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Chatterjee D, D’Brant LY, Hiller BM, Marmion DJ, Sandoval IM, Luk KC, Manfredsson FP, Messer A, Kordower JH, Butler DC. ENGINEERED NANOBODIES WITH PROGRAMMABLE TARGET ANTIGEN PROTEOLYSIS (PTAP) FUSIONS REGULATE INTRACELLULAR ALPHA-SYNUCLEIN IN VITRO AND IN VIVO. Res Sq 2024:rs.3.rs-4088206. [PMID: 38585932 PMCID: PMC10996777 DOI: 10.21203/rs.3.rs-4088206/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Alpha-synuclein (αSyn) aggregation and the formation of Lewy pathology (LP) is a foundational pathophysiological phenomenon in synucleinopathies. Delivering therapeutic single-chain and single-domain antibodies that bind pathogenic targets can disrupt intracellular aggregation. The fusion of antibody fragments to a negatively-charged proteasomal targeting motif (PEST) creates bifunctional constructs that enhance both solubility and turnover. With sequence-specific point mutations of PEST sequences that modulate proteasomal degradation efficiency, we report the creation of Programmable Target Antigen Proteolysis (PTAP) technology that can provide graded control over the levels of target antigens. We have previously demonstrated our lead anti-αSyn intrabody, VH14-PEST, is capable of reducing the pathological burden of synucleinopathy in vitro and in vivo. Here, we report a family of fully humanized VH14-PTAP constructs for controllable, therapeutic targeting of intracellular α-Syn. In cells, we demonstrate successful target engagement and efficacy of VH14-hPEST intrabodies, and validate proof-of-principle in human cells using 3D human organoids derived from PD-patient induced pluripotent stem cells (iPSC). In two synuclein-based rat models, PTAP intrabodies attenuated nigral αSyn pathology, preserved nigrostriatal dopaminergic tone, and slowed the propagation of αSyn pathology. These data demonstrate the potency of intracellular αSyn targeting as a method to alleviate pathology and highlight the potential clinical utility of PTAP intrabodies.
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Affiliation(s)
- Diptaman Chatterjee
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Lianna Y. D’Brant
- Regenerative Research Foundation, Neural Stem Cell Institute, Rensselaer, NY 12144
| | - Benjamin M. Hiller
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612
| | - David J. Marmion
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612
| | - Ivette M. Sandoval
- Department of Translational Neuroscience, Barrow Neurological Institute, Phoenix, AZ 85013
| | - Kelvin C. Luk
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19147
| | - Fredric P. Manfredsson
- Department of Translational Neuroscience, Barrow Neurological Institute, Phoenix, AZ 85013
| | - Anne Messer
- Regenerative Research Foundation, Neural Stem Cell Institute, Rensselaer, NY 12144
- Department of Biomedical Sciences, University at Albany, Albany, NY 12208
| | - Jeffrey H. Kordower
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612
- ASU-Banner Neurodegenerative Disease Research Center and School of Life Sciences, Arizona State University, Tempe, AZ 85281
| | - David C. Butler
- Regenerative Research Foundation, Neural Stem Cell Institute, Rensselaer, NY 12144
- Department of Biomedical Sciences, University at Albany, Albany, NY 12208
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Collier TJ, Begg L, Stancati JA, Mercado NM, Sellnow RC, Sandoval IM, Sortwell CE, Steece-Collier K. Quinpirole inhibits levodopa-induced dyskinesias at structural and behavioral levels: Efficacy negated by co-administration of isradipine. Exp Neurol 2023; 369:114522. [PMID: 37640098 PMCID: PMC10591902 DOI: 10.1016/j.expneurol.2023.114522] [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: 04/21/2023] [Revised: 08/06/2023] [Accepted: 08/20/2023] [Indexed: 08/31/2023]
Abstract
Dopamine depletion associated with parkinsonism induces plastic changes in striatal medium spiny neurons (MSN) that are maladaptive and associated with the emergence of the negative side-effect of standard treatment: the abnormal involuntary movements termed levodopa-induced dyskinesia (LID). Prevention of MSN dendritic spine loss is hypothesized to diminish liability for LID in Parkinson's disease. Blockade of striatal CaV1.3 calcium channels can prevent spine loss and significantly diminish LID in parkinsonian rats. While pharmacological antagonism with FDA approved CaV1 L-type channel antagonist dihydropyridine (DHP) drugs (e.g, isradipine) are potentially antidyskinetic, pharmacologic limitations of current drugs may result in suboptimal efficacy. To provide optimal CaV1.3 antagonism, we investigated the ability of a dual pharmacological approach to more potently antagonize these channels. Specifically, quinpirole, a D2/D3-type dopamine receptor (D2/3R) agonist, has been demonstrated to significantly reduce calcium current activity at CaV1.3 channels in MSNs of rats by a mechanism distinct from DHPs. We hypothesized that dual inhibition of striatal CaV1.3 channels using the DHP drug isradipine combined with the D2/D3 dopamine receptor agonist quinpirole prior to, and in conjunction with, levodopa would be more effective at preventing structural modifications of dendritic spines and providing more stable LID prevention. For these proof-of-principle studies, rats with unilateral nigrostriatal lesions received daily administration of vehicle, isradipine, quinpirole, or isradipine + quinpirole prior to, and concurrent with, levodopa. Development of LID and morphological analysis of dendritic spines were assessed. Contrary to our hypothesis, quinpirole monotherapy was the most effective at reducing dyskinesia severity and preventing abnormal mushroom spine formation on MSNs, a structural phenomenon previously associated with LID. Notably, the antidyskinetic efficacy of quinpirole monotherapy was lost in the presence of isradipine co-treatment. These findings suggest that D2/D3 dopamine receptor agonists when given in combination with levodopa and initiated in early-stage Parkinson's disease may provide long-term protection against LID. The negative interaction of isradipine with quinpirole suggests a potential cautionary note for co-administration of these drugs in a clinical setting.
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Affiliation(s)
- Timothy J Collier
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, 400 Monroe Ave. N.W., Grand Rapids, MI 49503, USA; Hauenstein Neuroscience Center, Mercy Health Saint Mary's, 220 Cherry St. S.E., Grand Rapids, MI 49503, USA.
| | - Lauren Begg
- Department of Biomedical Sciences, Grand Valley State University, 1 Campus Dr., Allendale, MI 49401, USA
| | - Jennifer A Stancati
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, 400 Monroe Ave. N.W., Grand Rapids, MI 49503, USA
| | - Natosha M Mercado
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, 400 Monroe Ave. N.W., Grand Rapids, MI 49503, USA
| | - Rhyomi C Sellnow
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, 400 Monroe Ave. N.W., Grand Rapids, MI 49503, USA; Cell and Molecular Biology Program, Michigan State University, East Lansing, MI 48824, USA
| | - Ivette M Sandoval
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, 400 Monroe Ave. N.W., Grand Rapids, MI 49503, USA; Hauenstein Neuroscience Center, Mercy Health Saint Mary's, 220 Cherry St. S.E., Grand Rapids, MI 49503, USA.
| | - Caryl E Sortwell
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, 400 Monroe Ave. N.W., Grand Rapids, MI 49503, USA; Hauenstein Neuroscience Center, Mercy Health Saint Mary's, 220 Cherry St. S.E., Grand Rapids, MI 49503, USA
| | - Kathy Steece-Collier
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, 400 Monroe Ave. N.W., Grand Rapids, MI 49503, USA; Hauenstein Neuroscience Center, Mercy Health Saint Mary's, 220 Cherry St. S.E., Grand Rapids, MI 49503, USA
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Caulfield ME, Vander Werp MJ, Stancati JA, Collier TJ, Sortwell CE, Sandoval IM, Manfredsson FP, Steece-Collier K. Downregulation of striatal CaV1.3 inhibits the escalation of levodopa-induced dyskinesia in male and female parkinsonian rats of advanced age. Neurobiol Dis 2023; 181:106111. [PMID: 37001610 DOI: 10.1016/j.nbd.2023.106111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/17/2023] [Accepted: 03/28/2023] [Indexed: 03/31/2023] Open
Abstract
In the past 25 years, the prevalence of Parkinson's disease (PD) has nearly doubled. Age remains the primary risk factor for PD and as the global aging population increases this trend is predicted to continue. Even when treated with levodopa, the gold standard dopamine (DA) replacement therapy, individuals with PD frequently develop therapeutic side effects. Levodopa-induced dyskinesia (LID), a common side effect of long-term levodopa use, represents a significant unmet clinical need in the treatment of PD. Previously, in young adult (3-month-old) male parkinsonian rats, we demonstrated that the silencing of CaV1.3 (Cacan1d) L-type voltage-gated calcium channels via striatal delivery of rAAV-CaV1.3-shRNA provides uniform protection against the induction of LID, and significant reduction of established severe LID. With the goal of more closely replicating a clinical demographic, the current study examined the effects of CaV1.3-targeted gene therapy on LID escalation in male and female parkinsonian rats of advanced age (18-month-old at study completion). We tested the hypothesis that silencing aberrant CaV1.3 channel activity in the parkinsonian striatum would prevent moderate to severe dyskinesia with levodopa dose escalation. To test this hypothesis, 15-month-old male and female F344 rats were rendered unilaterally parkinsonian and primed with low-dose (3-4 mg/kg) levodopa. Following the establishment of stable, mild dyskinesias, rats received an intrastriatal injection of either the Cacna1d-specific rAAV-CaV1.3-shRNA vector (CAV-shRNA), or the scramble control rAAV-SCR-shRNA vector (SCR-shRNA). Daily (M-Fr) low-dose levodopa was maintained for 4 weeks during the vector transduction and gene silencing window followed by escalation to 6 mg/kg, then to 12 mg/kg levodopa. SCR-shRNA-shRNA rats showed stable LID expression with low-dose levodopa and the predicted escalation of LID severity with increased levodopa doses. Conversely, complex behavioral responses were observed in aged rats receiving CAV-shRNA, with approximately half of the male and female subjects-therapeutic 'Responders'-demonstrating protection against LID escalation, while the remaining half-therapeutic 'Non-Responders'-showed LID escalation similar to SCR-shRNA rats. Post-mortem histological analyses revealed individual variability in the detection of Cacna1d regulation in the DA-depleted striatum of aged rats. However, taken together, male and female therapeutic 'Responder' rats receiving CAV-shRNA had significantly less striatal Cacna1d in their vector-injected striatum relative to contralateral striatum than those with SCR-shRNA. The current data suggest that mRNA-level silencing of striatal CaV1.3 channels maintains potency in a clinically relevant in vivo scenario by preventing dose-dependent dyskinesia escalation in rats of advanced age. As compared to the uniform response previously reported in young male rats, there was notable variability between individual aged rats, particularly females, in the current study. Future investigations are needed to derive the sex-specific and age-related mechanisms which underlie variable responses to gene therapy and to elucidate factors which determine the therapeutic efficacy of treatment for PD.
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Anwer DM, Gubinelli F, Kurt YA, Sarauskyte L, Jacobs F, Venuti C, Sandoval IM, Yang Y, Stancati J, Mazzocchi M, Brandi E, O'Keeffe G, Steece-Collier K, Li JY, Deierborg T, Manfredsson FP, Davidsson M, Heuer A. A comparison of machine learning approaches for the quantification of microglial cells in the brain of mice, rats and non-human primates. PLoS One 2023; 18:e0284480. [PMID: 37126506 PMCID: PMC10150977 DOI: 10.1371/journal.pone.0284480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 03/31/2023] [Indexed: 05/02/2023] Open
Abstract
Microglial cells are brain-specific macrophages that swiftly react to disruptive events in the brain. Microglial activation leads to specific modifications, including proliferation, morphological changes, migration to the site of insult, and changes in gene expression profiles. A change in inflammatory status has been linked to many neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease. For this reason, the investigation and quantification of microglial cells is essential for better understanding their role in disease progression as well as for evaluating the cytocompatibility of novel therapeutic approaches for such conditions. In the following study we implemented a machine learning-based approach for the fast and automatized quantification of microglial cells; this tool was compared with manual quantification (ground truth), and with alternative free-ware such as the threshold-based ImageJ and the machine learning-based Ilastik. We first trained the algorithms on brain tissue obtained from rats and non-human primate immunohistochemically labelled for microglia. Subsequently we validated the accuracy of the trained algorithms in a preclinical rodent model of Parkinson's disease and demonstrated the robustness of the algorithms on tissue obtained from mice, as well as from images provided by three collaborating laboratories. Our results indicate that machine learning algorithms can detect and quantify microglial cells in all the three mammalian species in a precise manner, equipotent to the one observed following manual counting. Using this tool, we were able to detect and quantify small changes between the hemispheres, suggesting the power and reliability of the algorithm. Such a tool will be very useful for investigation of microglial response in disease development, as well as in the investigation of compatible novel therapeutics targeting the brain. As all network weights and labelled training data are made available, together with our step-by-step user guide, we anticipate that many laboratories will implement machine learning-based quantification of microglial cells in their research.
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Affiliation(s)
- Danish M Anwer
- Behavioural Neuroscience Laboratory, Department of Experimental Medical Sciences, Lund University Lund, Sweden
| | - Francesco Gubinelli
- Behavioural Neuroscience Laboratory, Department of Experimental Medical Sciences, Lund University Lund, Sweden
| | - Yunus A Kurt
- Behavioural Neuroscience Laboratory, Department of Experimental Medical Sciences, Lund University Lund, Sweden
| | - Livija Sarauskyte
- Behavioural Neuroscience Laboratory, Department of Experimental Medical Sciences, Lund University Lund, Sweden
| | - Febe Jacobs
- Behavioural Neuroscience Laboratory, Department of Experimental Medical Sciences, Lund University Lund, Sweden
| | - Chiara Venuti
- Behavioural Neuroscience Laboratory, Department of Experimental Medical Sciences, Lund University Lund, Sweden
| | - Ivette M Sandoval
- Barrow Neurological Institute, Parkinson's Disease Research Unit, Department of Translational Neuroscience, Phoenix, Arizona, United States of America
| | - Yiyi Yang
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Jennifer Stancati
- Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America
| | - Martina Mazzocchi
- Brain Development and Repair Group, Department of Anatomy and Neuroscience University College Cork, Cork, Ireland
| | - Edoardo Brandi
- Neural Plasticity and Repair, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Gerard O'Keeffe
- Brain Development and Repair Group, Department of Anatomy and Neuroscience University College Cork, Cork, Ireland
| | - Kathy Steece-Collier
- Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America
| | - Jia-Yi Li
- Neural Plasticity and Repair, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Tomas Deierborg
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Fredric P Manfredsson
- Barrow Neurological Institute, Parkinson's Disease Research Unit, Department of Translational Neuroscience, Phoenix, Arizona, United States of America
| | - Marcus Davidsson
- Behavioural Neuroscience Laboratory, Department of Experimental Medical Sciences, Lund University Lund, Sweden
- Barrow Neurological Institute, Parkinson's Disease Research Unit, Department of Translational Neuroscience, Phoenix, Arizona, United States of America
| | - Andreas Heuer
- Behavioural Neuroscience Laboratory, Department of Experimental Medical Sciences, Lund University Lund, Sweden
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Abstract
The protein alpha-Synuclein (α-Syn) is a key contributor to the etiology of Parkinson’s disease (PD) with aggregation, trans-neuronal spread, and/or depletion of α-Syn being viewed as crucial events in the molecular processes that result in neurodegeneration. The exact succession of pathological occurrences that lead to neuronal death are still largely unknown and are likely to be multifactorial in nature. Despite this unknown, α-Syn dose and stability, autophagy-lysosomal dysfunction, and inflammation, amongst other cellular impairments, have all been described as participatory events in the neurodegenerative process. To that end, in this review we discuss the logical points for gene therapy to intervene in α-Syn-mediated disease and review the preclinical body of work where gene therapy has been used, or could conceptually be used, to ameliorate α-Syn induced neurotoxicity. We discuss gene therapy in the traditional sense of modulating gene expression, as well as the use of viral vectors and nanoparticles as methods to deliver other therapeutic modalities.
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Affiliation(s)
- Ivette M Sandoval
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
| | - David J Marmion
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
| | - Kimberly T Meyers
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
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Chen G, Kang SS, Wang Z, Ahn EH, Xia Y, Liu X, Sandoval IM, Manfredsson FP, Zhang Z, Ye K. Netrin-1 receptor UNC5C cleavage by active δ-secretase enhances neurodegeneration, promoting Alzheimer's disease pathologies. Sci Adv 2021; 7:7/16/eabe4499. [PMID: 33863723 PMCID: PMC8051868 DOI: 10.1126/sciadv.abe4499] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 02/26/2021] [Indexed: 05/22/2023]
Abstract
Netrin-1, a family member of laminin-related secreted proteins, mediates axon guidance and cell migration during neural development. T835M mutation in netrin receptor UNC5C predisposes to the late-onset Alzheimer's disease (AD) and increases neuronal cell death. However, it remains unclear how this receptor is molecularly regulated in AD. Here, we show that δ-secretase selectively cleaves UNC5C and escalates its proapoptotic activity, facilitating neurodegeneration in AD. Netrin deficiency activates δ-secretase that specifically cuts UNC5C at N467 and N547 residues and enhances subsequent caspase-3 activation, additively augmenting neuronal cell death. Blockade of δ-secretase cleavage of UNC5C diminishes T835M mutant's proapoptotic activity. Viral expression of δ-secretase-truncated UNC5C fragments into APP/PS1 mice strongly accelerates AD pathologies, impairing learning and memory. Conversely, deletion of UNC5C from netrin-1-depleted mice attenuates AD pathologies and rescues cognitive disorders. Hence, δ-secretase truncates UNC5C and elevates its neurotoxicity, contributing to AD pathogenesis.
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Affiliation(s)
- Guiqin Chen
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
| | - Seong Su Kang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Zhihao Wang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Eun Hee Ahn
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Yiyuan Xia
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Xia Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Ivette M Sandoval
- Parkinson's Disease Research Unit, Department of Neurobiology, Barrow Neurological Institute, 350 West Thomas Road, Phoenix, AZ 85013, USA
| | - Fredric P Manfredsson
- Parkinson's Disease Research Unit, Department of Neurobiology, Barrow Neurological Institute, 350 West Thomas Road, Phoenix, AZ 85013, USA
| | - Zhaohui Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
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Romoli B, Lozada AF, Sandoval IM, Manfredsson FP, Hnasko TS, Berg DK, Dulcis D. Neonatal Nicotine Exposure Primes Midbrain Neurons to a Dopaminergic Phenotype and Increases Adult Drug Consumption. Biol Psychiatry 2019; 86:344-355. [PMID: 31202491 PMCID: PMC7359410 DOI: 10.1016/j.biopsych.2019.04.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/20/2019] [Accepted: 04/01/2019] [Indexed: 01/24/2023]
Abstract
BACKGROUND Nicotine intake induces addiction through neuroplasticity of the reward circuitry, altering the activity of dopaminergic neurons of the ventral tegmental area. Prior work demonstrated that altered circuit activity can change neurotransmitter expression in the developing and adult brain. Here we investigated the effects of neonatal nicotine exposure on the dopaminergic system and nicotine consumption in adulthood. METHODS Male and female mice were used for two-bottle-choice test, progressive ratio breakpoint test, immunohistochemistry, RNAscope, quantitative polymerase chain reaction, calcium imaging, and DREADD (designer receptor exclusively activated by designer drugs)-mediated chemogenic activation/inhibition experiments. RESULTS Neonatal nicotine exposure potentiates drug preference in adult mice, induces alterations in calcium spike activity of midbrain neurons, and increases the number of dopamine-expressing neurons in the ventral tegmental area. Specifically, glutamatergic neurons are first primed to express transcription factor Nurr1, then acquire the dopaminergic phenotype following nicotine re-exposure in adulthood. Enhanced neuronal activity combined with Nurr1 expression is both necessary and sufficient for the nicotine-mediated neurotransmitter plasticity to occur. CONCLUSIONS Our findings illuminate a new mechanism of neuroplasticity by which early nicotine exposure primes the reward system to display increased susceptibility to drug consumption in adulthood.
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Affiliation(s)
| | | | | | | | | | | | - Davide Dulcis
- Department of Psychiatry, University of California San Diego, La Jolla, California.
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Steece‐Collier K, Stancati JA, Collier NJ, Sandoval IM, Mercado NM, Sortwell CE, Collier TJ, Manfredsson FP. Genetic silencing of striatal CaV1.3 prevents and ameliorates levodopa dyskinesia. Mov Disord 2019; 34:697-707. [PMID: 31002755 PMCID: PMC6563183 DOI: 10.1002/mds.27695] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/19/2019] [Accepted: 03/21/2019] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Levodopa-induced dyskinesias are an often debilitating side effect of levodopa therapy in Parkinson's disease. Although up to 90% of individuals with PD develop this side effect, uniformly effective and well-tolerated antidyskinetic treatment remains a significant unmet need. The pathognomonic loss of striatal dopamine in PD results in dysregulation and disinhibition of striatal CaV1.3 calcium channels, leading to synaptopathology that appears to be involved in levodopa-induced dyskinesias. Although there are clinically available drugs that can inhibit CaV1.3 channels, they are not adequately potent and have only partial and transient impact on levodopa-induced dyskinesias. METHODS To provide unequivocal target validation, free of pharmacological limitations, we developed a CaV1.3 shRNA to provide high-potency, target-selective, mRNA-level silencing of striatal CaV1.3 channels and examined its ability to impact levodopa-induced dyskinesias in severely parkinsonian rats. RESULTS We demonstrate that vector-mediated silencing of striatal CaV1.3 expression in severely parkinsonian rats prior to the introduction of levodopa can uniformly and completely prevent induction of levodopa-induced dyskinesias, and this antidyskinetic benefit persists long term and with high-dose levodopa. In addition, this approach is capable of ameliorating preexisting severe levodopa-induced dyskinesias. Importantly, motoric responses to low-dose levodopa remained intact in the presence of striatal CaV1.3 silencing, indicating preservation of levodopa benefit without dyskinesia liability. DISCUSSION The current data provide some of the most profound antidyskinetic benefit reported to date and suggest that genetic silencing of striatal CaV1.3 channels has the potential to transform treatment of individuals with PD by allowing maintenance of motor benefit of levodopa in the absence of the debilitating levodopa-induced dyskinesia side effect. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Kathy Steece‐Collier
- Department of Translational Science & Molecular MedicineCollege of Human Medicine, Michigan State UniversityGrand RapidsMIUSA
- Hauenstein Neuroscience CenterMercy Health Saint Mary's, Grand RapidsMichiganUSA
| | - Jennifer A. Stancati
- Department of Translational Science & Molecular MedicineCollege of Human Medicine, Michigan State UniversityGrand RapidsMIUSA
| | - Nicholas J. Collier
- Department of Translational Science & Molecular MedicineCollege of Human Medicine, Michigan State UniversityGrand RapidsMIUSA
| | - Ivette M. Sandoval
- Department of Translational Science & Molecular MedicineCollege of Human Medicine, Michigan State UniversityGrand RapidsMIUSA
- Hauenstein Neuroscience CenterMercy Health Saint Mary's, Grand RapidsMichiganUSA
| | - Natosha M. Mercado
- Department of Translational Science & Molecular MedicineCollege of Human Medicine, Michigan State UniversityGrand RapidsMIUSA
| | - Caryl E. Sortwell
- Department of Translational Science & Molecular MedicineCollege of Human Medicine, Michigan State UniversityGrand RapidsMIUSA
- Hauenstein Neuroscience CenterMercy Health Saint Mary's, Grand RapidsMichiganUSA
| | - Timothy J. Collier
- Department of Translational Science & Molecular MedicineCollege of Human Medicine, Michigan State UniversityGrand RapidsMIUSA
- Hauenstein Neuroscience CenterMercy Health Saint Mary's, Grand RapidsMichiganUSA
| | - Fredric P. Manfredsson
- Department of Translational Science & Molecular MedicineCollege of Human Medicine, Michigan State UniversityGrand RapidsMIUSA
- Hauenstein Neuroscience CenterMercy Health Saint Mary's, Grand RapidsMichiganUSA
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Xiang J, Wang ZH, Ahn EH, Liu X, Yu SP, Manfredsson FP, Sandoval IM, Ju G, Wu S, Ye K. Delta-secretase-cleaved Tau antagonizes TrkB neurotrophic signalings, mediating Alzheimer's disease pathologies. Proc Natl Acad Sci U S A 2019; 116:9094-9102. [PMID: 31004063 PMCID: PMC6500177 DOI: 10.1073/pnas.1901348116] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [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] [Indexed: 12/11/2022] Open
Abstract
BDNF, an essential trophic factor implicated in synaptic plasticity and neuronal survival, is reduced in Alzheimer's disease (AD). BDNF deficiency's association with Tau pathology in AD is well documented. However, the molecular mechanisms accounting for these events remain incompletely understood. Here we show that BDNF deprivation triggers Tau proteolytic cleavage by activating δ-secretase [i.e., asparagine endopeptidase (AEP)], and the resultant Tau N368 fragment binds TrkB receptors and blocks its neurotrophic signals, inducing neuronal cell death. Knockout of BDNF or TrkB receptors provokes δ-secretase activation via reducing T322 phosphorylation by Akt and subsequent Tau N368 cleavage, inducing AD-like pathology and cognitive dysfunction, which can be restored by expression of uncleavable Tau N255A/N368A mutant. Blocking the Tau N368-TrkB complex using Tau repeat-domain 1 peptide reverses this pathology. Thus, our findings support that BDNF reduction mediates Tau pathology via activating δ-secretase in AD.
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Affiliation(s)
- Jie Xiang
- Department of Neurobiology, Fourth Military Medical University, Xi'an, 710032 Shaanxi, People's Republic of China
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Zhi-Hao Wang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Eun Hee Ahn
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Xia Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Shan-Ping Yu
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322
| | - Fredric P Manfredsson
- Department of Translational Science & Molecular Medicine, Michigan State University, Grand Rapids, MI 49503
| | - Ivette M Sandoval
- Department of Translational Science & Molecular Medicine, Michigan State University, Grand Rapids, MI 49503
| | - Gong Ju
- Department of Neurobiology, Fourth Military Medical University, Xi'an, 710032 Shaanxi, People's Republic of China
| | - Shengxi Wu
- Department of Neurobiology, Fourth Military Medical University, Xi'an, 710032 Shaanxi, People's Republic of China
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322;
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10
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Sellnow RC, Newman JH, Chambers N, West AR, Steece-Collier K, Sandoval IM, Benskey MJ, Bishop C, Manfredsson FP. Regulation of dopamine neurotransmission from serotonergic neurons by ectopic expression of the dopamine D2 autoreceptor blocks levodopa-induced dyskinesia. Acta Neuropathol Commun 2019; 7:8. [PMID: 30646956 PMCID: PMC6332643 DOI: 10.1186/s40478-018-0653-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 12/19/2018] [Indexed: 12/01/2022] Open
Abstract
Levodopa-induced dyskinesias (LID) are a prevalent side effect of chronic treatment with levodopa (L-DOPA) for the motor symptoms of Parkinson’s disease (PD). It has long been hypothesized that serotonergic neurons of the dorsal raphe nucleus (DRN) are capable of L-DOPA uptake and dysregulated release of dopamine (DA), and that this “false neurotransmission” phenomenon is a main contributor to LID development. Indeed, many preclinical studies have demonstrated LID management with serotonin receptor agonist treatment, but unfortunately, promising preclinical data has not been translated in large-scale clinical trials. Importantly, while there is an abundance of convincing clinical and preclinical evidence supporting a role of maladaptive serotonergic neurotransmission in LID expression, there is no direct evidence that dysregulated DA release from serotonergic neurons impacts LID formation. In this study, we ectopically expressed the DA autoreceptor D2Rs (or GFP) in the DRN of 6-hydroxydopamine (6-OHDA) lesioned rats. No negative impact on the therapeutic efficacy of L-DOPA was seen with rAAV-D2Rs therapy. However, D2Rs treated animals, when subjected to a LID-inducing dose regimen of L-DOPA, remained completely resistant to LID, even at high doses. Moreover, the same subjects remained resistant to LID formation when treated with direct DA receptor agonists, suggesting D2Rs activity in the DRN blocked dyskinesogenic L-DOPA priming of striatal neurons. In vivo microdialysis confirmed that DA efflux in the striatum was reduced with rAAV-D2Rs treatment, providing explicit evidence that abnormal DA release from DRN neurons can affect LID. This is the first direct evidence of dopaminergic neurotransmission in DRN neurons and its modulation with rAAV-D2Rs gene therapy confirms the serotonin hypothesis in LID, demonstrating that regulation of serotonergic neurons achieved with a gene therapy approach offers a novel and potent antidyskinetic therapy.
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11
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Abstract
Today any researcher with the desire can easily purchase a viral vector. However, despite the availability of viral vectors themselves, the requisite knowledge that is absolutely essential to conducting a gene therapy experiment remains somewhat obscure and esoteric. To utilize viral vectors to their full potential, a large number of decisions must be made, in some instances prior to even obtaining the vector itself. For example, critical decisions include selection of the proper virus, selection of the proper expression cassette, whether to produce or purchase a viral vector, proper viral handling and storage, the most appropriate delivery method, selecting the proper controls, how to ensure your virus is expressing properly, and many other complex decisions that are essential to performing a successful gene therapy experiment. The need to make so many important decisions can be overwhelming and potentially prohibitive, especially to the novice gene therapist. In order to aid in this challenging process, here we provide an overview of basic gene therapy modalities and a decision tree that can be used to make oneself aware of the options available to the beginning gene therapist. This information can be used as a road map to help navigate the complex and perhaps confusing process of designing a successful gene therapy experiment.
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Affiliation(s)
- Matthew J Benskey
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Ivette M Sandoval
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
- Mercy Health Saint Mary's, Grand Rapids, MI, USA
| | - Kathryn Miller
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Rhyomi L Sellnow
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Aysegul Gezer
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Nathan C Kuhn
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Roslyn Vashon
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Fredric P Manfredsson
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA.
- Mercy Health Saint Mary's, Grand Rapids, MI, USA.
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12
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Abstract
Clustered regularly interspaced short palindromic repeat (CRISPR/Cas) system has emerged as an extremely useful tool for biological research and as a potential technology for gene therapy approaches. CRISPR/Cas mediated genome editing can be used to easily and efficiently modify endogenous genes in a large variety of cells and organisms. Furthermore, a modified version of the Cas9 nuclease has been developed that can be used for regulation of endogenous gene expression and labeling of genomic loci, among other applications. This chapter provides an introduction to the basis of the technology and a detail protocol for the most classic application: gene inactivation by CRISPR/Cas9 nuclease system from Streptococcus pyogenes. This workflow can be easily adapted for other CRISPR systems and applications.
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Affiliation(s)
- Ivette M Sandoval
- Department of Translational Science & Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA.
- Mercy Health Saint Mary's, Grand Rapids, MI, USA.
| | - Timothy J Collier
- Department of Translational Science & Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
- Mercy Health Saint Mary's, Grand Rapids, MI, USA
| | - Fredric P Manfredsson
- Department of Translational Science & Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
- Mercy Health Saint Mary's, Grand Rapids, MI, USA
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13
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Abstract
Adeno-associated virus (AAV) is an increasingly popular tool in the research laboratory, and use of this viral vector clinically is occurring at an accelerated pace. Nevertheless, despite its popularity, AAV is a relatively cumbersome virus to produce; however, significant efforts have been invested to develop, optimize, and simplify methodology that allows the generation of high-quality AAV with significantly increased production yields. Here we describe multiple modalities for production and purification of AAV particles produced in HEK293 cell cultures using an iodixanol density gradient. We include two methods adapted for harvesting virus from the culture media: tangential flow filtration (TFF) and polyethylene glycol precipitation (PEGylation). Moreover, we also describe the protocol for anion exchange chromatography, which can be used after the iodixanol gradient as an additional purification step. Last, we provide various protocols for determining virus titer.
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Affiliation(s)
- Ivette M Sandoval
- Department of Translational Science & Molecular Medicine, Michigan State University, Grand Rapids, MI, USA. .,Mercy Health Saint Mary's, Grand Rapids, MI, USA.
| | - Nathan M Kuhn
- Department of Translational Science & Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Fredric P Manfredsson
- Department of Translational Science & Molecular Medicine, Michigan State University, Grand Rapids, MI, USA.,Mercy Health Saint Mary's, Grand Rapids, MI, USA
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14
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Wang ZH, Wu W, Kang SS, Liu X, Wu Z, Peng J, Yu SP, Manfredsson FP, Sandoval IM, Liu X, Wang JZ, Ye K. BDNF inhibits neurodegenerative disease-associated asparaginyl endopeptidase activity via phosphorylation by AKT. JCI Insight 2018; 3:99007. [PMID: 30135302 DOI: 10.1172/jci.insight.99007] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [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: 12/04/2017] [Accepted: 07/03/2018] [Indexed: 12/13/2022] Open
Abstract
AEP is an age-dependent lysosomal asparaginyl endopeptidase that cleaves numerous substrates including tau and α-synuclein and mediates their pathological roles in neurodegenerative diseases. However, the molecular mechanism regulating this critical protease remains incompletely understood. Here, we show that Akt phosphorylates AEP on residue T322 upon brain-derived neurotrophic factor (BDNF) treatment and triggers its lysosomal translocation and inactivation. When BDNF levels are reduced in neurodegenerative diseases, AEP T322 phosphorylation is attenuated. Consequently, AEP is activated and translocates into the cytoplasm, where it cleaves both tau and α-synuclein. Remarkably, the unphosphorylated T322A mutant increases tau or α-synuclein cleavage by AEP and augments cell death, whereas phosphorylation mimetic T322E mutant represses these effects. Interestingly, viral injection of T322E into Tau P301S mice antagonizes tau N368 cleavage and tau pathologies, rescuing synaptic dysfunction and cognitive deficits. By contrast, viral administration of T322A into young α-SNCA mice elicits α-synuclein N103 cleavage and promotes dopaminergic neuronal loss, facilitating motor defects. Therefore, our findings support the notion that BDNF contributes to the pathogenesis of neurodegenerative diseases by suppressing AEP via Akt phosphorylation.
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Affiliation(s)
- Zhi-Hao Wang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA.,Department of Pathophysiology, Key Laboratory of Ministry of Education of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wanqiang Wu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA.,Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Seong Su Kang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Xia Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Zhiping Wu
- Departments of Structural Biology and Developmental Neurobiology, St. Jude Proteomics Facility, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Junmin Peng
- Departments of Structural Biology and Developmental Neurobiology, St. Jude Proteomics Facility, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Shan Ping Yu
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Fredric P Manfredsson
- Department of Translational Science & Molecular Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Ivette M Sandoval
- Department of Translational Science & Molecular Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Xuebo Liu
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Jian-Zhi Wang
- Department of Pathophysiology, Key Laboratory of Ministry of Education of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
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15
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Kang SS, Ahn EH, Zhang Z, Liu X, Manfredsson FP, Sandoval IM, Dhakal S, Iuvone PM, Cao X, Ye K. α-Synuclein stimulation of monoamine oxidase-B and legumain protease mediates the pathology of Parkinson's disease. EMBO J 2018; 37:embj.201798878. [PMID: 29769405 DOI: 10.15252/embj.201798878] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [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: 12/19/2017] [Revised: 04/01/2018] [Accepted: 04/09/2018] [Indexed: 12/31/2022] Open
Abstract
Dopaminergic neurodegeneration in Parkinson's disease (PD) is associated with abnormal dopamine metabolism by MAO-B (monoamine oxidase-B) and intracellular α-Synuclein (α-Syn) aggregates, called the Lewy body. However, the molecular relationship between α-Syn and MAO-B remains unclear. Here, we show that α-Syn directly binds to MAO-B and stimulates its enzymatic activity, which triggers AEP (asparagine endopeptidase; legumain) activation and subsequent α-Syn cleavage at N103, leading to dopaminergic neurodegeneration. Interestingly, the dopamine metabolite, DOPAL, strongly activates AEP, and the N103 fragment of α-Syn binds and activates MAO-B. Accordingly, overexpression of AEP in SNCA transgenic mice elicits α-Syn N103 cleavage and accelerates PD pathogenesis, and inhibition of MAO-B by Rasagiline diminishes α-Syn-mediated PD pathology and motor dysfunction. Moreover, virally mediated expression of α-Syn N103 induces PD pathogenesis in wild-type, but not MAO-B-null mice. Our findings thus support that AEP-mediated cleavage of α-Syn at N103 is required for the association and activation of MAO-B, mediating PD pathogenesis.
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Affiliation(s)
- Seong Su Kang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Eun Hee Ahn
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Zhentao Zhang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA.,Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xia Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Fredric P Manfredsson
- Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Ivette M Sandoval
- Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Susov Dhakal
- Department of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - P Michael Iuvone
- Department of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Xuebing Cao
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA .,Translational Center for Stem Cell Research, Department of Regenerative Medicine, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
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16
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Benskey MJ, Sellnow RC, Sandoval IM, Sortwell CE, Lipton JW, Manfredsson FP. Silencing Alpha Synuclein in Mature Nigral Neurons Results in Rapid Neuroinflammation and Subsequent Toxicity. Front Mol Neurosci 2018; 11:36. [PMID: 29497361 PMCID: PMC5819572 DOI: 10.3389/fnmol.2018.00036] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [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: 12/06/2017] [Accepted: 01/26/2018] [Indexed: 12/19/2022] Open
Abstract
Human studies and preclinical models of Parkinson’s disease implicate the involvement of both the innate and adaptive immune systems in disease progression. Further, pro-inflammatory markers are highly enriched near neurons containing pathological forms of alpha synuclein (α-syn), and α-syn overexpression recapitulates neuroinflammatory changes in models of Parkinson’s disease. These data suggest that α-syn may initiate a pathological inflammatory response, however the mechanism by which α-syn initiates neuroinflammation is poorly understood. Silencing endogenous α-syn results in a similar pattern of nigral degeneration observed following α-syn overexpression. Here we aimed to test the hypothesis that loss of α-syn function within nigrostriatal neurons results in neuronal dysfunction, which subsequently stimulates neuroinflammation. Adeno-associated virus (AAV) expressing an short hairpin RNA (shRNA) targeting endogenous α-syn was unilaterally injected into the substantia nigra pars compacta (SNc) of adult rats, after which nigrostriatal pathology and indices of neuroinflammation were examined at 7, 10, 14 and 21 days post-surgery. Removing endogenous α-syn from nigrostriatal neurons resulted in a rapid up-regulation of the major histocompatibility complex class 1 (MHC-1) within transduced nigral neurons. Nigral MHC-1 expression occurred prior to any overt cell death and coincided with the recruitment of reactive microglia and T-cells to affected neurons. Following the induction of neuroinflammation, α-syn knockdown resulted in a 50% loss of nigrostriatal neurons in the SNc and a corresponding loss of nigrostriatal terminals and dopamine (DA) concentrations within the striatum. Expression of a control shRNA did not elicit any pathological changes. Silencing α-syn within glutamatergic neurons of the cerebellum did not elicit inflammation or cell death, suggesting that toxicity initiated by α-syn silencing is specific to DA neurons. These data provide evidence that loss of α-syn function within nigrostriatal neurons initiates a neuronal-mediated neuroinflammatory cascade, involving both the innate and adaptive immune systems, which ultimately results in the death of affected neurons.
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Affiliation(s)
- Matthew J Benskey
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Rhyomi C Sellnow
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Ivette M Sandoval
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States.,Mercy Health Saint Mary's, Grand Rapids, MI, United States
| | - Caryl E Sortwell
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States.,Mercy Health Saint Mary's, Grand Rapids, MI, United States
| | - Jack W Lipton
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States.,Mercy Health Saint Mary's, Grand Rapids, MI, United States
| | - Fredric P Manfredsson
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States.,Mercy Health Saint Mary's, Grand Rapids, MI, United States
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17
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Manfredsson FP, Luk KC, Benskey MJ, Gezer A, Garcia J, Kuhn NC, Sandoval IM, Patterson JR, O'Mara A, Yonkers R, Kordower JH. Induction of alpha-synuclein pathology in the enteric nervous system of the rat and non-human primate results in gastrointestinal dysmotility and transient CNS pathology. Neurobiol Dis 2018; 112:106-118. [PMID: 29341898 DOI: 10.1016/j.nbd.2018.01.008] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [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: 10/09/2017] [Revised: 12/28/2017] [Accepted: 01/09/2018] [Indexed: 01/09/2023] Open
Abstract
Alpha-Synuclein (α-syn) is by far the most highly vetted pathogenic and therapeutic target in Parkinson's disease. Aggregated α-syn is present in sporadic Parkinson's disease, both in the central nervous system (CNS) and peripheral nervous system (PNS). The enteric division of the PNS is of particular interest because 1) gastric dysfunction is a key clinical manifestation of Parkinson's disease, and 2) Lewy pathology in myenteric and submucosal neurons of the enteric nervous system (ENS) has been referred to as stage zero in the Braak pathological staging of Parkinson's disease. The presence of Lewy pathology in the ENS and the fact that patients often experience enteric dysfunction before the onset of motor symptoms has led to the hypothesis that α-syn pathology starts in the periphery, after which it spreads to the CNS via interconnected neural pathways. Here we sought to directly test this hypothesis in rodents and non-human primates (NHP) using two distinct models of α-syn pathology: the α-syn viral overexpression model and the preformed fibril (PFF) model. Subjects (rat and NHP) received targeted enteric injections of PFFs or adeno-associated virus overexpressing the Parkinson's disease associated A53T α-syn mutant. Rats were evaluated for colonic motility monthly and sacrificed at 1, 6, or 12 months, whereas NHPs were sacrificed 12 months following inoculation, after which the time course and spread of pathology was examined in all animals. Rats exhibited a transient GI phenotype that resolved after four months. Minor α-syn pathology was observed in the brainstem (dorsal motor nucleus of the vagus and locus coeruleus) 1 month after PFF injections; however, no pathology was observed at later time points (nor in saline or monomer treated animals). Similarly, a histopathological analysis of the NHP brains revealed no pathology despite the presence of robust α-syn pathology throughout the ENS which persisted for the entirety of the study (12 months). Our study shows that induction of α-syn pathology in the ENS is sufficient to induce GI dysfunction. Moreover, our data suggest that sustained spread of α-syn pathology from the periphery to the CNS and subsequent propagation is a rare event, and that the presence of enteric α-syn pathology and dysfunction may represent an epiphenomenon.
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Affiliation(s)
- Fredric P Manfredsson
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States; Mercy Health Saint Mary's, Grand Rapids, MI, United States.
| | - Kelvin C Luk
- Department of Pathology and Laboratory Medicine, Center for Neurodegenerative Disease Research, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Matthew J Benskey
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Aysegul Gezer
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States; DO/PHD Physician Scientist Training Program, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, United States
| | - Joanna Garcia
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Nathan C Kuhn
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Ivette M Sandoval
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States; Mercy Health Saint Mary's, Grand Rapids, MI, United States
| | - Joseph R Patterson
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Alana O'Mara
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States; Undergraduate Neuroscience Program, Michigan State University, East Lansing, MI, United States
| | - Reid Yonkers
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States; Undergraduate Neuroscience Program, Michigan State University, East Lansing, MI, United States
| | - Jeffrey H Kordower
- Dept. of Neurological Science, Rush University Medical Center, Chicago, IL, United States; Center on Neurodegeneration, Van Andel Research Institute, Grand Rapids, MI, United States
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18
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Wang ZH, Liu P, Liu X, Manfredsson FP, Sandoval IM, Yu SP, Wang JZ, Ye K. Delta-Secretase Phosphorylation by SRPK2 Enhances Its Enzymatic Activity, Provoking Pathogenesis in Alzheimer's Disease. Mol Cell 2017; 67:812-825.e5. [PMID: 28826672 DOI: 10.1016/j.molcel.2017.07.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [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: 03/30/2017] [Revised: 06/28/2017] [Accepted: 07/19/2017] [Indexed: 01/06/2023]
Abstract
Delta-secretase, a lysosomal asparagine endopeptidase (AEP), simultaneously cleaves both APP and tau, controlling the onset of pathogenesis of Alzheimer's disease (AD). However, how this protease is post-translationally regulated remains unclear. Here we report that serine-arginine protein kinase 2 (SRPK2) phosphorylates delta-secretase and enhances its enzymatic activity. SRPK2 phosphorylates serine 226 on delta-secretase and accelerates its autocatalytic cleavage, leading to its cytoplasmic translocation and escalated enzymatic activities. Delta-secretase is highly phosphorylated in human AD brains, tightly correlated with SRPK2 activity. Overexpression of a phosphorylation mimetic (S226D) in young 3xTg mice strongly promotes APP and tau fragmentation and facilitates amyloid plaque deposits and neurofibrillary tangle (NFT) formation, resulting in cognitive impairment. Conversely, viral injection of the non-phosphorylatable mutant (S226A) into 5XFAD mice decreases APP and tau proteolytic cleavage, attenuates AD pathologies, and reverses cognitive defects. Our findings support that delta-secretase phosphorylation by SRPK2 plays a critical role in aggravating AD pathogenesis.
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Affiliation(s)
- Zhi-Hao Wang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Pathophysiology, Key Laboratory of Ministry of Education of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Pai Liu
- Emory College of Arts and Sciences, Emory University, Atlanta, GA 30322, USA
| | - Xia Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Fredric P Manfredsson
- Department of Translational Science and Molecular Medicine, Michigan State University, 333 Bostwick Avenue NE, Grand Rapids, MI 49503, USA
| | - Ivette M Sandoval
- Department of Translational Science and Molecular Medicine, Michigan State University, 333 Bostwick Avenue NE, Grand Rapids, MI 49503, USA
| | - Shan Ping Yu
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jian-Zhi Wang
- Department of Pathophysiology, Key Laboratory of Ministry of Education of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Co-innovation Center of Neuroregeneration, Nantong 226001, China.
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA; Translational Center for Stem Cell Research, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China.
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19
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Polinski NK, Manfredsson FP, Benskey MJ, Fischer DL, Kemp CJ, Steece-Collier K, Sandoval IM, Paumier KL, Sortwell CE. Impact of age and vector construct on striatal and nigral transgene expression. Mol Ther Methods Clin Dev 2016; 3:16082. [PMID: 27933309 PMCID: PMC5142515 DOI: 10.1038/mtm.2016.82] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 10/25/2016] [Indexed: 02/06/2023]
Abstract
Therapeutic protein delivery using viral vectors has shown promise in preclinical models of Parkinson's disease (PD) but clinical trial success remains elusive. This may partially be due to a failure to include advanced age as a covariate despite aging being the primary risk factor for PD. We investigated transgene expression following intracerebral injections of recombinant adeno-associated virus pseudotypes 2/2 (rAAV2/2), 2/5 (rAAV2/5), 2/9 (rAAV2/9), and lentivirus (LV) expressing green fluorescent protein (GFP) in aged versus young adult rats. Both rAAV2/2 and rAAV2/5 yielded lower GFP expression following injection to either the aged substantia nigra or striatum. rAAV2/9-mediated GFP expression was deficient in the aged striatonigral system but displayed identical transgene expression between ages in the nigrostriatal system. Young and aged rats displayed equivalent GFP levels following LV injection to the striatonigral system but LV-delivered GFP was deficient in delivering GFP to the aged nigrostriatal system. Notably, age-related transgene expression deficiencies revealed by protein quantitation were poorly predicted by GFP-immunoreactive cell counts. Further, in situ hybridization for the viral CβA promoter revealed surprisingly limited tropism for astrocytes compared to neurons. Our results demonstrate that aging is a critical covariate to consider when designing gene therapy approaches for PD.
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Affiliation(s)
- Nicole K Polinski
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, USA
- Neuroscience Graduate Program, Michigan State University, East Lansing, Michigan, USA
| | - Fredric P Manfredsson
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, USA
- Mercy Health Saint Mary’s, Grand Rapids, Michigan, USA
| | - Matthew J Benskey
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - D Luke Fischer
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Christopher J Kemp
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Kathy Steece-Collier
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, USA
- Mercy Health Saint Mary’s, Grand Rapids, Michigan, USA
| | - Ivette M Sandoval
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Katrina L Paumier
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Caryl E Sortwell
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, USA
- Mercy Health Saint Mary’s, Grand Rapids, Michigan, USA
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20
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Benskey MJ, Sandoval IM, Manfredsson FP. Continuous Collection of Adeno-Associated Virus from Producer Cell Medium Significantly Increases Total Viral Yield. Hum Gene Ther Methods 2016; 27:32-45. [PMID: 26863210 DOI: 10.1089/hgtb.2015.117] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The ability to efficiently produce large amounts of high-titer recombinant adeno-associated virus (AAV) is a prerequisite to the continued success of AAV as a gene therapy tool targeted toward large-animal preclinical studies or human clinical therapeutics. Current manufacturing procedures necessitate laborious and time-consuming purification procedures to obtain AAV particles of sufficient titer and purity for these demanding biomedical applications. The finding that AAV can be harvested and purified from producer cell medium may represent an efficient alternative to purifying AAV from cellular lysates. Here we sought to determine the maximum duration of time, and frequency within which AAV can be harvested from producer cell medium, in order to maximize the yield obtained from a single transfection preparation. Human embryonic kidney 293T cells were transfected with polyethylenimine to produce AAV2/5 expressing green fluorescent protein (GFP), and cellular medium was harvested every 2 days until a maximum duration of 19 days posttransfection. AAV2/5-GFP was released into producer cell medium at a steady state until 7 days posttransfection, at which time titers dropped dramatically. Harvesting medium every two days resulted in the maximum yield of AAV from a single preparation, and the cumulative yield of AAV harvested from the producer cell medium was 4-fold higher than the yield obtained from a traditional purification of AAV from cellular lysates. The AAV2/5 harvested from medium within the 7-day collection time-course mediated high levels of transduction in vivo, comparable to AAV2/5 harvested from cellular lysates. AAV purified from cell lysates showed increasing amounts of empty particles at 5 and 7 days posttransfection, whereas AAV purified from cell medium did not show an increase in the amount of empty particles throughout the 7-day time course. Finally, we extended these findings to AAV2/9, demonstrating that a comparable ratio of AAV2/9 particles are also released for up to 7 days posttransfection.
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Affiliation(s)
- Matthew J Benskey
- 1 Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University , Grand Rapids, Michigan
| | - Ivette M Sandoval
- 1 Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University , Grand Rapids, Michigan
| | - Fredric P Manfredsson
- 1 Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University , Grand Rapids, Michigan.,2 Mercy Health Saint Mary's , Grand Rapids, Michigan
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Paumier KL, Luk KC, Manfredsson FP, Kanaan NM, Lipton JW, Collier TJ, Steece-Collier K, Kemp CJ, Celano S, Schulz E, Sandoval IM, Fleming S, Dirr E, Polinski NK, Trojanowski JQ, Lee VM, Sortwell CE. Intrastriatal injection of pre-formed mouse α-synuclein fibrils into rats triggers α-synuclein pathology and bilateral nigrostriatal degeneration. Neurobiol Dis 2015; 82:185-199. [PMID: 26093169 DOI: 10.1016/j.nbd.2015.06.003] [Citation(s) in RCA: 257] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Revised: 06/08/2015] [Accepted: 06/09/2015] [Indexed: 12/15/2022] Open
Abstract
Previous studies demonstrate that intrastriatal injections of fibrillar alpha-synuclein (α-syn) into mice induce Parkinson's disease (PD)-like Lewy body (LB) pathology formed by aggregated α-syn in anatomically interconnected regions and significant nigrostriatal degeneration. The aim of the current study was to evaluate whether exogenous mouse α-syn pre-formed fibrils (PFF) injected into the striatum of rats would result in accumulation of LB-like intracellular inclusions and nigrostriatal degeneration. Sprague-Dawley rats received unilateral intrastriatal injections of either non-fibrillized recombinant α-syn or PFF mouse α-syn in 1- or 2- sites and were euthanized at 30, 60 or 180 days post-injection (pi). Both non-fibrillized recombinant α-syn and PFF α-syn injections resulted in phosphorylated α-syn intraneuronal accumulations (i.e., diffuse Lewy neurite (LN)- and LB-like inclusions) with significantly greater accumulations following PFF injection. LB-like inclusions were observed in several areas that innervate the striatum, most prominently the frontal and insular cortices, the amygdala, and the substantia nigra pars compacta (SNpc). α-Syn accumulations co-localized with ubiquitin, p62, and were thioflavin-S-positive and proteinase-k resistant, suggesting that PFF-induced pathology exhibits properties similar to human LBs. Although α-syn inclusions within the SNpc remained ipsilateral to striatal injection, we observed bilateral reductions in nigral dopamine neurons at the 180-day time-point in both the 1- and 2-site PFF injection paradigms. PFF injected rats exhibited bilateral reductions in striatal dopaminergic innervation at 60 and 180 days and bilateral decreases in homovanillic acid; however, dopamine reduction was observed only in the striatum ipsilateral to PFF injection. Although the level of dopamine asymmetry in PFF injected rats at 180 days was insufficient to elicit motor deficits in amphetamine-induced rotations or forelimb use in the cylinder task, significant disruption of ultrasonic vocalizations was observed. Taken together, our findings demonstrate that α-syn PFF are sufficient to seed the pathological conversion and propagation of endogenous α-syn to induce a progressive, neurodegenerative model of α-synucleinopathy in rats.
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Affiliation(s)
- Katrina L Paumier
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Mercy Health Hauenstein Neuroscience Medical Center, Grand Rapids, MI, USA.
| | - Kelvin C Luk
- Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Fredric P Manfredsson
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Mercy Health Hauenstein Neuroscience Medical Center, Grand Rapids, MI, USA
| | - Nicholas M Kanaan
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Mercy Health Hauenstein Neuroscience Medical Center, Grand Rapids, MI, USA
| | - Jack W Lipton
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Mercy Health Hauenstein Neuroscience Medical Center, Grand Rapids, MI, USA
| | - Timothy J Collier
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Mercy Health Hauenstein Neuroscience Medical Center, Grand Rapids, MI, USA
| | - Kathy Steece-Collier
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Mercy Health Hauenstein Neuroscience Medical Center, Grand Rapids, MI, USA
| | - Christopher J Kemp
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Stephanie Celano
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Emily Schulz
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Ivette M Sandoval
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Sheila Fleming
- Department of Psychology, University of Cincinnati, Cincinnati, OH, USA
| | - Elliott Dirr
- Department of Psychology, University of Cincinnati, Cincinnati, OH, USA
| | - Nicole K Polinski
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - John Q Trojanowski
- Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Virginia M Lee
- Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Caryl E Sortwell
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Mercy Health Hauenstein Neuroscience Medical Center, Grand Rapids, MI, USA
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Sandoval IM, Price BA, Gross AK, Chan F, Sammons JD, Wilson JH, Wensel TG. Abrupt onset of mutations in a developmentally regulated gene during terminal differentiation of post-mitotic photoreceptor neurons in mice. PLoS One 2014; 9:e108135. [PMID: 25264759 PMCID: PMC4180260 DOI: 10.1371/journal.pone.0108135] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 08/18/2014] [Indexed: 11/22/2022] Open
Abstract
For sensitive detection of rare gene repair events in terminally differentiated photoreceptors, we generated a knockin mouse model by replacing one mouse rhodopsin allele with a form of the human rhodopsin gene that causes a severe, early-onset form of retinitis pigmentosa. The human gene contains a premature stop codon at position 344 (Q344X), cDNA encoding the enhanced green fluorescent protein (EGFP) at its 3′ end, and a modified 5′ untranslated region to reduce translation rate so that the mutant protein does not induce retinal degeneration. Mutations that eliminate the stop codon express a human rhodopsin-EGFP fusion protein (hRho-GFP), which can be readily detected by fluorescence microscopy. Spontaneous mutations were observed at a frequency of about one per retina; in every case, they gave rise to single fluorescent rod cells, indicating that each mutation occurred during or after the last mitotic division. Additionally, the number of fluorescent rods did not increase with age, suggesting that the rhodopsin gene in mature rod cells is less sensitive to mutation than it is in developing rods. Thus, there is a brief developmental window, coinciding with the transcriptional activation of the rhodopsin locus, in which somatic mutations of the rhodopsin gene abruptly begin to appear.
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Affiliation(s)
- Ivette M. Sandoval
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Houston, Texas, United States of America
| | - Brandee A. Price
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Alecia K. Gross
- Department of Vision Science, University of Alabama Birmingham, Birmingham, Alabama, United States of America
| | - Fung Chan
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Houston, Texas, United States of America
| | - Joshua D. Sammons
- Department of Vision Science, University of Alabama Birmingham, Birmingham, Alabama, United States of America
| | - John H. Wilson
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Theodore G. Wensel
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Houston, Texas, United States of America
- * E-mail:
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Gilliam JC, Chang JT, Sandoval IM, Zhang Y, Li T, Pittler SJ, Chiu W, Wensel TG. Three-dimensional architecture of the rod sensory cilium and its disruption in retinal neurodegeneration. Cell 2013. [PMID: 23178122 DOI: 10.1016/j.cell.2012.10.038] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Defects in primary cilia lead to devastating disease because of their roles in sensation and developmental signaling but much is unknown about ciliary structure and mechanisms of their formation and maintenance. We used cryo-electron tomography to obtain 3D maps of the connecting cilium and adjacent cellular structures of a modified primary cilium, the rod outer segment, from wild-type and genetically defective mice. The results reveal the molecular architecture of the cilium and provide insights into protein functions. They suggest that the ciliary rootlet is involved in cellular transport and stabilizes the axoneme. A defect in the BBSome membrane coat caused defects in vesicle targeting near the base of the cilium. Loss of the proteins encoded by the Cngb1 gene disrupted links between the disk and plasma membranes. The structures of the outer segment membranes support a model for disk morphogenesis in which basal disks are enveloped by the plasma membrane.
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Affiliation(s)
- Jared C Gilliam
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
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Price BA, Sandoval IM, Chan F, Nichols R, Roman-Sanchez R, Wensel TG, Wilson JH. Rhodopsin gene expression determines rod outer segment size and rod cell resistance to a dominant-negative neurodegeneration mutant. PLoS One 2012; 7:e49889. [PMID: 23185477 PMCID: PMC3503812 DOI: 10.1371/journal.pone.0049889] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 10/17/2012] [Indexed: 01/26/2023] Open
Abstract
Two outstanding unknowns in the biology of photoreceptors are the molecular determinants of cell size, which is remarkably uniform among mammalian species, and the mechanisms of rod cell death associated with inherited neurodegenerative blinding diseases such as retinitis pigmentosa. We have addressed both questions by performing an in vivo titration with rhodopsin gene copies in genetically engineered mice that express only normal rhodopsin or an autosomal dominant allele, encoding rhodopsin with a disease-causing P23H substitution. The results reveal that the volume of the rod outer segment is proportional to rhodopsin gene expression; that P23H-rhodopsin, the most common rhodopsin gene disease allele, causes cell death via a dominant-negative mechanism; and that long term survival of rod cells carrying P23H-rhodopsin can be achieved by increasing the levels of wild type rhodopsin. These results point to promising directions in gene therapy for autosomal dominant neurodegenerative diseases caused by dominant-negative mutations.
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Affiliation(s)
- Brandee A. Price
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Ivette M. Sandoval
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Fung Chan
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Ralph Nichols
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Ramon Roman-Sanchez
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Graduate Program in Cellular and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Theodore G. Wensel
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States of America
- Graduate Program in Cellular and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - John H. Wilson
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Graduate Program in Cellular and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
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Price BA, Sandoval IM, Chan F, Simons DL, Wu SM, Wensel TG, Wilson JH. Mislocalization and degradation of human P23H-rhodopsin-GFP in a knockin mouse model of retinitis pigmentosa. Invest Ophthalmol Vis Sci 2011; 52:9728-36. [PMID: 22110080 PMCID: PMC3341127 DOI: 10.1167/iovs.11-8654] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [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: 09/23/2011] [Revised: 11/08/2011] [Accepted: 11/08/2011] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To engineer a knockin mouse model that can be used to monitor the effects of treatments on degradation and mislocalization of proline-to-histidine change at codon 23 (P23H) rhodopsin, a common cause of autosomal dominant retinitis pigmentosa (ADRP). The goal was to introduce a gene that expressed rhodopsin at low levels to avoid rapid retinal degeneration, and with a readily visible tag to make it easy to distinguish from wild type rhodopsin. METHODS One copy of the endogenous mouse rhodopsin gene was replaced with a mutant human rhodopsin gene that encodes P23H-rhodopsin fused to enhanced green fluorescent protein (GFP) at its C terminus. The gene includes a LoxP site in the sequence corresponding to the 5'-untranslated region, which greatly reduces translation efficiency. Characterized are the resulting heterozygous and homozygous P23H-hRho-GFP mouse lines for mRNA and protein expression, P23H-rhodopsin localization in rod cells, effects on visual function, and retinal degeneration. RESULTS The retinas of heterozygous P23H-hRho-GFP mice are morphologically and functionally very similar to those of wild type mice, and they display little cell death over time. P23H-hRho-GFP mice transcribe the knockin gene as efficiently as the endogenous mouse allele, but they contain much less of the protein product than do knockin mice expressing nonmutant hRho-GFP, indicating that substantial degradation of P23H-rRho-GFP occurs in mouse rod cells. The remaining P23H-hRho-GFP mislocalizes to the inner segment and outer nuclear layer, with only approximately 20% in rod outer segments. CONCLUSIONS P23H-hRho-GFP mice provide a valuable tool for evaluating the efficacy of potential therapies for ADRP that influence the levels or localization of P23H-rhodopsin.
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Affiliation(s)
- Brandee A. Price
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology, and
- the Departments of Molecular and Human Genetics and
| | - Ivette M. Sandoval
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology, and
| | - Fung Chan
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology, and
| | | | - Samuel M. Wu
- Ophthalmology, Baylor College of Medicine, Houston, Texas
| | - Theodore G. Wensel
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology, and
| | - John H. Wilson
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology, and
- the Departments of Molecular and Human Genetics and
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26
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Gross AK, Decker G, Chan F, Sandoval IM, Wilson JH, Wensel TG. Defective development of photoreceptor membranes in a mouse model of recessive retinal degeneration. Vision Res 2006; 46:4510-8. [PMID: 16979686 DOI: 10.1016/j.visres.2006.07.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [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: 06/15/2006] [Accepted: 07/19/2006] [Indexed: 11/28/2022]
Abstract
Retinal neurodegeneration occurs in several inherited diseases. Some of the most severe disease alleles involve mutations at the C-terminus of rhodopsin, but in no case is the pathogenic mechanism leading to cell death well understood. We have examined a mouse model of recessive retinal degeneration caused by a knock-in of a human rhodopsin-EGFP fusion gene (hrhoG/hrhoG) at the rhodopsin locus. Whereas heterozygous mutant mice were indistinguishable from control mice, homozygous mutant mice had retinal degeneration. We hypothesized that degeneration might be due to aberrant rhodopsin signaling; however, inhibiting signaling by rearing mice in total darkness had no effect on the rate of degeneration. Using confocal and electron microscopy, we identified the fundamental defect as failed biogenesis of disk membranes, which is observed at the earliest stages of outer segment development. These results reveal that in addition to its role in transport and sorting of rhodopsin to disk membranes, rhodopsin is also essential for formation of disks.
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Affiliation(s)
- Alecia K Gross
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
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