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Ihekwaba2004_NFkB_Sensitivity

ABSTRACT: This a model from the article: Sensitivity analysis of parameters controlling oscillatory signalling in the NF-kappaB pathway: the roles of IKK and IkappaBalpha. Ihekwaba AE, Broomhead DS, Grimley RL, Benson N, Kell DB Syst Biol (Stevenage) [2004 Jun;1(1):93-103 17052119 , Abstract: Analysis of cellular signalling interactions is expected to create an enormous informatics challenge, perhaps even greater than that of analysing the genome. A key step in the evolution towards a more quantitative understanding of signalling is to specify explicitly the kinetics of all chemical reaction steps in a pathway. We have reconstructed a model of the nuclear factor, kappaB (NF-kappaB) signalling pathway, containing 64 parameters and 26 variables, including steps in which the activation of the NF-kappaB transcription factor is intimately associated with the phosphorylation and ubiquitination of its inhibitor kappaB by a membrane-associated kinase, and its translocation from the cytoplasm to the nucleus. We apply sensitivity analysis to the model. This identifies those parameters in this (IkappaB)/NF-kappaB signalling system (containing only induced IkappaBalpha isoform) that most affect the oscillatory concentration of nuclear NF-kappaB (in terms of both period and amplitude). The intention is to provide guidance on which proteins are likely to be most significant as drug targets or should be exploited for further, more detailed experiments. The sensitivity coefficients were found to be strongly dependent upon the magnitude of the parameter change studied, indicating the highly non-linear nature of the system. Of the 64 parameters in the model, only eight to nine exerted a major control on nuclear NF-kappaB oscillations, and each of these involved as reaction participants either the IkappaB kinase (IKK) or IkappaBalpha, directly. This means that the dominant dynamics of the pathway can be reflected, in addition to that of nuclear NF-kappaB itself, by just two of the other pathway variables. This is conveniently observed in a phase-plane plot. To the extent possible under law, all copyright and related or neighbouring rights to this encoded model have been dedicated to the public domain worldwide. Please refer to CC0 Public Domain Dedication for more information. In summary, you are entitled to use this encoded model in absolutely any manner you deem suitable, verbatim, or with modification, alone or embedded it in a larger context, redistribute it, commercially or not, in a restricted way or not. To cite BioModels Database, please use: Li C, Donizelli M, Rodriguez N, Dharuri H, Endler L, Chelliah V, Li L, He E, Henry A, Stefan MI, Snoep JL, Hucka M, Le Novère N, Laibe C (2010) BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models. BMC Syst Biol., 4:92.

SUBMITTER: Lukas Endler

PROVIDER: BIOMD0000000230 | BioModels | 2009-08-19

REPOSITORIES: BioModels

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Sensitivity analysis of parameters controlling oscillatory signalling in the NF-kappaB pathway: the roles of IKK and IkappaBalpha.

Ihekwaba A E C AE Broomhead D S DS Grimley R L RL Benson N N Kell D B DB

Systems biology 20040601 1

Analysis of cellular signalling interactions is expected to create an enormous informatics challenge, perhaps even greater than that of analysing the genome. A key step in the evolution towards a more quantitative understanding of signalling is to specify explicitly the kinetics of all chemical reaction steps in a pathway. We have reconstructed a model of the nuclear factor, kappaB (NF-kappaB) signalling pathway, containing 64 parameters and 26 variables, including steps in which the activation ...[more]

PMID: 17052119

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Project description:Mitochondrial DNA-depleted human skin fibroblasts (HSF rho0) with suppressed oxidative phosphorylation were characterized by significant changes in the expression of 2100 nuclear genes, encoding numerous protein classes, in NF-kappaB and STAT3 signaling pathways and by decreased activity of the mitochondrial death pathway, compared to the parent rho+ HSF. In contrast, the extrinsic TRAIL/TRAIL-Receptor-mediated death pathway remained highly active, and exogenous TRAIL induced higher levels of apoptosis in rho0 cells compared to rho+ HSF. Global gene expression analysis using microarray and quantitative RT-PCR demonstrated that expression levels of many growth factors and their adaptor proteins (FGF13, HGF, IGFBP4, IGFBP6, IGFL2), cytokines (IL6, IL17B, IL18, IL19, IL28B) and cytokine receptors (IL1R1, IL21R, IL31RA) were substantially decreased after mitochondrial depletion. Some of these genes were targets of NF-kappaB and STAT3, and their protein products could regulate the STAT3 signaling pathway. Alpha-irradiation induced expression of several NF-kappaB/STAT3 target genes, including IL1A, IL1B, IL6, PTGS2/COX2 and MMP12, in rho+ HSF, but this response was substantially decreased in rho0 HSF. Suppression of the IKK-NF-kappaB pathway by the small molecular inhibitor BMS-345541 and of the JAK2-STAT3 pathway by AG490 dramatically increased TRAIL-induced apoptosis in the control and irradiated rho+ HSF. Inhibitory antibodies against IL6, the main activator of JAK2-STAT3 pathway, added into the cell media, also increased TRAIL-induced apoptosis in rho+ HSF. However, NF-kappaB activation was partially lost in mitochondrial DNA-depleted HSF resulting in downregulation of the basal or radiation-induced expression of numerous NF-kappaB targets, further suppressing IL6-JAK2-STAT3, that in concert with NF-kappaB, regulated protection against TRAIL-induced apoptosis. There are 12 total samples, 3 biological replicates each of HSF rho+ and rho0 cells that were not irradiated (control=C) or irradiated (alpha=A). Cells were harvested at 4 hours after treatment.

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Ihekwaba2004_NFkB_Sensitivity

Publications

Sensitivity analysis of parameters controlling oscillatory signalling in the NF-kappaB pathway: the roles of IKK and IkappaBalpha.

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