Cytokine-induced apoptosis and necrosis are preceded by disruption of the mitochondrial membrane potential (Deltapsi(m)) in pancreatic RINm5F cells: prevention by Bcl-2

Mol Cell Endocrinol. 2002 Apr 25;190(1-2):75-82. doi: 10.1016/s0303-7207(02)00009-6.

Abstract

The mechanisms of cytokine-induced beta-cell death are poorly characterised. In rat insulin-producing RINm5F cells, the combination of interleukin-1beta, interferon-gamma and tumour necrosis factor-alpha presently induced disruption of the mitochondrial membrane potential (Deltapsi(m)) as demonstrated by reduced JC-1 fluorescence. The reduction of Deltapsi(m) was maximal after 8 h and was preceded by increased formation of reactive oxygen species (ROS), as assessed by dichlorofluorescein-diacetate (DCFH-DA) fluorescence. A nitric oxide synthase-, but not a ROS-inhibitor, prevented cytokine-induced loss of Deltapsi(m). Overexpression of the anti-apoptotic protein Bcl-2 increased both JC-1 and DCFH-DA fluorescence, which was paralleled by protection against cytokine-induced apoptosis and necrosis. It is concluded that cytokines induce a nitric oxide-dependent disruption of Deltapsi(m) and that this may be a necessary event for both beta-cell apoptosis and necrosis. Bcl-2 may prevent beta-cell death by counteracting mitochondrial permeability transition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis*
  • Benzimidazoles / metabolism
  • Carbocyanines / metabolism
  • Catalase / metabolism
  • Cell Line
  • Enzyme Inhibitors / pharmacology
  • Flow Cytometry / methods
  • Fluoresceins / metabolism
  • Fluorescent Dyes / metabolism
  • Interferon-gamma / pharmacology*
  • Interleukin-1 / pharmacology*
  • Islets of Langerhans / drug effects
  • Islets of Langerhans / physiology
  • Membrane Potentials / drug effects*
  • Mitochondria / drug effects*
  • Mitochondria / metabolism
  • Necrosis*
  • Nitric Oxide Synthase / antagonists & inhibitors
  • Nitric Oxide Synthase / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Proto-Oncogene Proteins c-bcl-2 / metabolism*
  • Rats
  • Reactive Oxygen Species / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology*

Substances

  • Benzimidazoles
  • Carbocyanines
  • Enzyme Inhibitors
  • Fluoresceins
  • Fluorescent Dyes
  • Interleukin-1
  • Proto-Oncogene Proteins c-bcl-2
  • Reactive Oxygen Species
  • Tumor Necrosis Factor-alpha
  • diacetyldichlorofluorescein
  • 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine
  • Interferon-gamma
  • Catalase
  • Nitric Oxide Synthase