Signalling pathways involved in 1-nitropyrene (1-NP)-induced and 3-nitrofluoranthene (3-NF)-induced cell death in Hepa1c1c7 cells

Mutagenesis. 2009 Nov;24(6):481-93. doi: 10.1093/mutage/gep032. Epub 2009 Aug 24.

Abstract

We previously reported that 1-nitropyrene (1-NP) and 3-nitrofluoranthene (3-NF) elicited apoptotic cell death as well as non-apoptotic programmed cell deaths (PCDs) with paraptotic and necroptotic characteristics, respectively. In the present study, we have further confirmed and extended these findings. Flow cytometric analyses of 1-NP-exposed/3NF-exposed Hepa1c1c7 cells revealed that caspase-3 was only activated in the subpopulation of cells corresponding to that with classic apoptotic morphology. Immunocytochemical analysis indicated that leucocyte elastase inhibitor-derived DNaseII (LEI/L-DNaseII), apoptosis-inducing factor (AIF) and endonuclease G (EndoG) were more clearly translocated to the nucleus following 3-NF exposure than after 1-NP. These 3-NF-induced changes in AIF and EndoG translocation were reduced by necrostatin-1, an inhibitor of necroptotic cell death. Both compounds lead to accumulation of lipid droplets and induced DNA damage. Activation of checkpoint kinase (CHK) 1 and H2AX, but not ataxia telangiectasia mutated and CHK2, were observed. Furthermore, inhibition of p53 using pifithrin-alpha reduced the cell death induced by both compounds, suggesting a role of DNA damage/CHK1/p53 pathway in the death process. 1-NP-induced cell death was in addition characterized by increased oxidative damage and intracellular accumulation of Ca(2+). These findings further support the notion that 1-NP elicited apoptotic cell death and PCD with paraptotic characteristics, while 3-NF induced apoptosis and a PCD with necroptotic features.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Apoptosis Inducing Factor / biosynthesis
  • Ataxia Telangiectasia Mutated Proteins
  • Benzothiazoles / pharmacology
  • Cell Cycle Proteins / biosynthesis
  • Cell Death
  • Cell Line, Tumor
  • Cell Nucleus / metabolism
  • Checkpoint Kinase 1
  • Checkpoint Kinase 2
  • DNA Damage
  • DNA-Binding Proteins / biosynthesis
  • Endodeoxyribonucleases / biosynthesis
  • Fluorenes / toxicity*
  • Histones / biosynthesis
  • Humans
  • Protein Kinases / biosynthesis
  • Protein Serine-Threonine Kinases / biosynthesis
  • Pyrenes / toxicity*
  • Toluene / analogs & derivatives
  • Toluene / pharmacology
  • Tumor Suppressor Protein p53 / metabolism
  • Tumor Suppressor Proteins / biosynthesis

Substances

  • Apoptosis Inducing Factor
  • Benzothiazoles
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • Fluorenes
  • Histones
  • Pyrenes
  • TP53 protein, human
  • Tumor Suppressor Protein p53
  • Tumor Suppressor Proteins
  • Toluene
  • pifithrin
  • Protein Kinases
  • Checkpoint Kinase 2
  • ATM protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • CHEK1 protein, human
  • CHEK2 protein, human
  • Checkpoint Kinase 1
  • Protein Serine-Threonine Kinases
  • Endodeoxyribonucleases
  • endonuclease G
  • deoxyribonuclease II
  • 3-nitrofluoranthene
  • 1-nitropyrene