Project description:The mammalian innate immune system senses many bacterial stimuli through the toll-like receptor (TLR) family. Activation of the TLR4 receptor by bacterial lipopolysaccharide (LPS) is the most widely studied TLR pathway due to its central role in host responses to gram-negative bacterial infection and its contribution to endotoxemia and sepsis. Here we describe a genome-wide siRNA screen to identify genes regulating the mouse macrophage TNF-α and NF-κB responses to LPS. We include a secondary validation screen conducted with six independent siRNAs per gene to facilitate removal of off-target screen hits. We also provide microarray data from the same LPS-treated macrophage cells to facilitate downstream data analysis. These data provide a resource for analyzing gene function in the predominant pathway driving inflammatory signaling and cytokine expression in mouse macrophages.
Project description:The mammalian innate immune system senses many bacterial stimuli through the toll-like receptor (TLR) family. Activation of the TLR4 receptor by bacterial lipopolysaccharide (LPS) is the most widely studied TLR pathway due to its central role in host responses to gram-negative bacterial infection and its contribution to endotoxemia and sepsis. Here we describe a genome-wide siRNA screen to identify genes regulating the human macrophage TNF-α response to LPS. We include a secondary validation screen conducted with six independent siRNAs per gene to facilitate removal of off-target screen hits. We also provide microarray data from the same LPS-treated macrophage cells to facilitate downstream data analysis. These data provide a resource for analyzing gene function in the predominant pathway driving inflammatory cytokine expression in human macrophages.
Project description:Medicinal plants have shown great promise as a source of novel drug compounds for the treatment of inflammatory disorders. In our search for new entities with anti-inflammatory potential, the extracts of the whole plant of Saussurea heteromalla (family-Asteraceae), collected from Himalayas, were evaluated in the high throughput screen for TNF-α and IL-6 inhibitors. The plant has been found as a new source of chlorojanerin, a guaianolide type of sesquiterpene lactone. This is the first report on the potent anti-inflammatory activity of the compound. Chlorojanerin was shown to be significantly effective in inhibiting TNF-α and IL-6 production in LPS induced THP-1 cells (TNF-α, IC50 = 3µM and IL-6, IC50 = 0.8µM). The compound also blocked TNF-α and IL-6 production from LPS induced human monocytes and synovial cells from RA patients. Chlorojanerin also inhibited the binding of NF-κB in a GFP reporter assay system. Transcriptional profiling of the LPS stimulated THP-1 cells revealed that chlorojanerin exerted its anti-inflammatory effect by inhibiting the expression of genes involved in activating the transcription factor – NF-κB. Real time analysis of these genes validated the effect of chlorojanerin on the classical downstream targets of NF-κB. Thus, this study clearly delineated 8 targets specific for the effect of chlorojanerin on NF-κB induced signaling at the mRNA level. This work is a step towards the isolation and characterization of lead anti-inflammatory agents from the extract of Saussurea heteromalla, which can be developed into better therapeutic molecules targeted towards some specific inflammatory diseases. Single dye labelling with Cy3 for all treatment RNA samples. Treatments included unstimulated, LPS stimulated, Chlorjanerin treatment and dexamethasone treatment.
Project description:The model was constructed to describe TLR4 induced NF-κB activation in native bone marrow-derived macrophages. It included processes of ligand (lipopolysaccharide) recognition, formation of dimer receptor complex and further signal transduction through TRAF6/TAK1 complex that leads to the activation of IKKα/β kinase, which in turn enables the NF-κB transcription factor phosphorylation and translocation in the cell nucleus, and induction of IkB and WIP1 (as an example of induced protein that promotes NF-κB dephosphorylation 2) gene transcription. Models were based on the current knowledge of TLR signaling framework, protein interactions within the TLR4 pathway, and up-to-date mathematical models describing Toll receptor activation.
The major important additions were made to TLR4 signaling description:
1) Receptor dimerization process
2) The existence of a basal nuclear NF-κB level (translocation)
3) NF-κB phosphorylation by IKK complex
Project description:Cordyceps participates in various pharmacological activities including anti-tumor, and is involved in the regulation of NF-κB signaling pathway. However, the detailed role of cordycepin in suppression of NF-κB signaling pathway is less clear. In this study, we first analyzed the effect of cordyceps on NF-κB activity in TK-10 cells, and found that cordyceps resulted in a dose-dependent reduction in TNF-α-induced NF-κB activation. Here, we show that cordyceps mediated NF-kB inhibition induces apoptosis in TK-10 cells involved the serial activation of caspases. Moreover, we demonstrate that in addition to activating caspases, the cordyceps negatively modulates TNF-α-mediated NF-κB signaling to promote JNK activation, which results in apoptosis, and that NF-kB regulates antiapoptotic factor GADD45b and the JNK kinase MKK7. When the TNFα cytokine binds to the TNF receptor, IκB dissociates from NF-κB. As a result, the active NF-κB translocates to the nucleus. Cordyceps clearly prevented NF-κB from mobilizing to the nucleus, resulting in downregulation of GADD45b, whereas upregulation of MKK7 and phosphorylation of JNK (p-JNK). This increased Bax activation, leading to marked cordyceps-induced apoptosis. Bax subfamily proteins induced apoptosis through caspase-3. Furthermore, siRNA mediated inhibition of MKK7 downregulated p-JNK and The JNK inhibitor SP600125 strongly inhibited Bax. Thus, these results indicate that cordyceps inhibits NF-κB/GADD45b signaling activation to upregulate MKK7-JNK signaling pathway to induce apoptosis in TK-10 cells and support the potential of cordyceps as a therapeutic agent for renal cancer.
Project description:Lysine 9 di-methylation and lysine 27 tri-methylation of histone H3 (H3K9me2 and H3K27me3) are mostly linked to gene repression. However, functions of repressive histone methylation dynamics during inflammatory responses remain poorly understood. Here, we show that lysine demethylase 7A (KDM7A) and 6A (UTX) are rapidly transported to nuclear factor kappa-B (NF-κB) related elements in human endothelial cells in response to tumor necrosis factor (TNF)-α. KDM7A and UTX demethylate H3K9me2 and H3K27me3, respectively, and cooperatively activate NF-κB dependent inflammatory genes. Furthermore, using both in situ Hi-C and other 3C based technology, loops between super enhancers (SEs) are newly formed following TNF-α-stimuli at NF-κB-dependent inflammatory loci where KDM7A- and UTX-recruitment coincide. Collectively, these findings suggest that erasing of repressive histone marks by KDM7A and UTX within NF-κB-related elements might functionally associate with formation of SE-SE three-dimensional interactions and could be a cue signal during inflammatory responses in human endothelial cells.
Project description:Lysine 9 di-methylation and lysine 27 tri-methylation of histone H3 (H3K9me2 and H3K27me3) are mostly linked to gene repression. However, functions of repressive histone methylation dynamics during inflammatory responses remain poorly understood. Here, we show that lysine demethylase 7A (KDM7A) and 6A (UTX) are rapidly transported to nuclear factor kappa-B (NF-κB) related elements in human endothelial cells in response to tumor necrosis factor (TNF)-α. KDM7A and UTX demethylate H3K9me2 and H3K27me3, respectively, and cooperatively activate NF-κB dependent inflammatory genes. Furthermore, using both in situ Hi-C and other 3C based technology, loops between super enhancers (SEs) are newly formed following TNF-α-stimuli at NF-κB-dependent inflammatory loci where KDM7A- and UTX-recruitment coincide. Collectively, these findings suggest that erasing of repressive histone marks by KDM7A and UTX within NF-κB-related elements might functionally associate with formation of SE-SE three-dimensional interactions and could be a cue signal during inflammatory responses in human endothelial cells.
Project description:Lysine 9 di-methylation and lysine 27 tri-methylation of histone H3 (H3K9me2 and H3K27me3) are mostly linked to gene repression. However, functions of repressive histone methylation dynamics during inflammatory responses remain poorly understood. Here, we show that lysine demethylase 7A (KDM7A) and 6A (UTX) are rapidly transported to nuclear factor kappa-B (NF-κB) related elements in human endothelial cells in response to tumor necrosis factor (TNF)-α. KDM7A and UTX demethylate H3K9me2 and H3K27me3, respectively, and cooperatively activate NF-κB dependent inflammatory genes. Furthermore, using both in situ Hi-C and other 3C based technology, loops between super enhancers (SEs) are newly formed following TNF-α-stimuli at NF-κB-dependent inflammatory loci where KDM7A- and UTX-recruitment coincide. Collectively, these findings suggest that erasing of repressive histone marks by KDM7A and UTX within NF-κB-related elements might functionally associate with formation of SE-SE three-dimensional interactions and could be a cue signal during inflammatory responses in human endothelial cells.