Researchers in the Perelman School of Medicine at the University of Pennsylvania have determined the role of a key growth factor, found in skin cells of limited quantities in humans, which helps hair follicles form and regenerate during the wound healing process.
Researchers in the Perelman School of Medicine at the University of Pennsylvania have determined the role of a key growth factor, found in skin cells of limited quantities in humans, that helps hair follicles form and regenerate during the wound healing process. This growth factor, Fgf9, is initially secreted from gamma delta T cells, an unconventional, rare subset of T cells involved in the immune response. Once released, Fgf9 serves as the catalyst for a signal sent via the dermal Wnt pathway. The signal prompts further expression of Fgf9 in structural cells called fibroblasts, and adds to the generation of new hair follicles. Researchers believe that this growth factor could be used therapeutically for people with various hair and scalp disorders. The study appears in an advance online publication of Nature Medicine.
Credit: George Cotsarelis and Elsa Treffeisen/Penn Medicine
When this growth factor, called Fgf9, was overexpressed in a mouse model, there was a two- to three-fold increase in the number of new hair follicles produced. Researchers believe that this growth factor could be used therapeutically for people with various hair and scalp disorders. The study appears in an advance online publication of Nature Medicine.
"The findings help explain why humans don't regenerate their hair after wounding," said senior author George Cotsarelis, MD, professor and chair of Dermatology. "The study also points us to a way to treat wounds and grow hair."
Following up on earlier work, which showed that increased signaling from the Wnt pathway doubled the number of new hair follicles, the Penn team looked further upstream in the pathway and identified an important cascade of signals that prompt further expression, as well as perpetuate and amplify signals sent during a crucial phase of hair-follicle regeneration.
Fgf9 is initially secreted from gamma delta T cells, an unconventional, rare subset of T cells involved in the immune response. Once released, Fgf9 serves as the catalyst for a signal sent via the dermal Wnt pathway. The signal prompts further expression of Fgf9 in structural cells called fibroblasts, and adds to the generation of new hair follicles.
When a wound occurs in an adult person, hair follicle growth is blocked and the skin heals with a scar. However, hair does regenerate to a great extent in the wound-healing process in mice. The team compared how the process works in adult mice versus humans. Humans have low numbers of gamma delta T cells in their skin compared to mice, and this may explain why human skin scars but does not regenerate hair follicles.
In adult mice, the amount of Fgf9 secreted modulates hair-follicle regeneration after wounding. When Fgf9 was reduced, there was a decrease in wound-induced hair follicle growth. Conversely, when Fgf9 was increased, there was a two- to three-fold increase in the number of new hair follicles, equal to the amount seen in the mice expressing Wnt. Importantly, when the investigators added Fgf9 back to the wounds that do not normally regenerate, FGF9 triggered the molecular cascade of events necessary for skin and hair regeneration; thus, leaving the door open for using Fgf9 to treat wounds and hair loss in people.
The Penn team suggests that, given the differences in skin development and regeneration in response to wounding, treatments intended to compensate for the lack of Fgf9 may be most effective if timed with a wounding response. "Testing activators of Fgf9 or Wnt pathways during the wound healing process may be warranted," they stated.
The study was funded by the National Institutes of Health (R01AR46837, P30AR057217, RO1AR055309, R01HL105732, T32AR007465), the Edwin and Fannie Gray Hall Center for Human Appearance at Penn Medicine, and The Dermatology Foundation.
Additional collaborators on the research include co-lead authors Denise Gay and Ohsang Kwon, Zhikun Zhang, Michelle Spata, Maksim V Plikus, Phillip D. Holler, Zaixin Yang, Elsa Treffeisen, Arben Nace, X Zhang, Sheena Baratono and Sarah E. Millar from Penn's Department of Dermatology, along with collaborators from New York University Langone Medical Center (Mayumi Ito), Seoul National University College of Medicine, Chungnam National University in Daejeon, Korea, Texas A&M University Health Science Center, and Washington University School of Medicine.
Cotsarelis, Ito and Kwon are listed as inventors on patent applications related to hair-follicle neogenesis, Wnt and FGF9, which are owned by the University of Pennsylvania. Cotsarelis also serves on the scientific advisory board and has equity in Follica, a start-up company that has licensed related patents from the University of Pennsylvania starting in 2007. Cotsarelis was also a co-founder of Follica.
Penn Medicine is one of the world's leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System, which together form a $4.3 billion enterprise.
The Perelman School of Medicine has been ranked among the top five medical schools in the United States for the past 16 years, according to U.S. News & World Report's survey of research-oriented medical schools. The School is consistently among the nation's top recipients of funding from the National Institutes of Health, with $398 million awarded in the 2012 fiscal year.
The University of Pennsylvania Health System's patient care facilities include: The Hospital of the University of Pennsylvania -- recognized as one of the nation's top "Honor Roll" hospitals by U.S. News & World Report; Penn Presbyterian Medical Center; and Pennsylvania Hospital — the nation's first hospital, founded in 1751. Penn Medicine also includes additional patient care facilities and services throughout the Philadelphia region.
Penn Medicine is committed to improving lives and health through a variety of community-based programs and activities. In fiscal year 2012, Penn Medicine provided $827 million to benefit our community.
Kim Menard | EurekAlert!
NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures
17.11.2017 | National Institute of Standards and Technology (NIST)
High speed video recording precisely measures blood cell velocity
15.11.2017 | ITMO University
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
20.11.2017 | Earth Sciences
20.11.2017 | Earth Sciences
20.11.2017 | Life Sciences