Hu Han, Zhang Yangdong, Zheng Nan, Cheng Jianbo, Wang Jiaqi
Ministry of Agriculture-Milk Risk Assessment Laboratory, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.
State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.
Anim Sci J. 2016 Jan;87(1):84-91. doi: 10.1111/asj.12375. Epub 2015 Oct 15.
In this study, bovine mammary epithelial cells were used to study stress responses after cells were exposed to 42°C for 0.5, 1, 3, 5, 8 or 12 h, and 38°C as control. The transcription of the genes (HSP27, HSP70 and HSP90) of heat shock protein (Hsp) was significantly enhanced under heat stress (HS). The peak transcription of HSP70 was 14 times the control at 1 h. Expression of proteins Hsp27 and Hsp70 was gradually increased under HS, with rapid deposition of Hsp70 in epithelial cells. The major milk protein genes of β-casein (CSN2) and butyrophilin (BTN1A1) were down-regulated and the synthesis of total caseins was decreased. After the cells were under HS (42°C) for 1 or 5 h, the cells were cultured at 38°C for 1, 6, 12 or 24 h for recovery. When the cells were cultured at 38°C for 24 h after HS for 1 h, the transcription of HSP70, HSP90, CSN2 and BTN reached normal levels. Our results suggest that HS initiated Hsp synthesis and decreased the milk protein synthesis. Hsp70 is extremely sensitive to HS and mainly responsible for mammary cell protection from HS.
在本研究中，使用牛乳腺上皮细胞来研究细胞在42°C下暴露0.5、1、3、5、8或12小时以及在38°C作为对照的情况下的应激反应。热应激（HS）下热休克蛋白（Hsp）的基因（HSP27、HSP70和HSP90）转录显著增强。HSP70的转录峰值在1小时时是对照的14倍。Hsp27和Hsp70蛋白的表达在热应激下逐渐增加，Hsp70在上皮细胞中快速沉积。主要乳蛋白基因β-酪蛋白（CSN2）和嗜乳脂蛋白（BTN1A1）下调，总酪蛋白合成减少。细胞在42°C热应激1或5小时后，在38°C培养1、6、12或24小时用于恢复。当细胞在热应激1小时后在38°C培养24小时时，HSP70、HSP90、CSN2和BTN的转录达到正常水平。我们的结果表明，热应激启动了Hsp合成并降低了乳蛋白合成。Hsp70对热应激极其敏感，主要负责保护乳腺细胞免受热应激。
