Objective: To observe the effect of heat shock on tropoelastin mRNA and protein expression in cultured human dermal fibroblasts and to elucidate the possible role of heat shock in the development of solar elastosis in human skin.
Methods: Primary cultured human dermal fibroblasts were incubated in 43 degrees C water bath for 30 minutes, then returned to 37 degrees C, 5%(volume fraction) CO(2) atmosphere normal culture condition. The cells were harvested at hour 24 and 48 after heat treatment respectively. Total RNA was extracted from cell lysis and tropoelastin mRNA level was measured by Northern blot assay. Tropoelastin protein level in cultured supernatant was measured by Western blot assay.
Results: At hour 24 after heat treatment, the level of tropoelastin mRNA was enhanced to (163+/-12)% of control group (P<0.05). It was increased further to (221+/-22)% of control group at hour 48 after heat treatment (P<0.05). Similarly, the tropoelastin protein level was also increased to (149+/-12)% (P<0.05) at hour 24, and to (783+/-10)% (P<0.05) at hour 48 after heat shock as compared with control group.
Conclusion: Heat shock could up-regulate tropoelastin mRNA and protein expression in primary cultured human dermal fibroblasts, and the over-expression of tropoelastin might play some roles in the development of solar elastosis in photoaged skin.