A major determinant quantitative-trait locus responsible for atonic dermatitis-like skin lesions in NC/Nga mice is located on Chromosome 9
IMMUNOGENETICS
Authors: Kohara, Y; Tanabe, K; Matsuoka, K; Kanda, N; Matsuda, K; Karasuyama, H; Yonekawa, H
Abstract
NC/Nga (NC) is a newly discovered model mouse for human atopic dermatitis, NC mice showing specific symptoms such as dermatitis and overproduction of IgE. To detect the loci responsible for the onset of dermatitis in the mice, backcross (N2) progeny between (NCxMSM/MS)F1 and NC were generated, where MSM/MS is an inbred strain from Japanese wild mice, Mus musculus molossinus. Linkage disequilibrium between dermatitis and various chromosome-specific microsatellite markers was then examined in the N2 segregants with severe dermatitis. The analysis revealed that the locus of the major determinant (designated here as derm1) was tightly linked to D9Mit163, D9Mit72, D9Mit143, D9Mit103, D9Mit207, and D9Mit209, because these markers showed the highest and most significant chi (2) values. Since no recombination was observed among the markers in our linkage map, a radiation hybrid (RH) panel was applied to locate the derm1 locus more precisely. The markers were separated on the RH map, and their order was D9Mit163-D9Mit72-D9Mit143D9Mit103-D9Mit207-D9Mit209 from the centromere. Several functional candidate genes are located near the locus derm1. These candidates are Thy1, Cd3d, Cd3e, Cd3g, Il10ra, Il18, and Csk, all of which could be involved in allergic responses through effects on T-cell function. Of these candidates, Csk is the strongest for NC dermatitis, since its map position was most tightly linked to the derm1 locus.
Gene expression profiling of minor salivary glands clearly distinguishes primary Sjogren's syndrome patients from healthy control subjects
ARTHRITIS AND RHEUMATISM
Authors: Hjelmervik, TOR; Petersen, K; Jonassen, I; Jonsson, R; Bolstad, AI
Abstract
Objective. To identify gene expression signatures in minor salivary glands (MSGs) from patients with primary Sjogren's syndrome (SS). Methods. A 16K complementary DNA microarray was used to generate gene expression profiles in MSGs obtained from 10 patients with primary SS and 10 control subjects. The data were analyzed by 2 different strategies, one strict primary analysis and one subanalysis that allowed for inclusion of genes with no signal in more than 3 samples from each group. The results were validated by quantitative reverse transcriptase-polymerase chain reaction techniques. Results. We found a distinct difference in gene expression levels in MSGs, enabling a simple class prediction method to correctly classify 19 of the 20 samples as either patient or control, based on the top 5 differentially expressed genes. The 50 most differentially expressed genes in the primary SS group compared with the control group were all up-regulated, and a clear pattern of genes involved in chronic inflammation was found. CXCL13 and CD3D were expressed in ≥ 90% of primary SS patients and in ≤ 10% of the controls. Lymphotoxin β, as well as a number of major histocompatibility complex genes, cytokines, and lymphocyte activation factors, manifested its role in the pathogenesis of SS. Numerous type I interferon genes related to virus infection were found among the top 200 genes, with increased expression in primary SS. Interestingly, the expression of carbonic anhydrase II, which is essential in saliva production and secretion, and the apoptosis regulator Bcl-2-like 2 were down-regulated in primary SS patients. Conclusion. We have identified distinct gene expression profiles in MSGs from patients with primary SS that provide new knowledge about groups of genes that are up-regulated or down-regulated during disease, constituting an excellent platform for forthcoming functional studies.