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Objective Combined immunohistochemical and molecular classification using the Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) independently predicts prognosis in endometrial carcinoma (EC). As next-generation sequencing (NGS) is entering clinical practice, we evaluated whether more comprehensive immunomolecular profiling (CIMP), including NGS and extended immunohistochemical analysis, could further refine the current ProMisE classification. Methods A series of 120 consecutive ECs, classified according to ProMisE, was stained immunohistochemically for CD3, CD8, PD-L1, beta-catenin and L1CAM. An in-house 96 gene NGS panel was performed on a subset of 44 ECs, representing the 4 ProMisE subgroups (DNA polymerase epsilon catalytic subunit exonuclease domain mutated (POLEmut), mismatch repair deficient (MMRd), p53 abnormal (p53 abn) and no specific molecular profile (NSMP) ECs). Cases harboring non-hotspot POLE variants were analyzed with Illumina TruSight Oncology 500 NGS panel (TSO500) as a surrogate for whole-exome sequencing. Results Eight cases harbored POLE variants, half of which were hotspots. Using TSO500, non-hotspot POLE variants were classified as pathogenic (3) or variant of unknown significance (1). POLEmut and MMRd ECs typically showed higher numbers of CD3+/CD8+ tumor-infiltrating lymphocytes and higher PD-L1 expression in tumor-infiltrating immune cells. p53 abn ECs showed significantly higher L1CAM immunoreactivity and frequently harbored gene amplifications including HER2 (25%), but typically lacked ARID1A or PTEN variants. Beta-catenin-positivity and FGFR2 variants were predominantly found in NSMP ECs. Conclusions Our data show that CIMP adds significant value to EC characterization and may help to determine pathogenicity of non-hotspot POLE variants, encountered more frequently than expected in our series. In addition, CIMP may reveal ECs benefitting from immune checkpoint inhibition and allows upfront identification of targetable alterations, such as HER2 amplification in p53 abn ECs.

Cytogenetic abnormalities are powerful prognostic factors in multiple myeloma (MM) and are routinely analyzed by FISH on bone marrow (BM) plasma cells (PC). Although considered the gold standard, FISH experiments can be laborious and expensive. Therefore, array-CGH (aCGH) has been introduced as an alternative approach for detecting copy number aberrations (CNA), reducing the number of FISH experiments per case and yielding genome-wide information. Currently, next generation sequencing (NGS) technologies offer new perspectives for the diagnostic workup of malignant disorders. In this study, we examined ultra-low depth whole genome sequencing (LDS) as a valid alternative for aCGH for the detection of CNA in BM PC in MM. To this end, BM aspirates obtained in a diagnostic setting from 20 MM cases were analyzed. CD138+ cell-sorted samples were subjected to FISH analysis. DNA was extracted for subsequent aCGH and LDS analysis. CNA were detected by aCGH and LDS in all but one case. Importantly, all CNA identified by parallel first generation aCGH analysis were also detected by LDS, along with six additional CNA in five cases. One of these additional aberrations was in a region of prognostic importance in MM and was confirmed using FISH. However, risk stratification in these particular cases was unaffected. Thus, a perfectly concordant prognostication between array-CGH and LDS was observed. This validates LDS as a novel and cost-efficient tool for the detection of CNA in MM. ispartof: GENES CHROMOSOMES & CANCER vol:59 issue:8 pages:465-471 ispartof: location:United States status: published

Therapy resistance arises from heterogeneous drug-tolerant persister cells or minimal residual disease (MRD) through genetic and nongenetic mechanisms. A key question is whether specific molecular features of the MRD ecosystem determine which of these two distinct trajectories will eventually prevail. We show that, in melanoma exposed to mitogen-activated protein kinase therapeutics, emergence of a transient neural crest stem cell (NCSC) population in MRD concurs with the development of nongenetic resistance. This increase relies on a glial cell line-derived neurotrophic factor-dependent signaling cascade, which activates the AKT survival pathway in a focal adhesion kinase (FAK)-dependent manner. Ablation of the NCSC population through FAK inhibition delays relapse in patient-derived tumor xenografts. Strikingly, all tumors that ultimately escape this treatment exhibit resistance-conferring genetic alterations and increased sensitivity to extracellular signal-regulated kinase inhibition. These findings identify an approach that abrogates the nongenetic resistance trajectory in melanoma and demonstrate that the cellular composition of MRD deterministically imposes distinct drug resistance evolutionary paths. ispartof: CANCER CELL vol:39 issue:8 pages:1135-+ ispartof: location:United States status: published

Mutational analysis guides therapeutic decision making in patients with advanced-stage gastrointestinal stromal tumors (GISTs). We evaluated three targeted next-generation sequencing (NGS) assays, consecutively used over 4 years in our laboratory for mutational analysis of 162 primary GISTs: Agilent GIST MASTR, Illumina TruSight 26 and an in-house developed 96 gene panels. In addition, we investigated the feasibility of a more comprehensive approach by adding targeted RNA sequencing (Archer FusionPlex, 11 genes) in an attempt to reduce the number of Wild Type GISTs. We found KIT or PDGFRA mutations in 149 out of 162 GISTs (92.0%). Challenging KIT exon 11 alterations were initially missed by different assays in seven GISTs and typically represented deletions at the KIT intron 10-exon 11 boundary or large insertions/deletions (>24 base pairs). Comprehensive analysis led to the additional identification of driver alterations in 8/162 GISTs (4.9%): apart from BRAF and SDHA mutations (one case each), we found five GISTs harboring somatic neurofibromatosis type 1 (NF1) alterations (3.1%) and one case with an in-frame TRIM4-BRAF fusion not reported in GIST before. Eventually, no driver alteration was found in two out of 162 GISTs (1.2%) and three samples (1.9%) failed analysis. Our study shows that a comprehensive targeted NGS approach is feasible for routine mutational analysis of GIST, thereby substantially reducing the number of Wild Type GISTs, and highlights the need to optimize assays for challenging KIT exon 11 alterations.

Transgenic mice expressing human mutated superoxide dismutase 1 (SOD1) linked to familial forms of amyotrophic lateral sclerosis are frequently used as a disease model. We used the SOD1G93A mouse in a cross-breeding strategy to study the function of physiological prion protein (Prp). SOD1G93APrp-/- mice exhibited a significantly reduced life span, and an earlier onset and accelerated progression of disease, as compared with SOD1G93APrp+/+ mice. Additionally, during disease progression, SOD1G93APrp-/- mice showed impaired rotarod performance, lower body weight, and reduced muscle strength. Histologically, SOD1G93APrp-/- mice showed reduced numbers of spinal cord motor neurons and extended areas occupied by large vacuoles early in the course of the disease. Analysis of spinal cord homogenates revealed no differences in SOD1 activity. Using an unbiased proteomic approach, a marked reduction of glial fibrillary acidic protein and enhanced levels of collapsing response mediator protein 2 and creatine kinase were detected in SOD1G93APrp-/- versus SOD1G93A mice. In the course of disease, Bcl-2 decreases, nuclear factor-kappaB increases, and Akt is activated, but these changes were largely unaffected by Prp expression. Exclusively in double-transgenic mice, we detected a significant increase in extracellular signal-regulated kinase 2 activation at clinical onset. We propose that Prp has a beneficial role in the SOD1G93A amyotrophic lateral sclerosis mouse model by influencing neuronal and/or glial factors involved in antioxidative defense, rather than anti-apoptotic signaling.

2D DIGE is a promising approach to comparative proteome analysis known for a high sensitivity and high reproducibility compared with classical 2DE techniques. It offers new possibilities for the detection of cerebrospinal fluid (CSF) biomarkers in neurological diseases, such as dementia, amyotrophic lateral sclerosis or multiple sclerosis. We review the first studies using 2D DIGE for analysis of the CSF proteome in neurological diseases and discuss advantages, as well as drawbacks, of the methodological approach with special emphasis on CSF-related aspects.

DETECTED BY NANOSCALE CAPILLARY ISOELECTRIC FOCUSING IN CEREBROSPINAL FLUID, AS AN EARLY DIAGNOSTIC MARKER OF PARKINSON’S DISEASE DEMENTIA Steffen Halbgebauer, Hans-Wolfgang Klafki, Magdalena Nagl, Ute Haussmann, Sarah Jesse, Stefan Lehnert, Hilkka Soininen, Sanna-Kaisa Herukka, Petra Steinacker, Jens Wiltfang, Markus Otto, Experimental Neurology, University of Ulm, Ulm, Germany; 2 LVR-Klinikum Essen, Essen, Germany; 3 LVR-Klinikum Essen, Department of Psychiatry and Psychotherapy, University of Duisburg-Essen, Essen, Germany; Neurology Ulm, University of Ulm, Ulm, Germany; Kuopio University andUniversity Hospital, Kuopio, Finland; University of Eastern Finland, Kuopio, Finland; 7 University Ulm, Ulm, Germany; 8 Klinik f€ur Psychiatrie und Psychotherapie, G€ottingen, Germany. Contact e-mail: steffen.halbgebauer@uni-ulm.de

Oxidative phosphorylation in mitochondria is responsible for 90% of ATP synthesis in most cells. This essential housekeeping function is mediated by nuclear and mitochondrial genes encoding subunits of complex I to V of the respiratory chain. Although complex IV is the best studied of these complexes, the exact function of the striated muscle-specific subunit COX6A2 is still poorly understood. In this study, we show that Cox6a2-deficient mice are protected against high-fat diet-induced obesity, insulin resistance and glucose intolerance. This phenotype results from elevated energy expenditure and a skeletal muscle fiber type switch towards more oxidative fibers. At the molecular level we observe increased formation of reactive oxygen species, constitutive activation of AMP-activated protein kinase, and enhanced expression of uncoupling proteins. Our data indicate that COX6A2 is a regulator of respiratory uncoupling in muscle and we demonstrate that a novel and direct link exists between muscle respiratory chain activity and diet-induced obesity / insulin resistance. ispartof: PLoS One vol:8 issue:2 ispartof: location:United States status: published

Glial fibrillary acidic protein (GFAP) is an established indicator of astrogliosis. Therefore, variable cerebrospinal fluid (CSF) concentrations of this protein might reflect disease-specific pathologic profiles. In patients with narcolepsy, a loss of hypocretin-1 (hcrt-1) neurons in the brain and low concentrations of hcrt-1 in CSF have been reported. We performed a commercially available enzyme-linked immunosorbent assay to investigate if GFAP also is altered in the CSF of these patients. Here we detected significantly higher CSF levels of GFAP in patients with low hcrt-1 levels, of which the majority had a diagnosis of narcolepsy and cataplexy (NC); however, this finding was not observed in patients with hcrt-1 levels that were within reference range. In conclusion, GFAP may be useful as an additional disease biomarker in patients with narcolepsy, and this hypothesis should be investigated in larger studies.

The prevalence of Parkinson’s disease (PD) increases with age. Up to 50% of PD show cognitive decline in terms of a mild cognitive impairment already in early stages that predict the development of dementia, which can occur in up to 80% of PD patients over the long term, called Parkinson’s disease dementia (PDD). So far, diagnosis of PD/PDD is made according to clinical and neuropsychological examinations while laboratory data is only used for exclusion of other diseases. The aim of this study was the identification of possible biomarkers in cerebrospinal fluid (CSF) of PD, PDD and controls (CON) which predict the development of dementia in PD. For this, a proteomic approach optimized for CSF was performed using 18 clinically well characterized patients in a first step with subsequent validation using 84 patients. Here, we detected differentially sialylated isoforms of Serpin A1 as marker for differentiation of PD versus PDD in CSF. Performing 2Dimmunoblots, all PDD patients could be identified correctly (sensitivity 100%). Ten out of 24 PD patients showed Serpin A1 isoforms in a similar pattern like PDD, indicating a specificity of 58% for the test-procedure. In control samples, no additional isoform was detected. On the basis of these results, we conclude that differentially sialylated products of Serpin A1 are an interesting biomarker to indicate the development of a dementia during the course of PD. peerReviewed

BackgroundThe cyclic nucleotides cyclic adenosine-3',5'-monophosphate (cAMP) and cyclic guanosine-3',5'-monophosphate (cGMP) are important second messengers and are potential biomarkers for Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and Creutzfeldt-Jakob disease (CJD).Methodology/principal findingsHere, we investigated by liquid chromatography/tandem mass spectrometry (LC-MS/MS) the cerebrospinal fluid (CSF) concentrations of cAMP and cGMP of 82 patients and evaluated their diagnostic potency as biomarkers. For comparison with a well-accepted biomarker, we measured tau concentrations in CSF of CJD and control patients. CJD patients (n = 15) had lower cAMP (-70%) and cGMP (-55%) concentrations in CSF compared with controls (n = 11). There was no difference in PD, PD dementia (PDD) and ALS cases. Receiver operating characteristic (ROC) curve analyses confirmed cAMP and cGMP as valuable diagnostic markers for CJD indicated by the area under the curve (AUC) of 0.86 (cAMP) and 0.85 (cGMP). We calculated a sensitivity of 100% and specificity of 64% for cAMP and a sensitivity of 67% and specificity of 100% for cGMP. The combination of both nucleotides increased the sensitivity to 80% and specificity to 91% for the term cAMPxcGMP (AUC 0.92) and to 93% and 100% for the ratio tau/cAMP (AUC 0.99).Conclusions/significanceWe conclude that the CSF determination of cAMP and cGMP may easily be included in the diagnosis of CJD and could be helpful in monitoring disease progression as well as in therapy control.

Background: The total number of miRNA genes in a genome, expression of which is responsible for the miRNA repertoire of an organism, is not precisely known. Moreover, the question of how new miRNA genes arise during evolution is incompletely understood. Recent data in humans and opossum indicate that retrotranspons of the class of short interspersed nuclear elements have contributed to the growth of microRNA gene clusters. Method: We studied a large miRNA gene cluster in intron 10 of the mouse Sfmbt2 gene using bioinformatic tools. Results: Mice and rats are unique to harbor a 55-65 Kb DNA sequence in intron 10 of the Sfmbt2 gene. This intronic region is rich in regularly repeated B1 retrotransposons together with inverted self-complementary CA/TG microsatellites. The smallest repeats unit, called MSHORT1 in the mouse, was duplicated 9 times in a tandem head-to-tail array to form 2.5 Kb MLONG1 units. The center of the mouse miRNA gene cluster consists of 13 copies of MLONG1. BLAST analysis of MSHORT1 in the mouse shows that the repeat unit is unique for intron 10 of the Sfmbt2 gene and suggest a dual phase model for growth of the miRNA gene cluster: arrangment of 10 MSHORT1 units into MLONG1 and further duplication of 13 head-to-tail MLONG1 units in the center of the miRNA gene cluster. Rats have a similar arrangment of repeat units in intron 10 of the Sfmbt2 gene. The discrepancy between 65 miRNA genes in the mouse cluster as compared to only 1 miRNA gene in the corresponding rat repeat cluster is ascribed to sequence differences between MSHORT1 and RSHORT1 that result in lateral-shifted, less-stable miRNA precursor hairpins for RSHORT1. Conclusion: Our data provides new evidence for the emerging concept that lineage-specific retroposons have played an important role in the birth of new miRNA genes during evolution. The large difference in the number of miRNA genes in two closely related species (65 versus 1, mice versus rats) indicates that this species-specific evolution can be a rapid process. The authors wish to acknowledge Jerzy Jurka and the Genetic Information Research Institute for constructive discussions and support. We also thank Geert Verbeke and Yves Moreau for their valuable advice. The authors further thank Lieven Thorrez, Katleen Lemaire, Anica Schraenen, Leentje Van Lommel and Layka Abbasi Asbagh for reading the manuscript and helpful discussion. This work was supported by the Fonds voor Wetenschappelijk Onderzoek Vlaanderen (FWO grant G.0733.09N), the Katholieke Universiteit Leuven (SymBioSys: CoE EF/05/007, fellowships of SL and PJT) and by grant P41-LM006252 from the National Library of Medicine, National Institutes of Health, US (to VK).

We report on a hitherto poorly characterized class of genes that are expressed in all tissues, except in one. Often, these genes have been classified as housekeeping genes, based on their nearly ubiquitous expression. However, the specific repression in one tissue defines a special class of ‘‘disallowed genes.’’ In this paper, we used the intersection-union test to screen for such genes in a multi-tissue panel of genome-wide mRNA expression data. We propose that disallowed genes need to be repressed in the specific target tissue to ensure correct tissue function. We provide mechanistic data of repression with two metabolic examples, exercise-induced inappropriate insulin release and interference with ketogenesis in liver. Developmentally, this repression is established during tissue maturation in the early postnatal period involving epigenetic changes in histone methylation. In addition, tissue-specific expression of microRNAs can further diminish these repressed mRNAs. Together, we provide a systematic analysis of tissue-specific repression of housekeeping genes, a phenomenon that has not been studied so far on a genome-wide basis and, when perturbed, can lead to human disease. [Supplemental material is available online at http://www.genome.org. The microarray data have been submitted to the NCBI Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo/) under accession nos. GSE24207 and GSE24940.]

The clinical diagnosis of Creutzfeldt-Jakob disease (CJD) can be supported by several biochemical markers in cerebrospinal fluid (CSF) such as 14-3-3 proteins and tau protein. Unfortunately, none of the currently known markers are suited for screening or seems to be directly related to the pathophysiological process. A marker fulfilling these criteria might facilitate the early detection and might also serve in monitoring drug efficacy. Recently, the extracellular signal-regulated kinase ERK1/2 was detected in CSF of patients with neuropsychiatric disorders. Furthermore, ERK1/2 was reported to be activated in brains of animals infected with pathological prion protein. Therefore, we investigated CSF of 19 patients with CJD, 23 patients with other dementias including patients with Alzheimer's disease, and 12 patients with other neurological disorders. The measurement of ERK1/2 in the CSF samples was performed with an electrochemiluminescence assay and Western immunoblot. ERK1/2 and doubly phosphorylated ERK1/2 (pERK1/2) were detected in all patient groups. Significantly elevated mean levels of total ERK1/2 and pERK1/2 were found in the CJD patients. This increase was also observed in a CJD case that was negative for 14-3-3 protein or in CJD cases that had low levels of tau protein. Western immunoblot analysis suggested that ERK2 was the predominant form of ERKs present in our CSF samples. This pilot study suggests that ERK1/2 is a potential CSF biomarker for CJD, directly associated with the pathophysiological processes. Analysis of larger sample cohorts including other diseases with rapid neurodegeneration are required to confirm our findings.

Until today, a definite diagnosis of Creutzfeldt-Jakob disease (CJD) can only be made neuropathologically. At lifetime the early and differential diagnosis is often a problem. With SELDI we analyzed cerebrospinal fluid (CSF) from 32 CJD patients, 32 patients having other dementive diseases and 31 non-demented control subjects for diagnosis-dependent protein pattern differences. In a screening set of patients, peaks that discriminate best between groups were identified. These peaks were subsequently analyzed using an independent validation set of patients. Diagnostic accuracies were compared with established markers like tau protein and 14-3-3-protein. Potential marker proteins were purified and identified by LC-MS/MS. In the validation set only one peak of 8.6 kDa out of ten in the screening set could be confirmed. This protein was identified to be ubiquitin and increased levels in CSF (but not in serum) of CJD patients were confirmed by Western blot. Ubiquitin allows the correct diagnoses of that CJD cases missed by tau protein or 14-3-3-protein. We conclude that ubiquitin is a promising additional CSF biomarker for diagnosis of CJD, especially in differential diagnostically difficult cases. The selective increase of ubiquitin in CSF of CJD patients might point to an involvement of ubiquitin in pathophysiological process.

This paper connects Alu repeats, the most abundant repetitive elements in the human genome and microRNAs, small RNAs that alter gene expression at the post-transcriptional level. Base-pair complementarity could be demonstrated between the seed sequence of a subset of human microRNAs and Alu repeats that are integrated parallel (sense) in mRNAs. The most common target site coincides with the evolutionary most conserved part of Alu. A primate-specific gene cluster on chromosome 19 encodes the majority of miRNAs that target the most conserved sense Alu site. The individual miRNA genes within this cluster are flanked by an Alu-LINE signature, which has been duplicated with the clustered miRNA genes. Gene duplication events in this locus are supported by comparing repeat length variations of the LINE elements within the cluster with those in the rest of the chromosome. Thus, a dual relationship exists between an evolutionary young miRNA cluster and their Alu targets that may have evolved in the same time window. One hypothesis for this dual relationship is that these miRNAs could protect against too high rates of duplicative transposition, which would destroy the genome. This work was financially supported by a research grant to the FS laboratory (GOA 2004/11) and by SymBioSys, the K.U.Leuven Center of Excellence in Systems Biology. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) are neurodegenerative disorders with heterogeneous clinical presentation but common neuropathological characteristics and pathophysiological substrates, which led to the view of ALS and FTLD representing two manifestations of a clinicopathological spectrum. For both diseases, changes in metabolism of beta-amyloid precursor protein (APP) are reported. In a pilot study, we analyzed cerebrospinal fluid from patients of the ALS-FTLD spectrum for APP processing products. ALS patients show elevated absolute levels of soluble APP and a shift towards the nonamyloidogenic APP processing pathway in contrast to patients with FTLD or ALS + FTLD. Changes in Abeta pattern could be described, allowing separation of patients with pure FTLD from ALS + FTLD. Combination of sAPP and Abeta values improves group differentiation. These findings may provide information on pathophysiological processes in the ALS-FTLD disease spectrum and could have impact in neurochemical diagnosis. We propose to expand this study to larger patient groups comprising followed up cases with known neuropathology.

Metabolic changes in HD pathogenesis and mitochondrial dysfunction are supposed to be closely linked. HD patients lose significantly body weight despite normal or even increased food intake and impairment of ATP synthesis occurs even in pre-motor manifest HD expansion mutation carriers. The molecular mechanisms linking mutant huntingtin to mitochondrial dysfunction are still not understood. In a previous study we have investigated the mitochondrial proteome of brain and skeletal muscle of the transgenic R6/2 mice and the HdhQ-Knock in mice using the 2D-DIGE (2-dimensional differential in-gel electrophoresis) approach. Differentially expressed mitochondrial proteins in R6/2 mouse brains and skeletal muscle belonged to the citric acid cycle, the amino acid degradation pathway, mitochondrial fusion and heat shock proteins. Surprisingly, the majority of these proteins were upregulated in the R6/2 mice. The mitochondrial proteome alterations in the knock-in mouse model HdhQ were similar, although the total number of differently expressed mitochondrial proteins was lower. The upregulation of mitochondrial proteins in the HD transgenic mice was confirmed for some selected proteins. In contrast, no significant changes in expression were found for these proteins in whole tissue lysate, although qPCR data showed a reduction of mtDNA copy number for brain and skeletal muscle of the transgenic mice. Using a high resolution respirometry approach the functional consequences of mitochondrial changes were further studied. Mitochondrial respiration under maximum stimulation of oxidative phosphorylation was unchanged in brain of HD mice, but was decreased in M. soleus. Our data suggest that an overall lower number of mitochondria is compensated by an upregulation of several metabolic pathways, reflecting at least in part compensatory changes. Interestingly, the activity of oxidative phosphorylation seems to be maintained in the brain, but not in skeletal muscle.

Background Several observations indicate that mitochondrial dysfunction plays an important role in the pathogenesis of Huntington9s disease (HD). HD patients lose significant body weight despite normal or increased food intake and impairment of ATP synthesis occurs even in pre-motor manifest HD expansion mutation carriers. Alterations in mitochondrial function and structure include impairment of respiratory chain activity, decrease of Ca 2+ buffering capacity and an increase in size of mitochondria. Until now the molecular mechanisms linking mutant huntingtin to mitochondria dysfunction are not known. Aim Purify mitochondria from brain and skeletal muscle of two HD mouse models and analyse the proteome using a two dimensional differential in-gel electrophoresis (2D-DIGE) approach. Methods/techniques To get a more detailed picture of mitochondrial changes in HD we isolated mitochondria of brain and skeletal muscle of the exon-1 R6/2 mouse model and of the knock-in mouse models HdhQ20/HdhQ111. First, protocols for the isolation of mitochondria using subcellular fractionation/differential centrifugation were optimised and the purity of the mitochondrial fraction was confirmed by western blot. Mitochondrial lysates were then used for proteome analysis using a 2D-DIGE approach. Results In mitochondria of R6/2 mouse brains, mitochondrial proteins of the citric acid cycle, the amino acid degradation and mitochondria fusion were increased. Few selected mitochondrial proteins were downregulated. These results will be further corroborated by western blot and compared with changes in skeletal muscle and to proteome analysis of mitochondria from brain and skeletal muscle in the HdhQ knock-in mice. Conclusions These first results of a mitochondrial proteome analysis on mitochondria from R6/2 mouse brains demonstrating an increase of certain mitochondrial proteins involved in energy metabolism suggests that the observed alterations reflect at least in part compensatory changes.

BACKGROUND: The discrimination of bacterial meningitis (BM) versus viral meningitis (VM) shapes up as a problem, when laboratory data are not equivocal, in particular, when Gram stain is negative. METHODOLOGY/PRINCIPAL FINDINGS: With the aim to determine reliable marker for bacterial or viral meningitis, we subjected cerebrospinal fluid (CSF) to a quantitative proteomic screening. By using a recently established 2D-DIGE protocol which was adapted to the individual CSF flow, we compared a small set of patients with proven BM and VM. Thereby, we identified six potential biomarkers out of which Prostaglandin-H2 D-isomerase was already described in BM, showing proof of concept. In the subsequent validation phase on a more comprehensive collective of 80 patients, we could validate that in BM high levels of glial fibrillary acidic protein (GFAP) and low levels of soluble amyloid precursor protein alpha/beta (sAPPalpha/beta) are present as possible binding partner of Fibulin-1. CONCLUSIONS/SIGNIFICANCE: We conclude that our CSF flow-adapted 2D-DIGE protocol is valid especially in comparing samples with high differences in total protein and suppose that GFAP and sAPPalpha/beta have a high potential as additional diagnostic markers for differentiation of BM from VM. In the clinical setting, this might lead to an improved early diagnosis and to an individual therapy.

Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease that mainly causes degeneration of the upper and lower motor neurons, ultimately leading to paralysis and death within three to five years after first symptoms. The pathological mechanisms leading to ALS are still not completely understood. Several biomarker candidates have been proposed in cerebrospinal fluid (CSF). However, none of these has successfully translated into clinical routine. Part of the reason for this failure to translate may relate to differences across laboratories. For this reason, several of the most commonly used ALS biomarker candidates were evaluated on clinically well-defined ALS samples from six European centres in a multicentre sample-collection approach with centralized sample processing. Results showed that phosphorylated neurofilament heavy chain differentiated between ALS and control cases in all centres. We therefore propose that measurement of phosphorylated neurofilaments in CSF is the most promising candidate for translation into the clinical setting and might serve as a benchmark for other biomarker candidates.