HSF1 is important for protection of mouse epidermal cells against heart stress

Heat shock transcription factor 1 (HSF1) is essential for transcriptional activation of heat shock genes in response to heat shock in mammals, and is also involved in developmental processes. However, little is known about whether HSF1 regulates expression of heat shock proteins (HSPS) in the epidermis in the presence or absence of heat shock. Here we found that Hspa (Hsp110, Hsp90, Hsp70, Hsp60, Hsp40 and Hsp27) are expressed in unstressed epidermal cells of mouse, mostly by HSF1-independent pathway. To clarify the distribution of Hsp expression in mouse epidermis, we have approached this issue using an in vivo mouse model with chronic cutaneous inflammation and irritation by epicutaneous paintin 5% sodium dodecyl sulfate (SDS). We found that Hsp70 and Hsp27 are highly expressed in the upper epidermal layers, suggesting that their expression is related to keratinocyte differentiation. Hsp70 was highly induced in the mouse epidermis when the skin was exposed to heat shock in vivo. HSF1 is required for its induction, and HSF1-null epidermal cellswere more sensitive to heat shock than wild-type cells. These results indicate that HSF1 is important for protection of mouse epidermal cells against heat stress.

epidermis

heat shock protein

HSF

mouse

transcription