Creation of differentiation-specific genomic maps of human epidermis through laser capture microdissection
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ABSTRACT: We sought to understand the differences between the basal and suprabasal layers of normal human skin epidermis. Comparison of transcriptomes among basal epidermis, suprabasal epidermis, whole epidermis, and reticular dermis
Project description:Skin homeostasis is guided by spatiotemporal regulation of gene expression, establishing each stage of keratinocyte differentiation. The current study presents transcriptomic and chromatin profiling for the proliferating (basal) and differentiated (suprabasal) cell populations derived from neonate mice (p0-p2) skin epidermis. This multi-omic approach will enable idenitification of cell specific epidermal cross-talk central to the equlibirum.
Project description:We performed microarray analysis on laser-microdissected epidermis from healthy volunteers and psoriatic patients to identify genes dysregulated in lesional psoriatic epidermis
Project description:We performed microarray analysis on laser-microdissected epidermis from healthy volunteers and psoriatic patients to identify genes dysregulated in lesional psoriatic epidermis
Project description:We performed microarray analysis on laser-microdissected epidermis from patients with atopic dermatitis to identify genes dysregulated in uninvolved and involved lesional epidermis
Project description:We performed microarray analysis on laser-microdissected epidermis from patients with atopic dermatitis to identify genes dysregulated in uninvolved and involved lesional epidermis
Project description:We found Shh overexpression in epidermis can induce hair follicle neogenesis in wounded skin. We analyzed gene expression profile in dermis and epidermis of WT (control), LSL-Shh (Shh overexpression in epidermis) and E14.5d skin
Project description:Background: IL-17 is the defining cytokine of the Th17, Tc17, and γδ T cell populations that plays a critical role in mediating inflammation and autoimmunity. Psoriasis vulgaris is an inflammatory skin disease mediated by Th1 and Th17 cytokines with relevant contributions of IFN-γ, TNF-α, and IL-17. Despite the pivotal role IL-17 plays in psoriasis, and in contrast to the other key mediators involved in the psoriasis cytokine cascade that are capable of inducing broad effects on keratinocytes, IL-17 was demonstrated to regulate the expression of a limited number of genes in monolayer keratinocytes cultured in vitro. Methodology/Principal Findings: Given the clinical efficacy of anti-IL-17 agents is associated with an impressive reduction in a large set of inflammatory genes, we sought a full-thickness skin model that more closely resemble in vivo epidermal architecture. Using a reconstructed human epidermis (RHE), IL-17 was able to upregulate 419 gene probes and downregulate 216 gene probes. As possible explanation for the increased gene induction in the RHE model is that CEBPβ, the transcription factor regulating IL-17-responsive genes, is expressed in differentiated KCs. Conclusions/Significance: The genes identified in IL-17-treated RHE are likely relevant to the IL-17 effects in psoriasis, since ixekizumab (anti-IL-17A agent) strongly suppressed the “RHE” genes in psoriasis patients treated in vivo with this IL-17 antagonist. RHE samples were treated with IFNg, IL-22 and IL-17 and compared with control
Project description:In epidermal differentiation basal keratinocytes detach from the basement membrane, stop proliferating, and express a new set of structural proteins and enzymes, which results in an impermeable protein/lipid barrier that protects us. To define the transcriptional changes essential for this process, we purified large quantities of basal and suprabasal cells from human epidermis, using the expression of b4 integrin as the discriminating factor. The expected expression differences in cytoskeletal, cell cycle and adhesion genes confirmed the effective separation of the cell populations. Using DNA microarray chips, we comprehensively identify the differences in genes expressed in basal and differentiating layers of the epidermis, including the ECM components produced by the basal cells, the proteases in both the basal and suprabasal cells, and the lipid and steroid metabolism enzymes in suprabasal cells responsible for the permeability barrier. We identified the signaling pathways specific for the two populations, and found two previously unknown paracrine and one juxtacrine signaling pathway operating between the basal and suprabasal cells. Furthermore, using specific expression signatures, we identified a new set of late differentiation markers and mapped their chromosomal loci, as well as a new set of melanocyte-specific markers. The data represent a quantum jump in understanding the mechanisms of epidermal differentiation. Basal keratinocytes are defined as integrin b4-positive. Suprabasal sample contains all melanocytes as well. Basal (integrin b4+), suprabasal (b4-) and total epidermal keratinocytes. In duplicate, from 2 independent donors, breast reduction surgery.