Overexpression of epigen during embryonic development induces reversible, epidermal growth factor receptor-dependent sebaceous gland hyperplasia.

The epidermal growth factor receptor (EGFR) system is a key regulator of epithelial development and homeostasis. Its functions in the sebaceous gland (SG), however, remain poorly characterized. In this study, using a transgenic mouse line with tissue-specific and inducible expression of the EGFR ligand epigen, we showed that increased activation of the EGFR in skin keratinocytes results in enlarged SGs and increased sebum production.

Indian hedgehog controls proliferation and differentiation in skin tumorigenesis and protects against malignant progression.

Mutations in the hedgehog pathway drive the formation of tumors in many different organs, including the development of basal cell carcinoma in the skin. However, little is known about the role of epidermal Indian hedgehog (Ihh) in skin physiology. Using mouse genetics, we identified overlapping and distinct functions of Ihh in different models of epidermal tumorigenesis.

Lineage tracing of hair follicle stem cells in epidermal whole mounts.

Lineage tracing of tissue stem cells represents a powerful tool to address fundamental questions of deve-lopment, differentiation and cellular renewal in a natural tissue environment. The Cre/lox site-specific recombination system is increasingly used to genetically label specific cell populations to perform cell lineage tracing or fate mapping experiments in sophisticated mouse models. Here we describe a method of labeling and subsequent tracking stem cells of the hair follicle bulge region in mouse skin.

Stem cell dynamics in sebaceous gland morphogenesis in mouse skin.

The hair follicle (HF) and the sebaceous gland (SG) constitute the two integral parts of the pilosebaceous unit and significantly contribute to the barrier function of mammalian skin. Considerable progress has been made in our understanding how HF formation is regulated. However, the development of the SG is poorly understood, both at the molecular and cellular level.