Dendritic cells are contained within melanocytic nevus nests in vivo and can alter gene expression of epidermal melanocytes in vitro
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ABSTRACT: We sought to determine what if any changes dendritic cells induce in melanocytes when they are grown together (co-cultured) Comparison of transcriptomes among melanocytes alone, dendritic cells alone, and melanocytes after co-culture with dendritic cells
Project description:In this study, we sought to determine how IL-17 and TNF influence normal human melanocytes, either alone, or with both cytokines together. We reveal a dichotomous effect of IL-17 and TNF, which not only elicit essential mitogenic cytokines but also suppress melanogenesis by down-regulating genes of melanogenesis pathway Comparison of one batch of primary human melanocyte line cultured in serum free media, treated with TNF and/or IL-17, for either 24 or 48 hours.
Project description:Exposure to SEMA3E cause an immediate but transient collapse in F-actin of B16 melanocytes expressing the receptor PLXND1. Concomitant signal transduction by activated PLXND1 receptor mediated via its GTPase activating domain has a role in adapting the melanocytes to its micro-environment. To analyse these adaptive transcriptional responses B16 melanocytes were treated with SEMA3E for 2h to study early responses and for 8h to study prolonged responses. Cytochalasin D (8h) was used to distinguish the effects brough about by cytoskeletal collapse alone.
Project description:Little is known about the mechanisms underlying the localization of human melanocytes during embryogenesis, and how the characteristics of melanocytes differ in various body sites. Immunohistochemical studies of biopsy tissue obtained from four different anatomic sites (scalp, back, abdomen, and sole) of 31 aborted fetuses following the approval of the ethics committee for the study of human gene analysis revealed that the melanocyte-associated marker gp100 was expressed earlier in embryogenesis than other melanocyte markers. Human fetal melanocytes are initially localized in the epidermis, and then migrate to the hair buds from the epidermis but not the dermis. In the sole, melanocytes localize in eccrine sweat gland ducts. Cultured fetal melanocytes did not stain positively for any melanocyte markers other than MITF and nestin. When co-cultured with normal human keratinocytes and fibroblasts, fetal melanocytes stained positively for gp100. Gene expression studies indicated that fetal melanocytes were topographically diverse, especially sole-derived melanocytes compared with other melanocytes. Expression of several genes, including CHI3L1 and FGF7, was higher in sole-derived melanocytes. These findings suggest that human fetal melanocytes derived from the sole have different profiles both in vivo and in vitro compared with melanocytes from other sites.
Project description:Little is known about the mechanisms underlying the localization of human melanocytes during embryogenesis, and how the characteristics of melanocytes differ in various body sites. Immunohistochemical studies of biopsy tissue obtained from four different anatomic sites (scalp, back, abdomen, and sole) of 31 aborted fetuses following the approval of the ethics committee for the study of human gene analysis revealed that the melanocyte-associated marker gp100 was expressed earlier in embryogenesis than other melanocyte markers. Human fetal melanocytes are initially localized in the epidermis, and then migrate to the hair buds from the epidermis but not the dermis. In the sole, melanocytes localize in eccrine sweat gland ducts. Cultured fetal melanocytes did not stain positively for any melanocyte markers other than MITF and nestin. When co-cultured with normal human keratinocytes and fibroblasts, fetal melanocytes stained positively for gp100. Gene expression studies indicated that fetal melanocytes were topographically diverse, especially sole-derived melanocytes compared with other melanocytes. Expression of several genes, including CHI3L1 and FGF7, was higher in sole-derived melanocytes. These findings suggest that human fetal melanocytes derived from the sole have different profiles both in vivo and in vitro compared with melanocytes from other sites. In this study, microarray analyses were performed using cultured fetal melanocytes from 4 different sites (scalp, back, abdomen and sole) obtained at 19 WOG, and newborn normal epidermal melanocyte as a control. RNA purification was performed using an RNeasy Mini kit (Qiagen, Germany) and those 5 samples, were analyzed using GeneChip 1.0 ST Array (Affymetrix, CA, USA).
Project description:Melanocytes are surrounded by diverse cells including sensory neurons in our skin, but their interaction and functional importance has been poorly investigated. In this study, we found that melanocytes and nociceptive neurons contact more in human skin color patch tissue than control. Co-culture with human iPS cell-derived sensory neurons significantly induced morphogenesis and pigmentation of human melanocytes. To reveal melanocytes-stimulating factors secreted from neurons, we performed proteomic analyses and identified RGMB in the sensory neuron-conditioned media. RGMB protein induced morphogenesis and melanin production of melanocytes, demonstrating that RGMB is a melanocyte-stimulating factor released from sensory neurons. Transcriptome analysis suggested that the melanosome transport machinery could be controlled by RGMB, which led us to identify vesicle production response of melanocytes upon RGMB treatment. This study discovered a role of sensory neurons to modulate multiple aspects of human melanocytes through secretion of a key factor RGMB.
Project description:In order to facilitate understanding of pigment cell biology, we developed a method to concomitantly purify melanocytes, iridophores, and retinal pigmented epithelium from zebrafish, and analyzed their transcriptomes. Comparing expression data from these cell types and whole embryos allowed us to reveal gene expression co-enrichment in melanocytes and retinal pigmented epithelium, as well as in melanocytes and iridophores. We found 214 genes co-enriched in melanocytes and retinal pigmented epithelium, indicating the shared functions of melanin-producing cells. We found 62 genes significantly co-enriched in melanocytes and iridophores, illustrative of their shared developmental origins from the neural crest. This is also the first analysis of the iridophore transcriptome. Gene expression analysis for iridophores revealed extensive enrichment of specific enzymes to coordinate production of their guanine-based reflective pigment. We speculate the coordinated upregulation of specific enzymes from several metabolic pathways recycles the rate-limiting substrate for purine synthesis, phosphoribosyl pyrophosphate, thus constituting a guanine cycle. The purification procedure and expression analysis described here, along with the accompanying transcriptome-wide expression data, provide the first mRNA sequencing data for multiple purified zebrafish pigment cell types, and will be a useful resource for further studies of pigment cell biology. mRNA profiles of zebrafish pigment cells were generated using Illumina GAIIX sequencing
Project description:Notch1 Activation Confers Transforming Properties to Primary Human Melanocytes and Promotes Human Melanoma Progression We used microarrays to detail the global programme of gene expression underlying cellularisation and identified distinct classes of up-regulated genes during this process. Human neonatal melanocytes and Notch transformed human neonatal melanocytes were selected for RNA extraction and hybridization on Illumina gene expression array chip. Expression intensities were calculated and normalized for each gene probed on the array for all hybridizations using illumina Beadstudio#3 software. Microarray analyses were subsequently performed in GeneSpring to aid in the identification of genes differentially-expressed between Notch-infected and control melanocytes that may be responsible for the phenotypic changes described in the NIC-infected cells.