Patricia Rousselle is one of the French researchers, specialised in skin science, who was trained in the crucible of the Hospital Edouard Herriot in Lyon, where she was an intern in medical biology in the Laboratory of skin substitutes. “It is initially for the treatment of severely burned patients that the Edouard Herriot Hospital developed a dermatological expertise of a very high level,” she explains.
In 1988, Patricia Rousselle became interested in proteins involved in the mechanisms of adhesion of the epidermis. Autografts which were prepared by the laboratory from cultures of healthy epidermal cells taken from burnt patients were encountering many difficulties due to the lack of adhesion of some epidermal grafts.
She then joined Professor Burgeson’s team at the Shriners Hospital for Crippled Children (Portland, Oregon), who had just identified and characterized the collagen VII, which plays a major role in anchoring the epidermis to the dermis. Hence, she participated in the discovery of laminin-5 (LN-5), a protein that makes up the filaments involved in the skin adhesion.
Basic research and clinical applications
Additional researches were however necessary before considering clinical applications. “From the beginning we worked in partnership with cosmetic laboratories interested in the development of active ingredients designed for improving skin condition,” explains Patricia Rousselle.
She therefore continued here works, first in the service of Professor Petit for the treatment of severely burned patients, always within the Edouard Herriot Hospital in Lyons, then with Professor van der Rest’s team, at the Institute of Biology and Chemistry of Proteins (IBPC). She briefly returned to the United States for a post-PhD at the Cutaneous Biology Research Centre in the Harvard Medical School (Boston, Mass.), before finally joining the CNRS (French National Center for Scientific Research) in 1995.
At each stage, she questions herself on the prospects for implementation of her findings and seeks to combine basic and applied research. With some success, as can be seen by her numerous partnerships with pharmaceutical and cosmetic industries and with clinicians. “It is the originality of my thematic approaches,” she says modestly.
Shiseido was among the first laboratories interested in here works with the launch in the early 1990s of a range of anti-aging products promoting healing and skin repair. Other big names in cosmetics (Dior, Chanel, Yves Rocher) offered Patricia Rousselle and her team collaboration contracts for specific research missions.
In 2006, studies conducted on a peptide fragment of LN-5, in partnership with the Laboratoires d’Anjou, lead to the launch of the LCE balm from the Cebelia range. The balm, protected by a patent was acclaimed by a panel of consumers during the contest called Victoires de la Beauté 2009-2010.
"Restoring the activity of some proteins involved in epidermal junction seems to be more than ever a key element in the fight against signs of aging skin. This is why the cosmetic industry is interested in our works", explains Patricia Rousselle. She is also currently involved, with her team in the development of anti-aging actives related to the activity of proteoglycans as part of a partnership with BASF Beauty Care Solutions.
A Better understand of the mechanisms of skin aging
Over the past two decades, basic research has identified different molecules involved in the functioning of skin cells. According to Patricia Rousselle, this stage is probably completed. But there is a huge gap between the knowledge we have of a protein and understanding what role it has. “What we are currently studying now are the functions of this catalogue of proteins. We are in the understanding stage. Some of these proteins or cells which had been somewhat sidelined now appear in a new light as we understand a little better their usefulness.”
Scientists now have an excellent mapping of the different cells and molecules involved in skin aging and are investigating their interactions. “On the other hand, we know little about the mechanisms of disturbances involved during the aging process. For example, do they concern degradations or changes in proteins, of a significant diminution in protein synthesis or degradations related to enzymes? It is not because we know a protein that we know the functions and dysfunctions of it.”
The interest in having a better understanding of these cellular mechanisms and methods of analysis developed by scientists such as Patricia Rousselle goes of course far beyond the domain of cosmetics. “I’m more and more interested in aspects related to wound healing in order to develop therapeutic strategies which could be applied in the field of tissue repair and a partnership with the pharmaceutical company, Symatèse Biomatériaux gave birth to a joint patent. I have also developed an interest in adhesion proteins involved in tumorigenesis, to better understand the cellular mechanisms that come into play in the formation of cancers of epithelial origin,” she explains.