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:Developing strategies that promote the resolution of vascular inflammation and atherosclerosis remains a major therapeutic challenge. Here, we show that exosomes produced by naive bone marrow-derived macrophages (BMDM-exo) contain anti-inflammatory microRNA-99a/146b/378a that are further increased in exosomes produced by BMDM polarized with IL-4 (BMDM-IL-4-exo). These exosomal microRNAs suppress inflammation by targeting NF-kB and TNF-a signaling and foster M2 polarization in recipient macrophages. Repeated infusions of BMDM-IL-4-exo into Apoe_x0001_/_x0001_ mice fed a Western diet reduce excessive hematopoiesis in the bone marrow and thereby the number of myeloid cells in the circulation and macrophages in aortic root lesions. This also leads to a reduction in necrotic lesion areas that collectively stabilize atheroma. Thus, BMDM-IL-4-exo may represent a useful therapeutic approach for atherosclerosis and other inflammatory disorders by targeting NF-kB and TNF-a via microRNA cargo delivery.
Project description:The inhibitor of kB kinase (IKK) is the master regulator of the nuclear factor kB (NF-kB) pathway, involved in inflammatory, immune and apoptotic responses. In the ‘canonical’ NF-kB pathway, IKK phosphorylates inhibitor of kB (IkB) proteins and this triggers ubiquitin-mediated degradation of IkB, leading to release and nuclear translocation of NF-B transcription factors.
The data presented show that the IKK and IKK subunits recognize a YDDX docking site located within the disordered C-terminal region of IkBa. Our results also suggest that IKK contributes to the docking interaction with higher affinity as compared to IKK.
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: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.
Project description:Stringent regulation of TNF signaling prevents aberrant inflammation. TNF engages the canonical NF-kB pathway for activating the RelA:p50 heterodimer, which mediates specific expressions of pro-inflammatory and immune response genes. Importantly, the NF-kB system discriminates between time-varied TNF inputs. Negative feedback regulators of the canonical pathway, including IkBa, thought to ensure transient RelA:p50 responses to brief TNF stimulations. The noncanonical NF-kB pathway controls a separate RelB activity associated with immune differentiation. In a systems modeling approach, we uncovered an unexpected role of p100, a constituent of the noncanonical pathway, in TNF signaling. Brief TNF stimulation of p100-deficient cells produced an additional late NF-kB activity composed of the RelB:p50 heterodimer, which distorted the TNF-induced gene-expression program. Periodic TNF pulses augmented this RelB:p50 activity, which was reinforced by NF-kB-dependent RelB synthesis. In sum, the NF-kB system seems to engage distantly related molecular species for enforcing dynamical and gene controls of immune-activating TNF signaling.
Project description:Genome wide transcriptional profiling on liver mRNA retrieved from recombinant adenovirus A20 (rAd.A20) and rAd.bgalactosidase transduced livers, before and 24 hours after 78% extended liver resection. Overexpression of the NF-kB inhibitory protein A20 improves recovery of liver function and mass following extended liver resection and severe liver ischemia reperfusion injury in mice. In this project, we explored effects of A20 using transcriptional profiling on liver mRNA retrieved from recombinant adenovirus A20 (rAd.A20) and rAd.bgalactosidase transduced livers, before and 24 hours after 78% extended liver resection.
Project description:The current study is aimed on determine the functional impact of microRNA-378a-3p and microRNA-146b on embryo development. For such purpose, we supplemented miR-378/miR-146b mimics or inhibitors to the culture medium containing presumed zygotes at 1 dpi and cultured them until day 8, thus allowing miR-378/miR-146b mimics or inhibitors to influence further embryo development and quality. Further on, to gain more in-depth molecular insights, we performed transcriptome profiling of blastocysts cultured in the presence of miR-378/miR-146b mimics or inhibitors.