Klf4 and corticosteroids activate an overlapping set of transcriptional targets to accelerate in utero epidermal barrier acquisition.

Premature infants are at an increased risk for infections and dehydration because of incomplete development of the epidermis, which attains its essential function as a barrier only during the last stages of in utero development. When a premature birth is anticipated, antenatal corticosteroids are administered to accelerate lung epithelium differentiation. One pleiotropic, but beneficial, effect of antenatal corticosteroids is acceleration of skin barrier establishment by an unknown mechanism.

Connexin 26 regulates epidermal barrier and wound remodeling and promotes psoriasiform response.

Inflammatory skin disorders result in significant epidermal changes, including keratinocyte hyperproliferation, incomplete differentiation, and impaired barrier. Here we test whether, conversely, an impaired epidermal barrier can promote an inflammatory response. Mice lacking the transcription factor Kruppel-like factor 4 (Klf4) have a severe defect in epidermal barrier acquisition.

Long-range comparison of human and mouse Sprr loci to identify conserved noncoding sequences involved in coordinate regulation.

Mammalian epidermis provides a permeability barrier between an organism and its environment. Under homeostatic conditions, epidermal cells produce structural proteins, which are cross-linked in an orderly fashion to form a cornified envelope (CE). However, under genetic or environmental stress, specific genes are induced to rapidly build a temporary barrier.

Tetracycline-regulated transactivators driven by the involucrin promoter to achieve epidermal conditional gene expression.

To achieve conditional gene expression in the differentiated layers of the epidermis, we generated transgenic mice with the tetracycline-regulated transactivator proteins, tTA (tetracycline transactivator) and rtTA (reverse tetracycline transactivator), expressed from the human involucrin promoter. Interaction with tetracycline turns off or turns on the tTA and rtTA molecules, respectively, allowing for regulation of downstream target genes during development and postnatally. These transactivator lines were crossed with reporter mice driving LacZ expression from a tetracycline response element to analyze the specificity and levels of target gene expression.

Mouse Sprr locus: a tandem array of coordinately regulated genes.

Small PRoline Rich (SPRR) proteins are primary constituents of the cornified cell envelope, necessary to create a permeability barrier across the body's surface. The family of murine Sprr genes has diversified, enabling the body to construct slightly different types of barriers as needed for backskin, mouth, tongue, etc. The Sprr genes have remained tandemly arrayed within 220 kb on mouse Chromosome (Chr) 3.