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Lipopolysaccharide (LPS) is an endotoxin involved in a number of acute and chronic inflammatory syndromes. Although LPS‐induced signalling has been extensively studied, there are still mysteries remaining to be revealed. In the current study, we used high‐throughput phosphoproteomics to profile LPS‐initiated signalling and aimed to find novel mediators. A total of 448 phosphoproteins with 765 phosphorylation sites were identified, and we further validated that the phosphorylation of MARK2 on T208 was important for the regulation on LPS‐induced CXCL15 (human IL‐8 homolog), IL‐1β, IL‐6 and TNF‐α release, in which LKB1 had a significant contribution. In summary, induction of cytokines by LPS in mouse macrophage is regulated by LKB1‐MARK2 signals. Our study provides new clues for further exploring the underlying mechanisms of LPS‐induced diseases, and new therapeutic approaches concerning bacterial infection may be derived from these findings.

A novel and simple method to form water-dispersed magnetic nanoparticles was successfully developed through glucosaminic acid-surface modification of iron oxide nanoparticles. The resultant glucosaminic acid-modified magnetic nanoparticles (GA-MNPs) had not only good uniformity in spherical shape with diameter of about 10-13 nm, but also possessed excellent water-dispersity and stability. In cell culture experiments, the internalization of GA-MNPs into different kinds of cells was observed over a 5-day period. The results indicated that the internalization of GA-MNPs into mouse macrophage cells and mouse embryonic fibroblast cells was not observed after 40 h of culturing. However, the GA-MNPs were internalized quickly into cancer cells after just 24 h of culturing. TEM images of the GA-MNPs uptake in ECA-109 cells were used to study the internalization mechanisms of GA-MNPs and their distribution in ECA-109 cells. Additionally, a water-dispersed magnetic capture probe was prepared by immobilization of oligonucleotides onto GA-MNPs, and the probe was used for detection and separation of their complementary oligonucleotides sequence.

Trimethylamine N-oxide (TMAO) is a common metabolite of the L-carnitine, recently linked to atherosclerosis initiation and progression in mice. TMAO was associated with a modest increase in the RNA...

Increased plasma levels of human lipoprotein(a) (Lp(a)) are highly correlated with the development of atherosclerotic lesions. During our study, we investigated the effects of native and hypochlorite oxidized lipoprotein(a) (ox-Lp(a)) on nitric oxide production by the inducible nitric oxide synthase (iNOS) in lipopolysaccharide/interferon stimulated mouse macrophages (J774A.1). Ox-Lp(a) (0–2 μg/ml) induces a dose dependent inhibition of inducible nitric oxide synthesis. iNOS protein expression showed a dose dependent reduction as revealed by immunoblotting when cells were incubated with increasing amounts of ox-Lp(a). Ox-Lp(a) decreases iNOS mRNA synthesis as shown by reverse transcription-polymerase chain reaction. Ox-Lp(a) induced iNOS inhibition might contribute to the development of atherosclerotic lesions by reducing the anti-atherogenic effects of nitric oxide.

Solid Phase Peptide Synthetic Approaches to Mouse Macrophage Migration Inhibitory Factor (mMIF): Synthesis of Peptide Fragments for a Convergent Solid Phase Peptide Synthetic Strategy For a convergent solid phase synthesis of mMIF, the sequence was separated into 10 fragments leading C-terminal Pro and Gly positions. Racemization of Cys(Trt) was observed during the in situ activation process using TBTU/DIEA in stepwise SPPS and also during a fragment condensation of the protected fragment mMIF(53–69) with the MIF(62–69) peptide resin. To overcome “difficult sequence” problems arising during several stepwise syntheses different coupling methods were performed.

All newly synthesized compounds are evaluated for their pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) for the mouse macrophage cell line J774.

The structural requirements of sulfonamide-based hydroxamic acid 1 for inhibition of macrophage metalloelastase (MME) were investigated. A short aliphatic group at the R2 position together with an aromatic group at the R3 position significantly improved the inhibitory activity. Compounds 32, 34, and 40 were the most potent inhibitors of MME with IC50 values between 5 and 6 nM.

The present investigation was undertaken to study the potential role of extracellular calcium on the release of arachidonic acid from mouse peritoneal macrophages. Both in phorbol ester-treated and in Ca2+-depleted cells, a rapid release of arachidonic acid was seen in direct response to added Ca2+. The response was directly dependent on the extracellular Ca2+concentration, with a Ca2+ threshold of 100 nM. These results support the notion that arachidonic acid release in macrophages is functionally coupled to influx of external calcium.

A method is described for the analysis of [3H]-thymidine incorporation in microtitre cultures of bone marrow-derived mouse macrophage responding to macrophage colony-stimulating factor (CSF-1). [3H]-thymidine incorporation depends on cell density, culture medium, and the concentration of CSF-1 and serum, but is independent of Ca2+. Bone marrow-derived macrophages are strongly adherent, but adherence can be dissociated from [3H]-thymidine incorporation.