The SV2A protein is a glycoprotein present in the membranes of most synaptic vesicles. Although it is highly conserved during evolution, its
physiological role remains largely unknown. However, it has recently been demonstrated that a very effective anti-epileptic drug called
levetiracetam (Keppra
®
) binds to the SV2A protein. As SV2A knock-out animals start to experiment seizures around post-natal day 7 and die
in status epilepticus around post-natal day 15, a SV2A role in epilepsy has been suspected but is currently unproved.
This project aims to better understand how the SV2A protein may be involved in the occurrence of epilepsy. For this purpose, we used a
mouse line that allows the conditional invalidation of SV2A gene in hippocampal region (CA3 and dentate gyrus (DG)) from the postnatal
day 15 to the postnatal day 56 (Sv2A-cKO or Grik4:Sv2a-cKO).
The SV2A protein is a glycoprotein present in the membranes of most synaptic vesicles. Although it is highly conserved during evolution, its
physiological role remains largely unknown. However, it has recently been demonstrated that a very effective anti-epileptic drug called
levetiracetam (Keppra
®
) binds to the SV2A protein. As SV2A knock-out animals start to experiment seizures around post-natal day 7 and die
in status epilepticus around post-natal day 15, a SV2A role in epilepsy has been suspected but is currently unproved.
This project aims to better understand how the SV2A protein may be involved in the occurrence of epilepsy. For this purpose, we used a
mouse line that allows the conditional invalidation of SV2A gene in hippocampal region (CA3 and dentate gyrus (DG)) from the postnatal
day 15 to the postnatal day 56 (Sv2A-cKO or Grik4:Sv2a-cKO).
Study of the SV2A protein role in Epilepsy.
O. Bartholome*
1
, P.Van den Ackerveken*
1
, C. Menten
1
, M.E. Serrano Navacerrada
2
, V. Neirincks
1
, G. Becker
2
,A. Plainevaux
2
, S.
Wislet
1
,P. Leprince
1
and B. Rogister
1,3
1.Laboratory of Nervous System Diseases and Therapy, GIGA-Neuroscience, University of Liège, Liège, Belgium 2. University of Liège, GIGA-Research, Cyclotron Research
Center 3. Neurology Department, University Hospital, Liège, Belgium.
* These two authors equally contributed to this work
Contact
: odile.bartholome@ulg.ac.be
Our preliminary results show that SV2A-cKO adult animals do not exhibit spontaneous seizure neither exhibit a lower epileptic
threshold and do not compensate the absence of SV2A by overexpressing SV2B or C. However, the absence of SV2A in hippocampus
seems to modulate the expression of several other proteins involved in a membranous metabolism (exosome and/or vesicles and/or
myelin). Ongoing experiments are designed to confirm 2D-DIGE experiment and to investigate functions enriched in our network.
Our preliminary results show that SV2A-cKO adult animals do not exhibit spontaneous seizure neither exhibit a lower epileptic
threshold and do not compensate the absence of SV2A by overexpressing SV2B or C. However, the absence of SV2A in hippocampus
seems to modulate the expression of several other proteins involved in a membranous metabolism (exosome and/or vesicles and/or
myelin). Ongoing experiments are designed to confirm 2D-DIGE experiment and to investigate functions enriched in our network.
Conclusions
Introduction
Results
2. No significant change in Sv2B or Sv2C transcripts concentrations,
two other members of SV2 proteins family (paralogs of SV2A), in
hippocampus of Sv2A-cKO animals in comparison with the wild-type
(WT). Same observation for proteins expression (Data not shown)
2. Absence of a compensation phenomenon
by Sv2B and Sv2C.
Sv2B
Sv2C
1. Absence of an epileptic phenotype in the validated
Sv2A-cKO model.
1. A. Expression levels of SV2a genes determined by qRT-PCR on
CA1, CA3 and DG extract. Gene expression was normalized on
Gapdh level. Comparable reduction observed in western blot (Data
not shown) B. SV2A-cKO adult animals do not exhibit spontaneous
seizure (Data not shown) and have not a lowered epileptic
threshold after PTZ treatment.
3. 2D DIGE experiments of hippocampi proteomes
revealed interesting patterns.
2'; 3'-cyclic-nucleotide 3'-phosphodiesterase
ATP synthase subunit alpha; mitochondrial Aconitate hydratase
Alpha-enolase
Aspartate aminotransferase; mitochondrial Dihydrolipoyl dehydrogenase; mitochondrial
Dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex
Dihydropyrimidinase-related protein 5
Fructose-bisphosphate aldolase A
Gamma-enolase
Glutamine synthetase
Glyceraldehyde-3-phosphate dehydrogenase Heat shock cognate 71 kDa protein
Heterogeneous nuclear ribonucleoprotein H
Isocitrate dehydrogenase [NADP] cytoplasmic
Isocitrate dehydrogenase [NAD] subunit alpha; mitochondrial Ketimine reductase mu-crystallin
L-lactate dehydrogenase B chain
Malate dehydrogenase; cytoplasmic
Malate dehydrogenase; mitochondrial NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 10
Protein phosphatase 1 regulatory subunit 7
Pyruvate kinase PKM Stress-70 protein
Succinyl-CoA:3-ketoacid coenzyme A transferase 1 Tubulin alpha-1A chain
Tubulin beta-1 chain Tubulin beta-2A chain
