DERMAL STEM CELLS & TISSUE REGENERATION Dynamic Transcriptional and Epigenetic Regulation of Human Epidermal Keratinocyte Differentiation The authors used DeepCAGE, genome-wide profiling of histone modifications and retroviral integration analysis, to map transcripts, promoters, enhancers, and super-enhancers in prospectively isolated keratinocytes and transit-amplifying progenitors, and retrospectively defined keratinocyte stem cells. [Stem Cell Reports] Full Article Immobilized Epidermal Growth Factor Stimulates Persistent, Directed Keratinocyte Migration via Activation of PLCγ1 To address the hypothesis that tethered epidermal growth factor (EGF) can stimulate cell behaviors not achievable with soluble EGF, researchers examined single-cell movement and signaling in human immortalized keratinocytes treated with soluble or immobilized EGF. [FASEB J] Abstract The Influence of Citrate or PEG Coating on Silver Nanoparticle Toxicity to a Human Keratinocyte Cell Line Human keratinocytes were exposed for 24 and 48 hours to well-characterized 30 nm AgNPs coated either with citrate or with poly(ethylene glycol), and assessed for cell viability, reactive oxygen species, cytokine release, apoptosis and cell cycle dynamics. [Toxicol Lett] Abstract Effects of UV Rays and Thymol/Thymus vulgaris L. Extract in an Ex Vivo Human Skin Model: Morphological and Genotoxicological Assessment Scientists compared the acute effects induced by ultraviolet (UV)A and UVB rays on epidermal morphology and proliferation, cytotoxicity, and genotoxicity. Normal human skin explants were obtained from young healthy women after informed consent and cultured at the air-liquid interface overnight. [Cells Tissues Organs] Abstract Bioengineering a 3D Integumentary Organ System from iPS Cells Using an In Vivo Transplantation Model Researchers developed a novel in vivo transplantation model designated as a clustering-dependent embryoid body transplantation method and generated a bioengineered three-dimensional (3D) integumentary organ system, including appendage organs such as hair follicles and sebaceous glands, from induced pluripotent stem cells. [Sci Adv] Abstract | Press Release SKIN CANCERS & DISORDERS KLF13 Regulates the Differentiation-Dependent Human Papillomavirus Life Cycle in Keratinocytes through STAT5 and IL-8 Researchers showed that the transcription factor Kruppel-like factor 13 (KLF13) has a critical role in the human papillomavirus (HPV) life cycle. KLF13 is overexpressed in HPV-positive keratinocytes and cervical cancer cell lines. [Oncogene] Abstract Keratinocytes Express Functional CARD18, a Negative Regulator of Inflammasome Activation, and Its Altered Expression in Psoriasis May Contribute to Disease Pathogenesis Scientists demonstrated that keratinocytes express caspase recruitment domain family member 18 (CARD18) both at mRNA and protein levels and the expression increased in parallel with differentiation. The investigation of cellular inflammatory processes revealed that psoriasis-associated danger signals triggered the expression of inflammasome components and CARD18 as well as IL-1β production of keratinocytes. [Mol Immunol] Abstract Sakuranetin Induces Melanogenesis in B16BL6 Melanoma Cells through Inhibition of ERK and PI3K/AKT Signaling Pathways Investigators determined that sakuranetin strongly stimulates melanogenesis in B16BL6 melanoma cells in a dose-dependent manner. [Phytother Res] Abstract |