High resolution spatial investigation of intracellular oxygen in muscle cells.

Molecular oxygen (O2) is one of the most functionally relevant metabolites. O2 is essential for mito-chondrial aerobic respiration. Changes in O2 affect muscle metabolism and play a critical role in the maintenance of skeletal muscle mass, with lack of sufficient O2 resulting in detrimental loss of muscle mass and function. How exactly O2 is used by muscle cells is less known, mainly due to the lack of tools to address O2 dynamics at the cellular level. Here we discuss a new imaging method for the real time quantification of intracellular O2 in muscle cells based on a genetically encoded O2-responsive sensor, Myoglobin-mCherry. We show that we can spatially resolve and quantify intracellular O2 concentration in single muscle cells and that the spatiotemporal O2 gradient measured by the sensor is linked to, and reflects, functional metabolic changes occurring during the process of muscle differentiation. HighlightsO_LIReal time quantitation of intracellular oxygen with spatial resolution C_LIO_LIIdentification of metabolically active sites in single cells C_LIO_LIOxygen metabolism is linked to muscle differentiation C_LI