The cutaneous lipidome: Does ethnicity impact skin's lipid barrier?

Historically, skin research has focused on the properties of white Northern European (or Caucasian) skin. Consequently, our knowledge of skin biology in individuals from different ethnicities is much less advanced. There is also an assumption that treatments aiming to improve skin quality in white individuals will be equally beneficial in those with darker skin. However, data suggest that skin physiology, structure and mechanical function, is altered across different ethnic populations. However, it is unknown whether ethnicity impacts the epidermal barrier and its component lipids.
The epidermal lipid barrier is vital in protecting the body from environmental factors and contributes to our immune defenses. Bioactive lipids, such as ceramides, are key components of the stratum corneum (SC) and are intimately involved in the structure and function of both the permeability and immunological skin barriers. Furthermore, the lipid composition of SC is subject to seasonal changes, and can be affected by diseases such as atopic dermatitis, and the onset of ageing. Currently, our knowledge of how the epidermal lipidome influences barrier properties in ethnic skin is limited.
In this project we aim to identify differences in SC lipids in individuals across a wide-range of ethnic groups, assess whether gender and age can additionally impact epidermal lipid composition across different body sites, and explore the consequence of such alterations for the epidermal barrier's structure and function. Our experimental approach will be based on a human volunteer study accompanied by non-invasive biomechanical measures such as cutometry, analysis of SC lipids using mass spectrometry lipidomics, genetic analyses, and assessment of biochemical properties of skin samples by immunohistochemistry, histology, and atomic force microscopy.
The study outcomes will generate new scientific insight into the biology of ethnic skin, with the long-term aims of developing intervention strategies to address unmet needs of consumers with darker skin tones.