Live Imaging of Mitochondria in Kidney Tissue

Kidneys are highly aerobic organs and their function is tightly coupled to mitochondrial energy production. Renal tubular cells, particularly the proximal tubule (PT), require an abundance of mitochondria to provide sufficient energy for regulating fluid and electrolyte balance. Meanwhile, mitochondrial defects are implicated in a range of different kidney diseases. Multiphoton microscopy (MP) is a powerful tool that allows detailed study of mitochondrial morphology, dynamics, and function in kidney tissue. Here, we describe how MP can be used to image mitochondria in kidney tubular cells, either ex vivo in tissue slices or in vivo in living rodents, using both endogenous and exogenous fluorescent molecules. Moreover, changes in mitochondrial signals can be followed in real time in response to different insults or stimuli, in parallel with other important readouts of kidney tubular function, such as solute uptake and trafficking.