Project description:Primary human epidermal keratinocytes were exposed to in-vitro UVA-oxidized 1-palmitoyl-2-arachidonoyl-phosphatidylcholine or to UVA in presence and absence of a commercial UVA filter.
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:We conducted an analysis of N6-methyladenosine (m6A) modifications in HEK (primary human epidermal keratinocytes). The primary aim of this investigation was to establish a molecular framework elucidating the role of m6A modifications in modulating the functional of keratinocytes.
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:The study aimed to interrogate whether the 1,4-naphtoquinone derivative lawsone activates the aryl hydrocarbon receptor (AhR) downstream transcriptional program in keratinocytes and is capable of modulating skin homeostasis. The study has been performed on human primary epidermal keratinocytes (HEKs), which represent the first line of defense against exogenous molecules. HEK cells were treated with the vehicle control DMSO (control), stimulated with lawsone or with the TLR2 ligand Pam2CSK4. Transcriptional profiles of HEK cells were studied to investigate the regulation of AhR -related genes, Nrf2-related genes and epidermal differentiation and keratin genes. We demonstrated that lawsone was sensed by keratinocytes and activated AhR. In particular, lawsone efficiently activated the transcriptional program of AhR and promoted keratinocyte differentiation.
Project description:Both ephrins and their receptors are membrane bound, restricting their interactions to the sites of direct cell-to-cell interfaces. They are widely expressed, often co-expressed and regulate developmental processes, cell adhesion, motility, survival, proliferation, and differentiation. Both tumor suppressor and oncogene activities are ascribed to EFNs and Ephs in various contexts. A major conundrum regarding the EFN/Eph system concerns their large number and functional redundancy, given the promiscuous cross-activation of ligands and receptors and the overlapping intracellular signaling pathways. To address this issue, we treated human epidermal keratinocytes with 5 EFNAs individually and defined the transcriptional responses in the cells. We found that a large set of genes is coregulated by all EFNAs. However, while the responses to EFNA3, EFNA 4 and EFNA 5 are identical, the responses to EFNA1 and EFNA2 are characteristic and distinctive. All EFNAs induce epidermal differentiation markers and suppress cell adhesion genes, especially integrins. Ontological analysis shows that all EFNAs induce cornification and keratin genes, while suppressing wound-healing associated, signaling, receptor and ECM associated genes. Transcriptional targets of AP1 are selectively suppressed by EFNAs. EFNA1 and EFNA2, but not the EFNA3, EFNA4, EFNA5 cluster, regulate the members of the ubiquitin-associated proteolysis genes. EFNA1 specifically induces collagen production. Our results demonstrate that the EFN-Eph interactions in the epidermis, while promiscuous, are not redundant but specific. This suggests that different members of the EFN/Eph system have specific, clearly demarcated functions. Human epidermal keratinocytes are treated with 25 ng/ml EFNA1; EFNA2; EFNA3; EFNA4 or EFNA5 (all as Fc conjugates) for 24h.
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:Glucocorticoids (GCs) have a long history of use as therapeutic agents for numerous skin diseases. Surprisingly, their specific molecular effects are largely unknown. To characterize GC action in epidermis, we compared the transcriptional profiles of primary human keratinocytes untreated and treated with dexamethasone (DEX) for 1, 4, 24, 48 and 72 hours using large-scale microarray analyses. The majority of genes were found regulated only after 24 hours and remained regulated throughout the treatment. In addition to expected anti-inflammatory genes, we found that GCs regulate cell fate, tissue remodeling, cell motility, differentiation and metabolism. GCs not only effectively block signaling by TNF-alpha and IL-1 but also by IFN-gamma, which was not previously known. Specifically, GCs suppress the expression of essentially all IFN-gamma-regulated genes, including IFN-gamma receptor and STAT-1. GCs also block STAT-1 activation and nuclear translocation. Unexpectedly, GCs have anti-apoptotic effects in keratinocytes by inducing the expression of anti-apoptotic and repressing pro-apoptotic genes. Consequently, GCs treatment blocked UV-induced apoptosis of keratinocytes. GCs have a profound effect on wound healing by inhibiting cell motility and the expression of pro-angiogenic factor VEGF. They play an important role in tissue remodeling and scar formation by suppressing the expression of TGF-beta-1 and -2, MMP1, 2, 9 and 10 and inducing TIMP-2. Finally, GCs promote terminal stages of epidermal differentiation while simultaneously inhibiting the early stages. These results provide new insights into the beneficial and adverse effects of GCs in epidermis, defining the participating genes and mechanisms that coordinate the cellular responses important for GC-based therapies. Human epidermal keratinocytes are grown in delipidized, phenolphtalein-free medium and left as controls or treated with 0.1μM dexamethasone. Time course of treated and parallel control samples over a 72 hr period was performed twice with independent batches of cells.
Project description:Human epidermal keratinocytes were treated with 25 ng.ml EphB2 or EFNA4, both as-Fc conjugates (Sigma). Human epidermal keratinocytes are treated with 25 ng/ml EphB2 or EFNA4 Fc conjugates in a 48hr time course.