Hypoxia in skeletal muscles: from physiology to gene expression

Hypoxia is studied as a common clinical factor and a condition associated with a number of diseases. The responses induced by hypoxia in tissue are hypoxia severity and duration dependent. Compared with other tissues, skeletal muscles are relatively tolerant to hypoxia due to its low oxygen demand and its adaptation to hypoxia during physical exercise. This review focuses on molecular responses of skeletal muscles to hypoxia, with an emphasis on signaling pathway. Based on published works, hypoxia in skeletal muscle induces a number of responses involving energy metabolism, redox metabolism and angiogenesis. Signaling pathways including PI3K/Akt signaling, AMPK/mTOR signaling, HIF signaling as well as Notch signaling are widely involved in these responses. Energy metabolism associated signaling pathways such as PI3K/Akt signaling, AMPK/mTOR signaling are active during hypoxia in skeletal muscles.