2. Academic Validation
  3. Human erythrocytes release ATP by a novel pathway involving VDAC oligomerization independent of pannexin-1

Human erythrocytes release ATP by a novel pathway involving VDAC oligomerization independent of pannexin-1

  • Sci Rep. 2018 Jul 30;8(1):11384. doi: 10.1038/s41598-018-29885-7.
Irene Marginedas-Freixa 1 2,  Cora Lilia Alvarez 3 4,  Martina Moras 1 2,  María Florencia Leal Denis 3 5,  Claude Hattab 1 2,  François Halle 6,  Frédéric Bihel 6,  Isabelle Mouro-Chanteloup 1 2,  Sophie Denise Lefevre 1 2,  Caroline Le Van Kim 1 2,  Pablo Julio Schwarzbaum 3 7,  Mariano Anibal Ostuni 8 9
Affiliations

Affiliations

  • 1 UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015, Paris, France.
  • 2 Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015, Paris, France.
  • 3 Instituto de Química y Fisico-Química Biológicas "Prof. Alejandro C. Paladini", UBA, CONICET, Facultad de Farmacia y Bioquímica, Junín 956, Buenos Aires, Argentina.
  • 4 Universidad de Buenos Aires. Facultad Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina.
  • 5 Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Analítica y Fisicoquímica, Cátedra de Química Analítica, Buenos Aires, Argentina.
  • 6 UMR7200, Laboratoire d'Innovation Thérapeutique, Faculty of Pharmacy, University of Strasbourg, CNRS, 67400, Illkirch Graffenstaden, France.
  • 7 Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica. Cátedra de Química Biológica Superior, Buenos Aires, Argentina.
  • 8 UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015, Paris, France. [email protected].
  • 9 Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015, Paris, France. [email protected].
PMID: 30061676 DOI: 10.1038/s41598-018-29885-7
Abstract

We previously demonstrated that the translocase protein TSPO2 together with the voltage-dependent anion channel (VDAC) and adenine nucleotide transporter (ANT) were involved in a membrane transport complex in human red blood cells (RBCs). Because VDAC was proposed as a channel mediating ATP release in RBCs, we used TSPO ligands together with VDAC and ANT inhibitors to test this hypothesis. ATP release was activated by TSPO ligands, and blocked by inhibitors of VDAC and ANT, while it was insensitive to pannexin-1 blockers. TSPO ligand increased extracellular ATP (ATPe) concentration by 24-59% over the basal values, displaying an acute increase in [ATPe] to a maximal value, which remained constant thereafter. ATPe kinetics were compatible with VDAC mediating a fast but transient ATP efflux. ATP release was strongly inhibited by PKC and PKA inhibitors as well as by depleting intracellular cAMP or extracellular Ca2+, suggesting a mechanism involving protein kinases. TSPO ligands favoured VDAC polymerization yielding significantly higher densities of oligomeric bands than in unstimulated cells. Polymerization was partially inhibited by decreasing Ca2+ and cAMP contents. The present results show that TSPO ligands induce polymerization of VDAC, coupled to activation of ATP release by a supramolecular complex involving VDAC, TSPO2 and ANT.

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