Jocelyne Franchi

L’adipocyte dans une histoire d’amincissant

Resume De nos jours, dans les societes industrialisees, la mode veut que la femme soit mince. La « cellulite » ou lipodystrophie ne presente pas un caractere pathologique. Ses localisations preferentielles dans le bas du corps ont un retentissement esthetique important. Les produits amincissants doivent lutter localement contre l’expansion du tissu adipeux, l’infiltration d’eau et le relâchement des tissus, sans pour autant provoquer l’amaigrissement systemique.

Cell model of inflammation

Chemical and physical stimuli trigger a cutaneous response by first inducing the main epidermal cells, keratinocytes, to produce specific mediators that are responsible for the initiation of skin inflammation. Activation modulates cell communication, namely leucocyte recruitment and blood-to-skin extravasation through the selective barrier of the vascular ECs (endothelial cells). In the present study, we describe an in vitro model which takes into account the various steps of human skin inflammation, from keratinocyte activation to the adhesion of leucocytes to dermal capillary ECs. Human adult keratinocytes were subjected to stress by exposure to UV irradiation or neuropeptides, then the conditioned culture medium was used to mimic the natural micro-environmental conditions for dermal ECs. A relevant in vitro model must include appropriate cells from the skin. This is shown in the present study by the selective reaction of dermal ECs compared with EC lines from distinct origins, in terms of leucocyte recruitment, sensitivity to stress and nature of the stress-induced secreted mediators. This simplified model is suitable for the screening of anti-inflammatory molecules whose activity requires the presence of various skin cells.

Transcriptional effect of an Aframomum angustifolium seed extract on human cutaneous cells using low-density DNA chips.

Background  Studying photoexposed and photoprotected skin biopsies from young and aged women, it has been found that a specific zone, composed of the basal layers of the epidermis, the dermal epidermal junction, and the superficial dermis, is major target of aging and reactive oxygen species. We showed that this zone is characterized by significant variations at a transcriptional and/or protein levels.