1.
Genetic and pathological links between Parkinson's disease and the lysosomal disorder Sanfilippo syndrome.
Source
Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.
Abstract
BACKGROUND:
Parkinson's disease (PD) is a common neurodegenerative disorder of unknown etiology. The characteristic α-synuclein aggregation of PD is also a feature of Sanfilippo syndrome, a storage disorder caused by α-N-acetylglucosaminidase (NAGLU) gene mutations. We explored genetic links between these disorders and studied the pathology of Sanfilippo syndrome to investigate a common pathway toward α-synuclein aggregation.
METHODS:
We typed the 2 single-nucleotide polymorphisms that tag the common haplotypes of NAGLU in 926 PD patients and 2308 controls and also stained cortical tissue from 2 cases of Sanfilippo A syndrome using the anti-α-synuclein antibody, Per7.
RESULTS:
Allelic analysis showed an association between rs2071046 and risk for PD (P 1.3 × 10(-3) ). Intracellular α-synuclein accumulation was observed in the cortical tissue of both Sanfilippo A syndrome cases.
CONCLUSIONS:
This study suggests a possible role of NAGLU in susceptibility to PD while extending evidence for α-synuclein aggregation in the brain in lysosomal storage disorders. Our findings support a mechanism involving lysosomal dysfunction more generally in the pathogenesis of PD. © 2011 Movement Disorder Society.
Copyright © 2011 Movement Disorder Society.
Antibodies against alpha-synuclein reduce oligomerization in living cells.
Source
Rudbeck Laboratory, Department of Public Health/Geriatrics, Uppsala University, Uppsala, Sweden.
Abstract
Recent research implicates soluble aggregated forms of α-synuclein as neurotoxic species with a central role in the pathogenesis of Parkinson's disease and related disorders. The pathway by which α-synuclein aggregates is believed to follow a step-wise pattern, in which dimers and smaller oligomers are initially formed. Here, we used H4 neuroglioma cells expressing α-synuclein fused to hemi:GFP constructs to study the effects of α-synuclein monoclonal antibodieson the early stages of aggregation, as quantified by Bimolecular Fluorescence Complementation assay. Widefield and confocal microscopy revealed that cells treated for 48 h with monoclonal antibodies internalized antibodies to various degrees. C-terminal and oligomer-selective α-synuclein antibodies reduced the extent of α-synucleindimerization/oligomerization, as indicated by decreased GFP fluorescence signal. Furthermore, ELISA measurements on lysates and conditioned media from antibody treated cells displayed lower α-synuclein levels compared to untreated cells, suggesting increased protein turnover. Taken together, our results propose that extracellular administration of monoclonal antibodies can modify or inhibit early steps in the aggregation process of α-synuclein, thus providing further support for passive immunization against diseases with α-synuclein pathology.
Determining nuclear localization of alpha-synuclein in mouse brains.
Source
Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA; Department of Neurology, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, PR China.
Abstract
Alpha-synuclein (α-Syn) is a major component of Lewy bodies, abnormal protein aggregates that are present in neurons of patients with Parkinson's disease and other neurological disorders. Despite intensive investigation, the in vivo role of α-Syn in physiological and pathological processes is not fully understood. This study addresses a current debate on the nuclear localization of α-Syn protein in the brain. To assess the specificity of various α-Syn antibodies, we compared their staining patterns in wild-type mouse brains with that of the α-Syn knock-out mice. Among five different α-Synantibodies tested here, two generated intensive nuclear staining throughout the normal mouse brain. However, nuclear staining by these two antibodies was also present in neurons of the α-Syn knock-out mice. This provides evidence that the nuclear signal is not specifically related to the presence of α-Syn, but it rather results from the cross-reactivity of the two antibodies to some unknown antigens in neuronal nuclei. In mouse brain neurons, endogenous α-Syn proteins are primarily localized to neuronal processes and nerve terminals but present only at low levels in the cell bodies. This is different from a generally uniform distribution of exogenously expressed α-Syn in both cytoplasm and nuclei of heterologous cells and suggests that the neuritic enrichment of α-Syn in neurons may be mediated by their specific interactions with certain structural or molecular components in the neuropil.
Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.
Synuclein-γ (SNCG) protein expression is associated with poor outcome in endometrial adenocarcinoma.
Source
Department of Pathology, Roswell Park Cancer Institute, Buffalo, NY, USA.
Abstract
OBJECTIVE:
Synuclein-γ (SNCG) is a marker for adverse and aggressive disease in breast cancer. In previous study, we found SNCG mRNA to be overexpressed in uterine serous carcinoma compared to uterine endometrioid adenocarcinoma. The aim of this study is to explore the prognostic value of SNCG in patients with endometrial cancer.
METHODS:
279 endometrial cancer patients were retrieved from the archives. The tissue paraffin blocks were stained for SNCG antibody and its expression was correlated with clinicopathological prognostic factors.
RESULTS:
There was a positive association between SNCG(+) immunoexpression and tumor grade, tumor stage, type II carcinomas, deep myometrial invasion and lymphovascular invasion. A correlation between SNCG(+) and adverse outcomes, such as shorter overall survival (OS) and disease free survival (DFS), was also detected. Following adjuvant therapy (radiation and chemotherapy or chemotherapy alone), we observed a difference in 5years DFS rate between SNCG(+) (41.6%) and SNCG(-) patients (59.5%).
CONCLUSION:
Overexpression of SNCG seemed to be a predictor biomarker for aggressive tumor behavior and adverse outcome in patients with endometrial cancer. Future exploration of SNCG as a potential therapeutic target for selected patients could be of interest.
Copyright © 2011 Elsevier Inc. All rights reserved.
Immunohistochemical localization of aggresomal proteins in glial cytoplasmic inclusions in multiple system atrophy.
Source
Department of Pathology, Institute for Developmental Research, Aichi Human Service Center, 713-8 Kamiya, Kasugai, Aichi 480-0392 Japan Department of Embryology, Institute for Developmental Research, Aichi Human Service Center, 713-8 Kamiya, Kasugai, Aichi 480-0392 Japan Department of Neuropathology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582 Japan.
Abstract
Aims: Multiple system atrophy (MSA) is pathologically characterized by the formation of α-synuclein-containing glial cytoplasmic inclusions (GCIs) in oligodendrocytes. However, the mechanisms of GCI formation are not fully understood. Cellular machinery for the formation of aggresomes has been linked to the biogenesis of the Lewy body, a characteristic α-synuclein-containing inclusion of Parkinson's disease and dementia with Lewy bodies. Here we examined whether GCIs contain the components of aggresomes by immunohistochemistry. Methods: Sections from 5 patients with MSA were stained immunohistochemically with antibodies against aggresome-related proteins and analyzed in comparison with sections from 5 patients with no neurological disease. We evaluated the presence or absence of aggresome-related proteins in GCIs by double immunofluorescence and immuno-electron microscopy. Results: GCIs were clearly immunolabeled with antibodies against aggresome-related proteins, such as γ-tubulin, histone deacetylase 6 (HDAC6), and 20S proteasome subunits. Neuronal cytoplasmic inclusions (NCIs) were also immunopositive for these aggresome-related proteins. Double immunofluorescence staining and quantitative analysis demonstrated that the majority of GCIs contained these proteins, as well as other aggresome-related proteins, such as Hsp70, Hsp90, and 62 kDa protein/sequestosome 1 (p62/SQSTM1). Immuno-electron microscopy demonstrated immunoreactivities for γ-tubulin and HDAC6 along the fibrils comprising GCIs. Conclusions: Our results indicate that GCIs, and probably NCIs, share at least some characteristics with aggresomes in terms of their protein components. Therefore, GCIs and NCIs may be another manifestation of aggresome-related inclusion bodies observed in neurodegenerative diseases.
© 2011 The Authors. Neuropathology and Applied Neurobiology © 2011 British Neuropathological Society.
Conformation-dependent scFv antibodies specifically recognize the oligomers assembled from various amyloids and show colocalization of amyloid fibrils with oligomers in patients with amyloidoses.
Source
Tsinghua University School of Medicine, Haidian District, Beijing 100084, China.
Abstract
Increasing evidence indicates that amyloid aggregates, including oligomers, protofibrils or fibrils, are pivotal toxins in the pathogenesis of many amyloidoses such as Alzheimer's disease (AD), Parkinson's disease, Huntington's disease, prion-related diseases, type 2 diabetes and hereditary renal amyloidosis. Various oligomers assembled from different amyloid proteins share common structures and epitopes. Here we present data indicating that two oligomer-specific single chain variable fragment (scFv) antibodies isolated from a naïve human scFv library could conformation-dependently recognize oligomers assembled from α-synuclein, amylin, insulin, Aβ1-40, prion peptide 106-126 and lysozyme, and fibrils from lysozyme. Further investigation showed that both scFvs inhibited the fibrillization of α-synuclein, amylin, insulin, Aβ1-40 and prion peptide 106-126, and disaggregated their preformed fibrils. However, they both promoted the aggregation of lysozyme. Nevertheless, the two scFv antibodies could attenuate the cytotoxicity of all amyloids tested. Moreover, the scFvs recognized the amyloid oligomers in all types of plaques, Lewy bodies and amylin deposits in the brain tissues of AD and PD patients and the pancreas of type 2 diabetes patients respectively, and showed that most amyloid fibril deposits were colocalized with oligomers in the tissues. Such conformation-dependent scFv antibodies may have potential application in the investigation of aggregate structures, the mechanisms of aggregation and cytotoxicity of various amyloids, and in the development of diagnostic and therapeutic reagents for many amyloidoses.
Copyright © 2011 Elsevier B.V. All rights reserved.
γ-Synuclein is a promising new marker for staining reactive follicular dendritic cells, follicular dendritic cell sarcoma, Kaposi sarcoma, and benign and malignant vascular tumors.
Source
Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York 10467-2490, USA.
Abstract
Synucleins are small soluble proteins found in normal brain that facilitate rapid release of neurotransmitters. α-synucleinis a major component of the Lewy body of neurodegenerative diseases and γ-synuclein is a marker of aggressive carcinomas. As the role of γ-synuclein has not yet been investigated in the lymphoid system, we immunohistochemically stained normal lymphoid organs, lymph nodes with reactive lymphoid hyperplasia, and malignant lymphomas. The anti-γ-synuclein antibody strongly stained the follicular dendritic cell (FDC) meshworks and vascular and lymphatic endothelial cells in reactive lymphoid tissues, in B-cell lymphomas with a nodular pattern, and in angioimmunoblastic T-cell lymphomas. There were no γ-synuclein-positive FDC meshworks in B-cell or T-cell lymphomas with a diffuse pattern. This is in contrast to CD21, which only stained the arms of the FDCs; γ-synucleinhighlighted both the long slender cellular processes and the cell body, thereby clearly demonstrating the number of individual FDCs. In addition, γ-synuclein was strongly expressed by the neoplastic counterpart of reactive FDCs (FDC sarcoma) and by the neoplastic counterparts of normal lymphatic and vascular endothelial cells (Kaposi sarcoma, hemangioma, and angiosarcoma). Only a few spindle cell neoplasms (SSNs) derived from smooth muscle, peripheral nerve, or gastrointestinal stroma expressed γ-synuclein; however, γ-synuclein was not expressed by 11 other types of SSNs tested. These results suggest that γ-synuclein is a promising new adjunct marker for identifying reactive FDCs and for diagnosing FDC sarcoma and benign and malignant vascular tumors.
Study of the Adhesion of Neurodegenerative Proteins on Plasma-Modified and Coated Polypropylene Surfaces.
Abstract
The inner polymeric surface of an ELISA titration well is plasma-modified and coated with different surfactant molecules. The titration of neurodegenerative proteins markers (prion, Tau and α-synuclein), previously demonstrated as more efficient with such modified tubes, is related to the adhesion behaviour of these proteins and their corresponding captureantibodies. The adhesion process is studied in terms of anchoring and specific mechanisms. The proteins andantibodies binding onto such modified surfaces is related to the substrate hydrophilic character calculated from the angle contact measure, to the polymer surface charge measured through the streaming potential determination at different pH and the inner surface roughness determined from AFM images. Furthermore, the influence of the blocking agent used during the ELISA titration is also studied.
Structural impact of proline-directed pseudophosphorylation at AT8, AT100, and PHF1 epitopes on 441-residue tau.
Source
Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
Abstract
The intrinsically disordered protein tau becomes excessively phosphorylated and aggregates into neurofibrillary tangles in Alzheimer's disease. To obtain insight into the structural consequences of phosphorylation, we characterized a mutant protein of tau in which epitopes recognized by Alzheimer diagnostic antibodies were mimicked by mutation to glutamic acid [AT8 (S199E, S202E, T205E), AT100 (T212E and S214E), and PHF1 (S396E and S404E)]. A large number of distance restraints obtained from NMR paramagnetic relaxation enhancement in combination with ensemble conformer calculations demonstrate that pseudophosphorylation causes an opening of the transient folding of tau. Together with previous studies on the Parkinson-related protein α-synuclein, our data indicate that networks of transient long-range interactions are common properties of intrinsically disordered proteins and that their modulation is important for aggregation.
Macroautophagy and the proteasome are differently involved in the degradation of alpha-synuclein wild type and mutated A30P in an in vitro inducible model (PC12/TetOn).
Source
Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Milan, Italy.
Abstract
Many data suggest that alpha synuclein (α-syn) aggregation is involved in Parkinson's disease (PD) neurotoxicity and is accelerated by the pathogenetic point mutation A30P. The triplication of α-syn gene has been linked to early-onset familial PD, suggesting that the cellular dosage of α-syn is an important modulator of its toxicity. To verify this point, we developed an inducible model of α-syn expression (both wild type [WT] and mutated A30P) in rat PC12/TetOn cells. At low expression level, both α-syn(WT) and (A30P) did not aggregate, were not toxic, and displayed a protective action against oxidative stress triggered by hydrogen peroxide (H(2)O(2)). By increasing α-syn expression, its antioxidant function was no longer detectable as for the A30P form, but again no aggregation and cell death were present both for the WT and the mutated protein. To clarify why α-syn did not accumulate at high expression level, we inhibited macroautophagy by 3-methyladenine (3-MA) and the proteasome by MG132. In presence of 3-MA, α-syn(WT) accumulated, A11 anti-oligomer antibody-positive aggregates were detectable, and cell toxicity was evident, while proteasome inhibition did not increase α-syn(WT) accumulation. Macroautophagy or proteasome inhibition slightly increased α-syn(A30P) toxicity, with no detectable aggregation. This model can provide useful details about α-syn function, aggregation, and degradation pathways.
Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.
A comparison between rectal and colonic biopsies to detect Lewy pathology in Parkinson's disease.
Source
Inserm, U913, Nantes, F-44093, France; Inserm, CIC-04, Nantes, F-44093, France; University Nantes, Nantes, F-44093, France; CHU Nantes, Department of Neurology, Nantes, F-44093, France.
Abstract
We have shown that routine biopsies of the ascending colon obtained at colonoscopy allow the detection of Lewy neurites (LN) in the enteric nervous system (ENS) of Parkinson's disease (PD) patients. Although colonoscopy is a relatively safe procedure, it requires colon preparation and anesthesia. The present study was therefore undertaken to evaluate whether descending colon and rectal biopsies that are obtainable by rectosigmoidoscopy allow the detection of Lewy pathology in the ENS. A total of 9 controls and 26 PD patients were included and analyzed. Two biopsies were taken from the ascending, descending colon and rectum during the course of a total colonoscopy. Immunohistochemical analysis was performed using antibodies against phosphorylated alpha-synuclein to detect LN and neurofilaments 200kDa to label the neuronal structures. Biopsies from ascending, descending colon and rectum were morphologically comparable. LN were detected in the biopsies of ascending colon in 17 PD patients (65%), of descending colon in 11 patients (42%) and of rectum in only 6 patients (23%). No LN were seen in control biopsies. Our results show that Lewy pathology follows a rostrocaudal distribution in the colon and rectum of PD patients. Therefore, rectal biopsies have substantially lower sensitivity than ascending colon biopsies to detect Lewy pathology in the gut.
Copyright © 2011 Elsevier Inc. All rights reserved.
Biomarker candidates of neurodegeneration in Parkinson's disease for the evaluation of disease-modifying therapeutics.
Source
Department for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Füchsleinstrasse 15, 97080, Würzburg, Germany, manfred.gerlach@uni-wuerzburg.de.
Abstract
Reliable biomarkers that can be used for early diagnosis and tracking disease progression are the cornerstone of the development of disease-modifying treatments for Parkinson's disease (PD). The German Society of Experimental and Clinical Neurotherapeutics (GESENT) has convened a Working Group to review the current status of proposed biomarkers of neurodegeneration according to the following criteria and to develop a consensus statement on biomarker candidates for evaluation of disease-modifying therapeutics in PD. The criteria proposed are that the biomarker should be linked to fundamental features of PD neuropathology and mechanisms underlying neurodegeneration in PD, should be correlated to disease progression assessed by clinical rating scales, should monitor the actual disease status, should be pre-clinically validated, and confirmed by at least two independent studies conducted by qualified investigators with the results published in peer-reviewed journals. To date, available data have not yet revealed one reliable biomarker to detect early neurodegeneration in PD and to detect and monitor effects of drug candidates on the disease process, but some promising biomarker candidates, such as antibodies against neuromelanin, pathological forms of α-synuclein, DJ-1, and patterns of gene expression, metabolomic and protein profiling exist. Almost all of the biomarker candidates were not investigated in relation to effects of treatment, validated in experimental models of PD and confirmed in independent studies.
A novel molecular mechanism for nitrated {alpha}-synuclein-induced cell death.
Source
State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
Abstract
Although previous studies have demonstrated the involvement of nitrated α-synuclein in neurodegenerative disorders (synucleinopathies), the effects of nitrated α-synuclein and the molecular mechanisms underlying its toxicity are still unclear. In the present study, nitrated α-synuclein with four 3-nitrotyrosines (Tyr(39), Tyr(125), Tyr(133), and Tyr(136)) was obtained non-enzymatically by incubation with nitrite. The nitrated protein existed as a mixture of monomers, dimers, and polymers in solution. The nitrated α-synuclein could induce cell death in a time- and concentration-dependent manner when SH-SY5Y cells (a human neuroblastoma cell line) were incubated with the dimers and polymers. Treatment with anti-integrin α5β1 antibody partially rescued the SH-SY5Y cells from the cell death. Dot blotting and immunoprecipitation revealed that the nitrated protein bound to integrin on the cell membranes. Level of nitric oxide (NO) and calcium-independent inducible NO synthase (iNOS) activity increased during the initial stages of the treatment. The expression of phosphorylated focal adhesion kinase (FAK) decreased in the cells. Subsequently, an increase in caspase 3 activity was observed in SH-SY5Y cells. Our results demonstrate that activation of iNOS and inhibition of FAK may both be responsible for the cell death induced by nitrated α-synuclein. These data suggest that the cytotoxicity of nitrated α-synuclein is mediated via an integrin-iNOS/-FAK signaling pathway, and that the nitration of α-synuclein plays a role in neuronal degeneration.
Unmyelinated axons are more vulnerable to degeneration than myelinated axons of the cardiac nerve in Parkinson's disease.
Source
Department of Neurology, Kanto Central Hospital, Tokyo, Japan. orimo@kanto-ctr-hsp.com
Abstract
AIMS:
We recently demonstrated accumulation of α-synuclein aggregates of the cardiac sympathetic nerve in Parkinson's disease (PD) and a possible relationship between degeneration of the cardiac sympathetic nerve and α-synuclein aggregates. The aim of this study is to determine whether there is a difference in the degenerative process between unmyelinated and myelinated axons of the cardiac nerve.
METHODS:
We immunohistochemically examined cardiac tissues from four pathologically verified PD patients, nine patients with incidental Lewy body disease (ILBD) and five control subjects, using antibodies against neurofilament, myelin basic protein (MBP) and α-synuclein. First, we counted the number of neurofilament-immunoreactive axons not surrounded by MBP (unmyelinated axons) and those surrounded by MBP (myelinated axons). Next, we counted the number of unmyelinated and myelinated axons with α-synuclein aggregates.
RESULTS:
(i) The percentage of unmyelinated axons in PD (77.5 ± 9.14%) was significantly lower compared to that in control subjects (92.2 ± 2.40%). (ii) The ratio of unmyelinated axons with α-synuclein aggregates to total axons with α-synuclein aggregates in ILBD ranged from 94.4 to 100 (98.2 ± 2.18%). Among axons with α-synuclein aggregates, unmyelinated axons were the overwhelming majority, comprising 98.2%.
CONCLUSION:
These findings suggest that in PD unmyelinated axons are more vulnerable to degeneration than myelinated axons of the cardiac nerve, because α-synuclein aggregates accumulate much more abundantly in unmyelinated axons.
© 2011 The Authors. Neuropathology and Applied Neurobiology © 2011 British Neuropathological Society.
Protein disulfide isomerase immunopositive glial cytoplasmic inclusions in patients with multiple system atrophy.
Source
Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Kyoto, Japan.
Abstract
BACKGROUND:
Glial cytoplasmic inclusions (GCIs) are the pathological hallmarks of multiple system atrophy (MSA) and α-synuclein is abnormally deposited in GCIs. Protein disulfide isomerase (PDI) is a member of the thioredoxin superfamily and is believed to accelerate the folding of disulfide-bonded proteins by catalyzing the disulfide interchange reaction, which is the rate-limiting step during protein folding in the luminal space of the endoplasmic reticulum (ER). Nitric-oxide-induced (NO-induced) S-nitrosylation of PDI inhibits its enzymatic activity, leading to the accumulation of polyubiquitinated proteins, and activates the unfolded protein response in neurodegenerative diseases.
MATERIALS AND METHODS:
Postmortem brain specimens from five patients with MSA and five normal control brains were utilized in this immunohistochemical study.
RESULTS:
We found GCIs positive for anti-PDI antibody in the brain of patients with MSA. In addition, we observed colocalization of α-synuclein and leucine-rich repeat kinase 2 (LRRK2) with PDI in GCIs. As LRRK2 immunoreactivity is associated with one of the earliest oligodendrocytic abnormalities in MSA, colocalization of LRRK2 and PDI in GCIs may be a link to the ER stress of glial cells in the early stages of MSA.
CONCLUSIONS:
In MSA, NO may inhibit PDI by inducing S-nitrosylation, which inhibits its enzymatic activity and thus allows protein misfolding to occur.
Therapeutic effects of rapamycin on MPTP-induced Parkinsonism in mice.
Source
Department of Neurology, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai, China; Department of Neurology, The Fifth People Hospital of Fudan University, Shanghai, China.
Abstract
OBJECTIVE:
In neurodegenerative disorders such as Parkinson's disease (PD), autophagy is implicated in the process of dopaminergic neuron cell death. The α-synuclein protein is a major component of Lewy bodies and Lewy neurites, and mutations in α-synuclein have been implicated in the etiology of familial PD. The current work investigates the mechanisms underlying the therapeutic effects of the autophagy-stimulating antibiotic rapamycin in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD.
METHODS:
Male C57BL/6 mice were treated with intravenous rapamycin or saline control for 7days following MPTP administration. Immunohistochemistry and western blotting were used to detect alterations in the expression of PD biomarkers, including tyrosine hydroxylase (TH), and the level of autophagy was evaluated by the detection of both microtubule-associated protein light chain 3 (LC3) and α-synuclein cleavage. In addition, levels of monoamine neurotransmitters were measured in the striatum using high performance liquid chromatography (HPLC).
RESULTS:
Immunohistochemistry using antibodies against TH indicated that the number of dopaminergic neurons in the substantia nigra following MPTP treatment was significantly higher in rapamycin-treated mice compared with saline-treated controls (p<0.01). Levels of TH expression in the striatum were similar between the groups. α-Synucleinimmunoreactivity was significantly decreased in rapamycin-treated mice compared with controls (p<0.01). Immunoreactivity for LC3, however, was significantly higher in the rapamycin-treated animals than controls (p<0.01). The concentrations of both striatal dopamine, and the dopamine metabolite DOPAC, were significantly decreased in both MPTP-treated groups compared with untreated controls. The loss of DOPAC was less severe in rapamycin-treated mice compared with saline-treated mice (p<0.01) following MPTP treatment.
CONCLUSIONS:
These results demonstrate that treatment with rapamycin is able to rescue dopaminergic neurons and ameliorate the loss of DOPAC following MPTP treatment, likely via activation of autophagy/lysosome pathways. The use of rapamycin may therefore be a promising therapeutic agent for the treatment of PD.
Copyright © 2011. Published by Elsevier Ltd.
Enzyme-linked immunosorbent assays for alpha-synuclein with species and multimeric state specificities.
Source
Department of Anatomy, School of Medicine, Konkuk University, Seoul 143-701, South Korea.
Abstract
Abnormal intracellular deposition of aggregated α-synuclein is the characteristic feature of a number of neurological disorders, including Parkinson's disease (PD). Although α-synuclein is typically known as a cytosolic protein, a small amount is secreted by exocytosis in both monomeric and aggregated forms. The extracellular forms of α-synuclein in human body fluids, such as cerebrospinal fluid (CSF) and blood plasma, might be a diagnostic target for PD and related diseases. Here, we characterized a new set of monoclonal antibodies against α-synuclein, and using different combinations of antibodies, we established ELISA systems to specifically detect human α-synuclein, mouse and human α-synuclein together, and multimeric forms of α-synuclein in biological samples. By employing the Tyramide signal amplification method, the sensitivity of the assay was significantly improved to detect a concentration as low as ∼12.5 pg/ml. These assays might be useful tools for quantitative analysis of α-synuclein in various forms and with high sensitivity in diverse biological samples.
Copyright © 2011 Elsevier B.V. All rights reserved.
PrP(Sc)-specific antibodies with the ability to immunodetect prion oligomers.
Source
Department of Pathology and Infectious Diseases, Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom. mtayebi@rvc.ac.uk
Abstract
The development of antibodies with binding capacity towards soluble oligomeric forms of PrPSc recognised in the aggregation process in early stage of the disease would be of paramount importance in diagnosing prion diseases before extensive neuropathology has ensued. As blood transfusion appears to be efficient in the transmission of the infectious prion agent, there is an urgent need to develop reagents that would specifically recognize oligomeric forms of the abnormally folded prion protein, PrPSc.To that end, we show that anti-PrP monoclonal antibodies (called PRIOC mAbs) derived from mice immunised with native PrP-coated microbeads are able to immunodetect oligomers/multimers of PrPSc. Oligomer-specific immunoreactivity displayed by these PRIOC mAbs was demonstrated as large aggregates of immunoreactive deposits in prion-permissive neuroblastoma cell lines but not in equivalent non-infected or prn-p(0/0) cell lines. In contrast, an anti-monomer PrP antibody displayed diffuse immunoreactivity restricted to the cell membrane. Furthermore, our PRIOC mAbs did not display any binding with monomeric recombinant and cellular prion proteins but strongly detected PrPSc oligomers as shown by a newly developed sensitive and specific ELISA. Finally, PrioCantibodies were also able to bind soluble oligomers formed of Aβ and α-synuclein. These findings demonstrate the potential use of anti-prion antibodies that bind PrPSc oligomers, recognised in early stage of the disease, for the diagnosis of prion diseases in blood and other body fluids.
Autoantibodies against amyloid and glial-derived antigens are increased in serum and cerebrospinal fluid of Lewy body-associated dementias.
Source
Center of Neurology, Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. walter.maetzler@uni-tuebingen.de
Abstract
There is increasing evidence that in Lewy body-associated dementias (encompassing Parkinson's disease with dementia (PDD) and dementia with Lewy bodies (DLB)), the adaptive immune system is altered and the degenerative process includes glial cells in addition to neuronal structures. We therefore aimed to determine levels of autoantibodies against amyloid and glial-derived structures in these dementia types. Using a newly developed Enzyme-linked immunosorbent assay (ELISA), we measured levels of IgG autoantibodies against neuronal and glial structures in serum and cerebrospinal fluid of a total of 91 subjects (13 PDD, 14 DLB, 11 Alzheimer's disease (AD), 11 frontotemporal dementia (FTD), 11 vascular dementia patients (VaD), and 31 healthy controls). Autoantibody levels against α-synuclein, amyloid-β₄₂ (Aβ₄₂), myelin oligodendrocyte glycoprotein (MOG), myelin basic protein (MBP), and S100B were determined. In all groups, autoantibody levels were about three magnitudes higher in serum than in CSF. Serum autoantibody levels against α-synuclein, Aβ₄₂, MOG, MBP, and S100B were higher in PDD/DLB compared to tau-associated dementias (AD, FTD), VaD, and controls, respectively, with most of them reaching highly significant p-values. In cerebrospinal fluid (CSF), levels of antibodies against oligodendrocyte-derived antigens (MOG, MBP) were significantly increased in PDD/DLB. Increased levels of autoantibodies against both neuronal- and glial-derived antigens in serum and CSF of Lewy body-associated dementias indicate an altered activity of the adaptive immune system in these dementia types. The potential of neural-derived IgG autoantibodies as part of a biomarker panel for the diagnosis of Lewy body-associated dementias should be further evaluated.
- PMID:
- 21593566
- [PubMed - in process]
Passive immunization reduces behavioral and neuropathological deficits in an alpha-synuclein transgenic model of Lewy body disease.
Source
Department of Neurosciences, University of California San Diego, La Jolla, California, United States of America. emasliah@ucsd.edu
Abstract
Dementia with Lewy bodies (DLB) and Parkinson's Disease (PD) are common causes of motor and cognitive deficits and are associated with the abnormal accumulation of alpha-synuclein (α-syn). This study investigated whether passive immunization with a novel monoclonal α-syn antibody (9E4) against the C-terminus (CT) of α-syn was able to cross into the CNS and ameliorate the deficits associated with α-syn accumulation. In this study we demonstrate that 9E4 was effective at reducing behavioral deficits in the water maze, moreover, immunization with 9E4 reduced the accumulation of calpain-cleaved α-syn in axons and synapses and the associated neurodegenerative deficits. In vivo studies demonstrated that 9E4 traffics into the CNS, binds to cells that display α-syn accumulation and promotes α-syn clearance via the lysosomal pathway. These results suggest that passive immunization with monoclonal antibodiesagainst the CT of α-syn may be of therapeutic relevance in patients with PD and DLB.
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