Pluripotent stem cell technology: a promising remedy for hypopigmentation disorders

The epidermal melanocytes protect the skin from UV rays and their functional destruction causes pigmentation disorders. The mutations of melanocyte stem cells cause melanomas. The mechanism of melanocyte differentiation and defining characteristics of melanocyte stem cells in humans are still not fully known. The autologous cultured melanocytes may be useful in the treatment of vitiligo.1,2 In contrast to the foreskin melanocytes, expansion of adult melanocytes is not easy. Transplanted pigment cells are known to have repaired the affected area of skin discoloration from vitiligo. Vitiligo affects about two million people in the US. Vitiligo occurs when the body considers melanocytes, cells which give color to the skin, as foreign. In vitiligo the body’s own immune system attacks those cells, hence it is an autoimmune disease. Hair follicle has three types of stem cells which are vital to hair development. These incorporate epithelial stem cells (ESCs), melanocytes stem cells (MelSCs) and neural crest stem cells (NCSCs) which are known as human fetal stem cells (hFSCs).3 Modeling of neural crest induction, melanocyte specification, and disease-related pigmentation defects in hESCs and patient-specific iPSCs has been reported.4 The safety and tolerability of subretinal transplantation of human embryonic-stem-cell (hESCs)-derived retinal pigment epithelium in Asians for the treatment of macular degeneration has been reported.5 It has been confirmed that Proteaseactivated receptor-2 is involved in melanogenesis by mediating stem cell factor production in keratinocytes.6 The enthusiasm for vitiligo exploration is coordinated towards the repositories of stem cells, especially the hFSCs. We hereby summarize recent advances in studies of pluripotent stem cells and its utility in vitiligo with specific accentuation on hFSCs. Reconstruction of pigmentary system using stem cell technology