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Pan AL, Audrain M, Sakakibara E, Joshi R, Zhu X, Wang Q, Wang M, Beckmann ND, Schadt EE, Gandy S, Zhang B, Ehrlich ME, Salton SR. Dual-specificity protein phosphatase 6 (DUSP6) overexpression reduces amyloid load and improves memory deficits in male 5xFAD mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.24.554335. [PMID: 37662269 PMCID: PMC10473733 DOI: 10.1101/2023.08.24.554335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Background Dual specificity protein phosphatase 6 (DUSP6) was recently identified as a key hub gene in a causal network that regulates late-onset Alzheimer's disease. Importantly, decreased DUSP6 levels are correlated with an increased clinical dementia rating in human subjects, and DUSP6 levels are additionally decreased in the 5xFAD amyloidopathy mouse model. Methods AAV5-DUSP6 or AAV5-GFP (control) were stereotactically injected into the dorsal hippocampus (dHc) of female and male 5xFAD or wild type mice to overexpress DUSP6 or GFP. Spatial learning memory of these mice was assessed in the Barnes maze, after which hippocampal tissues were isolated for downstream analysis. Results Barnes maze testing indicated that DUSP6 overexpression in the dHc of 5xFAD mice improved memory deficits and was associated with reduced amyloid plaque load, Aß 1-40 and Aß 1-42 levels, and amyloid precursor protein processing enzyme BACE1, in male but not in female mice. Microglial activation and microgliosis, which are increased in 5xFAD mice, were significantly reduced by dHc DUSP6 overexpression in both males and females. Transcriptomic profiling of female 5xFAD hippocampus revealed upregulated expression of genes involved in inflammatory and extracellular signal-regulated kinase (ERK) pathways, while dHc DUSP6 overexpression in female 5xFAD mice downregulated a subset of genes in these pathways. A limited number of differentially expressed genes (DEGs) (FDR<0.05) were identified in male mice; gene ontology analysis of DEGs (p<0.05) identified a greater number of synaptic pathways that were regulated by DUSP6 overexpression in male compared to female 5xFAD. Notably, the msh homeobox 3 gene, Msx3 , previously shown to regulate microglial M1/M2 polarization and reduce neuroinflammation, was one of the most robustly upregulated genes in female and male wild type and 5xFAD mice overexpressing DUSP6. Conclusions In summary, our data indicate that DUSP6 overexpression in dHc reduced amyloid deposition and memory deficits in male but not female 5xFAD mice, whereas reduced neuroinflammation and microglial activation were observed in both males and females. The sex-dependent regulation of synaptic pathways by DUSP6 overexpression, however, correlated with the improvement of spatial memory deficits in male but not female 5xFAD.
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Poon CH, Wong STN, Roy J, Wang Y, Chan HWH, Steinbusch H, Blokland A, Temel Y, Aquili L, Lim LW. Sex Differences between Neuronal Loss and the Early Onset of Amyloid Deposits and Behavioral Consequences in 5xFAD Transgenic Mouse as a Model for Alzheimer's Disease. Cells 2023; 12:cells12050780. [PMID: 36899916 PMCID: PMC10000751 DOI: 10.3390/cells12050780] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/19/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023] Open
Abstract
A promising direction in the research on Alzheimer's Disease (AD) is the identification of biomarkers that better inform the disease progression of AD. However, the performance of amyloid-based biomarkers in predicting cognitive performance has been shown to be suboptimal. We hypothesise that neuronal loss could better inform cognitive impairment. We have utilised the 5xFAD transgenic mouse model that displays AD pathology at an early phase, already fully manifested after 6 months. We have evaluated the relationships between cognitive impairment, amyloid deposition, and neuronal loss in the hippocampus in both male and female mice. We observed the onset of disease characterized by the emergence of cognitive impairment in 6-month-old 5xFAD mice coinciding with the emergence of neuronal loss in the subiculum, but not amyloid pathology. We also showed that female mice exhibited significantly increased amyloid deposition in the hippocampus and entorhinal cortex, highlighting sex-related differences in the amyloid pathology of this model. Therefore, parameters based on neuronal loss might more accurately reflect disease onset and progression compared to amyloid-based biomarkers in AD patients. Moreover, sex-related differences should be considered in studies involving 5xFAD mouse models.
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Affiliation(s)
- Chi Him Poon
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - San Tung Nicholas Wong
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Jaydeep Roy
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Yingyi Wang
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Hui Wang Hujo Chan
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Harry Steinbusch
- Department of Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6211 LK Maastricht, The Netherlands
- Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Arjan Blokland
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, 6211 LK Maastricht, The Netherlands
| | - Yasin Temel
- Department of Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6211 LK Maastricht, The Netherlands
- Department of Neurosurgery, Maastricht University Medical Centre, Maastricht University, 6211 LK Maastricht, The Netherlands
| | - Luca Aquili
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
- College of Health and Education, Discipline of Psychology, Murdoch University, Perth 6150, Australia
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
- Correspondence:
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Kisler K, Sagare AP, Lazic D, Bazzi S, Lawson E, Hsu CJ, Wang Y, Ramanathan A, Nelson AR, Zhao Z, Zlokovic BV. Anti-malaria drug artesunate prevents development of amyloid-β pathology in mice by upregulating PICALM at the blood-brain barrier. Mol Neurodegener 2023; 18:7. [PMID: 36707892 PMCID: PMC9883925 DOI: 10.1186/s13024-023-00597-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 01/13/2023] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND PICALM is one of the most significant susceptibility factors for Alzheimer's disease (AD). In humans and mice, PICALM is highly expressed in brain endothelium. PICALM endothelial levels are reduced in AD brains. PICALM controls several steps in Aβ transcytosis across the blood-brain barrier (BBB). Its loss from brain endothelium in mice diminishes Aβ clearance at the BBB, which worsens Aβ pathology, but is reversible by endothelial PICALM re-expression. Thus, increasing PICALM at the BBB holds potential to slow down development of Aβ pathology. METHODS To identify a drug that could increase PICALM expression, we screened a library of 2007 FDA-approved drugs in HEK293t cells expressing luciferase driven by a human PICALM promoter, followed by a secondary mRNA screen in human Eahy926 endothelial cell line. In vivo studies with the lead hit were carried out in Picalm-deficient (Picalm+/-) mice, Picalm+/-; 5XFAD mice and Picalmlox/lox; Cdh5-Cre; 5XFAD mice with endothelial-specific Picalm knockout. We studied PICALM expression at the BBB, Aβ pathology and clearance from brain to blood, cerebral blood flow (CBF) responses, BBB integrity and behavior. RESULTS Our screen identified anti-malaria drug artesunate as the lead hit. Artesunate elevated PICALM mRNA and protein levels in Eahy926 endothelial cells and in vivo in brain capillaries of Picalm+/- mice by 2-3-fold. Artesunate treatment (32 mg/kg/day for 2 months) of 3-month old Picalm+/-; 5XFAD mice compared to vehicle increased brain capillary PICALM levels by 2-fold, and reduced Aβ42 and Aβ40 levels and Aβ and thioflavin S-load in the cortex and hippocampus, and vascular Aβ load by 34-51%. Artesunate also increased circulating Aβ42 and Aβ40 levels by 2-fold confirming accelerated Aβ clearance from brain to blood. Consistent with reduced Aβ pathology, treatment of Picalm+/-; 5XFAD mice with artesunate improved CBF responses, BBB integrity and behavior on novel object location and recognition, burrowing and nesting. Endothelial-specific knockout of PICALM abolished all beneficial effects of artesunate in 5XFAD mice indicating that endothelial PICALM is required for its therapeutic effects. CONCLUSIONS Artesunate increases PICALM levels and Aβ clearance at the BBB which prevents development of Aβ pathology and functional deficits in mice and holds potential for translation to human AD.
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Affiliation(s)
- Kassandra Kisler
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo St, Los Angeles, CA 90089 USA
| | - Abhay P. Sagare
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo St, Los Angeles, CA 90089 USA
| | - Divna Lazic
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo St, Los Angeles, CA 90089 USA
| | - Sam Bazzi
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo St, Los Angeles, CA 90089 USA
| | - Erica Lawson
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo St, Los Angeles, CA 90089 USA
| | - Ching-Ju Hsu
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo St, Los Angeles, CA 90089 USA
| | - Yaoming Wang
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo St, Los Angeles, CA 90089 USA
| | - Anita Ramanathan
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo St, Los Angeles, CA 90089 USA
| | - Amy R. Nelson
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo St, Los Angeles, CA 90089 USA
| | - Zhen Zhao
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo St, Los Angeles, CA 90089 USA
| | - Berislav V. Zlokovic
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo St, Los Angeles, CA 90089 USA
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O'Leary TP, Brown RE. Visuo-spatial learning and memory impairments in the 5xFAD mouse model of Alzheimer's disease: Effects of age, sex, albinism, and motor impairments. GENES, BRAIN, AND BEHAVIOR 2022; 21:e12794. [PMID: 35238473 PMCID: PMC9744519 DOI: 10.1111/gbb.12794] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 12/19/2021] [Indexed: 12/17/2022]
Abstract
The 5xFAD mouse model of Alzheimer's disease (AD) rapidly develops AD-related neuro-behavioral pathology. Learning and memory impairments in 5xFAD mice, however, are not always replicated and the size of impairments varies considerably across studies. To examine possible sources of this variability, we analyzed the effects of age, sex, albinism due to background genes (Tyrc , Oca2p ) and motor impairment on learning and memory performance of wild type and 5xFAD mice on the Morris water maze, from 3 to 15 months of age. The 5xFAD mice showed impaired learning at 6-9 months of age, but memory impairments were not detected with the test procedure used in this study. Performance of 5xFAD mice was profoundly impaired at 12-15 months of age, but was accompanied by slower swim speeds than wild-type mice and a frequent failure to locate the escape platform. Overall female mice performed worse than males, and reversal learning impairments in 5xFAD mice were more pronounced in females than males. Albino mice performed worse than pigmented mice, confirming that albinism can impair performance of 5xFAD mice independently of AD-related transgenes. Overall, these results show that 5xFAD mice have impaired learning performance at 6-9 months of age, but learning and memory performance at 12-15 months is confounded with motor impairments. Furthermore, sex and albinism should be controlled to provide an accurate assessment of AD-related transgenes on learning and memory. These results will help reduce variability across pre-clinical experiments with 5xFAD mice, and thus enhance the reliability of studies developing new therapeutics for AD.
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Affiliation(s)
- Timothy P. O'Leary
- Department of Psychology and NeuroscienceDalhousie UniversityHalifaxNova ScotiaCanada
| | - Richard E. Brown
- Department of Psychology and NeuroscienceDalhousie UniversityHalifaxNova ScotiaCanada
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5
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Marengo L, Armbrust F, Schoenherr C, Storck SE, Schmitt U, Zampar S, Wirths O, Altmeppen H, Glatzel M, Kaether C, Weggen S, Becker-Pauly C, Pietrzik CU. Meprin β knockout reduces brain Aβ levels and rescues learning and memory impairments in the APP/lon mouse model for Alzheimer's disease. Cell Mol Life Sci 2022; 79:168. [PMID: 35235058 PMCID: PMC8891209 DOI: 10.1007/s00018-022-04205-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 01/26/2022] [Accepted: 02/10/2022] [Indexed: 11/25/2022]
Abstract
β-Site amyloid precursor protein (APP) cleaving enzyme-1 (BACE1) is the major described β-secretase to generate Aβ peptides in Alzheimer's disease (AD). However, all therapeutic attempts to block BACE1 activity and to improve AD symptoms have so far failed. A potential candidate for alternative Aβ peptides generation is the metalloproteinase meprin β, which cleaves APP predominantly at alanine in p2 and in this study we can detect an increased meprin β expression in AD brain. Here, we report the generation of the transgenic APP/lon mouse model of AD lacking the functional Mep1b gene (APP/lon × Mep1b-/-). We examined levels of canonical and truncated Aβ species using urea-SDS-PAGE, ELISA and immunohistochemistry in brains of APP/lon mouse × Mep1b-/-. Additionally, we investigated the cognitive abilities of these mice during the Morris water maze task. Aβ1-40 and 1-42 levels are reduced in APP/lon mice when meprin β is absent. Immunohistochemical staining of mouse brain sections revealed that N-terminally truncated Aβ2-x peptide deposition is decreased in APP/lon × Mep1b-/- mice. Importantly, loss of meprin β improved cognitive abilities and rescued learning behavior impairments in APP/lon mice. These observations indicate an important role of meprin β within the amyloidogenic pathway and Aβ production in vivo.
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Affiliation(s)
- Liana Marengo
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Fred Armbrust
- Institute of Biochemistry, Unit for Degradomics of the Protease Web, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Caroline Schoenherr
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Steffen E. Storck
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Ulrich Schmitt
- Leibniz-Institute for Resilience Research, Mainz, Germany
| | - Silvia Zampar
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen (UMG), Göttingen, Germany
| | - Oliver Wirths
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen (UMG), Göttingen, Germany
| | - Hermann Altmeppen
- Institute of Neuropathology, University Medical Center HH-Eppendorf, Hamburg, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center HH-Eppendorf, Hamburg, Germany
| | | | - Sascha Weggen
- Department of Neuropathology, Heinrich Heine University, Düsseldorf, Germany
| | - Christoph Becker-Pauly
- Institute of Biochemistry, Unit for Degradomics of the Protease Web, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Claus U. Pietrzik
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Molecular Neurodegeneration, Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Duesbergweg 6, 55099 Mainz, Germany
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6
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Liang Y, Raven F, Ward JF, Zhen S, Zhang S, Sun H, Miller SJ, Choi SH, Tanzi RE, Zhang C. Upregulation of Alzheimer's Disease Amyloid-β Protein Precursor in Astrocytes Both in vitro and in vivo. J Alzheimers Dis 2021; 76:1071-1082. [PMID: 32597805 DOI: 10.3233/jad-200128] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND The amyloid cascade hypothesis of Alzheimer's disease (AD) posits that amyloid-β (Aβ) protein accumulation underlies the pathogenesis of the disease by leading to the formation of amyloid plaques, a pathologic hallmark of AD. Aβ is a proteolytic product of amyloid-β protein precursor (AβPP; APP), which is expressed in both neurons and astrocytes. Although considerable evidence shows that astrocytes may play critical roles in the pathogenesis of AD, the longitudinal changes of amyloid plaques in relationship to AβPP expression in astrocytes and cellular consequences are largely unknown. OBJECTIVE Here, we aimed to investigate astrocyte-related pathological changes of Aβ and AβPP using immunohistochemistry and biochemical studies in both animal and cell models. METHODS/RESULTS We utilized 5XFAD transgenic mice and found age-dependent upregulation of AβPP in astrocytes demonstrated with astrocytic reactive properties, which followed appearance of amyloid plaques in the brain. We also observed that AβPP proteins presented well-defined punctate immuno reactivity in young animals, whereas AβPP staining showed disrupted structures surrounding amyloid plaques in older mice. Moreover, we utilized astrocyte cell models and showed that pretreatment of Aβ42 resulted in downstream astrocyte autonomous changes, including up regulation in AβPP and BACE1 levels, as well as prolonged amyloidogenesis that could be reduced by pharmacological inhibition of BACE1. CONCLUSION Collectively, our results show that age-dependent AβPP up regulation in astrocytes is a key feature in AD, which will not only provide novel insights for understanding AD progression, but also may offer new therapeutic strategies for treating AD.
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Affiliation(s)
- Yingxia Liang
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.,Department of Anesthesiology, Weifang Medical University, Weifang, Shandong, China
| | - Frank Raven
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Joseph F Ward
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Sherri Zhen
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Siyi Zhang
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Haoqi Sun
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Sean J Miller
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Se Hoon Choi
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Can Zhang
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
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7
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Ali F, Baringer SL, Neal A, Choi EY, Kwan AC. Parvalbumin-Positive Neuron Loss and Amyloid-β Deposits in the Frontal Cortex of Alzheimer's Disease-Related Mice. J Alzheimers Dis 2020; 72:1323-1339. [PMID: 31743995 DOI: 10.3233/jad-181190] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Alzheimer's disease (AD) has several hallmark features including amyloid-β (Aβ) plaque deposits and neuronal loss. Here, we characterized Aβ plaque aggregation and parvalbumin-positive (PV) GABAergic neurons in 6-9-month-old 5xFAD mice harboring mutations associated with familial AD. We used immunofluorescence staining to compare three regions in the frontal cortex-prelimbic (PrL), cingulate (Cg, including Cg1 and Cg2), and secondary motor (M2) cortices-along with primary somatosensory (S1) cortex. We quantified the density of Aβ plaques, which showed significant laminar and regional vulnerability. There were more plaques of larger sizes in deep layers compared to superficial layers. Total plaque burden was higher in frontal regions compared to S1. We also found layer- and region-specific differences across genotype in the density of PV interneurons. PV neuron density was lower in 5xFAD mice than wild-type, particularly in deep layers of frontal regions, with Cg (-50%) and M2 (-39%) exhibiting the largest reduction. Using in vivo two-photon imaging, we longitudinally visualized the loss of frontal cortical PV neurons across four weeks in the AD mouse model. Overall, these results provide information about Aβ deposits and PV neuron density in a widely used mouse model for AD, implicating deep layers of frontal cortical regions as being especially vulnerable.
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Affiliation(s)
- Farhan Ali
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | | | - Arianna Neal
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Esther Y Choi
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Alex C Kwan
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
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8
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Barrett T, Marchalant Y, Park KH. p35 Hemizygous Deletion in 5xFAD Mice Increases Aβ Plaque Load in Males but Not in Females. Neuroscience 2019; 417:45-56. [DOI: 10.1016/j.neuroscience.2019.08.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 07/25/2019] [Accepted: 08/08/2019] [Indexed: 12/29/2022]
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9
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Moussa-Pacha NM, Abdin SM, Omar HA, Alniss H, Al-Tel TH. BACE1 inhibitors: Current status and future directions in treating Alzheimer's disease. Med Res Rev 2019; 40:339-384. [PMID: 31347728 DOI: 10.1002/med.21622] [Citation(s) in RCA: 141] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 05/22/2019] [Accepted: 06/13/2019] [Indexed: 12/28/2022]
Abstract
Alzheimer's disease (AD) is an irreversible, progressive neurodegenerative brain disorder with no current cure. One of the important therapeutic approaches of AD is the inhibition of β-site APP cleaving enzyme-1 (BACE1), which is involved in the rate-limiting step of the cleavage process of the amyloid precursor protein (APP) leading to the generation of the neurotoxic amyloid β (Aβ) protein after the γ-secretase completes its function. The produced insoluble Aβ aggregates lead to plaques deposition and neurodegeneration. BACE1 is, therefore, one of the attractive targets for the treatment of AD. This approach led to the development of potent BACE1 inhibitors, many of which were advanced to late stages in clinical trials. Nonetheless, the high failure rate of lead drug candidates targeting BACE1 brought to the forefront the need for finding new targets to uncover the mystery behind AD. In this review, we aim to discuss the most promising classes of BACE1 inhibitors with a description and analysis of their pharmacodynamic and pharmacokinetic parameters, with more focus on the lead drug candidates that reached late stages of clinical trials, such as MK8931, AZD-3293, JNJ-54861911, E2609, and CNP520. In addition, the manuscript discusses the safety concerns and insignificant physiological effects, which were highlighted for the most successful BACE1 inhibitors. Furthermore, the review demonstrates with increasing evidence that despite tremendous efforts and promising results conceived with BACE1 inhibitors, the latest studies suggest that their clinical use for treating Alzheimer's disease should be reconsidered. Finally, the review sheds light on alternative therapeutic options for targeting AD.
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Affiliation(s)
- Nour M Moussa-Pacha
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah, United Arab Emirates
| | - Shifaa M Abdin
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah, United Arab Emirates
| | - Hany A Omar
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah, United Arab Emirates.,College of Pharmacy and College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.,Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - Hasan Alniss
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah, United Arab Emirates.,College of Pharmacy and College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | - Taleb H Al-Tel
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah, United Arab Emirates.,College of Pharmacy and College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
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10
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Liu M, Huang Y, Qin J, Wang Y, Ke B, Yang Y. Inhibition of MAPKs Signaling Pathways Prevents Acrolein-Induced Neurotoxicity in HT22 Mouse Hippocampal Cells. Biol Pharm Bull 2019; 42:617-622. [PMID: 30700647 DOI: 10.1248/bpb.b18-00715] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Activation of mitogen-activated protein kinases (MAPKs) in neurons may underlie the pathogenesis of Alzheimer's disease (AD). Acrolein, a ubiquitous pollutant, has been reported to implicate in the etiology of AD. Our previous data showed that acrolein changed the levels of key AD-associated proteins, including advanced glycation end products (RAGE), A-disintegrin and metalloprotease (ADAM-10), and beta-site amyloid-beta peptide cleaving enzyme 1 (BACE-1). In this study, we investigated whether acrolein-induced alterations of AD-associated proteins are relevant to MAPKs activation, and strategies to inhibit MAPKs activation yield benefits to acrolein-induced neurotoxicity in HT22 mouse hippocampal cells. We found that acrolein activated MAPKs signaling pathways to mediate cells apoptosis, and then altered the levels of AD-associated proteins ADAM-10, BACE-1 and RAGE. Inhibitors of MAPKs signaling pathways attenuated the cells death and restored the proteins levels of ADAM-10, BACE-1 and RAGE in varying degrees induced by acrolein. Taken together, activated MAPKs signaling pathways should be underlying the pathology of acrolein-induced neuronal disorders. Inhibitors of MAPKs pathways might be promising agents for acrolein-related diseases, such as AD.
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Affiliation(s)
- MengTing Liu
- Department of Traditional Chinese Medicine, the First Affiliated Hospital, Sun Yat-sen University
| | - YingJuan Huang
- Department of Traditional Chinese Medicine, the First Affiliated Hospital, Sun Yat-sen University
| | - Jian Qin
- Department of Traditional Chinese Medicine, the First Affiliated Hospital, Sun Yat-sen University
| | - YuanYuan Wang
- Department of Traditional Chinese Medicine, the Eastern Hospital of the First Affiliated Hospital, Sun Yat-sen University
| | - Bin Ke
- Department of Traditional Chinese Medicine, the First Affiliated Hospital, Sun Yat-sen University
| | - YuBin Yang
- Department of Traditional Chinese Medicine, the First Affiliated Hospital, Sun Yat-sen University
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11
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Lazic D, Sagare AP, Nikolakopoulou AM, Griffin JH, Vassar R, Zlokovic BV. 3K3A-activated protein C blocks amyloidogenic BACE1 pathway and improves functional outcome in mice. J Exp Med 2019; 216:279-293. [PMID: 30647119 PMCID: PMC6363429 DOI: 10.1084/jem.20181035] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 10/05/2018] [Accepted: 10/30/2018] [Indexed: 12/29/2022] Open
Abstract
3K3A-activated protein C (APC), a cell-signaling analogue of endogenous blood serine protease APC, exerts vasculoprotective, neuroprotective, and anti-inflammatory activities in rodent models of stroke, brain injury, and neurodegenerative disorders. 3K3A-APC is currently in development as a neuroprotectant in patients with ischemic stroke. Here, we report that 3K3A-APC inhibits BACE1 amyloidogenic pathway in a mouse model of Alzheimer's disease (AD). We show that a 4-mo daily treatment of 3-mo-old 5XFAD mice with murine recombinant 3K3A-APC (100 µg/kg/d i.p.) prevents development of parenchymal and cerebrovascular amyloid-β (Aβ) deposits by 40-50%, which is mediated through NFκB-dependent transcriptional inhibition of BACE1, resulting in blockade of Aβ generation in neurons overexpressing human Aβ-precursor protein. Consistent with reduced Aβ deposition, 3K3A-APC normalized hippocampus-dependent behavioral deficits and cerebral blood flow responses, improved cerebrovascular integrity, and diminished neuroinflammatory responses. Our data suggest that 3K3A-APC holds potential as an effective anti-Aβ prevention therapy for early-stage AD.
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Affiliation(s)
- Divna Lazic
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA.,Department of Neurobiology, Institute for Biological Research, University of Belgrade, Belgrade, Republic of Serbia
| | - Abhay P Sagare
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Angeliki M Nikolakopoulou
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - John H Griffin
- The Scripps Research Institute, La Jolla, CA.,Department of Medicine, University of California, San Diego, San Diego, CA
| | - Robert Vassar
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Berislav V Zlokovic
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA .,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA
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12
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Consequences of Pharmacological BACE Inhibition on Synaptic Structure and Function. Biol Psychiatry 2018; 84:478-487. [PMID: 29945719 DOI: 10.1016/j.biopsych.2018.04.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 04/28/2018] [Accepted: 04/28/2018] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease is the most prevalent neurodegenerative disorder among elderly persons. Overt accumulation and aggregation of the amyloid-β peptide (Aβ) is thought to be the initial causative factor for Alzheimer's disease. Aβ is produced by sequential proteolytic cleavage of the amyloid precursor protein. Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) is the initial and rate-limiting protease for the generation of Aβ. Therefore, inhibiting BACE1 is considered one of the most promising therapeutic approaches for potential treatment of Alzheimer's disease. Currently, several drugs blocking this enzyme (BACE inhibitors) are being evaluated in clinical trials. However, high-dosage BACE-inhibitor treatment interferes with structural and functional synaptic plasticity in mice. These adverse side effects may mask the therapeutic benefit of lowering the Aβ concentration. In this review, we focus on the consequences of BACE inhibition-mediated synaptic deficits and the potential clinical implications.
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13
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Peters F, Salihoglu H, Rodrigues E, Herzog E, Blume T, Filser S, Dorostkar M, Shimshek DR, Brose N, Neumann U, Herms J. BACE1 inhibition more effectively suppresses initiation than progression of β-amyloid pathology. Acta Neuropathol 2018; 135:695-710. [PMID: 29327084 PMCID: PMC5904228 DOI: 10.1007/s00401-017-1804-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 12/28/2017] [Accepted: 12/29/2017] [Indexed: 01/04/2023]
Abstract
BACE1 is the rate-limiting protease in the production of synaptotoxic β-amyloid (Aβ) species and hence one of the prime drug targets for potential therapy of Alzheimer's disease (AD). However, so far pharmacological BACE1 inhibition failed to rescue the cognitive decline in mild-to-moderate AD patients, which indicates that treatment at the symptomatic stage might be too late. In the current study, chronic in vivo two-photon microscopy was performed in a transgenic AD model to monitor the impact of pharmacological BACE1 inhibition on early β-amyloid pathology. The longitudinal approach allowed to assess the kinetics of individual plaques and associated presynaptic pathology, before and throughout treatment. BACE1 inhibition could not halt but slow down progressive β-amyloid deposition and associated synaptic pathology. Notably, the data revealed that the initial process of plaque formation, rather than the subsequent phase of gradual plaque growth, is most sensitive to BACE1 inhibition. This finding of particular susceptibility of plaque formation has profound implications to achieve optimal therapeutic efficacy for the prospective treatment of AD.
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Affiliation(s)
- Finn Peters
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Hazal Salihoglu
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany
| | - Eva Rodrigues
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany
| | - Etienne Herzog
- Université Bordeaux, IINS, UMR 5297, 33000, Bordeaux, France
- CNRS, IINS, UMR 5297, 33000, Bordeaux, France
| | - Tanja Blume
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Severin Filser
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Mario Dorostkar
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany
- Center for Neuropathology and Prion Research, Ludwig-Maximilians University, Munich, Germany
| | - Derya R Shimshek
- Neuroscience, Novartis Institutes for BioMedical Research (NIBR), Basel, Switzerland
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Ulf Neumann
- Neuroscience, Novartis Institutes for BioMedical Research (NIBR), Basel, Switzerland
| | - Jochen Herms
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany.
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany.
- Center for Neuropathology and Prion Research, Ludwig-Maximilians University, Munich, Germany.
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14
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Iron dysregulates APP processing accompanying with sAPPα cellular retention and β-secretase inhibition in rat cortical neurons. Acta Pharmacol Sin 2018; 39:177-183. [PMID: 28836584 DOI: 10.1038/aps.2017.113] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 04/19/2017] [Indexed: 12/14/2022] Open
Abstract
Amyloid precursor protein (APP) and iron both play pivotal roles in the central nervous system, but whether and how iron influences the processing of endogenous APP in neurons remain unclear. Here, we investigated the regulatory effects and underlying mechanisms of iron on non-amyloidogenic and amyloidogenic processing of APP in rat primary cortical neurons. Treatment of the neurons with ferric ammonium citrate (FAC, 100 μmol/L) markedly facilitated the non-amyloidogenic processing of APP, as evidenced by a robust increase in α-secretase-derived carboxy-terminal fragment α (CTFα). Furthermore, the distribution of sAPPα was altered after iron treatment, and sAPPα remained in the cellular lysates instead of being secreted into the extracellular milieu. Moreover, the levels of APP amyloidogenic products, including sAPPβ and Aβ were both decreased. We further revealed that FAC did not alter the expression of β-secretase, but significantly suppressed its enzymatic activity in iron-treated neurons. In a cell-free β-secretase activity assay, FAC dose-dependently inhibited the activity of purified β-secretase with an IC50 value of 21.67 μmol/L. Our data provide the first evidence that iron overload alters the neuronal sAPPα distribution and directly inhibits β-secretase activity. These findings shed light on the regulatory mechanism of bio-metals on APP processing.
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15
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Pike CJ. Sex and the development of Alzheimer's disease. J Neurosci Res 2017; 95:671-680. [PMID: 27870425 DOI: 10.1002/jnr.23827] [Citation(s) in RCA: 244] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/17/2016] [Accepted: 06/20/2016] [Indexed: 12/20/2022]
Abstract
Men and women exhibit differences in the development and progression of Alzheimer's disease (AD). The factors underlying the sex differences in AD are not well understood. This Review emphasizes the contributions of sex steroid hormones to the relationship between sex and AD. In women, events that decrease lifetime exposure to estrogens are generally associated with increased AD risk, whereas estrogen-based hormone therapy administered near the time of menopause may reduce AD risk. In men, estrogens do not exhibit age-related reduction and are not significantly associated with AD risk. Rather, normal age-related depletions of testosterone in plasma and brain predict enhanced vulnerability to AD. Both estrogens and androgens exert numerous protective actions in the adult brain that increase neural functioning and resilience as well as specifically attenuating multiple aspects of AD-related neuropathology. Aging diminishes the activational effects of sex hormones in sex-specific manners, which is hypothesized to contribute to the relationship between aging and AD. Sex steroid hormones may also drive sex differences in AD through their organizational effects during developmental sexual differentiation of the brain. Specifically, sex hormone actions during early development may confer inherent vulnerability of the female brain to development of AD in advanced age. The combined effects of organizational and activational effects of sex steroids yield distinct sex differences in AD pathogenesis, a significant variable that must be more rigorously considered in future research. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Christian J Pike
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California
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16
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Preclinical models in the study of sex differences. Clin Sci (Lond) 2017; 131:449-469. [PMID: 28265036 DOI: 10.1042/cs20160847] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 12/13/2016] [Accepted: 01/03/2017] [Indexed: 02/06/2023]
Abstract
The biology of sex differences deals with the study of the disparities between females and males and the related biological mechanisms. Gender medicine focuses on the impact of gender and sex on human physiology, pathophysiology and clinical features of diseases that are common to women and men. The term gender refers to a complex interrelation and integration of sex-as a biological and functional determinant-and psychological and cultural behaviours (due to ethnical, social or religious background). The attention to the impact of gender differences on the pathophysiology and, therefore, on the clinical management of the most common diseases, such as cardiovascular diseases (CVD), neurodegenerative disorders, immune and autoimmune diseases as well as several tumours, is in fact often neglected. Hence, studies covering different fields of investigation and including sex differences in the pathogenesis, in diagnostic and prognostic criteria as well as in response to therapy appear mandatory. However, prerequisites for this development are preclinical studies, including in vitro and in vivo approaches. They represent the first step in the development of a drug or in the comprehension of the pathogenetic mechanisms of diseases, in turn a necessary step for the development of new or more appropriate therapeutic strategies. However, sex differences are still poorly considered and the great majority of preclinical studies do not take into account the relevance of such disparities. In this review, we describe the state of the art of these studies and provide some paradigmatic examples of key fields of investigation, such as oncology, neurology and CVD, where preclinical models should be improved.
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17
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Deleye S, Waldron AM, Verhaeghe J, Bottelbergs A, Wyffels L, Van Broeck B, Langlois X, Schmidt M, Stroobants S, Staelens S. Evaluation of Small-Animal PET Outcome Measures to Detect Disease Modification Induced by BACE Inhibition in a Transgenic Mouse Model of Alzheimer Disease. J Nucl Med 2017; 58:1977-1983. [PMID: 28611242 DOI: 10.2967/jnumed.116.187625] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 05/31/2017] [Indexed: 01/08/2023] Open
Abstract
In this study, we investigated the effects of chronic administration of an inhibitor of the β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) on Alzheimer-related pathology by multitracer PET imaging in transgenic APPPS1-21 (TG) mice. Methods: Wild-type (WT) and TG mice received vehicle or BACE inhibitor (60 mg/kg) starting at 7 wk of age. Outcome measures of brain metabolism, neuroinflammation, and amyloid-β pathology were obtained through small-animal PET imaging with 18F-FDG, 18F-peripheral benzodiazepine receptor (18F-PBR), and 18F-florbetapir (18F-AV45), respectively. Baseline scans were acquired at 6-7 wk of age and follow-up scans at 4, 7, and 12 mo. 18F-AV45 uptake was measured at 8 and 13 mo of age. After the final scans, histologic measures of amyloid-β (4G8), microglia (ionized calcium binding adaptor molecule 1), astrocytes (glial fibrillary acidic protein), and neuronal nuclei were performed. Results: TG mice demonstrated significant age-associated increases in 18F-AV45 uptake. An effect of treatment was observed in the cortex (P = 0.0014), hippocampus (P = 0.0005), and thalamus (P < 0.0001). Histology confirmed reduction of amyloid-β pathology in TG-BACE mice. Regardless of treatment, TG mice demonstrated significantly lower 18F-FDG uptake than WT mice in the thalamus (P = 0.0004) and hippocampus (P = 0.0332). Neuronal nucleus staining was lower in both TG groups in the thalamus and cortex. 18F-PBR111 detected a significant age-related increase in TG mice (P < 0.0001) but did not detect the treatment-induced reduction in activated microglia as demonstrated by histology. Conclusion: Although 18F-FDG, 18F-PBR111, and 18F-AV45 all detected pathologic alterations between TG and WT mice, only 18F-AV45 could detect an effect of BACE inhibitor treatment. However, changes in WT binding of 18F-AV45 undermine the specificity of this effect.
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Affiliation(s)
- Steven Deleye
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Ann-Marie Waldron
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | | | - Leonie Wyffels
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium.,Nuclear Medicine Department, University Hospital Antwerp, Antwerp, Belgium; and
| | | | - Xavier Langlois
- Foundational Neuroscience Center, Abbvie, Cambridge, Massachusetts
| | - Mark Schmidt
- Neuroscience Department, Janssen Pharmaceutica NV, Beerse, Belgium
| | - Sigrid Stroobants
- Nuclear Medicine Department, University Hospital Antwerp, Antwerp, Belgium; and
| | - Steven Staelens
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
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18
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Zhang JX, Zhang J, Li Y. Liver X receptor-β improves autism symptoms via downregulation of β-amyloid expression in cortical neurons. Ital J Pediatr 2016; 42:46. [PMID: 27154582 PMCID: PMC4859958 DOI: 10.1186/s13052-016-0249-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 04/03/2016] [Indexed: 11/10/2022] Open
Abstract
Background We study the effect of liver X receptor β (LXRβ) on β-amyloid (Aβ) peptide generation and autism behaviors by conducting an animal experiment. Methods In autistic mice treated with LXRβ agonist T0901317, enzyme linked immunosorbent assay was used to measure Aβ in brain tissue homogenates. Western blot was used to detect Aβ precursors, Aβ degradation and secretase enzymes, and expression of autophagy-related proteins and Ras/Raf/Erkl/2 signaling pathway proteins in brain tissue. Changes in autism spectrum disorder syndromes of the BTBR mice were compared before and after T0901317 treatment. Results Compared with the control group, autistic mice treated with LXRβ agonist T0901317 showed significantly lower Aβ level in brain tissue (P < 0.05), significantly higher Aβ degradation enzyme (NEP, IDE proteins) levels (all P < 0.05), significantly lower Aβ secretase enzyme BACE1 protein level (P < 0.05), and significantly lower Ras, P-C-Raf, C-Raf, P-Mekl/2, P-Erkl/2 protein levels (all P < 0.05). BTBR mice treated with T0901317 showed improvements in repetitive stereotyped behavior, inactivity, wall-facing standing time, self-combing time and center stay time, stayed longer in platform quadrant, and crossed the platform more frequently (all P < 0.05). Conclusions LXRβ could potentially reduce brain Aβ generation by inhibiting Aβ production and promoting Aβ degradation, thereby increasing the expression of autophagy-related proteins, reducing Ras/Raf/Erkl/2 signaling pathway proteins, and improving autism behaviors.
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Affiliation(s)
- Ji-Xiang Zhang
- Department of Clinical Psychology, Linyi People's Hospital, Linyi, 276000, China
| | - Jun Zhang
- Department of Children's Rehabilitation, Linyi People's Hospital, No.27 East Jiefang Road, Linyi, 276000, China.
| | - Ye Li
- Department of Outpatient Operation Room, Linyi People's Hospital, Linyi, 276000, China
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19
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Cognitive benefits of memantine in Alzheimer's 5XFAD model mice decline during advanced disease stages. Pharmacol Biochem Behav 2016; 144:60-6. [DOI: 10.1016/j.pbb.2016.03.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 02/11/2016] [Accepted: 03/02/2016] [Indexed: 01/05/2023]
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20
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Ohno M. Alzheimer's therapy targeting the β-secretase enzyme BACE1: Benefits and potential limitations from the perspective of animal model studies. Brain Res Bull 2016; 126:183-198. [PMID: 27093940 DOI: 10.1016/j.brainresbull.2016.04.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/05/2016] [Accepted: 04/10/2016] [Indexed: 01/18/2023]
Abstract
Accumulating evidence points to the amyloid-β (Aβ) peptide as the culprit in the pathogenesis of Alzheimer's disease (AD). β-Site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1) is a protease that is responsible for initiating Aβ production. Although precise mechanisms that trigger Aβ accumulation remain unclear, BACE1 inhibition undoubtedly represents an important intervention that may prevent and/or cure AD. Remarkably, animal model studies with knockouts, virus-delivered small interfering RNAs, immunization and bioavailable small-molecule agents that specifically inhibit BACE1 activity strongly support the idea for the therapeutic BACE1 inhibition. Meanwhile, a growing number of BACE1 substrates besides APP uncover new physiological roles of this protease, raising some concern regarding the safety of BACE1 inhibition. Here, I review recent progress in preclinical studies that have evaluated the efficacies and potential limitations of genetic/pharmacological inhibition of BACE1, with special focus on AD-associated phenotypes including synaptic dysfunction, neuron loss and memory deficits in animal models.
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Affiliation(s)
- Masuo Ohno
- Center for Dementia Research, Nathan Kline Institute, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA; Departments of Psychiatry, New York University Langone Medical Center, New York, NY 10016, USA.
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21
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Janssen L, Keppens C, De Deyn PP, Van Dam D. Late age increase in soluble amyloid-beta levels in the APP23 mouse model despite steady-state levels of amyloid-beta-producing proteins. Biochim Biophys Acta Mol Basis Dis 2015; 1862:105-12. [PMID: 26542217 DOI: 10.1016/j.bbadis.2015.10.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 10/01/2015] [Accepted: 10/29/2015] [Indexed: 10/22/2022]
Affiliation(s)
- Leen Janssen
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Cleo Keppens
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Peter P De Deyn
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; Department of Neurology and Memory Clinic, Hospital Network Antwerp (ZNA) Middelheim and Hoge Beuken, Antwerp, Belgium; University of Groningen, University Medical Center Groningen (UMCG), Department of Neurology and Alzheimer Research Center, Groningen, The Netherlands; Biobank, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Debby Van Dam
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; University of Groningen, University Medical Center Groningen (UMCG), Department of Neurology and Alzheimer Research Center, Groningen, The Netherlands.
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