Bérengère Fromy - It was during my PhD at the University of Glamorgan in Wales that a door towards biology opened. I was actually working on the mathematical modelling of the vascular effects induced by support stockings to optimize the choice of sizes. The model emphasised was common practice among Egyptians: bandage improves venous return. We were focused on macro-circulation but the model also demonstrated that light pressures could improve microcirculation, an unknown process in biology. Later on, I continued with a post-doctoral research work in Angers in the laboratory of Professor Jean-Louis Saumet to verify the existence of this microvascular process and investigate further the physiological mechanisms involved in the relationship between cutaneous microcirculation and mechanical stress. To this end, I developed a small pendulum, which coupled to a Doppler laser, enabled to measure blood flow in the skin when it is subjected to light pressures. Light pressure promotes blood microcirculation in healthy skin by inducing vasodilatation.
The theme I have been focusing on at the CNRS since 2002 is based on this work and this “mechanical sensitivity and cutaneous vasodilation” interaction. We are seeking to understand the skin’s defence mechanisms to fight effectively against mechanical stress.
Premium Beauty News - In 2012, you were awarded the CNRS bronze medal, for your work published in the prestigious journal Nature Medicine; what was the scope of this work?
Bérengère Fromy - We identified a pressure-induced vasodilation (PIV) signalling pathway in healthy skins that have the particularity to spontaneously adjust to mechanical stresses.
In pathological skin, this vasodilation is impaired or absent. We demonstrated the role of the ASIC3 mechano-sensitive channel in this physiological process. ASIC3 is activated under the application of local pressure and triggers sensory nerve endings that generate the release of neuropeptides vasodilators (CGRP, VIP, PACAP). These neuropeptides bind to endothelial cells that in turn release nerve relaxing prostaglandins and nitric oxide.
This naturally occurring process in healthy skin is less efficient in pathological skin with impaired endothelial cells, such as during ageing or diabetes. This condition contributes to the weakening of the skin under pressure, which can lead to bedsores. In the case of peripheral sensory neuropathy, the person has no nervous information to help detect the applied pressure, which results in worsening its defence capabilities against bedsores.
Premium Beauty News - Today, what is your outlook for the future?
Bérengère Fromy - This work offers several fields of application with, first, the medical field and the fight against bedsores. We are working on antioxidant treatments that could improve and restore the PIV process. The cosmetic sector is also taking interest in our work and in our ability to assess the functional quality of skin. Furthermore, we are continuing our work by studying the influence of skin viscoelastic properties on microvascular adjustment capabilities in the presence of mechanical stress. Changes in these rheological properties during ageing and in health conditions such as diabetes opens very promising avenues.