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

Nanomedicine. 2014 Nov;10(8):1843-52. doi: 10.1016/j.nano.2014.03.019. Epub 2014 Apr 22.

Abstract

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.

Keywords: Atg5; Autophagy; Brain; Lipid nanoparticles; Neurovascular damage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy-Related Protein 5
  • Brain / metabolism*
  • Cathepsin B / metabolism*
  • Lipids / chemistry*
  • Lysosomes / metabolism*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Mutant Strains
  • Microtubule-Associated Proteins / deficiency*
  • Microtubule-Associated Proteins / genetics
  • Nanoparticles / chemistry*

Substances

  • Atg5 protein, mouse
  • Autophagy-Related Protein 5
  • Lipids
  • Microtubule-Associated Proteins
  • Cathepsin B