1. Academic Validation
  2. Thrombin and the Protease-Activated Receptor-1 in Organophosphate-Induced Status Epilepticus

Thrombin and the Protease-Activated Receptor-1 in Organophosphate-Induced Status Epilepticus

  • J Mol Neurosci. 2019 Feb;67(2):227-234. doi: 10.1007/s12031-018-1228-6.
Valery Golderman 1 2 Efrat Shavit-Stein 3 Orna Gera 3 4 5 Joab Chapman 4 6 7 Arik Eisenkraft 8 Nicola Maggio 3 4 6 9
Affiliations

Affiliations

  • 1 Department of Neurology, The Chaim Sheba Medical Center, Tel HaShomer, 52621, Ramat Gan, Israel. valery.rodionov@gmail.com.
  • 2 Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel HaShomer, 52621, Ramat Gan, Israel. valery.rodionov@gmail.com.
  • 3 Department of Neurology, The Chaim Sheba Medical Center, Tel HaShomer, 52621, Ramat Gan, Israel.
  • 4 Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel HaShomer, 52621, Ramat Gan, Israel.
  • 5 Department of Physical Therapy, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
  • 6 Department of Neurology, Sackler School of Medicine, Tel Aviv University, 69978, Tel Aviv, Israel.
  • 7 Robert and Martha Harden Chair in Mental and Neurological Diseases, Sackler Faculty of Medicine, Tel Aviv, Israel.
  • 8 Institute for Research in Military Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
  • 9 Talpiot medical leadership program, Chaim Sheba Medical Center, Tel HaShomer, Ramat Gan, Israel.
Abstract

Organophosphates (OP) are a major threat to the health of soldiers and civilians due to their use as chemical weapons in war and in terror attacks. Among the acute manifestations of OP poisoning, status epilepticus (SE) is bearing the highest potential for long-term damages. Current therapies do not prevent brain damage and seizure-related brain injuries in OP-exposed humans. Thrombin is a serine protease known to have a fundamental function in the clotting cascade. It is highly expressed in the brain where we have previously found that it regulates synaptic transmission and plasticity. In addition, we have found that an excess of Thrombin in the brain leads to hyperexcitability and therefore seizures through a glutamate-dependent mechanism. In the current study, we carried out in vitro, ex vivo, and in vivo experiments in order to determine the role of Thrombin and its receptor PAR-1 in paraoxon-induced SE. Elevated Thrombin activity was found in the brain slices from mice that were treated (in vitro and in vivo) with paraoxon. Increased levels of PAR-1 and PERK proteins and decreased prothrombin mRNA were found in the brains of paraoxon-treated mice. Furthermore, ex vivo and in vivo electrophysiological experiments showed that exposure to paraoxon causes elevated electrical activity in CA1 and CA3 regions of the hippocampus. Moreover, a specific PAR-1 antagonist (SCH79797) reduced this activity. Altogether, these results reveal the importance of Thrombin and PAR-1 in paraoxon poisoning. In addition, the results indicate that Thrombin and PAR-1 may be a possible target for the treatment of paraoxon-induced status epilepticus.

Keywords

Organophosphates; PAR-1; Paraoxon; Status epilepticus; Thrombin.

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