Regulation of DMBT1 via NOD2 and TLR4 in intestinal epithelial cells modulates bacterial recognition and invasion

Multiomic spatial atlas shows deleted in malignant brain tumors 1 (DMBT1) glycoprotein is lost in colonic dysplasia

Colorectal cancer (CRC) is responsible for over 900,000 annual deaths worldwide. Emerging evidence supports pro-carcinogenic bacteria in the colonic microbiome are at least promotional in CRC development and may be causal. We previously showed toxigenic C. difficile from human CRC-associated bacterial biofilms accelerates tumorigenesis in ApcMin/+ mice, both in specific pathogen-free mice and in gnotobiotic mice colonized with a defined consortium of bacteria. To further understand host-microbe interactions during colonic tumorigenesis, we combined single-cell RNA-sequencing (scRNA-seq), spatial transcriptomics, and immunofluorescence to define the molecular spatial organization of colonic dysplasia in our consortium model with or without C. difficile. Our data show a striking bipartite regulation of Deleted in Malignant Brain Tumors 1 (DMBT1) in the inflamed versus dysplastic colon. From scRNA-seq, differential gene expression analysis of normal absorptive colonocytes at 2 weeks postinoculation showed DMBT1 upregulated by C. difficile compared to colonocytes from mice without C. difficile exposure. In contrast, our spatial transcriptomic analysis showed DMBT1 dramatically downregulated in dysplastic foci compared with normal-adjacent tissue. We further integrated our datasets to generate custom colonic dysplasia scores and ligand-receptor mapping. Validation with immunofluorescence showed DMBT1 protein downregulated in dysplastic foci from three mouse models of colonic tumorigenesis and in adenomatous dysplasia from human samples. Finally, we used mouse and human organoids to implicate WNT signaling in the downregulation of DMBT1 mRNA and protein. Together, our data reveal cell type-specific regulation of DMBT1, a potential mechanistic link between bacteria and colonic tumorigenesis. Published 2025. This article is a U.S. Government work and is in the public domain in the USA. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Multiomic analysis reveals cellular, transcriptomic and epigenetic changes in intestinal pouches of ulcerative colitis patients

Total proctocolectomy with ileal pouch anal anastomosis is the standard of care for patients with severe ulcerative colitis. We generated a cell-type-resolved transcriptional and epigenetic atlas of ileal pouches using scRNA-seq and scATAC-seq data from paired biopsy samples of the ileal pouch and the ileal segment above the pouch (pre-pouch) from patients (male=4, female=2), and paired biopsies of the terminal ileum and ascending colon from healthy individuals (male=3, female=3) serving as reference. Our study finds an additional population of absorptive and secretory epithelial cells within the pouch but not the pre-pouch. These pouch-specific enterocytes express a subset of colon-specific genes, including CEACAM5 and CD24. However, compared to normal colonocytes, expression of these genes is lower, and these enterocytes also express inflammatory and secretory genes while maintaining expression of some ileal-specific genes. This cell-type-resolved transcriptomic and epigenetic atlas of the ileal pouch establishes a reference for investigating pouch physiology and pathology.

Comparative transcriptome analysis reveals a serotype-specific immune response in Nile tilapia (Oreochromis niloticus) infected with Streptococcus agalactiae

Streptococcus agalactiae is a major causative agent of streptococcosis in Nile tilapia (Oreochromis niloticus) and understanding its etiology is important to ensure the sustainable development of global tilapia farming. Our research group recently observed contrasting disease patterns in animals infected with two different S. agalactiae serotypes (Ib and III). To better understand the basis for these divergent responses, we analyzed the brain transcriptome of Nile tilapia following bacterial exposure. Our findings revealed significant variation in the expression of genes involved in immune (e.g., CD209 antigen, granulin, C-X-C motif chemokine 10, prostacyclin synthase, and interleukins) and neuroendocrine (e.g., mmp13a, mmp9, brain aromatase, and pmch) pathways. The serotype Ib strain seems promptly recognized by the host, triggering a potent inflammatory response, whereas the serotype III strain elicited a less immediate response, resulting in more pronounced central nervous system (CNS) symptoms and behavioral effects. To the best of our knowledge, this is the first study to show serotype-specific immune responses to S. agalactiae in Nile tilapia. These findings are important for advancing disease management and control strategies in aquaculture. Identifying different immune reactions triggered by serotypes Ib and III may assist the development of more specific approaches for preventive measures, early detection, and effective treatment against streptococcosis.

Multiomic analysis reveals cellular, transcriptomic and epigenetic changes in intestinal pouches of ulcerative colitis patients

Total proctocolectomy with ileal pouch anal anastomosis is the standard of care for patients with severe ulcerative colitis. We generated a cell-type-resolved transcriptional and epigenetic atlas of ileal pouches using scRNA-seq and scATAC-seq data from paired biopsy samples of the ileal pouch and the ileal segment above the pouch (pre-pouch) from patients (male=4, female=2), and paired biopsies of the terminal ileum and ascending colon from healthy individuals (male=3, female=3) serving as reference. Our study finds previously uncharacterized populations of absorptive and secretory epithelial cells within the pouch but not the pre-pouch. These pouch-specific enterocytes express a subset of colon-specific genes, including CEACAM5 and CD24. However, compared to normal colonocytes, expression of these genes is lower, and these enterocytes also express inflammatory and secretory genes while maintaining expression of some ileal-specific genes. This cell-type-resolved transcriptomic and epigenetic atlas of the ileal pouch establishes a reference for investigating pouch physiology and pathology.

Cross-talk and mutual shaping between the immune system and the microbiota during an oyster's life

The Pacific oyster Crassostrea gigas lives in microbe-rich marine coastal systems subjected to rapid environmental changes. It harbours a diversified and fluctuating microbiota that cohabits with immune cells expressing a diversified immune gene repertoire. In the early stages of oyster development, just after fertilization, the microbiota plays a key role in educating the immune system. Exposure to a rich microbial environment at the larval stage leads to an increase in immune competence throughout the life of the oyster, conferring a better protection against pathogenic infections at later juvenile/adult stages. This beneficial effect, which is intergenerational, is associated with epigenetic remodelling. At juvenile stages, the educated immune system participates in the control of the homeostasis. In particular, the microbiota is fine-tuned by oyster antimicrobial peptides acting through specific and synergistic effects. However, this balance is fragile, as illustrated by the Pacific Oyster Mortality Syndrome, a disease causing mass mortalities in oysters worldwide. In this disease, the weakening of oyster immune defences by OsHV-1 µVar virus induces a dysbiosis leading to fatal sepsis. This review illustrates the continuous interaction between the highly diversified oyster immune system and its dynamic microbiota throughout its life, and the importance of this cross-talk for oyster health. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.

Probiotics to Prevent Celiac Disease and Inflammatory Bowel Diseases

The incidence of chronic inflammatory diseases (CIDs) is dramatically increasing in the developed world, resulting in an increased burden of disease in childhood. Currently, there are limited effective strategies for treating or preventing these conditions. To date, myriads of cross-sectional studies have described alterations in the composition of the gut microbiota in a variety of disease states, after the disease has already occurred. We suggest that to mechanically link these microbiome changes with disease pathogenesis, a prospective cohort design is needed to capture changes that precede or coincide with disease onset and symptoms. In addition, these prospective studies must integrate microbiological, metagenomic, meta transcriptomic and metabolomic data with minimal and standardized clinical and environmental metadata that allow to correctly compare and interpret the results of the analysis of the human microbiota in order to build a system-level model of the interactions between the host and the development of the disease. The creation of new biological computational models thus constructed will allow us to finally move from the detection of simple elements of "association" to the identification of elements of real "causality" allowing to provide a mechanistic approach to the exploration of the development of CIDs.This can only be done when these diseases are studied as complex biological networks. In this chapter we discuss the current knowledge regarding the contribution of the microbiome to CID in childhood, focusing on celiac disease and inflammatory bowel disease, with the overall aim of identifying pathways to shift research from descriptive to mechanistic approaches. We then examine how some components of the microbiota, through epigenetic reprogramming, can start the march from genetic predisposition to clinical expression of CIDs, thus opening up new possibilities for intervention, through microbiota therapy targeting the manipulation of the composition and function of the microbiota, for future applications of precision medicine and primary prevention.

Salivary Cystatin D Interactome in Patients with Systemic Mastocytosis: An Exploratory Study

Mastocytosis, a rare blood disorder characterized by the proliferation of clonal abnormal mast cells, has a variegated clinical spectrum and diagnosis is often difficult and delayed. Recently we proposed the cathepsin inhibitor cystatin D-R26 as a salivary candidate biomarker of systemic mastocytosis (SM). Its C26 variant is able to form multiprotein complexes (mPCs) and since protein-protein interactions (PPIs) are crucial for studying disease pathogenesis, potential markers, and therapeutic targets, we aimed to define the protein composition of the salivary cystatin D-C26 interactome associated with SM. An exploratory affinity purification-mass spectrometry method was applied on pooled salivary samples from SM patients, SM patient subgroups with and without cutaneous symptoms (SM+C and SM-C), and healthy controls (Ctrls). Interactors specifically detected in Ctrls were found to be implicated in networks associated with cell and tissue homeostasis, innate system, endopeptidase regulation, and antimicrobial protection. Interactors distinctive of SM-C patients participate to PPI networks related to glucose metabolism, protein S-nitrosylation, antibacterial humoral response, and neutrophil degranulation, while interactors specific to SM+C were mainly associated with epithelial and keratinocyte differentiation, cytoskeleton rearrangement, and immune response pathways. Proteins sensitive to redox changes, as well as proteins with immunomodulatory properties and activating mast cells, were identified in patients; many of them were involved directly in cytoskeleton rearrangement, a process crucial for mast cell activation. Although preliminary, these results demonstrate that PPI alterations of the cystatin D-C26 interactome are associated with SM and provide a basis for future investigations based on quantitative proteomic analysis and immune validation.

Coral-algal endosymbiosis characterized using RNAi and single-cell RNA-seq

Corals form an endosymbiotic relationship with the dinoflagellate algae Symbiodiniaceae, but ocean warming can trigger algal loss, coral bleaching and death, and the degradation of ecosystems. Mitigation of coral death requires a mechanistic understanding of coral-algal endosymbiosis. Here we report an RNA interference (RNAi) method and its application to study genes involved in early steps of endosymbiosis in the soft coral Xenia sp. We show that a host endosymbiotic cell marker called LePin (lectin and kazal protease inhibitor domains) is a secreted Xenia lectin that binds to algae to initiate phagocytosis of the algae and coral immune response modulation. The evolutionary conservation of domains in LePin among marine anthozoans performing endosymbiosis suggests a general role in coral-algal recognition. Our work sheds light on the phagocytic machinery and posits a mechanism for symbiosome formation, helping in efforts to understand and preserve coral-algal relationships in the face of climate change.

Impact of antibiotic perturbation on fecal viral communities in mice

Viruses and bacteriophages have a strong impact on intestinal barrier function and the composition and functional properties of commensal bacterial communities. Shifts of the fecal virome might be involved in human diseases, including inflammatory bowel disease (IBD). Loss-of-function variants in the nucleotide-binding oligomerization domain-containing protein 2 (NOD2) gene are associated with an increased risk of developing Crohn's disease, a subtype of human chronic IBD, where specific changes in fecal viral communities have also been described. To improve our understanding of the dynamics of the enteric virome, we longitudinally characterized the virome in fecal samples from wild-type C57BL/6J and NOD2 knock-out mice in response to an antibiotic perturbation. Sequencing of virus-like particles demonstrated both a high diversity and high interindividual variation of the murine fecal virome composed of eukaryotic viruses and bacteriophages. Antibiotics had a significant impact on the fecal murine virome. Viral community composition only partially recovered in the observation period (10 weeks after cessation of antibiotics) irrespective of genotype. However, compositional shifts in the virome and bacteriome were highly correlated, suggesting that the loss of specific phages may contribute to prolonged dysregulation of the bacterial community composition. We suggest that therapeutic interference with the fecal virome may represent a novel approach in microbiota-targeted therapies.

Defects in the expression of colonic host defense factors associate with barrier dysfunction induced by a high-fat/high-cholesterol diet

The effect of Western diets in the gastrointestinal system is largely mediated by their ability to promote alterations in the immunity and physiology of the intestinal epithelium, and to affect the composition of the commensal microbiota. To investigate the response of the colonic epithelium to high-fat/high-cholesterol diets (HFHCDs), we evaluated the synthesis of host defense factors involved in the maintenance of the colonic homeostasis. C57BL/6 mice were fed an HFHCD for 3 weeks and their colons were evaluated for histopathology, gene expression, and microbiota composition. In addition, intestinal permeability and susceptibility to Citrobacter rodentium were also studied. HFHCD caused colonic hyperplasia, loss of goblet cells, thinning of the mucus layer, moderate changes in the composition of the intestinal microbiota, and an increase in intestinal permeability. Gene expression analyses revealed significant drops in the transcript levels of Muc1, Muc2, Agr2, Atoh1, Spdef, Ang4, Camp, Tff3, Dmbt1, Fcgbp, Saa3, and Retnlb. The goblet cell granules of HFHCD-fed mice were devoid of Relmβ and Tff3, indicating defective production of those two factors critical for intestinal epithelial defense and homeostasis. In correspondence with these defects, colonic bacteria were in close contact with, and invading the epithelium. Fecal shedding of C. rodentium showed an increased bacterial burden in HFHCD-fed animals accompanied by increased epithelial damage. Collectively, our results show that HFHCD perturbs the synthesis of colonic host defense factors, which associate with alterations in the commensal microbiota, the integrity of the intestinal barrier, and the host's susceptibility to enteric infections.

A single cell survey of the microbial impacts on the mouse small intestinal epithelium

The small intestinal epithelial barrier inputs signals from the gut microbiota in order to balance physiological inflammation and tolerance, and to promote homeostasis. Understanding the dynamic relationship between microbes and intestinal epithelial cells has been a challenge given the cellular heterogeneity associated with the epithelium and the inherent difficulty of isolating and identifying individual cell types. Here, we used single-cell RNA sequencing of small intestinal epithelial cells from germ-free and specific pathogen-free mice to study microbe-epithelium crosstalk at the single-cell resolution. The presence of microbiota did not impact overall cellular composition of the epithelium, except for an increase in Paneth cell numbers. Contrary to expectations, pattern recognition receptors and their adaptors were not induced by the microbiota but showed concentrated expression in a small proportion of epithelial cell subsets. The presence of the microbiota induced the expression of host defense- and glycosylation-associated genes in distinct epithelial cell compartments. Moreover, the microbiota altered the metabolic gene expression profile of epithelial cells, consequently inducing mTOR signaling thereby suggesting microbe-derived metabolites directly activate and regulate mTOR signaling. Altogether, these findings present a resource of the homeostatic transcriptional and cellular impact of the microbiota on the small intestinal epithelium.

Proteomic analysis of exosomes in pacific oyster Crassostrea gigas during bacterial stimulation

Exosomes are 30-150 nm-sized extracellular vesicles of endocytic origin that are released into the extracellular environment and play roles in cell-cell communication. Accumulating research achievements demonstrated that exosomes could act as innate immune effectors that contribute to the host defense mechanism. To better understand the immune functions of exosomes in Crassostrea gigas against bacterial stimulation, the iTRAQ LC-MS/MS approach was applied to identifying differentially expressed proteins (DEPs) of exosomes in oyster post Staphylococcus aureus and Vibrio splendidus stimulation. A total of 9467 unique peptides corresponding to 1634 proteins were identified. Among them, 99 proteins were upregulated and 152 were downregulated after S. aureus infection. After V. splendidus infection, 431 proteins were identified as differentially abundant, including 76 that were upregulated and 355 were downregulated. Several proteins related to apoptosis, including E3 ubiquitin-protein ligase, eukaryotic translation initiation factor 3, and protein kinase C delta type were found up-regulated in the S. aureus stimulation group, indicating that the apoptosis process was involved in the response to S. aureus stimulation. Thirty up-regulated and 123 down-regulated proteins were identified as differentially abundant after both bacterial stimuli. Among them, some proteins related to the actin-myosin cytoskeleton process were down-regulated, indicating that phagocytosis may be inhibited in both bacterial stimuli. This study would enrich the C. gigas proteome database and provide information for further understanding the immune functions of oyster exosomes against bacterial infection.

Epithelial dysfunction is prevented by IL-22 treatment in a Citrobacter rodentium-induced colitis model that shares similarities with inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterized by a dysregulated intestinal epithelial barrier leading to breach of barrier immunity. Here we identified similar protein expression changes between IBD and Citrobacter rodentium-infected FVB mice with respect to dysregulation of solute transporters as well as components critical for intestinal barrier integrity. We attribute the disease associated changes in the model to the emergence of undifferentiated intermediate intestinal epithelial cells. Prophylactic treatment with IL-22.Fc in C. rodentium-infected FVB mice reduced disease severity and rescued the mice from lethality. Multi-omics and solute analyses revealed that IL-22.Fc treatment prevented disease-associated changes including disruption of the solute transporter machinery and restored proper physiological functions of the intestine, respectively. Taken together, we established the disease relevance of the C. rodentium-induced colitis model to IBD, demonstrated the protective role of IL-22 in amelioration of epithelial dysfunction and elucidated the molecular mechanisms with IL-22's effect on intestinal epithelial cells.

The copy number variation of DMBT1 gene effects body traits in two Chinese cattle breeds

Copy number variations (CNVs) belong to mutations in the genome level with loci in the region of genic or intergenic. It is through different effects (such as position effect and dose effect) that influence complex traits and diseases. Deleted in Malignant Brain Tumors 1 (DMBT1) gene is a member of the scavenger receptor cysteine-rich super family. In cattle, this gene has been associated with the susceptibility to bovine tuberculosis. In this study, a new CNV was found in DMBT1 gene of Chinese cattle breeds and tested in two different Chinese cattle breeds (Jiaxian red and Pinan) for frequency distribution analysis. Besides, the body size data such as body length, body height, chest girth, chest width, rump length, and rump girth for Jiaxian (JX) and Pinan (PN) cattle were collected and associated with the newly identified CNV. The CNV was significantly associated with the body length and chest girth of JX cattle, and the rump length of PN cattle (P < 0.05). Furthermore, the expression profile of the DMBT1 gene was tested in calves' tissues and the myoblasts differentiation. It was found that the DMBT1 gene expression was high in tuberculosis susceptible tissues (liver and lungs) at the calf stage and high in myoblast early differentiation. These tests were done using the qPCR method. As the result, the CNV of DMBT1 gene could be used as a candidate marker for bovine growth and health in marker-assisted selection (MAS) breeding.

Effects of equine SALSA on neutrophil phagocytosis and macrophage cytokine production

Salivary scavenger and agglutinin (SALSA) is a secreted protein with various immunomodulatory roles. In humans, the protein agglutinates and inactivates microorganisms, and inhibits the release of pro-inflammatory cytokines. Saliva, which is rich in SALSA, accelerates bacterial phagocytosis, but SALSA’s contribution is unclear. In horses, the functions of SALSA in inflammation remain undetermined, so they were investigated through phagocytosis and cytokine assays. Equine SALSA was purified from duodenal tissue, which contains abundant SALSA. To assess phagocytosis, fluorescently-labelled bacteria were incubated with 20, 10, 5, or 2.5 μg/mL of SALSA or phosphate buffered saline (PBS), and then incubated at 37°C or on ice with whole blood from seven healthy horses. Fluorescence was measured by gating on neutrophils using a flow cytometer, and compared between groups. To assess effects on cytokine production, alveolar macrophages were isolated from bronchoalveolar lavage fluid of five healthy horses and cultured in serum-free media for 24 hours with different concentrations of SALSA plus 1 μg/mL lipopolysaccharide (LPS), only LPS, or only media. Cytokines were measured in supernatant using an equine-specific multiplex bead immunoassay. There was significantly greater phagocytosis in samples incubated at 37°C compared to incubation on ice. Samples incubated with 20 μg/mL of SALSA at 37°C had less phagocytosis compared to samples with 10 or 2.5 μg/mL SALSA, or PBS. Alveolar macrophages incubated with SALSA plus LPS released significantly less CXC motif chemokine ligand 1, interleukin-8, interleukin-10, and tumor necrosis factor α, and more granulocyte colony stimulating factor (G-CSF), compared to macrophages incubated with LPS alone. These findings indicate anti-inflammatory effects, which may be due to interference with toll-like receptor 4 recognition of LPS or downstream signaling. Increase in G-CSF following incubation with SALSA suggests a novel mechanism for immunoregulation of alveolar macrophages by SALSA, addressing a knowledge gap regarding its functions in horses.

DMBT1 is upregulated in cystic fibrosis, affects ciliary motility, and is reduced by acetylcysteine

BACKGROUND

Cystic fibrosis (CF) is the most common genetic disorder in the Caucasian population. Despite remarkable improvements in morbidity and mortality during the last decades, the disease still limits survival and reduces quality of life of affected patients. Moreover, CF still represents substantial economic burden for healthcare systems. Inflammation and infection already start in early life and play important roles in pulmonary impairment. The aim of this study is to analyze the potential role of DMBT1, a protein with functions in inflammation, angiogenesis, and epithelial differentiation, in CF.

RESULTS

Immunohistochemically DMBT1 protein expression was upregulated in lung tissues of CF patients compared to healthy controls. Additionally, pulmonary expression of Dmbt1 was approximately 6-fold increased in an established transgenic mouse model of CF-like lung disease (ENaC tg) compared to wild-type mice as detected by qRT-PCR. Since acetylcysteine (ACC) has been shown to reduce inflammatory markers in the airways, its potential influence on DMBT1 expression was analyzed. A549 cells stably transfected with an expression plasmid encoding the largest (8kb) DMBT1 variant (DMBT1+ cells) or an empty vector control (DMBT1- cells) and incubated with ACC both showed significantly reduced DMBT1 concentrations in the culture medium (p = 0.0001). To further elucidate the function of DMBT1 in pulmonary airways, respiratory epithelial cells were examined by phase contrast microscopy. Addition of human recombinant DMBT1 resulted in altered cilia motility and irregular beat waves (p < 0.0001) suggesting a potential effect of DMBT1 on airway clearance.

CONCLUSIONS

DMBT1 is part of inflammatory processes in CF and may be used as a potential biomarker for CF lung disease and a potential tool to monitor CF progression. Furthermore, DMBT1 has a negative effect on ciliary motility thereby possibly compromising airway clearance. Application of ACC, leading to reduced DMBT1 concentrations, could be a potential therapeutic option for CF patients.

Oxidized phospholipids cause changes in jejunum mucus that induce dysbiosis and systemic inflammation

We previously reported that adding a concentrate of transgenic tomatoes expressing the apoA-I mimetic peptide 6F (Tg6F) to a Western diet (WD) ameliorated systemic inflammation. To determine the mechanism(s) responsible for these observations, Ldlr-/- mice were fed chow, a WD, or WD plus Tg6F. We found that a WD altered the taxonomic composition of bacteria in jejunum mucus. For example, Akkermansia muciniphila virtually disappeared, while overall bacteria numbers and lipopolysaccharide (LPS) levels increased. In addition, gut permeability increased, as did the content of reactive oxygen species and oxidized phospholipids in jejunum mucus in WD-fed mice. Moreover, gene expression in the jejunum decreased for multiple peptides and proteins that are secreted into the mucous layer of the jejunum that act to limit bacteria numbers and their interaction with enterocytes including regenerating islet-derived proteins, defensins, mucin 2, surfactant A, and apoA-I. Following WD, gene expression also decreased for Il36γ, Il23, and Il22, cytokines critical for antimicrobial activity. WD decreased expression of both Atoh1 and Gfi1, genes required for the formation of goblet and Paneth cells, and immunohistochemistry revealed decreased numbers of goblet and Paneth cells. Adding Tg6F ameliorated these WD-mediated changes. Adding oxidized phospholipids ex vivo to the jejunum from mice fed a chow diet reproduced the changes in gene expression in vivo that occurred when the mice were fed WD and were prevented with addition of 6F peptide. We conclude that Tg6F ameliorates the WD-mediated increase in oxidized phospholipids that cause changes in jejunum mucus, which induce dysbiosis and systemic inflammation.

Quercetin attenuates lipopolysaccharide-mediated inflammatory injury in human nasal epithelial cells via regulating miR-21/DMBT1/NF-κB axis

BACKGROUND

Quercetin (Qu) belongs to a flavonoid polyphenolic compound present in fruits and vegetables which has been confirmed to exert anti-inflammatory properties. Our study aimed to explore the impacts of quercetin on lipopolysaccharide (LPS)-induced inflammatory injury and signal transduction of miR-21/DMBT1/NF-κB axis in human nasal epithelial cells (HNEpC).

METHODS

HNEpCs were cultured and treated with 1 μg/mL of LPS and a gradient concentration (10, 100, and 200 μM) of quercetin for 24 h. Cell viability, apoptosis, and cytokines were detected to assess the inflammatory injury in LPS-exposed HNEpCs. The expressions of miR-21, DMBT1, and NF-κB mRNA were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The levels of DMBT1 and NF-κB protein were measured by western blotting.

RESULTS

LPS treatment reduced cell viability, promoted cell apoptosis and inflammatory response, down-regulated miR-21 expression and up-regulated DMBT1, and NF-κB in HNEpC cells. Quercetin exerted the opposite effects to attenuate LPS-induced inflammatory injury in HNEpC cells at a concentration-dependent way. Additionally, miR-21 directly targeted DMBT1 to reduce its expression and further inducing cell viability via inhibiting cell apoptosis and inflammatory response. MiR-21 inhibition or DMBT1 over-expression weakened the protective effects of quercetin against LPS-induced inflammatory injury in HNEpC cells.

CONCLUSIONS

Quercetin could protect HNEpC cells against LPS-induced inflammatory injury via inducing miR-21/DMBT1/NF-κB axis. Therefore, quercetin could be utilized as a potential compound to treat for allergic rhinitis.

Bronchial brush cytology, endobronchial biopsy, and SALSA immunohistochemistry in severe equine asthma

Horses with severe equine asthma (SEA), also known as heaves and recurrent airway obstruction, have persistent neutrophilic inflammation of the lower airways. Cytologic evaluation of bronchoalveolar lavage (BAL) fluid is commonly used to confirm the clinical diagnosis of SEA. However, the utility of microscopic assessment of bronchial brushings, endobronchial biopsies, and immunohistochemical detection of disease-associated biomarkers for the diagnosis of SEA remain poorly characterized. Salivary scavenger and agglutinin (SALSA) has anti-inflammatory properties and downregulated gene expression in SEA; therefore, it was investigated as a tissue biomarker for airway and systemic inflammation. Six asthmatic and 6 non-asthmatic horses were exposed to an inhaled challenge. Before and after challenge, samples of BAL fluid, bronchial brushing, and endobronchial biopsy were collected. Location of SALSA in biopsies was determined, and immunohistochemical label intensity was computed using image analysis software. Serum amyloid A (SAA) was measured to assess systemic inflammation. After challenge, neutrophil proportions were significantly higher in asthmatic versus non-asthmatic horses in BAL fluid (least squares means, 95% confidence interval: 80.9%, 57.2% to 93.1%, vs 3.6%, 1.1% to 10.7%) and in brush cytology slides (39.5%, 7.7% to 83.6%, vs 0.2%, 0% to 2.3%), illustrating the potential of brush cytology as an alternate modality to BAL for assessing intraluminal inflammation. Bronchial histopathologic findings and intensity of SALSA immunolabeling in surface and glandular epithelium were similar in asthmatic and non-asthmatic horses, indicating limited changes in bronchial tissue from the inhaled challenge. Increases in SAA indicated systemic inflammation, but SALSA immunolabeling did not change significantly.

Faecal proteome in clinically healthy dogs and cats: Findings in pooled faeces from 10 cats and 10 dogs

BACKGROUND

In the scientific literature, there are only a few manuscripts available on small animal faecal proteomics.

METHODS

In the present pilot study, this evaluation was performed using pooled faecal samples from 10 clinically healthy dogs and, for the first time, in 10 clinically healthy cats by mean of two-dimensional electrophoresis followed by liquid chromatography-tandem mass spectrometry.

RESULTS

Our results showed the presence of nine (albumin, alkaline phosphatase, chymotrypsin-C-like, cytosol aminopeptidase, elastase-3B/proteinase E, immunoglobulins and nuclear pore membrane glycoprotein 210) and 14 (albumin, caspase recruitment domain-containing protein, chymotrypsin-like, deleted in malignant brain tumours 1 protein-like, hypothetical protein LOC107375, immunoglobulin, kallikrein-1, superoxide dismutase, transthyretin precursor, interstitial collagenase-like) different proteins in canine and feline faeces, respectively.

CONCLUSION

These preliminary findings document the presence of a range of proteins in the faeces of apparently healthy dogs and cats and may serve as a basis for larger, prospective studies to establish reference proteomic data against which diseased populations can be compared.

Effects of Bacillus cereus PAS38 on Immune-Related Differentially Expressed Genes of Spleen in Broilers

This study mainly explored the immunomodulatory mechanisms of the probiotic Bacillus cereus PAS38 (PB) on broiler spleen. A total of 120 avian white feather broilers were randomly divided into 4 groups (N = 30), as follows: control (CNTL, fed with basal diet), PB (fed with diet supplemented with probiotic B. cereus PAS38), vaccine (VAC, fed with basal diet and injected with Newcastle disease virus vaccine), and vaccine + PB group (PBVAC, fed with basal diet supplemented with B. cereus PAS38 and injected with NDV vaccine). The experiment was conducted for 42 days. Twelve spleens were collected from four different groups, weighed, and cut into histological sections, and transcriptome analysis was performed using RNA-seq. Results of the spleen and histological section relative weights showed that feeding with probiotic B. cereus PAS38 and vaccination had a similar tendency to promote spleen development. Compared with the CNTL group, 21 immune-related genes were significantly downregulated in the PB and PBVAC groups. These genes were mainly involved in attenuating inflammatory response. The upregulated antimicrobial peptide NK-lysin and guanylate-binding protein 1 expression levels indicated that this strain enhanced the body's antimicrobial capacity. B. cereus PAS38 also amplified the broilers' immune response to the vaccine, which mainly reflected on nonspecific immunity. Hence, probiotic B. cereus PAS38 can regulate and promote the immune function of broilers.

DMBT1 amount in amniotic fluid depends on gestational age

OBJECTIVE

Amniotic fluid is a mixture containing many different proteins as immunomodulatory peptides and growth factors. The glycoprotein Deleted in Malignant Brain Tumors 1 (DMBT1) is participated in innate immunity, angiogenesis and epithelial differentiation. We analyzed the DMBT1 concentration in amniotic fluid during gestation.

METHODS

DMBT1 concentration was quantified by ELISA. Amniotic fluid samples were collected from preterm and term neonates. Effects of maternal or neonatal parameters were analyzed. To evaluate the source of DMBT1 we examined RNA of fetal tissue in relation to DMBT1 expression.

RESULTS

The median DMBT1 concentration in amniotic fluid was 54.4 ng/ml. Amniotic fluid obtained <28 weeks of gestation revealed significantly lower DMBT1 concentrations compared to ≥28 weeks. We found a positive correlation between DMBT1 concentration and gestational age (p = .026). The fetal DMBT1 expression was pronounced in the gastrointestinal tract.

CONCLUSIONS

The results showed that DMBT1 concentrations in amniotic fluid correlate with the gestational age during gestation and that the fetal gastrointestinal tract is a potential source of DMBT1.

BRIEF RATIONALE

Amniotic fluid contains not only nutrients, but also many immunomodulatory peptides and growth factors. Deleted in Malignant Brain Tumors 1 (DMBT1) is an innate immunity protein with functions in epithelial differentiation and angiogenesis. The aim of this research was to study the DMBT1 content and the factors affecting its concentration in amniotic fluid during gestation. In summary, the results obtained in this study showed that DMBT1 is a component of amniotic fluid and that DMBT1 concentrations in amniotic fluid correlate with gestational age. In addition to this, the fetal gastrointestinal tract is a potential source of DMBT1 detected in amniotic fluid.

Induction of the endogenous sialoglycan ligand for eosinophil death receptor Siglec-8 in chronic rhinosinusitis with hyperplastic nasal polyposis

Siglec-8, an immune-inhibitory sialoglycan binding lectin (S8), is expressed on the surface of eosinophils and mast cells, potent mediators of allergic inflammation. When S8 engages endogenous sialoglycan ligands, eosinophils undergo apoptosis and mast cell mediator release is inhibited. In the human airway, Siglec-8 ligands (S8L) are sialylated keratan sulfate chains carried on isoforms of the protein Deleted in Malignant Brain Tumors-1 (DMBT1), an immunoregulatory protein that we recently identified as the endogenous ligand for S8, DMBT1S8. We herein report that S8L is overexpressed in chronic rhinosinusitis with nasal polyposis (CRSwNP), a prevalent eosinophilic laden airway disease. Quantification and comparison of the degree to which DMBT1 carries the S8L by immunoblot analysis and lectin blot overlay, respectively, from nasal lavage showed that the S8L/DMBT1 ratio was significantly increased in CRSwNP vs control or CRS patients. We identified the histological sites of S8L and DMBT1 expression in fresh surgically resected human nasal polyps. Histochemistry of diseased polyps and adjacent non-diseased middle turbinate tissue from CRSwNP demonstrated colocalization of S8L and DMBT1 with highest staining in submucosal glands >> epithelium > stoma. S8L expression was specifically elevated in the submucosal glands and epithelium of polyp tissue compared to middle turbinate. We hypothesize that expression of the isoform of DMBT1 carrying the Siglec-8 binding sialoglycan, DMBT1S8, is induced in polyps of CRSwNP specifically at the site of disease, is produced in the submucosal glands of polyps and secreted into the lumen of the sinonasal cavity as a host response to mitigate eosinophil-mediated inflammation.

iTRAQ-Based Quantitative Proteomic Analysis of Intestines in Murine Polymicrobial Sepsis with Hydrogen Gas Treatment

Objective

Sepsis-associated intestinal injury has a higher morbidity and mortality in patients with sepsis, but there is still no effective treatment. Our research team has proven that inhaling 2% hydrogen gas (H₂) can effectively improve sepsis and related organ damage, but the specific molecular mechanism of its role is not clear. In this study, isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics analysis was used for studying the effect of H₂ on intestinal injury in sepsis.

Methods

Male C57BL/6J mice were used to prepare a sepsis model by cecal ligation and puncture (CLP). The 7-day survival rates of mice were measured. 4-kd fluorescein isothiocyanate-conjugated Dextran (FITC-dextran) blood concentration measurement, combined with hematoxylin-eosinstain (HE) staining and Western blotting, was used to study the effect of H₂ on sepsis-related intestinal damage. iTRAQ-based liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was used for studying the proteomics associated with H₂ for the treatment of intestinal injury.

Results

H₂ can significantly improve the 7-day survival rates of sepsis mice. The load of blood and peritoneal lavage bacteria was increased, and H₂ treatment can significantly reduce it. CLP mice had significant intestinal damage, and inhalation of 2% hydrogen could significantly reduce this damage. All 4194 proteins were quantified, of which 199 differentially expressed proteins were associated with the positive effect of H₂ on sepsis. Functional enrichment analysis indicated that H₂ may reduce intestinal injury in septic mice through the effects of thyroid hormone synthesis and nitrogen metabolism signaling pathway. Western blot showed that H₂ was reduced by down-regulating the expressions of deleted in malignant brain tumors 1 protein (DMBT1), insulin receptor substrate 2 (IRS2), N-myc downregulated gene 1 (NDRG1) and serum amyloid A-1 protein (SAA1) intestinal damage in sepsis mice.

Conclusion

A total of 199 differential proteins were related with H₂ in the intestinal protection of sepsis. H₂-related differential proteins were notably enriched in the following signaling pathways, including thyroid hormone synthesis signaling pathway, nitrogen metabolism signaling pathways, digestion and absorption signaling pathways (vitamins, proteins and fats). H₂ reduced intestinal injury in septic mice by down-regulating the expressions of SAA1, NDRG1, DMBT1 and IRS2.

Intestinal SALSA/dmbt1 levels are decreased in prematurely born infants

The first months of life represent a crucial time period for an infant. Alongside establishing the early microbiome, the mucosal immunological homeostasis is being developed. Both processes may be perturbed in prematurely born infants. The glycoprotein SALSA plays a role in mucosal inflammation and microbial clearance. It is one of the most abundant molecules on the intestinal mucosal surfaces in early life. SALSA binds to many types of microbes and host defence molecules like IgA, C1q and collectin molecules. We here describe the development in faecal SALSA levels during the first three months of life. During these 90 days, the median SALSA level in full-term babies decreased from 1100 μg/mL (range 49-17 000 μg/mL) to 450 μg/mL (range 33-1000 μg/mL). Lower levels of SALSA were observed in prematurely born infants in the same time period. Our novel observation thus indicates an impact of prematurity on an important component of the infant intestinal immune system. Changes in SALSA in early life may have an effect on the early establishment of the human microbiome.

Mass spectrometric characterisation of the circulating peptidome following oral glucose ingestion in control and gastrectomised patients

RATIONALE

Meal ingestion triggers secretion of a variety of gut and endocrine peptides important in diabetes research which are routinely measured by immunoassays. However, similarities between some peptides (glucagon, oxyntomodulin and glicentin) can cause specificity issues with immunoassays. We used a liquid chromatography/tandem mass spectrometry (LC/MS/MS) methodology to unambiguously monitor multiple gut peptides in human plasma.

METHODS

A simple acetonitrile-based protein precipitation step, followed by evaporation and solid-phase extraction, removed high-abundance proteins from samples prior to nano-LC/MS/MS analysis on an Orbitrap Q-Exactive Plus mass spectrometer using a data-dependent methodology. Database searching using PEAKS identified multiple gut-derived peptides, including peptides in the mid-pg/mL range. The relative levels of these and previously characterised peptides were assessed in plasma samples from gastrectomised and control subjects during an oral glucose tolerance test.

RESULTS

Analysis of plasma extracts revealed significantly elevated levels of a number of peptides following glucose ingestion in subjects who had undergone gastrectomy compared with controls. These included GLP-1(7-36), GLP-1(9-36), glicentin, oxyntomodulin, GIP(1-42), GIP(3-42), PYY(1-36), PYY(3-36), neurotensin, insulin and C-peptide. Motilin levels decreased following glucose ingestion. Results showed good correlation with immunoassay-derived concentrations of some peptides in the same samples. The gastrectomy group also had higher, but non-glucose-dependent, circulating levels of peptides from PIGR and DMBT1.

CONCLUSIONS

Overall, the approach showed that a fast, generic and reproducible LC/MS/MS methodology requiring only a small volume of plasma was capable of the multiplexed detection of a variety of diabetes-related peptides.

Immunohistochemical Localization of Deleted in Malignant Brain Tumors 1 in Normal Human Tissues

Deleted in malignant brain tumors 1 (DMBT1) is part of the innate immune system and is expressed on mucosal surfaces in various tissues throughout the human body. However, to date, the localization of DMBT1 has not been investigated systematically and comprehensively in normal human tissues. In this study, we analyzed the mRNA expression of DMBT1 in human tissue by quantitative real-time PCR and examined its localization and distribution in the tissue by immunohistochemical staining using the monoclonal DMBT1 antibody HYB213-6. Anti-ovalbumin was used as an isotype control. The highest level of mRNA expression of DMBT1 was found in the small intestine, and the expression level was high throughout the luminal digestive tract. The expression of DMBT1 was especially high in the luminal digestive tract and salivary glands. The lowest expression level was found in the spleen. Immunohistochemical staining showed a high expression level of DMBT1 on mucosal surfaces throughout the body. There was a clear correlation between the mRNA expression and immunohistochemical expression of DMBT1 in the tissue. DMBT1 is strongly expressed on mucosal surfaces and in salivary glands.

Postnatal Gut Immunity and Microbiota Development Is Minimally Affected by Prenatal Inflammation in Preterm Pigs

Chorioamnionitis (CA), resulting from intra-amniotic inflammation, is a frequent cause of preterm birth and exposes the immature intestine to bacterial toxins and/or inflammatory mediators before birth via fetal swallowing. This may affect intestinal immune development, interacting with the effects of enteral feeding and gut microbiota colonization just after birth. Using preterm pigs as model for preterm infants, we hypothesized that prenatal exposure to gram-negative endotoxin influences postnatal bacterial colonization and gut immune development. Pig fetuses were given intra-amniotic lipopolysaccharide (LPS) 3 days before preterm delivery by cesarean section and were compared with littermate controls (CON) at birth and after 5 days of formula feeding and spontaneous bacterial colonization. Amniotic fluid was collected for analysis of leukocyte counts and cytokines, and the distal small intestine was analyzed for endotoxin level, morphology, and immune cell counts. Intestinal gene expression and microbiota were analyzed by transcriptomics and metagenomics, respectively. At birth, LPS-exposed pigs showed higher intestinal endotoxin, neutrophil/macrophage density, and shorter villi. About 1.0% of intestinal genes were affected at birth, and DMBT1, a regulator of mucosal immune defense, was identified as the hub gene in the co-expression network. Genes related to innate immune response (TLR2, LBP, CD14, C3, SFTPD), neutrophil chemotaxis (C5AR1, CSF3R, CCL5), and antigen processing (MHC II genes and CD4) were also affected, and expression levels correlated with intestinal neutrophil/macrophage density and amniotic fluid cytokine levels. On day 5, LPS and CON pigs showed similar sensitivity to necrotizing enterocolitis, endotoxin levels, morphology, immune cell counts, gene expressions, and microbiota composition (except for difference in some low-abundant species). Our results show that CA markedly affects intestinal genes at preterm birth, including genes related to immune cell infiltration. However, a few days later, following the physiological adaptations to preterm birth, CA had limited effects on intestinal structure, function, gene expression, bacterial colonization, and necrotizing enterocolitis sensitivity. We conclude that short-term, prenatal intra-amniotic inflammation is unlikely to exert marked effects on intestinal immune development in preterm neonates beyond the immediate neonatal period.

Structures of SALSA/DMBT1 SRCR domains reveal the conserved ligand-binding mechanism of the ancient SRCR fold

The structures of SALSA SRCR domains 1 and 8 reveal a cation-dependent mechanism for ligand recognition, contributing to important roles in the immune system and cellular signalling. The cation-binding sites are conserved across all SRCR domains, suggesting conserved functional mechanisms.

The scavenger receptor cysteine-rich (SRCR) family of proteins comprises more than 20 membrane-associated and secreted molecules. Characterised by the presence of one or more copies of the ∼110 amino-acid SRCR domain, this class of proteins have widespread functions as antimicrobial molecules, scavenger receptors, and signalling receptors. Despite the high level of structural conservation of SRCR domains, no unifying mechanism for ligand interaction has been described. The SRCR protein SALSA, also known as DMBT1/gp340, is a key player in mucosal immunology. Based on detailed structural data of SALSA SRCR domains 1 and 8, we here reveal a novel universal ligand-binding mechanism for SALSA ligands. The binding interface incorporates a dual cation-binding site, which is highly conserved across the SRCR superfamily. Along with the well-described cation dependency on most SRCR domain–ligand interactions, our data suggest that the binding mechanism described for the SALSA SRCR domains is applicable to all SRCR domains. We thus propose to have identified in SALSA a conserved functional mechanism for the SRCR class of proteins.

Protein Deimination and Extracellular Vesicle Profiles in Antarctic Seabirds

Pelagic seabirds are amongst the most threatened of all avian groups. They face a range of immunological challenges which seem destined to increase due to environmental changes in their breeding and foraging habitats, affecting prey resources and exposure to pollution and pathogens. Therefore, the identification of biomarkers for the assessment of their health status is of considerable importance. Peptidylarginine deiminases (PADs) post-translationally convert arginine into citrulline in target proteins in an irreversible manner. PAD-mediated deimination can cause structural and functional changes in target proteins, allowing for protein moonlighting in physiological and pathophysiological processes. PADs furthermore contribute to the release of extracellular vesicles (EVs), which play important roles in cellular communication. In the present study, post-translationally deiminated protein and EV profiles of plasma were assessed in eight seabird species from the Antarctic, representing two avian orders: Procellariiformes (albatrosses and petrels) and Charadriiformes (waders, auks, gulls and skuas). We report some differences between the species assessed, with the narrowest EV profiles of 50-200 nm in the northern giant petrel Macronectes halli, and the highest abundance of larger 250-500 nm EVs in the brown skua Stercorarius antarcticus. The seabird EVs were positive for phylogenetically conserved EV markers and showed characteristic EV morphology. Post-translational deimination was identified in a range of key plasma proteins critical for immune response and metabolic pathways in three of the bird species under study; the wandering albatross Diomedea exulans, south polar skua Stercorarius maccormicki and northern giant petrel. Some differences in Gene Ontology (GO) biological and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways for deiminated proteins were observed between these three species. This indicates that target proteins for deimination may differ, potentially contributing to a range of physiological functions relating to metabolism and immune response, as well as to key defence mechanisms. PAD protein homologues were identified in the seabird plasma by Western blotting via cross-reaction with human PAD antibodies, at an expected 75 kDa size. This is the first study to profile EVs and to identify deiminated proteins as putative novel plasma biomarkers in Antarctic seabirds. These biomarkers may be further refined to become useful indicators of physiological and immunological status in seabirds-many of which are globally threatened.

The protective role of DMBT1 in cervical squamous cell carcinoma

To explore the possible influence of deleted in malignant brain tumor 1 (DMBT1) in cervical squamous cell carcinoma (CSCC). DMBT1 expression was detected by Real-time reverse transcription PCR (qRT-PCR) and immunohistochemistry in CSCC and adjacent normal tissues from 167 CSCC patients, and its relationship with clinicopathological features and prognosis was analyzed. Besides, the in vitro experiments, including MTT, Cell-Light EdU, Wound-healing, Transwell invasion, Annexin V-FITC/PI staining, qRT-PCR, and Western blot, were performed in SiHa and CaSKi cells, which were both divided into Blank, Vector, and DMBT1 groups. The mRNA level and the positive expression rate of DMBT1 in CSCC tissues were lower than the adjacent normal tissues. Moreover, DMBT1 positive rate was linked to FIGO stage, tumor diameter, lymph node metastasis, and tumor differentiation of CSCC. Besides, patients with positive DMBT1 expression had higher 5-year survival rate than those negative ones. According to the in vitro experiments, SiHa and CaSKi cells with overexpressed DMBT1 showed the inhibition of proliferative ability and the enhancement of apoptosis with the upregulated pro-apoptosis proteins (Bax and Cleaved caspase-3) and down-regulated anti-apoptosis protein Bcl-2. Moreover, compared with Blank group, DMBT1 group presented decrease in the migration and invasion of SiHa and CaSKi cells with the down-expression of interstitial markers (N-cadherin and Vimentin) and the up-expression of epithelial marker E-cadherin. DMBT1 was decreased in CSCC, whereas its overexpression can not only inhibit the proliferation, migration, and invasion, but induce the apoptosis of human CSCC cells, being a novel strategy for CSCC treatment.

Salivary Scavenger and Agglutinin (SALSA) Is Expressed in Mucosal Epithelial Cells and Decreased in Bronchial Epithelium of Asthmatic Horses

The Salivary Scavenger and Agglutinin (SALSA) protein is an innate immune protein with various alleged functions, including the regulation of inflammation and tissue remodeling. Transcriptomic studies of severe equine asthma (SEA) showed downregulation of the gene encoding SALSA in bronchial epithelium of asthmatic compared to non-asthmatic horses. This study aimed to characterize expression of SALSA in equine tissues by immunohistochemistry (IHC), corroborate potential differences in epithelial gene expression between asthmatic and non-asthmatic horses, and assess the structure of equine SALSA. An antibody against SALSA was validated through immunoprecipitation followed by mass spectrometry and Western blotting to recognize the equine protein. This antibody was applied to tissue microarrays (TMAs) containing 22 tissues each from four horses. A quantitative PCR assay was designed to compare gene expression for SALSA between six asthmatic and six non-asthmatic horses, before and after an asthmatic challenge, using cDNA from endoscopic bronchial biopsies as source material. The SALSA gene from bronchial cDNA samples of 10 horses, was amplified and sequenced, and translated to characterize the protein structure. Immunostaining for SALSA was detected in the mucosal surfaces of the trachea, bronchi, bronchioles, stomach, small intestine and bladder, in pancreatic and salivary gland ducts, and in uterine gland epithelium. Staining was strongest in the duodenum, and the intercalated ducts and Demilune cells of the salivary gland. SALSA was concentrated in the apical regions of the epithelial cell cytoplasm, suggestive of a secreted protein. Gene expression was significantly lower (p = 0.031) in asthmatic compared to non-asthmatic horses. Equine SALSA consisted of three to five scavenger receptor cysteine-rich (SRCR) domains, two CUB (C1r/C1s, uegf, bmp-1) domains and one Zona Pellucida domain. These domains mediate the binding of ligands involved in innate immunity. Varying numbers of SRCR domains were identified in different horses, indicating different isoforms. In summary, equine SALSA has a predilection for mucosal sites, has multiple isoforms, and has decreased expression in asthmatic horses, suggesting alterations in innate immunity in equine asthma.

DMBT1 has a protective effect on allergic rhinitis

OBJECTIVE

Deleted in malignant brain tumors 1 (DMBT1) is a secreted scavenger receptor cysteine-rich (SRCR) protein, predominantly expressed in nasal mucosal epithelial cells. In previous experiments, we found large amounts of DMBT1 present in the nasal cavity mucosa of allergic rhinitis (AR) patients. However, the exact role of DMBT1 in AR remains unclear. This study is to investigate the mechanism through which DMBT1 exerts its effects on AR progression.

METHOD

DMBT1 levels in the nasal lavage (NL) fluid and the nasal mucosa in AR and control groups were determined by ELISA and IHC. Next, mice were sensitized with ovalbumin; intranasal administrations of recombinant DMBT1 were then performed. DMBT1 in the nasal mucosa of mice were determined by IHC and WB. Nasal symptoms were estimated. IL-4 and IL-5 in BAL fluid and eosinophils infiltration in the nasal cavity were measured through ELISA and HE staining, respectively.

RESULTS

DMBT1 levels were found to be significantly higher in the NL fluid and nasal mucosa of AR patients and AR mice, compared to control groups (p < 0.01). Levels of IL-4 and IL-5 in BAL and infiltration of eosinophils into the nasal mucosa were significantly increased in AR mice, compared to control mice (p < 0.01). rDMBT1 significantly reduced the number of nasal sneezing and rubbings in AR mice (p < 0.01). It also inhibited the eosinophil infiltration in the nasal mucosa and significantly decreased the production of IL-4 and IL-5 in BAL (p < 0.01).

CONCLUSION

This study demonstrated that rDMBT1 alleviates AR progression in mice via inhibiting IL-4 and IL-5 production and eosinophils infiltration in the nasal cavity.

Citrobacter rodentium induces rapid and unique metabolic and inflammatory responses in mice suffering from severe disease

The mouse pathogen Citrobacter rodentium is used to model infections with enterohaemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC). Pathogenesis is commonly modelled in mice developing mild disease (e.g., C57BL/6). However, little is known about host responses in mice exhibiting severe colitis (e.g., C3H/HeN), which arguably provide a more clinically relevant model for human paediatric enteric infection. Infection of C3H/HeN mice with C. rodentium results in rapid colonic colonisation, coinciding with induction of key inflammatory signatures and colonic crypt hyperplasia. Infection also induces dramatic changes to bioenergetics in intestinal epithelial cells, with transition from oxidative phosphorylation (OXPHOS) to aerobic glycolysis and higher abundance of SGLT4, LDHA, and MCT4. Concomitantly, mitochondrial proteins involved in the TCA cycle and OXPHOS were in lower abundance. Similar to observations in C57BL/6 mice, we detected simultaneous activation of cholesterol biogenesis, import, and efflux. Distinctly, however, the pattern recognition receptors NLRP3 and ALPK1 were specifically induced in C3H/HeN. Using cell‐based assays revealed that C. rodentium activates the ALPK1/TIFA axis, which is dependent on the ADP‐heptose biosynthesis pathway but independent of the Type III secretion system. This study reveals for the first time the unfolding intestinal epithelial cells' responses during severe infectious colitis, which resemble EPEC human infections.

Species-specific mechanisms of cytotoxicity toward immune cells determine the successful outcome of Vibrio infections

Vibrio species cause infectious diseases in humans and animals, but they can also live as commensals within their host tissues. How Vibrio subverts the host defenses to mount a successful infection remains poorly understood, and this knowledge is critical for predicting and managing disease. Here, we have investigated the cellular and molecular mechanisms underpinning infection and colonization of 2 virulent Vibrio species in an ecologically relevant host model, oyster, to study interactions with marine Vibrio species. All Vibrio strains were recognized by the immune system, but only nonvirulent strains were controlled. We showed that virulent strains were cytotoxic to hemocytes, oyster immune cells. By analyzing host and bacterial transcriptional responses to infection, together with Vibrio gene knock-outs, we discovered that Vibrio crassostreae and Vibrio tasmaniensis use distinct mechanisms to cause hemocyte lysis. Whereas V. crassostreae cytotoxicity is dependent on a direct contact with hemocytes and requires an ancestral gene encoding a protein of unknown function, r5.7, V. tasmaniensis cytotoxicity is dependent on phagocytosis and requires intracellular secretion of T6SS effectors. We conclude that proliferation of commensal vibrios is controlled by the host immune system, preventing systemic infections in oysters, whereas the successful infection of virulent strains relies on Vibrio species-specific molecular determinants that converge to compromise host immune cell function, allowing evasion of the host immune system.

Intestinal Epithelial Cells and the Microbiome Undergo Swift Reprogramming at the Inception of Colonic Citrobacter rodentium Infection

The mouse pathogen C. rodentium is a widely used model for colonic infection and has been a major tool in fundamental discoveries in the fields of bacterial pathogenesis and mucosal immunology. Despite extensive studies probing acute C. rodentium infection, our understanding of the early stages preceding the infection climax remains relatively undetailed. To this end, we apply a multiomics approach to resolve temporal changes to the host and microbiome during early infection. Unexpectedly, we found immediate and dramatic responses occurring on the day of colonic infection, both in the host intestinal epithelial cells and in the microbiome. Our study suggests changes in cholesterol and carbon metabolism in epithelial cells are instantly induced upon pathogen detection in the colon, corresponding with a shift to primarily facultative anaerobes constituting the microbiome. This study contributes to our knowledge of disease pathogenesis and mechanisms of barrier regulation, which is required for development of novel therapeutics targeting the intestinal epithelium.

We used the mouse attaching and effacing (A/E) pathogen Citrobacter rodentium, which models the human A/E pathogens enteropathogenic Escherichia coli and enterohemorrhagic E. coli (EPEC and EHEC), to temporally resolve intestinal epithelial cell (IEC) responses and changes to the microbiome during in vivo infection. We found the host to be unresponsive during the first 3 days postinfection (DPI), when C. rodentium resides in the caecum. In contrast, at 4 DPI, the day of colonic colonization, despite only sporadic adhesion to the apex of the crypt, we observed robust upregulation of cell cycle and DNA repair processes, which were associated with expansion of the crypt Ki67-positive replicative zone, and downregulation of multiple metabolic processes (including the tricarboxylic acid [TCA] cycle and oxidative phosphorylation). Moreover, we observed dramatic depletion of goblet and deep crypt secretory cells and an atypical regulation of cholesterol homeostasis in IECs during early infection, with simultaneous upregulation of cholesterol biogenesis (e.g., 3-hydroxy-3-methylglutaryl–coenzyme A reductase [Hmgcr]), import (e.g., low-density lipoprotein receptor [Ldlr]), and efflux (e.g., AbcA1). We also detected interleukin 22 (IL-22) responses in IECs (e.g., Reg3γ) on the day of colonic colonization, which occurred concomitantly with a bloom of commensal Enterobacteriaceae on the mucosal surface. These results unravel a new paradigm in host-pathogen-microbiome interactions, showing for the first time that sensing a small number of pathogenic bacteria triggers swift intrinsic changes to the IEC composition and function, in tandem with significant changes to the mucosa-associated microbiome, which parallel innate immune responses.

DMBT1 involvement in the human aortic endothelial cell response to Streptococcus mutans

Streptococcus mutans is a causative organism of dental caries and has been reported to be associated with the development of cardiovascular disease (CVD). Previous studies have demonstrated that S. mutans invades human aortic endothelial cells (HAECs) and HAECs invaded by S. mutans produce higher levels of CVD-related cytokines than non-invaded HAECs. DMBT1 (deleted in malignant brain tumors 1), also known as salivary agglutinin or gp-340, belongs to the scavenger receptor cysteine-rich superfamily. DMBT1 is expressed in epithelial and non-epithelial tissues and has multiple functions. The interaction between S. mutans and DMBT1 has been demonstrated in cariogenesis, but DMBT1 involvement in CVD has not been examined. In this study, we investigated DMBT1 expression in HAECs stimulated with S. mutans and examined the role of DMBT1 in the interaction between S. mutans and HAECs. All of the tested S. mutans strains induced higher production levels of DMBT1 in HAECs than those in unstimulated HAECs. More S. mutans cells adhered to DMBT1 knock down HAECs than to DMBT1-producing HAECs. Invasion of DMBT1 knock down HAECs by S. mutans was stronger than that of DMBT1-producing HAECs, and externally added DMBT1 reduced bacterial invasion. Cytokine production by DMBT1 knock down HAECs by S. mutans stimulation was higher than that by DMBT1-producing HAECs. These phenomena seemed to be due to the effect of released DMBT1, namely, the inhibition of bacterial adherence to HAECs by DMBT1. These results suggest that DMBT1 plays a protective role against the S. mutans-induced CVD process in HAECs.

Ambient fine particulate matter inhibits innate airway antimicrobial activity in preschool children in e-waste areas

Ambient fine particulate matter (PM_2.5) is a risk factor for respiratory diseases. Previous studies suggest that PM_2.5 exposure may down-regulate airway antimicrobial proteins and peptides (AMPs), thereby accelerating airway pathogen infection. However, epidemiological research is scarce. Hence, we estimated the associations between individual PM_2.5 chronic daily intake (CDI) and the levels of the airway AMP salivary agglutinin (SAG), as well as peripheral leukocyte counts and pro-inflammatory cytokines, of preschool children in Guiyu (an e-waste area) and Haojiang (a reference area located 31.6 km to the east of Guiyu). We recruited 581 preschool children from Guiyu and Haojiang, of which 222 were included in this study for a matching design (Guiyu: n = 110 vs. Haojiang: n = 112). Air PM_2.5 pollution data was collected to calculate individual PM_2.5 CDI. The mean concentration of PM_2.5 in Guiyu was higher than in Haojiang, resulting in a higher individual PM_2.5 CDI. Concomitantly, saliva SAG levels were lower in Guiyu children (5.05 ng/mL) than in Haojiang children (8.68 ng/mL), and were negatively correlated with CDI. Additionally, peripheral counts of white blood cells, and the concentrations of interleukin-8 and tumor necrosis factor-alpha, in Guiyu children were greater than in Haojiang children, and were positively associated with CDI. Similar results were found for neutrophils and monocytes. To our knowledge, this is the first study on the relationship between PM_2.5 exposure and innate airway antimicrobial activity in children, in an e-waste area, showing that PM_2.5 pollution may weaken airway antimicrobial activity by down-regulation of saliva SAG levels, which might accelerate airway pathogen infection in children.

Chlamydia pneumoniae: An Etiologic Agent for Late-Onset Dementia

The disease known as late-onset Alzheimer's disease is a neurodegenerative condition recognized as the single most commonform of senile dementia. The condition is sporadic and has been attributed to neuronal damage and loss, both of which have been linked to the accumulation of protein deposits in the brain. Significant progress has been made over the past two decades regarding our overall understanding of the apparently pathogenic entities that arise in the affected brain, both for early-onset disease, which constitutes approximately 5% of all cases, as well as late-onset disease, which constitutes the remainder of cases. Observable neuropathology includes: neurofibrillary tangles, neuropil threads, neuritic senile plaques and often deposits of amyloid around the cerebrovasculature. Although many studies have provided a relatively detailed knowledge of these putatively pathogenic entities, understanding of the events that initiate and support the biological processes generating them and the subsequent observable neuropathology and neurodegeneration remain limited. This is especially true in the case of late-onset disease. Although early-onset Alzheimer's disease has been shown conclusively to have genetic roots, the detailed etiologic initiation of late-onset disease without such genetic origins has remained elusive. Over the last 15 years, current and ongoing work has implicated infection in the etiology and pathogenesis of late-onset dementia. Infectious agents reported to be associated with disease initiation are various, including several viruses and pathogenic bacterial species. We have reported extensively regarding an association between late-onset disease and infection with the intracellular bacterial pathogen Chlamydia pneumoniae. In this article, we review previously published data and recent results that support involvement of this unusual respiratory pathogen in disease induction and development. We further suggest several areas for future research that should elucidate details relating to those processes, and we argue for a change in the designation of the disease based on increased understanding of its clinical attributes.

Interleukin-22 promotes phagolysosomal fusion to induce protection against Salmonella enterica Typhimurium in human epithelial cells

Intestinal epithelial cells (IECs) play a key role in regulating immune responses and controlling infection. However, the direct role of IECs in restricting pathogens remains incompletely understood. Here, we provide evidence that IL-22 primed intestinal organoids derived from healthy human induced pluripotent stem cells (hIPSCs) to restrict Salmonella enterica serovar Typhimurium SL1344 infection. A combination of transcriptomics, bacterial invasion assays, and imaging suggests that IL-22-induced antimicrobial activity is driven by increased phagolysosomal fusion in IL-22-pretreated cells. The antimicrobial phenotype was absent in hIPSCs derived from a patient harboring a homozygous mutation in the IL10RB gene that inactivates the IL-22 receptor but was restored by genetically complementing the IL10RB deficiency. This study highlights a mechanism through which the IL-22 pathway facilitates the human intestinal epithelium to control microbial infection.

The yellowtail (Seriola quinqueradiata) genome and transcriptome atlas of the digestive tract

Seriola quinqueradiata (yellowtail) is the most widely farmed and economically important fish in aquaculture in Japan. In this study, we used the genome of haploid yellowtail fish larvae for de novo assembly of whole-genome sequences, and built a high-quality draft genome for the yellowtail. The total length of the assembled sequences was 627.3 Mb, consisting of 1,394 scaffold sequences (>2 kb) with an N50 length of 1.43 Mb. A total of 27,693 protein-coding genes were predicted for the draft genome, and among these, 25,832 predicted genes (93.3%) were functionally annotated. Given our lack of knowledge of the yellowtail digestive system, and using the annotated draft genome as a reference, we conducted an RNA-Seq analysis of its three digestive organs (stomach, intestine and rectum). The RNA-Seq results highlighted the importance of certain genes in encoding proteolytic enzymes necessary for digestion and absorption in the yellowtail gastrointestinal tract, and this finding will accelerate development of formulated feeds for this species. Since this study offers comprehensive annotation of predicted protein-coding genes, it has potential broad application to our understanding of yellowtail biology and aquaculture.

Role of microRNA-223 in the regulation of poly(ADP-ribose) polymerase in pediatric patients with Crohn's disease

OBJECTIVES

Crohn's disease (CD) is a multifactorial disease, characterized by oxidant-induced tissue injury with a possible activation of poly(ADP-ribose) polymerase (PARP)-1. MicroRNAs (miRs) can offer a potential link between the genetic susceptibility, environmental and immunologic factors in the pathogenesis of CD. Previously, PARP-1 was identified as a direct target gene of miR-223 in an epithelial cell line. Our aim was to examine PARP activation and miR-223 expression in colonic biopsies of pediatric CD. To support our in vivo findings, the effect of lipopolysaccharide (LPS) on same parameters was examined in HT-29 colonic epithelial cell line.

METHODS

Colonic biopsies were taken from patients with macroscopically inflamed and intact mucosa with CD and controls. LPS treated HT-29 cells served as our in vitro model. To analyze the PARP-1 expression real-time PCR, Western blot and immunohistochemical analyses were used. PARP-1 enzymatic activity was assessed on the basis of poly(ADP-ribosyl)ated proteins. Expression of miR-223 was examined by real-time PCR.

RESULTS

PARP-1 mRNA and miR-223 expression was significantly elevated, however, the amount of PARP-1 protein and poly(ADP-ribose) was reduced in pediatric CD compared to controls. LPS incubation did not affect the expression of PARP-1 mRNA, however, decreased miR-223 expression, and enhanced PARP-1 activity.

CONCLUSIONS

In our study, we showed that the expression of miR-223 is up-regulated and poly(ADP-ribosyl)ation is reduced in pediatric patients with CD. Moreover, we confirmed their opposite change in LPS treated epithelial cells, too. These data suggest that the hypofunctionality of PARP-1 may play a potential role in the pathomechanism of CD.

Transcriptional analyses provide new insight into the late-stage immune response of a diseased Caribbean coral

Increasing global temperatures due to climate change have resulted in respective increases in the severity and frequency of epizootics around the globe. Corals in particular have faced rapid declines due to disease outbreaks. Understanding immune responses and associated potential life-history trade-offs is therefore a priority. In the autumn of 2011, a novel disease of octocorals of the genus Eunicea was first documented in the Florida Keys. Termed Eunicea Black Disease (EBD), the disease is easily identified by the dark appearance of affected tissue, caused by a strong melanization response on the part of the host. In order to better understand the response of corals to EBD, we conducted full transcriptome analysis of 3 healthy and 3 diseased specimens of Eunicea calyculata collected from offshore southeast Florida. Differential expression and protein analyses revealed a strong, diverse immune response to EBD characterized by phagocytosis, adhesion and melanization on the part of the host. Furthermore, coexpression network analyses suggested this might come at the cost of reduced cell cycle progression and growth. This is in accordance with past histological studies of naturally infected hard corals, suggesting that potential trade-offs during infection may affect post-outbreak recovery of reef ecosystems by reducing both organismal growth and fecundity. Our findings highlight the importance of considering factors beyond mortality when estimating effects of disease outbreaks on ecosystems.

The intestinal complement system in inflammatory bowel disease: Shaping intestinal barrier function

The complement system is part of innate sensor and effector systems such as the Toll-like receptors (TLRs). It recognizes and quickly systemically and/or locally respond to microbial-associated molecular patterns (MAMPs) with a tailored defense reaction. MAMP recognition by intestinal epithelial cells (IECs) and appropriate immune responses are of major importance for the maintenance of intestinal barrier function. Enterocytes highly express various complement components that are suggested to be pivotal for proper IEC function. Appropriate activation of the intestinal complement system seems to play an important role in the resolution of chronic intestinal inflammation, while over-activation and/or dysregulation may worsen intestinal inflammation. Mice deficient for single complement components suffer from enhanced intestinal inflammation mimicking the phenotype of patients with chronic inflammatory bowel disease (IBD) such as Crohn's disease (CD) or ulcerative colitis (UC). However, the mechanisms leading to complement expression in IECs seem to differ markedly between UC and CD patients. Hence, how IECs, intestinal bacteria and epithelial cell expressed complement components interact in the course of IBD still remains to be mostly elucidated to define potential unique patterns contributing to the distinct subtypes of intestinal inflammation observed in CD and UC.

Different milk diets have substantial effects on the jejunal mucosal immune system of pre-weaning calves, as demonstrated by whole transcriptome sequencing

There is increasing evidence that nutrition during early mammalian life has a strong influence on health and performance in later life. However, there are conflicting data concerning the appropriate milk diet. This discrepancy particularly applies to ruminants, a group of mammals that switch from monogastric status to rumination during weaning. Little is known regarding how the whole genome expression pattern in the juvenile ruminant gut is affected by alternative milk diets. Thus, we performed a next-generation-sequencing-based holistic whole transcriptome analysis of the jejunum in male pre-weaned German Holstein calves fed diets with restricted or unlimited access to milk during the first 8 weeks of life. Both groups were provided hay and concentrate ad libitum. The analysis of jejunal mucosa samples collected 80 days after birth and four weeks after the end of the feeding regimes revealed 275 differentially expressed loci. While the differentially expressed loci comprised 67 genes encoding proteins relevant to metabolism or metabolic adaptation, the most distinct difference between the two groups was the consistently lower activation of the immune system in calves that experienced restricted milk access compared to calves fed milk ad libitum. In conclusion, different early life milk diets had significant prolonged effects on the intestinal immune system.

Use of Probiotics to Prevent Celiac Disease and IBD in Pediatrics

The incidence of chronic inflammatory diseases (CIDs) is increasing worldwide. Their dramatic rise associated with limited effective strategies to slow down these epidemics calls for a better understanding of their pathophysiology in order to decrease the burdens on childhood. Several cross-sectional studies have demonstrated the association between intestinal dysbiosis and active diseases. Although informative, these studies do not mechanistically link alterations of the microflora with disease pathogenesis and, therefore, with potential therapeutic targets. More prospective studies are needed to determine whether intestinal dysbiosis plays a causative role in the onset and development of CIDs. Furthermore, given the complexity of the microflora interaction with the host, it is necessary to design a systems-level model of interactions between the host and the development of disease by integrating microbiome, metagenomics, metatranscriptomics, and metabolomics with either clinical either environmental data.In this chapter we will discuss the current knowledge regarding the microbiome's contribution to celiac disease and inflammatory bowel disease with a particular focus on how probiotics may be used as potential preventive therapy for CIDs.

Transcriptomic responses of Biomphalaria pfeifferi to Schistosoma mansoni: Investigation of a neglected African snail that supports more S. mansoni transmission than any other snail species

BACKGROUND

Biomphalaria pfeifferi is highly compatible with the widespread human-infecting blood fluke Schistosoma mansoni and transmits more cases of this parasite to people than any other snail species. For these reasons, B. pfeifferi is the world's most important vector snail for S. mansoni, yet we know relatively little at the molecular level regarding the interactions between B. pfeifferi and S. mansoni from early-stage sporocyst transformation to the development of cercariae.

METHODOLOGY/PRINCIPAL FINDINGS

We sought to capture a portrait of the response of B. pfeifferi to S. mansoni as it occurs in nature by undertaking Illumina dual RNA-Seq on uninfected control B. pfeifferi and three intramolluscan developmental stages (1- and 3-days post infection and patent, cercariae-producing infections) using field-derived west Kenyan specimens. A high-quality, well-annotated de novo B. pfeifferi transcriptome was assembled from over a half billion non-S. mansoni paired-end reads. Reads associated with potential symbionts were noted. Some infected snails yielded fewer normalized S. mansoni reads and showed different patterns of transcriptional response than others, an indication that the ability of field-derived snails to support and respond to infection is variable. Alterations in transcripts associated with reproduction were noted, including for the oviposition-related hormone ovipostatin and enzymes involved in metabolism of bioactive amines like dopamine or serotonin. Shedding snails exhibited responses consistent with the need for tissue repair. Both generalized stress and immune factors immune factors (VIgLs, PGRPs, BGBPs, complement C1q-like, chitinases) exhibited complex transcriptional responses in this compatible host-parasite system.

SIGNIFICANCE

This study provides for the first time a large sequence data set to help in interpreting the important vector role of the neglected snail B. pfeifferi in transmission of S. mansoni, including with an emphasis on more natural, field-derived specimens. We have identified B. pfeifferi targets particularly responsive during infection that enable further dissection of the functional role of these candidate molecules.