The reconstructed epidermis with melanocytes: a new tool to study pigmentation and photoprotection.

The reconstruction of the epidermal melanin unit ex vivo has been achieved during the last decade, using the combination of previous cell culture techniques. The system reviewed is basically a modification of the Pruniéras model, using the air-liquid interface to grow differentiated keratinocytes, with the addition of 5% melanocytes in the seeding suspension, as well as the use of a more adapted culture medium. Repeated UVB irradiation induces a stimulation of melanogenesis macroscopically, and increases melanin concentration and melanosome transfer in reconstructs.

Epidermal reconstructs in vitiligo: an extrinsic factor is needed to trigger the disease.

The primary cellular or molecular targets accounting for melanocytes loss in vitiligo are not clearly identified. To study a putative latent epidermal defect in the epidermis of vitiligo patients, we performed in vitro studies using cultured vitiligo melanocytes and keratinocytes transplanted on to a dead de-epidermized dermis according to a variant of Pruniéras' technique. Control autologous constructs were made with keratinocytes and melanocytes of normal adult epidermis and vitiligo epidermis from perilesional skin.

Use of human skin reconstructs in the study of pigment modifiers.

Objective: To assay drugs that modify pigmentation (ie, agents that either enhance or decrease pigmentation) in a predictive in vitro model, as such drugs have been previously studied in vivo on human and animal skin.

Design: An epidermis was reconstructed with human keratinocytes and melanocytes. Epidermal reconstructs with melanocytes were made according to a variant of the model of Pruniéras and colleagues.

Ex vivo study of skin phototypes.

We studied skin phototypes ex vivo to validate a model of epidermal reconstruction with melanocytes. We made autologous epidermal reconstructs with keratinocytes and melanocytes of healthy donors of skin phototypes I to VI. Keratinocytes and melanocytes were seeded on a dead de-epidermized dermis (Pruniéras type) at a 1:20 melanocyte/keratinocyte ratio.