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Results for “comparative transcriptomics”

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PubMed2025

Clinical and molecular landscape of metastatic extramammary Paget's disease.

BACKGROUND: Extramammary Paget's disease (EMPD) is a rare malignancy without established systemic therapy. EMPD shares molecular features with breast cancer, such as human epidermal growth factor receptor 2 (HER2) and hormone receptor (HR) expression, but their clinical relevance remains unclear. MATERIALS AND METHODS: Tumors from 20 metastatic invasive EMPD cases were analyzed for molecular and biological features. Genomic features, transcriptomic profiles, and HER2 and HR expression status were investigated using immunohistochemistry, fluorescence in situ hybridization, and targeted-genome next-generation sequencing and nCounter BC360 panels. Metastatic breast cancer samples were used as a comparison to clarify metastatic EMPD's clinical relevance. RESULTS: Estrogen receptor expression was observed in 45% of EMPD tumors, while only 10% expressed progesterone receptor. HER2 was overexpressed in 30% of cases, and HER2-directed therapies were durably effective. Among 8 patients with NGS data, 63% (5/8) harbored oncogenic ERBB2 alterations independent of HER2 expression. BC360 profiling revealed biological differences between EMPD and breast cancer, particularly poor biological compatibility for HR-positive tumors. Immune profiling showed that a subset of EMPD tumors exhibited CD8+ T-cell signatures and PD-1/PD-L1 gene expression comparable to triple-negative breast cancer. The median overall survival was 22.1 months (95% CI, 12.0-42.2), with 16 patients (80%) treated with systemic therapy, including anti-HER2 therapy, hormonal therapy, or cytotoxic therapies based on their molecular features. CONCLUSIONS: This study highlights the unique molecular and biological features of metastatic EMPD, emphasizing the need for tailored treatment approaches. This information should be used to guide future clinical strategies for metastatic EMPD.

Humans↗

PubMed2005

Neurogenic potential of human mesenchymal stem cells revisited: analysis by immunostaining, time-lapse video and microarray.

The possibility of generating neural cells from human bone-marrow-derived mesenchymal stem cells (hMSCs) by simple in vitro treatments is appealing both conceptually and practically. However, whether phenotypic modulations observed after chemical manipulation of such stem cells truly represent a genuine trans-lineage differentiation remains to be established. We have re-evaluated the effects of a frequently reported biochemical approach, based on treatment with butylated hydroxyanisole and dimethylsulphoxide, to bring about such phenotypic conversion by monitoring the morphological changes induced by the treatment in real time, by analysing the expression of phenotype-specific protein markers and by assessing the modulation of transcriptome. Video time-lapse microscopy showed that conversion of mesenchymal stem cells to a neuron-like morphology could be reproduced in normal primary fibroblasts as well as mimicked by addition of drugs eliciting cytoskeletal collapse and disruption of focal adhesion contacts. Analysis of markers revealed that mesenchymal stem cells constitutively expressed multi-lineage traits, including several pertaining to the neural one. However, the applied ;neural induction' protocol neither significantly modulated the expression of such markers, nor induced de novo translation of other neural-specific proteins. Similarly, global expression profiling of over 21,000 genes demonstrated that gene transcription was poorly affected. Most strikingly, we found that the set of genes whose expression was altered by the inductive treatment did not match those sets of genes differentially expressed when comparing untreated mesenchymal stem cells and immature neural tissues. Conversely, by comparing these gene expression profiles with that obtained from comparisons between the same cells and an unrelated non-neural organ, such as liver, we found that the adopted neural induction protocol was no more effective in redirecting human mesenchymal stem cells toward a neural phenotype than toward an endodermal hepatic pathway.

Adult↗

PubMed2025

Widespread induction of SINE-RNA expression in the mouse brain following transient focal ischemia.

Ischemic stroke triggers rapid transcriptional changes in the brain, including the induction of noncoding RNAs, which are well-established regulators of post-stroke pathophysiology. Among the numerous classes of noncoding RNAs, short interspersed nuclear element RNAs (SINE-RNAs) are transcribed by Pol III and reported to be upregulated in various paradigms of cellular stress. In the ischemic brain, Pol III-driven gene expression is not well-studied and the expression of SINE-RNAs is virtually unmapped. In the current study, we used a mouse model of transient focal ischemia to evaluate for the first time post-stroke SINE-RNA expression in the cerebral cortex on a genome-wide scale. We observed SINE-RNA induction as early as 0 to 3 h of reperfusion and peak expression at 6 h of reperfusion, with 335 SINE-RNAs induced at this timepoint as compared to sham controls. Many of these transcripts remained induced through later timepoints during the acute phase of reperfusion (24 h). Fluorescence in situ hybridization against the SINE-RNAs, combined with immunohistochemistry for cell-type markers, revealed that these RNAs are localized to the nuclei of post-ischemic neurons and microglia in the ipsilateral cortex and hippocampus in both males and females. Further, we found that SINE-RNA expression was recapitulated in vitro following oxygen-glucose deprivation in HT22 hippocampal neurons, showing that they are reproducibly expressed in neurons in both in vivo and in vitro models of ischemia. Together, this is the first study to map genome-wide SINE-RNA expression in the post-ischemic brain and reveals a new layer of the noncoding transcriptome that may play a role in the post-stroke pathophysiology.

Animals↗

PubMed2006

Transcriptome analysis of the ischemia-reperfused remodeling myocardium: temporal changes in inflammation and extracellular matrix.

cDNA microarray analysis was performed to screen 15,000 genes and expressed sequence tags (ESTs) to identify changes in the ischemia-reperfused (I-R) rat myocardial transcriptome in the early (day 2) and late (day 7) inflammatory phases of acute myocardial infarction. Lists of candidate genes that were affected by I-R transiently (2 or 7 days only) or on a more sustained basis (2 and 7 days) were derived. The candidate genes represented three major functional categories: extracellular matrix, apoptosis, and inflammation. To expand on the findings from microarray studies that dealt with the two above-mentioned time points, tissues collected from days 0, 0.25, 2, 3, 5, and 7 after reperfusion were examined. Acute myocardial infarction resulted in upregulation of IL-6 and IL-18. Genes encoding extracellular matrix proteins such as types I and III collagen were upregulated in day 2, and that response progressively grew stronger until day 7 after I-R. Comparable response kinetics was exhibited by the candidate genes of the apoptosis category. Caspases-2, -3, and -8 were induced in response to acute infarction. Compared with the myocardial tissue from the sham-operated rats, tissue collected from the infarct region stained heavily positive for the presence of active caspase-3. Laser microdissection and pressure catapulting technology was applied to harvest infarct and adjacent noninfarct control tissue from a microscopically defined region in the rat myocardium. Taken together, this work presents the first evidence gained from the use of DNA microarrays to understand the molecular mechanisms implicated in the early and late inflammatory phases of the I-R heart.

Animals↗

PubMed2006

Transcriptional regulatory network analysis of developing human erythroid progenitors reveals patterns of coregulation and potential transcriptional regulators.

Deciphering the molecular basis for human erythropoiesis should yield information benefiting studies of the hemoglobinopathies and other erythroid disorders. We used an in vitro erythroid differentiation system to study the developing red blood cell transcriptome derived from adult CD34+ hematopoietic progenitor cells. mRNA expression profiling was used to characterize developing erythroid cells at six time points during differentiation (days 1, 3, 5, 7, 9, and 11). Eleven thousand seven hundred sixty-three genes (20,963 Affymetrix probe sets) were expressed on day 1, and 1,504 genes, represented by 1,953 probe sets, were differentially expressed (DE) with 537 upregulated and 969 downregulated. A subset of the DE genes was validated using real-time RT-PCR. The DE probe sets were subjected to a cluster metric and could be divided into two, three, four, five, or six clusters of genes with different expression patterns in each cluster. Genes in these clusters were examined for shared transcription factor binding sites (TFBS) in their promoters by comparing enrichment of each TFBS relative to a reference set using transcriptional regulatory network analysis. The sets of TFBS enriched in genes up- and downregulated during erythropoiesis were distinct. This analysis identified transcriptional regulators critical to erythroid development, factors recently found to play a role, as well as a new list of potential candidates, including Evi-1, a potential silencer of genes upregulated during erythropoiesis. Thus this transcriptional regulatory network analysis has yielded a focused set of factors and their target genes whose role in differentiation of the hematopoietic stem cell into distinct blood cell lineages can be elucidated.

Antigens, CD34↗

PubMed2006

Transcriptomes of human prostate cells.

BACKGROUND: The gene expression profiles of most human tissues have been studied by determining the transcriptome of whole tissue homogenates. Due to the solid composition of tissues it is difficult to study the transcriptomes of individual cell types that compose a tissue. To overcome the problem of heterogeneity we have developed a method to isolate individual cell types from whole tissue that are a source of RNA suitable for transcriptome profiling. RESULTS: Using monoclonal antibodies specific for basal (integrin beta4), luminal secretory (dipeptidyl peptidase IV), stromal fibromuscular (integrin alpha 1), and endothelial (PECAM-1) cells, respectively, we separated the cell types of the prostate with magnetic cell sorting (MACS). Gene expression of MACS-sorted cell populations was assessed with Affymetrix GeneChips. Analysis of the data provided insight into gene expression patterns at the level of individual cell populations in the prostate. CONCLUSION: In this study, we have determined the transcriptome profile of a solid tissue at the level of individual cell types. Our data will be useful for studying prostate development and cancer progression in the context of single cell populations within the organ.

Bone Morphogenetic Proteins↗

PubMed2024

Sulfonamide-induced DNA hypomethylation disturbed sugar metabolism in rice (Oryza sativa L.).

DNA methylation is well-accepted as a bridge to unravel the complex interplay between genome and environmental exposures, and its alteration regulated the cellular metabolic responses towards pollutants. However, the mechanism underlying site-specific aberrant DNA methylation and metabolic disorders under pollutant stresses remained elusive. Herein, the multilevel omics interferences of sulfonamides (i.e., sulfadiazine and sulfamerazine), a group of antibiotics pervasive in farmland soils, towards rice in 14 days of 1 mg/L hydroponic exposure were systematically evaluated. Metabolome and transcriptome analyses showed that 57.1-71.4 % of mono- and disaccharides were accumulated, and the differentially expressed genes were involved in the promotion of sugar hydrolysis, as well as the detoxification of sulfonamides. Most differentially methylated regions (DMRs) were hypomethylated ones (accounting for 87-95 %), and 92 % of which were located in the CHH context (H = A, C, or T base). KEGG enrichment analysis revealed that CHH-DMRs in the promoter regions were enriched in sugar metabolism. To reveal the significant hypomethylation of CHH, multi-spectroscopic and thermodynamic approaches, combined with molecular simulation were conducted to investigate the molecular interaction between sulfonamides and DNA in different sequence contexts, and the result demonstrated that sulfonamides would insert into the minor grooves of DNA, and exhibited a stronger affinity with the CHH contexts of DNA compared to CG or CHG contexts. Computational modeling of DNA 3D structures further confirmed that the binding led to a pitch increase of 0.1 Å and a 3.8° decrease in the twist angle of DNA in the CHH context. This specific interaction and the downregulation of methyltransferase CMT2 (log2FC = -4.04) inhibited the DNA methylation. These results indicated that DNA methylation-based assessment was useful for metabolic toxicity prediction and health risk assessment.

DNA Methylation↗

PubMed2005

Gene expression profiling in hypothalamus of immobilization-stressed mouse using cDNA microarray.

To investigate the effects of repeated immobilization-stress challenge on HPA axis, genomic transcriptome in the hypothalamus of immobilization-stressed mouse was analyzed by using cDNA microarray. With the 1.5-fold cutoff of arbitrary criteria, the expression levels of 108 genes out of 6016 genes were significantly modulated in the hypothalamus by the stress. Energy metabolism-, lipid metabolism-, and apoptosis- and signal transduction-related genes were activated while DNA repair-, protein biosynthesis-, and structure integrity-related genes were down-regulated in the hypothalamus. Eighteen genes among them were selected for RT-PCR analysis to confirm the change of their expression levels on agarose gels. Besides, dozens of novel genes, which have not been previously reported, were screened to be modulated by the immobilization stress through the transcriptome analysis. These genes are related to apoptosis, tumor-suppression, DNA-binding and protein folding, and thus may be used as potential targets for the development of therapeutics of chronic stress or depressant.

Animals↗

PubMed2026

jsPCA: fast, scalable, and interpretable identification of spatial domains and variable genes across multi-slice and multi-sample spatial transcriptomics data.

MOTIVATION: Spatial transcriptomics technologies record genome-wide measurements of gene expression with high spatial resolution. These technologies generate large and high-dimensional datasets requiring efficient automated methods for their analysis. We introduce joint spatial PCA (jsPCA), a novel, fast, scalable and interpretable method for the automatic identification of spatial domains and variable genes in multi-slice and multi-sample spatial transcriptomics data. RESULTS: jsPCA relies on a simple mathematical formulation of a spatial covariance defined as the product of the gene expression covariance with the spatial autocorrelation. The principal components of this spatial covariance yield a biologically meaningful low-dimensional representation. From this representation, spatial domains are derived by simple clustering and spatially variable genes are identified directly from the principal component coefficients. A joint representation of multiple slices and samples without spatial alignment is obtained by computing common principal components via joint diagonalization. By leveraging data sparsity and non-convex manifold optimization, jsPCA leads to computing time in the order of seconds to minutes, substantially outperforming state-of-the-art approaches. We benchmarked jsPCA against 10 state-of-the-art methods on two reference databases. Our approach demonstrated excellent performance, comparable or better than state-of-the-art methods, while being much faster, interpretable, and scalable to very large datasets.

Journal Article↗

PubMed2006

Mice and men: their promoter properties.

Using the two largest collections of Mus musculus and Homo sapiens transcription start sites (TSSs) determined based on CAGE tags, ditags, full-length cDNAs, and other transcript data, we describe the compositional landscape surrounding TSSs with the aim of gaining better insight into the properties of mammalian promoters. We classified TSSs into four types based on compositional properties of regions immediately surrounding them. These properties highlighted distinctive features in the extended core promoters that helped us delineate boundaries of the transcription initiation domain space for both species. The TSS types were analyzed for associations with initiating dinucleotides, CpG islands, TATA boxes, and an extensive collection of statistically significant cis-elements in mouse and human. We found that different TSS types show preferences for different sets of initiating dinucleotides and cis-elements. Through Gene Ontology and eVOC categories and tissue expression libraries we linked TSS characteristics to expression. Moreover, we show a link of TSS characteristics to very specific genomic organization in an example of immune-response-related genes (GO:0006955). Our results shed light on the global properties of the two transcriptomes not revealed before and therefore provide the framework for better understanding of the transcriptional mechanisms in the two species, as well as a framework for development of new and more efficient promoter- and gene-finding tools.

Animals↗

PubMed2026

Multiomics Integration Identifies a Molecular Subtype of Intrahepatic Cholangiocarcinoma With Enhanced Benefit From Adjuvant Therapy.

Intrahepatic cholangiocarcinoma (iCCA) is a molecularly heterogeneous liver cancer with a poor prognosis. Improved stratification is needed to guide postoperative therapy. In this study, we applied integrative multiomics analysis to classify iCCA and identify biomarkers predictive of adjuvant treatment benefit. Using publicly available datasets (including whole exome sequencing, RNA sequencing, proteomics, and phosphoproteomics from FU-iCCA cohort and a transcriptomic cohort GSE244807), we defined 3 robust molecular subtypes of iCCA. These subtypes exhibited distinct genomic alterations, pathway activation, and immune microenvironments, with significant differences in overall survival (OS). Through protein-protein interaction network analysis and consensus feature selection using 10 clustering algorithms, we prioritized 8 marker genes distinguishing the subtypes. A Cox proportional-hazards model constructed from these markers stratified patients into high- and low-risk groups. High-risk iCCA, characterized by elevated expression of markers such as CLDN18, MUC1, and MUC5AC, had significantly worse OS in the absence of adjuvant therapy. Notably, in an independent validation of 174 patients with iCCA who underwent resection (single-center cohort), high expression of any of these 3 markers were associated with markedly prolonged OS in patients who received adjuvant chemotherapy or chemoembolization, compared with those who did not. In contrast, marker-negative patients showed no clear benefit from adjuvant therapy. In conclusion, our multiomics approach identified a high-risk, mucin-enriched subtype of iCCA. CLDN18, MUC1, and MUC5AC emerge as candidate predictive biomarkers for adjuvant chemotherapy benefit in iCCA, warranting prospective validation to improve personalized postoperative management.

Humans↗

PubMed2003

Transcriptome analysis of two bovine muscles during ontogenesis.

Macro-arrays, on which 1339 human skeletal muscle cDNA clone inserts had been spotted as PCR products, were used to make large-scale measurement of gene expression in bovine muscles during ontogenesis. Ten complex cDNA targets derived from two mixed muscle samples, Rectus abdominis (rather red oxidative muscle, RA) and Semitendinosus (rather white glycolytic muscle, ST), were taken from foetuses at 4 different stages (110, 180, 210, and 260 days post-conception) and from 15-month-old young bulls to generate differential expression patterns. Each sample analysed was prepared from a pool of RNA extracted from muscle tissues sampled from at least 6 different animals. Approximately 200 expression signals were validated and taken into account to provide a first "bovine" muscle gene repertoire. Despite the relatively small number of probes and the heterologous approach, this made it possible to identify up to 7 genes differentially expressed between RA and ST, depending on age. From 110 days post-conception to 15 months of age, differences in the expression levels of 110 genes were detected in the four comparisons between two consecutive ages. By comparing 260 days post-conception foetal muscles and adult muscles, up to 87 genes were overexpressed, whereas only 7 genes were shown to be down-regulated. Among these genes, 33% have unknown biological functions. Taken together, the results reported here underline the importance of the last three months of gestation in muscle myogenesis, and highlight new genes involved in this process.

Adult↗

PubMed2006

Cellular response of Shewanella oneidensis to strontium stress.

The physiology and transcriptome dynamics of the metal ion-reducing bacterium Shewanella oneidensis strain MR-1 in response to nonradioactive strontium (Sr) exposure were investigated. Studies indicated that MR-1 was able to grow aerobically in complex medium in the presence of 180 mM SrCl2 but showed severe growth inhibition at levels above that concentration. Temporal gene expression profiles were generated from aerobically grown, mid-exponential-phase MR-1 cells shocked with 180 mM SrCl2 and analyzed for significant differences in mRNA abundance with reference to data for nonstressed MR-1 cells. Genes with annotated functions in siderophore biosynthesis and iron transport were among the most highly induced (>100-fold [P < 0.05]) open reading frames in response to acute Sr stress, and a mutant (SO3032::pKNOCK) defective in siderophore production was found to be hypersensitive to SrCl2 exposure, compared to parental and wild-type strains. Transcripts encoding multidrug and heavy metal efflux pumps, proteins involved in osmotic adaptation, sulfate ABC transporters, and assimilative sulfur metabolism enzymes also were differentially expressed following Sr exposure but at levels that were several orders of magnitude lower than those for iron transport genes. Precipitate formation was observed during aerobic growth of MR-1 in broth cultures amended with 50, 100, or 150 mM SrCl2 but not in cultures of the SO3032::pKNOCK mutant or in the abiotic control. Chemical analysis of this precipitate using laser-induced breakdown spectroscopy and static secondary ion mass spectrometry indicated extracellular solid-phase sequestration of Sr, with at least a portion of the heavy metal associated with carbonate phases.

Bacterial Proteins↗

PubMed2005

Transcriptomics applied to obesity and caloric restriction.

Caloric restriction still remains the most efficient way to promote weight loss. Deciphering the molecular basis of adaptation to energy restriction is critical for the tailoring of new therapeutic strategies. This review focuses on the recent input of gene profiling on adipose tissue in obesity pathogenesis and on the new insights on adaptations occurring during very low caloric diet (VLCD) in humans. Hypocaloric diets improve a wide range of metabolic parameters including lipolytic efficiency, insulin sensitivity, and inflammatory profile. In the subcutaneous white adipose tissue (scWAT) the VLCD induced a decrease in the mRNA levels for the antilipolytic alpha2-adrenergic receptor associated with changes in catecholamine-induced adipocyte lipolytic capacity. The improvement in insulin sensitivity was not associated with a change in subcutaneous adipose tissue adiponectin gene expression or in its plasma level, suggesting that adiponectin is not involved in the regulation of VLCD-induced improvement of insulin sensitivity and that there is a small contribution of subcutaneous adipose tissue to plasma adiponectin levels. Pangenomic microarray studies in human scWAT revealed that a panel of inflammatory markers and acute phase reactants were over expressed in obese compared to lean subjects. Caloric restriction improved the inflammatory profile of obese subjects through a decrease of pro-inflammatory factors and an increase of anti-inflammatory molecules. These genes were mostly expressed in the stroma vascular fraction of the adipose tissue. Specific cell-type isolation and immunohistochemistry demonstrated that monocyte/macrophage lineage cells were responsible for the expression of both mRNA and protein inflammatory markers. The acute phase proteins serum amyloid A was highly expressed in mature adipocytes from obese subjects. Caloric restriction decreased both serum amyloid mRNA and circulating levels. Obesity now clearly appears as chronic low-grade inflammation state. Modulation of the inflammatory pathways may represent new therapeutic targets for the treatment of obesity-related complications.

Adipose Tissue↗

PubMed2006

An efficient and high-throughput approach for experimental validation of novel human gene predictions.

A highly automated RT-PCR-based approach has been established to validate novel human gene predictions with no prior experimental evidence of mRNA splicing (ab initio predictions). Ab initio gene predictions were selected for high-throughput validation using predicted protein classification, sequence similarity to other genomes, colocalization with an MPSS tag, or microarray expression. Initial microarray prioritization followed by RT-PCR validation was the most efficient combination, resulting in approximately 35% of the ab initio predictions being validated by RT-PCR. Of the 7252 novel genes that were prioritized and processed, 796 constituted real transcripts. In addition, high-throughput RACE successfully extended the 5' and/or 3' ends of >60% of RT-PCR-validated genes. Reevaluation of these transcripts produced 574 novel transcripts using RefSeq as a reference. RT-PCR sequencing in combination with RACE on ab initio gene predictions could be used to define the transcriptome across all species.

Algorithms↗

PubMed2006

Proteomics identification of differentially expressed proteins associated with pollen germination and tube growth reveals characteristics of germinated Oryza sativa pollen.

Mature pollen from most plant species is metabolically quiescent; however, after pollination, it germinates quickly and gives rise to a pollen tube to transport sperms into the embryo sac. Because methods for collecting a large amount of in vitro germinated pollen grains for transcriptomics and proteomics studies from model plants of Arabidopsis and rice are not available, molecular information about the germination developmental process is lacking. Here we describe a method for obtaining a large quantity of in vitro germinating rice pollen for proteomics study. Two-dimensional electrophoresis of approximately 2300 protein spots revealed 186 that were differentially expressed in mature and germinated pollen. Most showed a changed level of expression, and only 66 appeared to be specific to developmental stages. Furthermore 160 differentially expressed protein spots were identified on mass spectrometry to match 120 diverse protein species. These proteins involve different cellular and metabolic processes with obvious functional skew toward wall metabolism, protein synthesis and degradation, cytoskeleton dynamics, and carbohydrate/energy metabolism. Wall metabolism-related proteins are prominently featured in the differentially expressed proteins and the pollen proteome as compared with rice sporophytic proteomes. Our study also revealed multiple isoforms and differential expression patterns between isoforms of a protein. These results provide novel insights into pollen function specialization.

Electrophoresis, Gel, Two-Dimensional↗

PubMed2000

Analysis of the yeast transcriptome with structural and functional categories: characterizing highly expressed proteins.

We analyzed 10 genome expression data sets by large-scale cross-referencing against broad structural and functional categories. The data sets, generated by different techniques (e.g. SAGE and gene chips), provide various representations of the yeast transcriptome (the set of all yeast genes, weighted by transcript abundance). Our analysis enabled us to determine features more prevalent in the transcriptome than the genome: i.e. those that are common to highly expressed proteins. Starting with simplest categories, we find that, relative to the genome, the transcriptome is enriched in Ala and Gly and depleted in Asn and very long proteins. We find, furthermore, that protein length and maximum expression level have a roughly inverse relationship. To relate expression level and protein structure, we assigned transmembrane helices and known folds (using PSI-blast) to each protein in the genome; this allowed us to determine that the transcriptome is enriched in mixed alpha-beta structures and depleted in membrane proteins relative to the genome. In particular, some enzymatic folds, such as the TIM barrel and the G3P dehydrogenase fold, are much more prevalent in the transcriptome than the genome, whereas others, such as the protein-kinase and leucine-zipper folds, are depleted. The TIM barrel, in fact, is overwhelmingly the 'top fold' in the transcriptome, while it only ranks fifth in the genome. The most highly enriched functional categories in the transcriptome (based on the MIPS system) are energy production and protein synthesis, while categories such as transcription, transport and signaling are depleted. Furthermore, for a given functional category, transcriptome enrichment varies quite substantially between the different expression data sets, with a variation an order of magnitude larger than for the other categories cross-referenced (e.g. amino acids). One can readily see how the enrichment and depletion of the various functional categories relates directly to that of particular folds.

Amino Acids↗

PubMed2005

Transcriptional profiling of Vibrio cholerae recovered directly from patient specimens during early and late stages of human infection.

Understanding gene expression by bacteria during the actual course of human infection may provide important insights into microbial pathogenesis. In this study, we evaluated the transcriptional profile of Vibrio cholerae, the causative agent of cholera, in clinical specimens from cholera patients. We collected samples of human stool and vomitus that were positive by dark-field microscopy for abundant vibrios and used a microarray to compare gene expression in organisms recovered directly from specimens collected during the early and late stages of human infection. Our results reveal that V. cholerae gene expression within the human host environment differs from patterns defined in in vitro models of pathogenesis. tcpA, the major subunit of the essential V. cholerae colonization factor, was significantly more highly expressed in early than in late stages of infection; however, the genes encoding cholera toxin were not highly expressed in either phase of human infection. Furthermore, expression of the virulence regulators toxRS and tcpPH was uncoupled. Interestingly, the pattern of gene expression indicates that the human upper intestine may be a uniquely suitable environment for the transfer of genetic elements that are important in the evolution of pathogenic strains of V. cholerae. These findings provide a more detailed assessment of the transcriptome of V. cholerae in the human host than previous studies of organisms in stool alone and have implications for cholera control and the design of improved vaccines.

Cholera↗