Project description:The mechanisms underlying pruritus of imiquimod (IMQ)-induced psoriasis remain poorly understood. In this study, we investigated whether there are certain key signaling molecules downstream of the recently identified peptides mediating itch in the spinal cord. We investigated the changes in the trascriptome by performing RNAseq of cervical spinal cords in control and IMQ-induced psoriasis. Our study represents the detailed analysis of transcriptomes of spinal cord in chronic itch model with biologic replicates, generated by RNA-seq technology.
Project description:Psoriasis is a chronic inflammatory skin disorder that is predominantly characterized by sharply demarcated chronic erythematous plaques. Although its etiological mechanisms are largely unknown, recent evidence suggests that the topical application of imiquimod (IMQ) cream causes psoriasis-like skin inflammation in humans and mice. Skin examined 4 hours after IMQ cream treatment. Results provide insight into the role of each knockout mice phenotype in the response to IMQ-induced psoriasis model.
Project description:Background: Imiquimod (IMQ) produces a cutaneous phenotype in mice frequently studied as an acute model of human psoriasis. Whether this phenotype depends on strain or sex has never been systematically investigated on a large scale. Such effects, however, could lead to conflicts among studies, while further impacting study outcomes and efforts to translate research findings. Methods: RNA-seq was used to evaluate the psoriasiform phenotype elicited by IMQ in both sexes of 7 mouse strains (C57BL/6J, BALB/cJ, CD1, DBA/1J, FVB/NJ, 129X1/SvJ and MOLF/EiJ). Results: In most strains, IMQ altered gene expression in a manner consistent with human psoriasis, partly due to innate immune activation and decreased homeostatic gene expression. The IMQ response of MOLF males was aberrant, however, with decreased expression of differentiation-associated genes (elevated in other strains). Key aspects of the IMQ response differed between the two most commonly studied strains (BALB/c and C57BL/6). Compared with BALB/c, the C57BL/6 phenotype showed increased expression of genes associated with DNA replication, IL-17A activation and CD8+ T cells, but decreased expression of genes associated with interferon signaling and CD4+ T cells. Surprisingly, although IMQ-induced expression shifts mirrored psoriasis, correspondence was similar or better for other human skin diseases (e.g., eschars, acne, atopic dermatitis). For BALB/c, MOLF, and 129X1 strains, genes altered by IMQ corresponded better to those altered in human skin infections or wounds compared with those altered in psoriasis lesions. Conclusions: These findings demonstrate strain-dependent aspects of IMQ dermatitis that warrant consideration in planning and interpreting experimental studies. We have further shown that IMQ does not uniquely model psoriasis but in fact triggers a core set of pathways active in diverse skin diseases. These observations challenge the view of IMQ dermatitis as a mouse phenotype uniquely appropriate for studying psoriasis as opposed to other human skin conditions.
Project description:Psoriasis is one of the most common dermatological disorders, characterized by increased epidermal hyperplasia and immune cell infiltration. Psychological stress has been reported to contribute to the severity, aggravation, and relapse of psoriasis. We developed a chronic restrain stress (CRS)-imiquimod (IMQ)-induced psoriasis-like mouse model and performed a comprehensive comparative transcriptomic and metabolic analysis with control mice, CRS-treated mice, and IMQ-treated mice to investigate how psychological stress affects psoriasis. We found that CRS-IMQ-induced psoriasis-like mice showed significant exacerbation of psoriasis-like skin inflammation compared with mice treated with IMQ only. Mice of the CRS+IMQ group showed increased expression of keratinocyte proliferation and differentiation genes, differential regulation of cytokines, and promotion of the linoleic acid metabolism. Our study provides new insights into the effects of psychological stress on psoriasis pathogenesis and the mechanisms involved, which provides clues for development of therapeutics or biomarkers.
Project description:TREX2 is a keratinocyte specific 3â-deoxyribonuclease that participates in the maintenance of skin homeostasis upon damage. This transcriptome analysis identified multiple genes and pathways deregulated by TREX2 loss in the IMQ-induced psoriasis-like model in mouse skin. mRNA sequencing of 5 biological replicates of skin from wild-type mice treated with Imiquimod and 6 of Trex2 knockout mice treated with Imiquimod
Project description:miR-146a acts as a negative feedback regulator of inflammation. To investigate the role of miR-146a in psoriasis psoriasiform skin inflammation was indeuced in Mir-146a-/- and wild type mice (C57BL6J) by topical applciation of imiquimod (IMQ)-cream (Aldara). Gene expression profiling (Affymetrix) was used to identify transcriptomic changes associated with psoriasis-like skin inflammation in wild type vs. miR-146a -/-mice. A daily topical dose of 31.25 mg of Aldara cream (5% IMQ) was applied on the right ear of miR-146a -/- and C57BL/6 mice on three consecutive days to induce psorisis-like skin inflammation. Mice were sacrificed at day 4. Ear flaps were collected for total RNA extraction and hybridization on Affymatrix GeneTitan plate format Gene ST 2.1 (mouse).
Project description:miR-146a acts as a negative feedback regulator of inflammation. To investigate the role of miR-146a in psoriasis psoriasiform skin inflammation was indeuced in Mir-146a-/- and wild type mice (C57BL6J) by topical applciation of imiquimod (IMQ)-cream (Aldara). Gene expression profiling (Affymetrix) was used to identify transcriptomic changes associated with psoriasis-like skin inflammation in wild type vs. miR-146a -/-mice.
Project description:Purpose: To compare epidermal LC transcriptomes of control group (wild-type IMQ-untreated C57/BL6 mice) and IMQ group (wild-type IMQ-treated C57/BL6 mice). Results: KEGG pathway analysis implied that lesional LCs were highly enriched in several inflammatory signalling pathways, including cytokine-cytokine receptor interactions, Th1, Th2 and Th17 cell differentiation, tumor necrosis factor signalling and IL-17 signalling pathways, complement and coagulation cascades, and NOD-like receptor signalling and PI3K-Akt signalling pathways. Gene set enrichment analysis plots revealed enrichment of cytokine activity, chemoattractant activity, protein lipid complex binding, and low-density lipoprotein particle binding gene sets in LCs from IMQ+ mice compared with IMQ- mice. Conclusions: These results confirmed a proinflammatory role for epidermal LCs in the pathogenesis of psoriasis.
Project description:To investigate the gene expression of imiquimod induced psoriasis-like mouse model, we have employed whole genome microarray as a discovery platform to identify genes differentially expressed compared with wild type C57BL6 mouse exposed to the vehicle of imiquimod. C57BL/6J mice at 6 to 8 weeks of age were applied to a daily topical dose of 62.5 mg of IMQ cream (5%) on the shaved back for 7 consecutive days. Control mice were treated with a same dose of vehicle cream.The total RNA was extracted by using TRIzol.