Glia and alpha-synuclein in neurodegeneration: A complex interaction

Abstractα-Synucleinopathies (ASP) comprise adult-onset, progressive neurodegenerative disorders such as Parkinson's disease (PD), dementia with Lewy bodies (DLB) and multiple system atrophy (MSA) that are characterized by α-synuclein (AS) aggregates in neurons or glia. PD and DLB feature neuronal AS-positive inclusions termed Lewy bodies (LB) whereas glial cytoplasmic inclusions (GCIs, Papp–Lantos bodies) are recognized as the defining hallmark of MSA. Furthermore, AS-positive cytoplasmic aggregates may also be seen in astroglial cells of PD/DLB and MSA brains. The glial AS-inclusions appear to trigger reduced trophic support resulting in neuronal loss. Moreover, microgliosis and astrogliosis can be found throughout the neurodegenerative brain and both are key players in the initiation and progression of ASP. In this review, we will highlight AS-dependent alterations of glial function and their impact on neuronal vulnerability thereby providing a detailed summary on the multifaceted role of glia in ASP

Arginase 1+ IL-10+ polymorphonuclear myeloid-derived suppressor cells are elevated in patients with active pemphigus and correlate with an increased Th2/Th1 response

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells, which are characterized by their capability to suppress T-cell responses. While MDSCs have been traditionally associated with cancer diseases, their role as regulators of autoimmune diseases is emerging. Pemphigus is a chronic autoimmune blistering skin disease characterized by dysregulated T-cell responses and autoantibody production. The role of MDSCs in pemphigus disease has not been defined yet. The aim of this study was to characterize MDSCs in pemphigus patients and to dissect their relationship with CD4(+) T-cell subsets and clinical disease assessments. For this purpose, we performed a cross-sectional analysis of 20 patients with pemphigus. Our results indicate that a population of CD66b(+)CD11b(+) polymorphonuclear-like MDSCs (PMN-MDSCs) is expanded in the peripheral blood mononuclear cell fraction of pemphigus patients compared to age-matched healthy donors. These PMN-MDSCs have the capability of suppressing allogeneic T-cell proliferation in vitro and show increased expression of characteristic effector molecules such as arginase I and interleukin-10. We further demonstrate that PMN-MDSCs are especially expanded in patients with active pemphigus, but not in patients in remission. Moreover, MDSC frequencies correlate with an increased Th2/Th1 cell ratio. In conclusion, the identification of a functional PMN-MDSC population suggests a possible role of these cells as regulators of Th cell responses in pemphigus

DNA methylation-based classification of central nervous system tumours.

Accurate pathological diagnosis is crucial for optimal management of patients with cancer. For the approximately 100 known tumour types of the central nervous system, standardization of the diagnostic process has been shown to be particularly challenging-with substantial inter-observer variability in the histopathological diagnosis of many tumour types. Here we present a comprehensive approach for the DNA methylation-based classification of central nervous system tumours across all entities and age groups, and demonstrate its application in a routine diagnostic setting. We show that the availability of this method may have a substantial impact on diagnostic precision compared to standard methods, resulting in a change of diagnosis in up to 12% of prospective cases. For broader accessibility, we have designed a free online classifier tool, the use of which does not require any additional onsite data processing. Our results provide a blueprint for the generation of machine-learning-based tumour classifiers across other cancer entities, with the potential to fundamentally transform tumour pathology

The impact of Rab5 on the formation of glial cytoplasmic inclusion : implications for multiple system atrophy

Multisystematrophie (MSA) wird als eine fortschreitende neurodegenerative Krankheit definiert, die geprägt ist durch sogenannte oligodendrogliale, zytoplasmatische Einschlüsse (GCIs). Das neuronale Protein -Synuklein (AS) gilt als eines der Hauptbestandteile von GCIs. Bis heute sind die exakten Mechanismen, welche an der Bildung von AS-positiven intrazycoplasmatischen Einschlüssen beteiligt sind nicht endgültig bekannt. Eine Hochregulierung des endozytotischen Proteins Rab5 in MSA Gehirnen wurde nachgewiesen. Diese Erhöhung des Proteins Rab5 könnte zu einer erhöhten endozytotischen Aktivität führen welche wiederum an der Bildung von intrazytoplasmatischen Einschlüssen beteiligt sein könnte. Das Ziel dieser Masterarbeit war es, die Aufnahme verschiedener AS Formen, sowie die Bildung von intrazytoplasmatischen Einschlüssen in Rab5 überexprimierenden Oligodendrozyten zu untersuchen. Die Zellen wurden genetische modifiziert um eine erhöhte Rab5 Expression zu erreichen und folglich mit verschiedenen extrazellulär zugegebenen AS Formen inkubiert. Die Aufnahme und die Ansammlung des rekombinanten löslichen und fibrillären AS (sAS, fAS) wurde mittels Immunzytochemie sowie der Western Blot-Methode (WB) ausgewertet. Beide Methoden bestätigten in Rab5 transfizierten Oligodendrozyten eine erhöhte Menge an Rab5 Protein im Vergleich zu nicht transfizierten Zellen. In Oligodendrozyten welche für 24 Stunden mit AS inkubierten worden waren, konnte aufgenommenes AS im Zytoplasma nachgewiesen werden. Die Größe der AS Einschlüsse zeigte keine signifikanten Unterschiede zwischen Rab5 überexprimierenden Zellen und Kontrollzellen welche kein Rab5 überexprimierten. Die Rab5 Überexpression war gekoppelt mit signifikant erhöhten LC3B Werten, wohingegen Oligodenrozyten, welche mit extrazellulären sAS oder fAS inkubiert worden waren eine Herabregulierung des Autophagie Markers LC3B in transfizierten und nicht transfizierten Zellen aufwiesen. Die Daten lassen vermuten, dass eine Rab5 Überexpression in Oligodendrozyten nicht zu einer erhöhten AS Aufnahme führt. Des Weiteren wurde gezeigt, dass eine Hochregulierung von Rab5 zu erhöhten Autophagie Werten führte, welche allerdings durch die Zugabe bzw. Aufnahme von extrazellulärem AS gesenkt wurden.Multiple system atrophy (MSA) is a progressive neurodegenerative disease characterized by oligodendroglial cytoplasmic inclusions (GCIs). The mainly neuronal protein -synuclein (AS) has been distinguished as the main component of GCIs. Yet, exact mechanisms involved in the formation of the AS-positive intracytoplasmic inclusions have not been described to this date. An upregulation of the endocytotic protein Rab5 has been described in MSA brains leading to the assumption that enhanced endocytosis might be involved in the formation of these inclusions. The objective of this Master thesis was to investigate the internalization and inclusion formation of different AS forms in oligodendroglial cells overexpressing Rab5. Oligodendroglial cells were genetically modified to overexpress Rab5 and then exposed to different forms of extracellular AS. The uptake and accumulation of recombinant soluble and fibrillized AS (sAS, fAS) was examined using immunocytochemistry and western blot (WB) analyses. WB analysis and immunofluorescence confirmed increased Rab5 levels in Rab5 transfected oligodendroglia compared to non-transfected oligodendrocytes. Exposure of oligodendroglial cells to AS for 24 hours resulted in AS internalization in the cytoplasm. The size of AS inclusions showed no significant difference in cells overexpressing Rab5 compared to non-transfected controls. Rab5 overexpression was linked to significantly increased LC3B levels, whereas oligodendrocytes incubated with extracellular sAS and fAS, induced autophagy downregulation in Rab5 transfected and non-transfected cells. These data suggest that Rab5 overexpression in oligodendroglial cells does not trigger an enhanced internalization of AS. Rab5 upregulation leads to increased autophagy levels, which however get reduced by adding extracellular AS.by Dominik BrückZusammenfassung in englischer und deutscher SpracheUniversität Innsbruck, Masterarbeit, 2015(VLID)85320

Reduced impact of nonverbal cues during integration of verbal and nonverbal emotional information in adults with high-functioning autism

BACKGROUND: When receiving mismatching nonverbal and verbal signals, most people tend to base their judgment regarding the current emotional state of others primarily on nonverbal information. However, individuals with high-functioning autism (HFA) have been described as having difficulties interpreting nonverbal signals. Recognizing emotional states correctly is highly important for successful social interaction. Alterations in perception of nonverbal emotional cues presumably contribute to misunderstanding and impairments in social interactions. METHODS: To evaluate autism-specific differences in the relative impact of nonverbal and verbal cues, 18 adults with HFA (14 male and four female subjects, mean age 36.7 years (SD 11.4) and 18 age, gender and IQ-matched typically developed controls [14 m/4 f, mean age 36.4 years (SD 12.2)] rated the emotional state of speakers in video sequences with partly mismatching emotional signals. Standardized linear regression coefficients were calculated as a measure of the reliance on the nonverbal and verbal components of the videos for each participant. Regression coefficients were then compared between groups to test the hypothesis that autistic adults base their social evaluations less strongly on nonverbal information. Further exploratory analyses were performed for differences in valence ratings and response times. RESULTS: Compared to the typically developed control group, nonverbal cue reliance was reduced in adults with high-functioning autism [t(23.14) = −2.44, p = 0.01 (one-sided)]. Furthermore, the exploratory analyses showed a tendency to avoid extreme answers in the HFA group, observable via less positive as well as less negative valence ratings in response to emotional expressions of increasingly strong valence. In addition, response time was generally longer in HFA compared to the control group [F (1, 33) = 10.65, p = 0.004]. CONCLUSION: These findings suggest reduced impact of nonverbal cues and longer processing times in the analysis of multimodal emotional information, which may be associated with a subjectively lower relevance of this information and/or more processing difficulties for people with HFA. The less extreme answering tendency may indicate a lower sensitivity for nonverbal valence expression in HFA or result from a tendency to avoid incorrect answers when confronted with greater uncertainty in interpreting emotional states

Primary intracranial spindle cell sarcoma with rhabdomyosarcoma-like features share a highly distinct methylation profile and DICER1 mutations

Patients with DICER1 predisposition syndrome have an increased risk to develop pleuropulmonary blastoma, cystic nephroma, embryonal rhabdomyosarcoma, and several other rare tumor entities. In this study, we identified 22 primary intracranial sarcomas, including 18 in pediatric patients, with a distinct methylation signature detected by array-based DNA-methylation profiling. In addition, two uterine rhabdomyosarcomas sharing identical features were identified. Gene panel sequencing of the 22 intracranial sarcomas revealed the almost unifying feature of DICER1 hotspot mutations (21/22; 95%) and a high frequency of co-occurring TP53 mutations (12/22; 55%). In addition, 17/22 (77%) sarcomas exhibited alterations in the mitogen-activated protein kinase pathway, most frequently affecting the mutational hotspots of KRAS (8/22; 36%) and mutations or deletions of NF1 (7/22; 32%), followed by mutations of FGFR4 (2/22; 9%), NRAS (2/22; 9%), and amplification of EGFR (1/22; 5%). A germline DICER1 mutation was detected in two of five cases with constitutional DNA available. Notably, none of the patients showed evidence of a cancer-related syndrome at the time of diagnosis. In contrast to the genetic findings, the morphological features of these tumors were less distinctive, although rhabdomyoblasts or rhabdomyoblast-like cells could retrospectively be detected in all cases. The identified combination of genetic events indicates a relationship between the intracranial tumors analyzed and DICER1 predisposition syndrome-associated sarcomas such as embryonal rhabdomyosarcoma or the recently described group of anaplastic sarcomas of the kidney. However, the intracranial tumors in our series were initially interpreted to represent various tumor types, but rhabdomyosarcoma was not among the typical differential diagnoses considered. Given the rarity of intracranial sarcomas, this molecularly clearly defined group comprises a considerable fraction thereof. We therefore propose the designation "spindle cell sarcoma with rhabdomyosarcoma-like features, DICER1 mutant" for this intriguing group.S

Actively personalized vaccination trial for newly diagnosed glioblastoma

Patients with glioblastoma currently do not sufficiently benefit from recent breakthroughs in cancer treatment that use checkpoint inhibitors1,2. For treatments using checkpoint inhibitors to be successful, a high mutational load and responses to neoepitopes are thought to be essential3. There is limited intratumoural infiltration of immune cells4 in glioblastoma and these tumours contain only 30–50 non-synonymous mutations5. Exploitation of the full repertoire of tumour antigens—that is, both unmutated antigens and neoepitopes—may offer more effective immunotherapies, especially for tumours with a low mutational load. Here, in the phase I trial GAPVAC-101 of the Glioma Actively Personalized Vaccine Consortium (GAPVAC), we integrated highly individualized vaccinations with both types of tumour antigens into standard care to optimally exploit the limited target space for patients with newly diagnosed glioblastoma. Fifteen patients with glioblastomas positive for human leukocyte antigen (HLA)-A*02:01 or HLA-A*24:02 were treated with a vaccine (APVAC1) derived from a premanufactured library of unmutated antigens followed by treatment with APVAC2, which preferentially targeted neoepitopes. Personalization was based on mutations and analyses of the transcriptomes and immunopeptidomes of the individual tumours. The GAPVAC approach was feasible and vaccines that had poly-ICLC (polyriboinosinic-polyribocytidylic acid-poly-l-lysine carboxymethylcellulose) and granulocyte–macrophage colony-stimulating factor as adjuvants displayed favourable safety and strong immunogenicity. Unmutated APVAC1 antigens elicited sustained responses of central memory CD8+ T cells. APVAC2 induced predominantly CD4+ T cell responses of T helper 1 type against predicted neoepitopes.</p

DNA methylation-based classification of central nervous system tumours

Accurate pathological diagnosis is crucial for optimal management of patients with cancer. For the approximately 100 known tumour types of the central nervous system, standardization of the diagnostic process has been shown to be particularly challenging - with substantial inter-observer variability in the histopathological diagnosis of many tumour types. Here we present a comprehensive approach for the DNA methylation-based classification of central nervous system tumours across all entities and age groups, and demonstrate its application in a routine diagnostic setting. We show that the availability of this method may have a substantial impact on diagnostic precision compared to standard methods, resulting in a change of diagnosis in up to 12% of prospective cases. For broader accessibility, we have designed a free online classifier tool, the use of which does not require any additional onsite data processing. Our results provide a blueprint for the generation of machine-learning-based tumour classifiers across other cancer entities, with the potential to fundamentally transform tumour pathology

DNA methylation-based classification of central nervous system tumours

Accurate pathological diagnosis is crucial for optimal management of patients with cancer. For the approximately 100 known tumour types of the central nervous system, standardization of the diagnostic process has been shown to be particularly challengingwith substantial inter-observer variability in the histopathological diagnosis of many tumour types. Here we present a comprehensive approach for the DNA methylation-based classification of central nervous system tumours across all entities and age groups, and demonstrate its application in a routine diagnostic setting. We show that the availability of this method may have a substantial impact on diagnostic precision compared to standard methods, resulting in a change of diagnosis in up to 12% of prospective cases. For broader accessibility, we have designed a free online classifier tool, the use of which does not require any additional onsite data processing. Our results provide a blueprint for the generation of machine-learning-based tumour classifiers across other cancer entities, with the potential to fundamentally transform tumour pathology