Project description:MicroRNA-223, a principal myeloid-specific anti-inflammatory microRNA, is dysregulated in numerous inflammatory conditions and cancers. We found that miR-223 deficient zebrafish displayed augmented neutrophilic inflammation, which was due primarily to elevated activation of the canonical NF-B pathway. To our surprise, the NF-B over-activation was restricted to the basal epithelial cells, a squamous layer permeable to oxygen and chemicals. MiR-223 was expressed in epithelial cells and directly down-regulated multiple components in the NF-B signaling pathway in zebrafish and human. Both phagocytic and epithelial miR-223 suppressed neutrophil wound response and NF-B activation in the basal epithelial cells. Together, our data provide the mechanism of the multifaceted role of miR-223 and highlight the previously overlooked relevance of epithelial cells in miR-223 related diseases.
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:Proinflammatory stimuli rapidly and globally remodel chromatin landscape, thereby enabling transcriptional responses. Yet, the mechanisms coupling chromatin regulators to the master regulatory inflammatory transcription factor NF-kB remain poorly understood. We report in human endothelial cells (ECs) that activated NF-kB binds to enhancers, provoking a rapid, global redistribution of BRD4 preferentially at super-enhancers, large enhancer domains highly bound by chromatin regulators. Newly established NF-kB super-enhancers drive nearby canonical inflammatory response genes. In both ECs and macrophages BET bromodomain inhibition prevents super-enhancer formation downstream of NF-kB activation, abrogating proinflammatory transcription. In TNFa-activated endothelium this culminates in functional suppression of leukocyte rolling, adhesion and transmigration. Sustained BET bromodomain inhibitor treatment of LDLr -/- animals suppresses atherogenesis, a disease process rooted in pathological vascular inflammation involving endothelium and macrophages. These data establish BET-bromodomains as key effectors of inflammatory response through their role in the dynamic, global reorganization of super-enhancers during NF-kB activation. Gene expression analysis of human endothelial cells in resting state, treatment with TNFalpha or TNFalpha with the BET bromodomain inhibitor JQ1
Project description:Proinflammatory stimuli rapidly and globally remodel chromatin landscape, thereby enabling transcriptional responses. Yet, the mechanisms coupling chromatin regulators to the master regulatory inflammatory transcription factor NF-kB remain poorly understood. We report in human endothelial cells (ECs) that activated NF-kB binds to enhancers, provoking a rapid, global redistribution of BRD4 preferentially at super-enhancers, large enhancer domains highly bound by chromatin regulators. Newly established NF-kB super-enhancers drive nearby canonical inflammatory response genes. In both ECs and macrophages BET bromodomain inhibition prevents super-enhancer formation downstream of NF-kB activation, abrogating proinflammatory transcription. In TNFa-activated endothelium this culminates in functional suppression of leukocyte rolling, adhesion and transmigration. Sustained BET bromodomain inhibitor treatment of LDLr -/- animals suppresses atherogenesis, a disease process rooted in pathological vascular inflammation involving endothelium and macrophages. These data establish BET-bromodomains as key effectors of inflammatory response through their role in the dynamic, global reorganization of super-enhancers during NF-kB activation. ChIP-Seq for various transcription factors, RNA Polymerase II, and histone modifications in human endothelial cells
Project description:Proinflammatory stimuli rapidly and globally remodel chromatin landscape, thereby enabling transcriptional responses. Yet, the mechanisms coupling chromatin regulators to the master regulatory inflammatory transcription factor NF-kB remain poorly understood. We report in human endothelial cells (ECs) that activated NF-kB binds to enhancers, provoking a rapid, global redistribution of BRD4 preferentially at super-enhancers, large enhancer domains highly bound by chromatin regulators. Newly established NF-kB super-enhancers drive nearby canonical inflammatory response genes. In both ECs and macrophages BET bromodomain inhibition prevents super-enhancer formation downstream of NF-kB activation, abrogating proinflammatory transcription. In TNFa-activated endothelium this culminates in functional suppression of leukocyte rolling, adhesion and transmigration. Sustained BET bromodomain inhibitor treatment of LDLr -/- animals suppresses atherogenesis, a disease process rooted in pathological vascular inflammation involving endothelium and macrophages. These data establish BET-bromodomains as key effectors of inflammatory response through their role in the dynamic, global reorganization of super-enhancers during NF-kB activation. Chem-Seq for the biotinylated small molecule JQ1 in untreated or TNFalpha treated human endothelial cells
Project description:We used a multi-omics approach to study the impact of miR-223 in the RAW cell line. We evidenced changes linked to cell death, histone acetylation, bone remodeling, RNA regulation. Changes in miR-223 expression altered the metabolic profile of cells including nucleotides. miR-223 impacted NF-kB levels, macrophage differentiation and osteoclastogenesis.
Project description:Mutations in KRAS occur in a variety of tumors of epithelial origin, driving the oncogenic phenotype.The NF-kB transcription factor pathway is important for oncogenic RAS to transform cells and to drive tumorigenesis in animal models. Recently TAK1, an upstream regulator of IKK which controls canonical NF-kB, was shown to be important for chemoresistance in pancreatic cancer and for regulating KRAS+ colorectal cancer cell growth and survival. Here we show that GSK-3alpha is upregulated by KRAS leading to interaction with TAK1 to stabilize the TAK1/TAB complex to promote IKK activity. Additionally, GSK-3alpha is required for promoting critical non-canonical NF-kB signaling in pancreatic cancer cells. Pharmacologic inhibition of GSK-3 suppresses growth of human pancreatic tumor explants, consistent with loss of expression of genes such as c-myc and TERT. These data identify GSK-3alpha as a key downstream effector of oncogenic RAS via its ability to coordinately regulate distinct NF-kB signaling pathways GSK-3 inhibition at 2 and 8 hours
Project description:The negative feedback mechanism is essential to maintain effective immunity and tissue homeostasis. 1,25-dihydroxyvitamin D (1,25(OH)2D3) modulates innate immune response, but the mechanism remains poorly understood. Here we report that vitamin D receptor (VDR) signaling attenuates Toll-like receptor-mediated inflammation by enhancing the negative feedback inhibition. VDR inactivation leads to a hyperinflammatory response in mice and macrophage cultures when challenged with lipopolysaccharide (LPS) due to miR-155 overproduction that excessively suppresses SOCS1, a key regulator that enhances the negative feedback loop. Deletion of miR-155 attenuates vitamin D suppression of LPS-induced inflammation, confirming that 1,25(OH)2D3 stimulates SOCS1 by down-regulating miR-155. 1,25(OH)2D3 down-regulates bic transcription by inhibiting NF-kappaB activation, which is mediated by a kappaB cis-DNA element located within the first intron of the bic gene. Together these data identify a novel regulatory mechanism for vitamin D to control innate immunity. MicroRNA arrays. Total RNAs were extracted from RAW264.7 cells (mouse macrophage line) treated with LPS (100ng/ml) in the presence or absence of 1,25(OH)2D3 (20 nM) overnight. MicroRNA profiling was performed using the miRCURY LNA microRNA Arrays (Exiqon, Vedvaek,Denmark) according to the manufacture'¹s standard protocols. The arrays were scanned with the GenePix 4000B scanner using the manufacturer's recommended settings. The raw data was extracted using GenePix Pro and imported into GeneSpring GX10 for analyses.
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.