1
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Nuñez-Diaz C, Andersson E, Schultz N, Pocevičiūtė D, Hansson O, Nilsson KPR, Wennström M. The fluorescent ligand bTVBT2 reveals increased p-tau uptake by retinal microglia in Alzheimer's disease patients and App NL-F/NL-F mice. Alzheimers Res Ther 2024; 16:4. [PMID: 38167557 PMCID: PMC10763304 DOI: 10.1186/s13195-023-01375-7] [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: 07/16/2023] [Accepted: 12/24/2023] [Indexed: 01/05/2024]
Abstract
BACKGROUND Amyloid beta (Aβ) deposits and hyperphosphorylated tau (p-tau) accumulation have been identified in the retina of Alzheimer's disease (AD) patients and transgenic AD mice. Previous studies have shown that retinal microglia engulf Aβ, but this property decreases in AD patients. Whether retinal microglia also take up p-tau and if this event is affected in AD is yet not described. In the current study, we use the p-tau-specific thiophene-based ligand bTVBT2 to investigate the relationship between disease progression and p-tau uptake by microglia in the retina of AD patients and AppNL-F/NL-F knock-in mice, an AD mouse model known to demonstrate extracellular Aβ plaques and dystrophic neurites in the brain from 6 months of age. METHODS Evaluation of bTVBT2 specificity and its presence within microglia was assessed by immunofluorescent staining of hippocampal sections and flat-mount retina samples from non-demented controls, AD patients, 3-, 9-, and 12-month-old AppNL-F/NL-F knock-in mice and 12- and 18-month-old wild type (WT) mice. We used ImageJ to analyze the amount of bTVBT2 inside Iba1-positive microglia. Co-localization between the ligand and p-tau variant Ser396/Ser404 (PHF-1), Aβ, phosphorylated TAR DNA binding protein 43 (pTDP-43), and islet amyloid polypeptide (IAPP) in the brain and retina was analyzed using confocal imaging. RESULTS Confocal imaging analysis showed that bTVBT2 binds to PHF-1- and AT8-positive aggregates inside retinal microglia, and not to Aβ, pTDP-43, or IAPP. The density of bTVBT2-positive microglia was higher in cases with a high Aβ load compared to those with a low Aβ load. This density correlated with the neurofibrillary tangle load in the brain, but not with retinal levels of high molecular weight (aggregated) Aβ40 or Aβ42. Analysis of AppNL-F/NL-F knock-in mouse retina further showed that 50% of microglia in 3-month-old AppNL-F/NL-F knock-in mice contained bTVBT2. The percentage significantly increased in 9- and 12-month-old mice. CONCLUSION Our study suggests that the microglial capability to uptake p-tau in the retina persists and intensifies with AD progression. These results also highlight bTVBT2 as a ligand of interest in future monitoring of retinal AD pathology.
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Affiliation(s)
- Cristina Nuñez-Diaz
- Cognitive Disorder Research Unit, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Emelie Andersson
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Nina Schultz
- Cognitive Disorder Research Unit, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Dovilė Pocevičiūtė
- Cognitive Disorder Research Unit, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Oskar Hansson
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
- Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - K Peter R Nilsson
- Department of Physics, Chemistry and Biology IFM, Linköping University, 581 83, Linköping, Sweden
| | - Malin Wennström
- Cognitive Disorder Research Unit, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden.
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2
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Wu CY, Chen HJ, Wu YC, Tsai SW, Liu YH, Bhattacharya U, Lin D, Tai HC, Kong KV. Highly Efficient Singlet Oxygen Generation by BODIPY-Ruthenium(II) Complexes for Promoting Neurite Outgrowth and Suppressing Tau Protein Aggregation. Inorg Chem 2023; 62:1102-1112. [PMID: 36622931 DOI: 10.1021/acs.inorgchem.2c03017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Singlet oxygen (1O2) has been recently identified as a key molecule against toxic Aβ aggregation, which is associated with the currently incurable Alzheimer's disease (AD). However, limited research has studied its efficiency against tau protein aggregation, the other major hallmark of AD. Herein, we designed and synthesized boron-dipyrromethene (BODIPY)-ruthenium conjugates and isolated three isomers. Under visible-light irradiation, the ε isomer can be photoactivated and efficiently generate singlet oxygen. Particularly, the complex demonstrated successful results in attenuating tauopathy─an appreciable decrease to 43 ± 2% at 100 nM. The photosensitizer was further found to remarkably promote neurite outgrowth and significantly increased the length and number of neurites in nerve cells. As a result of effective photoinduced singlet oxygen generation and proactive neurite outgrowth, the hybrid design has great potential for therapeutics for Alzheimer's disease.
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Affiliation(s)
- Cheng-Yun Wu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Hsin-Jou Chen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Yun-Chin Wu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Shu-Wei Tsai
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Yi-Hung Liu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | | | - Duo Lin
- Key Laboratory of OptoElectronic Science and Technology for Medicine, Ministry of Education, Fujian Provincial Key Laboratory for Photonics Technology, Digital Fujian Internet-of-Things Laboratory of Environment Monitoring, Fujian Normal University, Fuzhou 350007, China
| | - Hwan-Ching Tai
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Kien Voon Kong
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
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3
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Tau aggregation and its relation to selected forms of neuronal cell death. Essays Biochem 2021; 65:847-857. [PMID: 34897457 PMCID: PMC8709892 DOI: 10.1042/ebc20210030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/17/2021] [Accepted: 11/17/2021] [Indexed: 12/12/2022]
Abstract
How neurons die in neurodegenerative diseases is still unknown. The distinction between apoptosis as a genetically controlled mechanism, and necrosis, which was viewed as an unregulated process, has blurred with the ever-increasing number of necrotic-like death subroutines underpinned by genetically defined pathways. It is therefore pertinent to ask whether any of them apply to neuronal cell death in tauopathies. Although Alzheimer's disease (AD) is the most prevalent tauopathy, tauopathies comprise an array of over 30 diseases in which the cytoplasmic protein tau aggregates in neurons, and also, in some diseases, in glia. Animal models have sought to distil the contribution of tau aggregation to the cell death process but despite intensive research, no one mechanism of cell death has been unequivocally defined. The process of tau aggregation, and the fibrillar structures that form, touch on so many cellular functions that there is unlikely to be a simple linear pathway of death; as one is blocked another is likely to take the lead. It is timely to ask how far we have advanced into defining whether any of the molecular players in the new death subroutines participate in the death process. Here we briefly review the currently known cell death routines and explore what is known about their participation in tau aggregation-related cell death. We highlight the involvement of cell autonomous and the more recent non-cell autonomous pathways that may enhance tau-aggregate toxicity, and discuss recent findings that implicate microglial phagocytosis of live neurons with tau aggregates as a mechanism of death.
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4
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Brelstaff JH, Mason M, Katsinelos T, McEwan WA, Ghetti B, Tolkovsky AM, Spillantini MG. Microglia become hypofunctional and release metalloproteases and tau seeds when phagocytosing live neurons with P301S tau aggregates. SCIENCE ADVANCES 2021; 7:eabg4980. [PMID: 34669475 PMCID: PMC8528424 DOI: 10.1126/sciadv.abg4980] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 08/26/2021] [Indexed: 05/03/2023]
Abstract
The microtubule-associated protein tau aggregates in multiple neurodegenerative diseases, causing inflammation and changing the inflammatory signature of microglia by unknown mechanisms. We have shown that microglia phagocytose live neurons containing tau aggregates cultured from P301S tau mice due to neuronal tau aggregate-induced exposure of the “eat me” signal phosphatidylserine. Here, we show that after phagocytosing tau aggregate-bearing neurons, microglia become hypophagocytic while releasing seed-competent insoluble tau aggregates. These microglia express a senescence-like phenotype, demonstrated by acidic β-galactosidase activity, secretion of paracrine senescence-associated cytokines, and maturation of matrix remodeling enzymes, results that are corroborated in P301S mouse brains and ex vivo brain slices. In particular, the nuclear factor κB–dependent activation of matrix metalloprotease 3 (MMP3/stromelysin1) was replicated in brains from patients with tauopathy. These data show that microglia that have been activated to ingest live tau aggregates-bearing neurons behave hormetically, becoming hypofunctional while acting as vectors of tau aggregate spreading.
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Affiliation(s)
- Jack H. Brelstaff
- Department of Clinical Neurosciences, Clifford Allbutt Building, University of Cambridge, Cambridge CB2 0AH, UK
| | - Matthew Mason
- Department of Clinical Neurosciences, Clifford Allbutt Building, University of Cambridge, Cambridge CB2 0AH, UK
| | - Taxiarchis Katsinelos
- Department of Clinical Neurosciences, Clifford Allbutt Building, University of Cambridge, Cambridge CB2 0AH, UK
- UK Dementia Research Institute Cambridge, Island Research Building, University of Cambridge, Cambridge CB2 0AH, UK
| | - William A. McEwan
- Department of Clinical Neurosciences, Clifford Allbutt Building, University of Cambridge, Cambridge CB2 0AH, UK
- UK Dementia Research Institute Cambridge, Island Research Building, University of Cambridge, Cambridge CB2 0AH, UK
| | - Bernardino Ghetti
- Department of Pathology and Laboratory Medicine, Indiana University, Indianapolis, IN, USA
| | - Aviva M. Tolkovsky
- Department of Clinical Neurosciences, Clifford Allbutt Building, University of Cambridge, Cambridge CB2 0AH, UK
| | - Maria Grazia Spillantini
- Department of Clinical Neurosciences, Clifford Allbutt Building, University of Cambridge, Cambridge CB2 0AH, UK
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5
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McMurray L, Macdonald JA, Ramakrishnan NK, Zhao Y, Williamson DW, Tietz O, Zhou X, Kealey S, Fagan SG, Smolek T, Cubinkova V, Žilka N, Spillantini MG, Tolkovsky AM, Goedert M, Aigbirhio FI. Synthesis and Assessment of Novel Probes for Imaging Tau Pathology in Transgenic Mouse and Rat Models. ACS Chem Neurosci 2021; 12:1885-1893. [PMID: 33689290 PMCID: PMC8176454 DOI: 10.1021/acschemneuro.0c00790] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Aggregated tau protein is a core pathology present in several neurodegenerative diseases. Therefore, the development and application of positron emission tomography (PET) imaging radiotracers that selectively bind to aggregated tau in fibril form is of importance in furthering the understanding of these disorders. While radiotracers used in human PET studies offer invaluable insight, radiotracers that are also capable of visualizing tau fibrils in animal models are important tools for translational research into these diseases. Herein, we report the synthesis and characterization of a novel library of compounds based on the phenyl/pyridinylbutadienylbenzothiazoles/benzothiazolium (PBB3) backbone developed for this application. From this library, we selected the compound LM229, which binds to recombinant tau fibrils with high affinity (Kd = 3.6 nM) and detects with high specificity (a) pathological 4R tau aggregates in living cultured neurons and mouse brain sections from transgenic human P301S tau mice, (b) truncated human 151-351 3R (SHR24) and 4R (SHR72) tau aggregates in transgenic rat brain sections, and (c) tau neurofibrillary tangles in brain sections from Alzheimer's disease (3R/4R tau) and progressive supranuclear palsy (4R tau). With LM229 also shown to cross the blood-brain barrier in vivo and its effective radiolabeling with the radioisotope carbon-11, we have established a novel platform for PET translational studies using rodent transgenic tau models.
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Affiliation(s)
- Lindsay McMurray
- Molecular Imaging Chemistry Laboratory, Wolfson Brain Imaging Centre, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | | | - Nisha Kuzhuppilly Ramakrishnan
- Molecular Imaging Chemistry Laboratory, Wolfson Brain Imaging Centre, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - Yanyan Zhao
- Molecular Imaging Chemistry Laboratory, Wolfson Brain Imaging Centre, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - David W. Williamson
- Molecular Imaging Chemistry Laboratory, Wolfson Brain Imaging Centre, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - Ole Tietz
- Molecular Imaging Chemistry Laboratory, Wolfson Brain Imaging Centre, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - Xiaoyun Zhou
- Molecular Imaging Chemistry Laboratory, Wolfson Brain Imaging Centre, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - Steven Kealey
- Molecular Imaging Chemistry Laboratory, Wolfson Brain Imaging Centre, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - Steven G. Fagan
- Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - Tomáš Smolek
- Axon Neuroscience R&D Services SE, Bratislava, Slovak Republic 811 02
| | | | - Norbert Žilka
- Axon Neuroscience R&D Services SE, Bratislava, Slovak Republic 811 02
| | - Maria Grazia Spillantini
- Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - Aviva M. Tolkovsky
- Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - Michel Goedert
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Franklin I. Aigbirhio
- Molecular Imaging Chemistry Laboratory, Wolfson Brain Imaging Centre, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
- Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
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6
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Stepanchuk A, Tahir W, Nilsson KPR, Schatzl HM, Stys PK. Early detection of prion protein aggregation with a fluorescent pentameric oligothiophene probe using spectral confocal microscopy. J Neurochem 2020; 156:1033-1048. [PMID: 32799317 DOI: 10.1111/jnc.15148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/14/2020] [Accepted: 07/31/2020] [Indexed: 11/30/2022]
Abstract
Misfolding of the prion protein (PrP) and templating of its pathological conformation onto cognate proteins causes a number of lethal disorders of central nervous system in humans and animals, such as Creutzfeldt-Jacob disease, chronic wasting disease and bovine spongiform encephalopathy. Structural rearrangement of PrPC into PrPSc promotes aggregation of misfolded proteins into β-sheet-rich fibrils, which can be visualized by conformationally sensitive fluorescent probes. Early detection of prion misfolding and deposition might provide useful insights into its pathophysiology. Pentameric formyl thiophene acetic acid (pFTAA) is a novel amyloid probe that was shown to sensitively detect various misfolded proteins, including PrP. Here, we compared sensitivity of pFTAA staining and spectral microscopy with conventional methods of prion detection in mouse brains infected with mouse-adapted 22L prions. pFTAA bound to prion deposits in mouse brain sections exhibited a red-shifted fluorescence emission spectrum, which quantitatively increased with disease progression. Small prion deposits were detected as early as 50 days post-inoculation, well before appearance of clinical signs. Moreover, we detected significant spectral shifts in the greater brain parenchyma as early as 25 days post-inoculation, rivaling the most sensitive conventional method (real-time quaking-induced conversion). These results showcase the potential of pFTAA staining combined with spectral imaging for screening of prion-infected tissue. Not only does this method have comparable sensitivity to established techniques, it is faster and technically simpler. Finally, this readout provides valuable information about the spatial distribution of prion aggregates across tissue in the earliest stages of infection, potentially providing valuable pathophysiological insight into prion transmission.
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Affiliation(s)
- Anastasiia Stepanchuk
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Waqas Tahir
- Calgary Prion Research Unit, Department of Comparative Biology & Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - K Peter R Nilsson
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Hermann M Schatzl
- Calgary Prion Research Unit, Department of Comparative Biology & Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - Peter K Stys
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
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7
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Brelstaff J, Tolkovsky AM, Ghetti B, Goedert M, Spillantini MG. Living Neurons with Tau Filaments Aberrantly Expose Phosphatidylserine and Are Phagocytosed by Microglia. Cell Rep 2020; 24:1939-1948.e4. [PMID: 30134156 PMCID: PMC6161320 DOI: 10.1016/j.celrep.2018.07.072] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 05/23/2018] [Accepted: 07/21/2018] [Indexed: 10/28/2022] Open
Abstract
Tau protein forms insoluble filamentous inclusions that are closely associated with nerve cell death in many neurodegenerative diseases. How neurons die in these tauopathies is unclear. We report that living neurons with tau inclusions from P301S-tau mice expose abnormally high amounts of phosphatidylserine because of the production of reactive oxygen species (ROS). Consequently, co-cultured phagocytes (BV2 cells or primary microglia) identify and phagocytose the living neurons, thereby engulfing insoluble tau inclusions. To facilitate engulfment, neurons induce contacting microglia to secrete the opsonin milk-fat-globule EGF-factor-8 (MFGE8) and nitric oxide (NO), whereas neurons with tau inclusions are rescued when MFGE8 or NO production is prevented. MFGE8 expression is elevated in transgenic P301S-tau mouse brains with tau inclusions and in tau inclusion-rich brain regions of several human tauopathies, indicating shared mechanisms of disease. Preventing phagocytosis of living neurons will preserve them for treatments that inhibit tau aggregation and toxicity.
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Affiliation(s)
- Jack Brelstaff
- Department of Clinical Neurosciences, Clifford Allbutt Building, University of Cambridge, Cambridge, CB2 0AH, UK
| | - Aviva M Tolkovsky
- Department of Clinical Neurosciences, Clifford Allbutt Building, University of Cambridge, Cambridge, CB2 0AH, UK.
| | - Bernardino Ghetti
- Department of Pathology and Laboratory Medicine, Indiana University, Indianapolis, IN, USA
| | - Michel Goedert
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Maria Grazia Spillantini
- Department of Clinical Neurosciences, Clifford Allbutt Building, University of Cambridge, Cambridge, CB2 0AH, UK.
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8
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Whiten DR, Zuo Y, Calo L, Choi M, De S, Flagmeier P, Wirthensohn DC, Kundel F, Ranasinghe RT, Sanchez SE, Athauda D, Lee SF, Dobson CM, Gandhi S, Spillantini M, Klenerman D, Horrocks MH. Nanoscopic Characterisation of Individual Endogenous Protein Aggregates in Human Neuronal Cells. Chembiochem 2018; 19:2033-2038. [PMID: 30051958 PMCID: PMC6220870 DOI: 10.1002/cbic.201800209] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 07/08/2018] [Indexed: 11/25/2022]
Abstract
The aberrant misfolding and subsequent conversion of monomeric protein into amyloid aggregates characterises many neurodegenerative disorders, including Parkinson's and Alzheimer's diseases. These aggregates are highly heterogeneous in structure, generally of low abundance and typically smaller than the diffraction limit of light (≈250 nm). To overcome the challenges these characteristics pose to the study of endogenous aggregates formed in cells, we have developed a method to characterise them at the nanometre scale without the need for a conjugated fluorophore. Using a combination of DNA PAINT and an amyloid-specific aptamer, we demonstrate that this technique is able to detect and super-resolve a range of aggregated species, including those formed by α-synuclein and amyloid-β. Additionally, this method enables endogenous protein aggregates within cells to be characterised. We found that neuronal cells derived from patients with Parkinson's disease contain a larger number of protein aggregates than those from healthy controls.
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Affiliation(s)
- Daniel R. Whiten
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Yukun Zuo
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Laura Calo
- Department of Clinical NeurosciencesUniversity of CambridgeHills RoadCambridgeCB2 0AHUK
| | | | - Suman De
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Patrick Flagmeier
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | | | - Franziska Kundel
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Rohan T. Ranasinghe
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Santiago E. Sanchez
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Dilan Athauda
- UCL Institute of NeurologyQueen SquareLondonWC1N 3BGUK
| | - Steven F. Lee
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | | | - Sonia Gandhi
- UCL Institute of NeurologyQueen SquareLondonWC1N 3BGUK
| | | | - David Klenerman
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
- UK Dementia Research InstituteUniversity of CambridgeCambridgeCB2 0XYUK
| | - Mathew H. Horrocks
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
- Present addresses: EaStCHEM School of ChemistryUniversity of EdinburghDavid Brewster RoadEdinburghEH9 3FJUK
- UK Dementia Research InstituteUniversity of EdinburghEdinburghUK
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9
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Taylor C, Meisl G, Horrocks MH, Zetterberg H, Knowles TPJ, Klenerman D. Extrinsic Amyloid-Binding Dyes for Detection of Individual Protein Aggregates in Solution. Anal Chem 2018; 90:10385-10393. [PMID: 30059210 PMCID: PMC6127805 DOI: 10.1021/acs.analchem.8b02226] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 07/30/2018] [Indexed: 01/23/2023]
Abstract
Protein aggregation is a key molecular feature underlying a wide array of neurodegenerative disorders, including Alzheimer's and Parkinson's diseases. To understand protein aggregation in molecular detail, it is crucial to be able to characterize the array of heterogeneous aggregates that are formed during the aggregation process. We present here a high-throughput method to detect single protein aggregates, in solution, from a label-free aggregation reaction, and we demonstrate the approach with the protein associated with Parkinson's disease, α-synuclein. The method combines single-molecule confocal microscopy with a range of amyloid-binding extrinsic dyes, including thioflavin T and pentameric formylthiophene acetic acid, and we show that we can observe aggregates at low picomolar concentrations. The detection of individual aggregates allows us to quantify their numbers. Furthermore, we show that this approach also allows us to gain structural insights from the emission intensity of the extrinsic dyes that are bound to aggregates. By analyzing the time evolution of the aggregate populations on a single-molecule level, we then estimate the fragmentation rate of aggregates, a key process that underlies the multiplication of pathological aggregates. We additionally demonstrate that the method permits the detection of these aggregates in biological samples. The capability to detect individual protein aggregates in solution opens up a range of new applications, including exploiting the potential of this method for high-throughput screening of human biofluids for disease diagnosis and early detection.
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Affiliation(s)
- Christopher
G. Taylor
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United
Kingdom
| | - Georg Meisl
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United
Kingdom
| | - Mathew H. Horrocks
- EaStCHEM
School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
- U.K.
Dementia Research Institute, University
of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Henrik Zetterberg
- Clinical
Neurochemistry Laboratory, Department of Psychiatry and Neurochemistry,
Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Mölndal 413 45, Sweden
- Sobell
Department of Motor Neuroscience and Movement Disorders, UCL Institute
of Neurology, University College London, Queen Square, London WC1N 3BG, United
Kingdom
| | - Tuomas P. J. Knowles
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United
Kingdom
- Cavendish
Laboratory, Department of Physics, University
of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - David Klenerman
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United
Kingdom
- U.K.
Dementia Research Institute, University
of Cambridge, Cambridge CB2 0XY, United Kingdom
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10
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Kundel F, Tosatto L, Whiten DR, Wirthensohn DC, Horrocks MH, Klenerman D. Shedding light on aberrant interactions - a review of modern tools for studying protein aggregates. FEBS J 2018; 285:3604-3630. [PMID: 29453901 DOI: 10.1111/febs.14409] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/27/2018] [Accepted: 02/12/2018] [Indexed: 12/15/2022]
Abstract
The link between protein aggregation and neurodegenerative disease is well established. However, given the heterogeneity of species formed during the aggregation process, it is difficult to delineate details of the molecular events involved in generating pathological aggregates from those producing soluble monomers. As aberrant aggregates are possible pharmacological targets for the treatment of neurodegenerative diseases, the need to observe and characterise soluble oligomers has pushed traditional biophysical techniques to their limits, leading to the development of a plethora of new tools capable of detecting soluble oligomers with high precision and specificity. In this review, we discuss a range of modern biophysical techniques that have been developed to study protein aggregation, and give an overview of how they have been used to understand, in detail, the aberrant aggregation of amyloidogenic proteins associated with the two most common neurodegenerative disorders, Alzheimer's disease and Parkinson's disease.
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Affiliation(s)
| | - Laura Tosatto
- Centre for Integrative Biology, Università degli Studi di Trento, Italy
| | | | | | | | - David Klenerman
- Department of Chemistry, University of Cambridge, UK.,UK Dementia Research Institute, University of Cambridge, UK
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11
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Abstract
Tau misfolding is a major cause of neurodegeneration, tauopathies being a growing group of diseases in which tau forms insoluble aggregates, best known in Alzheimer disease as neurofibrillary tangles (NFTs). Many transgenic mouse models of tauopathies have been generated, but it has been difficult to demonstrate disease in primary brain neurons from these mice because neurons need to be harvested within a few days of birth and tau fails to produce NFTs. Transgenic mice have been generated that express the 0N4R isoform of human tau mutated at amino acid 301 (P301S mice) under the Thy1.2 promoter. These mice, which model an inherited form of frontotemporal dementia, develop NFTs around 5 months of age. Taking advantage of the fact that Thy1.2 is expressed in the peripheral nervous system, we found that dorsal root ganglion (DRG) neurons express P301S tau and develop tau pathology along a similar time course to that found in central nervous system neurons in mice. Thus, NFTs are well-developed around 5 months of age. Because DRG neurons can be cultured from adult mice for months, they have proven to be an excellent model for studying how tau pathology develops and for screening compounds that may ameliorate tau pathology. Here we present a detailed protocol for the preparation of long-term DRG neuron cultures and describe how to study whether activation of autophagy ameliorates tau pathology.
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12
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Zha GB, Shen M, Gu XS, Yi S. Changes in microtubule-associated protein tau during peripheral nerve injury and regeneration. Neural Regen Res 2016; 11:1506-1511. [PMID: 27857758 PMCID: PMC5090857 DOI: 10.4103/1673-5374.191227] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Tau, a primary component of microtubule-associated protein, promotes microtubule assembly and/or disassembly and maintains the stability of the microtubule structure. Although the importance of tau in neurodegenerative diseases has been well demonstrated, whether tau is involved in peripheral nerve regeneration remains unknown. In the current study, we obtained sciatic nerve tissue from adult rats 0, 1, 4, 7, and 14 days after sciatic nerve crush and examined tau mRNA and protein expression levels and the location of tau in the sciatic nerve following peripheral nerve injury. The results from our quantitative reverse transcription polymerase chain reaction analysis showed that compared with the uninjured control sciatic nerve, mRNA expression levels for both tau and tau tubulin kinase 1, a serine/threonine kinase that regulates tau phosphorylation, were decreased following peripheral nerve injury. Our western blot assay results suggested that the protein expression levels of tau and phosphorylated tau initially decreased 1 day post nerve injury but then gradually increased. The results of our immunohistochemical labeling showed that the location of tau protein was not altered by nerve injury. Thus, these results showed that the expression of tau was changed following sciatic nerve crush, suggesting that tau may be involved in peripheral nerve repair and regeneration.
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Affiliation(s)
- Guang-Bin Zha
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Mi Shen
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Xiao-Song Gu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Sheng Yi
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
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