Smart-seq analysis comparing melanocytes from Spry1flox/flox mice tail epidermis to the melanocytes derived from Spry1 epidermis specific knockout mice tail and back epidermis
Ontology highlight
ABSTRACT: The function and survival of melanocytes is regulated by an elaborate network of paracrine factors synthesized mainly by epidermal keratinocytes. Keratinocytes and melanocytes respond to UV exposure by eliciting a tanning response. However, how keratinocytes and melanocytes interact in the absence of UV exposure is unknown. Here, we demonstrate that after Spry1 knockout in epidermal keratinocytes, melanocyte stem cells (McSCs) in the hair follicle exit the stem cell niche without depleting the pool of these cells. We also found that McSCs migrate to the epidermis in a Scf/C-kit-dependent manner induced by a tanning-like response resulting from Spry1 loss in epidermal keratinocytes. Once there, these cells differentiate into functional melanocytes. These findings show the potential for developing therapies for skin pigmentation disorders by manipulating McSCs.
Project description:We found that Spry1 epidermis specific knockout give rise to back epidermis hyperpigmentaiton highly mimicks tanning response in mouse
Project description:Smart-seq analysis comparing melanocytes from Spry1flox/flox mice tail epidermis to the melanocytes derived from Spry1 epidermis specific knockout mice tail and back epidermis
Project description:[original Title] Comparison of expression data of primary murine melanocytes from aryl hydrocarbon deficient mice and corresponding wild-type C57BL/6 mice Melanin is produced exclusively by melanocytes and melanogenesis is the vital response to protect skin cells against Ultraviolet B (UVB)-induced DNA damage. The aryl hydrocarbon receptor (AhR) is a transcription factor, which may be involved in the physiological tanning response. Normal murine melanocytes express functional AhR. We tested gene expression in WT versus AhR-deficient mice primary murine melanocytes, isolated from the skin and cultivated for several passages. Skin epidermal cells from 2 individual C57BL/6 mice and 2 individual AhR-deficient mice (deletion of exon2, AhRtm1Bra) were grown for 6-8 weeks in selection medium to propagate melanocytes.
Project description:Ultraviolet (UV) radiation is a major melanoma risk factor, yet underlying mechanisms remain poorly understood. Here we introduce a mouse model permitting fluorescence-aided melanocyte imaging and isolation following in vivo UV irradiation. We use expression profiling to show that activated neonatal skin melanocytes isolated following a melanomagenic UVB dose bear a distinct, persistent interferon-response signature, including genes associated with immunoevasion. UVB-induced melanocyte activation, characterized by aberrant growth and migration, was abolished by antibody-mediated systemic blockade of interferon-gamma (IFN-gamma), but not type-I interferons. IFN-gamma was produced by macrophages recruited to neonatal skin by UVB-induced chemokine receptor Ccr2 ligands. Admixed recruited skin macrophages enhanced transplanted melanoma growth by inhibiting apoptosis; notably, IFN-gamma blockade abolished macrophage-associated melanoma growth and survival. IFN-gamma-producing macrophages were identified in 70% of human melanomas examined. Our data reveal an unanticipated role for IFN-gamma in promoting melanocytic cell survival/immunoevasion, and suggest IFN-gamma-R signaling represents a novel therapeutic melanoma target. Biologic replicates of UVA- and UVB-treated mouse melanocytes, as well as untreated mouse melanocytes and mouse keratinocytes, were used to define melanocyte expression signatures associated with UV treatment.
Project description:Epidermal melanocytes form synaptic-like contacts with cutaneous nerve fibers but the functional outcome of this connection remains elusive. In this pilot study, we used our fully humanized re-innervated skin organ culture model to investigate whether melanocyte-nerve fibers interaction play a role in UV-B-induced melanogenesis. UV-B-irradiation significantly enhanced melanin content and tyrosinase activity in re-innervated skin ex vivo compared to non-innervated controls, indicating that neuronal presence is essential for exacerbating pigmentation upon UV-B irradiation in long-term culture. Comparative transcriptomic analysis between laser-capture-microdissected melanocytes from freshly embedded human skin and published microarray data on in vitro primary melanocytes identified Semaphorin-4A (SEMA4A) as possible mediator of melanocyte-nerve fibers interactions. SEMA4A protein levels in Gp100+ epidermal melanocytes were significantly higher in re-innervated skin than in skin alone, and reduced by UV-B treatment. Analysis of melanocytes in vitro showed reduced SEMA4A protein expression 24h after UV-B-irradiation while SEMA4A secretion into the medium was increased. In sensory neurons, conditioned media (CM) from UV-B irradiated melanocytes stimulated tubulin expression and axon growth. Re-transfer of CM from neurons that received CM from melanocytes back to melanocytes resulted into significant increased melanin content only when the CM derived from neurons previously receiving CM from UV-B irradiated melanocytes. These findings highlight the importance of melanocyte-neuron interactions for UV-B-induced melanogenesis and suggest that secreted proteins (e.g. SEMA4A) can function as a novel target in the treatment of hypo- and hyperpigmentation disorders.
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:To investigated the functional characteristics and molecular mechanisms underlying senescence in UV irradiated melanocytes. We performed gene expression profiling analysis using data obtained from RNA-seq of 3 normal melanocytes and 3 UV-irradiated senescent melanocytes.
Project description:[original Title] Comparison of expression data of primary murine melanocytes from aryl hydrocarbon deficient mice and corresponding wild-type C57BL/6 mice Melanin is produced exclusively by melanocytes and melanogenesis is the vital response to protect skin cells against Ultraviolet B (UVB)-induced DNA damage. The aryl hydrocarbon receptor (AhR) is a transcription factor, which may be involved in the physiological tanning response. Normal murine melanocytes express functional AhR. We tested gene expression in WT versus AhR-deficient mice primary murine melanocytes, isolated from the skin and cultivated for several passages.
Project description:To investigated the functional characteristics and molecular mechanisms underlying senescence in UV irradiated melanocytes. We performed gene expression profiling analysis using data obtained from scRNA-seq of UV-irradiated senescent melanocytes.
Project description:This experiment was designed to show the similarity among normal human epidermal melanocytes, melanocytes derived from human 3F-induced pluripotent stem (iPS) cells, and human 3F-iPS cells. Human 3F-iPS cells without c-myc were established and then differentiated into melanocytes. The differentiated cells were collected and the gene expression profile was compared to normal human epidermal melanocytes (NHEMs) and orginal 3F-iPS cells.