Mayumi Ito, PhD

Assistant Professor; Departments of Dermatology and Cell Biology

Cell Biology, Dermatology

Dermatology, Regenerative Medicine, Stem Cell Biology





Contact Information

522 First Avenue
Smilow Research Center
Floor 4, Room 410
New York, NY 10016

Tel: (212) 263-9254

The regulation of stem cells in cutaneous tissue regeneration

Heterotypic stem cell communication during hair follicle regeneration (Rabbani et al., Cell 2011)

Colored hair regeneration is a result of the collaboration between two distinct stem cell populations, hair follicle-epithelial stem cells and melanocyte stem cells. Epithelial stem cells regenerate hair. Melanocyte stem cells, on the other hand, become melanocytes that produce pigment for the hair. We asked how these different stem cell types coordinate their response during hair follicle regeneration. Utilizing mouse genetic models, we discovered that Wnt signal is essential for coordinated actions of stem cells of these two lineages. Wnt activation drives differentiation into pigment-producing melanocytes, whereas in epithelial stem cells, Wnt signaling not only dictates hair follicle formation but also regulates melanocyte stem cell proliferation. Our study provided a mechanism for how different cell types coordinate their response during the regeneration of a complex mammalian organ.

Melanocyte stem cells migrate to the epidermis during wound healing and after UVB irradiation (Chou et al., Nature Medicine 2013)

Our study shows that melanocyte stem cells in the hair follicle give rise to functional skin epidermal melanocytes, following wounding as well as UVB-irradiation. This result suggests that hair follicle melanocyte stem cells can be the origin of epidermal melanocytes that are responsible for post inflammatory hyper-pigmentation, UV-induced skin-tanning, and ultimately melanoma. We are trying to understand the signaling events controlling melanocyte stem cells as this may reveal strategies to regenerate epidermal or hair melanocytes lost as a result of a disease or injury.

Nail epithelial stem cells and digit regeneration (Takeo et al., Nature 2013)

We found nail epithelial stem cells and showed that these stem cells activate Wnt signaling during nail differentiation. Moreover, we demonstrated that nail stem cell differentiation is required for regeneration of mouse digits following amputation. We are currently investigating interactions between nail epithelial cells and underlying mesenchymal cells in efforts to dissect molecular mechanisms regulating digit regeneration upon amputation.