A phosphatidylinositol transfer protein alpha-dependent survival factor protects cultured primary neurons against serum deprivation-induced cell death

J Neurochem. 2006 May;97(3):707-15. doi: 10.1111/j.1471-4159.2006.03729.x. Epub 2006 Mar 29.

Abstract

Selective neuronal loss is a prominent feature in both acute and chronic neurological disorders. Recently, a link between neurodegeneration and a deficiency in the lipid transport protein phosphatidylinositol transfer protein alpha (PI-TPalpha) has been demonstrated. In this context it may be of importance that fibroblasts overexpressing PI-TPalpha are known to produce and secrete bioactive survival factors that protect fibroblasts against UV-induced apoptosis. In the present study it was investigated whether the conditioned medium of cells overexpressing PI-TPalpha (CMalpha) has neuroprotective effects on primary neurons in culture. We show that CMalpha is capable of protecting primary, spinal cord-derived motor neurons from serum deprivation-induced cell death. Since the conditioned medium of wild-type cells was much less effective, we infer that the neuroprotective effect of CMalpha is linked (in part) to the PI-TPalpha-dependent production of arachidonic acid metabolites. The neuroprotective activity of CMalpha is partly inhibited by suramin, a broad-spectrum antagonist of G-protein coupled receptors. Western blot analysis shows that brain cortex and spinal cord express relatively high levels of PI-TPalpha, suggesting that the survival factor may be produced in neuronal tissue. We propose that the bioactive survival factor is implicated in neuronal survival. If so, PI-TPalpha could be a promising target to be evaluated in studies on the prevention and treatment of neurological disorders.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Astrocytes / metabolism
  • Cell Survival / drug effects
  • Cells, Cultured
  • Cerebral Cortex / metabolism
  • Culture Media, Serum-Free / pharmacology*
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • Embryo, Mammalian
  • Gene Expression / physiology
  • Immunohistochemistry / methods
  • Liver / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Confocal / methods
  • Models, Biological
  • Motor Neurons / cytology
  • Motor Neurons / drug effects*
  • Phospholipid Transfer Proteins / pharmacology*
  • Rats
  • Rats, Wistar
  • Spinal Cord / cytology
  • Time Factors

Substances

  • Culture Media, Serum-Free
  • Phospholipid Transfer Proteins