Erythrocyte peripheral type benzodiazepine receptor/voltage-dependent anion channels are upregulated by Plasmodium falciparum

Blood. 2011 Aug 25;118(8):2305-12. doi: 10.1182/blood-2011-01-329300. Epub 2011 Jul 27.

Abstract

Plasmodium falciparum relies on anion channels activated in the erythrocyte membrane to ensure the transport of nutrients and waste products necessary for its replication and survival after invasion. The molecular identity of these anion channels, termed "new permeability pathways" is unknown, but their currents correspond to up-regulation of endogenous channels displaying complex gating and kinetics similar to those of ligand-gated channels. This report demonstrates that a peripheral-type benzodiazepine receptor, including the voltage dependent anion channel, is present in the human erythrocyte membrane. This receptor mediates the maxi-anion currents previously described in the erythrocyte membrane. Ligands that block this peripheral-type benzodiazepine receptor reduce membrane transport and conductance in P falciparum-infected erythrocytes. These ligands also inhibit in vitro intraerythrocytic growth of P falciparum. These data support the hypothesis that dormant peripheral-type benzodiazepine receptors become the "new permeability pathways" in infected erythrocytes after up-regulation by P falciparum. These channels are obvious targets for selective inhibition in anti-malarial therapies, as well as potential routes for drug delivery in pharmacologic applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antimalarials / pharmacology
  • Benzodiazepinones / pharmacology
  • Diazepam / pharmacology
  • Erythrocytes / drug effects
  • Erythrocytes / metabolism*
  • Erythrocytes / parasitology*
  • Humans
  • In Vitro Techniques
  • Ion Channel Gating
  • Isoquinolines / pharmacology
  • Ligands
  • Malaria, Falciparum / blood
  • Malaria, Falciparum / drug therapy
  • Malaria, Falciparum / genetics
  • Malaria, Falciparum / parasitology
  • Plasmodium falciparum / drug effects
  • Plasmodium falciparum / metabolism*
  • Plasmodium falciparum / pathogenicity
  • RNA, Messenger / blood
  • RNA, Messenger / genetics
  • Receptors, GABA-A / blood*
  • Receptors, GABA-A / drug effects
  • Up-Regulation
  • Voltage-Dependent Anion Channels / blood*
  • Voltage-Dependent Anion Channels / genetics

Substances

  • Antimalarials
  • Benzodiazepinones
  • Isoquinolines
  • Ligands
  • RNA, Messenger
  • Receptors, GABA-A
  • Voltage-Dependent Anion Channels
  • 4'-chlorodiazepam
  • Diazepam
  • PK 11195