vasoactive-intestinal-peptide and erbstatin

We recently shown a novel neuro-immune competition between vasoactive intestinal peptide (VIP) and PGD2 for CRTH2 receptor, and that genistein augmented VIP and PGD2-induced eosinophil chemotaxis. However, there are neither studies on the CRTH2 gene expression in allergic rhinitis (AR) nor in the effect of tyrosine kinase inhibitors in CRTH2 gene regulation. Our Objectives were to study the gene expression modulation of CRTH2 receptor in AR patients and the effect of tyrosine kinase inhibitors (TKIs) on CRTH2 gene modulation. Nasal provocation tests, ELISA, qRT-PCR, western blot, flow cytometry and chemotaxis assays in modified micro-Boyden chambers, were all used, to achieve our objectives. Herein we show that AR patients increased the amounts of VIP and PGD2 in their nasal secretions in the early phase reaction, however CRTH2 gene expression from leukocytes recovered in their nasal secretions was upregulated only during the late phase reaction. The TKIs; Genistein, Erbstatin and Herbimycin A, induced the gene expression of CRTH2 and increased the protein content of CRTH2 in both human lymphocytes and eosinophils. This was functional as PGD2/VIP-induced eosinophil chemotaxis was augmented by the TKIs and inhibited by pervanadate, the tyrosine phosphatase inhibitor. These results open channels for therapeutic modalities targeting CRTH2 molecules in AR.

Topics: Adult; Antigens, Dermatophagoides; Cell Movement; Cells, Cultured; Eosinophils; Female; Gene Expression Regulation; Genistein; Humans; Hydroquinones; Lymphocytes; Male; Nasal Mucosa; Neuroimmunomodulation; Prostaglandin D2; Protein Kinase Inhibitors; Receptors, Immunologic; Receptors, Prostaglandin; Rhinitis, Allergic; Rifabutin; Vasoactive Intestinal Peptide

The mediators involved in eosinophil accumulation in diseases such as allergy continue to be an area of interest, even though little is known regarding the signaling involved in the human cell type recruitment. In the present study, we demonstrate a novel modulatory role of tyrosine kinase and tyrosine phosphatase activities on normal human eosinophil chemotaxis induced by different groups of chemoattractant.. Purified eosinophils were obtained from normal healthy volunteers with the CD16-negative procedure. Chemotactic activities against platelet-activating factor (PAF), vasoactive intestinal peptide (VIP) and eotaxin were assessed using a 48-well microchemotaxis chamber assay. Purified eosinophils were pretreated with herbimycin A, erbastatin or pervanadate to examine the role of tyrosine kinase in chemoattractant signaling.. Pretreatment of eosinophils with the tyrosine kinase inhibitors herbimycin A and erbstatin significantly blocked chemotaxis induced by eotaxin whilst both inhibitors augmented chemotaxis induced by VIP; however, they had no effect on PAF-induced chemotaxis. On the other hand, pretreatment of eosinophils with the phosphotyrosine phosphatase inhibitor pervanadate resulted in augmentation of eotaxin-induced chemotaxis and inhibition of VIP-induced chemotaxis, but it had no effect on PAF-induced chemotaxis.. These results suggest that protein kinase plays a modulatory role in eosinophil chemotaxis induced by various chemoattractants.

Topics: Benzoquinones; Chemokine CCL11; Chemokines, CC; Chemotactic Factors, Eosinophil; Chemotaxis, Leukocyte; Cytokines; Enzyme Inhibitors; Eosinophils; Humans; Hydroquinones; In Vitro Techniques; Lactams, Macrocyclic; Platelet Activating Factor; Protein Tyrosine Phosphatases; Protein-Tyrosine Kinases; Quinones; Rifabutin; Vanadates; Vasoactive Intestinal Peptide