INVESTIGADORES
RONDA Ana Carolina
artículos
Título:
ERK and p38 MAPK are involved in the antiapoptotic action of 17beta-Estradiol in skeletal muscle cells
Autor/es:
ANA CAROLINA RONDA; ANDREA VASCONSUELO; RICARDO BOLAND
Revista:
JOURNAL OF ENDOCRINOLOGY
Editorial:
BIOSCIENTIFICA LTD
Referencias:
Año: 2010 vol. 206 p. 235 - 246
ISSN:
0022-0795
Resumen:
17beta-Estradiol E2 stimulates the mitogen-activated protein kinases (MAPKs) in various cellular types. We have shown that the hormone activates extracellular-regulated kinase (ERK) and p38 MAPK in skeletal muscle cells. However, the functions of MAPK modulation by the estrogen in muscle cells have not been studied yet. We have recently reported antiapoptotic actions of E2 in C2C12 cells. Here, the role of MAPKs mediating the hormone effect in muscle cells was investigated. The results showed that cells exposed to 0.5 mM hydrogen peroxide H2O2 presented cytoskeleton disorganization, mitochondrial redistribution, and picnotic/fragmented nuclei. Pretreatment with 10-8 M E2 prevented these morphological apoptotic characteristics, except in the presence of ERK or p38 MAPK inhibitors, U0126 and SB203580 respectively. Mitochondrial membrane integrity was also studied. Preincubation of cultures with 10-8 M E2 abrogated H2O2 effects such as Janus Green oxidation, presence of cytochrome c oxidase activity in the cytoplasm, and SMAC/DIABLO release from mitochondria. When MAPKs were inhibited, the hormone could not prevent mitochondrial membrane damage exerted by oxidative stress. Blocking experiments with small interfering RNAs confirmed that both ERK and p38 MAPKs mediate the antiapoptotic effects of the hormone at the mitochondrial level. Further, some of the molecular mechanisms involved were also investigated. Thus, E2 was able to induce AKT (Ser473) and BAD (Ser112) phosphorylation in C2C12 cells in the absence or in the presence of H2O2  but not when the cultures were incubated with H2O2 and MAPK inhibitors. Altogether, these results show that E(2) exerts a survival action in skeletal muscle cells involving ERK and p38 MAPK activation.