INVESTIGADORES
VASCONSUELO Andrea Anahi
congresos y reuniones científicas
Título:
Protective Role of Sex Hormones in Apoptosis of Skeletal Muscle
Autor/es:
PRONSATO LUCIA; ANA RONDA; MILANESI LORENA; VASCONSUELO ANDREA; RICARDO BOLAND
Lugar:
Buenos Aires
Reunión:
Congreso; AAOMM; 2009
Resumen:
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The loss of muscle mass and
strength with aging, also referred to as sarcopenia, is a prevalent condition
among elderly and predicts adverse outcomes, including disability,
institutionalization and mortality. Sarcopenia has been associated to a deficit
of sex hormones since the levels of estrogens and/or testosterone decline upon
ageing. Although the mechanisms underlying sarcopenia are far for being
clarified, evidence suggests that an age-related acceleration of myocyte loss
via apoptosis might represent a mechanism responsible for muscle loss
performance. Furthermore, increased levels of apoptosis have also been reported
in old rats undergoing muscle atrophy. We previously demonstrated that 17β-estradiol
(E2) inhibits apoptosis in C2C12 murine skeletal muscle cells through estrogen
receptors (ERs) with non classical localization involving PI3K/Akt, MAPKs and
HSP27. Here, using siRNAs to silence ER isoforms, we show that E2 activates
ERK2 through ERa and p38 MAPK
stimulation is independent of ERs. We confirmed that E2 is able to abrogate
apoptosis through MAPKs in primary cultures of neonate mouse skeletal muscle.
Also, we prove that testosterone blocks apoptosis as E2. Typical changes of
apoptosis such as nuclear fragmentation, cytoskeleton disorganization,
mitochondrial reorganization/dysfunction and cytochrome c release induced by H2O2
were abolished when C2C12 cells were preincubated with testosterone. Further
studies are required to establish whether there is a parallelism between the
mechanisms triggered by both hormones which might be involved in muscle
pathologies associated to apoptosis. The data presented deepen the knowledge on
the molecular basis of sex hormone-dependent sarcopenia.