Harvard scientist published an article "Cell" to clarify the "alternative tanning" approach to skin

Scientists at MGH discovered that an enzyme called nicotinamide nucleotide transhydrogenase (NNT) that mediates the deposition of melanin plays a key role in the production of melanin, a pigment that protects the skin from harmful ultraviolet rays.

"Skin pigmentation and its regulation are very important because pigments have an important protective effect on UV-related skin cancer," said David Fisher, director of MGH's dermatology department and senior corresponding author

Through laboratory studies on human and animal models of skin, MGH researchers simulated the natural protection that exists in people with dark pigments

Fisher explained: "We initially hypothesized that this enzyme produces melanin by oxidizing the amino acid, tyrosine, in the melanosomes (which is responsible for the synthesis of storage compartments)

However, they were surprised to find that the amount of melanin produced is largely regulated by a completely different chemical mechanism, which can ultimately be traced back to NNT in the mitochondria, which has the ability to change skin pigmentation

The researchers found that topical application of NNT small molecule inhibitors can cause human skin to darken, while mice with reduced NNT function showed increased hair pigmentation

"We are excited about the discovery of a unique pigmentation mechanism because it can pave the way for a new method of skin darkening and protection against NNT after additional research and safety evaluation," Elisabeth Roider said She was previously a researcher at MGH and the lead author and co-author of the study

Fisher is a professor of dermatology and pediatrics at Harvard Medical School and the director of the MGH Skin Biology Research Center and the Melanoma Center

NNT mediates redox-dependent pigmentation via a UVB- and MITF-independent mechanism