08/10/14 Animal models of PSP Luc BUEE Inserm, CHR-­‐University of Lille France Today’s talk •  Environmental Toxins •  GeneJcs & Tau transgenic models (FTDP-­‐17 mutaJons, tau overexpression) •  EpigeneJcs & KO dicer •  Tau secreJon, tau strains & spreading •  Open up on therapeuJcs Today’s talk •  Environmental Toxins •  GeneJcs & Tau transgenic models (FTDP-­‐17 mutaJons, tau overexpression) •  EpigeneJcs & KO dicer •  Tau secreJon & spreading •  Open up on therapeuJcs 1 08/10/14 PSP in French Caribbean τ 74
τ 74
τ 69
τ 69
τ 64
τ 64
τ 60
τ 60
Guadeloupe PSP Guam P
P
AD Today’s talk •  Environmental Toxins •  GeneJcs & Tau transgenic models (FTDP-­‐17 mutaJons, tau overexpression) –  Tau pathology –  NeuroinflammaJon •  EpigeneJcs & KO dicer •  Tau secreJon & spreading •  Open up on therapeuJcs 2 08/10/14 GeneJc / 4R Tau Tau transgenic mice Tau transgenic mice •  Theory versus experimental –  Choice of the mutaJon –  Choice of the promoter –  Choice of the isoform •  Which phenotypes? –  Neuronal versus glial –  CorJcal, subcorJcal, brainstem… 3 08/10/14 THY-­‐Tau mice (1N4R G272V/P301S) Tau transgenic mice overexpress pro-inflammatory markers
Microarray experiments (FC>2)
12 month old THY-Tau22 vs. WT mice
Biological
processes
Sample
frequency
Background
frequency
Genes
Immune
response
8/29 (27,6%)
479/33218
(1,4%)
Ccl3, C3, H2-Ab1,
Ccl4, Cd74, Ccl5,
Clec7a, Cxcl5
Inflammatory
response
THY-Tau22
WT
6/29 (20,7%)
241/33218
(0,7%)
Ccl3, C3, Ccl4, Ccl5,
Clec7a, Cxcl5
Defense
response
7/29 (24,1%)
474/33218
(1,4%)
Ccl3, C3, Ccl4, Cd74,
Ccl5, Clec7a, Cxcl5
Immune system
process
8/29 (27,6%)
820/33218
(2,5%)
Ccl3, C3, H2-Ab1,
Ccl4, Cd74, Ccl5,
Clec7a, Cxcl5
Response to
wounding
6/29 (20,7%)
357/33218
(1,1%)
Ccl3, C3, Ccl4, Ccl5,
Clec7a, Cxcl5
Chemotaxis
4/29 (13,8%)
111/33218
(0,3%)
Ccl3, Ccl4, Ccl5, Cxcl5
Response to
stress
8/29 (27,6%)
1154/33218
(3,5%)
Response to
external
stimulus
6/28 (20,7%)
587/33218
(1,8%)
Response to
stimulus
10/29 (34,5%)
2279/33218
(6,9%)
Martin Figeac
Ccl3, C3, Creb313,
Ccl4, Cd74, Ccl5,
Clec7, Cxcl5
Ccl3, C3, Ccl4, Ccl5,
Clec7a, Cxcl5
Ccl3, Zic-1, C3,
Creb313, H2-Ab1,
Ccl4, Cd74, Ccl5,
Clec7a, Cxcl5
Microglia
pathogen CD11b
CD68
phagocytosis Microglia CD45
Innate immune response 3 months CD11b
12 months 4 08/10/14 Today’s talk •  Environmental Toxins •  GeneJcs & Tau transgenic models (FTDP-­‐17 mutaJons, tau overexpression) •  EpigeneJcs & KO dicer –  HyperphosphorylaJon –  miRNA124 & E10 splicing •  Tau secreJon & spreading •  Open up on therapeuJcs miRNAs regulate gene expression •  Small (19–22 nt), endogenous non-­‐coding RNAs •  Encoded in the genome • Wide range of expression: Few to 100,000 copies per cell •  EsJmated that ~25-­‐50 % of all genes are regulated by miRNAs •  Each miRNA can regulate up to 100+ different genes •  Each gene can be regulated by mulJple miRNAs Proof of principle – Dicer cKO mice
•  Progressive neurodegeneration
•  Reduced brain size
•  Enlarged ventricles
•  Inflammation
•  Neuritic and synaptic changes
•  Apoptosis (in some cases)
X
~21nt
Hum Mol Genet 2010
5 08/10/14 miRNAs and Tau exon 10 splicing
(The analysis of Dicer cKO mice)
Smith P, Delay C et al. Hum Mol Genet 2012
Tau splicing in
progressive supranuclear palsy
E2 E3
E10
E2 E3
τ 74 τ 69
τ 74 τ 69
τ 64
τ 64
E10
τ 60 Ex : Alzheimer’s disease Ex : Progressive Supranuclear palsy *
*
*
p-Tau
Tau E2
Tau E2
*
Tau
Tau E10
E10
p-Tau
Tau E10
Smith P, Delay C et al. Hum Mol Genet 2012
Searching for miRNA/gene candidates
9
10
9
miR-132
(decrease in PSP)
PTBP2
11
11
Tau
miRNA may explain
some changes in
Tauopathies such as
Tau phosphorylation
and Tau splicing
6 08/10/14 Today’s talk •  Environmental Toxins •  GeneJcs & Tau transgenic models (FTDP-­‐17 mutaJons, tau overexpression) •  EpigeneJcs & KO dicer •  Tau secreJon & spreading –  Tau strains –  differenJal spreading of 3R and 4R isoforms •  Open up on therapeuJcs 7 08/10/14 8 08/10/14 TAU PATHOLOGY SPREADING Subiculum
CA1
IL
30 µm
30 µm
Caudal
30 µm
Rostral
IS
hTau46WT!
+2.7 +1.7 +0.7 -0.3 -1.3 -2.3 -3.3 -4.3 -5.3 -6.3 -7.3 -8.3
IS
Hyper Pi Tau
Misfolded Tau
Aggregated
Tau
AT8!
MC1!
AT100!
+2.20 mm
8 months!
Aggregated Tau
4 months!
Aggregated Tau
2 months!
The trans-­‐synap-c transfer of wt tau protein mediates progressive tau pathology IS -7.60 mm
ISOFORMS, MUTATIONS AND PROPAGATION …? InjecJon Site Rostral secondary regions Caudal secondary regions +5.7 +4.7 +3.7 +2.7 +1.7 +0,5 -0.3 -1.3 -2.3 -3.3 -4.3 -5.3 -6.3 -7.3 -8.3
-8.4 ± 0.2
+0.8 ± 1.2
***
*
+5.4 ± 0.2
-3.3 ± 0.5
h1N4R WT
-7.5 ± 0.2
h1N4R P332S
-7.5 ± 0.2
h1N4R P301L
*
***
Pathology progression
30 µm
Dujardin S. et al. Acta Neuropathol Commun 2014 DP
-7.8 ± 0.3
+1.0 ± 1.5
-3.1 ± 1.0
-7.6± 0.4
h1N3R WT
h1N3R P332S
9 08/10/14 Open up new therapeuJcs Therapeu?c strategies Compounds InhibiJon of tau phosphorylaJon – kinase inhibiJon LiCl, thiadiazolidinones, thiazoles, paullones, indirubines… Enhancing tau dephosphorylaJon – phosphatase acJvaJon Sodium selenate Increase tau glycosylaJon Thiamet G Decrease tau aggregaJon Methylene Blue (Phenothiazins), anthraquinones, aminothienopyridazines… Microtubule stabilizaJon Epothilone D, NAP Enhancing tau proteolysis trehalose Immunotherapy AcJve (phospho-­‐pepJdes) or passive (anJbodies) Others (neurotrophins, alternaJve splicing…) -­‐ Conclusions •  Numerous animal models are available •  Lowering Tau levels may be an interesJng approach but Tau has different physiological roles •  Tau immunotherapy works in experimental models – What about pathological Tau?? •  Is Tau alternaJve splicing the real target? •  PrognosJc markers from animal models? 10 

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