Project description:LPS (10 μg/50 μl PBS; E. coli Serotype 055:B5, Sigma-Aldrich) was administered onto the nares. Baseline levels of genes in mice treated with vehicle (Hanks Balanced Salt solution (HBSS) and PBS), Intranasal S100s (10 μg/50 μl HBSS) were given 2 h before LPS; control mice received equal volumes of PBS and HBSS. Mice were sacrificed 4 h post LPS inhalation. Expression of inflammatory genes was evaluated with the RT-qPCR array. Relative quantities of mRNA in duplicate samples were obtained using the LightCycler® 480 Software 1.5 and the Efficiency-Method.
Project description:Recombinant-murine S100A8 were used at 10 mg/50 ml in Hanks Balanced Salt solution (HBSS) or control HBSS administered onto the nares of BALB/C mice. To assess direct effects, mice were sacrificed 1, 4, 6, or 12 h post-inhalation of S100A8. Because S100A8 is reported to initiate proinflammatory responses by ligating TLR4 and/or RAGE, a quantitative PCR array was developed to analyze 49 genes, selected to reflect potential acute inflammatory changes induced by ligation of these receptors. Expression of inflammatory genes was evaluated with the RT-qPCR array. Relative quantities of mRNA in duplicate samples were obtained using the LightCycler® 480 Software 1.5 and the Efficiency-Method.
Project description:Recombinant-murine S100A9 were used at 10 mg/50 ml in Hanks Balanced Salt solution (HBSS) or control HBSS administered onto the nares of BALB/C mice. To assess direct effects, mice were sacrificed 1, 4, 6, or 12 h post-inhalation of S100A9. Because S100A9 is reported to initiate proinflammatory responses by ligating TLR4 and/or RAGE, a quantitative PCR array was developed to analyze 49 genes, selected to reflect potential acute inflammatory changes induced by ligation of these receptors. Expression of inflammatory genes was evaluated with the RT-qPCR array. Relative quantities of mRNA in duplicate samples were obtained using the LightCycler® 480 Software 1.5 and the Efficiency-Method.
Project description:Recombinant-murine S100A8 and the corresponding Cys42 to Ala42 mutant were used at 10 mg/50 ml HBSS administered onto the nares of BALB/C mice. To assess direct effects, mice were sacrificed 1, 4, 6, 12 or 20 h post-inhalation of S100A8 or 12 and 20 h post-inhalation of Ala42S100A8. For comparison with Dex inhalation (used at 10 mg/50 ml HBSS), lungs were harvested 6 and 12 h post administration. Because S100A8 is reported to initiate proinflammatory responses by ligating TLR4 and/or RAGE, a quantitative PCR array was developed to analyse 63 genes, selected to reflect potential acute inflammatory changes induced by ligation of these receptors. Expression of inflammatory genes was evaluated with the RT-qPCR array. Relative quantities of mRNA in duplicate samples were obtained using the LightCyclerM-BM-. 480 Software 1.5 and the Efficiency-Method.
Project description:Recombinant-murine S100A8 and the corresponding Cys42 to Ala42 mutant were used at 10 mg/50 ml HBSS administered onto the nares of BALB/C mice. To assess direct effects, mice were sacrificed 1, 4, 6, 12 or 20 h post-inhalation of S100A8 or 12 and 20 h post-inhalation of Ala42S100A8. For comparison with Dex inhalation (used at 10 mg/50 ml HBSS), lungs were harvested 6 and 12 h post administration. Because S100A8 is reported to initiate proinflammatory responses by ligating TLR4 and/or RAGE, a quantitative PCR array was developed to analyse 63 genes, selected to reflect potential acute inflammatory changes induced by ligation of these receptors. Expression of inflammatory genes was evaluated with the RT-qPCR array. Relative quantities of mRNA in duplicate samples were obtained using the LightCyclerM-BM-. 480 Software 1.5 and the Efficiency-Method.
Project description:INTRODUCTION: The objective was to evaluate the changes in S100A8 S100A9, and their complex (S100A8/S100A9) in cartilage during the onset of osteoarthritis (OA) as opposed to inflammatory arthritis. METHODS: S100A8 and S100A9 protein localization were determined in antigen-induced inflammatory arthritis in mice, mouse femoral head cartilage explants stimulated with interleukin-1 (IL-1), and in surgically-induced OA in mice. Microarray expression profiling of all S100 proteins in cartilage was evaluated at different times after initiation of degradation in femoral head explant cultures stimulated with IL-1 and surgically-induced OA. The effect of S100A8, S100A9 or the complex on the expression of aggrecan (Acan), collagen II (Col2a1), disintegrin and metalloproteases with thrombospondin motifs (Adamts1, Adamts 4 &Adamts 5), matrix metalloproteases (Mmp1, Mmp3, Mmp13 &Mmp14) and tissue inhibitors of metalloproteinases (Timp1, Timp2 &Timp3), by primary adult ovine articular chondrocytes was determined using real time quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: Stimulation with IL-1 increased chondrocyte S100a8 and S100a9 mRNA and protein levels. There was increased chondrocyte mRNA expression of S100a8 and S100a9 in early but not late mouse OA. However, loss of the S100A8 staining in chondrocytes occurred as mouse OA progressed, in contrast to the positive reactivity for both S100A8 and S100A9 in chondrocytes in inflammatory arthritis in mice. Homodimeric S100A8 and S100A9, but not the heterodimeric complex, significantly upregulated chondrocyte Adamts1, Adamts4 and Adamts 5, Mmp1, Mmp3 and Mmp13 gene expression, while collagen II and aggrecan mRNAs were significantly decreased. CONCLUSIONS: Chondrocyte derived S100A8 and S100A9 may have a sustained role in cartilage degradation in inflammatory arthritis. In contrast, while these proteins may have a role in initiating early cartilage degradation in OA by upregulating MMPs and aggrecanases, their reduced expression in late stages of OA suggests they do not have an ongoing role in cartilage degradation in this non-inflammatory arthropathy.
Project description:Alarmins S100A8 and S100A9 are endogenous molecules released in response to environmental triggers and cellular damage. They are constitutively expressed in immune cells such as monocytes and neutrophils and their expression is upregulated under inflammatory conditions. The molecular mechanisms that regulate inflammatory pathways in tendinopathy are largely unknown therefore identifying early immune effectors is essential to understanding the pathology. Based on our previous investigations highlighting tendinopathy as an alarmin mediated pathology we sought evidence of S100A8 & A9 expression in a human model of tendinopathy and thereafter, to explore mechanisms whereby S100 proteins may regulate release of inflammatory mediators and matrix synthesis in human tenocytes. Immunohistochemistry and quantitative RT-PCR showed S100A8 & A9 expression was significantly upregulated in tendinopathic tissue compared with control. Furthermore, treating primary human tenocytes with exogenous S100A8 & A9 significantly increased protein release of IL-6, IL-8, CCL2, CCL20 and CXCL10; however, no alterations in genes associated with matrix remodelling were observed at a transcript level. We propose S100A8 & A9 participate in early pathology by modulating the stromal microenvironment and influencing the inflammatory profile observed in tendinopathy. S100A8 and S100A9 may participate in a positive feedback mechanism involving enhanced leukocyte recruitment and release of pro-inflammatory cytokines from tenocytes that perpetuates the inflammatory response within the tendon in the early stages of disease.
Project description:S100A8 and S100A9 are myeloid cell-derived proteins that are elevated in several types of inflammatory lung disorders. Pro- and anti-inflammatory properties are reported and these proteins are proposed to activate TLR4. S100A8 and S100A9 can function separately, likely through distinct receptors but a systematic comparison of their effects in vivo are limited. Here we assess inflammation in murine lung following S100A9 and S100A8/A9 inhalation. Unlike S100A8, S100A9 promoted mild neutrophil and lymphocyte influx, possibly mediated in part, by increased mast cell degranulation and selective upregulation of some chemokine genes, particularly CXCL-10. S100 proteins did not significantly induce proinflammatory mediators including TNF-α, interleukin-1β (IL-1β), IL-6 or serum amyloid A3 (SAA3). In contrast to S100A8, neither preparation induced S100A8 or IL-10 mRNA/protein in airway epithelial cells, or in tracheal epithelial cells in vitro. Like S100A8, S100A9 and S100A8/A9 reduced neutrophil influx in acute lung injury provoked by lipopolysaccharide (LPS) challenge but were somewhat less inhibitory, possibly because of differential effects on expression of some chemokines, IL-1β, SAA3 and IL-10. Novel common pathways including increased induction of an NAD+-dependent protein deacetylase sirtuin-1 that may reduce NF-κB signalling, and increased STAT3 activation may reduce LPS activation. Results suggest a role for these proteins in normal homeostasis and protective mechanisms in the lung.