Project description:Environmental stimuli are known to contribute to psoriasis pathogenesis and that of other autoimmune diseases, but the mechanism is unknown. Here we show that the aryl hydrocarbon receptor (AhR), a transcription factor that senses environmental stimuli, modulates pathology in psoriasis. AhR-activating ligands reduced inflammation in the lesional skin of psoriasis patients, whereas AhR antagonists upregulated inflammation. Similarly, AhR signaling via the endogenous FICZ ligand reduced the inflammatory response in the imiquimod-induced model of psoriasis and AhR deficient mice exhibited a substantial exacerbation of the disease, compared to AhR sufficient controls. Non-haematopoietic cells, in particular keratinocytes, were responsible for this hyper-inflammatory response, which involved increased reactivity to IL-1beta and upregulation of AP-1 family members of transcription factors. Thus, our data suggest a critical role for AhR in the regulation of inflammatory responses and open the possibility for novel therapeutic strategies in chronic inflammatory disorders. Total RNA obtained from skin explants taken from psoriatic patients or healthy donors cultured in the presence of AhR agonist or antagonist
Project description:[original Title] Comparison of expression data of primary murine melanocytes from aryl hydrocarbon deficient mice and corresponding wild-type C57BL/6 mice Melanin is produced exclusively by melanocytes and melanogenesis is the vital response to protect skin cells against Ultraviolet B (UVB)-induced DNA damage. The aryl hydrocarbon receptor (AhR) is a transcription factor, which may be involved in the physiological tanning response. Normal murine melanocytes express functional AhR. We tested gene expression in WT versus AhR-deficient mice primary murine melanocytes, isolated from the skin and cultivated for several passages. Skin epidermal cells from 2 individual C57BL/6 mice and 2 individual AhR-deficient mice (deletion of exon2, AhRtm1Bra) were grown for 6-8 weeks in selection medium to propagate melanocytes.
Project description:[original Title] Comparison of expression data of primary murine melanocytes from aryl hydrocarbon deficient mice and corresponding wild-type C57BL/6 mice Melanin is produced exclusively by melanocytes and melanogenesis is the vital response to protect skin cells against Ultraviolet B (UVB)-induced DNA damage. The aryl hydrocarbon receptor (AhR) is a transcription factor, which may be involved in the physiological tanning response. Normal murine melanocytes express functional AhR. We tested gene expression in WT versus AhR-deficient mice primary murine melanocytes, isolated from the skin and cultivated for several passages.
Project description:Environmental stimuli are known to contribute to psoriasis pathogenesis and that of other autoimmune diseases, but the mechanism is unknown. Here we show that the aryl hydrocarbon receptor (AhR), a transcription factor that senses environmental stimuli, modulates pathology in psoriasis. AhR-activating ligands reduced inflammation in the lesional skin of psoriasis patients, whereas AhR antagonists upregulated inflammation. Similarly, AhR signaling via the endogenous FICZ ligand reduced the inflammatory response in the imiquimod-induced model of psoriasis and AhR deficient mice exhibited a substantial exacerbation of the disease, compared to AhR sufficient controls. Non-haematopoietic cells, in particular keratinocytes, were responsible for this hyper-inflammatory response, which involved increased reactivity to IL-1beta and upregulation of AP-1 family members of transcription factors. Thus, our data suggest a critical role for AhR in the regulation of inflammatory responses and open the possibility for novel therapeutic strategies in chronic inflammatory disorders. Total RNA obtained from skin explants taken from AhR heterozygous or knock-out mice treated pericutaneously with imiquimod for 0 and 2d.
Project description:This SuperSeries is composed of the following subset Series: GSE15857: The Aryl Hydrocarbon Receptor Regulates Tissue-Specific Dioxin-Dependent and Dioxin-Independent Gene Batteries: Kidney GSE15858: The Aryl Hydrocarbon Receptor Regulates Tissue-Specific Dioxin-Dependent and Dioxin-Independent Gene Batteries: Liver Refer to individual Series
Project description:CaMK4 has an important function in autoimmune diseases, and the contribution of CaMK4 in psoriasis remains obscure. Here, we show that CaMK4 expression is significantly increased in psoriatic lesional skin from psoriasis patients compared to healthy human skin as well as inflamed skin from an imiquimod (IMQ)-induced mouse model of psoriasis compared to healthy mouse skin. Camk4-deficient (Camk4−/−) mice treated with IMQ exhibit reduced severity of psoriasis compared to wild-type (WT) mice. There are more macrophages and fewer IL-17A+γδ TCR+ cells in the skin of IMQ-treated Camk4−/− mice compared to IMQ-treated WT mice. CaMK4 inhibits IL-10 production by macrophages, thus allowing excessive psoriatic inflammation. Deletion of Camk4 in macrophages alleviates IMQ-induced psoriatic inflammation in mice. In keratinocytes, CaMK4 inhibits apoptosis as well as promotes cell proliferation and the expression of pro-inflammatory genes such as S100A8 and CAMP. Taken together, these data indicate that CaMK4 regulates IMQ-induced psoriasis by sustaining inflammation and provides a potential target for psoriasis treatment.