Date of Award
Bachelor of Science
assay, follicle, hormone, cells, regulation
Human follicle stimulating hormone (hFSH) is a gonadotropin responsible for regulating reproductive systems by stimulation of Sertoli cells in males and granulosa cells in females. The hFSH receptor (hFSHR) is a seven transmembrane receptor that belongs to the G protein coupled receptor family. The receptor is functionally connected to a G protein on the inside of the cell. Once FSH activates its receptor, a cascade of signaling begins, resulting in the activation of adenylyl cyclase, which increases the intracellular levels of cAMP. In addition, hFSHR stimulation also activates the p44/42 MAP kinase. The spike in cAMP activates the enzyme protein kinase A (PKA), which triggers a series of downstream effectors resulting in follicular stimulation and gametogenesis.Previous work in the Cohen Lab has shown that hFSHR is located in cholesterol-rich, detergent-resistant microdomains known as lipid rafts. In an HEK293 cell line stably expressing hFSHR, disruption of lipid rafts by the cholesterol chelator methyl beta-cyclodextrin (MCD) interferes with PKA activation. Current research is focused on the relevance of hFSHR lipid raft residency in the human granulosa cell line hGrC1; focusing in particular on the activation of signal transduction pathways by hFSHR. The goal was to develop an enzyme-based, quantitative, non-radioactive assay for cAMP stimulation that could be used to study the effects of lipid raft disruption by MβCD on hFSHR signaling in hGrC1 cells. The galactosidase assay showed quantitative dose-dependent responses to hFSH, which indicated that it should be useful for testing MβCD to further determine lipid raft dependence of hFSHR signaling. Studying the regulation of signaling by hFSHR provides more insight into the receptor function and potentially represents new approaches to contraception or treatment of infertility.
Geisel, Gregory, "Quantification of HFSHR Signaling to Determine LIPID Raft Residency" (2017). Honors Theses. 249.