Stearoyl lysophosphatidylcholine prevents lipopolysaccharide-induced extracellular release of high mobility group box-1 through AMP-activated protein kinase activation.

Previous studies have suggested that stearoyl lysophosphatidlycholine (LPC) protects against lethal experimental sepsis by inhibiting lipopolysaccharide (LPS)-induced extracellular release of high-mobility group box 1 (HMGB1). However, limited information exists on the mechanism by which stearoyl-LPC suppresses the extracellular release of HMGB1 in monocyte/macrophages stimulated with LPS. In this study, we found that stearoyl-LPC increased the phosphorylation of AMP-activated protein kinase (AMPK) in macrophages. Exposure of LPS-stimulated macrophages to stearoyl-LPC decreased the extracellular release of HMGB1 in peritoneal macrophages, which were inhibited by the AMPK inhibitor, compound C. In addition, stearoyl-LPC-mediated suppression of HMGB1 release was abolished by siRNA-mediated knock-down of AMPKα1. Stearoyl-LPC increased the phosphorylation of acetyl-CoA carboxylase (ACC), a downstream target of activated AMPK, in mice lungs and decreased HMGB1 levels in bronchoalveolar lavage fluids in mice administered LPS. These results reveal a novel mechanism by which stearoyl-LPC regulates LPS-mediated cellular translocation of HMGB1.

Sauchinone, a lignan from Saururus chinensis, attenuates neutrophil pro-inflammatory activity and acute lung injury.

Previous studies have shown that sauchinone modulates the expression of inflammatory mediators through mitogen-activated protein kinase (MAPK) pathways in various cell types. However, little information exists about the effect of sauchinone on neutrophils, which play a crucial role in inflammatory process such as acute lung injury (ALI). We found that sauchinone decreased the phosphorylation of p38 MAPK in lipopolysaccharide (LPS)-stimulated murine bone marrow neutrophils, but not ERK1/2 and JNK. Exposure of LPS-stimulated neutrophils to sauchinone or SB203580, a p38 inhibitor, diminished production of tumor necrosis factor (TNF)-α and macrophage inflammatory protein (MIP)-2 compared to neutrophils cultured with LPS. Treatment with sauchinone decreased the level of phosphorylated ribosomal protein S6 (rpS6) in LPS-stimulated neutrophils. Systemic administration of sauchinone to mice led to reduced levels of phosphorylation of p38 and rpS6 in mice lungs given LPS, decreased TNF-α and MIP-2 production in bronchoalveolar lavage fluid, and also diminished the severity of LPS-induced lung injury, as determined by reduced neutrophil accumulation in the lungs, wet/dry weight ratio, and histological analysis. These results suggest that sauchinone diminishes LPS-induced neutrophil activation and ALI.

Urinary trypsin inhibitor attenuates lipopolysaccharide-induced neutrophil activation.

BACKGROUND: Urinary trypsin inhibitor (UTI), which is speculated to have anti-inflammatory effects, is one of serine protease inhibitors found in human urine and blood. The present study was conducted to clarify the effect of urinary trypsin inhibitor (UTI) on human neutrophil activation and its intracellular signaling mechanism in vitro. METHODS: To assess the possible interactions between UTI and lipopolysaccharide (LPS) in neutrophil activation, neutrophils from human blood were incubated with varying concentrations of UTI (1, 10, 100, 1,000 and 10,000 U/ml) plus LPS (100 ng/ml) or LPS alone in 24-well plates (5 × 10(6) cells/well). We measured protein levels for interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α) using enzyme-linked immunosorbent assay (ELISA) kits after 4 hours of incubation period. To elucidate the intracellular signaling pathway, we also measured the levels of phosphorylation of p38, ERK1/2 and JNK via Western blot analysis. Moreover, the nuclear levels of nuclear factor-kappa B (NF-κB) were determined with electrophoretic mobility shift assays (EMSA). RESULTS: UTI decreased the expression of inflammatory cytokines, including TNF-α and IL-6, and activation of intracellular signaling pathways, such as JNK, but not P38, ERK1/2 and nuclear translocation of NF-κB. CONCLUSIONS: UTI can attenuate LPS-induced neutrophil responses and may partially contribute to the treatment of neutrophil-mediated inflammatory diseases.

[Effects of NaCl stress on the exogenous gene expression in transgenic poplar plants].

The expressions of BtCry1Ac insect-resistance genes and rhizogenesis genes and their response to NaCl stress were studied using tissue culture plants of high transgenic insect-resistant 'poplar 741' and transpolygenes 741 (insect-resistant genes and T-DNA of Ri plasmid). The results showed that IAA and GA contents increased quickly, plant root number increased and root length reduced after rhizogenesis and hormone synthesis related gene in Ri T-DNA were inserted into the genome of poplar (Figs.2, 3, 8 and 9). Plant height, root number, chlorophyll content, IAA and GA contents decreased gradually with an increase in NaCl stress intensity (Figs.1, 2, 4-6, 8 and 9). Apiece index change extent of transgenic rol gene plant was smaller than transgenic Bt gene plant and non-transgenic plant. Bt toxin protein content of transgenic rol gene plant increased significantly under NaCl stress (Fig.7). Our results indicate that the expressions of the foreign genes changed with the changes of the environmental conditions.