Inhibitor of growth-4 promotes IκB promoter activation to suppress NF-κB signaling and innate immunity

Ing4 is a member of the inhibitor of growth (ING) family of chromatin-modifying proteins. Biochemical experiments indicate that Ing4 is a subunit of the HB01-JADE-hEAF6 histone acetyltransferase complex responsible for most nucleosomal histone H4 acetylation in eukaryotes, and transfection studies suggest that Ing4 may regulate a wide variety of cellular processes, including DNA repair, apoptosis, cell-cycle regulation, metastasis, angiogenesis, and tumor suppression. However, in vivo evidence for a physiological role for Ing4 in cell-growth regulation is lacking. We have generated Ing4-deficient mice to explore the role of Ing4 in development, tumorigenesis, and in NF-κB signaling. Ing4-null mice develop normally and are viable. Although mice deficient for Ing4 fail to form spontaneous tumors, they are hypersensitive to LPS treatment and display elevated cytokine responses. Macrophages isolated from Ing4-null mice have increased levels of nuclear p65/RelA protein, resulting in increased RelA binding to NF-κB target promoters and up-regulation of cytokine gene expression. However, increased promoter occupancy by RelA in LPS-stimulated, Ing4-null cells does not always correlate with increased NF-κB target-gene expression, as RelA activation of a subset of cytokine promoters also requires Ing4 for proper histone H4 acetylation. Furthermore, activation of the IκBα promoter by RelA is also Ing4-dependent, and LPS-stimulated, Ing4-null cells have reduced levels of IκBα promoter H4 acetylation and IκB gene expression. Thus, Ing4 negatively regulates the cytokine-mediated inflammatory response in mice by facilitating NF-κB activation of IκB promoters, thereby suppressing nuclear RelA levels and the activation of select NF-κB target cytokines.     

CSNK2A2 promotes hepatocellular carcinoma progression through activation of NF-κB pathway

Introduction and ObjectivesBreast and non-small cell lung cancers harbor an upregulated CSNK2A2 oncogene that encodes the protein kinase CK2 alpha', a catalytic subunit of the highly conserved serine/threonine kinase CK2. However, its role and biological significance in hepatocellular carcinoma (HCC) remains unclear.Materials and MethodsWestern-blotting and immunohistochemistry were used to measure the expression of CSNK2A2 in HCC tumor tissues and cell lines. CCK8, Hoechst staining, transwell, tube formation assay in vitro and nude mice experiments in vivo were used to measure the effects of CSNK2A2 on HCC proliferation, apoptosis, metastasis, angiogenesis and tumor formation.ResultsIn the study, we showed that CSNK2A2 was highly expressed in HCC comparison with matched control tissues, and was linked with lower survival of patients. Additional experiments indicated that silencing of CSNK2A2 promoted HCC cell apoptosis, while inhibited HCC cells migrating, proliferating, angiogenesis both in vitro and in vivo. These effects were also accompanied by reduced expression of NF-κB target genes, including CCND1, MMP9 and VEGF. Moreover, treatment with PDTC counteracted the promotional effects of CSNK2A2 on HCC cells.ConclusionsOverall, our results suggested that CSNK2A2 could promote HCC progression by activating the NF-κB pathway, and this could serve as a biomarker for future prognostic and therapeutic applications.     

Platelet microparticles-containing miR-4306 inhibits human monocyte-derived macrophages migration through VEGFA/ERK1/2/NF-κB signaling pathways

Platelets are major sources of microparticles (MPs) in peripheral bloodstream, and platelet-secreted MPs (P-MPs) transfer biological information to neighboring cells. In the present study, we found that the platelet- and P-MPs-derived microRNA-4306 (miR-4306) expression were downregulated in coronary artery disease (CAD) and platelet-derived miR-4306 was an independent poor prognostic factor in CAD. Plasma miRNA-4306 mainly cofractionated with MPs instead of Argonaute2 complexes or HDL. P-MPs could effectively deliver miR-4306 into human monocyte-derived macrophages (HMDMs). MiR-4306 noticeably inhibited the HMDMs migration in vitro and reduced the number of macrophage cells in cardiac tissue in myocardial infarction mice. This functional impact of miR-4306 was mediated directly through VEGFA to inhibit ERK/NF-κB signaling. In conclusion, our study suggested that intercellular transfer of miR-4306 by platelet microparticles inhibited the HMDMs migration through VEGFA/ERK1/2/NF-κB signaling pathways.     

Chronic epithelial NF-κB activation accelerates APC loss and intestinal tumor initiation through iNOS up-regulation

The role of NF-κB activation in tumor initiation has not been thoroughly investigated. We generated Ikkβ(EE)(IEC) transgenic mice expressing constitutively active IκB kinase β (IKKβ) in intestinal epithelial cells (IECs). Despite absence of destructive colonic inflammation, Ikkβ(EE)(IEC) mice developed intestinal tumors after a long latency. However, when crossed to mice with IEC-specific allelic deletion of the adenomatous polyposis coli (Apc) tumor suppressor locus, Ikkβ(EE)(IEC) mice exhibited more β-catenin(+) early lesions and visible small intestinal and colonic tumors relative to Apc(+/ΔIEC) mice, and their survival was severely compromised. IEC of Ikkβ(EE)(IEC) mice expressed high amounts of inducible nitric oxide synthase (iNOS) and elevated DNA damage markers and contained more oxidative DNA lesions. Treatment of Ikkβ(EE)(IEC)/Apc(+/ΔIEC) mice with an iNOS inhibitor decreased DNA damage markers and reduced early β-catenin(+) lesions and tumor load. The results suggest that persistent NF-κB activation in IEC may accelerate loss of heterozygocity by enhancing nitrosative DNA damage.     

Diplacone reduces homocysteine-induced vascular endothelial cell injury by inhibiting oxidative stress and NF-κB signaling pathway

<正>Objective In this experiment,human umbilical vein endothelial cells were induced by HHcy in vitro,and the inflammatory damage model of vascular endothelial cells was established,the effect of Diplacone on human umbilical vein endothelial cells was observed by pretreatment with Diplacone,and further explored the possible protective mechanism of Diplacone on vascular endothelial cells. Methods Human umbilical vein endothelial     

S100A8/A9 aggravates post-ischemic heart failure through activation of RAGE-dependent NF-κB signaling

The extracellular heterodimeric protein S100A8/A9 activates the innate immune system through activation of the receptor of advanced glycation end products (RAGE) and Toll-like receptors. As activation of RAGE has recently been associated with sustained myocardial inflammation and heart failure (HF) we studied the role of S100A8/A9 in the development of post-ischemic HF. Hypoxia led to sustained induction of S100A8/A9 accompanied by increased nuclear factor (NF-)κB binding activity and increased expression of pro-inflammatory cytokines in cardiac fibroblasts and macrophages. Knockdown of either S100A8/A9 or RAGE rescued the induction of pro-inflammatory cytokines and NF-κB activation after hypoxia. In a murine model of post-ischemic HF both cardiac RNA and protein levels of S100A8/A9 were elevated as soon as 30 min after hypoxia with sustained activation up to 28 days after ischemic injury. Treatment with recombinant S100A8/A9 resulted in reduced cardiac performance following ischemia/reperfusion. Chimera experiments after bone marrow transplantation demonstrated the importance of RAGE expression on immune cells for their recruitment to the injured myocardium aggravating post-ischemic heart failure. Signaling studies in isolated ventricles indicated that MAP kinases JNK, ERK1/2 as well as NF-κB mediate signals downstream of S100A8/A9-RAGE in post-ischemic heart failure. Interestingly, cardiac performance was not affected by administration of S100A8/A9 in RAGE^?/?-mice, which demonstrated significantly improved cardiac recovery compared to WT-mice. Our study provides evidence that sustained activation of S100A8/A9 critically contributes to the development of post-ischemic HF driving the progressive course of HF through activation of RAGE.     

NF-κB与神经损伤

核因子-κB（NF-κB）是一种广泛存在于真核细胞内,可将信息从胞浆传至胞核并引起相应基因表达的重要转录因子。近年研究表明,NF-κB存在于神经系统几乎所有类型的细胞中,主要包括神经元、星形胶质细胞、小胶质细胞和少突细胞,在神经塑型、神经发育及神经变性等过程中具有独特作用。广泛参与神经系统的病理、生理过程。现就NF-κB与神经损伤的关系及其研究进展综述如下。     

NF-κB与心血管疾病

本文就NF－κB与IκB的一般特征；NF－κB在某些心血管病变中的作用；药物和基因产物抑制剂对NF－κB的作用；NF－κB的检测方法等方面进行了综述。     

Polydatin ameliorates experimental diabetes-induced fibronectin through inhibiting the activation of NF-κB signaling pathway in rat glomerular mesangial cells

A number of studies have recently demonstrated the involvement of nuclear factor-kappa B (NF-κB) activation and the subsequent coordinated inflammatory responses in the pathogenesis of diabetic nephropathy (DN). Polydatin has been shown to have the ability of anti-adhesive inflammation. However, the possible protective and beneficial effects of polydatin on DN via suppressing inflammatory damage and extracellular matrix (ECM) accumulation are not fully elucidated. We found that the polydatin could inhibit the induction and activity of NF-κB, and meanwhile ameliorating ECM accumulation in streptozotocin-diabetic rats. We aimed to investigate the effect of polydatin on fibronectin (FN) protein expression, and to elucidate its potential mechanism involving the NF-κB inflammatory signaling pathway in rat glomerular mesangial cells (GMCs) cultured under high glucose. The results revealed that polydatin significantly suppressed high glucose-induced FN production, inhibited NF-κB nuclear translocation, reduced the DNA-binding activity of NF-κB, as well as decreased the protein expression of ICAM-1 and TGF-β in GMCs. These findings suggested that polydatin significantly represses high glucose-induced FN expression in rat GMCs, which may be closely related to its inhibition of the NF-κB signaling pathway. Hence, we elucidated the potential mechanisms of the anti-inflammatory effects and ECM accumulation alleviation of polydatin in GMCs of DN in vitro.