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Cools R, Kerkhofs K, Leitao RCF, Bormans G. Preclinical Evaluation of Novel PET Probes for Dementia. Semin Nucl Med 2023; 53:599-629. [PMID: 37149435 DOI: 10.1053/j.semnuclmed.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/24/2023] [Indexed: 05/08/2023]
Abstract
The development of novel PET imaging agents that selectively bind specific dementia-related targets can contribute significantly to accurate, differential and early diagnosis of dementia causing diseases and support the development of therapeutic agents. Consequently, in recent years there has been a growing body of literature describing the development and evaluation of potential new promising PET tracers for dementia. This review article provides a comprehensive overview of novel dementia PET probes under development, classified by their target, and pinpoints their preclinical evaluation pathway, typically involving in silico, in vitro and ex/in vivo evaluation. Specific target-associated challenges and pitfalls, requiring extensive and well-designed preclinical experimental evaluation assays to enable successful clinical translation and avoid shortcomings observed for previously developed 'well-established' dementia PET tracers are highlighted in this review.
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Affiliation(s)
- Romy Cools
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Kobe Kerkhofs
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; NURA, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Renan C F Leitao
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
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2
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Giraudo A, Pallavicini M, Bolchi C. Small molecule ligands for α9* and α7 nicotinic receptors: a survey and an update, respectively. Pharmacol Res 2023; 193:106801. [PMID: 37236412 DOI: 10.1016/j.phrs.2023.106801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/16/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023]
Abstract
The α9- and α7-containing nicotinic acetylcholine receptors (nAChRs) mediate numerous physiological and pathological processes by complex mechanisms that are currently the subject of intensive study and debate. In this regard, selective ligands serve as invaluable investigative tools and, in many cases, potential therapeutics for the treatment of various CNS disfunctions and diseases, neuropathic pain, inflammation, and cancer. However, the present scenario differs significantly between the two aforementioned nicotinic subtypes. Over the past few decades, a large number of selective α7-nAChR ligands, including full, partial and silent agonists, antagonists, and allosteric modulators, have been described and reviewed. Conversely, reports on selective α9-containing nAChR ligands are relatively scarce, also due to a more recent characterization of this receptor subtype, and hardly any focusing on small molecules. In this review, we focus on the latter, providing a comprehensive overview, while providing only an update over the last five years for α7-nAChR ligands.
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Affiliation(s)
- Alessandro Giraudo
- Department of Pharmaceutical Sciences, University of Milan, via Mangiagalli 25, I-20133 Milano, Italy
| | - Marco Pallavicini
- Department of Pharmaceutical Sciences, University of Milan, via Mangiagalli 25, I-20133 Milano, Italy
| | - Cristiano Bolchi
- Department of Pharmaceutical Sciences, University of Milan, via Mangiagalli 25, I-20133 Milano, Italy.
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3
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Fontana IC, Kumar A, Nordberg A. The role of astrocytic α7 nicotinic acetylcholine receptors in Alzheimer disease. Nat Rev Neurol 2023; 19:278-288. [PMID: 36977843 DOI: 10.1038/s41582-023-00792-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2023] [Indexed: 03/30/2023]
Abstract
The ongoing search for therapeutic interventions in Alzheimer disease (AD) has highlighted the complexity of this condition and the need for additional biomarkers, beyond amyloid-β (Aβ) and tau, to improve clinical assessment. Astrocytes are brain cells that control metabolic and redox homeostasis, among other functions, and are emerging as an important focus of AD research owing to their swift response to brain pathology in the initial stages of the disease. Reactive astrogliosis - the morphological, molecular and functional transformation of astrocytes during disease - has been implicated in AD progression, and the definition of new astrocytic biomarkers could help to deepen our understanding of reactive astrogliosis along the AD continuum. As we highlight in this Review, one promising biomarker candidate is the astrocytic α7 nicotinic acetylcholine receptor (α7nAChR), upregulation of which correlates with Aβ pathology in the brain of individuals with AD. We revisit the past two decades of research into astrocytic α7nAChRs to shed light on their roles in the context of AD pathology and biomarkers. We discuss the involvement of astrocytic α7nAChRs in the instigation and potentiation of early Aβ pathology and explore their potential as a target for future reactive astrocyte-based therapeutics and imaging biomarkers in AD.
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Affiliation(s)
- Igor C Fontana
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Amit Kumar
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Agneta Nordberg
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.
- Theme Inflammation and Aging, Karolinska University Hospital, Stockholm, Sweden.
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4
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Ni R. PET imaging in animal models of Parkinson's disease. Behav Brain Res 2023; 438:114174. [PMID: 36283568 DOI: 10.1016/j.bbr.2022.114174] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 09/20/2022] [Accepted: 09/27/2022] [Indexed: 12/05/2022]
Abstract
Alpha-synucleinopathies, such as Parkinson's disease, dementia with Lewy bodies and multiple system atrophy, are characterized by aberrant accumulation of alpha-synuclein and synaptic dysfunction leading to motor and cognitive deficits. Animal models of alpha-synucleinopathy have greatly facilitated the mechanistic understanding of the disease and the development of therapeutics. Various transgenic, alpha-synuclein fibril-injected, and toxin-injected animal models of Parkinson's disease and multiple system atrophy that recapitulate the disease pathology have been developed and widely used. Recent advances in positron emission tomography have allowed the noninvasive visualization of molecular alterations, underpinning behavioral dysfunctions in the brains of animal models and the longitudinal monitoring of treatment effects. Imaging studies in these disease animal models have employed multi-tracer PET designs to reveal dopaminergic deficits together with other molecular alterations. This review focuses on the development of new positron emission tomography tracers and studies of alpha-synuclein, synaptic vesicle glycoprotein 2A neurotransmitter receptor deficits such as dopaminergic receptor, dopaminergic transporter, serotonergic receptor, vesicular monoamine transporter 2, hypometabolism, neuroinflammation, mitochondrial dysfunction and leucine rich repeat kinase 2 in animal models of Parkinson's disease. The outstanding challenges and emerging applications are outlined, such as investigating the gut-brain-axis by using positron emission tomography in animal models, and provide a future outlook.
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Affiliation(s)
- Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Institute for Biomedical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland.
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5
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Yadav D, Kumar P. Restoration and targeting of aberrant neurotransmitters in Parkinson's disease therapeutics. Neurochem Int 2022; 156:105327. [PMID: 35331828 DOI: 10.1016/j.neuint.2022.105327] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/18/2022] [Accepted: 03/17/2022] [Indexed: 12/13/2022]
Abstract
Neurotransmitters are considered as a fundamental regulator in the process of neuronal growth, differentiation and survival. Parkinson's Disease (PD) occurs due to extensive damage of dopamine-producing neurons; this causes dopamine deficits in the midbrain, followed by the alternation of various other neurotransmitters (glutamate, GABA, serotonin, etc.). It has been observed that fluctuation of neurotransmission in the basal ganglia exhibits a great impact on the pathophysiology of PD. Dopamine replacement therapy, such as the use of L-DOPA, can increase the dopamine level, but it majorly ameliorates the motor symptoms and is also associated with long-term complications (for e.g., LID). While the non-dopaminergic system can efficiently target non-motor symptoms, for instance, the noradrenergic system regulates the synthesis of BDNF via the MAPK pathway, which is important in learning and memory. Herein, we briefly discuss the role of different neurotransmitters, implementation of neurotransmitter receptors in PD. We also illustrate the recent advances of neurotransmitter-based drugs, which are currently under in vivo and clinical studies. Reinstating normal neurotransmitter levels has been believed to be advantageous in the treatment of PD. Thus, there is an increasing demand for drugs that can specifically target the neurotransmission system and reinstate the normal levels of neurotransmitters, which might prevent or delay neurodegeneration in PD.
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Affiliation(s)
- Divya Yadav
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi, India; Delhi Technological University (Formerly Delhi College of Engineering), Delhi, 110042, India
| | - Pravir Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi, India; Delhi Technological University (Formerly Delhi College of Engineering), Delhi, 110042, India.
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Nag S, Miranda-Azpiazu P, Jia Z, Datta P, Arakawa R, Moein MM, Yang Z, Tu Y, Lemoine L, Ågren H, Nordberg A, Långström B, Halldin C. Development of 11C-Labeled ASEM Analogues for the Detection of Neuronal Nicotinic Acetylcholine Receptors (α7-nAChR). ACS Chem Neurosci 2022; 13:352-362. [PMID: 35020351 PMCID: PMC8815074 DOI: 10.1021/acschemneuro.1c00730] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
![]()
The
homo-pentameric
alpha 7 receptor is one of the major types
of neuronal nicotinic acetylcholine receptors (α7-nAChRs) related
to cognition, memory formation, and attention processing. The mapping
of α7-nAChRs by PET pulls a lot of attention to realize the
mechanism and development of CNS diseases such as AD, PD, and schizophrenia.
Several PET radioligands have been explored for the detection of the
α7-nAChR. 18F-ASEM is the most functional for in vivo quantification of α7-nAChRs in the human brain.
The first aim of this study was to initially use results from in silico
and machine learning techniques to prescreen and predict the binding
energy and other properties of ASEM analogues and to interpret these
properties in terms of atomic structures using 18F-ASEM
as a lead structure, and second, to label some selected candidates
with carbon-11/hydrogen-3 (11C/3H) and to evaluate
the binding properties in vitro and in vivo using the labeled candidates. In silico predictions are obtained
from perturbation free-energy calculations preceded by molecular docking,
molecular dynamics, and metadynamics simulations. Machine learning
techniques have been applied for the BBB and P-gp-binding properties.
Six analogues of ASEM were labeled with 11C, and three
of them were additionally labeled with 3H. Binding properties
were further evaluated using autoradiography (ARG) and PET measurements
in non-human primates (NHPs). Radiometabolites were measured in NHP
plasma. All six compounds were successfully synthesized. Evaluation
with ARG showed that 11C-Kln83 was preferably binding to
the α7-nAChR. Competition studies showed that 80% of the total
binding was displaced. Further ARG studies using 3H-KIn-83
replicated the preliminary results. In the NHP PET study, the distribution
pattern of 11C-KIn-83 was similar to other α7 nAChR
PET tracers. The brain uptake was relatively low and increased by
the administration of tariquidar, indicating a substrate of P-gp.
The ASEM blocking study showed that 11C-KIn-83 specifically
binds to α7 nAChRs. Preliminary in vitro evaluation
of KIn-83 by ARG with both 11C and 3H and in vivo evaluation in NHP showed favorable properties for
selectively imaging α7-nAChRs, despite a relatively low brain
uptake.
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Affiliation(s)
- Sangram Nag
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Patricia Miranda-Azpiazu
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Zhisheng Jia
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Prodip Datta
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Ryosuke Arakawa
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Mohammad Mahdi Moein
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Zhou Yang
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Yaoquan Tu
- Division of Theoretical Chemistry and Biology, Royal Institute of Technology (KTH), 11428 Stockholm, Sweden
| | - Laetitia Lemoine
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, 141 52 Stockholm Sweden
| | - Hans Ågren
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Agneta Nordberg
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, 141 52 Stockholm Sweden
- Theme Aging, Karolinska University Hospital, 141 52 Stockholm, Sweden
| | - Bengt Långström
- Department of Chemistry, Uppsala University, 75123 Uppsala, Sweden
| | - Christer Halldin
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
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Cao L, Kong Y, Ji B, Ren Y, Guan Y, Ni R. Positron Emission Tomography in Animal Models of Tauopathies. Front Aging Neurosci 2022; 13:761913. [PMID: 35082657 PMCID: PMC8784812 DOI: 10.3389/fnagi.2021.761913] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/30/2021] [Indexed: 12/18/2022] Open
Abstract
The microtubule-associated protein tau (MAPT) plays an important role in Alzheimer's disease and primary tauopathy diseases. The abnormal accumulation of tau contributes to the development of neurotoxicity, inflammation, neurodegeneration, and cognitive deficits in tauopathy diseases. Tau synergically interacts with amyloid-beta in Alzheimer's disease leading to detrimental consequence. Thus, tau has been an important target for therapeutics development for Alzheimer's disease and primary tauopathy diseases. Tauopathy animal models recapitulating the tauopathy such as transgenic, knock-in mouse and rat models have been developed and greatly facilitated the understanding of disease mechanisms. The advance in PET and imaging tracers have enabled non-invasive detection of the accumulation and spread of tau, the associated microglia activation, metabolic, and neurotransmitter receptor alterations in disease animal models. In vivo microPET studies on mouse or rat models of tauopathy have provided significant insights into the phenotypes and time course of pathophysiology of these models and allowed the monitoring of treatment targeting at tau. In this study, we discuss the utilities of PET and recently developed tracers for evaluating the pathophysiology in tauopathy animal models. We point out the outstanding challenges and propose future outlook in visualizing tau-related pathophysiological changes in brain of tauopathy disease animal models.
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Affiliation(s)
- Lei Cao
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Changes Technology Corporation Ltd., Shanghai, China
| | - Yanyan Kong
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Bin Ji
- Department of Radiopharmacy and Molecular Imaging, School of Pharmacy, Fudan University, Shanghai, China
| | - Yutong Ren
- Guangdong Robotics Association, Guangzhou, China
| | - Yihui Guan
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
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8
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Chaney AM, Lopez-Picon FR, Serrière S, Wang R, Bochicchio D, Webb SD, Vandesquille M, Harte MK, Georgiadou C, Lawrence C, Busson J, Vercouillie J, Tauber C, Buron F, Routier S, Reekie T, Snellman A, Kassiou M, Rokka J, Davies KE, Rinne JO, Salih DA, Edwards FA, Orton LD, Williams SR, Chalon S, Boutin H. Prodromal neuroinflammatory, cholinergic and metabolite dysfunction detected by PET and MRS in the TgF344-AD transgenic rat model of AD: a collaborative multi-modal study. Am J Cancer Res 2021; 11:6644-6667. [PMID: 34093845 PMCID: PMC8171096 DOI: 10.7150/thno.56059] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/15/2021] [Indexed: 12/25/2022] Open
Abstract
Mouse models of Alzheimer's disease (AD) are valuable but do not fully recapitulate human AD pathology, such as spontaneous Tau fibril accumulation and neuronal loss, necessitating the development of new AD models. The transgenic (TG) TgF344-AD rat has been reported to develop age-dependent AD features including neuronal loss and neurofibrillary tangles, despite only expressing APP and PSEN1 mutations, suggesting an improved modelling of AD hallmarks. Alterations in neuronal networks as well as learning performance and cognition tasks have been reported in this model, but none have combined a longitudinal, multimodal approach across multiple centres, which mimics the approaches commonly taken in clinical studies. We therefore aimed to further characterise the progression of AD-like pathology and cognition in the TgF344-AD rat from young-adults (6 months (m)) to mid- (12 m) and advanced-stage (18 m, 25 m) of the disease. Methods: TgF344-AD rats and wild-type (WT) littermates were imaged at 6 m, 12 m and 18 m with [18F]DPA-714 (TSPO, neuroinflammation), [18F]Florbetaben (Aβ) and [18F]ASEM (α7-nicotinic acetylcholine receptor) and with magnetic resonance spectroscopy (MRS) and with (S)-[18F]THK5117 (Tau) at 15 and 25 m. Behaviour tests were also performed at 6 m, 12 m and 18 m. Immunohistochemistry (CD11b, GFAP, Aβ, NeuN, NeuroChrom) and Tau (S)-[18F]THK5117 autoradiography, immunohistochemistry and Western blot were also performed. Results: [18F]DPA-714 positron emission tomography (PET) showed an increase in neuroinflammation in TG vs wildtype animals from 12 m in the hippocampus (+11%), and at the advanced-stage AD in the hippocampus (+12%), the thalamus (+11%) and frontal cortex (+14%). This finding coincided with strong increases in brain microgliosis (CD11b) and astrogliosis (GFAP) at these time-points as assessed by immunohistochemistry. In vivo [18F]ASEM PET revealed an age-dependent increase uptake in the striatum and pallidum/nucleus basalis of Meynert in WT only, similar to that observed with this tracer in humans, resulting in TG being significantly lower than WT by 18 m. In vivo [18F]Florbetaben PET scanning detected Aβ accumulation at 18 m, and (S)-[18F]THK5117 PET revealed subsequent Tau accumulation at 25m in hippocampal and cortical regions. Aβ plaques were low but detectable by immunohistochemistry from 6 m, increasing further at 12 and 18 m with Tau-positive neurons adjacent to Aβ plaques at 18 m. NeuroChrom (a pan neuronal marker) immunohistochemistry revealed a loss of neuronal staining at the Aβ plaques locations, while NeuN labelling revealed an age-dependent decrease in hippocampal neuron number in both genotypes. Behavioural assessment using the novel object recognition task revealed that both WT & TgF344-AD animals discriminated the novel from familiar object at 3 m and 6 m of age. However, low levels of exploration observed in both genotypes at later time-points resulted in neither genotype successfully completing the task. Deficits in social interaction were only observed at 3 m in the TgF344-AD animals. By in vivo MRS, we showed a decrease in neuronal marker N-acetyl-aspartate in the hippocampus at 18 m (-18% vs age-matched WT, and -31% vs 6 m TG) and increased Taurine in the cortex of TG (+35% vs age-matched WT, and +55% vs 6 m TG). Conclusions: This multi-centre multi-modal study demonstrates, for the first time, alterations in brain metabolites, cholinergic receptors and neuroinflammation in vivo in this model, validated by robust ex vivo approaches. Our data confirm that, unlike mouse models, the TgF344-AD express Tau pathology that can be detected via PET, albeit later than by ex vivo techniques, and is a useful model to assess and longitudinally monitor early neurotransmission dysfunction and neuroinflammation in AD.
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9
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Vetel S, Foucault-Fruchard L, Tronel C, Buron F, Vergote J, Bodard S, Routier S, Sérrière S, Chalon S. Neuroprotective and anti-inflammatory effects of a therapy combining agonists of nicotinic α7 and σ1 receptors in a rat model of Parkinson's disease. Neural Regen Res 2021; 16:1099-1104. [PMID: 33269756 PMCID: PMC8224116 DOI: 10.4103/1673-5374.300451] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
To date there is no treatment able to stop or slow down the loss of dopaminergic neurons that characterizes Parkinson’s disease. It was recently observed in a rodent model of Alzheimer’s disease that the interaction between the α7 subtype of nicotinic acetylcholine receptor (α7-nAChR) and sigma-1 receptor (σ1-R) could exert neuroprotective effects through the modulation of neuroinflammation which is one of the key components of the pathophysiology of Parkinson’s disease. In this context, the aim of the present study was to assess the effects of the concomitant administration of N-(3R)-1-azabicyclo[2.2.2]oct-3-yl-furo[2,3-c]pyridine-5-carboxamide (PHA) 543613 as an α7-nAChR agonist and 2-(4-morpholinethyl) 1-phenylcyclohexanecarboxylate (PRE)-084 as a σ1-R agonist in a well-characterized 6-hydroxydopamine rat model of Parkinson’s disease. The animals received either vehicle separately or the dual therapy PHA/PRE once a day until day 14 post-lesion. Although no effect was noticed in the amphetamine-induced rotation test, our data has shown that the PHA/PRE treatment induced partial protection of the dopaminergic neurons (15–20%), assessed by the dopamine transporter density in the striatum and immunoreactive tyrosine hydroxylase in the substantia nigra. Furthermore, this dual therapy reduced the degree of glial activation consecutive to the 6-hydroxydopamine lesion, i.e, the 18 kDa translocation protein density and glial fibrillary acidic protein staining in the striatum, and the CD11b and glial fibrillary acidic protein staining in the substantia nigra. Hence, this study reports for the first time that concomitant activation of α7-nAChR and σ1-R can provide a partial recovery of the nigro-striatal dopaminergic neurons through the modulation of microglial activation. The study was approved by the Regional Ethics Committee (CEEA Val de Loire n°19) validated this protocol (Authorization N°00434.02) on May 15, 2014.
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Affiliation(s)
- Steven Vetel
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
| | | | - Claire Tronel
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
| | - Frédéric Buron
- Institut de Chimie Organique et Analytique, ICOA, UMR CNRS 7311, Université d'Orléans, Orléans, France
| | - Jackie Vergote
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
| | - Sylvie Bodard
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
| | - Sylvain Routier
- Institut de Chimie Organique et Analytique, ICOA, UMR CNRS 7311, Université d'Orléans, Orléans, France
| | - Sophie Sérrière
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
| | - Sylvie Chalon
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
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Zeng Z, Roussakis AA, Lao-Kaim NP, Piccini P. Astrocytes in Parkinson's disease: from preclinical assays to in vivo imaging and therapeutic probes. Neurobiol Aging 2020; 95:264-270. [PMID: 32905922 DOI: 10.1016/j.neurobiolaging.2020.07.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/30/2020] [Accepted: 07/14/2020] [Indexed: 12/11/2022]
Abstract
Parkinson's disease (PD) is increasingly thought to be associated with glial pathology. Recently, research in neurodegenerative disorders has applied a greater focus to better understanding the role of astrocytes in the disease pathophysiology. In this article, we review results from the latest preclinical and clinical work, including functional imaging studies on astrocytes in PD and highlight key molecules that may prove valuable as biomarkers. We discuss how astrocytes may contribute to the initiation and progression of PD. We additionally present trials of investigational medicinal products and the current background for the design of future clinical trials.
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Affiliation(s)
- Zhou Zeng
- Department of Brain Sciences, Imperial College London, Neurology Imaging Unit, London, UK; Department of Neurology, Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | | | - Nicholas P Lao-Kaim
- Department of Brain Sciences, Imperial College London, Neurology Imaging Unit, London, UK
| | - Paola Piccini
- Department of Brain Sciences, Imperial College London, Neurology Imaging Unit, London, UK.
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11
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Donat CK, Hansen HH, Hansen HD, Mease RC, Horti AG, Pomper MG, L’Estrade ET, Herth MM, Peters D, Knudsen GM, Mikkelsen JD. In Vitro and In Vivo Characterization of Dibenzothiophene Derivatives [ 125I]Iodo-ASEM and [ 18F]ASEM as Radiotracers of Homo- and Heteromeric α7 Nicotinic Acetylcholine Receptors. Molecules 2020; 25:molecules25061425. [PMID: 32245032 PMCID: PMC7144377 DOI: 10.3390/molecules25061425] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/25/2020] [Accepted: 02/27/2020] [Indexed: 12/18/2022] Open
Abstract
The α7 nicotinic acetylcholine receptor (α7 nAChR) is involved in several cognitive and physiologic processes; its expression levels and patterns change in neurologic and psychiatric diseases, such as schizophrenia and Alzheimer’s disease, which makes it a relevant drug target. Development of selective radioligands is important for defining binding properties and occupancy of novel molecules targeting the receptor. We tested the in vitro binding properties of [125I]Iodo-ASEM [(3-(1,4-diazabycyclo[3.2.2]nonan-4-yl)-6-(125I-iododibenzo[b,d]thiopentene 5,5-dioxide)] in the mouse, rat and pig brain using autoradiography. The in vivo binding properties of [18F]ASEM were investigated using positron emission tomography (PET) in the pig brain. [125I]Iodo-ASEM showed specific and displaceable high affinity (~1 nM) binding in mouse, rat, and pig brain. Binding pattern overlapped with [125I]α-bungarotoxin, specific binding was absent in α7 nAChR gene-deficient mice and binding was blocked by a range of α7 nAChR orthosteric modulators in an affinity-dependent order in the pig brain. Interestingly, relative to the wild-type, binding in β2 nAChR gene-deficient mice was lower for [125I]Iodo-ASEM (58% ± 2.7%) than [125I]α-bungarotoxin (23% ± 0.2%), potentially indicating different binding properties to heteromeric α7β2 nAChR. [18F]ASEM PET in the pig showed high brain uptake and reversible tracer kinetics with a similar spatial distribution as previously reported for α7 nAChR. Blocking with SSR-180,711 resulted in a significant decrease in [18F]ASEM binding. Our findings indicate that [125I]Iodo-ASEM allows sensitive and selective imaging of α7 nAChR in vitro, with better signal-to-noise ratio than previous tracers. Preliminary data of [18F]ASEM in the pig brain demonstrated principal suitable kinetic properties for in vivo quantification of α7 nAChR, comparable to previously published data.
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Affiliation(s)
- Cornelius K. Donat
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
- Department of Brain Sciences, Imperial College London, London W12 0 LS, UK
- Correspondence: (C.K.D.); (J.D.M.); Tel.: +45-40205378 (J.D.M)
| | - Henrik H. Hansen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
| | - Hanne D. Hansen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
| | - Ronnie C. Mease
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (R.C.M.); (A.G.H.); (M.G.P.)
| | - Andrew G. Horti
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (R.C.M.); (A.G.H.); (M.G.P.)
| | - Martin G. Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (R.C.M.); (A.G.H.); (M.G.P.)
| | - Elina T. L’Estrade
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark;
- Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Matthias M. Herth
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark;
- Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | | | - Gitte M. Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
| | - Jens D. Mikkelsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
- Correspondence: (C.K.D.); (J.D.M.); Tel.: +45-40205378 (J.D.M)
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