- Email: [email protected]
PS1 BUT NOT BY ENDOGENOUS APP IN TAU TRANSGENIC MICE
Poster Presentations: P4 analysis of brain tissue confirmed that additional treatment with OA caused behavioral and morphological hallmarks observed in human tauopathy. Data of our experiment indicate that lithium chloride can improve cognitive processes in tauopathic rats. Additionally, lithium chloride restored the pattern of intraneuronal expression of endogenous tau protein and its two phosphorylated forms, p-TauS231 and p-TauS404. Conclusions: These results indicate that presented novel animal model of human tauopathy mimics several pathologies observed in progressive dementia and is susceptible to pharmacological intervention. Therefore, it could be useful instrument to identify novel biomarkers, drug targets and therapeutic approaches for tauopathies. P4-004
ABNORMAL PROCESSING AND MISFOLDING OF TAU IS MODULATED BY ENDOGENOUS TAU AND MUTANT APP/PS1 BUT NOT BY ENDOGENOUS APP IN TAU TRANSGENIC MICE
Jean-Pierre Brion1, Kunie Ando2, Celine Heraud3, Karelle Leroy3, Virginie Stygelbout4, 1Universite Libre de Bruxelles, Brussels, Belgium; 2 ICM institute, Paris, France; 3Universite Libre de Bruxelles, Brussels, Belgium; 4Universite Libre de Bruxelles Brussels, Belgium. Contact e-mail: [email protected] Background: Expression of mutant tau leads to the formation of fibrillar aggregates in animal models of Alzheimer’s disease and other human tauopathies, but it is not completely deciphered to which extent the abnormal misfolding of tau in these aggregates fully reproduce the post-translational modifications of tau observed in human tauopathies, an essential validation step for these models. We have investigated the role of changed expression levels of some genes for their ability to modify the abnormal processing of tau to generate models closer to human tauopathies. Methods: Transgenic mice expressing an FTD mutant tau (Tg30 mice) in absence of endogenous wild-type tau, of endogenous APP or in presence of FAD mutant APP and PS1, have been analyzed for their behavioral deficits and the extent of tau aggregation and tau misprocessing. Results: Tg30 mice invalidated for their endogenous tau gene had increased motor impairment, higher levels of phosphorylated and insoluble tau and increased density of NFT in the brain despite lower levels of total tau. 5xFAD x Tg30 mice exhibited a severe increase in motor deficiency and a dramatically increased load in NFT. Insoluble tau in 5xFAD x Tg30 mice compared to insoluble tau in Tg30 mice showed increased phosphorylation, enhanced misfolding and a higher recruitment of endogenous wild-type mouse tau. Inactivation of the APP gene did not change significantly tau pathology in APP-/- x Tg30 mice. Despite these changes in tau misprocessing, some forms of oligomeric tau were not detected in these mice models. Conclusions: These results suggest that increased abnormal misfolding of tau in these animal models is modulated by relative ratios of mutant tau versus non-mutant tau and by expression of mutant APP or PS1, that act as tau-modifiers genes, but is not dependent of expression of endogenous APP. Tg30xtau -/- and 5xFAD x Tg30 mice thus mimics more faithfully, but not completely, tau pathology observed in human tauopathies. P4-005
ENTORHINAL TAU PATHOLOGY AFFECTS LOCAL NEURONS AND CORTICAL THETA OSCILLATIONS DURING MEMORY ACQUISITION
Stephanie E. Tanninen1, Mark D. Morrissey1, Ronald L. Klein2, Kaori Takehara-Nishiuchi1, 1University of Toronto, Toronto, Ontario, Canada; 2Louisiana State University Health Sciences Center, Shreveport, Louisiana, United States. Contact e-mail: stephanie.tanninen@mail. utoronto.ca Background: The accumulation of hyper-phosphorylated tau protein in the entorhinal cortex is one of the first abnormalities observed in Alzheimer’s disease (AD). The entorhinal cortex is reciprocally connected with many cortical regions critical for memory formation and expression.
P785
Entorhinal tau pathology would therefore disrupt the transfer of information within the cortical memory network, resulting in memory impairments in AD. Methods: To test this hypothesis, we expressed, through transduction with a viral vector, an excess of human tau with the P301L mutation (tau rats) or green fluorescent protein as a control (GFP rats), specifically in the entorhinal cortex of adult rats. We then tested the rats’ ability to acquire an associative memory in trace eye blink conditioning while monitoring local field potentials in the hippocampus, a major efferent target of the entorhinal cortex. Results: One month after transduction, approximately 20% of neurons were filled with hyper-phosphorylated tau and the area adjacent to the injection sites showed signs of astrogliosis and neurofibrillary tangles. When tested in trace eye blink conditioning, the tau rats formed the association between a tone and eyelid stimulation in a comparable manner to the GFP rats; however, the hippocampus of the tau rats had relatively smaller amplitude of theta oscillations during conditioning in comparison to GFP rats. Conclusions: Thus, minor entorhinal tau pathology alters hippocampal neuronal activity even before memory impairments become apparent. P4-006
DEFICITS IN THE NATURAL CIRCULAR RNA (CIRCRNA) ‘SPONGE’ FOR MIRNA-7 (CIRS7) IN ALZHEIMER’S DISEASE (AD): MIRNA-7 UPREGULATION, AND DOWN-REGULATION OF THE KEY PHAGOCYTOSIS PROTEIN UBIQUITIN LIGASE A (UBE2A)
J.M. Hill1, Walter J. Lukiw2, Surjyadipta Bhattacharjee1, Yuhai Zhao3, Peter N. Alexandrov4, Prerna Dua5, Aileen I. Pogue6, 1Louisiana State University, New Orleans, Louisiana, United States; 2Louisiana State University Neuroscience Center, New Orleans, Louisiana, United States; 3Louisiana State University Neuroscience Center, New Orleans, Louisiana, United States; 4Russian Academy of Medical Sciences, Moscow, Russia; 5LA Technical University, Ruston, Louisiana, United States; 6 Alchem Biotek Corporation, Toronto, Ontario, Canada. Contact e-mail: [email protected] Background: Circular RNAs (circRNAs) are a naturally occurring family of noncoding RNAs (ncRNAs) highly represented in the eukaryotic transcriptome and enriched in the mammalian brain. Traditional methods of RNA detection and analysis requiring a free 5’ or 3’ ribonucleotide terminus may have significantly underestimated circRNA abundance and significance in eukaryotic cells.Specific ncRNAs such as the evolutionary ancient microRNA-7 (miRNA-7; chr 9q21.32) are not only highly abundant in human brain, but are also associated with a circRNA for miRNA-7 (ciRS-7), in the same tissues. ciRS-7 contains multiple, tandem anti-miRNA-7 sequences, acting as a kind of endogenous, competing, anticomplementary mi RNA ’sponge’ to adsorb, and hence quench, normal miRNA-7 functions. Methods: 5xFAD mice; Ab42-peptide- and/or TNFa-induced stress; AD post-mortem tissues; bioinformatics; DNA array and RNA sequencing; human brain cells; LED-Northern dot blot analysis; micro-RNA array; mRNA array; NF-kB-inhibitors CAY10512,curcumin, CAPE; RT-PCR; CFH-luciferase-reporter transfection; RNaseR; selective ribonuclease assay; Western analysis and immunoassay. Results: Using enhanced hybridization techniques, RNA sequencing, miRNA/mRNA array technologies and circularity-sensitive circRNA probes such asRNaseR, we provide initial evidence of a mis-regulated miRNA-7-circRNA system in sporadic AD hippocampal CA1. Deficits in ciRS-7, and ciRS-7 ’sponging activities’ might be expected to increase ambient miRNA-7 levels in ADaffected brain cells, as is observed, to ultimately contribute to the downregulation of selective miRNA-7-sensitive messenger RNA (mRNA) targets. Up-regulated miRNA-7 (due to a deficiency in ciRS-7 ’sponging’ effects) was found to down-regulate AD-relevant targets, such as, the ubiquitin protein ligase A (UBE2A; miRNA-7-UBE2A mRNA 3’-UTR energy of association, E A ¼ -23 kcal/mol). UBE2A, an autophagic, phagocytic protein essential in the clearance of amyloid peptides in AD and other progressive inflammatory degenerations of the human CNS, is depleted in
ABNORMAL PROCESSING AND MISFOLDING OF TAU IS MODULATED BY ENDOGENOUS TAU AND MUTANT APP/PS1 BUT NOT BY ENDOGENOUS APP IN TAU TRANSGENIC MICE
Jean-Pierre Brion1, Kunie Ando2, Celine Heraud3, Karelle Leroy3, Virginie Stygelbout4, 1Universite Libre de Bruxelles, Brussels, Belgium; 2 ICM institute, Paris, France; 3Universite Libre de Bruxelles, Brussels, Belgium; 4Universite Libre de Bruxelles Brussels, Belgium. Contact e-mail: [email protected] Background: Expression of mutant tau leads to the formation of fibrillar aggregates in animal models of Alzheimer’s disease and other human tauopathies, but it is not completely deciphered to which extent the abnormal misfolding of tau in these aggregates fully reproduce the post-translational modifications of tau observed in human tauopathies, an essential validation step for these models. We have investigated the role of changed expression levels of some genes for their ability to modify the abnormal processing of tau to generate models closer to human tauopathies. Methods: Transgenic mice expressing an FTD mutant tau (Tg30 mice) in absence of endogenous wild-type tau, of endogenous APP or in presence of FAD mutant APP and PS1, have been analyzed for their behavioral deficits and the extent of tau aggregation and tau misprocessing. Results: Tg30 mice invalidated for their endogenous tau gene had increased motor impairment, higher levels of phosphorylated and insoluble tau and increased density of NFT in the brain despite lower levels of total tau. 5xFAD x Tg30 mice exhibited a severe increase in motor deficiency and a dramatically increased load in NFT. Insoluble tau in 5xFAD x Tg30 mice compared to insoluble tau in Tg30 mice showed increased phosphorylation, enhanced misfolding and a higher recruitment of endogenous wild-type mouse tau. Inactivation of the APP gene did not change significantly tau pathology in APP-/- x Tg30 mice. Despite these changes in tau misprocessing, some forms of oligomeric tau were not detected in these mice models. Conclusions: These results suggest that increased abnormal misfolding of tau in these animal models is modulated by relative ratios of mutant tau versus non-mutant tau and by expression of mutant APP or PS1, that act as tau-modifiers genes, but is not dependent of expression of endogenous APP. Tg30xtau -/- and 5xFAD x Tg30 mice thus mimics more faithfully, but not completely, tau pathology observed in human tauopathies. P4-005
ENTORHINAL TAU PATHOLOGY AFFECTS LOCAL NEURONS AND CORTICAL THETA OSCILLATIONS DURING MEMORY ACQUISITION
Stephanie E. Tanninen1, Mark D. Morrissey1, Ronald L. Klein2, Kaori Takehara-Nishiuchi1, 1University of Toronto, Toronto, Ontario, Canada; 2Louisiana State University Health Sciences Center, Shreveport, Louisiana, United States. Contact e-mail: stephanie.tanninen@mail. utoronto.ca Background: The accumulation of hyper-phosphorylated tau protein in the entorhinal cortex is one of the first abnormalities observed in Alzheimer’s disease (AD). The entorhinal cortex is reciprocally connected with many cortical regions critical for memory formation and expression.
P785
Entorhinal tau pathology would therefore disrupt the transfer of information within the cortical memory network, resulting in memory impairments in AD. Methods: To test this hypothesis, we expressed, through transduction with a viral vector, an excess of human tau with the P301L mutation (tau rats) or green fluorescent protein as a control (GFP rats), specifically in the entorhinal cortex of adult rats. We then tested the rats’ ability to acquire an associative memory in trace eye blink conditioning while monitoring local field potentials in the hippocampus, a major efferent target of the entorhinal cortex. Results: One month after transduction, approximately 20% of neurons were filled with hyper-phosphorylated tau and the area adjacent to the injection sites showed signs of astrogliosis and neurofibrillary tangles. When tested in trace eye blink conditioning, the tau rats formed the association between a tone and eyelid stimulation in a comparable manner to the GFP rats; however, the hippocampus of the tau rats had relatively smaller amplitude of theta oscillations during conditioning in comparison to GFP rats. Conclusions: Thus, minor entorhinal tau pathology alters hippocampal neuronal activity even before memory impairments become apparent. P4-006
DEFICITS IN THE NATURAL CIRCULAR RNA (CIRCRNA) ‘SPONGE’ FOR MIRNA-7 (CIRS7) IN ALZHEIMER’S DISEASE (AD): MIRNA-7 UPREGULATION, AND DOWN-REGULATION OF THE KEY PHAGOCYTOSIS PROTEIN UBIQUITIN LIGASE A (UBE2A)
J.M. Hill1, Walter J. Lukiw2, Surjyadipta Bhattacharjee1, Yuhai Zhao3, Peter N. Alexandrov4, Prerna Dua5, Aileen I. Pogue6, 1Louisiana State University, New Orleans, Louisiana, United States; 2Louisiana State University Neuroscience Center, New Orleans, Louisiana, United States; 3Louisiana State University Neuroscience Center, New Orleans, Louisiana, United States; 4Russian Academy of Medical Sciences, Moscow, Russia; 5LA Technical University, Ruston, Louisiana, United States; 6 Alchem Biotek Corporation, Toronto, Ontario, Canada. Contact e-mail: [email protected] Background: Circular RNAs (circRNAs) are a naturally occurring family of noncoding RNAs (ncRNAs) highly represented in the eukaryotic transcriptome and enriched in the mammalian brain. Traditional methods of RNA detection and analysis requiring a free 5’ or 3’ ribonucleotide terminus may have significantly underestimated circRNA abundance and significance in eukaryotic cells.Specific ncRNAs such as the evolutionary ancient microRNA-7 (miRNA-7; chr 9q21.32) are not only highly abundant in human brain, but are also associated with a circRNA for miRNA-7 (ciRS-7), in the same tissues. ciRS-7 contains multiple, tandem anti-miRNA-7 sequences, acting as a kind of endogenous, competing, anticomplementary mi RNA ’sponge’ to adsorb, and hence quench, normal miRNA-7 functions. Methods: 5xFAD mice; Ab42-peptide- and/or TNFa-induced stress; AD post-mortem tissues; bioinformatics; DNA array and RNA sequencing; human brain cells; LED-Northern dot blot analysis; micro-RNA array; mRNA array; NF-kB-inhibitors CAY10512,curcumin, CAPE; RT-PCR; CFH-luciferase-reporter transfection; RNaseR; selective ribonuclease assay; Western analysis and immunoassay. Results: Using enhanced hybridization techniques, RNA sequencing, miRNA/mRNA array technologies and circularity-sensitive circRNA probes such asRNaseR, we provide initial evidence of a mis-regulated miRNA-7-circRNA system in sporadic AD hippocampal CA1. Deficits in ciRS-7, and ciRS-7 ’sponging activities’ might be expected to increase ambient miRNA-7 levels in ADaffected brain cells, as is observed, to ultimately contribute to the downregulation of selective miRNA-7-sensitive messenger RNA (mRNA) targets. Up-regulated miRNA-7 (due to a deficiency in ciRS-7 ’sponging’ effects) was found to down-regulate AD-relevant targets, such as, the ubiquitin protein ligase A (UBE2A; miRNA-7-UBE2A mRNA 3’-UTR energy of association, E A ¼ -23 kcal/mol). UBE2A, an autophagic, phagocytic protein essential in the clearance of amyloid peptides in AD and other progressive inflammatory degenerations of the human CNS, is depleted in