HSP 47 is a specific chaperone of pro-collagen. This heat shock protein is responsible for the correct 3-dimentional organization of pro-collagen and its control-quality prior secretion. The aim of the study is to evaluate the level of HSP47 in aged, photoaged and senescent fibroblasts and its modulation by a plant extract (Salix Alba).
We measured the level of HSP47 and/or pro-collagen expression in fibroblasts by real time RT-PCR (mRNA transcripts) and by flow cytometry (immuno-chemistry technique for measurement of arbitrary fluorescence intensity). We used immuno-chemistry techniques and confocal microscopy to vizualized the cellular localization of HSP 47 and pro-collagen. These parameters were compared with different age-donors, non senescent and senescent fibroblasts. Fibroblasts were irradiated by a non cytotoxic dose of UVA (6 J/cm2 ) and HSP 47 level was evaluated. Salix Alba extract was tested for its capacity to modulate HSP 47 expression.
We showed colocalization of HSP47 and procollagen by confocal microscopy, indicating that HSP47 could play a role of procollagen molecular chaperone in our cellular model. We showed that HSP47 level is decreased in old-donor cells, senescent and irradiated cells. This decrease can be modulated by a salix alba extract (polyphenols rich) in a dose dependent manner.
The evaluation of HSP 47 expression in our experimental conditions can lead to a new approach of aging and photoaging pointing out the implication of this chaperone in these pathophysiologic phenomenons. Modulation of HSP 47 expression by molecules family could be of cosmetic and/or dermatologic interest.