The skin barrier protects organisms from drying out and is the first line of defense against micro-organisms, UV radiation and heat. To maintain and restore the skin barrier, the interfollicular epidermis and its appendages must continously be renewed. Different populations of stem- and progenitor cells guarantee constant self-renewal under steady state conditions and sufficient plasticity for the fast replacement of lost tissue in case of injury. The overall goal of our laboratory is to understand how regulators of cell structure integrate with regulators of metabolic activity, proliferation and inflammation to control skin barrier formation and homeostasis.

Overall, we focus on three main research questions:

  1. How do cell adhesion and polarity pathways regulate barrier formation, self-renewal and homeostasis in a stratified epithelium?
  2. How do cell adhesion and polarity pathways couple to signal transduction pathways to regulate stem cell behavior, barrier function and tissue homeostasis?
  3. How do age-associated alterations in molecular regulators of cell architecture alter progenitor cell behavior and result in impairment of the skin barrier?

To address these questions we have chosen mouse epidermis as one in vivo model system. In this self-renewing tissue, cells derived from the basal layer continuously rearrange and move into suprabasal layers while undergoing differentiation. Ultimately, this differentiation process results in the formation of the largest physical barrier of the organism. Formation and maintenance of this barrier is not only crucial for skin homeostasis but also directly affect the function of other organs. Several stem/progenitor cell populations have been described that maintain turnover of epidermal compartments.