Transcriptome study of colon epithelial cells in Reg3a-transgenic mice
Ontology highlight
ABSTRACT: The human C-type lectin Reg3a (HIP/PAP) is an antimicrobial peptide that kills Gram-positive bacteria. Reg3a preserves gut microbiota homeostasis, reinforces intestinal barrier function and thereby helps to fight induced colitis in mice. Transcriptomic data revealed an upregulation of numerous genes involved in the robustness of the intestinal barrier, and the biosynthesis pathway of mucin core 1 and 3 O-glycans.
Project description:Antimicrobial peptides (AMPs) serve key proposed roles in defending the urinary tract against invading uropathogens, but individual AMPs bearing greatest responsibility for these functions remain largely unknown. We identified RegIIIγ as the most transcriptionally upregulated AMP in bladder transcriptomes following uropathogenic Escherichia coli (UPEC) infection. We confirmed induction of RegIIIγ mRNA during cystitis and pyelonephritis by quantitative RT-PCR. Immunoblotting demonstrates increased bladder and urinary RegIIIγ protein levels following UPEC infection. Immunostaining localizes RegIIIγ protein to urothelial cells of infected bladders and kidneys. Human patients with cystitis and pyelonephritis exhibit increased urine levels of the orthologous HIP/PAP protein. Recombinant RegIIIγ protein does not demonstrate bactericidal activity toward UPEC in vitro, but does kill Staphylococcus saprophyticus in a dose-dependent manner. RegIIIγ knockout and control urinary tracts contain comparable bacterial burden following experimental inoculation of UPEC as well as Gram-positive uropathogens. Thus, while RegIIIγ and HIP/PAP expression occurs in human and murine UTI, their specific functions in the urinary tract remain uncertain.
Project description:Many species of pathogenic bacteria harbor critical plasmid-encoded virulence factors, and yet the regulation of plasmid replication is often poorly understood despite playing key role in plasmid-encoded gene expression. Human pathogenic Yersinia, including the plague agent Yersinia. pestis and its close relative Y. pseudotuberculosis, require the type III secretion system (T3SS) virulence factor to subvert host defense mechanisms and colonize host tissues. The Yersinia T3SS is encoded on the IncFII plasmid for Yersinia virulence (pYV). Several layers of gene regulation enables a large increase in expression of Yersinia T3SS genes at mammalian body temperature. Surprisingly, T3SS expression is also controlled at the level of gene dosage. The number of pYV molecules relative to the number of chromosomes per cell, referred to as plasmid copy number, increases with temperature. The ability to increase and maintain elevated pYV plasmid copy number, and therefore T3SS gene dosage, at 37˚C is important for Yersinia virulence. In addition, pYV is highly stable in Yersinia at all temperatures, despite being dispensable for growth outside the host. Yet how Yersinia reinforces elevated plasmid replication and plasmid stability remains unclear. In this study, we show that the chromosomal gene pcnB encoding the polyadenylase PAP I is required for regulation of pYV plasmid copy number (PCN), maintenance of pYV in the bacterial population outside the host, robust T3SS activity, and Yersinia virulence in a mouse infection model. Likewise, pcnB/PAP I is also required for robust expression of the Shigella flexneri virulence plasmid-encoded T3SS that, similar to Yersinia, is encoded on a virulence plasmid whose replication is regulated by sRNA. Furthermore, Yersinia and Shigella pcnB/PAP I is required for maintaining normal PCN of model antimicrobial resistance (AMR) plasmids whose replication is regulated by sRNA, thereby increasing antibiotic resistance by ten-fold. These data suggest that pcnB/PAP I contributes to the spread and stabilization of sRNA-regulated virulence and AMR plasmids in bacterial pathogens, and is essential in maintaining the gene dosage required to mediate plasmid-encoded traits. Importantly pcnB/PAP I has been bioinformatically identified in many species of bacteria despite being studied in only a few species to date. Our work highlights the potential importance of pcnB/PAP I in antibiotic resistance, and shows for the first time that pcnB/PAP I reinforces PCN andpromotes virulence plasmid stability in natural pathogenic hosts with a direct impact on bacterial virulence.
Project description:Whole-transcript expression array analysis of intestinal epithelial cells from TNBS-induced colitis mice treated with vehicle or I3C demonstrated several differentially expressed genes Downregulation of AhR expression in colitis mice was associated with downregulation of various antimicrobial peptides such as α-defensin 1, β-defensin1, reg1, reg4, reg3a and reg3b. However, treatment with I3C, an AhR ligand, increased the expression of AhR and AMPs such as α-defensin 1
Project description:REG3A is highly expressed in pancreatic tissues, but its significance is unclear. We found that REG3A overexpressed in paracancerous acinar cells interacted with EGFR on tumor cells to stimulate downstream tumor growth signals and promote the occurrence and development of tumors
Project description:We employed HITS-CLIP to map genome wide Star-PAP mRNA binding and define the role of RBM10 on global Star-PAP mRNA association. We show a transcriptome-wide association of Star-PAP which is diminished on cellular Star-PAP depletion. HITs-CLIP data analysis of RBM10 knockdown and pulldown with anti Star-PAP antibody on HEK293 cells indicates significance of RBM10 in Star-PAP and mRNA association.
Project description:At the base of the intestinal crypt, long-lived Lgr5+ stem cells are intercalated by Paneth cells that provide essential niche signals for stem-cell maintenance. This unique epithelial anatomy makes the intestinal crypt one of the most accessible models for the study of adult stem cell biology. The glycosylation patterns of this compartment are poorly characterized and the impact of glycans on stem cell differentiation remains largely unexplored. We found that Paneth cells, but not Lgr5+ stem cells, express abundant terminal N-acetyllactosamine (LacNAc). Employing an enzymatic method to edit glycans in cultured crypt organoids, we assessed the functional role of LacNAc in the intestinal crypt. We show that blocking access to LacNAc on Paneth cells leads to hyperproliferation of the neighbouring Lgr5+ stem cells, which is accompanied by the down-regulation of genes that are known as negative regulators of proliferation
Project description:Antimicrobial proteins of the REG3 family represent, like a wide variety of C-type lectins to which they belong, the first line of protection against infections and transformed cells. Their expression is inducible, particularly in response to inflammation, making their role in cancer biology less clear and controversial, as an immune-inflammation background may pre-exist or co-exist. We show that REG3A presents a suppressive role of REG3A in hepatocellular carcinoma (HCC) in a mouse models of HCC driven by c-MYC. By comparing the transcriptional profiles of liver tumors from MYC-REG3A-TG mice with those from MYC-TG mice, we found that MYC-REG3A tumors belonged to the S3 and G5 molecular subclasses of the human HCC classification proposed by Hoshida et al. and Boyault et al., respectively, subclasses that concentrate well-differentiated and CTNNB1-mutated HCCs. Tumors from MYC-TG mice exhibited features of S1 and G2/G3 subclasses. Results of the GSEA analysis indicate marked differential gene expression profiles. MYC-REG3A tumors and adjacent liver are enriched in metabolic pathways including bile acid, xenobiotic, and fatty acid metabolism, oxidative phosphorylation, and activation of Wnt/β-catenin signaling, whereas transcriptional reprogramming of MYC-TG mouse livers resulted in activation of cell cycle-, inflammation-, and glycolysis-related pathways as expected.
Project description:To assess the selectivity of SLC16A3/MCT4 inhibitor slCeMM1, we derived diazirine-alkyne photoaffinity probe (slCeMM1-PAP). We next used HAP1 and MDAMB231 cell lines for MS experiment, comparing the enrichment of proteins by slCeMM1-PAP and conditions where slCeMM1-PAP was competed with slCeMM1 or it’s structurally related inactive control (S1_007). We found that among proteins enriched by slCeMM1-PAP, only SLC16A3 was competed by slCeMM1, but not S1_007, confirming the SLC16A3 engagement by slCeMM1 and suggesting overall good selectivity of slCeMM1.
Project description:Objectives: Obstructive Sleep Apnea (OSA) is related to repeated upper airway collapse, intermittent hypoxia, and intestinal barrier dysfunction. The resulting damage to the intestinal barrier may affect or be affected by the intestinal microbiota. Methods: A prospective case-control was used, including 48 subjects from Sleep Medicine Center of Nanfang Hospital. Sleep apnea was diagnosed by overnight polysomnography. Fecal samples and blood samples were collected from subjects to detect intestinal microbiome composition (by 16S rDNA gene amplification and sequencing) and intestinal barrier biomarkers – intestinal fatty acid-binding protein (I-FABP) and D-lactic acid (D-LA) (by ELISA and colorimetry, respectively). Results: The severity of OSA was related to differences in the structure and composition of the intestinal microbiome. Enriched Fusobacterium, Megamonasa, Lachnospiraceae_UCG_006, and reduced Anaerostipes was found in patients with severe OSA. Enriched Ruminococcus_2, Lachnoclostridium, Lachnospiraceae_UCG_006, and Alloprevotella was found in patients with high intestinal barrier biomarkers. Lachnoclostridium and Lachnospiraceae_UCG_006 were the common dominant bacteria of OSA and intestinal barrier damage. Fusobacterium and Peptoclostridium was independently associated with apnea-hypopnea index (AHI). The dominant genera of severe OSA were also related to glucose, lipid, neutrophils, monocytes and BMI. Network analysis identified links between the intestinal microbiome, intestinal barrier biomarkers, and AHI. Conclusions: The study confirms that changes in the intestinal microbiota are related to intestinal barrier biomarkers among patients in OSA. These changes may play a pathophysiological role in the systemic inflammation and metabolic comorbidities associated with OSA, leading to multi-organ morbidity of OSA.