Caspase-2 mediates triglyceride (TG)-induced macrophage cell death

BMB Rep. 2017 Oct;50(10):510-515. doi: 10.5483/bmbrep.2017.50.10.106.

Abstract

Triglyceride (TG) accumulation causes macrophage cell death, which affects the development of atherosclerosis. Here, we examined whether caspase-2 is implicated in TG-induced macrophage cell death. We found that caspase-2 activity is increased in TG-treated THP-1 macrophages, and that inhibition of caspase-2 activity drastically inhibits TG-induced cell death. We previously reported that TG-induced macrophage cell death is triggered by caspase-1, and thus investigated the relationship between caspase-2 and caspase-1 in TG-induced macrophage cell death. Inhibition of caspase-2 activity decreased caspase-1 activity in TG-treated macrophages. However, caspase-1 inhibition did not affect caspase-2 activity, suggesting that caspase-2 is upstream of caspase-1. Furthermore, we found that TG induces activation of caspase-3, -7, -8, and -9, as well as cleavage of PARP. Inhibition of caspase-2 and -1 decreased TG-induced caspase-3, -7, -8, and -9 activation and PARP cleavage. Taken together, these results suggest that TG-induced macrophage cell death is mediated via the caspase-2/caspase-1/apoptotic caspases/PARP pathways. [BMB Reports 2017; 50(10): 510-515].

MeSH terms

  • Apoptosis / drug effects
  • Apoptosis / physiology
  • Caspase 2 / metabolism*
  • Caspase 3 / metabolism
  • Cell Death / drug effects
  • Cell Line, Tumor
  • Cysteine Endopeptidases / metabolism*
  • Enzyme Activation
  • Humans
  • Macrophages / cytology*
  • Macrophages / drug effects
  • Macrophages / enzymology
  • Macrophages / metabolism*
  • Mitochondria / metabolism
  • Triglycerides / metabolism*
  • Triglycerides / physiology

Substances

  • Triglycerides
  • CASP2 protein, human
  • Caspase 2
  • Caspase 3
  • Cysteine Endopeptidases