Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers Identify Signals that Cause Hair Follicles to Sprout

20.03.2003


The delicate interplay of two chemical signals coaxes stem cells into becoming hair follicles, according to new research by scientists at the Howard Hughes Medical Institute at The Rockefeller University.

The research has implications for understanding hair growth and hair-follicle development, and it may also help explain how diverse structures, such as teeth and lungs, are formed or how some forms of skin cancer develop.

In an article published in the March 20, 2003, issue of the journal Nature, researchers led by HHMI investigator Elaine Fuchs at The Rockefeller University discovered that two signaling molecules, Wnt and noggin, influence immature stem cells to begin the process of forming hair follicles.



According to Fuchs, studies in her laboratory and others revealed the possible involvement of Wnt and other proteins in the signal transduction pathways that trigger hair-follicle formation. In previous studies, Fuchs and her colleagues produced an abnormally furry mouse with high numbers of hair follicles by genetically altering the animals to produce a stabilized form of a protein called beta-catenin. They also knew that beta-catenin was affected by the Wnt protein. Among the other proteins they implicated in hair-follicle formation was “lymphoid enhancer-binding factor 1” (Lef1), which is part of a transcription complex that controls gene activity.

“One of the aspects that scientists have been trying to understand in development of hair follicles, tooth buds, mammary glands and lungs is how these various transduction pathways work together,” said Fuchs.

The researchers also had evidence that a second mechanism, involving a signaling molecule called bone morphogenetic protein (BMP), is also required for creating epithelial buds — pockets in the skin that are the precursors of hair follicles.

Through experiments using mouse skin cell cultures and skin from embryonic mice with various genes knocked out, the researchers showed that Wnt stabilizes beta-catenin and increases its concentrations in the target stem cell. In concert, noggin inhibits BMP, leading to production of Lef1. In addition, beta-catenin activates Lef1, which in turn downregulates the gene for the protein E-cadherin. E-cadherin is important in cell adhesion. Reduced levels of E-cadherin trigger reduction of cell adhesion structures, called adherens junctions, a process important in initiating formation of the epithelial bud.

“Unlike the earlier experiments, in which we genetically altered the animals, in these experiments, we have altered the stem cells using external factors that the skin normally makes,” said Fuchs. “And in doing so, we have been able to elicit the initial responses that occur in the development of the hair follicles.

“The other important advance is that we now understand how Wnt and inhibition of the BMP signaling pathway work together by regulating this transcription factor complex. The discovery provides insights into how signals simultaneously operate together to activate a particular event, in this case, a transcription factor.”

The findings also hint at how different kinds of cells interact to produce epithelial buds, said Fuchs. “These signals are probably coming from different cells within the skin,” said Fuchs. “The Wnt pathway is likely coming from adjacent epithelial cells, and the noggin pathway from mesenchymal cells. But, they’re working together on a single skin stem cell to produce an activated transcription factor.” Mesenchymal cells are unspecialized cells in embryonic skin from which the dermis will develop.

“How these signal transduction pathways are merging was not understood before, and we now have a much clearer picture of why they need to be there at the same place and time in the developing skin,” said Fuchs.

According to Fuchs, the findings also have implications for understanding how some forms of skin cancer arise. “Our studies suggest that too much or too little E-cadherin can be a bad thing,” she said. “Just the right amount of E-cadherin is needed to loosen the adhesion of the stem cells in the epithelium, to allow them to remodel and grow downward to form the hair follicle. What’s interesting is researchers have found reduced levels of adherens junctions in squamous cell carcinomas of the skin. So, we think our findings may be relevant, because they suggest that if the E-cadherin levels are reduced too much, there can still be a downgrowth of the skin, but one that’s deregulated. The early stages of hair follicle morphogenesis resemble, to some extent, what happens in the development of a tumor mass.”

The studies in Fuchs’s laboratory seek to understand fundamental aspects of hair follicle formation, which could eventually suggest new ways to restore or inhibit hair growth. “These studies raise the possibility that drugs to activate these natural factors could promote hair follicle growth in wanted places, and inhibitory drugs could prevent hair growth in unwanted places,” she said.

Among the next steps in the research, said Fuchs, is to understand how the newly discovered machinery involved in epithelial bud formation links to the later steps that causes mature hair-producing follicles to sprout.

Jim Keeley | Howard Hughes Medical Institute
Further information:
http://www.hhmi.org/news/fuchs2.html

More articles from Life Sciences:

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

nachricht Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>