The Role and Expression of TFEB in Contracting Skeletal Muscle Myotubes

The maintenance of the mitochondrial pool is essential for the beneficial effects that are seen following an acute bout of contractile activity. Mitochondrial quality control consists of two pathways, mitochondrial biogenesis and mitochondrial autophagy, termed mitophagy. However, the mechanisms and activation of mitophagy in skeletal muscle remain generally elusive. Specifically, we are interested in mitophagy that occurs during or immediately following exercise in skeletal muscle. Recently, transcription factor EB (TFEB) has been identified as a key player as the master regulator of lysosomal biogenesis. To identify the unknown role that TFEB plays in mitophagy, we utilized a cell culture model of skeletal muscle myotubes. We examined the transcription and activation of TFEB and its downstream targets following acute exercise and recovery and following chronic exercise. We found that TFEB is activated following exercise and that it plays an important role in the transcription of mitophagy genes.