1
|
Burton AH, Jiao B, Bai Q, Van Laar VS, Wheeler TB, Watkins SC, Bruchez MP, Burton EA. Full-field exposure of larval zebrafish to narrow waveband LED light sources at defined power and energy for optogenetic applications. J Neurosci Methods 2024; 401:110001. [PMID: 37914002 PMCID: PMC10843659 DOI: 10.1016/j.jneumeth.2023.110001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 10/15/2023] [Accepted: 10/27/2023] [Indexed: 11/03/2023]
Abstract
BACKGROUND Optogenetic approaches in transparent zebrafish models have provided numerous insights into vertebrate neurobiology. The purpose of this study was to develop methods to activate light-sensitive transgene products simultaneously throughout an entire larval zebrafish. NEW METHOD We developed a LED illumination stand and microcontroller unit to expose zebrafish larvae reproducibly to full field illumination at defined wavelength, power, and energy. RESULTS The LED stand generated a sufficiently flat illumination field to expose multiple larval zebrafish to high power light stimuli uniformly, while avoiding sample bath warming. The controller unit allowed precise automated delivery of predetermined amounts of light energy at calibrated power. We demonstrated the utility of the approach by driving photoconversion of Kaede (398 nm), photodimerization of GAVPO (450 nm), and photoactivation of dL5**/MG2I (661 nm) in neurons throughout the CNS of larval zebrafish. Observed outcomes were influenced by both total light energy and its rate of delivery, highlighting the importance of controlling these variables to obtain reproducible results. COMPARISON WITH EXISTING METHODS Our approach employs inexpensive LED chip arrays to deliver narrow-waveband light with a sufficiently flat illumination field to span multiple larval zebrafish simultaneously. Calibration of light power and energy are built into the workflow. CONCLUSIONS The LED illuminator and controller can be constructed from widely available materials using the drawings, instructions, and software provided. This approach will be useful for multiple optogenetic applications in zebrafish and other models.
Collapse
Affiliation(s)
- Alexander H Burton
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Undergraduate Program in Chemical and Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Binxuan Jiao
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Tsinghua University Medical School, Beijing, China
| | - Qing Bai
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
| | - Victor S Van Laar
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
| | - Travis B Wheeler
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Simon C Watkins
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA; Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, USA
| | - Marcel P Bruchez
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, USA; Molecular Biosensors and Imaging Center, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Edward A Burton
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Geriatric Research Education and Clinical Center, Pittsburgh VA Healthcare System, Pittsburgh, PA, USA.
| |
Collapse
|
2
|
Van Laar AD, Webb KR, Keeney MT, Van Laar VS, Zharikov A, Burton EA, Hastings TG, Glajch KE, Hirst WD, Greenamyre JT, Rocha EM. Transient exposure to rotenone causes degeneration and progressive parkinsonian motor deficits, neuroinflammation, and synucleinopathy. NPJ Parkinsons Dis 2023; 9:121. [PMID: 37567894 PMCID: PMC10421849 DOI: 10.1038/s41531-023-00561-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 07/17/2023] [Indexed: 08/13/2023] Open
Abstract
Individuals with Parkinson's disease (PD) typically receive a diagnosis once they have developed motor symptoms, at which point there is already significant loss of substantia nigra dopamine neurons, α-synuclein accumulation in surviving neurons, and neuroinflammation. Consequently, the point of clinical presentation may be too late to initiate disease-modifying therapy. In contrast to this clinical reality, animal models often involve acute neurodegeneration and potential therapies are tested concurrently or shortly after the pathogenic insult has begun rather than later when diagnostic clinical symptoms emerge. Therefore, we sought to develop a model that reflects the clinical situation more accurately. Middle-aged rats (7-9 months-old) received a single daily intraperitoneal injection of rotenone for 5 consecutive days and were observed over the next 8-9 months. Rotenone-treated rats showed transient motor slowing and postural instability during exposure but recovered within 9 days of rotenone cessation. Rats remained without behavioral deficits for 3-4 months, then developed progressive motor abnormalities over the ensuing months. As motor abnormalities began to emerge 3 months after rotenone exposure, there was significant loss of nigral dopaminergic neurons and significant microglial activation. There was delayed accumulation of α-synuclein in neurons of the substantia nigra and frontal cortex, which was maximal at 9 months post-rotenone. In summary, a brief temporally-remote exposure to rotenone causes delayed and progressive behavioral and neuropathological changes similar to Parkinson's disease. This model mimics the human clinical situation, in which pathogenesis is well-established by the time diagnostic motor deficits appear. As such, this model may provide a more relevant experimental system in which to test disease-modifying therapeutics.
Collapse
Affiliation(s)
- Amber D Van Laar
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Katherine R Webb
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
| | - Matthew T Keeney
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Victor S Van Laar
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alevtina Zharikov
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Edward A Burton
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
- Geriatric Research, Education and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, PA, 15240, USA
| | - Teresa G Hastings
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kelly E Glajch
- Neurodegenerative Diseases Research Unit, Biogen, Cambridge, MA, 02142, USA
| | - Warren D Hirst
- Neurodegenerative Diseases Research Unit, Biogen, Cambridge, MA, 02142, USA
| | - J Timothy Greenamyre
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Emily M Rocha
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
3
|
Ford MM, George BE, Van Laar VS, Holleran KM, Naidoo J, Hadaczek P, Vanderhooft LE, Peck EG, Dawes MH, Ohno K, Bringas J, McBride JL, Samaranch L, Forsayeth JR, Jones SR, Grant KA, Bankiewicz KS. GDNF gene therapy for alcohol use disorder in male non-human primates. Nat Med 2023; 29:2030-2040. [PMID: 37580533 PMCID: PMC10602124 DOI: 10.1038/s41591-023-02463-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 06/15/2023] [Indexed: 08/16/2023]
Abstract
Alcohol use disorder (AUD) exacts enormous personal, social and economic costs globally. Return to alcohol use in treatment-seeking patients with AUD is common, engendered by a cycle of repeated abstinence-relapse episodes even with use of currently available pharmacotherapies. Repeated ethanol use induces dopaminergic signaling neuroadaptations in ventral tegmental area (VTA) neurons of the mesolimbic reward pathway, and sustained dysfunction of reward circuitry is associated with return to drinking behavior. We tested this hypothesis by infusing adeno-associated virus serotype 2 vector encoding human glial-derived neurotrophic factor (AAV2-hGDNF), a growth factor that enhances dopaminergic neuron function, into the VTA of four male rhesus monkeys, with another four receiving vehicle, following induction of chronic alcohol drinking. GDNF expression ablated the return to alcohol drinking behavior over a 12-month period of repeated abstinence-alcohol reintroduction challenges. This behavioral change was accompanied by neurophysiological modulations to dopamine signaling in the nucleus accumbens that countered the hypodopaminergic signaling state associated with chronic alcohol use, indicative of a therapeutic modulation of limbic circuits countering the effects of alcohol. These preclinical findings suggest gene therapy targeting relapse prevention may be a potential therapeutic strategy for AUD.
Collapse
Affiliation(s)
- Matthew M Ford
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Portland, OR, USA
- Department of Psychology, Lewis & Clark College, Portland, OR, USA
| | - Brianna E George
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston Salem, NC, USA
| | - Victor S Van Laar
- Department of Neurological Surgery, The Ohio State University, Columbus, OH, USA
| | - Katherine M Holleran
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston Salem, NC, USA
| | - Jerusha Naidoo
- Department of Neurological Surgery, The Ohio State University, Columbus, OH, USA
- Department of Neurological Surgery, University of California, San Francisco, CA, USA
| | - Piotr Hadaczek
- Department of Neurological Surgery, The Ohio State University, Columbus, OH, USA
- Department of Neurological Surgery, University of California, San Francisco, CA, USA
| | - Lauren E Vanderhooft
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Portland, OR, USA
| | - Emily G Peck
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston Salem, NC, USA
| | - Monica H Dawes
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston Salem, NC, USA
| | - Kousaku Ohno
- Department of Neurological Surgery, University of California, San Francisco, CA, USA
| | - John Bringas
- Department of Neurological Surgery, University of California, San Francisco, CA, USA
| | - Jodi L McBride
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Portland, OR, USA
| | - Lluis Samaranch
- Department of Neurological Surgery, The Ohio State University, Columbus, OH, USA
- Department of Neurological Surgery, University of California, San Francisco, CA, USA
| | - John R Forsayeth
- Department of Neurological Surgery, University of California, San Francisco, CA, USA
| | - Sara R Jones
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston Salem, NC, USA
| | - Kathleen A Grant
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Portland, OR, USA.
| | - Krystof S Bankiewicz
- Department of Neurological Surgery, The Ohio State University, Columbus, OH, USA.
- Department of Neurological Surgery, University of California, San Francisco, CA, USA.
| |
Collapse
|
4
|
Van Laar AD, Van Laar VS, San Sebastian W, Merola A, Bradley Elder J, Lonser RR, Bankiewicz KS. An Update on Gene Therapy Approaches for Parkinson's Disease: Restoration of Dopaminergic Function. J Parkinsons Dis 2021; 11:S173-S182. [PMID: 34366374 PMCID: PMC8543243 DOI: 10.3233/jpd-212724] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
At present there is a significant unmet need for clinically available treatments for Parkinson’s disease (PD) patients to stably restore balance to dopamine network function, leaving patients with inadequate management of symptoms as the disease progresses. Gene therapy is an attractive approach to impart a durable effect on neuronal function through introduction of genetic material to reestablish dopamine levels and/or functionally recover dopaminergic signaling by improving neuronal health. Ongoing clinical gene therapy trials in PD are focused on enzymatic enhancement of dopamine production and/or the restoration of the nigrostriatal pathway to improve dopaminergic network function. In this review, we discuss data from current gene therapy trials for PD and recent advances in study design and surgical approaches.
Collapse
Affiliation(s)
- Amber D Van Laar
- Asklepios BioPharmaceutical, Inc., Columbus, OH, USA.,Department of Neurology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Victor S Van Laar
- Department of Neurological Surgery, Ohio State University College of Medicine, Columbus, OH, USA
| | - Waldy San Sebastian
- Asklepios BioPharmaceutical, Inc., Columbus, OH, USA.,Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Aristide Merola
- Department of Neurology, College of Medicine, the Ohio State University, Columbus, OH, USA
| | - J Bradley Elder
- Department of Neurological Surgery, Ohio State University College of Medicine, Columbus, OH, USA
| | - Russell R Lonser
- Department of Neurological Surgery, Ohio State University College of Medicine, Columbus, OH, USA
| | - Krystof S Bankiewicz
- Department of Neurological Surgery, Ohio State University College of Medicine, Columbus, OH, USA.,Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| |
Collapse
|
5
|
Van Laar VS, Chen J, Zharikov AD, Bai Q, Di Maio R, Dukes AA, Hastings TG, Watkins SC, Greenamyre JT, St Croix CM, Burton EA. α-Synuclein amplifies cytoplasmic peroxide flux and oxidative stress provoked by mitochondrial inhibitors in CNS dopaminergic neurons in vivo. Redox Biol 2020; 37:101695. [PMID: 32905883 PMCID: PMC7486459 DOI: 10.1016/j.redox.2020.101695] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/17/2020] [Accepted: 08/17/2020] [Indexed: 12/21/2022] Open
Abstract
Convergent evidence implicates impaired mitochondrial function and α-Synuclein accumulation as critical upstream events in the pathogenesis of Parkinson's disease, but comparatively little is known about how these factors interact to provoke neurodegeneration. We previously showed that α-Synuclein knockdown protected rat substantia nigra dopaminergic neurons from systemic exposure to the mitochondrial complex I inhibitor rotenone. Here we show that motor abnormalities prior to neuronal loss in this model are associated with extensive α-Synuclein-dependent cellular thiol oxidation. In order to elucidate the underlying events in vivo we constructed novel transgenic zebrafish that co-express, in dopaminergic neurons: (i) human α-Synuclein at levels insufficient to provoke neurodegeneration or neurobehavioral abnormalities; and (ii) genetically-encoded ratiometric fluorescent biosensors to detect cytoplasmic peroxide flux and glutathione oxidation. Live intravital imaging of the intact zebrafish CNS at cellular resolution showed unequivocally that α-Synuclein amplified dynamic cytoplasmic peroxide flux in dopaminergic neurons following exposure to the mitochondrial complex I inhibitors MPP+ or rotenone. This effect was robust and clearly evident following either acute or prolonged exposure to each inhibitor. In addition, disturbance of the resting glutathione redox potential following exogenous hydrogen peroxide challenge was augmented by α-Synuclein. Together these data show that α-Synuclein is a critical determinant of the redox consequences of mitochondrial dysfunction in dopaminergic neurons. The findings are important because the mechanisms underlying α-Synuclein-dependent reactive oxygen species fluxes and antioxidant suppression might provide a pharmacological target in Parkinson's disease to prevent progression from mitochondrial dysfunction and oxidative stress to cell death. Extensive neuronal thiol oxidation in a rat PD model is α-Synuclein-dependent. Peroxide flux and glutathione oxidation can be imaged in live transgenic zebrafish. α-Synuclein amplifies cytosolic peroxide flux in dopaminergic neurons. α-Synuclein exacerbates dynamic disturbances of the glutathione redox potential. The underlying molecular mechanisms may provide therapeutic targets in PD.
Collapse
Affiliation(s)
- Victor S Van Laar
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jianming Chen
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alevtina D Zharikov
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Qing Bai
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Roberto Di Maio
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - April A Dukes
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Teresa G Hastings
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Simon C Watkins
- Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, USA; Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - J Timothy Greenamyre
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Claudette M St Croix
- Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, USA; Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Edward A Burton
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA; Geriatric Research, Education and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, PA, USA.
| |
Collapse
|
6
|
Abstract
There are currently no treatments that hinder or halt the inexorable progression of Parkinson's disease (PD). While the etiology of PD remains elusive, evidence suggests that early dysfunction of mitochondrial respiration and homeostasis play a major role in PD pathogenesis. The mitochondrial structural protein Mic60, also known as mitofilin, is critical for maintaining mitochondrial architecture and function. Loss of Mic60 is associated with detrimental effects on mitochondrial homeostasis. Growing evidence now implicates Mic60 in the pathogenesis of PD. In this review, we discuss the data supporting a role of Mic60 and mitochondrial dysfunction in PD. We will also consider the potential of Mic60 as a therapeutic target for treating neurological disorders.
Collapse
Affiliation(s)
- Victor S Van Laar
- Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, United States
| | - P Anthony Otero
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, United States.,Division of Neuropathology, Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Cellular and Molecular Pathology (CMP) Program, Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Teresa G Hastings
- Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, United States.,Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sarah B Berman
- Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, United States.,Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, PA, United States
| |
Collapse
|
7
|
Van Laar VS, Arnold B, Berman SB. Primary Embryonic Rat Cortical Neuronal Culture and Chronic Rotenone Treatment in Microfluidic Culture Devices. Bio Protoc 2019; 9:e3192. [PMID: 31106236 DOI: 10.21769/bioprotoc.3192] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
In the study of neurodegenerative diseases, it is imperative to study the cellular and molecular changes associated with pathogenesis in the relevant cell type, central nervous system neurons. The unique compartmentalized morphology and bioenergetic needs of primary neurons present complications for their study in culture. Recent microculture techniques utilizing microfluidic culture devices allows for environmental separation and analysis of neuronal cell bodies and neurites in culture. Here, we present our protocol for culture of primary neurons in microfluidic devices and their chronic treatment with the Parkinson's disease (PD) relevant toxicant rotenone. In addition, we present a method for reuse of devices for culture. This culture methodology presents advantages for evaluating early pathogenic cellular and molecular changes in neurons in a compartment-specific manner.
Collapse
Affiliation(s)
- Victor S Van Laar
- University of Pittsburgh Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA.,The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Beth Arnold
- University of Pittsburgh Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA.,The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Sarah B Berman
- University of Pittsburgh Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA.,The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA.,Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
| |
Collapse
|
8
|
Dukes AA, Bai Q, Van Laar VS, Zhou Y, Ilin V, David CN, Agim ZS, Bonkowsky JL, Cannon JR, Watkins SC, Croix CMS, Burton EA, Berman SB. Live imaging of mitochondrial dynamics in CNS dopaminergic neurons in vivo demonstrates early reversal of mitochondrial transport following MPP(+) exposure. Neurobiol Dis 2016; 95:238-49. [PMID: 27452482 DOI: 10.1016/j.nbd.2016.07.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/30/2016] [Accepted: 07/20/2016] [Indexed: 01/09/2023] Open
Abstract
Extensive convergent evidence collectively suggests that mitochondrial dysfunction is central to the pathogenesis of Parkinson's disease (PD). Recently, changes in the dynamic properties of mitochondria have been increasingly implicated as a key proximate mechanism underlying neurodegeneration. However, studies have been limited by the lack of a model in which mitochondria can be imaged directly and dynamically in dopaminergic neurons of the intact vertebrate CNS. We generated transgenic zebrafish in which mitochondria of dopaminergic neurons are labeled with a fluorescent reporter, and optimized methods allowing direct intravital imaging of CNS dopaminergic axons and measurement of mitochondrial transport in vivo. The proportion of mitochondria undergoing axonal transport in dopaminergic neurons decreased overall during development between 2days post-fertilization (dpf) and 5dpf, at which point the major period of growth and synaptogenesis of the relevant axonal projections is complete. Exposure to 0.5-1.0mM MPP(+) between 4 and 5dpf did not compromise zebrafish viability or cause detectable changes in the number or morphology of dopaminergic neurons, motor function or monoaminergic neurochemistry. However, 0.5mM MPP(+) caused a 300% increase in retrograde mitochondrial transport and a 30% decrease in anterograde transport. In contrast, exposure to higher concentrations of MPP(+) caused an overall reduction in mitochondrial transport. This is the first time mitochondrial transport has been observed directly in CNS dopaminergic neurons of a living vertebrate and quantified in a PD model in vivo. Our findings are compatible with a model in which damage at presynaptic dopaminergic terminals causes an early compensatory increase in retrograde transport of compromised mitochondria for degradation in the cell body. These data are important because manipulation of early pathogenic mechanisms might be a valid therapeutic approach to PD. The novel transgenic lines and methods we developed will be useful for future studies on mitochondrial dynamics in health and disease.
Collapse
Affiliation(s)
- April A Dukes
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Qing Bai
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Victor S Van Laar
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Yangzhong Zhou
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; Tsinghua University Medical School, Beijing, China
| | - Vladimir Ilin
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Christopher N David
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; MSTP program, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Zeynep S Agim
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
| | - Joshua L Bonkowsky
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
| | - Simon C Watkins
- Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, USA; Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Claudette M St Croix
- Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, USA; Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Edward A Burton
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA; Geriatric Research, Education and Clinical Center, Pittsburgh Veterans' Affairs Healthcare System, Pittsburgh, PA, USA.
| | - Sarah B Berman
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
9
|
Van Laar VS, Berman SB, Hastings TG. Mic60/mitofilin overexpression alters mitochondrial dynamics and attenuates vulnerability of dopaminergic cells to dopamine and rotenone. Neurobiol Dis 2016; 91:247-61. [PMID: 27001148 DOI: 10.1016/j.nbd.2016.03.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 03/04/2016] [Accepted: 03/16/2016] [Indexed: 12/15/2022] Open
Abstract
Mitochondrial dysfunction has been implicated in Parkinson's disease (PD) neuropathology. Mic60, also known as mitofilin, is a protein of the inner mitochondrial membrane and a key component of the mitochondrial contact site and cristae junction organizing system (MICOS). Mic60 is critical for maintaining mitochondrial membrane structure and function. We previously demonstrated that mitochondrial Mic60 protein is susceptible to both covalent modification and loss in abundance following exposure to dopamine quinone. In this study, we utilized neuronally-differentiated SH-SY5Y and PC12 dopaminergic cell lines to examine the effects of altered Mic60 levels on mitochondrial function and cellular vulnerability in response to PD-relevant stressors. Short hairpin RNA (shRNA)-mediated knockdown of endogenous Mic60 protein in neuronal SH-SY5Y cells significantly potentiated dopamine-induced cell death, which was rescued by co-expressing shRNA-insensitive Mic60. Conversely, in PC12 and SH-SY5Y cells, Mic60 overexpression significantly attenuated both dopamine- and rotenone-induced cell death as compared to controls. Mic60 overexpression in SH-SY5Y cells was also associated with increased mitochondrial respiration, and, following rotenone exposure, increased spare respiratory capacity. Mic60 knockdown cells exhibited suppressed respiration and, following rotenone treatment, decreased spare respiratory capacity. Mic60 overexpression also affected mitochondrial fission/fusion dynamics. PC12 cells overexpressing Mic60 exhibited increased mitochondrial interconnectivity. Further, both PC12 cells and primary rat cortical neurons overexpressing Mic60 displayed suppressed mitochondrial fission and increased mitochondrial length in neurites. These results suggest that altering levels of Mic60 in dopaminergic neuronal cells significantly affects both mitochondrial homeostasis and cellular vulnerability to the PD-relevant stressors dopamine and rotenone, carrying implications for PD pathogenesis.
Collapse
Affiliation(s)
- Victor S Van Laar
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sarah B Berman
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
| | - Teresa G Hastings
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
10
|
Van Laar VS, Roy N, Liu A, Rajprohat S, Arnold B, Dukes AA, Holbein CD, Berman SB. Glutamate excitotoxicity in neurons triggers mitochondrial and endoplasmic reticulum accumulation of Parkin, and, in the presence of N-acetyl cysteine, mitophagy. Neurobiol Dis 2014; 74:180-93. [PMID: 25478815 DOI: 10.1016/j.nbd.2014.11.015] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 11/14/2014] [Accepted: 11/18/2014] [Indexed: 10/24/2022] Open
Abstract
Disruption of the dynamic properties of mitochondria (fission, fusion, transport, degradation, and biogenesis) has been implicated in the pathogenesis of neurodegenerative disorders, including Parkinson's disease (PD). Parkin, the product of gene PARK2 whose mutation causes familial PD, has been linked to mitochondrial quality control via its role in regulating mitochondrial dynamics, including mitochondrial degradation via mitophagy. Models using mitochondrial stressors in numerous cell types have elucidated a PINK1-dependent pathway whereby Parkin accumulates on damaged mitochondria and targets them for mitophagy. However, the role Parkin plays in regulating mitochondrial homeostasis specifically in neurons has been less clear. We examined whether a stressor linked to neurodegeneration, glutamate excitotoxicity, elicits Parkin-mitochondrial translocation and mitophagy in neurons. We found that brief, acute exposure to glutamate causes Parkin translocation to mitochondria in neurons, in a calcium- and N-methyl-d-aspartate (NMDA) receptor-dependent manner. In addition, we found that Parkin accumulates on endoplasmic reticulum (ER) and mitochondrial/ER junctions following excitotoxicity, supporting a role for Parkin in mitochondrial-ER crosstalk in mitochondrial homeostasis. Despite significant Parkin-mitochondria translocation, however, we did not observe mitophagy under these conditions. To further investigate, we examined the role of glutamate-induced oxidative stress in Parkin-mitochondria accumulation. Unexpectedly, we found that glutamate-induced accumulation of Parkin on mitochondria was promoted by the antioxidant N-acetyl cysteine (NAC), and that co-treatment with NAC facilitated Parkin-associated mitophagy. These results suggest the possibility that mitochondrial depolarization and oxidative damage may have distinct pathways associated with Parkin function in neurons, which may be critical in understanding the role of Parkin in neurodegeneration.
Collapse
Affiliation(s)
- Victor S Van Laar
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Nikita Roy
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA; School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Annie Liu
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA; School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Swati Rajprohat
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Beth Arnold
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - April A Dukes
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Cory D Holbein
- Department of Statistics, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Sarah B Berman
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA.
| |
Collapse
|
11
|
Van Laar VS, Berman SB. The interplay of neuronal mitochondrial dynamics and bioenergetics: implications for Parkinson's disease. Neurobiol Dis 2012; 51:43-55. [PMID: 22668779 DOI: 10.1016/j.nbd.2012.05.015] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Revised: 05/07/2012] [Accepted: 05/24/2012] [Indexed: 12/15/2022] Open
Abstract
The dynamic properties of mitochondria (mitochondrial fission, fusion, transport biogenesis and degradation) are critical for neuronal function and health, and dysregulation of mitochondrial dynamics has been increasingly linked to the pathogenesis of Parkinson's disease (PD). Mitochondrial dynamics and bioenergetics are interconnected, and this is of particular importance in neurons, which have a unique bioenergetic profile due to their energetic dependence on mitochondria and specialized, compartmentalized energetic needs. In this review, we summarize the interplay of mitochondrial dynamics and bioenergetics, and its particular relevance for neurodegeneration. Evidence linking dysregulation of mitochondrial dynamics to PD is presented from both toxin and genetic models, including newly emerging details of how PD-relevant genes PTEN-induced kinase 1 (PINK1) and Parkin regulate fission, fusion, mitophagy and transport. Finally, we discuss how neuronal bioenergetics may impact PD-relevant regulation of mitochondrial dynamics, and possible implications for understanding the role of mitochondrial dynamics in PD.
Collapse
Affiliation(s)
- Victor S Van Laar
- University of Pittsburgh Department of Neurology, Pittsburgh Institute for Neurodegenerative Diseases, Pittsburgh, PA 15213, USA
| | | |
Collapse
|
12
|
Van Laar VS, Arnold B, Cassady SJ, Chu CT, Burton EA, Berman SB. Bioenergetics of neurons inhibit the translocation response of Parkin following rapid mitochondrial depolarization. Hum Mol Genet 2010; 20:927-40. [PMID: 21147754 DOI: 10.1093/hmg/ddq531] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Recent studies delineate a pathway involving familial Parkinson's disease (PD)-related proteins PINK1 and Parkin, in which PINK1-dependent mitochondrial accumulation of Parkin targets depolarized mitochondria towards degradation through mitophagy. The pathway has been primarily characterized in cells less dependent on mitochondria for energy production than neurons. Here we report that in neurons, unlike other cells, mitochondrial depolarization by carbonyl cyanide m-chlorophenyl hydrazone did not induce Parkin translocation to mitochondria or mitophagy. PINK1 overexpression increased basal Parkin accumulation on neuronal mitochondria, but did not sensitize them to depolarization-induced Parkin translocation. Our data suggest that bioenergetic differences between neurons and cultured cell lines contribute to these different responses. In HeLa cells utilizing usual glycolytic metabolism, mitochondrial depolarization robustly triggered Parkin-mitochondrial translocation, but this did not occur in HeLa cells forced into dependence on mitochondrial respiration. Declining ATP levels after mitochondrial depolarization correlated with the absence of induced Parkin-mitochondrial translocation in both HeLa cells and neurons. However, intervention allowing neurons to maintain ATP levels after mitochondrial depolarization only modestly increased Parkin recruitment to mitochondria, without evidence of increased mitophagy. These data suggest that changes in ATP levels are not the sole determinant of the different responses between neurons and other cell types, and imply that additional mechanisms regulate mitophagy in neurons. Since the Parkin-mitophagy pathway is heavily dependent on bioenergetic status, the unique metabolic properties of neurons likely influence the function of this pathway in the pathogenesis of PD.
Collapse
Affiliation(s)
- Victor S Van Laar
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | | | | | | | | | | |
Collapse
|
13
|
Van Laar VS, Mishizen AJ, Cascio M, Hastings TG. Proteomic identification of dopamine-conjugated proteins from isolated rat brain mitochondria and SH-SY5Y cells. Neurobiol Dis 2009; 34:487-500. [PMID: 19332121 DOI: 10.1016/j.nbd.2009.03.004] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2008] [Revised: 03/13/2009] [Accepted: 03/13/2009] [Indexed: 11/30/2022] Open
Abstract
Dopamine oxidation has been previously demonstrated to cause dysfunction in mitochondrial respiration and membrane permeability, possibly related to covalent modification of critical proteins by the reactive dopamine quinone. However, specific mitochondrial protein targets have not been identified. In this study, we utilized proteomic techniques to identify proteins directly conjugated with (14)C-dopamine from isolated rat brain mitochondria exposed to radiolabeled dopamine quinone (150 microM) and differentiated SH-SY5Y cells treated with (14)C-dopamine (150 microM). We observed a subset of rat brain mitochondrial proteins that were covalently modified by (14)C-dopamine, including chaperonin, ubiquinol-cytochrome c reductase core protein 1, glucose regulated protein 75/mitochondrial HSP70/mortalin, mitofilin, and mitochondrial creatine kinase. We also found the Parkinson's disease associated proteins ubiquitin carboxy-terminal hydrolase L1 and DJ-1 to be covalently modified by dopamine in both brain mitochondrial preparations and SH-SY5Y cells. The susceptibility of the identified proteins to covalent modification by dopamine may carry implications for their role in the vulnerability of dopaminergic neurons in Parkinson's disease pathogenesis.
Collapse
Affiliation(s)
- Victor S Van Laar
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | | | | | | |
Collapse
|
14
|
Abstract
In Parkinson's disease, oxidative stress is implicated in protein misfolding and aggregation, which may activate the unfolded protein response by the endoplasmic reticulum (ER). Dopamine (DA) can initiate oxidative stress via H(2)O(2) formation by DA metabolism and by oxidation into DA quinone. We have previously shown that DA quinone induces oxidative protein modification, mitochondrial dysfunction in vitro, and dopaminergic cell toxicity in vivo and in vitro. In this study, we used cysteine- and lysine-reactive fluorescent dyes with 2D difference in-gel electrophoresis, mass spectrometry, and peptide mass fingerprint analysis to identify proteins in PC12 cell mitochondrial-enriched fractions that were altered in abundance following DA exposure (150 muM, 16 h). Quantitative changes in proteins labeled with fluorescent dyes indicated increases in a subset of proteins after DA exposure: calreticulin, ERp29, ERp99, Grp58, Grp78, Grp94 and Orp150 (149-260%), and decreased levels of aldolase A (39-42%). Changes in levels of several proteins detected by 2D difference in-gel electrophoresis were confirmed by western blot. Using this unbiased proteomics approach, our findings demonstrated that in PC12 cells, DA exposure leads to a cellular response indicative of ER stress prior to the onset of cell death, providing a potential link between DA and the unfolded protein response in the pathogenesis of Parkinson's disease.
Collapse
Affiliation(s)
- April A Dukes
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | | | | | | |
Collapse
|
15
|
Van Laar VS, Dukes AA, Cascio M, Hastings TG. Proteomic analysis of rat brain mitochondria following exposure to dopamine quinone: implications for Parkinson disease. Neurobiol Dis 2008; 29:477-89. [PMID: 18226537 PMCID: PMC2713672 DOI: 10.1016/j.nbd.2007.11.007] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2007] [Revised: 10/31/2007] [Accepted: 11/08/2007] [Indexed: 12/23/2022] Open
Abstract
Oxidative stress and mitochondrial dysfunction have been linked to dopaminergic neuron degeneration in Parkinson disease. We have previously shown that dopamine oxidation leads to selective dopaminergic terminal degeneration in vivo and alters mitochondrial function in vitro. In this study, we utilized 2-D difference in-gel electrophoresis to assess changes in the mitochondrial proteome following in vitro exposure to reactive dopamine quinone. A subset of proteins exhibit decreased fluorescence labeling following dopamine oxidation, suggesting a rapid loss of specific proteins. Amongst these proteins are mitochondrial creatine kinase, mitofilin, mortalin, the 75 kDa subunit of NADH dehydrogenase, and superoxide dismutase 2. Western blot analyses for mitochondrial creatine kinase and mitofilin confirmed significant losses in isolated brain mitochondria exposed to dopamine quinone and PC12 cells exposed to dopamine. These results suggest that specific mitochondrial proteins are uniquely susceptible to changes in abundance following dopamine oxidation, and carry implications for mitochondrial stability in Parkinson disease neurodegeneration.
Collapse
Affiliation(s)
- Victor S. Van Laar
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
- the Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
| | - April A. Dukes
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
- the Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
| | - Michael Cascio
- Department of Molecular Genetics & Biochemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
| | - Teresa G. Hastings
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
- the Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
| |
Collapse
|