Premium Beauty News - The works of the team you are heading are focusing on the functionality and dynamics of skin tissue. What is about it exactly?
Dominique Sigaudo-Roussel - At first, my team was mostly interested in skin micro-circulation. Using non-invasive models, we study the effect of environment, like the effects of the application of a pressure on the interactions between small nerve fibres in the skin and blood vessels especially in young, elderly and diabetic people. In 2013, following a reorganization of the unit to which the team belongs, we merged with the team of Pascal Sommer, which is focusing on elastogenesis in the extracellular matrix and on aging models. This remodelling of the team broadened the field of investigation to the elastic component. It also provided access to in-vitro techniques that will allow us to study very specific cellular interactions to the integrated model and the influence of pressure stress.
We are interested in the responses given by the skin under pressure stresses, whether they are light as in a massage, or stronger, which can lead to skin lesions such as ulcers, necrotic lesions. Our current work focuses on the influence of elastic fibres in neuro-vascular interactions and on the relationship with pressure. Which genes, which signalling pathways are activated, which receptors come into play? How does the tissue regenerate? What functionalities are affected? And what are their changes over time? These studies have a particular resonance with the world of cosmetics, since a pressure is exerted during the application of a cosmetic cream on the skin, but also with the world of therapeutic pharmacology with the issue on chronic skin injuries.
Premium Beauty News - What biological mechanisms have you highlighted recently?
Dominique Sigaudo-Roussel - We published this year in the journal Nature Medicine  the finding on the role played by a stretch receptor in the transduction of a low pressure and which interacts with our mechanism. We have shown that low pressure could predict the behaviour of skin under high pressure. This relationship was observed for the past 10 years or more, and we were recently able to highlight it. Depending on the kinetics of reperfusion to the release of pressure, the tissue will become necrotic or not after 24h. The stretch receptor involved is the ASIC3 and the neuropeptide the CGRP, a molecule known for many years as being involved in inflammatory reactions, but which, depending on its tissue concentration, may induce other effects. Hence, we are revisiting the concept of the CGRP molecule.
Premium Beauty News - In your speech at the last European Dermocosmetology Days on the topic of healing, you mentioned external parameters – psychological and well-being in particular – as factors influencing the response of the skin under pressure stress.
Dominique Sigaudo-Roussel - Indeed, we have observed that the induction of pain can have a deleterious effect on the micro vascular response at the measured pressure on a skin area away from the pain. The nervous system reacts to pain, it sends chemical signals, triggers the synthesis of stress molecules and we can see the behaviour of the skin change in response to low pressure. If the pain receptors are blocked, we recover the micro vascular response to pressure.
By extrapolating on a healthy person, we could test the quality of the skin depending on the stress state of the person, conditions of application of the product, and of self-esteem. This could be done by acting on a receiver, a cellular or molecular partner to highlight these mechanisms and modulate the influence of this psychic world. The human body responds to its environment, sometimes it adapts to it, sometimes it deregulates and this, depending on the chronicity of harmful environments but also on one’s individual capabilities.
To date, we take account of these observations and always incorporate a questionnaire on the mood and feeling of volunteers with regards to pain, in our clinical studies.
Premium Beauty News - What is your insight on the future of skin care?
Dominique Sigaudo-Roussel - The skin sends many messages, be they metabolic or psychological. Through the mechanisms that we discover our aim is not about knowing how to repair an injury faster but how best fix and prevent it from reappearing again over time. I’m in a spirit of prevention, of being able to “avoid that”, by investing in the quality of skin. In my view, the future of skincare will lie in holistic approaches, through the mode of application, the environment and not just by treating the site but by taking into account the person as a whole.
At the level of my research team, we have a great conceptual strength encompassing the functionality and dynamics of the skin with an approach ranging from epigenetics to cell, culture including the human being taken in its individuality. This is a good program ahead of us for the next 10 years.