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1.
Nat Commun ; 11(1): 6221, 2020 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-33277488

RESUMO

Peroxisomes are vital organelles that compartmentalize critical metabolic reactions, such as the breakdown of fats, in eukaryotic cells. Although peroxisomes typically are considered to consist of a single membrane enclosing a protein lumen, more complex peroxisomal membrane structure has occasionally been observed in yeast, mammals, and plants. However, technical challenges have limited the recognition and understanding of this complexity. Here we exploit the unusually large size of Arabidopsis peroxisomes to demonstrate that peroxisomes have extensive internal membranes. These internal vesicles accumulate over time, use ESCRT (endosomal sorting complexes required for transport) machinery for formation, and appear to derive from the outer peroxisomal membrane. Moreover, these vesicles can harbor distinct proteins and do not form normally when fatty acid ß-oxidation, a core function of peroxisomes, is impaired. Our findings suggest a mechanism for lipid mobilization that circumvents challenges in processing insoluble metabolites. This revision of the classical view of peroxisomes as single-membrane organelles has implications for all aspects of peroxisome biogenesis and function and may help address fundamental questions in peroxisome evolution.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Ácidos Graxos/metabolismo , Membranas Intracelulares/metabolismo , Peroxissomos/metabolismo , Arabidopsis/genética , Compartimento Celular , Retículo Endoplasmático/metabolismo , Endossomos/metabolismo , Células Epidérmicas/metabolismo , Microscopia Confocal , Plantas Geneticamente Modificadas , Transporte Proteico , Plântula/citologia , Plântula/metabolismo , Imagem com Lapso de Tempo/métodos
2.
Nat Commun ; 11(1): 5645, 2020 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-33159086

RESUMO

The formation of hair follicles, a landmark of mammals, requires complex mesenchymal-epithelial interactions and it is commonly believed that embryonic epidermal cells are the only cells that can respond to hair follicle morphogenetic signals in vivo. Here, we demonstrate that epithelial stem cells of non-skin origin (e.g. that of cornea, oesophagus, vagina, bladder, prostate) that express the transcription factor Tp63, a master gene for the development of epidermis and its appendages, can respond to skin morphogenetic signals. When exposed to a newborn skin microenvironment, these cells express hair-follicle lineage markers and contribute to hair follicles, sebaceous glands and/or epidermis renewal. Our results demonstrate that lineage restriction is not immutable and support the notion that all Tp63-expressing epithelial stem cells, independently of their embryonic origin, have latent skin competence explaining why aberrant hair follicles or sebaceous glands are sometimes observed in non-skin tissues (e.g. in cornea, vagina or thymus).


Assuntos
Células Epidérmicas/metabolismo , Epiderme/metabolismo , Folículo Piloso/metabolismo , Células-Tronco/metabolismo , Transativadores/metabolismo , Animais , Epiderme/crescimento & desenvolvimento , Feminino , Humanos , Masculino , Camundongos , Ratos , Transativadores/genética
3.
Development ; 147(22)2020 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-33191273

RESUMO

Cell divisions and cell-fate decisions require stringent regulation for proper tissue development and homeostasis. The mammalian epidermis is a highly organized tissue structure that is sustained by epidermal stem cells (ESCs) that balance self-renewal and cell-fate decisions to establish a protective barrier, while replacing dying cells during homeostasis and in response to injury. Extensive work over past decades has provided insights into the regulatory mechanisms that control ESC specification, self-renewal and maintenance during different stages of the lifetime of an organism. In this Review, we discuss recent findings that have furthered our understanding of key regulatory features that allow ESCs to establish a functional barrier during development and to maintain tissue homeostasis in adults.


Assuntos
Células Epidérmicas/metabolismo , Epiderme/embriologia , Epiderme/crescimento & desenvolvimento , Homeostase/genética , Células-Tronco/metabolismo , Animais , Diferenciação Celular/fisiologia , Linhagem da Célula/fisiologia , Proliferação de Células/fisiologia , Autorrenovação Celular/fisiologia , Humanos , Transcrição Genética , Cicatrização/fisiologia
4.
Nat Commun ; 11(1): 5434, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33116143

RESUMO

The interfollicular epidermis (IFE) forms a water-tight barrier that is often disrupted in inflammatory skin diseases. During homeostasis, the IFE is replenished by stem cells in the basal layer that differentiate as they migrate toward the skin surface. Conventionally, IFE differentiation is thought to be stepwise as reflected in sharp boundaries between its basal, spinous, granular and cornified layers. The transcription factor GRHL3 regulates IFE differentiation by transcriptionally activating terminal differentiation genes. Here we use single cell RNA-seq to show that murine IFE differentiation is best described as a single step gradualistic process with a large number of transition cells between the basal and spinous layer. RNA-velocity analysis identifies a commitment point that separates the plastic basal and transition cell state from unidirectionally differentiating cells. We also show that in addition to promoting IFE terminal differentiation, GRHL3 is essential for suppressing epidermal stem cell expansion and the emergence of an abnormal stem cell state by suppressing Wnt signaling in stem cells.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Células Epidérmicas/citologia , Células Epidérmicas/metabolismo , Fatores de Transcrição/metabolismo , Animais , Animais Recém-Nascidos , Diferenciação Celular , Linhagem da Célula , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Epiderme/embriologia , Epiderme/metabolismo , Feminino , Perfilação da Expressão Gênica , Idade Gestacional , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Gravidez , Análise de Célula Única , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética
5.
Nat Commun ; 11(1): 4239, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32843640

RESUMO

How stem cells give rise to epidermis is unclear despite the crucial role the epidermis plays in barrier and appendage formation. Here we use single cell-RNA sequencing to interrogate basal stem cell heterogeneity of human interfollicular epidermis and find four spatially distinct stem cell populations at the top and bottom of rete ridges and transitional positions between the basal and suprabasal epidermal layers. Cell-cell communication modeling suggests that basal cell populations serve as crucial signaling hubs to maintain epidermal communication. Combining pseudotime, RNA velocity, and cellular entropy analyses point to a hierarchical differentiation lineage supporting multi-stem cell interfollicular epidermal homeostasis models and suggest that transitional basal stem cells are stable states essential for proper stratification. Finally, alterations in differentially expressed transitional basal stem cell genes result in severe thinning of human skin equivalents, validating their essential role in epidermal homeostasis and reinforcing the critical nature of basal stem cell heterogeneity.


Assuntos
Diferenciação Celular , Células Epidérmicas/citologia , Homeostase , Células-Tronco/citologia , Comunicação Celular/genética , Diferenciação Celular/genética , Linhagem da Célula/genética , Células Epidérmicas/metabolismo , Epiderme/metabolismo , Prepúcio do Pênis/citologia , Prepúcio do Pênis/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Recém-Nascido , Queratinócitos/citologia , Queratinócitos/metabolismo , Masculino , Modelos Biológicos , Transdução de Sinais , Células-Tronco/metabolismo
6.
Proc Natl Acad Sci U S A ; 117(30): 17796-17807, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32651268

RESUMO

Fluctuation in signal transduction pathways is frequently observed during mammalian development. However, its role in regulating stem cells has not been explored. Here we tracked spatiotemporal ERK MAPK dynamics in human epidermal stem cells. While stem cells and differentiated cells were distinguished by high and low stable basal ERK activity, respectively, we also found cells with pulsatile ERK activity. Transitions from Basalhi-Pulselo (stem) to Basalhi-Pulsehi, Basalmid-Pulsehi, and Basallo-Pulselo (differentiated) cells occurred in expanding keratinocyte colonies and in response to differentiation stimuli. Pharmacological inhibition of ERK induced differentiation only when cells were in the Basalmid-Pulsehi state. Basal ERK activity and pulses were differentially regulated by DUSP10 and DUSP6, leading us to speculate that DUSP6-mediated ERK pulse down-regulation promotes initiation of differentiation, whereas DUSP10-mediated down-regulation of mean ERK activity promotes and stabilizes postcommitment differentiation. Levels of MAPK1/MAPK3 transcripts correlated with DUSP6 and DUSP10 transcripts in individual cells, suggesting that ERK activity is negatively regulated by transcriptional and posttranslational mechanisms. When cells were cultured on a topography that mimics the epidermal-dermal interface, spatial segregation of mean ERK activity and pulses was observed. In vivo imaging of mouse epidermis revealed a patterned distribution of basal cells with pulsatile ERK activity, and down-regulation was linked to the onset of differentiation. Our findings demonstrate that ERK MAPK signal fluctuations link kinase activity to stem cell dynamics.


Assuntos
Diferenciação Celular , Células Epidérmicas/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células-Tronco/metabolismo , Animais , Técnicas de Cultura de Células , Proliferação de Células , Ativação Enzimática , Células Epidérmicas/citologia , Queratinócitos/metabolismo , Mamíferos , Camundongos , Fosfoproteínas Fosfatases/metabolismo , Transdução de Sinais , Células-Tronco/citologia
7.
Cell Prolif ; 53(9): e12881, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32700456

RESUMO

OBJECTIVES: EREG (epiregulin), a member of the epidermal growth factor (EGF) family, plays a role in inflammation, wound healing, normal physiology and malignancies. However, little is known about its function on hair growth. MATERIALS AND METHODS: Cell growth assay, QPCR and immunostaining were carried out. Telogen-to-anagen transition and organ culture were conducted. ROS level was monitored by staining DCFDA. RESULTS: We investigated the hair inductive effect of EREG and the mechanism of stimulation on DPCs and ORS cells during hair cycling. Whereas EREG promoted hair growth, EREG knockdown inhibited hair growth as evidenced by telogen-to-anagen transition and organ culture models. EREG was expressed in epidermal cells including ORS cells in vivo. EREG activated phospho-ErbB4 in DPCs during hair cycling and stimulated DPCs via ErbB4 activation in vitro. In terms of the underlying mechanism, reactive oxygen species (ROS) played a key role in DPC stimulation. EREG also activated phospho-EGF receptor (EGFR) in epidermal cells including matrix and ORS cells in vivo and stimulated ORS cells via EGFR activation in vitro. CONCLUSIONS: EREG, which is released from ORS cells, activated EGFR and ErbB4 on epidermal cells and DPCs during hair cycling, respectively. As a result, EREG stimulated epidermal cells a positive feedback and DPCs via regulating ROS generation for hair growth. Therefore, EREG therapy may be a novel solution for hair loss treatment.


Assuntos
Epirregulina/metabolismo , Receptores ErbB/metabolismo , Cabelo/crescimento & desenvolvimento , Receptor ErbB-4/metabolismo , Animais , Linhagem Celular , Proliferação de Células , Derme/citologia , Derme/metabolismo , Células Epidérmicas/citologia , Células Epidérmicas/metabolismo , Epiderme/metabolismo , Cabelo/metabolismo , Humanos , Masculino , Camundongos , Espécies Reativas de Oxigênio/metabolismo
8.
Nat Commun ; 11(1): 2988, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32532976

RESUMO

Tissue homeostasis requires regulation of cell-cell communication, which relies on signaling molecules and cell contacts. In skin epidermis, keratinocytes secrete factors transduced by melanocytes into signaling cues promoting their pigmentation and dendrite outgrowth, while melanocytes transfer melanin pigments to keratinocytes to convey skin photoprotection. How epidermal cells integrate these functions remains poorly characterized. Here, we show that caveolae are asymmetrically distributed in melanocytes and particularly abundant at the melanocyte-keratinocyte interface in epidermis. Caveolae in melanocytes are modulated by ultraviolet radiations and keratinocytes-released factors, like miRNAs. Preventing caveolae formation in melanocytes increases melanin pigment synthesis through upregulation of cAMP signaling and decreases cell protrusions, cell-cell contacts, pigment transfer and epidermis pigmentation. Altogether, we identify that caveolae serve as molecular hubs that couple signaling outputs from keratinocytes to mechanical plasticity of pigment cells. The coordination of intercellular communication and contacts by caveolae is thus crucial to skin pigmentation and tissue homeostasis.


Assuntos
Cavéolas/metabolismo , Queratinócitos/metabolismo , Melanócitos/metabolismo , Pigmentação da Pele/fisiologia , Pele/metabolismo , Caveolina 1/metabolismo , Comunicação Celular/fisiologia , Comunicação Celular/efeitos da radiação , Células Cultivadas , Técnicas de Cocultura , Células Epidérmicas/metabolismo , Epiderme/metabolismo , Epiderme/ultraestrutura , Células HeLa , Humanos , Queratinócitos/citologia , Melanócitos/citologia , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Transdução de Sinais/fisiologia , Transdução de Sinais/efeitos da radiação , Pele/citologia , Pele/ultraestrutura , Raios Ultravioleta
9.
Nat Cell Biol ; 22(7): 779-790, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32451440

RESUMO

Tissue stem cells are the cell of origin for many malignancies. Metabolites regulate the balance between self-renewal and differentiation, but whether endogenous metabolic pathways or nutrient availability predispose stem cells towards transformation remains unknown. Here, we address this question in epidermal stem cells (EpdSCs), which are a cell of origin for squamous cell carcinoma. We find that oncogenic EpdSCs are serine auxotrophs whose growth and self-renewal require abundant exogenous serine. When extracellular serine is limited, EpdSCs activate de novo serine synthesis, which in turn stimulates α-ketoglutarate-dependent dioxygenases that remove the repressive histone modification H3K27me3 and activate differentiation programmes. Accordingly, serine starvation or enforced α-ketoglutarate production antagonizes squamous cell carcinoma growth. Conversely, blocking serine synthesis or repressing α-ketoglutarate-driven demethylation facilitates malignant progression. Together, these findings reveal that extracellular serine is a critical determinant of EpdSC fate and provide insight into how nutrient availability is integrated with stem cell fate decisions during tumour initiation.


Assuntos
Carcinoma de Células Escamosas/patologia , Transformação Celular Neoplásica/patologia , Células Epidérmicas/patologia , Ácidos Cetoglutáricos/metabolismo , Serina/metabolismo , Células-Tronco/patologia , Animais , Carcinoma de Células Escamosas/metabolismo , Diferenciação Celular , Transformação Celular Neoplásica/metabolismo , Células Cultivadas , Células Epidérmicas/metabolismo , Feminino , Humanos , Masculino , Camundongos , Células-Tronco/metabolismo
10.
Biochim Biophys Acta Mol Cell Res ; 1867(8): 118722, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32302667

RESUMO

Dermal fibroblasts seem critical for epidermal maturation and differentiation and recent work demonstrated that diseased fibroblasts may drive pathophysiological processes. Nevertheless, still very little is known about the actual crosstalk between epidermal keratinocytes and dermal fibroblasts and the impact of dermal fibroblasts on epidermal maturation and differentiation. Aiming for a more fundamental understanding of the impact of the cellular crosstalk between keratinocytes and fibroblasts on the skin homeostasis, we generated full-thickness skin equivalents with and without fibroblasts and subsequently analysed them for the expression of skin differentiation markers, their barrier function, skin lipid content and epidermal cell signalling. Skin equivalents without fibroblasts consistently showed an impaired differentiation and dysregulated expression of skin barrier and tight junction proteins, increased skin permeability, and a decreased skin lipid/protein ratio. Most interestingly, impaired Ras/Raf/ERK/MEK signalling was evident in skin equivalents without fibroblasts. Our data clearly indicate that the epidermal-dermal crosstalk between keratinocytes and fibroblasts is critical for adequate skin differentiation and that fibroblasts orchestrate epidermal differentiation processes.


Assuntos
Células Epidérmicas/metabolismo , Fibroblastos/metabolismo , Homeostase/fisiologia , Queratinócitos/metabolismo , Pele/metabolismo , Diferenciação Celular , Células Epidérmicas/patologia , Epiderme/metabolismo , Homeostase/genética , Humanos , Queratinócitos/patologia , Permeabilidade , Pele/patologia , Absorção Cutânea
11.
Cell ; 181(3): 492-494, 2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32234524

RESUMO

The 2020 Canada Gairdner International Award has been awarded to Elaine Fuchs for her discovery of the role of adult skin stem cells in homeostasis, wound repair, inflammation, and cancer. These insights have established a foundation for basic knowledge on how adult stem cells form, maintain, and repair tissues and have provided the groundwork for additional exploration and discovery of pathways in other stem cell systems.


Assuntos
Células-Tronco Adultas/metabolismo , Células-Tronco Adultas/fisiologia , Pele/metabolismo , Animais , Distinções e Prêmios , Canadá , Células Epidérmicas/metabolismo , Feminino , História do Século XX , História do Século XXI , Homeostase/fisiologia , Humanos , Neoplasias/metabolismo , Cicatrização/fisiologia
12.
Cell ; 181(3): 604-620.e22, 2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32259486

RESUMO

During embryonic and postnatal development, organs and tissues grow steadily to achieve their final size at the end of puberty. However, little is known about the cellular dynamics that mediate postnatal growth. By combining in vivo clonal lineage tracing, proliferation kinetics, single-cell transcriptomics, and in vitro micro-pattern experiments, we resolved the cellular dynamics taking place during postnatal skin epidermis expansion. Our data revealed that harmonious growth is engineered by a single population of developmental progenitors presenting a fixed fate imbalance of self-renewing divisions with an ever-decreasing proliferation rate. Single-cell RNA sequencing revealed that epidermal developmental progenitors form a more uniform population compared with adult stem and progenitor cells. Finally, we found that the spatial pattern of cell division orientation is dictated locally by the underlying collagen fiber orientation. Our results uncover a simple design principle of organ growth where progenitors and differentiated cells expand in harmony with their surrounding tissues.


Assuntos
Células Epidérmicas/metabolismo , Epiderme/crescimento & desenvolvimento , Pele/crescimento & desenvolvimento , Animais , Animais não Endogâmicos , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Linhagem da Célula/genética , Proliferação de Células/fisiologia , Células Cultivadas , Células Epidérmicas/patologia , Epiderme/metabolismo , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Células-Tronco/citologia
13.
Adv Wound Care (New Rochelle) ; 9(4): 161-173, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32117580

RESUMO

Objective: Activation of epidermal stem cells (EpSCs) from their quiescent niche is an integral component of wound reepithelialization and involves Wnt/ß-catenin (ß-Cat) signaling and remodeling of the actin cytoskeleton. The aim of this study was to investigate the effect of Flightless I (Flii), a cytoskeletal protein and inhibitor of wound healing, on EpSC activation during wound repair. Approach: Genetically modified Flii mice (Flii knockdown: Flii+/- , wild type: WT, Flii overexpressing: FliiTg/Tg ) received two incisional wounds along the lateral axis of the dorsal skin. Indicators of EpSC activation (epidermal growth factor receptor 1 [EGFR1], leucine-rich repeats and immunoglobulin-like domains-1 [Lrig1], K14), Wnt/ß-Cat signaling (Lgr6, Flap2, ß-Cat, and axis inhibition protein 2 [Axin2]), and cell proliferation (proliferating cell nuclear antigen [PCNA]) were assessed using immunohistochemistry. ß-Cat stabilization was examined using western blotting with cell cycling and differentiation of isolated CD34+ITGA6high EpSCs examined using real time-quantitative polymerase chain reaction after treatment with wound-conditioned media. Results: Flii+/- led to increased numbers of activated EpSCs expressing PCNA, elevated EGFR1, and decreased Lrig1. EpSCs in Flii+/- hair follicle niches adjacent to the wounds also showed expression of Wnt-activation markers including increased ß-Cat and Lgr6, and decreased Axin2. EpSCs (CD34+ITGA6high) isolated from Flii+/- unwounded skin showed elevated expression of cell-cycling genes including ΔNp63, filaggrin (Fila), involucrin (Invo), cyclin D1 (Ccnd1), and cell-division cycle protein-20 (Cdc20); and elevated ΔNp63 and Invo after treatment with wound-conditioned media compared with WT and FliiTg/Tg counterparts. Innovation: Flii was identified as an inhibitor of EpSC activation that may explain its negative effects on wound reepithelialization. Conclusion: Flii may inhibit EpSC activation by interrupting Wnt/ß-Cat signaling. Strategies that reduce Flii may increase activation of EpSCs and promote reepithelialization of wounds.


Assuntos
Células Epidérmicas/metabolismo , Proteínas dos Microfilamentos/metabolismo , Nicho de Células-Tronco/genética , Células-Tronco/metabolismo , Transativadores/metabolismo , Cicatrização/genética , Animais , Proliferação de Células/genética , Modelos Animais de Doenças , Feminino , Técnicas de Silenciamento de Genes , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Proteínas dos Microfilamentos/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Pele/lesões , Pele/metabolismo , Transativadores/genética , Via de Sinalização Wnt/genética , beta Catenina/metabolismo
14.
Genes Cells ; 25(6): 391-401, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32167217

RESUMO

Vesicular transport serves as an important mechanism for cell shape regulation during development. Although the semaphorin signaling molecule, a well-known regulator of axon guidance, induces endocytosis in the growth cone and the axonal transport of vertebrate neurons, the underlying molecular mechanisms remain largely unclear. Here, we show that the Caenorhabditis elegans SNT-1/synaptotagmin-UNC-41/stonin2 system, whose role in synaptic vesicle recycling in neurons has been studied extensively, is involved in semaphorin-regulated vesicular transport in larval epidermal cells. Mutations in the snt-1/unc-41 genes strongly suppressed the cell shape defects of semaphorin mutants. The null mutation in the semaphorin receptor gene, plx-1, altered the expression and localization pattern of endocytic and exocytic markers in the epidermal cells while repressing the transport of SNT-1-containing vesicles toward late endosome/lysosome pathways. Our findings suggest that the nematode semaphorins regulate the vesicular transport in epidermal cells in a manner distinct from that of vertebrate semaphorins in neurons.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Células Epidérmicas/metabolismo , Semaforinas/metabolismo , Vesículas Sinápticas/metabolismo , Sinaptotagminas/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Animais , Animais Geneticamente Modificados , Transporte Biológico Ativo/genética , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Endocitose/genética , Endossomos/genética , Endossomos/metabolismo , Exocitose/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Lisossomos/genética , Lisossomos/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Interferência de RNA , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Semaforinas/genética , Transdução de Sinais/genética , Sinaptotagminas/genética , Proteínas de Transporte Vesicular/genética
15.
Int J Mol Sci ; 21(7)2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32218335

RESUMO

The terminal differentiation of the epidermis is a complex physiological process. During the past few decades, medical genetics has shown that defects in the stratum corneum (SC) permeability barrier cause a myriad of pathological conditions, ranging from common dry skin to lethal ichthyoses. Contrarily, molecular phylogenetics has revealed that amniotes have acquired a specialized form of cytoprotection cornification that provides mechanical resilience to the SC. This superior biochemical property, along with desiccation tolerance, is attributable to the proper formation of the macromolecular protein-lipid complex termed cornified cell envelopes (CE). Cornification largely depends on the peculiar biochemical and biophysical properties of loricrin, which is a major CE component. Despite its quantitative significance, loricrin knockout (LKO) mice have revealed it to be dispensable for the SC permeability barrier. Nevertheless, LKO mice have brought us valuable lessons. It is also becoming evident that absent loricrin affects skin homeostasis more profoundly in many more aspects than previously expected. Through an extensive review of aggregate evidence, we discuss herein the functional significance of the thiol-rich protein loricrin from a biochemical, genetic, pathological, metabolic, or immunological aspect with some theoretical and speculative perspectives.


Assuntos
Proteínas de Membrana/metabolismo , Animais , Diferenciação Celular , Permeabilidade da Membrana Celular , Células Epidérmicas/citologia , Células Epidérmicas/metabolismo , Epiderme/metabolismo , Homeostase , Humanos , Proteínas de Membrana/genética
16.
Chem Biol Interact ; 321: 109025, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-32135139

RESUMO

Epigenetic regulation is one of the driving forces in the process of carcinogenesis. Corosolic acid (CA); triterpenoid abundantly found in Lagerstroemia speciosa L. is known to modulate various cellular process including cellular oxidative stress and signaling kinases in various diseases, including skin cancer. Genetic mutations in early stages of skin cancer are well-documented, the epigenetic alterations remain elusive. In the present study, we identified the transcriptomic gene expression changes with RNAseq and genome-wide DNA CpG methylation changes with DNA methylseq to profile the early stage transcriptomic and epigenomic changes using tumor promoter TPA-mediated mouse epidermal epithelial JB6 P+ cells. JB6 P+ cells were treated with TPA and Corosolic acid by 7.5uM optimized by MTS assay. Differentiated expressed genes (DEGs) and Differentially methylated genes (DMRs) were analyzed by R software. Ingenuity Pathway Analysis (IPA) was employed to understand the differential regulation of specific pathways. Novel TPA induced differentially overexpressed genes like tumor promoter Prl2c2, small prolin rich protein (Sprr2h) was reported which was downregulated by corosolic acid treatment. Several cancer related pathways were identified by Ingenuity Pathways Analysis (IPA) including p53, Erk, TGF beta signaling pathways. Moreover, differentially methylated regions (DMRs) in genes like Dusp22 (Dual specificity protein phosphatase 22), Rassf (tumor suppressor gene family, Ras association domain family) in JB6 P+ cells were uncovered which are altered by TPA and are reversed by CA treatment. Interestingly, genes like CDK1 (Cyclin-dependent kinases 1) and RASSF2 (Ras association domain family member 2) observed to be differentially methylated and expressed which was further modulated by corosolic acid treatment, validated by qPCR. Given study indicated gene expression changes to DNA CpG methylation epigenomic changes modulated various molecular pathways in TPA-induced JB6 cells and revealed that CA can potentially reverse these changes which deciphering novel molecular targets for future prevention of early stages of skin cancer studies in human.


Assuntos
Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/metabolismo , Metilação de DNA/efeitos dos fármacos , Células Epidérmicas/efeitos dos fármacos , Células Epidérmicas/metabolismo , Triterpenos/farmacologia , Animais , Carcinógenos/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Transformação Celular Neoplásica/genética , Ilhas de CpG/efeitos dos fármacos , Células Epidérmicas/patologia , Epigênese Genética/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Camundongos , Compostos Fitoquímicos/farmacologia , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/metabolismo , Acetato de Tetradecanoilforbol/toxicidade , Transcriptoma/efeitos dos fármacos
17.
In Vitro Cell Dev Biol Anim ; 56(3): 200-212, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32198676

RESUMO

Simulated microgravity can significantly affect various cell types and multiple systems of the human body, such as cardiovascular system, skeletal muscle system, and immune system, and is known to cause anemia and loss of electrolyte and fluids. Epidermal stem cells (EpSCs) were cultured in a rotary cell culture system (RCCS) bioreactor to simulate microgravity. The metabolites of EpSCs were identified by liquid chromatography-mass spectrometry (LC-MS). Compared with normal gravity (NG) group, a total of 57 different metabolites of EpSCs were identified (P < 0.05, VIP > 1), including lipids and lipid-like molecules (51 molecules), amino acids (5 molecules), nucleosides, nucleotides, and analogues (1 molecule). According to the partial least squares discriminant analysis (PLS-DA) score plot, a VIP > 1 and P < 0.05 were obtained for the 57 different metabolites, of which 23 molecules were significantly downregulated and 34 were significantly upregulated in simulated microgravity (SMG) group. These results showed that SMG has a significant impact on different pathways, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that multiple pathways were involved, mainly the amino acid metabolism pathway, lipid metabolism pathway, membrane transport pathway, and cell growth and death pathways. Thus, the metabolic profile of EpSCs was changed under SMG. Exploring the metabolic profile of EpSCs would be helpful to further understand the growth characteristics of EpSCs under SMG, which will provide a new approach to explore the metabolomics mechanism of stress injury and repair trauma under SMG.


Assuntos
Células Epidérmicas/metabolismo , Células-Tronco/metabolismo , Simulação de Ausência de Peso , Células Cultivadas , Gravitação , Humanos , Metabolismo dos Lipídeos , Metaboloma , Metabolômica
18.
Cell Tissue Bank ; 21(2): 257-264, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32103403

RESUMO

To characterize the tolerance of different types of human epidermal cells to trypsinization in vitro and develop a new method to separate and purify melanocytes according to their tolerance to trypsinization. Epidermal cells were obtained by separating the epidermis from human foreskins. Some of those cells were used for routine culture, and then were subjected to differential trypsin digestion. The remaining epidermal cells were resuspended in a 0.25% trypsin solution and then were neutralized by the addition of bovine serum at different time points. Immunofluorescence staining of HMB45, K15 and vimentin was used to identify melanocytes, keratinocytes and fibroblasts, respectively. We found that Keratinocytes, melanocytes and fibroblasts are primary cells obtained from conventional cultures of human skin. Purified keratinocytes and melanocytes can be obtained by conventional differential trypsin digestion, but fibroblasts in the melanocyte population quickly gain a survival advantage after passage. With longer trypsin digestion times, the number of adherent cells decreased, the time required for cell attachment increased, and the proportion of melanocytes increased. There were no obvious keratinocytes in cell populations obtained after 12 h of trypsinization of epidermal cells, and more short spindle-shaped melanocytes appeared, all of which were HMB45-positive. In conclusion, the tolerance of human epidermal melanocytes to trypsinization in vitro was better than epidermal keratinocytes, and that property can be used to purify melanocytes and was better than traditional differential trypsin digestion. The morphology of cells that survived the long-term trypsin digestion changed and they had good proliferative activity, but seemed to be more immature.


Assuntos
Células Epidérmicas/metabolismo , Tripsina/metabolismo , Células Epidérmicas/citologia , Humanos , Masculino , Melanócitos/citologia
19.
J Plant Physiol ; 245: 153108, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31927218

RESUMO

Wild barley Hordeum spontaneum (WB) is the progenitor of a cultivated barley Hordeum vulgare (CB). Understanding efficient mechanisms evolved by WB to cope with abiotic stresses may open prospects of transferring these promising traits to the high yielding CB genotypes. This study aimed to investigate the strategies that WB plants utilise in regard to the control of stomatal operation and ionic homeostasis to deal with salinity stress, one of the major threats to the global food security. Twenty-six genotypes of WB and CB were grown under glasshouse conditions and exposed to 300 mM NaCl salinity treatment for 5 weeks followed by their comprehensive physiological assessment. WB had higher relative biomass than CB when exposed to salinity stress. Under saline conditions, WB plants were able to keep constant stomatal density (SD) while SD significantly decreased in CB. The higher SD in WB also resulted in a higher stomatal conductance (gs) under saline conditions, with gs reduction being 51% and 72% in WB and CB, respectively. Furthermore, WB showed faster stomatal response to light, indicating their better ability to adapt to changing environmental conditions. Experiments with isolated epidermal strips indicated that CB genotypes have the higher stomatal aperture when incubated in 80 mM KCl solution, and its aperture declined when KCl was substituted by NaCl. On the contrary, WB genotype had the highest stomatal aperture being exposed to 80 mM NaCl suggesting that WB plants may use Na+ instead of K+ for stomata movements. Overall, our data suggest that CB employ a stress-escaping strategy by reducing stomata density, to conserve water, when grown under salinity conditions. WB, on a contrary, is capable of maintaining relatively constant stomata density, faster stomatal movement and higher gs under saline conditions.


Assuntos
Hordeum/fisiologia , Estômatos de Plantas/crescimento & desenvolvimento , Estômatos de Plantas/fisiologia , Tolerância ao Sal/fisiologia , Biomassa , Clorofila/metabolismo , Escuridão , Células Epidérmicas/química , Células Epidérmicas/metabolismo , Células Epidérmicas/fisiologia , Genótipo , Hordeum/metabolismo , Luz , Fenótipo , Folhas de Planta/metabolismo , Estômatos de Plantas/química , Estômatos de Plantas/metabolismo , Potássio/metabolismo , Sódio/metabolismo , Água/metabolismo
20.
Int J Mol Sci ; 21(3)2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31991834

RESUMO

The ß-blocker carvedilol prevents ultraviolet (UV)-induced skin cancer, but the mechanism is unknown. Since carvedilol possesses antioxidant activity, this study investigated whether carvedilol prevents oxidative photodamage of skin, a precursor event in skin carcinogenesis. The effects of carvedilol, metoprolol (a ß-blocker without antioxidant property), and 4-hydroxycarbazole (4-OHC, a carvedilol synthesis intermediate and a free radical scavenger) were compared on UV- or H2O2-induced cell death and reactive oxygen species (ROS) production in murine epidermal JB6 P+ cells. Although carvedilol attenuated cell death, metoprolol and 4-OHC failed to show protective effects. As expected, increased cellular ROS induced by H2O2 or UV was abolished by carvedilol and 4-OHC, but not by metoprolol. Consistently, carvedilol attenuated the formation of UV-induced cyclobutane pyrimidine dimers (CPDs) and release of prostaglandin E2 in JB6 P+ cells. Carvedilol's activity was further confirmed in full thickness 3D human reconstituted skin, where carvedilol attenuated UV-mediated epidermal thickening, the number of Ki-67 and p53 positive cells as well as CPD formation. Based on pathway-specific Polymerase Chain Reaction (PCR) Array analysis, carvedilol treatment in many cases normalized UV-induced expression changes in DNA repair genes. Thus, carvedilol's photoprotective activity is not attributed to ß-blockade or direct ROS-scavenging capacity, but likely via DNA repair regulation.


Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Carvedilol/farmacologia , Células Epidérmicas/efeitos dos fármacos , Células Epidérmicas/efeitos da radiação , Raios Ultravioleta/efeitos adversos , Animais , Técnicas de Cultura de Células , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/efeitos da radiação , Citocinas/metabolismo , Dano ao DNA/efeitos dos fármacos , Dinoprostona/metabolismo , Células Epidérmicas/metabolismo , Humanos , Peróxido de Hidrogênio , Mediadores da Inflamação , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
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