More than just a physical barrier

Salus aegroti suprema lex - Das Wohl des Kranken sei höchstes Gesetz (Foto: Rüdiger Labahn / Universität zu Lübeck)

Traditionally seen as a physical barrier, the skin is now recognized as a metabolic organ capable of regulating various aspects of systemic physiology. Additionally, the skin responds to external cues such as light and temperature, which play a crucial role in local control of cutaneous functions like pigmentation. Recent evidence, however, indicates that these skin responses can also induce effects in distant organs (e.g., brain and liver).

At the cellular level, the skin is metabolically active and highly heterogeneous. A varied population of keratinocytes, melanocytes, fibroblasts, immune cells, and adipocytes collectively regulates skin physiology. The interaction among these cells, known as the skin interactome, is still not well understood, but it is essential in controlling several skin processes. The interplay between the cells is further influenced by the local circadian clock, which also controls daily rhythms in DNA repair, immune defense, and metabolism.

The temporal organization of the skin is sensitive to different conditions, such as cutaneous diseases (e.g., psoriasis), but also metabolic stress (e.g., diabetes and obesity). Evidence shows that patients with obesity have a wide range of cutaneous issues, which seem to be associated with disrupted cutaneous circadian rhythms that contribute to a widespread dampening of rhythmic gene expression in pathways controlling immunity, collagen turnover, and barrier function. These obesity-induced alterations compromise the skin's integrity, resulting in increased transepidermal water loss, impaired wound healing, and heightened susceptibility to infection.

In this talk, I will share why I chose this research direction, outline the current state-of-the-art, and discuss how I plan to tackle important unresolved questions using a combination of different experimental models and techniques. 

• Dr. rer. nat. Leonardo Vinicius Monteiro de Assis schließt mit der Antrittsvorlesung seine Habilitation an der Universität zu Lübeck im Fachgebiet Molekulare Physiologie ab.