scholarly journals Lipid defect underlies selective skin barrier impairment of an epidermal-specific deletion of Gata-3

2006 ◽  
Vol 175 (4) ◽  
pp. 661-670 ◽  
Author(s):  
Cristina de Guzman Strong ◽  
Philip W. Wertz ◽  
Chenwei Wang ◽  
Fan Yang ◽  
Paul S. Meltzer ◽  
...  

Skin lies at the interface between the complex physiology of the body and the external environment. This essential epidermal barrier, composed of cornified proteins encased in lipids, prevents both water loss and entry of infectious or toxic substances. We uncover that the transcription factor GATA-3 is required to establish the epidermal barrier and survive in the ex utero environment. Analysis of Gata-3 mutant transcriptional profiles at three critical developmental stages identifies a specific defect in lipid biosynthesis and a delay in differentiation. Genomic analysis identifies highly conserved GATA-3 binding sites bound in vivo by GATA-3 in the first intron of the lipid acyltransferase gene AGPAT5. Skin from both Gata-3−/− and previously characterized barrier-deficient Kruppel-like factor 4−/− newborns up-regulate antimicrobial peptides, effectors of innate immunity. Comparison of these animal models illustrates how impairment of the skin barrier by two genetically distinct mechanisms leads to innate immune responses, as observed in the common human skin disorders psoriasis and atopic dermatitis.

Author(s):  
Sara Gonçalves ◽  
Isabel Gaivão

The term cosmetics refers to a product applied to the body for the purpose of beautifying, cleansing or improving appearance and enhancing attractive features. The natural cosmetics market has grown since the consumer took consciousness of the concept of natural-based ingredients. A great number of cosmetics have noxious and chemically-potent substances and have an ecological impact on the environment. A study performed by the Danish Council THINK Chemicalsfound that in total 65 chemicals of concern were found in 39 products. This means consumers are exposed to these chemicals, perhaps in a daily basis. They also found that three products contained illegal ingredients in the European Union. Thus, the use of natural and organic cosmetics becomes increasingly important. This requires a strong investigation into the benefits that fruits and plants can bring to health. The PhD project will focus on four natural ingredients common in the Trás-os-Montes area: almond (Prunus dulcis), elderberry (Sambucus nigra), olive (Olea europaea) and grapes (Vitis vinifera). The general purpose of this PhD project is to evaluate the cosmetic properties of the natural ingredients towards the DNA integrity promotion. Additionally, it is intended to evaluate genoprotection, longevity and prolificacy of the natural ingredients in Drosophila melanogaster. The short life cycle, the distinct developmental stages, the availability of various tools and reagents, known genome sequence and the physiological similarity of Drosophila with humans make them an excellent in vivo model organism to rapidly test toxicity in whole organism and elucidate the molecular mechanisms underlying the toxicity. The natural product with the best result will be used to evaluate genoprotection in human lymphocytes. These are used as a surrogate tissue, as they are easily obtained, in large numbers, do not require cell culture, are diploids and are almost all in the same phase of the cell cycle. This project is in an initial phase and lacks results, which will be available along this year.


2020 ◽  
Author(s):  
Aayushi Uberoi ◽  
Casey Bartow-McKenney ◽  
Qi Zheng ◽  
Laurice Flowers ◽  
Amy Campbell ◽  
...  

SUMMARYThe epidermis forms a barrier that defends the body from desiccation and entry of harmful substances, while sensing and integrating environmental signals. The tightly orchestrated cellular changes required for the proper formation and maintenance of this epidermal barrier occur in the context of the skin microbiome. Using germ free mice, we demonstrate the microbiota is necessary for proper differentiation and repair of the epidermal barrier. These effects were mediated by the aryl hydrocarbon receptor (AHR) in keratinocytes, a xenobiotic receptor also implicated in epidermal differentiation. Murine skin lacking keratinocyte AHR was more susceptible to barrier damage and infection, during steady state and epicutaneous sensitization. Colonization with a defined consortium of human skin isolates restored barrier competence in an AHR-dependent manner. We reveal a fundamental mechanism whereby the microbiota regulates skin barrier formation and repair, with far-reaching implications for the numerous skin disorders characterized by epidermal barrier dysfunction.


2006 ◽  
Vol 26 (23) ◽  
pp. 8976-8983 ◽  
Author(s):  
Iwona Grad ◽  
Thomas A. McKee ◽  
Sara M. Ludwig ◽  
Gary W. Hoyle ◽  
Patricia Ruiz ◽  
...  

ABSTRACT The functions of molecular chaperones have been extensively investigated biochemically in vitro and genetically in bacteria and yeast. We have embarked on a functional genomic analysis of the Hsp90 chaperone machine in the mouse by disrupting the p23 gene using a gene trap approach. p23 is an Hsp90 cochaperone that is thought to stabilize Hsp90-substrate complexes and, independently, to act as the cytosolic prostaglandin E2 synthase. Gene deletions in budding and fission yeasts and knock-down experiments with the worm have not revealed any clear in vivo requirements for p23. We find that p23 is not essential for overall prenatal development and morphogenesis of the mouse, which parallels the observation that it is dispensable for proliferation in yeast. In contrast, p23 is absolutely necessary for perinatal survival. Apart from an incompletely formed skin barrier, the lungs of p23 null embryos display underdeveloped airspaces and substantially reduced expression of surfactant genes. Correlating with the known function of glucocorticoids in promoting lung maturation and the role of p23 in the assembly of a hormone-responsive glucocorticoid receptor-Hsp90 complex, p23 null fibroblast cells have a defective glucocorticoid response. Thus, p23 contributes a nonredundant, temporally restricted, and tissue-specific function during mouse development.


2020 ◽  
Vol 2 (338) ◽  
pp. 56-61
Author(s):  
D. U. Seksenova ◽  
B. K. Esimov ◽  
Z. A. Ibragimova

Sarkosporidiosis is a chronic animal disease that often results in death. In animals with severe damage to the body by sarkosporidiosis, weakness, tissue depletion and hydremia are observed. Sarcocyst development occurs in muscle cells and tissues. It is known that in vivo predators become infected by eating meat from animals affected by sarcocysts. Sarcocysts secrete toxic substances, sarcocystin and sarcosporiocin, which lead to the death of animals within 5-20 hours. In chronic conditions in animals, salt deposits form around numerous sarcocysts and pronounced skeletal muscle hydremia is also observed. Sarcocystosis can be detected only after the death of animals. The corpses of animals must be examined microscopically, severely damaged corpses should be buried to a depth of 2 meters. When conducting microscopic studies of slices taken from samples of affected animal meat, a diagnosis is established. The proposed work is devoted to study the fauna and cycles of the development of micromorphology of representatives of the genus Sarcocystis of some rodents and birds. To achieve this research, an experiment was conducted with small vertebrates. The goal of our work is to identify the distribution of sarcosporidia of some species of rodents and birds, to study the morphology of the detected sarcosporidia, and their life cycle. The results of the study can be used for the epizootological characterization of sarcocystosis of rodents and birds. The study of the life cycle and specific structure is necessary for the diagnosis of species of the genus Sarcocystis. Yellow ground squirrel, house mouse and chukar can serve as a laboratory example in the study of mammalian and bird sarcocystosis. Ultrastructure materials and the life cycle of sarcosporidia can be used in studying the courses “Parasitology” and “Invertebrate Zoology”. There are 5 articles that were published on materials of this work.


2021 ◽  
pp. 158-166
Author(s):  
Olga B. Tamrazova ◽  
Nataliya F. Dubovets ◽  
Anait V. Tamrazova ◽  
Sergey P. Seleznev

Epidermis plays an important role in protecting the body from negative environmental influences. The horny layer plays a special role in carrying out these functions. Skin defense mechanisms are multistage and include 5 protective barriers responsible for maintaining the integrity and performing the main functions of the skin. The first one is a microbial barrier – determined by commensal flora which prevents contamination of pathogenic microorganisms; the second one is a physical barrier preventing mechanical skin damage, penetration of allergens and microorganisms; the third one is a chemical barrier achieved by forming pH and components of natural moisturizing factor as well as epidermal lipids; the fourth one – immune barrier – Langerhans cells, tissue basophils, lymphocytes etc.;the fifth is the neurosensory barrier – numerous nerve endings transmitting signals of skin integrity damage and controlling metabolic processes and homeostasis maintenance. Epidermal barrier of newborns and infants is imperfect and differs in its structure and functional activity from that of adults. Children’s skin is prone to excessive dryness, irritation, allergic reactions and inflammation. For young children, it is very important to minimize the risk of these manifestations. Individual selection and use of emollients in the basic care of infants promotes the functional stability of five protective «frontiers» of the epidermal barrier: prevents skin damage when exposed to unfavorable environmental factors, reduces TEWL, supports the normal microbiome, has antipruritic and anti-inflammatory action. Modern emollients restore the hydrolipidic layer of the epidermis and prevent the development of dermatitis and skin infection in children. An important role when choosing an emollient is played by its texture, which can be represented by a lotion, cream, balm, ointment. Chemically, creams, lotions and balms are emulsions, i.e. they consist of two immiscible components – fat (oil) and water. In this case, one of the components is in the other in the form of tiny droplets. Most skin diseases faced by young children are related to the integrity of the epidermis, which is why daily care should be primarily focused on protecting the skin barrier


2015 ◽  
Vol 396 (11) ◽  
pp. 1163-1179 ◽  
Author(s):  
Marina Le Lamer ◽  
Laurence Pellerin ◽  
Marie Reynier ◽  
Laura Cau ◽  
Valérie Pendaries ◽  
...  

Abstract The main function of the epidermis is to establish a vital multifunctional barrier between the body and its external environment. A defective epidermal barrier is one of the key features of atopic dermatitis (AD), a chronic and relapsing inflammatory skin disorder that affects up to 20% of children and 2–3% of adults and often precedes the development of allergic rhinitis and asthma. This review summarizes recent discoveries on the origin of the skin barrier alterations in AD at the structural protein level, including hereditary and acquired components. The consequences of the epidermal barrier alteration on our current understanding of the pathogenesis of AD, and its possible implications on the treatment of patients, are discussed here.


2015 ◽  
Vol 71 (8) ◽  
pp. 522-526
Author(s):  
Katarzyna Czepiel-Mil ◽  
Aleksandra Łoś ◽  
Patrycja Marczewska

Entomotoxicology deals with the analysis of toxic substances contained in arthropods that feed on dead bodies. Arthropods are a source of material for investigation when a human or animal body is in an advanced state of decomposition. Various chemical air pollutants, drugs, xenobiotics and pesticides can accumulate in the bodies of insect larvae. Entomotoxicology often involves examining insect larvae that have introduced to their metabolism various kinds of pharmaceuticals taken by people when they were alive. Chemical compounds which can cause death affect the development rate of arthropods living on corpses, delay colonization of insects by several days, or affect their number. Some compounds act as attractants or repellents and thereby influence how quickly insects appear on the body. Others have a mixed effect on insect development. During the initial development stage of the insect they act as an attractant, but in subsequent stages they slow down its development or act as a repellent. The concentration of chemical compounds accumulated in the bodies of larvae is different than in human tissues. Sometimes insects are better indicators of the presence of chemical compounds than material taken from the internal organs of a dead body. Moreover, the quantity of toxins detected in arthropods differs at different developmental stages. The concentration of a xenobiotic in the body of an insect depends on its type, the stage of development of the insect, and the part of the body it was collected from. Studies have determined that the best place to collect entomotoxicological samples is the internal organs (e.g. the liver). If this is not possible, insects are collected from the head area and the muscles. Due to the low popularity of entomotoxicological testing, this type of evidence often is either not collected at all or collected improperly, preventing valuable information from being obtained. Thus there is a need to verify and standardize methods for safeguarding arthropods for the purposes of entomological toxicology


2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.


Author(s):  
А.А. Раецкая ◽  
С.В. Калиш ◽  
С.В. Лямина ◽  
Е.В. Малышева ◽  
О.П. Буданова ◽  
...  

Цель исследования. Доказательство гипотезы, что репрограммированные in vitro на М3 фенотип макрофаги при введении в организм будут существенно ограничивать развитие солидной карциномы in vivo . Методика. Рост солидной опухоли инициировали у мышей in vivo путем подкожной инъекции клеток карциномы Эрлиха (КЭ). Инъекцию макрофагов с нативным М0 фенотипом и с репрограммированным M3 фенотипом проводили в область формирования солидной КЭ. Репрограммирование проводили с помощью низких доз сыворотки, блокаторов факторов транскрипции STAT3/6 и SMAD3 и липополисахарида. Использовали две схемы введения макрофагов: раннее и позднее. При раннем введении макрофаги вводили на 1-е, 5-е, 10-е и 15-е сут. после инъекции клеток КЭ путем обкалывания макрофагами с четырех сторон область развития опухоли. При позднем введении, макрофаги вводили на 10-е, 15-е, 20-е и 25-е сут. Через 15 и 30 сут. после введения клеток КЭ солидную опухоль иссекали и измеряли ее объем. Эффект введения макрофагов оценивали качественно по визуальной и пальпаторной характеристикам солидной опухоли и количественно по изменению ее объема по сравнению с группой без введения макрофагов (контроль). Результаты. Установлено, что M3 макрофаги при раннем введении от начала развития опухоли оказывают выраженный антиопухолевый эффект in vivo , который был существенно более выражен, чем при позднем введении макрофагов. Заключение. Установлено, что введение репрограммированных макрофагов M3 ограничивает развитие солидной карциномы в экспериментах in vivo . Противоопухолевый эффект более выражен при раннем введении М3 макрофагов. Обнаруженные в работе факты делают перспективным разработку клинической версии биотехнологии ограничения роста опухоли, путем предварительного программирования антиопухолевого врожденного иммунного ответа «в пробирке». Aim. To verify a hypothesis that macrophages reprogrammed in vitro to the M3 phenotype and injected into the body substantially restrict the development of solid carcinoma in vivo . Methods. Growth of a solid tumor was initiated in mice in vivo with a subcutaneous injection of Ehrlich carcinoma (EC) cells. Macrophages with a native M0 phenotype or reprogrammed towards the M3 phenotype were injected into the region of developing solid EC. Reprogramming was performed using low doses of serum, STAT3/6 and SMAD3 transcription factor blockers, and lipopolysaccharide. Two schemes of macrophage administration were used: early and late. With the early administration, macrophages were injected on days 1, 5, 10, and 15 following the injection of EC cells at four sides of the tumor development area. With the late administration, macrophages were injected on days 10, 15, 20, and 25. At 15 and 30 days after the EC cell injection, the solid tumor was excised and its volume was measured. The effect of macrophage administration was assessed both qualitatively by visual and palpation characteristics of solid tumor and quantitatively by changes in the tumor volume compared with the group without the macrophage treatment. Results. M3 macrophages administered early after the onset of tumor development exerted a pronounced antitumor effect in vivo , which was significantly greater than the antitumor effect of the late administration of M3 macrophages. Conclusion. The observed significant inhibition of in vivo growth of solid carcinoma by M3 macrophages makes promising the development of a clinical version of the biotechnology for restriction of tumor growth by in vitro pre-programming of the antitumor, innate immune response.


2020 ◽  
Author(s):  
Johannes Karges ◽  
Shi Kuang ◽  
Federica Maschietto ◽  
Olivier Blacque ◽  
Ilaria Ciofini ◽  
...  

<div>The use of photodynamic therapy (PDT) against cancer has received increasing attention overthe recent years. However, the application of the currently approved photosensitizers (PSs) is somehow limited by their poor aqueous solubility, aggregation, photobleaching and slow clearance from the body. To overcome these limitations, there is a need for the development of new classes of PSs with ruthenium(II) polypyridine complexes currently gaining momentum. However, these compounds generally lack significant absorption in the biological spectral window, limiting their application to treat deep-seated or large tumors. To overcome this drawback, ruthenium(II) polypyridine complexes designed in silico with (E,E’)-4,4´-bisstyryl 2,2´-bipyridine ligands showed impressive 1- and 2-Photon absorption up to a magnitude higher than the ones published so far. While non-toxic in the dark, these compounds were found phototoxic in various 2D monolayer cells, 3D multicellular tumor spheroids and be able to eradicate a multiresistant tumor inside a mouse model upon clinically relevant 1-Photon and 2 Photon excitation.</div>


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