Bcl-2 protects against apoptosis induced by antimycin A and bongkrekic acid without restoring cellular ATP levels

Biochim Biophys Acta. 2002 Apr 22;1554(1-2):57-65. doi: 10.1016/s0005-2728(02)00213-x.

Abstract

Several studies indicate that mitochondrial ATP production as well as ADP/ATP exchange across mitochondrial membranes are impaired during apoptosis. We investigated whether Bcl-2 could protect against cell death under conditions in which ATP metabolism is inhibited. Inhibition of ATP production using antimycin A (AA) (complex III inhibition) combined with inhibition of ADP/ATP exchange by bongkrekic acid (BA) (adenine nucleotide translocator (ANT) inhibition) induced a sharp decrease in total cellular ATP in FL5.12 parental cells (to 35% of untreated controls after 24 h of incubation). Within 24 and 48 h, 38% and 75% of the cells had died, respectively. However, in stably transfected FL5.12 Bcl-2 subclones, no cell death occurred under these experimental conditions. Similar results were obtained with Jurkat and Bcl-2 overexpressing Jurkat cells. Total cellular ATP levels were equally affected in FL5.12 Bcl-2 overexpressing cells and FL5.12 parental cells. This indicates that Bcl-2 overexpressing cells are able to survive with very low cellular ATP content. Furthermore, Bcl-2 did not protect against cell death by restoring ATP levels. This suggests that, under these conditions, Bcl-2 acts by inhibiting the signalling cascade triggered by the inhibitors that would normally lead to apoptosis.

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • Animals
  • Antimycin A / pharmacology*
  • Apoptosis / drug effects*
  • Blotting, Western
  • Bongkrekic Acid / pharmacology*
  • Cell Line
  • DNA Damage
  • Flow Cytometry
  • Humans
  • Jurkat Cells
  • Mice
  • Mitochondria / drug effects
  • Oxygen Consumption
  • Proto-Oncogene Proteins c-bcl-2 / physiology*

Substances

  • Proto-Oncogene Proteins c-bcl-2
  • Bongkrekic Acid
  • Antimycin A
  • Adenosine Triphosphate