Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “brain proteomics”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources

Behavioural manipulation in a grasshopper harbouring hairworm: a proteomics approach.

The parasitic Nematomorph hairworm, Spinochordodes tellinii (Camerano) develops inside the terrestrial grasshopper, Meconema thalassinum (De Geer) (Orthoptera: Tettigoniidae), changing the insect's responses to water. The resulting aberrant behaviour makes infected insects more likely to jump into an aquatic environment where the adult parasite reproduces. We used proteomics tools (i.e. two-dimensional gel electrophoresis (2-DE), computer assisted comparative analysis of host and parasite protein spots and MALDI-TOF mass spectrometry) to identify these proteins and to explore the mechanisms underlying this subtle behavioural modification. We characterized simultaneously the host (brain) and the parasite proteomes at three stages of the manipulative process, i.e. before, during and after manipulation. For the host, there was a differential proteomic expression in relation to different effects such as the circadian cycle, the parasitic status, the manipulative period itself, and worm emergence. For the parasite, a differential proteomics expression allowed characterization of the parasitic and the free-living stages, the manipulative period and the emergence of the worm from the host. The findings suggest that the adult worm alters the normal functions of the grasshopper's central nervous system (CNS) by producing certain 'effective' molecules. In addition, in the brain of manipulated insects, there was found to be a differential expression of proteins specifically linked to neurotransmitter activities. The evidence obtained also suggested that the parasite produces molecules from the family Wnt acting directly on the development of the CNS. These proteins show important similarities with those known in other insects, suggesting a case of molecular mimicry. Finally, we found many proteins in the host's CNS as well as in the parasite for which the function(s) are still unknown in the published literature (www) protein databases. These results support the hypothesis that host behavioural changes are mediated by a mix of direct and indirect chemical manipulation.

Animals↗

Changes in the brain protein levels following administration of kainic acid.

Kainic acid (KA), a potent neurotoxin and excitatory amino acid, leads to derangements and modulation of brain proteins. No global brain protein expression pattern induced by KA-treatment has been reported yet. We therefore studied the effect of systemic KA administration on the levels of brain proteins. Rats were injected placebo or KA intraperitoneally and brain was taken after one week. The mitochondrial and cytosolic fractions of the brain proteins were analyzed by proteomics technologies and the levels of selected proteins were quantified using specific software. Heat shock protein HSP 27 was exclusively detected in brains of animals treated with KA, whereas the glucose regulated protein GRP 78 was downregulated. The levels of neurofilaments and alpha-internexin were significantly decreased and a fragment of tubulin alpha-1 chain was manifold increased in KA-brains. The mitochondrial enzymes dihydrolipoamide dehydrogenase, ATP synthase beta chain and isocitrate dehydrogenase were reduced and pyruvate kinase M1 was increased following KA treatment. We conclude that the concomitant determination of the brain proteins indicates altered regulation of heat shock proteins, neuronal death, cytoskeletal disruption, and mitochondrial derangement by systemic KA administration. This report confirms and extends previous studies on the effect of KA on the expression of brain proteins and suggests that our analytical system can serve as a model for neurotoxicological, neurobiological, and neuropathological proteome studies.

Animals↗

Proteomic analysis of acrylamide-protein adduct formation in rat brain synaptosomes.

Evidence suggests that the neurological defects (gait abnormalities, foot splay, and skeletal muscle weakness) associated with acrylamide (ACR) intoxication are mediated by impaired neurotransmission at central and peripheral synapses. ACR can form adducts with nucleophilic residues on proteins and thereby alter corresponding structure and function. To evaluate protein adduction in nerve terminals as a possible mechanism of action, recombinant N-ethylmaleimide sensitive factor (NSF) was exposed in vitro to ACR (10 micromol) and mass spectrometry (MS) was used to identify adduct sites. MS analyses demonstrated that ACR formed adducts with sulfhydryl groups on cysteine residues (carbamoylethylcysteine, or CEC) of NSF. Ex vivo incubation of whole brain synaptosomes with ACR (0.001-1.0 M) produced concentration-dependent increases in CEC that were inversely correlated to reductions in neurotransmitter release that occurred over the same neurotoxicant concentration range. In synaptosomes isolated from rats intoxicated at a higher (50 mg/kg per day x 3, 5, 8, or 11 days) or a lower (21 mg/kg per day x 14, 21, or 28 day) ACR dose rate, CEC levels increased progressively up to a moderate level of neurotoxicity. To identify protein adducts, synaptosomal proteins labeled by ex vivo 14C-ACR exposure were separated by gel electrophoresis and probed by immunoblot analysis. Results showed that NSF and the SNARE protein, SNAP-25, were tentative ACR targets. Subsequent experiments indicated that ACR exposure increased synaptosomal levels of the 7S SNARE core complex, which is consistent with inhibition of NSF, SNAP-25 function, or both. These data suggest that adduction of cysteine residues on NSF and certain SNARE proteins might be causally involved in the nerve terminal dysfunction induced by ACR.

Acrylamides↗

Application of proteomics technology to the field of neurotrauma.

Near-completion of the Human Genome Project has stimulated scientists to begin looking for the next step in unraveling normal and abnormal functions within biological systems. Consequently, there is new focus on the role of proteins in these processes. Proteomics is a burgeoning field that may provide a valuable approach to evaluate the post-traumatic central nervous system (CNS). Although we cannot provide a comprehensive assessment of all methods for protein analysis, this report summarizes some of the newer proteomic technologies that have propelled this field into the limelight and that are available to most researchers in neurotrauma. Three technical approaches (two-dimensional gel electrophoresis, direct analysis by mass spectrometry, including two-dimensional chromatography coupled to mass spectrometry and isotope coded affinity tags, and antibody technologies) are reviewed, and their advantages and disadvantages presented. A discussion of proteomic technology in the context of brain and spinal cord trauma follows, addressing current and future challenges. Proteomics will likely be very useful for developing diagnostic predictors after CNS injury and for mapping changes in proteins after injury in order to identify new therapeutic targets. Neurotrauma results in complex alterations to the biological systems within the nervous system, and these changes evolve over time. Exploration of the "new nervous system" that follows injury will require methods that can both fully assess and simplify this complexity.

Antibodies↗

Uncovering the signaling networks of disseminated glioblastoma cells in vivo with INSIGHT.

Dysregulation of intracellular signaling networks underpins cancer. Yet, resolving signaling networks within distinct or rare cell types in cancer in vivo has been unattainable. Here we develop INSIGHT by integrating cell sorting with mass spectrometry to enable quantitative phosphoproteomics and proteomics of discrete cell types from fixed tissues. Using INSIGHT, we map the signaling network within disseminating glioblastoma cells from patient-derived xenografts implanted in mice. Disseminating tumor cells undergo a proteome-wide shift from proliferative to mesenchymal, neural progenitor-like cell states. In parallel, signaling network and global kinase activity are rewired, transitioning from cell cycle-associated circuitries to those governing synaptic function, neuronal migration, and ion channel activity. Changes begin at the tumor margin and persist in distant brain parenchyma. Hornerin and phosphorylation of Ca²⁺-permeable GluA2 at Y876 were identified as mediators of glioblastoma progression. INSIGHT enables systems-level dissection of cell-type-specific signaling circuitries in vivo across wide range of biological systems.

Glioblastoma↗

A rat brain protein expression map including cytosolic and enriched mitochondrial and microsomal fractions.

Proteomics is a powerful tool to screen brain protein expression but the methodology is hampered by low abundance of proteins or compartmentalization or overload of high-abundance proteins. It was therefore the aim of the study to determine the expression of brain proteins by using enriched cellular subfractions and pre-electrophoretic chromatographical separation of brain homogenates. We used two-dimensional electrophoresis with subsequent matrix-assisted laser desorption/ionization (MALDI) detection and characterization of brain proteins. Subfractionation into cytosolic, mitochondrial and microsomal compartments was performed by ultracentrifugation. Pre-electrophoretic fractionation of the cytosolic fractions was carried out by ion exchange column chromatography. We detected and identified a large series of 437 proteins in rat brain and have shown proteins specific for the individual subcellular compartments. These proteins included housekeeping, signaling, cytoskeletal, intermediary metabolism, antioxidant proteins on the one and neuron and synaptosomal specific proteins on the other hand. Using fractionations of brain homogenates we were able to improve the power of the method on forming the basis for brain protein expressional studies and providing a reference map as a powerful tool for the neuroscientist.

Animals↗

Exploring the O-GlcNAc proteome: direct identification of O-GlcNAc-modified proteins from the brain.

The covalent modification of intracellular proteins by O-linked beta-N-acetylglucosamine (O-GlcNAc) is emerging as a crucial regulatory posttranslational modification akin to phosphorylation. Numerous studies point to the significance of O-GlcNAc in cellular processes such as nutrient sensing, protein degradation, and gene expression. Despite its importance, the breadth and functional roles of O-GlcNAc are only beginning to be elucidated. Advances in our understanding will require the development of new strategies for the detection and study of O-GlcNAc-modified proteins in vivo. Herein we report the direct, high-throughput analysis of O-GlcNAc-glycosylated proteins from the mammalian brain. The proteins were identified by using a chemoenzymatic approach that exploits an engineered galactosyltransferase enzyme to selectively label O-GlcNAc proteins with a ketone-biotin tag. The tag permits enrichment of low-abundance O-GlcNAc species from complex mixtures and localization of the modification to short amino acid sequences. Using this approach, we discovered 25 O-GlcNAc-glycosylated proteins from the brain, including regulatory proteins associated with gene expression, neuronal signaling, and synaptic plasticity. The functional diversity represented by this set of proteins suggests an expanded role for O-GlcNAc in regulating neuronal function. Moreover, the chemoenzymatic strategy described here should prove valuable for identifying O-GlcNAc-modified proteins in various tissues and facilitate studies of the physiological significance of O-GlcNAc across the proteome.

Acetylglucosamine↗

Midkine attenuates amyloid-β fibril assembly and plaque formation.

Proteomic profiling of Alzheimer disease (AD) brains has identified numerous understudied proteins, including midkine (MDK), that are highly upregulated and correlated with amyloid-β (Aβ) from the early disease stage but their roles in disease progression are not fully understood. Here, we present that MDK attenuates Aβ assembly and influences amyloid formation in the 5xFAD amyloidosis mouse model. MDK protein mitigates fibril formation of both Aβ40 and Aβ42 peptides according to thioflavin T fluorescence, circular dichroism, negative-stain electron microscopy and nuclear magnetic resonance analyses. Knockout of the Mdk gene in 5xFAD increased amyloid formation and microglial activation in the brain. Further comprehensive mass-spectrometry-based profiling of the whole proteome and detergent-insoluble proteome in these mouse models indicated significant accumulation of Aβ and Aβ-correlated proteins, along with microglial components. Thus, our structural and mouse model studies reveal a protective role of MDK in counteracting amyloid pathology in AD.

Animals↗

Identification of disease markers in human cerebrospinal fluid using lipidomic and proteomic methods.

Lipids comprise the bulk of the dry mass of the brain. In addition to providing structural integrity to membranes, insulation to cells and acting as a source of energy, lipids can be rapidly converted to mediators of inflammation or to signaling molecules that control molecular and cellular events in the brain. The advent of soft ionization procedures such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) have made it possible for compositional studies of the diverse lipid structures that are present in brain. These include phospholipids, ceramides, sphingomyelin, cerebrosides, cholesterol and their oxidized derivatives. Lipid analyses have delineated metabolic defects in disease conditions including mental retardation, Parkinson's Disease (PD), schizophrenia, Alzheimer's Disease (AD), depression, brain development, and ischemic stroke. In this review, we examine the structure of the major lipid classes in the brain, describe methods used for their characterization, and evaluate their role in neurological diseases. The potential utility of characterizing lipid markers in the brain, with specific emphasis on disease mechanisms, will be discussed. Additionally, we describe several proteomic strategies for characterizing lipid-metabolizing proteins in human cerebrospinal fluid (CSF). These proteins may be potential therapeutic targets since they transport lipids required for neuronal growth or convert lipids into molecules that control brain physiology. Combining lipidomics and proteomics will enhance existing knowledge of disease pathology and increase the likelihood of discovering specific markers and biochemical mechanisms of brain diseases.

Biomarkers↗

Ecto-F1Fo ATP synthase/F1 ATPase: metabolic and immunological functions.

PURPOSE OF REVIEW: Until recently, F1Fo ATP synthase expression was believed to be strictly confined to mitochondria where it generates most cellular ATP. This paper reviews the recent evidence for an extra-mitochondrial expression of its components by immunofluorescence, biochemistry and proteomics studies. It discusses its possible implications in an ecto-nucleotide metabolism and its pathophysiological role in normal and tumoral cells. RECENT FINDINGS: F1Fo ATP synthase components have been identified as cell-surface receptors for apparently unrelated ligands in the course of studies carried out on angiogenesis, lipoprotein metabolism, innate immunity, hypertension, or regulation of food intake. SUMMARY: F1Fo ATP synthase is expressed on endothelial cells where it binds angiostatin, regulates surface ATP levels, and modulates endothelial cell proliferation and differentiation. Through binding of apolipoprotein A-I, a similar complex, expressed on hepatocytes, regulates lipoprotein internalization. On tumors, it is recognized in association with apolipoprotein A-I by the antigen receptor of circulating cytotoxic lymphocytes of the gammadelta subtype and thus promotes an innate tumor cell recognition and lysis. It binds enterostatin on brain cells. Biochemistry and proteomics studies indicate an enrichment of F1Fo components in lipid rafts selectively with some other mitochondrial proteins, suggesting intracellular traffic connections between mitochondria and other membrane compartments. Finally, depending on cell type and environment, it can generate ATP or ADP which may transfer a downstream signal to purinergic receptors.

Animals↗

Proteome analysis of primary neurons and astrocytes from rat cerebellum.

Neurons and astrocytes are predominant cell types in brain and have distinguished morphological and functional features. Although several proteomics studies were carried out on the brain, work on individual brain cells is limited. Generating individual proteomes of neurons and astrocytes, however, is mandatory to assign protein expression to cell types rather than to tissues. We aimed to provide maps of rat primary neurons and astrocytes using two-dimensional gel electrophoresis with subsequent in-gel digestion, followed by MALDI-TOF/TOF. 428 protein spots corresponding to 226 individual proteins in neurons and 406 protein spots representing 228 proteins in astrocytes were unambiguously identified. Proteome data include proteins from several cascades differentially expressed in neurons and astrocytes, and specific expressional patterns of antioxidant, signaling, chaperone, cytoskeleton, nucleic acid binding, proteasomal, and metabolic proteins are demonstrated. We herein present a reference database of primary rat primary neuron and astrocyte proteomes and provide an analytical tool for these structures. The concomitant expressional patterns of several protein classes are given and potential neuronal and astrocytic marker candidates are presented.

Animals↗

Proteomic analysis of the ventromedial nucleus of the hypothalamus (pars lateralis) in the female rat.

The use of proteomics to study changes in the expression of CNS proteins, which may underlie the regulation of physiological and/or behavioral responses, represents an emerging application of this technology. In the current study, the Palkovits' microdissection method was evaluated as a means of obtaining proteomic data from discrete brain nuclei. The pars lateralis of the ventromedial nucleus of the hypothalamus (VMN) was chosen for the initial studies because of its established role in the expression of gonadal hormone dependent female sexual behavior. The VMN from ovariectomized rats was microdissected from 300 microm frozen brain sections using a 500 microm punch. Total proteins were separated using 2-DE. A group consensus of 432 protein spots, visualized by SYPRO Ruby stain, was obtained from gels from four independent VMN samples. A low mean CV and high gel-to-gel correlation coefficients indicate that reproducible 2-DE gels can be generated from microdissected tissue samples. Proteins from the mediobasal hypothalamus (MBH) were also separated on 2-DE gels. Evaluation of the 2-DE maps from the VMN and the MBH revealed different protein profiles, and indicates that microdissection improves the detection of low-abundance proteins, and reduces the relative occurrence of abundant proteins on 2-DE maps.

Animals↗

Gene profiling of laser-microdissected brain regions and sub-regions.

The application of transcriptomics and proteomics approaches to accurately dissected anatomically-defined brain regions and sub-regions remains a central focus of current neurobiological investigations as well as a necessary step towards single-neuron neurogenomics and neuroproteomics. A protocol is described for the simple, rapid, and reproducible laser microdissection of brain regions and sub-regions for microarray-based gene expression analyses from individual rats or mice using two rounds of in vitro transcription (IVT). The results presented also demonstrate that the current Affymetrix GeneChip arrays are well suited for this experimental design with high reproducibility and limited effects of the shortening of target RNA caused by the double IVT approach.

Animals↗

Peptide motifs: building the clathrin machinery.

Clathrin-coated vesicles (CCVs) form at the plasma membrane, where they select cargo for endocytic entry into cells, and at the trans-Golgi network (TGN) and the endosomal system, where they generate carrier vesicles that transport proteins between these compartments. We have used subcellular fractionation and tandem mass spectrometry to identify proteins associated with brain CCVs. The resulting proteome contained a near complete inventory of the major functional proteins of synaptic vesicles (SVs), suggesting that clathrin-mediated endocytosis provides a major mechanism to recycle SV membrane proteins following neurotransmitter release. Additionally, we identified several new components of the machineries for clathrin-mediated membrane budding, including enthoprotin/epsinR and NECAP 1/2. These proteins bind with high specificity to the ear domains of the clathrin adaptor proteins (APs)-1 and -2, and, intriguingly, they each utilize novel peptide motifs based around the core sequence ØXXØ. Detailed mutational analysis of these motifs, coupled with structural studies of the ear domains, has revealed the basis of their specificity for clathrin adaptors. Moreover, the motifs have now been recognized in multiple proteins functioning in clathrin-mediated membrane trafficking, revealing new mechanisms in the formation and function of CCVs. Thus, proteomics analysis of isolated organelles can provide insights ranging from peptide motifs to global organelle function.

Animals↗

Protein oxidation and lipid peroxidation in brain of subjects with Alzheimer's disease: insights into mechanism of neurodegeneration from redox proteomics.

Alzheimer's disease (AD), the leading cause of dementia, involves regionalized neuronal death, synaptic loss, and an accumulation of intraneuronal, neurofibrillary tangles and extracellular senile plaques. Although the initiating causes leading to AD are unknown, a number of previous studies reported the role of oxidative stress in AD brain. Postmortem analysis of AD brain showed elevated markers of oxidative stress including protein nitrotyrosine, carbonyls in proteins, lipid oxidation products, and oxidized DNA bases. In this review, we focus our attention on the role of protein oxidation and lipid peroxidation in the pathogenesis of AD. Particular attention is given to the current knowledge about the redox proteomics identification of oxidatively modified proteins in AD brain.

Alzheimer Disease↗

Mitochondrial dysfunction in schizophrenia: evidence for compromised brain metabolism and oxidative stress.

The etiology and pathophysiology of schizophrenia remain unknown. A parallel transcriptomics, proteomics and metabolomics approach was employed on human brain tissue to explore the molecular disease signatures. Almost half the altered proteins identified by proteomics were associated with mitochondrial function and oxidative stress responses. This was mirrored by transcriptional and metabolite perturbations. Cluster analysis of transcriptional alterations showed that genes related to energy metabolism and oxidative stress differentiated almost 90% of schizophrenia patients from controls, while confounding drug effects could be ruled out. We propose that oxidative stress and the ensuing cellular adaptations are linked to the schizophrenia disease process and hope that this new disease concept may advance the approach to treatment, diagnosis and disease prevention of schizophrenia and related syndromes.

Brain↗

Expression of calpastatin, minopontin, NIPSNAP1, rabaptin-5 and neuronatin in the phenylketonuria (PKU) mouse brain: possible role on cognitive defect seen in PKU.

Phenylketonuria (PKU) is an inborn error of amino acid metabolism. Phenylalanine hydroxylase (PAH) deficiency results in accumulation of phenylalanine (Phe) in the brain and leads to pathophysiological abnormalities including cognitive defect, if Phe diet is not restricted. Neuronatin and 4-nitrophenylphosphatase domain and non-neuronal SNAP25-like protein homolog 1 (NIPSNAP1) reportedly have role in memory. Therefore, gene expression was examined in the brain of mouse model for PKU. Microarray expression analysis revealed reduced expression of calpastatin, NIPSNAP 1, rabaptin-5 and minopontin genes and overexpression of neuronatin gene in the PKU mouse brain. Altered expression of these genes was further confirmed by one-step real time RT-PCR analysis. Western blot analysis of the mouse brain showed reduced levels of calpastatin and rabaptin-5 and higher amount of neuronatin in PKU compared to the wild type. These observations in the PKU mouse brain suggest that altered expression of these genes resulting in abnormal proteome. These changes in the PKU mouse brain are likely to contribute cognitive impairment seen in the PKU mouse, if documented also in patients with PKU.

Animals↗

Redefining ALS: Large-scale proteomic profiling reveals a prolonged pre-diagnostic phase with immune, muscular, metabolic, and brain involvement.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder with a largely unknown duration and pathophysiology of the pre-diagnostic phase, especially for the common non-monogenic form. METHODS: We leveraged the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort with up to 30 years of follow-up to identify incident ALS cases across five European countries. Pre-diagnostic plasma samples from initially healthy participants underwent high-throughput proteomic profiling (7,285 protein markers, SomaScan). Cox proportional hazards models based on 4,567 participants (including 172 incident ALS cases) were used to identify protein biomarkers associated with future ALS diagnosis. Top results were indirectly validated in two independent case-control studies of prevalent ALS (n=417 ALS, 852 controls). Functional annotation included cross-disease comparisons, gene set and tissue enrichment testing, organ-specific proteomic clocks, and the application of large-language models (LLM). FINDINGS: Five proteins (SECTM1, CA3, THAP4, KLHL41, SLC26A7) were identified as significant pre-diagnostic ALS biomarkers (FDR=0.05), detectable approximately two decades before diagnosis. Of these, all except SECTM1 were indirectly validated in independent cohorts of prevalent ALS cases, supporting their clinical significance. Additionally, 22 nominally significant (p<0.05) pre-diagnostic biomarkers were FDR-significant in prevalent ALS with consistent effect directions. Cross-disease comparisons with pre-diagnostic Parkinson's and Alzheimer's disease suggested a largely specific pre-diagnostic ALS biomarker signature. Gene ontology and tissue enrichment highlighted early involvement of immune, muscle, metabolic, and digestive processes. Furthermore, analyses of proteomic clocks revealed accelerated aging in brain-cognition, immune, and muscle tissues before clinical diagnosis. Druggability and LLM analyses revealed possible therapeutic targets and novel strategies, emphasizing translational relevance. INTERPRETATION: Our study provides first evidence of ultra-early molecular changes in common ALS up to two decades prior to clinical onset, mainly affecting immune, muscle, metabolic, digestive, and cognitive systems. Our study nominates several compelling candidates for risk stratification studies and novel therapeutic targets for early intervention. FUNDING: Clinical Research in ALS and Related Disorders for Therapeutic Development (CreATe) Consortium, Cure Alzheimer's Fund, Michael J Fox Foundation, Interdisciplinary Centre for Clinical Research, University M&#xfc;nster.

Journal Article↗