Murine areola formation requires combination of mechanical strain and hormones.

摘要

Skin is the largest mechanoresponsive organ, and it contains diverse cell types with a range of mechanosensory functions. In mammals, there are specific regions of the skin that are dedicated to unique and particular interactions with the environment. Accordingly, they are composed of cell types that display unique patterns of differentiation that are critical for their proper function. The nipple is an example of specialized epidermis that not only responds to hormones, but also must withstand the mechanical strain of nursing. Previous studies in our laboratory have identified nipple epidermal markers including increased filaggrin, and the site-specific expression of keratins, K2e and a K6 immunoreactive protein[1, 2]. At this time, the impact of hormones and mechanical strain on the various cell types found within the nipple and their differentiation has not yet been delineated. This thesis explores the impact of pregnancy and lactation and its effects on nipple growth, including the formation of the functional areola. Murine areola formation was characterized by an expansion of thickened, specialized epidermis into the region surrounding the nipple, changes in connective tissue, and hair shaft loss. Understanding the role mechanical strain and hormones of the reproductive cycle play in regulating the expansion of the specialized epidermis of the nipple will give rise to a better understanding on how the underlying mesenchyme interacts with its given epidermal counterparts, as well as provide insight into strategies for improved wound healing or regeneration of the structure.