Induced pluripotent stem (iPS) cells have been repeatedly generated from a tiny number of keratinocytes attached to a single hair plucked from a human scalp by a team of US researchers in what is a major advance in the field of stem cell therapy.
Juan Carlos Izpisua Belmonte, who led the study at the Salk Institute for Biological Studies, said that the breakthrough provided a practical and simple alternative for the generation of patient- and disease-specific stem cells, which had been hampered by the low efficiency of the reprogramming process.
The researcher also said that the new process could spare patients invasive procedures to collect suitable starting material, as it only needs a single human hair.
"Having a very efficient and practical way of generating patient-specific stem cells, which unlike human embryonic stem cells, wouldn't be rejected by the patient's immune system after transplantation brings us a step closer to the clinical application of stem cell therapy," Nature Biotechnology quoted Dr. Belmonte, a professor in the Gene Expression Laboratory and director of the Center of Regenerative Medicine in Barcelona, Spain, as saying.
Keratinocytes form the uppermost layer of skin and produce keratin, a tough protein that is the primary constituent of hair, nails and skin. They originate in the basal layer of the epidermis, from where they move up through the different layers of the epidermis and are eventually shed.
Dr. Belmonte insisted that it was still to be determined why keratinocytes appear to be much more malleable than other cell types.
"We checked a whole rainbow of cells and found keratinocytes to be the easiest to be reprogrammed. It is still not clear exactly why that is and knowing it will be very important for the technology to develop fully," he said.