Project description:Analysis of cultured epidermal keratinocytes treated with interleukin-4 (IL-4) and interleukin-13 (IL-13). IL-4 and IL-13 are up-regulated in atopic dermatitis. Results provide insight into the role of IL-4 and IL-13 cytokines in the pathogenesis of atopic dermatitis. Analysis of epidermal keratinocytes transfected with dual oxidase 1 (DUOX1) siRNA knockdown before treatment with IL-4 and IL-13. DUOX1 is one of the NOX family members of NADPH oxidases whose primary function is ROS generation. Results provide insight into the role of the incraesed expression of DUOX1 in IL-4/IL-13-treated NHEK for IL4/IL13 signaling. IL-4 and IL-13 induced gene expression in human epidermal keratinocytes (NHEK) was measured at 48 hours. Gene expression in NHEK tranfected with 10 nM DUOX1 siRNA followed by treatment with 100 ng/ml IL-4 and 100 ng/ml IL-13 was measured at 48 hours. Three independent experiments were performed using different strains for each experiment.
Project description:Analysis of cultured epidermal keratinocytes treated with interleukin-4 (IL-4) and interleukin-13 (IL-13). IL-4 and IL-13 are up-regulated in atopic dermatitis. Results provide insight into the role of IL-4 and IL-13 cytokines in the pathogenesis of atopic dermatitis. Analysis of epidermal keratinocytes transfected with dual oxidase 1 (DUOX1) siRNA knockdown before treatment with IL-4 and IL-13. DUOX1 is one of the NOX family members of NADPH oxidases whose primary function is ROS generation. Results provide insight into the role of the incraesed expression of DUOX1 in IL-4/IL-13-treated NHEK for IL4/IL13 signaling.
Project description:<p>Transcription factor p63 is a key regulator of epidermal keratinocyte proliferation and differentiation. Mutations in the p63 DNA-binding domain are associated with Ectrodactyly Ectodermal Dysplasia Cleft Lip/Palate (EEC) syndrome. Underlying molecular mechanism of these mutations however remain unclear. Here we characterized the transcriptome and epigenome of p63 mutant keratinocytes derived from EEC patients. The transcriptome of p63 mutant keratinocytes deviated from the normal epidermal cell identity. Epigenomic analyses showed an altered enhancer landscape in p63 mutant keratinocytes contributed by loss of p63-bound active enhancers and by unexpected gain of enhancers. The gained enhancers were frequently bound by deregulated transcription factors such as RUNX1. Reversing RUNX1 overexpression partially rescued deregulated gene expression and the altered enhancer landscape. Our findings identify an unreported disease mechanism whereby mutant p63 rewires the enhancer landscape and affects epidermal cell identity, consolidating the pivotal role of p63 in controlling the enhancer landscape of epidermal keratinocytes.</p>
Project description:In psoriasis lesions, a diverse mixture of cytokines is upregulated which influence each other generating a complex inflammatory situation. Although this is the case, the inhibition of Interleukin-17A (IL-17A) alone showed unprecedented clinical results in patients, indicating that IL-17A is a critical inducer of psoriasis pathogenesis. To elucidate IL-17A-driven keratinocyte-intrinsic signaling pathways, we treated monolayers of normal human epidermal keratinocytes in vitro with a mixture of 6 cytokines (IL-17A, TNF-a, IL-17C, IL-22, IL-36g and IFN-g) involved in psoriasis, to mimic the inflammatory milieu in psoriasis lesions. Microarray and gene set enrichment analysis revealed that this cytokine mixture induced similar gene expression changes with the previous transcriptome studies using psoriasis lesions. Importantly, we identified a set of IL-17A-regulated genes in keratinocytes, which recapitulate typical psoriasis genes exemplified by DEFB4A, S100A7, IL19 and CSF3, based on differences in the expression profiles of cells stimulated with 6 cytokines versus cells stimulated with only 5 cytokines lacking IL-17A. Furthermore a specific IL-17A-induced gene, NFKBIZ, which encodes IkappaB-zeta, a transcriptional regulator for NF-kappaB, was demonstrated to have a significant role for IL-17A-induced gene expression. Thus, we present novel in vitro data from normal human keratinocytes that would help elucidating the IL-17A-driven keratinocyte activation in psoriasis. Cytokine mixture-induced gene expression in primary normal human epidermal keratinocytes (NHEKs) was measured at 24 hours after exposure. NHEKs were exposed to the combination of selected six cytokines (IL-17A: 100 ng/ml, TNF-a: 10 ng/ml, IFN-g: 10 ng/ml, IL-17C: 100 ng/ml, IL-22: 100 ng/ml, IL-36g: 500 ng/ml) , or to the different combinations of five of the six cytokines (in total, 7 different treatments and one untreated control). No replicate experiments were conducted.
Project description:To understand the role of epidermal keratinocytes in immunopathology of skin diseases with predominant T helper (Th) cell responses, we measured the genome-wide transcriptional profile of human keratinocytes in response to IFNgamma, IL-4, IL-17A or IL-22, major cytokines produced by Th1, Th2, Th17 or Th22 cells, respectively. IL-6 was also included in the transcriptional profile analysis because a variety of pro-inflammatory stimuli stimulate human keratinocytes to produce IL-6 that has an autocrine or paracrine role in epidermal immunity. We aimed to discover commonly expressed genes in human keratinocytes in response to pro-inflammatory cytokines, which would be associated with common pathophysiological responses in various skin diseases such as skin permeability barrier disruption or epidermal hyperplasia. Normal human keratinocytes (NHKs) were stimulated with IFNγ, IL-4, IL-6, IL-17A and IL-22 for 24 hours and harvested for total RNA extraction and hybridization on Affymetrix microarrays.
Project description:Cellular FLICE-inhibitory protein (cFLIP) prevents the development of dermatitis by blocking TNFα-dependent apoptosis of keratinocytes. However, it is unclear whether TNFα-independent signal might also contribute to the development of dermatitis in epidermis-specific Cflar-deficient (Cflar) mice. Here we show that Cflar;Tnfrsf1a-/- mice were born at the expected Mendelian ratio, but developed severe dermatitis and succumbed soon after birth. While keratinocytes still died by apoptosis, expression of epidermal differentiation markers, such as Loricrin, Filaggrin, and Keratin (Krt)10, but not Krt5 were severely downregulated in the skin of Cflar;Tnfrsf1a-/- mice at both mRNA and protein levels. Conversely, inflammatory cytokines, such as interleukin (IL)-6 and Il17a were elevated in the skin of Cflar ;Tnfrsf1a-/- mice. Treatment of primary keratinocytes with IL-6, to a lesser extent IL-17A suppressed expression of Loricrin, Filaggrin, and Krt10. Together, cFLIP suppresses TNFR1-independent apoptosis of keratinocytes and prevents IL-6-dependent blockade of epidermal differentiation.
Project description:In the early stages of wound healing, keratinocytes become “activated” and release inflammatory molecules such as interleukin-1 and interleukin-8 that are linked to innate immune responses and neutrophil recruitment. It is unclear, however, whether keratinocytes release molecules linked to adaptive immune responses, e.g. CCL20, in their early state of activation without signals from infiltrating T cells. This study aims to isolate the immediate alterations in protective and inflammatory gene expression that occur in epidermal keratinocytes, with a particular focus on molecules associated with cell-mediated immunity. We used dispase-separated epidermis, followed by intercellular disassociation by trypsinization, as a model for epidermal injury. We obtained a pure population of keratinocytes using flow cytometry. As a control for uninjured epidermis, we performed laser capture microdissection on normal human skin. Sorted keratinocytes had an early burst of upregulated gene expression, which included CCL20, IL-15, IL-23A, IFN-κ, and several antimicrobial peptides. Our results provide insight into the potential role of keratinocytes as contributors to cell-mediated inflammation, and expand knowledge about gene modulation that occurs during early wound healing. Our findings may be relevant to cutaneous diseases such as psoriasis, where micro-injury can trigger the formation of psoriatic plaques at the site of trauma. Compare keratinocyte response to cell disassociation with (1) epidermal samples isolated by laser caputre microscopy and (2) cultured KCs