ECE2023 Poster Presentations Reproductive and Developmental Endocrinology (108 abstracts)
Protein kinase B (Akt) blockade inhibits LH/hCG-mediated 17,20-lyase, but not 17α-hydroxylase activity of CYP17a1 in mouse Leydig cell steroidogenesis
Elia Paradiso 1 , Clara Lazzaretti 1 , Samantha Sperduti 1,2 , Beatrice Melli 3 , Carmela Perri 1 , Sara D’Alessandro 1,3 , Lara Baschieri 1,3 , Elisa Mascolo 1 , Neena Roy 1 , Manuela Simoni 1,2,4 & Livio Casarini 1,2
1Unit of Endocrinology-University of Modena and Reggio Emilia, Department of Biomedical, Metabolic and Neural Sciences, Modena, Italy; 2University of Modena and Reggio Emilia, Center for Genomic Research, Modena, Italy; 3University of Modena and Reggio Emilia, International Ph.D. School in Clinical and Experimental Medicine (CEM), Modena, Italy; 4Azienda Ospedaliero-Universitaria di Modena, Department of Medical Specialties, Baggiovara Hospital, Modena, Italy
Androgens are sex steroid hormones fundamental for human reproduction. In males, they are produced upon luteinizing hormone (LH) action through its specific receptor (LHCGR) expressed in Leydig cells, supporting spermatogenesis. The human chorionic gonadotropin (hCG), acting on the same receptor but not expressed in men, is administered to improve testosterone synthesis in specific pathological contexts, such as hypogonadotropic hypogonadism and cryptorchidism. In vitro studies demonstrated that LHCGR mediates hormone-specific signaling patterns. In particular, LH mediates survival events in human ovarian cells, specifically induced via protein kinase B (AKT) phosphorylation, while hCG is relatively weak in inducing the same effect. We investigated the role of protein kinase B (Akt) in the modulation of Δ4 steroidogenic enzymes’ activity, in the mouse Leydig tumor cell line (mLTC1). Cells were treated for 0-24 h with the 3-times 50% effective concentration of LH and hCG, in the presence and in the absence of the specific Akt inhibitor 3CAI. Cell signaling analysis was performed by bioluminescence resonance energy transfer (BRET) and Western blotting, while the expression of key target genes was investigated by real-time PCR. The synthesis of progesterone, 17α-hydroxy (OH)-progesterone and testosterone was measured by immunoassay. Control experiments for cell viability and caspase 3 activation were performed as well. We found that both hormones activated cAMP and downstream effectors, such as extracellularly-regulated kinase 1/2 (Erk1/2) and cAMP response element-binding protein (Creb), as well as Akt, and the transcription of Stard1, Hsd3b2, Cyp17a1 and Hsd17b3 genes, boosting the Δ4 steroidogenic pathway. Interestingly, Akt blockade decreased selectively Cyp17a1 expression levels, inhibiting its 17,20-lyase, but not the 17-hydroxylase activity (Kruskal Wallis test and Dunn’s post-test; P<0.05; n=9). This effect is consistent with lower Cyp17a1 affinity to 17α-OH-progesterone than progesterone. As a result, cell treatment with 3CAI resulted in 17α-OH-progesterone accumulation at 16-24 h and decreased testosterone levels after 24 h (two-way ANOVA and Bonferroni post-test; P<0.05, n=16). In conclusion, in the mouse Leydig cell line mLCT1, we found substantial Akt dependence of the 17,20-lyase activity and testosterone synthesis. Our results indicate that different intracellular pathways modulate selectively the dual activity of Cyp17a1.
Article tools
My recent searches
My recently viewed abstracts
Authors
Endocrine Abstracts
ISSN 1470-3947 (print) | ISSN 1479-6848 (online)
© Bioscientifica 2024 |
Privacy policy |
Cookie settings
BiosciAbstracts
Bioscientifica Abstracts is the gateway to a series of products that provide a permanent, citable record of abstracts for biomedical and life science conferences.
Find out more