125 HSP27 a key element of skin regulation subjected to climate variations

Humidity, along with other climatic factors such as temperature, can impact the skin health. Indeed, our is daily exposed to humidity and temperature variations. All around world, varies from low high relative (45% 90%). In addition, reach 44°C under sun exposure. The rare studies available show that causes several changes in (dryness, itchiness, impairment of desquamation process, roughness, loss elasticity). Unfortunately, most were performed on murine models, they remain inconclusive about real effects variations human Thus, we developed explant models (heat stress, stress a combined heat stresses model) order understand effect climate physiology. We analyzed epidermis thickness expression profiles loricrin (LOR), filaggrin (FLG), keratin 10 (K10), HSP27. These markers chosen upon their relevance homeostasis. all conditions studied an thickening was observed suggesting keratinocyte proliferation. skins differentiation process delayed decreased. early K10 occurs disorganized start process. keratinocytes seems be sustained overstimulated uncontrolled found different environmental modulate HSP27, central protein regulating LOR (differentiation process), synthesis processing proFLG FLG (epidermis physiology). Our results showed (humidity and/ or temperature) through modulation HSP27 are responsible weakening barrier function due