Stem cells, stem cell niche and antler development

Abstract

Annual full regeneration of deer antlers has been proved to be a stem cell-based process, and antler stem cells (ASC) reside in both antlerogenic periosteum (AP) and pedicle periosteum (PP). In this review, we first put forward a hypothesis that the closely associated skin is the primary component of ASC niche and then provide results testing this hypothesis. Membrane insertion experiments confirmed that interactions between ASC and the associated skin are indispensible for both antler generation and regeneration, and these are achieved through exchanging diffusible molecules. Intradermal AP transplantation study demonstrated that both epidermal and dermal papilla cells are involved in these interactions. Further, the AP inversion experiment indicated that the initial inductive signal originates from the ASC resident in the AP cellular layer, although the AP fibrous layer is naturally adjacent to skin. Experimental manipulation to the niche has profound effects on antler development. We believe that eventual identification of these interactive molecules will not only greatly enhance our knowledge of antler development, but also have significant impacts on regenerative medicine in general.