Montagna Symposium on Light and the Skin – Day 1
Montagna Symposium on the Biology of the Skin
Skamania Lodge, Stevenson, WA
By Guest Blogger Sancy Leachman, MD, PhD
Greetings from the Montagna Symposium! As many of the “old-timers” in dermatology know, this topic-directed symposium on the biology of the skin has a tradition of identifying the most important scientific breakthroughs in dermatology and of recruiting leadership to develop a cutting-edge program around that topic. All of this intellectual excitement occurs in relative seclusion (this year in the Columbia River Gorge) to foster an atmosphere of reflective collegiality and collaborative problem solving.
This year’s selected topic is “Light and the Skin: How Light Sustains, Damages, Treats, Images, and Modifies Skin Biology” and the program has been developed by four world-renowned leaders in the field of photobiology and pigmentation: Rox Anderson (Program Chair), and David Fisher, Barbara Gilchrest, and Steven Jacques (Session Chairs). Together, they have worked with Molly Kulesz-Martin (Symposium Director) to create a thought-provoking program exploring the biological effects of light and how light can be used to image and treat the skin. My motivation to blog throughout this meeting is to transmit some of the energy and excitement we are experiencing to dermatologic scientists that are unable to be present this year, including our friends from the NIH who are unable to attend secondary to the government shutdown.
One of the topics that struck me as being particularly intriguing or paradigm challenging was that of pigmentation diversity. Why is there so much diversity of human pigmentation and how does that impact the risk for skin cancer including melanoma? I found it quite thought-provoking to consider the multiple functions of MC1R, not just in pigmentation, but also in the oxidative stress/DNA damage responses, apoptosis, and curiously, in the role it appears to play in addiction and pain sensation. These multiple cellular and molecular roles suggest that melanocytes play roles in the skin beyond production of pigment and may be important mediators of other neurological (e.g. pain) or light sensing processes. There is clearly a complex interaction between pigmentation genes, skin phenotypes, and environmental exposures to UV that, as Dr. Gilchrest mentioned, “are likely to be coordinately regulated toward a common purpose and selected by nature to safeguard and protect the genome, which in skin translates into cancer prevention. Unfortunately one of these safeguards is phtoaging.” Some of the most interesting conversation I heard on this topic was “off-line.” Nina Jablonski’s work was discussed from the perspective of a strong evolutionary pressure for lightening of the skin (via MC1R heterogeneity) as human migration extended into Northern, light-poor regions. It was suggested that part of this evolutionary pressure might be related to decreased maternal/fetal survival in individuals with rickets. It struck me that MC1R polymorphism effects on both pigmentation and pain might represent a remarkably efficient biological use of a single molecule, simultaneously reducing vitamin D deficiency and pain associated with sunburn. Finally, concern was expressed that investigation of pigmentation diversity has been hampered by a fear that such research may be interpreted as racial or discriminatory in nature. Spanning the fields of genetics, biochemistry, medicine and evolution highlights the purpose and strength of the Montagna.