11^th Global Dermatologists Congress

Biography

Biography: Michel R. Hanna

Abstract

Hair follicle (HF) morphogenesis and regeneration depend on intensive and reciprocal interactions between epithelial and mesenchymal components. Currently, attempts to regenerate HFs depend on combining receptive epithelial and trichogenic dermal mesenchymal components and grafting them into an in vivo environment. Unfortunately human HF bulge stem cells (BSCs) are not suitable for this purpose because the isolation and propagation of human HF BSCs for tissue engineering purposes remains a challenge. Here we developed a strategy to differentiate human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) into CD200⁺/ITGA6⁺ BSCs that can reconstitute the epithelial components of the HF. Importantly, co-transplantation of hESCs or hiPSC-derived CD200⁺/ITGA6⁺ cells with trichogenic mice dermal cells into immunodeficient nude mice resulted in HF formation. Histological analysis revealed that the obtained HFs posses all HF lineages including the hair shaft and the inner and outer root sheaths. Human HF stem cell markers such as keratin-15 were detected in reconstituted HFs. The human origin of the epithelial cells in the new HFs was confirmed by positive reactivity for human-specific nuclear antigen. In this context derivation of functional HF BSCs capable of inducing a new hair formation suggest a major step toward developing cell-based treatments for alopecia.