The effect of heat stress on apoptosis and heat shock protein expression in fibroblast cells derived from native chicken embryos

Abstract

The objective of this study was to determine the effects of heat stress on apoptosis and heat shock protein (HSP) expression in embryonic fibroblasts derived from native chicken. Fibroblasts derived from Pradu-Hangdum Chiangmai embryos (PC) and KKU.55 (PK) were cultured at regular temperature (control group; 37 °C for 24 h) and heat stress (42 °C for 6, 12, and 24 h) to measure apoptotic rate and HSP expression. After being treated at 42 °C for 12 and 24 h, PC and PK cells had a higher apoptotic rate than those control and 42 °C for 6 h treated groups (P < 0.05). In addition, the apoptotic rate of PC cells in both control and 42 °C treated groups was significantly increased when compared to PK cells (P < 0.05). The expression levels of HSP70 and HSP90 were much higher in PK cells when exposed to 42 °C for 24 h significantly different compared to the control and those exposed to 42 °C for 6 or 12 h (P < 0.05). Furthermore, the expression levels of HSP70 and HSP90 were higher in PC cells treated at 42 °C for 24 h than in the control group (P < 0.05), nevertheless, not significantly different when compared to the heat-treated groups (42°C for 6 and 12 h) (P > 0.05). However, after being treated at 42 °C for 24 h, the expression level of HSP70 and HSP90 in PK cells was significantly higher than in the PC cells (P < 0.05). We conclude that fibroblasts derived from PK embryos have more thermotolerance than PC derived cells when cells were exposed to high temperatures for a long time.