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Competing Interests: Declaration of competing interest Dr. Rosenthal: Dr. Rosenthal receives research funding support from the NINDS, the Daniel B. and Florence E. Green Family Foundation, the Macks Family Foundation, and the National Ataxia Foundation. She receives additional programmatic support from the Gordon and Marilyn Macklin Foundation. She receives salary support for her role as the site Principal Investigator for research studies with Biohaven Pharmaceuticals and Pfizer and for serving on the Clinical Events Committee for a research study with Functional Neuromodulation. She also serves on the steering committees for the Parkinson Study Group's research study with both UCB and Bial Pharmaceuticals. Dr. Rosenthal also served on an advisory board for Reata pharmaceuticals and Biohaven Pharmaceuticals. Dr. Phillips: Dr. Phillips has no conflicts of interest to declare. Dr. Mari: Dr. Mari is a paid consultant for GB Sciences, AbbVie, and Ipsen. He is a speaker for AbbVie, Supernus, and Acadia. He holds shares in Sensory Cloud, NeuroReserve, GB Sciences, Neunos, D&D PharmaTech. He is a co-founder and CMO of Neuraly, Inc. and Z NeuroSciences, LLC.

Accumulating evidence suggests an involvement of sphingolipids, vital components of cell membranes and regulators of cellular processes, in the pathophysiology of both Parkinson's disease and major depressive disorder, indicating a potential common pathway in these neuropsychiatric conditions. Based on this interaction of sphingolipids and synuclein proteins, we explored the gene expression patterns of α-, β-, and γ-synuclein in a knockout mouse model deficient for acid sphingomyelinase (ASM), an enzyme catalyzing the hydrolysis of sphingomyelin to ceramide, and studied associations with behavioral parameters. Normalized Snca , Sncb , and Sncg gene expression was determined by quantitative PCR in twelve brain regions of sex-mixed homozygous (ASM-/-, n = 7) and heterozygous (ASM+/-, n = 7) ASM-deficient mice, along with wild-type controls (ASM+/+, n = 5). The expression of all three synuclein genes was brain region-specific but independent of ASM genotype, with β-synuclein showing overall higher levels and the least variation. Moreover, we discovered correlations of gene expression levels between brain regions and depression- and anxiety-like behavior and locomotor activity, such as a positive association between Snca mRNA levels and locomotion. Our results suggest that the analysis of synuclein genes could be valuable in identifying biomarkers and comprehending the common pathological mechanisms underlying various neuropsychiatric disorders.

In this work, we explored the intrinsic disorder status of the three members of the synuclein family of proteins-α-, β-, and γ-synucleins-and showed that although all three human synucleins are highly disordered, the highest levels of disorder are observed in γ-synuclein. Our analysis of the peculiarities of the amino acid sequences and modeled 3D structures of the human synuclein family members revealed that the pathological mutations A30P, E46K, H50Q, A53T, and A53E associated with the early onset of Parkinson's disease caused some increase in the local disorder propensity of human α-synuclein. A comparative sequence-based analysis of the synuclein proteins from various evolutionary distant species and evaluation of their levels of intrinsic disorder using a set of commonly used bioinformatics tools revealed that, irrespective of their origin, all members of the synuclein family analyzed in this study were predicted to be highly disordered proteins, indicating that their intrinsically disordered nature represents an evolutionary conserved and therefore functionally important feature. A detailed functional disorder analysis of the proteins in the interactomes of the human synuclein family members utilizing a set of commonly used disorder analysis tools showed that the human α-synuclein interactome has relatively higher levels of intrinsic disorder as compared with the interactomes of human β- and γ- synucleins and revealed that, relative to the β- and γ-synuclein interactomes, α-synuclein interactors are involved in a much broader spectrum of highly diversified functional pathways. Although proteins interacting with three human synucleins were characterized by highly diversified functionalities, this analysis also revealed that the interactors of three human synucleins were involved in three common functional pathways, such as the synaptic vesicle cycle, serotonergic synapse, and retrograde endocannabinoid signaling. Taken together, these observations highlight the critical importance of the intrinsic disorder of human synucleins and their interactors in various neuronal processes.

Sodiun Oxybate (SO) has a number of attributes that may mitigate the metabolic stress on the substantia nigra pars compacta (SNpc) dopaminergic (DA) neurons in Parkinson's disease (PD). These neurons function at the borderline of energy sufficiency. SO is metabolized to succinate and supplies energy to the cell by generating ATP. SO is a GABAB agonist and, as such, also arrests the high energy requiring calcium pace-making activity of these neurons. In addition, blocking calcium entry impedes the synaptic release and subsequent neurotransmission of aggregated synuclein species. As DA neurons degenerate, a homeostatic failure exposes these neurons to glutamate excitotoxicity, which in turn accelerates the damage. SO inhibits the neuronal release of glutamate and blocks its agonistic actions. Most important, SO generates NADPH, the cell's major antioxidant cofactor. Excessive free radical production within DA neurons and even more so within activated microglia are early and key features of the degenerative process that are present long before the onset of motor symptoms. NADPH maintains cell glutathione levels and alleviates oxidative stress and its toxic consequences. SO, a histone deacetylase inhibitor also suppresses the expression of microglial NADPH oxidase, the major source of free radicals in Parkinson brain. The acute clinical use of SO at night has been shown to reduce daytime sleepiness and fatigue in patients with PD. With long-term use, its capacity to supply energy to DA neurons, impede synuclein transmission, block excitotoxicity and maintain an anti-oxidative redox environment throughout the night may delay the onset of PD and slow its progress.

Parkinson's disease (PD) is one of the most disabling diseases of the central nervous system, seriously affecting health and quality of life for the elderly. The present study aimed to explore the effects of nuclear receptor subfamily 4 group A member 2 (Nurr1) and nuclear factor‑κB (NF‑κB) on the progression of Parkinson's disease (PD). Pheochromocytoma (PC12) cells were pretreated with the NF‑κB inhibitor quinazoline (QNZ) or transfected with small interfering (si)RNA‑NF‑κB, followed by the addition of lipopolysaccharide (LPS). After culturing for 24 h, Cell Counting Kit‑8 (CCK‑8) was utilized to measure cell viability. Next, the expression levels of interleukin (IL)‑1β, IL‑6 and tumor necrosis factor (TNF)‑α were determined using the relevant Enzyme‑linked immunosorbent assay kits. Expression levels of p65, tyrosine hydroxylase (TH), α‑Synuclein (A‑SYN) and Nurr1 were examined by immunofluorescence and western blotting. CCK‑8 results showed that the cell viability was significantly reduced in the LPS group than in the control group (P<0.05), whereas QNZ and si‑NF‑κB demonstrated significantly enhanced viability induced by LPS (P<0.05). After LPS induction, the levels of IL‑1β, IL‑6 and TNF‑α were significantly elevated when compared with those in the control group (P<0.05), whereas QNZ and NF‑κB interference partially restored their levels. Additionally, after LPS induction, the expression of p65 and A‑SYN was higher, while the expression of TH and Nurr1 was lower. However, QNZ and NF‑κB treatment significantly reversed the expression levels induced by LPS (P<0.05). Finally, it was observed that NF‑κB may be negatively associated with Nurr1. In conclusion, inhibition of NF‑κB may reduce the production of inflammatory factors by upregulating Nurr1 and TH and downregulating A‑SYN, thus relieving the inflammatory response in PD.

Specific proteins accumulate in neurodegenerative disease, and human genetics has indicated a causative role for many. In most cases, however, the mechanisms remain poorly understood. Degeneration is thought to involve a gain of abnormal function, although we do not know the normal function of many proteins implicated. The protein α-synuclein accumulates in the Lewy pathology of Parkinson's disease and related disorders, and mutations in α-synuclein cause degeneration, but we have not known its normal function or how it triggers disease. α-Synuclein localizes to presynaptic boutons and interacts with membranes in vitro. Overexpression slows synaptic vesicle exocytosis, and recent data suggest a normal role for the endogenous synucleins in dilation of the exocytic fusion pore. Disrupted membranes also appear surprisingly prominent in Lewy pathology. Synuclein thus interacts with membranes under both physiological and pathological conditions, suggesting that the normal function of synuclein may illuminate its role in degeneration.

Neurodegenerative diseases are a heterogeneous group of disorders characterized by gradual progressive neuronal loss in the central nervous system. Unfortunately, the pathogenesis of many of these diseases remains unknown. Synucleins are a family of small, highly charged proteins expressed predominantly in neurons. Following their discovery, much has been learned about their structure, function, interaction with other proteins and role in neurodegenerative disease over the last two decades. One of these proteins, α-Synuclein (α-Syn), appears to be involved in many neurodegenerative disorders. These include Parkinson's disease (PD), dementia with Lewy bodies (DLB), Rapid Eye Movement Sleep Behavior Disorder (RBD) and Pure Autonomic Failure (PAF), i.e., collectively termed α-synucleinopathies. This review focuses on α-Syn dysfunction in neurodegeneration and assesses its role in synucleinopathies from a biochemical, genetic and neuroimaging perspective., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Parkinsonism is one of the most common aging neurodegenerative disorders. This study aims to compare the therapeutic effect of stem cell versus its conditioned medium in the Parkinsonism model. Parkinsonism was induced by daily subcutaneous injection of 0.5 mg/kg of rotenone dissolved in dimethyl sulfoxide for 28 days. Fifty rats were divided randomly into five groups: control, dimethyl sulfoxide, Parkinsonism, stem cell-treated, and conditioned medium-treated groups. Midbrain specimens were obtained for histological, immunohistochemical, and biochemical studies. Lewy bodies were observed in the Parkinsonism group in the dopaminergic neuron and neuropil as well. Almost all of the pathological changes were clearly ameliorated in both stem cell- and conditioned medium-treated groups as confirmed by biochemical, histological, and immunohistochemical (anti-nestin, anti-glial fibrillary acidic protein, and anti-α synuclein) studies. However, the conditioned medium showed more superior therapeutic effect establishing nearly the normal histological architecture of substantia nigra. These results may pave the future for using stem cell-conditioned medium as a more convenient and effective adjuvant therapy in Parkinsonism and other neurodegenerative disorders., (© 2020 Wiley Periodicals LLC.)

Aim: The aim of this study is to investigate the possible protective effects of mitoquinone and oleandrin on rotenone induced Parkinson's disease in zebrafish. Materials and methods: Adult zebrafish were exposed to rotenone and mitoquinone for 30 days. Biochemical parameters were determined by spectrophotometric method and Parkinson's disease-related gene expressions were determined by reverse transcription polymerase chain reaction method. Measurement of neurotransmitters was performed by liquid chromatography tandem-mass spectrometry instrument. The accumulation of synuclein was demonstrated by immunohistochemical staining. In vitro thiazolyl blue tetrazolium bromide method was applied to determine the mitochondrial function of synaptosomal brain fractions using rotenone as a neurotoxic agent and mitoquinone and oleandrin as neuroprotective agents. Results: Mitoquinone improved the oxidant-antioxidant balance and neurotransmitter levels that were disrupted by rotenone. Mitoquinone also ameliorated the expressions of Parkinson's disease-related gene expressions that were disrupted by rotenone. According to thiazolyl blue tetrazolium bromide assay results, mitoquinone and oleandrin increased mitochondrial function which was decreased due to rotenone exposure. Conclusion: Based on the results of our study, positive effects of mitoquinone were observed in Parkinson's disease model induced by rotenone in zebrafish.

A variety of cellular processes, including vesicle clustering in the presynaptic compartment, are impaired in Parkinson's disease and have been closely associated with α-synuclein oligomerization. Emerging evidence proves the existence of α-synuclein-related pathology in the peripheral nervous system, even though the presence of α-synuclein oligomers in situ in living patients remains poorly investigated. In this case-control study, we show previously undetected α-synuclein oligomers within synaptic terminals of autonomic fibres in skin biopsies by means of the proximity ligation assay and propose a procedure for their quantification (proximity ligation assay score). Our study revealed a significant increase in α-synuclein oligomers in consecutive patients with Parkinson's disease compared to consecutive healthy controls (P < 0.001). Proximity ligation assay score (threshold value > 96 using receiver operating characteristic) was found to have good sensitivity, specificity and positive predictive value (82%, 86% and 89%, respectively). Furthermore, to disclose the role of putative genetic predisposition in Parkinson's disease aetiology, we evaluated the differential accumulation of oligomers in a unique cohort of 19 monozygotic twins discordant for Parkinson's disease. The significant difference between patients and healthy subjects was confirmed in twins. Intriguingly, although no difference in median values was detected between consecutive healthy controls and healthy twins, the prevalence of healthy subjects positive for proximity ligation assay score was significantly greater in twins than in the consecutive cohort (47% versus 14%, P = 0.019). This suggests that genetic predisposition is important, but not sufficient, in the aetiology of the disease and strengthens the contribution of environmental factors. In conclusion, our data provide evidence that α-synuclein oligomers accumulate within synaptic terminals of autonomic fibres of the skin in Parkinson's disease for the first time. This finding endorses the hypothesis that α-synuclein oligomers could be used as a reliable diagnostic biomarker for Parkinson's disease. It also offers novel insights into the physiological and pathological roles of α-synuclein in the peripheral nervous system., (© The Author(s) (2020). Published by Oxford University Press on behalf of the Guarantors of Brain.)

Voltage-dependent anion channel (VDAC) is the major pathway for the transport of ions and metabolites across the mitochondrial outer membrane. Among the three known mammalian VDAC isoforms, VDAC3 is the least characterized, but unique functional roles have been proposed in cellular and animal models. Yet, a high-sequence similarity between VDAC1 and VDAC3 is indicative of a similar pore-forming structure. Here, we conclusively show that VDAC3 forms stable, highly conductive voltage-gated channels that, much like VDAC1, are weakly anion selective and facilitate metabolite exchange, but exhibit unique properties when interacting with the cytosolic proteins α-synuclein and tubulin. These two proteins are known to be potent regulators of VDAC1 and induce similar characteristic blockages (on the millisecond time scale) of VDAC3, but with 10- to 100-fold reduced on-rates and altered α-synuclein blocking times, indicative of an isoform-specific function. Through cysteine scanning mutagenesis, we found that VDAC3's cysteine residues regulate its interaction with α-synuclein, demonstrating VDAC3-unique functional properties and further highlighting a general molecular mechanism for VDAC isoform-specific regulation of mitochondrial bioenergetics., (© 2019 Queralt-Martín et al.)

The pathological hallmark of synucleinopathies, including Lewy body dementia and Parkinson's disease (PD), is the presence of Lewy bodies, which are primarily composed of intracellular inclusions of misfolded α-synuclein (α-syn) among other proteins. α-Syn is found in extracellular biological fluids in PD patients and has been implicated in modulating immune responses in the central nervous system (CNS) and the periphery. Natural killer (NK) cells are innate effector lymphocytes that are present in the CNS in homeostatic and pathological conditions. NK cell numbers are increased in the blood of PD patients and their activity is associated with disease severity; however, the role of NK cells in the context of α-synucleinopathies has never been explored. Here, we show that human NK cells can efficiently internalize and degrade α-syn aggregates via the endosomal/lysosomal pathway. We demonstrate that α-syn aggregates attenuate NK cell cytotoxicity in a dose-dependent manner and decrease the release of the proinflammatory cytokine, IFN-γ. To address the role of NK cells in PD pathogenesis, NK cell function was investigated in a preformed fibril α-syn-induced mouse PD model. Our studies demonstrate that in vivo depletion of NK cells in a preclinical mouse PD model resulted in exacerbated motor deficits and increased phosphorylated α-syn deposits. Collectively, our data provide a role of NK cells in modulating synuclein pathology and motor symptoms in a preclinical mouse model of PD, which could be developed into a therapeutic for PD and other synucleinopathies., Competing Interests: The authors declare no competing interest.

The prion-like spreading and accumulation of specific protein aggregates appear to be central to the pathogenesis of many human diseases, including Alzheimer's and Parkinson's. Accumulating evidence indicates that inoculation of tissue extracts from diseased individuals into suitable experimental animals can in many cases induce the aggregation of the disease-associated protein, as well as related pathological lesions. These findings, together with the history of the prion field, have raised the questions about whether such disease-associated protein aggregates are transmissible between humans by casual or iatrogenic routes, and, if so, do they propagate enough in the new host to cause disease? These practical considerations are important because real, and perhaps even only imagined, risks of human-to-human transmission of diseases such as Alzheimer's and Parkinson's may force costly changes in clinical practice that, in turn, are likely to have unintended consequences. The prion field has taught us that a single protein, PrP, can aggregate into forms that can propagate exponentially in vitro, but range from being innocuous to deadly when injected into experimental animals in ways that depend strongly on factors such as conformational subtleties, routes of inoculation, and host responses. In assessing the hazards posed by various disease-associated, self-propagating protein aggregates, it is imperative to consider both their actual transmissibilities and the pathological consequences of their propagation, if any, in recipient hosts.

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease. As there is no permanent cure for the disease, the use of herbal compounds with antioxidant potential will be an effective approach for controlling the progression of disease. In this context the effect of tangeritin (a polymethoxy flavone concentrated in the peels of citrus fruits) was studied at final doses of 5, 10 and 20 μM on PD model flies. The doses were established in diet and the PD flies were allowed to feed on it for 24 days. The effect was studied on cognitive impairments. Immunostaining of brain sections for tyrosine hydroxylase was also performed. The docking studies were also carried out to give a plausible binding site of tangeritin on alpha synuclein molecule. The results of the study showed that tangeritin is effective in improving the cognitive impairments., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Gene therapy is currently an irreversible approach, without possibilities to fine-tune or halt the expression of a therapeutic gene product. Especially when expressing neurotrophic factors to treat neurodegenerative disorders, options to regulate transgene expression levels might be beneficial. We thus developed an advanced single-genome inducible AAV vector for expression of GDNF, under control of the approved small molecule drug mifepristone. In the rat brain, GDNF expression can be induced over a wide range up to three hundred-fold over endogenous background, and completely returns to baseline within 3-4 weeks. When applied with appropriate serotype and titre, the vector is absolutely free of any non-induced background expression. In the BACHD model of Huntington's disease we demonstrate that the vector can be kept in a continuous ON-state for extended periods of time. In a model of Parkinson's disease we demonstrate that repeated short-term expression of GDNF restores motor capabilities in 6-OHDA-lesioned rats. We also report on sex-dependent pharmacodynamics of mifepristone in the rodent brain. Taken together, we show that wide-range and high-level induction, background-free, fully reversible and therapeutically active GDNF expression can be achieved under tight pharmacological control by this novel AAV - "Gene Switch" vector., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Immunohistochemical (IHC) α-synuclein (Asyn) pathology in peripheral biopsies may be a biomarker of Parkinson disease (PD). The multi-center Systemic Synuclein Sampling Study (S4) is evaluating IHC Asyn pathology within skin, colon and submandibular gland biopsies from 60 PD and 20 control subjects. Asyn pathology is being evaluated by a blinded panel of specially trained neuropathologists. Preliminary work assessed 2 candidate immunoperoxidase methods using a set of PD and control autopsy-derived sections from formalin-fixed, paraffin-embedded blocks of the 3 tissues. Both methods had 100% specificity; one, utilizing the 5C12 monoclonal antibody, was more sensitive in skin (67% vs 33%), and was chosen for further use in S4. Four trainee neuropathologists were trained to perform S4 histopathology readings; in subsequent testing, their scoring was compared to that of the trainer neuropathologist on both glass slides and digital images. Specificity and sensitivity were both close to 100% with all readers in all tissue types on both glass slides and digital images except for skin, where sensitivity averaged 75% with digital images and 83.5% with glass slides. Semiquantitative (0-3) density score agreement between trainees and trainer averaged 67% for glass slides and 62% for digital images.

Many studies aimed at advancing our understanding of the mechanisms of protein stabilization that support the survival of organisms under harsh environmental conditions are focused on deciphering the role of osmolytes as additives in the stabilization of protein. The exact interaction of an osmolyte with protein has been a matter of debate for a long time, but a clear unifying statement still cannot be provided regarding the actual behavior of the osmolyte. A literature survey reveals that there exist a large number of scholarly articles as well as elegant reviews that could aid a resolution of some problems of understanding systems comprising osmolytes and proteins. Additionally, there is no doubt from a vast literature survey that osmolytes display stabilizing behavior toward proteins. However, there are also a number of research articles available in the open literature that emphasize the destabilizing effects of osmolytes on protein stability and function. Therefore, a complete acquaintance of each osmolyte with respect to each protein is one of the most challenging tasks in the development of protein formulation and may be still needed in order to reliably administer the correct protein formulations through injection only. The lack of a comprehensive evaluation of a broad range of these osmolytes in protein systems stimulated our interest for the present perspective in this research field. To the best of our knowledge, this perspective delineates the most recent successful advances in the open literature and also on the basis of our research experience and should aid current researchers in the field of protein stabilization to develop new strategies.

Background: Pineoblastoma is a rare malignant tumor of the pineal gland, which is more common in children., Methods: We retrospectively reviewed 18 cases of pineoblastoma in children (10 girls), including general, clinical, and therapeutic information, and factors affecting prognosis., Results: The median age of the children was 51.7 months (range, 19-156 months). Presenting symptoms included vomiting (64.70%), headache (47.06%), weak or unsteady walking (35.29%), and nausea (29.41%). Rarer symptoms (1 patient each) included limb rigidity, inability to speak, double vision, fever, and Parinaud syndrome. Five and 13 children, respectively, underwent subtotal and gross total resection; 5 and 13 children received adjuvant craniospinal irradiation therapy and chemotherapy. Two children received both craniospinal irradiation and chemotherapy. The 5-year overall survival of the patients was 27.8% (5/18). The survival rate of children older than 4 years (66.7%) was significantly higher than that of younger children (8.3%). The 5-year overall survival rate of boys (50.7%) was higher than that of girls (10.0%); that of children who underwent gross total resection (30.8%) was higher than that of children who underwent subtotal resection (20.0%); and that of children treated with adjuvant craniospinal irradiation (50.7%) was higher than that of those not given craniospinal irradiation (10.0%). However, in each of these 3 comparisons the differences were not significant., Conclusion: Pineoblastoma is rare but often fatal, especially in children younger than 4 years. Survival rates tend to be higher in boys, children undergoing gross total resection (rather than subtotal), and those given craniospinal irradiation., (Copyright © 2018 Elsevier Inc. All rights reserved.)

As newly synthesized polypeptides emerge from the ribosome, it is crucial that they fold correctly. To prevent premature aggregation, nascent chains interact with chaperones that facilitate folding or prevent misfolding until protein synthesis is complete. Nascent polypeptide-associated complex (NAC) is a ribosome-associated chaperone that is important for protein homeostasis. However, how NAC binds its substrates remains unclear. Using native electrospray ionization MS (ESI-MS), limited proteolysis, NMR, and cross-linking, we analyzed the conformational properties of NAC from Caenorhabditis elegans and studied its ability to bind proteins in different conformational states. Our results revealed that NAC adopts an array of compact and expanded conformations and binds weakly to client proteins that are unfolded, folded, or intrinsically disordered, suggestive of broad substrate compatibility. Of note, we found that this weak binding retards aggregation of the intrinsically disordered protein α-synuclein both in vitro and in vivo These findings provide critical insights into the structure and function of NAC. Specifically, they reveal the ability of NAC to exploit its conformational plasticity to bind a repertoire of substrates with unrelated sequences and structures, independently of actively translating ribosomes., (© 2018 by The American Society for Biochemistry and Molecular Biology, Inc.)

The synucleinopathies-Parkinson's disease, dementia with Lewy bodies, multiple system atrophy, and pure autonomic failure-result from distinct patterns of abnormal α-synuclein aggregation throughout the nervous system. Autonomic dysfunction in these disorders results from variable involvement of the central and peripheral autonomic networks. The major pathologic hallmark of Parkinson's disease and dementia with Lewy bodies is Lewy bodies and Lewy neurites; of multiple system atrophy, oligodendroglial cytoplasmic inclusions; and of pure autonomic failure, peripheral neuronal cytoplasmic inclusions. Clinical manifestations include orthostatic hypotension, thermoregulatory dysfunction, gastrointestinal dysmotility, and urogenital dysfunction with neurogenic bladder and sexual dysfunction. Strong evidence supports isolated idiopathic rapid eye movement sleep disorder as a significant risk factor for the eventual development of synucleinopathies with autonomic and/or motor involvement. In contrast, some neurologically normal elderly individuals have Lewy-related pathology. Future work may reveal protective or vulnerability factors that allow some patients to harbor Lewy pathology without overt autonomic dysfunction. © 2018 International Parkinson and Movement Disorder Society., (© 2018 International Parkinson and Movement Disorder Society.)

Dysfunction of the autonomic nervous system afflicts most patients with Parkinson disease and other synucleinopathies such as dementia with Lewy bodies, multiple system atrophy, and pure autonomic failure, reducing quality of life and increasing mortality. For example, gastrointestinal dysfunction can lead to impaired drug pharmacodynamics causing a worsening in motor symptoms, and neurogenic orthostatic hypotension can cause syncope, falls, and fractures. When recognized, autonomic problems can be treated, sometimes successfully. Discontinuation of potentially causative/aggravating drugs, patient education, and nonpharmacological approaches are useful and should be tried first. Pathophysiology-based pharmacological treatments that have shown efficacy in controlled trials of patients with synucleinopathies have been approved in many countries and are key to an effective management. Here, we review the treatment of autonomic dysfunction in patients with Parkinson disease and other synucleinopathies, summarize the nonpharmacological and current pharmacological therapeutic strategies including recently approved drugs, and provide practical advice and management algorithms for clinicians, with focus on neurogenic orthostatic hypotension, supine hypertension, dysphagia, sialorrhea, gastroparesis, constipation, neurogenic overactive bladder, underactive bladder, and sexual dysfunction. © 2018 International Parkinson and Movement Disorder Society., (© 2018 International Parkinson and Movement Disorder Society.)

Inactivation of constitutive autophagy results in the formation of cytoplasmic inclusions in neurons, but the relationship between impaired autophagy and Lewy bodies (LBs) as well as the in vivo process of formation remains unknown. Synuclein, a component of LBs, is the defining characteristic of Parkinson's disease (PD). Here, we characterize dopamine (DA) neuron-specific autophagy-deficient mice and provide in vivo evidence for LB formation. Synuclein deposition is preceded by p62 and resulted in the formation of inclusions containing synuclein and p62. The number and size of these inclusions were gradually increased in neurites rather than soma with aging. These inclusions may facilitate peripheral failures. As a result, DA neuron loss and motor dysfunction including the hindlimb defect were observed in 120-week-old mice. P62 aggregates derived from an autophagic defect might serve as "seeds" and can potentially be cause of LB formation.

Parkinson's disease (PD) is recognized as the most common neurodegenerative movement disorder and results in debilitating motor deficits. The accumulation and spread of neurotoxic synuclein aggregates in the form of Lewy bodies is a key pathological feature of PD. Chronic activation of the NLRP3 inflammasome by protein aggregates is emerging as a major pathogenic mechanism in progressive neurodegenerative disorders and is considered an important therapeutic target. Recently the ketone body, β-hydroxy butyrate (BHB), was shown to efficiently inhibit the NLRP3 inflammasome in macrophages, and in vivo models of inflammatory disease. Furthermore, BHB can readily cross the blood brain barrier suggesting that it could have therapeutic benefits for the management of PD. In this study, we evaluated if BHB could inhibit chronic microglial inflammasome activation induced by pathological fibrillar synuclein aggregates. Interestingly, we found that BHB treatment almost completely blocked all aspects of inflammasome activation and pyroptosis induced by ATP and monosodium urate (MSU) crystals, consistent with previously published reports in macrophages. Surprisingly however, BHB did not inhibit inflammasome activation and release of IL-1β or caspase-1 induced by synuclein fibrils. Our results demonstrate that BHB does not block the upstream pathways regulating inflammasome activation by synuclein fibrils and suggest that synuclein mediated inflammasome activation proceeds via distinct mechanisms compared to traditional NLRP3 activators such as ATP and MSU.

Gerstmann-Sträussler-Scheinker disease (GSS) is an autosomal, dominantly inherited prion disease. In this study, we present different complicated brain pathologies determined postmortem of monozygotic GSS twin sisters. Case 1 showed cerebellar ataxia at the age of 58 years, and died at 66 years. Case 2 became symptomatic at the age of 75 years, and died at 79 years. There was a 17-year difference in the age of onset between the twins. Postmortem examination revealed numerous prion protein (PrP) plaques in the brains of both cases. The spongiform change and brain atrophy in case 1 were more severe compared with those in case 2. Western-blot analysis identified proteinase-resistant PrP (PrPres) at the molecular weight of 21-30 kDa and 8 kDa in the twins. Gel filtration revealed that PrPres was mainly composed of PrP oligomer. PrPres signal patterns were similar between the twins. Additionally, case 1 showed α-synucleinopathy and case 2 showed Alzheimer disease pathology. These different proteinopathies were involved in the amyloid plaque formations of both cases. The degree of GSS pathology was mainly related to disease duration. The amyloid plaque formations could be decorated by concomitant neuropathological changes such as α-synucleinopathy and tauopathy., (© 2017 American Association of Neuropathologists, Inc. All rights reserved.)

Objective: To determine the usefulness of dopamine transporter (DAT) imaging to identify idiopathic rapid eye movement sleep behavior disorder (IRBD) patients at risk for short-term development of clinically defined synucleinopathy., Methods: Eighty-seven patients with polysomnography-confirmed IRBD underwent 123 I-FP-CIT DAT-SPECT. Results were compared to 20 matched controls without RBD who underwent DAT-SPECT. In patients, FP-CIT uptake was considered abnormal when values were two standard deviations below controls' mean uptake. After DAT-SPECT, patients were followed up during 5.7 ± 2.2 (range, 2.6-9.9) years., Results: Baseline DAT deficit was found in 51 (58.6%) patients. During follow-up, 25 (28.7%) subjects developed clinically defined synucleinopathy (Parkinson's disease in 11, dementia with Lewy bodies in 13, and multiple system atrophy in 1) with mean latency of 3.2 ± 1.9 years from imaging. Kaplan-Meier survival analysis showed increased risk of incident synucleinopathy in patients with abnormal DAT-SPECT than with normal DAT-SPECT (20% vs 6% at 3 years, 33% vs 18% at 5 years; log rank test, p = 0.006). Receiver operating characteristics curve revealed that reduction of FP-CIT uptake in putamen greater than 25% discriminated patients with DAT deficit who developed synucleinopathy from patients with DAT deficit that remained disease free after 3 years of follow-up. At 5-year follow-up, DAT-SPECT had 75% sensitivity, 51% specificity, 44% positive predictive value, 80% negative predictive value, and likelihood ratio 1.54 to predict synucleinopathy., Interpretation: DAT-SPECT identifies IRBD patients at short-term risk for synucleinopathy. Decreased FP-CIT putamen uptake greater than 25% predicts synucleinopathy after 3 years' follow-up. These observations may be useful to select candidates for disease modification trials in IRBD. Ann Neurol 2017;82:419-428., (© 2017 American Neurological Association.)

Proteinaceous inclusions, called Lewy bodies, are used as a pathological hallmark for Parkinson's disease (PD). Lewy bodies contain insoluble α-synuclein (aSyn) and many other ubiquitinated proteins, suggesting a role for protein degradation system failure in the PD pathogenesis. Indeed, proteasomal dysfunction has been linked to PD but commonly used in vivo toxin models, such as 6-OHDA or MPTP, do not have a significant effect on the proteasomal system or protein aggregation. Therefore, we wanted to study the characteristics of a proteasomal inhibitor, lactacystin, as a PD model on young and adult mice. To study this, we performed stereotactic microinjection of lactacystin above the substantia nigra pars compacta in young (2 month old) and adult (12-14 month old) C57Bl/6 mice. Motor behavior was measured by locomotor activity and cylinder tests, and the markers of neuroinflammation, aSyn, and dopaminergic system were assessed by immunohistochemistry and HPLC. We found that lactacystin induced a Parkinson's disease-like motor phenotype 5-7 days after injection in young and adult mice, and this was associated with widespread neuroinflammation based on glial cell markers, aSyn accumulation in substantia nigra, striatal dopamine decrease, and loss of dopaminergic cell bodies in the substantia nigra and terminals in the striatum. When comparing young and adult mice, adult mice were more sensitive for dopaminergic degeneration after lactacystin injection that further supports the use of adult mice instead of young when modeling neurodegeneration. Our data showed that lactacystin is useful in modeling various aspects of Parkinson's disease, and taken together, our findings emphasize the role of a protein degradation deficit in Parkinson's disease pathology, and support the use of proteasomal inhibitors as Parkinson's disease models.

Recent studies have demonstrated that hyperphosphorylation of tau protein plays a role in neuronal toxicities of α-synuclein (ASYN) in neurodegenerative disease such as familial Alzheimer's disease (AD), dementia with Lewy bodies (DLB) and Parkinson's disease. Using a transgenic mouse model of Parkinson's disease (PD) that expresses GFP-ASYN driven by the PDGF-β promoter, we investigated how accumulation of ASYN impacted axonal function. We found that retrograde axonal trafficking of brain-derived neurotrophic factor (BDNF) in DIV7 cultures of E18 cortical neurons was markedly impaired at the embryonic stage, even though hyperphosphorylation of tau was not detectable in these neurons at this stage. Interestingly, we found that overexpressed ASYN interacted with dynein and induced a significant increase in the activated levels of small Rab GTPases such as Rab5 and Rab7, both key regulators of endocytic processes. Furthermore, expression of ASYN resulted in neuronal atrophy in DIV7 cortical cultures of either from E18 transgenic mouse model or from rat E18 embryos that were transiently transfected with ASYN-GFP for 72 hrs. Our studies suggest that excessive ASYN likely alters endocytic pathways leading to axonal dysfunction in embryonic cortical neurons in PD mouse models.

Human inflammatory breast cancer (IBC) and canine inflammatory mammary cancer (CIMC) are the most aggressive forms of mammary cancer. Current research aims to identify new therapeutic targets. Here, we investigated gene expression levels of biomarkers associated with the inflammatory microenvironment. A total of 32 formalin-fixed paraffin-embedded samples of canine mammary carcinoma (CIMC = 26; non-CIMC = 6) were used and their cDNA subjected to quantitative polymerase chain reaction (qPCR) to establish gene expression levels for mediators commonly implicated in linking carcinogenesis with inflammation. Gene expression differences between CIMC and non-CIMC types were obtained for cyclooxygenase 2 (COX-2) (P = 0.004), synuclein gamma (SNCG) (P = 0.006), tribbles 1 (P = 0.025), vascular endothelial growth factor (VEGF) (P = 0.017) and CSF1R (P = 0.045). Among these biomarkers correlations were found, particularly between SNCG and tribbles 1 (r = 0.512, P = 0.001). The efficient metastasis of CIMC is intimately linked to components in the tumour microenvironment. This study suggests that upregulation and correlation of SNCG and tribbles 1 deserves to be further explored., (© 2016 John Wiley & Sons Ltd.)

Study Objectives: To determine the association of excessive daytime sleepiness (EDS) with the conversion of neurodegenerative diseases in patients with idiopathic REM sleep behavior disorder (iRBD)., Methods: A total of 179 patients with iRBD (79.1% males, mean age = 66.3 ± 9.8 years) were consecutively recruited. Forty-five patients with Epworth Sleepiness Scale score ≥14 were defined as having EDS. Demographic, clinical, and polysomnographic data were compared between iRBD patients with and without EDS. The risk of developing neurodegenerative diseases was examined using Cox proportional hazards model., Results: After a mean follow-up of 5.8 years (SD = 4.3 years), 50 (27.9%) patients developed neurodegenerative diseases. There was a significantly higher proportion of conversion in patients with EDS compared to those without EDS (42.2 % vs. 23.1%, p = .01). EDS significantly predicted an increased risk of developing neurodegenerative diseases (adjusted hazard ratios [HR] = 2.56, 95% confidence interval [CI] 1.37 to 4.77) after adjusting for age, sex, body mass index, current depression, obstructive sleep apnea, and periodic limb movements during sleep. Further analyses demonstrated that EDS predicted the conversion of Parkinson's disease (PD) (adjusted HR = 3.55, 95% CI 1.59 to 7.89) but not dementia (adjusted HR = 1.48, 95% CI 0.44 to 4.97)., Conclusions: EDS is associated with an increased risk of developing neurodegenerative diseases, especially PD, in patients with iRBD. Our findings suggest that EDS is a potential clinical biomarker of α-synucleinopathies in iRBD., (© Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Despite considerable research to uncover them, the anatomic and neuropathologic correlates of memory impairment in dementia with Lewy bodies (DLB) remain unclear. While some studies have implicated Lewy bodies in the neocortex, others have pointed to α-synuclein pathology in the hippocampus. We systematically examined hippocampal Lewy pathology and its distribution in hippocampal subfields in 95 clinically and neuropathologically characterized human cases of DLB, finding that α-synuclein pathology was highest in two hippocampal-related subregions: the CA2 subfield and the entorhinal cortex (EC). While the EC had numerous classic somatic Lewy bodies, CA2 contained mainly Lewy neurites in presumed axon terminals, suggesting the involvement of the EC → CA2 circuitry in the pathogenesis of DLB symptoms. Clinicopathological correlations with measures of verbal and visual memory supported a role for EC Lewy pathology, but not CA2, in causing these memory deficits. Lewy pathology in CA1-the main output region for CA2-correlated best with results from memory testing despite a milder pathology. This result indicates that CA1 may be more functionally relevant than CA2 in the context of memory impairment in DLB. These correlations remained significant after controlling for several factors, including concurrent Alzheimer's pathology (neuritic plaques and neurofibrillary tangles) and the interval between time of testing and time of death. Our data suggest that although hippocampal Lewy pathology in DLB is predominant in CA2 and EC, memory performance correlates most strongly with CA1 burden. SIGNIFICANCE STATEMENT This study provides a detailed neuropathologic analysis of hippocampal Lewy pathology in human patients with autopsy-confirmed dementia with Lewy bodies. The approach-informed by regional molecular markers, concurrent Alzheimer's pathology analysis, and relevant clinical data-helps tease out the relative contribution of Lewy pathology to memory dysfunction in the disease. Levels of Lewy pathology were found to be highest in the hippocampal CA2 subregion and entorhinal cortex, implicating a potentially overlooked circuit in disease pathogenesis. However, correlation with memory performance was strongest with CA1. This unexpected finding suggests that Lewy pathology must reach a critical burden across hippocampal circuitry to contribute to memory dysfunction beyond that related to other factors, notably coexisting Alzheimer's disease tau pathology., (Copyright © 2017 the authors 0270-6474/17/371675-10$15.00/0.)

Synucleins (α, β, γ-synuclein) are a family of abundant presynaptic proteins. α-Synuclein is causally linked to the pathogenesis of Parkinson's disease (PD). In an effort to define their physiological and pathological function or functions, we investigated the effects of deleting synucleins and overexpressing α-synuclein PD mutations, in mice, on synapse architecture using electron microscopy (EM) and cryoelectron tomography (cryo-ET). We show that synucleins are regulators of presynapse size and synaptic vesicle (SV) pool organization. Using cryo-ET, we observed that deletion of synucleins increases SV tethering to the active zone but decreases the inter-linking of SVs by short connectors. These ultrastructural changes were correlated with discrete protein phosphorylation changes in αβγ-synuclein-/- neurons. We also determined that α-synuclein PD mutants (PARK1/hA30P and PARK4/hα-syn) primarily affected presynaptic cytomatrix proximal to the active zone, congruent with previous findings that these PD mutations decrease neurotransmission. Collectively, our results suggest that synucleins are important orchestrators of presynaptic terminal topography., (Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.)

The objective of this study is to understand the impairment of learning and memory in mouse after chronic nitrite exposure. The animal model of nitrite exposure in mouse was created with the daily intubation of nitrite in adult healthy male mice for 3 months. Furthermore, the mouse's learning and memory abilities were tested with Morris water maze, and the expression of Synaptophysin and γ-Synuclein was visualized with immunocytochemistry and Western blot. Our results showed that nitrite exposure significantly prolonged the escape latency period (ELP) and decreased the values of the frequency across platform (FAP) as well as the accumulative time in target quadrant (ATITQ) compared to control, in dose-dependent manner. In addition, after nitrite exposure, synaptophysin (SYN) positive buttons in the visual cortex was reduced, in contrast the increase of γ-synuclein positive cells. The results above were supported by Western blot as well. We conclude that nitrite exposure could lead to a decline in mice's learning and memory. The overexpression of γ-synuclein contributed to the synaptic loss, which is most likely the cause of learning and memory impairment. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1720-1730, 2016., (© 2015 Wiley Periodicals, Inc.)

Background: Exposure to the commonly used dithiocarbamate (DTC) pesticides is associated with an increased risk of developing Parkinson disease (PD), although the mechanisms by which they exert their toxicity are not completely understood., Objective: We studied the mechanisms of ziram's (a DTC fungicide) neurotoxicity in vivo., Methods: Zebrafish (ZF) embryos were utilized to determine ziram's effects on behavior, neuronal toxicity, and the role of synuclein in its toxicity., Results: Nanomolar-range concentrations of ziram caused selective loss of dopaminergic (DA) neurons and impaired swimming behavior. Because ziram increases α-synuclein (α-syn) concentrations in rat primary neuronal cultures, we investigated the effect of ziram on ZF γ-synuclein 1 (γ1). ZF express 3 synuclein isoforms, and ZF γ1 appears to be the closest functional homologue to α-syn. We found that recombinant ZF γ1 formed fibrils in vitro, and overexpression of ZF γ1 in ZF embryos led to the formation of neuronal aggregates and neurotoxicity in a manner similar to that of α-syn. Importantly, knockdown of ZF γ1 with morpholinos and disruption of oligomers with the molecular tweezer CLR01 prevented ziram's DA toxicity., Conclusions: These data show that ziram is selectively toxic to DA neurons in vivo, and this toxicity is synuclein-dependent. These findings have important implications for understanding the mechanisms by which pesticides may cause PD. Citation: Lulla A, Barnhill L, Bitan G, Ivanova MI, Nguyen B, O'Donnell K, Stahl MC, Yamashiro C, Klärner FG, Schrader T, Sagasti A, Bronstein JM. 2016. Neurotoxicity of the Parkinson disease-associated pesticide ziram is synuclein-dependent in zebrafish embryos. Environ Health Perspect 124:1766-1775; http://dx.doi.org/10.1289/EHP141., Competing Interests: G.B., F.-G.K., and T.S. are co-inventors of U.S. patent no. 8,791,092 and European Patent Application 10 708 075.6, Molecular Tweezers for the Treatment of Amyloid-Related Diseases. The other authors declare they have no actual or potential competing financial interests.

The synuclein (syn) family comprises three proteins: α-, β- and γ-syns. In humans, they are involved in neurodegenerative diseases such as Parkinson's disease and in tumors. Members of the syn family were sequenced in representative species of all vertebrates and the comparative analysis of amino acid sequences suggests that syns are evolutionarily conserved, but information about their expression in vertebrate lineages is still scarce and completely lacking in reptiles. In this study, the expression of genes coding for α-, β- and γ-syns was analyzed in the green lizard Anolis carolinensis by semiquantitative RT-PCR and Western blot. Results demonstrate good expression levels of the three syns in the lizard nervous system, similarly to human syns. This, together with the high identity between lizard and human syns, suggests that these proteins fulfill evolutionarily conserved functions. However, differences between lizard and humans in the expression of syn variants (two different variants of γ-syn were detected in A. carolinensis) and differences in some amino acids in key positions for the regulation of protein conformation and affinity for lipid and metal ions also suggest that these proteins may have acquired different functional specializations in the two lineages.

Neurogenic orthostatic hypotension and supine hypertension are common manifestations of cardiovascular dysautonomia in Parkinson's disease and related synucleinopathies. Because these disorders are haemodynamic opposites, improvement in one might be achieved at the expense of worsening of the other. Thus, management decisions necessitate assessment of the individual risks for patients with coexistent neurogenic orthostatic hypotension and supine hypertension. Whereas neurogenic orthostatic hypotension poses risks for falls and can be associated with cognitive impairment in the short term, chronic supine hypertension can be associated with stroke and myocardial infarction in the long term. Because few clinical trial data exist for outcomes in patients with coexistent neurogenic orthostatic hypotension and supine hypertension, clinicians need to balance, on the basis of comorbidities and disease staging, the potential immediate benefits of treatment for neurogenic orthostatic hypotension and the long-term risks of supine hypertension treatment in each patient. Future research needs to focus on ascertaining a safe degree of supine hypertension when treating neurogenic orthostatic hypotension; the effectiveness of nocturnal antihypertensive therapy in patients with coexistent neurogenic orthostatic hypotension and supine hypertension; and the prevalence, scope, and therapeutic requirements for managing neurogenic orthostatic hypotension that manifests with falls or cognitive impairment, but without postural lightheadedness or near syncope., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Unlabelled: Pathologic inclusions define α-synucleinopathies that include Parkinson's disease (PD). The most common genetic cause of PD is the G2019S LRRK2 mutation that upregulates LRRK2 kinase activity. However, the interaction between α-synuclein, LRRK2, and the formation of α-synuclein inclusions remains unclear. Here, we show that G2019S-LRRK2 expression, in both cultured neurons and dopaminergic neurons in the rat substantia nigra pars compact, increases the recruitment of endogenous α-synuclein into inclusions in response to α-synuclein fibril exposure. This results from the expression of mutant G2019S-LRRK2, as overexpression of WT-LRRK2 not only does not increase formation of inclusions but reduces their abundance. In addition, treatment of primary mouse neurons with LRRK2 kinase inhibitors, PF-06447475 and MLi-2, blocks G2019S-LRRK2 effects, suggesting that the G2019S-LRRK2 potentiation of inclusion formation depends on its kinase activity. Overexpression of G2019S-LRRK2 slightly increases, whereas WT-LRRK2 decreases, total levels of α-synuclein. Knockdown of total α-synuclein with potent antisense oligonucleotides substantially reduces inclusion formation in G2019S-LRRK2-expressing neurons, suggesting that LRRK2 influences α-synuclein inclusion formation by altering α-synuclein levels. These findings support the hypothesis that G2019S-LRRK2 may increase the progression of pathological α-synuclein inclusions after the initial formation of α-synuclein pathology by increasing a pool of α-synuclein that is more susceptible to forming inclusions., Significance Statement: α-Synuclein inclusions are found in the brains of patients with many different neurodegenerative diseases. Point mutation, duplication, or triplication of the α-synuclein gene can all cause Parkinson's disease (PD). The G2019S mutation in LRRK2 is the most common known genetic cause of PD. The interaction between G2019S-LRRK2 and α-synuclein may uncover new mechanisms and targets for neuroprotection. Here, we show that expression of G2019S-LRRK2 increases α-synuclein mobility and enhances aggregation of α-synuclein in primary cultured neurons and in dopaminergic neurons of the substantia nigra pars compacta, a susceptible brain region in PD. Potent LRRK2 kinase inhibitors, which are being developed for clinical use, block the increased α-synuclein aggregation in G2019S-LRRK2-expressing neurons. These results demonstrate that α-synuclein inclusion formation in neurons can be blocked and that novel therapeutic compounds targeting this process by inhibiting LRRK2 kinase activity may slow progression of PD-associated pathology., (Copyright © 2016 the authors 0270-6474/16/367416-13$15.00/0.)

Aims: This preclinical study was aimed at determining whether pharmacological targeting of transcription factor NRF2, a master controller of many homeostatic genes, might provide a disease-modifying therapy in the animal model of Parkinson's disease (PD) that best reproduces the main hallmark of this pathology, that is, α-synucleinopathy, and associated events, including nigral dopaminergic cell death, oxidative stress, and neuroinflammation., Results: Pharmacological activation of NRF2 was achieved at the basal ganglia by repurposing dimethyl fumarate (DMF), a drug already in use for the treatment of multiple sclerosis. Daily oral gavage of DMF protected nigral dopaminergic neurons against α-SYN toxicity and decreased astrocytosis and microgliosis after 1, 3, and 8 weeks from stereotaxic delivery to the ventral midbrain of recombinant adeno-associated viral vector expressing human α-synuclein. This protective effect was not observed in Nrf2-knockout mice. In vitro studies indicated that this neuroprotective effect was correlated with altered regulation of autophagy markers SQTSM1/p62 and LC3 in MN9D, BV2, and IMA 2.1 and with a shift in microglial dynamics toward a less pro-inflammatory and a more wound-healing phenotype. In postmortem samples of PD patients, the cytoprotective proteins associated with NRF2 expression, NQO1 and p62, were partly sequestered in Lewy bodies, suggesting impaired neuroprotective capacity of the NRF2 signature., Innovation: These experiments provide a compelling rationale for targeting NRF2 with DMF as a therapeutic strategy to reinforce endogenous brain defense mechanisms against PD-associated synucleinopathy., Conclusion: DMF is ready for clinical validation in PD. Antioxid. Redox Signal. 25, 61-77.

The studies of microbes have been instrumental in combatting infectious diseases, but they have also led to great insights into basic biological mechanism like DNA replication, transcription, and translation of mRNA. In particular, the studies of bacterial viruses, also called bacteriophage, have been quite useful to study specific cellular processes because of the ease to isolate their DNA, mRNA, and proteins. Here, I review the recent discovery of how properties of the filamentous phage M13 emerge as a novel approach to combat neurodegenerative diseases., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Amyloid-β, tau, and α-synuclein, or more specifically their soluble oligomers, are the aetiologic molecules in Alzheimer's disease, tauopathies, and α-synucleinopathies, respectively. These proteins have been shown to interact to accelerate each other's pathology. Clinical studies of amyloid-β-targeting therapies in Alzheimer's disease have revealed that the treatments after disease onset have little benefit on patient cognition. These findings prompted us to explore a preventive medicine which is orally available, has few adverse effects, and is effective at reducing neurotoxic oligomers with a broad spectrum. We initially tested five candidate compounds: rifampicin, curcumin, epigallocatechin-3-gallate, myricetin, and scyllo-inositol, in cells expressing amyloid precursor protein (APP) with the Osaka (E693Δ) mutation, which promotes amyloid-β oligomerization. Among these compounds, rifampicin, a well-known antibiotic, showed the strongest activities against the accumulation and toxicity (i.e. cytochrome c release from mitochondria) of intracellular amyloid-β oligomers. Under cell-free conditions, rifampicin inhibited oligomer formation of amyloid-β, tau, and α-synuclein, indicating its broad spectrum. The inhibitory effects of rifampicin against amyloid-β and tau oligomers were evaluated in APPOSK mice (amyloid-β oligomer model), Tg2576 mice (Alzheimer's disease model), and tau609 mice (tauopathy model). When orally administered to 17-month-old APPOSK mice at 0.5 and 1 mg/day for 1 month, rifampicin reduced the accumulation of amyloid-β oligomers as well as tau hyperphosphorylation, synapse loss, and microglial activation in a dose-dependent manner. In the Morris water maze, rifampicin at 1 mg/day improved memory of the mice to a level similar to that in non-transgenic littermates. Rifampicin also inhibited cytochrome c release from the mitochondria and caspase 3 activation in the hippocampus. In 13-month-old Tg2576 mice, oral rifampicin at 0.5 mg/day for 1 month decreased amyloid-β oligomer accumulation, tau hyperphosphorylation, synapse loss, and microglial activation, but not amyloid deposition. Rifampicin treatment to 14-15-month-old tau609 mice at 0.5 and 1 mg/day for 1 month also reduced tau oligomer accumulation, tau hyperphosphorylation, synapse loss, and microglial activation in a dose-dependent fashion, and improved the memory almost completely at 1 mg/day. In addition, rifampicin decreased the level of p62/sequestosome-1 in the brain without affecting the increased levels of LC3 (microtubule-associated protein light chain 3) conversion, suggesting the restoration of autophagy-lysosomal function. Considering its prescribed dose and safety in humans, these results indicate that rifampicin could be a promising, ready-to-use medicine for the prevention of Alzheimer's disease and other neurodegenerative diseases., (© The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Spinal cord injury causes neuronal death, limiting subsequent regeneration and recovery. Thus, there is a need to develop strategies for improving neuronal survival after injury. Relative to our understanding of axon regeneration, comparatively little is known about the mechanisms that promote the survival of damaged neurons. To address this, we took advantage of lamprey giant reticulospinal neurons whose large size permits detailed examination of post-injury molecular responses at the level of individual, identified cells. We report here that spinal cord injury caused a select subset of giant reticulospinal neurons to accumulate synuclein, a synaptic vesicle-associated protein best known for its atypical aggregation and causal role in neurodegeneration in Parkinson's and other diseases. Post-injury synuclein accumulation took the form of punctate aggregates throughout the somata and occurred selectively in dying neurons, but not in those that survived. In contrast, another synaptic vesicle protein, synaptotagmin, did not accumulate in response to injury. We further show that the post-injury synuclein accumulation was greatly attenuated after single dose application of either the "molecular tweezer" inhibitor, CLR01, or a translation-blocking synuclein morpholino. Consequently, reduction of synuclein accumulation not only improved neuronal survival, but also increased the number of axons in the spinal cord proximal and distal to the lesion. This study is the first to reveal that reducing synuclein accumulation is a novel strategy for improving neuronal survival after spinal cord injury., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: To describe the clinical phenotype of idiopathic rapid eye movement (REM) sleep behavior disorder (IRBD) at presentation in a sleep center., Methods: Clinical history review of 203 consecutive patients with IRBD identified between 1990 and 2014. IRBD was diagnosed by clinical history plus video-polysomnographic demonstration of REM sleep with increased electromyographic activity linked to abnormal behaviors., Results: Patients were 80% men with median age at IRBD diagnosis of 68 y (range, 50-85 y). In addition to the already known clinical picture of IRBD, other important features were apparent: 44% of the patients were not aware of their dream-enactment behaviors and 70% reported good sleep quality. In most of these cases bed partners were essential to convince patients to seek medical help. In 11% IRBD was elicited only after specific questioning when patients consulted for other reasons. Seven percent did not recall unpleasant dreams. Leaving the bed occurred occasionally in 24% of subjects in whom dementia with Lewy bodies often developed eventually. For the correct diagnosis of IRBD, video-polysomnography had to be repeated in 16% because of insufficient REM sleep or electromyographic artifacts from coexistent apneas. Some subjects with comorbid obstructive sleep apnea reported partial improvement of RBD symptoms following continuous positive airway pressure therapy. Lack of therapy with clonazepam resulted in an increased risk of sleep related injuries. Synucleinopathy was frequently diagnosed, even in patients with mild severity or uncommon IRBD presentations (e.g., patients who reported sleeping well, onset triggered by a life event, nocturnal ambulation) indicating that the development of a neurodegenerative disease is independent of the clinical presentation of IRBD., Conclusions: We report the largest IRBD cohort observed in a single center to date and highlight frequent features that were not reported or not sufficiently emphasized in previous publications. Physicians should be aware of the full clinical expression of IRBD, a sleep disturbance that represents a neurodegenerative disease., Commentary: A commentary on this article appears in this issue on page 7., (© 2016 Associated Professional Sleep Societies, LLC.)

The duration and strength of the dopaminergic signal are regulated by the dopamine transporter (DAT). Drug addiction and neurodegenerative and neuropsychiatric diseases have all been associated with altered DAT activity. The membrane localization and the activity of DAT are regulated by a number of intracellular proteins. α-Synuclein, a protein partner of DAT, is implicated in neurodegenerative disease and drug addiction. Little is known about the regulatory mechanisms of the interaction between DAT and α-synuclein, the cellular location of this interaction, and the functional consequences of this interaction on the basal, amphetamine-induced DAT-mediated dopamine efflux, and membrane microdomain distribution of the transporter. Here, we found that the majority of DAT·α-synuclein protein complexes are found at the plasma membrane of dopaminergic neurons or mammalian cells and that the amphetamine-mediated increase in DAT activity enhances the association of these proteins at the plasma membrane. Further examination of the interaction of DAT and α-synuclein revealed a transient interaction between these two proteins at the plasma membrane. Additionally, we found DAT-induced membrane depolarization enhances plasma membrane localization of α-synuclein, which in turn increases dopamine efflux and enhances DAT localization in cholesterol-rich membrane microdomains., (© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.)

Aggregation and fibril formation of human alpha-Synuclein (αS) are neuropathological hallmarks of Parkinson's disease and other synucleinopathies. The molecular mechanisms of αS aggregation and fibrillogenesis are largely unknown. Several studies suggested a sequence of events from αS dimerization via oligomerization and pre-fibrillar aggregation to αS fibril formation. In contrast to αS, little evidence suggests that γS can form protein aggregates in the brain, and for βS its neurotoxic properties and aggregation propensities are controversially discussed. These apparent differences in aggregation behavior prompted us to investigate the first step in Synuclein aggregation, i.e. the formation of dimers or oligomers, by Bimolecular Fluorescence Complementation in cells. This assay showed some Synuclein-specific limitations, questioning its performance on a single cell level. Nevertheless, we unequivocally demonstrate that all Synucleins can interact with each other in a very similar way. Given the divergent aggregation properties of the three Synucleins this suggests that formation of dimers is not predictive for the aggregation of αS, βS or γS in the aged or diseased brain., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Synucleins are small, soluble proteins expressed primarily in neural tissue and in certain tumors. The synuclein family consists of three members: α-, β-, and γ-synucleins present only in vertebrates. Members of the synuclein family have high sequence identity, especially in the N-terminal regions. The synuclein gene family came into the spotlight, when one of its members, α-synuclein, was found to be associated with Parkinson's disease and other neurodegenerative disorders, whereas γ-synuclein was linked to several forms of cancer. There are a lot of controversy and exciting debates concerning members of the synuclein family, including their normal functions, toxicity, role in pathology, transmission between cells and intracellular localization. Important findings which remain undisputable for many years are synuclein localization in synapses and their role in the regulation of synaptic vesicle trafficking, whereas their presence and function in mitochondria and nucleus is a debated topic. In this review, we present the data on the localization of synucleins in two intracellular organelles: the nucleus and mitochondria., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Genetic linkage studies and genome wide analysis have provided insights into complex medical diseases. Mycobacterium avium ss. paratuberculosis (MAP) causes Johne's disease, an important enteric inflammatory disease mostly studied in ruminant animals. MAP is also the putative cause of Crohn's disease. Moreover, MAP has been linked to other inflammatory diseases: sarcoidosis, Blau syndrome, autoimmune diabetes, autoimmune thyroiditis and multiple sclerosis. Genetic studies reveal an association between Parkinson's disease (PD), leprosy and Crohn's disease and since discovered, these findings have been considered "surprising". Autophagy and ubiquitin-proteosome systems are cellular systems that both fight intracellular pathogens (xenophagy) and maintain cellular protein quality control. PD is a common neurodegenerative disease that manifests clinically as a profound movement disorder. The recognized genetic defects of PD create disruption of cellular homeostasis that result in protein folding abnormalities of PD called Lewy bodies. Those same genetic defects are associated with susceptibility to intracellular pathogens, including mycobacteria. It is now understood that PD Lewy body pathology starts in the enteric nervous system and "spreads" to the brain in a retrograde fashion via the vagus nerve. This is the same process by which prions affect the brain. Lewy body pathology of the enteric nervous system predates the Lewy body pathology of the central nervous system (CNS) by years or even decades. This article proposes that genetic defects associated with PD also result in a permissive environment for MAP infection--ineffective xenophagy. It postulates that beginning as an enteric infection, MAP--via the vagus nerve--initiates a pathologic process that results in a targeted neuroinvasion of the CNS. The article proposes that MAP infection and resultant PD pathology are due, in the genetically at-risk and age dependant, to the consumptive exhaustion of the protein quality control systems., (Copyright © 2014 Elsevier B.V. All rights reserved.)