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At least 289 records · Page 16Linked to original sources

Proteomics reveals protein profile changes in doxorubicin--treated MCF-7 human breast cancer cells.

MCF-7 cells are extensively used as a cell model to investigate human breast tumors and the cellular mechanism of antitumor drugs such as doxorubicin (DOX), an anthracycline antitumor drug widely used in clinical chemotherapy. To understand the effects of DOX on the protein expression, we perform a comprehensive proteomics to survey global changes in proteins after DOX treatment in MCF-7 cells. Exposure of MCF-7 cells to 0.1 microM DOX for 2 days induced a differentiation-like phenotype with prominent perinuclear autocatalytic vacuoles, abundant filamentous material, and irregular microvilli at the cell surface. In this study, we also present a proteome reference map of MCF-7 cells with 21 identified protein spots via analysis of N-terminal sequencing, mass spectrometry, immunoblot and/or computer matching with protein database. Based on the proteome map, we found that DOX causes a markedly decrease in the levels of three isoforms of heat shock protein 27 (HSP27) whereas the levels of other stress associated proteins including HSP60, calreticulin, and protein disulfide isomerase were not significantly altered in DOX-treated MCF-7 cells. Taken together, we suggest that that action of DOX on breast tumor cells may be partly related to dysregulation of HSP27 expression. Modulation of HSP27 levels may be a clinically useful potential target for design of antitumor drugs and controlling breast tumor growth.

Antineoplastic Agents↗

Proteomics of Staphylococcus aureus--current state and future challenges.

This paper presents a short review of the proteome of Staphylococcus aureus, a gram-positive human pathogen of increasing importance for human health as a result of the increasing antibiotic resistance. A proteome reference map is shown which can be used for future studies and is followed by a demonstration of how proteomics could be applied to obtain new information on S. aureus physiology. The proteomic approach can provide new data on the regulation of metabolism as well as of the stress or starvation responses. Proteomic signatures encompassing specific stress or starvation proteins are excellent tools to predict the physiological state of a cell population. Furthermore proteomics is very useful for analysing the size and function of known and unknown regulons and will open a new dimension in the comprehensive understanding of regulatory networks in pathogenicity. Finally, some fields of application of S. aureus proteomics are discussed, including proteomics and strain evaluation, the role of proteomics for analysis of antibiotic resistance or for discovering new targets and diagnostics tools. The review also shows that the post-genome era of S. aureus which began in 2001 with the publication of the genome sequence is still in a preliminary stage, however, the consequent application of proteomics in combination with DNA array techniques and supported by bioinformatics will provide a comprehensive picture on cell physiology and pathogenicity in the near future.

Bacterial Proteins↗

Proteomic studies on low- and high-grade human brain astrocytomas.

Human brain astrocytomas range from the indolent low-grade to the highly infiltrating and aggressive high-grade form, also known as glioblastoma multiforme. The extensive heterogeneity of astrocytic tumors complicates their pathological classification. In this study, we compared the protein pattern of low-grade fibrillary astrocytomas to that of glioblastoma multiforme by 2D electrophoresis. The level of most proteins remains unchanged between the different grade tumors and only few differences are reproducibly observable. Fifteen differentially expressed proteins, as well as seventy conserved spots, were identified by mass spectrometry. Western and immnunohistochemical analysis confirmed the differential expression of the identified proteins. These data provide an initial reference map for brain gliomas. Among the proteins more highly expressed in glioblastoma multiforme, we found peroxiredoxin 1 and 6, the transcription factor BTF3, and alpha-B-crystallin, whereas protein disulfide isomerase A3, the catalytic subunit of the cAMP-dependent protein kinase, and the glial fibrillary acidic protein are increased in low-grade astrocytomas. Our findings contribute to deepening our knowledge of the factors that characterize this class of tumors and, at the same time, can be applied toward the development of novel molecular biomakers potentially useful for an accurate classification of the grade of astrocytomas.

Astrocytoma↗

Proteome analysis of membrane and cell wall associated proteins from Staphylococcus aureus.

Pathogenesis of Staphylococcus aureus, an opportunistic human pathogen, is complex and involves many virulence factors including an array of surface proteins (adhesins) that promote bacterial interactions with extracellular matrix components. A better understanding of these interactions can be achieved by studying the expression of membrane and cell wall associated proteins using a proteome analysis approach. To accomplish this, our goal here was to construct a reference map of membrane and cell wall associated proteins for S. aureus. Various lytic and solubilization methods have been tested to identify a suitable methodology for detection of these proteins in two-dimensional electrophoresis (2DE). Results demonstrate that cell lysis with lysostaphin, which lyses staphylococcal peptidoglycan, followed by solubilization with urea, thiourea, amidosulfobetaine 14 (ASB 14) and dithiothreitol (DTT) is an effective method, yielding a sample comprising proteins of wide molecular ranges and isoelectric points with minimum contamination from cytosolic proteins. Mass spectrometric analysis was employed to identify the membrane and cell surface proteins present in the sample and consequently an initial proteomic map of membrane and cell wall associated proteins for S. aureus is presented.

Bacterial Proteins↗

Primary cell cultures arising from normal kidney and renal cell carcinoma retain the proteomic profile of corresponding tissues.

Renal cell carcinoma (RCC) tissue is composed of a mixture of neoplastic and normal cells, which complicate proteome analysis. The aim of our study was to investigate whether it is feasible to establish primary cell cultures of RCC and of renal cortex maintaining the tissue phenotype along with a more homogeneous and enriched cytological material. Fourteen (82.3%) primary cultures from 17 surgical cases were established and characterized by morphology, growth rate, immunocytochemistry, and molecular analysis performed by Real-time PCR, Western blotting, two-dimensional electrophoresis (2-DE), and mass spectrometry. Cultures showed >90% cytokeratine-positive epithelial cells. In primary tumor cultures, the molecular phenotype of manganese superoxide dismutase and heat shock protein 27 was the same as that found in tumor tissues with overexpression and increased number of isoforms. Moreover, 27 out 28 specific proteins and their isoforms, present in spots excised from 2-DE gel of cortex or RCC cultures, corresponded to those identified on the 2-DE tissue cortex reference map, suggesting that these primary cultures retain the proteomic profile of the corresponding tissues.

Adult↗

The nuclear proteome of chickpea (Cicer arietinum L.) reveals predicted and unexpected proteins.

Nuclear proteins constitute a highly organized, complex network that plays diverse roles during cellular development and other physiological processes. The yeast nuclear proteome corresponds to about one-fourth of the total cellular proteins, suggesting the involvement of the nucleus in a number of diverse functions. In an attempt to understand the complexity of plant nuclear proteins, we have developed a proteome reference map of a legume, chickpea, using two-dimensional gel electrophoresis (2-DE). Approximately, 600 protein spots were detected, and LC-ESI-MS/MS analyses led to the identification of 150 proteins that have been implicated in a variety of cellular functions. The largest percentage of the identified proteins was involved in signaling and gene regulation (36%), while 17% were involved in DNA replication and transcription. The chickpea nuclear proteome indicates the presence of few new nuclear proteins of unknown functions vis-à-vis many known resident proteins. To the best of our knowledge, this is the first report of a nuclear proteome of an unsequenced genome.

Chromatography, Liquid↗

The proteomics of ageing.

Proteomics provides an extremely powerful tool for the study of variations in protein expression between individuals, different disease states and different conditions. One of the major challenges facing the medical profession in the forthcoming decades is to understand the changes that occur in individuals as they become older and to attempt to develop means to improve the quality of life for the otherwise healthy ageing population. The present study describes the first phase of such an investigation in which the protein composition of human skeletal muscle samples from young and aged subjects are compared. These results provide the beginning of a Human Aged Skeletal Muscle Profile reference map which is an essential first step to further investigations.

Aging↗

Medial septal lesions disrupt spatial mapping ability in rats.

Rats with lesions of the medial septum were more likely to begin swimming in the wrong direction, swim farther, and, therefore, require more time to find a platform hidden in a Morris water tank than were control rats. Although the performance of the rats with medial septal lesions did improve over trials, their asymptotic performance also failed to equal that of the controls. Movement of the platform to a new position in the tank disrupted the performance of both groups, and, again, the rats with medial septal lesions were slower to locate the moved platform. However, this deficit was completely eliminated when a visual cue indicating the location of the moved platform was introduced. We suggest that these data indicate that damage to the septo-hippocampal cholinergic projection system produces a deficit in the formation or utilization of a spatial map (reference memory) that represents the location of a place with respect to the surrounding distal cues.

Animals↗

Event-related potential indicators of text integration across sentence boundaries.

An event-related potentials (ERPs) study examined word-to-text integration processes across sentence boundaries. In a two-sentence passage, the accessibility of a referent for the first content word of the second sentence (the target word) was varied by the wording of the first sentence in one of the following ways: lexically (explicitly using a form of the target word); conceptually (using a paraphrase of the target word), and situationally (encouraging an inference concerning the referent of the target word). A baseline condition had no coreference between the two sentences. ERP results on the target word indicated multiple effects related to word identification and word-to-referent mapping processes. Both the explicit and paraphrase conditions, but not the inference condition, showed a reduced N400 relative to the baseline condition, consistent with immediate integration by lexico-semantic processes. A 300-ms effect (P300) was found in the paraphrase condition. The results were consistent with an immediate integration hypothesis and furthermore differentiated a lexical (N200), a conceptual (P300), and a situational (N400) component for this integration. The conceptual basis appears not to extend to predictive inferences.

Adolescent↗

Mitotic and salivary gland chromosome analyses in the Musca domestica L. (house fly) (Diptera: Muscidae).

The mitotic chromosomes in Musca domestica consist of five pairs of autosomes and an X, Y sex chromosome pair. They respond to C-banding with procentric bands on all autosomes and deep staining over most of the X and Y chromosomes. Polytene chromosomes were previously found in several larval and pupal tissue of Musca domestica. Polytene chromosome reference maps of the two sexual and the five autosomal chromosomes of Musca domestica from salivary gland cells are shown. Characteristic features of each chromosome are described identifying areas that are difficult to analyse.

Animals↗

Characterization of human plasma glycoproteins separated by two-dimensional gel electrophoresis.

Purification of protein isoforms for the characterization of post-translational modifications, such as glycosylation, can be laborious and demanding. We report a means of determining monosaccharide composition and the identity of glycoproteins from a single spot on a two-dimensional (2-D) gel. The sensitivity of the method depends on the degree of glycosylation of the protein. We show that bovine fetuin can be analyzed and identified at the level of 100 pmol. 2-D reference maps enable quick identification of glycoprotein isoforms, and the nature of glycosylation differences. Human sera glycoforms were isolated by micropreparative 2-D PAGE using a narrow-range immobilized pH gradient. Single spots excised from one polyvinylidene difluoride blot of a 2-D gel were used sequentially for sialic acid analysis, neutral and amino sugar analysis, and finally amino acid analysis. The glycosylation variations in isoforms of human fetuin and alpha-1-antitrypsin were determined. The amino acid composition, in conjunction with protein pI and MW, successfully identified the glycoproteins.

Animals↗

Checking the geographical origin of oak wood: molecular and statistical tools.

New methods for better identification of timber geographical origin would constitute an important technical element in the forest industry, for phytosanitary certification procedures or in the chain of custody developed for the certification of timber from sustainably managed forests. In the case of the European white oaks, a detailed reference map of chloroplast (cp) DNA variation across the range exists, and we propose here to use the strong geographical structure, characterized by a differentiation of western vs. eastern populations, for the purpose of oak wood traceability. We first developed cpDNA markers permitting the characterization of haplotype on degraded DNA obtained from wood samples. The techniques were subsequently validated by confirming the full correspondence between genotypes obtained from living tissues (buds) and from wood collected from the same individual oak. Finally, a statistical procedure was used to test if the haplotype composition of a lot of wood samples is consistent with its presumed geographical origin. Clearly, the technique cannot permit the unambiguous identification of wood products of unknown origin but can be used to check the conformity of genetic composition of wood samples with the region of alleged origin. This could lead to major applications not only in the forest industry but also in archaeology or in palaeobotany.

DNA Primers↗

Proteomic profiling of bone marrow mesenchymal stem cells upon transforming growth factor beta1 stimulation.

Bone marrow mesenchymal stem cells (MSCs) can differentiate into different types of cells and have tremendous potential for cell therapy and tissue engineering. Transforming growth factor beta1 (TGF-beta) plays an important role in cell differentiation and vascular remodeling. We showed that TGF-beta induced cell morphology change and an increase in actin fibers in MSCs. To determine the global effects of TGF-beta on MSCs, we employed a proteomic strategy to analyze the effect of TGF-beta on the human MSC proteome. By using two-dimensional gel electrophoresis and electrospray ionization coupled to quadrupole/time-of-flight tandem mass spectrometers, we have generated a proteome reference map of MSCs, and we identified approximately 30 proteins with an increase or decrease in expression or phosphorylation in response to TGF-beta. The proteins regulated by TGF-beta included cytoskeletal proteins, matrix synthesis proteins, membrane proteins, metabolic enzymes, etc. TGF-beta increased the expression of smooth muscle alpha-actin and decreased the expression of gelsolin. Overexpression of gelsolin inhibited TGF-beta-induced assembly of smooth muscle alpha-actin; on the other hand, knocking down gelsolin expression enhanced the assembly of alpha-actin and actin filaments without significantly affecting alpha-actin expression. These results suggest that TGF-beta coordinates the increase of alpha-actin and the decrease of gelsolin to promote MSC differentiation. This study demonstrates that proteomic tools are valuable in studying stem cell differentiation and elucidating the underlying molecular mechanisms.

Actins↗

New insights into the rat spermatogonial proteome: identification of 156 additional proteins.

Despite the essential role played by spermatogonia in testicular function, little is known about these cells. To improve our understanding of their biology, our group recently identified a set of 53 spermatogonial proteins using two-dimensional (2-D) gel electrophoresis and mass spectrometry. To continue this work, we investigated a subset of the spermatogonial proteome using narrow range immobilized pH gradients to favor the detection of less abundant proteins. A 2-D reference map of spermatogonia in the pH range 4-9 was created, and protein entities fractionated in a pH 5-6 2-D gel were further processed for protein identification. A new set of 156 polypeptides was identified by peptide mass fingerprinting and tandem mass spectrometry. These polypeptides corresponded to 102 different proteins, which reflect the complexity of post-translational modifications. Seventy-nine of these proteins were identified for the first time in spermatogonia. All identified proteins were classified into functional groups. This work represents a first step toward the establishment of a systematic spermatogonia protein database.

Animals↗

Expression and function of proteins during development of the basal region in rice seedlings.

A differential display of proteins with a two-dimensional polyacrylamide gel electrophoresis approach was used to analyze protein expression changes during development of the basal region in rice seedlings (Oryza sativa L. cv. Nipponbare). The proteins were detected as 700 Coomassie Brilliant Blue-stained spots with pI values from around 3.5 to 9.0. A proteome reference map was established for the basal region of two-week-old seedlings. The basal region proteome map was used to analyze quantitative variations in the tissue during development from 2-, 4-, 6-, 8-, and 10-week-old seedlings. During development, 31 proteins were up-regulated, and 30 proteins were down-regulated compared with the 2-week-old basal region proteome map. The main functions of these proteins were primary metabolism and protein synthesis or maintenance. Calreticulin precursor, enolase, and voltage-dependent anion channel were identified among the up- and down-regulated proteins. The twin spots of calreticulin precursor and enolase with different pI values are possibly due to post-translational modifications such as phosphorylation. In addition, seven proteins showed developmental stage-specific expression. All of the developmentally regulated proteins of the basal region were clustered by the S-system, a differential equation that fit to time course of cluster and analyzed for cluster relationships. Proteins with unknown functions were tentatively assigned to functional groups based on cluster relationships. Basal region development proteome data will be valuable for resolving questions in functional genomics. In addition, cluster analysis of the basal region proteome during development will be useful for the assessment of functional proteins.

Electrophoresis, Gel, Two-Dimensional↗

Analysis of high-resolution HapMap of DTNBP1 (Dysbindin) suggests no consistency between reported common variant associations and schizophrenia.

DTNBP1 was first identified as a putative schizophrenia-susceptibility gene in Irish pedigrees, with a report of association to common genetic variation. Several replication studies have reported confirmation of an association to DTNBP1 in independent European samples; however, reported risk alleles and haplotypes appear to differ between studies, and comparison among studies has been confounded because different marker sets were employed by each group. To facilitate evaluation of existing evidence of association and further work, we supplemented the extensive genotype data, available through the International HapMap Project (HapMap), about DTNBP1 by specifically typing all associated single-nucleotide polymorphisms reported in each of the studies of the Centre d'Etude du Polymorphisme Humain (CEPH)-derived HapMap sample (CEU). Using this high-density reference map, we compared the putative disease-associated haplotype from each study and found that the association studies are inconsistent with regard to the identity of the disease-associated haplotype at DTNBP1. Specifically, all five "replication" studies define a positively associated haplotype that is different from the association originally reported. We further demonstrate that, in all six studies, the European-derived populations studied have haplotype patterns and frequencies that are consistent with HapMap CEU samples (and each other). Thus, it is unlikely that population differences are creating the inconsistency of the association studies. Evidence of association is, at present, equivocal and unsatisfactory. The new dense map of the region may be valuable in more-comprehensive follow-up studies.

Alleles↗

Proteomic profiling of rat bone marrow mesenchymal stem cells induced by 5-azacytidine.

Mesenchymal stem cells (MSCs) can differentiate into different types of cells and thus have tremendous potential for cell therapy and tissue engineering. 5-Azacytidine (5-aza), a DNA demethylation reagent, has been reported to induce MSCs to differentiate into cardiomyocytes in vitro. To determine a global effect of 5-aza on MSCs, we investigated the protein expressions of rat MSCs with two-dimensional gel electrophoresis (2-DE). We have generated a proteome reference map of rat MSCs, and have successfully identified 34 proteins with MALDI-TOF-MS analysis. Nine proteins showed distinct regulation in MSCs after 5-aza treatment. The proteins regulated by 5-aza included cytoskeletal proteins, cadmium-binding proteins, and metabolic proteins, etc. These proteins have been reported to be involved in cell proliferation and differentiation through different signaling pathways, and the molecular mechanism of MSCs differentiation is discussed at the proteome level.

Animals↗

CholeraSeq: a comprehensive genomic pipeline for cholera surveillance and near real-time outbreak investigation.

SUMMARY: Next Generation Sequencing is widely deployed in cholera-endemic regions, yet an end-to-end reproducible pipeline that unifies read QC, filtering, reference mapping, variant calling/annotation, recombination screening, and extraction of parsimony informative sites/variant codons, phylogenetic inference for downstream phylodynamic and epidemiological analyses have been lacking, slowing outbreak investigation and public health response. CholeraSeq is a high-throughput genomics pipeline for cholera genomic surveillance. It ingests consensus genomes, short read sequence data, draft assemblies, and scales seamlessly from local to cloud environments. To accelerate epidemiological context placement of new outbreak strains, we provide a curated ready-to-use core genome alignment compiled from public data, enabling flexible, fast, integration of new samples for outbreak investigations. AVAILABILITY AND IMPLEMENTATION: CholeraSeq is freely available on the GitHub platform https://github.com/CERI-KRISP/CholeraSeq. CholeraSeq is implemented in Nextflow with a modular design building upon the nf-core community standards.

Cholera↗