Bioalternatives dispose de nombreux modèles in vitro :
- modèle de vieillissement intrinsèque :
- fibroblastes dermiques humains « âgés » (modèle de Hayflick)
- derme équivalent « âgés » (modèle de Hayflick)
- modèle de vieillissement accéléré :
- fibroblastes dermiques humains vieillis par stress oxydatif (H2O2)
- peaux reconstruites humaines en milieu carencé
- modèle de photo-vieillissement :
- fibroblastes dermiques humains soumis à rayonnement UVA, infra-rouge ou solaire
- peaux reconstruites humaines photo-vieillies
sur lesquels il peut-être possible au cas par cas d’évaluer l’effet anti-âge d’actifs cosmétiques sur :
- le renouvellement cellulaire (prolifération, migration et différenciation cellulaire)
- la synthèse et dégradation de la matrice extracellulaire (collagène, élastine, acide hyaluronique, MMPs…)
- l’expression de marqueurs de sénescence
- la production de radicaux libres
Parmi l’ensemble des tests d’évaluation proposés par Bioalternatives dans le domaine du vieillissement cutané, voici quelques exemples :
Development of a new model of reconstructed aged skin useful to study antiageing effects of cosmetic compounds
/dans Cell and tissue engineering, Ingénierie cellulaire et tissulaire, Skin ageing, Vieillissement cutané /par GuillaumeThe development of new anti-ageing products needs performant in vitro models mimicking morphological changes and physiological modifications appearing during skin ageing. In order to have access to a simple model mimicking the epidermis ageing but in relation with a normal dermis, we have developed a new in vitro model of reconstructed skin comprising an aged epidermis covering a reconstructed dermis built with collagen and normal (young) fibroblasts.
Androgens induce sebaceous differentiation in sebocyte cells expressing a stable functional androgen receptor
/dans Acné, Acne, Cell and tissue engineering, Ingénierie cellulaire et tissulaire, Sebaceous gland regulation, Vieillissement cutané /par GuillaumeIn order to study the impact of active androgens in sebocytes, we constructed a stable human sebocyte cell line derived from SEBO662 [17] constitutively expressing a fully functional AR. In these SEBO662 AR+ cells, dihydrotestosterone (DHT) induced AR nuclear translocation and the strong modulation of a set of transcripts (RASD1, GREB1…) known to be androgen-sensitive in other androgenic cells and tissues.
Effect of C-xyloside on morphogenesis of the dermal epidermal junction in aged female skin. An ultrastuctural pilot study
/dans Cosmetics, Cosmétique, Skin ageing, Vieillissement cutané /par GuillaumeThese 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.
Reduced expression of the adhesion protein tensin1 in cultured human dermal fibroblasts affects collagen gel contraction
/dans Cosmetics, Cosmétique, Skin ageing, Vieillissement cutané /par Guillaumetensin1 plays an important role in cell-matrix interaction and that a reduced expression might contribute to the dermal alterations observed during skin ageing