Different chemical proteomic approaches to identify the targets of lapatinib.

The process of identifying the protein targets and off-targets of a biologically active compound is of great importance in modern drug discovery. Various chemical proteomics approaches have been established for this purpose. To compare the different approaches, and to understand which method would provide the best results, we have chosen the EGFR inhibitor lapatinib as an example molecule.

Immunomodulatory effects of azithromycin on the establishment of lipopolysaccharide tolerance in mice.

Recent reports suggest that azithromycin can shift macrophage polarization towards the alternatively activated M2 phenotype. In order to investigate its immunomodulatory activity in vivo, the influence of azithromycin on survival and cytokine production was assessed in the LPS tolerance model which is characterized by an M2 skewed response. For induction of tolerance, mice received an intraplantar injection of 30 μg LPS, 24 h prior to intravenous challenge with 350 μg LPS.

Impairment of lysosomal functions by azithromycin and chloroquine contributes to anti-inflammatory phenotype.

Azithromycin and chloroquine have been shown to exhibit anti-inflammatory activities in a number of cellular systems, but the mechanisms of these activities have still not been clarified unequivocally. Since both drugs are cationic, accumulate in acidic cellular compartments and bind to phospholipids with a consequent increase in lysosomal pH and induce phospholipidosis, we examined the relevance of these common properties to their anti-inflammatory activities. We compared also these effects with effects of concanamycin A, compound which inhibits acidification of lysosomes.

Anti-inflammatory mechanism of action of azithromycin in LPS-stimulated J774A.1 cells.

Azithromycin is a macrolide antibiotic with well-described anti-inflammatory properties which can be attributed, at least partially, to its action on macrophages. We have previously shown, with 18 different macrolide molecules, that IL-6 and PGE₂ inhibition correlates with macrolide accumulation, as well as with their binding to phospholipids in J774A.1 cells.

Fluorescently labeled macrolides as a tool for monitoring cellular and tissue distribution of azithromycin.

Exceptional therapeutic effects of macrolides in treating various infections and inflammatory conditions can be significantly contributed to their unique pharmacokinetic properties. Macrolides accumulate in cells and tissues, with concentrations usually 10 to more than 100 times higher of those measured in plasma. Intracellular distribution of macrolides has so far been examined using extensive subcellular fractionation techniques, radiolabeled compounds and conventional pharmacokinetic methods.

Tebrophen--an old polyphenol drug with anticancer potential.

In vitro high-throughput screening was carried out in order to detect new activities for old drugs and to select compounds for the drug development process comprising new indications. Tebrophen, a known antiviral drug, was found to inhibit activities on inflammation and cancer related targets. In primary screening this semisynthetic halogenated polyphenol was identified to inhibit the activities of kinases ZAP-70 and Lck (IC₅₀ 0.

Valosin containing protein (VCP) interacts with macrolide antibiotics without mediating their anti-inflammatory activities.

In addition to antibacterial activity, some macrolide antibiotics, such as azithromycin and clarithromycin, also exhibit anti-inflammatory properties in vitro and in vivo, although the targets and mechanism(s) of action remain unknown. The aim of the present study was to identify protein targets of azithromycin and clarithromycin which could potentially explain their anti-inflammatory effects. Using chemical proteomics approach, based on compound-immobilized affinity chromatography, valosin containing protein (VCP) was identified as a potential target of the macrolides.

Intensity of macrolide anti-inflammatory activity in J774A.1 cells positively correlates with cellular accumulation and phospholipidosis.

Some macrolide antibiotics were reported to inhibit interleukin-6 (IL6) and prostaglandin-E2 (PGE(2)) production by bacterial lipopolysaccharide (LPS) stimulated J774A.1 cells. Macrolides are also known to accumulate in cells and some were proven inducers of phospholipidosis.

Azithromycin inhibits macrophage interleukin-1β production through inhibition of activator protein-1 in lipopolysaccharide-induced murine pulmonary neutrophilia.

Macrolide antibiotics, including azithromycin, also possess anti-inflammatory properties. However, the molecular mechanism(s) of activity as well as the target cells for their action have not been unambiguously identified as yet. In this study, the effects of azithromycin on lipopolysaccharide (LPS)-induced pulmonary neutrophilia were investigated in mice.

Homology modeling of human Fyn kinase structure: discovery of rosmarinic acid as a new Fyn kinase inhibitor and in silico study of its possible binding modes.

Tyrosine phosphorylation represents a unique signaling process that controls metabolic pathways, cell activation, growth and differentiation, membrane transport, apoptosis, neural, and other functions. We present here the three-dimensional structure of Fyn tyrosine kinase, a Src-family enzyme involved in T-cell receptor signal transduction. The structure of Fyn was modeled for homology using the Sybyl-Composer suite of programs for modeling.