Analysis of gene expression during Calcium induced differentiation of human primary keratinocytes (NHEK)
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ABSTRACT: Human primary keratinocytes were collected at 0, 1, 3, 6, 12, 24 and 48 hours after addition of 1.8mM Calcium and RNA was extracted. Primary normal human keratinocytes (NHEK) were collected and RNA was extracted 0, 1, 3, 6, 12, 24, and 48 after addition of 1.8mM Calcium.
Project description:Human primary keratinocytes were depleted of MLL2 by siRNA and induced to differentiated for 2 days by addition of Calcium Primary normal human keratinocytes were transfected with MLL2 or scrambled control siRNA using RNAi max (Life Technologies). 24 hours post transfection medium was raised to 1.8mM calcium to induce differentiation. Cells were collected 48 hours later.
Project description:Human primary keratinocytes were depleted of GRHL3 by siRNA and induced to differentiated for 2 days by addition of Calcium Primary normal human keratinocytes were transfected with GRHL3 or scrambled control siRNA using RNAi max (Life Technologies). 24 hours post transfection medium was raised to 1.8mM to induce differentiation. Cells were collected 48 hours later.
Project description:The antagonistic actions of Polycomb and Trithorax are responsible for proper cell fate determination in mammalian tissues. In the epidermis, a self-renewing epithelium, previous work has shown that release from Polycomb repression only partially explains differentiation gene activation. We now show that Trithorax is also a key regulator of epidermal differentiation, not only through activation of genes repressed by Polycomb in progenitor cells, but also through activation of genes independent of regulation by Polycomb. The differentiation associated transcription factor GRHL3/GET1 recruits the ubiquitously expressed Trithorax complex to a subset of differentiation genes. Examination of WDR5 and GRHL3 binding in human differentited primary keratinocytes (NHEK). High calcium medium was added to NHEK cells at 50% confluency to induce differentiation. Cells were collected for ChIP 24 hours after addition of high calcium medium. ChIP with Wdr5 and Grhl3 antibodies, and an input control were sequenced.
Project description:During epithelial tissue morphogenesis, developmental progenitor cells undergo dynamic adhesive and cytoskeletal remodeling to trigger proliferation and migration. Transcriptional mechanisms that restrict such mild form of epithelial plasticity to maintain lineage-restricted differentiation in committed epithelial tissues are poorly understood. Here we report that simultaneous ablation of transcriptional repressor-encoding Ovol1 and Ovol2 results in expansion and blocked terminal differentiation of embryonic epidermal progenitor cells. Conversely, mice overexpressing Ovol2 in their skin epithelia exhibit precocious differentiation accompanied by smaller progenitor cell compartments. We show that Ovol1/2-deficient epidermal cells fail to undertake alpha-catenin–driven actin cytoskeletal reorganization and adhesive maturation, and exhibit changes that resemble epithelial-to-mesenchymal transition (EMT). Remarkably, these alterations as well as defective terminal differentiation are reversed upon depletion of EMT-promoting transcriptional factor Zeb1. Collectively, our findings reveal Ovol-Zeb1-a-catenin sequential repression and highlight novel functions of Ovol as gatekeepers of epithelial adhesion and differentiation by inhibiting progenitor-like traits and epithelial plasticity. Isolated keratinocytes from control, Ovol1 knockout and Ovol1/2 double knockout were physically isolated for RNA extraction and hybridization on Affymetrix microarrays. In order to identify differentiation changes, we isolated the keratinocytes from mouse skin and allowed them to grow in culture for 2-5 days, then added calcium and allowed them to grow another 3-5 days.
Project description:To determine if fibroblasts could be reprogrammed to a keratinocyte phenotype p63+KLF4 or LacZ expressing retroviruses were transduced into primary human neonatal fibroblasts. Global gene expression profiling using U133 plus 2.0 arrays were used to deteremine the extent of reprogramming to a keratinocyte phenoypte upon transduction with p63+KLF4. Fibroblasts transduced with p63+KLF4 were also treated +/- high calcium to determine if treatment with calcium could induce differentiation of these cells. Microarray analysis was also performed on cells treated +/- calcium. For gene expression profiling, cultured human fibroblasts were infected with LacZ or p63+KLF4 expressing retroviruses. p63+KLF4 cells were also treated +/- calcium. Microarray analysis using Affymetrix HG-U133 2.0 plus arrays was performed on duplicate samples.
Project description:During epithelial tissue morphogenesis, developmental progenitor cells undergo dynamic adhesive and cytoskeletal remodeling to trigger proliferation and migration. Transcriptional mechanisms that restrict such mild form of epithelial plasticity to maintain lineage-restricted differentiation in committed epithelial tissues are poorly understood. Here we report that simultaneous ablation of transcriptional repressor-encoding Ovol1 and Ovol2 results in expansion and blocked terminal differentiation of embryonic epidermal progenitor cells. Conversely, mice overexpressing Ovol2 in their skin epithelia exhibit precocious differentiation accompanied by smaller progenitor cell compartments. We show that Ovol1/2-deficient epidermal cells fail to undertake alpha-catenin–driven actin cytoskeletal reorganization and adhesive maturation, and exhibit changes that resemble epithelial-to-mesenchymal transition (EMT). Remarkably, these alterations as well as defective terminal differentiation are reversed upon depletion of EMT-promoting transcriptional factor Zeb1. Collectively, our findings reveal Ovol-Zeb1-a-catenin sequential repression and highlight novel functions of Ovol as gatekeepers of epithelial adhesion and differentiation by inhibiting progenitor-like traits and epithelial plasticity. Isolated keratinocytes from control, Ovol1 knockout and Ovol1/2 double knockout were physically isolated for RNA extraction and hybridization on Affymetrix microarrays. In order to identify primary changes, we isolated the keratinocytes from mouse skin and allowed them to grow in culture for 2-5 days.
Project description:In this study we aim to determine the role of IL-4/STAT6 in gene expression in human keratinocytes using RNA-sequencing approach. Human keratinocytes were cultured for 2 or 5 days with calcium chloride to induce terminal differentiation as determined by the expression of epidermal differentiation complex genes. The cells were then stimulated with IL-4 for 3 and 24 hours, or along the 5 days culture period. We observed that IL-4 inhibits fully differentiation of keratinocytes, induces genes involved with production of inflammatory mediators, and reduces the healing capacity of human keratinocytes. Moreover, STAT6 controlled important genes involved with calcium binding, inflammation and epidermis development. Human keratinocytes were differentiated with calcium chloride for 2 days and incubated with media alone or 20ng/ml of recombinant human IL-4 for 3 and 24 hours. Human keratinocytes were differentiated with calcium chloride for 5 days with or wihout recombinant human IL-4 (20ng/ml). Keratinocytes transfected with control or STAT6 siRNA were differentiated with calcium chloride for 2 days and then stimulated with recombinant huma IL-4 for 24 hours.
Project description:While several physiological skin parameters vary in a circadian manner, the identity of genes participating in chronobiology of skin remains unknown, leading us to define the circadian transcriptome of mouse skin at two different stages of the hair cycle, telogen and anagen. The circadian transcriptomes of telogen and anagen skin are largely distinct, with the former dominated by genes involved in cell proliferation and metabolism. The expression of many metabolic genes is antiphasic to cell cycle related genes, the former peaking during the day and the latter peaking at the night. Consistently, accumulation of reactive oxygen species, a byproduct of oxidative phosphorylation, and S-phase are antiphasic to each other in telogen skin. Furthermore, the circadian variation in S-phase is controlled by BMAL1 intrinsic to keratinocytes as keratinocyte-specific deletion of Bmal1 obliterates time of day dependent synchronicity of cell division in the epidermis leading to a constitutively elevated cell proliferation. Consistent with higher cellular susceptibility to UV-induced DNA damage during S phase, we found that mice are most sensitive to UVB-induced DNA damage in the epidermis at night. As maximum numbers of keratinocytes go through S phase in the late afternoon in the human epidermis, we speculate that in humans the circadian clock imposes regulation of epidermal cell proliferation such that skin is at a particularly vulnerable stage during times of maximum UV exposure, thus contributing to the high incidence of human skin cancers. Whole skin was collected at 4 hour intervals for 48 hours. Where ZT number indicates the number of hours elapsed from when lights are switched on. ZT0 = lights on (6am). ZT12=lights off (6pm). Total RNA was purified from the skin of each mouse and equal amount of RNA from the 3 replicates for each time point were pooled. Telogen samples were collected from skin of P46 male mice.
Project description:While several physiological skin parameters vary in a circadian manner, the identity of genes participating in chronobiology of skin remains unknown, leading us to define the circadian transcriptome of mouse skin at two different stages of the hair cycle, telogen and anagen. The circadian transcriptomes of telogen and anagen skin are largely distinct, with the former dominated by genes involved in cell proliferation and metabolism. The expression of many metabolic genes is antiphasic to cell cycle related genes, the former peaking during the day and the latter peaking at the night. Consistently, accumulation of reactive oxygen species, a byproduct of oxidative phosphorylation, and S-phase are antiphasic to each other in telogen skin. Furthermore, the circadian variation in S-phase is controlled by BMAL1 intrinsic to keratinocytes as keratinocyte-specific deletion of Bmal1 obliterates time of day dependent synchronicity of cell division in the epidermis leading to a constitutively elevated cell proliferation. Consistent with higher cellular susceptibility to UV-induced DNA damage during S phase, we found that mice are most sensitive to UVB-induced DNA damage in the epidermis at night. As maximum numbers of keratinocytes go through S phase in the late afternoon in the human epidermis, we speculate that in humans the circadian clock imposes regulation of epidermal cell proliferation such that skin is at a particularly vulnerable stage during times of maximum UV exposure, thus contributing to the high incidence of human skin cancers. Whole skin was collected at ZT22. Where ZT number indicates the number of hours elapsed from when lights are switched on. ZT0 = lights on (6am). ZT12=lights off (6pm). Het mice designate a presence of one Bmal1 mutant allele and one wt allele. KO mice designate mice germline deleted for both copies of Bmal1 allele. Total RNA was purified from the skin of each biological littermate replicate.
Project description:While several physiological skin parameters vary in a circadian manner, the identity of genes participating in chronobiology of skin remains unknown, leading us to define the circadian transcriptome of mouse skin at two different stages of the hair cycle, telogen and anagen. The circadian transcriptomes of telogen and anagen skin are largely distinct, with the former dominated by genes involved in cell proliferation and metabolism. The expression of many metabolic genes is antiphasic to cell cycle related genes, the former peaking during the day and the latter peaking at the night. Consistently, accumulation of reactive oxygen species, a byproduct of oxidative phosphorylation, and S-phase are antiphasic to each other in telogen skin. Furthermore, the circadian variation in S-phase is controlled by BMAL1 intrinsic to keratinocytes as keratinocyte-specific deletion of Bmal1 obliterates time of day dependent synchronicity of cell division in the epidermis leading to a constitutively elevated cell proliferation. Consistent with higher cellular susceptibility to UV-induced DNA damage during S phase, we found that mice are most sensitive to UVB-induced DNA damage in the epidermis at night. As maximum numbers of keratinocytes go through S phase in the late afternoon in the human epidermis, we speculate that in humans the circadian clock imposes regulation of epidermal cell proliferation such that skin is at a particularly vulnerable stage during times of maximum UV exposure, thus contributing to the high incidence of human skin cancers. Whole skin was collected at 4 hour intervals for 48 hours. ZT number indicates the number of hours elapsed from when lights are switched on. ZT0 = lights on (6am). ZT12=lights off (6pm). Total RNA was purified from the skin of each mouse and equal amount of RNA from the 3 replicates for each time point were pooled. Anagen samples were collected from skin of P30 male mice.