Inflammatory tendencies and overproduction of IL-17 in the colon of young NOD mice are counteracted with diet change

ObjectiveDietary factors influence diabetes development in the NOD mouse. Diet affects the composition of microbiota in the distal intestine, which may subsequently influence intestinal immune homeostasis. However, the specific effects of antidiabetogenic diets on gut immunity and the explicit associations between intestinal immune disruption and type 1 diabetes onset remain unclear.Research design and methodsGut microbiota of NOD mice fed a conventional diet or ProSobee formula were compared using gas chromatography. Colonic lamina propria immune cells were characterized in terms of activation markers, cytokine mRNA and Th17 and Foxp3(+) T-cell numbers, using real-time PCR and flow cytometry. Activation of diabetogenic CD4 T-cells by purified B-cells was assessed in both groups. Immune tolerance to autologous commensal bacteria was evaluated in vitro using thymidine-incorporation tests.ResultsYoung NOD mice showed a disturbed tolerance to autologous commensal bacteria. Increased numbers of activated CD4 T-cells and (CD11b(+)CD11c(+)) dendritic cells and elevated levels of Th17 cells and IL23 mRNA were moreover observed in colon lamina propria. These phenomena were abolished when mice were fed an antidiabetogenic diet. The antidiabetogenic diet also altered the expression levels of costimulatory molecules and the capacity of peritoneal B-cells to induce insulin-specific CD4 T-cell proliferation.ConclusionsYoung NOD mice show signs of subclinical colitis, but the symptoms are alleviated by a diet change to an antidiabetogenic diet. Disrupted immune tolerance in the distal intestine may influence peritoneal cell pools and B-cell-mediated activation of diabetogenic T-cells

Correction: Activation of Notch Signaling Is Required for Cholangiocarcinoma Progression and Is Enhanced by Inactivation of p53 In Vivo.

[This corrects the article DOI: 10.1371/journal.pone.0077433.]

Activation of Notch Signaling Is Required for Cholangiocarcinoma Progression and Is Enhanced by Inactivation of p53 <i>In Vivo</i>

<div><p>Cholangiocacinoma (CC) is a cancer disease with rising incidence. Notch signaling has been shown to be deregulated in many cancers. However, the role of this signaling pathway in the carcinogenesis of CC is still not fully explored. In this study, we investigated the effects of Notch inhibition by γ-secretase inhibitor IX (GSI IX) in cultured human CC cell lines and we established a transgenic mouse model with liver specific expression of the intracellular domain of Notch (Notch-ICD) and inactivation of tumor suppressor p53. GSI IX treatment effectively impaired cell proliferation, migration, invasion, epithelial to mesenchymal transition and growth of softagar colonies. <i>In vivo</i> overexpression of Notch-ICD together with an inactivation of p53 significantly increased tumor burden and showed CC characteristics. <i>Conclusion</i>: Our study highlights the importance of Notch signaling in the tumorigenesis of CC and demonstrates that additional inactivation of p53 <i>in vivo</i>.</p></div

Epithelial mesenchymal transition and pancreatic tumor initiating CD44+/EpCAM+ cells are inhibited by γ-secretase inhibitor IX.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a high rate of metastasis. Recent studies have indicated that the Notch signalling pathway is important in PDAC initiation and maintenance, although the specific cell biological roles of the pathway remain to be established. Here we sought to examine this question in established pancreatic cancer cell lines using the γ-secretase inhibitor IX (GSI IX) to inactivate Notch. Based on the known roles of Notch in development and stem cell biology, we focused on effects on epithelial mesenchymal transition (EMT) and on pancreatic tumor initiating CD44+/EpCAM+ cells. We analyzed the effect of the GSI IX on growth and epithelial plasticity of human pancreatic cancer cell lines, and on the tumorigenicity of pancreatic tumor initiating CD44+/EpCAM+ cells. Notably, apoptosis was induced after GSI IX treatment and EMT markers were selectively targeted. Furthermore, under GSI IX treatment, decline in the growth of pancreatic tumor initiating CD44+/EpCAM+ cells was observed in vitro and in a xenograft mouse model. This study demonstrates a central role of Notch signalling pathway in pancreatic cancer pathogenesis and identifies an effective approach to inhibit selectively EMT and suppress tumorigenesis by eliminating pancreatic tumor initiating CD44+/EpCAM+ cells

GSI IX attenuate invasion of human cholangiocarcinoma cells.

<p>SZ1 (A) and TFK1 (A) cell lines were treated for 48 h with control (DMSO) and GSI (5 µM, 20 µM, 40 µM) to investigate the effect of GSI on invasiveness of human cholangiocarcinoma cell lines. The number of cells that invaded through the membrane was determined by light microscope (20X magnification) counterstained and invasion index (B,C) was calculated as described in Material and Methods and plotted in bar graphs. Both TFK1 and SZ1 showed significant decrease in number of invading cells by light microscope. P values were calculated with ANOVA analysis of variance along with Bonferroni post test. The error bar represents standard deviation. Differences were considered as statistically significant (*) when the P-value was less <0.05.</p

Summary of observation in NotchICD :: AlbCre :: p53 L/L mice.

<p>Summary of observation in NotchICD :: AlbCre :: p53 L/L mice.</p

NICD overexpression and loss of p53 is influencing the tumor development of cholangiocarcinomas in mice.

<p>Macro- und microscopic pictures of mice with expression of AlbCre and Notch-ICD and inactivation of p53 at different timepoints like indicated. Each mouse was dissected at the indicated timepoint. H&E staining (20X magnification) was performed and analysis was accordingly done in collaboration with an independent pathologist. Note, there was no tumor either macroscopically or microscopically detected with an age of 3 month. Starting with an age of 6 month, mice with expression of AlbCre, Notch-ICD and loss of p53 developed cholangiocarcinomas.</p