DHT and E2 as modulators of apoptotic signaling in rat Sertoli cells

• Author(s): Simões, Vera Lúcia Silveira
• Date: 2012
• Persistent ID: http://hdl.handle.net/10400.6/1115
• Origin: Ubi Thesis - Conhecimento Online
• Subject(s): Células de Sertoli; Apoptose; Androgénios; Estrogénios; Caspases
• Document Type: Master Thesis
• Language: English

Description

Apoptosis is an important regulatory event in testicular homeostasis and optimization of sperm production. Sertoli cells (SCs) form the blood-testis barrier creating a special microenvironment where germ cells develop and are under strict hormonal control. Estrogens and androgens are known to play critical roles in SCs functioning, improving their in vitro survival by preventing apoptotic progression. Herein, the influence of 17β-estradiol (E2) and 5α-dihydrotestosterone (DHT) on the apoptotic signaling pathways of immature rat cultured SCs was studied. For that purpose key points of the apoptotic pathway that interact with the mitochondria were chosen and the mRNA expression and/or protein levels of several apoptotic markers such as p53, the pro-apoptotic Bcl2 family member Bax, the apoptosis-inducing factor (AIF) and caspase-3 and 9 were evaluated. Caspase-3 activity was also evaluated as an endpoint marker of apoptosis. E2 and DHT down-regulated the mRNA transcript levels of p53, Bax, caspase-9 and caspase-3. The protein levels of AIF were reduced after DHT treatment while E2-treated cells decreased the cleaved caspase-9 protein levels. The apoptotic endpoint Caspase-3 activity presented highly decreased levels after hormonal treatment. Taken together, these results showed that E2 and DHT act as apoptotic signaling modulators in in vitro immature rat SCs suggesting that androgens and estrogens may be capable of modulating independent pathways of the apoptotic event by regulating different pro-apoptotic factors.