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Nuebling GS, Plesch E, Ruf VC, Högen T, Lorenzl S, Kamp F, Giese A, Levin J. Binding of Metal-Ion-Induced Tau Oligomers to Lipid Surfaces Is Enhanced by GSK-3β-Mediated Phosphorylation. ACS Chem Neurosci 2020; 11:880-887. [PMID: 32069020 DOI: 10.1021/acschemneuro.9b00459] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
While fibrillar deposits of hyperphosphorylated protein tau are a key hallmark of several neurodegenerative diseases such as Alzheimer's disease, small oligomers have been speculated to be the key toxic aggregate species. Trivalent metal ions were shown to promote tau oligomer formation in vitro. However, little is known about potential intercellular spreading mechanisms or toxic modes of action of such oligomers. We investigated interactions of tau monomers and Fe3+/Al3+-induced oligomers with small unilamellar vesicles derived from 1-palmitoyl-2-oleoyl-phosphatidylcholine (neutral, liquid-crystalline phase) and dipalmitoyl-phosphatidylcholine (neutral, gel-phase). We further evaluated the influence of glycogen synthase kinase 3β (GSK-3β)-mediated tau phosphorylation applying the single-particle fluorescence spectroscopy techniques fluorescence correlation spectroscopy, fluorescence intensity distribution analysis, and scanning for intensely fluorescent targets. In these experiments, no binding to neutral lipid surfaces was observed for tau monomers. In contrast, metal-ion-induced tau oligomers showed a gain of function in binding to neutral lipid surfaces. Of note, tau phosphorylation by GSK-3β increased both oligomer formation and membrane affinity of the resulting oligomers. In conclusion, our data imply a pathological gain of function of metal-ion-induced oligomers of hyperphosphorylated tau, enabling membrane binding irrespective of surface charge even at nanomolar protein concentrations.
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Maurer A, Leonov A, Ryazanov S, Herfert K, Kuebler L, Buss S, Schmidt F, Weckbecker D, Linder R, Bender D, Giese A, Pichler BJ, Griesinger C. 11 C Radiolabeling of anle253b: a Putative PET Tracer for Parkinson's Disease That Binds to α-Synuclein Fibrils in vitro and Crosses the Blood-Brain Barrier. ChemMedChem 2020; 15:411-415. [PMID: 31859430 PMCID: PMC7079211 DOI: 10.1002/cmdc.201900689] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 12/18/2019] [Indexed: 11/09/2022]
Abstract
There is an urgent clinical need for imaging of α-synuclein (αSyn) fibrils, the hallmark biomarker for Parkinson's disease, in neurodegenerative disorders. Despite immense efforts, promising tracer candidates for nuclear imaging of αSyn are rare. Diphenyl pyrazoles are known modulators of αSyn aggregation and thus bear potential for non-invasive detection of this biomarker in vivo. Here we demonstrate high-affinity binding of the family member anle253b to fibrillar αSyn and present a high-yielding site-selective radiosynthesis route for 11 C radiolabeling using in-situ generated [11 C]formaldehyde and reductive methylation. Radio-HPLC of the tracer after incubation with rat serum in vitro shows excellent stability of the molecule. Positron emission tomography in healthy animals is used to assess the pharmacokinetics and biodistribution of the tracer, showing good penetration of the blood-brain barrier and low background binding to the non-pathological brain.
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Jecmenica Lukic M, Kurz C, Respondek G, Grau-Rivera O, Compta Y, Gelpi E, Troakes C, van Swieten JC, Giese A, Roeber S, Arzberger T, Höglinger G. Copathology in Progressive Supranuclear Palsy: Does It Matter? Mov Disord 2020; 35:984-993. [PMID: 32125724 DOI: 10.1002/mds.28011] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 02/01/2020] [Accepted: 02/04/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The influence of concomitant brain pathologies on the progression rate in PSP is unclear. OBJECTIVES To analyze the frequency and severity of copathologies and their impact on the progression in PSP. METHODS We analyzed clinic-pathological features of 101 PSP patients. Diagnoses and stages of copathologies were established according to standardized criteria, including Alzheimer's disease-related pathology, argyrophilic grains, Lewy-related pathology, transactive response DNA-binding protein 43 pathology, fused in sarcoma pathology, cerebral amyloid angiopathy, and small vessel disease. Demographic data and major clinical milestones (frequency and latency to onset) were extracted from patients' files. RESULTS Only 8% of 101 patients presented with pure PSP pathology without any copathology. Alzheimer's disease-related pathology was the most frequent (84%), followed by argyrophilic grains (58%), both occurring as single copathology or in combination with other proteinopathies or cerebrovascular disease. Lewy-related and transactive response DNA-binding protein 43 copathology occurred rarely (8% and 6%, respectively). Fused in sarcoma-positive cases were not found. While being common, copathology was mostly mild in severity, with the exception of frequently widespread argyrophilic grains. Small vessel disease was also frequent (65%). Cerebral amyloid angiopathy occurred only in the presence of Alzheimer's disease-related changes (25%). The copathologies did not have major impact on prevalence and time frame of major disease milestones. CONCLUSIONS In PSP, concomitant neurodegenerative proteinopathies or cerebrovascular diseases are frequent, but generally mild in severity. Our data confirmed that four repeat tau is still the most relevant target for PSP, whereas the impact of copathologies on progression rate appears to be of less importance. This is relevant information for the development of disease-modifying therapies. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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Osterman A, Ruf VC, Domingo C, Nitsche A, Eichhorn P, Zimmermann H, Seelos K, Zange S, Dimitriadis K, Pfister HW, Thye T, Giese A, Tappe D, Böhm S. Travel-associated neurological disease terminated in a postmortem diagnosed atypical HSV-1 encephalitis after high-dose steroid therapy - a case report. BMC Infect Dis 2020; 20:150. [PMID: 32070282 PMCID: PMC7029604 DOI: 10.1186/s12879-020-4859-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 02/06/2020] [Indexed: 12/27/2022] Open
Abstract
Background Human encephalitis can originate from a variety of different aetiologies, of which infection is the most common one. The diagnostic work-up is specifically challenging in patients with travel history since a broader spectrum of unfamiliar additional infectious agents, e. g. tropical disease pathogens, needs to be considered. Here we present a case of encephalitis of unclear aetiology in a female traveller returning from Africa, who in addition developed an atypical herpes simplex virus (HSV) encephalitis in close temporal relation with high-dose steroid treatment. Case presentation A previously healthy 48-year-old female presented with confusion syndrome and impaired vigilance which had developed during a six-day trip to The Gambia. The condition rapidly worsened to a comatose state. Extensive search for infectious agents including a variety of tropical disease pathogens was unsuccessful. As encephalitic signs persisted despite of calculated antimicrobial and antiviral therapy, high-dose corticosteroids were applied intravenously based on the working diagnosis of an autoimmune encephalitis. The treatment did, however, not improve the patient’s condition. Four days later, bihemispheric signal amplification in the insular and frontobasal cortex was observed on magnetic resonance imaging (MRI). The intracranial pressure rapidly increased and could not be controlled by conservative treatment. The patient died due to tonsillar herniation 21 days after onset of symptoms. Histological examination of postmortem brain tissue demonstrated a generalized lymphocytic meningoencephalitis. Immunohistochemical reactions against HSV-1/2 indicated an atypical manifestation of herpesviral encephalitis in brain tissue. Moreover, HSV-1 DNA was detected by a next-generation sequencing (NGS) metagenomics approach. Retrospective analysis of cerebrospinal fluid (CSF) and serum samples revealed HSV-1 DNA only in specimens one day ante mortem. Conclusions This case shows that standard high-dose steroid therapy can contribute to or possibly even trigger fulminant cerebral HSV reactivation in a critically ill patient. Thus, even if extensive laboratory diagnostics including wide-ranging search for infectious pathogens has been performed before and remained without results, continuous re-evaluation of potential differential diagnoses especially regarding opportunistic infections or reactivation of latent infections is of utmost importance, particularly if new symptoms occur.
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Saravanan MS, Ryazanov S, Leonov A, Nicolai J, Praest P, Giese A, Winter R, Khemtemourian L, Griesinger C, Killian JA. The small molecule inhibitor anle145c thermodynamically traps human islet amyloid peptide in the form of non-cytotoxic oligomers. Sci Rep 2019; 9:19023. [PMID: 31836748 PMCID: PMC6911113 DOI: 10.1038/s41598-019-54919-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 11/15/2019] [Indexed: 01/09/2023] Open
Abstract
Type 2 diabetes (T2DM) is associated with aggregation of the human islet amyloid polypeptide (hIAPP) into cytotoxic amyloid species. Here we tested the effect of a diphenylpyrazole (DPP)-derived small molecule inhibitor, anle145c, on cytotoxicity and on aggregation properties of hIAPP. We demonstrate that incubation of hIAPP with the inhibitor yields ~10 nm-sized non-toxic oligomers, independent of the initial aggregation state of hIAPP. This suggests that anle145c has a special mode of action in which anle145c-stabilized oligomers act as a thermodynamic sink for the preferred aggregation state of hIAPP and anle145c. We also demonstrate that the inhibitor acts in a very efficient manner, with sub-stoichiometric concentrations of anle145c being sufficient to (i) inhibit hIAPP-induced death of INS-1E cells, (ii) prevent hIAPP fibril formation in solution, and (iii) convert preformed hIAPP fibrils into non-toxic oligomers. Together, these results indicate that anle145c is a promising candidate for inhibition of amyloid formation in T2DM.
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Siller S, Lauseker M, Giese A, Tonn JC, Niyazi KM, Thon N, Suchorska B, Kreth FW. PATH-04. INFLUENCE OF INDIVIDUAL CpG METHYLATION STATUS OF THE MGMT PROMOTOR ON OUTCOME IN ADULT PATIENTS WITH GLIOBLASTOMA MULTIFORME RECEIVING ALKYLATING AGENT TREATMENT. Neuro Oncol 2019. [DOI: 10.1093/neuonc/noz175.600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
BACKGROUND
Methylation of O-6-methylguanine-DNA-methyltransferase (MGMT) promotor causes gene silencing and has been associated with a favourable prognosis in patients with glioblastoma multiforme (GBM) receiving alkylating chemotherapy. However, analysis of MGMT promotor methylation is usually reported as a cut-off depending on the results of the correspondent CpG-site testing. This approach disregards a possible heterogeneity concerning the methylation status within the individual CpG-sites and its possible association with prognosis in GBM patients. The current study aimed at elucidating the association between methylation of CpG-sites 74–98 within the MGMT promotor region and outcome in GBM patients receiving alkylating agents.
METHODS
Individual methylation status of 230 patients with histologically proven GBM following concomitant radio-chemotherapy with TMZ after stereotactic biopsy or open tumor resection was assessed by the Sanger-sequencing approach. Methylation of CpG-sites 74–98 within the MGMT promotor region was defined according to a ratio of cytosine/thymine peak > 50%. The total number of methylated CpG-sites was correlated with outcome using proportional hazards models. In a subset of 34 patients, a correlation between individual CpG-site methylation and MGMT mRNA-expression was performed.
RESULTS
Median progression-free (PFS) and overall survival (OS) were 7.8 and 14.6months, respectively. The cumulative total number of methylated loci within the CpG-sites 74–98 was strongly associated with both PFS and OS and retained its prognostic influence on outcome in multivariate models (p< 0.001). Furthermore, a linear coherence between the total number of methylated CpG-sites 74–98 and survival parameters could be observed. Moreover, low number of methylated CpG-sites was observed in tumor specimen with a high mRNA-expression and vice versa (Spearman-correlation-coefficient: -0.62).
CONCLUSION
Our data suggest a strong linear coherence between outcome and the total number of methylated CpG-sites 74–98, thus an up-front analysis of the individual GpC-site methylation status prior to initiation of alkylating chemotherapy might help improving treatment response in GBM patients.
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Böck J, Remmele CW, Dittrich M, Müller T, Kondova I, Persengiev S, Bontrop RE, Ade CP, Kraus TFJ, Giese A, El Hajj N, Schneider E, Haaf T. Cell Type and Species-specific Patterns in Neuronal and Non-neuronal Methylomes of Human and Chimpanzee Cortices. Cereb Cortex 2019; 28:3724-3739. [PMID: 30085031 PMCID: PMC6132288 DOI: 10.1093/cercor/bhy180] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 07/13/2018] [Indexed: 12/04/2022] Open
Abstract
Epigenetic changes have likely contributed to the large size and enhanced cognitive abilities of the human brain which evolved within the last 2 million years after the human–chimpanzee split. Using reduced representation bisulfite sequencing, we have compared the methylomes of neuronal and non-neuronal cells from 3 human and 3 chimpanzee cortices. Differentially methylated regions (DMRs) with genome-wide significance were enriched in specific genomic regions. Intraspecific methylation differences between neuronal and non-neuronal cells were approximately 3 times more abundant than interspecific methylation differences between human and chimpanzee cell types. The vast majority (>90%) of human intraspecific DMRs (including DMRs in retrotransposons) were hypomethylated in neurons, compared with glia. Intraspecific DMRs were enriched in genes associated with different neuropsychiatric disorders. Interspecific DMRs were enriched in genes showing human-specific brain histone modifications. Human–chimpanzee methylation differences were much more frequent in non-neuronal cells (n. DMRs = 666) than in neurons (n. DMRs = 96). More than 95% of interspecific DMRs in glia were hypermethylated in humans. Although without an outgroup we cannot assign whether a change in methylation occurred in the human or chimpanzee lineage, our results are consistent with a wave of methylation affecting several hundred non-neuronal genes during human brain evolution.
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Wegrzynowicz M, Bar-On D, Calo' L, Anichtchik O, Iovino M, Xia J, Ryazanov S, Leonov A, Giese A, Dalley JW, Griesinger C, Ashery U, Spillantini MG. Depopulation of dense α-synuclein aggregates is associated with rescue of dopamine neuron dysfunction and death in a new Parkinson's disease model. Acta Neuropathol 2019; 138:575-595. [PMID: 31165254 PMCID: PMC6778064 DOI: 10.1007/s00401-019-02023-x] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 04/20/2019] [Accepted: 04/30/2019] [Indexed: 12/13/2022]
Abstract
Parkinson’s disease (PD) is characterized by the presence of α-synuclein aggregates known as Lewy bodies and Lewy neurites, whose formation is linked to disease development. The causal relation between α-synuclein aggregates and PD is not well understood. We generated a new transgenic mouse line (MI2) expressing human, aggregation-prone truncated 1–120 α-synuclein under the control of the tyrosine hydroxylase promoter. MI2 mice exhibit progressive aggregation of α-synuclein in dopaminergic neurons of the substantia nigra pars compacta and their striatal terminals. This is associated with a progressive reduction of striatal dopamine release, reduced striatal innervation and significant nigral dopaminergic nerve cell death starting from 6 and 12 months of age, respectively. In the MI2 mice, alterations in gait impairment can be detected by the DigiGait test from 9 months of age, while gross motor deficit was detected by rotarod test at 20 months of age when 50% of dopaminergic neurons in the substantia nigra pars compacta are lost. These changes were associated with an increase in the number and density of 20–500 nm α-synuclein species as shown by dSTORM. Treatment with the oligomer modulator anle138b, from 9 to 12 months of age, restored striatal dopamine release, prevented dopaminergic cell death and gait impairment. These effects were associated with a reduction of the inner density of large α-synuclein aggregates and an increase in dispersed small α-synuclein species as revealed by dSTORM. The MI2 mouse model recapitulates the progressive dopaminergic deficit observed in PD, showing that early synaptic dysfunction is associated to fine behavioral motor alterations, precedes dopaminergic axonal loss and neuronal death that become associated with a more consistent motor deficit upon reaching a certain threshold. Our data also provide new mechanistic insight for the effect of anle138b’s function in vivo supporting that targeting α-synuclein aggregation is a promising therapeutic approach for PD.
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Respondek G, Grimm MJ, Piot I, Arzberger T, Compta Y, Englund E, Ferguson LW, Gelpi E, Roeber S, Giese A, Grossman M, Irwin DJ, Meissner WG, Nilsson C, Pantelyat A, Rajput A, van Swieten JC, Troakes C, Höglinger GU. Validation of the movement disorder society criteria for the diagnosis of 4-repeat tauopathies. Mov Disord 2019; 35:171-176. [PMID: 31571273 DOI: 10.1002/mds.27872] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 08/17/2019] [Accepted: 09/03/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The Movement Disorder Society criteria for progressive supranuclear palsy introduced the category "probable 4-repeat (4R)-tauopathy" for joint clinical diagnosis of progressive supranuclear palsy and corticobasal degeneration. OBJECTIVES To validate the accuracy of these clinical criteria for "probable 4R-tauopathy" to predict underlying 4R-tauopathy pathology. METHODS Diagnostic accuracy for 4R-tauopathies according to the established criteria was estimated retrospectively in autopsy-confirmed patients with progressive supranuclear palsy and corticobasal degeneration (grouped as 4R-tauopathies), and Parkinson's disease, multiple system atrophy, and frontotemporal lobar degeneration (grouped as non-4R-tauopathies). RESULTS We identified 250 cases with progressive supranuclear palsy (N = 195) and corticobasal degeneration (N = 55) and with and non-4R-tauopathies (N = 161). Sensitivity and specificity of "probable 4R-tauopathy" was 10% and 99% in the first year and 59% and 88% at final record. CONCLUSIONS The new diagnostic category "probable 4R-tauopathy" showed high specificity and may be suitable for the recruitment of patients with progressive supranuclear palsy and corticobasal degeneration into therapeutic trials targeting 4R-tauopathy. The low sensitivity underpins the need for diagnostic biomarkers. © 2019 International Parkinson and Movement Disorder Society.
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Camilleri A, Ghio S, Caruana M, Weckbecker D, Schmidt F, Kamp F, Leonov A, Ryazanov S, Griesinger C, Giese A, Cauchi RJ, Vassallo N. Tau-induced mitochondrial membrane perturbation is dependent upon cardiolipin. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183064. [PMID: 31521630 DOI: 10.1016/j.bbamem.2019.183064] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 08/26/2019] [Accepted: 09/10/2019] [Indexed: 01/14/2023]
Abstract
Misfolding and aggregate formation by the tau protein has been closely related with neurotoxicity in a large group of human neurodegenerative disorders, which includes Alzheimer's disease. Here, we investigate the membrane-active properties of tau oligomers on mitochondrial membranes, using minimalist in vitro model systems. Thus, exposure of isolated mitochondria to oligomeric tau evoked a disruption of mitochondrial membrane integrity, as evidenced by a combination of organelle swelling, efflux of cytochrome c and loss of the mitochondrial membrane potential. Tau-induced mitochondrial dysfunction occurred independently of the mitochondrial permeability transition (mPT) pore complex. Notably, mitochondria were rescued by pre-incubation with 10-N-nonyl acridine orange (NAO), a molecule that specifically binds cardiolipin (CL), the signature phospholipid of mitochondrial membranes. Additionally, NAO prevented direct binding of tau oligomers to isolated mitochondria. At the same time, tau proteins exhibited high affinity to CL-enriched membranes, whilst permeabilisation of lipid vesicles also strongly correlated with CL content. Intriguingly, using single-channel electrophysiology, we could demonstrate the formation of non-selective ion-conducting tau nanopores exhibiting multilevel conductances in mito-mimetic bilayers. Taken together, the data presented here advances a scenario in which toxic cytosolic entities of tau protein would target mitochondrial organelles by associating with their CL-rich membrane domains, leading to membrane poration and compromised mitochondrial structural integrity.
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Siller S, Lauseker M, Giese A, Tonn J, Niyazi K, Thon N, Suchorska B, Kreth F. P14.02 Influence of individual CpG methylation status on outcome in adult patients with glioblastoma multiforme receiving alkylating agent treatment. Neuro Oncol 2019. [DOI: 10.1093/neuonc/noz126.238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background: Methylation of the O-6-methylguanine-DNA methyltransferase (MGMT) promotor causes gene silencing and has been associated with a favourable prognosis in patients with glioblastoma multiforme (GBM) receiving alkylating chemotherapy. However, analysis of MGMT promotor methylation is usually reported as a cut-off depending on the results of the correspondent CpG site testing. This approach disregards a possible heterogeneity concerning the methylation status within the individual CpG sites and its possible association with prognosis in GBM patients. The current study aimed at elucidating the association between methylation of CpG sites 74–98 within the MGMT promotor region and outcome in GBM patients receiving alkylating agents.
Material and Methods: Individual methylation status of 230 patients with histologically proven GBM following concomitant radio-chemotherapy with TMZ after stereotactic biopsy or open tumor resection (OTR) was assessed by the Sanger sequencing (Sseq) approach. Methylation of CpG sites 74–98 within the MGMT promotor region was defined according to a ratio of cytosine /thymine peak >50%. The total number of methylated CpG sites as well as clinical factors such as age, Karnofsky Performance Score (KPS) and mode of surgical procedure were correlated with outcome using proportional hazards models. In a subset of 34 patients, a correlation between individual CpG methylation and MGMT mRNA expression was performed.
Results: Median progression-free (PFS) and overall survival (OS) were 7.8 and 14.6 months, respectively. Alongside younger age, KPS> 80 and OTR, the cumulative total number of methylated loci within the CpG sites 74–98 was strongly associated with both PFS and OS and retained its prognostic influence on outcome in multivariate models (p <0.001). Furthermore, a linear coherence between the total number of methylated CpG sites 74–98 and survival parameters could be observed. Moreover, low number of methylated CpG sites was observed in tumor specimen with a high mRNA expression and vice versa (Spearman correlation coefficient: -0.62).
Conclusion: In contrast to the concept of dichotomizing the MGMT promotor status into ‘methylated’ and ‘non-methylated’, our approach shows a clear heterogeneity within the methylation status of the CpG sites 74–98 within the GBM tumor specimens. Our data suggest a strong correlation between outcome and the total number of methylated CpG sites, thus an up-front analysis of the individual GpC site methylation status prior to initiation of alkylating chemotherapy might help to improve treatment response in GBM patients.
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Ghio S, Camilleri A, Caruana M, Ruf VC, Schmidt F, Leonov A, Ryazanov S, Griesinger C, Cauchi RJ, Kamp F, Giese A, Vassallo N. Cardiolipin Promotes Pore-Forming Activity of Alpha-Synuclein Oligomers in Mitochondrial Membranes. ACS Chem Neurosci 2019; 10:3815-3829. [PMID: 31356747 DOI: 10.1021/acschemneuro.9b00320] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Aggregation of the amyloid-forming α-synuclein (αS) protein is closely associated with the etiology of Parkinson's disease (PD), the most common motor neurodegenerative disorder. Many studies have shown that soluble aggregation intermediates of αS, termed oligomers, permeabilize a variety of phospholipid membranes; thus, membrane disruption may represent a key pathogenic mechanism of αS toxicity. Given the centrality of mitochondrial dysfunction in PD, we therefore probed the formation of ion-permeable pores by αS oligomers in planar lipid bilayers reflecting the complex phospholipid composition of mitochondrial membranes. Using single-channel electrophysiology, we recorded distinct multilevel conductances (100-400 pS) with stepwise current transitions, typical of protein-bound nanopores, in mitochondrial-like membranes. Crucially, we observed that the presence of cardiolipin (CL), the signature phospholipid of mitochondrial membranes, enhanced αS-lipid interaction and the membrane pore-forming activity of αS oligomers. Further, preincubation of isolated mitochondria with a CL-specific dye protected against αS oligomer-induced mitochondrial swelling and release of cytochrome c. Hence, we favor a scenario in which αS oligomers directly porate a local lipid environment rich in CL, for instance outer mitochondrial contact sites or the inner mitochondrial membrane, to induce mitochondrial dysfunction. Pharmacological modulation of αS pore complex formation might thus preserve mitochondrial membrane integrity and alleviate mitochondrial dysfunction in PD.
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Brendel M, Deussing M, Blume T, Kaiser L, Probst F, Overhoff F, Peters F, von Ungern-Sternberg B, Ryazanov S, Leonov A, Griesinger C, Zwergal A, Levin J, Bartenstein P, Yakushev I, Cumming P, Boening G, Ziegler S, Herms J, Giese A, Rominger A. Late-stage Anle138b treatment ameliorates tau pathology and metabolic decline in a mouse model of human Alzheimer's disease tau. Alzheimers Res Ther 2019; 11:67. [PMID: 31370885 PMCID: PMC6670231 DOI: 10.1186/s13195-019-0522-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 07/22/2019] [Indexed: 01/22/2023]
Abstract
BACKGROUND Augmenting the brain clearance of toxic oligomers with small molecule modulators constitutes a promising therapeutic concept against tau deposition. However, there has been no test of this concept in animal models of Alzheimer's disease (AD) with initiation at a late disease stage. Thus, we aimed to investigate the effects of interventional late-stage Anle138b treatment, which previously indicated great potential to inhibit oligomer accumulation by binding of pathological aggregates, on the metabolic decline in transgenic mice with established tauopathy in a longitudinal 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) study. METHODS Twelve transgenic mice expressing all six human tau isoforms (hTau) and ten controls were imaged by FDG-PET at baseline (14.5 months), followed by randomization into Anle138b treatment and vehicle groups for 3 months. FDG-PET was repeated after treatment for 3 months, and brains were analyzed by tau immunohistochemistry. Longitudinal changes of glucose metabolism were compared between study groups, and the end point tau load was correlated with individual FDG-PET findings. RESULTS Tau pathology was significantly ameliorated by late-stage Anle138b treatment when compared to vehicle (frontal cortex - 53%, p < 0.001; hippocampus - 59%, p < 0.005). FDG-PET revealed a reversal of metabolic decline during Anle138b treatment, whereas the vehicle group showed ongoing deterioration. End point glucose metabolism in the brain of hTau mice had a strong correlation with tau deposition measured by immunohistochemistry (R = 0.92, p < 0.001). CONCLUSION Late-stage oligomer modulation effectively ameliorated tau pathology in hTau mice and rescued metabolic function. Molecular imaging by FDG-PET can serve for monitoring effects of Anle138b treatment.
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Levin J, Maaß S, Schuberth M, Giese A, Oertel WH, Poewe W, Trenkwalder C, Wenning GK, Mansmann U, Südmeyer M, Eggert K, Mollenhauer B, Lipp A, Löhle M, Classen J, Münchau A, Kassubek J, Gandor F, Berg D, Egert-Schwender S, Eberhardt C, Paul F, Bötzel K, Ertl-Wagner B, Huppertz HJ, Ricard I, Höglinger GU. Safety and efficacy of epigallocatechin gallate in multiple system atrophy (PROMESA): a randomised, double-blind, placebo-controlled trial. Lancet Neurol 2019; 18:724-735. [PMID: 31278067 DOI: 10.1016/s1474-4422(19)30141-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 03/24/2019] [Accepted: 03/27/2019] [Indexed: 12/23/2022]
Abstract
BACKGROUND Multiple system atrophy is a rare neurodegenerative disease characterised by aggregation of α-synuclein in oligodendrocytes and neurons. The polyphenol epigallocatechin gallate inhibits α-synuclein aggregation and reduces associated toxicity. We aimed to establish if epigallocatechin gallate could safely slow disease progression in patients with multiple system atrophy. METHODS We did a randomised, double-blind, parallel group, placebo-controlled clinical trial at 12 specialist centres in Germany. Eligible participants were older than 30 years; met consensus criteria for possible or probable multiple system atrophy and could ambulate independently (ie, were at Hoehn and Yahr stages 1-3); and were on stable anti-Parkinson's, anti-dysautonomia, anti-dementia, and anti-depressant regimens (if necessary) for at least 1 month. Participants were randomly assigned (1:1) to epigallocatechin gallate or placebo (mannitol) via a web-generated permuted blockwise randomisation list (block size=2) that was stratified by disease subtype (parkinsonism-predominant disease vs cerebellar-ataxia-predominant disease). All participants and study personnel were masked to treatment assignment. Participants were given one hard gelatin capsule (containing either 400 mg epigallocatechin gallate or mannitol) orally once daily for 4 weeks, then one capsule twice daily for 4 weeks, and then one capsule three times daily for 40 weeks. After 48 weeks, all patients underwent a 4-week wash-out period. The primary endpoint was change in motor examination score of the Unified Multiple System Atrophy Rating Scale (UMSARS) from baseline to 52 weeks. Efficacy analyses were done in all people who received at least one dose of study medication. Safety was analysed in all people who received at least one dose of the study medication to which they had been randomly assigned. This trial is registered with ClinicalTrials.gov (NCT02008721) and EudraCT (2012-000928-18), and is completed. FINDINGS Between April 23, 2014, and Sept 3, 2015, 127 participants were screened and 92 were randomly assigned-47 to epigallocatechin gallate and 45 to placebo. Of these, 67 completed treatment and 64 completed the study (altough one of these patients had a major protocol violation). There was no evidence of a difference in the mean change from baseline to week 52 in motor examination scores on UMSARS between the epigallocatechin gallate (5·66 [SE 1·01]) and placebo (6·60 [0·99]) groups (mean difference -0·94 [SE 1·41; 95% CI -3·71 to 1·83]; p=0·51). Four patients in the epigallocatechin gallate group and two in the placebo group died. Two patients in the epigallocatechin gallate group had to stop treatment because of hepatotoxicity. INTERPRETATION 48 weeks of epigallocatechin gallate treatment did not modify disease progression in patients with multiple system atrophy. Epigallocatechin gallate was overall well tolerated but was associated with hepatotoxic effects in some patients, and thus doses of more than 1200 mg should not be used. FUNDING ParkinsonFonds Deutschland, German Parkinson Society, German Neurology Foundation, Lüneburg Foundation, Bischof Dr Karl Golser Foundation, and Dr Arthur Arnstein Foundation.
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Bartels M, Weckbecker D, Kuhn PH, Ryazanov S, Leonov A, Griesinger C, Lichtenthaler SF, Bötzel K, Giese A. Iron-mediated aggregation and toxicity in a novel neuronal cell culture model with inducible alpha-synuclein expression. Sci Rep 2019; 9:9100. [PMID: 31235814 PMCID: PMC6591385 DOI: 10.1038/s41598-019-45298-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 03/11/2019] [Indexed: 01/25/2023] Open
Abstract
Parkinson's disease (PD) represents an increasing problem in society. The oligomerization of alpha-synuclein (αSyn) is a suggested key event in its pathogenesis, yet the pathological modes of action remain to be fully elucidated. To identify potential disease-modifying therapeutics and to study αSyn-mediated toxic mechanisms, we established cell lines with inducible overexpression of different αSyn constructs: αSyn, αSyn coupled to the fluorescence protein Venus (αSyn-Venus), and αSyn coupled to the N-terminal or C-terminal part of Venus (V1S and SV2, respectively) for a bimolecular fluorescence complementation assay (BiFC). Inducibility was achieved by applying modified GAL4-UAS or Cre-loxP systems and addition of tebufenozide or 4-OH-tamoxifen, respectively. Expression constructs were stably integrated into the host genome of H4 neuroglioma cells by lentiviral transduction. We here demonstrate a detailed investigation of the expression characteristics of inducible H4 cells showing low background expression and high inducibility. We observed increased protein load and aggregation of αSyn upon incubation with DMSO and FeCl3 along with an increase in cytotoxicity. In summary, we present a system for the creation of inducibly αSyn-overexpressing cell lines holding high potential for the screening for modulators of αSyn aggregation and αSyn-mediated toxicity.
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Baiardi S, Redaelli V, Ripellino P, Rossi M, Franceschini A, Moggio M, Sola P, Ladogana A, Fociani P, Magherini A, Capellari S, Giese A, Caughey B, Caroppo P, Parchi P. Prion-related peripheral neuropathy in sporadic Creutzfeldt-Jakob disease. J Neurol Neurosurg Psychiatry 2019; 90:424-427. [PMID: 30355606 DOI: 10.1136/jnnp-2018-319221] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/04/2018] [Accepted: 09/28/2018] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To assess whether the involvement of the peripheral nervous system (PNS) belongs to the phenotypic spectrum of sporadic Creutzfeldt-Jakob disease (sCJD). METHODS We examined medical records of 117 sCJDVV2 (ataxic type), 65 sCJDMV2K (kuru-plaque type) and 121 sCJDMM(V)1 (myoclonic type) subjects for clinical symptoms, objective signs and neurophysiological data. We reviewed two diagnostic nerve biopsies and looked for abnormal prion protein (PrPSc) by western blotting and real-time quaking-induced conversion (RT-QuIC) in postmortem PNS samples from 14 subjects. RESULTS Seventy-five (41.2%) VV2-MV2K patients, but only 11 (9.1%) MM(V)1, had symptoms or signs suggestive of PNS involvement occurring at onset in 18 cases (17 VV2-MV2K, 9.3%; and 1 MM(V)1, 0.8%) and isolated in 6. Nerve biopsy showed a mixed predominantly axonal and demyelinating neuropathy in two sCJDMV2K. Electromyography showed signs of neuropathy in half of the examined VV2-MV2K patients. Prion RT-QuIC was positive in all CJD PNS samples, whereas western blotting detected PrPSc in the sciatic nerve in one VV2 and one MV2K. CONCLUSIONS Peripheral neuropathy, likely related to PrPSc deposition, belongs to the phenotypic spectrum of sCJDMV2K and VV2 and may mark the clinical onset. The significantly lower prevalence of PNS involvement in typical sCJDMM(V)1 suggests that the PNS tropism of sCJD prions is strain dependent.
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Ruf VC, Nübling GS, Willikens S, Shi S, Schmidt F, Levin J, Bötzel K, Kamp F, Giese A. Different Effects of α-Synuclein Mutants on Lipid Binding and Aggregation Detected by Single Molecule Fluorescence Spectroscopy and ThT Fluorescence-Based Measurements. ACS Chem Neurosci 2019; 10:1649-1659. [PMID: 30605594 DOI: 10.1021/acschemneuro.8b00579] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Six α-synuclein (aSyn) point mutations are currently known to be associated with familial parkinsonism: A30P, E46K, H50Q, G51D, A53E, and A53T. We performed a comprehensive in vitro analysis to study the impact of all aSyn mutations on lipid binding and aggregation behavior. Markedly reduced lipid binding of A30P, moderately attenuated binding of G51D, and only very slightly reduced binding for the other mutants were observed. A30P was particularly prone to form metal ion induced oligomers, whereas A53T exhibited only weak tendencies to form oligomers. In turn, fibril formation occurred rapidly in H50Q, G51D, and A53T, but only slowly in A30P, suggesting mutants prone to form oligomers tend to form fibrils to a lesser extent. This was supported by the observation that fibril formation of wild type aSyn, A30P, and A53T was impaired in the presence of ferric iron. Additionally, we found the aggregation kinetics of mixtures of A30P or A53T and wt aSyn to be determined by the faster aggregating aSyn variant. Our results implicate differential mechanisms playing a role in aSyn pathology on the molecular level. This might contribute to a better understanding of Parkinson's disease pathogenesis and provide potential links to develop prevention strategies and disease-modifying therapy.
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Grimm MJ, Respondek G, Stamelou M, Arzberger T, Ferguson L, Gelpi E, Giese A, Grossman M, Irwin DJ, Pantelyat A, Rajput A, Roeber S, van Swieten JC, Troakes C, Antonini A, Bhatia KP, Colosimo C, van Eimeren T, Kassubek J, Levin J, Meissner WG, Nilsson C, Oertel WH, Piot I, Poewe W, Wenning GK, Boxer A, Golbe LI, Josephs KA, Litvan I, Morris HR, Whitwell JL, Compta Y, Corvol JC, Lang AE, Rowe JB, Höglinger GU. How to apply the movement disorder society criteria for diagnosis of progressive supranuclear palsy. Mov Disord 2019; 34:1228-1232. [PMID: 30884545 PMCID: PMC6699888 DOI: 10.1002/mds.27666] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/10/2019] [Accepted: 02/18/2019] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND The Movement Disorder Society criteria for progressive supranuclear palsy define diagnostic allocations, stratified by certainty levels and clinical predominance types. We aimed to study the frequency of ambiguous multiple allocations and to develop rules to eliminate them. METHODS We retrospectively collected standardized clinical data by chart review in a multicenter cohort of autopsy-confirmed patients with progressive supranuclear palsy, to classify them by diagnostic certainty level and predominance type and to identify multiple allocations. RESULTS Comprehensive data were available from 195 patients. More than one diagnostic allocation occurred in 157 patients (80.5%). On average, 5.4 allocations were possible per patient. We developed four rules for Multiple Allocations eXtinction (MAX). They reduced the number of patients with multiple allocations to 22 (11.3%), and the allocations per patient to 1.1. CONCLUSIONS The proposed MAX rules help to standardize the application of the Movement Disorder Society criteria for progressive supranuclear palsy. © 2019 International Parkinson and Movement Disorder Society.
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Suchorska B, Giese A, Biczok A, Unterrainer M, Weller M, Drexler M, Bartenstein P, Schüller U, Tonn JC, Albert NL. Identification of time-to-peak on dynamic 18F-FET-PET as a prognostic marker specifically in IDH1/2 mutant diffuse astrocytoma. Neuro Oncol 2019; 20:279-288. [PMID: 29016996 DOI: 10.1093/neuonc/nox153] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Background Stratification of glioma according to isocitrate dehydrogenase 1/2 (IDH1/2) mutation and 1p/19q codeletion status has gained major importance in the new World Health Organization (WHO) classification. Parameters derived from uptake dynamics of 18F-fluoro-ethyl-tyrosine PET (18F-FET-PET) such as minimal time-to-peak (TTPmin) allow discrimination between different prognostic glioma subgroups, too. The present study is aimed at exploring whether TTPmin analysis provides prognostic information beyond the WHO classification. Methods Three hundred patients with newly diagnosed WHO 2007 grades II-IV gliomas with 18F-FET-PET imaging at diagnosis were grouped into 4 subgroups (IDH1/2 mut-1p/19q codel; IDH1/2 mut-1p/19q non-codel; IDH1/2 wildtype WHO grade II and III tumors; and glioblastoma). Clinical and imaging factors such as age, Karnofsky performance score, treatment, TTPmin, and maximal tumor-to-brain ratio (TBRmax) were analyzed with regard to progression-free and overall survival (PFS and OS) via univariate and multivariate regression analysis. Results PFS and OS were longest in the IDH1/2 mut-1p/19q codel subgroup, followed by IDH1/2 mut-1p/19q non-codel, IDH1/2 wildtype, and GBM (P < 0.001). Further, outcome stratified by TTPmin with a cutoff of 17.5 minutes revealed significantly longer PFS and OS in patients with TTPmin >17.5 minutes (P < 0.001 for PFS and OS). Lower TBRmax values or the absence of 18F-FET uptake was also associated with favorable outcome in the entire group. In the subgroup analyses, longer median TTPmin was associated with improved outcome specifically in the IDH1/2 mut-1p/19q non-codel group. Conclusion 18F-FET-PET-derived dynamic analysis defines prognostically distinct subgroups of IDH1/2 mutant-1p/19q non-codel gliomas which cannot be distinguished as yet by molecular marker analysis.
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Martinez Hernandez A, Urbanke H, Gillman AL, Lee J, Ryazanov S, Agbemenyah HY, Benito E, Jain G, Kaurani L, Grigorian G, Leonov A, Rezaei-Ghaleh N, Wilken P, Arce FT, Wagner J, Fuhrmann M, Caruana M, Camilleri A, Vassallo N, Zweckstetter M, Benz R, Giese A, Schneider A, Korte M, Lal R, Griesinger C, Eichele G, Fischer A. The diphenylpyrazole compound anle138b blocks Aβ channels and rescues disease phenotypes in a mouse model for amyloid pathology. EMBO Mol Med 2019; 10:32-47. [PMID: 29208638 PMCID: PMC5760857 DOI: 10.15252/emmm.201707825] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Alzheimer's disease is a devastating neurodegenerative disease eventually leading to dementia. An effective treatment does not yet exist. Here we show that oral application of the compound anle138b restores hippocampal synaptic and transcriptional plasticity as well as spatial memory in a mouse model for Alzheimer's disease, when given orally before or after the onset of pathology. At the mechanistic level, we provide evidence that anle138b blocks the activity of conducting Aβ pores without changing the membrane embedded Aβ-oligomer structure. In conclusion, our data suggest that anle138b is a novel and promising compound to treat AD-related pathology that should be investigated further.
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Vettermann FJ, Neumann JE, Suchorska B, Bartenstein P, Giese A, Dorostkar MM, Albert NL, Schüller U. K27M midline gliomas display malignant progression by imaging and histology. Neuropathol Appl Neurobiol 2019; 43:458-462. [PMID: 27997032 DOI: 10.1111/nan.12371] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 11/25/2016] [Indexed: 01/01/2023]
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Heras-Garvin A, Weckbecker D, Ryazanov S, Leonov A, Griesinger C, Giese A, Wenning GK, Stefanova N. Anle138b modulates α-synuclein oligomerization and prevents motor decline and neurodegeneration in a mouse model of multiple system atrophy. Mov Disord 2018; 34:255-263. [PMID: 30452793 PMCID: PMC6492169 DOI: 10.1002/mds.27562] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 10/23/2018] [Accepted: 10/24/2018] [Indexed: 01/21/2023] Open
Abstract
Background MSA is a fatal neurodegenerative disease characterized by autonomic failure and severe motor impairment. Its main pathological hallmark is the accumulation of α‐synuclein in oligodendrocytes, leading to glial and neuronal dysfunction and neurodegeneration. These features are recapitulated in the PLP‐hαSyn mouse model expressing human α‐synuclein in oligodendrocytes. At present, there is no effective disease‐modifying therapy. Previous experiments have shown that the aggregation inhibitor, anle138b, reduces neurodegeneration and behavioral deficits in mouse models of other proteinopathies. Objectives To test the therapeutic potential of anle138b in a mouse model of MSA. Methods Two‐month‐old PLP‐hαSyn mice were fed over a period of 4 months with pellets containing anle138b at two different doses (0.6 and 2 g/kg) and compared to healthy controls and PLP‐hαSyn mice fed with placebo pellets. At the end of the treatment, behavioral and histological analyses were performed. Results We observed a reversal of motor function to healthy control levels when PLP‐hαSyn mice were treated with both doses of anle138b. Histological and molecular analyses showed a significant reduction in α‐synuclein oligomers and glial cytoplasmic inclusions in animals fed with anle138b compared to nontreated mice. These animals also present preservation of dopaminergic neurons and reduction in microglial activation in SN correlating with the α‐synuclein reduction observed. Conclusions Anle138b reduces α‐synuclein accumulation in PLP‐hαSyn mice, leading to neuroprotection, reduction of microglial activation, and preservation of motor function supporting the use of anle138b in a future clinical trial for MSA. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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Schnell O, Albrecht V, Pfirrmann D, Eigenbrod S, Krebs B, Romagna A, Siller S, Giese A, Tonn JC, Schichor C. MGMT promoter methylation is not correlated with integrin expression in malignant gliomas: clarifying recent clinical trial results. Med Oncol 2018; 35:103. [PMID: 29882028 DOI: 10.1007/s12032-018-1162-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 05/31/2018] [Indexed: 11/28/2022]
Abstract
Integrin alpha-v-beta-3 (αvβ3) is important for invasive tumor growth and angiogenesis in glioblastomas (GBM). However, recent clinical trials on inhibition of this integrin led to ambiguous results whether patients with methylated or unmethylated 6O-methylguanine methyltransferase (MGMT) promoter might profit from this kind of therapy. Therefore, we addressed the still unanswered question about a possible correlation between integrin αvβ3 expression and MGMT promoter methylation in GBM. For this purpose, tumor samples from newly diagnosed and untreated GBM patients with methylated (n = 22) or unmethylated (n = 17) MGMT promoter were simultaneously analyzed for integrin αvβ3 expression by an automated immunohistochemical staining platform. Interestingly, subsequent semi-quantitative analysis by a special imaging software did not show any difference in integrin expression between patients with methylated or unmethylated MGMT promoter status. Moreover, further analysis of the integrin subunits via ELISA from histologic sections revealed that there is no difference in integrin subunit expression between these patients. Hence, our results are important for designing future clinical trials with respect to treatment stratification, while it still has to be identified which other molecular factors determine differential responses to targeted anti-integrin αvβ3 treatment.
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Suchorska B, Schüller U, Biczok A, Kreth FW, Lenski M, Albert NL, Giese A, Ertl-Wagner B, Ingrisch M, Tonn J. Contrast enhancement as a prognostic factor in IDH1/2 mutant glioma. J Clin Oncol 2018. [DOI: 10.1200/jco.2018.36.15_suppl.2029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Reiner AM, Schmidt F, Ryazanov S, Leonov A, Weckbecker D, Deeg AA, Griesinger C, Giese A, Zinth W. Photophysics of diphenyl-pyrazole compounds in solutions and α-synuclein aggregates. Biochim Biophys Acta Gen Subj 2018; 1862:800-807. [DOI: 10.1016/j.bbagen.2017.12.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/24/2017] [Accepted: 12/18/2017] [Indexed: 12/25/2022]
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