[What's new in dermatological research?].

Dermatological research has been very active this year. Most of the numerous fields investigated involve the mechanisms of cutaneous regeneration and barrier function. A novel target of early ultraviolet-induced skin photodamage, the Syk kinase, has been recently identified. Synergistic relationship between telomere damage and cutaneous progerin production during cell senescence may also participate in the natural skin aging process. Interestingly, ultraviolet radiation induces an inhibitory effect on subcutaneous lipogenesis. Androgenetic alopecia or common baldness is not characterized by loss of hair follicle stem cells but by a defect in the conversion of hair follicle stem cells into active progenitor cells. It has been shown that the cornified envelope functions not only as a physicomechanical barrier, but also as both a biochemical line of antoxidant defense and an immunological line of defense. Like human papillomaviruses, Merckel cell polyomavirus belongs to the skin microbiome and different studies have demonstrated the protective role of epidermal resident microflora through the activation of innate immunity. Production of antimicrobial peptides and the activation of inflammasome and plasmacytoid dendritic cells are involved in the modulation of the cutaneous barrier function. Results from different studies suggest that IL-22 and IL-36 may be common mediators of both innate and adaptive immune responses. All these pathways interact not only to maintain cutaneous homeostasis and integrity (wound healing) but also to regulate autoinflammatory and autoimmune dermatoses (psoriasis, lupus, rosacea, atopic dermatitis, etc...). In addition, molecular mechanisms that regulate T helper type 2 differentiation and the retention at the site of inflammation of Th2 cells have been identified. New promising therapeutic targets for different chronic dermatosis are thus suggested. Mechanobiology and mechanotransduction are also emerging fields that investigate mechanical interactions between living cells and their environment and the conversion of mechanical cues into biochemical signals. Electronic second skin is now a current concept through bio-integrated epidermal electronics platforms used for different monitoring and stimulations of body functions.