Melanocytic Cells Research Articles

BMP4-Induced Differentiation of Human Hair Follicle Neural Crest Stem Cells into Precursor Melanocytes from Hair Follicle Bulge.

BackgroundVitiligo is a skin depigmentation disorder, for which, repigmentation treatment with combined follicular unit extraction (FUE) graft and narrowband ultraviolet B (NBUVB) is considered superior to micro-punch graft therapy. BMP4 can induce MITF expression in Neural crest stem cells (NCSCs), and α-MSH subsequently promotes the differentiation of MITF-expressing cells along the melanocyte lineage.ObjectiveTo investigate why FUE grafting is superior to epidermal mini grafting in promoting hair follicles (HF) melanocyte cell survival and longevity, we planned the in vitro experiments HF bulge NCSCs differentiate into melanocyte precursors under the co-treatment of BMP4 and α-MSH.MethodsCells that migrated from the HF bulge of scalp were cultured and assessed using immunofluorescence. Transcriptome analysis was performed on RNA sequencing results.ResultsBasic fibroblast growth factor promotes the proliferation and survival of NCSCs, with spontaneous differentiation into SOX10+/SOX2+ glial progenitors, but not into SOX10+/MITF+ precursor melanocytes. Both BMP4 and α-MSH promoted the differentiation into MITF-expressing cells. RNA sequencing revealed a downregulation in neuregulin-1 (NRG1) and sermaphorin 3C (SEMA3C), and upregulation in WNT10A. Furthermore, FUE grafting had a source of reservoir melanocytes superior to mini- grafting in treatment for vitiligo.ConclusionWe obtained SOX10+/MITF+ precursor melanocytes through an induction of differentiation along the melanocyte lineage by BMP4 and α-MSH. According to the RNA sequencing results that NRG1 and SEMA3C were downregulated and WNT10A was upregulated, we postulated that HF NCSCs differentiated into melanocyte by co-treatment of BMP4 and α-MSH. Overall, FUE grafting is a more robust and substitutive treatment option for vitiligo.

A descriptive observational study on clinical and dermoscopic features of benign melanocytic neoplasms.

Benign melanocytic neoplasms have nests of melanocytic cells and show characteristic dermoscopic features. Clinical and dermoscopic features have not been studied previously in the Indian population. To study the clinical, epidemiological and dermoscopic patterns of benign melanocytic neoplasms. This was a descriptive, observational, single centre study. In 107 patients with melanocytic neoplasms, 167 lesions were clinically examined and studied under the dermoscope and histopathological examination was done when indicated. The lesions were broadly divided as acquired and congenital. Five main dermoscopic patterns were seen-globular, homogenous, reticular, parallel and streaks. If there were two of these patterns in a particular lesion, it was termed 'mixed pattern'. The presence of three or more patterns was called 'multicomponent pattern'. Various other features were also observed. The majority of patients belonged to the third decade with a female preponderance. History of increased UV exposure and family history was significant in acquired nevi. The dermoscopic pattern progressed from predominantly reticular in junctional nevi to predominantly globular in compound nevi and lesser pigment in intradermal nevi, with more vascular structures. The congenital melanocytic nevi showed additional features of comedo- like lesions, milia- like cysts, perifollicular pigmentary changes and increased colour variation. Even though colour variation was observed in both acquired and congenital lesions, no signs of dysplasia were seen on histopathology. A larger sample size is required, with follow up of lesions. No parallel studies in brown skinned population were found for exact comparison. Benign melanocytic proliferations are often neglected in our country. This study will help in understanding the course, clinical features and dermoscopic patterns of various benign melanocytic neoplasms, and will be a step forward towards research in our population. To the best of our knowledge, this is the first study of its kind in India.

Evaluation of chitosan gel on burn wound healing and keratinocytes function

Skin burns are common skin injuries that can result from exposure to various sources of heat by which, depending on the cause, different degrees of burns are generated. In restoration of superficial burns by re-epithelialization, the skin is rebuilt, but the skin color is different than the healthy tissue. Keratinocytes represent the major cells of the epidermis. These cells are sourced from ectoderm and are continuously being formed from the basal level. The main task of these cells is to make the protein keratin. During differentiation, keratinocytes move toward the superficial layers of the epidermis and generate more keratin. These cells are colorless, but by manipulating melanocytes (the melanocyte cells produce pigment in the skin), one can control the darkness degree of the skin. Keratinocytes, in particular, produce chemical signals which, in turn, are responsible for regulating the distribution and amount of melanin pigment in melanocytes. In this study, using an aluminum stamp weighing 85 grams, at a temperature of 80 ◦C, superficial burns, of 2nd degree, were generated on six rabbits. The rabbits were divided into two groups; a control group and the second one in which a chitosan (CHI) gel was used as a dressing. After treatment, histopathology tests and the TEM results confirmed that, in the CHI treatment group, the restoration led to acceptable results. It was shown that if the repair was performed with a CHI based gel, the keratinocyte appeared with their original structure after restoration, but if the treatment was done without the CHI dressing, the number of these cells increased, more stimulation of melanocytes occurred and, ultimately, it led to an unwanted color change of the burnt area.

Raman Trapping Microscopy for Non-invasive Analysis of Biological Samples.

Raman microscopy is an emerging tool in biomedicine. It provides label-free and non-invasive analysis of biological cells. Due to its high biochemical specificity, Raman spectroscopy can be used to acquire spectral fingerprints that allow characterizing cells types and states. Here, we present a methodological approach for implementing Raman microscopy in skin cell measurements. Raman spectra can clearly identify keratinocytes, fibroblasts, and melanocytes cells that are involved in the production of autologous skin grafts. Consequently, Raman microscopy is a promising tool that can be used to analyze single cells and to test the quality of therapeutic cell products.

Melanoma mutations modify melanocyte dynamics in co-culture with keratinocytes or fibroblasts.

Melanocytic cell interactions are integral to skin homeostasis, and affect the outcome of multiple diseases, including cutaneous pigmentation disorders and melanoma. By using automated-microscopy and machine-learning-assisted morphology analysis of primary human melanocytes in co-culture, we performed combinatorial interrogation of melanocyte genotypic variants and functional assessment of lentivirus-introduced mutations. Keratinocyte-induced melanocyte dendricity, an indicator of melanocyte differentiation, was reduced in the melanocortin 1 receptor (MC1R) R/R variant strain and by NRAS.Q61K and BRAF.V600E expression, while expression of CDK4.R24C and RAC1.P29S had no detectable effect. Time-lapse tracking of melanocytes in co-culture revealed dynamic interaction phenotypes and hyper-motile cell states that indicated that, in addition to the known role in activating mitogenic signalling, MEK-pathway-activating mutations may also allow melanocytes to escape keratinocyte control and increase their invasive potential. Expanding this combinatorial platform will identify other therapeutic target mutations and melanocyte genetic variants, as well as increase understanding of skin cell interactions.

Role of alpha-melanocyte stimulating hormone (α-MSH) in modulating the molecular mechanism adopted by melanocytes of Bos indicus under UVR stress.

Ultraviolet radiations (UVR) are responsible for a wide variety of acute and chronic effects on the animal skin. However, the effect of UVR-induced oxidative stress and protection through paracrine factors on animal skin has received little attention. We previously demonstrated how heat stress-induced adaptation in Bos indicus melanocytes was dependent on the level of melanin and reduction of apoptosis. Therefore, in the present investigation, the survival mechanisms adopted by melanocytes under UV stress and the role of α-MSH in cell survival under in vitro conditions were studied. After the treatment of melanocyte cells with UVR (using Osram ultravitalux 300W lamp), analysis of Gene expression using Real-Time PCR was done to study the adopted molecular pathways under stressful conditions. In addition, α-MSH was used to assess its modulating role in cell survival under stress. This study revealed the increase in the expression of genes related to melanogenesis, cell cycle, heat shock proteins, and apoptosis of the cells after UVR stress and demonstrated the role of paracrine factor (α-MSH) in elevating the protection response to stressful conditions like UVR stress by increasing the melanogenesis and decreasing the mitochondrial-mediated apoptosis. Based on the results of the present study, it can be stated that α-MSH can play a pivotal role in the protection of animal skin cells under stressful conditions in climate-changing scenario.

Nano Schiff base and its metal complexes: Synthesis, Characterization tools, biological applications and molecular docking studies Walaa H. Mahmouda,b*, Ahmed M. Refaata, Gehad G. Mohameda, b a. Chemistry Department, Faculty of Science, Cairo University, Giza, 126103, Egypt b. Egypt Nanotechnology Center, Cairo University, 6th October City, Giza, El-Sheikh Zayed, 12588, Egypt

A total of eight new metal complex derivatives of 4,4'-((1Z,1'Z)-(naphthalene-1,8-diylbis(azanylylidene))bis(methanylylidene))dibenzaldehyde, H2L with the metal ions Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) have been successfully prepared in alcoholic medium. The complexes obtained are characterized quantitatively and qualitatively by using micro elemental analysis, conductivity measurements, FT-IR spectroscopy, UV–Vis spectroscopy, mass spectroscopy, 1HNMR, magnetic susceptibility, thermal (TG/DTG) and SEM data to illuminate their structures. The data showed that the complexes had composition of MH2L type. From the spectral study, all the complexes obtained as monomeric structure and the metals center moieties are six-coordinated with an octahedral geometry. 1H NMR spectral data of the ligand (H2L) and its Zn(II) and Cd(II) complexes agreed well with the proposed structures. Thermogravimetric data (TG and DTG) were also studied. SEM analysis confirm the nano-structures of the ligand and some of its complexes. The preliminary in vitro antibacterial and antifungal screening activity revealed that complexes showed moderate activity against tested bacterial strains and slightly higher compared to the ligand (H2L). Anticancer activity of the ligand and its metal complexes were evaluated in human cancer (MCF-7 cells viability) and human normal melanocytes (HFB-4) cell lines. The binding between H2L with receptors of crystal structure of S. aureus (PDB ID: 3Q8U), crystal structure of sialidase NanC of Streptococcus pneumoniae (4YW4), receptors of breast cancer mutant oxidoreductase (PDB ID: 3HB5) and crystal structure of Escherichia coli (PDB ID: 3T88) were expected and set in details using molecular docking.

GNAQQ209L expression initiated in multipotent neural crest cells drives aggressive melanoma of the central nervous system.

Primary leptomeningeal melanocytic neoplasms represent a spectrum of rare tumors originating from melanocytes of the leptomeninges, which are the inner two membranes that protect the central nervous system. Like other non-epithelial melanocytic lesions, they bear frequent oncogenic mutations in the heterotrimeric G protein alpha subunits, GNAQ or GNA11. In this study, we used Plp1-creERT to force the expression of oncogenic GNAQQ209L in the multipotent neural crest cells of the ventro-medial developmental pathway, beginning prior to melanocyte cell differentiation. We found that this produces leptomeningeal melanocytic neoplasms, including cranial melanocytomas, spinal melanocytomas, and spinal melanomas, in addition to blue nevus-like lesions in the dermis. GNAQQ209L drove different phenotypes depending upon when during embryogenesis (E9.5, E10.5, or E11.5) it was induced by tamoxifen and which Cre driver (Plp1-creERT, Tyr-creERT2 , or Mitf-cre) was used. Given these differences, we propose that melanocytes go through temporary phases where they become sensitive to the oncogenic effects of GNAQQ209L . R26-fs-GNAQQ209L ; Plp1-creERT mice will be useful for defining biomarkers for potentially aggressive leptomeningeal melanocytomas and for developing new therapeutics for advanced disease.

MiR-652 Promotes Proliferation and Migration of Uveal Melanoma Cells by Targeting HOXA9.

BackgroundDysregulation of the microRNA (miRNA) network is a typical feature of many cancers. However, the key specific miRNAs involved in uveal melanoma carcinogenesis are largely unknown.Material/MethodsRT-qPCR was used to detected miR-652 expression in uveal melanoma tissues and cell lines. miR-652 inhibitor was transfected into uveal melanoma cells to decrease miR-652 expression and determine the biological role of miR-652 by CCK-8 and wound healing assays. Bioinformatic analysis and dual luciferase reporter assay were used to predict and validate the target gene of miR-652. HOXA9 siRNA was transfected into cells to confirm that miR-652 relies on regulation of HOXA9 to regulate cell proliferation and migration.ResultsRT-qPCR showed that miR-652 was overexpressed in uveal melanoma cell lines (MUM-2B, MEL270) compared with melanocyte cells (ARPE-19). Overexpression of miR-652 was also observed in uveal melanoma compared to paired non-tumor tissues. Downregulation of miR-652 inhibited the cell proliferation ability and migration ability of uveal melanoma cells. Using bioinformatic analysis, HOXA9 was found to be a potential target gene of miR-652. The direct regulation of HOXA9 by miR-652 was experimentally validated in uveal melanoma cells by dual luciferase assay and Western blotting. We also observed that miR-652 promoted HIF-1α signaling via repression of HOXA9 in uveal melanoma cells. Silencing of HOXA9 attenuated the miR-652 inhibitor decreased cell growth rate and decreased migration ability in uveal melanoma cells.ConclusionsOur data demonstrate an oncogenic role of miR-652 in uveal melanoma, showing that miR-652 may be a useful biomarker for prediction of prognosis for patients with uveal melanoma.

Impact of ultraviolet radiation on dermal and epidermal DNA damage in a human pigmented bilayered skin substitute.

Our laboratory has developed a scaffold-free cell-based method of tissue engineering to produce bilayered tissue-engineered skin substitutes (TESs) from epidermal and dermal cells. However, TES pigmentation is absent or heterogeneous after grafting, due to a suboptimal number of melanocytes in culture. Our objectives were to produce TESs with a sufficient quantity of melanocytes from different pigmentation phototypes (light and dark) to achieve a homogeneous color and to evaluate whether the resulting pigmentation was photoprotective against ultraviolet radiation (UVR)-induced DNA damage in the dermis and the epidermis. TESs were cultured using different concentrations of melanocytes (100, 200, and 1,500 melanocytes/mm2 ), and pigmentation was evaluated in vitro and after grafting onto an athymic mouse excisional model. Dermal and epidermal DNA damage was next studied, exposing pigmented TESs to 13 and 32.5 J/cm2 UVR in vitro. We observed that melanocyte cell density increased with culture time until reaching a plateau corresponding to the cell distribution of native skin. Pigmentation of melanocyte-containing TESs was similar to donor skin, with visible melanin transfer from melanocytes to keratinocytes. The amount of melanin in TESs was inversely correlated to the UVR-induced formation of cyclobutane pyrimidine dimer in dermal fibroblasts and keratinocytes. Our results indicate that the pigmentation conferred by the addition of melanocytes in TESs protects against UVR-induced DNA damage. Therefore, autologous pigmented TESs could ensure photoprotection after grafting.

MITF: an evolutionarily conserved transcription factor in the sea urchin Paracentrotus lividus.

Microphthalmia-associated transcription factor (MITF) is a member of MYC superfamily, associated with melanocyte cells, as it was discovered in depigmented mice. However, over the last years it was found to be involved in many cellular signaling pathways, among which oncogenesis, osteoclast differentiation, and stress response. In mammals, Mitf gene mutations can cause diverse syndromes affecting pigmentation of eyes or skin, bone defects and melanomas. As MITF protein homologs were also found in some invertebrates, we have isolated and characterized the MITF cDNAs from the sea urchin Paracentrotus lividus, referred to as Pl-Mitf. The in silico study of the secondary and tertiary structure of Pl-Mitf protein showed high conserved regions mostly lying in the DNA binding domain. To understand the degree of evolutionary conservation of MITF, a phylogenetic analysis was performed comparing the Pl-Mitf deduced protein with proteins from different animal species. Moreover, the analysis of temporal and spatial expression pattern of Pl-Mitf mRNA showed that it was expressed from the onset of gastrulation of the sea urchin embryo to the pluteus larva, specifically in primary mesenchymes cells (PMCs), the sea urchin skeletogenic cells, and in the forming archenteron, the larval gut precursor. In silico protein-protein interactions analysis was used to understand the association of MITF with other proteins. Our results put in evidence the conservation of the MITF protein among vertebrates and invertebrates and may provide new perspectives on the pathways underlying sea urchin development, even if further functional analyses are needed.

Characterization and Establishment of an Immortalized Rabbit Melanocyte Cell Line Using the SV40 Large T Antigen.

Melanocytes (MCs) are specialized cells that synthesize melanin within the melanosome. Cultured MCs are useful in order to study their role in relation to pigmentation. However, MC isolation is laborious and the obtained cells have a limited culture time. In this study, we transformed lentivirus-mediated simian virus 40 Large T (SV40-LT) into primary rabbit melanocytes (Pri RMCs) to establish an immortalized cell line. Morphologically, the immortalized RMCs (Im RMC) were indistinguishable from the Pri RMCs, and dendrites were visible following Dopa staining. No significant differences in cell proliferation or growth between immortalized and primary RMCs were observed. Based on melanocyte-specific markers, the expression of MITF, TYR, and TYRP1 were detected by PCR, immunofluorescence staining, and western blot analysis. Through karyotype, soft agar, and tumorigenesis assays, the immortalized RMCs did not undergo malignant transformation. Our results show that Im RMCs can be used as a tool cell for future MC studies on the pigmentation mechanisms of fur animals.

On\u2013off switching of cell cycle and melanogenesis regulation of melanocytes by non-thermal atmospheric pressure plasma-activated medium

Non-thermal atmospheric pressure (NAP) plasma has demonstrated potential in biomedical applications, such as cancer treatment, bactericidal sterilization, and cell growth promotion or inhibition. In this study, for the first time, we demonstrated on–off switching of cell cycle progression and regulated melanogenesis in normal human skin melanocytes by NAP plasma-activated medium (PAM). The melanocytes were exposed to NAP plasma at durations varying from 0 to 20 min, and the effects of PAM on cell proliferation, cell cycle progression, and melanogenesis were investigated. Although PAM showed no cytotoxicity, the proliferation of melanocytes was inhibited. The melanocyte cell cycle was arrested by PAM for a relatively short period (48 h), after which it recovered slowly. PAM promoted melanogenesis through the activation of the enzymes tyrosinase, tyrosinase-related protein-1, and tyrosinase-related protein-2. These effects seem to be related to reactive oxygen species induced by PAM. Our finding that PAM modulates the cell cycle may provide insight into the recurrence of cancer. The regulation of the melanogenesis of melanocytes may facilitate the control of skin tone without incurring negative side effects.

Growth Hormone Upregulates Melanocyte-Inducing Transcription Factor Expression and Activity via JAK2-STAT5 and SRC Signaling in GH Receptor-Positive Human Melanoma.

Growth hormone (GH) facilitates therapy resistance in the cancers of breast, colon, endometrium, and melanoma. The GH-stimulated pathways responsible for this resistance were identified as suppression of apoptosis, induction of epithelial-to-mesenchymal transition (EMT), and upregulated drug efflux by increased expression of ATP-binding cassette containing multidrug efflux pumps (ABC-transporters). In extremely drug-resistant melanoma, ABC-transporters have also been reported to mediate drug sequestration in intracellular melanosomes, thereby reducing drug efficacy. Melanocyte-inducing transcription factor (MITF) is the master regulator of melanocyte and melanoma cell fate as well as the melanosomal machinery. MITF targets such as the oncogene MET, as well as MITF-mediated processes such as resistance to radiation therapy, are both known to be upregulated by GH. Therefore, we chose to query the direct effects of GH on MITF expression and activity towards conferring chemoresistance in melanoma. Here, we demonstrate that GH significantly upregulates MITF as well as the MITF target genes following treatment with multiple anticancer drug treatments such as chemotherapy, BRAF-inhibitors, as well as tyrosine-kinase inhibitors. GH action also upregulated MITF-regulated processes such as melanogenesis and tyrosinase activity. Significant elevation in MITF and MITF target gene expression was also observed in mouse B16F10 melanoma cells and xenografts in bovine GH transgenic (bGH) mice compared to wild-type littermates. Through pathway inhibitor analysis we identified that both the JAK2-STAT5 and SRC activities were critical for the observed effects. Additionally, a retrospective analysis of gene expression data from GTEx, NCI60, CCLE, and TCGA databases corroborated our observed correlation of MITF function and GH action. Therefore, we present in vitro, in vivo, and in silico evidence which strongly implicates the GH–GHR axis in inducing chemoresistance in human melanoma by driving MITF-regulated and ABC-transporter-mediated drug clearance pathways.

In Vitro Characterization and Evaluation of Silver Nanoparticles Cytotoxicity on Human “Liver and Breast” Cancer Cells Versus Normal Melanocytes

Introduction: In the field of medicine, silver nanoparticles (Ag NPs) with their distinctive characteristics represent an interesting new cancer therapy. Cancer is a serious disease, despite the recent advances in its treatment; there are still some cases that are resistant to the current therapy.Aim of the work: This study aimed at examining the characteristics of 2 forms of silver nanomaterial (Ag NPs 1 and Ag NPs 2) and investigating their effect on breast cancer (MCF7) and liver cancer (HEP-G2) as well as on human normal melanocytes cell lines (HBF4).Materials and methods: It was found that both samples of nanoparticles have negative surface charge and their mean sizes were 9.02 nm and 24.6 nm respectively. Both Ag NPs 1 and Ag NPs 2 had a dose- dependent cytotoxicity on MCF7 and HEP-G2 with negligible effect on normal cell line (HBF4) measured by MTT assay.Results: Inhibitory Concentration 50 of Ag NPs1 and Ag NPs2 were 20.06 and 16.03 nmol/ml respectively. The resultant cell death was via apoptosis as illustrated by the inverted light microscopy. RT-PCR assessment revealed significant upregulation in Caspase 3 gene expression in the malignant cell lines exposed to each silver nanomaterials and remarkable downregulation VEGF and upregulation in TNF-α in either cancer cell line exposed to Ag NPs2 only. Meanwhile, the change in these cellular markers was minimal in normal human melanocyte cell line.Conclusion: This study indicates that silver nanoparticles can be used as anticancer agent with minimal effect on normal tissues. The cell viability depends not only on the size of Ag NPs but also their shape, surface charge and degree of repulsion between particles and aggregation.

576 The role of hepatocyte growth factor in human hair follicle – dermal white adipose tissue communication

Although human dermal white adipose tissue (DWAT) envelopes scalp hair follicles (HFs), their underlying bidirectional communication remains unexplored. Recently, we determined that culturing human HFs with surrounding DWAT promoted hair growth and pigmentation ex vivo. The current study aimed to further expand knowledge of the human DWAT-HF axis. Intriguingly, proteomic analysis identified hepatocyte growth factor (HGF) as the most abundantly-secreted DWAT product within long-term HF+DWAT ex vivo cultures. Therefore, we chose to stimulate HFs with HGF ex vivo. Both HFs cultured with DWAT, or HGF in the absence of DWAT showed a significantly increased pigment content, number of gp100+ melanocyte cells and melanocyte dendrites. These positive effects were partially ablated by a neutralizing HGF antibody added to HF+DWAT. As expected, HGF-treated HFs displayed increased proliferation and decreased apoptosis within matrix keratinocytes, effects mirrored by culturing HFs with surrounding DWAT. Transcriptomic analysis of HFs treated with HGF (6hr) revealed that HGF up-regulated PAX3 and SOX10, as well as VEGFA and WNT5B. Gene expression analysis on 24hr cultures coupled with IPA revealed that key Wnt pathway inhibitors are down-regulated in HFs treated with HGF, whereas Wnt agonists, WNT6 and WNT10B, show an upward trend for HF+HGF and HF+DWAT. Here we provide the first evidence that human DWAT communicates with adjacent scalp HFs by secreting HGF, one of the most potent promoters of hair growth and pigmentation. This study designates human perifollicular adipocytes and HGF-dependent DWAT-HF communication an intriguing novel target for therapeutic intervention in the future management of disorders of hair growth or pigmentation.

530 Local inhibition of MEK/AKT prevents cellular growth in human congenital melanocytic nevi

Large congenital melanocytic nevi (lCMN) management is based exclusively on iterative surgical procedures in the absence of validated medical therapy. The aim of our study was to develop an intra-lesional medical treatment for lCMN. Seventeen patients harboring NRAS-mutated lCMN were included. Nevocytes obtained from lCMN displayed an overactivation of MAPK and AKT pathways when compared to primary melanocytes. MEK and AKT inhibitors reduced nevosphere diameter in sphere-forming assays, as well as nevocyte cell viability and proliferation in in vitro assays. Standardized lCMN explants were then cultured ex vivo with the same inhibitors which induced a decrease in MelanA+ and Sox10+ cells in both epidermis and dermis. A similar reduction in melanocyte cell numbers was not observed in control normal skin explants. Finally, intradermal injections of these inhibitors were performed within standardized lCMN xenografts in Rag2-/- mice. They induced a dramatic decrease in nevocytes in treated lCMN xenografts which persisted 30 days after the end of treatment. Melanocytes in control normal skin xenografts were not affected by a similar treatment. Using nevus explant and xenograft preclinical models, we demonstrated that intradermal MEK/AKT inhibition might serve as neo-adjuvant therapy for the treatment of NRAS-mutated CMN to avoid iterative surgeries.

IDR-1018 induces cell proliferation, migration, and reparative gene expression in 2D culture and 3D human skin equivalents.

Skin lesions are associated with functional/cosmetic problems for those afflicted. Scarless regeneration is a challenge, not limited to the skin, and focus of active investigation. Recently, the host defense peptide innate defense regulatory peptide 1018 (IDR-1018) has shown exciting regenerative properties. Nevertheless, literature regarding IDR-1018 regenerative potential is scarce and limited to animal models. Here, we evaluated the regenerative potential of IDR-1018 using human 2D and 3D human skin equivalents. First, we investigated IDR-1018 using human cells found in skin-primary fibroblasts, primary keratinocytes, and the MeWo melanocytes cell line. IDR-1018 promoted cell proliferation and expression of marker of proliferation Ki-67, matrix metalloproteinase 1, and hyaluronan synthase 2 by fibroblasts. In keratinocytes, a drastic increase in expression was observed for Ki-67, matrix metalloproteinase 1, C-X-C motif chemokine receptor type 4, C-X-C motif chemokine receptor type 7, fibroblast growth factor 2, hyaluronan synthase 2, vascular endothelial growth factor, and elastin, reflecting an intense stimulation of these cells. In melanocytes, increased migration and proliferation were observed following IDR-1018 treatment. The capacity of IDR-1018 to promote dermal contraction was verified using a dermal model. Finally, using a 3D human skin equivalent lesion model, we revealed that the regenerative potential of IDR1018, previously tested in mice and pigs, is valid for human skin tissue. Lesions closed faster in IDR-1018-treated samples, and the gene expression signature observed in 2D was reproduced in the 3D human skin equivalents. Overall, the present data show the regenerative potential of IDR-1018 in an experimental system comprising human cells, underscoring the potential application for clinical investigation.

Human Skin Lightening Efficacy of Resveratrol and Its Analogs: From in Vitro Studies to Cosmetic Applications.

Antioxidants are deemed useful in controlling oxidative stress associated with extrinsic skin aging and pigmentation disorders. Resveratrol is a polyphenol compound found in many edible plants such as Vitis vinifera, and its inhibitory effects on the catalytic activity, gene expression, and posttranslational modifications of tyrosinase, a key enzyme in the melanin biosynthetic pathway, provide a mechanistic basis for its antimelanogenic effects seen in melanocytic cells, three-dimensionally reconstituted skin models, and in vivo animal models. As a potent antioxidant and a modulator of nuclear factor erythroid 2-related factor 2 (Nrf2), and sirtuin 1, resveratrol can also regulate multiple signaling pathways associated with inflammation and premature aging. Recent clinical studies have supported the efficacy of resveratrol and its analogs, such as resveratryl triacetate (RTA) and resveratryl triglycolate (RTG), in human skin lightening and antiaging. These findings suggest that resveratrol and its analogs are potentially useful as skin lightening and antiaging agents in cosmetics.

Diagnosis of melanoma from dermoscopic images using a deep depthwise separable residual convolutional network

Melanoma is one of the four major types of skin cancers caused by malignant growth in the melanocyte cells. It is the rarest one, accounting to only 1% of all skin cancer cases. However, it is the deadliest among all the skin cancer types. Owing to its rarity, efficient diagnosis of the disease becomes rather difficult. Here, a deep depthwise separable residual convolutional algorithm is introduced to perform binary melanoma classification on a dermoscopic skin lesion image dataset. Prior to training the model with the dataset noise removal from the images using non-local means filter is performed followed by enhancement using contrast-limited adaptive histogram equilisation over discrete wavelet transform algorithm. Images are fed to the model as multi-channel image matrices with channels chosen across multiple color spaces based on their ability to optimize the performance of the model. Proper lesion detection and classification ability of the model are tested by monitoring the gradient weighted class activation maps and saliency maps, respectively. Dynamic effectiveness of the model is shown through its performance in multiple skin lesion image datasets. The proposed model achieved an ACC of 99.50% on international skin imaging collaboration (ISIC), 96.77% on PH2, 94.44% on DermIS and 95.23% on MED-NODE datasets.