substrate of the gaba transporter, gat3, improves...
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Sted og datoDias 1Enhedens
Substrate of the GABA transporter, GAT3, improves functional recovery after a focal ischemic stroke in mice
Maria E.K. Lie, PhD student
Department of Drug Design and PharmacologyUniversity of Copenhagen, Denmark
Department of Anatomy University of Otago, New Zealand
24th of August 2017, Dias 2
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Maria Lie: [email protected]
Involvement of tonic GABA-mediated inhibition in stroke
Department of Drug Design and Pharmacology
(GABAAR antagonist)
Clarkson et al., 2010, Nature, 468:305-309
A GABAergic synapse and localization of the GABA transporters (GATs)
astrocyte
GABAAR
GABA
GAT1
GAT3GABA
GABAAR
Cl- Cl-
Peri-infarct:
•GAT3: • Impaired function• Lowered expression
•GAT1 is unaffected
3-14 days post-stroke
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Maria Lie: [email protected]
Department of Drug Design and Pharmacology
(inverse agonist of α5-containing GABAA receptors)
Grid-w
alk
ing
Cylinder
Clarkson et al., 2010, Nature, 468:305-309
Decreased tonic inhibition promotes functional recovery post-stroke
Motor performance:
24th of August 2017, Dias 4
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Maria Lie: [email protected]
Hypothesis
Aims:
1.Determine the temporal expression profile of GAT3 after a photothrombotic stroke
2.Investigate the effect of L-isoserine on functional recovery and GAT3 expression after a photothrombotic stroke
Department of Drug Design and Pharmacology
Hypothesis and aim
To
nic
in
hib
itio
n
Time (days post stroke)
3 7 14 ?
Acute ChronicSub-acute
Intracellular
Extracellular
GAT3
Na
+
Na
+
L-isoserine:
GAT3 selective substrate inhibitor
Intracellular
Extracellula
To
nic
in
hib
itio
n
Time (days post stroke)
3 7 14 ?
Acute ChronicSub-acute
r
GAT3
Na
+
Na
+
Functional recovery
Substrate (L-isoserine)
Hypothesis: L-isoserine increases GAT3 expression and increases functional recovery
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Maria Lie: [email protected]
Photothrombotic stroke to forelimb motor cortex
Department of Drug Design and Pharmacology
Infarct (1.5 mm lateral to Bregma)
Anesth
esia
Cold light source (15 min)
Rose Bengal
2.
Infarct volume IHC: GAT3Stroke
Behavior: Pre-op
L-Isoserine: low (IC50) and high concentration (10xIC50)
7 days 14 days 28 days 42 days
Cylinder: pre-op post stroke Grid-walking:post stroke
* * * * * * * *1.
*GAT3 expression at 1, 3 and 6 hours and 1, 3, 7, 14 and 28 days post-stroke by WB
Stroke
C57BL/6J male mice
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Aim 1 - GAT3 protein levels are decreased post-stroke
Department of Drug Design and Pharmacology
mean±SD, n=642 days
mean±SD, n=5-6
Lie et al., JCBFM, In revision
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Infarct volume
Aim 2 - L-Isoserine increases functional recovery
Department of Drug Design and Pharmacology
mean±SD, n=6-8
CylinderGrid-walking
mean±SD, n=6-8
Lie et al., JCBFM, In revision
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Maria Lie: [email protected]
Aim 2- L-Isoserine increases the GAT3 expression post-stroke
Department of Drug Design and Pharmacology
mean±SD, n=6Lie et al., JCBFM, In revision
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Maria Lie: [email protected]
Summary of key resultsSummary of key results and hypothesis
Department of Drug Design and Pharmacology
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Maria Lie: [email protected]
Acknowledgements
Department of Drug Design and Pharmacology
Andrew Clarkson Emma GowingPetrine Wellendorph Louise Thiesen
Nils Ole Dalby Nina Johansen
Department of Drug Design and PharmacologyWellendorph group: Department of Anatomy
Funding:
24th of August 2017, Dias 11
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Maria Lie: [email protected]
Thanks for your attention
Department of Drug Design and Pharmacology