High resolution spatial investigation of intracellular oxygen in muscle cells

Molecular oxygen (O ₂ ) is one of the most functionally relevant metabolites. O ₂ is essential for mito-chondrial aerobic respiration. Changes in O ₂ affect muscle metabolism and play a critical role in the maintenance of skeletal muscle mass, with lack of sufficient O ₂ resulting in detrimental loss of muscle mass and function. How exactly O ₂ is used by muscle cells is less known, mainly due to the lack of tools to address O ₂ dynamics at the cellular level. Here we discuss a new imaging method for the real time quantification of intracellular O ₂ in muscle cells based on a genetically encoded O ₂ -responsive sensor, Myoglobin-mCherry. We show that we can spatially resolve and quantify intracellular O ₂ concentration in single muscle cells and that the spatiotemporal O ₂ gradient measured by the sensor is linked to, and reflects, functional metabolic changes occurring during the process of muscle differentiation.

Real time quantitation of intracellular oxygen with spatial resolutionIdentification of metabolically active sites in single cellsOxygen metabolism is linked to muscle differentiation.