Beclin-1-mediated Autophagy Protects Against Cadmium-activated Apoptosis via the Fas/FasL Pathway in Primary Rat Proximal Tubular Cell Culture

Sci Rep. 2017 Apr 20;7(1):977. doi: 10.1038/s41598-017-00997-w.

Abstract

The Fas/FasL signaling pathway is one of the primary apoptosis pathways, but the involvement and regulatory mechanism of this pathway by autophagy remain unclear. Here we demonstrated that cadmium (Cd) activated the Fas/FasL apoptosis pathway in rat proximal tubular (rPT) cells; this was accompanied by simultaneous activation of autophagy resulted in reduced apoptosis. In this model, we induced autophagy through RAPA and further demonstrated that autophagy protects against activation of Fas/FasL signaling and apoptosis. The antiapoptotic effect of autophagy was blocked by 3-MA, an autophagy inhibitor. The interactions between Beclin-1 and Fas, FasL, FADD, caspase-8 and BID/tBID were relatively weak, with the exception of cleaved caspase-8, indicated that minimal interactions between these proteins and Beclin-1 are involved in maintaining the balance of autophagy and apoptosis. Beclin-1 precipitated with cleaved caspase-8 in a dose-dependent mannter, and the expression was increased by siRNA against Beclin-1. These data suggested that Beclin-1-mediated autophagy impairs the expression and function of cleaved caspase-8 to protect against Cd-induced activation of apopotosis through Fas/FasL signaling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Autophagy
  • Beclin-1 / metabolism*
  • Cadmium / toxicity*
  • Caspase 8 / metabolism
  • Cells, Cultured
  • Dose-Response Relationship, Drug
  • Fas Ligand Protein / metabolism*
  • Gene Expression Regulation / drug effects
  • Kidney Tubules, Proximal / cytology*
  • Kidney Tubules, Proximal / drug effects
  • Kidney Tubules, Proximal / metabolism
  • Lipid Peroxidation / drug effects
  • Oxidative Stress / drug effects
  • Primary Cell Culture
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects
  • fas Receptor / metabolism*

Substances

  • Beclin-1
  • Becn1 protein, rat
  • Fas Ligand Protein
  • Fas protein, rat
  • Faslg protein, rat
  • fas Receptor
  • Cadmium
  • Casp8 protein, rat
  • Caspase 8