Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Researchers Successfully Reprogram Keratinocytes Attached to a Single Hair

The first reports of the successful reprogramming of adult human cells back into so-called induced pluripotent stem (iPS) cells, which by all appearances looked and acted liked embryonic stem cells created a media stir. But the process was woefully inefficient: Only one out of 10,000 cells could be persuaded to turn back the clock.

Now, a team of researchers led by Juan Carlos Izpisúa Belmonte at the Salk Institute for Biological Studies, succeeded in boosting the reprogramming efficiency more than 100fold, while cutting the time it takes in half. In fact, they repeatedly generated iPS cells from the tiny number of keratinocytes attached to a single hair plucked from a human scalp.

Their method, published ahead of print in the Oct. 17, 2008 online edition of Nature Biotechnology, not only provides 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, but also spares patients invasive procedures to collect suitable starting material, since the process only requires 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,” says Belmonte, PhD., a professor in the Gene Expression Laboratory and director of the Center of Regenerative Medicine in Barcelona, Spain.

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.

While scientists have successfully reprogrammed different types of mouse cells (fibroblasts, liver and intestinal cells), skin fibroblasts were the only human cell type they had ever tried their hands on. Fibroblasts help make the connective tissue in the body and are the primary cell type in the deeper layers of the skin, where they are responsible for wound healing and the secretion of proteins that form collagen.

For the first set of experiments, first author Trond Aasen, Ph.D., a postdoctoral researcher at the Center of Regenerative Medicine in Barcelona, used viral vectors to slip the genes for the master regulators Oct4, Sox2, as well as Klf4 and c-Myc into keratinocytes cultured from human skin explants. After only 10 days — instead of the more typical three to four weeks — one out of 100 hundred cells grew into a tiny colony with all the markings of a typical human embryonic stem cell colony.

The researchers then successfully prodded what they call keratinocyte-derived iPS cells or KiPS cells to distinguish them from fibroblast-derived iPS cells into becoming all the cell types in the human body, including heart muscle cells and dopamine-producing neurons, which are affected by Parkinson’s disease.

Taking advantage of the high efficiency of the keratinocyte reprogramming process, Aasen decided to test whether he could establish KiPS cells from minute amounts of biological samples. “We plucked a single hair from a co-worker’s scalp and cultured the keratinocytes, which are found in the outer root sheet area,” recalls Aasen. He then successfully reprogrammed these cells into bona fide KiPS cells.

Just why keratinocytes appear to be much more malleable than other cell types is still an open question. “We checked a whole rainbow of cells and found keratinocytes to be the easiest to be reprogrammed,” says Belmonte. “It is still not clear exactly why that is and knowing it will be very important for the technology to develop fully,” he speculates.

They researchers did find one hint, though. When they compared the expression profiles of genes related to stem cell identity, growth or differentiation between keratinocytes, fibroblasts, human embryonic stem cells (hESC) and KiPS cells, keratinocytes had more in common with hESCs and KiPS cells than with fibroblasts.

Researchers who also contributed to the study include Angel Raya, Ph.D., Maria J. Barrero, Ph.D., Elena Garreta, Ph.D., Antonella Consiglio, Ph.D., Federico Gonzales, Ph.D., Rita Vassena, Ph.D., Josipa Bilic, Ph.D., Vladimir Pekarik, Ph.D., Gustavo Tiscornia, Ph.D., Michael Edel, Ph.D., and Stéphanie Boué, Ph.D., at the Center of Regenerative Medicine in Barcelona, Spain.

The Salk Institute for Biological Studies in La Jolla, California, is an independent nonprofit organization dedicated to fundamental discoveries in the life sciences, the improvement of human health and the training of future generations of researchers. Jonas Salk, M.D., whose polio vaccine all but eradicated the crippling disease poliomyelitis in 1955, opened the Institute in 1965 with a gift of land from the City of San Diego and the financial support of the March of Dimes.

Mauricio Minotta | Newswise Science News
Further information:

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>