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We previously identified the gene expression of renin-angiotensin system in human monocyte-derived dendritic cells (DCs). This study was conducted to examine the mechanisms by which angiotensin II and captopril, the inhibitor of the angiotensin-converting enzyme (ACE), affect human DCs. In DCs, lipopolysaccharide (LPS)-induced production of tumor necrosis factor-alpha (TNF-alpha), interleukin-(IL)-1alpha, IL-10, IL-12, and IL-18 was significantly inhibited by captopril. In contrast, angiotensin II treatment resulted in a significant increase in TNF-alpha and IL-6 protein biosynthesis by DCs. In addition, we have studied the global expression of 2400 genes in DCs from two donors. Here, we demonstrated the specific down-regulation of the ACE gene expression in captopril-treated DCs. Our finding indicates the possible activation of NF-kappaB through the up-regulation of expressions of MEFV gene (encoding PYRIN protein) and heterogeneous nuclear ribonucleoprotein R in DCs. This is the first study on the modulation of cytokine and gene expression by angiotensin II and captopril in DCs.

To obtain basic information towards applying a dibenzofuran (DF)-degrader Terrabacter sp. strain DBF63 to bioremediate dioxin-contaminated soil, we investigated the degradative potential of strain DBF63 for either chlorinated or polychlorinated dibenzo-p-dioxins and dibenzofurans (ClxDD/ClxDF) in soil. In the soil slurry system with a soil to water ratio of 1:5 (w/v), the DF-grown DBF63 cells degraded 90% of 1 ppm 2,8-Cl2DF, whereas only 40% of 1 ppm 2,3-Cl2DD during the 7-day incubation. The degradation rates of 2-CIDF, 2-ClDD, 2,8-Cl2DF and 2,3-Cl2DF by strain DBF63 in the soil slurry system (5-day incubation) were approximately 89%, 65%, 78% and 32%, respectively. These results suggest that strain DBF63 was able to degrade mono- to dichlorinated dibenzofurans more effectively than mono- to dichlorinated dibenzo-p-dioxins. Using the same soil slurry system, we performed a preliminary bioremediation experiment using the actual dioxin-contaminated soil at an incineration site. We found that approximately 10% of tetra- to hexa-chlorinated congeners was decreased by a single inoculation with DBF63 cells within a 7-day incubation.