Dermatite atopique, généralités

La DA constitue la dermatose la plus fréquente chez les enfants : 65% des patients ont moins d’un an et 85% sont âgés de moins 5 ans. La prévalence de cette pathologie est en constante augmentation atteignant aujourd’hui 10 à 25% de la population.

Atopic dermatitis: physio-pathology and clinical signs

Atopic dermatitis is the most common dermatosis affecting children: 65% of the patients are less than a year old and 85% are below 5 years. The prevalence of this pathology is constantly on the rise and currently affects 10 to 25% of the population.

Involvement of IL-1 and Oncostatin M in acanthosis associated with hypertensive leg ulcer

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Hypertensive leg ulcer (HLU) is an inflammatory disease characterized by intense pain, alteration of vascularization, and skin necrosis. The optimal treatment relies on surgical removal of necrotic tissues covered by a split-skin graft.

Foreskin-isolated keratinocytes provide successful extemporaneous autologous paediatric skin grafts

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We report a successful method for grafting paediatric males presenting large severe burns through direct spreading of autologous foreskin keratinocytes. This alternative method is easy to implement, improves the quality of skin and minimizes associated donor site morbidity. in vitro studies have highlighted the potential of foreskin tissue for graft applications and could help in tissue selection with the prospect of grafting burns for girls.

Keratinocytes under fire of proinflammatory cytokines: Bonafide innate immune cells involved in the physiopathology of chronic atopic dermatitis and psoriasis

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Specific cytokine environment deregulation plays a central role on skin morphology and innate immunity, moving towards specific pathologies and opening the way to new therapeutic strategies.

Cystinosin is a melanosomal protein that regulates melanin synthesis

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In vitro studies showed that cystinosin was located at melanosomes. CTNS silencing led to a 75% reduction of melanin synthesis that was caused by a degradation of tyrosinase by lysosomal proteases. Our results objectify the pigmentation defect in patients with cystinosis. We also identify the role of CTNS in melanogenesis and add a new gene to the list of the genes involved in the control of skin and hair pigmentation.
Inflammatory-loop-

Dermatite atopique, phase d’initiation et d’activation

Les lésions cutanées permettent le passage facilité d’un antigène auquel l’individu aura été préalablement sensibilisé.
Coupe de peau atopique

Dermatite atopique, réponse immune et lésions cutanées

Réponse immunitaire Th2/Th22 et autres acteurs de la dermatite atopique Après polarisation , les lymphocytes T Th2 et Th22 migrent vers la zone lésionnelle où ils libèrent respectivement des cytokines de type Th2 (IL-4, IL-5, IL-13, IL-31, TNF-α) et Th22 (IL-22). Ces cytokines Th2/Th22 ont différentes fonctions dans la réponse immunitaire :

The gap junction protein Cx43 is involved in the bone-targeted metastatic behaviour of human prostate cancer cells

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We investigated the effect of the increased Cx43 expression, by retroviral infection, on the metastatic behaviour of two well-characterized cell lines (PC-3 and LNCaP) representing different stages of PCa progression. It appeared that Cx43 differently behaved in those cell lines and induced different phenotypes.

Effect of C-xyloside on morphogenesis of the dermal epidermal junction in aged female skin. An ultrastuctural pilot study

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These data suggest that topical C-xyloside application in vivo may be efficient in inducing a better dermal-epidermal cohesion when such a junction is deficient, as is the case in photo-aged or chronologically aged skin. Moreover, a statistically significant increase in CD44 expression was noted in the epidermis of C-xyloside-treated compared to the placebo treated skin areas.

CCL20 and β-defensin-2 induce arrest of human Th17 cells on inflamed endothelium in vitro under flow conditions

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These results indicate that Ag-specific activation will initially contribute to CCR6-mediated Th17 cell trafficking toward and sequestration in inflamed tissue, but that it eventually results in a transitory state of nonresponsiveness to further stimulation of these cells with CCR6 ligands, thus permitting their subsequent migration out of the inflamed site.

Quantitative and qualitative study in keratinocytes from foreskin in children: Perspective application in paediatric burns

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Keratinocytes from foreskin have a high capacity for division. A potential source of cells to provide coverage in paediatric burns.

Skin inflammation induced by the synergistic action of IL17A, IL22, OSM, IL1α and TNFα recapitulates some features of psoriasis

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Our results demonstrate the important potentiating activities of IL17A, IL22, oncostatin M, TNF-alpha, and IL1alpha on keratinocytes. This is particularly interesting in the context of psoriasis where these cytokines are overexpressed and could synergize to play an important role in upregulation of chemokines and antimicrobial peptides production.

Human embryonic stem-cell derivatives for full reconstruction of the pluristratified epidermis: a preclinical study

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To assess whether the keratinocyte progeny of human embryonic stem cells (hESCs) could be used to form a temporary skin substitute for use in patients awaiting autologous grafts, we investigated the cells' capability of constructing a pluristratified epidermis.
burns

Cultured keratinocyte cells from foreskin and future application for burns in children

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The keratinocytes resulting from foreskin have a high capacity of division. These cells can divide a long time before differentiation. The observations enable us to propose with our patients the keratinocytes from foreskin for wound healing especially for burns in children.
CEACAM1

Cytokine-induced CEACAM1 expression on keratinocytes is characteristic for psoriatic skin and contributes to a prolonged lifespan of neutrophils

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These results show that cytokine-induced cell-surface expression of CEACAM1 by keratinocytes in the context of a psoriatic environment might contribute to the persistence of neutrophils and thus to ongoing inflammation and the decreased propensity for skin infection, typical for patients with psoriasis.
Lipolytic

Lipolytic effect of a polyphenolic citrus dry extract of red orange, grapefruit, orange (Sinetrol) in human body fat adipocytes. Mechanism of action by inhibition of cAMP-Phosphodiesterase (PDE)

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The present study investigated the lipolytic (break of fat stored) effect of a citrus-based polyphenolic dietary supplement (SINETROL) at human adipocytes (ex vivo), body fat (clinical) and biochemical levels (inhibition of phosphodiesterase).
tensin1

Reduced expression of the adhesion protein tensin1 in cultured human dermal fibroblasts affects collagen gel contraction

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tensin1 plays an important role in cell-matrix interaction and that a reduced expression might contribute to the dermal alterations observed during skin ageing
interleukin 22

A role for T cell-derived interleukin 22 in psoriatic skin inflammation

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This study indicate that interleukin 22 is a cytokine produced by skin-infiltrating lymphocytes that is potentially involved in initiation and/or maintenance of the pathogenesis of psoriasis.
OSM

OSM (Oncostatin M) secreted by skin infiltrating T lymphocytes is a potent keratinocyte activator involved in skin inflammation

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These results demonstrate that OSM and its receptor play an important role in cutaneous inflammatory responses in general and that the specific effects of OSM are associated with distinct inflammatory diseases depending on the cytokine environment.