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Farrell C, Mumford P, Wiseman FK. Rodent Modeling of Alzheimer's Disease in Down Syndrome: In vivo and ex vivo Approaches. Front Neurosci 2022; 16:909669. [PMID: 35747206 PMCID: PMC9209729 DOI: 10.3389/fnins.2022.909669] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/16/2022] [Indexed: 12/30/2022] Open
Abstract
There are an estimated 6 million people with Down syndrome (DS) worldwide. In developed countries, the vast majority of these individuals will develop Alzheimer's disease neuropathology characterized by the accumulation of amyloid-β (Aβ) plaques and tau neurofibrillary tangles within the brain, which leads to the early onset of dementia (AD-DS) and reduced life-expectancy. The mean age of onset of clinical dementia is ~55 years and by the age of 80, approaching 100% of individuals with DS will have a dementia diagnosis. DS is caused by trisomy of chromosome 21 (Hsa21) thus an additional copy of a gene(s) on the chromosome must cause the development of AD neuropathology and dementia. Indeed, triplication of the gene APP which encodes the amyloid precursor protein is sufficient and necessary for early onset AD (EOAD), both in people who have and do not have DS. However, triplication of other genes on Hsa21 leads to profound differences in neurodevelopment resulting in intellectual disability, elevated incidence of epilepsy and perturbations to the immune system. This different biology may impact on how AD neuropathology and dementia develops in people who have DS. Indeed, genes on Hsa21 other than APP when in three-copies can modulate AD-pathogenesis in mouse preclinical models. Understanding this biology better is critical to inform drug selection for AD prevention and therapy trials for people who have DS. Here we will review rodent preclinical models of AD-DS and how these can be used for both in vivo and ex vivo (cultured cells and organotypic slice cultures) studies to understand the mechanisms that contribute to the early development of AD in people who have DS and test the utility of treatments to prevent or delay the development of disease.
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Tallino S, Winslow W, Bartholomew SK, Velazquez R. Temporal and brain region-specific elevations of soluble Amyloid-β 40-42 in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease. Aging Cell 2022; 21:e13590. [PMID: 35290711 PMCID: PMC9009111 DOI: 10.1111/acel.13590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 02/13/2022] [Accepted: 03/01/2022] [Indexed: 12/12/2022] Open
Abstract
Down syndrome (DS) is a leading cause of intellectual disability that also results in hallmark Alzheimer's disease (AD) pathologies such as amyloid beta (Aβ) plaques and hyperphosphorylated tau. The Ts65Dn mouse model is commonly used to study DS, as trisomic Ts65Dn mice carry 2/3 of the triplicated gene homologues as occur in human DS. The Ts65Dn strain also allows investigation of mechanisms common to DS and AD pathology, with many of these triplicated genes implicated in AD; for example, trisomic Ts65Dn mice overproduce amyloid precursor protein (APP), which is then processed into soluble Aβ40-42 fragments. Notably, Ts65Dn mice show alterations to the basal forebrain, which parallels the loss of function in this region observed in DS and AD patients early on in disease progression. However, a complete picture of soluble Aβ40-42 accumulation in a region-, age-, and sex-specific manner has not yet been characterized in the Ts65Dn model. Here, we show that trisomic mice accumulate soluble Aβ40-42 in the basal forebrain, frontal cortex, hippocampus, and cerebellum in an age-specific manner, with elevation in the frontal cortex and hippocampus as early as 4 months of age. Furthermore, we detected sex differences in accumulation of Aβ40-42 within the basal forebrain, with females having significantly higher Aβ40-42 at 7-8 months of age. Lastly, we show that APP expression in the basal forebrain and hippocampus inversely correlates with Aβ40-42 levels. This spatial and temporal characterization of soluble Aβ40-42 in the Ts65Dn model allows for further exploration of the role soluble Aβ plays in the progression of other AD-like pathologies in these key brain regions.
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Affiliation(s)
- Savannah Tallino
- Arizona State University‐Banner Neurodegenerative Disease Research Center at the Biodesign Institute Arizona State University Tempe Arizona USA
- School of Life Sciences Arizona State University Tempe Arizona USA
| | - Wendy Winslow
- Arizona State University‐Banner Neurodegenerative Disease Research Center at the Biodesign Institute Arizona State University Tempe Arizona USA
| | - Samantha K. Bartholomew
- Arizona State University‐Banner Neurodegenerative Disease Research Center at the Biodesign Institute Arizona State University Tempe Arizona USA
| | - Ramon Velazquez
- Arizona State University‐Banner Neurodegenerative Disease Research Center at the Biodesign Institute Arizona State University Tempe Arizona USA
- School of Life Sciences Arizona State University Tempe Arizona USA
- Arizona Alzheimer’s Consortium Phoenix Arizona USA
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Atas-Ozcan H, Brault V, Duchon A, Herault Y. Dyrk1a from Gene Function in Development and Physiology to Dosage Correction across Life Span in Down Syndrome. Genes (Basel) 2021; 12:1833. [PMID: 34828439 PMCID: PMC8624927 DOI: 10.3390/genes12111833] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/15/2021] [Accepted: 11/18/2021] [Indexed: 01/12/2023] Open
Abstract
Down syndrome is the main cause of intellectual disabilities with a large set of comorbidities from developmental origins but also that appeared across life span. Investigation of the genetic overdosage found in Down syndrome, due to the trisomy of human chromosome 21, has pointed to one main driver gene, the Dual-specificity tyrosine-regulated kinase 1A (Dyrk1a). Dyrk1a is a murine homolog of the drosophila minibrain gene. It has been found to be involved in many biological processes during development and in adulthood. Further analysis showed its haploinsufficiency in mental retardation disease 7 and its involvement in Alzheimer's disease. DYRK1A plays a role in major developmental steps of brain development, controlling the proliferation of neural progenitors, the migration of neurons, their dendritogenesis and the function of the synapse. Several strategies targeting the overdosage of DYRK1A in DS with specific kinase inhibitors have showed promising evidence that DS cognitive conditions can be alleviated. Nevertheless, providing conditions for proper temporal treatment and to tackle the neurodevelopmental and the neurodegenerative aspects of DS across life span is still an open question.
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Affiliation(s)
- Helin Atas-Ozcan
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (H.A.-O.); (V.B.); (A.D.)
| | - Véronique Brault
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (H.A.-O.); (V.B.); (A.D.)
| | - Arnaud Duchon
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (H.A.-O.); (V.B.); (A.D.)
| | - Yann Herault
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (H.A.-O.); (V.B.); (A.D.)
- Université de Strasbourg, CNRS, INSERM, Celphedia, Phenomin-Institut Clinique de la Souris (ICS), 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
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Miguel JC, Perez SE, Malek-Ahmadi M, Mufson EJ. Cerebellar Calcium-Binding Protein and Neurotrophin Receptor Defects in Down Syndrome and Alzheimer's Disease. Front Aging Neurosci 2021; 13:645334. [PMID: 33776745 PMCID: PMC7994928 DOI: 10.3389/fnagi.2021.645334] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/04/2021] [Indexed: 12/11/2022] Open
Abstract
Cerebellar hypoplasia is a major characteristic of the Down syndrome (DS) brain. However, the consequences of trisomy upon cerebellar Purkinje cells (PC) and interneurons in DS are unclear. The present study performed a quantitative and qualitative analysis of cerebellar neurons immunostained with antibodies against calbindin D-28k (Calb), parvalbumin (Parv), and calretinin (Calr), phosphorylated and non-phosphorylated intermediate neurofilaments (SMI-34 and SMI-32), and high (TrkA) and low (p75NTR) affinity nerve growth factor (NGF) receptors as well as tau and amyloid in DS (n = 12), Alzheimer's disease (AD) (n = 10), and healthy non-dementia control (HC) (n = 8) cases. Our findings revealed higher Aβ42 plaque load in DS compared to AD and HC but no differences in APP/Aβ plaque load between HC, AD, and DS. The cerebellar cortex neither displayed Aβ40 containing plaques nor pathologic phosphorylated tau in any of the cases examined. The number and optical density (OD) measurements of Calb immunoreactive (-ir) PC soma and dendrites were similar between groups, while the number of PCs positive for Parv and SMI-32 were significantly reduced in AD and DS compared to HC. By contrast, the number of SMI-34-ir PC dystrophic axonal swellings, termed torpedoes, was significantly greater in AD compared to DS. No differences in SMI-32- and Parv-ir PC OD measurements were observed between groups. Conversely, total number of Parv- (stellate/basket) and Calr (Lugaro, brush, and Golgi)-positive interneurons were significantly reduced in DS compared to AD and HC. A strong negative correlation was found between counts for Parv-ir interneurons, Calr-ir Golgi and brush cells, and Aβ42 plaque load. Number of TrkA and p75NTR positive PCs were reduced in AD compared to HC. These findings suggest that disturbances in calcium binding proteins play a critical role in cerebellar neuronal dysfunction in adults with DS.
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Affiliation(s)
- Jennifer C. Miguel
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, United States
| | - Sylvia E. Perez
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, United States
| | - Michael Malek-Ahmadi
- Department of Biomedical Informatics, Banner Alzheimer's Institute, Phoenix, AZ, United States
| | - Elliott J. Mufson
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, United States
- Department of Neurology, Barrow Neurological Institute, Phoenix, AZ, United States
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Cannavo C, Tosh J, Fisher EMC, Wiseman FK. Using mouse models to understand Alzheimer's disease mechanisms in the context of trisomy of chromosome 21. PROGRESS IN BRAIN RESEARCH 2019; 251:181-208. [PMID: 32057307 DOI: 10.1016/bs.pbr.2019.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
People who have Down syndrome are at significantly elevated risk of developing early onset Alzheimer's disease that causes dementia (AD-DS). Here we review recent progress in modeling the development of AD-DS in mouse models. These studies provide insight into mechanisms underlying Alzheimer's disease and generate new clinical research questions. In addition, they suggest potential new targets for disease prevention therapies.
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Affiliation(s)
- Claudia Cannavo
- Department of Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom; UK Dementia Research Institute at University College, London, United Kingdom
| | - Justin Tosh
- Department of Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom
| | - Elizabeth M C Fisher
- Department of Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom; The London Down Syndrome Consortium (LonDownS), London, United Kingdom
| | - Frances K Wiseman
- Department of Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom; The London Down Syndrome Consortium (LonDownS), London, United Kingdom; UK Dementia Research Institute at University College, London, United Kingdom.
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Illouz T, Madar R, Biragyn A, Okun E. Restoring microglial and astroglial homeostasis using DNA immunization in a Down Syndrome mouse model. Brain Behav Immun 2019; 75:163-180. [PMID: 30389461 PMCID: PMC6358279 DOI: 10.1016/j.bbi.2018.10.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 09/22/2018] [Accepted: 10/23/2018] [Indexed: 12/20/2022] Open
Abstract
Down Syndrome (DS), the most common cause of genetic intellectual disability, is characterized by over-expression of the APP and DYRK1A genes, located on the triplicated chromosome 21. This chromosomal abnormality leads to a cognitive decline mediated by Amyloid-β (Aβ) overproduction and tau hyper-phosphorylation as early as the age of 40. In this study, we used the Ts65Dn mouse model of DS to evaluate the beneficial effect of a DNA vaccination against the Aβ1-11 fragment, in ameliorating Aβ-related neuropathology and rescue of cognitive and behavioral abilities. Anti-Aβ1-11 vaccination induced antibody production and facilitated clearance of soluble oligomers and small extracellular inclusions of Aβ from the hippocampus and cortex of Ts65Dn mice. This was correlated with reduced neurodegeneration and restoration of the homeostatic phenotype of microglial and astroglial cells. Vaccinated Ts65Dn mice performed better in spatial-learning tasks, exhibited reduced motor hyperactivity typical for this strain, and restored short-term memory abilities. Our findings support the hypothesis that DS individuals may benefit from active immunotherapy against Aβ from a young age by slowing the progression of dementia.
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Affiliation(s)
- Tomer Illouz
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 5290002, Israel; The Paul Feder Laboratory on Alzheimer's Disease Research, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Ravit Madar
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 5290002, Israel; The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel; The Paul Feder Laboratory on Alzheimer's Disease Research, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Arya Biragyn
- Laboratory of Molecular Biology and Immunology, NIA, NIH, MD 21224, USA
| | - Eitan Okun
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 5290002, Israel; The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel; The Paul Feder Laboratory on Alzheimer's Disease Research, Bar-Ilan University, Ramat Gan 5290002, Israel.
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Tramutola A, Lanzillotta C, Barone E, Arena A, Zuliani I, Mosca L, Blarzino C, Butterfield DA, Perluigi M, Di Domenico F. Intranasal rapamycin ameliorates Alzheimer-like cognitive decline in a mouse model of Down syndrome. Transl Neurodegener 2018; 7:28. [PMID: 30410750 PMCID: PMC6218962 DOI: 10.1186/s40035-018-0133-9] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/11/2018] [Indexed: 02/08/2023] Open
Abstract
Background Down syndrome (DS) individuals, by the age of 40s, are at increased risk to develop Alzheimer-like dementia, with deposition in brain of senile plaques and neurofibrillary tangles. Our laboratory recently demonstrated the disturbance of PI3K/AKT/mTOR axis in DS brain, prior and after the development of Alzheimer Disease (AD). The aberrant modulation of the mTOR signalling in DS and AD age-related cognitive decline affects crucial neuronal pathways, including insulin signaling and autophagy, involved in pathology onset and progression. Within this context, the therapeutic use of mTOR-inhibitors may prevent/attenuate the neurodegenerative phenomena. By our work we aimed to rescue mTOR signalling in DS mice by a novel rapamycin intranasal administration protocol (InRapa) that maximizes brain delivery and reduce systemic side effects. Methods Ts65Dn mice were administered with InRapa for 12 weeks, starting at 6 months of age demonstrating, at the end of the treatment by radial arms maze and novel object recognition testing, rescued cognition. Results The analysis of mTOR signalling, after InRapa, demonstrated in Ts65Dn mice hippocampus the inhibition of mTOR (reduced to physiological levels), which led, through the rescue of autophagy and insulin signalling, to reduced APP levels, APP processing and APP metabolites production, as well as, to reduced tau hyperphosphorylation. In addition, a reduction of oxidative stress markers was also observed. Discussion These findings demonstrate that chronic InRapa administration is able to exert a neuroprotective effect on Ts65Dn hippocampus by reducing AD pathological hallmarks and by restoring protein homeostasis, thus ultimately resulting in improved cognition. Results are discussed in term of a potential novel targeted therapeutic approach to reduce cognitive decline and AD-like neuropathology in DS individuals.
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Affiliation(s)
- Antonella Tramutola
- 1Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Chiara Lanzillotta
- 1Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Eugenio Barone
- 1Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.,2Universidad Autònoma de Chile, Instituto de Ciencias Biomédicas, Facultad de alud, Avenida Pedro de Valdivia 425, Providencia, Santiago, Chile
| | - Andrea Arena
- 1Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Ilaria Zuliani
- 1Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Luciana Mosca
- 1Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Carla Blarzino
- 1Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - D Allan Butterfield
- 3Department of Chemistry and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055 USA
| | - Marzia Perluigi
- 1Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Fabio Di Domenico
- 1Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
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Tili E, Mezache L, Michaille JJ, Amann V, Williams J, Vandiver P, Quinonez M, Fadda P, Mikhail A, Nuovo G. microRNA 155 up regulation in the CNS is strongly correlated to Down's syndrome dementia. Ann Diagn Pathol 2018; 34:103-109. [PMID: 29661714 DOI: 10.1016/j.anndiagpath.2018.03.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 03/23/2018] [Indexed: 12/30/2022]
Abstract
This study examined the molecular correlates of Down's dementia. qRTPCR for chromosome 21 microRNAs was correlated with in situ hybridization, immunohistochemistry for microRNA targets, mRNAs located on chromosome 21, and neurofibrillary tangles in human and the Ts65 dn mouse Down's model. qRTPCR for the microRNAs on the triplicated chromosome showed miR-155 dominance in brain tissues (14.3 fold increase, human and 24.2 fold increase, mouse model) that co-expressed with hyperphosphorylated tau protein. miR-155 was not elevated in Alzheimer's disease or neonates with Downs' syndrome. Chromosome 21 genes APP/BA-42, DYRK1a and BACH1 were not correlated to pathologic changes in Down's dementia. Validated CNS targets of miR-155 that were present in controls and Alzheimer's disease but lacking in Down's dementia brains included BACH1, CoREST1, bcl6, BIM, bcl10, cyclin D, and SAPK4. It is concluded that Down's dementia strongly correlated with overexpression of chromosome 21 microRNA 155 with concomitant reduction of multiple CNS-functional targets. This study highlights the need for anatomic pathologists to determine the specific and diverse pathways cells may take to form neurofibrillary tangles in the different dementias.
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Affiliation(s)
- Esmerina Tili
- Department of Anesthesiology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; Department of Cancer Biology and Genetics, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Louisa Mezache
- Department of Neurosciences, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Jean-Jacques Michaille
- Department of Cancer Biology and Genetics, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; BioPerox-IL, UB-INSERM IFR #100, Universite de Bourgogne-Franche Comte, Faculte Gabriel, 6 Bd, Gabriel, 21000 Dijon, France
| | | | | | | | | | - Paolo Fadda
- OSU Comprehensive Cancer Center, Columbus, OH 43210, USA
| | | | - Gerard Nuovo
- GNOME Diagnostics, Powell, OH 43065, USA; OSU Comprehensive Cancer Center, Columbus, OH 43210, USA.
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Illouz T, Madar R, Griffioen K, Okun E. A protocol for quantitative analysis of murine and human amyloid-β1-40 and 1-42. J Neurosci Methods 2017; 291:28-35. [DOI: 10.1016/j.jneumeth.2017.07.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 07/09/2017] [Accepted: 07/22/2017] [Indexed: 01/10/2023]
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10
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Cai Z, Yan Y, Wang Y. Minocycline alleviates beta-amyloid protein and tau pathology via restraining neuroinflammation induced by diabetic metabolic disorder. Clin Interv Aging 2013; 8:1089-95. [PMID: 23983461 PMCID: PMC3749817 DOI: 10.2147/cia.s46536] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Compelling evidence has shown that diabetic metabolic disorder plays a critical role in the pathogenesis of Alzheimer's disease, including increased expression of β-amyloid protein (Aβ) and tau protein. Evidence has supported that minocycline, a tetracycline derivative, protects against neuroinflammation induced by neurodegenerative disorders or cerebral ischemia. This study has evaluated minocycline influence on expression of Aβ protein, tau phosphorylation, and inflammatory cytokines (interleukin-1β and tumor necrosis factor-α) in the brain of diabetic rats to clarify neuroprotection by minocycline under diabetic metabolic disorder. METHOD An animal model of diabetes was established by high fat diet and intraperitoneal injection of streptozocin. In this study, we investigated the effect of minocycline on expression of Aβ protein, tau phosphorylation, and inflammatory cytokines (interleukin-1β and tumor necrosis factor-α) in the hippocampus of diabetic rats via immunohistochemistry, western blotting, and enzyme-linked immunosorbent assay. RESULTS These results showed that minocycline decreased expression of Aβ protein and lowered the phosphorylation of tau protein, and retarded the proinflammatory cytokines, but not amyloid precursor protein. CONCLUSION On the basis of the finding that minocycline had no influence on amyloid precursor protein and beta-site amyloid precursor protein cleaving enzyme 1 which determines the speed of Aβ generation, the decreases in Aβ production and tau hyperphosphorylation by minocycline are through inhibiting neuroinflammation, which contributes to Aβ production and tau hyperphosphorylation. Minocycline may also lower the self-perpetuating cycle between neuroinflammation and the pathogenesis of tau and Aβ to act as a neuroprotector. Therefore, the ability of minocycline to modulate inflammatory reactions may be of great importance in the selection of neuroprotective agents, especially in chronic conditions like diabetes and Alzheimer's disease.
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Affiliation(s)
- Zhiyou Cai
- Department of Neurology, the Lu'an Affiliated Hospital of Anhui Medical University, Lu'an People's Hospital, Lu'an, Anhui Province, People's Republic of China.
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Molecular and cellular alterations in Down syndrome: toward the identification of targets for therapeutics. Neural Plast 2012; 2012:171639. [PMID: 22848846 PMCID: PMC3403492 DOI: 10.1155/2012/171639] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 04/18/2012] [Accepted: 04/19/2012] [Indexed: 12/25/2022] Open
Abstract
Down syndrome is a complex disease that has challenged molecular and cellular research for more than 50 years. Understanding the molecular bases of morphological, cellular, and functional alterations resulting from the presence of an additional complete chromosome 21 would aid in targeting specific genes and pathways for rescuing some phenotypes. Recently, progress has been made by characterization of brain alterations in mouse models of Down syndrome. This review will highlight the main molecular and cellular findings recently described for these models, particularly with respect to their relationship to Down syndrome phenotypes.
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Lockrow JP, Fortress AM, Granholm ACE. Age-related neurodegeneration and memory loss in down syndrome. Curr Gerontol Geriatr Res 2012; 2012:463909. [PMID: 22545043 PMCID: PMC3318235 DOI: 10.1155/2012/463909] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 11/21/2011] [Indexed: 01/10/2023] Open
Abstract
Down syndrome (DS) is a condition where a complete or segmental chromosome 21 trisomy causes variable intellectual disability, and progressive memory loss and neurodegeneration with age. Many research groups have examined development of the brain in DS individuals, but studies on age-related changes should also be considered, with the increased lifespan observed in DS. DS leads to pathological hallmarks of Alzheimer's disease (AD) by 40 or 50 years of age. Progressive age-related memory deficits occurring in both AD and in DS have been connected to degeneration of several neuronal populations, but mechanisms are not fully elucidated. Inflammation and oxidative stress are early events in DS pathology, and focusing on these pathways may lead to development of successful intervention strategies for AD associated with DS. Here we discuss recent findings and potential treatment avenues regarding development of AD neuropathology and memory loss in DS.
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Affiliation(s)
- Jason P. Lockrow
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
| | - Ashley M. Fortress
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
| | - Ann-Charlotte E. Granholm
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
- Center on Aging, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
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Gotti S, Caricati E, Panzica G. Alterations of brain circuits in Down syndrome murine models. J Chem Neuroanat 2011; 42:317-26. [DOI: 10.1016/j.jchemneu.2011.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 09/04/2011] [Accepted: 09/06/2011] [Indexed: 10/17/2022]
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Dysfunction of the ubiquitin-proteasome system in the cerebellum of aging Ts65Dn mice. Exp Neurol 2011; 232:114-8. [PMID: 21867700 DOI: 10.1016/j.expneurol.2011.08.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 07/22/2011] [Accepted: 08/08/2011] [Indexed: 01/09/2023]
Abstract
In the cerebellum of adult-aging Ts65Dn mice, a murine model of Down syndrome, Purkinje cells undergo degeneration. Searching for the cause of Purkinje cell degeneration, we have studied the ubiquitin-proteasome system (UPS) in the cerebellum of aging Ts65Dn mice. Inhibition of UPS is sufficient to induce neuron degeneration and death. Proteasome chymotrypsin-like proteolytic activity was reduced by 35% in the cerebellum of Ts65Dn mice in comparison with euploid animals. Accordingly, Western blot analysis of ubiquitin showed an increase in ubiquitinated proteins. Immunocytochemistry for ubiquitin revealed strongly positive intranuclear inclusions in Purkinje cells and large neurons of cerebellar nuclei. The Western blot analysis of ubiquitin in nuclear protein extracts confirmed the increase of ubiquitinated proteins in the cell nuclei. After FUS immunocytochemistry, large intranuclear inclusions were visible in Purkinje cells and large neurons of cerebellar nuclei in Ts65Dn mice. Together, data indicate a possible role for proteasome inhibition in the cerebellar neurodegeneration in Ts65Dn mice.
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Lomoio S, Necchi D, Mares V, Scherini E. A single episode of neonatal seizures alters the cerebellum of immature rats. Epilepsy Res 2010; 93:17-24. [PMID: 21094593 DOI: 10.1016/j.eplepsyres.2010.10.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 10/22/2010] [Indexed: 11/28/2022]
Abstract
PURPOSE to test whether a single episode of early-life seizures may interfere with the development of the cerebellum. The cerebellum is particularly vulnerable in infants, since it is characterized by an important postnatal histogenesis that leads to the settling of adult circuitry. METHODS seizures were induced in 10-day-old Wistar rats with a single convulsive dose (80μg/g b.w., s.c.) of pentylentetrazole (PTZ). Immediately after rats were treated with (3)H-thymidine ((3)HTdR, 2.5μCi/g b.w, s.c.). Rats were killed 4h later and paraffin sections of the cerebellar vermis were processed for (3)HTdR autoradiography and immunocytochemistry for 2/3 subunits of AMPA glutamate receptor (GluR2/3), glutamate transporter 1 (GLT1) and calbindin. RESULTS seizures reduced the proliferation rate of cells in the external germinal layer. Purkinje cells showed increased GluR2/3 immunoreactivity. However, some Purkinje cells were unstained or lost. Increased GLT1 immunoreactivity was present in glial cells surrounding Purkinje cells. Calbindin immunoreaction confirmed that some Purkinje cells were missed. The remaining Purkinje cells showed large spheroids along the course of their axon. CONCLUSIONS data indicate that seizures lead to a loss and alteration of Purkinje cells in the cerebellum of immature rats. Since at 10 days of life Purkinje cells are no more proliferating, the loss of Purkinje cells should be permanent.
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Affiliation(s)
- Selene Lomoio
- Department of Animal Biology, Laboratory of Cell Biology and Neurobiology, University of Pavia, via Ferrata 1, 27100 Pavia, Italy
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Ruparelia A, Wiseman F, Sheppard O, Tybulewicz VL, Fisher EM. Down syndrome and the molecular pathogenesis resulting from trisomy of human chromosome 21. J Biomed Res 2010; 24:87-99. [PMID: 23554618 PMCID: PMC3596542 DOI: 10.1016/s1674-8301(10)60016-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Indexed: 01/12/2023] Open
Abstract
Chromosome copy number aberrations, anueploidies, are common in the human population but generally lethal. However, trisomy of human chromosome 21 is compatible with life and people born with this form of aneuploidy manifest the features of Down syndrome, named after Langdon Down who was a 19(th) century British physician who first described a group of people with this disorder. Down syndrome includes learning and memory deficits in all cases, as well as many other features which vary in penetrance and expressivity in different people. While Down syndrome clearly has a genetic cause - the extra dose of genes on chromosome 21 - we do not know which genes are important for which aspects of the syndrome, which biochemical pathways are disrupted, or, generally how design therapies to ameliorate the effects of these disruptions. Recently, with new insights gained from studying mouse models of Down syndrome, specific genes and pathways are being shown to be involved in the pathogenesis of the disorder. This is opening the way for exciting new studies of potential therapeutics for aspects of Down syndrome, particularly the learning and memory deficits.
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Affiliation(s)
- Aarti Ruparelia
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
| | - Frances Wiseman
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
| | - Olivia Sheppard
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
| | | | - Elizabeth M.C. Fisher
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
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