Follicle Stimulating Hormone (FSH) Induction of Aromatase and Luteinizing Hormone Receptor (LHR) is Dependent, in part, on the Protein Kinase A Regulatory-Rho-Guanine Nucleotide Exchange Factor AKAP13

Monday, September 22, 2014 — Poster Session II
4:00 p.m. – 6:00 p.m.	FAES Academic Center	NICHD	MOLBIO-4

Authors

• KM Devine
• PH Driggers
• SC Su
• JH Segars

Abstract

Background: FSH drives ovarian folliculogenesis via protein kinase A (PKA). PKA-anchoring-protein-13 (AKAP13) is induced during human ovary follicular development and regulates PKA activation through RII-regulatory-subunit binding. We sought to determine the role of AKAP13 in FSH receptor signaling in COV434, an FSH-responsive human granulosa cell line. Methods: qRT-PCR confirmed endogenous expression of akap13. Cultured cells were transfected with control siRNA or siRNA directed against akap13 and treated with 1IU/mL FSH for 10min-72h. qRT-PCR quantified aromatase and lhr transcripts. Western Blot assessed relative CREB phosphorylation. Results: FSH treatment resulted in a 2.5-fold induction of aromatase mRNA by 32h. Relative CREB phosphorylation increased ∼2 fold (p=0.03) after 10min FSH treatment. AKAP13 siRNA transfection decreased akap13 mRNA 40-85%. AKAP13 knockdown lowered basal transcripts of aromatase 50-60% (p=0.04). Induction of aromatase and lhr message following ∼48h FSH treatment was reduced 56% (p<0.001) and 50% (p<0.001) respectively. Conclusions: Optimal lhr and aromatase messages in COV434 required akap13. Our findings suggest that AKAP13 may be required in granulosa cells for normal FSH induction of LHR and aromatase, which are essential for ovulation. Further studies into the molecular impact of AKAP13 deficiency in the ovary has potential to yield significant insight into human ovulatory disorders.

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