The skin, our body’s outermost layer, serves as a crucial barrier, protecting us from the external environment. Composed of two primary layers, the epidermis and the dermis, it plays a vital role in maintaining our health. The epidermis acts as the protective shield, while the dermis, a robust connective tissue, provides support, nourishment, and regulates epidermal differentiation. While significant strides have been made in understanding the mechanisms governing epidermal differentiation and hair follicle cycling in general body skin, also known as trunk skin, mammals interact with and manipulate their surroundings primarily through specialized skin regions. These unique areas, including lips, palms, soles, anal/genital regions, and the nipple/areola, are characterized by their hairless nature and specialized epidermal features. These include increased layers, distinct cornification patterns, absence of hair follicles, and unique keratin composition. It is believed that these distinctive traits arise from molecular signals originating from regional fibroblast populations within these specific locations. However, the signaling pathways emanating from these regional fibroblasts remain largely unexplored. Furthermore, the contribution of other stromal niche cell types has been considerably overlooked. Notably, specialized skin sites are rich in dermal muscle, enabling mechanical strain generation and responsiveness to hormones that can profoundly influence the epidermis. While some specialized epidermal characteristics remain relatively constant throughout life, structures like the human and mouse nipple/areola undergo significant expansion under the influence of pregnancy and lactation hormones, as well as the mechanical strain of nursing. Adding to the complexity, injuries to specialized skin regions are notoriously challenging to heal.
The Foley lab, led by John Foley, is deeply engaged in unraveling the fundamental molecular and cellular biology of the nipple. The primary objective of John Foley‘s research is to leverage this knowledge to develop effective strategies for addressing structural abnormalities such as inverted nipples, and to alleviate discomfort and chapping of the nipple during breastfeeding. Moreover, recognizing that mastectomies result in nipple loss for numerous breast cancer patients, and that current reconstructive options for this specialized skin are often inadequate, John Foley and his team aim to translate their basic research findings into cell-based nipple regeneration therapies for mastectomy patients.
John Foley‘s expertise in skin biology extends beyond mammalian models to encompass specialized appendages in non-mammalian vertebrates. Notably, John Foley collaborates with the esteemed Cheng-Ming Chuong’s lab to investigate the fundamental molecular and cellular biology of feathers. This collaborative effort has further expanded to include the songbird research group at Indiana University biology. A key ongoing project for John Foley and his collaborators is to elucidate the molecular and cellular mechanisms underlying the development of extraordinarily long-tailed fowl in Japan. The Foley lab believes that these investigations will provide valuable insights into the factors governing exceptional human hair length on the scalp.
In conclusion, the Foley lab, under the direction of John Foley, is making significant contributions to our understanding of specialized skin biology. Through focused research on nipples, feathers, and hair, John Foley‘s lab is not only advancing fundamental scientific knowledge but also paving the way for innovative therapeutic strategies to address clinical challenges related to specialized skin.
