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Real-time Live-cell Flow Cytometry to Investigate Calcium Influx, Pore Formation, and Phagocytosis by P2X7 Receptors in Adult Neural Progenitor Cells
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Effects of toxic cellular stresses and divalent cations on the human P2X7 cell death receptor

Mélody Dutot1, Hong Liang, Thierry Pauloin

  • 1Laboratoire de Toxicologie, Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris Descartes, Paris, France. melody.dutot@univ-paris5.fr

Molecular Vision
|May 21, 2008
PubMed
Abstract

Insights

Human ocular epithelia respond to toxic stress via the P2X7 receptor. This study shows how preservatives and oxidants activate this receptor, offering potential for new ophthalmic solutions.

Area of Science:

  • Ocular biology
  • Cellular toxicology
  • Purinergic signaling

Background:

  • The P2X7 receptor plays a role in cellular responses to stress.
  • Understanding ocular epithelial responses to toxins is crucial for eye health.
  • The P2X7 receptor's function in different ocular tissues requires further investigation.

Purpose of the Study:

  • To investigate the role of the P2X7 receptor in human ocular epithelial cells under toxic stress.
  • To explore how common ocular toxins modulate P2X7 receptor activity.
  • To identify potential therapeutic strategies involving ionic solutions.

Main Methods:

  • Confocal fluorescence microscopy and impression cytology were used to detect the P2X7 receptor.
  • P2X7 receptor activation and inhibition were assessed using specific agonists and antagonists with the YO-PRO-1 test.
  • Toxic stresses were induced using benzalkonium chloride and tert-butyl hydroperoxide.

Main Results:

  • Human ocular cell lines express the P2X7 receptor, confirmed by antibody reactivity and functional assays.
  • Benzalkonium chloride induced membrane permeabilization via P2X7 pore opening in conjunctival and corneal cells.
  • Tert-butyl hydroperoxide activated the P2X7 receptor in retinal pigment epithelium, and ionic solutions modulated its activity.

Conclusions:

  • A novel pathway for epithelial cell apoptosis/cytolysis through P2X7 receptor activation by toxic stresses was identified.
  • Modulation of P2X7 receptor activity by ionic solutions suggests potential for new ophthalmic formulations.
  • Extracellular cations like Ca(2+) and Mg(2+) influence P2X7 receptor activation, paving the way for novel therapeutic approaches.

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