Interleukin-22 regulates B3GNT7 expression to induce fucosylation of glycoproteins in intestinal epithelial cells

Fucosylation of glycoproteins and glycolipids: opposing roles in cholera intoxication

Cholera toxin (CT) is the etiological agent of cholera. Here we report that multiple classes of fucosylated glycoconjugates function in CT binding and intoxication of intestinal epithelial cells. In Colo205 cells, knockout (KO) of B3GNT5, which encodes an enzyme required for synthesis of lacto and neolacto series glycosphingolipids (GSLs), reduces CT binding but sensitizes cells to intoxication. Overexpressing B3GNT5 to generate more fucosylated GSLs confers protection against intoxication, indicating that fucosylated GSLs act as decoy receptors for CT. KO of B3GALT5 causes increased production of fucosylated O-linked and N-linked glycoproteins and leads to increased CT binding and intoxication. KO of B3GNT5 in B3GALT5-KO cells eliminates production of fucosylated GSLs but increases intoxication, identifying fucosylated glycoproteins as functional receptors for CT. These findings provide insight into the molecular determinants regulating CT sensitivity of host cells.

Oxytocin Alleviates Colitis and Colitis-Associated Colorectal Tumorigenesis via Noncanonical Fucosylation

Colon cancer is increasing worldwide and is commonly regarded as hormone independent, yet recent reports have implicated sex hormones in its development. Nevertheless, the role of hormones from the hypothalamus-hypophysis axis in colitis-associated colorectal cancer (CAC) remains uncertain. In this study, we observed a significant reduction in the expression of the oxytocin receptor (OXTR) in colon samples from both patient with colitis and patient with CAC. To investigate further, we generated mice with an intestinal-epithelium-cell-specific knockout of OXTR. These mice exhibited markedly increased susceptibility to dextran-sulfate-sodium-induced colitis and dextran sulfate sodium/azoxymethane-induced CAC compared to wild-type mice. Our findings indicate that OXTR depletion impaired the inner mucus of the colon epithelium. Mechanistically, oxytocin was found to regulate Mucin 2 maturation through β1-3-N-acetylglucosaminyltransferase 7 (B3GNT7)-mediated fucosylation. Interestingly, we observed a positive correlation between B3GNT7 expression and OXTR expression in human colitis and CAC colon samples. Moreover, the simultaneous activations of OXTR and fucosylation by l-fucose significantly alleviated tumor burden. Hence, our study unveils oxytocin's promising potential as an affordable and effective therapeutic intervention for individuals affected by colitis and CAC.

High albumen height by expression of GALNT9 and thin eggshell by decreased Ca2+ transportation caused high hatchability in Huainan partridge chicken

Hatchability could be quite different among individuals of indigenous chicken breed which might be affected by the egg quality. In this study, hatchability was individually recorded among 800 forty-wk-old Huainan partridge chickens. The chickens were then divided into high and low hatchability groups (HH and LH group) with 50 birds in each group. Egg quality was further determined in the 2 groups. Eight birds from each group were selected for slaughtering and tissue, responsible for egg formation, collection for structure observation by staining and candidate gene expression by transcriptome analysis. The hatchability in HH was 100% and 61.18% in LH. The eggshell thickness and shell strength were significantly lower, while the albumen height and Haugh unit were significantly higher in HH group than those in LH group (P < 0.05). The magnum weight and index, and the expression of polypeptide N-acetylgalactosaminyltransferase 9 (GALNT9), which responsible for thick albumen synthesis, in HH group were also significantly higher than that of LH group (P < 0.05). Compared with the LH group, there were 702 differentially expressed genes (DEGs) in HH group, of which 402 were up-regulated and 300 were down-regulated. Candidate genes of calbindin 1 (CALB1) and solute carrier family 26 member 9 (SLC26A9), which regulate calcium signaling pathway so as to affect Ca2+ transportation, exhibited significant high and low expression, respectively, in HH group compared to those in LH group (P < 0.05). Therefore, indigenous chicken with high expression of GALNT9 in magnum to form thick albumen to provide more protein for embryo, while high CALB1 and low expression of SLC26A9 to decrease Ca2+ transportation so as to form a thinner eggshell and provide better gas exchange during embryo development.

IL-22 promotes mucin-type O-glycosylation and MATH1+ cell-mediated amelioration of intestinal inflammation

The interleukin (IL)-22 cytokine can be protective or inflammatory in the intestine. It is unclear if IL-22 receptor (IL-22Ra1)-mediated protection involves a specific type of intestinal epithelial cell (IEC). By using a range of IEC type-specific Il22Ra1 conditional knockout mice and a dextran sulfate sodium (DSS) colitis model, we demonstrate that IL-22Ra1 signaling in MATH1+ cells (goblet and progenitor cells) is essential for maintaining the mucosal barrier and intestinal tissue regeneration. The IL-22Ra1 signaling in IECs promotes mucin core-2 O-glycan extension and induces beta-1,3-galactosyltransferase 5 (B3GALT5) expression in the colon. Adenovirus-mediated expression of B3galt5 is sufficient to rescue Il22Ra1IEC mice from DSS colitis. Additionally, we observe a reduction in the expression of B3GALT5 and the Tn antigen, which indicates defective mucin O-glycan, in the colon tissue of patients with ulcerative colitis. Lastly, IL-22Ra1 signaling in MATH1+ progenitor cells promotes organoid regeneration after DSS injury. Our findings suggest that IL-22-dependent protective responses involve O-glycan modification, proliferation, and differentiation in MATH1+ progenitor cells.

Gut permeability among Astronauts during Space missions

The space environment poses substantial challenges to human physiology, including potential disruptions in gastrointestinal health. Gut permeability has only recently become widely acknowledged for its potential to cause adverse effects on a systemic level, rendering it a critical factor to investigate in the context of spaceflight. Here, we propose that astronauts experience the onset of leaky gut during space missions supported by transcriptomic and metagenomic analysis of human and murine samples. A genetic map contributing to intestinal permeability was constructed from a systematic review of current literature. This was referenced against our re-analysis of three independent transcriptomic datasets which revealed significant changes in gene expression patterns associated with the gut barrier. Specifically, in astronauts during flight, we observed a substantial reduction in the expression genes that are crucial for intestinal barrier function, goblet cell development, gut microbiota modulation, and immune responses. Among rodent spaceflight studies, differential expression of cytokines, chemokines, and genes which regulate mucin production and post-translational modifications suggest a similar dysfunction of intestinal permeability. Metagenomic analysis of feces from two murine studies revealed a notable reduction probiotic, short chain fatty acid-producing bacteria and an increase in the Gram-negative pathogens, including Citrobacter rodentium, Enterobacter cloacea, Klebsiella aerogenes, and Proteus hauseri which promote LPS circulation, a recipe for barrier disruption and systemic inflammatory activation. These findings emphasize the critical need to understand the underlying mechanisms and develop interventions to maintain gastrointestinal health in space.

A non-human primate model for human norovirus infection

Norovirus infection can cause gastrointestinal disease in humans. Development of therapies and vaccines against norovirus have been limited by the lack of a suitable and reliable animal model. Here we established rhesus macaques as an animal model for human norovirus infection. We show that rhesus macaques are susceptible to oral infection with human noroviruses from two different genogroups. Variation in duration of virus shedding (days to weeks) between animals, evolution of the virus over the time of infection, induction of virus-specific adaptive immune responses, susceptibility to reinfection and preferential replication of norovirus in the jejunum of rhesus macaques was similar to infection reported in humans. We found minor pathological signs and changes in epithelial cell surface glycosylation patterns in the small intestine during infection. Detection of viral protein and RNA in intestinal biopsies confirmed the presence of the virus in chromogranin A-expressing epithelial cells, as it does in humans. Thus, rhesus macaques are a promising non-human primate model to evaluate vaccines and therapeutics against norovirus disease.

Identification of glycogene-based prognostic signature and validation of B3GNT7 as a potential biomarker and therapeutic target in breast cancer

BACKGROUND

Breast cancer is the most common cancer worldwide, with the fifth highest mortality rate among all cancers and high risk of metastasis. However, potential biomarkers and molecular mechanisms underlying the stratification of breast cancer in terms of clinical outcomes remain to be investigated. Therefore, we aimed to find a novel prognostic biomarker and therapeutic target for breast cancer patients.

METHODS

Unsupervised hierarchical clustering was used to perform comprehensive transcriptomic study of total 185 glycogenes in public datasets of breast cancer with clinicopathological and survival information. A glycogene-based signature for subtype classification was discovered using Limma packages, and relevance to four known molecular features was identified by GSVA. Experimental verification was performed and biological functions of B3GNT7 were characterized by quantitative RT-PCR, western blot, transwell assays, and lectin immunofluorescence staining in breast cancer cells.

RESULTS

A 23-glycogene signature was identified for the classification of breast cancer. Among the 23 glycogenes, B3GNTs showed significantly positive associations with ER-/Her2- subtype in breast cancer patients (n = 2655). Overexpressed B3GNT7 were correlated with poor prognosis in breast cancer patients based on public datasets. B3GNT7 depletion inhibited cell proliferation, migration, and invasion, and decreased global fucosylation in MDA-MB-231 and HCC1937 breast cancer cells.

CONCLUSIONS

Herein, we discovered a unique 23-gene signature for breast cancer patient glycogene-type classification. Among these genes, B3GNT7 was shown to be a potential biomarker for unfavorable outcomes and therapeutic target of breast cancer.

Proton Pump Inhibitors Modulate Gene Expression Profile in Esophageal Mucosa and Microbiome

OBJECTIVE

Proton pump inhibitors (PPIs) are commonly used to manage children with upper gastrointestinal symptoms and without a formal diagnosis. We investigated the effect of PPIs on esophageal mucosal transcriptome and active microbiota in children with normal esophagi. Furthermore, we examined whether the differences in host esophageal mucosal gene expression were driven by an underlying esophageal epithelial cell type composition.

METHODS

Using metatranscriptomics, the host transcriptional and active microbial profiles were captured from 17 esophageal biopsy samples (PPI naïve [PPI-], n = 7; PPI exposed [PPI+], n = 10) collected from children without any endoscopic and histologic abnormalities in their esophagus (normal esophagus). Deconvolution computational analysis was performed with xCell to assess if the observed epithelial gene expression changes were related to the cell type composition in the esophageal samples.

RESULTS

The median (IQR) age of our cohort was 14 years (12-16) with female (63%) preponderance. Both groups were similar in terms of their demographics and clinical features. Compared with PPI-, the PPI+ had upregulation of 27 genes including the MUC genes. The cell type composition was similar between the PPI- and PPI+ groups. Prevotella sp and Streptococcus sp were abundant in PPI+ group.

CONCLUSIONS

In children with normal esophagus, PPI exposure can be associated with upregulation of esophageal mucosal homeostasis and epithelial cell function genes in a cell-type independent manner, and an altered esophageal microbiome. Additional studies are warranted to validate our findings and to investigate the causal effect of PPIs on the normal esophageal epithelium and microbial communities.

Fucosylated glycoproteins and fucosylated glycolipids play opposing roles in cholera intoxication

Cholera toxin (CT) is the etiological agent of cholera. Here we report that multiple classes of fucosylated glycoconjugates function in CT binding and intoxication of intestinal epithelial cells. In Colo205 cells, knockout of B3GNT5, the enzyme required for synthesis of lacto- and neolacto-series glycosphingolipids (GSLs), reduces CT binding but sensitizes cells to intoxication. Overexpressing B3GNT5 to generate more fucosylated GSLs confers protection against intoxication, indicating that fucosylated GSLs act as decoy receptors for CT. Knockout (KO) of B3GALT5 causes increased production of fucosylated O-linked and N-linked glycoproteins, and leads to increased CT binding and intoxication. Knockout of B3GNT5 in B3GALT5 KO cells eliminates production of fucosylated GSLs but increases intoxication, identifying fucosylated glycoproteins as functional receptors for CT. These findings provide insight into molecular determinants regulating CT sensitivity of host cells.

Glycosyltransferases in Cancer: Prognostic Biomarkers of Survival in Patient Cohorts and Impact on Malignancy in Experimental Models

Background: Glycosylation changes are a main feature of cancer. Some carbohydrate epitopes and expression levels of glycosyltransferases have been used or proposed as prognostic markers, while many experimental works have investigated the role of glycosyltransferases in malignancy. Using the transcriptomic data of the 21 TCGA cohorts, we correlated the expression level of 114 glycosyltransferases with the overall survival of patients. Methods: Using the Oncolnc website, we determined the Kaplan−Meier survival curves for the patients falling in the 15% upper or lower percentile of mRNA expression of each glycosyltransferase. Results: Seventeen glycosyltransferases involved in initial steps of N- or O-glycosylation and of glycolipid biosynthesis, in chain extension and sialylation were unequivocally associated with bad prognosis in a majority of cohorts. Four glycosyltransferases were associated with good prognosis. Other glycosyltransferases displayed an extremely high predictive value in only one or a few cohorts. The top were GALNT3, ALG6 and B3GNT7, which displayed a p < 1 × 10−9 in the low-grade glioma (LGG) cohort. Comparison with published experimental data points to ALG3, GALNT2, B4GALNT1, POFUT1, B4GALT5, B3GNT5 and ST3GAL2 as the most consistently malignancy-associated enzymes. Conclusions: We identified several cancer-associated glycosyltransferases as potential prognostic markers and therapeutic targets.