Expression of Amphiregulin Is Regulated in Cultured Human Keratinocytes and in Developing Fetal Skin

• Published in: Journal of investigative dermatology Vol. 105; no. 6; pp. 802 - 809
• Main Authors: Piepkorn, Michael, Underwood, Robert A., Henneman, Crystal, Smith, Lynne T.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.1995
• Subjects: Adult; Amphiregulin; Animals; Antibodies, Monoclonal - immunology; Blotting, Western; Cells, Cultured; EGF Family of Proteins; epidermal growth factor; epidermal growth factor receptor; Female; Fetus - metabolism; Glycoproteins - analysis; Glycoproteins - immunology; Growth Substances - analysis; Growth Substances - immunology; Humans; Intercellular Signaling Peptides and Proteins; Keratinocytes - chemistry; Mice; Morphogenesis; Pregnancy; Skin - chemistry; epidermal growth factor; epidermal growth factor receptor
• ISSN: 0022-202X; 1523-1747
• DOI: 10.1111/1523-1747.ep12326567

Previous studies have indicated that amphiregulin is a major autocrine factor for human keratinocytes. To evaluate the possibilities that amphiregulin could function in fetal skin morphogenesis and contribute to the growth regulation of epidermis, immunostaining with a specific anti-amphiregulin monoclonal antibody was observed at different stages of fetal skin development, and the results were compared with neonatal and adult skin specimens and cultured neonatal keratinocytes. Immunoreactive amphiregulin was readily detected in the periderm and basal epidermal layers of embryonic epidermis but became gradually less detectable in the periderm concurrent with an increase in staining of the spinous layer as it developed during the fetal period. Basal and spinous keratinocyte expression of amphiregulin was predominantly cytoplasmic, but with punctate nuclear foci, and this pattern persisted into the neonatal period. At all developmental stages, epithelial and mesenchymal cells of the follicle were reactive, often in a nuclear pattern. Dermal mesenchymal cell were increasingly reactive in late fetal skin, but the staining decreased postnatally. In adult skin only randomly scattered nuclei of spinous keratinocytes and follicular structures such as the inner root sheath were stained. Examination by scanning laser confocal microscopy of cultured neonatal keratinocytes showed a nonrandom distribution of amphiregulin to the peripheral cytoplasm and plasma membranes at the outer perimeter of cell colonies, with much less reactivity of apposed keratinocyte membranes at interior sites. Nuclei were heterogeneously stained. Amphiregulin reactivity declined at higher cell densities. These data indicate that expression of amphiregulin is regulated in vitro and developmentally during cutaneous morphogenesis.