Light exposure activates retina ganglion cell lysophosphatidic acid acyl transferase and phosphatidic acid phosphatase by a c-fos-dependent mechanism

J Neurochem. 1999 Sep;73(3):1228-35. doi: 10.1046/j.1471-4159.1999.0731228.x.

Abstract

We previously reported that the biosynthesis of phospholipids in the avian retina is altered by light stimulation, increasing significantly in ganglion cells in light and in photoreceptor cells in dark. In the present work, we have determined that light significantly increases the incorporation of [3H]glycerol into retina ganglion cell glycerophospholipids in vivo by a Fos-dependent mechanism because an oligonucleotide antisense to c-fos mRNA substantially blocked the light-dark differences. We also studied in vitro the enzyme activities of phosphatidate phosphohydrolase (PAPase), lysophosphatidate acyl transferase (AT II), and phosphatidylserine synthase from retinas of chickens exposed to light or dark. Higher PAPase I and AT II activities were found in incubations of retinal ganglion cells from animals exposed to light; no increase was observed in preparations obtained from light-exposed animals treated with the c-fos antisense oligonucleotide. No light-dark differences were found in phosphatidylserine synthase activity. These findings support the idea that a coordinated photic regulation of PAPase I and AT II is taking place in retina ganglion cells. This constitutes a reasonable mechanism to obtain an overall increased synthesis of glycerophospholipids in stimulated cells that is mediated by the expression of Fos-like proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chickens
  • Darkness
  • Enzyme Activation
  • Fluorescent Antibody Technique
  • Glycerol / metabolism
  • Isoenzymes / metabolism
  • Light
  • Oligonucleotides, Antisense / chemistry
  • Oligonucleotides, Antisense / pharmacology
  • Phosphatidate Phosphatase / metabolism*
  • Phosphorus Radioisotopes
  • Proto-Oncogene Proteins c-fos / biosynthesis*
  • Proto-Oncogene Proteins c-fos / genetics
  • RNA, Messenger / chemistry
  • Retinal Ganglion Cells / enzymology*
  • Retinal Ganglion Cells / radiation effects
  • Tritium

Substances

  • Isoenzymes
  • Oligonucleotides, Antisense
  • Phosphorus Radioisotopes
  • Proto-Oncogene Proteins c-fos
  • RNA, Messenger
  • Tritium
  • Phosphatidate Phosphatase
  • Glycerol