Project description:A three-dimensional culture system of keratinocytes is able to mimic the formation of stratified epidermis. Air-exposure treatment is essential to promote keratinocyte differentiation. During the culture, we compared the transcripts in the cells with (Air) and without (Liq; submerged) air-exposure. Then, since rocking (shaking) the culture dish enabled to recover the keratinocyte differentiation despite the submerged culture (Liq), a comparative study between with and without rocking was also carried out to investigate the characteristics of the restored differentiation by RNA-seq. Transcriptome analyses revealed the expected similar pattern of the transcripts between air-exposure and rocking culture, which differed from those in Liq culture.
Project description:Immunotherapies targeting IL-17 greatly improve plaque psoriasis. Most previous studies on IL-17 focused on the Th17 immune response, but investigation of the effects of IL-17A on psoriatic epidermal structure are limited. Using an in vitro three-dimensional (3D) human epidermis model, we investigated the effects of IL-17A and IL-17C on morphological changes and gene expression. IL-17A directly suppressed the formation of the granular layer, whereas IL-17C did not. IL-17A significantly downregulated the gene expression of profilaggrin (FLG), which is a major component of keratohyalin granules in the granular layer. Global gene expression analysis of this 3D epidermis model showed that both IL-17A and IL-17C upregulated S100A7A and type 1 interferon-related genes including MX1, IFI44L, XAF1 and IFIT1. However, only IL-17A directly downregulated keratinocyte differentiation-related and cornified envelope-related genes including FLG, LOR, C1ORF68, LCE1E, LCE1B, KRT10, CST6 and RPTN. In conclusion, IL-17A, a systemic inflammatory cytokine, affected keratinization in our 3D epidermis model. In contrast, IL-17C, a locally produced cytokine, did not have strong effects on keratinization. Targeting IL-17A does not only reduce inflammation but it may also directly affect epidermal differentiation in psoriasis.
Project description:To characterize the global transcriptome of human keratinocyte stem cells (KSC) and keratinocyte progenitors (KP), primary basal keratinocyte subpopulations enriched in quiescent stem cells [Itg-α6bright / Trf-Rdim] or in cycling progenitors [Itg-α6bright / Trf-Rbright] were purified by flow cytometry from human skin samples. Sorted keratinocytes were then seeded in culture plates and maintained in culture medium overnight (15 hours), and genome-wide transcriptome analysis of these two subpopulations was directly performed, in order to globally maintain the initial phenotypes. After RNA preparation, gene profiling was performed using oligonucleotide microarrays (26068 probes). LOWESS normalisation was applied. Keywords: epidermis, keratinocyte stem cells, progenitors, transcriptome, stemness
Project description:To characterize the global transcriptome of human keratinocyte stem cells (KSC) and keratinocyte progenitors (KP), primary basal keratinocyte subpopulations enriched in quiescent stem cells [Itg-?6bright / Trf-Rdim] or in cycling progenitors [Itg-?6bright / Trf-Rbright] were purified by flow cytometry from human skin samples. Sorted keratinocytes were then seeded in culture plates and maintained in culture medium overnight (15 hours), and genome-wide transcriptome analysis of these two subpopulations was directly performed, in order to globally maintain the initial phenotypes. After RNA preparation, gene profiling was performed using oligonucleotide microarrays (26068 probes). LOWESS normalisation was applied. Keywords: epidermis, keratinocyte stem cells, progenitors, transcriptome, stemness Dye-swap hybridization were performed. Slides were scanned with a Genepix 4000 microarray scanner (Axon Instruments, Molecular devices, Sunnyvale, CA). For each hybridized spot, the Cy3 and Cy5 fluorescence values were obtained by using Genepix Pro 4.0 software (Axon Instruments) and were saved as a result file
Project description:To investigate how air-liquid interface stimulation induces epidermal differentiation, we carried out RNA-seq on three-dimensional culture with and without air exposure.
Project description:The nucleus of epidermal keratinocytes (KCs) is a complex and highly compartmentalized organelle, whose structure is markedly changed during terminal differentiation and transition of the genome from a transcriptionally active state seen in the basal and spinous epidermal cells to a fully inactive state in the keratinized cells of the cornified layer. Here, using multicolor confocal microscopy, followed by computational image analysis and mathematical modeling, we demonstrate that in normal mouse footpad epidermis, transition of KCs from basal epidermal layer to the granular layer is accompanied by marked differences in nuclear architecture and microenvironment including the following: (i) decrease in the nuclear volume; (ii) decrease in expression of the markers of transcriptionally active chromatin; (iii) internalization and decrease in the number of nucleoli; (iv) increase in the number of pericentromeric heterochromatic clusters; and (v) increase in the frequency of associations between the pericentromeric clusters, chromosomal territory 3, and nucleoli. These data suggest a role for nucleoli and pericentromeric heterochromatin clusters as organizers of nuclear microenvironment required for proper execution of gene expression programs in differentiating KCs, and provide important background information for further analyses of alterations in the topological genome organization seen in pathological skin conditions, including disorders of epidermal differentiation and epidermal tumors.
Project description:Colorectal cancer (CRC) shows the high mortality and morbidity. The mortal number of patients and the morbid number of patients with CRC is also increasing. However, the genes which relate to promote tumorigenesis in CRC remain unclear. In order to investigate specific genes and pathways involved in CRC tumorigenesis, we compared genes expressed between three dimensional cultures and control two-dimensional cultures. Total RNA was prepared from the CRC cell lines under the condition of two-dimensional culture and three dimensional culture.
Project description:In epidermis, granular keratinocytes are responsible for the synthesis of a great number of proteins of high tissue-specificity, and required for the epidermal barrier establishment and the regulation of the desquamation process. This project aims at characterizing the physiopathological function of genes implicated in these processes, and in the short term, defining their expression level in the course of keratinocyte differentiation. Pangenomic oligonucleotide microarrays are used to compare their expression between two cell populations enriched in basal or granular keratinocytes (T1 and T4 fractions resp.), obtained by successive incubations in trypsin solution of six independent normal human epidermis samples. Real-time quantitative PCR experiments were further performed to ensure the validity of the profiling for each candidate gene identified from microarrays data, and results of this multitechnique approach will be the object of a forthcoming publication. These results will be the basis for a better understanding of dermatological hyperkeratotic pathologies. Within epidermis, keratinocytes achieve a differentiation program culminating in cornification, a programmed cell death required for the establishment of the barrier function. A complex genetic regulatory network underlies the numerous biochemical modifications taking place in the last living cells, the granular keratinocytes (GKs), but very few transcription factors specific from this process were identified. Here we describe a large-scale, multitechnique approach performed on cells purified from normal human epidermis, and mainly focused on identification of these regulators. We performed microarray experiments to compare gene expression in cell fractions enriched in granular or basal keratinocytes. These data, with in silico promoter analysis for 52 differentiation markers, and exploitation of an EST library from GKs, were filtered according to gene products’ known or putative function and ESTs number in UniGene database, and allowed identification of 298 candidates out of 3,662 genes potentially specific from the last differentiation steps. Half were detected for the first time in epidermis and quantified by quantitative real-time PCR. These genes are linked to various aspects of GKs function, including structural components, lipid metabolism and secretory apparatus, cell signaling, and regulation of transcription. Forty-nine new differentiation-associated genes were identified, and 38 transcription factors in 92 were positively or negatively regulated in the course of differentiation, therefore possibly involved in the final differentiation of GKs. These data give new leads to have a global view of the network involved in epidermal barrier function, and allow in the future a better understanding of several pathologies, including genodermatoses of unknown aetiology. Keywords: Cell type comparison Six independent samples of normal human epidermis were used for this study. For three samples, technical replicates (at the labelling step) were performed (ie AQQ003, AQQ005 and AQQ011 slides are dye-swaps of AQQ002, AQQ004 and AQQ010, respectively). Data from each pair of “swap arrays” were merged and considered as coming from three simple arrays (named AQQ002dw, AQQ004dw and AQQ010dw) for statistical analysis. For each slide, T4 is the test sample (total RNA from granular keratinocytes), and T1 the reference sample (total RNA from basal keratinocytes of the same subject), and both come from the same biological sample.
Project description:SAGE libraries from cultured, differentiated keratinocytes and human epidermis, both normal and affected by actinic keratosis Keywords = Keratinocyte, Epidermis, Homo sapiens, Actinic Keratosis, TNF alpha