The role of the p38-activated protein kinase signaling pathway-mediated autophagy in cadmium-exposed monogonont rotifer Brachious koreanus

Aquat Toxicol. 2018 Jan:194:46-56. doi: 10.1016/j.aquatox.2017.11.002. Epub 2017 Nov 10.

Abstract

Autophagy is a 'self-eating' system that regulates the degradation of cellular components and is involved in various biological processes including survival and development. However, despite its crucial role in organisms, the regulatory mechanism of autophagy remains largely unclear, particularly in invertebrates. In this study, conserved autophagy in the rotifer Brachionus koreanus in response to cadmium (Cd) exposure was verified by measuring acidic vesicle organelles using acridine orange (AO) and neutral red (NR) staining, and by detecting LC3 I/II on Western blot and immunofluorescence. We also demonstrated activation of p38 mitogen-activated protein kinase (MAPK) in response to Cd-induced oxidative stress, leading to the induction of autophagy in B. koreanus. This was further verified by analysis of MAPK protein levels and immunofluorescence of LC3 I/II after treatment with reactive oxygen species (ROS) scavengers and inhibitors specific to MAPKs. We propose a p38 MAPK-mediated regulatory mechanism of autophagy in B. koreanus in response to Cd-induced oxidative stress. This study will contribute to a better understanding of autophagic processes in invertebrates and its modulation by environmental stressors.

Keywords: Autophagy; LC3 I/II; Mitogen-activated protein kinases; Rotifer; p38 MAPK.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Autophagy / drug effects*
  • Cadmium / metabolism
  • Cadmium / toxicity*
  • Helminth Proteins / metabolism
  • Humans
  • MAP Kinase Signaling System / drug effects*
  • Microscopy, Electron, Transmission
  • Microscopy, Fluorescence
  • Microtubule-Associated Proteins / chemistry
  • Microtubule-Associated Proteins / metabolism
  • Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • Mitogen-Activated Protein Kinases / metabolism
  • Oxidative Stress / drug effects
  • Phosphorylation / drug effects
  • Reactive Oxygen Species / metabolism
  • Rotifera / drug effects
  • Rotifera / growth & development
  • Rotifera / metabolism*
  • Sequence Alignment
  • Water Pollutants, Chemical / toxicity*

Substances

  • Helminth Proteins
  • Microtubule-Associated Proteins
  • Reactive Oxygen Species
  • Water Pollutants, Chemical
  • Cadmium
  • Mitogen-Activated Protein Kinases