PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “brain proteomics”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 55 records · Page 3Linked to original sources

Proteomic mapping of brain plasma membrane proteins.

Proteomics is potentially a powerful technology for elucidating brain function and neurodegenerative diseases. So far, the brain proteome has generally been analyzed by two-dimensional gel electrophoresis, which usually leads to the complete absence of membrane proteins. We describe a proteomic approach for profiling of plasma membrane proteins from mouse brain. The procedure consists of a novel method for extraction and fractionation of membranes, on-membrane digestion, diagonal separation of peptides, and high-sensitivity analysis by advanced MS. Breaking with the classical plasma membrane fractionation approach, membranes are isolated without cell compartment isolation, by stepwise depletion of nonmembrane molecules from entire tissue homogenate by high-salt, carbonate, and urea washes followed by treatment of the membranes with sublytic concentrations of digitonin. Plasma membrane is further enriched by of density gradient fractionation and protein digested on-membrane by endoproteinase Lys-C. Released peptides are separated, fractions digested by trypsin, and analyzed by LC-MS/MS. In single experiments, the developed technology enabled identification of 862 proteins from 150 mg of mouse brain cortex. Further development and miniaturization allowed analysis of 15 mg of hippocampus, revealing 1,685 proteins. More that 60% of the identified proteins are membrane proteins, including several classes of ion channels and neurotransmitter receptors. Our work now allows in-depth study of brain membrane proteomes, such as of mouse models of neurological disease.

Animals↗

Proteomics in brain research: potentials and limitations.

The advent of proteomics techniques has been enthusiastically accepted in most areas of biology and medicine. In neuroscience, a host of applications was proposed ranging from neurotoxicology, neurometabolism, determination of the proteome of the individual brain areas in health and disease, to name a few. Only recently, the limitations of the method have been shown, hampering the rapid spreading of the technology, which in principle consists of two-dimensional gel electrophoresis with in-gel protein digestion of protein spots and identification by mass-spectrometrical approaches or microsequencing. The identification, including quantification using specific software, of brain protein classes, like enzymes, cytoskeleton proteins, heat shock proteins/chaperones, proteins of the transcription and translation machinery, synaptosomal proteins, antioxidant proteins, is a clear domain of proteomics. Furthermore, the concomitant detection of several hundred proteins on a gel allows the demonstration of an expressional pattern, rather generated by a reliable, protein-chemical method than by immunoreactivity, proposed by protein-arrays. An additional advantage is that hitherto unknown proteins, so far only proposed from their nucleic acid structure, designated as hypothetical proteins, can be identified as brain proteins. As to shortcomings and disadvantages of the method we would point to the major problem, the failure to separate hydrophobic proteins. There is so far no way to analyse the vast majority of these proteins in gels. Several other analytical problems need to be overcome, but once the latter problem can be solved, there is nothing to stop the method for a large scale analysis of membrane proteins in neuroscience.

Animals↗

Quantitative proteomic profiling of membrane proteins from the mouse brain cortex, hippocampus, and cerebellum using the HysTag reagent: mapping of neurotransmitter receptors and ion channels.

Analysis of the brain proteome and studying brain diseases through clinical biopsies and animal disease models require methods of quantitative proteomics that are sensitive and allow identification and quantification of low abundant membrane proteins from minute amount of tissue. Taking advantage of recently developed methods for isolation of membrane proteins from 10-20 mg brain tissue [Nielsen, P.Aa., Olsen, J.V., Podtelejnokov, A.V., Andersen, J.R., Mann, M., Wiśniewski, J.R., 2005. Proteomic mapping of brain plasma membrane proteins. Mol. Cell. Proteomics 4, 402--408] and the HysTag-quantification method [Olsen, J.V., Andersen, J.R., Nielsen, P.Aa., Nielsen, M.L., Figeys, D., Mann, M., Wiśniewski, J.R., 2004. HysTag---A novel proteomic qualification tool applied to differential analysis of membrane proteins from distinct areas of mouse brain. Mol. Cell. Proteomics 3, 82--92] we performed quantitative proteomic analysis of three functionally distinct compartments of mouse brain: cortex, hippocampus, and cerebellum. In total, 976 unique peptides corresponding to 555 unique proteins were quantified. Up to 20-fold differences in the levels of some proteins between brain areas were measured. For many quantified proteins--as for glutamate receptors, calcium channel subunits, and ATP-ases--an excellent correlation between our proteomic data and previously published mRNA expression levels or intensity of immunostaining was found. Our results clearly demonstrate differences in levels of membrane proteins mapped in distinct brain compartments and offer a technology that allows in depth study of brain membrane proteomes, such as mouse models of neurological diseases.

Animals↗

Molecular Signatures of Neurodegenerative Diseases Identified by Proteomic and Phosphoproteomic Analyses in Aging Mouse Brain.

A central hallmark of neurodegenerative diseases is the irreversible accumulation of misfolded proteins in the brain by aberrant phosphorylation. Understanding the mechanisms underlying protein phosphorylation and its role in pathological protein aggregation within the context of aging is crucial for developing therapeutic strategies aimed at preventing or reversing such diseases. Here, we applied multi-protease digestion and quantitative mass spectrometry to compare and characterize dysregulated proteins and phosphosites in the mouse brain proteome using three different age groups: young-adult (3-4 months), middle-age (10 months), and old mice (19-21 months). Proteins associated with senescence, neurodegeneration, inflammation, cell cycle regulation, the p53 hallmark pathway, and cytokine signaling showed significant age-dependent changes in abundances and level of phosphorylation. Several proteins implicated in Alzheimer's disease (AD) and Parkinson's disease (PD) including tau (Mapt), Nefh, and Dpysl2 (also known as Crmp2) were hyperphosphorylated in old mice brain suggesting their susceptibility to the diseases. Cdk5 and Gsk3b, which are known to phosphorylate Dpysl2 at multiple specific sites, had also increased phosphorylation levels in old mice suggesting a potential crosstalk between them to contribute to AD. Hapln2, which promotes α-synuclein aggregation in patients with PD, was one of the proteins with highest abundance in old mice. CD9, which regulates senescence through the PI3K-AKT-mTOR-p53 signaling was upregulated in old mice and its regulation was correlated with the activation of phosphorylated AKT1. Overall, the findings identify a significant association between aging and the dysregulation of proteins involved in various pathways linked to neurodegenerative diseases with potential therapeutic implications.

Animals↗

[Effect of some active Chinese herbal fraction on brain tissue proteomic profile of ischemic mouse].

OBJECTIVE: To study the effect of some active Chinese herbal fraction on protein expression of brain tissue in ischemic mouse with proteomic technique. METHODS: Ischemia-reperfusion mice were treated with baicalin, geniposide, cholic acid and concha margaritifera respectively for 3 hrs, and then their brain tissue were taken to extract the total protein. Protein expression in ischemic mouse brain was analyzed with surface-enhanced laser desorption/inionation-time of flight-mass spectra (SELDI-TOF-MS) protein-chip. RESULTS: The four components tested had effect on 3 target proteins at 5373Da, 5707Da and 15103Da, showing the nature of multi-target and with different action on protein expression. CONCLUSION: Protein-chip is an effective approach for exploring the pharmacological mechanism of Chinese herbal fraction.

Animals↗

Identification of proteins whose expression is up- or down-regulated in the mushroom bodies in the honeybee brain using proteomics.

To identify protein(s) with different expression patterns in the mushroom bodies (MBs) in the honeybee brain, we compared the protein profiles of MBs and optic lobes (OLs) using proteomics. Two-dimensional gel electrophoresis revealed that five and three spots were selectively expressed in the MBs or OLs, respectively. Liquid chromatography tandem mass spectrometry analysis identified juvenile hormone diol kinase and glyceraldehyde-3-phosphate dehydrogenase as MB- and OL-selective proteins, respectively. In situ hybridization revealed that jhdk expression was upregulated in MB neuron subsets, whereas gapdh expression was downregulated, indicating that MBs have a distinct gene and protein expression profile in the honeybee brain.

Animals↗

Gaining knowledge from previously unexplained spectra-application of the PTM-Explorer software to detect PTM in HUPO BPP MS/MS data.

A novel software tool named PTM-Explorer has been applied to LC-MS/MS datasets acquired within the Human Proteome Organisation (HUPO) Brain Proteome Project (BPP). PTM-Explorer enables automatic identification of peptide MS/MS spectra that were not explained in typical sequence database searches. The main focus was detection of PTMs, but PTM-Explorer detects also unspecific peptide cleavage, mass measurement errors, experimental modifications, amino acid substitutions, transpeptidation products and unknown mass shifts. To avoid a combinatorial problem the search is restricted to a set of selected protein sequences, which stem from previous protein identifications using a common sequence database search. Prior to application to the HUPO BPP data, PTM-Explorer was evaluated on excellently manually characterized and evaluated LC-MS/MS data sets from Alpha-A-Crystallin gel spots obtained from mouse eye lens. Besides various PTMs including phosphorylation, a wealth of experimental modifications and unspecific cleavage products were successfully detected, completing the primary structure information of the measured proteins. Our results indicate that a large amount of MS/MS spectra that currently remain unidentified in standard database searches contain valuable information that can only be elucidated using suitable software tools.

Amino Acid Sequence↗

Impacts of hnRNP A1 Splicing Inhibition on the Brain Remyelination Proteome.

Oligodendrocytes, the myelinating cells in the central nervous system, are implicated in several neurological disorders marked by dysfunctional RNA-binding proteins (RBPs). The present study aimed at investigating the role of hnRNP A1 in the proteome of the corpus callosum, prefrontal cortex, and hippocampus of a murine cuprizone-induced demyelination model. Right after the cuprizone insult, we administered an hnRNP A1 splicing activity inhibitor and analyzed its impact on brain remyelination by nanoESI-LC-MS/MS label-free proteomic analysis to assess the biological processes affected in these brain regions. Significant alterations in essential myelination proteins highlighted the involvement of hnRNP A1 in maintaining myelin integrity. Pathways related to sphingolipid and endocannabinoid signaling were affected, as well as the synaptic vesicle cycle and GABAergic synapses. Although behavioral impairments were not observed, molecular changes suggest potential links to memory, synaptic function, and neurotransmission processes. These findings enhance our understanding of the multifaceted roles of hnRNP A1 in the central nervous system, providing valuable insights for future investigations and therapeutic interventions in neurodegenerative and demyelinating diseases.

Animals↗

The rat brain hippocampus proteome.

The hippocampus is crucial in memory storage and retrieval and plays an important role in stress response. In humans, the CA1 area of hippocampus is one of the first brain areas to display pathology in Alzheimer's disease. A comprehensive analysis of the hippocampus proteome has not been accomplished yet. We applied proteomics technologies to construct a two-dimensional database for rat brain hippocampus proteins. Hippocampus samples from eight months old animals were analyzed by two-dimensional electrophoresis and the proteins were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The database comprises 148 different gene products, which are in the majority enzymes, structural proteins and heat shock proteins. It also includes 39 neuron specific gene products. The database may be useful in animal model studies of neurological disorders.

Animals↗

Neuroproteomics: expression profiling of the brain's proteomes in health and disease.

The term "proteome" describes the protein complement of a genome. Proteomes of cells are dynamic and are directly affected by environmental factors, such as stress and/or drug treatment, or as a result of aging and disease. One of the distinct advantages of proteomic analysis, not attainable with RNA expression data, is the ability to fractionate the cell's proteins into various subpopulations. In neuroscience, "neuromics" (proteomics in the central nervous system) is in its infancy, with a paucity of studies in the context of the brain. One of the objectives of this review is to illustrate the potential of neuromics to profile differences in the distribution of thousands of proteins as a function of disease markers. We have previously used this approach to determine the effects of varied postmortem interval in examining human brain tissue and to identify biomarkers. Here we review proteomic studies of schizophrenia, Alzheimer's disease, and Parkinson's disease. Experimental results regarding Parkinson's disease are presented to illustrate the potential of neuromics to identify pathways of pathogenesis and novel therapeutic targets.

Alzheimer Disease↗

Changes in the brain mitochondrial proteome of male Sprague-Dawley rats treated with manganese chloride.

To probe the mitochondrial involvement in Mn intoxicity, aliquots of brain mitochondria samples from control and treated (30 mg/kg manganese chloride, ip) male Sprague-Dawley rats were separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and searched for protein abundance changes induced by Mn exposure. The electrophoretic separation resolved over 300 distinct spots as visualized by colloidal Coomassie blue (CCB), of which three spots were induced and three spots were inhibited after Mn exposure in all the five brain mitochondria preparations. Analysis by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) indicated that these spots are calcium-transporting ATPase type 2C (ATP-dependent Ca(2+) pump PMR1); 60-kDa heat shock protein; Mitochondrial transmembrane GTPase FZO1B; ATP-binding cassette, sub-family b; Long-chain-fatty-acid-CoA ligase; ATP Synthase Beta Chain; and Succinate dehydrogenase flavoprotein subunit. The changes of the mitochondrial ATP synthase beta-subunit and Succinate dehydrogenase flavoprotein subunit indicate an effected level of mitochondrial ATP content and/or ATP-producing capacity. This result provides suggestion that respiratory chain complexes were implicated in the mitochondrial dysfunction induced by Mn intoxicity. And the changes of 60-kDa heat shock protein and ATP-dependent Ca(2+) pump PMR1 expression indicate that the Ca homeostasis and stress effect were involved in Mn intoxicity.

Adenosine Triphosphate↗

Acute toxicity profile of cadmium revealed by proteomics in brain tissue of Paralichthys olivaceus: potential role of transferrin in cadmium toxicity.

An analytical approach using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) separated proteins from the brain tissue of the fish Paralichthys olivaceus. Approximately 600 protein spots were detected from the brain sample when applying 600 microg protein to a 2D-PAGE gel in the pH range 3.5-10.0. Compared to a control sample, significant changes of 24 protein spots were observed in the fish tissue exposed to acute toxicity of seawater cadmium (SCAT) at 10 ppm for 24h. Among these spots, nine were down-regulated, nine were up-regulated, two showed high expression, and four showed low expression. The collected spots were identified by peptide mass fingerprinting (PMF) and database search, and they were further classified by LOC tree, a hierarchical system of support vector machines which predict their sub-cellular localization. The amount of transferrin expression in brain cells decreased linearly with the increase of SCAT concentration in seawater. Among the 24 proteins identified on a 2D-PAGE gel, 9 demonstrated a synchronous response to acute cadmium, suggesting that they might represent a biomarker profile. Based on their variable levels and trends on the 2D-PAGE gel this protein (likely to be transferrin) suggesting they might be utilized as biomarkers to investigate cadmium pollution levels in seawater and halobios survival, as well as to evaluate the degree of risk of human fatalities. The results indicate that the application of multiple biomarkers has an advantage over a single biomarker for monitoring levels of environmental contamination.

Animals↗

Analysis of the mouse proteome. (I) Brain proteins: separation by two-dimensional electrophoresis and identification by mass spectrometry and genetic variation.

The total protein of the mouse brain was fractionated into three fractions, supernatant, pellet extract and rest pellet suspension, by a procedure that avoids any loss of groups or classes of proteins. The supernatant proteins were resolved to a maximum by large-gel two-dimensional electrophoresis. Two-dimensional patterns from ten individual mice of the commonly used inbred strain C57BL/6 (species: Mus musculus) were prepared. The master pattern was subjected to densitometry, computer-assisted image analysis and treatment with our spot detection program. The resulting two-dimensional pattern, a standard pattern for mouse brain supernatant proteins, was divided into 40 squares, calibrated, and specified by providing each spot with a number. The complete pattern and each of the 40 squares are shown in our homepage (http://www.charite.de/ humangenetik). The standard pattern comprises 8767 protein spots. To identify the proteins known so far in the brain fraction investigated, a first set of 200 spots was analyzed by matrix-assisted laser desorption/ionization - mass spectrometry (MALDI-MS) after in-gel digestion. By screening protein databases 115 spots were identified; by extending the analysis to selected, genetically variant protein spots, 166 spots (including some spot series) were identified in total. This number was increased to 331 by adding protein spots identified indirectly by a genetic approach. By comparing the two-dimensional patterns from C57BL/6 mice with those of another mouse species (Mus spretus), more than 1000 genetically variant spots were detected. The genetic analysis allowed us to recognize spot families, i.e., protein spots that represent the same protein but that are post-translationally modified. If some members of the family were identified, the whole family was considered as being identified. Spot families were investigated in more detail, and interpreted as the result of protein modification or degradation. Genetic analysis led to the interesting finding that the size of spot families, i.e., the extent of modification or degradation of a protein, can be genetically determined. The investigation presented is a first step towards a systematic analysis of the proteome of the mouse. Proteome analysis was shown to become more efficient, and, at the same time, linked to the genome, by combining protein analytical and genetic methods.

Animals↗

Mapping the causal chain from genetic risk variants to lipid dysmetabolism in Parkinson's disease.

The molecular pathways linking genetic variants to Parkinson's disease (PD) onset and progression remain incompletely defined; however, risk alleles in multiple genes, including GBA1, strongly implicate lipid metabolism. To systematically identify causal biomarker signatures, we analysed comprehensive metabolome profiles from blood plasma in 149 PD patients and 150 controls, along with complementary genetic, RNA-sequencing and metabolic data from other available clinical and pathologic cohorts. Using colocalization and summary-data-based Mendelian randomization, we tested whether expression and metabolic quantitative trait loci mediate the association between implicated genetic variants and PD risk. We further integrated differential metabolomics and proteomics from blood and brain to reveal pertinent mechanisms. We show that common PD risk variants at the serine palmitoyltransferase small subunit B (SPTSSB) locus, a key regulator of de novo sphingolipid biosynthesis, are associated with increased SPTSSB brain expression and elevated plasma ceramides. Additional analyses strongly support our hypothesis that a common SPTSSB causal variant is responsible for PD risk as well as the expression and metabolic quantitative trait loci. Multiple sphingolipids and fatty acid derivatives were perturbed in PD, and we identified both unique and shared features with the Alzheimer's disease metabolome. A PD acylcarnitine signature was further replicated in human post-mortem brain tissue, when comparing those with or without preclinical Lewy body pathology. Integrated analysis of complementary brain proteomic profiles revealed dysregulation of mitochondrial processes dependent on acylcarnitines, including fatty acid beta-oxidation, the tricarboxylic acid cycle and oxidative phosphorylation. Our results identify promising biomarkers and reveal a causal chain linking genetic variation to altered gene/protein expression, lipid dysmetabolism, and the manifestation of PD.

Humans↗

Loss of ovarian function and estrogen therapy remodel the brain's synaptic and metabolic proteome.

Menopause is linked to cognitive decline and reduced brain metabolism, whereas estrogen (E2) therapy has been shown to mitigate these effects. Understanding the molecular mechanisms by which ovarian hormones and E2 influence neuroprotection is essential for developing strategies to maintain brain health in women. In this study, we examined how the loss of ovarian hormones, with or without E2 treatment, affects the brain proteome and mitochondrial energy production in aged female C57BL/6J mice (36-40 wk). The mice underwent sham or ovariectomy (OVX) surgery and were fed a high-fat diet for 10 wk; 6 wk after surgery, OVX mice received either sesame oil or E2 treatment for 4 wk. Proteomic analysis of brain homogenates revealed 4,992 proteins regulated by E2, with pathway analysis showing increased signaling proteins related to synaptogenesis. OVX reduced proteins involved in synaptic function, branched-chain amino acid and ketone metabolism, the tricarboxylic acid cycle, and oxidative phosphorylation (Complexes I, IV, and V), whereas E2 restored protein expression within these pathways. Despite alterations in OxPhos proteins, basal and state 3 mitochondrial respiration remained unchanged, although notable impairments in Complex IV enzymatic activity were apparent in OVX, which were partially reversed by E2 treatment. Overall, these results indicate that E2 supports brain health by maintaining proteins crucial for synaptic integrity and metabolism, while partially offsetting the functional decline in mitochondrial bioenergetics associated with menopause.NEW & NOTEWORTHY The menopausal transition, marked by declining estrogen levels, alters cognition, neuroplasticity, and brain metabolism. Although hormone therapy benefits cognition, its molecular effects on the brain remain unclear. Using whole-brain proteomics in aged ovariectomized (OVX) mice with or without estrogen treatment, we found that OVX reduced proteins linked to synaptogenesis and mitochondrial metabolism. Estrogen reversed these declines, restoring pathways supporting neuronal signaling and energy balance, identifying estrogen-regulated proteins critical for maintaining brain health during menopause.

Animals↗

Comparative proteome analysis of the hippocampus implicates chromosome 6q in schizophrenia.

Comparative brain proteome analysis is a new strategy to discover proteins and therefore genes whose altered expression may underlie schizophrenia. This strategy does not require an a priori theory of the pathogenesis or the mode of inheritance of schizophrenia. Using proteome analysis we previously compared the hippocampal proteome, that is, those proteins expressed by the hippocampal genome, of seven schizophrenic individuals with the hippocampal proteome of seven control individuals, matched for age and post mortem delay.1 We found 18 proteins that were significantly altered in concentration in the schizophrenic hippocampus (P < 0.05), when compared to control tissue. One of these proteins was characterised, by N-terminal sequencing, as diazepam binding inhibitor whose gene maps to 6q12-q21. Here we characterise a further three of the 18 proteins as: manganese superoxide dismutase, 6q25.3, T-complex protein 1, 6q25.3-q26 and collapsin response mediator protein 2, 8p21. That three of these four characterised proteins should map to the long arm of the same chromosome is significant (P < 0.002) and suggests the importance of chromosome 6q in schizophrenia. These results indicate that antioxidant defence is altered in the schizophrenic hippocampus and suggest that segregation distortion, of schizophrenia susceptibility genes, may be a possible causative factor in the high incidence of schizophrenia. Molecular Psychiatry (2000) 5, 85-90.

Carrier Proteins↗

Blood-brain barrier genomics, proteomics, and new transporter discovery.

The blood-brain barrier (BBB) is an impermeable cellular interface that physically separates the blood from the interstices of the brain. The endothelial cells lining the brain blood vessels form the principle barrier, and their unique phenotype is a consequence of dynamic interactions with several perivascular cell types present in the brain parenchyma. In addition, BBB dysfunction has been observed in the large majority of neurological diseases, but the causes of aberrant vascular behavior are generally unknown. Because of its barrier phenotype, drug delivery to the brain has also proven to be a very difficult task. Global genomics and proteomics analyses are currently being used to examine BBB function in healthy and diseased brain to better characterize this dynamic interface. It is becoming increasingly evident that these approaches have the potential to clarify the unique attributes of a healthy BBB, to identify therapeutic targets in diseased brain, and to identify novel conduits for noninvasive delivery of drugs against these targets. This review will discuss the application of genomics and proteomics to blood-brain barrier research and will offer views on the prospects of such approaches.

Animals↗