1
|
Cranston AL, Kraev I, Stewart MG, Horsley D, Santos RX, Robinson L, Dreesen E, Armstrong P, Palliyil S, Harrington CR, Wischik CM, Riedel G. Rescue of synaptosomal glutamate release defects in tau transgenic mice by the tau aggregation inhibitor hydromethylthionine. Cell Signal 2024; 121:111269. [PMID: 38909930 DOI: 10.1016/j.cellsig.2024.111269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 06/13/2024] [Accepted: 06/20/2024] [Indexed: 06/25/2024]
Abstract
Glutamatergic neurotransmission, important for learning and memory, is disrupted in different ways in patients with Alzheimer's disease (AD) and frontotemporal dementia (FTD) tauopathies. We have previously reported that two tau transgenic mouse models, L1 and L66, produce different phenotypes resembling AD and FTD, respectively. The AD-like L1 model expresses the truncated core aggregation domain of the AD paired helical filament (PHF) form of tau (tau296-390) whereas the FTD-like L66 model expresses full-length tau carrying two mutations at P301S/G335D. We have used synaptosomes isolated from these mice to investigate K+-evoked glutamate release and, if abnormal, to determine responsiveness to hydromethylthionine, a tau aggregation inhibitor previously shown to reduce tau pathology in these models. We report that the transgenes in these two mouse lines cause opposite abnormalities in glutamate release. Over-expression of the core tau unit in L1 produces a significant reduction in glutamate release and a loss of Ca2+-dependency compared with wild-type control mice. Full-length mutant tau produces an increase in glutamate release that retains normal Ca2+-dependency. Chronic pre-treatment with hydromethylthionine normalises both reduced (L1) and excessive glutamate (L66) and restores normal Ca2+-dependency in L1 mice. This implies that both patterns of impairment are the result of tau aggregation, but that the direction and Ca2+-dependency of the abnormality is determined by expression of the disease-specific transgene. Our results lead to the conclusion that the tauopathies need not be considered a single entity in terms of the downstream effects of pathological aggregation of tau protein. In this case, directionally opposite abnormalities in glutamate release resulting from different types of tau aggregation in the two mouse models can be corrected by hydromethylthionine. This may help to explain the activity of hydromethylthionine on cognitive decline and brain atrophy in both AD and behavioural-variant FTD.
Collapse
Affiliation(s)
- Anna L Cranston
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill AB25 2ZD, UK
| | - Igor Kraev
- School of Life, Health and Chemical Sciences, The Open University, Milton Keynes MK7 6AA, UK
| | - Mike G Stewart
- School of Life, Health and Chemical Sciences, The Open University, Milton Keynes MK7 6AA, UK
| | - David Horsley
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill AB25 2ZD, UK
| | - Renato X Santos
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill AB25 2ZD, UK
| | - Lianne Robinson
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill AB25 2ZD, UK
| | - Eline Dreesen
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill AB25 2ZD, UK
| | - Paul Armstrong
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill AB25 2ZD, UK
| | - Soumya Palliyil
- Scottish Biologics Facility, University of Aberdeen, Foresterhill AB25 2ZP, UK
| | - Charles R Harrington
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill AB25 2ZD, UK; TauRx Therapeutics Ltd, 395 King Street, Aberdeen, AB24 5RP, UK
| | - Claude M Wischik
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill AB25 2ZD, UK; TauRx Therapeutics Ltd, 395 King Street, Aberdeen, AB24 5RP, UK
| | - Gernot Riedel
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill AB25 2ZD, UK.
| |
Collapse
|
2
|
Hole KL, Zhu B, Huggon L, Brown JT, Mason JM, Williams RJ. Tau P301L disengages from the proteosome core complex and neurogranin coincident with enhanced neuronal network excitability. Cell Death Dis 2024; 15:429. [PMID: 38890273 PMCID: PMC11189525 DOI: 10.1038/s41419-024-06815-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 06/04/2024] [Accepted: 06/07/2024] [Indexed: 06/20/2024]
Abstract
Tauopathies are characterised by the pathological accumulation of misfolded tau. The emerging view is that toxic tau species drive synaptic dysfunction and potentially tau propagation before measurable neurodegeneration is evident, but the underlying molecular events are not well defined. Human non-mutated 0N4R tau (tauWT) and P301L mutant 0N4R tau (tauP301L) were expressed in mouse primary cortical neurons using adeno-associated viruses to monitor early molecular changes and synaptic function before the onset of neuronal loss. In this model tauP301L was differentially phosphorylated relative to tauwt with a notable increase in phosphorylation at ser262. Affinity purification - mass spectrometry combined with tandem mass tagging was used to quantitatively compare the tauWT and tauP301L interactomes. This revealed an enrichment of tauP301L with ribosomal proteins but a decreased interaction with the proteasome core complex and reduced tauP301L degradation. Differences in the interaction of tauP301L with members of a key synaptic calcium-calmodulin signalling pathway were also identified, most notably, increased association with CaMKII but reduced association with calcineurin and the candidate AD biomarker neurogranin. Decreased association of neurogranin to tauP301L corresponded with the appearance of enhanced levels of extracellular neurogranin suggestive of potential release or leakage from synapses. Finally, analysis of neuronal network activity using micro-electrode arrays showed that overexpression of tauP301L promoted basal hyperexcitability coincident with these changes in the tau interactome and implicating tau in specific early alterations in synaptic function.
Collapse
Affiliation(s)
- Katriona L Hole
- Department of Life Sciences, University of Bath, Bath, UK
- The Francis Crick Institute, London, UK
| | - Bangfu Zhu
- Department of Life Sciences, University of Bath, Bath, UK
| | - Laura Huggon
- Department of Life Sciences, University of Bath, Bath, UK
- UK Dementia Research Institute at King's College London, London, UK
| | - Jon T Brown
- Department of Clinical and Biomedical Sciences, University of Exeter, Exeter, UK
| | - Jody M Mason
- Department of Life Sciences, University of Bath, Bath, UK
| | | |
Collapse
|
3
|
Alves SS, Servilha-Menezes G, Rossi L, da Silva Junior RMP, Garcia-Cairasco N. Evidence of disturbed insulin signaling in animal models of Alzheimer's disease. Neurosci Biobehav Rev 2023; 152:105326. [PMID: 37479008 DOI: 10.1016/j.neubiorev.2023.105326] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 06/02/2023] [Accepted: 07/17/2023] [Indexed: 07/23/2023]
Abstract
Since glucose reuptake by neurons is mostly independent of insulin, it has been an intriguing question whether insulin has or not any roles in the brain. Consequently, the identification of insulin receptors in the central nervous system has fueled investigations of insulin functions in the brain. It is also already known that insulin can influence glucose reuptake by neurons, mostly during activities that have the highest energy demand. The identification of high density of insulin receptors in the hippocampus also suggests that insulin may present important roles related to memory. In this context, studies have reported worse performance in cognitive tests among diabetic patients. In addition, alterations in the regulation of central insulin pathways have been observed in the brains of Alzheimer's disease (AD) patients. In fact, some authors have proposed AD as a third type of diabetes and recently, our group proposed insulin resistance as a common link between different AD hypotheses. Therefore, in the present narrative review, we intend to revise and gather the evidence of disturbed insulin signaling in experimental animal models of AD.
Collapse
Affiliation(s)
- Suélen Santos Alves
- Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo (FMRP-USP), Brazil
| | - Gabriel Servilha-Menezes
- Department of Physiology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Brazil
| | - Leticia Rossi
- Department of Physiology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Brazil
| | - Rui Milton Patrício da Silva Junior
- Department of Physiology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Brazil; Institute of Neuroscience of Castilla y León, University of Salamanca, Salamanca, Spain
| | - Norberto Garcia-Cairasco
- Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo (FMRP-USP), Brazil; Department of Physiology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Brazil.
| |
Collapse
|
4
|
Anglada-Huguet M, Endepols H, Sydow A, Hilgers R, Neumaier B, Drzezga A, Kaniyappan S, Mandelkow E, Mandelkow EM. Reversal of Tau-Dependent Cognitive Decay by Blocking Adenosine A1 Receptors: Comparison of Transgenic Mouse Models with Different Levels of Tauopathy. Int J Mol Sci 2023; 24:ijms24119260. [PMID: 37298211 DOI: 10.3390/ijms24119260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/12/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023] Open
Abstract
The accumulation of tau is a hallmark of several neurodegenerative diseases and is associated with neuronal hypoactivity and presynaptic dysfunction. Oral administration of the adenosine A1 receptor antagonist rolofylline (KW-3902) has previously been shown to reverse spatial memory deficits and to normalize the basic synaptic transmission in a mouse line expressing full-length pro-aggregant tau (TauΔK) at low levels, with late onset of disease. However, the efficacy of treatment remained to be explored for cases of more aggressive tauopathy. Using a combination of behavioral assays, imaging with several PET-tracers, and analysis of brain tissue, we compared the curative reversal of tau pathology by blocking adenosine A1 receptors in three mouse models expressing different types and levels of tau and tau mutants. We show through positron emission tomography using the tracer [18F]CPFPX (a selective A1 receptor ligand) that intravenous injection of rolofylline effectively blocks A1 receptors in the brain. Moreover, when administered to TauΔK mice, rolofylline can reverse tau pathology and synaptic decay. The beneficial effects are also observed in a line with more aggressive tau pathology, expressing the amyloidogenic repeat domain of tau (TauRDΔK) with higher aggregation propensity. Both models develop a progressive tau pathology with missorting, phosphorylation, accumulation of tau, loss of synapses, and cognitive decline. TauRDΔK causes pronounced neurofibrillary tangle assembly concomitant with neuronal death, whereas TauΔK accumulates only to tau pretangles without overt neuronal loss. A third model tested, the rTg4510 line, has a high expression of mutant TauP301L and hence a very aggressive phenotype starting at ~3 months of age. This line failed to reverse pathology upon rolofylline treatment, consistent with a higher accumulation of tau-specific PET tracers and inflammation. In conclusion, blocking adenosine A1 receptors by rolofylline can reverse pathology if the pathological potential of tau remains below a threshold value that depends on concentration and aggregation propensity.
Collapse
Affiliation(s)
- Marta Anglada-Huguet
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
| | - Heike Endepols
- Institute of Radiochemistry and Experimental Molecular Imaging, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
- Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50923 Cologne, Germany
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Straße, 52428 Jülich, Germany
| | - Astrid Sydow
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
| | - Ronja Hilgers
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
| | - Bernd Neumaier
- Institute of Radiochemistry and Experimental Molecular Imaging, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Straße, 52428 Jülich, Germany
- Max Planck Institute for Metabolism Research, 50931 Cologne, Germany
| | - Alexander Drzezga
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
- Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50923 Cologne, Germany
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Molecular Organization of the Brain (INM-2), Wilhelm-Johnen-Straße, 52428 Jülich, Germany
| | - Senthilvelrajan Kaniyappan
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
- MPI Neurobiology Behavior-caesar, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
- Department of Neurodegenerative Diseases and Geriatric Psychiatry, University of Bonn, 53127 Bonn, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
- MPI Neurobiology Behavior-caesar, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
- Department of Neurodegenerative Diseases and Geriatric Psychiatry, University of Bonn, 53127 Bonn, Germany
| | - Eva-Maria Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
- MPI Neurobiology Behavior-caesar, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| |
Collapse
|
5
|
Mazzo F, Butnaru I, Grubisha O, Ficulle E, Sanger H, Fitzgerald G, Pan F, Pasqui F, Murray T, Monn J, Li X, Hutton M, Bose S, Schiavo G, Sher E. Metabotropic Glutamate Receptors Modulate Exocytotic Tau Release and Propagation. J Pharmacol Exp Ther 2022; 383:117-128. [PMID: 36116796 DOI: 10.1124/jpet.122.001307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/05/2022] [Indexed: 01/07/2023] Open
Abstract
Using synaptosomes purified from the brains of two transgenic mouse models overexpressing mutated human tau (TgP301S and Tg4510) and brains of patients with sporadic Alzheimer's disease, we showed that aggregated and hyperphosphorylated tau was both present in purified synaptosomes and released in a calcium- and synaptosome-associated protein of 25 kDa (SNAP25)-dependent manner. In all mouse and human synaptosomal preparations, tau release was inhibited by the selective metabotropic glutamate receptor 2/3 (mGluR2/3) agonist LY379268, an effect prevented by the selective mGlu2/3 antagonist LY341495. LY379268 was also able to block pathologic tau propagation between primary neurons in an in vitro microfluidic cellular model. These novel results are transformational for our understanding of the molecular mechanisms mediating tau release and propagation at synaptic terminals in Alzheimer's disease and suggest that these processes could be inhibited therapeutically by the selective activation of presynaptic G protein-coupled receptors. SIGNIFICANCE STATEMENT: Pathological tau release and propagation are key neuropathological events underlying cognitive decline in Alzheimer's disease patients. This paper describes the role of regulated exocytosis, and the soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) protein SNAP25, in mediating tau release from rodent and human synaptosomes. This paper also shows that a selective mGluR2/3 agonist is highly effective in blocking tau release from synaptosomes and tau propagation between neurons, opening the way to the discovery of novel therapeutic approaches to this devastating disease.
Collapse
Affiliation(s)
- Francesca Mazzo
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Ioana Butnaru
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Olivera Grubisha
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Elena Ficulle
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Helen Sanger
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Griffin Fitzgerald
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Feng Pan
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Francesca Pasqui
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Tracey Murray
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - James Monn
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Xia Li
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Michael Hutton
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Suchira Bose
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Giampietro Schiavo
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| | - Emanuele Sher
- Eli Lilly and Company Ltd, Neuroscience, Bracknell, United Kingdom (F.M., O.G., E.F., H.S., Fr.P., T.M., S.B., E.S.); UK Dementia Research Institute at UCL, University College London, London, United Kingdom (I.B., G.S.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (G.F., Fe.P., J.M., X.L., M.H.); and Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom (G.S.)
| |
Collapse
|
6
|
Schmidt S, Holzer M, Arendt T, Sonntag M, Morawski M. Tau Protein Modulates Perineuronal Extracellular Matrix Expression in the TauP301L-acan Mouse Model. Biomolecules 2022; 12:biom12040505. [PMID: 35454094 PMCID: PMC9027016 DOI: 10.3390/biom12040505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/21/2022] [Accepted: 03/24/2022] [Indexed: 02/04/2023] Open
Abstract
Tau mutations promote the formation of tau oligomers and filaments, which are neuropathological signs of several tau-associated dementias. Types of neurons in the CNS are spared of tau pathology and are surrounded by a specialized form of extracellular matrix; called perineuronal nets (PNs). Aggrecan, the major PN proteoglycans, is suggested to mediate PNs neuroprotective function by forming an external shield preventing the internalization of misfolded tau. We recently demonstrated a correlation between aggrecan amount and the expression and phosphorylation of tau in a TauP310L-acan mouse model, generated by crossbreeding heterozygous aggrecan mice with a significant reduction of aggrecan and homozygous TauP301L mice. Neurodegenerative processes have been associated with changes of PN structure and protein signature. In this study, we hypothesized that the structure and protein expression of PNs in this TauP310L-acan mouse is regulated by tau. Immunohistochemical and biochemical analyses demonstrate that protein levels of PN components differ between TauP301LHET-acanWT and TauP301LHET-acanHET mice, accompanied by changes in the expression of protein phosphatase 2 A. In addition, tau can modulate PN components such as brevican. Co-immunoprecipitation experiments revealed a physical connection between PN components and tau. These data demonstrate a complex, mutual interrelation of tau and the proteoglycans of the PN.
Collapse
|
7
|
Walker CK, Herskowitz JH. Dendritic Spines: Mediators of Cognitive Resilience in Aging and Alzheimer's Disease. Neuroscientist 2021; 27:487-505. [PMID: 32812494 PMCID: PMC8130863 DOI: 10.1177/1073858420945964] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cognitive resilience is often defined as the ability to remain cognitively normal in the face of insults to the brain. These insults can include disease pathology, such as plaques and tangles associated with Alzheimer's disease, stroke, traumatic brain injury, or other lesions. Factors such as physical or mental activity and genetics may contribute to cognitive resilience, but the neurobiological underpinnings remain ill-defined. Emerging evidence suggests that dendritic spine structural plasticity is one plausible mechanism. In this review, we highlight the basic structure and function of dendritic spines and discuss how spine density and morphology change in aging and Alzheimer's disease. We note evidence that spine plasticity mediates resilience to stress, and we tackle dendritic spines in the context of cognitive resilience to Alzheimer's disease. Finally, we examine how lifestyle and genetic factors may influence dendritic spine plasticity to promote cognitive resilience before discussing evidence for actin regulatory kinases as therapeutic targets for Alzheimer's disease.
Collapse
Affiliation(s)
- Courtney K. Walker
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
| | - Jeremy H. Herskowitz
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
| |
Collapse
|
8
|
Subramanian J, Savage JC, Tremblay MÈ. Synaptic Loss in Alzheimer's Disease: Mechanistic Insights Provided by Two-Photon in vivo Imaging of Transgenic Mouse Models. Front Cell Neurosci 2020; 14:592607. [PMID: 33408613 PMCID: PMC7780885 DOI: 10.3389/fncel.2020.592607] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/25/2020] [Indexed: 01/05/2023] Open
Abstract
Synapse loss is the strongest correlate for cognitive decline in Alzheimer's disease. The mechanisms underlying synapse loss have been extensively investigated using mouse models expressing genes with human familial Alzheimer's disease mutations. In this review, we summarize how multiphoton in vivo imaging has improved our understanding of synapse loss mechanisms associated with excessive amyloid in the living animal brain. We also discuss evidence obtained from these imaging studies for the role of cell-intrinsic calcium dyshomeostasis and cell-extrinsic activities of microglia, which are the immune cells of the brain, in mediating synapse loss.
Collapse
Affiliation(s)
- Jaichandar Subramanian
- Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS, United States
| | - Julie C Savage
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Marie-Ève Tremblay
- Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada.,Department of Molecular Medicine, Université Laval, Québec City, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
9
|
Müller-Thomsen L, Borgmann D, Morcinek K, Schröder S, Dengler B, Moser N, Neumaier F, Schneider T, Schröder H, Huggenberger S. Consequences of hyperphosphorylated tau on the morphology and excitability of hippocampal neurons in aged tau transgenic mice. Neurobiol Aging 2020; 93:109-123. [PMID: 32278495 DOI: 10.1016/j.neurobiolaging.2020.03.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/06/2020] [Accepted: 03/10/2020] [Indexed: 12/31/2022]
Abstract
The intracellular accumulation of hyperphosphorylated tau characterizes many neurodegenerative diseases such as Alzheimer's disease and frontotemporal dementia. A critical role for tau is supported by studies in transgenic mouse models expressing the P301L mutation with accumulation of hyperphosphorylated human tau in hippocampal pyramidal neurons of aged mice. Especially, the somatodendritic mislocalization of hyperphosphorylated tau seems to affect the neuronal network of the hippocampus. To show the consequences of aggregation of hyperphosphorylated tau within hippocampal neurons of aged mice, the CA1 pyramidal cells were analyzed morphologically and electrophysiologically. Here we demonstrate in the P301L pR5 mouse model that hyperphosphorylated tau leads to an increase in stubby spines and filopodia, as well as a decrease in total dendritic length of hippocampal pyramidal neurons due to a decrease in apical dendritic length and nodes. This atrophy is in line with the significant reduction in CA1 long-term potentiation. Furthermore, mutant tau induced a depolarized threshold for action potential initiation and an increased current of inward rectifying potassium channels, which should lead, together with the long-term potentiation decrease, to a decreased excitability of CA1 neurons.
Collapse
Affiliation(s)
| | - Diba Borgmann
- Department II of Anatomy, University of Cologne, Cologne, Germany
| | - Kerstin Morcinek
- Department II of Anatomy, University of Cologne, Cologne, Germany
| | - Sophia Schröder
- Department II of Anatomy, University of Cologne, Cologne, Germany
| | - Brigitte Dengler
- Department II of Anatomy, University of Cologne, Cologne, Germany
| | - Natasha Moser
- Department II of Anatomy, University of Cologne, Cologne, Germany
| | - Felix Neumaier
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Toni Schneider
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | | | - Stefan Huggenberger
- Department II of Anatomy, University of Cologne, Cologne, Germany; Institute of Anatomy and Clinical Morphology, Faculty of Health, Witten/Herdecke University, Witten, Germany
| |
Collapse
|
10
|
Samaey C, Schreurs A, Stroobants S, Balschun D. Early Cognitive and Behavioral Deficits in Mouse Models for Tauopathy and Alzheimer's Disease. Front Aging Neurosci 2019; 11:335. [PMID: 31866856 PMCID: PMC6908963 DOI: 10.3389/fnagi.2019.00335] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 11/19/2019] [Indexed: 12/12/2022] Open
Abstract
Neurocognitive disorders, among which Alzheimer's disease (AD), have become one of the major causes of death in developed countries. No effective disease-modifying therapy is available, possibly because current treatments are administered too late to still be able to intervene in the disease progress. AD is characterized by a gradual onset with subclinical neurobiological and behavioral changes that precede diagnosis with years to even decades. The earlier the diagnosis, the earlier potential treatments can be tested and started. Mouse models are valuable to study the possible causes underlying early phases of neuropathology and their reflection in behavior and other biomarkers, to help improve preclinical detection and diagnosis of AD. Here, we assessed cognitive functioning and social behavior in transgenic mice expressing tau pathology only (Tau-P301L) or a combination of amyloid and tau pathology [amyloid precursor protein (APP)-V717I × Tau-P301L]. The mice were subjected to a variety of behavioral tasks at an age of 3-6 months, i.e., at an early phase of their AD-like pathology. We hypothesized that compared to age-matched wild-type controls, transgenic mice would show specific impairments in both cognitive and non-cognitive tasks. In line with our expectations, transgenic mice showed decreased cognitive flexibility in the Morris water maze, decreased exploratory behavior, decreased performance in a nesting task, and increased anxiety-like behavior. In accordance with the amyloid-cascade hypothesis, some of the behavioral measures showed more severe deficits in APP-V717I × Tau-P301L compared to Tau-P301L mice, indicating an exacerbation of disease processes due to the co-occurrence of amyloid and tau pathology. Our study supports the use of behavioral markers as early indicators of ongoing AD pathology during the preclinical phase.
Collapse
Affiliation(s)
- Celine Samaey
- Brain and Cognition, KU Leuven, Leuven, Belgium.,Center for Clinical Psychiatry, KU Leuven, Leuven, Belgium
| | - An Schreurs
- Brain and Cognition, KU Leuven, Leuven, Belgium.,Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Stijn Stroobants
- Brain and Cognition, KU Leuven, Leuven, Belgium.,Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Detlef Balschun
- Brain and Cognition, KU Leuven, Leuven, Belgium.,Leuven Brain Institute, KU Leuven, Leuven, Belgium
| |
Collapse
|
11
|
Wang X, Williams D, Müller I, Lemieux M, Dukart R, Maia IBL, Wang H, Woerman AL, Schmitt-Ulms G. Tau interactome analyses in CRISPR-Cas9 engineered neuronal cells reveal ATPase-dependent binding of wild-type but not P301L Tau to non-muscle myosins. Sci Rep 2019; 9:16238. [PMID: 31700063 PMCID: PMC6838314 DOI: 10.1038/s41598-019-52543-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 10/03/2019] [Indexed: 11/09/2022] Open
Abstract
Protein interactions of Tau are of interest in efforts to decipher pathogenesis in Alzheimer's disease, a subset of frontotemporal dementias, and other tauopathies. We CRISPR-Cas9 edited two human cell lines to generate broadly adaptable models for neurodegeneration research. We applied the system to inducibly express balanced levels of 3-repeat and 4-repeat wild-type or P301L mutant Tau. Following 12-h induction, quantitative mass spectrometry revealed the Parkinson's disease-causing protein DJ-1 and non-muscle myosins as Tau interactors whose binding to Tau was profoundly influenced by the presence or absence of the P301L mutation. The presence of wild-type Tau stabilized non-muscle myosins at higher steady-state levels. Strikingly, in human differentiated co-cultures of neuronal and glial cells, the preferential interaction of non-muscle myosins to wild-type Tau depended on myosin ATPase activity. Consistently, transgenic P301L Tau mice exhibited reduced phosphorylation of regulatory myosin light chains known to activate this ATPase. The direct link of Tau to non-muscle myosins corroborates independently proposed roles of Tau in maintaining dendritic spines and mitochondrial fission biology, two subcellular niches affected early in tauopathies.
Collapse
Affiliation(s)
- Xinzhu Wang
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Ontario, M5T 2S8, Canada.,Department of Laboratory Medicine & Pathobiology, University of Toronto, Ontario, M5S 1A8, Canada
| | - Declan Williams
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Ontario, M5T 2S8, Canada.,Department of Laboratory Medicine & Pathobiology, University of Toronto, Ontario, M5S 1A8, Canada
| | - Iris Müller
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Ontario, M5T 2S8, Canada
| | - Mackenzie Lemieux
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Ontario, M5T 2S8, Canada
| | - Ramona Dukart
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Ontario, M5S 1A8, Canada
| | - Isabella B L Maia
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Ontario, M5T 2S8, Canada
| | - Hansen Wang
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Ontario, M5T 2S8, Canada
| | - Amanda L Woerman
- Department of Neurology, University of California San Francisco, California, 94158, USA
| | - Gerold Schmitt-Ulms
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Ontario, M5T 2S8, Canada. .,Department of Laboratory Medicine & Pathobiology, University of Toronto, Ontario, M5S 1A8, Canada.
| |
Collapse
|
12
|
Tan R, Lam AJ, Tan T, Han J, Nowakowski DW, Vershinin M, Simó S, Ori-McKenney KM, McKenney RJ. Microtubules gate tau condensation to spatially regulate microtubule functions. Nat Cell Biol 2019; 21:1078-1085. [PMID: 31481790 PMCID: PMC6748660 DOI: 10.1038/s41556-019-0375-5] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 07/18/2019] [Indexed: 01/18/2023]
Abstract
Tau is an abundant microtubule-associated protein in neurons. Tau aggregation into insoluble fibrils is a hallmark of Alzheimer's disease and other types of dementia1, yet the physiological state of tau molecules within cells remains unclear. Using single-molecule imaging, we directly observe that the microtubule lattice regulates reversible tau self-association, leading to localized, dynamic condensation of tau molecules on the microtubule surface. Tau condensates form selectively permissible barriers, spatially regulating the activity of microtubule-severing enzymes and the movement of molecular motors through their boundaries. We propose that reversible self-association of tau molecules, gated by the microtubule lattice, is an important mechanism of the biological functions of tau, and that oligomerization of tau is a common property shared between the physiological and disease-associated forms of the molecule.
Collapse
Affiliation(s)
- Ruensern Tan
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Aileen J Lam
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Tracy Tan
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Jisoo Han
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, Davis, CA, USA
| | | | - Michael Vershinin
- Department of Physics & Astronomy, University of Utah, Salt Lake City, UT, USA
| | - Sergi Simó
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, Davis, CA, USA
| | | | - Richard J McKenney
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA.
| |
Collapse
|
13
|
Govaerts K, Lechat B, Struys T, Kremer A, Borghgraef P, Van Leuven F, Himmelreich U, Dresselaers T. Longitudinal assessment of cerebral perfusion and vascular response to hypoventilation in a bigenic mouse model of Alzheimer's disease with amyloid and tau pathology. NMR IN BIOMEDICINE 2019; 32:e4037. [PMID: 30489666 DOI: 10.1002/nbm.4037] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 10/22/2018] [Accepted: 10/23/2018] [Indexed: 06/09/2023]
Abstract
Alzheimer's disease is the most common neurodegenerative disease, and many patients also present with vascular dysfunction. In this study, we aimed to assess cerebral blood flow (CBF) and cerebrovascular response (CVR) as early, pre-symptomatic (3 months of age), imaging markers in a bigenic model of Alzheimer's disease (APP.V717IxTau.P301L, biAT) and in the monogenic parental strains. We further developed our previously published combination of pulsed arterial spin labeling perfusion MRI and hypo-ventilation paradigm, which allows weaning of the mice from the ventilator. Furthermore, the commonly used isoflurane anesthesia induces vasodilation and is thereby inherently a vascular challenge. We therefore assessed perfusion differences in the mouse models under free-breathing isoflurane conditions. We report (i) that we can determine CBF and hypoventilation-based CVR under ketamine/midazolam anesthesia and wean mice from the ventilator, making it a valuable tool for assessment of CBF and CVR in mice, (ii) that biAT mice exhibit lower cortical CBF than wild-type mice at age 3 months, (iii) that CVR was increased in both biAT and APP.V717I mice but not in Tau.P301L mice, identifying the APP genotype as a strong influencer of brain CVR and (iv) that perfusion differences at baseline are masked by the widely used isoflurane anesthesia.
Collapse
Affiliation(s)
- Kristof Govaerts
- Biomedical MRI/MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Benoit Lechat
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Tom Struys
- Morphology Research Group, Biomedical Research Institute, Universiteit Hasselt, Hasselt, Belgium
| | - Anna Kremer
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Peter Borghgraef
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Fred Van Leuven
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Uwe Himmelreich
- Biomedical MRI/MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Tom Dresselaers
- Biomedical MRI/MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| |
Collapse
|
14
|
Ahlemeyer B, Halupczok S, Rodenberg-Frank E, Valerius KP, Baumgart-Vogt E. Endogenous Murine Amyloid-β Peptide Assembles into Aggregates in the Aged C57BL/6J Mouse Suggesting These Animals as a Model to Study Pathogenesis of Amyloid-β Plaque Formation. J Alzheimers Dis 2018; 61:1425-1450. [DOI: 10.3233/jad-170923] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Barbara Ahlemeyer
- Institute for Anatomy and Cell Biology, Division of Medical Cell Biology, Justus Liebig University, Giessen, Germany
| | - Sascha Halupczok
- Institute for Anatomy and Cell Biology, Division of Medical Cell Biology, Justus Liebig University, Giessen, Germany
| | - Elke Rodenberg-Frank
- Institute for Anatomy and Cell Biology, Division of Medical Cell Biology, Justus Liebig University, Giessen, Germany
| | - Klaus-Peter Valerius
- Institute for Anatomy and Cell Biology, Division of Medical Cell Biology, Justus Liebig University, Giessen, Germany
| | - Eveline Baumgart-Vogt
- Institute for Anatomy and Cell Biology, Division of Medical Cell Biology, Justus Liebig University, Giessen, Germany
| |
Collapse
|
15
|
Jurado S. AMPA Receptor Trafficking in Natural and Pathological Aging. Front Mol Neurosci 2018; 10:446. [PMID: 29375307 PMCID: PMC5767248 DOI: 10.3389/fnmol.2017.00446] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/21/2017] [Indexed: 01/09/2023] Open
Abstract
α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) enable most excitatory transmission in the brain and are crucial for mediating basal synaptic strength and plasticity. Because of the importance of their function, AMPAR dynamics, activity and subunit composition undergo a tight regulation which begins as early as prenatal development and continues through adulthood. Accumulating evidence suggests that the precise regulatory mechanisms involved in orchestrating AMPAR trafficking are challenged in the aging brain. In turn dysregulation of AMPARs can be linked to most neurological and neurodegenerative disorders. Understanding the mechanisms that govern AMPAR signaling during natural and pathological cognitive decline will guide the efforts to develop most effective ways to tackle neurodegenerative diseases which are one of the primary burdens afflicting an increasingly aging population. In this review, I provide a brief overview of the molecular mechanisms involved in AMPAR trafficking highlighting what is currently known about how these processes change with age and disease. As a particularly well-studied example of AMPAR dysfunction in pathological aging I focus in Alzheimer’s disease (AD) with special emphasis in how the production of neurofibrillary tangles (NFTs) and amyloid-β plaques may contribute to disruption in AMPAR function.
Collapse
Affiliation(s)
- Sandra Jurado
- Instituto de Neurociencias CSIC-UMH, San Juan de Alicante, Spain
| |
Collapse
|
16
|
Zempel H, Dennissen FJA, Kumar Y, Luedtke J, Biernat J, Mandelkow EM, Mandelkow E. Axodendritic sorting and pathological missorting of Tau are isoform-specific and determined by axon initial segment architecture. J Biol Chem 2017; 292:12192-12207. [PMID: 28536263 DOI: 10.1074/jbc.m117.784702] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 05/21/2017] [Indexed: 11/06/2022] Open
Abstract
Subcellular mislocalization of the microtubule-associated protein Tau is a hallmark of Alzheimer disease (AD) and other tauopathies. Six Tau isoforms, differentiated by the presence or absence of a second repeat or of N-terminal inserts, exist in the human CNS, but their physiological and pathological differences have long remained elusive. Here, we investigated the properties and distributions of human and rodent Tau isoforms in primary forebrain rodent neurons. We found that the Tau diffusion barrier (TDB), located within the axon initial segment (AIS), controls retrograde (axon-to-soma) and anterograde (soma-to-axon) traffic of Tau. Tau isoforms without the N-terminal inserts were sorted efficiently into the axon. However, the longest isoform (2N4R-Tau) was partially retained in cell bodies and dendrites, where it accelerated spine and dendrite growth. The TDB (located within the AIS) was impaired when AIS components (ankyrin G, EB1) were knocked down or when glycogen synthase kinase-3β (GSK3β; an AD-associated kinase tethered to the AIS) was overexpressed. Using superresolution nanoscopy and live-cell imaging, we observed that microtubules within the AIS appeared highly dynamic, a feature essential for the TDB. Pathomechanistically, amyloid-β insult caused cofilin activation and F-actin remodeling and decreased microtubule dynamics in the AIS. Concomitantly with these amyloid-β-induced disruptions, the AIS/TDB sorting function failed, causing AD-like Tau missorting. In summary, we provide evidence that the human and rodent Tau isoforms differ in axodendritic sorting and amyloid-β-induced missorting and that the axodendritic distribution of Tau depends on AIS integrity.
Collapse
Affiliation(s)
- Hans Zempel
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany; CAESAR Research Center, 53175 Bonn, Germany; Max Planck Institute for Metabolism Research, 50931 Cologne, Germany; University of Bonn, 53113 Bonn, Germany.
| | - Frank J A Dennissen
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany; CAESAR Research Center, 53175 Bonn, Germany
| | - Yatender Kumar
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany; Max Planck Institute for Metabolism Research, 50931 Cologne, Germany
| | - Julia Luedtke
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany; CAESAR Research Center, 53175 Bonn, Germany
| | - Jacek Biernat
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany; CAESAR Research Center, 53175 Bonn, Germany
| | - Eva-Maria Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany; CAESAR Research Center, 53175 Bonn, Germany; Max Planck Institute for Metabolism Research, 50931 Cologne, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany; CAESAR Research Center, 53175 Bonn, Germany; Max Planck Institute for Metabolism Research, 50931 Cologne, Germany.
| |
Collapse
|
17
|
Helboe L, Egebjerg J, Barkholt P, Volbracht C. Early depletion of CA1 neurons and late neurodegeneration in a mouse tauopathy model. Brain Res 2017; 1665:22-35. [PMID: 28411086 DOI: 10.1016/j.brainres.2017.04.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 03/27/2017] [Accepted: 04/05/2017] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) and tauopathies, such as frontotemporal dementia (FTD), are characterized by formation of neurofibrillary tangles consisting of hyperphosphorylated tau. Further neuropathological characteristics include synaptic loss, neurodegeneration and brain atrophy. Here, we explored the association between hyperphosphorylated tau species, brain atrophy, synaptic and neuronal loss in a mouse model (rTg4510) carrying the human tau (hTau) P301L mutation found in a familiar form of FTD. We established that hTau expression during the first 6 postnatal weeks was important for the progression of tauopathy in rTg4510 mice. Short term suppression of postnatal hTau expression delayed the onset of tau pathology by approximately 6months in this model. Early postnatal hTau expression was detrimental to CA1 neurons of the hippocampus and reduced neuronal numbers in 6-10weeks young rTg4510 mice prior to the appearance of hyperphosphorylated hTau species in the hippocampus. Hyperphosphorylated hTau species emerged from 10 to 24weeks of age and were associated with increased ubiquitin levels, gliosis, and brain atrophy and preceded the synaptic loss and CA1 neurodegeneration that occurred at 48weeks of age. We present two consequences of hTau expression in CA1 in rTg4510 mice: an early decrease in neuron number already established prior to the presence of hyperphosphorylated tau species and a later neurodegeneration dependent on hyperphosphorylated tau. Neurodegeneration and synaptic protein loss were completely prevented when hTau expression was suppressed prior to the appearance of hyperphosphorylated tau species. Suppression of hTau expression after the onset of tau hyperphosphorylation and tangle pathology initiated at 16weeks partially rescued neuronal loss at 48weeks of age, while a reduction of neurodegeneration was no longer possible when hTau suppression was introduced as late as at 24weeks of age. Our results in rTg4510 mice argue that it is promising to lower hyperphosphorylated tau species at early stages of tau pathology to protect from neurodegeneration.
Collapse
Affiliation(s)
- Lone Helboe
- Department of Neurodegeneration, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark
| | - Jan Egebjerg
- Department of Neurodegeneration, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark
| | | | - Christiane Volbracht
- Department of Neurodegeneration, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark.
| |
Collapse
|
18
|
Buccarello L, Grignaschi G, Castaldo AM, Di Giancamillo A, Domeneghini C, Melcangi RC, Borsello T. Sex Impact on Tau-Aggregation and Postsynaptic Protein Levels in the P301L Mouse Model of Tauopathy. J Alzheimers Dis 2017; 56:1279-1292. [DOI: 10.3233/jad-161087] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Lucia Buccarello
- Department of Neuroscience, IRCCS-Mario Negri Institute for Pharmacological Research, Milan, Italy
- Department of Health, Animal Science and Food Safety, Universitá degli Studi di Milano, Italy
| | - Giuliano Grignaschi
- Department of Neuroscience, IRCCS-Mario Negri Institute for Pharmacological Research, Milan, Italy
| | - Anna Maria Castaldo
- Department of Neuroscience, IRCCS-Mario Negri Institute for Pharmacological Research, Milan, Italy
- Department of Biomedical Sciences for Health, Universitá degli Studi di Milano, Italy
| | - Alessia Di Giancamillo
- Department of Health, Animal Science and Food Safety, Universitá degli Studi di Milano, Italy
| | - Cinzia Domeneghini
- Department of Health, Animal Science and Food Safety, Universitá degli Studi di Milano, Italy
| | - Roberto Cosimo Melcangi
- Department of Pharmacological and Biomolecular Sciences, Universitá degli Studi di Milano, Italy
| | - Tiziana Borsello
- Department of Neuroscience, IRCCS-Mario Negri Institute for Pharmacological Research, Milan, Italy
- Department of Pharmacological and Biomolecular Sciences, Universitá degli Studi di Milano, Italy
| |
Collapse
|
19
|
Mild Traumatic Brain Injury of Tau.P301L Mice Results in an Impairment of Neural Plasticity. ARCHIVES OF NEUROSCIENCE 2016. [DOI: 10.5812/archneurosci.38039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
20
|
Grimm A, Mensah-Nyagan AG, Eckert A. Alzheimer, mitochondria and gender. Neurosci Biobehav Rev 2016; 67:89-101. [DOI: 10.1016/j.neubiorev.2016.04.012] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 04/11/2016] [Accepted: 04/20/2016] [Indexed: 10/21/2022]
|
21
|
Hansen HH, Barkholt P, Fabricius K, Jelsing J, Terwel D, Pyke C, Knudsen LB, Vrang N. The GLP-1 receptor agonist liraglutide reduces pathology-specific tau phosphorylation and improves motor function in a transgenic hTauP301L mouse model of tauopathy. Brain Res 2016; 1634:158-170. [DOI: 10.1016/j.brainres.2015.12.052] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 12/18/2015] [Accepted: 12/22/2015] [Indexed: 01/10/2023]
|
22
|
Lee NJ, Song JM, Cho HJ, Sung YM, Lee T, Chung A, Hong SH, Cifelli JL, Rubinshtein M, Habib LK, Capule CC, Turner RS, Pak DTS, Yang J, Hoe HS. Hexa (ethylene glycol) derivative of benzothiazole aniline promotes dendritic spine formation through the RasGRF1-Ras dependent pathway. Biochim Biophys Acta Mol Basis Dis 2015; 1862:284-95. [PMID: 26675527 DOI: 10.1016/j.bbadis.2015.12.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 11/16/2015] [Accepted: 12/04/2015] [Indexed: 11/24/2022]
Abstract
Our recent study demonstrated that an amyloid-β binding molecule, BTA-EG4, increases dendritic spine number via Ras-mediated signaling. To potentially optimize the potency of the BTA compounds, we synthesized and evaluated an amyloid-β binding analog of BTA-EG4 with increased solubility in aqueous solution, BTA-EG6. We initially examined the effects of BTA-EG6 on dendritic spine formation and found that BTA-EG6-treated primary hippocampal neurons had significantly increased dendritic spine number compared to control treatment. In addition, BTA-EG6 significantly increased the surface level of AMPA receptors. Upon investigation into the molecular mechanism by which BTA-EG6 promotes dendritic spine formation, we found that BTA-EG6 may exert its effects on spinogenesis via RasGRF1-ERK signaling, with potential involvement of other spinogenesis-related proteins such as Cdc42 and CDK5. Taken together, our data suggest that BTA-EG6 boosts spine and synapse number, which may have a beneficial effect of enhancing neuronal and synaptic function in the normal healthy brain.
Collapse
Affiliation(s)
- Nathanael J Lee
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Jung Min Song
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Hyun-Ji Cho
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Cheomdan-ro, Dong-gu, Daegu 701-300, Republic of Korea
| | - You Me Sung
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA; Department of Neurology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Taehee Lee
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Andrew Chung
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Sung-Ha Hong
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA; Department of Neurology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Jessica L Cifelli
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mark Rubinshtein
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Lila K Habib
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Christina C Capule
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - R Scott Turner
- Department of Neurology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Daniel T S Pak
- Department of Pharmacology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Jerry Yang
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Hyang-Sook Hoe
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA; Department of Neurology, Georgetown University Medical Center, Washington, DC 20057, USA; Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Cheomdan-ro, Dong-gu, Daegu 701-300, Republic of Korea.
| |
Collapse
|
23
|
Jadhav S, Cubinkova V, Zimova I, Brezovakova V, Madari A, Cigankova V, Zilka N. Tau-mediated synaptic damage in Alzheimer's disease. Transl Neurosci 2015; 6:214-226. [PMID: 28123806 PMCID: PMC4936631 DOI: 10.1515/tnsci-2015-0023] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/04/2015] [Indexed: 12/16/2022] Open
Abstract
Synapses are the principal sites for chemical communication between neurons and are essential for performing the dynamic functions of the brain. In Alzheimer’s disease and related tauopathies, synapses are exposed to disease modified protein tau, which may cause the loss of synaptic contacts that culminate in dementia. In recent decades, structural, transcriptomic and proteomic studies suggest that Alzheimer’s disease represents a synaptic disorder. Tau neurofibrillary pathology and synaptic loss correlate well with cognitive impairment in these disorders. Moreover, regional distribution and the load of neurofibrillary lesions parallel the distribution of the synaptic loss. Several transgenic models of tauopathy expressing various forms of tau protein exhibit structural synaptic deficits. The pathological tau proteins cause the dysregulation of synaptic proteome and lead to the functional abnormalities of synaptic transmission. A large body of evidence suggests that tau protein plays a key role in the synaptic impairment of human tauopathies.
Collapse
Affiliation(s)
- Santosh Jadhav
- Institute of Neuroimmunology, Slovak Academy of Sciences, Centre of Excellence for Alzheimer's Disease and Related Disorders, Dubravska 9, 845 10 Bratislava, Slovak Republic
| | - Veronika Cubinkova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Centre of Excellence for Alzheimer's Disease and Related Disorders, Dubravska 9, 845 10 Bratislava, Slovak Republic; Axon Neuroscience SE, Grosslingova 45, Bratislava, Slovak Republic
| | - Ivana Zimova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Centre of Excellence for Alzheimer's Disease and Related Disorders, Dubravska 9, 845 10 Bratislava, Slovak Republic; Axon Neuroscience SE, Grosslingova 45, Bratislava, Slovak Republic
| | - Veronika Brezovakova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Centre of Excellence for Alzheimer's Disease and Related Disorders, Dubravska 9, 845 10 Bratislava, Slovak Republic
| | - Aladar Madari
- Small animal clinic, University of Veterinary Medicine and Pharmacy, Komenskeho 73, Kosice, Slovak Republic
| | - Viera Cigankova
- Department of Anatomy, Histology and Physiology, University of Veterinary Medicine and Pharmacy, Komenskeho 73, 041 81 Kosice, Slovak Republic
| | - Norbert Zilka
- Institute of Neuroimmunology, Slovak Academy of Sciences, Centre of Excellence for Alzheimer's Disease and Related Disorders, Dubravska 9, 845 10 Bratislava, Slovak Republic; Axon Neuroscience SE, Grosslingova 45, Bratislava, Slovak Republic
| |
Collapse
|
24
|
Xu H, Rösler TW, Carlsson T, de Andrade A, Bruch J, Höllerhage M, Oertel WH, Höglinger GU. Memory deficits correlate with tau and spine pathology in P301SMAPTtransgenic mice. Neuropathol Appl Neurobiol 2014; 40:833-43. [DOI: 10.1111/nan.12160] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 05/21/2014] [Indexed: 12/15/2022]
Affiliation(s)
- Hong Xu
- Department of Neurology; Technical University Munich; Munich Germany
- Department of Translational Neurodegeneration; German Center for Neurodegenerative Diseases (DZNE); Munich Germany
| | - Thomas W. Rösler
- Department of Translational Neurodegeneration; German Center for Neurodegenerative Diseases (DZNE); Munich Germany
| | - Thomas Carlsson
- Department of Pharmacology; Institute of Neuroscience and Physiology; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
- Department of Neurology; Philipps-University; Marburg Germany
| | - Anderson de Andrade
- Department of Translational Neurodegeneration; German Center for Neurodegenerative Diseases (DZNE); Munich Germany
- Department of Neurology; Philipps-University; Marburg Germany
| | - Julius Bruch
- Department of Neurology; Technical University Munich; Munich Germany
- Department of Translational Neurodegeneration; German Center for Neurodegenerative Diseases (DZNE); Munich Germany
| | | | | | - Günter U. Höglinger
- Department of Neurology; Technical University Munich; Munich Germany
- Department of Translational Neurodegeneration; German Center for Neurodegenerative Diseases (DZNE); Munich Germany
- Department of Neurology; Philipps-University; Marburg Germany
| |
Collapse
|
25
|
Lost after translation: missorting of Tau protein and consequences for Alzheimer disease. Trends Neurosci 2014; 37:721-32. [PMID: 25223701 DOI: 10.1016/j.tins.2014.08.004] [Citation(s) in RCA: 185] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/08/2014] [Accepted: 08/12/2014] [Indexed: 12/19/2022]
Abstract
Tau is a microtubule-associated-protein that is sorted into neuronal axons in physiological conditions. In Alzheimer disease (AD) and other tauopathies, Tau sorting mechanisms fail and Tau becomes missorted into the somatodendritic compartment. In AD, aberrant amyloid-β (Aβ) production might trigger Tau missorting. The physiological axonal sorting of Tau depends on the developmental stage of the neuron, the phosphorylation state of Tau and the microtubule cytoskeleton. Disease-associated missorting of Tau is connected to increased phosphorylation and aggregation of Tau, and impaired microtubule interactions. Disease-causing mechanisms involve impaired transport, aberrant kinase activation, non-physiological interactions of Tau, and prion-like spreading. In this review we focus on the physiological and pathological (mis)sorting of Tau, the underlying mechanisms, and effects in disease.
Collapse
|
26
|
Crespo-Biel N, Theunis C, Borghgraef P, Lechat B, Devijver H, Maurin H, Van Leuven F. Phosphorylation of protein Tau by GSK3β prolongs survival of bigenic Tau.P301L×GSK3β mice by delaying brainstem tauopathy. Neurobiol Dis 2014; 67:119-32. [DOI: 10.1016/j.nbd.2014.03.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 03/20/2014] [Accepted: 03/25/2014] [Indexed: 10/25/2022] Open
|
27
|
Rudinskiy N, Hawkes JM, Wegmann S, Kuchibhotla KV, Muzikansky A, Betensky RA, Spires-Jones TL, Hyman BT. Tau pathology does not affect experience-driven single-neuron and network-wide Arc/Arg3.1 responses. Acta Neuropathol Commun 2014; 2:63. [PMID: 24915991 PMCID: PMC4229905 DOI: 10.1186/2051-5960-2-63] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 05/21/2014] [Indexed: 11/14/2022] Open
Abstract
Intraneuronal neurofibrillary tangles (NFTs) – a characteristic pathological feature of Alzheimer’s and several other neurodegenerative diseases – are considered a major target for drug development. Tangle load correlates well with the severity of cognitive symptoms and mouse models of tauopathy are behaviorally impaired. However, there is little evidence that NFTs directly impact physiological properties of host neurons. Here we used a transgenic mouse model of tauopathy to study how advanced tau pathology in different brain regions affects activity-driven expression of immediate-early gene Arc required for experience-dependent consolidation of long-term memories. We demonstrate in vivo that visual cortex neurons with tangles are as likely to express comparable amounts of Arc in response to structured visual stimulation as their neighbors without tangles. Probability of experience-dependent Arc response was not affected by tau tangles in both visual cortex and hippocampal pyramidal neurons as determined postmortem. Moreover, whole brain analysis showed that network-wide activity-driven Arc expression was not affected by tau pathology in any of the brain regions, including brain areas with the highest tangle load. Our findings suggest that intraneuronal NFTs do not affect signaling cascades leading to experience-dependent gene expression required for long-term synaptic plasticity.
Collapse
|
28
|
Maurin H, Lechat B, Borghgraef P, Devijver H, Jaworski T, Van Leuven F. Terminal hypothermic Tau.P301L mice have increased Tau phosphorylation independently of glycogen synthase kinase 3α/β. Eur J Neurosci 2014; 40:2442-53. [DOI: 10.1111/ejn.12595] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 03/20/2014] [Accepted: 03/23/2014] [Indexed: 01/28/2023]
Affiliation(s)
- Hervé Maurin
- Experimental Genetics Group LEGTEGG; Department of Human Genetics; KU Leuven; Campus Gasthuisberg ON1 06.602 Herestraat 49 B-3000 Leuven Belgium
| | - Benoit Lechat
- Experimental Genetics Group LEGTEGG; Department of Human Genetics; KU Leuven; Campus Gasthuisberg ON1 06.602 Herestraat 49 B-3000 Leuven Belgium
| | - Peter Borghgraef
- Experimental Genetics Group LEGTEGG; Department of Human Genetics; KU Leuven; Campus Gasthuisberg ON1 06.602 Herestraat 49 B-3000 Leuven Belgium
| | - Herman Devijver
- Experimental Genetics Group LEGTEGG; Department of Human Genetics; KU Leuven; Campus Gasthuisberg ON1 06.602 Herestraat 49 B-3000 Leuven Belgium
| | | | - Fred Van Leuven
- Experimental Genetics Group LEGTEGG; Department of Human Genetics; KU Leuven; Campus Gasthuisberg ON1 06.602 Herestraat 49 B-3000 Leuven Belgium
| |
Collapse
|
29
|
Erez H, Shemesh OA, Spira ME. Rescue of tau-induced synaptic transmission pathology by paclitaxel. Front Cell Neurosci 2014; 8:34. [PMID: 24574970 PMCID: PMC3918585 DOI: 10.3389/fncel.2014.00034] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 01/23/2014] [Indexed: 12/30/2022] Open
Abstract
Behavioral and electrophysiological studies of Alzheimer’s disease (AD) and other tauopathies have revealed that the onset of cognitive decline correlates better with synaptic dysfunctions than with hallmark pathologies such as extracellular amyloid-β plaques, intracellular hyperphosphorylated tau or neuronal loss. Recent experiments have also demonstrated that anti-cancer microtubule (MT)-stabilizing drugs can rescue tau-induced behavioral decline and hallmark neuron pathologies. Nevertheless, the mechanisms underlying tau-induced synaptic dysfunction as well as those involved in the rescue of cognitive decline by MTs-stabilizing drugs remain unclear. Here we began to study these mechanisms using the glutaminergic sensory-motoneuron synapse derived from Aplysia ganglia, electrophysiological methods, the expression of mutant-human tau (mt-htau) either pre or postsynaptically and the antimitotic drug paclitaxel. Expression of mt-htau in the presynaptic neurons led to reduced excitatory postsynaptic potential (EPSP) amplitude generated by rested synapses within 3 days of mt-htau expression, and to deeper levels of homosynaptic depression. mt-htau-induced synaptic weakening correlated with reduced releasable presynaptic vesicle pools as revealed by the induction of asynchronous neurotransmitter release by hypertonic sucrose solution. Paclitaxel totally rescued tau-induced synaptic weakening by maintaining the availability of the presynaptic vesicle stores. Postsynaptic expression of mt-htau did not impair the above described synaptic-transmission parameters for up to 5 days. Along with earlier confocal microscope observations from our laboratory, these findings suggest that tau-induced synaptic dysfunction is the outcome of impaired axoplasmic transport and the ensuing reduction in the releasable presynaptic vesicle stores rather than the direct effects of mt-htau or paclitaxel on the synaptic release mechanisms.
Collapse
Affiliation(s)
- Hadas Erez
- Department of Neurobiology, The Life Sciences Institute, The Hebrew University of Jerusalem Jerusalem, Israel
| | - Or A Shemesh
- Department of Neurobiology, The Life Sciences Institute, The Hebrew University of Jerusalem Jerusalem, Israel
| | - Micha E Spira
- Department of Neurobiology, The Life Sciences Institute, The Hebrew University of Jerusalem Jerusalem, Israel
| |
Collapse
|
30
|
Early structural and functional defects in synapses and myelinated axons in stratum lacunosum moleculare in two preclinical models for tauopathy. PLoS One 2014; 9:e87605. [PMID: 24498342 PMCID: PMC3912020 DOI: 10.1371/journal.pone.0087605] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 12/21/2013] [Indexed: 02/04/2023] Open
Abstract
The stratum lacunosum moleculare (SLM) is the connection hub between entorhinal cortex and hippocampus, two brain regions that are most vulnerable in Alzheimer's disease. We recently identified a specific synaptic deficit of Nectin-3 in transgenic models for tauopathy. Here we defined cognitive impairment and electrophysiological problems in the SLM of Tau.P301L mice, which corroborated the structural defects in synapses and dendritic spines. Reduced diffusion of DiI from the ERC to the hippocampus indicated defective myelinated axonal pathways. Ultrastructurally, myelinated axons in the temporoammonic pathway (TA) that connects ERC to CA1 were damaged in Tau.P301L mice at young age. Unexpectedly, the myelin defects were even more severe in bigenic biGT mice that co-express GSK3β with Tau.P301L in neurons. Combined, our data demonstrate that neuronal expression of protein Tau profoundly affected the functional and structural organization of the entorhinal-hippocampal complex, in particular synapses and myelinated axons in the SLM. White matter pathology deserves further attention in patients suffering from tauopathy and Alzheimer's disease.
Collapse
|
31
|
Hoffmann NA, Dorostkar MM, Blumenstock S, Goedert M, Herms J. Impaired plasticity of cortical dendritic spines in P301S tau transgenic mice. Acta Neuropathol Commun 2013; 1:82. [PMID: 24344647 PMCID: PMC3880070 DOI: 10.1186/2051-5960-1-82] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 11/01/2013] [Indexed: 12/02/2022] Open
Abstract
Background Illuminating the role of the microtubule-associated protein tau in neurodegenerative diseases is of increasing importance, supported by recent studies establishing novel functions of tau in synaptic signalling and cytoskeletal organization. In severe dementias like Alzheimer’s disease (AD), synaptic failure and cognitive decline correlate best with the grade of tau-pathology. To address synaptic alterations in tauopathies, we analyzed the effects of mutant tau expression on excitatory postsynapses in vivo. Results Here we followed the fate of single dendritic spines in the neocortex of a tauopathy mouse model, expressing human P301S mutated tau, for a period of two weeks. We observed a continuous decrease in spine density during disease progression, which we could ascribe to a diminished fraction of gained spines. Remaining spines were enlarged and elongated, thus providing evidence for morphological reorganization in compensation for synaptic dysfunction. Remarkably, loss of dendritic spines in cortical pyramidal neurons occurred in the absence of neurofibrillary tangles (NFTs). Therefore, we consider prefibrillar tau species as causative for the observed impairment in spine plasticity. Conclusions Dendritic spine plasticity and morphology are altered in layer V cortical neurons of P301S tau transgenic mice in vivo. This does not coincide with the detection of hyperphosphorylated tau in dendritic spines.
Collapse
|
32
|
Song JM, DiBattista AM, Sung YM, Ahn JM, Turner RS, Yang J, Pak DTS, Lee HK, Hoe HS. A tetra(ethylene glycol) derivative of benzothiazole aniline ameliorates dendritic spine density and cognitive function in a mouse model of Alzheimer's disease. Exp Neurol 2013; 252:105-13. [PMID: 24316432 DOI: 10.1016/j.expneurol.2013.11.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 10/25/2013] [Accepted: 11/22/2013] [Indexed: 11/19/2022]
Abstract
We recently reported that the tetra(ethylene glycol) derivative of benzothiazole aniline, BTA-EG4, acts as an amyloid-binding small molecule that promotes dendritic spine density and cognitive function in wild-type mice. This raised the possibility that BTA-EG4 may benefit the functional decline seen in Alzheimer's disease (AD). In the present study, we directly tested whether BTA-EG4 improves dendritic spine density and cognitive function in a well-established mouse model of AD carrying mutations in APP, PS1 and tau (APPswe;PS1M146V;tauP301L, 3xTg AD mice). We found that daily injections of BTA-EG4 for 2 weeks improved dendritic spine density and cognitive function of 3xTg AD mice in an age-dependent manner. Specifically, BTA-EG4 promoted both dendritic spine density and morphology alterations in cortical layers II/III and in the hippocampus at 6-10 months of age compared to vehicle-injected mice. However, at 13-16 months of age, only cortical spine density was improved without changes in spine morphology. The changes in dendritic spine density correlated with Ras activity, such that 6-10 month old BTA-EG4 injected 3xTg AD mice had increased Ras activity in the cortex and hippocampus, while 13-16 month old mice only trended toward an increase in Ras activity in the cortex. Finally, BTA-EG4 injected 3xTg AD mice at 6-10 months of age showed improved learning and memory; however, only minimal improvement was observed at 13-16 months of age. This behavioral improvement corresponds to a decrease in soluble Aβ 40 levels. Taken together, these findings suggest that BTA-EG4 may be beneficial in ameliorating the synaptic loss seen in early AD.
Collapse
Affiliation(s)
- Jung Min Song
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA
| | | | - You Me Sung
- College of Pharmacy, Seoul National University, South Korea
| | - Joo Myung Ahn
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA
| | - R Scott Turner
- Department of Neurology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Jerry Yang
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Daniel T S Pak
- Department of Pharmacology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Hey-Kyoung Lee
- Department of Neuroscience, Johns Hopkins University, Baltimore, MD 20218, USA; Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Hyang-Sook Hoe
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA; Department of Neurology, Georgetown University Medical Center, Washington, DC 20057, USA.
| |
Collapse
|
33
|
Kopeikina KJ, Polydoro M, Tai HC, Yaeger E, Carlson GA, Pitstick R, Hyman BT, Spires-Jones TL. Synaptic alterations in the rTg4510 mouse model of tauopathy. J Comp Neurol 2013; 521:1334-53. [PMID: 23047530 DOI: 10.1002/cne.23234] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 09/07/2012] [Accepted: 10/02/2012] [Indexed: 01/01/2023]
Abstract
Synapse loss, rather than the hallmark amyloid-β (Aβ) plaques or tau-filled neurofibrillary tangles (NFT), is considered the most predictive pathological feature associated with cognitive status in the Alzheimer's disease (AD) brain. The role of Aβ in synapse loss is well established, but despite data linking tau to synaptic function, the role of tau in synapse loss remains largely undetermined. Here we test the hypothesis that human mutant P301L tau overexpression in a mouse model (rTg4510) will lead to age-dependent synaptic loss and dysfunction. Using array tomography and two methods of quantification (automated, threshold-based counting and a manual stereology-based technique) we demonstrate that overall synapse density is maintained in the neuropil, implicating synapse loss commensurate with the cortical atrophy known to occur in this model. Multiphoton in vivo imaging reveals close to 30% loss of apical dendritic spines of individual pyramidal neurons, suggesting these cells may be particularly vulnerable to tau-induced degeneration. Postmortem, we confirm the presence of tau in dendritic spines of rTg4510-YFP mouse brain by array tomography. These data implicate tau-induced loss of a subset of synapses that may be accompanied by compensatory increases in other synaptic subtypes, thereby preserving overall synapse density. Biochemical fractionation of synaptosomes from rTg4510 brain demonstrates a significant decrease in expression of several synaptic proteins, suggesting a functional deficit of remaining synapses in the rTg4510 brain. Together, these data show morphological and biochemical synaptic consequences in response to tau overexpression in the rTg4510 mouse model.
Collapse
Affiliation(s)
- Katherine J Kopeikina
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Gendreau KL, Hall GF. Tangles, Toxicity, and Tau Secretion in AD - New Approaches to a Vexing Problem. Front Neurol 2013; 4:160. [PMID: 24151487 PMCID: PMC3801151 DOI: 10.3389/fneur.2013.00160] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 09/26/2013] [Indexed: 12/14/2022] Open
Abstract
When the microtubule (MT)-associated protein tau is not bound to axonal MTs, it becomes hyperphosphorylated and vulnerable to proteolytic cleavage and other changes typically seen in the hallmark tau deposits (neurofibrillary tangles) of tau-associated neurodegenerative diseases (tauopathies). Neurofibrillary tangle formation is preceded by tau oligomerization and accompanied by covalent crosslinking and cytotoxicity, making tangle cytopathogenesis a natural central focus of studies directed at understanding the role of tau in neurodegenerative disease. Recent studies suggest that the formation of tau oligomers may be more closely related to tau neurotoxicity than the presence of the tangles themselves. It has also become increasingly clear that tau pathobiology involves a wide variety of other cellular abnormalities including a disruption of autophagy, vesicle trafficking mechanisms, axoplasmic transport, neuronal polarity, and even the secretion of tau, which is normally a cytosolic protein, to the extracellular space. In this review, we discuss tau misprocessing, toxicity and secretion in the context of normal tau functions in developing and mature neurons. We also compare tau cytopathology to that of other aggregation-prone proteins involved in neurodegeneration (alpha synuclein, prion protein, and APP). Finally, we consider potential mechanisms of intra- and interneuronal tau lesion spreading, an area of particular recent interest.
Collapse
Affiliation(s)
- Kerry L Gendreau
- Department of Biological Sciences, University of Massachusetts Lowell , Lowell, MA , USA
| | | |
Collapse
|
35
|
Theunis C, Crespo-Biel N, Gafner V, Pihlgren M, López-Deber MP, Reis P, Hickman DT, Adolfsson O, Chuard N, Ndao DM, Borghgraef P, Devijver H, Van Leuven F, Pfeifer A, Muhs A. Efficacy and safety of a liposome-based vaccine against protein Tau, assessed in tau.P301L mice that model tauopathy. PLoS One 2013; 8:e72301. [PMID: 23977276 PMCID: PMC3747157 DOI: 10.1371/journal.pone.0072301] [Citation(s) in RCA: 176] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 07/09/2013] [Indexed: 11/19/2022] Open
Abstract
Progressive aggregation of protein Tau into oligomers and fibrils correlates with cognitive decline and synaptic dysfunction, leading to neurodegeneration in vulnerable brain regions in Alzheimer's disease. The unmet need of effective therapy for Alzheimer's disease, combined with problematic pharmacological approaches, led the field to explore immunotherapy, first against amyloid peptides and recently against protein Tau. Here we adapted the liposome-based amyloid vaccine that proved safe and efficacious, and incorporated a synthetic phosphorylated peptide to mimic the important phospho-epitope of protein Tau at residues pS396/pS404. We demonstrate that the liposome-based vaccine elicited, rapidly and robustly, specific antisera in wild-type mice and in Tau.P301L mice. Long-term vaccination proved to be safe, because it improved the clinical condition and reduced indices of tauopathy in the brain of the Tau.P301L mice, while no signs of neuro-inflammation or other adverse neurological effects were observed. The data corroborate the hypothesis that liposomes carrying phosphorylated peptides of protein Tau have considerable potential as safe and effective treatment against tauopathies, including Alzheimer's disease.
Collapse
Affiliation(s)
- Clara Theunis
- Experimental Genetics Group, Department Human Genetics, KU Leuven, Leuven, Belgium
| | - Natalia Crespo-Biel
- Experimental Genetics Group, Department Human Genetics, KU Leuven, Leuven, Belgium
| | | | | | | | | | | | | | | | | | - Peter Borghgraef
- Experimental Genetics Group, Department Human Genetics, KU Leuven, Leuven, Belgium
| | - Herman Devijver
- Experimental Genetics Group, Department Human Genetics, KU Leuven, Leuven, Belgium
| | - Fred Van Leuven
- Experimental Genetics Group, Department Human Genetics, KU Leuven, Leuven, Belgium
- * E-mail:
| | | | | |
Collapse
|
36
|
Maurin H, Lechat B, Dewachter I, Ris L, Louis JV, Borghgraef P, Devijver H, Jaworski T, Van Leuven F. Neurological characterization of mice deficient in GSK3α highlight pleiotropic physiological functions in cognition and pathological activity as Tau kinase. Mol Brain 2013; 6:27. [PMID: 23705847 PMCID: PMC3671145 DOI: 10.1186/1756-6606-6-27] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 05/22/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND GSK3β is involved in a wide range of physiological functions, and is presumed to act in the pathogenesis of neurological diseases, from bipolar disorder to Alzheimer's disease (AD). In contrast, the GSK3α isozyme remained largely ignored with respect to both aspects. RESULTS We generated and characterized two mouse strains with neuron-specific or with total GSK3α deficiency. Behavioral and electrophysiological analysis demonstrated the physiological importance of neuronal GSK3α, with GSK3β not compensating for impaired cognition and reduced LTP. Interestingly, the passive inhibitory avoidance task proved to modulate the phosphorylation status of both GSK3 isozymes in wild-type mice, further implying both to function in cognition. Moreover, GSK3α contributed to the neuronal architecture of the hippocampal CA1 sub-region that is most vulnerable in AD. Consequently, practically all parameters and characteristics indicated that both GSK3 isoforms were regulated independently, but that they acted on the same physiological functions in learning and memory, in mobility and in behavior. CONCLUSIONS GSK3α proved to be regulated independently from GSK3β, and to exert non-redundant physiological neurological functions in general behavior and in cognition. Moreover, GSK3α contributes to the pathological phosphorylation of protein Tau.
Collapse
Affiliation(s)
- Hervé Maurin
- Experimental Genetics Group - LEGTEGG, Department Human Genetics, KULeuven, B-3000, Leuven, Belgium
| | - Benoit Lechat
- Experimental Genetics Group - LEGTEGG, Department Human Genetics, KULeuven, B-3000, Leuven, Belgium
| | - Ilse Dewachter
- Experimental Genetics Group - LEGTEGG, Department Human Genetics, KULeuven, B-3000, Leuven, Belgium
| | - Laurence Ris
- Department Neurosciences, University Mons-Hainaut, B-7000, Mons, Belgium
| | - Justin V Louis
- Experimental Genetics Group - LEGTEGG, Department Human Genetics, KULeuven, B-3000, Leuven, Belgium
| | - Peter Borghgraef
- Experimental Genetics Group - LEGTEGG, Department Human Genetics, KULeuven, B-3000, Leuven, Belgium
| | - Herman Devijver
- Experimental Genetics Group - LEGTEGG, Department Human Genetics, KULeuven, B-3000, Leuven, Belgium
| | - Tomasz Jaworski
- Present address: Nencki Institute Experimental Biology, 3 Pasteur Street, 02-093, Warsaw, Poland
| | - Fred Van Leuven
- Experimental Genetics Group - LEGTEGG, Department Human Genetics, KULeuven, B-3000, Leuven, Belgium
| |
Collapse
|
37
|
Maurin H, Seymour CM, Lechat B, Borghgraef P, Devijver H, Jaworski T, Schmidt MV, Kuegler S, Van Leuven F. Tauopathy differentially affects cell adhesion molecules in mouse brain: early down-regulation of nectin-3 in stratum lacunosum moleculare. PLoS One 2013; 8:e63589. [PMID: 23704923 PMCID: PMC3660566 DOI: 10.1371/journal.pone.0063589] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 04/04/2013] [Indexed: 11/19/2022] Open
Abstract
Cell adhesion molecules are important structural substrates, required for synaptic plasticity and synaptogenesis. CAMs differ widely in their expression throughout different brain regions and their specific structural and functional roles in the brain remain to be elucidated. Here, we investigated selected cell adhesion molecules for alterations in expression levels and neuronal localization in validated mouse models for Alzheimer's disease that mimic the age-related progression of amyloid accumulation and tauopathy. Among the cell adhesion molecules analyzed, Nectin-3 expression was affected most and specifically in all mouse models with tauopathy. In particular was Nectin-3 depleted from the specific region of the hippocampus, known as the stratum lacunosum and moleculare, in mice that express wild-type or mutant human protein Tau, either chronically or sub-acutely. Tauopathy progresses from the entorhinal cortex to the hippocampus by unknown mechanisms that could involve transport by the myelinated axons of the temporoammonic and perforant pathways. The decreased expression of Nectin-3 in the stratum lacunosum moleculare is an early marker of impaired transport, and eventual synaptic problems, caused by beginning tauopathy.
Collapse
Affiliation(s)
- Hervé Maurin
- Experimental Genetics Group - LEGTEGG, Dept Human Genetics, KULeuven, Leuven, Belgium
| | - Claire Marie Seymour
- Experimental Genetics Group - LEGTEGG, Dept Human Genetics, KULeuven, Leuven, Belgium
| | - Benoit Lechat
- Experimental Genetics Group - LEGTEGG, Dept Human Genetics, KULeuven, Leuven, Belgium
| | - Peter Borghgraef
- Experimental Genetics Group - LEGTEGG, Dept Human Genetics, KULeuven, Leuven, Belgium
| | - Herman Devijver
- Experimental Genetics Group - LEGTEGG, Dept Human Genetics, KULeuven, Leuven, Belgium
| | - Tomasz Jaworski
- Experimental Genetics Group - LEGTEGG, Dept Human Genetics, KULeuven, Leuven, Belgium
| | | | | | - Fred Van Leuven
- Experimental Genetics Group - LEGTEGG, Dept Human Genetics, KULeuven, Leuven, Belgium
- * E-mail:
| |
Collapse
|
38
|
Nilsen LH, Rae C, Ittner LM, Götz J, Sonnewald U. Glutamate metabolism is impaired in transgenic mice with tau hyperphosphorylation. J Cereb Blood Flow Metab 2013; 33:684-91. [PMID: 23340677 PMCID: PMC3652703 DOI: 10.1038/jcbfm.2012.212] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In neurodegenerative diseases including Alzheimer's disease and frontotemporal dementia, the protein tau is hyperphosphorylated and eventually aggregates to develop neurofibrillary tangles. Here, the consequences of tau hyperphosphorylation on both neuronal and astrocytic metabolism and amino-acid neurotransmitter homeostasis were assessed in transgenic mice expressing the pathogenic mutation P301L in the human tau gene (pR5 mice) compared with nontransgenic littermate controls. Mice were injected with the neuronal and astrocytic substrate [1-(13)C]glucose and the astrocytic substrate [1,2-(13)C]acetate. Hippocampus and cerebral cortex extracts were analyzed using (1)H and (13)C nuclear magnetic resonance spectroscopy, gas chromatography-mass spectrometry and high-performance liquid chromatography. The glutamate level was reduced in the hippocampus of pR5 mice, accompanied by reduced incorporation of (13)C label derived from [1-(13)C]glucose in glutamate. In the cerebral cortex, glucose utilization as well as turnover of glutamate, glutamine, and GABA, were increased. This was accompanied by a relative increase in production of glutamate via the pyruvate carboxylation pathway in cortex. Overall, we revealed that astrocytes as well as glutamatergic and GABAergic neurons in the cortex of pR5 mice were in a hypermetabolic state, whereas in the hippocampus, where expression levels of mutant human tau are the highest, glutamate homeostasis was impaired.
Collapse
Affiliation(s)
- Linn Hege Nilsen
- Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | | | | | | | | |
Collapse
|
39
|
Crimins JL, Rocher AB, Luebke JI. Electrophysiological changes precede morphological changes to frontal cortical pyramidal neurons in the rTg4510 mouse model of progressive tauopathy. Acta Neuropathol 2012; 124:777-95. [PMID: 22976049 DOI: 10.1007/s00401-012-1038-9] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 08/20/2012] [Accepted: 08/21/2012] [Indexed: 12/14/2022]
Abstract
Whole-cell patch-clamp recordings and high-resolution morphometry were used to assess functional and structural properties of layer 3 pyramidal neurons in early (<4 months) and advanced (>8 months) stages of tauopathy in frontal cortical slices prepared from rTg4510 tau mutant (P301L) mice. In early tauopathy, dendritic architecture is preserved. In advanced tauopathy, neurons can be categorized as either "atrophic" (58 %)-exhibiting marked atrophy of the apical tuft, or "intact" (42 %)-with normal apical tufts and, in some instances, proliferative sprouting of oblique branches of the apical trunk. Approximately equal numbers of atrophic and intact neurons contain neurofibrillary tangles (NFTs) or are tangle-free, lending further support to the idea that NFTs per se are not toxic. Spine density is decreased due to a specific reduction in mushroom spines, but filopodia are increased in both atrophic and intact neurons. By contrast to these morphological changes, which are robust only in the advanced stage, significant electrophysiological changes are present in the early stage and persist in the advanced stage in both atrophic and intact neurons. The most marked of these changes are: a depolarized resting membrane potential, an increased depolarizing sag potential and increased action potential firing rates-all indicative of hyperexcitability. Spontaneous excitatory postsynaptic currents are not reduced in frequency or amplitude in either stage. The difference in the time course of functionally important electrophysiological changes versus regressive morphological changes implies differences in pathogenic mechanisms underlying functional and structural changes to neurons during progressive tauopathy.
Collapse
Affiliation(s)
- Johanna L Crimins
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118, USA
| | | | | |
Collapse
|
40
|
Human P301L-mutant tau expression in mouse entorhinal-hippocampal network causes tau aggregation and presynaptic pathology but no cognitive deficits. PLoS One 2012; 7:e45881. [PMID: 23029293 PMCID: PMC3454317 DOI: 10.1371/journal.pone.0045881] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 08/22/2012] [Indexed: 12/20/2022] Open
Abstract
Accumulation of hyperphosphorylated tau in the entorhinal cortex (EC) is one of the earliest pathological hallmarks in patients with Alzheimer’s disease (AD). It can occur before significant Aβ deposition and appears to “spread” into anatomically connected brain regions. To determine whether this early-stage pathology is sufficient to cause disease progression and cognitive decline in experimental models, we overexpressed mutant human tau (hTauP301L) predominantly in layer II/III neurons of the mouse EC. Cognitive functions remained normal in mice at 4, 8, 12 and 16 months of age, despite early and extensive tau accumulation in the EC. Perforant path (PP) axon terminals within the dentate gyrus (DG) contained abnormal conformations of tau even in young EC-hTau mice, and phosphorylated tau increased with age in both the EC and PP. In old mice, ultrastructural alterations in presynaptic terminals were observed at PP-to-granule cell synapses. Phosphorylated tau was more abundant in presynaptic than postsynaptic elements. Human and pathological tau was also detected within hippocampal neurons of this mouse model. Thus, hTauP301L accumulation predominantly in the EC and related presynaptic pathology in hippocampal circuits was not sufficient to cause robust cognitive deficits within the age range analyzed here.
Collapse
|
41
|
Abstract
Aggregation-prone proteins associated with neurodegenerative disease, such as α synuclein and β amyloid, now appear to share key prion-like features with mammalian prion protein, such as the ability to recruit normal proteins to aggregates and to translocate between neurons. These features may shed light on the genesis of stereotyped lesion development patterns in conditions such as Alzheimer disease and Lewy Body dementia. We discuss the qualifications of tau protein as a possible "prionoid" mediator of lesion spread based on recent characterizations of the secretion, uptake and transneuronal transfer of human tau isoforms in a variety of tauopathy models, and in human patients. In particular, we consider (1) the possibility that prionoid behavior of misprocessed tau in neurodegenerative disease may involve other aggregation-prone proteins, including PrP itself, and (2) whether "prionlike" tau lesion propagation might include mechanisms other than protein-protein templating.
Collapse
Affiliation(s)
- Garth F Hall
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, USA.
| | | |
Collapse
|
42
|
Crespo-Biel N, Theunis C, Van Leuven F. Protein tau: prime cause of synaptic and neuronal degeneration in Alzheimer's disease. Int J Alzheimers Dis 2012; 2012:251426. [PMID: 22720188 PMCID: PMC3376502 DOI: 10.1155/2012/251426] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 03/16/2012] [Indexed: 12/02/2022] Open
Abstract
The microtubule-associated protein Tau (MAPT) is a major component of the pathogenesis of a wide variety of brain-damaging disorders, known as tauopathies. These include Alzheimer's disease (AD), denoted as secondary tauopathy because of the obligatory combination with amyloid pathology. In all tauopathies, protein Tau becomes aberrantly phosphorylated, adopts abnormal conformations, and aggregates into fibrils that eventually accumulate as threads in neuropil and as tangles in soma. The argyrophilic neurofibrillary threads and tangles, together denoted as NFT, provide the postmortem pathological diagnosis for all tauopathies. In AD, neurofibrillary threads and tangles (NFTs) are codiagnostic with amyloid depositions but their separated and combined contributions to clinical symptoms remain elusive. Importantly, NFTs are now considered a late event and not directly responsible for early synaptic dysfunctions. Conversely, the biochemical and pathological timeline is not exactly known in human tauopathy, but experimental models point to smaller Tau-aggregates, termed oligomers or multimers, as synaptotoxic in early stages. The challenge is to molecularly define these Tau-isoforms that cause early cognitive and synaptic impairments. Here, we discuss relevant studies and data obtained in our mono- and bigenic validated preclinical models, with the perspective of Tau as a therapeutic target.
Collapse
Affiliation(s)
| | | | - Fred Van Leuven
- Experimental Genetics Group (LEGTEGG), Department of Human Genetics, KU Leuven, Campus Gasthuisberg ON1-06.602, Herestraat 49, 3000 Leuven, Belgium
| |
Collapse
|
43
|
Van der Jeugd A, Hochgräfe K, Ahmed T, Decker JM, Sydow A, Hofmann A, Wu D, Messing L, Balschun D, D'Hooge R, Mandelkow EM. Cognitive defects are reversible in inducible mice expressing pro-aggregant full-length human Tau. Acta Neuropathol 2012; 123:787-805. [PMID: 22532069 PMCID: PMC4979687 DOI: 10.1007/s00401-012-0987-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 03/20/2012] [Accepted: 04/12/2012] [Indexed: 01/19/2023]
Abstract
Neurofibrillary lesions of abnormal Tau are hallmarks of Alzheimer disease and frontotemporal dementias. Our regulatable (Tet-OFF) mouse models of tauopathy express variants of human full-length Tau in the forebrain (CaMKIIα promoter) either with mutation ΔK280 (pro-aggregant) or ΔK280/I277P/I308P (anti-aggregant). Co-expression of luciferase enables in vivo quantification of gene expression by bioluminescence imaging. Pro-aggregant mice develop synapse loss and Tau-pathology including missorting, phosphorylation and early pretangle formation, whereas anti-aggregant mice do not. We correlated hippocampal Tau pathology with learning/memory performance and synaptic plasticity. Pro-aggregant mice at 16 months of gene expression exhibited severe cognitive deficits in Morris water maze and in passive-avoidance paradigms, whereas anti-aggregant mice were comparable to controls. Cognitive impairment of pro-aggregant mice was accompanied by loss of hippocampal LTP in CA1 and CA3 areas and by a reduction of synaptic proteins and dendritic spines, although no neuronal loss was observed. Remarkably, memory and LTP recovered when pro-aggregant Tau was switched-OFF for ~4 months, Tau phosphorylation and missorting were reversed, and synapses recovered. Moreover, soluble and insoluble pro-aggregant hTau40 disappeared, while insoluble mouse Tau was still present. This study links early Tau pathology without neurofibrillary tangles and neuronal death to cognitive decline and synaptic dysfunction. It demonstrates that Tau-induced impairments are reversible after switching-OFF pro-aggregant Tau. Therefore, our mouse model may mimic an early phase of AD when the hippocampus does not yet suffer from irreversible cell death but cognitive deficits are already striking. It offers potential to evaluate drugs with regard to learning and memory performance.
Collapse
Affiliation(s)
- Ann Van der Jeugd
- Laboratory of Biological Psychology, Dept. Psychology, K.U.Leuven, Tiensestraat 102, 3000 Leuven, Belgium
| | - Katja Hochgräfe
- DZNE (German Center for Neurodegenerative Diseases) and CAESAR Research Center, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Tariq Ahmed
- Laboratory of Biological Psychology, Dept. Psychology, K.U.Leuven, Tiensestraat 102, 3000 Leuven, Belgium
| | - Jochen M. Decker
- DZNE (German Center for Neurodegenerative Diseases) and CAESAR Research Center, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Astrid Sydow
- Max-Planck-Institute for Neurological Research, Gleuelerstr. 50, 50931 Cologne, Germany
| | - Anne Hofmann
- Max-Planck-Institute for Neurological Research, Gleuelerstr. 50, 50931 Cologne, Germany
| | - Dan Wu
- DZNE (German Center for Neurodegenerative Diseases) and CAESAR Research Center, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
- Max-Planck-Institute for Neurological Research, Gleuelerstr. 50, 50931 Cologne, Germany
| | - Lars Messing
- DZNE (German Center for Neurodegenerative Diseases) and CAESAR Research Center, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Detlef Balschun
- Laboratory of Biological Psychology, Dept. Psychology, K.U.Leuven, Tiensestraat 102, 3000 Leuven, Belgium
| | - Rudi D'Hooge
- Laboratory of Biological Psychology, Dept. Psychology, K.U.Leuven, Tiensestraat 102, 3000 Leuven, Belgium
| | - Eva-Maria Mandelkow
- DZNE (German Center for Neurodegenerative Diseases) and CAESAR Research Center, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
- Max-Planck-Institute for Neurological Research, Gleuelerstr. 50, 50931 Cologne, Germany
| |
Collapse
|
44
|
Abstract
Accumulation of neurofibrillary tangles (NFT), intracellular inclusions of fibrillar forms of tau, is a hallmark of Alzheimer Disease. NFT have been considered causative of neuronal death, however, recent evidence challenges this idea. Other species of tau, such as soluble misfolded, hyperphosphorylated, and mislocalized forms, are now being implicated as toxic. Here we review the data supporting soluble tau as toxic to neurons and synapses in the brain and the implications of these data for development of therapeutic strategies for Alzheimer's disease and other tauopathies.
Collapse
|