulting in spermatogenesis in males and oogenesis in females. FSHR resides in microdomains of the cell membrane called lipid rafts, characterized by their high concentrations of cholesterol and sphingolipids. Lipid rafts have been shown to play a role in the control and regulation of the signaling of proteins that reside in them, such as FSHR. Recent research suggests that sphingosine-1-phosphate mediates FSH-induced cell viability but not steroidogenesis. Due to this, we hypothesized that disruption of the sphingolipids would lead to alteration in FSHR signaling, connecting the role of sphingosine-1-phosphate to lipid raft structure. HEK293 cells stably expressing FSHR were treated with myriocin (Myr) or Fumonisin B1 (FB1) to disrupt sphingolipid synthesis. Cells were put through a 30-minute time course of FSH treatment and FSHR signaling was evaluated through western blots monitoring the activation of the p44/42 MAPK pathway. It was expected that both sphingolipid-disrupting agents would display a decrease in p44/42 signaling. Both treatments decreased p44/42 MAPK activation with Fumonsin B1 causing a greater decrease. Although it is unclear how this would affect cell viability in native granulosa cells it is consistent with the effect of alterations in sphingosine-1-phosphate and that the effect is from disruption of lipid rafts. Further testing is needed to fully understand the effect of these lipid raft disruptors on other signaling pathways such as the FSH-dependent production of cAMP. Collectively, research will provide a better understanding of sexual reproductive pathways, hopefully assisting in the creation of more effective and readily available contraceptives. Supported by the Union College student research grants and faculty research funds.