INVESTIGADORES
BUITRAGO Claudia Graciela
congresos y reuniones científicas
Título:
. 17b- ESTRADIOL STIMULATES THE PHOSPHORYLATION OF Elk-1 AND CREB TRANSCRIPTION FACTORS TROUGH MAPK ACTIVATION IN MUSCLE CELLS
Autor/es:
RONDA A C; BUITRAGO C; RUSSO DE BOLAND A; BOLAND R
Lugar:
Philadelphia, USA
Reunión:
Congreso; 28th Annual Meeting of American Society for Bone and Mineral Research.; 2006
Resumen:
Steroid hormones, including 17b-estradiol, stimulate by a non-transcriptional mechanism the activities of components of signal transduction pathways in various cell types. The ERK1/2 and p38 MAPK pathways which mediate rapid responses to extracellular stimuli have been extensively characterized. Although there is evidence that 17b-estradiol participates in the development of the skeletal muscle phenotype, the rapid effects of estrogens in this tissue are poorly understood.
In the present work, using the skeletal muscle cell line C2C12 as experimental model, we demonstrate by western blot analysis with phosphospecific antibodies that 17b-estradiol phosphorylates and activates ERK1/2 and p38 MAPK, in a time-dependent fashion, maximal effects being observed at 15 min. The effects of the hormone on ERK and p38 were abolished by MAPK specific inhibitors U0126 and SB203580. 17b-estradiol induced the phosphorylation of CREB and Elk-1 transcription factors in an ERK1/2 and p38-dependent manner. 17b-estradiol also increased c-Fos levels via ERK1/2 and p38 MAPK.
These results suggest that 17b-estradiol regulates early gene expression in skeletal muscle cells through MAPK-mediated activation of CREB and Elk-1, a mechanism congruent with the anabolic action of estrogens in this tissue.