Mayumi Ito, PhD

Photo of [title]

Associate Professor of Dermatology
Ph.D. 2003 Nagoya University

Ito Lab
Stem Cell Biology, Dermatology, Regenerative Medicine
Wound Healing, Adult Skin Stem Cell, Digit Regeneration, Hair Follicle Regeneration

Contact Information

Smilow Research Center
522 First Avenue. 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. 

Selected Publications: 


  • Chou, WC; Takeo, M; Rabbani, P Hu, H; Lee, W; Chung, YR; Carucci, J; Overbeek, P; Ito, M. Direct migration of follicular melanocyte stem cells to the epidermis after wounding or UVB irradiation is dependent on Mc1r signaling.  Nature medicine 2013 Jul;19(7):924-929. PMID: 23749232
  • Gay, D; Kwon, O; Zhang, Z; Spata, M; Plikus, MV; Holler, PD; Ito, M; Yang, Z; Treffeisen, E; Kim, CD; Nace, A; Zhang, X; Baratono, S; Wang, F; Ornitz, DM; Millar, SE; Cotsarelis, G. Fgf9 from dermal gammadelta T cells induces hair follicle neogenesis after wound. Nature medicine 2013 Jul;19(7):916-923. PMID: 23727932
  • Myung, PS; Takeo, M; Ito, M; Atit, RP. Epithelial wnt ligand secretion is required for adult hair follicle growth and regeneration.  Journal of investigative dermatology 2013 Jan;133(1):31-41. PMID: 22810306
  • Takeo, M; Chou, WC; Sun, Q; Lee, W; Rabbani, P; Loomis, C; Taketo, MM; Ito, M. Wnt activation in nail epithelium couples nail growth to digit regeneration. Nature 2013 Jul;499(7457):228-232. PMID: 23760480
  • Myung P and Ito M. (2012) Dissecting the Bulge in Hair Regeneration. J Clin. Invest. 122(2):448-54. PMID: 22293183
  • Rabbani P, Takeo M, Chou W, Myung P, Bosenberg M,ChinM, Taketo, M, Ito M. (2011) Coordinated activation of Wnt signaling in epithelial and melanocyte stem cells initiates pigmented hair regeneration. Cell 145(6): 941-956. PMID: 21663796
  • Myung P, Andl T, Ito M. (2009) Defining hair follicle stem cell (Part II) (Review). J Cutan Pathol 36: 1134-1137. PMID: 19712246
  • Myung P, Andl T, Ito M. (2009) Defining hair follicle stem cell (Review). J Cutan Pathol. 36:1031-1034. PMID: 19674210
  • Ito M,YangZ, Andl T, Cui C, Kim N, Millar S, Cotsarelis G. (2007) Wnt-dependent de novo hair follicle regeneration in adult mouse skin following wounding. Nature 17:316-320. PMID: 17507982
  • Ito M, Liu Y, Yang Z, Nguyen J, Liang F, Morris R, Cotsarelis G (2005). Stem cells in the hair follicle bulge contribute to wound repair but not to homeostasis of the epidermis. Nature Med; 11:1351-1354. PMID: 16288281