American journal of physiology. Cell physiology
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Am. J. Physiol., Cell Physiol. · Aug 2012
Denervation-induced mitochondrial dysfunction and autophagy in skeletal muscle of apoptosis-deficient animals.
Skeletal muscle undergoes remarkable adaptations in response to chronic decreases in contractile activity, such as a loss of muscle mass, decreases in both mitochondrial content and function, as well as the activation of apoptosis. Although these adaptations are well known, questions remain regarding the signaling pathways that mediated these changes. Autophagy is an organelle turnover pathway that could contribute to these adaptations. ⋯ Interestingly, denervation markedly increased the localization of LC3II to subsarcolemmal mitochondria, and this was more pronounced in the DKO animals. Thus denervation-induced muscle disuse activates both apoptotic and autophagic signaling pathways in muscle, and autophagic protein expression does not exhibit a compensatory increase in the presence of attenuated apoptosis. However, the absence of Bax and Bak may represent a potential signal to trigger mitophagy in muscle.