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Calmodulin-dependent and -independent apoptosis in cell of a Drosophila neuronal cell line

K Ui-Tei1, M Nagano, S Sato

  • 1Department of Pharmacology, Nippon Medical School, Bunkyo-ku, Tokyo 113-8602, Japan. tei@nms.ac.jp

Apoptosis : an International Journal on Programmed Cell Death
|March 10, 2001
PubMed

Insights

This study reveals two distinct apoptotic pathways in Drosophila neurons. One pathway requires intracellular calcium and calmodulin, while the other uses extracellular calcium and bypasses calmodulin, offering insights into neuronal cell death mechanisms.

Area of Science:

  • Neuroscience
  • Cell Biology
  • Biochemistry

Background:

  • Apoptosis, or programmed cell death, is crucial for neuronal development and function.
  • Understanding the molecular pathways of neuronal apoptosis is essential for addressing neurological disorders.

Purpose of the Study:

  • To elucidate the distinct apoptotic pathways in neurons.
  • To investigate the role of calcium ions and calmodulin in chemically induced neuronal apoptosis.

Main Methods:

  • Utilized a Drosophila larval central nervous system neuronal cell line.
  • Induced apoptosis using calcium ionophore (A23187), protein kinase inhibitor (H-7), RNA synthesis inhibitor (actinomycin D), and protein synthesis inhibitor (cycloheximide).
  • Examined the role of extracellular vs. intracellular calcium and calmodulin inhibition (W-7).

Main Results:

  • All tested chemicals induced apoptosis requiring calcium ions, with varying sources (extracellular for A23187, intracellular for H-7, actinomycin D, cycloheximide).
  • Calmodulin inhibition (W-7) blocked apoptosis induced by H-7, actinomycin D, and cycloheximide, but not by A23187.
  • Two distinct apoptotic pathways were identified: a calmodulin-dependent pathway (pathway H) and a calmodulin-independent pathway (pathway A).

Conclusions:

  • Neuronal apoptosis can proceed through at least two distinct pathways.
  • Pathway H involves intracellular calcium and calmodulin, while pathway A involves extracellular calcium and is calmodulin-independent.
  • These findings contribute to a deeper understanding of the regulation of neuronal cell death.

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