Research Suggests New Options in Treating Skin Pigment ProblemsAugust 23, 2007CincinnatI-Melanocytes are not the only cells responsible for differences in skin coloration. New research from the University of Cincinnati (UC) has shown that some of the most basic cells on the skin's surface influence pigment production and help regulate skin coloration. The finding offers hope for new approaches to the treatment of pigmentation disorders that leave the skin disfigured by light or dark blotches. In a two-year, preclinical dermatological study, Raymond Boissy, PhD, and his team found that cells known as keratinocytes express certain characteristics that could control skin pigmentation. Keratinocytes are surface skin cells that make up about 96 percent of the skin's outer layer (epidermis). The cells give the skin structural integrity and protect the body from infection. Melanocytes, the body's melanin-producing cells, make up another 2 percent of the epidermis. Melanin is the chemical responsible for skin pigmentation or color. Boissy says his team's findings could help scientists develop new drugs that alter the physiological processes that cause pigmentation disorders such as vitiligo-white blotches that occur near the body's orifices and joints-and melasma, a disorder characterized by dark pigmented lesions. "We've isolated specific physiological properties that regulate the melanocytes' functional abilities," explains Boissy, UC professor of dermatology and principal investigator for the study. "This is an important discovery because many pigment diseases are the result of deregulation of the melanocyte." "Now we have a new set of molecules to investigate that may help create uniform skin color-both for patients with pigment disorders or serious burn wounds as well as those seeking improved cosmetic skin appearance," he adds. The UC-led study, published in the September issue of The FASEB Journal, is the first to identify a specific model for manipulating melanin production in the body by using keratinocytes. Previous research has shown that keratinocytes receive "packages" of pigment granules (melanosomes) from melanocytes. In dark-skinned people, these packages are dispersed throughout the cell individually, creating a larger surface area that absorbs more light than skin cells of light-skinned people, which disperse pigment in clusters. "This was the first clue that keratinocytes played a role in skin coloration outside of genetic factors regulating the melanocyte," says Boissy. "Further study showed there was no informational difference between the melanosomes in keratinocytes for dark and light skin responsible for sorting within the keratinocyte. The cells sorted themselves based on ethnic background, so we wanted to learn more about the factors that influence skin pigmentation." For this study, Boissy and his team developed a human skin substitute model using a combination of keratinocytes and melanocytes derived from donated light and dark skin. These mixed cells were transplanted into a mouse model and allowed to grow into the skin substitute for about three months. "We found that by transplanting keratinocytes from light-skinned individuals to bioengineered skin substitutes produced a lightening effect," says Boissy. "The same effect resulted when keratinocytes from dark-skinned individuals were transplanted into the skin substitute, creating a darkening effect. "Surprisingly," he adds, "intermediate skin color was obtained when melanocytes and keratinocytes were combined from light and dark skin together" In addition, the researchers discovered that the keratinocytes also influenced how much pigment is actually produced. Boissy says the effect is subtle, but it shows that it's not just genetics of the melanocyte that determines skin coloration. Collaborators in this study include Yasuko Yoshida, Akira Hachiya, PhD, Atsushi Ohuchi, Takashi Kitahara, PhD, and Yoshinori Takema, PhD, of Kao Biological Science Laboratories in Japan, and Marty Visscher, PhD of Cincinnati Children's Hospital Research Foundation. Boissy has no financial interest in Kao Biological Sciences Laboratories, sponsor of the study. University of Cincinnati |
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| Related Keratinocytes Current Events and Keratinocytes News Articles First reconstitution of an epidermis from human embryonic stem cells Stem cell research is making great strides. This is yet again illustrated by a study carried out by the I-STEM* Institute (I-STEM/ Inserm UEVE U861/AFM), published in the Lancet on 21 November 2009. The I-STEM team, directed by Marc Peschanski has just succeeded in recreating a whole epidermis from human embryonic stem cells. UAB researchers report breakthrough in HPV research UAB (University of Alabama at Birmingham) researchers have developed a new, inexpensive and efficient method for producing and studying a type of human papillomavirus (HPV) that causes cervical cancer. The process could speed understanding of how the virus functions and causes diseases, and lead to new prevention or treatment options. Genetic breakdown in Fanconi anemia may have link to HPV-associated cancer A genetic malfunction that causes DNA instability in people with the blood disorder Fanconi anemia may put them at high risk for squamous cell carcinomas linked to human papillomavirus (HPV), according to a study posted online ahead of print by Oncogene. Natural compound in broccoli could treat devastating genetic skin disorder The compound sulforaphane whose natural precursors are found at high levels in broccoli and other cruciferous vegetables has been hailed for its chemopreventive powers against cancer. Antioxidants could provide all-purpose radiation protection Two common dietary molecules found in legumes and bran could protect DNA from the harmful effects of radiation, researchers from the University of Maryland report. Inositol and inositol hexaphosphate (IP6) protected both human skin cells and a skin cancer-prone mouse from exposure to ultraviolet B (UVB) radiation, the damaging radiation found in sunlight. Protein protects anti-cancer gene from chemical shutdown A protein that is largely absent in one type of skin cancer protects an important gene in a cell's defense against harmful mutations from being silenced. Small molecules may explain psoriasis A research team at the Swedish medical university Karolinska Institutet has shown for the time that microRNA, small RNA molecules, may play an important role in the development of inflammatory skin diseases such as psoriasis and atopic eczema. Caspase-14 protects our skin against UVB and dehydration Ultraviolet rays can be harmful to our skin and pave the way to the onset of skin cancers. VIB researchers connected to Ghent University have demonstrated that the caspase-14 protein - whose function has been unknown up to now - not only plays a role in maintaining the balance of moisture in the skin but also offers protection against UVB rays. 'Guardian of the genome' protein found to underlie skin tanning A protein known as the "master watchman of the genome" for its ability to guard against cancer-causing DNA damage has been found to provide an entirely different level of cancer protection: By prompting the skin to tan in response to ultraviolet light from the sun, it deters the development of melanoma skin cancer, the fastest-increasing form of cancer in the world. Mice cloned from skin cells Healthy and viable mice that survive until adulthood have, for the first time, been cloned from adult stem cells. Scientists from Rockefeller University, including Howard Hughes Medical Institute investigator Elaine Fuchs, used cells called keratinocyte stem cells, which represent a new model system for cloning. More Keratinocytes Current Events and Keratinocytes News Articles |
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