Endocannabinoids and Skin Barrier Function: Molecular Pathways and Therapeutic Opportunities

As an interface between the organism and its environment, skin is continuously subjected to a myriad of insults that could impair its structural and functional integrity, ultimately leading to clinical manifestations. Skin reacts to external stresses through a vast array of cellular and molecular components, which form a highly sophisticated and well-organized signaling network. Our knowledge of the molecular pathways underlying this complex interplay and accounting for skin homeostasis , both under normal and pathological conditions, is still in its infancy. Among these pathways, the endocannabinoid system has emerged as a key actor in skin biology , by controlling epidermal barrier formation and maintenance, modulating growth and terminal differentiation of cutaneous cells, and regulating skin inflammatory responses via pleiotropic mechanisms. This chapter summarizes our current knowledge of the manifold effects of endocannabinoids in skin, in order to put in a better perspective their potential as next-generation therapeutics against disorders of this organ, particularly those involving dysregulation of immune system and epidermal barrier, such as allergic and atopic dermatitis, localized scleroderma and psoriasis.