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Roles of caspases in the programmed cell death of motoneurons in vivo

H Yaginuma1, N Sato, S Homma

  • 1Department of Anatomy, School of Medicine, Fukushima Medical University, Japan. h-yaginm@fmu.ac.jp

Archives of Histology and Cytology
|February 13, 2002
PubMed

Insights

Caspases (casp-3 and casp-9) are not essential for motoneuron programmed cell death but delay the process. Without caspases, motoneurons exhibit delayed, non-apoptotic death with distinct morphological changes.

Area of Science:

  • Neuroscience
  • Cell Biology
  • Developmental Biology

Background:

  • Caspases are key executioners of programmed cell death.
  • Their role in developmental motoneuron death was previously assumed essential.

Purpose of the Study:

  • To investigate the necessity of caspases in developmental motoneuron programmed cell death.
  • To characterize the morphology of caspase-independent cell death.

Main Methods:

  • Genetic deletion of casp-3 and casp-9 in developing mouse motoneurons.
  • Inhibition of caspases in chick embryo motoneurons.
  • Morphological analysis of dying motoneurons.

Main Results:

  • Motoneuron cell loss occurred at normal levels despite caspase absence, but was delayed.
  • Caspase-deficient motoneurons showed non-apoptotic morphology with reduced chromatin condensation and cytoplasmic vacuolization.
  • These findings suggest caspases facilitate, but are not indispensable for, motoneuron death.

Conclusions:

  • Caspases play a role in, but are not required for, developmental motoneuron programmed cell death.
  • Alternative caspase-independent pathways likely exist for motoneuron elimination.
  • Caspases may function to expedite the removal of cells destined for death.

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