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Domenicale C, Magnabosco S, Morari M. Modeling Parkinson's disease in LRRK2 rodents. Neuronal Signal 2023; 7:NS20220040. [PMID: 37601008 PMCID: PMC10432857 DOI: 10.1042/ns20220040] [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: 04/20/2023] [Revised: 07/21/2023] [Accepted: 07/31/2023] [Indexed: 08/22/2023] Open
Abstract
Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are associated with familial and sporadic forms of Parkinson's disease (PD). Sporadic PD and LRRK2 PD share main clinical and neuropathological features, namely hypokinesia, degeneration of nigro-striatal dopamine neurons and α-synuclein aggregates in the form of Lewy bodies. Animals harboring the most common LRRK2 mutations, i.e. p.G2019S and p.R1441C/G, have been generated to replicate the parkinsonian phenotype and investigate the underlying pathogenic mechanisms. Disappointingly, however, LRRK2 rodents did not consistently phenocopy hypokinesia and nigro-striatal degeneration, or showed Lewy body-like aggregates. Instead, LRRK2 rodents manifested non-motor signs and dysregulated transmission at dopaminergic and non-dopaminergic synapses that are reminiscent of behavioral and functional network changes observed in the prodromal phase of the disease. LRRK2 rodents also manifested greater susceptibility to different parkinsonian toxins or stressors when subjected to dual-hit or multiple-hit protocols, confirming LRRK2 mutations as genetic risk factors. In conclusion, LRRK2 rodents represent a unique tool to identify the molecular mechanisms through which LRRK2 modulates the course and clinical presentations of PD and to study the interplay between genetic, intrinsic and environmental protective/risk factors in PD pathogenesis.
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Affiliation(s)
- Chiara Domenicale
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44121 Ferrara, Italy
| | - Stefano Magnabosco
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44121 Ferrara, Italy
| | - Michele Morari
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44121 Ferrara, Italy
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2
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Dopamine Transporter, PhosphoSerine129 α-Synuclein and α-Synuclein Levels in Aged LRRK2 G2019S Knock-In and Knock-Out Mice. Biomedicines 2022; 10:biomedicines10040881. [PMID: 35453631 PMCID: PMC9027615 DOI: 10.3390/biomedicines10040881] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/07/2022] [Accepted: 04/09/2022] [Indexed: 02/04/2023] Open
Abstract
The G2019S mutation in leucine rich-repeat kinase 2 (LRRK2) is a major cause of familial Parkinson’s disease. We previously reported that G2019S knock-in mice manifest dopamine transporter dysfunction and phosphoSerine129 α-synuclein (pSer129 α-syn) immunoreactivity elevation at 12 months of age, which might represent pathological events leading to neuronal degeneration. Here, the time-dependence of these changes was monitored in the striatum of 6, 9, 12, 18 and 23-month-old G2019S KI mice and wild-type controls using DA uptake assay, Western analysis and immunohistochemistry. Western analysis showed elevation of membrane dopamine transporter (DAT) levels at 9 and 12 months of age, along with a reduction of vesicular monoamine transporter 2 (VMAT2) levels at 12 months. DAT uptake was abnormally elevated from 9 to up to 18 months. DAT and VMAT2 level changes were specific to the G2019S mutation since they were not observed in LRRK2 kinase-dead or knock-out mice. Nonetheless, dysfunctional DAT uptake was not normalized by acute pharmacological inhibition of LRRK2 kinase activity with MLi-2. Immunoblot analysis showed elevation of pSer129 α-syn levels in the striatum of 12-month-old G2019S KI mice, which, however, was not confirmed by immunohistochemical analysis. Instead, total α-syn immunoreactivity was found elevated in the striatum of 23-month-old LRRK2 knock-out mice. These data indicate mild changes in DA transporters and α-syn metabolism in the striatum of 12-month-old G2019S KI mice whose pathological relevance remains to be established.
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3
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Klonarakis M, De Vos M, Woo E, Ralph L, Thacker JS, Gil-Mohapel J. The three sisters of fate: Genetics, pathophysiology and outcomes of animal models of neurodegenerative diseases. Neurosci Biobehav Rev 2022; 135:104541. [DOI: 10.1016/j.neubiorev.2022.104541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 11/28/2021] [Accepted: 01/13/2022] [Indexed: 02/07/2023]
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4
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Lawana V, Um SY, Rochet JC, Turesky RJ, Shannahan JH, Cannon JR. Neuromelanin Modulates Heterocyclic Aromatic Amine-Induced Dopaminergic Neurotoxicity. Toxicol Sci 2021; 173:171-188. [PMID: 31562763 DOI: 10.1093/toxsci/kfz210] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Heterocyclic aromatic amines (HAAs) are mutagens and potential human carcinogens. Our group and others have demonstrated that HAAs may also produce selective dopaminergic neurotoxicity, potentially relevant to Parkinson's disease (PD). The goal of this study was to elucidate mechanisms of HAA-induced neurotoxicity through examining a translational biochemical weakness of common PD models. Neuromelanin is a pigmented byproduct of dopamine metabolism that has been debated as being both neurotoxic and neuroprotective in PD. Importantly, neuromelanin is known to bind and potentially release dopaminergic neurotoxicants, including HAAs (eg, β-carbolines such as harmane). Binding of other HAA subclasses (ie, aminoimidazoaazarenes) to neuromelanin has not been investigated, nor has a specific role for neuromelanin in mediating HAA-induced neurotoxicity been examined. Thus, we investigated the role of neuromelanin in modulating HAA-induced neurotoxicity. We characterized melanin from Sepia officinalis and synthetic dopamine melanin, proposed neuromelanin analogs with similar biophysical properties. Using a cell-free assay, we demonstrated strong binding of harmane and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) to neuromelanin analogs. To increase cellular neuromelanin, we transfected SH-SY5Y neuroblastoma cells with tyrosinase. Relative to controls, tyrosinase-expressing cells exhibited increased neuromelanin levels, cellular HAA uptake, cell toxicity, and oxidative damage. Given that typical cellular and rodent PD models form far lower neuromelanin levels than humans, there is a critical translational weakness in assessing HAA-neurotoxicity. The primary impacts of these results are identification of a potential mechanism by which HAAs accumulate in catecholaminergic neurons and support for the need to conduct neurotoxicity studies in systems forming neuromelanin.
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Affiliation(s)
- Vivek Lawana
- School of Health Sciences.,Purdue Institute for Integrative Neuroscience
| | | | - Jean-Christophe Rochet
- Purdue Institute for Integrative Neuroscience.,Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907
| | - Robert J Turesky
- Department of Medicinal Chemistry, Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455
| | | | - Jason R Cannon
- School of Health Sciences.,Purdue Institute for Integrative Neuroscience
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5
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Pathogenic LRRK2 requires secondary factors to induce cellular toxicity. Biosci Rep 2021; 40:226517. [PMID: 32975566 PMCID: PMC7560525 DOI: 10.1042/bsr20202225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/08/2020] [Accepted: 09/24/2020] [Indexed: 12/02/2022] Open
Abstract
Pathogenic mutations in the leucine-rich repeat kinase 2 (LRRK2) gene belong to the most common genetic causes of inherited Parkinson’s disease (PD) and variations in its locus increase the risk to develop sporadic PD. Extensive research efforts aimed at understanding how changes in the LRRK2 function result in molecular alterations that ultimately lead to PD. Cellular LRRK2-based models revealed several potential pathophysiological mechanisms including apoptotic cell death, LRRK2 protein accumulation and deficits in neurite outgrowth. However, highly variable outcomes between different cellular models have been reported. Here, we have investigated the effect of different experimental conditions, such as the use of different tags and gene transfer methods, in various cellular LRRK2 models. Readouts included cell death, sensitivity to oxidative stress, LRRK2 relocalization, α-synuclein aggregation and neurite outgrowth in cell culture, as well as neurite maintenance in vivo. We show that overexpression levels and/or the tag fused to LRRK2 affect the relocalization of LRRK2 to filamentous and skein-like structures. We found that overexpression of LRRK2 per se is not sufficient to induce cellular toxicity or to affect α-synuclein-induced toxicity and aggregate formation. Finally, neurite outgrowth/retraction experiments in cell lines and in vivo revealed that secondary, yet unknown, factors are required for the pathogenic LRRK2 effects on neurite length. Our findings stress the importance of technical and biological factors in LRRK2-induced cellular phenotypes and hence imply that conclusions based on these types of LRRK2-based assays should be interpreted with caution.
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Petiet A. Current and Emerging MR Methods and Outcome in Rodent Models of Parkinson's Disease: A Review. Front Neurosci 2021; 15:583678. [PMID: 33897339 PMCID: PMC8058186 DOI: 10.3389/fnins.2021.583678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 03/05/2021] [Indexed: 12/03/2022] Open
Abstract
Parkinson’s disease (PD) is a major neurodegenerative disease characterized by massive degeneration of the dopaminergic neurons in the substantia nigra pars compacta, α-synuclein-containing Lewy bodies, and neuroinflammation. Magnetic resonance (MR) imaging plays a crucial role in the diagnosis and monitoring of disease progression and treatment. A variety of MR methods are available to characterize neurodegeneration and other disease features such as iron accumulation and metabolic changes in animal models of PD. This review aims at giving an overview of how those physiopathological features of PD have been investigated using various MR methods in rodent models. Toxin-based and genetic-based models of PD are first described. MR methods for neurodegeneration evaluation, iron load, and metabolism alterations are then detailed, and the main findings are provided in those models. Ultimately, future directions are suggested for neuroinflammation and neuromelanin evaluations in new animal models.
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Affiliation(s)
- Alexandra Petiet
- Centre de Neuroimagerie de Recherche, Institut du Cerveau, Paris, France.,Inserm U1127, CNRS UMR 7225, Sorbonne Universités, Paris, France
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Kelly K, Chang A, Hastings L, Abdelmotilib H, West AB. Genetic background influences LRRK2-mediated Rab phosphorylation in the rat brain. Brain Res 2021; 1759:147372. [PMID: 33600829 DOI: 10.1016/j.brainres.2021.147372] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 01/11/2021] [Accepted: 02/09/2021] [Indexed: 11/16/2022]
Abstract
Pathogenic missense mutations in the leucine-rich repeat kinase 2 gene, encoding LRRK2, results in the upregulation of Rab10 and Rab12 phosphorylation in different cells and tissues. Here, we evaluate levels of the LRRK2 kinase substrates pT73-Rab10 and pS106-Rab12 proteins in rat brain tissues from different genetic backgrounds. Whereas lines of Sprague Dawley rats have equivalent levels of pT73-Rab10 and pS106-Rab12 similar to Lrrk2 knockout rats, Long-Evans rats have levels of pT73-Rab10 and pS106-Rab12 comparable to G2019S-LRRK2 BAC transgenic rats. Strong LRRK2 kinase inhibitors are ineffective at reducing pT73-Rab10 and pS106-Rab12 levels in the Sprague Dawley rats, but potently reduce pT73-Rab10 and pS106-Rab12 levels in Long-Evans rats. Oral administration of the PFE-360 LRRK2 kinase inhibitor fails to provide neuroprotection from dopaminergic neurodegeneration caused by rAAV2/1-mediated overexpression of A53T-αsynuclein in Sprague Dawley rats. These results highlight substantial differences in LRRK2-mediated Rab10 and Rab12 phosphorylation in commonly utilized rat genetic backgrounds and suggest LRRK2 may not play a central role in Rab phosphorylation or mutant αsynuclein toxicity in Sprague Dawley rats.
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Affiliation(s)
- Kaela Kelly
- Duke Center for Neurodegeneration Research, Department of Pharmacology and Cancer Biology, Duke University, Durham, NC, USA
| | - Allison Chang
- Duke Center for Neurodegeneration Research, Department of Pharmacology and Cancer Biology, Duke University, Durham, NC, USA
| | - Lyndsay Hastings
- Duke Center for Neurodegeneration Research, Department of Pharmacology and Cancer Biology, Duke University, Durham, NC, USA
| | - Hisham Abdelmotilib
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Andrew B West
- Duke Center for Neurodegeneration Research, Department of Pharmacology and Cancer Biology, Duke University, Durham, NC, USA.
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Ke M, Chong CM, Zhu Q, Zhang K, Cai CZ, Lu JH, Qin D, Su H. Comprehensive Perspectives on Experimental Models for Parkinson's Disease. Aging Dis 2021; 12:223-246. [PMID: 33532138 PMCID: PMC7801282 DOI: 10.14336/ad.2020.0331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 03/31/2020] [Indexed: 11/19/2022] Open
Abstract
Parkinson’s disease (PD) ranks second among the most common neurodegenerative diseases, characterized by progressive and selective loss of dopaminergic neurons. Various cross-species preclinical models, including cellular models and animal models, have been established through the decades to study the etiology and mechanism of the disease from cell lines to nonhuman primates. These models are aimed at developing effective therapeutic strategies for the disease. None of the current models can replicate all major pathological and clinical phenotypes of PD. Selection of the model for PD largely relies on our interest of study. In this review, we systemically summarized experimental PD models, including cellular and animal models used in preclinical studies, to understand the pathogenesis of PD. This review is intended to provide current knowledge about the application of these different PD models, with focus on their strengths and limitations with respect to their contributions to the assessment of the molecular pathobiology of PD and identification of the therapeutic strategies for the disease.
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Affiliation(s)
- Minjing Ke
- 1State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Cheong-Meng Chong
- 1State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Qi Zhu
- 1State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Ke Zhang
- 1State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Cui-Zan Cai
- 1State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Jia-Hong Lu
- 1State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Dajiang Qin
- 2Guangzhou Regenerative Medicine and Health Guangdong Laboratory, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,3South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Huanxing Su
- 1State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
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Lee JW, Deng DF, Lee J, Kim K, Jung HJ, Choe Y, Park SH, Yoon M. The adverse effects of selenomethionine on skeletal muscle, liver, and brain in the steelhead trout (Oncorhynchus mykiss). ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2020; 80:103451. [PMID: 32599160 DOI: 10.1016/j.etap.2020.103451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 04/21/2020] [Accepted: 06/25/2020] [Indexed: 06/11/2023]
Abstract
Juvenile Oncorhynchus mykiss (average weight: 22.3 g) were fed one of five selenomethionine diets (1.09, 8.79, 15.37, 30.79, or 61.58 mg Se/kg diet). After 4 weeks, hepatic catalase activity over 15.37 mg Se/kg diets was significantly decreased, and the glutathione peroxidase activity over 30.79 mg Se/kg diets was elevated compared to the controls. In the brain, the dopamine levels at 61.58 mg Se/kg diet and the serotonin levels over 15.37 mg Se/kg diets were significantly increased, whereas the 3,4-dihydroxyphenylacetic acid, homovanillic acid, and dopamine turnover, and the 5-hydroxyindoleacetic acid and serotonin turnover over 30.79 mg Se/kg diets were decreased. In muscle, the 3-nitrotyrosine level over 15.37 mg Se/kg diets, acetylcholine esterase activity over 30.79 mg Se/kg diets, and histological alterations over 8.79 mg Se/kg diets were increased. Our current results showed that selenomethionine disrupted dopamine and serotonin metabolism in the brain and damaged the neuromuscular system in skeletal muscle.
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Affiliation(s)
- Jang-Won Lee
- Department of Integrated Bioindustry, Sejong University, Seoul 05006, South Korea.
| | - Dong-Fang Deng
- School of Freshwater Sciences, University of Wisconsin, Milwaukee, WI 53217, USA
| | - Jinsu Lee
- Department of Integrated Bioindustry, Sejong University, Seoul 05006, South Korea
| | - Kiyoung Kim
- Department of Medical Biotechnology, Soonchunhyang University, Asan 31538, South Korea
| | - Hyun Jin Jung
- Aging Neuroscience Research Group, Korea Brain Research Institute, Daegu 41068, South Korea
| | - Youngshik Choe
- Aging Neuroscience Research Group, Korea Brain Research Institute, Daegu 41068, South Korea
| | - Seung Hwa Park
- Department of Anatomy, Konkuk University School of Medicine, Seoul 05029, South Korea
| | - Minjung Yoon
- Department of Horse, Companion and Wild Animal Science, Kyungpook National University, Sangju 37224, South Korea.
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Seegobin SP, Heaton GR, Liang D, Choi I, Blanca Ramirez M, Tang B, Yue Z. Progress in LRRK2-Associated Parkinson's Disease Animal Models. Front Neurosci 2020; 14:674. [PMID: 32765209 PMCID: PMC7381130 DOI: 10.3389/fnins.2020.00674] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 06/02/2020] [Indexed: 12/19/2022] Open
Abstract
Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most frequent cause of familial Parkinson's disease (PD). Several genetic manipulations of the LRRK2 gene have been developed in animal models such as rodents, Drosophila, Caenorhabditis elegans, and zebrafish. These models can help us further understand the biological function and derive potential pathological mechanisms for LRRK2. Here we discuss common phenotypic themes found in LRRK2-associated PD animal models, highlight several issues that should be addressed in future models, and discuss emerging areas to guide their future development.
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Affiliation(s)
- Steven P. Seegobin
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - George R. Heaton
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Dongxiao Liang
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Department of Neurology, Xiangya Hospital, Central South University, Hunan, China
| | - Insup Choi
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Marian Blanca Ramirez
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Hunan, China
| | - Zhenyu Yue
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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11
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Schildt A, Walker MD, Dinelle K, Miao Q, Schulzer M, O'Kusky J, Farrer MJ, Doudet DJ, Sossi V. Single Inflammatory Trigger Leads to Neuroinflammation in LRRK2 Rodent Model without Degeneration of Dopaminergic Neurons. JOURNAL OF PARKINSONS DISEASE 2020; 9:121-139. [PMID: 30452424 DOI: 10.3233/jpd-181446] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Leucine-rich repeat kinase 2 (LRRK2) mutations are the most common genetic risk factor for Parkinson's disease (PD). While the corresponding pathogenic mechanisms remain largely unknown, LRRK2 has been implicated in the immune system. OBJECTIVE To assess whether LRRK2 mutations alter the sensitivity to a single peripheral inflammatory trigger, with ultimate impact on dopaminergic integrity, using a longitudinal imaging-based study design. METHODS Rats carrying LRRK2 p.G2019S and non-transgenic (NT) littermates were treated peripherally with lipopolysaccharide (LPS). They were monitored over 10 months with PET markers for neuroinflammation and dopaminergic integrity, and with behavioral testing. Tyrosine hydroxylase and CD68 expression were assessed postmortem, 12 months after LPS treatment, in the striatum and substantia nigra. RESULTS Longitudinal [11C]PBR28 PET imaging revealed that LPS treatment caused inflammation in the brain, increasing over time, as compared to saline (corrected p = 0.008). LPS treated LRRK2 animals exhibited significantly increased neuroinflammation in the cortex and ventral-regions compared to saline treated animals (LRRK2 and NT) at 10 months post treatment, with the increase in [11C]PBR28 binding from baseline averaging 0.128±0.045 g/mL. For LPS treated NT animals, the increase was not significant. CD68 immunohistochemistry data supported the imaging results, but without reaching statistical significance. No dopaminergic degeneration was observed. CONCLUSION A single peripheral inflammatory trigger elicited long lasting, progressive neuroinflammation. A trend for an exacerbated inflammatory response in LRRK2 animals compared to NT controls was observed. Translationally, this implies that repeated exposure to inflammatory triggers may be needed for LRRK2 mutation carriers to develop active PD.
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Affiliation(s)
- Anna Schildt
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada.,Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Matthew D Walker
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
| | - Katherine Dinelle
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, BC, Canada
| | | | - Michael Schulzer
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - John O'Kusky
- Department of Pathology, University of British Columbia, Vancouver, BC, Canada
| | - Matthew J Farrer
- Department of Medical Genetics, Centre for Applied Neurogenetics, University of British Columbia, Vancouver, BC, Canada
| | - Doris J Doudet
- Department of Medicine, Division of Neurology, University of British Columbia, Vancouver, BC, Canada
| | - Vesna Sossi
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
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12
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Syeda T, Foguth RM, Llewellyn E, Cannon JR. PhIP exposure in rodents produces neuropathology potentially relevant to Alzheimer's disease. Toxicology 2020; 437:152436. [PMID: 32169473 PMCID: PMC7218929 DOI: 10.1016/j.tox.2020.152436] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/01/2020] [Accepted: 03/09/2020] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD) is a public health crisis due to debilitating cognitive symptoms and lack of curative treatments, in the context of increasing prevalence. Thus, it is critical to identify modifiable risk factors. High levels of meat consumption may increase AD risk. Many toxins are formed during meat cooking such as heterocyclic aromatic amines (HAAs). Our prior studies have shown that HAAs produce dopaminergic neurotoxicity. Given the mechanistic and pathological overlap between AD and dopaminergic disorders we investigated whether exposure to 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP), a prevalent dietary HAA formed during high-temperature meat cooking, may produce AD-relevant neurotoxicity. Here, C57BL/6 mice were treated with 100 or 200 mg/kg PhIP for 8 h or 75 mg/kg for 4 weeks and 16 weeks. PhIP exposure for 8 h produced oxidative damage, and AD-relevant alterations in hippocampal synaptic proteins, Amyloid-beta precursor protein (APP), and β-Site amyloid precursor protein cleaving enzyme 1 (BACE1). PhIP exposure for 4 weeks resulted in an increase in BACE1. PhIP exposure for 16 weeks resulted in increased hippocampal oxidative damage, APP, BACE1, Aβ aggregation, and tau phosphorylation. Quantification of intracellular nitrotyrosine revealed oxidative damage in cholinergic neurons after 8 h, 4 weeks and 16 weeks of PhIP exposure. Our study demonstrates that increase in oxidative damage, APP and BACE1 might be a possible mechanism by which PhIP promotes Aβ aggregation. Given many patients with AD or PD exhibit neuropathological overlap, our study suggests that HAA exposure should be further studied for roles in mediating pathogenic overlap.
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Affiliation(s)
- Tauqeerunnisa Syeda
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, United States; Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, IN, 47907, United States
| | - Rachel M Foguth
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, United States; Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, IN, 47907, United States
| | - Emily Llewellyn
- Summer Research Opportunities Program, Purdue, University, West Lafayette, IN, 47907, United States; Department of Biology, Utah Valley University, Orem, Utah, 84058, United States
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, United States; Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, IN, 47907, United States.
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13
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Delic V, Beck KD, Pang KCH, Citron BA. Biological links between traumatic brain injury and Parkinson's disease. Acta Neuropathol Commun 2020; 8:45. [PMID: 32264976 PMCID: PMC7137235 DOI: 10.1186/s40478-020-00924-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 03/26/2020] [Indexed: 12/19/2022] Open
Abstract
Parkinson's Disease (PD) is a progressive neurodegenerative disorder with no cure. Clinical presentation is characterized by postural instability, resting tremors, and gait problems that result from progressive loss of A9 dopaminergic neurons in the substantia nigra pars compacta. Traumatic brain injury (TBI) has been implicated as a risk factor for several neurodegenerative diseases, but the strongest evidence is linked to development of PD. Mild TBI (mTBI), is the most common and is defined by minimal, if any, loss of consciousness and the absence of significant observable damage to the brain tissue. mTBI is responsible for a 56% higher risk of developing PD in U.S. Veterans and the risk increases with severity of injury. While the mounting evidence from human studies suggests a link between TBI and PD, fundamental questions as to whether TBI nucleates PD pathology or accelerates PD pathology in vulnerable populations remains unanswered. Several promising lines of research point to inflammation, metabolic dysregulation, and protein accumulation as potential mechanisms through which TBI can initiate or accelerate PD. Amyloid precursor protein (APP), alpha synuclein (α-syn), hyper-phosphorylated Tau, and TAR DNA-binding protein 43 (TDP-43), are some of the most frequently reported proteins upregulated following a TBI and are also closely linked to PD. Recently, upregulation of Leucine Rich Repeat Kinase 2 (LRRK2), has been found in the brain of mice following a TBI. Subset of Rab proteins were identified as biological substrates of LRRK2, a protein also extensively linked to late onset PD. Inhibition of LRRK2 was found to be neuroprotective in PD and TBI models. The goal of this review is to survey current literature concerning the mechanistic overlap between TBI and PD with a particular focus on inflammation, metabolic dysregulation, and aforementioned proteins. This review will also cover the application of rodent TBI models to further our understanding of the relationship between TBI and PD.
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Affiliation(s)
- Vedad Delic
- Laboratory of Molecular Biology, VA New Jersey Health Care System, Research and Development (Mailstop 15), 385 Tremont Ave, East Orange, NJ, 07018, USA.
- NeuroBehavioral Research Laboratory, VA New Jersey Health Care System, Research and Development (Mailstop 15), 385 Tremont Ave, East Orange, NJ, 07018, USA.
| | - Kevin D Beck
- NeuroBehavioral Research Laboratory, VA New Jersey Health Care System, Research and Development (Mailstop 15), 385 Tremont Ave, East Orange, NJ, 07018, USA
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers- New Jersey Medical School, Newark, NJ, 07103, USA
| | - Kevin C H Pang
- NeuroBehavioral Research Laboratory, VA New Jersey Health Care System, Research and Development (Mailstop 15), 385 Tremont Ave, East Orange, NJ, 07018, USA
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers- New Jersey Medical School, Newark, NJ, 07103, USA
| | - Bruce A Citron
- Laboratory of Molecular Biology, VA New Jersey Health Care System, Research and Development (Mailstop 15), 385 Tremont Ave, East Orange, NJ, 07018, USA
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers- New Jersey Medical School, Newark, NJ, 07103, USA
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di Caudo C, Martínez-Valbuena I, Mundiñano IC, Gennetier A, Hernandez M, Carmona-Abellan M, Marcilla Garcia I, Kremer EJ, Luquin R. CAV-2-Mediated GFP and LRRK2 G2019S Expression in the Macaca fascicularis Brain. Front Mol Neurosci 2020; 13:49. [PMID: 32269512 PMCID: PMC7109318 DOI: 10.3389/fnmol.2020.00049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 03/09/2020] [Indexed: 12/30/2022] Open
Abstract
Parkinson’s disease is characterized by motor and nonmotor symptoms that gradually appear as a consequence of the selective loss of dopaminergic neurons in the substantia nigra pars compacta. Currently, no treatment can slow Parkinson’s disease progression. Inasmuch, there is a need to develop animal models that can be used to understand the pathophysiological mechanisms underlying dopaminergic neuron death. The initial goal of this study was to determine if canine adenovirus type 2 (CAV-2) vectors are effective gene transfer tools in the monkey brain. A second objective was to explore the possibility of developing a large nonhuman primate that expresses one of the most common genetic mutations causing Parkinson’s disease. Our studies demonstrate the neuronal tropism, retrograde transport, biodistribution, and efficacy of CAV-2 vectors expressing GFP and leucine-rich repeat kinase 2 (LRRK2G2019S) in the Macaca fascicularis brain. Our data also suggest that following optimization CAV-2-mediated LRRK2G2019S expression could help us model the neurodegenerative processes of this genetic subtype of Parkinson’s disease in monkeys.
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Affiliation(s)
- Carla di Caudo
- Division of Neuroscience, Center for Applied Medical Research (CIMA), Universidad de Navarra, Pamplona, Spain.,Department of Neurology, Clinica Universidad de Navarra, Pamplona, Spain
| | - Ivan Martínez-Valbuena
- Division of Neuroscience, Center for Applied Medical Research (CIMA), Universidad de Navarra, Pamplona, Spain.,Department of Neurology, Clinica Universidad de Navarra, Pamplona, Spain.,Instituto de Investigación Sanitaria de Navarra (IDISNA), Pamplona, Spain
| | - Iñaki-Carril Mundiñano
- Division of Neuroscience, Center for Applied Medical Research (CIMA), Universidad de Navarra, Pamplona, Spain
| | - Aurelie Gennetier
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, CNRS, Montpellier, France
| | - Maria Hernandez
- Division of Neuroscience, Center for Applied Medical Research (CIMA), Universidad de Navarra, Pamplona, Spain.,Instituto de Investigación Sanitaria de Navarra (IDISNA), Pamplona, Spain
| | - Mar Carmona-Abellan
- Division of Neuroscience, Center for Applied Medical Research (CIMA), Universidad de Navarra, Pamplona, Spain.,Department of Neurology, Clinica Universidad de Navarra, Pamplona, Spain
| | - Irene Marcilla Garcia
- Division of Neuroscience, Center for Applied Medical Research (CIMA), Universidad de Navarra, Pamplona, Spain
| | - Eric J Kremer
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, CNRS, Montpellier, France
| | - Rosario Luquin
- Division of Neuroscience, Center for Applied Medical Research (CIMA), Universidad de Navarra, Pamplona, Spain.,Department of Neurology, Clinica Universidad de Navarra, Pamplona, Spain.,Instituto de Investigación Sanitaria de Navarra (IDISNA), Pamplona, Spain
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15
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Cresto N, Gaillard MC, Gardier C, Gubinelli F, Diguet E, Bellet D, Legroux L, Mitja J, Auregan G, Guillermier M, Josephine C, Jan C, Dufour N, Joliot A, Hantraye P, Bonvento G, Déglon N, Bemelmans AP, Cambon K, Liot G, Brouillet E. The C-terminal domain of LRRK2 with the G2019S mutation is sufficient to produce neurodegeneration of dopaminergic neurons in vivo. Neurobiol Dis 2019; 134:104614. [PMID: 31605779 DOI: 10.1016/j.nbd.2019.104614] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 09/04/2019] [Accepted: 09/16/2019] [Indexed: 02/06/2023] Open
Abstract
The G2019S substitution in the kinase domain of LRRK2 (LRRK2G2019S) is the most prevalent mutation associated with Parkinson's disease (PD). Neurotoxic effects of LRRK2G2019S are thought to result from an increase in its kinase activity as compared to wild type LRRK2. However, it is unclear whether the kinase domain of LRRK2G2019S is sufficient to trigger degeneration or if the full length protein is required. To address this question, we generated constructs corresponding to the C-terminal domain of LRRK2 (ΔLRRK2). A kinase activity that was increased by G2019➔S substitution could be detected in ΔLRRK2. However biochemical experiments suggested it did not bind or phosphorylate the substrate RAB10, in contrast to full length LRRK2. The overexpression of ΔLRRK2G2019S in the rat striatum using lentiviral vectors (LVs) offered a straightforward and simple way to investigate its effects in neurons in vivo. Results from a RT-qPCR array analysis indicated that ΔLRRK2G2019S led to significant mRNA expression changes consistent with a kinase-dependent mechanism. We next asked whether ΔLRRK2 could be sufficient to trigger neurodegeneration in the substantia nigra pars compacta (SNc) in adult rats. Six months after infection of the substantia nigra pars compacta (SNc) with LV-ΔLRRK2WT or LV-ΔLRRK2G2019S, the number of DA neurons was unchanged. To examine whether higher levels of ΔLRRK2G2019S could trigger degeneration we cloned ΔLRRK2 in AAV2/9 construct. As expected, AAV2/9 injected in the SNc led to neuronal expression of ΔLRRK2WT and ΔLRRK2G2019S at much higher levels than those obtained with LVs. Six months after injection, unbiased stereology showed that AAV-ΔLRRK2G2019S produced a significant ~30% loss of neurons positive for tyrosine hydroxylase- and for the vesicular dopamine transporter whereas AAV-ΔLRRK2WT did not. These findings show that overexpression of the C-terminal part of LRRK2 containing the mutant kinase domain is sufficient to trigger degeneration of DA neurons, through cell-autonomous mechanisms, possibly independent of RAB10.
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Affiliation(s)
- Noémie Cresto
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Marie-Claude Gaillard
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Camille Gardier
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Francesco Gubinelli
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Elsa Diguet
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France; Institut de Recherche SERVIER, Neuropsychiatry Department, 125 chemin de ronde, 78290 Croissy sur Seine, France
| | - Déborah Bellet
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Laurine Legroux
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Julien Mitja
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Gwenaëlle Auregan
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Martine Guillermier
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Charlène Josephine
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Caroline Jan
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Noëlle Dufour
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Alain Joliot
- Homeoprotein and Plasticity, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, PSL Research University, Paris, France
| | - Philippe Hantraye
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Gilles Bonvento
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Nicole Déglon
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; Lausanne University Medical School (CHUV), Department of Clinical Neurosciences (DNC), Laboratory of Cellular and Molecular Neurotherapies (LNCM), Lausanne, Switzerland; Lausanne University Medical School (CHUV), Neuroscience Research Center (CRN), Laboratory of Cellular and Molecular Neurotherapies (LNCM), Lausanne, Switzerland
| | - Alexis-Pierre Bemelmans
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Karine Cambon
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Géraldine Liot
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France
| | - Emmanuel Brouillet
- CEA, DRF, Institut de Biologie Françoise Jacob, Molecular Imaging Research Center (MIRCen), F-92265 Fontenay-aux-Roses, France; CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), F-92265 Fontenay-aux-Roses, France.
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Developmental exposure to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) selectively decreases brain dopamine levels in Northern leopard frogs. Toxicol Appl Pharmacol 2019; 377:114623. [PMID: 31195004 DOI: 10.1016/j.taap.2019.114623] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 05/31/2019] [Accepted: 06/08/2019] [Indexed: 12/15/2022]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are synthetic compounds that are a major public health concern due to widespread use, long environmental and biological half-lives, detection in most human plasma samples, and links to multiple adverse health outcomes. The literature suggests that some PFAS may be neurotoxic. However, there are major gaps in the literature with respect to how environmentally-relevant doses during development may influence the nervous system. To address this gap, we utilized a sentinel species, Northern leopard frogs (Lithobates pipiens) to determine the effects of developmental exposure to environmentally relevant perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) on major neurotransmitter systems. Frog larvae at Gosner stage 25 were exposed to 10, 100, or 1000 ppb PFOS or PFOA for 30 days before neurochemical analysis. High performance liquid chromatography (HPLC) with electrochemical detection or fluorescent detection assays was used to measure neurotransmitter levels, which were normalized to protein levels in each sample. Dopamine (DA) decreased significantly in the brains of frogs treated with PFOA (1000 ppb) and PFOS (100 and 1000 ppb). Significant increases in DA turnover also resulted from PFOA and PFOS treatment. Neither PFOS, nor PFOA produced detectable alterations in serotonin (nor its metabolite), norepinephrine, gamma-amino butyric acid (GABA), glutamate, or acetylcholine. PFAS body burdens showed that PFOS accumulated relative to dose, while PFOA did not. These data suggest that DArgic neurotransmission is selectively affected in developmentally exposed amphibians and that PFAS should be evaluated for a potential role in diseases that target the DA system.
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Rudyk C, Dwyer Z, Hayley S. Leucine-rich repeat kinase-2 (LRRK2) modulates paraquat-induced inflammatory sickness and stress phenotype. J Neuroinflammation 2019; 16:120. [PMID: 31174552 PMCID: PMC6554960 DOI: 10.1186/s12974-019-1483-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 04/18/2019] [Indexed: 01/11/2023] Open
Abstract
Background Leucine-rich repeat kinase 2 (LRRK2) is a common gene implicated in Parkinson’s disease (PD) and is also thought to be fundamentally involved in numerous immune functions. Thus, we assessed the role of LRRK2 in the context of the effects of the environmental toxicant, paraquat, that has been implicated in PD and is known to affect inflammatory processes. Methods Male LRRK2 knockout (KO) and transgenic mice bearing the G2019S LRRK2 mutation (aged 6–8 months) or their littermate controls were exposed to paraquat (two times per week for 3 weeks), and sickness measures, motivational scores, and total home-cage activity levels were assessed. Following sacrifice, western blot and ELISA assays were performed to see whether or not LRRK2 expression would alter processes related to plasticity, immune response processes, or the stress response. Results Paraquat-induced signs of sickness, inflammation (elevated IL-6), and peripheral toxicity (e.g., organ weight) were completely prevented by LRRK2 knockout. In fact, LRRK2 knockout dramatically reduced not only signs of illness, but also the motivational (nest building) and home-cage activity deficits induced by paraquat. Although LRRK2 deficiency did not affect the striatal BDNF reduction that was provoked by paraquat, it did blunt the corticosterone elevation induced by paraquat, raising the possibility that LRRK2 may modulate aspects of the HPA stress axis. Accordingly, we found that transgenic mice bearing the G2019S LRRK2 mutation had elevated basal corticosterone, along with diminished hippocampal 5-HT1A levels. Conclusion We are the first to show the importance of LRRK2 in the peripheral neurotoxic and stressor-like effects of paraquat. These data are consistent with LRRK2 playing a role in the general inflammatory tone and stressor effects induced by environmental toxicant exposure.
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Affiliation(s)
- Chris Rudyk
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Zach Dwyer
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Shawn Hayley
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
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Breger LS, Fuzzati Armentero MT. Genetically engineered animal models of Parkinson's disease: From worm to rodent. Eur J Neurosci 2018; 49:533-560. [PMID: 30552719 DOI: 10.1111/ejn.14300] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 11/13/2018] [Accepted: 11/16/2018] [Indexed: 12/26/2022]
Abstract
Parkinson's disease (PD) is a progressive neurological disorder characterised by aberrant accumulation of insoluble proteins, including alpha-synuclein, and a loss of dopaminergic neurons in the substantia nigra. The extended neurodegeneration leads to a drop of striatal dopamine levels responsible for disabling motor and non-motor impairments. Although the causes of the disease remain unclear, it is well accepted among the scientific community that the disorder may also have a genetic component. For that reason, the number of genetically engineered animal models has greatly increased over the past two decades, ranging from invertebrates to more complex organisms such as mice and rats. This trend is growing as new genetic variants associated with the disease are discovered. The EU Joint Programme - Neurodegenerative Disease Research (JPND) has promoted the creation of an online database aiming at summarising the different features of experimental models of Parkinson's disease. This review discusses available genetic models of PD and the extent to which they adequately mirror the human pathology and reflects on future development and uses of genetically engineered experimental models for the study of PD.
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Affiliation(s)
- Ludivine S Breger
- Institut des Maladies Neurodégénératives, CNRS UMR 5293, Centre Broca Nouvelle Aquitaine, Université de Bordeaux, Bordeaux cedex, France
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Abstract
LRRK2 mutations are associated with the loss of neurons, that is to say toxicity, in patients and in experimental model systems. However, the mechanisms by which mutations can be linked to neurodegeneration are not fully defined. Here I will argue that mechanism in this context encompasses a variety of levels of information. Mutations or alterations in gene expression at a genetic level are one set of mechanisms that are reflected at the biochemical level likely in enhanced or persistent function of LRRK2. By impacting cellular pathways, prominently including changes in autophagy but also microtubule function, mitochondria and protein synthesis, in neurons and immune cells, the LRRK2 brain is primed for neurodegeneration in an age-dependent manner. These concepts have implications for not only modeling LRRK2 disease but also perhaps for Parkinson's disease more generally, including the development of therapeutic modalities.
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Tillmann S, Awwad HM, Eskelund AR, Treccani G, Geisel J, Wegener G, Obeid R. Probiotics Affect One-Carbon Metabolites and Catecholamines in a Genetic Rat Model of Depression. Mol Nutr Food Res 2018; 62:e1701070. [PMID: 29453804 PMCID: PMC5900923 DOI: 10.1002/mnfr.201701070] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 01/22/2018] [Indexed: 12/21/2022]
Abstract
SCOPE Probiotics may influence one-carbon (C1) metabolism, neurotransmitters, liver function markers, or behavior. METHODS AND RESULTS Male adult Flinders Sensitive Line rats (model of depression, FSL; n = 22) received Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 (109 or 1010 colony-forming units per day) or vehicle for 10 weeks. The controls, Flinders Resistant Line rats (FRL, n = 8), only received vehicle. C1-related metabolites were measured in plasma, urine, and different tissues. Monoamine concentrations were measured in plasma, hippocampus, and prefrontal cortex. Vehicle-treated FSL rats had higher plasma concentrations of betaine, choline, and dimethylglycine, but lower plasma homocysteine and liver S-adenosylmethionine (SAM) than FRLs. FSL rats receiving high-dose probiotics had lower plasma betaine and higher liver SAM compared to vehicle-treated FSL rats. FSLs had higher concentrations of norepinephrine, dopamine, and serotonin than FRLs across various brain regions. Probiotics decreased plasma dopamine in FSLs in a dose-dependent manner. There were no detectable changes in liver function markers or behavior. CONCLUSIONS Probiotics reduced the flow of methyl groups via betaine, increased liver SAM, and decreased plasma dopamine and norepinephrine. Since these changes in methylation and catecholamine pathways are known to be involved in several diseases, future investigation of the effect of probiotics is warranted.
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Affiliation(s)
- Sandra Tillmann
- Translational Neuropsychiatry UnitDepartment of Clinical MedicineAarhus UniversityRisskovDenmark
| | - Hussain M. Awwad
- Saarland University HospitalDepartment of Clinical Chemistry and Laboratory MedicineHomburg/SaarGermany
| | - Amanda R. Eskelund
- Translational Neuropsychiatry UnitDepartment of Clinical MedicineAarhus UniversityRisskovDenmark
| | - Giulia Treccani
- Translational Neuropsychiatry UnitDepartment of Clinical MedicineAarhus UniversityRisskovDenmark
| | - Juergen Geisel
- Saarland University HospitalDepartment of Clinical Chemistry and Laboratory MedicineHomburg/SaarGermany
| | - Gregers Wegener
- Translational Neuropsychiatry UnitDepartment of Clinical MedicineAarhus UniversityRisskovDenmark
| | - Rima Obeid
- Saarland University HospitalDepartment of Clinical Chemistry and Laboratory MedicineHomburg/SaarGermany
- Aarhus Institute of Advanced StudiesAarhus UniversityAarhus CDenmark
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Tozzi A, Tantucci M, Marchi S, Mazzocchetti P, Morari M, Pinton P, Mancini A, Calabresi P. Dopamine D2 receptor-mediated neuroprotection in a G2019S Lrrk2 genetic model of Parkinson's disease. Cell Death Dis 2018; 9:204. [PMID: 29434188 PMCID: PMC5833812 DOI: 10.1038/s41419-017-0221-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 12/04/2017] [Accepted: 12/12/2017] [Indexed: 12/17/2022]
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder in which genetic and environmental factors synergistically lead to loss of midbrain dopamine (DA) neurons. Mutation of leucine-rich repeated kinase2 (Lrrk2) genes is responsible for the majority of inherited familial cases of PD and can also be found in sporadic cases. The pathophysiological role of this kinase has to be fully understood yet. Hyperactivation of Lrrk2 kinase domain might represent a predisposing factor for both enhanced striatal glutamatergic release and mitochondrial vulnerability to environmental factors that are observed in PD. To investigate possible alterations of striatal susceptibility to mitochondrial dysfunction, we performed electrophysiological recordings from the nucleus striatum of a G2019S Lrrk2 mouse model of PD, as well as molecular and morphological analyses of G2019S Lrrk2-expressing SH-SY5Y neuroblastoma cells. In G2019S mice, we found reduced striatal DA levels, according to the hypothesis of alteration of dopaminergic transmission, and increased loss of field potential induced by the mitochondrial complex I inhibitor rotenone. This detrimental effect is reversed by the D2 DA receptor agonist quinpirole via the inhibition of the cAMP/PKA intracellular pathway. Analysis of mitochondrial functions in G2019S Lrrk2-expressing SH-SY5Y cells revealed strong rotenone-induced oxidative stress characterized by reduced Ca2+ buffering capability and ATP synthesis, production of reactive oxygen species, and increased mitochondrial fragmentation. Importantly, quinpirole was able to prevent all these changes. We suggest that the G2019S-Lrrk2 mutation is a predisposing factor for enhanced striatal susceptibility to mitochondrial dysfunction induced by exposure to mitochondrial environmental toxins and that the D2 receptor stimulation is neuroprotective on mitochondrial function, via the inhibition of cAMP/PKA intracellular pathway. We suggest new possible neuroprotective strategies for patients carrying this genetic alteration based on drugs specifically targeting Lrrk2 kinase domain and mitochondrial functionality.
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Affiliation(s)
- Alessandro Tozzi
- Santa Lucia Foundation IRCCS, Rome, Italy
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia, Perugia, Italy
| | - Michela Tantucci
- Neurological clinic, Department of Medicine, University of Perugia, Santa Maria della Misericordia Hospital, Perugia, Italy
| | - Saverio Marchi
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Petra Mazzocchetti
- Neurological clinic, Department of Medicine, University of Perugia, Santa Maria della Misericordia Hospital, Perugia, Italy
| | - Michele Morari
- Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Paolo Pinton
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Andrea Mancini
- Neurological clinic, Department of Medicine, University of Perugia, Santa Maria della Misericordia Hospital, Perugia, Italy
| | - Paolo Calabresi
- Santa Lucia Foundation IRCCS, Rome, Italy.
- Neurological clinic, Department of Medicine, University of Perugia, Santa Maria della Misericordia Hospital, Perugia, Italy.
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22
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Creed RB, Goldberg MS. New Developments in Genetic rat models of Parkinson's Disease. Mov Disord 2018; 33:717-729. [PMID: 29418019 DOI: 10.1002/mds.27296] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 12/04/2017] [Accepted: 12/10/2017] [Indexed: 12/12/2022] Open
Abstract
Preclinical research on Parkinson's disease has relied heavily on mouse and rat animal models. Initially, PD animal models were generated primarily by chemical neurotoxins that induce acute loss of dopaminergic neurons in the substantia nigra. On the discovery of genetic mutations causally linked to PD, mice were used more than rats to generate laboratory animals bearing PD-linked mutations because mutagenesis was more difficult in rats. Recent advances in technology for mammalian genome engineering and optimization of viral expression vectors have increased the use of genetic rat models of PD. Emerging research tools include "knockout" rats with disruption of genes in which mutations have been causally linked to PD, including LRRK2, α-synuclein, Parkin, PINK1, and DJ-1. Rats have also been increasingly used for transgenic and viral-mediated overexpression of genes relevant to PD, particularly α-synuclein. It may not be realistic to obtain a single animal model that completely reproduces every feature of a human disease as complex as PD. Nevertheless, compared with mice with the same mutations, many genetic rat animal models of PD better reproduce key aspects of PD including progressive loss of dopaminergic neurons in the substantia nigra, locomotor behavior deficits, and age-dependent formation of abnormal α-synuclein protein aggregates. Here we briefly review new developments in genetic rat models of PD that may have greater potential for identifying underlying mechanisms, for discovering novel therapeutic targets, and for developing greatly needed treatments to slow or halt disease progression. © 2018 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Rose B Creed
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Matthew S Goldberg
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
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23
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Agim ZS, Cannon JR. Alterations in the nigrostriatal dopamine system after acute systemic PhIP exposure. Toxicol Lett 2018; 287:31-41. [PMID: 29378243 DOI: 10.1016/j.toxlet.2018.01.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 01/10/2018] [Accepted: 01/23/2018] [Indexed: 11/30/2022]
Abstract
Heterocyclic amines (HCAs) are primarily formed during cooking of meat at high temperature. HCAs have been extensively studied as mutagens and possible carcinogens. Emerging data suggest that HCAs are neurotoxic and may be relevant to Parkinson's disease (PD) etiology. However, the majority of HCAs have not been evaluated for in vivo neurotoxicity. Here, we investigated acute in vivo neurotoxicity of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). PhIP is the most prevalent genotoxin in many types of meats. Adult, male Sprague-Dawley rats were subjected to acute, systemic PhIP at doses and time-points that have been extensively utilized in cancer studies (100 and 200 mg/kg for 8, 24 h) and evaluated for changes in dopaminergic, serotoninergic, GABAergic, and glutamatergic neurotransmission. PhIP exposure resulted in decreased striatal dopamine metabolite levels and dopamine turnover in the absence of changes to vesicular monoamine transporter 2 levels; other neurotransmitter systems were unaffected. Quantification of intracellular nitrotyrosine revealed higher levels of oxidative damage in dopaminergic neurons in the substantia nigra after PhIP exposure, while other neuronal populations were less sensitive. These changes occurred in the absence of an overt lesion to the nigrostriatal dopamine system. Collectively, our study suggests that acute PhIP treatment in vivo targets the nigrostriatal dopaminergic system and that PhIP should be further examined in chronic, low-dose studies for PD relevance.
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Affiliation(s)
- Zeynep Sena Agim
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, United States; Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, IN 47907, United States.
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, United States; Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, IN 47907, United States.
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24
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The impact of murine LRRK2 G2019S transgene overexpression on acute responses to inflammatory challenge. Brain Behav Immun 2018; 67:246-256. [PMID: 28893563 DOI: 10.1016/j.bbi.2017.09.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 08/07/2017] [Accepted: 09/02/2017] [Indexed: 02/07/2023] Open
Abstract
The most common Parkinson's disease (PD) mutation is the gain-of-function LRRK2 G2019S variant, which has also been linked to inflammatory disease states. Yet, little is known of the role of G2019S in PD related complex behavioral or immune/hormonal processes in response to inflammatory/toxicant challenges. Hence, we characterized the behavioral, neuroendocrine-immune and central monoaminergic responses in G2019S overexpressing mutants following systemic interferon-gamma (IFN-γ) or lipopolysaccharide (LPS) administration. Although LPS markedly (and IFN-γ modestly in some cases) increased cytokine and corticosterone levels, while inducing pronounced sickness and home-cage activity deficits, the G2019S mutation had no effect on these parameters. No differences were observed with regards to brain microglia with the acute LPS injection, regardless of genotype. Nor did the G2019S mutation influence neurotransmitter levels within the medial prefrontal cortex or paraventricular nucleus of the hypothalamus. However, the LRRK2 G2019S transgenic mice did have altered monoamine levels within the striatum and hippocampus. Indeed, G2019S mice had altered basal levels and turnover of dopamine within the striatum, along with changes in hippocampal serotonin and norepinephrine activity in response to LPS and IFN-γ. The present findings suggest the importance of murine G2019S in hippocampal and striatal neurotransmission, but that the transgene didn't appear to be involved in functional behavioral and stress-like hormonal and cytokine changes provoked by inflammatory insults.
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25
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Park J, Lee JW, Cooper SC, Broxmeyer HE, Cannon JR, Kim CH. Parkinson disease-associated LRRK2 G2019S transgene disrupts marrow myelopoiesis and peripheral Th17 response. J Leukoc Biol 2017; 102:1093-1102. [PMID: 28751472 DOI: 10.1189/jlb.1a0417-147rr] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 07/06/2017] [Accepted: 07/07/2017] [Indexed: 12/12/2022] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disease, whereas Crohn's disease is an inflammatory bowel disease. Interestingly, polymorphisms in the LRRK2 gene have been identified as risk factors for both diseases. LRRK2 G2019S is the most prevalent mutation found in PD. To gain insights into the role of the LRRK2 G2019S gene on the development and activation of the immune system in the brain-gut axis, we investigated the effect of LRRK2 G2019S on bone marrow myeloid progenitors and myeloid cell function in the periphery. We used bacterial artificial chromosome transgenic rats harboring the human LRRK2 G2019S gene. LRRK2 G2019S transgene decreased the numbers of monocytic and granulocytic progenitors in the bone marrow. However, the numbers of peripheral, immature myeloid cells with suppressive activity were increased in the gut and blood circulation of LRRK2 G2019S compared with control rats in various acute and chronic inflammatory responses. In inflammatory conditions, Th17 cell activity was suppressed, but tissue-associated phylum Bacteroidetes was abnormally increased in the intestine of LRRK2 G2019S rats. The abnormally expanded myeloid cells because of the LRRK2 G2019S gene were highly suppressive on Th17 cell differentiation. Moreover, we found that inhibition of LRRK2 kinase affects myeloid progenitors and myeloid cell differentiation. Taken together, the results indicate that abnormal LRRK2 activity can alter bone marrow myelopoiesis, peripheral myeloid cell differentiation, and intestinal immune homeostasis. These findings may have ramifications in immune and inflammatory responses in patients with LRRK2 abnormalities.
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Affiliation(s)
- Jeongho Park
- Laboratory of Immunology and Hematopoiesis, Department of Comparative Pathobiology, Purdue University, West Lafayette, Indiana, USA
| | - Jang-Won Lee
- School of Health Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Scott C Cooper
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Hal E Broxmeyer
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, Indiana, USA.,Purdue Institute of Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Chang H Kim
- Laboratory of Immunology and Hematopoiesis, Department of Comparative Pathobiology, Purdue University, West Lafayette, Indiana, USA; .,Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA.,Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, USA.,Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA; and.,Purdue Institute of Inflammation, Immunology and Infectious Diseases, Purdue University, West Lafayette, Indiana, USA
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26
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Tapias V, Hu X, Luk KC, Sanders LH, Lee VM, Greenamyre JT. Synthetic alpha-synuclein fibrils cause mitochondrial impairment and selective dopamine neurodegeneration in part via iNOS-mediated nitric oxide production. Cell Mol Life Sci 2017; 74:2851-2874. [PMID: 28534083 DOI: 10.1007/s00018-017-2541-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/20/2017] [Accepted: 05/15/2017] [Indexed: 12/21/2022]
Abstract
Intracellular accumulation of α-synuclein (α-syn) are hallmarks of synucleinopathies, including Parkinson's disease (PD). Exogenous addition of preformed α-syn fibrils (PFFs) into primary hippocampal neurons induced α-syn aggregation and accumulation. Likewise, intrastriatal inoculation of PFFs into mice and non-human primates generates Lewy bodies and Lewy neurites associated with PD-like neurodegeneration. Herein, we investigate the putative effects of synthetic human PFFs on cultured rat ventral midbrain dopamine (DA) neurons. A time- and dose-dependent accumulation of α-syn was observed following PFFs exposure that also underwent phosphorylation at serine 129. PFFs treatment decreased the expression levels of synaptic proteins, caused alterations in axonal transport-related proteins, and increased H2AX Ser139 phosphorylation. Mitochondrial impairment (including modulation of mitochondrial dynamics-associated protein content), enhanced oxidative stress, and an inflammatory response were also detected in our experimental paradigm. In attempt to unravel a potential molecular mechanism of PFFs neurotoxicity, the expression of inducible nitric oxide synthase was blocked; a significant decline in protein nitration levels and protection against PFFs-induced DA neuron death were observed. Combined exposure to PFFs and rotenone resulted in an additive toxicity. Strikingly, many of the harmful effects found were more prominent in DA rather than non-DA neurons, suggestive of higher susceptibility to degenerate. These findings provide new insights into the role of α-syn in the pathogenesis of PD and could represent a novel and valuable model to study DA-related neurodegeneration.
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Affiliation(s)
- Victor Tapias
- Department of Neurology and Neuroscience, Weill Cornell Medicine, 525 East 68th Street, New York, NY, 10065, USA. .,Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 1300 York Ave, New York, NY, 10065, USA.
| | - Xiaoping Hu
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15260, USA.,Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Kelvin C Luk
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Laurie H Sanders
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15260, USA.,Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Virginia M Lee
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - J Timothy Greenamyre
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15260, USA.,Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, 15260, USA.,Pittsburgh VA Healthcare System, Pittsburgh, PA, 15206, USA
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27
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Longo F, Mercatelli D, Novello S, Arcuri L, Brugnoli A, Vincenzi F, Russo I, Berti G, Mabrouk OS, Kennedy RT, Shimshek DR, Varani K, Bubacco L, Greggio E, Morari M. Age-dependent dopamine transporter dysfunction and Serine129 phospho-α-synuclein overload in G2019S LRRK2 mice. Acta Neuropathol Commun 2017; 5:22. [PMID: 28292328 PMCID: PMC5351259 DOI: 10.1186/s40478-017-0426-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/08/2017] [Indexed: 12/13/2022] Open
Abstract
Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common genetic cause of Parkinson’s disease. Here, we investigated whether the G2019S LRRK2 mutation causes morphological and/or functional changes at nigro-striatal dopamine neurons. Density of striatal dopaminergic terminals, nigral cell counts, tyrosine hydroxylase protein levels as well as exocytotic dopamine release measured in striatal synaptosomes, or striatal extracellular dopamine levels monitored by in vivo microdialysis were similar between ≥12-month-old G2019S knock-in mice and wild-type controls. In vivo striatal dopamine release was insensitive to the LRRK2 inhibitor Nov-LRRK2-11, and was elevated by the membrane dopamine transporter blocker GBR-12783. However, G2019S knock-in mice showed a blunted neurochemical and motor activation response to GBR-12783 compared to wild-type controls. Western blot and dopamine uptake analysis revealed an increase in dopamine transporter levels and activity in the striatum of 12-month-old G2019S KI mice. This phenotype correlated with a reduction in vesicular monoamine transporter 2 levels and an enhancement of vesicular dopamine uptake, which was consistent with greater resistance to reserpine-induced hypolocomotion. These changes were not observed in 3-month-old mice. Finally, Western blot analysis revealed no genotype difference in striatal levels of endogenous α-synuclein or α-synuclein bound to DOPAL (a toxic metabolite of dopamine). However, Serine129-phosphorylated α-synuclein levels were higher in 12-month-old G2019S knock-in mice. Immunohistochemistry confirmed this finding, also showing no genotype difference in 3-month-old mice. We conclude that the G2019S mutation causes progressive dysfunctions of dopamine transporters, along with Serine129-phosphorylated α-synuclein overload, at striatal dopaminergic terminals, which are not associated with dopamine homeostasis dysregulation or neuron loss but might contribute to intrinsic dopaminergic terminal vulnerability. We propose G2019S knock-in mice as a presymptomatic Parkinson’s disease model, useful to investigate the pathogenic interaction among genetics, aging, and internal or environmental factors leading to the disease.
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28
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Daher JPL. Interaction of LRRK2 and α-Synuclein in Parkinson's Disease. ADVANCES IN NEUROBIOLOGY 2017; 14:209-226. [PMID: 28353286 DOI: 10.1007/978-3-319-49969-7_11] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Parkinson's disease (PD) is a progressively debilitating neurodegenerative syndrome. It is best described as a movement disorder characterized by motor dysfunctions, progressive degeneration of dopaminergic neurons of the substantia nigra pars compacta, and abnormal intraneuronal protein aggregates, named Lewy bodies and Lewy neurites. Nevertheless, knowledge of the molecular events leading to this pathophysiology is incomplete. To date, only mutations in the α-synuclein and LRRK2-encoding genes have been associated with typical findings of clinical and pathologic PD. LRRK2 appears to have a central role in the pathogenesis of PD as it is associated with α-synuclein pathology and other proteins implicated in neurodegeneration. Thus, LRRK2 dysfunction may influence the accumulation of α-synuclein and its pathology through diverse pathomechanisms altering cellular functions and signaling pathways, including immune system, autophagy, vesicle trafficking, and retromer complex modulation. Consequently, development of novel LRRK2 inhibitors can be justified to treat the neurodegeneration associated with abnormal α-synuclein accumulation.
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Affiliation(s)
- João Paulo Lima Daher
- Faculty of Medicine, School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia. .,Neuroscience Research Australia, Barker St, Randwick, NSW, 2031, Australia.
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29
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Xiong Y, Dawson TM, Dawson VL. Models of LRRK2-Associated Parkinson's Disease. ADVANCES IN NEUROBIOLOGY 2017; 14:163-191. [PMID: 28353284 DOI: 10.1007/978-3-319-49969-7_9] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common genetic causes of Parkinson's disease (PD) and also one of the strongest genetic risk factors in sporadic PD. The LRRK2 protein contains a GTPase and a kinase domain and several protein-protein interaction domains. Both in vitro and in vivo assays in different model systems have provided tremendous insights into the molecular mechanisms underlying LRRK2-induced dopaminergic neurodegeneration. Among all the model systems, animal models are crucial tools to study the pathogenesis of human disease. How do the animal models recapitulate LRRK2-induced dopaminergic neuronal loss in human PD? To answer this question, this review focuses on the discussion of the animal models of LRRK2-associated PD including genetic- and viral-based models.
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Affiliation(s)
- Yulan Xiong
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Department of Anatomy and Physiology, Kansas State University College of Veterinary Medicine, Manhattan, KS, 66506, USA.
| | - Ted M Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Adrienne Helis Malvin Medical Research Foundation, New Orleans, LA, 70130-2685, USA.
| | - Valina L Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Adrienne Helis Malvin Medical Research Foundation, New Orleans, LA, 70130-2685, USA. .,Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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30
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Wise JP, Cannon J. From the Cover: Alterations in Optineurin Expression and Localization in Pre-clinical Parkinson's Disease Models. Toxicol Sci 2016; 153:372-81. [PMID: 27473339 DOI: 10.1093/toxsci/kfw133] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Parkinson's disease (PD) is a progressive neurodegenerative disease that affects ∼5 million people around the world. PD etiopathogenesis is poorly understood and curative or disease modifying treatments are not available. Mechanistic studies have identified numerous pathogenic pathways that overlap with many other neurodegenerative diseases. Mutations in the protein optineurin (OPTN) have recently been identified as causative factors for glaucoma and amyotrophic lateral sclerosis. OPTN has multiple recognized roles in neurons, notably in mediating autophagic flux, which has been found to be disrupted in most neurodegenerative diseases. OPTN(+ )aggregates have preliminarily been identified in cytoplasmic inclusions in numerous neurodegenerative diseases, however, whether OPTN has a role in PD pathogenesis has yet to be tested. Thus, we chose to test the hypothesis that OPTN expression and localization would be modulated in pre-clinical PD models. To test our hypothesis, we characterized midbrain OPTN expression in normal rats and in a rat rotenone PD model. For the first time, we show that OPTN is enriched in dopamine neurons in the midbrain, and its expression is modulated by rotenone treatment in vivo Here, animals were sampled at time-points both prior to overt neurodegeneration and after severe behavioral deficits, where a lesion to the nigrostriatal dopamine system is present. The effect and magnitude of OPTN expression changes are dependent on duration of treatment. Furthermore, OPTN colocalizes with LC3 (autophagic vesicle marker) and alpha-synuclein positive puncta in rotenone-treated animals, potentially indicating an important role in autophagy and PD pathogenesis.
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Affiliation(s)
- John Pierce Wise
- *School of Health Sciences, Purdue University, West Lafayette, Indiana 47907
| | - Jason Cannon
- *School of Health Sciences, Purdue University, West Lafayette, Indiana 47907
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31
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Langston RG, Rudenko IN, Cookson MR. The function of orthologues of the human Parkinson's disease gene LRRK2 across species: implications for disease modelling in preclinical research. Biochem J 2016; 473:221-32. [PMID: 26811536 PMCID: PMC5165698 DOI: 10.1042/bj20150985] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In the period since LRRK2 (leucine-rich repeat kinase 2) was identified as a causal gene for late-onset autosomal dominant parkinsonism, a great deal of work has been aimed at understanding whether the LRRK2 protein might be a druggable target for Parkinson's disease (PD). As part of this effort, animal models have been developed to explore both the normal and the pathophysiological roles of LRRK2. However, LRRK2 is part of a wider family of proteins whose functions in different organisms remain poorly understood. In this review, we compare the information available on biochemical properties of LRRK2 homologues and orthologues from different species from invertebrates (e.g. Caenorhabditis elegans and Drosophila melanogaster) to mammals. We particularly discuss the mammalian LRRK2 homologue, LRRK1, and those species where there is only a single LRRK homologue, discussing examples where each of the LRRK family of proteins has distinct properties as well as those cases where there appear to be functional redundancy. We conclude that uncovering the function of LRRK2 orthologues will help to elucidate the key properties of human LRRK2 as well as to improve understanding of the suitability of different animal models for investigation of LRRK2-related PD.
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Affiliation(s)
- Rebekah G. Langston
- Cell Biology and Gene Expression Section, Laboratory of Neurogenetics, NIA, NIH, Bethesda, MD, 20892
| | - Iakov N. Rudenko
- Cell Biology and Gene Expression Section, Laboratory of Neurogenetics, NIA, NIH, Bethesda, MD, 20892
| | - Mark R. Cookson
- Cell Biology and Gene Expression Section, Laboratory of Neurogenetics, NIA, NIH, Bethesda, MD, 20892
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32
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Sloan M, Alegre-Abarrategui J, Potgieter D, Kaufmann AK, Exley R, Deltheil T, Threlfell S, Connor-Robson N, Brimblecombe K, Wallings R, Cioroch M, Bannerman DM, Bolam JP, Magill PJ, Cragg SJ, Dodson PD, Wade-Martins R. LRRK2 BAC transgenic rats develop progressive, L-DOPA-responsive motor impairment, and deficits in dopamine circuit function. Hum Mol Genet 2016; 25:951-63. [PMID: 26744332 PMCID: PMC4754049 DOI: 10.1093/hmg/ddv628] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 12/29/2015] [Indexed: 11/13/2022] Open
Abstract
Mutations in leucine-rich repeat kinase 2 (LRRK2) lead to late-onset, autosomal dominant Parkinson's disease, characterized by the degeneration of dopamine neurons of the substantia nigra pars compacta, a deficit in dopamine neurotransmission and the development of motor and non-motor symptoms. The most prevalent Parkinson's disease LRRK2 mutations are located in the kinase (G2019S) and GTPase (R1441C) encoding domains of LRRK2. To better understand the sequence of events that lead to progressive neurophysiological deficits in vulnerable neurons and circuits in Parkinson's disease, we have generated LRRK2 bacterial artificial chromosome transgenic rats expressing either G2019S or R1441C mutant, or wild-type LRRK2, from the complete human LRRK2 genomic locus, including endogenous promoter and regulatory regions. Aged (18-21 months) G2019S and R1441C mutant transgenic rats exhibit L-DOPA-responsive motor dysfunction, impaired striatal dopamine release as determined by fast-scan cyclic voltammetry, and cognitive deficits. In addition, in vivo recordings of identified substantia nigra pars compacta dopamine neurons in R1441C LRRK2 transgenic rats reveal an age-dependent reduction in burst firing, which likely results in further reductions to striatal dopamine release. These alterations to dopamine circuit function occur in the absence of neurodegeneration or abnormal protein accumulation within the substantia nigra pars compacta, suggesting that nigrostriatal dopamine dysfunction precedes detectable protein aggregation and cell death in the development of Parkinson's disease. In conclusion, our longitudinal deep-phenotyping provides novel insights into how the genetic burden arising from human mutant LRRK2 manifests as early pathophysiological changes to dopamine circuit function and highlights a potential model for testing Parkinson's therapeutics.
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Affiliation(s)
- Max Sloan
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics
| | | | - Dawid Potgieter
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics
| | - Anna-Kristin Kaufmann
- Oxford Parkinson's Disease Centre, Medical Research Council Brain Network Dynamics Unit, Department of Pharmacology and
| | - Richard Exley
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics
| | - Thierry Deltheil
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics
| | - Sarah Threlfell
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics
| | | | | | - Rebecca Wallings
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics
| | - Milena Cioroch
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics
| | - David M Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - J Paul Bolam
- Oxford Parkinson's Disease Centre, Medical Research Council Brain Network Dynamics Unit, Department of Pharmacology and
| | - Peter J Magill
- Oxford Parkinson's Disease Centre, Medical Research Council Brain Network Dynamics Unit, Department of Pharmacology and
| | - Stephanie J Cragg
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics,
| | - Paul D Dodson
- Oxford Parkinson's Disease Centre, Medical Research Council Brain Network Dynamics Unit, Department of Pharmacology and
| | - Richard Wade-Martins
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics,
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Daher JPL, Abdelmotilib HA, Hu X, Volpicelli-Daley LA, Moehle MS, Fraser KB, Needle E, Chen Y, Steyn SJ, Galatsis P, Hirst WD, West AB. Leucine-rich Repeat Kinase 2 (LRRK2) Pharmacological Inhibition Abates α-Synuclein Gene-induced Neurodegeneration. J Biol Chem 2015; 290:19433-44. [PMID: 26078453 DOI: 10.1074/jbc.m115.660001] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Indexed: 12/19/2022] Open
Abstract
Therapeutic approaches to slow or block the progression of Parkinson disease (PD) do not exist. Genetic and biochemical studies implicate α-synuclein and leucine-rich repeat kinase 2 (LRRK2) in late-onset PD. LRRK2 kinase activity has been linked to neurodegenerative pathways. However, the therapeutic potential of LRRK2 kinase inhibitors is not clear because significant toxicities have been associated with one class of LRRK2 kinase inhibitors. Furthermore, LRRK2 kinase inhibitors have not been tested previously for efficacy in models of α-synuclein-induced neurodegeneration. To better understand the therapeutic potential of LRRK2 kinase inhibition in PD, we evaluated the tolerability and efficacy of a LRRK2 kinase inhibitor, PF-06447475, in preventing α-synuclein-induced neurodegeneration in rats. Both wild-type rats as well as transgenic G2019S-LRRK2 rats were injected intracranially with adeno-associated viral vectors expressing human α-synuclein in the substantia nigra. Rats were treated with PF-06447475 or a control compound for 4 weeks post-viral transduction. We found that rats expressing G2019S-LRRK2 have exacerbated dopaminergic neurodegeneration and inflammation in response to the overexpression of α-synuclein. Both neurodegeneration and neuroinflammation associated with G2019S-LRRK2 expression were mitigated by LRRK2 kinase inhibition. Furthermore, PF-06447475 provided neuroprotection in wild-type rats. We could not detect adverse pathological indications in the lung, kidney, or liver of rats treated with PF-06447475. These results demonstrate that pharmacological inhibition of LRRK2 is well tolerated for a 4-week period of time in rats and can counteract dopaminergic neurodegeneration caused by acute α-synuclein overexpression.
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Affiliation(s)
- João P L Daher
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Hisham A Abdelmotilib
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Xianzhen Hu
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Laura A Volpicelli-Daley
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Mark S Moehle
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Kyle B Fraser
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Elie Needle
- the Pfizer Neuroscience Research Unit, Cambridge, Massachusetts
| | - Yi Chen
- the Pfizer Neuroscience Research Unit, Cambridge, Massachusetts
| | - Stefanus J Steyn
- Pfizer Pharmacokinetics, Dynamics, and Metabolism Cambridge, Cambridge, Massachusetts 02139, and
| | - Paul Galatsis
- Pfizer Worldwide Medicinal Chemistry, Cambridge, Massachusetts 02139
| | - Warren D Hirst
- the Pfizer Neuroscience Research Unit, Cambridge, Massachusetts
| | - Andrew B West
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama 35294,
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Moehle MS, Daher JPL, Hull TD, Boddu R, Abdelmotilib HA, Mobley J, Kannarkat GT, Tansey MG, West AB. The G2019S LRRK2 mutation increases myeloid cell chemotactic responses and enhances LRRK2 binding to actin-regulatory proteins. Hum Mol Genet 2015; 24:4250-67. [PMID: 25926623 DOI: 10.1093/hmg/ddv157] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 04/27/2015] [Indexed: 12/20/2022] Open
Abstract
The Leucine rich repeat kinase 2 (LRRK2) gene is genetically and biochemically linked to several diseases that involve innate immunity. LRRK2 protein is highly expressed in phagocytic cells of the innate immune system, most notably in myeloid cells capable of mounting potent pro-inflammatory responses. Knockdown of LRRK2 protein in these cells reduces pro-inflammatory responses. However, the effect of LRRK2 pathogenic mutations that cause Parkinson's disease on myeloid cell function is not clear but could provide insight into LRRK2-linked disease. Here, we find that rats expressing G2019S LRRK2 have exaggerated pro-inflammatory responses and subsequent neurodegeneration after lipopolysaccharide injections in the substantia nigra, with a marked increase in the recruitment of CD68 myeloid cells to the site of injection. While G2019S LRRK2 expression did not affect immunological homeostasis, myeloid cells expressing G2019S LRRK2 show enhanced chemotaxis both in vitro in two-chamber assays and in vivo in response to thioglycollate injections in the peritoneum. The G2019S mutation enhanced the association between LRRK2 and actin-regulatory proteins that control chemotaxis. The interaction between G2019S LRRK2 and actin-regulatory proteins can be blocked by LRRK2 kinase inhibitors, although we did not find evidence that LRRK2 phosphorylated these interacting proteins. These results suggest that the primary mechanism of G2019S LRRK2 with respect to myeloid cell function in disease may be related to exaggerated chemotactic responses.
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Affiliation(s)
- Mark S Moehle
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics
| | | | | | - Ravindra Boddu
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA and
| | | | | | - George T Kannarkat
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Malú G Tansey
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Andrew B West
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics,
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Abstract
Interactions between genetic and environmental factors are thought to contribute to the pathogenesis of the majority of Parkinson's disease (PD) cases. However, our understanding of these interactions is at an early stage. Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of hereditary PD. Penetrance of LRRK2 mutations is incomplete and variable, suggesting that other environmental or genetic factors may contribute to the development of the disorder. Recently, using animal models, several attempts have been made to understand if LRRK2 may mediate sensitivity to environmental neurotoxicants. Here, we critically review the most current data on how LRRK2 mutations influence neurotoxicity in PD models.
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Affiliation(s)
- Jang-Won Lee
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA
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36
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Progressive dopaminergic alterations and mitochondrial abnormalities in LRRK2 G2019S knock-in mice. Neurobiol Dis 2015; 78:172-95. [PMID: 25836420 DOI: 10.1016/j.nbd.2015.02.031] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 02/19/2015] [Accepted: 02/21/2015] [Indexed: 01/19/2023] Open
Abstract
Mutations in the LRRK2 gene represent the most common genetic cause of late onset Parkinson's disease. The physiological and pathological roles of LRRK2 are yet to be fully determined but evidence points towards LRRK2 mutations causing a gain in kinase function, impacting on neuronal maintenance, vesicular dynamics and neurotransmitter release. To explore the role of physiological levels of mutant LRRK2, we created knock-in (KI) mice harboring the most common LRRK2 mutation G2019S in their own genome. We have performed comprehensive dopaminergic, behavioral and neuropathological analyses in this model up to 24months of age. We find elevated kinase activity in the brain of both heterozygous and homozygous mice. Although normal at 6months, by 12months of age, basal and pharmacologically induced extracellular release of dopamine is impaired in both heterozygous and homozygous mice, corroborating previous findings in transgenic models over-expressing mutant LRRK2. Via in vivo microdialysis measurement of basal and drug-evoked extracellular release of dopamine and its metabolites, our findings indicate that exocytotic release from the vesicular pool is impaired. Furthermore, profound mitochondrial abnormalities are evident in the striatum of older homozygous G2019S KI mice, which are consistent with mitochondrial fission arrest. We anticipate that this G2019S mouse line will be a useful pre-clinical model for further evaluation of early mechanistic events in LRRK2 pathogenesis and for second-hit approaches to model disease progression.
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