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P2-117 Genetics modifiers of beta-amyloid metabolism and deposition in the mouse
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Poster Session P2: Animal and Cellular Models - Animal Models, Transgenic
GENETICS MODIFIERS OF BETA-AMYLOID METABOLISM AND DEPOSITION IN THE MOUSE
Brace T. Lamb*, Davis C. Ryman, Yuan Gao, Laura S. Kulnane. Case Western Reserve University, Cleveland, OH, USA. Contact e-mail: btl @po. cwru. edu
Background: Alzheimer's disease (AD) is a multigenic neurodegenerative disorder characterized by distinct neuropathological hallmarks including deposits of the [3-amyloid (A~) peptide. While increasing evidence suggests that altered APP processing and A[3 metabolism is a common feature of AD, the relationship between the levels of A[3 and various APP products and the onset of AD remains unclear. Notably, even within families containing the same early-onset FAD mutation, substantial variation in symptoms, age of onset, pathology, duration and penetrance is exhibited suggesting the presence of modifier loci for A[3 metabolism and AD in these families. Objective(s): We have undertaken a screen to characterize and identify genetic factors that modify APP processing, A[~ metabolism and A[3 deposition using the mouse as a model system. Methods: A mutant human APP yeast artificial chromsome transgene was transferred to four inbred mouse strains and analyzed for alterations in APP processing, A~ metabolism and A[~ deposition throughout their lifespan. Results: Despite similar levels of holo-APP expression in the congenic strains, the levels of both APP C-terminal fragments as well as brain and plasma A[~ in young animals varied by genetic background. Furthermore, extensive variation in A[3 deposition was also observed between the genetic backgrounds. We will report on a detailed analysis of the congenic strains throughout their lifespan as well as present our initial genetic mapping studies on a large group of F2 animals designed at identifying quantitative trait loci that alter A[3 metabolism and deposition.
deficit in AD11 mice. Methods and Results: Cortical synaptic plasticity was evaluated at two different ages: 2-months of age, i.e. an early stage of neuronal degeneration, and 9-10 months of age, a stage in which neurodegeneration is almost fully blown. Expression of LTP in AD11 mice was evaluated by using high frequency stimulation (HFS) of the white matter and recording from layer II-III in occipital cortical slices. HFS induced a stable LTP in 2-month-old wild type mice. In contrast, HFS failed to evoke a stable potentiation of FPs in slices from 2-month-old A D l l mice At 10 months of age, wild type mice showed a normal expression of LTP, while in A D l l mice LTP was completely absent. Acute and local application of the cholinesterase inhibitor Galantamine (llxM) rescued LTP in the cortex of 2-month-old A D l l mice. On the contrary, Galantamine was unable to rescue LTP in the cortex of 10-month-old AD11 mice. To establish whether Galantamine was able to prevent the onset of learning and memory deficits in A D l l mice, it was administered i.p. to A D l l mice from 2 to 4.5 months of age. Untreated A D l l were clearly impaired in the Object Recognition Test with respect to wild type mice. Galantamine treated A D l l mice did not differ from wild type mice. A second group of AD11 mice was treated from 4 to 6 months of age: also in these case Galantamine was effective in ameliorating the memory deficits in A D l l mice. Conclusions: The behavioural data are in agreement with the effects of Galantamine on the neuropathological aspects in AD11 mice, while the impairment of long term cortical synaptic plasticity can be rescued by Galantamine, at early but not late stages of neurodegeneration.
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ALTERATIONS OF INTRACELLULAR C A 2+ HOMEOSTASIS IN A TRIPLE TRANSGENIC MODEL (PS1M14oT, APPsw~, TAUp301L) OF ALZHEIMER'S DISEASE
Ian E Smith*, Salvatore Oddo, KJm N. Green, Frank M. LaFerla. University of California, Irvine, Irvine, CA, USA. Contact e-mail: ismith @uci. edu
Background: Changes in intracellular Ca 2+ ([Ca2+]i) are important for
Conclusion: These studies demonstrate that APP processing, A~ metabolism and A[3 deposition are regulated by genetic background and that detailed genetic mapping and candidate gene analysis of these phenotypes in mice should provide new insights into the factors that regulate AD pathogenesis. Supported by the National Institutes of Health, the Alzlieimer's Association and the American Health Assistance Foundation.
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E F F E C T S O F THE CHOLINESTERASE I N H I B I T O R GALANTAMINE IN A MOUSE MODEL O F
ALZHEIMER'S DISEASE, THE ANTI-NERVE G R O W T H F A C T O R A D l l TRANSGENIC MICE Simona Capsoni .1 , Nicola Origlia 1, Olivia Comparini 2, Nicoletta Berardi2, Luciano Domenici2,3, Antonino Cattaneo 1,3.1 Lay Line Genomics S.p.A., Rome, Italy; 2Neuroscience Institute, CNR, Pisa, Italy; Slnternational School for Advanced Studies, Trieste, Italy. Contact e-mail: s. capsoni@ laylinegenomics, eom
Background: In AD 11 mice, the neutralization of nerve growth factor (NGF) activity by transgenic antibodies leads to an Alzheimer-like phenotype that includes neurofibrillary tangles, beta amyloid deposition, a decrease in the number of basal forebrain cholinergic neurons, cortical synaptic plasticity impairment and behavioural deficits. Objectives: In this study, we investigated the effects of Galantamine (acetylcholine esterase inhibitor and nAChR allosteric potentiating ligand) on cortical LTP and behavioral
a number of physiological and pathophysiological processes including synaptic plasticity, control of cell excitability and mediation of neural gene expression. Alterations of [Ca2+]i homeostasis has been implicated in the pathogenesis of Alzheimer's disease (AD) including affecting production of amyloid beta, hyperphosphorylation of tau, and increased vulnerability to cell death. Recently our lab has developed a triple transgenic mouse model of AD (3xTg-AD) that develops both plaque and tangle pathology in AD-relevant brain regions. Objective: Given the role for dysregulation of [Ca2+]i homeostasis in AD, here we investigate the role of altered Ca 2+ signaling in neurons of 3xTg-AD mice. Methods: Cortical neuronal cultures were isolated from 15-day old embryonic non-transgenic (NonTg) and 3xTg-AD mice. Neurons were cultured and used between days 12-16 following isolation. [Ca2+]i was monitored in fura-2 loaded cells. Results: Bath application of 50mM KC1 caused a peak rise of [Ca2+]i in Non-Tg cortical neurons that was not significantly different compared with 3xTg-AD neurons. Subsequent application of caffeine in a Ca 2+ containing media induced rises of [Ca2+]i that was significantly enhanced in 3xTg-AD neurons as compared with Non-Tg neurons. Inhibition of caffeine-induced Ca ~+ release was demonstrated by ryanodine (20tzM) in both Non-Tg and 3xTg-AD neurons. Inhibition of SERCA following KC1 pre-pulse with cyclopiazonic acid (in CaZ+-free media) inhibited caffeine-induced rises of [Ca2+]i in 21/22 Non-Tg neurons, yet only inhibited approximately 50% of caffeine-induced rises of [CaZ+]i in 3xTg-AD neurons. Biochemical data show increased expression of SERCA-2B in 3xTg-AD neurons as compared with Non-Tg neurons. Conclusion: Our results suggest that caffeine-induced rises in Ca2+are enhanced in 3xTg-AD neurons that may be attributable to increased expression of SERCA-2B. Acknowledgements: Supported by grants from NIH (AG17968 and AG26175).
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Poster Session P2: Animal and Cellular Models - Animal Models, Transgenic
GENETICS MODIFIERS OF BETA-AMYLOID METABOLISM AND DEPOSITION IN THE MOUSE
Brace T. Lamb*, Davis C. Ryman, Yuan Gao, Laura S. Kulnane. Case Western Reserve University, Cleveland, OH, USA. Contact e-mail: btl @po. cwru. edu
Background: Alzheimer's disease (AD) is a multigenic neurodegenerative disorder characterized by distinct neuropathological hallmarks including deposits of the [3-amyloid (A~) peptide. While increasing evidence suggests that altered APP processing and A[3 metabolism is a common feature of AD, the relationship between the levels of A[3 and various APP products and the onset of AD remains unclear. Notably, even within families containing the same early-onset FAD mutation, substantial variation in symptoms, age of onset, pathology, duration and penetrance is exhibited suggesting the presence of modifier loci for A[3 metabolism and AD in these families. Objective(s): We have undertaken a screen to characterize and identify genetic factors that modify APP processing, A[~ metabolism and A[3 deposition using the mouse as a model system. Methods: A mutant human APP yeast artificial chromsome transgene was transferred to four inbred mouse strains and analyzed for alterations in APP processing, A~ metabolism and A[~ deposition throughout their lifespan. Results: Despite similar levels of holo-APP expression in the congenic strains, the levels of both APP C-terminal fragments as well as brain and plasma A[~ in young animals varied by genetic background. Furthermore, extensive variation in A[3 deposition was also observed between the genetic backgrounds. We will report on a detailed analysis of the congenic strains throughout their lifespan as well as present our initial genetic mapping studies on a large group of F2 animals designed at identifying quantitative trait loci that alter A[3 metabolism and deposition.
deficit in AD11 mice. Methods and Results: Cortical synaptic plasticity was evaluated at two different ages: 2-months of age, i.e. an early stage of neuronal degeneration, and 9-10 months of age, a stage in which neurodegeneration is almost fully blown. Expression of LTP in AD11 mice was evaluated by using high frequency stimulation (HFS) of the white matter and recording from layer II-III in occipital cortical slices. HFS induced a stable LTP in 2-month-old wild type mice. In contrast, HFS failed to evoke a stable potentiation of FPs in slices from 2-month-old A D l l mice At 10 months of age, wild type mice showed a normal expression of LTP, while in A D l l mice LTP was completely absent. Acute and local application of the cholinesterase inhibitor Galantamine (llxM) rescued LTP in the cortex of 2-month-old A D l l mice. On the contrary, Galantamine was unable to rescue LTP in the cortex of 10-month-old AD11 mice. To establish whether Galantamine was able to prevent the onset of learning and memory deficits in A D l l mice, it was administered i.p. to A D l l mice from 2 to 4.5 months of age. Untreated A D l l were clearly impaired in the Object Recognition Test with respect to wild type mice. Galantamine treated A D l l mice did not differ from wild type mice. A second group of AD11 mice was treated from 4 to 6 months of age: also in these case Galantamine was effective in ameliorating the memory deficits in A D l l mice. Conclusions: The behavioural data are in agreement with the effects of Galantamine on the neuropathological aspects in AD11 mice, while the impairment of long term cortical synaptic plasticity can be rescued by Galantamine, at early but not late stages of neurodegeneration.
F
P
•
ALTERATIONS OF INTRACELLULAR C A 2+ HOMEOSTASIS IN A TRIPLE TRANSGENIC MODEL (PS1M14oT, APPsw~, TAUp301L) OF ALZHEIMER'S DISEASE
Ian E Smith*, Salvatore Oddo, KJm N. Green, Frank M. LaFerla. University of California, Irvine, Irvine, CA, USA. Contact e-mail: ismith @uci. edu
Background: Changes in intracellular Ca 2+ ([Ca2+]i) are important for
Conclusion: These studies demonstrate that APP processing, A~ metabolism and A[3 deposition are regulated by genetic background and that detailed genetic mapping and candidate gene analysis of these phenotypes in mice should provide new insights into the factors that regulate AD pathogenesis. Supported by the National Institutes of Health, the Alzlieimer's Association and the American Health Assistance Foundation.
•f•
E F F E C T S O F THE CHOLINESTERASE I N H I B I T O R GALANTAMINE IN A MOUSE MODEL O F
ALZHEIMER'S DISEASE, THE ANTI-NERVE G R O W T H F A C T O R A D l l TRANSGENIC MICE Simona Capsoni .1 , Nicola Origlia 1, Olivia Comparini 2, Nicoletta Berardi2, Luciano Domenici2,3, Antonino Cattaneo 1,3.1 Lay Line Genomics S.p.A., Rome, Italy; 2Neuroscience Institute, CNR, Pisa, Italy; Slnternational School for Advanced Studies, Trieste, Italy. Contact e-mail: s. capsoni@ laylinegenomics, eom
Background: In AD 11 mice, the neutralization of nerve growth factor (NGF) activity by transgenic antibodies leads to an Alzheimer-like phenotype that includes neurofibrillary tangles, beta amyloid deposition, a decrease in the number of basal forebrain cholinergic neurons, cortical synaptic plasticity impairment and behavioural deficits. Objectives: In this study, we investigated the effects of Galantamine (acetylcholine esterase inhibitor and nAChR allosteric potentiating ligand) on cortical LTP and behavioral
a number of physiological and pathophysiological processes including synaptic plasticity, control of cell excitability and mediation of neural gene expression. Alterations of [Ca2+]i homeostasis has been implicated in the pathogenesis of Alzheimer's disease (AD) including affecting production of amyloid beta, hyperphosphorylation of tau, and increased vulnerability to cell death. Recently our lab has developed a triple transgenic mouse model of AD (3xTg-AD) that develops both plaque and tangle pathology in AD-relevant brain regions. Objective: Given the role for dysregulation of [Ca2+]i homeostasis in AD, here we investigate the role of altered Ca 2+ signaling in neurons of 3xTg-AD mice. Methods: Cortical neuronal cultures were isolated from 15-day old embryonic non-transgenic (NonTg) and 3xTg-AD mice. Neurons were cultured and used between days 12-16 following isolation. [Ca2+]i was monitored in fura-2 loaded cells. Results: Bath application of 50mM KC1 caused a peak rise of [Ca2+]i in Non-Tg cortical neurons that was not significantly different compared with 3xTg-AD neurons. Subsequent application of caffeine in a Ca 2+ containing media induced rises of [Ca2+]i that was significantly enhanced in 3xTg-AD neurons as compared with Non-Tg neurons. Inhibition of caffeine-induced Ca ~+ release was demonstrated by ryanodine (20tzM) in both Non-Tg and 3xTg-AD neurons. Inhibition of SERCA following KC1 pre-pulse with cyclopiazonic acid (in CaZ+-free media) inhibited caffeine-induced rises of [Ca2+]i in 21/22 Non-Tg neurons, yet only inhibited approximately 50% of caffeine-induced rises of [CaZ+]i in 3xTg-AD neurons. Biochemical data show increased expression of SERCA-2B in 3xTg-AD neurons as compared with Non-Tg neurons. Conclusion: Our results suggest that caffeine-induced rises in Ca2+are enhanced in 3xTg-AD neurons that may be attributable to increased expression of SERCA-2B. Acknowledgements: Supported by grants from NIH (AG17968 and AG26175).