Multiple death pathways in retina-derived 661W cells following growth factor deprivation: crosstalk between caspases and calpains

Cell Death Differ. 2005 Jul;12(7):796-804. doi: 10.1038/sj.cdd.4401621.

Abstract

During development of the mammalian retina, neurons that do not succeed in establishing functional synaptic connections are eliminated by apoptosis, allowing the formation of a finely tuned network. Growth factors play a crucial role in controlling the balance between apoptosis and survival signals not only at developmental stages but also in long-term preservation of retinal functions. In the present work, we explore the apoptotic mechanisms triggered by growth factor deprivation of retina-derived 661W cells. Under serum starvation conditions, these cone photoreceptors underwent cell death with participation of caspase-9, -3 and -12. Interestingly, inhibition of caspases did not prevent apoptosis but only resulted in a temporary delay. We show m-calpain activation in parallel with caspases, indicating that more than one execution pathway is available to cone photoreceptors. Moreover, crosstalk of the caspase and calpain pathways was detected, suggesting a loop that may act to amplify the apoptotic cascade.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis* / drug effects
  • Calpain / antagonists & inhibitors
  • Calpain / metabolism*
  • Caspase Inhibitors
  • Caspases / metabolism*
  • Culture Media, Serum-Free / pharmacology
  • Enzyme Activation / drug effects
  • Growth Substances / deficiency*
  • Growth Substances / metabolism
  • Leucine / analogs & derivatives
  • Leucine / pharmacology
  • Mice
  • Retinal Cone Photoreceptor Cells / cytology*
  • Retinal Cone Photoreceptor Cells / enzymology
  • Retinal Cone Photoreceptor Cells / metabolism*

Substances

  • Caspase Inhibitors
  • Culture Media, Serum-Free
  • Growth Substances
  • acetyl-leucinal-nor-leucinal
  • Calpain
  • Caspases
  • m-calpain
  • Leucine