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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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Li J, Chen P, Bao Y, Sun Y, He J, Liu X. PET Imaging of Vesicular Monoamine Transporter 2 in Early Diabetic Retinopathy Using [ 18F]FP-(+)-DTBZ. Mol Imaging Biol 2021; 22:1161-1169. [PMID: 31650482 DOI: 10.1007/s11307-019-01443-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Diabetic retinopathy (DR) is characterized by dopaminergic neuron loss in the retina of the eyes. [18F]fluoropropyl-(+)-dihydrotetrabenazine ([18F]FP-(+)-DTBZ) positron emission tomography (PET) has been shown to detect dopaminergic neuron loss. The study is to investigate the feasibility of PET imaging with [18F]FP-(+)-DTBZ for early diagnosis of diabetic retinopathy (DR) in diabetes mellitus (DM) rat models. METHODS The DM rat model was established by a single intraperitoneal injection of streptozotocin (STZ) (65 mg/kg). After 4 weeks, 8 weeks, and 12 weeks of STZ injection, the retinas of the rats were evaluated by electroretinogram (ERG), color fundus photography (CFP), fundus fluorescein angiography (FFA), and small animal PET scan with [18F]FP-(+)-DTBZ by targeting vesicular monoamine transporter 2 (VMAT2). [18F]FP-(+)-DTBZ uptake in retina was quantified as standardized uptake value (SUV). Immunofluorescence staining and Western blot were also performed to confirm the expression level of VMAT2 in retina. RESULTS ERG dysfunction was observed at 8 weeks in STZ-diabetic rats, evidenced by smaller amplitudes of oscillatory potentials (OPs) when compared with OPs in normal rats. CFP and FFA showed no significant difference in vascular leakage and neovascularization between STZ-diabetic retinas and normal ones until 8 weeks. PET imaging revealed that the SUV of [18F]FP-(+)-DTBZ was significantly lower in the STZ-diabetic retinas compared with the normal ones as early as of week 4. The results from immunofluorescence staining and Western blots confirmed the early findings in PET imaging studies. CONCLUSIONS Early DR can be non-invasively detected with PET imaging using [18F]FP-(+)-DTBZ targeting VMAT2. The expression level of VMAT2 in retina may act as a new biomarker for early DR diagnosis.
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Affiliation(s)
- Jun Li
- Department of Nuclear Medicine, Huashan Hospital, Fudan University, No. 12 Urumchi Middle Road, Jing'an District, Shanghai, 200040, China
- Department of Radiology and Medical imaging, University of Virginia, Charlottesville, VA, 22908, USA
| | - Ping Chen
- Department of Nuclear Medicine, Huashan Hospital, Fudan University, No. 12 Urumchi Middle Road, Jing'an District, Shanghai, 200040, China
| | - Yong Bao
- Department of Pharmacology and Biochemistry, School of Pharmacy, Fudan University, Shanghai, 201203, China
| | - Yu Sun
- Department of Nuclear Medicine, Huashan Hospital, Fudan University, No. 12 Urumchi Middle Road, Jing'an District, Shanghai, 200040, China
| | - Jiang He
- Department of Radiology and Medical imaging, University of Virginia, Charlottesville, VA, 22908, USA
| | - Xingdang Liu
- Department of Nuclear Medicine, Huashan Hospital, Fudan University, No. 12 Urumchi Middle Road, Jing'an District, Shanghai, 200040, China.
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Post MR, Sulzer D. The chemical tools for imaging dopamine release. Cell Chem Biol 2021; 28:748-764. [PMID: 33894160 PMCID: PMC8532025 DOI: 10.1016/j.chembiol.2021.04.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 02/23/2021] [Accepted: 04/06/2021] [Indexed: 02/07/2023]
Abstract
Dopamine is a modulatory neurotransmitter involved in learning, motor functions, and reward. Many neuropsychiatric disorders, including Parkinson's disease, autism, and schizophrenia, are associated with imbalances or dysfunction in the dopaminergic system. Yet, our understanding of these pervasive public health issues is limited by our ability to effectively image dopamine in humans, which has long been a goal for chemists and neuroscientists. The last two decades have witnessed the development of many molecules used to trace dopamine. We review the small molecules, nanoparticles, and protein sensors used with fluorescent microscopy/photometry, MRI, and PET that shape dopamine research today. None of these tools observe dopamine itself, but instead harness the biology of the dopamine system-its synthetic and metabolic pathways, synaptic vesicle cycle, and receptors-in elegant ways. Their advantages and weaknesses are covered here, along with recent examples and the chemistry and biology that allow them to function.
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Affiliation(s)
- Michael R Post
- Department of Psychiatry, Columbia University Medical Center, New York, NY, USA; Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA.
| | - David Sulzer
- Departments of Psychiatry, Neurology, and Pharmacology, Columbia University Medical Center, New York, NY, USA; Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA.
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Liu C, Tang J, Xu Y, Cao S, Fang Y, Zhao C, Chen Z. Molar activity of [ 18F]FP-(+)-DTBZ radiopharmaceutical: Determination and its effect on quantitative analysis of VMAT2 autoradiography. J Pharm Biomed Anal 2021; 203:114212. [PMID: 34153939 DOI: 10.1016/j.jpba.2021.114212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 04/24/2021] [Accepted: 06/13/2021] [Indexed: 10/21/2022]
Abstract
[18F]fluoropropyl-(+)-dihydrotetrabenazine ([18F]FP-(+)-DTBZ) is a rising positron tracer for imaging vesicular monoamine transporter II (VMAT2) in the central nervous system. The present work was to develop a novel chromatographic method capable of the molar activity (Am) determination of [18F]FP-(+)-DTBZ. As a complement work of the Am measurement, we also investigated the effect of Am on the quantitative analysis of VMAT2 autoradiography with [18F]FP-(+)-DTBZ. The Am determination was performed by high performance liquid chromatography (HPLC) using the non-radioactive standard (FP-(+)-DTBZ) for calibration plot of peak area against concentration. Based on this correlation, the Am of [18F]FP-(+)-DTBZ was calculated and corrected to the end of synthesis. In the quantitative analysis of in vitro VMAT2 autoradiography, the striatum radioactivity uptake together with the uptake ratio of striatum versus cortex reduced along with the decrease of Am and the increase of the FP-(+)-DTBZ content. Therefore, the Am and the corresponding FP-(+)-DTBZ content have a significant effect on the quantitative analysis of VMAT2 autoradiography using [18F]FP-(+)-DTBZ.
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Affiliation(s)
- Chunyi Liu
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063, China
| | - Jie Tang
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063, China
| | - Yingjiao Xu
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063, China; Department of Radiopharmaceuticals, School of Pharmacy, Nanjing Medical University, Nanjing, 211166, China
| | - Shanshan Cao
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063, China
| | - Yi Fang
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063, China
| | - Chao Zhao
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063, China
| | - Zhengping Chen
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063, China.
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Xu Y, Tang J, Liu C, Zhao C, Cao S, Yu H, Chen Z, Xie M. MicroPET imaging of vesicular monoamine transporter 2 revealed the potentiation of (+)-dihydrotetrabenazine on MPTP-induced degeneration of dopaminergic neurons. Nucl Med Biol 2021; 96-97:9-18. [PMID: 33647803 DOI: 10.1016/j.nucmedbio.2021.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/10/2021] [Accepted: 02/11/2021] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Vesicular monoamine transporter 2 (VMAT2) has been associated with the risk of PD. Genetic reduction of VMAT2 level is reported to increase the vulnerability for dopaminergic neurodegeneration. In this study, by using in vivo microPET imaging with a VMAT2 radioligand [18F]fluoropropyl-(+)-dihydrotetrabenazine ([18F]FP-(+)-DTBZ), we investigated the enhanced role of inhibiting VMAT2 in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced loss of dopaminergic neurons. METHODS The (+)-α-dihydrotetrabenazine ((+)-DTBZ, an inhibitor of VMAT2, 5 mg/kg), or MPTP (low dose (ld): 10 mg/kg, high dose (hd): 30 mg/kg) or both of them were intraperitoneally injected into C57BL/6 mice for 5 or 10 consecutive days. MicroPET imaging with [18F]FP-(+)-DTBZ was performed to test the dopaminergic neuronal integrity. [18F]FP-(+)-DTBZ uptake in striatum was quantified as standardized uptake value (SUV). The pathological changes in the striata and substantia nigra were confirmed by measuring the DA contents and immunohistochemical staining of tyrosine hydroxylase (TH). RESULTS In vivo imaging results showed that the striatal SUVs of both DTBZ&MPTPld and MPTPhd groups were substantially declined compared to the baseline. Moreover, the striatal uptakes of [18F]FP-(+)-DTBZ in DTBZ&MPTPld and MPTPhd groups were obviously lower than the control, DTBZ group and MPTPld group. Notably, the decrease of the striatal uptake in the DTBZ&MPTPld/10d group was more serious than the DTBZ&MPTPld/5d group and comparable to the MPTPhd group. Consistently, the ratios of DA metabolites to DA in DTBZ&MPTPld/10d and MPTPhd mice were significantly increased. The correlation analysis showed that SUVs were highly correlated to the striatal dopaminergic fiber density and TH-positive dopaminergic neuron number in the substantia nigra. CONCLUSIONS MicroPET brain imaging with [18F]FP-(+)-DTBZ noninvasively revealed that (+)-DTBZ co-administration significantly aggravated the neurotoxicity of MPTP to dopaminergic neurons, suggesting that inhibition of VMAT2 may be related to the pathogenesis of PD and tracing VMAT2 activity with PET imaging is of potential value in monitoring PD progression.
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Affiliation(s)
- Yingjiao Xu
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu 214063, China; Department of Radiopharmaceuticals, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Jie Tang
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu 214063, China
| | - Chunyi Liu
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu 214063, China
| | - Chao Zhao
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu 214063, China
| | - Shanshan Cao
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu 214063, China
| | - Huixin Yu
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu 214063, China
| | - Zhengping Chen
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu 214063, China.
| | - Minhao Xie
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu 214063, China; Department of Radiopharmaceuticals, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China.
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Tang J, Xu Y, Liu C, Fang Y, Cao S, Zhao C, Huang H, Zou M, Chen Z. PET imaging with [ 18F]FP-(+)-DTBZ in 6-OHDA-induced partial and full unilaterally-lesioned model rats of Parkinson's disease and the correlations to the biological data. Nucl Med Biol 2020; 90-91:1-9. [PMID: 32861175 DOI: 10.1016/j.nucmedbio.2020.08.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/19/2020] [Accepted: 08/13/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE The deficit of dopaminergic neurons in the nigrostriatal pathway is one of the pathological features of Parkinson's disease (PD). The decline of vesicular monoamine transporter type 2 (VMAT2) has been verified to relate with the severity of PD. The purpose of this study was to evaluate the ability of [18F]fluoropropyl-(+)-dihydrotetrabenazine ([18F]FP-(+)-DTBZ) to detect dopaminergic neuron dysfunction in a standard rat model of PD using PET imaging. Specifically, two different doses of 6-hydroxydopamine (6-OHDA) were injected unilaterally into the medial forebrain bundle (MFB) to create the models with two different severities. METHODS Male Sprague-Dawley rats were intracranially injected with 8 μg 6-OHDA (partial lesion group), 16 μg 6-OHDA (full lesion group) and vehicle (sham group) into MFB, respectively. Thirty minutes static [18F]FP-(+)-DTBZ microPET scanning was performed to determine the dopaminergic neuron integrity on the 28th day post-injection and the behavioral tests were carried out in the next two days. Then, the rats were decapitated, and the brains were collected for biogenic amines content analysis or dissected for autoradiography and immunohistochemical (IHC) staining. The correlations of PET results to the behavioral, biological, histological, autoradiography results were analyzed, respectively. RESULTS The standardized uptake value ratio (ST to CB) of [18F]FP-(+)-DTBZ in the ipsilateral striata decreased significantly in partial lesion group and full lesion group. Compared with the sham group, the ratio of the standardized uptake value in ipsilateral striatum to that in contralateral striatum decreased by 57.09 ± 2.30% (full lesion group) and 25.31 ± 5.70% (partial lesion group), respectively. The dopaminergic neuronal dysfunction was corroborated by in vitro autoradiography, IHC, and quantitative analysis of DA as well as its metabolites concentration tests. The motor function impairments of 6-OHDA-treated animals were manifested by a series of behavioral tests. The results of microPET imaging were linearly correlated with behavioral, biological, histological, and autoradiography results, respectively. CONCLUSION Our data suggest that [18F]FP-(+)-DTBZ may be useful for detecting different degrees of dopaminergic neuronal lesions by PET imaging in PD models induced by 6-OHDA.
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Affiliation(s)
- Jie Tang
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China
| | - Yingjiao Xu
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China; Nanjing Medical University, Nanjing 211166, China
| | - Chunyi Liu
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China
| | - Yi Fang
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China
| | | | - Chao Zhao
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China
| | - Hongbo Huang
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China
| | - Meifen Zou
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China
| | - Zhengping Chen
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China.
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Influence of intranasal exposure of MPTP in multiple doses on liver functions and transition from non-motor to motor symptoms in a rat PD model. Naunyn Schmiedebergs Arch Pharmacol 2019; 393:147-165. [PMID: 31468077 DOI: 10.1007/s00210-019-01715-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 08/15/2019] [Indexed: 12/14/2022]
Abstract
Besides the effects on the striatum, the impairment of visceral organs including liver functions has been reported in Parkinson's disease (PD) patients. However, it is yet unclear if liver functions are affected in the early stage of the disease before the motor phase has appeared. The aim of our present study was thus to assess the effect of intranasal administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in different doses on striatum and liver functions. Deterioration of non-motor activities appeared on single exposure to MPTP along with rise in striatum oxidative stress and decline in antioxidant levels. Decreases in dopamine, noradrenaline, and GABA and increase in serotonin were detected in striatum. Motor coordination was impaired with a single dose of MPTP, and with repeated MPTP exposure, there was further significant impairment. Locomotor activity was affected from second exposure of MPTP, and the impairment increased with third MPTP exposure. Impairment of liver function through increase in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels was observed after first MPTP insult, and it worsened with second and third administrations. First administration of MPTP triggered systemic inflammation showing significant increase in inflammatory markers in the liver. Our data shows for the first time that an intranasal route of entry of MPTP affects liver from the non-motor phase of PD itself, occurring concomitantly with the reduction of striatal dopamine. It also suggests that a single dose is not enough to bring about progression of the disease from non-motor to locomotor deficiency, and a repeated dose is needed to establish the motor severity phase in the rat intranasal MPTP model.
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Chen HH, Chang PC, Wey SP, Chen PM, Chen C, Chan MH. Therapeutic effects of honokiol on motor impairment in hemiparkinsonian mice are associated with reversing neurodegeneration and targeting PPARγ regulation. Biomed Pharmacother 2018; 108:254-262. [DOI: 10.1016/j.biopha.2018.07.095] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/16/2018] [Accepted: 07/18/2018] [Indexed: 02/07/2023] Open
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Mouse models of neurodegenerative disease: preclinical imaging and neurovascular component. Brain Imaging Behav 2017; 12:1160-1196. [PMID: 29075922 DOI: 10.1007/s11682-017-9770-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neurodegenerative diseases represent great challenges for basic science and clinical medicine because of their prevalence, pathologies, lack of mechanism-based treatments, and impacts on individuals. Translational research might contribute to the study of neurodegenerative diseases. The mouse has become a key model for studying disease mechanisms that might recapitulate in part some aspects of the corresponding human diseases. Neurodegenerative disorders are very complicated and multifactorial. This has to be taken in account when testing drugs. Most of the drugs screening in mice are very difficult to be interpretated and often useless. Mouse models could be condiderated a 'pathway models', rather than as models for the whole complicated construct that makes a human disease. Non-invasive in vivo imaging in mice has gained increasing interest in preclinical research in the last years thanks to the availability of high-resolution single-photon emission computed tomography (SPECT), positron emission tomography (PET), high field Magnetic resonance, Optical Imaging scanners and of highly specific contrast agents. Behavioral test are useful tool to characterize different animal models of neurodegenerative pathology. Furthermore, many authors have observed vascular pathological features associated to the different neurodegenerative disorders. Aim of this review is to focus on the different existing animal models of neurodegenerative disorders, describe behavioral tests and preclinical imaging techniques used for diagnose and describe the vascular pathological features associated to these diseases.
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Quantitative analysis of the therapeutic effect of magnolol on MPTP-induced mouse model of Parkinson's disease using in vivo 18F-9-fluoropropyl-(+)-dihydrotetrabenazine PET imaging. PLoS One 2017; 12:e0173503. [PMID: 28257461 PMCID: PMC5336287 DOI: 10.1371/journal.pone.0173503] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 02/21/2017] [Indexed: 02/04/2023] Open
Abstract
18F-9-Fluoropropyl-(+)-dihydrotetrabenazine [18F-FP-(+)-DTBZ] positron emission tomography (PET) has been shown to detect dopaminergic neuron loss associated with Parkinson’s disease (PD) in human and neurotoxin-induced animal models. A polyphenol compound, magnolol, was recently proposed as having a potentially restorative effect in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)- or 6-hydroxydopamine-treated animal models. In this study, 18F-FP-(+)-DTBZ PET was used to determine the therapeutic efficacy of magnolol in an MPTP–PD mouse model that was prepared by giving an intraperitoneally (i.p.) daily dose of 25 mg/kg MPTP to male C57BL/6 mice for 5 consecutive days. Twenty-minute static 18F-FP-(+)-DTBZ PET scans were performed before MPTP treatment and 5 days after the termination of MPTP treatment to set up the baseline control. Half of the MPTP-treated mice then received a daily dose of magnolol (10 mg/kg dissolved in corn oil, i.p.) for 6 days. 18F-FP-(+)-DTBZ PET imaging was performed the day after the final treatment. All 18F-FP-(+)-DTBZ PET images were analysed and the specific uptake ratio (SUr) was calculated. Ex vivo autoradiography (ARG) and corresponding immunohistochemistry (IHC) studies were conducted to confirm the distribution of dopaminergic terminals in the striatum. The striatal SUr ratios of 18F-FP-(+)-DTBZ PET images for the Sham, the MPTP, and the MPTP + Magnolol-treated groups were 1.25 ± 0.05, 0.75 ± 0.06, and 1.00 ± 0.11, respectively (n = 4 for each group). The ex vivo 18F-FP-(+)-DTBZ ARG and IHC results correlated favourably with the PET imaging results. 18F-FP-(+)-DTBZ PET imaging suggested that magnolol post-treatment may reverse the neuronal damage in the MPTP-lesioned PD mice. In vivo imaging of the striatal vesicular monoamine transporter type 2 (VMAT2) distribution using 18F-FP-(+)-DTBZ animal PET is a useful method to evaluate the efficacy of therapeutic drugs i.e., magnolol, for the management of PD.
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Beck G, Shinzawa K, Hayakawa H, Baba K, Sumi-Akamaru H, Tsujimoto Y, Mochizuki H. Progressive Axonal Degeneration of Nigrostriatal Dopaminergic Neurons in Calcium-Independent Phospholipase A2β Knockout Mice. PLoS One 2016; 11:e0153789. [PMID: 27078024 PMCID: PMC4831782 DOI: 10.1371/journal.pone.0153789] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 04/04/2016] [Indexed: 11/19/2022] Open
Abstract
Calcium-independent phospholipase A2β (iPLA2β, PLA2G6) is essential for the remodeling of membrane glycerophospholipids. Mutations in this gene are responsible for autosomal recessive, young onset, L-dopa-responsive parkinsonism (PARK14), suggesting a neurodegenerative condition in the nigrostriatal dopaminergic system in patients with PLA2G6 mutations. We previously observed slowly progressive motor deficits in iPLA2β-knockout (KO) mice. To clarify whether a deficiency of iPLA2β leads to the degeneration of nigrostriatal dopaminergic neurons, we analyzed the striatum of iPLA2β-KO mice. At all clinical stages, nerve terminals in the striatum were immunopositive for tyrosine hydroxylase (TH) and dopamine transporter (DAT) in wild-type (WT) control mice. In iPLA2β-KO mice, focal loss of nerve terminals positive for TH and DAT was found from 56 weeks (early clinical stage), although iPLA2β-KO mice at 56 weeks showed no significant decrease in the number of dopaminergic neurons in the substantia nigra compared with age-matched WT mice, as reported previously. At 100 weeks (late clinical stage), greater decreases in DAT immunoreactivity were observed in the striatum of iPLA2β-KO mice. Moreover, strongly TH-positive structures, presumed to be deformed axons, were observed in the neuropils of the striatum of iPLA2β-KO mice starting at 15 weeks (preclinical stage) and increased with age. These results suggest that the degeneration of dopaminergic neurons occurs mainly in the distal region of axons in iPLA2β-KO mice.
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Affiliation(s)
- Goichi Beck
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Koei Shinzawa
- Department of Medical Genetics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Hideki Hayakawa
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Kousuke Baba
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Hisae Sumi-Akamaru
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Yoshihide Tsujimoto
- Department of Medical Genetics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan
| | - Hideki Mochizuki
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- * E-mail:
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Siva Senkar Reddy N, Srinivas Reddy A, Yadav J, Subba Reddy B. The stereoselective total synthesis of (−)-dihydrotetrabenazine. Tetrahedron Lett 2012. [DOI: 10.1016/j.tetlet.2012.10.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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