Inhibiting autophagy promotes endoplasmic reticulum stress and the ROS‑induced nod‑like receptor 3‑dependent proinflammatory response in HepG2 cells

Mol Med Rep. 2016 Oct;14(4):3999-4007. doi: 10.3892/mmr.2016.5708. Epub 2016 Sep 5.

Abstract

Inflammation and endoplasmic reticulum (ER) stress are key contributors to insulin resistance and metabolic disease, and interleukin (IL)‑1β is involved in insulin resistance. The present study aimed to investigated the role of autophagy in LPS‑induced ER stress and inflammation, which may provide evidence for controlling metabolic disease associated with inflammation. Lipopolysaccharide (LPS) induced the activation of ER stress and the nod‑like receptor 3‑dependent expression of IL‑1β and caspase‑1, as shown by western blotting, which contributed to HepG2 cell death. This also involved the generation of mitochondrial reactive oxygen species and the autophagy signaling response, which are derived from the ER stress pathway. The percentage of apoptotic cells was measured by flow cytometry with fluorescein isothiocyanate/propidium iodide staining. Reactive oxygen species formation was detected by flow cytometry using the peroxide sensitive fluorescent probe 2',7'‑dichlorofluorescin diacetate. Autophagy activation was measured by western blotting and confirmed using transmission electron microscopy. Furthermore, inhibiting autophagy promoted ER stress and the proinflammatory response in addition to cell death. These findings provide insights into the protective role of autophagy in LPS‑induced cell death and ER stress, and further identified the association of autophagy, ER stress and inflammation in HepG2 cells.

MeSH terms

  • Autophagy*
  • Endoplasmic Reticulum Stress*
  • Hep G2 Cells
  • Hepatocytes / cytology
  • Hepatocytes / immunology*
  • Humans
  • Inflammasomes / immunology
  • Inflammation / immunology*
  • Interleukin-1beta / immunology
  • Lipopolysaccharides / immunology*
  • NLR Family, Pyrin Domain-Containing 3 Protein / immunology*
  • Reactive Oxygen Species / immunology*

Substances

  • Inflammasomes
  • Interleukin-1beta
  • Lipopolysaccharides
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • NLRP3 protein, human
  • Reactive Oxygen Species