title: Interactions of thyroid hormone and FSH in the regulation of rat granulosa cell apoptosis.
abstract: Thyroid hormone (TH) is important for normal reproductive function. Our previous studies indicate that FSH increases preantral follicle growth in vitro, a response markedly enhanced by triiodothyronine (T3). However, the nature of this hormonal interaction is poorly understood. The objective of this study was to determine if and how T3 modulate FSH-induced expression and actions of granulosa cell intracellular survival and death intermediates. We investigated the possible involvement of Src and PI3K/Akt pathway in the regulation of granulosa cell survival. We demonstrated that, while ineffective alone (0.1-100 nM), T3 markedly enhanced FSH (100 ng/ml)-induced granulosa cell phospho-Src and phospho-Akt contents and Xiap expression in vitro. The effects of T3 were concentration-dependent, with maximal responses at 1.0 nM. FSH alone decreased Fas Ligand (FasL) content irrespective of the presence of T3. Co-treatment of cell with T3 and FSH decreased Fas content, although neither hormone alone elicited a significant response. Taken together, the present study demonstrates that T3 potentiates the cell survival action of FSH through Src- and PI3K-mediated Xiap up-regulation and decreased Fas and FasL expression.
authors.affiliation: State Key Laboratory for Agro-Biotechnology, College of Biological Science, China Agricultural University, Beijing, Peoples' Republic of China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.forename: Guoliang
authors.initials: G
authors.lastname: Xia
authors.forename: Benjamin K
authors.initials: BK
authors.lastname: Tsang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001483:Base Sequence; D015153:Blotting, Western; D017931:DNA Primers; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D006107:Granulosa Cells / Q000166:cytology*; D020287:In Situ Nick-End Labeling; D016133:Polymerase Chain Reaction; D051381:Rats; D013963:Thyroid Hormones / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D013963:Thyroid Hormones; D005640:Follicle Stimulating Hormone