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Byline: Tadaatsu Imaizumi (1), Masaharu Hatakeyama (1), Kageaki Taima (2), Akira Ishikawa (1), Koji Yamashita (1), Hidemi Yoshida (1), Kei Satoh (1) Keywords: double-stranded RNA; vascular endothelial cells; epithelial neutrophil activating peptide-78; interleukin-4 Abstract: Epithelial neutophil activating peptide-78 (ENA-78)/CXCL-5 is a member of CXC chemokines. ENA-78 was originally described as a factor produced by epithelial cells only. But other types of cells including vascular endothelial cells also produce it. ENA-78 production by endothelial cells may be important for the regulation of neutrophil activation in inflammatory reactions. Polyinosinic-polycytidylic acid (poly IC) is a synthetic double-stranded RNA, which mimics the viral infection when applied to cells and affects the expression of various genes related to inflammatory reactions. In the present study, we examined the effect of poly IC on the expression of ENA-78 in human umbilical vein endothelial cells (HUVEC). HUVEC in culture were treated with poly IC and the expression of ENA-78 mRNA and protein were analyzed by reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay. Poly IC induced ENA-78 expression in time- and concentration-dependent manners. Th2-type cytokine IL-4 partially inhibited the induction of ENA-78 by poly IC. 2-Aminopurine, an inhibitor of dsRNA-dependent kinase, suppressed the induction of ENA-78 by poly IC. ENA-78 may be involved in the inflammatory reactions elicited by viral infection in endothelial cells. Author Affiliation: (1) Department of Vascular Biology, Institute of Brain Science, Hirosaki University School of Medicine, Hirosaki, Japan (2) The Second Department of Internal Medicine, Hirosaki University School of Medicine, Hirosaki, Japan Article History: Registration Date: 20/12/2004

Byline: Ivone Martins Cipriano (1), Mario Mariano (1), Edna Freymuller (2), Celia Regina Whitaker Carneiro (1) Keywords: epithelioid cells; granuloma; macrophages; IL-4; GM-CSF Abstract: Epithelioid cells (ECs) found in granulomas are thought to derive from mononuclear phagocytes. Although GM-CSF and/or IL-4 are known to promote cell differentiation their role in the development of ECs has never been demonstrated. Here we showed that mouse macrophages treated exclusively with recombinant IL-4 (rIL-4) differentiate into epithelioid-like cells. Macrophages cultivated with rIL-4 presented a fried-egg shape, and ultrastructural studies revealed membrane interdigitations, cytoplasmic vesicles, prominent Golgi complex, and rough endoplasmic reticulum. Compared with controls, rIL-4 treated cells displayed increased expression of MHC class II molecules and of Migration Inhibitory Factor-Related Protein-14. Whereas mannose receptor-mediated phagocytosis was increased, FcI3-receptor mediated phagocytosis and the production of nitric oxide were decreased in treated cultures. All these features overlap those reported for ECs from granulomatous lesions. In conclusion, treatment of mouse peritoneal macrophages with rIL-4 drives their in vitro differentiation to an epithelioid phenotype and provides a tool to investigate the biology of ECs. Author Affiliation: (1) Department of Microbiology, Immunology and Parasitology, Federal University of Sao Paulo, Sao Paulo, Brazil (2) Electron Microscopy Center, Federal University of Sao Paulo, Sao Paulo, Brazil Article History: Registration Date: 20/10/2004

Byline: K. Noguchi (1), M. Shitashige (2), H. Watanabe (1), S. Murota (2), I. Ishikawa (1) Abstract: The purpose of the present study was to investigate the involvement of cyclooxygease-1 (COX-1) and cyclooxygenase-2 (COX-2) in prostaglandin (PG) production by human periodontal ligament (PDL) fibroblasts stimulated with a proinflammatory cytokine, inerleukin-1[beta] (IL-1[beta]), and to examine the effect of interleukin-4 (IL-4), a Th2 cytokine, and interferon-I3 (IFN-I3), a Th1 cytokine, on PG production by the cells. IL-1[beta]-stimulated PDL fibroblasts produced prostaglandin E.sub.2 (PGE.sub.2) in a time-dependent manner. Indomethacin, a non-selective COX-1/COX-2 inhibitor, and NS-398, a selective COX-2 inhibitor, completely inhibited PGE.sub.2 production by IL-1[beta]-stimulated cells. Northern blot analysis showed that COX-2 mRNA was detected in IL-1[beta]-stimulated PDL cells, although not detected in unstimulated cells, while expression of COX-1 mRNA was in the same extent in both the cells. Dexamethasone inhibited COX-2 mRNA expression, COX activity and PGE.sub.2 production in IL-1[beta]-stimulated cells. IL-4 and IFN-I3 suppressed PGE.sub.2 production by IL-1[beta]-stimulated PDL fibroblasts, but COX activity enhanced by IL-1[beta] treatment was significantly inhibited by IL-4, not by IFN-I3. Northern blot analysis showed that IL-4 depressed COX-2 mRNA expression with no effect on COX-1 mRNA expression. On the other hand, IFN-I3 had no effect on expression of COX-1 and -2 mRNA. These data suggest that COX-2 is primarily responsible for PGE.sub.2 production by IL-1[beta]-stimulated human PDL fibroblasts and that IL-4 inhibited PGE.sub.2 production by IL-1[beta]-stimulated PDL fibroblasts through down-regulation of COX-2 expression, while IFN-I3 suppressed the PGE.sub.2 production with no effect on COX-2 expression. Author Affiliation: (1) Department of Periodontology, Graduate School, Faculty of Dentistry, Tokyo Medical and Dental University, 1--5--45, Yushima, Bunkyo-ku, Tokyo, 113--8549, Japan (2) Department of Physiological Chemistry, Graduate School, Faculty of Dentistry, Tokyo Medical and Dental University, 1--5--45, Yushima, Bunkyo-ku, Tokyo, 113--8549, Japan Article History: Registration Date: 14/10/2004