Activation of neutral sphingomyelinase 2 by starvation induces cell-protective autophagy via an increase in Golgi-localized ceramide

Cell Death Dis. 2018 Jun 4;9(6):670. doi: 10.1038/s41419-018-0709-4.

Abstract

Autophagy is essential for optimal cell function and survival, and the entire process accompanies membrane dynamics. Ceramides are produced by different enzymes at different cellular membrane sites and mediate differential signaling. However, it remains unclear which ceramide-producing pathways/enzymes participate in autophagy regulation under physiological conditions such as nutrient starvation, and what the underlying mechanisms are. In this study, we demonstrate that among ceramide-producing enzymes, neutral sphingomyelinase 2 (nSMase2) plays a key role in autophagy during nutrient starvation. nSMase2 was rapidly and stably activated upon starvation, and the enzymatic reaction in the Golgi apparatus facilitated autophagy through the activation of p38 MAPK and inhibition of mTOR. Moreover, nSMase2 played a protective role against cellular damage depending on autophagy. These findings suggest that nSMase2 is a novel regulator of autophagy and provide evidence that Golgi-localized ceramides participate in cytoprotective autophagy against starvation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy*
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone / pharmacology
  • Ceramides / metabolism*
  • Enzyme Activation
  • Golgi Apparatus / metabolism*
  • Male
  • Mice, Inbred C57BL
  • PC12 Cells
  • Parkinson Disease / pathology
  • Protein Serine-Threonine Kinases / metabolism
  • Rats
  • Sphingomyelin Phosphodiesterase / metabolism*
  • Starvation
  • Stress, Physiological
  • TOR Serine-Threonine Kinases / metabolism
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Ceramides
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone
  • Protein Serine-Threonine Kinases
  • TOR Serine-Threonine Kinases
  • p38 Mitogen-Activated Protein Kinases
  • Smpd3 protein, rat
  • Sphingomyelin Phosphodiesterase