Atg5 deficit exaggerates the lysosome formation and cathepsin B activation in mice brain after lipid nanoparticles injection.

The present study was designed to investigate the role of autophagy-lysosome signaling in the brain after application of nanoparticles. Here, lipid nanoparticles (LNs) induced elevations of Atg5, P62, LC3 and cathepsin B in mice brain. The transmission electron microscopy revealed a dramatic elevation of lysosome vacuoles colocalized with LNs cluster inside the neurons in mice brain. Immunoblot data revealed abnormal expression of cathepsin B in brain cortex following LNs injection, whereas its expression was further elevated in Atg5(+/-) mice. The importance of Atg5 in the LNs-induced autophagy-lysosome cascade was further supported by our finding that neurovascular response was exaggerated in Atg5(+/-) mice. In addition, the siRNA knockdown of Atg5 significantly blunted the increasing of LC3 and P62 in LNs-treated Neuro-2a cells. Taken together, we propose that LNs induce autophagy-lysosome signaling and neurovascular response at least partially via an Atg5-dependent pathway. FROM THE CLINICAL EDITOR: These authors investigated autophagy-lysosome signaling in the mouse brain after application of lipid nanoparticles and report that these nanoparticles induce autophagy-lysosome signaling and neurovascular response at least partially via an Atg5-dependent pathway.