Mechanisms and Repair of Skin Barrier Dysfunction: The TLC Strategy

The skin barrier functions as a key line of defense with physical, chemical, microbial, and immunological components that act synergistically to protect the body against extrinsic antigens, microbes, and ultraviolet rays and prevent loss of nutrients and moisture from the body. Skin barrier dysfunction is caused by various factors, including environmental stressors, genetic predisposition, psychological stress, and inadequate nutrition. These factors can lead to metabolic, immunological, and microbial disorders of the skin barrier, which are associated with skin diseases, such as sensitive skin, rosacea, atopic dermatitis, and psoriasis, and can significantly diminish quality of life. Significant progress has been made in the development of strategies to repair skin barrier dysfunctions. In this review, we propose a repair strategy based on the "TLC" concept: "target skin disruption, lock in moisture, and connect skin cells." Targeting skin disruption involves the implementation of interventions for skin barrier disorders, including ceramide supplementation, pH regulation, and optimized immunomodulation, to restore the metabolic, immunological, and microbial balance of the skin. Locking in moisture involves promoting moisturization and moisture retention to enhance skin hydration by reducing water loss and promoting water absorption and transport. Connecting skin cells involves the restoration of intercellular connections and the lipid bilayer structure of the stratum corneum, thereby enhancing epidermal connectivity and reinforcing the skin barrier. This multilevel strategy offers new avenues for mitigating skin barrier dysfunctions and related diseases and is of great significance in clinical applications.