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Dues DJ, Nguyen APT, Becker K, Ma J, Moore DJ. Hippocampal subfield vulnerability to α-synuclein pathology precedes neurodegeneration and cognitive dysfunction. NPJ Parkinsons Dis 2023; 9:125. [PMID: 37640722 PMCID: PMC10462636 DOI: 10.1038/s41531-023-00574-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 08/22/2023] [Indexed: 08/31/2023] Open
Abstract
Cognitive dysfunction is a salient feature of Parkinson's disease (PD) and Dementia with Lewy bodies (DLB). The onset of dementia reflects the spread of Lewy pathology throughout forebrain structures. The mere presence of Lewy pathology, however, provides limited indication of cognitive status. Thus, it remains unclear whether Lewy pathology is the de facto substrate driving cognitive dysfunction in PD and DLB. Through application of α-synuclein fibrils in vivo, we sought to examine the influence of pathologic inclusions on cognition. Following stereotactic injection of α-synuclein fibrils within the mouse forebrain, we measured the burden of α-synuclein pathology at 1-, 3-, and 6-months post-injection within subregions of the hippocampus and cortex. Under this paradigm, the hippocampal CA2/3 subfield was especially susceptible to α-synuclein pathology. Strikingly, we observed a drastic reduction of pathology in the CA2/3 subfield across time-points, consistent with the consolidation of α-synuclein pathology into dense somatic inclusions followed by neurodegeneration. Silver-positive degenerating neurites were observed prior to neuronal loss, suggesting that this might be an early feature of fibril-induced neurotoxicity and a precursor to neurodegeneration. Critically, mice injected with α-synuclein fibrils developed progressive deficits in spatial learning and memory. These findings support that the formation of α-synuclein inclusions in the mouse forebrain precipitate neurodegenerative changes that recapitulate features of Lewy-related cognitive dysfunction.
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Affiliation(s)
- Dylan J Dues
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI, USA
| | - An Phu Tran Nguyen
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI, USA
| | - Katelyn Becker
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI, USA
| | - Jiyan Ma
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI, USA
- Chinese Institute for Brain Research, Beijing, China
| | - Darren J Moore
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI, USA.
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Dues DJ, Nguyen APT, Becker K, Ma J, Moore DJ. Hippocampal subfield vulnerability to α-synuclein pathology precedes neurodegeneration and cognitive dysfunction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.12.536572. [PMID: 37090590 PMCID: PMC10120695 DOI: 10.1101/2023.04.12.536572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Cognitive dysfunction is a salient feature of Parkinson's disease (PD) and Dementia with Lewy bodies (DLB). The onset of dementia reflects the spread of Lewy pathology throughout forebrain structures. The mere presence of Lewy pathology, however, provides limited indication of cognitive status. Thus, it remains unclear whether Lewy pathology is the de facto substrate driving cognitive dysfunction in PD and DLB. Through application of α-synuclein fibrils in vivo , we sought to examine the influence of pathologic inclusions on cognition. Following stereotactic injection of α-synuclein fibrils within the mouse forebrain, we measured the burden of α-synuclein pathology at 1-, 3-, and 6-months post-injection within subregions of the hippocampus and cortex. Under this paradigm, the hippocampal CA2/3 subfield was especially susceptible to α- synuclein pathology. Strikingly, we observed a drastic reduction of pathology in the CA2/3 subfield across time-points, consistent with the consolidation of α-synuclein pathology into dense somatic inclusions followed by neurodegeneration. Silver-positive degenerating neurites were observed prior to neuronal loss, suggesting that this might be an early feature of fibril-induced neurotoxicity and a precursor to neurodegeneration. Critically, mice injected with α-synuclein fibrils developed progressive deficits in spatial learning and memory. These findings support that the formation of α-synuclein inclusions in the mouse forebrain precipitate neurodegenerative changes that recapitulate features of Lewy-related cognitive dysfunction. Highlights Mice injected with α-synuclein fibrils develop hippocampal and cortical α- synuclein pathology with a dynamic regional burden at 1-, 3-, and 6-months post-injection.Silver-positive neuronal processes are an early and enduring degenerative feature of the fibril model, while extensive neurodegeneration of the hippocampal CA2/3 subfield is detected at 6-months post-injection.Mice exhibit progressive hippocampal-dependent spatial learning and memory deficits.Forebrain injection of α-synuclein fibrils may be used to model aspects of Lewy-related cognitive dysfunction.
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Affiliation(s)
- Dylan J. Dues
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan, USA
| | - An Phu Tran Nguyen
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan, USA
| | - Katelyn Becker
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan, USA
| | - Jiyan Ma
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan, USA
| | - Darren J. Moore
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan, USA
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Arezoumandan S, Xie SX, Cousins KAQ, Mechanic-Hamilton DJ, Peterson CS, Huang CY, Ohm DT, Ittyerah R, McMillan CT, Wolk DA, Yushkevich P, Trojanowski JQ, Lee EB, Grossman M, Phillips JS, Irwin DJ. Regional distribution and maturation of tau pathology among phenotypic variants of Alzheimer's disease. Acta Neuropathol 2022; 144:1103-1116. [PMID: 35871112 PMCID: PMC9936795 DOI: 10.1007/s00401-022-02472-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/02/2022] [Accepted: 07/14/2022] [Indexed: 01/26/2023]
Abstract
Alzheimer's disease neuropathologic change (ADNC) is clinically heterogenous and can present with a classic multidomain amnestic syndrome or focal non-amnestic syndromes. Here, we investigated the distribution and burden of phosphorylated and C-terminally cleaved tau pathologies across hippocampal subfields and cortical regions among phenotypic variants of Alzheimer's disease (AD). In this study, autopsy-confirmed patients with ADNC, were classified into amnestic (aAD, N = 40) and non-amnestic (naAD, N = 39) groups based on clinical criteria. We performed digital assessment of tissue sections immunostained for phosphorylated-tau (AT8 detects pretangles and mature tangles), D421-truncated tau (TauC3, a marker for mature tangles and ghost tangles), and E391-truncated tau (MN423, a marker that primarily detects ghost tangles), in hippocampal subfields and three cortical regions. Linear mixed-effect models were used to test regional and group differences while adjusting for demographics. Both groups showed AT8-reactivity across hippocampal subfields that mirrored traditional Braak staging with higher burden of phosphorylated-tau in subregions implicated as affected early in Braak staging. The burden of phosphorylated-tau and TauC3-immunoreactive tau in the hippocampus was largely similar between the aAD and naAD groups. In contrast, the naAD group had lower relative distribution of MN423-reactive tangles in CA1 (β = - 0.2, SE = 0.09, p = 0.001) and CA2 (β = - 0.25, SE = 0.09, p = 0.005) compared to the aAD. While the two groups had similar levels of phosphorylated-tau pathology in cortical regions, there was higher burden of TauC3 reactivity in sup/mid temporal cortex (β = 0.16, SE = 0.07, p = 0.02) and MN423 reactivity in all cortical regions (β = 0.4-0.43, SE = 0.09, p < 0.001) in the naAD compared to aAD. In conclusion, AD clinical variants may have a signature distribution of overall phosphorylated-tau pathology within the hippocampus reflecting traditional Braak staging; however, non-amnestic AD has greater relative mature tangle pathology in the neocortex compared to patients with clinical amnestic AD, where the hippocampus had greatest relative burden of C-terminally cleaved tau reactivity. Thus, varying neuronal susceptibility to tau-mediated neurodegeneration may influence the clinical expression of ADNC.
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Affiliation(s)
- Sanaz Arezoumandan
- Digital Neuropathology Laboratory, Department of Neurology, Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Penn Frontotemporal Degeneration Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Sharon X Xie
- Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Katheryn A Q Cousins
- Penn Frontotemporal Degeneration Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Dawn J Mechanic-Hamilton
- Department of Neurology, Penn Memory Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Department of Neurology, Penn Alzheimer's Disease Research Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Claire S Peterson
- Digital Neuropathology Laboratory, Department of Neurology, Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Penn Frontotemporal Degeneration Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Camille Y Huang
- Digital Neuropathology Laboratory, Department of Neurology, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Daniel T Ohm
- Digital Neuropathology Laboratory, Department of Neurology, Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Penn Frontotemporal Degeneration Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Ranjit Ittyerah
- Penn Image Computing and Science Lab, Department of Radiology, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Corey T McMillan
- Penn Frontotemporal Degeneration Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Department of Neurology, Penn Alzheimer's Disease Research Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - David A Wolk
- Department of Neurology, Penn Memory Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Department of Neurology, Penn Alzheimer's Disease Research Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Paul Yushkevich
- Department of Neurology, Penn Alzheimer's Disease Research Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Penn Image Computing and Science Lab, Department of Radiology, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - John Q Trojanowski
- Department of Neurology, Penn Alzheimer's Disease Research Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Edward B Lee
- Department of Neurology, Penn Alzheimer's Disease Research Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Murray Grossman
- Penn Frontotemporal Degeneration Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Jeffrey S Phillips
- Penn Frontotemporal Degeneration Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - David J Irwin
- Digital Neuropathology Laboratory, Department of Neurology, Perelman School of Medicine, Philadelphia, PA, 19104, USA.
- Penn Frontotemporal Degeneration Center, Perelman School of Medicine, Philadelphia, PA, 19104, USA.
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