Analysis of highly expressed genes in monocytes from atopic dermatitis patients.

BACKGROUND: Monocytes, macrophages, and antigen-presenting cells (APCs) are key effectors of both innate and acquired immune responses. Such cells have been implicated in the pathogenesis of some inflammatory diseases. Differential gene expression in CD14-positive cells from patients with atomic dermatitis (AD) was studied using real-time quantitative RT-PCR to measure transcription levels of selected genes. METHODS: PBMCs were prepared by Ficoll gradient separation from 30 AD patients (the anti-mite-specific IgE RAST score: 0.75 to >100 UA/ml) and 10 healthy adult individuals (the RAST score: <0.34-0.37 UA/ml) and CD14-positive cells were selected. A total of 64 genes was selected for study from groups of genes with different molecular function. RESULTS: Genes involved in MHC class I antigen presentation, such as beta(2)-microglobulin, subunits of an immunoproteasome and ATP-binding cassette transporter TAP2 were expressed at higher levels in the AD patients than in the healthy controls. The genes for Toll-like receptors, CD36 and IFNgamma receptor were also upregulated in the AD patients. These genes are involved in MHC class I antigen presentation, recognition of bacterial pathogens and apoptotic cells. CONCLUSIONS: The upregulation of genes suggests that circulating monocytes in AD patients may be primed to differentiate into effector cells by conditions associated with AD. The upregulation of genes may prove to be a useful marker for AD.

Identification of highly expressed genes in peripheral blood T cells from patients with atopic dermatitis.

BACKGROUND: Analysis of genes that are differentially expressed in patients with atopic dermatitis (AD) and normal individuals will provide important information on the underlying molecular pathogenetic mechanisms of AD. METHODS: Transcript of freshly isolated peripheral blood T cells from 59 individuals were analyzed with a fluorescent differential display (FDD) method. Ninety-two differentially expressed genes were identified in this manner. Additionally, real-time quantitative RT-PCR was employed to investigate the expression of the FDD-selected genes and also genes related to T cell function. RESULTS: A number of genes, including CC chemokine receptor 4, T cell-specific tyrosine kinase (Emt/Itk), integrin beta1, integrin alpha6, IQGAP1 and MAR/SAR DNA-binding protein (SATB1), were shown to be more highly expressed in patients with moderate and/or severe AD than in controls or patients with mild AD. Because the products of these upregulated genes influence chemotaxis, adhesion, migration and Th2 polarization, it is suggested that in more severe AD, circulating T cells may function differently in this regard. Several other genes, the role of which in T cell function is currently unknown, were also found to be differentially expressed in AD. These included the heat shock protein 40 and vasopressin-activated calcium-mobilizing receptor 1. CONCLUSION: The upregulated genes identified in this work may serve as useful markers for moderate to severe AD as opposed to normal or mild AD and also as markers indicating progression to more severe AD. Further functional characterization will provide a better understanding of the pathophysiology of circulating T cells in AD.

Analysis of novel disease-related genes in bronchial asthma.

Bronchial asthma is a complex disease characterized by airway inflammation involving interleukin (IL)-4 and IL-13. We have applied microarray analyses to human bronchial epithelial cultures to probe for genes regulated by these cytokines and have identified a subset of disease-relevant genes by comparison with cDNA libraries derived from normal and asthmatic bronchial biopsies. Squamous cell carcinoma antigen-1 (SCCA1) and SCCA2, the cysteine and serine protease inhibitors, respectively, showed the highest expression by IL-4 and IL-13, and particularly, SCCA1 was significantly increased in the asthmatic cDNA library. STAT6 was shown to be involved in expression of SCCA1 and SCCA2 in vitro. Furthermore, serum levels of SCCA were also elevated in asthmatic patients. Taken together, it was supposed that SCCA may play some role in the pathogenesis of bronchia asthma, and measuring its serum level may be relevant for diagnosing or monitoring the status of bronchial asthma. In a complex disorder such as asthma, this combination of in vitro and in vivo genomic approaches is a powerful discriminatory method enabling identification of novel disease-related genes and their mechanisms of regulation.

Identification of an alternative splicing variant of cathepsin C/dipeptidyl-peptidase I.

Cathepsin C/dipeptidyl-peptidase I is a papain-like lysosomal cysteine proteinase implicated in the processing of various proenzymes to their active forms. In this study, we identified an alternative splicing variant of cathepsin C in both human and mouse species for the first time. The variant messenger RNA (mRNA) encodes 137 amino acids corresponding to the first and second exons, followed by additional 31 amino acids. The two newly recognized exons are located in the former intron 2. The variant mRNA is distributed ubiquitously, but predominantly in kidney, placenta, and lymph nodes. Furthermore, both interleukin 4 (IL-4) and IL-13, but not a range of cytokines induce expression of the variant in bronchial epithelial cells. These results indicate that the variant may play a role in regulating the biological activities of cathepsin C, involved in the pathogenesis of bronchial asthma.

Analysis of gene expression patterns during glucocorticoid-induced apoptosis using oligonucleotide arrays.

To determine the genes responsible for mediating the effects of glucocorticoids (GCs) on leukemic cells, transcriptional changes in GC-sensitive human pre-B leukemia 697 cells during GC-induced apoptosis were monitored using oligonucleotide microarrays. To circumvent the challenge of recovering mRNAs from dying cells, we compared the pattern of gene expression with that of 697 cells protected from apoptosis by transfection with bcl-2. Of the 12,000 genes examined for their response to GC, 93 genes were induced and 28 genes were repressed, many of which are known to be implicated in signal transduction, growth arrest, and transcription. These included the signal transduction-related genes encoding SOCS1, SOCS2, FKBP51, DSCR1, p56lck, and four protein kinase phosphatases. Growth arrest-related genes encoding p19(INK4d) and several Myc inhibitors were induced in response to the GC treatment. Anti-proliferative- or apoptosis-related genes encoding BTG1, BTG2, and granzyme A were also found to be transcriptionally up-regulated by GC. In addition, the regulation of genes encoding the glucocorticoid receptor and steroid receptor coactivator-1 suggested autoregulation of a GC-mediated signaling pathway.