International immunopharmacology
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Int. Immunopharmacol. · Nov 2013
ReviewNeutrophil cell surface receptors and their intracellular signal transduction pathways.
Neutrophils play a critical role in the host defense against bacterial and fungal infections, but their inappropriate activation also contributes to tissue damage during autoimmune and inflammatory diseases. Neutrophils express a large number of cell surface receptors for the recognition of pathogen invasion and the inflammatory environment. ⋯ Here we provide an overview of the receptors involved in neutrophil activation and the intracellular signal transduction processes they trigger. This knowledge is crucial for understanding how neutrophils participate in antimicrobial host defense and inflammatory tissue damage and may also point to possible future targets of the pharmacological therapy of neutrophil-mediated autoimmune or inflammatory diseases.
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Int. Immunopharmacol. · Nov 2013
Increased expression of heat shock protein 70 in chronic obstructive pulmonary disease.
Heat shock protein 70 (HSP70) plays a critical role in the process of inflammation and innate immunity response under environmental stress. ⋯ Our study clarified that increased expression of HSP70 is closely related to COPD disease severity and smoking status. Extracellular HSP70 regulated chemokine productions and EGFR phosphorylation and plays an important role in the CSE-induced inflammatory and innate immunity responses in bronchial epithelia cells.
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Int. Immunopharmacol. · Nov 2013
A tetrahydroisoquinoline alkaloid THI-28 reduces LPS-induced HMGB1 and diminishes organ injury in septic mice through p38 and PI3K/Nrf2/HO-1 signals.
We investigated whether THI-28 [1-4-(hydroxyphenylethyl)-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline] inhibits release of high mobility group box 1 (HMGB1), a late phase cytokine of sepsis, in lipopolysaccharide (LPS)-stimulated RAW264.7 cells through heme oxygenase (HO)-1 induction so that it shows beneficial effects in the cecal ligation and puncture (CLP)-induced septic mouse model. Silencing of target genes (HO-1, Nrf-2) or pharmacological signal inhibitors was exploited to investigate the HO-1 induction by THI-28. The dependency of HO-1 by THI-28 on survival rate and circulating HMGB1 level was tested in CLP-induced septic mice. ⋯ Decreasing p-IκBα by THI-28 resulted in inhibition of NF-κB activity which was reversed by silencing HO-1 RNA in LPS-activated cells. Most importantly, increased survival and reduction of liver and kidney injury and circulating HMGB1 levels by THI-28 in CLP-mice were reversed by ZnPPIX, HO-1 inhibitor. Taken together, these findings suggest that the novel compound THI-28 induces the expression of HO-1 by activating the PI3K and p38 MAPK pathways and suppressed HMGB1 and iNOS production in LPS-treated macrophages and septic mice, which may be useful in treating organ injury due to sepsis.
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Int. Immunopharmacol. · Nov 2013
Ulinastatin is a novel candidate drug for sepsis and secondary acute lung injury, evidence from an optimized CLP rat model.
Ulinastatin is a potent multivalent serine protease inhibitor, which was recently found with therapeutic potentials in treating sepsis, and the most life-threatening complication of critically ill population. However, the pharmacological features and possible mechanisms need to be further elucidated in reliable and clinical relevant sepsis models. As known, sepsis induced by surgery of cecal ligation and puncture (CLP) is widely accepted as the gold standard animal model, but the inconsistency of outcomes is the most obvious problem. ⋯ Ulinastatin was also found to be effective in ameliorating sepsis-related ALI, a syndrome most frequent and fatal in sepsis. The molecular mechanism investigation showed that ulinastatin's protection against ALI was probably related to the down-regulation of NF-κB activity and inhibition of TNF-α, IL-6 and elastase expressions in the lung tissue. In conclusion, based on a successful establishment of optimized rat CLP model ulinastatin is proved to be an effective candidate for sepsis treatment, due to its anti-inflammation and anti-protease activities that ameliorate systemic disorders, prevent organ injuries and thus improve the survival outcomes of sepsis in animals.
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Int. Immunopharmacol. · Nov 2013
The p38 MAPK inhibitor JLU1124 inhibits the inflammatory response induced by lipopolysaccharide through the MAPK-NF-κB pathway in RAW264.7 macrophages.
Our previous results showed that JLU1124 is a potent p38 mitogen-activated protein kinase (MAPK) inhibitor. Compared to the classic p38 MAPK inhibitor SB203580, JLU1124 inhibits p38 phosphorylation at low concentrations without cytotoxicity on cells. p38 MAPK is a known target for inflammation treatment. Thus, we became interested in whether JLU1124 has anti-inflammatory effects. ⋯ Furthermore, our results showed that JLU1124 inhibits NF-κB inhibitor (IκB)α phosphorylation, nuclear translocation and transcriptional activity of NF-κB induced by LPS which may be through suppression of Akt phosphorylation. In conclusion, our study indicates that JLU1124 efficiently inhibits p38 phosphorylation and has anti-inflammatory effects in LPS-treated RAW264.7 macrophages. The anti-inflammatory mechanism of JLU1124 is mainly through decreasing Akt phosphorylation and inhibiting IκBα phosphorylation, thus suppressing NF-κB activation and nuclear translocation.