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Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death
09:18

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death

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Bacterial inhibition of phosphatidylcholine synthesis triggers apoptosis in the brain

Janine Zweigner1, Suzanne Jackowski, Shannon H Smith

  • 1Department of Infectious Diseases, St. Jude Children's Research Hospital, 332 North Lauderdale Street, Memphis, TN 38105, USA.

The Journal of Experimental Medicine
|July 9, 2004
PubMed

Insights

Bacterial meningitis triggers brain cell apoptosis by inhibiting phosphatidylcholine (PtdCho) biosynthesis. Supplementing PtdCho precursors offers therapeutic potential against this neurological damage.

Area of Science:

  • Neuroscience
  • Microbiology
  • Biochemistry

Background:

  • Streptococcus pneumoniae causes bacterial meningitis, a leading cause of death and neurological deficits.
  • Hippocampal neuron apoptosis is a hallmark of meningitis-induced brain damage.
  • Phosphatidylcholine (PtdCho) is vital for neuronal membrane integrity; its deficiency induces apoptosis.

Purpose of the Study:

  • To investigate the mechanism by which pneumococcal infection induces apoptosis in brain cells.
  • To determine if bacterial manipulation of PtdCho biosynthesis is involved in meningitis pathogenesis.
  • To explore therapeutic strategies targeting PtdCho metabolism for meningitis-induced brain injury.

Main Methods:

  • Investigated the effect of Streptococcus pneumoniae infection on brain cell apoptosis.
  • Assessed the impact of infection on phosphatidylcholine (PtdCho) biosynthesis pathways.
  • Utilized apoptosis inhibitors and PtdCho precursors (lyso-phosphatidylcholine, cytidine diphosphocholine) in cellular and murine models of meningitis.

Main Results:

  • Pneumococcal infection inhibits bacterial PtdCho biosynthesis, leading to apoptosis in various brain cells.
  • This bacterial-dependent inhibition of PtdCho synthesis was not prevented by general apoptosis inhibitors.
  • Supplementation with lyso-phosphatidylcholine prevented cell death, and cytidine diphosphocholine treatment reduced hippocampal damage in infected mice.

Conclusions:

  • Bacterial inhibition of phosphatidylcholine (PtdCho) biosynthesis is a novel mechanism driving apoptosis in meningitis.
  • This pathway represents a critical event in the pathogenesis of pneumococcal meningitis.
  • Targeting PtdCho biosynthesis or supplementing precursors presents a promising therapeutic avenue for treating meningitis-associated neurological damage.

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