“Role of hsp27 in the anti-apoptotic effects of 17beta-estradiol in skeletal muscle cells”.

VASCONSUELO, ANDREA; MILANESI, LORENA; PRONSATO, LUCÍA; BOLAND, RICARDO

Mar del Plata, Argentina

Congreso; XLIII Reunión anual de la SAIB; 2007

We previously demonstrated antiapoptotic effects 17b-estradiol (E2) at physiological dosis in skeletal muscle cells (C2C12 murine cell line). This protective effect involved estrogen receptors b and a and fast activation of the PI3K/Akt/Bad pathway. In the present study, we established that the antiapoptotic action of E2 requires the participation of heat shock protein 27 (HSP27). RT-PCR and immunocytochemistry assays showed that 17β-estradiol at longer treatment times regulates HSPs expression in C2C12 cells whereas inhibition, by the hormone, of caspase-3 cleavage was evidenced. Moreover, in presence of quercetin, the inhibitory effect of E2 on caspase-3 cleavage was diminished. Co-immunoprecipitation assays demonstrated the interaction of HSP27 with caspase-3 in non-apoptotic cells. These results reveal a novel aspect of the mechanism of HSP27-mediated 17β-estradiol antiapoptotic activity, not reported before for any estrogen target cell, namely modulation of caspase-3 activity.