Lucie Simonetti

The anti-ageing potential of a new jasmonic acid derivative (LR2412): in vitro evaluation using reconstructed epidermis episkin™

Abstract:  Jasmonic acid is involved in plant wound repair and tissue regeneration, but no study has been reported in human skin. The effect of a jasmonic acid derivative, tetra‐hydro‐jasmonic acid (LR2412, 1 and 10 μm) was investigated on an in vitro reconstructed skin model, Episkin™. Using real time RTQPCR studies, results showed an increase in hyaluronan synthase 2 (HAS2) and hyaluronase synthase 3 (HAS3) expression. Furthermore, an increase in hyaluronic acid (HA) deposits in basal and suprabasal layers of the epidermis was observed. The percentage of positive Ki67 keratinocytes in the basal layer as well as the epidermis thickness were seen to increase. Immunohistochemistry studies showed that the synthesis of late differentiation proteins filaggrin and transglutaminase 1 was not modified. The human epidermis is known to thin with age while HA content has been reported to decrease. These results illustrate the potential of LR2412 in counteracting signs of skin ageing.

Proteomic analysis identifies new biomarkers for postmenopausal and dry skin

Abstract:  A proteomic analysis of stratum corneum (SC) samples of normal healthy skin revealed the presence of more than 70 proteins by 2D electrophoresis. The majority of these proteins to our knowledge have not yet been described in normal SC. We analysed by Western blot the levels of 25 proteins in the SC taken from postmenopausal and dry skin compared with young and normal skin, respectively. In postmenopausal skin, there was a significantly increased amount of heat shock protein 27, plakoglobin and desmoglein 1, whereas transglutaminase 3, apolipoprotein D and acid ceramidase levels were significantly reduced compared with the SC of young skin. We confirmed corneodesmosin as a marker of dry skin. In addition, we showed for the first time that the levels of both phosphatidylethanolamine‐binding protein 1 and annexin A2 were significantly increased in the SC of dry skin compared with the SC of normal skin. These results suggest that a proteomic analysis of the SC obtained using a non‐invasive varnish stripping method is an attractive alternative to invasive methods to better characterize changes in the physiology of ageing and dry skin.