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Schwehr BJ, Hartnell D, Ellison G, Hindes MT, Milford B, Dallerba E, Hickey SM, Pfeffer FM, Brooks DA, Massi M, Hackett MJ. Fluorescent probes for neuroscience: imaging ex vivo brain tissue sections. Analyst 2024. [PMID: 39171617 DOI: 10.1039/d4an00663a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
Neurobiological research relies heavily on imaging techniques, such as fluorescence microscopy, to understand neurological function and disease processes. However, the number and variety of fluorescent probes available for ex vivo tissue section imaging limits the advance of research in the field. In this review, we outline the current range of fluorescent probes that are available to researchers for ex vivo brain section imaging, including their physical and chemical characteristics, staining targets, and examples of discoveries for which they have been used. This review is organised into sections based on the biological target of the probe, including subcellular organelles, chemical species (e.g., labile metal ions), and pathological phenomenon (e.g., degenerating cells, aggregated proteins). We hope to inspire further development in this field, given the considerable benefits to be gained by the greater availability of suitably sensitive probes that have specificity for important brain tissue targets.
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Affiliation(s)
- Bradley J Schwehr
- Curtin University, School of Molecular and Life Sciences, Perth, WA, Australia 6845.
| | - David Hartnell
- Curtin University, School of Molecular and Life Sciences, Perth, WA, Australia 6845.
- Curtin University, Curtin Health Innovation Research Institute, Perth, WA, Australia 6102
| | - Gaewyn Ellison
- Curtin University, School of Molecular and Life Sciences, Perth, WA, Australia 6845.
- Curtin University, Curtin Health Innovation Research Institute, Perth, WA, Australia 6102
| | - Madison T Hindes
- Clinical and Health Sciences, University of South Australia, Adelaide, South Australia 5000
| | - Breah Milford
- Curtin University, School of Molecular and Life Sciences, Perth, WA, Australia 6845.
| | - Elena Dallerba
- Curtin University, School of Molecular and Life Sciences, Perth, WA, Australia 6845.
| | - Shane M Hickey
- Clinical and Health Sciences, University of South Australia, Adelaide, South Australia 5000
| | - Frederick M Pfeffer
- School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Doug A Brooks
- Clinical and Health Sciences, University of South Australia, Adelaide, South Australia 5000
| | - Massimiliano Massi
- Curtin University, School of Molecular and Life Sciences, Perth, WA, Australia 6845.
| | - Mark J Hackett
- Curtin University, School of Molecular and Life Sciences, Perth, WA, Australia 6845.
- Curtin University, Curtin Health Innovation Research Institute, Perth, WA, Australia 6102
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2
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Espargaró A, Álvarez-Berbel I, Busquets MA, Sabate R. In Vivo Assays for Amyloid-Related Diseases. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2024; 17:433-458. [PMID: 38598824 DOI: 10.1146/annurev-anchem-061622-023326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
Amyloid-related diseases, such as Alzheimer's and Parkinson's disease, are devastating conditions caused by the accumulation of abnormal protein aggregates known as amyloid fibrils. While assays involving animal models are essential for understanding the pathogenesis and developing therapies, a wide array of standard analytical techniques exists to enhance our understanding of these disorders. These techniques provide valuable information on the formation and propagation of amyloid fibrils, as well as the pharmacokinetics and pharmacodynamics of candidate drugs. Despite ethical concerns surrounding animal use, animal models remain vital tools in the search for treatments. Regardless of the specific animal model chosen, the analytical methods used are usually standardized. Therefore, the main objective of this review is to categorize and outline the primary analytical methods used in in vivo assays for amyloid-related diseases, highlighting their critical role in furthering our understanding of these disorders and developing effective therapies.
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Affiliation(s)
- Alba Espargaró
- 1Department of Pharmacy and Pharmaceutical Technology and Department of Physical Chemistry, School of Pharmacy, University of Barcelona, Barcelona, Spain;
- 2Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, Barcelona, Spain
| | - Irene Álvarez-Berbel
- 1Department of Pharmacy and Pharmaceutical Technology and Department of Physical Chemistry, School of Pharmacy, University of Barcelona, Barcelona, Spain;
| | - Maria Antònia Busquets
- 1Department of Pharmacy and Pharmaceutical Technology and Department of Physical Chemistry, School of Pharmacy, University of Barcelona, Barcelona, Spain;
- 2Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, Barcelona, Spain
| | - Raimon Sabate
- 1Department of Pharmacy and Pharmaceutical Technology and Department of Physical Chemistry, School of Pharmacy, University of Barcelona, Barcelona, Spain;
- 2Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, Barcelona, Spain
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3
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Chisholm TS, Hunter CA. A closer look at amyloid ligands, and what they tell us about protein aggregates. Chem Soc Rev 2024; 53:1354-1374. [PMID: 38116736 DOI: 10.1039/d3cs00518f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
The accumulation of amyloid fibrils is characteristic of neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease. Detecting these fibrils with fluorescent or radiolabelled ligands is one strategy for diagnosing and better understanding these diseases. A vast number of amyloid-binding ligands have been reported in the literature as a result. To obtain a better understanding of how amyloid ligands bind, we have compiled a database of 3457 experimental dissociation constants for 2076 unique amyloid-binding ligands. These ligands target Aβ, tau, or αSyn fibrils, as well as relevant biological samples including AD brain homogenates. From this database significant variation in the reported dissociation constants of ligands was found, possibly due to differences in the morphology of the fibrils being studied. Ligands were also found to bind to Aβ(1-40) and Aβ(1-42) fibrils with similar affinities, whereas a greater difference was found for binding to Aβ and tau or αSyn fibrils. Next, the binding of ligands to fibrils was shown to be largely limited by the hydrophobic effect. Some Aβ ligands do not fit into this hydrophobicity-limited model, suggesting that polar interactions can play an important role when binding to this target. Finally several binding site models were outlined for amyloid fibrils that describe what ligands target what binding sites. These models provide a foundation for interpreting and designing site-specific binding assays.
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Affiliation(s)
- Timothy S Chisholm
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1 EW, UK.
| | - Christopher A Hunter
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1 EW, UK.
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4
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Zhuang C, Chen B, Wu S, Xu L, Zhang X, Zheng X, Chen Y, Geng Y, Guan J, Lin Y, Wilman AH, Wu R. Repurposing of the PET Probe Prototype PiB for Label and Radiation-Free CEST MRI Molecular Imaging of Amyloid. ACS Chem Neurosci 2023; 14:4344-4351. [PMID: 38061891 PMCID: PMC10741654 DOI: 10.1021/acschemneuro.3c00539] [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: 08/16/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 12/21/2023] Open
Abstract
Positron emission tomography (PET) probes are specific and sensitive while suffering from radiation risk. It is worthwhile to explore the chemical emission saturation transfer (CEST) effects of the probe prototypes and repurpose them for CEST imaging to avoid radiation. In this study, we used 11C-PiB as an example of a PET probe for detecting amyloid and tested the feasibility of repurposing this PET probe prototype, PiB, for CEST imaging. After optimizing the parameters through preliminary phantom experiments, we used APP/PS1 transgenic mice and age-matched C57 mice for in vivo CEST magnetic resonance imaging (MRI) of amyloid. Furthermore, the pathological assessment was conducted on the same brain slices to evaluate the correlation between the CEST MRI signal abnormality and β-amyloid deposition detected by immunohistochemical staining. In our results, the Z-spectra revealed an apparent CEST effect that peaked at approximately 6 ppm. APP/PS1 mice as young as 9 months injected with PiB showed a significantly higher CEST effect compared to the control groups. The hyperintense region was correlated with the Aβ deposition shown by pathological staining. In conclusion, repurposing the PET probe prototype for CEST MRI imaging is feasible and enables label- and radiation-free detection of the amyloid while maintaining the sensitivity and specificity of the ligand. This study opens the door to developing CEST probes based on PET probe prototypes.
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Affiliation(s)
- Caiyu Zhuang
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
- Department
of Radiology, First Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Beibei Chen
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Shuohua Wu
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Liang Xu
- Department
of Medical Imaging, Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen 518107, China
| | - Xiaolei Zhang
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Xinhui Zheng
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Yue Chen
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Yiqun Geng
- Laboratory
of Molecular Pathology, Shantou University
Medical College, Shantou 515041, China
| | - Jitian Guan
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Yan Lin
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
- Provincial
Key Laboratory for Breast Cancer Diagnosis and Treatment, Shantou 515041, China
| | - Alan H. Wilman
- The Department
of Biomedical Engineering, University of
Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Renhua Wu
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
- Provincial
Key Laboratory for Breast Cancer Diagnosis and Treatment, Shantou 515041, China
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5
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Zhang T, Chen X, Yuan C, Pang X, Shangguan P, Liu Y, Han L, Sun J, Lam JWY, Liu Y, Wang J, Shi B, Zhong Tang B. Near-Infrared Aggregation-Induced Emission Luminogens for In Vivo Theranostics of Alzheimer's Disease. Angew Chem Int Ed Engl 2023; 62:e202211550. [PMID: 36336656 DOI: 10.1002/anie.202211550] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Indexed: 11/09/2022]
Abstract
Optimized theranostic strategies for Alzheimer's disease (AD) remain almost absent from bench to clinic. Current probes and drugs attempting to prevent β-amyloid (Aβ) fibrosis encounter failures due to the blood-brain barrier (BBB) penetration challenge and blind intervention time window. Herein, we design a near-infrared (NIR) aggregation-induced emission (AIE) probe, DNTPH, via balanced hydrophobicity-hydrophilicity strategy. DNTPH binds selectively to Aβ fibrils with a high signal-to-noise ratio. In vivo imaging revealed its excellent BBB permeability and long-term tracking ability with high-performance AD diagnosis. Remarkably, DNTPH exhibits a strong inhibitory effect on Aβ fibrosis and promotes fibril disassembly, thereby attenuating Aβ-induced neurotoxicity. DNTPH treatment significantly reduced Aβ plaques and rescued learning deficits in AD mice. Thus, DNTPH serves as the first AIE in vivo theranostic agent for real-time NIR imaging of Aβ plaques and AD therapy simultaneously.
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Affiliation(s)
- Tianfu Zhang
- Department of Chemistry, the Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Xiaoyu Chen
- Henan-Macquarie University Joint Centre for Biomedical Innovation, School of Life Sciences, Henan University, 475004, Kaifeng, China
| | - Congmin Yuan
- Department of Chemistry, the Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Xiaobin Pang
- Henan Key Laboratory of Brain Targeted Bio-nanomedicine, School of Life Sciences & School of Pharmacy, Henan University, 475004, Kaifeng, China
| | - Ping Shangguan
- Henan-Macquarie University Joint Centre for Biomedical Innovation, School of Life Sciences, Henan University, 475004, Kaifeng, China
| | - Yisheng Liu
- Henan-Macquarie University Joint Centre for Biomedical Innovation, School of Life Sciences, Henan University, 475004, Kaifeng, China
| | - Lulu Han
- Henan-Macquarie University Joint Centre for Biomedical Innovation, School of Life Sciences, Henan University, 475004, Kaifeng, China
| | - Jianwei Sun
- Department of Chemistry, the Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Jacky W Y Lam
- Department of Chemistry, the Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yang Liu
- Henan Key Laboratory of Brain Targeted Bio-nanomedicine, School of Life Sciences & School of Pharmacy, Henan University, 475004, Kaifeng, China
| | - Jiefei Wang
- Henan-Macquarie University Joint Centre for Biomedical Innovation, School of Life Sciences, Henan University, 475004, Kaifeng, China
| | - Bingyang Shi
- Henan-Macquarie University Joint Centre for Biomedical Innovation, School of Life Sciences, Henan University, 475004, Kaifeng, China.,Centre for motor neuron disease, Macquarie Medical School, Faculty of Medicine & Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ben Zhong Tang
- Department of Chemistry, the Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.,School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, 518172, Shenzhen, Guangdong, China
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6
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Chiang CW, Chien YC, Yu WJ, Ho CY, Wang CY, Wang TW, Chiang CS, Keng PY. Polymer-Coated Nanoparticles for Therapeutic and Diagnostic Non- 10B Enriched Polymer-Coated Boron Carbon Oxynitride (BCNO) Nanoparticles as Potent BNCT Drug. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2936. [PMID: 34835699 PMCID: PMC8618246 DOI: 10.3390/nano11112936] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 11/16/2022]
Abstract
Boron neutron capture therapy (BNCT) is a powerful and selective anti-cancer therapy utilizing 10B-enriched boron drugs. However, clinical advancement of BCNT is hampered by the insufficient loading of B-10 drugs throughout the solid tumor. Furthermore, the preparation of boron drugs for BNCT relies on the use of the costly B-10 enriched precursor. To overcome these challenges, polymer-coated boron carbon oxynitride (BCNO) nanoparticles, with ~30% of boron, were developed with enhanced biocompatibility, cell uptake, and tumoricidal effect via BNCT. Using the ALTS1C1 cancer cell line, the IC50 of the PEG@BCNO, bare, PEI@BCNO were determined to be 0.3 mg/mL, 0.1 mg/mL, and 0.05 mg/mL, respectively. As a proof-of-concept, the engineered non-10B enriched polymer-coated BCNO exhibited excellent anti-tumor effect via BNCT due to their high boron content per nanoparticle and due to the enhanced cellular internalization and retention compared to small molecular 10B-BPA drug. The astrocytoma ALTS1C1 cells treated with bare, polyethyleneimine-, and polyethylene glycol-coated BCNO exhibited an acute cell death of 24, 37, and 43%, respectively, upon 30 min of neutron irradiation compared to the negligible cell death in PBS-treated and non-irradiated cells. The radical approach proposed in this study addresses the expensive and complex issues of B-10 isotope enrichment process; thus, enabling the preparation of boron drugs at a significantly lower cost, which will facilitate the development of boron drugs for BNCT.
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Affiliation(s)
- Chen-Wei Chiang
- Department of Material Science and Engineering, National Tsing Hua University, Hsinchu City 300, Taiwan; (C.-W.C.); (Y.-C.C.); (C.-Y.H.); (C.-Y.W.); (T.-W.W.)
| | - Yun-Chen Chien
- Department of Material Science and Engineering, National Tsing Hua University, Hsinchu City 300, Taiwan; (C.-W.C.); (Y.-C.C.); (C.-Y.H.); (C.-Y.W.); (T.-W.W.)
| | - Wen-Jui Yu
- Department of Biomedical Engineering and Environmental Science, National Tsing Hua University, Hsinchu City 300, Taiwan; (W.-J.Y.); (C.-S.C.)
| | - Chia-Yu Ho
- Department of Material Science and Engineering, National Tsing Hua University, Hsinchu City 300, Taiwan; (C.-W.C.); (Y.-C.C.); (C.-Y.H.); (C.-Y.W.); (T.-W.W.)
| | - Chih-Yi Wang
- Department of Material Science and Engineering, National Tsing Hua University, Hsinchu City 300, Taiwan; (C.-W.C.); (Y.-C.C.); (C.-Y.H.); (C.-Y.W.); (T.-W.W.)
| | - Tzu-Wei Wang
- Department of Material Science and Engineering, National Tsing Hua University, Hsinchu City 300, Taiwan; (C.-W.C.); (Y.-C.C.); (C.-Y.H.); (C.-Y.W.); (T.-W.W.)
| | - Chi-Shiun Chiang
- Department of Biomedical Engineering and Environmental Science, National Tsing Hua University, Hsinchu City 300, Taiwan; (W.-J.Y.); (C.-S.C.)
| | - Pei-Yuin Keng
- Department of Material Science and Engineering, National Tsing Hua University, Hsinchu City 300, Taiwan; (C.-W.C.); (Y.-C.C.); (C.-Y.H.); (C.-Y.W.); (T.-W.W.)
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7
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Karmakar A, Mallick T, Fouzder C, Mukhuty A, Mondal S, Pramanik A, Kundu R, Mandal D, Begum NA. Unfolding the Role of a Flavone-Based Fluorescent Antioxidant towards the Misfolding of Amyloid Proteins: An Endeavour to Probe Amyloid Aggregation. J Phys Chem B 2020; 124:11133-11144. [DOI: 10.1021/acs.jpcb.0c08729] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Abhijit Karmakar
- Department of Chemistry, Visva-Bharati (Central University), Santiniketan 731235, WB, India
| | - Tamanna Mallick
- Department of Chemistry, Visva-Bharati (Central University), Santiniketan 731235, WB, India
| | - Chandrani Fouzder
- Department of Zoology, Visva-Bharati (Central University), Santiniketan 731235, WB, India
| | - Alpana Mukhuty
- Department of Zoology, Visva-Bharati (Central University), Santiniketan 731235, WB, India
| | - Samiran Mondal
- Department of Chemistry, Rammohan College, Kolkata 700009, WB, India
| | - Anup Pramanik
- Department of Chemistry, Sidho-Kanho-Birsha University, Purulia 723104, WB, India
| | - Rakesh Kundu
- Department of Zoology, Visva-Bharati (Central University), Santiniketan 731235, WB, India
| | - Debabrata Mandal
- Department of Chemistry, University College of Science and Technology, University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata 700009, WB, India
| | - Naznin Ara Begum
- Department of Chemistry, Visva-Bharati (Central University), Santiniketan 731235, WB, India
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8
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Oliveira AC, Costa T, Justino LLG, Fausto R, Morfin JF, Tóth É, Geraldes CFGC, Burrows HD. Photophysical studies on lanthanide(III) chelates conjugated to Pittsburgh compound B as luminescent probes targeted to Aβ amyloid aggregates. Photochem Photobiol Sci 2020; 19:1522-1537. [PMID: 32966544 DOI: 10.1039/d0pp00214c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The photophysical properties of Eu3+ and Tb3+ complexes of DOTAGA and DO3A-monoamide conjugates of the Pittsburgh compound B (PiB) chromophore, prepared using linkers of different lengths and flexibilities, and which form stable negatively charged (LnL1), and uncharged (LnL2) complexes, respectively, were studied as potential probes for optical detection of amyloid aggregates. The phenylbenzothiazole (PiB) moiety absorbs light at wavelengths longer than 330 nm with a high molar absorption coefficient in both probes, and acts as an antenna in these systems. The presence of the luminescent Ln3+ ion quenches the excited states of PiB through an energy transfer process from the triplet state of PiB to the metal centre, and structured emission is seen from Eu3+ and Tb3+. The luminescence study indicates the presence of a 5D4 → T1 back transfer process in the Tb3+ complexes. It also provides insights on structural properties of the Eu3+ complexes, such as the high symmetry environment of the Eu3+ ion in a single macrocyclic conformation and the presence of one water molecule in its inner coordination sphere. The overall quantum yield of luminescence of EuL1 is higher than for EuL2. However, their low values reflect the low overall sensitization efficiency of the energy transfer process, which is a consequence of the large distances between the metal center and the antenna, especially in the EuL2 complex. DFT calculations confirmed that the most stable conformation of the Eu3+ complexes involves a combination of a square antiprismatic (SAP) geometry of the chelate and an extended conformation of the linker. The large calculated average distances between the metal center and the antenna point to the predominance of the Förster energy transfer mechanism, especially for EuL2. This study provides insights into the behavior of amyloid-targeted Ln3+ complexes as optical probes, and contributes towards their rational design.
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Affiliation(s)
- Alexandre C Oliveira
- University of Coimbra, Coimbra Chemistry Centre (CQC), Department of Chemistry, 3004-535 Coimbra, Portugal.
| | - Telma Costa
- University of Coimbra, Coimbra Chemistry Centre (CQC), Department of Chemistry, 3004-535 Coimbra, Portugal.
| | - Licinia L G Justino
- University of Coimbra, Coimbra Chemistry Centre (CQC), Department of Chemistry, 3004-535 Coimbra, Portugal.
| | - Rui Fausto
- University of Coimbra, Coimbra Chemistry Centre (CQC), Department of Chemistry, 3004-535 Coimbra, Portugal.
| | - Jean-François Morfin
- Centre de Biophysique Moléculaire, CNRS, UPR 4301, Université d'Orléans, Rue Charles Sadron, 45071 Orléans Cedex 2, France
| | - Éva Tóth
- Centre de Biophysique Moléculaire, CNRS, UPR 4301, Université d'Orléans, Rue Charles Sadron, 45071 Orléans Cedex 2, France
| | - Carlos F G C Geraldes
- University of Coimbra, Coimbra Chemistry Centre (CQC), Department of Chemistry, 3004-535 Coimbra, Portugal. and University of Coimbra, Department of Life Sciences, Calçada Martim de Freitas, 3000-393 Coimbra, Portugal. and CIBIT/ICNAS - Instituto de Ciências Nucleares Aplicadas à Saúde, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal
| | - Hugh D Burrows
- University of Coimbra, Coimbra Chemistry Centre (CQC), Department of Chemistry, 3004-535 Coimbra, Portugal.
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9
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Jia J, Zhang L, Song J, Dai J, Cui M. Discovery of Diphenoxy Derivatives with Flexible Linkers as Ligands for β-Amyloid Plaques. Mol Pharm 2020; 17:4089-4100. [PMID: 32845647 DOI: 10.1021/acs.molpharmaceut.0c00537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The highly rigid and planar scaffolds with π-conjugated systems have been widely considered to be indispensable for β-amyloid (Aβ) binding ligands. In this study, a library of diphenoxy compounds with different types of more flexible linkers as Aβ ligands were synthesized and evaluated. Most of them displayed good affinity (Ki < 100 nM) for Aβ1-42 aggregates, and some ligands even showed values of Ki less than 10 nM. Structure-activity relationship analysis revealed that modification on the linkers or substituents tolerated great flexibility, which challenged the long-held belief that rigid and planar structures are exclusively favored for Aβ binding. Three ligands were labeled by iodine-125, and they exhibited good properties in vitro and in vivo, which further supported that this flexible scaffold was potential and promising for the development of Aβ imaging agents.
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Affiliation(s)
- Jianhua Jia
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China.,Department of Radiological Medicine and Oncology, College of Basic Medicine, Chongqing Medical University, Chongqing 400016, P. R. China
| | - Longfei Zhang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Jia Song
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Jiapei Dai
- Wuhan Institute for Neuroscience and Neuroengineering, South-Central University for Nationalities, Wuhan 430074, P. R. China
| | - Mengchao Cui
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
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10
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Lantz L, Shirani H, Klingstedt T, Nilsson KPR. Synthesis and Characterization of Thiophene-based Donor-Acceptor-Donor Heptameric Ligands for Spectral Assignment of Polymorphic Amyloid-β Deposits. Chemistry 2020; 26:7425-7432. [PMID: 32022335 PMCID: PMC7318160 DOI: 10.1002/chem.201905612] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Indexed: 11/29/2022]
Abstract
Protein deposits are associated with many devastating diseases and fluorescent ligands able to visualize these pathological entities are essential. Here, we report the synthesis of thiophene‐based donor–acceptor–donor heptameric ligands that can be utilized for spectral assignment of distinct amyloid‐β (Aβ) aggregates, one of the pathological hallmarks in Alzheimer's disease. The ability of the ligands to selectively distinguish Aβ deposits was abolished when the chemical composition of the ligands was altered. Our findings provide the structural and functional basis for the development of new fluorescent ligands that can distinguish between aggregated proteinaceous species consisting of the same peptide or protein. In addition, such ligands might aid in interpreting the potential role of polymorphic Aβ deposits in the pathogenesis of Alzheimer's disease.
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Affiliation(s)
- Linda Lantz
- Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
| | - Hamid Shirani
- Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
| | - Therése Klingstedt
- Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
| | - K Peter R Nilsson
- Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
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11
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Salahuddin P, Khan RH, Uversky VN. Comprehensive analysis of the molecular docking of small molecule inhibitors to the Aβ1–40peptide and its Osaka-mutant: insights into the molecular mechanisms of Aβ-peptide inhibition. J Biomol Struct Dyn 2019; 38:4536-4566. [DOI: 10.1080/07391102.2019.1697367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Parveen Salahuddin
- DISC, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India
| | - Rizwan Hasan Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India
| | - Vladimir N. Uversky
- Protein Research Group, Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Russia
- Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Molecular Medicine and USF Health Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
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12
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Aliyan A, Cook NP, Martí AA. Interrogating Amyloid Aggregates using Fluorescent Probes. Chem Rev 2019; 119:11819-11856. [DOI: 10.1021/acs.chemrev.9b00404] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Amir Aliyan
- Pasargad Institute for Advanced Innovative Solutions (PIAIS), Tehran, Iran 1991633361
- Khatam University, Tehran, Iran 1991633356
| | - Nathan P. Cook
- Department of Chemistry, Williams College, Williamstown, Massachusetts 01267, United States
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13
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Molavipordanjani S, Emami S, Hosseinimehr SJ. 99mTc-labeled Small Molecules for Diagnosis of Alzheimer’s Disease: Past, Recent and Future Perspectives. Curr Med Chem 2019; 26:2166-2189. [DOI: 10.2174/0929867325666180410104023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 01/21/2018] [Accepted: 04/05/2018] [Indexed: 01/22/2023]
Abstract
Background:
Alzheimer’s disease (AD) is an age-related progressive neurodegenerative disease.
Its prominent hallmarks are extracellular deposition of β-amyloids (amyloid plaques), intracellular
neurofibrillary tangles (NTFs), neurodegeneration and finally loss of cognitive function. Hence, AD diagnosis
in the early stage and monitoring of the disease are of great importance.
Methods:
In this review article, we have reviewed recent efforts for design, synthesis and evaluation of
99mTc labeled small molecule for AD imaging purposes.
Results:
These small molecules include derivatives of Congo red, benzothiazole, benzofuran, benzoxazole,
naphthalene, biphenyl, chalcone, flavone, aurone, stilbene, curcumin, dibenzylideneacetone,
quinoxaline, etc. The different aspects of 99mTc-labeled small molecules including chemical structure,
their affinity toward amyloid plaques, BBB permeation and in vivo/vitro stability will be discussed.
Conclusion:
The findings of this review confirm the importance of 99mTc-labeled small molecules for AD
imaging. Future studies based on the pharmacophore of these designed compounds are needed for improvement
of these molecules for clinical application.
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Affiliation(s)
- Sajjad Molavipordanjani
- Department of Radiopharmacy, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
| | - Saeed Emami
- Department of Medicinal Chemistry and Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
| | - Seyed Jalal Hosseinimehr
- Department of Radiopharmacy, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
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14
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Khan RH, Siddiqi MK, Uversky VN, Salahuddin P. Molecular docking of Aβ1–40 peptide and its Iowa D23N mutant using small molecule inhibitors: Possible mechanisms of Aβ-peptide inhibition. Int J Biol Macromol 2019; 127:250-270. [DOI: 10.1016/j.ijbiomac.2018.12.271] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 12/21/2018] [Accepted: 12/31/2018] [Indexed: 12/11/2022]
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15
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Jun YW, Cho SW, Jung J, Huh Y, Kim Y, Kim D, Ahn KH. Frontiers in Probing Alzheimer's Disease Biomarkers with Fluorescent Small Molecules. ACS CENTRAL SCIENCE 2019; 5:209-217. [PMID: 30834309 PMCID: PMC6396189 DOI: 10.1021/acscentsci.8b00951] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Indexed: 05/13/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia. The pathogenesis of the disease is associated with aggregated amyloid-β, hyperphosphorylated tau, a high level of metal ions, abnormal enzyme activities, and reactive astrocytes. This outlook gives an overview of fluorescent small molecules targeting AD biomarkers for ex vivo and in vivo imaging. These chemical imaging probes are categorized based on the potential biomarkers, and their pros and cons are discussed. Guidelines for designing new sensing strategies as well as the desirable properties to be pursued for AD fluorescence imaging are also provided.
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Affiliation(s)
- Yong Woong Jun
- Department
of Chemistry, Pohang University of Science
and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Republic
of Korea
| | - Seo Won Cho
- Department
of Chemistry, Pohang University of Science
and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Republic
of Korea
| | - Junyang Jung
- Department of Anatomy and Neurobiology,
College of Medicine, Center for Converging
Humanities, and Biomedical Science Institute, Kyung Hee
University, 26 Kyungheedae-Ro, Dongdaemun-Gu, Seoul 02447, Republic of Korea
| | - Youngbuhm Huh
- Department of Anatomy and Neurobiology,
College of Medicine, Center for Converging
Humanities, and Biomedical Science Institute, Kyung Hee
University, 26 Kyungheedae-Ro, Dongdaemun-Gu, Seoul 02447, Republic of Korea
| | - YoungSoo Kim
- Integrated
Science and Engineering Division, Department of Pharmacy, and Yonsei
Institute of Pharmaceutical Sciences, Yonsei
University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- (Y.K.)
E-mail:
| | - Dokyoung Kim
- Department of Anatomy and Neurobiology,
College of Medicine, Center for Converging
Humanities, and Biomedical Science Institute, Kyung Hee
University, 26 Kyungheedae-Ro, Dongdaemun-Gu, Seoul 02447, Republic of Korea
- (D.K.) E-mail:
| | - Kyo Han Ahn
- Department
of Chemistry, Pohang University of Science
and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Republic
of Korea
- (K.H.A.) E-mail:
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16
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Tu LH, Tseng NH, Tsai YR, Lin TW, Lo YW, Charng JL, Hsu HT, Chen YS, Chen RJ, Wu YT, Chan YT, Chen CS, Fang JM, Chen YR. Rationally designed divalent caffeic amides inhibit amyloid-β fibrillization, induce fibril dissociation, and ameliorate cytotoxicity. Eur J Med Chem 2018; 158:393-404. [PMID: 30227353 DOI: 10.1016/j.ejmech.2018.08.084] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 08/28/2018] [Accepted: 08/28/2018] [Indexed: 12/16/2022]
Abstract
One of the pathologic hallmarks in Alzheimer's disease (AD) is extracellular senile plaques composed of amyloid-β (Aβ) fibrils. Blocking Aβ self-assembly or disassembling Aβ aggregates by small molecules would be potential therapeutic strategies to treat AD. In this study, we synthesized a series of rationally designed divalent compounds and examined their effects on Aβ fibrillization. A divalent amide (2) derived from two molecules of caffeic acid with a propylenediamine linker of ∼5.0 Å in length, which is close to the distance of adjacent β sheets in Aβ fibrils, showed good potency to inhibit Aβ(1-42) fibrillization. Furthermore, compound 2 effectively dissociated the Aβ(1-42) preformed fibrils. The cytotoxicity induced by Aβ(1-42) aggregates in human neuroblastoma was reduced in the presence of 2, and feeding 2 to Aβ transgenic C. elegans rescued the paralysis phenotype. In addition, the binding and stoichiometry of 2 to Aβ(1-40) were demonstrated by using electrospray ionization-traveling wave ion mobility-mass spectrometry, while molecular dynamic simulation was conducted to gain structural insights into the Aβ(1-40)-2 complex.
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Affiliation(s)
- Ling-Hsien Tu
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan
| | | | - Ya-Ru Tsai
- Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan
| | - Tien-Wei Lin
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Yi-Wei Lo
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Jien-Lin Charng
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Hua-Ting Hsu
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Yu-Sheng Chen
- Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan
| | - Rong-Jie Chen
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Ying-Ta Wu
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Yi-Tsu Chan
- Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan
| | - Chang-Shi Chen
- Department of Biochemistry and Molecular Biology, National Cheng Kung University, Tainan, Taiwan
| | - Jim-Min Fang
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan; Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan.
| | - Yun-Ru Chen
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan.
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17
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Arja K, Elgland M, Nilsson KPR. Synthesis and Characterization of Oligothiophene-Porphyrin-Based Molecules That Can Be Utilized for Optical Assignment of Aggregated Amyloid-β Morphotypes. Front Chem 2018; 6:391. [PMID: 30234103 PMCID: PMC6129614 DOI: 10.3389/fchem.2018.00391] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 08/13/2018] [Indexed: 12/14/2022] Open
Abstract
Molecular tools for fluorescent imaging of protein aggregates are essential for understanding the significance of these pathological hallmarks in proteopathic neurodegenerative diseases, such as Alzheimer's disease. Here, we report the synthesis of a series of oligothiophene porphyrin hybrids, OTPHs, and the evaluation of these dyes for fluorescent imaging of beta-amyloid aggregates in tissue sections from a transgenic mouse model with Alzheimer's disease pathology. The OTPHs proved to be successful for spectral and lifetime imaging assessment of protein deposits and our findings confirm that the enhanced spectral range and distinct lifetime diversity of these novel tools allow a more precise assessment of heterogeneous amyloid morphology compared with the corresponding oligothiophene dye. In addition, the chemical identity of the porphyrin moiety, as well as the spacing between the two optical active moieties, influenced the OTPHs performance for fluorescent assignment of the protein deposits. We foresee that our findings will aid in the chemical design of dyes that can be utilized as optical tools for studying the polymorphic nature of protein aggregates associated with proteopathic neurodegenerative diseases.
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Affiliation(s)
- Katriann Arja
- Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Mathias Elgland
- Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - K Peter R Nilsson
- Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
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18
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Zhang J, Sandberg A, Konsmo A, Wu X, Nyström S, Nilsson KPR, Konradsson P, LeVine H, Lindgren M, Hammarström P. Detection and Imaging of Aβ1-42 and Tau Fibrils by Redesigned Fluorescent X-34 Analogues. Chemistry 2018. [DOI: 10.1002/chem.201800501] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Jun Zhang
- Division of chemistry; Department of Physics, Chemistry and Biology; Linköping University; 581 83 Linköping Sweden
| | - Alexander Sandberg
- Division of chemistry; Department of Physics, Chemistry and Biology; Linköping University; 581 83 Linköping Sweden
| | - Audun Konsmo
- Department of Physics; The Norwegian University of Science and Technology; 7491 Trondheim Norway
| | - Xiongyu Wu
- Division of chemistry; Department of Physics, Chemistry and Biology; Linköping University; 581 83 Linköping Sweden
| | - Sofie Nyström
- Division of chemistry; Department of Physics, Chemistry and Biology; Linköping University; 581 83 Linköping Sweden
| | - K. Peter R. Nilsson
- Division of chemistry; Department of Physics, Chemistry and Biology; Linköping University; 581 83 Linköping Sweden
| | - Peter Konradsson
- Division of chemistry; Department of Physics, Chemistry and Biology; Linköping University; 581 83 Linköping Sweden
| | - Harry LeVine
- Sanders-Brown Center on Aging; University of Kentucky; Lexington KY 40536-0230 USA
| | - Mikael Lindgren
- Division of chemistry; Department of Physics, Chemistry and Biology; Linköping University; 581 83 Linköping Sweden
- Department of Physics; The Norwegian University of Science and Technology; 7491 Trondheim Norway
| | - Per Hammarström
- Division of chemistry; Department of Physics, Chemistry and Biology; Linköping University; 581 83 Linköping Sweden
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19
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Zemanek G, Jagusiak A, Chłopaś K, Piekarska B, Stopa B. Congo red fluorescence upon binding to macromolecules – a possible explanation for the enhanced intensity. BIO-ALGORITHMS AND MED-SYSTEMS 2017. [DOI: 10.1515/bams-2017-0010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
AbstractThe present study attempts to explain the reason for the selective generation of an increase in intensity of Congo red (CR) fluorescence as an effect of the dye interacting with proteins and polysaccharides. This supramolecular dye, which creates ribbon-shaped micelles in aqueous solutions when excited with blue light (470 nm), presents low fluorescence with a maximum within the orange-red light range (approximately 600 nm). In the same conditions, CR-stained preparations of heat-denatured proteins, some native proteins (e.g. cell surface receptors) and cellulose show intense orange-red fluorescence when observed using a fluorescence microscope. The fluormetric measurements showed that the factors that cause the dissociation of the ribbon-shaped CR micelle – ethanol, urea, dimethyl sulfoxide (DMSO) and cholate – all contributed to a significant increase in the fluorescence intensity of the CR solutions. The fluorescence measurements of CR bound to the immunoglobulin light lambda (L λ) chain and soluble carboxymethyl cellulose (CMC) showed a fluorescence intensity which was many times higher. In the case of the denatured (65°C) immunoglobulin L λ chain, the fluorescence intensity significantly exceeded the values observed for the factors which break down the CR micelles. The dissociation of the ribbon-shaped micelles and the complexation of the monomeric CR form with polymers are two of the factors explaining the intense fluorescence of protein and polysaccharide preparations stained with CR.
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20
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Tu P, Fu H, Cui M. Compounds for imaging amyloid-β deposits in an Alzheimer's brain: a patent review. Expert Opin Ther Pat 2015; 25:413-23. [PMID: 25746836 DOI: 10.1517/13543776.2015.1007953] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
INTRODUCTION β-amyloid (Aβ) plaques in the brain are regarded as a hallmark of Alzheimer's disease (AD), and the imaging of Aβ is a critical step for early diagnosis. Extensive research has been done to develop probes for targeting Aβ with available imaging modalities. AREAS COVERED In this review, the authors give an overview of published patents and papers about the discovery and development of compounds possessing potential utilization in imaging Aβ for the diagnosis of AD. SciFinder is the main electronic database for patent study in this review. EXPERT OPINION Despite achievements in Aβ imaging, there is still a need to develop innovative compounds with selectivity and high affinity to Aβ. Positron emission tomography imaging agents will still be the trend in the field in the short term. Due to the low costs for single-photon emission computed tomography (SPECT) and the excellent nuclear properties of (99m)Tc, substantial research should be conducted on the development of the probes for SPECT. Refining the current imaging techniques and in the meantime developing new efficient imaging multimodality and compounds would be a promising approach to imaging Aβ.
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Affiliation(s)
- Peiyu Tu
- Beijing Normal University, College of Chemistry, Key Laboratory of Radiopharmaceuticals, Ministry of Education , Beijing 100875 , P.R. China +86 10 58808891 ; +86 10 58808891 ;
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21
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Freire S, Rodríguez‐Prieto F, Ríos Rodríguez MC, Penedo JC, Al‐Soufi W, Novo M. Towards Ratiometric Sensing of Amyloid Fibrils In Vitro. Chemistry 2015; 21:3425-34. [DOI: 10.1002/chem.201406110] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Sonia Freire
- Department of Physical Chemistry, Faculty of Science, Campus Lugo, University of Santiago de Compostela, Campus Universitario s/n, 27001 Lugo (Spain)
| | - Flor Rodríguez‐Prieto
- Department of Physical Chemistry, Faculty of Chemistry and CIQUS, Campus Santiago de Compostela, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain)
| | - M. Carmen Ríos Rodríguez
- Department of Physical Chemistry, Faculty of Chemistry and CIQUS, Campus Santiago de Compostela, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain)
| | - J. Carlos Penedo
- SUPA School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (UK)
| | - Wajih Al‐Soufi
- Department of Physical Chemistry, Faculty of Science, Campus Lugo, University of Santiago de Compostela, Campus Universitario s/n, 27001 Lugo (Spain)
| | - Mercedes Novo
- Department of Physical Chemistry, Faculty of Science, Campus Lugo, University of Santiago de Compostela, Campus Universitario s/n, 27001 Lugo (Spain)
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22
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Satpati D, Korde A, Sarma HD, Banerjee S. Synthesis and evaluation of a phenylbenzothiazole-based 99mTc(CO)3-radiotracer for possible application in imaging of β-amyloid plaques in Alzheimer’s disease. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3548-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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23
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Small-molecule theranostic probes: a promising future in neurodegenerative diseases. Int J Cell Biol 2013; 2013:150952. [PMID: 24324497 PMCID: PMC3845517 DOI: 10.1155/2013/150952] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 09/03/2013] [Indexed: 12/15/2022] Open
Abstract
Prion diseases are fatal neurodegenerative illnesses, which include Creutzfeldt-Jakob disease in humans and scrapie, chronic wasting disease, and bovine spongiform encephalopathy in animals. They are caused by unconventional infectious agents consisting primarily of misfolded, aggregated, β -sheet-rich isoforms, denoted prions, of the physiological cellular prion protein (PrP(C)). Many lines of evidence suggest that prions (PrP(Sc)) act both as a template for this conversion and as a neurotoxic agent causing neuronal dysfunction and cell death. As such, PrP(Sc) may be considered as both a neuropathological hallmark of the disease and a therapeutic target. Several diagnostic imaging probes have been developed to monitor cerebral amyloid lesions in patients with neurodegenerative disorders (such as Alzheimer's disease, Parkinson's disease, and prion disease). Examples of these probes are Congo red, thioflavin T, and their derivatives. We synthesized a series of styryl derivatives, denoted theranostics, and studied their therapeutic and/or diagnostic potentials. Here we review the salient traits of these small molecules that are able to detect and modulate aggregated forms of several proteins involved in protein misfolding diseases. We then highlight the importance of further studies for their practical implications in therapy and diagnostics.
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24
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Mathis CA, Mason NS, Lopresti BJ, Klunk WE. Development of positron emission tomography β-amyloid plaque imaging agents. Semin Nucl Med 2013; 42:423-32. [PMID: 23026364 DOI: 10.1053/j.semnuclmed.2012.07.001] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
For 100 years, β-amyloid (Aβ) plaques and neurofibrillary tangles (NFTs) have been recognized as the neuropathological hallmarks of Alzheimer's disease (AD), and their presence or absence could only be assessed postmortem using stains and dyes that identified these microscopic structures. Approximately 10 years ago, the first successful Aβ plaque-specific positron emission tomography (PET) imaging study was conducted in a living human subject clinically diagnosed with probable AD using the (11)C-labeled radiopharmaceutical Pittsburgh Compound B (PiB). Laboratory studies and preclinical evaluations to design PiB began a decade earlier than the first human PiB PET study and involved chemical modifications of different well-known dyes that bound specifically to the extended β-pleated sheets that comprise the fibrils of amyloid proteins such as Aβ plaques, NFTs, α-synuclein deposits, and prions. These preclinical studies were conducted in our laboratories at the University of Pittsburgh, starting with Congo red derivatives, followed by Chrysamine G derivatives, followed by X-series compounds, and finally with neutral derivatives of thioflavin-T. The in vitro and in vivo evaluations of the different derivatives as candidate PET radioligands for imaging Aβ plaques and neurofibrillary tangles in human brain are described in this review, along with the specific evaluation criteria by which the candidate radioligands were judged. Out of these studies came PiB, a PET radioligand that binds selectively and with high affinity to only fibrillar forms of Aβ. PiB has been used in many different human research protocols throughout the world and has demonstrated the usefulness of assessing the Aβ plaque status of subjects many years before the clinical diagnosis of probable AD. Recently, longer-lived (18)F-radiolabeled Aβ-selective radiopharmaceuticals have been developed. It is likely that the full clinical impact of these imaging agents will be realized by identifying presymptomatic subjects who would benefit from early drug treatments with future disease-modifying AD therapeutics.
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Affiliation(s)
- Chester A Mathis
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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25
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Espargaró A, Sabate R, Ventura S. Thioflavin-S staining coupled to flow cytometry. A screening tool to detect in vivo protein aggregation. MOLECULAR BIOSYSTEMS 2012; 8:2839-44. [PMID: 22868714 DOI: 10.1039/c2mb25214g] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Amyloid deposits are associated with an increasing number of human disorders, including Alzheimer's and Parkinson's diseases. Recent studies provide compelling evidence for the existence of amyloid-like conformations in the insoluble bacterial inclusion bodies (IBs) produced during the recombinant expression of amyloidogenic proteins. This makes prokaryotic cells a physiologically relevant system to study the mechanisms of in vivo amyloid deposition. We show here that the application of flow cytometry to detect Thioflavin-S (Th-S) fluorescence provides a fast, robust, quantitative, non-invasive method to screen for the presence of in vivo intracellular amyloid-like aggregates in bacteria, with potential application in the analysis of the impact of genetic mutations or chemical compounds on the aggregation of disease-associated polypeptides.
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Affiliation(s)
- Alba Espargaró
- Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, 08193-Bellaterra, Barcelona, Spain
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26
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Common benzothiazole and benzoxazole fluorescent DNA intercalators for studying Alzheimer Aβ1-42 and prion amyloid peptides. Biotechniques 2012; 52:000113873. [DOI: 10.2144/000113873] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 05/04/2012] [Indexed: 11/23/2022] Open
Abstract
Amyloids are fibrillar protein aggregates associated with a number of neurodegenerative pathologies including Alzheimer and Creutzfeldt—Jakob disease. The study of amyloids is usually based on fluorescence with the dye thioflavin-T. Although a number of amyloid binding compounds have been synthesized, many are nonfluorescent or not readily available for research use. Here we report on a class of commercial benzothiazole/benzoxazole containing fluorescent DNA intercalators from Invitrogen that possess the ability to bind amyloid Aβ1-42 peptide and hamster prion. These dyes fluoresce from 500–750 nm and are available as dimers or monomers. We demonstrate that these dyes can be used as acceptors for thioflavin-T fluorescence resonance energy transfer as well as reporter groups for binding studies with Congo red and chrysamine G. As more potential therapeutic compounds for these diseases are generated, there is a need for simple and inexpensive methods to monitor their interactions with amyloids. The fluorescent dyes reported here are readily available and can be used as tools for biochemical studies of amyloid structures and in vitro screening of potential therapeutics.
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27
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Svedberg MM, Rahman O, Hall H. Preclinical studies of potential amyloid binding PET/SPECT ligands in Alzheimer's disease. Nucl Med Biol 2012; 39:484-501. [PMID: 22226025 DOI: 10.1016/j.nucmedbio.2011.10.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 09/23/2011] [Accepted: 10/02/2011] [Indexed: 01/13/2023]
Abstract
Visualizing the neuropathological hallmarks amyloid plaques and neurofibrillary tangles of Alzheimer's disease in vivo using positron emission tomography (PET) or single photon emission computed tomography will be of great value in diagnosing the individual patient and will also help in our understanding of the disease. The successful introduction of [(11)C]PIB as a PET tracer for the amyloid plaques less than 10 years ago started an intensive research, and numerous new compounds for use in molecular imaging of the amyloid plaques have been developed. The candidates are based on dyes like thioflavin T, Congo red and chrysamine G, but also on other types such as benzoxazoles, curcumin and stilbenes. In the present review, we present methods of the radiochemistry and preclinical evaluation as well as the main properties of some of these compounds.
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Affiliation(s)
- Marie M Svedberg
- Department of Medicinal Chemistry, Preclinical PET Platform, Uppsala University, Uppsala, Sweden
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28
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Klingstedt T, Nilsson KPR. Conjugated polymers for enhanced bioimaging. Biochim Biophys Acta Gen Subj 2011; 1810:286-96. [DOI: 10.1016/j.bbagen.2010.05.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Revised: 04/22/2010] [Accepted: 05/05/2010] [Indexed: 10/19/2022]
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29
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Yarmoluk SM, Kovalska VB, Volkova KD. Optimized Dyes for Protein and Nucleic Acid Detection. ADVANCED FLUORESCENCE REPORTERS IN CHEMISTRY AND BIOLOGY III 2011. [DOI: 10.1007/978-3-642-18035-4_5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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30
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Li S, He H, Cui W, Gu B, Li J, Qi Z, Zhou G, Liang CM, Feng XY. Detection of Aβ Plaques by a Novel Specific MRI Probe Precursor CR-BSA-(Gd-DTPA)n in APP/PS1 Transgenic Mice. Anat Rec (Hoboken) 2010; 293:2136-43. [DOI: 10.1002/ar.21209] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Zhuang ZP, Kung MP, Ono M, Hou C, Kung HF. Syntheses of Two Potential Ligands for Tc-99m Labeling as Diagnosis Agents of Alzheimer's Disease. CHINESE J CHEM 2010. [DOI: 10.1002/cjoc.20030210722] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Arai H, Okamura N, Furukawa K, Kudo Y. Geriatric medicine, Japanese Alzheimer's disease neuroimaging initiative and biomarker development. TOHOKU J EXP MED 2010; 221:87-95. [PMID: 20467230 DOI: 10.1620/tjem.221.87] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Due to a change in disease spectrum in aged countries, the primary role of geriatricians should be directed to an appropriate management and prevention of 1) cognitive decline and dementia, 2) swallowing and aspiration pneumonia and 3) falls and fractures. Management of dementia constitutes a central part in the practice of geriatric medicine in order to support independence of life in elderly people. The current paradigm of cognitive function-based testing for the diagnosis and treatment of Alzheimer's disease (AD) is going to drastically shift to a biomarker-based test approach, a shift that will correspond to the emergence of disease-modifying drugs. In addition, a new molecular imaging technique that visualizes neuronal protein deposits or pathological features has been developed in Japan and the U.S.A. Based on these achievements, the Alzheimer's Disease Neuroimaging Initiative (ADNI) was proposed and initiated in 2005. The ADNI is a long-term observational study being conducted in the U.S.A., Europe, Australia, and Japan using identical protocols. The objectives of ADNI are: 1) to establish methodology which will allow standard values related to long-term changes in imaging data, such as MRI and PET, in patients with AD and mild cognitive impairment and normal elderly persons; 2) to obtain clinical indices, psychological test data, and blood/cerebrospinal fluid biomarkers to demonstrate the validity of image-based surrogate markers; and 3) to establish optimum methods to monitor the therapeutic effects of disease-modifying drugs for AD. Patient enrollment in the Japanese ADNI has begun in July 2008. Imaging of AD pathology not only acts as a reliable biomarker with which to assay curative drug development by novel pharmaceutical companies, but it also helps health promotion toward AD prevention.
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Affiliation(s)
- Hiroyuki Arai
- Department of Geriatrics and Gerontology, Division of Brain Science, Institute of Development, Aging, and Cancer, Tohoku University. FO11547/1
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Studies of Interaction Between Cyanine Dye T-284 and Fibrillar Alpha-Synuclein. J Fluoresc 2010; 20:1267-74. [DOI: 10.1007/s10895-010-0678-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 05/05/2010] [Indexed: 12/24/2022]
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Groenning M. Binding mode of Thioflavin T and other molecular probes in the context of amyloid fibrils-current status. J Chem Biol 2010; 3:1-18. [PMID: 19693614 PMCID: PMC2816742 DOI: 10.1007/s12154-009-0027-5] [Citation(s) in RCA: 441] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Accepted: 08/04/2009] [Indexed: 10/20/2022] Open
Abstract
Because understanding amyloid fibrillation in molecular detail is essential for development of strategies to control amyloid formation and overcome neurodegenerative disorders, increased understanding of present molecular probes as well as development of new probes are of utmost importance. To date, the binding modes of these molecular probes to amyloid fibrils are by no means adequately described or understood, and the large number of studies on Thioflavin T (ThT) and Congo Red (CR) binding have resulted in models that are incomplete and conflicting. Different types of binding sites are likely to be present in amyloid fibrils with differences in binding modes. ThT may bind in channels running parallel to the long axis of the fibril. In the channels, ThT may bind in either a monomeric or dimeric form of which the molecular conformation is likely to be planar. CR may bind in grooves formed along the β-sheets as a planar molecule in either a monomeric or supramolecular form.
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Affiliation(s)
- Minna Groenning
- Department of Pharmaceutics and Analytical Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
- IFM, Department of Chemistry, Linköping University, 581 83 Linköping, Sweden
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Waxman EA, Emmer KL, Giasson BI. Residue Glu83 plays a major role in negatively regulating alpha-synuclein amyloid formation. Biochem Biophys Res Commun 2009; 391:1415-20. [PMID: 20026050 DOI: 10.1016/j.bbrc.2009.12.079] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Accepted: 12/11/2009] [Indexed: 01/03/2023]
Abstract
Alpha-synuclein (alpha-syn) amyloid filaments are the major ultrastructural component of pathological inclusions that define several neurodegenerative disorders, including Parkinson disease and other disorders that are collectively termed synucleinopathies. Since the aggregation of alpha-syn is associated with the etiology of these diseases, defining the molecular elements that influence this process may have important therapeutics implication. The deletions of major portions of the hydrophobic region of alpha-syn (Delta74-79 and Delta71-82) impair the ability to form amyloid. However, mutating residue E83 to an A restored the ability of these proteins to form amyloid. Additionally supporting an inhibitory role of residue E83 on amyloid formation, mutating this residue to an A enhanced amyloid formation in the presence of small molecule inhibitors, such as dopamine and EGCG. Our data, therefore, suggest that the presence and placement of the highly charged E83 residue plays a significant inhibitory role in alpha-syn amyloid formation and these findings provide important insights in the planning of therapeutic agents that may be capable of preventing alpha-syn amyloid formation.
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Affiliation(s)
- Elisa A Waxman
- Department of Pharmacology, University of Pennsylvania School of Medicine, 3620 Hamilton Walk, 125 John Morgan Building, Philadelphia, PA 19104-6084, USA
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Okamura N, Fodero-Tavoletti MT, Kudo Y, Rowe CC, Furumoto S, Arai H, Masters CL, Yanai K, Villemagne VL. Advances in molecular imaging for the diagnosis of dementia. ACTA ACUST UNITED AC 2009; 3:705-16. [DOI: 10.1517/17530050903133790] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Childers WS, Mehta AK, Lu K, Lynn DG. Templating Molecular Arrays in Amyloid’s Cross-β Grooves. J Am Chem Soc 2009; 131:10165-72. [DOI: 10.1021/ja902332s] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- W. Seth Childers
- Center for Fundamental and Applied Molecular Evolution (FAME), and Department of Chemistry and Biology, Emory University, Atlanta, Georgia 30322
| | - Anil K. Mehta
- Center for Fundamental and Applied Molecular Evolution (FAME), and Department of Chemistry and Biology, Emory University, Atlanta, Georgia 30322
| | - Kun Lu
- Center for Fundamental and Applied Molecular Evolution (FAME), and Department of Chemistry and Biology, Emory University, Atlanta, Georgia 30322
| | - David G. Lynn
- Center for Fundamental and Applied Molecular Evolution (FAME), and Department of Chemistry and Biology, Emory University, Atlanta, Georgia 30322
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In vitro characterisation of BF227 binding to alpha-synuclein/Lewy bodies. Eur J Pharmacol 2009; 617:54-8. [PMID: 19576880 DOI: 10.1016/j.ejphar.2009.06.042] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Revised: 06/06/2009] [Accepted: 06/22/2009] [Indexed: 11/23/2022]
Abstract
Amyloid-beta (Abeta) plaques are a pathological hallmark of Alzheimer's disease and a current target for positron emission tomography (PET) imaging agents. Whilst [(11)C]-PiB is currently the most widely used PET ligand in clinic, a novel family of benzoxazole compounds have shown promise as Abeta imaging agents; particularly BF227. We characterised the in vitro binding of [(18)F]-BF227 toward alpha-synuclein to address its selectivity for Abeta pathology, to establish whether [(18)F]-BF227 binds to alpha-synuclein/Lewy bodies, in addition to Abeta plaques. In vitro [(18)F]-BF227 saturation studies were conducted with 200 nM alpha-synuclein or Abeta(1-42) fibrils or 100 microg of Alzheimer's disease, pure dementia with Lewy bodies or control brain homogenates. Non-specific binding was established with PiB (1 microM). In vitro binding studies indicated that [(18)F]-BF227 binds with high affinity to two binding sites on Abeta(1-42) fibrils (K(D1) = 1.31 and K(D2) = 80 nM, respectively) and to one class of binding sites on alpha-synuclein fibrils (K(D) = 9.63 nM). [(18)F]-BF227 bound to Abeta-containing Alzheimer's disease brain (K(D) = 25 +/- 0.5 nM), but failed to bind to Abeta-free dementia with Lewy bodies or age-matched control homogenates. Moreover, BF227 labelled both Abeta plaques and Lewy bodies in immunohistochemical/fluorescence analysis of human Alzheimer's disease and Parkinson's disease brain sections, respectively. This study suggests that [(18)F]-BF227 is not Abeta-selective. Evaluation of BF227 as a potential biomarker for Parkinson's disease is warranted.
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Small organic probes as amyloid specific ligands - Past and recent molecular scaffolds. FEBS Lett 2009; 583:2593-9. [DOI: 10.1016/j.febslet.2009.04.016] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 04/08/2009] [Accepted: 04/09/2009] [Indexed: 12/29/2022]
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Fodero-Tavoletti MT, Rowe CC, McLean CA, Leone L, Li QX, Masters CL, Cappai R, Villemagne VL. Characterization of PiB binding to white matter in Alzheimer disease and other dementias. J Nucl Med 2009; 50:198-204. [PMID: 19164220 DOI: 10.2967/jnumed.108.057984] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
UNLABELLED 11C-Pittsburgh Compound B (11C-PiB) PET has demonstrated significantly higher PiB retention in the gray matter of Alzheimer disease (AD) patients than in healthy controls (HCs). PiB is similarly retained within the white matter of HC and AD brains. Although the specificity of PiB for Abeta plaques in gray matter has been well described, the nature of PiB binding to white matter remains unclear. In this study, we characterized the binding of PiB to human white matter homogenates. METHODS In vitro binding studies were conducted using 3H-PiB (0.1-500 nM) and white matter brain homogenates (100 microg) from 3 AD patients and 3 HCs. Nonspecific binding was determined using PiB (1 microM). White matter from the same patients was also analyzed by immunofluorescence/immunohistochemistry (IF/IHC) microscopy and Western blotting for Abeta expression. White matter kinetics were also characterized in vivo through 11C-PiB PET studies in 27 HCs and 34 patients with dementia. IF/IHC experiments were conducted on 1 postmortem patient with dementia, to compare with the 11C-PiB distribution volume ratio data acquired 23 mo earlier. RESULTS In vitro saturation studies indicated that 3H-PiB binds nonspecifically to white matter brain homogenates. PiB fluorescence staining of AD and HC brain sections was consistent with absence of Abeta in IHC staining. Higher gray matter-to-white matter ratios were observed in IHC images than in 11C-PiB PET images. CONCLUSION These studies suggest that PiB binding to white matter is mainly nonsaturable and nonspecific and that PiB retention in the 11C-PiB PET studies is largely attributable to slower PiB white matter kinetics.
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Affiliation(s)
- Michelle T Fodero-Tavoletti
- Department of Pathology, University of Melbourne, and Department of Nuclear Medicine, Centre for PET, Austin Hospital, Heidelberg, Victoria, Australia
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Affiliation(s)
- William E. Klunk
- Department of Psychiatry and Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Chester A. Mathis
- Department of Radiology, Pharmacology, and Pharmaceutical Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA
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Henriksen G, Yousefi BH, Drzezga A, Wester HJ. Development and evaluation of compounds for imaging of beta-amyloid plaque by means of positron emission tomography. Eur J Nucl Med Mol Imaging 2008; 35 Suppl 1:S75-81. [PMID: 18224319 DOI: 10.1007/s00259-007-0705-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE The proof of concept for in vivo targeting of beta-amyloid plaques (Abeta) in patients with Alzheimer's disease (AD) by means of nuclear imaging methods has been shown in recent clinical studies. METHODS For positron emission tomography (PET), the five compounds [(11)C]PIB, 3'[(18)F]FPIB, [(18)F]FDDNP, [(11)C]SB-13 and [(18)F]F-SB-13 have been developed by a formal charge neutralisation of agents used for staining of AD brain post mortem. RESULTS In AD-patients, these compounds have been shown to possess a selective uptake in the brain regions known to have a high Abeta-load. Progress towards tracers with proportionality between tracer uptake and quantity of Abeta-load, of use for longitudinal studies of AD patients, is addressed in the current development of Abeta-tracers. CONCLUSION Despite the extensive information on the structure-affinity relationship of several Abeta-binding compounds, data on the regional brain binding kinetics-beyond uptake in healthy rodents-have been obtained only for a few compounds. Recent results indicate that PET-imaging of Abeta-deposits in transgenic rodent models of AD is feasible which may be valuable for a more relevant preclinical evaluation of Abeta-tracers.
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Affiliation(s)
- Gjermund Henriksen
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München, Ismaningerstrasse 22, München, Germany.
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43
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Fluorescent N-arylaminonaphthalene sulfonate probes for amyloid aggregation of alpha-synuclein. Biophys J 2008; 94:4867-79. [PMID: 18339734 DOI: 10.1529/biophysj.107.125211] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The deposition of fibrillar structures (amyloids) is characteristic of pathological conditions including Alzheimer's and Parkinson's diseases. The detection of protein deposits and the evaluation of their kinetics of aggregation are generally based on fluorescent probes such as thioflavin T and Congo red. In a search for improved fluorescence tools for studying amyloid formation, we explored the ability of N-arylaminonaphthalene sulfonate (NAS) derivatives to act as noncovalent probes of alpha-synuclein (AS) fibrillation, a process linked to Parkinson's disease and other neurodegenerative disorders. The compounds bound to fibrillar AS with micromolar K(d)s, and exhibited fluorescence enhancement, hyperchromism, and high anisotropy. We conclude that the probes experience a hydrophobic environment and/or restricted motion in a polar region. Time- and spectrally resolved emission intensity and anisotropy provided further information regarding structural features of the protein and the dynamics of solvent relaxation. The steady-state and time-resolved parameters changed during the course of aggregation. Compared with thioflavin T, NAS derivatives constitute more sensitive and versatile probes for AS aggregation, and in the case of bis-NAS detect oligomeric as well as fibrillar species. They can function in convenient, continuous assays, thereby providing useful tools for studying the mechanisms of amyloid formation and for high-throughput screening of factors inhibiting and/or reversing protein aggregation in neurodegenerative diseases.
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Fodero-Tavoletti MT, Smith DP, McLean CA, Adlard PA, Barnham KJ, Foster LE, Leone L, Perez K, Cortés M, Culvenor JG, Li QX, Laughton KM, Rowe CC, Masters CL, Cappai R, Villemagne VL. In vitro characterization of Pittsburgh compound-B binding to Lewy bodies. J Neurosci 2007; 27:10365-71. [PMID: 17898208 PMCID: PMC6673163 DOI: 10.1523/jneurosci.0630-07.2007] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Dementia with Lewy bodies (DLB) is pathologically characterized by the presence of alpha-synuclein-containing Lewy bodies within the neocortical, limbic, and paralimbic regions. Like Alzheimer's disease (AD), Abeta plaques are also present in most DLB cases. The contribution of Abeta to the development of DLB is unclear. [11C]-Pittsburgh compound B ([11C]-PIB) is a thioflavin-T derivative that has allowed in vivo Abeta burden to be quantified using positron emission tomography (PET). [11C]-PIB PET studies have shown similar high cortical [11C]-PIB binding in AD and DLB subjects. To establish the potential binding of PIB to alpha-synuclein in DLB patients, we characterized the in vitro binding of PIB to recombinant human alpha-synuclein and DLB brain homogenates. Analysis of the in vitro binding studies indicated that [3H]-PIB binds to alpha-synuclein fibrils but with lower affinity than that demonstrated/reported for Abeta(1-42) fibrils. Furthermore, [3H]-PIB was observed to bind to Abeta plaque-containing DLB brain homogenates but failed to bind to DLB homogenates that were Abeta plaque-free ("pure DLB"). Positive PIB fluorescence staining of DLB brain sections colocalized with immunoreactive Abeta plaques but failed to stain Lewy bodies. Moreover, image quantification analysis suggested that given the small size and low density of Lewy bodies within the brains of DLB subjects, any contribution of Lewy bodies to the [11C]-PIB PET signal would be negligible. These studies indicate that PIB retention observed within the cortical gray matter regions of DLB subjects in [11C]-PIB PET studies is largely attributable to PIB binding to Abeta plaques and not Lewy bodies.
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Affiliation(s)
- Michelle T. Fodero-Tavoletti
- Department of Pathology
- Bio21 Institute, and
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
| | - David P. Smith
- Department of Pathology
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
| | - Catriona A. McLean
- Department of Anatomical Pathology, Alfred Hospital, Prahran, Victoria 3181, Australia, and
| | - Paul A. Adlard
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
| | - Kevin J. Barnham
- Department of Pathology
- Bio21 Institute, and
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
| | | | | | - Keyla Perez
- Department of Pathology
- Bio21 Institute, and
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
| | - Mikhalina Cortés
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
| | - Janetta G. Culvenor
- Department of Pathology
- Centre for Neuroscience, The University of Melbourne, Melbourne, Victoria 3010, Australia
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
| | - Qiao-Xin Li
- Department of Pathology
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
| | - Katrina M. Laughton
- Department of Pathology
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
| | | | - Colin L. Masters
- Department of Pathology
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
| | - Roberto Cappai
- Department of Pathology
- Bio21 Institute, and
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
| | - Victor L. Villemagne
- Department of Pathology
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
- Centre for PET, Austin Hospital, Heidelberg, Victoria 3084, Australia
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Abstract
The use of molecular imaging techniques in the central nervous system (CNS) has a rich history. Most of the important developments in imaging-such as computed tomography, magnetic resonance imaging, single photon emission computed tomography, and positron emission tomography-began with neuropsychiatric applications. These techniques and modalities were then found to be useful for imaging other organs involved with various disease processes. Molecular imaging of the CNS has enabled scientists and researchers to understand better the basic biology of brain function and the way in which various disease processes affect the brain. Unlike other organs, the brain is not easily accessible, and it has a highly selective barrier at the endothelial cell level known as the blood-brain barrier. Furthermore, the brain is the most complex cellular network known to exist. Various neurotransmitters act in either an excitatory or an inhibitory fashion on adjacent neurons through a multitude of mechanisms. The various neuronal systems and the myriad of neurotransmitter systems become altered in many diseases. Some of the most devastating diseases, including Alzheimer disease, Parkinson disease, brain tumors, psychiatric disease, and numerous degenerative neurologic diseases, affect only the brain. Molecular neuroimaging will be critical to the future understanding and treatment of these diseases. Molecular neuroimaging of the brain shows tremendous promise for clinical application. In this article, the current state and clinical applications of molecular neuroimaging will be reviewed.
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Affiliation(s)
- Dima A Hammoud
- Department of Radiology, Johns Hopkins University School of Medicine, 1550 Orleans St, CRB-2, Room 492, Baltimore, MD 21231, USA
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Flaherty DP, Walsh SM, Kiyota T, Dong Y, Ikezu T, Vennerstrom JL. Polyfluorinated Bis-styrylbenzene β-Amyloid Plaque Binding Ligands. J Med Chem 2007; 50:4986-92. [PMID: 17845017 DOI: 10.1021/jm070085f] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
beta-Amyloid (Abeta) binding affinities and specificities for six bis-styrylbenzenes with multiple magnetically equivalent fluorine atoms in the form of a tetrafluorophenyl core or symmetrical trifluoromethyl and trifluoromethoxy groups were determined by means of fluorescence titrations with amyloid peptide Abeta1-40 and a novel in vitro fluorescence-based assay using APP/PS1 transgenic mouse brain sections. Bis-styrylbenzenes with a tetrafluorophenyl core had increased Abeta binding affinities compared to their monofluorophenyl or phenyl counterparts. Bis-styrylbenzenes with carboxylic acid functional groups had lower Abeta binding affinities than their neutral counterparts. Selected bis-styrylbenzenes were demonstrated to have good blood-brain barrier penetration capabilities. These data extend the SAR of bis-styrylbenzene Abeta binding and provide direction for the development of a noninvasive probe for early detection of Alzheimer's disease using 19F MRI.
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Affiliation(s)
- Daniel P Flaherty
- University of Nebraska Medical Center, College of Pharmacy, 986025 Nebraska Medical Center, Omaha, Nebraska 68198, USA
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47
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Reinke AA, Gestwicki JE. Structure?activity Relationships of Amyloid Beta-aggregation Inhibitors Based on Curcumin: Influence of Linker Length and Flexibility. Chem Biol Drug Des 2007; 70:206-15. [PMID: 17718715 DOI: 10.1111/j.1747-0285.2007.00557.x] [Citation(s) in RCA: 245] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Self-assembly of amyloid beta into fibrillar plaques is characteristic of Alzheimer's disease and oligomers of this peptide are believed to be involved in neurodegeneration. Natural organic dyes, such as congo red and curcumin, bind tightly to amyloid beta and, at higher concentrations, block its self-assembly. The ability of these molecules to prevent amyloid accumulation has generated interest in understanding which of their structural features contribute to inhibitory potency. In general, amyloid beta ligands tend to be flat, planar molecules with substituted aromatic end groups; however, a comprehensive structure-activity study has not been reported. To better understand these ligands, we surveyed the effect of three prominent features on inhibition of amyloid aggregation: the presence of two aromatic end groups, the substitution pattern of these aromatics, and the length and flexibility of the linker region. We found that modification of any one of the modules has profound effects on activity. Further, we report that the optimal length of the linker lies within a surprisingly narrow regime (6-19 A). These results offer insight into the key chemical features required for inhibiting amyloid beta aggregation. In turn, these findings help define the nature of the docking site for small molecules on the amyloid beta surface.
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Affiliation(s)
- Ashley A Reinke
- Department of Pathology and the Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109-2216, USA
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48
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Volkova KD, Kovalska VB, Balanda AO, Vermeij RJ, Subramaniam V, Slominskii YL, Yarmoluk SM. Cyanine dye–protein interactions: Looking for fluorescent probes for amyloid structures. ACTA ACUST UNITED AC 2007; 70:727-33. [PMID: 17467807 DOI: 10.1016/j.jbbm.2007.03.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 03/20/2007] [Accepted: 03/21/2007] [Indexed: 11/24/2022]
Abstract
We ascertained the ability to detect fibrillar beta-lactoglobulin (BLG) of a series of mono-, tri-, penta-, and heptamethinecyanines based on benzothiazole and benzimidazole heterocycles, and of benzothiazole squaraine. Fluorescence properties of these cyanine dyes were measured in the unbound state and in the presence of monomeric and fibrillar BLG and compared with those for the commercially available benzothiazole dye Thioflavin T. The correlation between the chemical nature of the dye molecules and the ability of dyes to bind aggregated proteins was established. We found that meso-substituted cyanines with amino substituents in heterocycle in contrast to the corresponding unsubstituted dyes have a binding preference to fibrillar BLG and a noticeable fluorescence response in the presence of the aggregated protein. For the squaraines and benzimidazole penthamethinecyanines studied, fluorescence emission increased both in the presence of native and fibrillar protein. The trimethinecyanines T-49 and SH-516 exhibit specifically increased fluorescence in the presence of fibrillar BLG. These dyes demonstrated the same or higher emission intensity and selectivity to aggregated BLG as Thioflavin T, and are proposed for application in selective fluorescent detection of aggregated proteins.
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Affiliation(s)
- K D Volkova
- Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 150 Zabolotnogo St., 03143 Kyiv, Ukraine
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49
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Wu C, Wang Z, Lei H, Zhang W, Duan Y. Dual binding modes of Congo red to amyloid protofibril surface observed in molecular dynamics simulations. J Am Chem Soc 2007; 129:1225-32. [PMID: 17263405 DOI: 10.1021/ja0662772] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Congo red has been used to identify amyloid fibrils in tissues for more than 80 years and is also a weak inhibitor to both amyloid-beta fibril formation and toxicity. However, the specificity of the binding and its inhibition mechanism remain unclear. Using all-atom molecular dynamics simulations with the explicit solvent model, we have identified and characterized two specific binding modes of Congo red molecules to a protofibril formed by an amyloidogenic fragment (GNNQQNY) of the yeast prion protein Sup35. The observation of dual-mode was consistent with the experimentally observed dual-mode binding to Abeta fibrils by a series of compounds similar to Congo red. In the primary mode, Congo red bound to a regular groove formed by the first three residues (GNN) of the beta-strands along the beta-sheet extension direction. Comparative simulations demonstrated that Thioflavin T also bound to the grooves on KLVFFAE protofibril surface. Because of the ubiquitous long grooves on the amyloid fibril surface, we propose that this binding interaction could be a general recognition mode of amyloid fibrils by Congo red, Thioflavin T, and other long flat molecules. In the secondary mode, Congo red bound parallel to the beta-strands on the edge or in the middle of a beta-sheet. The primary binding mode of Congo red and GNNQQNY protofibril was more stable than the secondary mode by -5.7 kcal/mol as estimated by the MM-GBSA method. Detailed analysis suggests that the hydrophobic interactions play important roles for burial of the hydrophobic part of the Congo red molecules. Two potential inhibition mechanisms of disrupting beta-sheet stacking were inferred from the primary mode, which could be exploited for the development of non-peptidic amyloid-specific inhibitors.
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Affiliation(s)
- Chun Wu
- UC Davis Genome Center and Department of Applied Science, University of California, Davis, California 95616, USA
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50
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Kudo Y. Development of amyloid imaging PET probes for an early diagnosis of Alzheimer's disease. MINIM INVASIV THER 2007; 15:209-13. [PMID: 16966133 DOI: 10.1080/13645700600836000] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Progressive accumulation of senile plaques (SPs) is one of the major neuropathological features of Alzheimer's Disease (AD) that precedes cognitive decline. Noninvasive detection of SPs could, therefore, be a potential diagnostic test for early or presymptomatic detection of AD patients. For this purpose, many attempts have been made to visualize AD-specific pathological changes in the living brain. Currently, a most practical method for the in vivo measurement of SP depositions is using positron emission tomography (PET) and contrast agent that specifically label SPs. We have developed a novel compound 2-[2-(2-dimethylaminothiazol-5-yl) ethenyl]-6-[2-(fluoro)ethoxy] benzoxazole (BF-227) as a candidate for an amyloid imaging probe for PET. BF-227 displayed high affinity to synthetic amyloid beta fibrils and clearly stained both SPs and diffuse plaques in AD brain sections. Intravenous administration of [11C]BF-227 into normal mice indicated that this labeled tracer readily penetrated the blood brain barrier (BBB) and was washed out quickly from brain tissue. Currently, we have investigated the clinical trial of [11C]BF-227 in healthy subjects and AD patients.
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Affiliation(s)
- Yukitsuka Kudo
- Tohoku University Biomedical Engineering Research Organization (TUBERO), Sendai, Japan.
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