304 research outputs found
The role of interleukin-1 receptors in brain cell signalling
IL-1α and IL-1β are two IL-1 agonists which signals at the same receptor complex composed of IL-1R1/IL-1RAcP. However, IL-1α and IL-1β exert differential actions. A recent CNS-specific IL-1 receptor accessory protein, called IL-1RAcPb, has been characterised but its actions are unknown. In T cell line, over expression of IL-1RAcPb negatively regulate IL-1 action (Smith et al, 2009), but over-expression of IL-1RAcPb in HEK cell line induces IL-1 signaling (Lu et al, 2008). The role of IL-1RAcPb has not been studied in primary cells. The aim of this project was to investigate the role of IL-1RAcPb in IL-1-induced actions in neurones and glia, and to determine IL-1α and IL-1β differential actions in these two cell types. The role of IL-1RAcPb in IL-1-induced protein expression and IL 1α and IL-1β differential effects were investigated by treating WT and IL 1RAcPb-/- neurones and glia with IL-1α or IL-1β in the presence or absence of IL-1RA for 24 h followed by assessment of IL-6 induction by ELISA. The mechanism of IL-1RAcPb actions were studied by examining the effects of IL-1α or IL-1β on p38, ERK1/2 and Src kinase activation in neurones and glia by Western blot analysis. SB203580 (p38 inhibitor), UO126 (ERK1/2 inhibitor), and PP2 (Src kinase inhibitor) were used to determine the contribution of p38, ERK1/2 and Src kinase activation to IL-1-induced IL-6 synthesis in neuronal cultures. In WT neurones, IL-1α and IL-1β were equipotent at inducing IL-6 synthesis and p38 activation, whilst both ligands failed to induce ERK1/2 or Src kinase activation. In IL-1RAcPb-/- neurones, IL-1α and IL-1β induced similar levels of IL-6, but IL-1β was more potent than IL-1α at inducing p38 activation. IL-1α-induced p38 activation was reduced in IL-1RAcPb-/- neurones compared to WT neurones. In contrast to WT neurones, ERK1/2 was activated in IL-1RAcPb-/- neurones in response to IL-1α, whilst Src kinase was not activated by IL-1α or IL 1β. IL-1-induced IL-6 synthesis was abolished by IL-1RA, SB203580, UO126 and PP2. Interestingly PP2, a specific Src kinase inhibitor also partially inhibited basal ERK1/2 activity. In WT glial cells, IL-1α was more potent than IL-1β at inducing IL-6 synthesis but both cytokines induced ERK1/2 activation with equal potency. In IL-1RAcPb-/- glia, IL-1α and IL-1β were equally potent at inducing IL-6 synthesis and ERK1/2 activation. However, IL-α-induced-IL-6 synthesis was reduced in IL 1RAcPb-/- glia compared to WT glia. In both WT and IL-1RAcPb-/- glia, IL-1α and IL-1β induced p38 activation but not Src kinase activation . In conclusion, this study showed that in neurones, IL-1RAcPb may contribute to IL-1α-induced p38 activation but negatively regulates IL-1-induced ERK1/2 activation, therefore IL-1RAcPb may have specific effects on different signalling pathways. The effect of IL-1RAcPb could also be cell specific, as IL 1RAcPb contributed to IL-1α-induced p38 signalling in neurones but IL-6 production in glia. The role of IL-1RAcPb remains largely unknown and more investigations are required to elucidate its role in IL-1 signalling in the brain.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
The chemical and computational biology of inflammation
Non-communicable diseases (NCD) such as cancer, heart disease and cerebrovascular injury are dependent on or aggravated by inflammation. Their prevention and treatment is arguably one of the greatest challenges to medicine in the 21st century. The pleiotropic, proinflammatory cytokine; interleukin-l beta (IL-l~) is a primary, causative messenger of inflammation. Lipopolysaccharide (LPS) induction ofIL-l~ expression via toll-like receptor 4 (TLR4) in myeloid cells is a robust experimental model of inflammation and is driven in large part via p38-MAPK and NF-KB signaling networks. The control of signaling networks involved in IL-l~ expression is distributed and highly complex, so to perturb intracellular networks effectively it is often necessary to modulate several steps simultaneously. However, the number of possible permutations for intervention leads to a combinatorial explosion in the experiments that would have to be performed in a complete analysis. We used a multi-objective evolutionary algorithm (EA) to optimise reagent combinations from a dynamic chemical library of 33 compounds with established or predicted targets in the regulatory network controlling IL-l ~ expression. The EA converged on excellent solutions within 11 generations during which we studied just 550 combinations out of the potential search space of - 9 billion. The top five reagents with the greatest contribution to combinatorial effects throughout the EA were then optimised pair- wise with respect to their concentrations, using an adaptive, dose matrix search protocol. A p38a MAPK inhibitor (30 ± 10% inhibition alone) with either an inhibitor of IKB kinase (12 ± 9 % inhibition alone) or a chelator of poorly liganded iron (19 ± 8 % inhibition alone) yielded synergistic inhibition (59 ± 5 % and 59 ± 4 % respectively, n=7, p≥O.04 for both combinations, tested by one way ANOVA with Tukey's multiple test correction) of macrophage IL-l~ expression. Utilising the above data, in conjunction with the literature, an LPS-directed transcriptional map of IL-l ~ expression was constructed. Transcription factors (TF) targeted by the signaling networks coalesce at precise nucleotide binding elements within the IL-l~ regulatory DNA. Constitutive binding of PU.l and C/EBr-~ TF's are obligate for IL-l~ expression. The findings in this thesis suggest that PU.l and C/EBP-~ TF's form scaffolds facilitating dynamic control exerted by other TF's, as exemplified by c-Jun. Similarly, evidence is emerging that epigenetic factors, such as the hetero-euchromatin balance, are also important in the relative transcriptional efficacy in different cell types. Evolutionary searches provide a powerful and general approach to the discovery of novel combinations of pharmacological agents with potentially greater therapeutic indices than those of single drugs. Similarly, construction of signaling network maps aid the elucidation of pharmacological mechanism and are mandatory precursors to the development of dynamic models. The symbiosis of both approaches has provided further insight into the mechanisms responsible for IL-lβ expression, and reported here provide a - platform for further developments in understanding NCD's dependent on or aggravated by inflammation.EThOS - Electronic Theses Online ServiceBBSRCEPSRCGBUnited Kingdo
Evaluation of the CHUMS Child Bereavement Group : A Pilot Study Examining Statistical and Clinical Change
This is an Accepted Manuscript of an article published by Taylor & Francis in Death Studies on 7 February 2015, available online at: http://dx.doi.org/10.1080/07481187.2014.913085.This article describes the largest evaluation of a UK child bereavement service to date. Change was assessed using conventional statistical tests as well as clinical significance methodology. Consistent with the fact that the intervention was offered on a universal, preventative basis, bereaved young people experienced a statistically significant, small to medium-sized decrease in symptoms over time. This change was equivalent across child age and gender. Type of bereavement had a slight impact on change when rated by parents. Potential clinical implications are highlighted, and various limitations are discussed that we hope to address using an experimental design in future researchPeer reviewedFinal Accepted Versio
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