Search

Abstract Synucleinopathies such as Parkinson’s disease (PD) are defined by the accumulation and aggregation of the α-synuclein protein in neurons, glia and other tissues. We have previously shown that destabilization of α-synuclein tetramers is associated with familial PD due to SNCA mutations and demonstrated brain-region specific alterations of α-synuclein multimers in sporadic PD patients following the classical Braak spreading theory. In this study, we assessed relative levels of disordered and higher-ordered multimeric forms of cytosolic α-synuclein in blood from familial PD with G51D mutations and sporadic PD patients. We used an adapted in vitro-cross-linking protocol for human EDTA-whole blood. The relative levels of higher-ordered α-synuclein tetramers were diminished in blood from familial PD and sporadic PD patients compared to controls. Interestingly, the relative amount of α-synuclein tetramers was already decreased in asymptomatic G51D carriers, supporting the hypothesis that α-synuclein multimer destabilization precedes the development of clinical PD. Our data, therefore suggest that measuring α-synuclein tetramers in blood may have potential as a facile biomarker assay for early detection and quantitative tracking of PD progression.

Abstract Headache is one of the most common neurological manifestations of COVID-19, but it is unclear whether chronic headache as a symptom of Post-COVID-19 is associated with ongoing CNS damage. We compared cerebrospinal fluid (CSF) levels of markers of CNS damage and inflammation in Post-COVID-19 patients with persistent headache to hospitalized acute COVID-19 patients with neurological symptoms and to non-COVID-19 disease-controls. CSF levels of neurofilament light chain, Ubiquitin carboxyl-terminal hydrolase L1 and Tau were similar in patients with persistent headache in post-COVID-19 compared to acute COVID-19 patients and all control groups. Levels of glial fibrillary astrocytic protein were lower in patients with persistent headache in post-COVID-19 compared to some control groups of patients with neurological disease. Therefore, our pilot study of CSF markers indicates that persistent post-COVID-19 headache is not a sign of underlying neuronal damage or glial activation.

Abstract The spinocerebellar ataxias (SCA) comprise a group of inherited neurodegenerative diseases. SCA3 is the most common form, caused by the expansion of CAG repeats within the ataxin 3 (ATXN3) gene. The mutation results in the expression of an abnormal protein, containing long polyglutamine (polyQ) stretches. The polyQ stretch confers a toxic gain of function and leads to misfolding and aggregation of ATXN3 in neurons. Thus, modulators of ATXN3 expression could potentially ameliorate the pathology in SCA3 patients. Therefore, we generated a CRISPR/Cas9 modified ATXN3-Exon4-Luciferase (ATXN3-LUC) genomic fusion- and control cell lines to perform a reporter cell line-based high-throughput screen comprising 2640 bioactive compounds, including the FDA approved drugs. We found no unequivocal inhibitors of, but identified statins as activators of the LUC signal in the ATXN3-LUC screening cell line. We further confirmed that Simvastatin treatment of wild type SK-N-SH cells increases ATXN3 mRNA and protein levels which likely results from direct binding of the activated sterol regulatory element binding protein 1 (SREBP1) to the ATXN3 promotor. Finally, we observed an increase of normal and expanded ATXN3 protein levels in a patient-derived cell line upon Simvastatin treatment, underscoring the potential medical relevance of our findings.

The aim of this study was to employ artificial intelligence (AI)-based magnetic resonance imaging (MRI) brain volumetry to potentially distinguish between idiopathic normal pressure hydrocephalus (iNPH), Alzheimer’s disease (AD), and age- and sex-matched healthy controls (CG) by evaluating cortical, subcortical, and ventricular volumes. Additionally, correlations between the measured brain and ventricle volumes and two established semi-quantitative radiologic markers for iNPH were examined. An IRB-approved retrospective analysis was conducted on 123 age- and sex-matched subjects (41 iNPH, 41 AD, and 41 controls), with all of the iNPH patients undergoing routine clinical brain MRI prior to ventriculoperitoneal shunt implantation. Automated AI-based determination of different cortical and subcortical brain and ventricular volumes in mL, as well as calculation of population-based normalized percentiles according to an embedded database, was performed; the CE-certified software mdbrain v4.4.1 or above was used with a standardized T1-weighted 3D magnetization-prepared rapid gradient echo (MPRAGE) sequence. Measured brain volumes and percentiles were analyzed for between-group differences and correlated with semi-quantitative measurements of the Evans’ index and corpus callosal angle: iNPH patients exhibited ventricular enlargement and changes in gray and white matter compared to AD patients and controls, with the most significant differences observed in total ventricular volume (+67%) and the lateral (+68%), third (+38%), and fourth (+31%) ventricles compared to controls. Global ventriculomegaly and marked white matter reduction with concomitant preservation of gray matter compared to AD and CG were characteristic of iNPH, whereas global and frontoparietally accentuated gray matter reductions were characteristic of AD. Evans’ index and corpus callosal angle differed significantly between the three groups and moderately correlated with the lateral ventricular volumes in iNPH patients [Evans’ index (r > 0.83, p ≤ 0.001), corpus callosal angle (r < −0.74, p ≤ 0.001)]. AI-based MRI volumetry in iNPH patients revealed global ventricular enlargement and focal brain atrophy, which, in contrast to healthy controls and AD patients, primarily involved the supratentorial white matter and was marked temporomesially and in the midbrain, while largely preserving gray matter. Integrating AI volumetry in conjunction with traditional radiologic measures could enhance iNPH identification and differentiation, potentially improving patient management and therapy response assessment.

Abstract Introduction The phospholipase A2 group VI gene (PLA2G6) encodes an enzyme that catalyzes the hydrolytic release of fatty acids from phospholipids. Four neurological disorders with infantile, juvenile, or early adult‐onset are associated with PLA2G6 genetic alterations, namely infantile neuroaxonal dystrophy (INAD), atypical neuroaxonal dystrophy (ANAD), dystonia‐parkinsonism (DP), and autosomal recessive early‐onset parkinsonism (AREP). Few studies in Africa reported PLA2G6‐associated disorders and none with parkinsonism of late adult onset. Material and Methods The patients were clinically assessed following UK Brain Bank diagnostic criteria and International Parkinson and Movement Disorder Society's Unified Parkinson's Disease Rating Scale (MDS‐UPDRS). Brain MRI without contrast was performed. Genetic testing was done using a custom‐made Twist panel, screening 34 known genes, 27 risk factors, and 8 candidate genes associated with parkinsonism. Filtered variants were PCR‐amplified and validated using Sanger sequencing and also tested in additional family members to study their segregation. Result Two siblings born to consanguineous parents developed parkinsonism at the age of 58 and 60 years, respectively. MRI showed an enlarged right hippocampus in patient 2, but no overt abnormalities indicative of INAD or iron deposits. We found two heterozygous variants in PLA2G6, an in‐frame deletion NM_003560:c.2070_2072del (p.Val691del) and a missense variant NM_003560:c.956C>T (p.Thr319Met). Both variants were classified as pathogenic. Conclusion This is the first case in which PLA2G6 is associated with late‐onset parkinsonism. Functional analysis is needed to confirm the dual effect of both variants on the structure and function of iPLA2β.

The spinocerebellar ataxias (SCA) comprise a group of inherited neurodegenerative diseases. Machado–Joseph Disease (MJD) or spinocerebellar ataxia 3 (SCA3) is the most common autosomal dominant form, caused by the expansion of CAG repeats within the ataxin-3 (ATXN3) gene. This mutation results in the expression of an abnormal protein containing long polyglutamine (polyQ) stretches that confers a toxic gain of function and leads to misfolding and aggregation of ATXN3 in neurons. As a result of the neurodegenerative process, SCA3 patients are severely disabled and die prematurely. Several screening approaches, e.g., druggable genome-wide and drug library screenings have been performed, focussing on the reduction in stably overexpressed ATXN3(polyQ) protein and improvement in the resultant toxicity. Transgenic overexpression models of toxic ATXN3, however, missed potential modulators of endogenous ATXN3 regulation. In another approach to identify modifiers of endogenous ATXN3 expression using a CRISPR/Cas9-modified SK-N-SH wild-type cell line with a GFP-T2A-luciferase (LUC) cassette under the control of the endogenous ATXN3 promotor, four statins were identified as potential activators of expression. We here provide an overview of the high throughput screening approaches yet performed to find compounds or genomic modifiers of ATXN3(polyQ) toxicity in different SCA3 model organisms and cell lines to ameliorate and halt SCA3 progression in patients. Furthermore, the putative role of cholesterol in neurodegenerative diseases (NDDs) in general and SCA3 in particular is discussed.

IntroductionTranscranial focused ultrasound therapy (tcFUS) offers precise thermal ablation for treating Parkinson's disease and essential tremor. However, the manual fine-tuning of fiber tracking and segmentation required for accurate treatment planning is time-consuming and demands expert knowledge of complex neuroimaging tools. This raises the question of whether a fully automated pipeline is feasible or if manual intervention remains necessary.MethodsWe investigate the dependence on fiber tractography algorithms, segmentation approaches, and degrees of automation, specifically for essential tremor therapy planning. For that purpose, we compare an automatic pipeline with a manual approach that requires the manual definition of the target point and is based on FMRIB software library (FSL) and other open-source tools.ResultsOur findings demonstrate the high feasibility of automatic fiber tracking and the automated determination of standard treatment coordinates. Employing an automatic fiber tracking approach and deep learning (DL)–supported standard coordinate calculation, we achieve anatomically meaningful results comparable to a manually performed FSL-based pipeline. Individual cases may still exhibit variations, often stemming from differences in region of interest (ROI) segmentation. Notably, the DL-based approach outperforms registration-based methods in producing accurate segmentations. Precise ROI segmentation proves crucial, surpassing the importance of fine-tuning parameters or selecting algorithms. Correct thalamus and red nucleus segmentation play vital roles in ensuring accurate pathway computation.ConclusionThis study highlights the potential for automation in fiber tracking algorithms for tcFUS therapy, but acknowledges the ongoing need for expert verification and integration of anatomical expertise in treatment planning.

BackgroundParkinson’s disease (PD) is characterized by motor disorders and the composition of Lewy bodies (LBs) in the substantia nigra. Due to the lack of a definitive biomarker, the current treatments do not modify the progression of PD. Recently, researchers revealed lipid dysregulation and some potential volatile biomarkers of PD related to a unique odor from PD patients by metabolomics of sebum, which is supposed to cause a potential change for skin microflora. In this study, we identified the 4 Malassezia species in PD patients and compared them with healthy controls.MethodsWe collected 95 sebum samples (47 PDs and 48 Controls) by cotton swabs and extracted the DNA. The identification of Malassezia species was performed by Nested PCR. Specific primers for each species were used to amplify corresponding yeasts in each sample.ResultsM. restricta and M. globosa are the most common species for both groups. The prevalence of M. slooffiae and M. sympodialis were significantly higher in the PD group compared with controls (63.8% vs. 29.1 and 74.5% vs. 54.2% respectively), the binary logistic regression model further indicated that M. slooffiae (OR = 9.358, p

Glioblastoma is the most common and aggressive primary tumor of the central nervous system with poor outcome. Current gold standard treatment is surgical resection followed by a combination of radio- and chemotherapy. Efficacy of temozolomide (TMZ), the primary chemotherapeutic agent, depends on the DNA methylation status of the O6-methylguanine DNA methyltransferase (MGMT), which has been identified as a prognostic biomarker in glioblastoma patients. Clinical studies revealed that glioblastoma patients with hypermethylated MGMT promoter have a better response to TMZ treatment and a significantly improved overall survival. In this study, we thus used the CRISPRoff genome editing tool to mediate targeted DNA methylation within the MGMT promoter region. The system carrying a CRISPR-deactivated Cas9 (dCas9) fused with a methyltransferase (Dnmt3A/3L) domain downregulated MGMT expression in TMZ-resistant human glioblastoma cell lines through targeted DNA methylation. The reduction of MGMT expression levels reversed TMZ resistance in TMZ-resistant glioblastoma cell lines resulting in TMZ induced dose-dependent cell death rates. In conclusion, we demonstrate targeted RNA-guided methylation of the MGMT promoter as a promising tool to overcome chemoresistance and improve the cytotoxic effect of TMZ in glioblastoma.

Abstract Recent studies have indicated that long-term neurological sequelae after COVID-19 are not accompanied by an increase of canonical biomarkers of central nervous system injury in blood, but subgroup stratifications are lacking. This is a particular concern in chronic headache, which can be a leading symptom of Post-COVID diseases associated with neuronal damage such as vasculitis or autoimmune encephalitis. We here compared patients with mild Post-COVID-19 syndrome and persistent headache (persistent Post-COVID-19 headache) lasting longer than 12 weeks after the initial serological diagnosis, to patients with mild and severe COVID-19 and COVID-19-negative controls. Levels of neurofilament light chain and glial fibrillary astrocytic protein, i.e. markers of neuronal damage and reactive astrogliosis, were lower in blood from patients with persistent Post-COVID-19 headache compared to patients with severe COVID-19. Hence, our pilot serological study indicates that long-term Post-COVID-19 headache may not be a sign of underlying neuronal damage or neuroinflammation.

Abstract Little is known about the specific anaesthesiological and multidisciplinary management of high-intensity focused ultrasound (HIFU) in uterine fibroids. This observational single-center study is the first reporting on an interdisciplinary approach to optimize outcome following ultrasound (US)-guided HIFU in German-speaking countries. A sample of forty patients with symptomatic uterine fibroids was treated by HIFU. Relevant treatment parameters such as total treatment time for intervention, anaesthesia, and sonication time as well as total energy, body temperature, peri-interventional medication and complications were analyzed. Interventional variables did not correlate significantly either with opioid dose or with body temperature. The average fibroid volume reduction rate was 37.8% ± 23.5%, 48.5% ± 22.0% and 70.2% ± 25.5% after 3, 6 and 12 months, respectively. No major anaesthesiological complications occurred apart from an epileptic seizure prior to HIFU treatment in one patient. Peri-procedural hyperthermia (> 37.5 °C) occurred in two patients. Post-procedural two patients experienced a sciatic nerve irritation up to one year; one patient with very large treated fibroid experienced strong short-lasting post-procedural pain. There were two complication-free pregnancies of HIFU-treated patients. Multidisciplinary management is crucial to optimize safety and outcome of US-guided HIFU for uterine fibroids. Peri-procedural pain and temperature management are critical points where an adequate collaboration between anesthesiologist and interventionalist is mandatory.

Abstract Multiplications, mutations and dysregulation of the alpha synuclein gene (SNCA) are associated with the demise of dopaminergic neurons and are considered to play important roles in the pathogenesis of familial and sporadic forms of Parkinson’s disease. Regulation of SNCA expression might thus be an appropriate target for treatment. We aimed to identify specific modulators of SNCA transcription, generated CRISPR/Cas9 modified SNCA-GFP-luciferase (LUC) genomic fusion- and control cell lines and screened a library of 1649 bioactive compounds, including the FDA approved drugs. We found no inhibitors but three selective activators which increased SNCA mRNA and protein levels.

Abstract Background Idiopathic intracranial hypertension (IIH) is characterized by increased intracranial pressure without evidence of a tumor or any other underlying cause. Headache and visual disturbances are frequent complaints of IIH patients, but little is known about other symptoms. In this study, we evaluated the patients’ perspective on the burden of IIH. Methods For this cross-sectional study, we developed an online survey for patients with IIH containing standardized evaluations of headache (HIT-6), sleep (PROMIS Sleep Disturbance Scale) and depression (MDI) in relation to BMI, lumbar puncture opening pressure (LP OP) and treatment. Results Between December 2019 and February 2020, 306 patients completed the survey. 285 (93 %) were female, mean age was 36.6 years (± 10.8), mean BMI 34.2 (± 7.3) and mean LP OP at diagnosis was 37.8 cmH2O (± 9.5). 219 (72 %) of the participants were obese (BMI ≥ 30); 251 (82 %) reported severe impacting headaches, 140 (46 %) were suffering from sleep disturbances and 169 (56 %) from depression. Higher MDI scores correlated with higher BMI and increased sleep disturbances. Patients with a normalized LP opening pressure reported less headaches, less sleep disturbances and less depression than those with a constantly elevated opening pressure. Conclusions In addition to headaches and visual disturbances, sleep disturbances and depression are frequent symptoms in IIH and contribute to the patients’ burden. Structured questionnaires can help to identify IIH patients’ needs and can lead to personalized and better treatment.

Abstract Background Recent studies suggested the existence of (poly-)microbial infections in human brains. These have been described either as putative pathogens linked to the neuro-inflammatory changes seen in Parkinson’s disease (PD) and Alzheimer’s disease (AD) or as a “brain microbiome” in the context of healthy patients’ brain samples. Methods Using 16S rRNA gene sequencing, we tested the hypothesis that there is a bacterial brain microbiome. We evaluated brain samples from healthy human subjects and individuals suffering from PD (olfactory bulb and pre-frontal cortex), as well as murine brains. In line with state-of-the-art recommendations, we included several negative and positive controls in our analysis and estimated total bacterial biomass by 16S rRNA gene qPCR. Results Amplicon sequencing did detect bacterial signals in both human and murine samples, but estimated bacterial biomass was extremely low in all samples. Stringent reanalyses implied bacterial signals being explained by a combination of exogenous DNA contamination (54.8%) and false positive amplification of host DNA (34.2%, off-target amplicons). Several seemingly brain-enriched microbes in our dataset turned out to be false-positive signals upon closer examination. We identified off-target amplification as a major confounding factor in low-bacterial/high-host-DNA scenarios. These amplified human or mouse DNA sequences were clustered and falsely assigned to bacterial taxa in the majority of tested amplicon sequencing pipelines. Off-target amplicons seemed to be related to the tissue’s sterility and could also be found in independent brain 16S rRNA gene sequences. Conclusions Taxonomic signals obtained from (extremely) low biomass samples by 16S rRNA gene sequencing must be scrutinized closely to exclude the possibility of off-target amplifications, amplicons that can only appear enriched in biological samples, but are sometimes assigned to bacterial taxa. Sequences must be explicitly matched against any possible background genomes present in large quantities (i.e., the host genome). Using close scrutiny in our approach, we find no evidence supporting the hypothetical presence of either a brain microbiome or a bacterial infection in PD brains. Video abstract

Abstract Background IgG-class autoantibodies to N-Methyl-D-Aspartate (NMDA)-type glutamate receptors define a novel entity of autoimmune encephalitis. Studies examining the prevalence of NMDA IgA/IgM antibodies in patients with Parkinson disease with/without dementia produced conflicting results. We measured NMDA antibodies in a large, well phenotyped sample of Parkinson patients without and with cognitive impairment (n = 296) and controls (n = 295) free of neuropsychiatric disease. Detailed phenotyping and large numbers allowed statistically meaningful correlation of antibody status with diagnostic subgroups as well as quantitative indicators of disease severity and cognitive impairment. Methods NMDA antibodies were analysed in the serum of patients and controls using well established validated assays. We used anti-NMDA antibody positivity as the main independent variable and correlated it with disease status and phenotypic characteristics. Results The frequency of NMDA IgA/IgM antibodies was lower in Parkinson patients (13%) than in controls (22%) and higher than in previous studies in both groups. NMDA IgA/IgM antibodies were neither significantly associated with diagnostic subclasses of Parkinson disease according to cognitive impairment, nor with quantitative indicators of disease severity and cognitive impairment. A positive NMDA antibody status was positively correlated with age in controls but not in Parkinson patients. Conclusion It is unlikely albeit not impossible that NMDA antibodies play a significant role in the pathogenesis or progression of Parkinson disease e.g. to Parkinson disease with dementia, while NMDA IgG antibodies define a separate disease of its own.

Background: Epigenetic factors including DNA methylation contribute to specific patterns of gene expression. Gene–environment interactions can change the methylation status in the brain, and accumulation of these epigenetic changes over a lifespan may be co-responsible for a neurodegenerative disease like Parkinson’s disease, which that is characterised by a late onset in life. Aims: To determine epigenetic modifications in the brains of Parkinson’s disease patients. Patients and Methods: DNA methylation patterns were compared in the cortex tissue of 14 male PD patients and 10 male healthy individuals using the Illumina Methylation 450 K chip. Subsequently, DNA methylation of candidate genes was evaluated using bisulphite pyrosequencing, and DNA methylation of cytochrome P450 2E1 (CYP2E1) was characterized in DNA from blood mononuclear cells (259 PD patients and 182 healthy controls) and skin fibroblasts (10 PD patients and 5 healthy controls). Protein levels of CYP2E1 were analysed using Western blot in human cortex and knock-out mice brain samples. Results: We found 35 hypomethylated and 22 hypermethylated genes with a methylation M-value difference >0.5. Decreased methylation of cytochrome P450 2E1 (CYP2E1) was associated with increased protein levels in PD brains, but in peripheral tissues, i.e., in blood cells and skin fibroblasts, DNA methylation of CYP2E1 was unchanged. In CYP2E1 knock-out mice brain alpha-synuclein (SNCA) protein levels were down-regulated compared to wild-type mice, whereas treatment with trichloroethylene (TCE) up-regulated CYP2E1 protein in a dose-dependent manner in cultured cells. We further identified an interconnected group of genes associated with oxidative stress, such as Methionine sulfoxide reductase A (MSRA) and tumour protein 73 (TP73) in the brain, which again were not paralleled in other tissues and appeared to indicate brain-specific changes. Conclusions: Our study revealed surprisingly few dysmethylated genes in a brain region less affected in PD. We confirmed hypomethylation of CYP2E1.

Neurodegenerative diseases (NDD) such as Alzheimer's (AD) and Parkinson's disease (PD) are distinct clinical entities, however, the aggregation of key neuronal proteins, presumably leading to neuronal demise appears to represent a common mechanism. It has become evident, that advanced glycation end products (AGEs) trigger the accumulation of such modified proteins, which eventually contributes to pathological aspect of NDDs. Increased levels of AGEs are found in amyloid plaques in AD brains and in both advanced and early PD (incidental Lewy body disease). The molecular mechanisms by which AGE dependent modifications may modulate the susceptibility towards NDDs, however, remain enigmatic and it is unclear, whether AGEs may serve as biomarker of NDD. In the present study, we examined AGEs (CML: Carboxymethyllysine and CEL: Carboxyethyllysine), markers of oxidative stress and micronutrients in the plasma of PD and AD patients and controls. As compared to healthy controls, AD females displayed lower levels of CEL while higher levels of CML were found in AD and PD patients. A somewhat similar pattern was observed for protein carbonyls (PC), revealing lower values exclusively in AD females, whereas AD males displayed significantly higher values compared to healthy controls and PD. Sex-specific differences were also observed for other relevant markers such as malondialdehyde, 3-nitrotyrosine, γ -tocopherols, retinol, plasma proteins and α-carotene, while α-tocopherols, β-carotene, lutein/zeaxanthin, β-cryptoxanthin and lycopene showed no relevant association. Taken together, our study suggests yet unappreciated differences of the distribution of AGEs among the sexes in NDD. We therefore suggest to make a clear distinction between sexes when analyzing oxidative (AGEs)-related stress and carbonyl-related stress and vitamins.

Induced neurons, but not induced pluripotent stem cell (iPSC)-derived neurons, preserve age-related traits. Here, the authors demonstrate that blood-derived induced neural stem cells (iNSCs), despite lacking a pluripotency transit, lose age-related signatures.

Abstract Background Genetic predisposition and epigenetic alterations are both considered to contribute to sporadic neurodegenerative diseases (NDDs) such as Parkinson’s disease (PD). Since cell reprogramming and the generation of induced pluripotent stem cells (iPSCs) are themselves associated with major epigenetic remodeling, it remains unclear to what extent iPSC-derived neurons lend themselves to model epigenetic disease-associated changes. A key question to be addressed in this context is whether iPSC-derived neurons exhibit epigenetic signatures typically observed in neurons derived from non-reprogrammed human embryonic stem cells (hESCs). Results Here, we compare mature neurons derived from hESC and isogenic human iPSC generated from hESC-derived neural stem cells. Genome-wide 450 K-based DNA methylation and HT12v4 gene array expression analyses were complemented by a deep analysis of selected genes known to be involved in NDD. Our studies show that DNA methylation and gene expression patterns of isogenic hESC- and iPSC-derived neurons are markedly preserved on a genome-wide and single gene level. Conclusions Overall, iPSC-derived neurons exhibit similar DNA methylation patterns compared to isogenic hESC-derived neurons. Further studies will be required to explore whether the epigenetic patterns observed in iPSC-derived neurons correspond to those detectable in native brain neurons.

Parkinson’s disease (PD) is the second most common age-related neurodegenerative disease. Accumulating evidence demonstrates that alpha-synuclein (α-Syn), an apparently predominant neuronal protein, is a major contributor to PD pathology. As α-Syn is also highly abundant in blood, particularly in red blood cells (RBCs) and platelets, this in turn raises the question on the function of presumably dysfunctional α-Syn in “peripheral” cells and its putative effect on the other enclosed constituents. Herein, we detected the internal variance in erythrocytes of PD patients by Raman spectroscopy, but no measurable amount of erythrocytic behavioural change (eryptosis) or any haemoglobin variation was noticed. An elevated level of plasmin-antiplasmin complexes (PAP) was observed in the plasma of PD patients, indicating activation of the fibrinolytic system, but platelet activation after thrombin stimulation was not altered. Sex-specific patterns were noticed for blood coagulation factor XIII and factor XII activity in PD patients. Additionally, the alterations in homocysteine levels which have often been observed in PD patients were found to be independent from L-DOPA usage and PAP levels. Furthermore, a selective gene expression analysis identified subsets of genes related to different blood-associated compartments (RBCs, platelets, coagulation-fibrinolysis) also involved in PD-related pathways.

Parkinson’s disease (PD) is the second most common neurodegenerative disorder next to Alzheimer’s disease. Most PD cases are considered to be sporadic and despite considerable scientific effort, the underlying cause(s) still remain(s) enigmatic. In particular, it is unknown to which extent epigenetic alterations contribute to the pathophysiology of this devastating disorder. This is partly due to the fact that appropriate PD models are not yet available. Moreover, epigenetic patterns and mechanisms are species specific and murine systems reflect only a few of the idiosyncrasies of human neurons. For several years now, patient-specific stem cell-derived neural and non-neural cells have been employed to overcome this limitation allowing the analysis and establishment of humanized disease models for PD. Thus, several studies tried to dissect epigenetic alterations such as aberrant DNA methylation or microRNA patterns using lund human mesencephalic cell lines or neurons derived from (patient-specific) induced pluripotent stem cells. These studies demonstrate that human neurons have the potential to be used as model systems for the study of epigenetic modifications in PD such as characterizing epigenetic changes, correlating epigenetic changes to gene expression alterations and hopefully using these insights for the development of novel therapeutics. However, more research is required to define the epigenetic (age-associated) landscape of human in vitro neurons and compare these to native neurons before they can be established as suitable models for epigenetic studies in PD. In this review, we summarize the knowledge about epigenetic studies performed on human neuronal PD models, and we discuss advantages and current limitations of these (stem cell-derived) neuronal models for the study of epigenetic alterations in PD.

Emerging evidence suggests an inverse association between cancer and neurodegenerative diseases (NDD). Although phenotypically different, both diseases display a significant imbalance in the ubiquitination/deubiquitination processes. Therefore, we particularly investigated the expression of ubiquitin C-terminal hydrolases (UCHs: UCH-L1, UCH-L3, UCH-L5 and BAP1), a subfamily of deubiquitinating enzymes (DUBs), using publically available datasets (GTEx, TCGA) and observed altered expression of UCH-L1, UCH-L3, UCH-L5 in 17 cancer types. Interestingly, UCH-L1 (known to be enriched in neurons and interacting with the Parkinson’s disease-associated protein α-synuclein) appeared to be a prognostic indicator of unfavorable outcome in endometrial and urothelial cancer, while increased expression of UCH-L3 and UCH-L5 was associated with poor survival in liver and thyroid cancer, respectively. In normal tissues, UCH-L1 was found to be strongly expressed in the cerebral cortex and hypothalamus, while UCH-L3 expression was somewhat higher in the testis. The occurrence of mutation rates in UCHs also suggests that BAP1 and UCH-L5 may play a more dominant role in cancers than UCH-L1 and UCH-L3. We also characterized the functional context and configuration of the repeat elements in the promoter of DUBs genes and found that UCHs are highly discriminatory for catabolic function and are mainly enriched with LINE/CR1 repeats. Regarding the thesis of an inverse association between cancer and NDD, we observed that among all DUBs, UCHs are the one most involved in both entities. Considering a putative therapeutic potential based on presumed common mechanisms, it will be useful to determine whether other DUBs can compensate for the loss of UCH activity under physiological conditions. However, experimental evidence is required to substantiate this argument.

As a deubiquitinating enzyme (DUB), the physiological substrates of ataxin-3 (ATX-3) remain elusive, which limits our understanding of its normal cellular function and that of pathogenic mechanism of spinocerebellar ataxia type 3 (SCA3). Here, we identify p53 to be a novel substrate of ATX-3. ATX-3 binds to native and polyubiquitinated p53 and deubiquitinates and stabilizes p53 by repressing its degradation through the ubiquitin (Ub)-proteasome pathway. ATX-3 deletion destabilizes p53, resulting in deficiency of p53 activity and functions, whereas ectopic expression of ATX-3 induces selective transcription/expression of p53 target genes and promotes p53-dependent apoptosis in both mammalian cells and the central nervous system of zebrafish. Furthermore, the polyglutamine (polyQ)-expanded ATX-3 retains enhanced interaction and deubiquitination catalytic activity to p53 and causes more severe p53-dependent neurodegeneration in zebrafish brains and in the substantia nigra pars compacta (SNpc) or striatum of a transgenic SCA3 mouse model. Our findings identify a novel molecular link between ATX-3 and p53-mediated cell death and provide an explanation for the direct involvement of p53 in SCA3 disease pathogenesis.

Background. Postural instability in Parkinson’s disease (PD) increases the risk of falls and is not improved by pharmacological therapy. Objective. We performed a double-blind, randomized sham-controlled study to test the effects of stochastic resonance (whole body vibration) therapy on postural stability in PD. Methods. Fifty-six PD participants were allocated to either experimental or sham groups. The experimental group received four series of vibration over eight days, with each series consisting of six stimulus trains of 60-second duration using a randomized whole body vibration. Participants allocated to the control group received a sham treatment. Results. Within-group analysis revealed that postural stability in the experimental group improved by 17.5% (p=0.005) comparing experimental and sham groups. The between-group analysis of change after treatment comparing both groups also showed a significant improvement of postural stability (p=0.03). Only in the within-group analysis several items were improved after Bonferroni correction, too, rigor 41.6% (p=0.001), bradykinesia 23.7% (p=0.001), tremor 30.8% (p=0.006), and UPDRSIII sum score 23.9% (p=0.000), but did not reach the level of significance in the between-group analysis. Conclusions. Stochastic resonance therapy significantly enhanced postural stability even in individuals with increased risk of falling. Thus it offers a potential supplementation to canonical treatments of PD.

Increasing evidence has linked inflammatory processes to neurodegenerative disorders, including Alzheimer's and Parkinson's disease (PD). Tumor necrosis factor alpha (TNF-alpha) is a key inflammatory cytokine and several studies linked increased TNF-alpha to dopaminergic cell death in PD. The TNF-alpha promoter sequence contains several CpG dinucleotides located within or next to transcription factor binding sites. To test the hypothesis whether the methylation state of the TNF-alpha promoter contributes to increased expression of TNF-alpha in PD we compared DNA from different brain regions (substantia nigra pars compacta (SNpc) and cortex) of PD patients and neurologically healthy, age and sex matched controls by bisulfite sequencing of the TNF-alpha promoter region. The TNF-alpha promoter DNA from SNpc was significantly less methylated in comparison to DNA from cortex; however both in PD patients and controls. Although there was a tendency for hypomethylation in PD, our analysis of the 10 CpGs in the TNF-alpha core promoter region (−258 to −35 relative to the TSS) revealed no particular pattern in PD patients compared to control and identified no particular hypomethylated position in cortex or SNpc DNA. Electrophoretic mobility shift and luciferase reporter assays showed that methylation of specific solitary CpG in the TNF-alpha promoter resulted in reduced binding of the transcription factors AP-2 and Sp1, respectively, and suppressed TNF-alpha promoter activity.The brain region specific methylation state of solitary CpG in the TNF-alpha promoter thus determines transcription factor binding efficacy and TNF-alpha expression. A lesser degree of methylation of the TNF-alpha promoter in SNpc cells could underlie the increased susceptibility of dopaminergic neurons to TNF-alpha mediated inflammatory reactions.

Children with hereditary severe hyperhomocysteinemia present with a variety of neurological impairment, and mild hyperhomocysteinemia has been associated with neurodegeneration in the elderly. The link of hyperhomocysteinemia to neurological dysfunction is unknown. We investigated mitochondrial mechanisms of homocysteine (HCys) neurotoxicity in rat dopaminergic pheochromocytoma cells, human neuroblastoma cells and primary rat cerebellar granule neurons. HCys dose dependently impaired cytochrome c oxidase (COX) activity as well as stability and induced reactive oxygen species and apoptotic cell death. We found that HCys binds the COX cofactor Cu2+, and Cu2+ supplementation prior to HCys treatment preserved COX activity and prevented cell death. The Cu2+ chelating action of HCys and impairement of COX activity represent novel mechanisms of HCys neurotoxicity, which might be preventable by supplementation of Cu2+.

BACKGROUND: Hyperhomocysteinemia is an independent risk factor for stroke and other vascular events. The variant methylenetetrahydrofolate reductase (MTHFR) C677T is associated with elevated homocysteine levels, cardiovascular disease and stroke, which supports a causal relationship between hyperhomocysteinemia and vascular disease. However, MTHFR variants have also been reported to be associated with smoking behavior, which could be an important confounder. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the MTHFR variants C677T and A1298C in two independent samples of 525 and 535 individuals, respectively. 21% of the non-smokers, but only 12% of the smokers were homozygous carriers of both MTHFR wildtype alleles, i.e. 677CC and 1298AA (Chi² = 15.8; p

Epigenetic changes, including histone modifications or chromatin remodeling are regulated by a large number of human genes. We developed a strategy to study the coordinate regulation of such genes, and to compare different cell populations or tissues. A set of 150 genes, comprising different classes of epigenetic modifiers was compiled. This new tool was used initially to characterize changes during the differentiation of human embryonic stem cells (hESC) to central nervous system neuroectoderm progenitors (NEP). qPCR analysis showed that more than 60% of the examined transcripts were regulated, and >10% of them had a >5-fold increased expression. For comparison, we differentiated hESC to neural crest progenitors (NCP), a distinct peripheral nervous system progenitor population. Some epigenetic modifiers were regulated into the same direction in NEP and NCP, but also distinct differences were observed. For instance, the remodeling ATPase SMARCA2 was up-regulated >30-fold in NCP, while it remained unchanged in NEP; up-regulation of the ATP-dependent chromatin remodeler CHD7 was increased in NEP, while it was down-regulated in NCP. To compare the neural precursor profiles with those of mature neurons, we analyzed the epigenetic modifiers in human cortical tissue. This resulted in the identification of 30 regulations shared between all cell types, such as the histone methyltransferase SETD7. We also identified new markers for post-mitotic neurons, like the arginine methyl transferase PRMT8 and the methyl transferase EZH1. Our findings suggest a hitherto unexpected extent of regulation, and a cell type-dependent specificity of epigenetic modifiers in neurodifferentiation.

Hyposmia is one of the early signs in Idiopathic Parkinson´s Disease (PD). Olfactory stimuli were applied during fMRI scanning to show disease-related modulation of central nervous system structures and to advance our understanding of olfactory dysfunction in PD patients. All participants received either unpleasant stimuli smelling like rotten eggs or pleasant ones smelling like roses. Using a block design at a 1.5 T scanner we investigated a total of 8 PD patients (mean age 60 ± 10.9 years) and 13 age matched controls (mean age 58 ± 9.6 years). PD duration ranged from 1 to 9 years (mean 6.63 years); patients had an average “Unified Parkinson’s Disease Rating Scale III” score of 23.25 (range, 6-46). Olfactory function was established using the “Sniffin’ Sticks” test battery. Patients tended to rate the stimuli presented during fMRI scans as less intense, but also as more pleasant than controls. FMRI results revealed differences between PD patients and controls which depended on the type of stimulation. While both pleasant and unpleasant stimulation was associated with lower activation in the amygdalo-hippocampal complex in patients compared to controls, increased activity in response to pleasant stimuli was observed in the striatum and the left inferior frontal gyrus. In contrast, unpleasant stimulation led to hypoactivation of the ventral striatum in patients (but not in controls) and did not enhance left inferior frontal activity. These results may partly reflect differences between PD patients and healthy controls in the processing of primary dimensions of odors, intensity and valence.

Parkinson's disease (PD), the second most frequent neurodegenerative disorder at old age, can be caused by elevated expression or the A53T missense mutation of the presynaptic protein alpha-synuclein (SNCA). PD is characterized pathologically by the preferential vulnerability of the dopaminergic nigrostriatal projection neurons.Here, we used two mouse lines overexpressing human A53T-SNCA and studied striatal dysfunction in the absence of neurodegeneration to understand early disease mechanisms. To characterize the progression, we employed young adult as well as old mice. Analysis of striatal neurotransmitter content demonstrated that dopamine (DA) levels correlated directly with the level of expression of SNCA, an observation also made in SNCA-deficient (knockout, KO) mice. However, the elevated DA levels in the striatum of old A53T-SNCA overexpressing mice may not be transmitted appropriately, in view of three observations. First, a transcriptional downregulation of the extraneural DA degradation enzyme catechol-ortho-methytransferase (COMT) was found. Second, an upregulation of DA receptors was detected by immunoblots and autoradiography. Third, extensive transcriptome studies via microarrays and quantitative real-time RT-PCR (qPCR) of altered transcript levels of the DA-inducible genes Atf2, Cb1, Freq, Homer1 and Pde7b indicated a progressive and genotype-dependent reduction in the postsynaptic DA response. As a functional consequence, long term depression (LTD) was absent in corticostriatal slices from old transgenic mice.Taken together, the dysfunctional neurotransmission and impaired synaptic plasticity seen in the A53T-SNCA overexpressing mice reflect early changes within the basal ganglia prior to frank neurodegeneration. As a model of preclinical stages of PD, such insights may help to develop neuroprotective therapeutic approaches.