From hair follicle stem cells to neuronal cells

26 March 2011

Dr Catherine Jomary

Stem cell biologist
Bio-Plus Services, Belgium

Cell-based therapy is a rational approach for replacing lost neurons following injury or neurodegenerative disease. Therapeutic strategies based on cell-replacement approaches offer the prospect of being able to restore neuronal function independently of the underlying causes or stages of degeneration.

A wide range of stem cells from various sources, including adult stem cells, embryonic stem cells, and induced pluripotent stem (iPS) cells are currently being investigated for their potential to differentiate into neurons for therapeutic applications.

While there is encouraging development regarding transplanted iPS cells, their tumorigenic capacity is a major obstacle for clinical application. Recently, pluripotent adult skin stem cells isolated from the bulge region of the hair follicle (hfPS) has emerged as an easily available alternative source for autologous therapeutic transplantation.

These cells originate from the neural crest and can self renew and differentiate into a variety of cell types upon induction by various micro-environmental cues. Under specific differentiation conditions in vitro, these cells can produce neurons, glia, smooth muscle cells, chondrocytes and melanocytes. Transplanted hfPS cells have been shown to support nerve regeneration in severed sciatic nerve and severed spinal cord mice models, and induce significant functional recovery.

Considering their broad differentiation potential, they represent an alternative source of stem cells for restorative therapy of neurodegenerative diseases. For example, to date there is no effective treatment to slow or stop the loss of retinal neurons associated with retinal dystrophies.

Cell replacement approaches using hfPS cells offer the prospect of being able to restore visual function independently of the underlying causes or stages of the disease. Our studies showed that hfPS cells can not only be differentiated into retinal neurons but can also be integrated into the retinal tissue. We propose that they can be considered as an autologous source of cells for transplantation to treat retinal degenerative diseases.