Premium Beauty News - You defended a doctoral thesis in 2011 on skin aging, in what context did you do it?
Morgan Dos Santos - I had the chance to do my doctoral thesis in an interface position between the academic and industrial sectors. Indeed, a collaboration took place between the CNRS, through the laboratory of Dr. Patricia Rousselle from the Institute of Biology and Chemistry of Proteins (CNRS/UCBL), and BASF Beauty Care Solutions. The topic was "the role of heparan sulfate proteoglycans of the basal lamina during skin aging" [1] . The aim was to identify new biological targets involved at the level of the dermo-epidermal junction (DEJ) in the aging process and in skin homeostasis.
Under the direction of Dr. Patricia Rousselle, an internationally recognized expert in the area of dermo-epidermal junction - also called epidermal basal lamina - we studied the qualitative and quantitative changes of some partners during the aging process and the associated effects. This small area located between the epidermis and the dermis regulates a great number of fundamental processes in the skin such as differentiation, proliferation, and presents over time striking histological differences. Until now, research work had focused mainly on the study of collagen and glycoproteins present at this level. Proteoglycans are well known at the dermis level but much less at the DEJ level. All our results evidence that a significant decrease of the perlecan synthesis – the main proteoglycan of basal lamina – takes a part in the thinning and in the epidermal differentiation defects observed during aging.
Premium Beauty News - What methods and approach did you use for your study?
Morgan Dos Santos - We had a multi-pronged approach, namely, a tissue, cellular and molecular approach. First, the expression of proteoglycans was studied from a fundamental point of view, analysing them qualitatively and quantitatively at the tissue and cellular level and during aging. An immunohistological analysis of a cohort of normal human skin from donors ranging from 22 to 73 years of age showed a drastic diminution of perlecan at the DEJ. Biochemical studies combined to genomic analyses demonstrated that the decrease in the expression of perlecan was not caused by a degradation of the protein itself but by a decrease in the transcriptional activity of keratinocytes. We then validated our observations on different three-dimensional models of reconstructed skin mimicking some characteristics of aging. For this, we took advantage of the knowledge and expertise of Dr. Odile Damour, Head of the Laboratory of Skin Replacement in Lyon and internationally recognized in the field of tissue engineering. We were able to approach the molecular mechanisms by which these proteoglycans could influence the epidermal differentiation. Generally speaking, the constituents of aging are well identified but our understanding of the associated mechanisms is not complete. With our findings on proteoglycans, we have contributed to make some progress on this subject.
Premium Beauty News - What was at stake for your industry partner?
Morgan Dos Santos - Having discovered new biological targets associated to aging and having approached the mechanisms involved, it was interesting to see if some compounds were able to restore the expression of proteoglycans involved in aging processes. For this, an identification and screening of molecules by our industrial partner was performed on a simple cell model and then on a three-dimensional model. Some chemical and natural compounds proved being particularly effective.
Premium Beauty News - What prospects does your work offer?
Morgan Dos Santos - There will be some academic but also industrial spin-offs. In the short term, this work will lead to a publication in a scientific journal. At the industrial level, this work will be the basis for future industrial development. We have already made some in vitro evaluations on the potential of some molecules to restore the expression of these partners. This work could have some repercussions in the areas of skin repair and cosmetics.
On a personal level, my wish is to continue to study skin aging. In addition, I had the chance of being in contact with experts in skin biology, namely Dr. Patricia Rousselle and Dr. Odile Damour, both references in their field and belonging to the Lyon centre of expertise in dermocosmetics with the CED being its reflection. And to be able to contribute to the development of an active ingredient in connection with the findings was a great opportunity and I am grateful for the confidence that BASF Beauty Care Solutions placed in me.
