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Inflammatory response of esophageal epithelium in combined-type esophagitis in rats: a transcriptome analysis.

Recent studies have shown that esophageal mucosal inflammatory response is involved in the pathophysiology of gastro-esophageal reflux disease. The aim of the present study was to identify specific gene expression profiles of the esophageal mucosa in a rat model of combined-type chronic reflux esophagitis. Esophagogastroduodenal anastomosis was carried out in male Wistar rats by anastomosing the jejunum to the gastroesophageal junction under diethyl-ether inhalation anesthesia. Esophageal epithelial cells were obtained from esophagi of rats by laser capture microdissection. Preparation of cRNA and target hybridization were performed according to the Affymetrix GeneChip eukaryotic small sample target labeling assay protocol. The gene expression profile was evaluated by the rat toxicology U34 GeneChip. Array data analysis was carried out using Affymetrix GeneChip operating software, ingenuity pathway analysis software, and Gene Springs software. A comparison between esophagitis and sham-operated rats 2 weeks after the operation revealed that 368 probes (36%) were significantly affected, i.e. 185 probes were up-regulated, and 183 probes were down-regulated, both at levels of at least 1.5-fold in the esophagitis rats. Ingenuity signal analysis of 207 affected probes revealed the interleukin-6 signaling pathway as the most significantly affected caronical pathway. In addition, the expression of many genes associated with cytokine and transcription factor was enhanced in the esophagitis rats. This transcriptome approach provided insight into genes and putative genetic pathways thought to be affected by stimulation with gastroduodenal refluxates.

Animals↗

Conserved innate immunity components limit transgene expression in adult planarians.

The planarian flatworm Schmidtea mediterranea has become a powerful model for studying whole-body regeneration, tissue patterning, and stem cell regulation. Yet the absence of reliable tools for transgene expression still limits the elucidation of molecular mechanisms in in this system. Here, we establish a proof-of-principle system for plasmid-based expression of NanoLuciferase (NanoLuc) in S. mediterranea, employing commercially available transfection reagents and a panel of endogenous promoter sequences. Despite successful delivery, reporter expression remained low and transient. To identify biological barriers to robust transgene expression, we investigated the role of innate immune pathways. Candidate gene searches and biochemical pull-down of cytoplasmic DNA coupled to mass spectrometry identified several planarian homologs of conserved immune regulators and putative DNA sensors. Through RNA interference screening of conserved innate immune components, we uncover roles for S. mediterranea homologs of Tank-binding kinase 1 (TBK1) and macrophage mannose receptor 1 (MRC1) as potent repressors of transgene expression. Transcriptomic and functional analyses further implicate TBK1 in regulating broad innate immune and stress-response programs, akin to its vertebrate function. Together, our findings demonstrate that innate immune signaling limits transgene expression in S. mediterranea and suggest that modulating these pathways may be key to enabling stable and efficient genetic manipulation in planarians.

Animals↗

Role for glyoxalase I in Alzheimer's disease.

P301L mutant tau transgenic mice develop neurofibrillary tangles, a histopathologic hallmark of Alzheimer's disease and frontotemporal dementia (FTDP-17). To identify differentially expressed genes and to gain insight into pathogenic mechanisms, we performed a stringent analysis of the microarray dataset obtained with RNA from whole brains of P301L mutant mice and identified a single up-regulated gene, glyoxalase I. This enzyme plays a critical role in the detoxification of dicarbonyl compounds and thereby reduces the formation of advanced glycation end products. In situ hybridization analysis revealed expression of glyoxalase I in all brain areas analyzed, both in transgenic and control mice. However, levels of glyoxalase I protein were significantly elevated in P301L brains, as shown by Western blot analysis and immunohistochemistry. Moreover, a glyoxalase I-specific antiserum revealed many intensely stained flame-shaped neurons in Alzheimer's disease brain compared with brains from nondemented controls. In addition, we examined a single nucleotide polymorphism predicting a nonconservative amino acid substitution at position 111 (E111A) in ethnically independent populations. We identified significant and consistent deviations from Hardy-Weinberg equilibrium, which points to the presence of selection forces. The E111A single nucleotide polymorphism was not associated with the risk for Alzheimer's disease in the overall population. Together, our data demonstrate the potential of transcriptomics applied to animal models of human diseases. They suggest a previously unidentified role for glyoxalase I in neurodegenerative disease.

Alzheimer Disease↗

Drosophila host defense after oral infection by an entomopathogenic Pseudomonas species.

Drosophila has been shown to be a valuable model for the investigation of host-pathogen interactions. Study of the Drosophila immune response has been hampered, however, by the lack of true Drosophila pathogens. In nearly all studies reported, the bacteria used were directly injected within the body cavity of the insect, bypassing the initial steps of a natural interaction. Here, we report the identification of a previously uncharacterized bacterial species, Pseudomonas entomophila (Pe), which has the capacity to induce the systemic expression of antimicrobial peptide genes in Drosophila after ingestion. In contrast to previously identified bacteria, Pe is highly pathogenic to both Drosophila larvae and adults, and its persistence in larvae leads to a massive destruction of gut cells. Using this strain, we have analyzed the modulation of the larval transcriptome upon bacterial infection. We found that natural infection by Pe induces a dramatic change in larval gene expression. In addition to immunity genes, our study identifies many genes associated with Pe pathogenesis that have been previously unreported.

Animals↗

Spurious spatial periodicity of co-expression in microarray data due to printing design.

Global transcriptome data is increasingly combined with sophisticated mathematical analyses to extract information about the functional state of a cell. Yet the extent to which the results reflect experimental bias at the expense of true biological information remains largely unknown. Here we show that the spatial arrangement of probes on microarrays and the particulars of the printing procedure significantly affect the log-ratio data of mRNA expression levels measured during the Saccharomyces cerevisiae cell cycle. We present a numerical method that filters out these technology-derived contributions from the existing transcriptome data, leading to improved functional predictions. The example presented here underlines the need to routinely search and compensate for inherent experimental bias when analyzing systematically collected, internally consistent biological data sets.

Cell Cycle↗

Organization of the Caenorhabditis elegans small non-coding transcriptome: genomic features, biogenesis, and expression.

Recent evidence points to considerable transcription occurring in non-protein-coding regions of eukaryote genomes. However, their lack of conservation and demonstrated function have created controversy over whether these transcripts are functional. Applying a novel cloning strategy, we have cloned 100 novel and 61 known or predicted Caenorhabditis elegans full-length ncRNAs. Studying the genomic environment and transcriptional characteristics have shown that two-thirds of all ncRNAs, including many intronic snoRNAs, are independently transcribed under the control of ncRNA-specific upstream promoter elements. Furthermore, the transcription levels of at least 60% of the ncRNAs vary with developmental stages. We identified two new classes of ncRNAs, stem-bulge RNAs (sbRNAs) and snRNA-like RNAs (snlRNAs), both featuring distinct internal motifs, secondary structures, upstream elements, and high and developmentally variable expression. Most of the novel ncRNAs are conserved in Caenorhabditis briggsae, but only one homolog was found outside the nematodes. Preliminary estimates indicate that the C. elegans transcriptome contains approximately 2700 small non-coding RNAs, potentially acting as regulatory elements in nematode development.

Animals↗

Livestock Multi-Omics Integration: A Systematic Framework From Statistical Association to Causal Interpretation.

Livestock multi-omics integration is key to unraveling complex trait regulation, yet systematic, livestock-specific strategies remain scarce. This review traces the progression from single-omics accumulation to multi-dimensional integration, highlighting how large-scale genomic, epigenomic, and transcriptomic projects lay the foundation for functional dissection. We identify core impediments: extreme species diversity, marked data heterogeneity, limited sample sizes, and a pervasive reduction of multi-omics data to simplistic differential screens, resulting in low translational efficiency. We critically appraise four common pitfalls-overinterpreting correlation as causation, relegating proteomics to corroborating transcriptomics, incomplete microbiome-host integration lacking environmental context, and systematic neglect of metabolic fluxomics-and show how exposomics and fluxomics add necessary causal and dynamic dimensions. To address these, we propose a livestock-adapted three-tier analytical framework: (1) statistical association of cross-omics covariation patterns; (2) machine learning-driven feature mining and integrative modeling; and (3) causal interpretation encompassing Mendelian randomization, prior-knowledge-guided network inference, and physical causal evidence via fluxomics and metabolic control analysis. We further discuss how multimodal sequencing (single-cell, spatial, temporal) and generative AI can fundamentally mitigate heterogeneity and strengthen causal evidence. Finally, we outline future priorities in database standardization, livestock-specific benchmarking, and translational pipelines, charting a path from correlation-centric reporting to mechanistic causality and precision breeding.

Animals↗

Integrative genomics elucidates the evolutionary, temporal, and developmental origins of a hydrocephalus risk gene.

INTRODUCTION: A prior integrative, multi-omics human genetics and functional genomics study identified maelstrom (MAEL), a gene involved in regulation of DNA transposon activity and genome structure, as a transcriptome-wide predictor of hydrocephalus (HC) in the brain cortex. Here we expand on this discovery and further characterize the evolutionary origin and expression of MAEL across developmental timescales and cell-lineages in the neonatal human brain towards a mechanistic understanding how variation in MAEL expression may cause HC. OBJECTIVE: To characterize the evolutionary, temporal, developmental, and lineages of MAEL expression in HC and the developing human brain. METHODS: Ensembl was used to delineate the evolution and taxonomy of MAEL across species. Analysis of single-cell RNA sequencing (scRNA-seq) of 49 brain regions across pre- and post-natal timescales from the Developing Human Brain Atlas (Allen Institute) identified temporal and spatial MAEL expression patterns. We quantified MAEL expression in primary cortical brain tissue obtained during the surgical treatment of HC. RESULTS: We performed taxonomic gene-mapping to define the evolutionary origin of MAEL to assess suitability for mechanistic characterization in vitro and in vivo across species. We find that MAEL is among the top 0.01% human-specific genes and < 50% sequence homology among commonly used model organisms with highly divergent functions, necessitating mechanistic validation in human tissue. scRNA-seq of the non-disease prenatal human brain identified MAEL expression enriched in cortical excitatory neurons, which was recapitulated in primary HC brain tissue obtained during surgery. Finally, using scRNA-seq of primary HC brain tissue, we functionally validated reduced MAEL expression, consistent with a prior human TWAS analysis. CONCLUSIONS: We identify the evolutionary, temporal, and developmental expression pattern of MAEL in the neonatal human brain. We also provide direct evidence for reduced MAEL expression in human HC brain tissue. These data, at least in part, implicate reduced MAEL expression underlying human HC across etiologies.

Journal Article↗

Marked increase in CC chemokine gene expression in both human and mouse mast cell transcriptomes following Fcepsilon receptor I cross-linking: an interspecies comparison.

Rodent mast cells (MCs) are common experimental tools but are somewhat different from their human counterparts in their responses to certain cytokines and drugs. We examined the expression of more than 10 000 distinct genes in human and mouse cultured MCs using high-density oligonucleotide probe arrays to find molecules similarly regulated and expressed by the 2 MC types. After stimulation via high-affinity Fcepsilon receptor I (FcepsilonRI), the transcriptional levels of several CC chemokines were markedly increased, and I-309 (CCL1), macrophage inflammatory protein-1alpha (MIP-1alpha) (CCL3) and MIP-1beta (CCL4) were found among the 10 most increased human and mouse transcripts from approximately 12 000 genes (including some expressed sequence tags). In addition, a costimulatory molecule that was originally found on the membrane of activated T cells, 4-1BB (CD137), was found among the 10 most increased transcripts. The FcepsilonRI-induced expression of CC chemokines and 4-1BB was also detected at the protein level in both MC types. The conservation of these responses suggests that MCs play a crucial role in recruitment of various CCR-expressing cells into the tissue in a manner dependent on immunoglobin E, and that FcepsilonRI-mediated induction of several CC chemokines and 4-1BB is highly conserved between human and mouse. Interspecies comparison studies at the whole genome expression level should be useful for the interpretation of experimental data obtained in animal models of human pathobiology.

Animals↗

Surveillance of transcriptomes in basic military trainees with normal, febrile respiratory illness, and convalescent phenotypes.

Gene expression profiles permit analysis of host immune response at the transcriptome level. We used the Pax gene Blood RNA (PAX) System and Affymetrix microarrays (HG-U133A&B) to survey profiles in basic military trainees and to classify them as healthy, febrile respiratory illness (FRI) without adenovirus, FRI with adenovirus, and convalescent from FRI with adenovirus. We assessed quality metrics of RNA processing for microarrays. Class prediction analysis discovered nested sets of transcripts that could categorize the phenotypes with optimized accuracy of 99% (nonfebrile vs febrile, P<0.0005), 87% (healthy vs convalescent, P=0.001), and 91% (febrile without vs with adenovirus, P<0.0005). The discovered set for classification of nonfebrile vs febrile patients consisted of 40 transcripts with functions related to interferon induced genes, complement cascades, and TNF and IL1 signaling. The set of seven transcripts for distinguishing healthy vs convalescent individuals included those associated with ribosomal structure, humoral immunity, and cell adhesion. The set of 10 transcripts for distinguishing FRI without vs with adenovirus had functions related to interferon induced genes, IL1 receptor accessory protein, and cell interactions. These results are the first in vivo demonstration of classification of infectious diseases via host signature transcripts and move us towards using the transcriptome in bio-surveillance.

Adenovirus Infections, Human↗

Rv3133c/dosR is a transcription factor that mediates the hypoxic response of Mycobacterium tuberculosis.

Unlike many pathogens that are overtly harmful to their hosts, Mycobacterium tuberculosis can persist for years within humans in a clinically latent state. Latency is often linked to hypoxic conditions within the host. Among M. tuberculosis genes induced by hypoxia is a putative transcription factor, Rv3133c/DosR. We performed targeted disruption of this locus followed by transcriptome analysis of wild-type and mutant bacilli. Nearly all the genes powerfully regulated by hypoxia require Rv3133c/DosR for their induction. Computer analysis identified a consensus motif, a variant of which is located upstream of nearly all M. tuberculosis genes rapidly induced by hypoxia. Further, Rv3133c/DosR binds to the two copies of this motif upstream of the hypoxic response gene alpha-crystallin. Mutations within the binding sites abolish both Rv3133c/DosR binding as well as hypoxic induction of a downstream reporter gene. Also, mutation experiments with Rv3133c/DosR confirmed sequence-based predictions that the C-terminus is responsible for DNA binding and that the aspartate at position 54 is essential for function. Together, these results demonstrate that Rv3133c/DosR is a transcription factor of the two-component response regulator class, and that it is the primary mediator of a hypoxic signal within M. tuberculosis.

Aspartic Acid↗

The coccolithovirus microarray: an array of uses.

The Coccolithoviridae is a recently discovered family of giant algal viruses. Here, we review the genomic and transcriptomic characterization of this family based on the results generated from a coccolithovirus microarray. The microarray has been used to aid the annotation of the genome, to investigate the infection process at the transcriptional level and to assess the diversity in genomic content within the family.

Genes, Viral↗

Laparoscopic donor nephrectomy gene expression profiling reveals upregulation of stress and ischemia associated genes compared to control kidneys.

We compared gene expression profiles from six donor kidneys prior to surgical manipulation to six kidneys removed after laparoscopic donor nephrectomy (LDN) and several hours of CO2 pneumoperitoneum. Biopsies were obtained from renal cortex and hybridized to Affymetrix HG-U133A GeneChips. For control kidneys, we identified 1380 genes present on all six samples that had a signal intensity >1,000. Functional classification of these revealed genes for cellular signaling (201; 15%), regulation of transcription (156; 11%), cellular transport (144; 10%) and cellular metabolism (111; 8%). A class comparison between the controls and LDN kidneys yielded 865 differentially expressed genes. Functional classification of the 502 genes differentially upregulated in LDN kidneys identified associations with apoptosis, cell adhesion, cell signaling, regulation of cell growth/proliferation, immune/inflammation, ischemia/stress response and proteolysis/peptidolysis. These data demonstrate an altered renal transcriptome induced by several hours of CO2 pneumoperitoneum and laparoscopic surgery characterized by upregulation of ischemia and injury associated genes.

Adult↗

Global transcriptome analysis of Staphylococcus aureus response to hydrogen peroxide.

Staphylococcus aureus responds with protective strategies against phagocyte-derived reactive oxidants to infect humans. Herein, we report the transcriptome analysis of the cellular response of S. aureus to hydrogen peroxide-induced oxidative stress. The data indicate that the oxidative response includes the induction of genes involved in virulence, DNA repair, and notably, anaerobic metabolism.

Gene Expression Profiling↗

Fecal microbiota transplantation promotes type 2 mucosal immune responses with colonic epithelium proliferation in patients with recurrent Clostridioides difficile.

BACKGROUNDFecal microbiota transplantation (FMT) is the most effective therapy for recurrent Clostridioides difficile infection (rCDI), yet its mechanism of action remains poorly understood.METHODSWe report the results of a clinical trial of patients undergoing FMT therapy for rCDI (n = 16), which analyzed colon biopsies, plasma, PBMCs, and stool at the time of FMT and 2-month follow-up. Plasma and colon biopsy samples were also collected from healthy controls for comparison with patients with rCDI. Microbiome composition, colonic gene expression, and immune changes were evaluated through high-throughput sequencing and immunoprofiling via flow cytometry.RESULTSNo patients experienced recurrence at follow-up. FMT significantly altered the intestinal microbiome but had no significant impact on the systemic immune system. In contrast, FMT promoted broad changes in colonic transcriptional profiles compared with both pre-FMT and healthy control biopsies, inhibiting genes associated with proinflammatory signaling and upregulating type 2 immunity and proliferative pathways (Myc and mTORC1). FMT increased expression of IL-33 and the type 2 immune EGFR family ligand amphiregulin, potentially explaining upregulation of Myc and mTORC1 pathways. Spatial transcriptomics demonstrated that these changes were localized to the colonic epithelium. Comparison of transcriptional profiles with available single-cell gene sets determined that post-FMT biopsies were enriched in signatures associated with proliferative cell types while repressing signatures of differentiated colonocytes.CONCLUSIONWe conclude that FMT promotes proliferation of the colonic epithelium in patients with rCDI, which may drive regeneration and protect against subsequent CDI.TRIAL REGISTRATIONClinicaltrials.gov NCT02797288.FUNDINGThis work was funded by grants from the NIH.

Adult↗

Deciphering B-ZIP transcription factor interactions in vitro and in vivo.

Over the last 15 years, numerous studies have addressed the structural rules that regulate dimerization stability and dimerization specificity of the leucine zipper, a dimeric parallel coiled-coil domain that can either homodimerize or heterodimerize. Initially, these studies were performed with a limited set of B-ZIP proteins, sequence-specific DNA binding proteins that dimerize using the leucine zipper domain to bind DNA. A global analysis of B-ZIP leucine zipper dimerization properties can be rationalized using a limited number of structural rules [J.R. Newman, A.E. Keating, Comprehensive identification of human bZIP interactions with coiled-coil arrays, Science 300 (2003) 2097-2101]. Today, however, access to the genomic sequences of many different organisms has made possible the annotation of all B-ZIP proteins from several species and has generated a bank of data that can be used to refine, and potentially expand, these rules. Already, a comparative analysis of the B-ZIP proteins from Arabidopsis thaliana and Homo sapiens has revealed that the same amino acids are used in different patterns to generate diverse B-ZIP dimerization patterns [C.D. Deppmann, A. Acharya, V. Rishi, B. Wobbes, S. Smeekens, E.J. Taparowsky, C. Vinson, Dimerization specificity of all 67 B-ZIP motifs in Arabidopsis thaliana: a comparison to Homo sapiens B-ZIP motifs, Nucleic Acids Res. 32 (2004) 3435-3445]. The challenge ahead is to investigate the biological significance of different B-ZIP protein-protein interactions. Gaining insight at this level will rely on ongoing investigations to (a) define the role of target DNA on modulating B-ZIP dimerization partners, (b) characterize the B-ZIP transcriptome in various cells and tissues through mRNA microarray analysis, (c) identify the genomic localization of B-ZIP binding at a genomic level using the chromatin immunoprecipitation assay, and (d) develop more sophisticated imaging technologies to visualize dimer dynamics in single cells and whole organisms. Studies of B-ZIP family leucine zipper dimerization and the regulatory mechanisms that control their biological activities could serve as a paradigm for deciphering the biophysical and biological parameters governing other well-characterized protein-protein interaction motifs. This review will focus on the dimerization specificity of coiled-coil proteins, particularly the human B-ZIP transcription family that consists of 53 proteins that use the leucine zipper coiled-coil as a dimerization motif.

Amino Acid Motifs↗

Protein profiling and GC-MS product analysis provide insights into lignite solubilization and bioconversion by Lysinibacillus sphaericus strain SH19.

Lignite biosolubilization offers a mild route for valorizing low-rank coal, although the microbial processes that accompany solubilization remain incompletely defined. Here, an endogenous isolate designated Lysinibacillus sphaericus strain SH19 was evaluated using nitric-acid-pretreated Shengli lignite. Under the selected working conditions (4 M nitric-acid pretreatment, initial pH 8, 40&#xb0;C, and 16 days), the apparent solubilization rate reached 66.81%. Changes in A450, residual solid mass, culture pH, and extracellular protein concentration showed that chemical pretreatment and bacterial culture were both associated with the release of soluble lignite-derived material. SDS-PAGE and two-dimensional electrophoresis revealed treatment-associated differences in extracellular and intracellular protein patterns. LC-MS/MS analysis of excised protein spots yielded 85 candidate protein assignments; the revised supplementary table reports PEAKS scores, sequence coverage, peak area, and unique-peptide counts and highlights the limited support for several entries. GC-MS analysis produced 33 tentative library assignments in the solubilized fraction, but siloxane- and silyl-related signals were treated as possible analytical background, and no pathway was inferred from these assignments alone. Together, the data identify strain SH19 as a promising lignite-biosolubilizing isolate and provide candidate proteins and product signals for future validation. The proposed process model remains exploratory because direct enzyme assays, inhibitor experiments, carbon-balance measurements, transcriptomic or genetic validation, complete GC-MS blank subtraction, and authentic-standard confirmation were not available.

Bacillaceae↗

Construction and characterization of a highly redundant Pseudomonas aeruginosa genomic library prepared from 12 clinical isolates: application to studies of gene distribution among populations.

OBJECTIVE: To create, array, and characterize a pooled, high-coverage, genomic library composed of multiple biofilm-forming clinical strains of the opportunistic pathogen, Pseudomonas aeruginosa (PA). Twelve strains were obtained from patients with otorrhea, otitis media, and cystic fibrosis as a resource for investigating: difference in the transcriptomes of planktonic and biofilm envirovars; the size of the PA supragenome and determining the number of virulence genes available at the population level; and the distributed genome hypothesis. METHODS: High molecular weight genomic DNAs from 12 clinical PA strains were individually hydrodynamically sheared to produce mean fragment sizes of approximately 1.5 kb. Equimolar amounts of the 12 sheared genomic DNAs were then pooled and used in the construction of a genomic library with approximately 250,000 clones that was arrayed and subjected to quality control analyses. RESULTS: Restriction endonuclease and sequence analyses of 686 clones picked at random from the library demonstrated that >75% of the clones contained inserts larger than 0.5 kb with the desired mean insert size of 1.4 kb. Thus, this library provides better than 4.5x coverage for each of the genomes from the 12 components clinical PA isolates. Our sequencing effort ( approximately 1 million nucleotides to date) reveals that 13% of the clones present in this library are not represented in the genome of the reference P. aeruginosa strain PA01. CONCLUSIONS: Our data suggests that reliance on a single laboratory strain, such as PA01, as being representative of a pathogenic bacterial species will fail to identify many important genes, and that to obtain a complete picture of complex phenomena, including bacterial pathogenesis and the genetics of biofilm development will require characterization of the P. aeruginosa population-based supra-genome.

Child, Preschool↗