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Biomedical subjects

Ullrich Wüllner

Publications and source records attributed to Ullrich Wüllner.

At least 19 recordsLinked to original sources
PubMed2007

Data protection in biomaterial banks for Parkinson's disease research: the model of GEPARD (Gene Bank Parkinson's Disease Germany).

Parkinson's disease (PD) is the second most common neurodegenerative disease. Although 10 gene loci have been identified to cause a Parkinsonian syndrome, these loci account only for a minority of PD patients. Large, systematic research programs are required to collect, store, and analyze DNA samples and clinical information to support further discovery of additional genetic components of PD or other movement disorders. Such programs facilitate research into the relationship between genotype and phenotype. The German Competence Network on Parkinson's disease (CNP) initiated the Gene Bank Parkinson's Disease Germany (GEPARD), providing an administrative and scientific infrastructure for the storage of DNA and clinical data that are electronically accessible and protective of patient rights. In this article, we offer guidance on how to establish a framework for a clinical genetic data and DNA bank, and describe GEPARD as a model that may be useful to other local, national, and international research groups developing similar programs.

Computer Security↗
PubMed2006

Ataxin-3 represses transcription via chromatin binding, interaction with histone deacetylase 3, and histone deacetylation.

Ataxin-3 (AT3), the disease protein in spinocerebellar ataxia type 3 (SCA3), has been associated with the ubiquitin-proteasome system and transcriptional regulation. Here we report that normal AT3 binds to target DNA sequences in specific chromatin regions of the matrix metalloproteinase-2 (MMP-2) gene promoter and represses transcription by recruitment of the histone deacetylase 3 (HDAC3), the nuclear receptor corepressor (NCoR), and deacetylation of histones bound to the promoter. Both normal and expanded AT3 physiologically interacted with HDAC3 and NCoR in a SCA3 cell model and human pons tissue; however, normal AT3-containing protein complexes showed increased histone deacetylase activity, whereas expanded AT3-containing complexes had reduced deacetylase activity. Consistently, histone analyses revealed an increased acetylation of total histone H3 in expanded AT3-expressing cells and human SCA3 pons. Expanded AT3 lost the repressor function and displayed altered DNA/chromatin binding that was not associated with recruitment of HDAC3, NCoR, and deacetylation of the promoter, allowing aberrant MMP-2 transcription via the transcription factor GATA-2. For transcriptional repression normal AT3 cooperates with HDAC3 and requires its intact ubiquitin-interacting motifs (UIMs), whereas aberrant transcriptional activation by expanded AT3 is independent of the UIMs but requires the catalytic cysteine of the ubiquitin protease domain. These findings demonstrate that normal AT3 binds target promoter regions and represses transcription of a GATA-2-dependent target gene via formation of histone-deacetylating repressor complexes requiring its UIM-associated function. Expanded AT3 aberrantly activates transcription via its catalytic site and loses the ability to form deacetylating repressor complexes on target chromatin regions.

Amino Acid Motifs↗
PubMed2006

Homocysteine and carotid intima-media thickness in a german population: lack of clinical relevance.

BACKGROUND AND PURPOSE: Common carotid artery intima-media thickness (CCA IMT) is a predictor of stroke. This study aimed to analyze whether homocysteine (Hcys) metabolism influences CCA IMT. METHODS: We analyzed the association of personal, clinical, and biochemical data (multivariate analysis) and of 9 polymorphisms involved in Hcys metabolism (ANOVA) with CCA IMT in 714 individuals of 187 families. RESULTS: CCA IMT was significantly predicted by age, sex, creatinine levels, lipoprotein(a) levels, pack-years of smoking, the presence of hypertension, and the presence of diabetes mellitus but not by Hcys levels. Homozygosity for the T allele of the polymorphism methylenetetrahydrofolate reductase c.677C>T was significantly associated with higher Hcys levels but not with a higher CCA IMT. CONCLUSIONS: These data do not support the thesis that elevated Hcys levels are causally involved in cerebrovascular disease.

Aged↗
PubMed2006

Binding of copper is a mechanism of homocysteine toxicity leading to COX deficiency and apoptosis in primary neurons, PC12 and SHSY-5Y cells.

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 Cu(2+), and Cu(2+) supplementation prior to HCys treatment preserved COX activity and prevented cell death. The Cu(2+) chelating action of HCys and impairement of COX activity represent novel mechanisms of HCys neurotoxicity, which might be preventable by supplementation of Cu(2+).

Animals↗
PubMed2006

Transcriptional changes in multiple system atrophy and Parkinson's disease putamen.

Multiple system atrophy (MSA) and sporadic, non-mendelian Parkinson's disease (PD) are progressive neurodegenerative disorders with overlapping clinical symptoms and pathology. The etiology of both disorders is unknown, and complex combinations of multiple susceptibility genes and environmental factors are thought to be involved. Both disorders are characterized by ubiquitous alpha-synuclein aggregates in distinct regions and cell types of the central nervous system. In PD, alpha-synuclein-positive aggregates appear to be largely neuronal while in MSA oligodendroglial inclusions prevail. In PD patients, the alpha-synuclein pathology is thought to evolve in a rather regular pattern, starting in the brainstem and olfactory bulb and extending gradually onto the substantia nigra and ultimately the cerebral cortex while the cerebellum is largely spared. MSA pathology has not been graded in a similar way yet; neuropathological analyses revealed neurodegeneration and gliosis primarily in the brainstem, midbrain and basal ganglia and the cerebellum, while the cortex is largely spared. To identify disease-specific transcriptional patterns in MSA, we chose CNS regions differentially affected in MSA and PD for comparative gene expression profiling: putamen, cerebellum and occipital cortex. Four genes were regulated in both MSA and PD putamen and twelve in MSA and PD cerebellum. Regulated transcripts were validated using real-time quantitative RT-PCR, and immunohistochemistry was performed for the most significantly downregulated transcripts in MSA and PD putamen, GPR86 and RGS14, associated with G protein signaling and transcriptional regulation.

Aged↗
PubMed2006

In vitro evaluation of nicotinic acetylcholine receptors with 2-[18F]F-A85380 in Parkinson's disease.

Nicotinic acetylcholine receptors (nAChR) are involved in many physiological functions and appear to be affected in neurodegenerative diseases like Alzheimer's disease and Parkinson's disease (PD). Here, we describe the in vitro evaluation of nAChRs in PD with 2-[18F]F-A85380, a ligand with high affinity to the beta2 nAChR subunit. Autoradiography with 2-[18F]F-A85380 in untreated rat brain corresponded to the known distribution of alpha4beta2 nAChRs with high uptake in the thalamus, moderate uptake in the striatum and cortex and low uptake in the cerebellum (47%, 43% and 19% of the thalamus, respectively). The localization of alpha4beta2 nAChRs in the striatum was investigated in rodents with unilateral lesion of the substantia nigra. 2-[18F]F-A85380 binding was significantly reduced in the striatum ipsilateral to the lesion side (to 64% of the contralateral side), indicating that a fraction of alpha4beta2 nAChRs is located on dopaminergic terminals, whereas another fraction resides on striatal interneurons or cortical afferents. Similarly, in human brain sections of PD patients, 2-[18F]F-A85380 uptake was significantly reduced not only in the caudate and putamen but also in the thalamus (approximately 30% of the binding of control brain in all three regions); within the striatum, nAChRs in the putamen were significantly more severely affected as in the caudate. The observed pattern of alpha4beta2* nAChR loss demonstrates the potential of 2-[18F]F-A85380 for further investigations of this positron emission tomography ligand for in vivo studies of alpha4beta2* nAChRs in PD.

Animals↗
PubMed2006

An arginine/lysine-rich motif is crucial for VCP/p97-mediated modulation of ataxin-3 fibrillogenesis.

Arginine/lysine-rich motifs typically function as targeting signals for the translocation of proteins to the nucleus. Here, we demonstrate that such a motif consisting of four basic amino acids in the polyglutamine protein ataxin-3 (Atx-3) serves as a recognition site for the interaction with the molecular chaperone VCP. Through this interaction, VCP modulates the fibrillogenesis of pathogenic forms of Atx-3 in a concentration-dependent manner, with low concentrations of VCP stimulating fibrillogenesis and excess concentrations suppressing it. No such effect was observed with a mutant Atx-3 variant, which does not contain a functional VCP interaction motif. Strikingly, a stretch of four basic amino acids in the ubiquitin chain assembly factor E4B was also discovered to be critical for VCP binding, indicating that arginine/lysine-rich motifs might be generally utilized by VCP for the targeting of proteins. In vivo studies with Drosophila models confirmed that VCP selectively modulates aggregation and neurotoxicity induced by pathogenic Atx-3. Together, these results define the VCP-Atx-3 association as a potential target for therapeutic intervention and suggest that it might influence the progression of spinocerebellar ataxia type 3.

Adenosine Triphosphatases↗
PubMed2006

Feasibility of 2-deoxy-2-[18F]fluoro-D-glucose- A85380-PET for imaging of human cardiac nicotinic acetylcholine receptors in vivo.

Nicotinic acetylcholine receptors mediate the parasympathetic autonomic control of cardiac function. Aim of this study was the assessment of cardiac nicotinic acetylcholine receptor distribution with a novel (alpha4beta2) nicotinic acetylcholine receptor PET ligand (2-deoxy-2- [18F]fluoro-D-glucose-A85380) in humans. Five healthy volunteers without cardiac disease and six patients with either Parkinson's disease or multiple system atrophy without additional overt cardiac disease were evaluated with 2-deoxy-2-[18F]fluoro-D-glucose-A85380 PET-imaging to assess the cardiac parasympathetic innervation and the putative impact of both disorders. 2-deoxy-2- [18F]fluoro-D-glucose-A85380 whole body PET-scans were performed on a Siemens PET/CT biograph(TM) 75.4 min +/- 6.7 after i.v. injection of 371.2 +/- 58.1 MBq. Average count rate density of left ventricle ROI's and a standard ROI in the right lung were measured within three consecutive slices of 10.0 mm thickness. Heart-to-lung ratios were calculated in each volunteer and patient. Tracer uptake in the left ventricle could be measured in all of the five volunteers and the six patients. Heart-to-lung ratios in the volunteer group were not different from patients suffering from Parkinson's disease or MSA (3.2 +/- 0.5 vs 3.2 +/- 0.8 and 2.96+/-0.7, mean +/- SD), respectively. Human cardiac nicotinic acetylcholine receptors can be visualized and measured by 2-deoxy-2- [18F]fluoro-D-glucose-A85380 PET scans both in cardiac-healthy subjects and patients suffering from Parkinson's disease or multiple system atrophy. The heart- as well as the lung-tracer uptake was almost constant throughout all subjects leading to a good target-to-background ratio. These first results suggest no impact of either PD or MSA on cardiac nicotinic acetylcholine receptors.

Aged↗
PubMed2006

The cystathionine beta-synthase variant c.844_845ins68 protects against CNS demyelination in X-linked adrenoleukodystrophy.

The clinical course of X-linked adrenoleukodystrophy (X-ALD) is of unexplained heterogeneity. Major X-ALD phenotypes are the progressive childhood cerebral form (CCALD) with early confluent cerebral demyelination and the adult-onset adrenomyeloneuropathy (AMN). Adult AMN may present with demyelinated foci of the CNS (adrenoleukomyeloneuropathy, ALMN) or without ("pure" AMN). Activated methionine is essential for CNS myelination, and methionine metabolism is important for glutathione synthesis, which may influence neurodegeneration. Cystathionine beta-synthase (CBS) is a key enzyme of methionine metabolism. The CBS variant c.844_845ins68 (p.-) may influence the availability of activated methionine as well as of glutathione. In this study, we analyzed this variant in genomic DNA samples of 86 X-ALD patients. We observed the allele carrying the insertion in 12 of 49 patients without CNS demyelination ("pure" AMN), but in none of the 37 patients with CNS demyelination (CCALD or ALMN; chi(2)=10.531; p=0.001). We conclude that the insertion allele of CBS c.844_845ins68 protected X-ALD patients against CNS demyelination in our study sample. These data suggest that the individual conditions in methionine metabolism may be a disease modifier of X-ALD. Since methionine metabolism can easily be influenced by vitamin and amino acid substitution, this observation could be a basis of novel treatment strategies in this yet untreatable disease. (c) 2006 Wiley-Liss, Inc.

Adrenoleukodystrophy↗
PubMed2006

Qigong exercise for the symptoms of Parkinson's disease: a randomized, controlled pilot study.

Irrespective of limited evidence, not only traditional physiotherapy, but also a wide array of complementary methods are applied by patients with Parkinson's disease (PD). We evaluated the immediate and sustained effects of Qigong on motor and nonmotor symptoms of PD, using an add-on design. Fifty-six patients with different levels of disease severity (mean age/standard deviation [SD], 63.8/7.5 years; disease duration 5.8/4.2 years; 43 men [76%]) were recruited from the outpatient movement disorder clinic of the Department of Neurology, University of Bonn. We compared the progression of motor symptoms assessed by Unified Parkinson's Disease Rating Scale motor part (UPDRS-III) in the Qigong treatment group (n = 32) and a control group receiving no additional intervention (n = 24). Qigong exercises were applied as 90-minute weekly group instructions for 2 months, followed by a 2 months pause and a second 2-month treatment period. Assessments were carried out at baseline, 3, 6, and 12 months. More patients improved in the Qigong group than in the control group at 3 and 6 months (P = 0.0080 at 3 months and P = 0.0503 at 6 months; Fisher's exact test). At 12 months, there was a sustained difference between groups only when changes in UPDRS-III were related to baseline. Depression scores decreased in both groups, whereas the incidence of several nonmotor symptoms decreased in the treatment group only.

Aged↗
PubMed2005

A rare truncating mutation in ADH1C (G78Stop) shows significant association with Parkinson disease in a large international sample.

BACKGROUND: Alcohol dehydrogenases (ADHs) may be involved in the pathogenesis of neurodegenerative disorders because of their multiple roles in detoxification pathways and retinoic acid synthesis. In a previous study, significant association of an ADH class IV allele with Parkinson disease (PD) was found in a Swedish sample. PATIENTS: The previously associated single-nucleotide polymorphism plus 12 further polymorphisms in the ADH cluster on human chromosome 4q23 were screened for association in an extension of the original sample that now included 123 Swedish PD patients and 127 geographically matched control subjects. A rare nonsense single-nucleotide polymorphism in ADH1C (G78stop, rs283413) was identified in 3 of these patients but in no controls. To obtain sufficient power to detect a possible association of this rare variant with disease, we screened a large international sample of 1076 PD patients of European ancestry and 940 matched controls. RESULTS: The previously identified association with an ADH class IV allele remained significant (P<.02) in the extended Swedish study. Furthermore, in the international collaboration, the G78stop mutation in ADH1C was found in 22 (2.0%) of the PD patients but only in 6 controls (0.6%). This association was statistically significant (chi(2)(1) = 7.5; 2-sided P = .007; odds ratio, 3.25 [95% confidence interval, 1.31-8.05]). In addition, the G78stop mutation was identified in 4 (10.0%) of 40 Caucasian index cases with PD with mainly hereditary forms of the disorder. CONCLUSION: Findings presented herein provide further evidence for mutations in genes encoding ADHs as genetic risk factors for PD.

Adult↗
PubMed2005

Dopamine transporter positron emission tomography in spinocerebellar ataxias type 1, 2, 3, and 6.

BACKGROUND: The spinocerebellar ataxias (SCAs) are a genetically heterogeneous group of autosomal dominant ataxias: some mutations, including SCA1, SCA2, and SCA3, are multisystemic disorders characterized by a variety of noncerebellar symptoms while others, like SCA6, give rise to a pure cerebellar syndrome. OBJECTIVE: To identify impairments of the dopaminergic system and regional changes of glucose metabolism in SCA1, SCA2, SCA3, and SCA6. METHODS: We used [11C]d-threo-methylphenidate and [18F]fluorodeoxyglucose positron emission tomography to identify cerebral dopamine terminal loss and specific regional metabolic patterns in SCA1, SCA2, SCA3, and SCA6. RESULTS: The binding potential of [11C]d-threo-methylphenidate was reduced in the striatum in SCA2 and SCA3; in contrast to patients with Parkinson disease, no increased susceptibility of the putamen was evident. Decreased regional cerebral glucose metabolism was found in the cerebellum of all patients with SCA, the brainstem of SCA1, SCA2, SCA3, the thalamus and putamen of SCA3, and the parietal cortex of patients with SCA2. A trend toward increased regional cerebral glucose metabolism was found in the temporal cortex of all patients with SCA, pronounced in SCA6. CONCLUSIONS: Specific biochemical patterns point to different mechanisms of neuronal dysfunction in SCA1, SCA2, SCA3, and SCA6; dopamine terminal loss is severe in SCA2 but distinct from Parkinson disease.

Adult↗
PubMed2005

Multiple regions of alpha-synuclein are associated with Parkinson's disease.

alpha-Synuclein is considered to play an important role in the pathogenesis of both the rare familial and the common sporadic forms of Parkinson's disease. Previous reports primarily have tested the association of alpha-synuclein promoter polymorphisms with idiopathic Parkinson's disease, but results are controversial. We first characterized the linkage disequilibrium structure of the alpha-synuclein gene region with a dense set of 56 genetic markers and subsequently performed two independent case-control association analyses using tagging markers. We could distinguish two large linkage disequilibrium blocks spanning the alpha-synuclein gene. Several markers within the 3'-block around exons 5 and 6 showed strong association with Parkinson's disease (p = 0.00009). Effects of the associated variants might be mediated by regulatory elements in this highly conserved region or by a frequency shift in a previously described splice variant lacking exon 5. A direct association with promoter polymorphisms could not be replicated in our sample set. A second set of markers in the 5'-block of the gene were also significantly associated with Parkinson's disease, when young patients and female subjects were analyzed separately. These findings indicate locus heterogeneity for the pathogenesis of Parkinson's disease in different genetic or physiological environments, related to sex and age.

Age Factors↗
PubMed2005

New mutations in protein kinase Cgamma associated with spinocerebellar ataxia type 14.

Autosomal dominant cerebellar ataxias (ADCA) are a heterogeneous group of neurological disorders. Point mutations in the gene encoding protein kinase Cgamma (PRKCG) are responsible for spinocerebellar ataxia 14 (SCA14). We screened for mutations in the PRKCG gene, in a large series of 284 ADCA index cases, mostly French (n=204) and German (n=48), in whom CAG repeat expansions in the known SCA genes were previously excluded. Six mutations were found that segregated with the disease and were not detected on 560 control chromosomes, including F643L (exon 18), already reported in another French kindred. Five new missense mutations were identified in exons 4 (C114Y/G123R/G123E), 10 (G360S) and 18 (V692G). All but one (V692G) were located in highly conserved regions of the regulatory or catalytic domains of the protein. All six SCA14 families were French and there was no evidence of reduced penetrance. The phenotype consisted in a very slowly progressive cerebellar ataxia with a mean age at onset of 33.5+/-14.2 years (range 15 to 60 years), occasionally associated with executive dysfunction, myoclonus, myorythmia, tremor or decreased vibration sense. SCA14 represented only 1.5% (7/454) of French ADCA families but none of the German families. It should, however, be considered in patients with slowly progressive ADCA, particularly when myoclonus and cognitive impairment are present.

Adolescent↗
PubMed2005

Common variants of LRRK2 are not associated with sporadic Parkinson's disease.

Multiple mutations in the gene for the leucine-rich repeat kinase (LRRK2) cause autosomal dominant late-onset parkinsonism (PARK8). The Gly2019Ser mutation appears to be common in different populations. To investigate whether this novel gene influences the non-Mendelian sporadic form of Parkinson's disease, we genotyped 121 single nucleotide polymorphisms comprehensively covering the entire LRRK2 gene region in a set of 340 Parkinson's disease patients and 680 matched control subjects from Germany. No association could be demonstrated. We have therefore no evidence for the existence of a common variant in LRRK2 that has a strong influence on Parkinson's disease risk.

Age of Onset↗