Professor Richard Weller

My research has two focuses: the effect of ultraviolet on systemic health; and on eczema.

Personal Chair of Medical Dermatology / Honorary Consultant Dermatologist

Centre for Inflammation Research

Contact details

Web: University profile

Group members

Jiayue Gu, PhD student

Fiona Cunningham, PhD student

Research interests

Ultraviolet radiation from sunlight is the major environmental risk factor for skin cancer, and this has dominated dermatologists' view of sunlight for the century since this was confirmed. UV-induced skin cancer is, however, almost exclusively a disease of white skinned people. Work performed by my group and a small number of others internationally is identifying various health benefits of sun exposure. Vitamin D only accounts for a few of these health benefits, and identification of further mechanisms of UV-induced benefits is an important area of future research. The earliest people migrating to NW Europe after the last glacial maximum 8,500 years before the present day had brown skin. The transition to white skin occurred relatively rapidly as Neolithic agriculturalists replaced the original Mesolithic hunter-gatherers around 5,000 years before present. The reasons for this rapid change are unclear, but presumably are related to the need to maximise evolutionary fitness in a low light, high latitude environment.

Ultraviolet radiation and the skin

In 1996 I made the first description of nitric oxide (NO) production on the skin surface. NO at the time was known to dilate blood vessels and thus help regulate blood pressure - work for which the discoverers received the Nobel Prize for Medicine or Physiology in 1998 - but it was also involved in control of a number of other functions. Initially working in Aberdeen and Edinburgh and then at Heinrich-Heine University, Dusseldorf and the University of Pittsburgh I set out to uncover the role of this naturally produced NO in the skin. Following the standard dermatological dogma of the time I spent my time in Germany and America looking at the effects of NO on keratinocyte (skin cell) survival after sun exposure. Although I was able to show effects of NOS derived NO in inhibiting apoptosis in cell culture and murine models, I was unable to replicate this in man. Developing my work in Edinburgh on healthy volunteers, I was able to show that human skin contains large stores of nitrogen oxides (NOx) and that these are photo-reduced by UV radiation releasing NO to the circulation, with systemic effects, in particular lowering of BP. This work is summarised in a TED talk.

Work from my group and with a number of international collaborators is now finding a growing number of physiological and homeostatic processes that are dependent on this UV-skin NO mobilisation pathway. Partly spurred on by the discovery of this mechanism, the risk-benefit ratio for population sunlight exposure is being reconsidered in Europe, Australia and the USA. It is becoming clear that Vitamin D synthesis is not the only sun-dependent homeostatic mechanism, and may in fact only account for a small part of health benefits attributed to sun exposure. We have recently shown that UVA independently of vitamin D correlates inversely with deaths from COVID, which has important public health implications.

The advent of large prospective cohort studies, which include robust measures of sunlight exposure at baseline now enable us to accurately identify how sunlight exposure affects disease at population level. Using the UK Biobank we have been able to show that for a middle-aged British population, increased sunlight exposure correlates with reduced all-cause, cardiovascular and cancer mortality. The UV-nitric oxide pathway I have previously identified is probably responsible for much of the cardiovascular benefit of sunlight exposure, but the reduction in cancer mortality is intriguing, and almost certainly due to an additional mechanism(s). We are now investigating this, and specifically looking at the effects of UV on immune regulation in man. This body of research calls into question the current anti-sun public health advice

Biographical Profile

I graduated in medicine at St Thomas' Hospital, University of London (now part of King's College, London) and undertook my general/internal medicine training in the north of England and in Australia. Having gained my MRCP, I trained in dermatology at the Institute of Dermatology (St John's) in London and in Aberdeen and Edinburgh. I spent some time out of my clinical training to complete a research MD degree. Having completed my dermatology training, I gained a scholarship from the University of Edinburgh, and spent three years in postdoctoral research training in the laboratories of Professor Victoria Kolb-Bachofen, Heinrich-Heine Universität, Dusseldorf, and of Dr Tim Billiar, University of Pittsburgh, USA. I was recruited from America to the post of Senior Lecturer and, latterly, Reader in Dermatology and Principal Investigator at the Centre for Inflammation Research, University of Edinburgh. My time is divided between clinical duties, where I am an honorary NHS Consultant Dermatologist with a particular interest in medical dermatology and eczema, and the University where I am active in research and teaching.