takaomi saido
TRANSCRIPT
Greetings: RIKEN BSI Proteolytic Neuroscience Laboratory
BSI Central Building, April 17, 2014.
Takaomi C. SaidoLaboratory for Proteolytic NeuroscienceRIKEN Brain Science InstituteJAPAN
Alzforum WebinerApril 22, 2014
2nd generation mouse models of Alzheimer’s disease:12 years of work and future perspectives
Crossing Tg mice overexpressing mutant APP with other Tg mice is a risky paradigm.
Example: APP-Tg X Calpastatin-Tg/KO.
0
20
40
60
80
100
0 10 20 30 40 50 60
Age (weeks)
Pro
po
rtio
n s
urv
ivin
g (
%) WT
CS-KO
APP/CS-Tg
APP-TgAPP-TgCS-KO (+/-)
APP-TgCS-KO (-/-)
Effect of calpastatin (CS) overexpression & deficiency on life span of APP-Tg mice
Higuchi et al. FASEB J. (2012)
2nd generation KI mouse model of A amyloidosis: β APPNL-F
β-cleavage site γ-cleavage site
67
1
Aβ42Aβ40
R Y Hhumanization
Aβ:3-fold
NL
SEVKM DAEFGHDSGFEVRHQKLVFFAEDVGSNKGAIIGLMVGGVV IA TVIVITLVMLK
67
0
Overproduction of Aβ1-42 Aβ42/Aβ40 ratio: 30-fold
F Beyreuther/Iberianmutation
Saito et al. (Nat Neurosci, 2014)
Overproduction of APPsβ
NL-F
Relevant negative control?
A negative control for the 2nd generation KI mouse model: APPNL
β-cleavage site γ-cleavage site
67
1
Aβ42Aβ40
R Y Hhumanization
Aβ:3-fold
NL
SEVKM DAEFGHDSGFEVRHQKLVFFAEDVGSNKGAIIGLMVGGVV IA TVIVITLVMLK
67
0
Overproduction of Aβ1-40/42
Saito et al. (Nat Neurosci, 2014)
Age of onset: 50-60 years
Overproduction of APPsβ
NL
Relevant negative control!
500 µm
Am
yloi
d bu
rden
(%) HippocampusCortex
4G8 15 mo 18 mo12 mo9 mo
21 mo 24 mo
Age-dependent Aβ deposition in NL-F/NL-F
Aβ deposition could be detected from 6 mo of NL-F/NL-F brains.
APP KICS-KO
CS-KO; APP KI
Modulation of calpain activity in APP-KI mouse brain by crossbreeding with Calpastatin (CS)-KO mice
New!
Survival of APPNL/F-KI x Calpastatin (CS)-KO mice
CS deficiency did not affect the survival of APPNL-F KI mice at least up to 20 months.
1. Role of inflammation2. Role of various proteases3. Effect of Aβ vaccination4. Effect of ApoE45. Effect of the environmental
enrichment6. Effect of various diets and
supplements7. Others (Tau, Dynamin, Arc, etc.)
Major issues to be re-addressed
3 rd generation KI mouse model of A amyloidosis: APPβ NL-G-F
β-cleavage site γ-cleavage site
67
1
Aβ42Aβ40
R Y Hhumanization
NL
SEVKM DAEFGHDSGFEVRHQKLVFFAEDVGSNKGAIIGLMVGGVV IA TVIVITLVMLK
67
0
F Beyreuther/Iberianmutation
Saito et al. (Nat Neurosci, 2014)
SEVNL DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVV IA TVFVITLVMLK
G (Arctic mutation)
Oligomerization-prone
NL-G-F
500 µm
2 months 4 months 7 months
Aβ42 pathology of NL-G-F KI mice
Neuroinflammation in APPNL-G-F/NL-G-F KI
Greater neuroinflammation was found around the plaques in APPNL-G-F/NL-G-F mice than aged APPNL-F/NL-F KI mice.
APPNL-F/NL-F (24 mo) APPNL-G-F/NL-G-F (9 mo)
Aβ(82E1) microglia astrocyte merge
Differential utility of NL-F and NL-G-F mice
1. NL-F: Mechanism of Aβ deposition (up-stream targets).
2. NL-G-F: Mechanism of inflammation, tauopathy and neurodegeneration (down-stream targets).
Finally, we should compare our mice with APPNL/NL mice crossbred with mutant presenilin 1 (PS1) knockin mice24, which also overproduce Aβ 42 without overexpressing APP. These APP/PS1 double knockin mice are comparable to the APPNL-F/NL-F mice in this respect. There are, however, two major difficulties that limit the utility of the double knockin mice. The first is that they are doubly homozygous: crossing them with other mutant mice is practically impossible. To our knowledge, no researchers have done so as yet. The second is that presenilin mutations affect biological processes other than γ-cleavage of APP25; no perfect negative controls exist. It should also be noted that the function(s) of PS1 may, at least in part, differ between humans and mice26.
RIKEN BSI Lab. for Proteolytic Neuroscience
Takashi SaitoNobuhisa Iwata (Nagasaki U)
Makoto Higuchi (NIR)Jiro TakanoSatoshi TsubukiPer NilssonNaomasa KakiyaKaori TsukakoshiHayato IsshikiKo SatoShoko Hashimoto
Contributors and Collaborators
RIKEN BSI Lab. for Behavioral Genetics Shigeyoshi ItoharaNational Institute for Geriatrics and Gerontology
Akihiko TakashimaUniversity of Minnesota Karen Hsiao-AsheNovartis Institute of Medical Research
Matthias StaufenbielJichi Medical University
Shin-ichi MuramatsuHarvard Medical School
Cynthia Lemere