Taken together, our results indicate great potential for the use of S28463 as an antiinflammatory therapeutic agent for the management of chronic asthma.

Secretory leukocyte protease inhibitor (SLPI) is an anti-inflammatory protein that is observed at high levels in asthma patients. Resiquimod, a TLR7/8 ligand, is protective against acute and chronic asthma, and it increases SLPI expression of macrophages in vitro. However, the protective role played by SLPI and the interactions between the SLPI and resiquimod pathways in the immune response occurring in allergic asthma have not been fully elucidated. To evaluate the role of SLPI in the development of asthma phenotypes and the effect of resiquimod treatment on SLPI, we assessed airway resistance and inflammatory parameters in the lungs of OVA-induced asthmatic SLPI transgenic and knockout mice and in mice treated with resiquimod. Compared with wild-type mice, allergic SLPI transgenic mice showed a decrease in lung resistance (p < 0.001), airway eosinophilia (p < 0.001), goblet cell hyperplasia (p < 0.001), and plasma IgE levels (p < 0.001). Allergic SLPI knockout mice displayed phenotype changes significantly more severe compared with wild-type mice. These phenotypes included lung resistance (p < 0.001), airway eosinophilia (p < 0.001), goblet cell hyperplasia (p < 0.001), cytokine levels in the lungs (p < 0.05), and plasma IgE levels (p < 0.001). Treatment of asthmatic transgenic mice with resiquimod increased the expression of SLPI and decreased inflammation in the lungs; resiquimod treatment was still effective in asthmatic SLPI knockout mice. Taken together, our study showed that the expression of SLPI protects against allergic asthma phenotypes, and treatment by resiquimod is independent of SLPI expression, displayed through the use of transgenic and knockout SLPI mice.

The solute carrier family 11 member 1 (SLC11A1) gene is strictly regulated and exclusively expressed in myeloid lineage cells. However, little is known about the transcriptional regulation of the SLC11A1 gene during myeloid development. In this study, we used HL-60 cells as a model to investigate the regulatory elements/factors involved in the transactivation of the SLC11A1 gene during phorbol 12-myristate 13-acetate (PMA)-induced macrophage differentiation of HL-60 cells. Promoter deletion analysis showed that a 7-base AP-1-like element (TGACTCT) was critical for the responsiveness of the SLC11A1 promoter to PMA. Stimulation by PMA induced the binding of ATF-3 and the recruitment of two components of the SWI/SNF complex, BRG1 and ␤-actin, to this element in an ATF-3-dependent manner. RNAi-mediated depletion of ATF-3 or BRG1 markedly decreased SLC11A1 gene expression and its promoter activity induced by PMA. Luciferase reporter experiments demonstrated that ATF-3 cooperated with BRG1 and ␤-actin to activate the SLC11A1 promoter. Furthermore, we showed that PMA can induce the proximal (GT/AC) n repeat sequence to convert to the Z-DNA structure in the SLC11A1 gene promoter, and depletion of BRG1 resulted in a significant decrease of Z-DNA formation. Our results demonstrated that recruitment of the SWI/SNF complex initiated Z-DNA formation and subsequently helped to transactivate the SLC11A1 gene.The solute carrier family 11 member 1 (SLC11A1) gene, also known as Ity/Lsh/BCG or natural resistance-associated macrophage 1 (NRAMP1) gene, is associated with host resistance to infection. In mice, mutations in the Slc11a1 gene, whether naturally occurring or experimentally induced, cause susceptibility to infection with unrelated intracellular pathogens such as Salmonella, Leishmania, and Mycobacteria (1-5). The multiple pleiotropic effects of the SLC11A1 gene on macrophage activation, including regulation of the chemokine KC and cytokines (e.g. TNF␣), as well as induction of nitric oxide (NO) release, MHC class II molecule expression, and oxidative burst (6, 7), display its potential importance in autoimmune and infectious diseases. In humans, polymorphic variants of the SLC11A1 gene are associated with susceptibility to infectious diseases such as tuberculosis, leprosy, and HIV infection, as well as autoimmune diseases such as rheumatoid arthritis, sarcoidosis, diabetes, and Crohn disease (6,8). Furthermore, the polymorphisms of the SLC11A1 gene have been linked with esophageal cancer risk (9).In humans, the SLC11A1 gene is located on chromosome 2q35 and has 15 exons spanning about 14 kb. The gene encodes a transmembrane protein exclusively expressed in the myeloid lineage as follows: monocytes, macrophages, polymorphonuclear neutrophils, and dendritic cells (10, 11). SLC11A1 gene expression is strictly regulated during myeloid development, and SLC11A1 protein expression parallels with its mRNA level (12), suggesting that SLC11A1 expression may be controlled primarily at the level of transcription. The human promyelocy...

Airway responsiveness is the ability of the airways to respond to bronchoconstricting stimuli by reducing their diameter. Airway hyperresponsiveness has been associated with asthma susceptibility in both humans and murine models, and it has been shown to be a complex and heritable trait. In particular, the A/J mouse strain is known to have hyperresponsive airways, while the C57BL/6 strain is known to be relatively refractory to bronchoconstricting stimuli. We analyzed recombinant congenic strains (RCS) of mice generated from these hyper- and hyporesponsive parental strains to identify genetic loci underlying the trait of airway responsiveness in response to methacholine as assessed by whole-body plethysmography. Our screen identified 16 chromosomal regions significantly associated with airway hyperresponsiveness (genome-wide P 73 cM), chromosome 7 (>63 cM), chromosome 8 (52-67 cM), chromosome 10 (3-7 cM and >68 cM), and chromosome 12 (25-38 cM and >52 cM). Our data identify several likely candidate genes from the 16 regions, including Ddr2, Hc, Fbn1, Flt3, Utrn, Enpp2, and Tsc.