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M Jernås

Publications and source records attributed to M Jernås.

5 recordsLinked to original sources
PubMed2006

A network-based analysis of allergen-challenged CD4+ T cells from patients with allergic rhinitis.

We performed a network-based analysis of DNA microarray data from allergen-challenged CD4(+) T cells from patients with seasonal allergic rhinitis. Differentially expressed genes were organized into a functionally annotated network using the Ingenuity Knowledge Database, which is based on manual review of more than 200,000 publications. The main function of this network is the regulation of lymphocyte apoptosis, a role associated with several genes of the tuber necrosis factor superfamily. The expression of TNFRSF4, one of the genes in this family, was found to be 48 times higher in allergen-challenged cells than in diluent-challenged cells. TNFRSF4 is known to inhibit apoptosis and to enhance Th2 proliferation. Examination of a different material of allergen-stimulated peripheral blood mononuclear cells showed a higher number of interleukin-4(+) type 2 CD4(+) T (Th2) cells in patients than in controls (P<0.01), as well as a higher number of non-apoptotic Th2 cells in patients (P<0.01). The number of Th2 cells expressing TNFRSF4, TNFSF7 and TNFRSF1B was also significantly higher in patients. Treatment with anti-TNFSF4 resulted in a significantly decreased number of Th2 cells (P<0.05). A logical inference from all this is that the proliferation of allergen-challenged Th2 cells is associated with a decreased apoptosis of Th2 cells and an increase in TNFRSF4 signalling.

Adolescent↗
PubMed2006

Increased levels of acylation-stimulating protein in interleukin-6-deficient (IL-6(-/-)) mice.

IL-6-deficient (IL-6(-/-)) mice develop obesity at 6-7 months of age. To elucidate the mechanisms of this mature-onset obesity, global gene expression profiles of 3-month-old preobese IL-6(-/-) were compared with those of IL-6(+/+) mice using DNA arrays. Genes that were up-regulated in IL-6(-/-) mice included the factors transthyretin and properdin in white adipose tissue and adipsin in muscle. These factors have been shown to influence the formation of acylation-stimulating protein (ASP), a cleavage product of complement C3. ASP stimulates the synthesis of triacylglycerol in adipocytes, and ASP-deficient mice are resistant to diet-induced obesity. In line with the increases in transthyretin, properdin, and adipsin, ASP levels in serum were increased by 31-54% in IL-6(-/-) compared with IL-6(+/+) mice. Furthermore, IL-6 replacement treatment in IL-6(-/-) mice decreased ASP levels significantly by 25-60%. In conclusion, ASP levels are increased in preobese IL-6(-/-) mice. This increase may result in increased triacylglycerol formation and uptake in IL-6(-/-) adipocytes and thereby contribute to the development of obesity in IL-6(-/-) mice.

Adipocytes↗
PubMed2006

Increased expression of aquaporin 3 in atopic eczema.

BACKGROUND: Dry skin in atopic eczema depends on increased water loss. The mechanisms behind this are poorly understood. The aim of this work was to identify genes that may contribute to water loss in eczema. METHODS: Affymetrix DNA microarrays U133A were used to analyse gene expression in skin biopsies from 10 patients with atopic eczema and 10 healthy controls. RESULTS: DNA microarray analysis showed up-regulation of 262 genes and down-regulation of 129 genes in atopic eczema. The known functions of these genes were analysed using Gene Ontology to identify genes that could contribute to increased water loss. This led to identification of aquaporin 3 (AQP3), which has a key role in hydrating healthy epidermis. Increased expression of AQP3 was found in eczema compared with healthy skin. This was confirmed with real-time polymerase chain reaction (P<0.001). In healthy skin, epidermal AQP3 immunoreactivity was weak and mainly found in the stratum basale. A gradient was formed with decreasing AQP3 staining in the lower layers of the stratum spinosum. By contrast, in acute and chronic atopic eczema strong AQP3 staining was found in both the stratum basale and the stratum spinosum. CONCLUSIONS: Aquaporin 3 is the predominant aquaporin in human skin. Increased expression and altered cellular distribution of AQP3 is found in eczema and this may contribute to water loss.

Adult↗
PubMed2002

DNA microarrays to study gene expression in allergic airways.

BACKGROUND: Allergic rhinitis results from interactions between a large number of cells and mediators in different compartments of the body. DNA microarrays allow simultaneous measurement of expression of thousands of genes in the same tissue sample. OBJECTIVE: To study gene expression in nasal mucosal biopsies from patients with allergic rhinitis using DNA micro-arrays. METHODS: Nasal biopsies were obtained from 14 patients with symptomatic birch pollen-induced allergic rhinitis and five healthy controls. RNA was extracted from the biopsies and pooled into one patient pool and one control pool. These were analysed in duplicate with DNA micro-arrays containing more than 12 000 known genes. RESULTS: Approximately half of the genes were expressed in the patient and control samples. Guided by the current literature we chose 32 genes of possible relevance to allergic airway inflammation and investigated their relative expression. Among these, transcripts encoding immunoglobulins and their receptors were most abundant. The expression of cytokines and growth factors was low, whereas their corresponding receptors and cell surface markers displayed higher expression levels. IgA had the highest expression of all 12 626 genes. RT-PCR showed that IgA1 was the predominant subclass. This was confirmed by the protein level in nasal fluids. Allergen-specific IgA was significantly higher in patients than in controls and correlated significantly with eosinophil granulae proteins. CONCLUSION: DNA micro-array analysis can be used to identify genes of possible relevance to allergic airway inflammation. In this study, the expression profile in the nasal mucosa was quantitatively dominated by immunoglobulins, particularly IgA. Protein analyses in nasal fluids indicated a role for allergen-specific IgA in eosinophil degranulation.

Adult↗