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1.
Int J Cosmet Sci ; 44(6): 703-718, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35980652

RESUMO

OBJECTIVES: The aim of this study was to compare the data of conductance and capacitance measurements of facial skin hydration and to evaluate and discuss the advantages and disadvantages of the different approaches. METHODS: We measured skin capacitance (Corneometer® CM 825) and skin conductance (Skicon-200EX®) on 30 pre-defined facial sites of 125 Chinese women, resulting in 3750 readings per device. The data were analysed and compared, and continuous colour maps were generated on a 3D avatar for capacitance, conductance, relative difference (Δ%) and correlation (R-value) by interpolating between the individual readings and converting the values to colours. This visualization allows a better interpretation of the results. RESULTS: The complexity of facial skin hydration is revealed by this approach. The similarities and discrepancies in the facial hydration maps are clearly apparent. Due to the superiority of the Skicon in measuring high hydration levels, differences in skin hydration were evident on the forehead compared with the Corneometer maps, which may be related to the more superficial measurement of the Skicon within the stratum corneum. Conversely, a greater understanding of the complexity of facial skin hydration in the nasolabial fold was obvious when using the Corneometer. The best congruence between the instruments was found at two specific but separated facial areas, one around the inner eye region and the other one on a line between the nasolabial sulcus and the oblique, lateral jaw. Interestingly, the data were not normally distributed for both instruments and they had opposite skews. All facial clusters were statistically different from each other (p < 0.001), except the cheek and jaw for the Skicon. Larger than expected percentage coefficients of variance were found for the Corneometer on some facial sites that might be explainable by differences in stratum corneum physiology and biochemistry. Corneometer values of 48 AU and Skicon values of 132 µS were taken as the cutoff for normally hydrated facial skin. CONCLUSIONS: Both devices have their advantages and disadvantages suggesting that bio-instrumental measurement of skin hydration is actually more complicated than commonly thought and that the different facial zones and the use of multiple instrumentation have not been adequately considered.


OBJECTIFS: L'objectif de cette étude était de comparer des données issues de mesures d'hydratation de la peau du visage par conductance et capacité électrique, et d'évaluer et discuter les avantages et désavantages de ces différentes approches. METHODES: La capacité électrique de la peau (Corneometer® CM 825) et saconductance (Skicon-200EX®) ont été mesurées en 30 points pré-définis du visage de 125 femmes chinoises, menant ainsi à 3750 mesures par appareil. Les données ont été analysées et comparées, puis transposées visuellement sur avatar 3D via la création de cartographies continues de couleur par conversion de chaque valeur en une coordonnée de couleur et interpolation colorielle entre les différents points. Des cartographies de capacité électrique, de conductance ainsi que celle de la différence relative (Δ%) et de corrélation (R-value) ont été générées, ces visualisations permettant de mieux interpréter les résultats. RESULTS: Cette étude a mis en lumière la complexité de l'hydratation de la peau du visage. Les similarités et différences entre les cartographies d'hydratation faciale apparaissent clairement. Du fait de la supériorité du Skicon pour la mesure de hauts taux d'hydratation, des différences sont clairement visualisées entre les cartographies d'hydratation des deux appareils au niveau du front, et pourraient être dues à une mesure plus superficielle au sein du stratum corneum avec le Skicon. A l'inverse, l'utilisation du Corneometer permet une bien meilleure compréhension de la complexité de l'hydratation de la peau au niveau du sillon nasogénien. Les appareils montrent les résultats les plus similaires au niveau de deux zones spécifiques et séparées du visage, une au niveau du coin interne de l'œil et l'autre sur une ligne séparant le sillon nasolabial et l'oblique latéral de la machoire. Il est intéressant de noter que les distributions des données ne suivent pas une loi normale, pour aucun des deux appareils, et présentent des biais de distribution opposés. Tous les résultats obtenus au niveau des clusters faciaux étudiés montrent des différences statistiquement significatives entre eux (p⟨0.001), à l'exception de la joue et de la mâchoire, avec le Skicon. Des pourcentages de coefficients de variation plus élevés qu'attendus ont été obtenus avec le Corneometer en certaines zones du visage, qui pourraient être expliqués par des différences physiologiques et biochimiques du stratum corneum. Des valeurs de 48 UA avec le Corneometer et de 132 µS avec le Skicon ont été retenues comme valeurs seuil d'une peau du visage normalement hydratée. CONCLUSIONS: Les deux appareils montrent des avantages et désavantages, suggérant que la mesure bio-instrumentale de l'hydratation cutanée du visage est en réalité plus compliquée que communément admise et qu'une approche multiinstrumentale n'a pas été suffisamment considérée à ce jour pour appréhender les différentes zones du visages.


Assuntos
Água Corporal , Pele , Humanos , Feminino , Fenômenos Fisiológicos da Pele , Epiderme/fisiologia , China
2.
PLoS Comput Biol ; 18(8): e1010368, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-36037236

RESUMO

Maintenance of epidermal thickness is critical to the barrier function of the skin. Decreased tissue thickness, specifically in the stratum corneum (the outermost layer of the tissue), causes discomfort and inflammation, and is related to several severe diseases of the tissue. In order to maintain both stratum corneum thickness and overall tissue thickness it is necessary for the system to balance cell proliferation and cell loss. Cell proliferation in the epidermis occurs in the basal layer and causes constant upwards movement in the tissue. Cell loss occurs when dead cells at the top of the tissue are lost to the environment through a process called desquamation. Desquamation is thought to occur through a gradual reduction in adhesion between cells, due to the cleaving of adhesion proteins by enzymes, in the stratum corneum. In this paper we will investigate combining a (mass action) subcellular model of desquamation with a three dimensional (cell centre based) multicellular model of the interfollicular epidermis to better understand maintenance of epidermal thickness. Specifically, our aim is to determine if a hypothesised biological model for the degradation of cell-cell adhesion, from the literature, is sufficient to maintain a steady state tissue thickness. These investigations show the model is able to provide a consistent rate of cell loss in the multicellular model. This loss balances proliferation, and hence maintains a homeostatic tissue thickness. Moreover, we find that multiple proliferative cell populations in the basal layer can be represented by a single proliferative cell population, simplifying investigations with this model. The model is used to investigate a disorder (Netherton Syndrome) which disrupts desquamation. The model shows how biochemical changes can cause disruptions to the tissue, resulting in a reduced tissue thickness and consequently diminishing the protective role of the tissue. A hypothetical treatment result is also investigated: we compare the cases of a partially effective homogeneous treatment (where all cells partially recover) and a totally effective heterogeneous treatment (in which a proportion of the cells totally recover) with the aim to determine the difference in the response of the tissue to these different scenarios. Results show an increased benefit to corneum thickness from the heterogeneous treatment over the homogeneous treatment.


Assuntos
Células Epidérmicas , Epiderme , Adesão Celular , Proliferação de Células , Epiderme/fisiologia , Proteínas/metabolismo
3.
Curr Top Dev Biol ; 150: 129-148, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35817501

RESUMO

The interfollicular epidermis is the multilayered epithelium that forms the outer layer of the skin. It is maintained by stem cells that are attached to a basement membrane, which lies on top of the underlying connective tissue, the dermis. Cells undergo terminal differentiation as they detach from the basement membrane and move toward the outer epidermal surface. Over time, many of the molecular regulators of this process have been identified. It is now is clear that these pathways also receive critical input from the physical properties of the tissue. In this review, we describe how changes in these factors regulate differentiation and how new insights from single cell RNA sequencing could provide validation or challenge to the existing experimental models.


Assuntos
Adesivos , Células Epidérmicas , Adesivos/metabolismo , Diferenciação Celular , Epiderme/fisiologia , Humanos , Pele
4.
Dermatology ; 238(5): 829-836, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35537419

RESUMO

Twenty years after the cloning, characterization, and identification of interleukin (IL)-22 in 2000, the precise biological role of this cytokine in healthy and unhealthy skin is not completely known. The aim of this review is to provide an overview on the recent knowledge available in literature about the origin, sources, targets, molecular mechanism of action, and clinical issues regarding IL-22. Last but not least, recent experimental evidence obtained in a 3D model of organotypic culture of normal human skin highlights its homeostatic role and will be discussed in detail, as personal observations. As most of the data concerning IL-22 immunomodulating activity are obtained from mouse models, this work offers a new perspective on its clinical role. The hypothesis herein advanced is that IL-22 profoundly affects keratinocyte terminal differentiation, whereas, in order to induce a proliferation impairment, a more complex psoriatic-like microenvironment is needed.


Assuntos
Epiderme/fisiologia , Interleucinas/fisiologia , Dermatopatias , Animais , Homeostase , Humanos , Queratinócitos , Camundongos , Psoríase , Pele , Dermatopatias/fisiopatologia
5.
J Wound Care ; 31(4): 294-303, 2022 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-35404699

RESUMO

OBJECTIVE: This study assesses anonymous patient-level data on the use of sub-epidermal moisture (SEM) assessment technology as a tool in the prevention of pressure ulceration in at-risk hospital patients. METHOD: The relationship between technology-generated prompts for clinical action (patient turning, application of pressure redistributing equipment, heel protection or cream) and consequent clinical action was evaluated using data cross-tabulations (using data aggregated over multiple anatomical sites); in a multilevel model with patients clustered within wards, clustered in turn within hospitals, and controlling for additional patient- and institution-level factors; and using receiver operating characteristic (ROC) analyses of anatomy-specific data. The ability of the SEM assessment technology to detect deep and early-stage pressure ulcers/injuries on specific anatomical areas of a patient's body on admission, earlier than visual and tactile skin tissue assessments (STA), was assessed. RESULTS: A total of 15,574 patient assessments ('cases') were reported on 1995 patients. Most incidences of nurse action were in response to a prompt from SEM assessments (4944/5494; 90.0%). An SEM delta (Δ)≥0.6 resulted in nurse action in 4944/13,071 cases (37.8%). The multilevel model revealed strong evidence that SEM Δ prompts were significantly associated with nurse action (p<0.001; adjusted odds ratio: 1.99). CONCLUSION: In this study, SEM assessment technology effectively prompted nurse action moreso than skin reddening diagnosed via trained clinician judgement and STAs. While baseline responses of nurses' actions remained low, with or without SEM Δ prompts, findings verified the 'clinical utility' of SEM assessment technology as an objective prompt for early clinical action over and above existing mechanisms.


Assuntos
Lesão por Pressão , Epiderme/fisiologia , Hospitais , Humanos , Incidência , Lesão por Pressão/diagnóstico , Lesão por Pressão/prevenção & controle , Pele
6.
Sci Rep ; 12(1): 795, 2022 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-35039587

RESUMO

The epidermal basement membrane deteriorates with aging. We previously reported that basement membrane reconstruction not only serves to maintain epidermal stem/progenitor cells in the epidermis, but also increases collagen fibrils in the papillary dermis. Here, we investigated the mechanism of the latter action. Collagen fibrils in the papillary dermis were increased in organotypic human skin culture treated with matrix metalloproteinase and heparinase inhibitors. The expression levels of COL5A1 and COL1A1 genes (encoding collagen type V α 1 chain and collagen type I α 1 chain, respectively) were increased in fibroblasts cultured with conditioned medium from a skin equivalent model cultured with the inhibitors and in keratinocytes cultured on laminin-511 E8 fragment-coated plates. We then examined cytokine expression, and found that the inhibitors increased the expression of PDGF-BB (platelet-derived growth factor consisting of two B subunits) in epidermis. Expression of COL5A1 and COL1A1 genes was increased in cultured fibroblasts stimulated with PDGF-BB. Further, the bifunctional inhibitor hydroxyethyl imidazolidinone (HEI) increased skin elasticity and the thickness of the papillary dermis in the skin equivalent. Taken together, our data suggests that reconstructing the basement membrane promotes secretion of PDGF-BB by epidermal keratinocytes, leading to increased collagen expression at the papillary dermis.


Assuntos
Membrana Basal/fisiologia , Epiderme/fisiologia , Colágenos Associados a Fibrilas/fisiologia , Fibroblastos/metabolismo , Fibroblastos/fisiologia , Regeneração/fisiologia , Envelhecimento da Pele/patologia , Envelhecimento da Pele/fisiologia , Membrana Basal/metabolismo , Becaplermina/genética , Becaplermina/metabolismo , Células Cultivadas , Cadeia alfa 1 do Colágeno Tipo I/genética , Cadeia alfa 1 do Colágeno Tipo I/metabolismo , Colágeno Tipo V/genética , Colágeno Tipo V/metabolismo , Células Epidérmicas/metabolismo , Epiderme/metabolismo , Epiderme/patologia , Colágenos Associados a Fibrilas/genética , Colágenos Associados a Fibrilas/metabolismo , Expressão Gênica , Humanos , Queratinócitos/metabolismo , Metaloproteinases da Matriz/farmacologia , Regeneração/genética
7.
J Invest Dermatol ; 142(1): 77-87.e10, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34284046

RESUMO

HDAC inhibitors show therapeutic promise for skin malignancies; however, the roles of specific HDACs in adult epidermal homeostasis and in disease are poorly understood. We find that homozygous epidermal codeletion of Hdac1 and Hdac2 in adult mouse epidermis causes reduced basal cell proliferation, apoptosis, inappropriate differentiation, and eventual loss of Hdac1/2-null keratinocytes. Hdac1/2-deficient epidermis displays elevated acetylated p53 and increased expression of the senescence gene p16. Loss of p53 partially restores basal proliferation, whereas p16 deletion promotes long-term survival of Hdac1/2-null keratinocytes. In activated GLI2-driven pre-basal cell carcinoma, Hdac1/2 deletion dramatically reduces proliferation and increases apoptosis, and knockout of either p53 or p16 partially rescues both proliferation and basal cell viability. Topical application of the HDAC inhibitor romidepsin to the normal epidermis or to GLI2ΔN-driven lesions produces similar defects to those caused by genetic Hdac1/2 deletion, and these are partially rescued by loss of p16. These data reveal essential roles for HDAC1/2 in maintaining proliferation and survival of adult epidermal and basal cell carcinoma progenitors and suggest that the efficacy of therapeutic HDAC1/2 inhibition will depend in part on the mutational status of p53 and p16.


Assuntos
Carcinoma Basocelular/metabolismo , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Epiderme/fisiologia , Queratinócitos/fisiologia , Neoplasias Cutâneas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Antibióticos Antineoplásicos/farmacologia , Antibióticos Antineoplásicos/uso terapêutico , Apoptose , Carcinogênese , Carcinoma Basocelular/tratamento farmacológico , Carcinoma Basocelular/genética , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Inibidor p16 de Quinase Dependente de Ciclina/genética , Depsipeptídeos/farmacologia , Depsipeptídeos/uso terapêutico , Histona Desacetilase 1/antagonistas & inibidores , Histona Desacetilase 1/genética , Histona Desacetilase 2/antagonistas & inibidores , Histona Desacetilase 2/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Lesões Pré-Cancerosas , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/genética , Proteína Supressora de Tumor p53/genética
8.
Skin Res Technol ; 28(2): 382-387, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34751477

RESUMO

INTRODUCTION: Skin provides critical barrier properties that enable terrestrial life. Myriad research has focused on the "water barrier" to transepidermal water loss (TEWL) despite there being a multitude of skin barrier properties. We asked what other barrier properties may have been overlooked and compiled data demonstrating the "electrolyte barrier" to be of potential clinical relevance. METHODS: A literature search was conducted through PubMed, Embase, Google Scholar, and Web of Science databases for the following keywords: "transepidermal" or "epidermal" or "cutaneous" or "skin" or "percutaneous" and "ion" or "sodium" or "chloride" or "potassium" or "electrolyte" and "flux" or "egression." Textbooks at the University of California, San Francisco were also hand reviewed. Experimental studies quantifying in vivo or ex vivo percutaneous egression of ions in response to human skin barrier perturbation were included. RESULTS: Experimental damage to skin, mostly by tape-stripping, frequently induced increased ion flux rates through the epidermis, in addition to increases in TEWL values. Interestingly, barrier perturbation did not always result in a concomitant rise in TEWL and transepidermal ion flux rates, such as in delipidization, indicating a distinction between the two barriers. CONCLUSION: Quantifying the percutaneous egression of ions in response to physical or chemical alterations may offer additional data that are not to be captured with TEWL studies exclusively. Continued efforts should be made to: (1) advance this technique as a method of assessing skin status and (2) enhance our understanding of other barriers and mechanisms.


Assuntos
Pele , Perda Insensível de Água , Epiderme/fisiologia , Humanos , Pele/metabolismo , Absorção Cutânea , Água/metabolismo , Perda Insensível de Água/fisiologia
9.
Exp Dermatol ; 31(4): 459-474, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34726302

RESUMO

It was long considered that the role of epidermal keratinocytes is solely to construct a water-impermeable protective membrane, the stratum corneum, at the uppermost layer of the skin. However, in the last two decades, it has been found that keratinocytes contain multiple sensory systems that detect environmental changes, including mechanical stimuli, sound, visible radiation, electric fields, magnetic fields, temperature and chemical stimuli, and also a variety of receptor molecules associated with olfactory or taste sensation. Moreover, neurotransmitters and their receptors that play crucial roles in the brain are functionally expressed in keratinocytes. Recent studies have demonstrated that excitation of keratinocytes can induce sensory perception in the brain. Here, we review the sensory and information processing capabilities of keratinocytes. We discuss the possibility that epidermal keratinocytes might represent the earliest stage in the development of the brain during the evolution of vertebrates.


Assuntos
Epiderme , Queratinócitos , Animais , Epiderme/fisiologia , Queratinócitos/fisiologia , Pele
10.
Med Sci Monit ; 27: e932978, 2021 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-34923566

RESUMO

Chronic wounds have become an increasing medical and economic problem of aging societies because they are difficult to manage. Tissue engineering provides new perspectives for the clinically applicable skin substitutes. Epidermal keratinocytes play an important role in wound epithelization and construction of tissue-engineered skin substitutes. How to obtain a large number of autologous epidermal keratinocytes in a short time is the main problem that limits the application of tissue-engineered skin and epidermal cell membranes. Developing an appropriate method for reproducing the biological potential of cell-cell interactions and simulating the three-dimensional structure between cells has great significance for epidermal keratinocytes expansion and full-thickness skin regeneration. In this article, we propose the concept of tissue-engineered skin regeneration units (TESRUs) as the smallest unit with complete full-thickness skin regeneration ability. First, autologous dermal fibroblasts are cultured in biodegradable macroporous microcarriers to provide the mesenchyme support. Second, autologous epidermal keratinocytes and autologous melanocytes are incubated with the fibroblasts-loaded microcarriers and expand in vitro. Incorporating the above co-culture method into the macroporous microcarriers is reasonable for maintaining cell-cell interactions in spatial and temporal context and providing a suitable growth niche for epidermal keratinocytes. Moreover, TESRUs are composed of fibroblasts, keratinocytes, and melanocytes and have complete full-thickness skin regeneration ability. We suggest that TESRUs could be a promising strategy to repair full-thickness skin defects for clinical applications if the hypothesis proves to be practical.


Assuntos
Epiderme/crescimento & desenvolvimento , Queratinócitos/fisiologia , Regeneração/fisiologia , Engenharia Tecidual/métodos , Cicatrização , Epiderme/fisiologia , Humanos , Modelos Biológicos
11.
Int J Mol Sci ; 22(21)2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34769105

RESUMO

The epidermis is a living, multilayered barrier with five functional levels, including a physical, a chemical, a microbial, a neuronal, and an immune level. Altogether, this complex organ contributes to protect the host from external aggression and to preserve its integrity. In this review, we focused on the different functional aspects.


Assuntos
Epiderme/fisiologia , Epiderme/microbiologia , Humanos , Imunidade , Microbiota , Células Receptoras Sensoriais/fisiologia
12.
ACS Appl Mater Interfaces ; 13(46): 55747-55755, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34780689

RESUMO

Precisely detecting epidermal pulse waves with pressure sensors is crucial for pulse-based personalized health-monitoring technologies. However, developing a pressure sensor that simultaneously demonstrates high sensitivity and an ultrabroad pressure range and a convenient fabrication process for large-scale production is a considerable challenge. Herein, by utilizing a commercial conductive fabric (CF) and a silica gel film, we develop a high-performance pressure sensor (HPPS) for the monitoring of human physiological signals. Based on convenient turnover formwork technology, the silica gel film was fabricated by replicating the microstructure of the sandpaper surface. This microstructure and the plain weave structure on the CF surface together provide a sharp increase in the contact-separation area and structural compressibility, which are beneficial for the enhancement of output performance. Made of these two materials, the graded microstructured HPPS holds high sensitivity (4.5 mV/Pa), an ultrabroad pressure range (0-30 kPa), a wide working frequency bandwidth (up to 35 Hz), decent stability (>50,000 cycles), and a simple fabrication process that is suitable for large-scale production. Given these noticeable features, the developed HPPS not only succeeds in precisely detecting subtle pulse waves on various positions of different people but can also objectively capture changes in cardiovascular parameters caused by exercise training at different intensities in real time. These findings exhibit the enormous potential application of HPPS in tracking an individual's health status and comprehensively evaluating exercise intensity.


Assuntos
Epiderme/fisiologia , Monitorização Fisiológica , Pulso Arterial , Dispositivos Eletrônicos Vestíveis , Condutividade Elétrica , Géis/química , Humanos , Tamanho da Partícula , Pressão , Dióxido de Silício/química , Têxteis
13.
Nat Genet ; 53(11): 1564-1576, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34650237

RESUMO

Transcription factors bind DNA sequence motif vocabularies in cis-regulatory elements (CREs) to modulate chromatin state and gene expression during cell state transitions. A quantitative understanding of how motif lexicons influence dynamic regulatory activity has been elusive due to the combinatorial nature of the cis-regulatory code. To address this, we undertook multiomic data profiling of chromatin and expression dynamics across epidermal differentiation to identify 40,103 dynamic CREs associated with 3,609 dynamically expressed genes, then applied an interpretable deep-learning framework to model the cis-regulatory logic of chromatin accessibility. This analysis framework identified cooperative DNA sequence rules in dynamic CREs regulating synchronous gene modules with diverse roles in skin differentiation. Massively parallel reporter assay analysis validated temporal dynamics and cooperative cis-regulatory logic. Variants linked to human polygenic skin disease were enriched in these time-dependent combinatorial motif rules. This integrative approach shows the combinatorial cis-regulatory lexicon of epidermal differentiation and represents a general framework for deciphering the organizational principles of the cis-regulatory code of dynamic gene regulation.


Assuntos
Epiderme/fisiologia , Modelos Genéticos , Elementos Reguladores de Transcrição , Diferenciação Celular/genética , Cromatina/genética , Epigenoma , Regulação da Expressão Gênica , Genes Reporter , Estudo de Associação Genômica Ampla , Humanos , Queratinócitos/citologia , Queratinócitos/fisiologia , Redes Neurais de Computação , Dermatopatias/genética , Fatores de Transcrição/genética
14.
PLoS One ; 16(8): e0256025, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34379702

RESUMO

Many cephalopods such as octopi and squid can purposefully and rapidly change their skin color. Furthermore, it is widely known that some octopi have the ability to rapidly change the color and unevenness of their skin to mimic their surroundings. However, there has been little research published on the mechanisms by which an octopus recognizes its surrounding landscape and changes its skin pattern. We are unaware of any hypothetical model that explains this mimicry mechanism to date. In this study, the mechanism of octopus skin pattern change was assumed to be based on the Turing pattern model. Here, pattern formation using the Turing model was realized using an equivalent filter calculation model and a cellular automaton instead of directly solving the differential equations. It was shown that this model can create various patterns using two feature parameters. Furthermore, for visual recognition where two features are extracted from the Turing pattern image, a method that requires minimal calculation using the characteristics of the cellular Turing pattern model is proposed. These two calculations can be expressed in the same mathematical frame based on the cellular automaton model using a convolution filter. As a result, a model that is capable of extracting features from patterns and reconstructing those patterns rapidly can be created. This represents a basic model of the mimicry mechanism of octopi. Further, this study demonstrates the potential for creating a model with minimal learning calculation for application to machine learning.


Assuntos
Biomimética , Padronização Corporal , Simulação por Computador , Epiderme/fisiologia , Modelos Biológicos , Octopodiformes/fisiologia , Pigmentação da Pele , Animais
15.
Int J Mol Sci ; 22(16)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34445339

RESUMO

Both agonist studies and loss-of-function models indicate that PPARγ plays an important role in cutaneous biology. Since PPARγ has a high level of basal activity, we hypothesized that epidermal PPARγ would regulate normal homeostatic processes within the epidermis. In this current study, we performed mRNA sequencing and differential expression analysis of epidermal scrapings from knockout mice and wildtype littermates. Pparg-/-epi mice exhibited a 1.5-fold or greater change in the expression of 11.8% of 14,482 identified transcripts. Up-regulated transcripts included those for a large number of cytokines/chemokines and their receptors, as well as genes associated with inflammasome activation and keratinization. Several of the most dramatically up-regulated pro-inflammatory genes in Pparg-/-epi mouse skin included Igfl3, 2610528A11Rik, and Il1f6. RT-PCR was performed from RNA obtained from non-lesional full-thickness skin and verified a marked increase in these transcripts, as well as transcripts for Igflr1, which encodes the receptor for Igfl3, and the 2610528A11Rik receptor (Gpr15). Transcripts for Il4 were detected in Pparg-/-epi mouse skin, but transcripts for Il17 and Il22 were not detected. Down-regulated transcripts included sebaceous gland markers and a number of genes associated with lipid barrier formation. The change in these transcripts correlates with an asebia phenotype, increased transepidermal water loss, alopecia, dandruff, and the appearance of spontaneous inflammatory skin lesions. Histologically, non-lesional skin showed hyperkeratosis, while inflammatory lesions were characterized by dermal inflammation and epidermal acanthosis, spongiosis, and parakeratosis. In conclusion, loss of epidermal Pparg alters a substantial set of genes that are associated with cutaneous inflammation, keratinization, and sebaceous gland function. The data indicate that epidermal PPARγ plays an important role in homeostatic epidermal function, particularly epidermal differentiation, barrier function, sebaceous gland development and function, and inflammatory signaling.


Assuntos
Dermatite/genética , Epiderme/metabolismo , PPAR gama/fisiologia , Fenômenos Fisiológicos da Pele/genética , Animais , Células Cultivadas , Dermatite/metabolismo , Dermatite/patologia , Dermatite/fisiopatologia , Epiderme/fisiologia , Homeostase/genética , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Especificidade de Órgãos/genética , PPAR gama/genética , PPAR gama/metabolismo
16.
Nat Commun ; 12(1): 4880, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385444

RESUMO

Accurate and imperceptible monitoring of electrophysiological signals is of primary importance for wearable healthcare. Stiff and bulky pregelled electrodes are now commonly used in clinical diagnosis, causing severe discomfort to users for long-time using as well as artifact signals in motion. Here, we report a ~100 nm ultra-thin dry epidermal electrode that is able to conformably adhere to skin and accurately measure electrophysiological signals. It showed low sheet resistance (~24 Ω/sq, 4142 S/cm), high transparency, and mechano-electrical stability. The enhanced optoelectronic performance was due to the synergistic effect between graphene and poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), which induced a high degree of molecular ordering on PEDOT and charge transfer on graphene by strong π-π interaction. Together with ultra-thin nature, this dry epidermal electrode is able to accurately monitor electrophysiological signals such as facial skin and brain activity with low-motion artifact, enabling human-machine interfacing and long-time mental/physical health monitoring.


Assuntos
Eletrodos , Eletrofisiologia/métodos , Epiderme/fisiologia , Desenho de Equipamento/métodos , Monitorização Fisiológica/métodos , Dispositivos Eletrônicos Vestíveis , Artefatos , Compostos Bicíclicos Heterocíclicos com Pontes/química , Condutividade Elétrica , Eletrofisiologia/instrumentação , Eletrofisiologia/normas , Desenho de Equipamento/normas , Grafite/química , Humanos , Estrutura Molecular , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/normas , Movimento (Física) , Polímeros/química , Poliestirenos/química , Pele
17.
Mol Neurobiol ; 58(10): 5327-5337, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34297315

RESUMO

Schwann cells (SCs) are considered potentially attractive candidates for transplantation therapies in neurodegenerative diseases. However, problems arising from the isolation and expansion of the SCs restrict their clinical applications. Establishing an alternative Schwann-like cell type is a prerequisite. Epidermal neural crest stem cells (EPI-NCSCs) are well studied for their autologous accessibility, along with the ability to produce major neural crest derivatives and neurotrophic factors. In the current study, we explored insulin influence, a well-known growth factor, on directing EPI-NCSCs into the Schwann cell (SC) lineage. EPI-NCSCs were isolated from rat hair bulge explants. The viability of cells treated with a range of insulin concentrations (0.05-100 µg/ml) was defined by MTT assay at 24, 48, and 72 h. The gene expression profiles of neurotrophic factors (BDNF, FGF-2, and IL-6), key regulators involved in the development of SC (EGR-1, SOX-10, c-JUN, GFAP, OCT-6, EGR-2, and MBP), and oligodendrocyte (PDGFR-α and NG-2) were quantified 1 and 9 days post-treatment with 0.05 and 5 µg/ml insulin. Furthermore, the protein expression of nestin (stemness marker), SOX-10, PDGFR-α, and MBP was analyzed following the long-term insulin treatment. Insulin downregulated the early-stage SC differentiation marker (EGR-1) and increased neurotrophins (BDNF and IL-6) and pro-myelinating genes, including OCT-6, SOX-10, EGR-2, and MBP, as well as oligodendrocyte differentiation markers, upon exposure for 9 days. Insulin can promote EPI-NCSC differentiation toward SC lineage and possibly oligodendrocytes. Thus, employing insulin might enhance the EPI-NCSCs efficiency in cell transplantation strategies.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Epiderme/efeitos dos fármacos , Insulina/farmacologia , Crista Neural/efeitos dos fármacos , Células-Tronco Neurais/efeitos dos fármacos , Células de Schwann/efeitos dos fármacos , Animais , Diferenciação Celular/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Epiderme/fisiologia , Hipoglicemiantes/farmacologia , Masculino , Crista Neural/citologia , Crista Neural/fisiologia , Células-Tronco Neurais/fisiologia , Ratos , Ratos Wistar , Células de Schwann/fisiologia
18.
Int J Mol Sci ; 22(13)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201667

RESUMO

Human plasma-derived bilayered skin substitutes were successfully used by our group to produce human-based in vitro skin models for toxicity, cosmetic, and pharmaceutical testing. However, mechanical weakness, which causes the plasma-derived fibrin matrices to contract significantly, led us to attempt to improve their stability. In this work, we studied whether an increase in fibrin concentration from 1.2 to 2.4 mg/mL (which is the useful fibrinogen concentration range that can be obtained from plasma) improves the matrix and, hence, the performance of the in vitro skin cultures. The results show that this increase in fibrin concentration indeed affected the mechanical properties by doubling the elastic moduli and the maximum load. A structural analysis indicated a decreased porosity for the 2.4 mg/mL hydrogels, which can help explain this mechanical behavior. The contraction was clearly reduced for the 2.4 mg/mL matrices, which also allowed for the growth and proliferation of primary fibroblasts and keratinocytes, although at a somewhat reduced rate compared to the 1.2 mg/mL gels. Finally, both concentrations of fibrin gave rise to organotypic skin cultures with a fully differentiated epidermis, although their lifespans were longer (25-35%) in cultures with more concentrated matrices, which improves their usefulness. These systems will allow the generation of much better in vitro skin models for the testing of drugs, cosmetics and chemicals, or even to "personalized" skin for the diagnosis or determination of the most effective treatment possible.


Assuntos
Diferenciação Celular , Derme/citologia , Epiderme/fisiologia , Fibrina/metabolismo , Hidrogéis/metabolismo , Queratinócitos/citologia , Tecidos Suporte/química , Proliferação de Células , Células Cultivadas , Derme/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Hidrogéis/química , Queratinócitos/metabolismo , Pele/citologia , Pele/metabolismo , Engenharia Tecidual
19.
Genes (Basel) ; 12(5)2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34069986

RESUMO

The transition of amniotes to a fully terrestrial lifestyle involved the adaptation of major molecular innovations to the epidermis, often in the form of epidermal appendages such as hair, scales and feathers. Feathers are diverse epidermal structures of birds, and their evolution has played a key role in the expansion of avian species to a wide range of lifestyles and habitats. As with other epidermal appendages, feather development is a complex process which involves many different genetic and protein elements. In mammals, many of the genetic elements involved in epidermal development are located at a specific genetic locus known as the epidermal differentiation complex (EDC). Studies have identified a homologous EDC locus in birds, which contains several genes expressed throughout epidermal and feather development. A family of avian EDC genes rich in aromatic amino acids that also contain MTF amino acid motifs (EDAAs/EDMTFs), that includes the previously reported histidine-rich or fast-protein (HRP/fp), an important marker in feather development, has expanded significantly in birds. Here, we characterize the EDAA gene family in birds and investigate the evolutionary history and possible functions of EDAA genes using phylogenetic and sequence analyses. We provide evidence that the EDAA gene family originated in an early archosaur ancestor, and has since expanded in birds, crocodiles and turtles, respectively. Furthermore, this study shows that the respective amino acid compositions of avian EDAAs are characteristic of structural functions associated with EDC genes and feather development. Finally, these results support the hypothesis that the genes of the EDC have evolved through tandem duplication and diversification, which has contributed to the evolution of the intricate avian epidermis and epidermal appendages.


Assuntos
Aves/genética , Aves/fisiologia , Epiderme/fisiologia , Família Multigênica/genética , Motivos de Aminoácidos/genética , Aminoácidos/genética , Animais , Biomarcadores/metabolismo , Evolução Molecular , Plumas/fisiologia , Mamíferos/genética , Mamíferos/fisiologia , Proteínas/genética , Sequências de Repetição em Tandem/genética
20.
Curr Biol ; 31(15): 3275-3291.e5, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34107301

RESUMO

The epidermis is a stratified epithelium in which structural and functional features are polarized across multiple cell layers. This type of polarity is essential for establishing the epidermal barrier, but how it is created and sustained is poorly understood. Previous work identified a role for the classic cadherin/filamentous-actin network in establishment of epidermal polarity. However, little is known about potential roles of the most prominent epidermal intercellular junction, the desmosome, in establishing epidermal polarity, in spite of the fact that desmosome constituents are patterned across the apical to basal cell layers. Here, we show that desmosomes and their associated intermediate filaments (IFs) are key regulators of mechanical polarization in epidermis, whereby basal and suprabasal cells experience different forces that drive layer-specific functions. Uncoupling desmosomes and IF or specific targeting of apical desmosomes through depletion of the superficial desmosomal cadherin, desmoglein 1, impedes basal stratification in an in vitro competition assay and suprabasal tight junction barrier functions in 3D reconstructed epidermis. Surprisingly, disengaging desmosomes from IF also accelerated the expression of differentiation markers, through precocious activation of the mechanosensitive transcriptional regulator serum response factor (SRF) and downstream activation of epidermal growth factor receptor family member ErbB2 by Src family kinase (SFK)-mediated phosphorylation. This Dsg1-SFK-ErbB2 axis also helps maintain tight junctions and barrier function later in differentiation. Together, these data demonstrate that the desmosome-IF network is a critical contributor to the cytoskeletal-adhesive machinery that supports the polarized function of the epidermis.


Assuntos
Desmossomos , Epiderme , Caderinas , Desmoplaquinas , Desmossomos/fisiologia , Células Epidérmicas , Epiderme/fisiologia
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