Autophagy assessment in circulating leukocytes.

The activation of autophagy has long been recognized as a central mechanism of healthspan and lifespan regulation at the organismal level, thus spurring major interest in identifying pharmacological or lifestyle interventions able to ignite the autophagic reaction in vivo. Consistently, there is growing need for the implementation in the preclinical practice of an "autophagometer," to be intended as a simple and non-invasive method to measure the autophagic flux in living organisms. Using fasting as the prototypical trigger of autophagy, we describe here a system (based on a leupeptin-based assay and video-flow cytometric detection of LC3B puncta) to quantitate autophagy in circulating leukocytes in mouse. We suggest that this method can be reliably used in the experimental routine to validate the pro-autophagy action of candidate drugs in vivo.