Project description:Aim: The precise role of microRNAs in inflammatory disease has been less clear. The present study investigated the effect of microRNA (miR-146b) on improving intestinal inflammation. Methods: The microRNA profile in IL-10-deficient mice was examined using microRNA arrays and miR-146b was selected for the following experiments. The expression vectors containing either the whole sequence of miR-146b or its siRNA were intraperitoneally administered to the dextran sulfate sodium (DSS)-induced colitis mouse. Results: The overexpression of miR-146b activated the NF-kB pathway, improved the epithelial barrier function, relieved intestinal inflammation in the DSS-induced colitis mice, and improved the survival rate of mice with lethal colitis. Furthermore, this amelioration of the intestinal inflammation by miR-146b was negated by the inhibitor for NF-kB pathway. Conclusion: The modulation of miR-146b expression is a potentially useful therapy for the treatment of intestinal inflammation through the activation of the NF-kB pathway.
Project description:Aim: The precise role of microRNAs in inflammatory disease has been less clear. The present study investigated the effect of microRNA (miR-146b) on improving intestinal inflammation. Methods: The microRNA profile in IL-10-deficient mice was examined using microRNA arrays and miR-146b was selected for the following experiments. The expression vectors containing either the whole sequence of miR-146b or its siRNA were intraperitoneally administered to the dextran sulfate sodium (DSS)-induced colitis mouse. Results: The overexpression of miR-146b activated the NF-kB pathway, improved the epithelial barrier function, relieved intestinal inflammation in the DSS-induced colitis mice, and improved the survival rate of mice with lethal colitis. Furthermore, this amelioration of the intestinal inflammation by miR-146b was negated by the inhibitor for NF-kB pathway. Conclusion: The modulation of miR-146b expression is a potentially useful therapy for the treatment of intestinal inflammation through the activation of the NF-kB pathway. Mice: The present studies were approved by the Institutional Animal Care and Use Committee of the Asahikawa Medical College. C57BL/6 and IL-10-/- mice were purchased from Sankyo Labo Service Co., Inc. (Tokyo, Japan) and Jackson Laboratories (Bar Harbor, ME), respectively. Large intestines with or without treatments were removed, rinsed with saline, and the epithelium was gently sheared off with glass slides for protein determination. microRNA arrays: RNA was extracted from the large intestines of mice with Trizol and then was immediately frozen in liquid nitrogen. Next, the microRNA expression profiles of large intestine in wild-type and IL-10-deficient mouse were investigated using the mirVanaTM miRNA bioarray (Filgene, Inc., Japan). Any more than 2-fold differences were considered to indicate a significant change.
Project description:The canonical NF-kB module induces nuclear translocation of RelA heterodimers from the latent cytoplasmic complexes. RelA directs inflammatory immune responses against microbial entities. However, aberrant RelA activity also triggers destructive inflammation, including those associated with inflammatory bowel disease (IBD). What provokes this pathological RelA activity remains unclear. As such, the noncanonical NF-kB pathway activates RelB heterodimers and mediates immune organogenesis. Because NF-kB-activating pathways are interlinked, we asked if noncanonical NF-kB signaling exacerbated intestinal inflammation. Our investigation revealed recurrent engagement of the noncanonical pathway in human IBD. In a mouse model of chemical colitis, the noncanonical NF-kB signaling gene Nfkb2 aggravated inflammation by amplifying the RelA activity induced in intestinal epithelial cells. Our mechanistic studies clarified that noncanonical signaling augmented the abundance of latent RelA complexes leading to hyperactive canonical NF-kB response in the colitogenic gut. In sum, latent dimer homeostasis appears to link noncanonical NF-kB signaling to RelA-driven inflammatory pathologies.
Project description:Nf-kB activity is associated with the key pathological features of chronic respiratory diseases including epithelial remodelling, excess mucous production, and submucosal gland hyperplasia. However, the role of Nf-kB activity in airway epithelial differentiation remains controversial. In the present study we demonstrate that Nf-kB adaptor protein Myd88 deficiency promotes increased airway submucosal gland abundance and abnormal epithelial differentiation in proximal adult airways. Abnormal airway differentiation was not developmentally determined, became exacerbated following acute lung injury, and did not involve altered epithelial proliferation or apoptosis. Instead, we demonstrate that tracheal Myd88 deficiency promotes upregulation of a unique gene expression profile that includes activation of alternate, Myd88-independent Nf-kB signalling. Finally, we show that these effects are not intrinsically maintained in vitro using an air-liquid interface epithelial culture. This finding indicates that Myd88 deficiency promotes adult airway remodelling by regulating non-epithelial, non-cell autonomous Nf-kB activity. 20 microarray samples of whole trachea RNA in total: 5 samples wildtype control tissue 5 samples Myd88 KO control tissue 5 samples wildtype 3 day polidocanol injury tissue 5 samples Myd88 KO 3 day polidocanol injury tissue
Project description:The mucosal epithelium plays a key role in regulating immune homeostasis. Dysregulation of epithelial barrier function is associated with mucosal inflammation. Expression of claudin-2, a pore-forming tight junction protein, is highly upregulated during inflammatory bowel disease (IBD) and, due to its association with epithelial permeability, has been postulated to promote inflammation. Furthermore, claudin-2 also regulates colonic epithelial cell proliferation and intestinal nutrient absorption. However, the precise role of claudin-2 in regulating colonic epithelial and immune homeostasis remains unclear. Here, we demonstrate, using Villin-Claudin-2 transgenic (Cl-2TG) mice, that increased colonic claudin-2 expression unexpectedly protects mice against experimentally induced colitis and colitis-associated cancer. Notably, Cl-2TG mice exhibited increased colon length and permeability as compared with wild type (WT) littermates. However, despite their leaky colon, Cl-2TG mice subjected to experimental colitis were immune compromised, with reduced induction of TLR-2, TLR-4, Myd-88 expression and NF-kB and STAT3 activation. Most importantly, colonic macrophages in Cl-2TG mice exhibited an anergic phenotype. Claudin-2 overexpression also increased colonocyte proliferation and provided protection against colitis-induced colonocyte death. Taken together, our findings have revealed a critical role of claudin-2 in regulating colonic homeostasis, suggesting novel therapeutic strategies for inflammatory conditions of the gastrointestinal tract. 8-10 weeks old male Villin-Claudin-2 transgenic mice and WT littermates were provided either normal drinking water (control) or Dextran Sodium Sulfate (DSS: 4% w/v) for 10 days. 3 replicates each.
Project description:Nf-kB activity is associated with the key pathological features of chronic respiratory diseases including epithelial remodelling, excess mucous production, and submucosal gland hyperplasia. However, the role of Nf-kB activity in airway epithelial differentiation remains controversial. In the present study we demonstrate that Nf-kB adaptor protein Myd88 deficiency promotes increased airway submucosal gland abundance and abnormal epithelial differentiation in proximal adult airways. Abnormal airway differentiation was not developmentally determined, became exacerbated following acute lung injury, and did not involve altered epithelial proliferation or apoptosis. Instead, we demonstrate that tracheal Myd88 deficiency promotes upregulation of a unique gene expression profile that includes activation of alternate, Myd88-independent Nf-kB signalling. Finally, we show that these effects are not intrinsically maintained in vitro using an air-liquid interface epithelial culture. This finding indicates that Myd88 deficiency promotes adult airway remodelling by regulating non-epithelial, non-cell autonomous Nf-kB activity.
Project description:The mucosal epithelium plays a key role in regulating immune homeostasis. Dysregulation of epithelial barrier function is associated with mucosal inflammation. Expression of claudin-2, a pore-forming tight junction protein, is highly upregulated during inflammatory bowel disease (IBD) and, due to its association with epithelial permeability, has been postulated to promote inflammation. Furthermore, claudin-2 also regulates colonic epithelial cell proliferation and intestinal nutrient absorption. However, the precise role of claudin-2 in regulating colonic epithelial and immune homeostasis remains unclear. Here, we demonstrate, using Villin-Claudin-2 transgenic (Cl-2TG) mice, that increased colonic claudin-2 expression unexpectedly protects mice against experimentally induced colitis and colitis-associated cancer. Notably, Cl-2TG mice exhibited increased colon length and permeability as compared with wild type (WT) littermates. However, despite their leaky colon, Cl-2TG mice subjected to experimental colitis were immune compromised, with reduced induction of TLR-2, TLR-4, Myd-88 expression and NF-kB and STAT3 activation. Most importantly, colonic macrophages in Cl-2TG mice exhibited an anergic phenotype. Claudin-2 overexpression also increased colonocyte proliferation and provided protection against colitis-induced colonocyte death. Taken together, our findings have revealed a critical role of claudin-2 in regulating colonic homeostasis, suggesting novel therapeutic strategies for inflammatory conditions of the gastrointestinal tract.
Project description:ARID1A is frequently mutated in ovarian clear-cell carcinoma (OCCC) and often co-exists with activating mutations of PIK3CA. Although induction of pro-inflammatory cytokines has been observed in this cancer, the mechanism by which the two mutations synergistically activate cytokine genes remains elusive. Here we established an in vitro model of OCCC by introducing ARID1A knock-down and mutant PIK3CA in a normal human ovarian epithelial cell line, which resulted in cell transformation and cytokine gene induction. We demonstrate that loss of ARID1A impairs the recruitment of the Sin3A-HDAC complex, while PIK3CA mutation releases RelA from IkB, leading to cytokine gene activation. We show that an NF-kB inhibitor partly attenuates proliferation of OCCC and improves the efficacy of carboplatin both in cell culture and a mouse model. Our study thus reveals the mechanistic link between ARID1A/PIK3CA mutations and cytokine gene induction in OCCC, and suggests NF-kB inhibition can be a potential therapeutic option.
Project description:A member of the nuclear receptors, retinoic acid-related orphan receptor a (RORa) is an important transcription factor for various biological processes including circadian rhythm, metabolic regulation, immune cell development and cancer. Here we found that RORa is important for intestinal homeostasis by negatively regulating the transcriptional activity of NF-kB, a major inflammatory regulator in intestinal epithelial cells. Intestinal Rora-deficient mice found were highly susceptible to DSS-induced injury. Transcriptome analysis showed that intestine-specific Rora deletion causes regulatory impairment of NF-kB signaling leading to excessive inflammatory responses. RORa specifically binds to the NF-kB target promoter and inhibits transcriptional activity for transcriptional repression of NF-kB activity via histone deacetylase 3 (HDAC3). Taken together, RORa plays a pivotal role in the homeostatic regulation of intestinal epithelial cells in inflammatory conditions. Therefore, therapeutic strategies designed to modulate RORa activity may be beneficial in the treatment of chronic inflammatory diseases such as Inflammatory bowel disease (IBD).
Project description:NF-kB pathway activation is the hallmark of hematological malignancies. In multiple myeloma (MM), a large variety of genomic alterations leading to either inactivation of repressor such as TRAF3, CYLD or cIAP1/2 or amplification of activators such as CD40 or NIK collectively contribute to frequently deregulate NF-kB signaling. In order to evaluate the prognostic impact of NF-kB mutations in MM, we performed a comprehensive analysis of a panel of newly diagnosed patients with cIAP1/2 biallelic deletion. We found that all patients have dysregulated NF-kB pathway and the majority of them presented t(4;14). Then we analyzed clinical outcome of 37 MM at presentation with t(4;14) and treated with bortezomib according to their NF-kB status. We showed that increase of NF-kB activity confers prolonged event-free survival. Altogether, our data suggest that NF-kB activation resulting from NF-kB mutations (ie cIAP1/2 deletion) or other mechanisms improves outcome of t(4;14)-positive MM treated with bortezomib.