Structure and function of the Golgi apparatus of human dermic fobroblasts in the ageing process : towards an innovative strategy of screening dermocosmetically active agents with anti-ageing effect ; Structure et fonctions de l'appareil de Golgi chez les fibroblastes dermiques humains lors du vieillissement : vers une stratégie innovante de criblaged'actifs dermo-cosmétiques à effets anti-age?

Skin is an important organ of the human body representing a protective structure in direct contactwith the external environment. During aging, skin undergoes dramatic changes including alteration ofdermal cells and components. Among these, fibroblasts synthetize and secrete a large variety ofcomponents and degrading enzymes involved in the modulation of dermal structure and functions. It isestablished that modification of the secreted components and enzymes during aging is related to dermisdegradation. This work aims to characterize aging-related alteration in fibroblasts. For this purpose, three aged human dermal primary fibroblast models have been developed. A transcriptomic study, using real-time quantitative PCR, has also been undertaken and has shown modifications in the expression of genesencoding dermal proteins. Using these results and in order to develop “anti-aging” cosmetic ingredients, extracts from polysaccharides-rich plant and microbial cells have been prepared and their efficiency evaluated on skin explants.As the Golgi apparatus is a major organelle of the secretory pathway, its structural organization has been investigated in fibroblasts using microscopy. The data show a marked alteration of trans-Golgi network morphology in aged cells. In contrast to its small and compact structure in young cells, the trans-Golgi network displays a large and expanded configuration in senescent cells. In addition, a transcriptomic analysis reveals that the expression of some genes, related to Golgi shape and/or function, is significantly modified in senescent cells. These genes could be then, used as innovating targets for the screening of novel dermo-cosmetic products with anti-aging activity. ; La peau est un organe se trouvant à l’interface de notre organisme et de notre environnement. Ellesubit un vieillissement qui se traduit par des modifications affectant ses différentes couches. Parmi celles-cile derme est particulièrement affecté. Les fibroblastes, présents dans le derme, synthétisent des moléculesde ...