INVESTIGADORES
RONDA Ana Carolina
congresos y reuniones científicas
Título:
ESTROGEN RECEPTORS, MAPKS AND HSP27 ARE LINKED IN THE ANTIAPOPTOTIC EFFECT OF 17B-ESTRADIOL IN SKELETAL MUSCLE CELLS
Autor/es:
RONDA ANA; VASCONSUELO ANDREA; BOLAND RICARDO
Lugar:
DENVER, COLORADO, USA
Reunión:
Congreso; 31TH ASBMR ANNUAL MEETING; 2009
Institución organizadora:
American Society for Bone and Mineral Reasearch (ASBMR)
Resumen:
We previously showed that 17beta-estradiol (E2), at physiological concentrations, abrogates apoptosis in murine skeletal muscle C2C12 cells. It was demonstrated that the antiapoptotic action of the hormone is mediated by estrogen receptors (ERs), HSP27 and MAPKs. To further characterize the molecular mechanism activated by the steroid in muscle, in the present study we investigated relationships between ERs, MAPKs and HSP27. First, the protective action of E2 was evaluated in primary cultures of mouse skeletal muscle to validate the use of the C2C12 cell line. Comparable results were obtained. The role of ER in activation of ERKs and p38 MAPK by E2 was then studied in presence of ICI182780. By Western blot assays we found that ER participates in ERK2 but not in p38 MAPK phosphorylation. To confirm these results, similar experiments were carried out using C2C12 cells transfected with siRNAs against ER alpha and beta. E2 activated ERK2 through ER alpha but neither isoform was involved in p38 MAPK phosphorylation. In addition, 17beta-estradiol increased HSP27 expression. Evidence obtained showed that the protective role of the hormone requires the participation of HSP27 in C2C12 cells. Furthermore, immunocytochemical and co-immunoprecipitation assays demonstrated colocalization and interaction of HSP27 with ERs, indicating a role for HSP27 mediating the survival signaling of the steroid in muscle cells. These findings contribute to the knowledge of estrogen regulation of skeletal muscle metabolism.