Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Cisplatin cytotoxicity of auditory cells requires secretions of proinflammatory cytokines via activation of ERK and NF-kappaB.

ABSTRACT: The ototoxicity of cisplatin, a widely used chemotherapeutic agent, involves a number of mechanisms, including perturbation of redox status, increase in lipid peroxidation, and formation of DNA adducts. In this study, we demonstrate that cisplatin increased the early immediate release and de novo synthesis of proinflammatory cytokines, including TNF-alpha, IL-1beta, and IL-6, through the activation of ERK and NF-kappaB in HEI-OC1 cells, which are conditionally immortalized cochlear cells that express hair cell markers. Both neutralization of proinflammatory cytokines and pharmacologic inhibition of ERK significantly attenuated the death of HEI-OC1 auditory cells caused by cisplatin and proinflammatory cytokines. We also observed a significant increase in the protein and mRNA levels of proinflammatory cytokines in both serum and cochleae of cisplatin-injected rats, which was suppressed by intraperitoneal injection of etanercept, an inhibitor of TNF-alpha. Immunohistochemical studies revealed that TNF-alpha expression was mainly located in the spiral ligament, spiral limbus, and the organ of Corti in the cochleae of cisplatin-injected rats. NF-kappaB protein expression, which overlapped with terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling-positive signal, was very strong in specific regions of the cochleae, including the organ of Corti, spiral ligament, and stria vascularis. These results indicate that proinflammatory cytokines, especially TNF-alpha, play a central role in the pathophysiology of sensory hair cell damage caused by cisplatin.

SUBMITTER: So H

PROVIDER: S-EPMC2538433 | biostudies-other | 2007 Sep

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

IkappaBeta, a nuclear IkappaB protein, positively regulates the NF-kappaB-mediated expression of proinflammatory cytokines.

Project description:NF-kappaB is a key mediator for inducible transcription of various proinflammatory genes in innate immune responses, and its activity is strictly regulated by several IkappaB proteins. Although signaling pathways leading from pattern recognition receptors to NF-kappaB's activation in the cytoplasm have been studied extensively, the detail regulatory mechanisms of NF-kappaB-mediated transcriptional activity in the nucleus still remain unclear. Here we describe a unique member of the nuclear IkappaB protein family, IkappaBeta. In a gene expression analysis of dendritic cells, we found a unique gene encoding an uncharacterized protein with ankyrin repeats. As it was structurally related to the IkappaB family, the protein was named "IkappaBeta" and further characterized in the innate immune response. IkappaBeta was widely expressed in various tissues and predominantly located in the nucleus. Moreover, biochemical analysis showed that IkappaBeta associated with the p50 subunit of NF-kappaB. Knockdown of IkappaBeta by siRNA suppressed the transcription of a subset of NF-kappaB-mediated proinflammatory cytokines in LPS-stimulated and poly (I:C)-transfected macrophages. These results indicate that IkappaBeta regulates the NF-kappaB-mediated transcription of a wide variety of proinflammatory genes, playing a crucial role in the regulation of innate immune responses.

| S-EPMC2900662 | biostudies-literature

Anti-inflammatory effects of liquiritigenin as a consequence of the inhibition of NF-kappaB-dependent iNOS and proinflammatory cytokines production.

Project description:Glycyrrhizae radix has been widely used as a cytoprotective, plant-derived medicine. We have identified a flavanoid, liquiritigenin, as an active component in extracts of Glycyrrhizae radix. This research investigated the effects of liquiritigenin on the induction of inducible NOS (iNOS) and proinflammatory cytokines by lipopolysaccharide (LPS) in Raw264.7 cells, and on paw oedema in rats.iNOS expression was determined by western blotting, real-time reverse transcription-PCR and reporter gene analyses. Tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta and IL-6 were assayed by ELISA. Gel shift assay and immunoblotting were used to assess NF-kappaB activation. The effect of liquiritigenin on acute inflammation in vivo was evaluated using carrageenan-induced paw oedema.Treatment of Raw264.7 cells with liquiritigenin caused inhibition of LPS-induced NF-kappaB DNA binding activity, due to repression of I-kappaBalpha phosphorylation and degradation. Liquiritigenin treatment prevented LPS from increasing the levels of iNOS protein and mRNA in a concentration-dependent manner. Liquiritigenin also suppressed the production of TNF-alpha, IL-1beta and IL-6 from Raw264.7 cells after LPS. In rats, liquiritigenin treatment inhibited formation of paw oedema induced by carrageenan.These results demonstrate that liquiritigenin exerts anti-inflammatory effects, which results from the inhibition of NF-kappaB activation in macrophages, thereby decreasing production of iNOS and proinflammatory cytokines. Our findings showing inhibition by liquiritigenin of paw oedema as well as inflammatory gene induction will help to understand the pharmacology and mode of action of liquiritigenin, and of the anti-inflammatory use of Glycyrrhizae radix.

| S-EPMC2438972 | biostudies-other

Toll receptor-mediated Drosophila immune response requires Dif, an NF-kappaB factor.

Project description:The induction of immunity genes in Drosophila has been proposed to be dependent on Dorsal, Dif, and Relish, the NF-kappaB-related factors. Here we provide genetic evidence that Dif is required for the induction of only a subset of antimicrobial peptide genes. The results show that the presence of Dif without Dorsal is sufficient to mediate the induction of drosomycin and defensin. We also demonstrate that Dif is a downstream component of the Toll signaling pathway in activating the drosomycin expression. These results reveal that individual members of the NF-kappaB family in Drosophila have distinct roles in immunity and development.

| S-EPMC316597 | biostudies-literature

NF-kappaB activation and potentiation of proinflammatory responses by the Helicobacter pylori CagA protein.

Project description:The Helicobacter pylori immunodominant protein, CagA, is associated with severe gastritis and carcinoma. Injection of CagA into gastric epithelial cells by type IV secretion leads to actin-cytoskeletal rearrangements and cell scattering. CagA has been reported to have no role in the induction of transcription factor NF-kappaB and IL-8, which are crucial determinants for chronic inflammation. Here, we provide several lines of evidence showing that CagA is able to induce IL-8 in a time- and strain-dependent manner. We also show that by exchanging specific cagA genes, high IL-8-inducing H. pylori strains could be converted into low inducing strains and vice versa. Our results suggest that IL-8 release induced by CagA occurs via a Ras-->Raf-->Mek-->Erk-->NF-kappaB signaling pathway in a Shp-2- and c-Met-independent manner. Thus, CagA is a multifunctional protein capable of effecting both actin remodeling and potentiation of chemokine release.

| S-EPMC1166591 | biostudies-literature

Co-activation of ERK, NF-kappaB, and GADD45beta in response to ionizing radiation.

Project description:NF-kappaB has been well documented to play a critical role in signaling cell stress reactions. The extracellular signal-regulated kinase (ERK) regulates cell proliferation and survival. GADD45beta is a primary cell cycle element responsive to NF-kappaB activation in anti-apoptotic responses. The present study provides evidence demonstrating that NK-kappaB, ERK and GADD45beta are co-activated by ionizing radiation (IR) in a pattern of mutually dependence to increase cell survival. Stress conditions generated in human breast cancer MCF-7 cells by the administration of a single exposure of 5 Gy IR resulted in the activation of ERK but not p38 or JNK, along with an enhancement of the NF-kappaB transactivation and GADD45beta expression. Overexpression of dominant negative Erk (DN-Erk) or pre-exposure to ERK inhibitor PD98059 inhibited NF-kappaB. Transfection of dominant negative mutant IkappaB that blocks NF-kappaB nuclear translocation, inhibited ERK activity and GADD45beta expression and increased cell radiosensitivity. Interaction of p65 and ERK was visualized in living MCF-7 cells by bimolecular fluorescence complementation analysis. Antisense inhibition of GADD45beta strikingly blocked IR-induced NF-kappaB and ERK but not p38 and JNK. Overall, these results demonstrate a possibility that NF-kappaB, ERK, and GADD45beta are able to coordinate in a loop-like signaling network to defend cells against the cytotoxicity induced by ionizing radiation.

| S-EPMC4130153 | biostudies-literature

NF-kappaB is required for survival of immature auditory hair cells in vitro.

Project description:Damage to auditory hair cells in the inner ear as a consequence of aging, disease, acoustic trauma, or exposure to ototoxins underlies most cases of hearing impairment. Because the mammalian ear cannot replace damaged hair cells, loss of hearing is irreversible and progressive throughout life. One of the current goals of inner ear biology is to develop therapeutic strategies to prevent hair cell degeneration. Although important progress has been made in discovering factors that mediate hair cell death, very little is known about the molecular pathway(s) that signal survival. Here we considered the role of NF-kappaB, a ubiquitous transcription factor that plays a major role in the regulation of many apoptosis- and stress-related genes, in mediating hair cell survival. NF-kappaB was detected in a constitutively active form in the organ of Corti of 5-day-old rats. Selective inhibition of NF-kappaB through use of a cell-permeable inhibitory peptide in vitro caused massive degeneration of hair cells within 24 h of inhibitor application. Hair cell death occurred through an apoptotic pathway through activation of caspase-3 and may involve transcriptional down-regulation of the gadd45beta gene, an anti-apoptotic NF-kappaB target. In view of our results, it seems likely that NF-kappaB may participate in normal hair cell function.

| S-EPMC2504590 | biostudies-literature

Ionizing radiation-induced NF-kappaB activation requires PARP-1 function to confer radioresistance.

Project description:Recent reports implicate poly(ADP-ribose) polymerase-1 (PARP-1) in the activation of nuclear factor kappaB (NF-kappaB). We investigated the role of PARP-1 in the NF-kappaB signalling cascade induced by ionizing radiation (IR). AG14361, a potent PARP-1 inhibitor, was used in two breast cancer cell lines expressing different levels of constitutively activated NF-kappaB, as well as mouse embryonic fibroblasts (MEFs) proficient or deficient for PARP-1 or NF-kappaB p65. In the breast cancer cell lines, AG14361 had no effect on IR-induced degradation of IkappaBalpha or nuclear translocation of p50 or p65. However, AG14361 inhibited IR-induced NF-kappaB-dependent transcription of a luciferase reporter gene. Similarly, in PARP-1(-/-) MEFs, IR-induced nuclear translocation of p50 and p65 was normal, but kappaB binding and transcriptional activation did not occur. AG14361 sensitized both breast cancer cell lines to IR-induced cell killing, inhibited IR-induced XIAP expression and increased caspase-3 activity. However, AG14361 failed to increase IR-induced caspase activity when p65 was knocked down by siRNA. Consistent with this, AG14361 sensitized p65(+/+) but not p65(-/-) MEFs to IR. We conclude that PARP-1 activity is essential in the upstream regulation of IR-induced NF-kappaB activation. These data indicate that potentiation of IR-induced cytotoxicity by AG14361 is mediated solely by inhibition of NF-kappaB activation.

| S-EPMC2642763 | biostudies-literature

Helicobacter pylori proinflammatory protein up-regulates NF-kappaB as a cell-translocating Ser/Thr kinase.

Project description:There has been considerable interest in virulence genes in the plasticity region of Helicobacter pylori, but little is known about many of these genes. JHP940, one of the virulence factors encoded by the plasticity region of H. pylori strain J99, is a proinflammatory protein that induces tumor necrosis factor-alpha and interleukin-8 secretion as well as enhanced translocation of NF-?B in cultured macrophages. Here we have characterized the structure and function of JHP940 to provide the framework for better understanding its role in inflammation by H. pylori. Our work demonstrates that JHP940 is the first example of a eukaryotic-type Ser/Thr kinase from H. pylori. We show that JHP940 is catalytically active as a protein kinase and translocates into cultured human cells. Furthermore, the kinase activity is indispensable for indirectly up-regulating phosphorylation of NF-?B p65 at Ser276. Our results, taken together, contribute significantly to understanding the molecular basis of the role of JHP940 in inflammation and subsequent pathogenesis caused by H. pylori. We propose to rename the jhp940 gene as ctkA (cell translocating kinase A).

| S-EPMC3003084 | biostudies-literature

Blockage of NF-kappaB by IKKbeta- or RelA-siRNA rather than the NF-kappaB super-suppressor IkappaBalpha mutant potentiates adriamycin-induced cytotoxicity in lung cancer cells.

Project description:Ambiguous roles of genotoxic anticancer therapeutic-induced NF-kappaB activation in regulating gene expression (activation or suppression) and apoptosis (anti- or pro-apoptosis) have recently been suggested. In order to clarify this controversy and determine the usefulness of NF-kappaB blockage for sensitizing anticancer therapy, we have systematically investigated the effect of distinct NF-kappaB-blocking approaches on lung cancer cells' responses to Adriamycin-induced cytotoxicity. The results show that Adriamycin-induced NF-kappaB activation functions as a transcriptional activator triggering the expression of anti-apoptotic genes. Blocking NF-kappaB with IKKbeta- or RelA siRNA substantially sensitized Adriamycin-induced cytotoxicity, suggesting that the NF-kappaB pathway could be a target for sensitizing lung cancer cells to Adriamycin's anticancer effect. Surprisingly, although it effectively blocks NF-kappaB activation, the IkappaBalpha super-suppressor (IkappaBalphaAA) antagonized Adriamycin-induced cell death. Additionally, the induction of death receptor 5 (DR5), which contributes to Adriamycin-induced cytotoxicity, was not affected by NF-kappaB blockage. Thus, our results suggest that Adriamycin-induced NF-kappaB is a transcriptional activator that protects lung cancer cells against apoptosis, and IKKbeta- or RelA siRNA rather than IkappaBalphaAA is an appropriate NF-kappaB blocking approach for sensitizing lung cancer cells to Adriamycin-induced cytotoxicity.

| S-EPMC2688738 | biostudies-literature

The ubiquitin-editing enzyme A20 requires RNF11 to downregulate NF-kappaB signalling.

Project description:The RING domain protein RNF11 is overexpressed in breast cancers and promotes tumour growth factor-beta (TGF-beta) signalling. RNF11 has been proposed to regulate TGF-beta signalling by interacting with HECT- and SCF-type E3 ligases; however, the role of RNF11 in other signalling pathways is poorly understood. Here, we demonstrate a novel function of RNF11 as a negative regulator of NF-kappaB and jun N-terminal kinase (JNK) signalling pathways. Knockdown of RNF11 with siRNA resulted in persistent tumour necrosis factor (TNF)- and lipopolysaccharide (LPS)-mediated NF-kappaB and JNK signalling. RNF11 interacted with the NF-kappaB inhibitor A20 and its regulatory protein TAX1BP1 in a stimulus-dependent manner. RNF11 negatively regulated RIP1 and TRAF6 ubiquitination upon stimulation with TNF and LPS, respectively. Furthermore, RNF11 was required for A20 to interact with and inactivate RIP1 to inhibit TNF-mediated NF-kappaB activation. Our studies reveal that RNF11, together with TAX1BP1 and Itch, is an essential component of an A20 ubiquitin-editing protein complex that ensures transient activation of inflammatory signalling pathways.

| S-EPMC2657574 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data