232 ARTICLE TECHNIQUE Hyalurosome Le rôle du HA dans le processus de cicatri- Conclusion HAd est commercialisé sous le nom sation nous a conduit à mesurer l’effet de commercial Epidermosil . ■® HAd (et du cortisol) dans un « scratch Le stress psychologique a de multiples Jean-François Nicolaÿ test ». Dans ce modèle expérimental, effets négatifs sur la peau et on peut dire Directeur Scientifi que une monocouche de kératinocytes est qu’il la fait vieillir prématurément. Une cible Scientifi c Director « incisée » (Figure 4, t0)puis on mesure moléculaire intéressante est le hyalurosome 24 heures après comment la « plaie » s’est dont l’intégrité est nécessaire au maintien Pascale Prouhèze résorbée. Comme attendu, le cortisol de l’homéostasie cutanée. Son altération Attachée de Recherche – Laboratoire de retarde le comblement (10)car il réprime les par le cortisol, le principal médiateur des Biologie 2 deux mécanismes impliqués : la proliféra- effets négatifs du stress, induit de nombreux Research Associate - Biology Laboratory 2 tion et la mobilité cellulaire. HAd s’oppose signes du vieillissement (atrophie cutanée, EXSYMOL aux effets du cortisol, et le comblement xérose, réponse aux facteurs de croissance est plus rapide (Figure 4, t24h) : les kérati- diminuée, cicatrisation ralentie…). Notre nocytes sont plus nombreux et mieux étude montre qu’HAd, un actif dermo- répartis. L’observation des fi lopodes des cosmétique à base d’acide hyaluronique, kératinocytes au bord de la plaie montre favorise l’assemblage du hyalurosome (ce que le traitement augmente leur nombre qui conduit à un métabolisme optimal), et et leurs longueurs. ainsi limite les effets du cortisol. References: (1)Barnes, L., et al. J. Invest. Dermatol., vol. 133, (2013), pp. 1017-1026 (2)Bornschögl, T. Cytoskeleton, vol. 70, n°10 (2013), pp. 590-603 (3)Schäfer, C., et al. Exp. Cell Res., vol. 315, (2009), pp. 1212-1224 (4)Ghazi, K., et al. PLoS ONE, vol.7, n°11 (2012), H e48351 y (5)96, (2002), pp. 23-43Schäcke, H., et al. Pharmacol. & Therapeuthics, vol. (6)Altemus, M., et al. J. Invest. Dermatol., vol. 117, (2001), pp. 309-317 (7)Fukuda, S., et al. Int. J. Cosm. Sci., vol. 37, (2015), pp. 63-69 (8)Kaya, G., et al. PLoS Medecine, vol. 3, n°12 (2006), FIGURE 4 : e493 SCRATCH TEST AVEC DES KÉRATINOCYTES EXPOSÉS AU CORTISOL AVEC OU SANS TRAITEMENT (9)Morand, B et al. Proceedings of the IFSCC congress, AVEC HAD. LES FLÈCHES MONTRENT LES FILOPODES QUI PERMETTENT LA MIGRATION. (2013), pp. 251-254 SCRATCH TEST WITH KERATINOCYTES EXPOSED TO CORTISOL WITH AND WITHOUT TREATMENT (10)Prouheze, P., et al. IFSCC Mag., vol. 3, (2017), pp. WITH HAD. THE ARROWS SHOW THE FILOPODIA THAT MAKE MIGRATION POSSIBLE. 141-147 assembly of the hyalurosome (by binding acid production(10), but HAd also counters Conclusion to the CD44). It has been proven that the the effects of cortisol (Figure 3). molecular weight of HA could play on The role that HA plays in the healing Psychological stress has various the affi nity for its CD44 receptor(4, 8), and process led us to measure the impact of negative effects on the skin and causes with this in mind, we have developed HAd (and of cortisol) using a “scratch it to age prematurely. The hyalurosome, a derivative (HAd) with the optimal test”. In this experimental model, an the integrity of which is a vital part of molecular weight and an improvedincision was made in a single layer ofmaintaining the skin’s homeostasis, is an bio-availability. HAd contains a fragment keratinocytes (Figure 4, t0) and the degree interesting molecular target in this respect. of hyaluronic acid that has been combined to which the “wound” had reduced measu- The changes to the hyalurosome brought with a vehicle molecule in the form of red after 24 hours. As expected, cortisol about by cortisol, as the primary media- MTS (MethylTriSilanol) to amplify its delayed the wound fi lling process(10)since tor of the negative effects of stress, are effects and improve its bio-availability.(9) it suppresses the two mechanisms at play, responsible for many of the signs of ageing We have unambiguously demonstrated namely cell proliferation and cell mobility. (skin atrophy, xerosis, reduced response the “atrophogenic” effects of cortisol on HAd counters the effects of cortisol and the to growth factors, delayed healing, etc). both reconstructed human epidermises wound fi lls more quickly (Figure 4, t24h), Our study showed that the hyaluronic and human skin, with HAd helping to meaning that there are more keratinocytes acid-based dermocosmetic active ingre- limit atrophy in both models(10) and that they are better distributed. An dient HAd encourages the assembly of . In mechanistic terms, we have shown observation of the keratinocyte fi lopodia the hyalurosome (which helps to optimise that HAd encourages the assembly of the around the edges of the wound shows that the metabolism) and therefore limits the hyalurosome, indicating its cytostimulating(10) treatment results in an increase in both effects of cortisol. HAd is marketed under effects and its ability to boost hyaluronic their number and their length. the trade name Epidermosil. ■® 2018 - Guide des ingrédients cosmétiques Expression Cosmétique