脂多糖对奶牛乳腺上皮细胞毒性作用及乳蛋白合成的影响

Cytotoxicity of LPS and effects on milk protein synthesis in dairy cow mammary epithelial cells

试验旨在通过不同浓度的脂多糖(LPS)处理奶牛乳腺上皮细胞,研究LPS对奶牛乳腺上皮细胞及乳蛋白信号通路关键基因的影响。采用MTT法,LDH活性检测和细胞形态学观察,研究LPS对奶牛乳腺上皮细胞的毒性作用。利用q RT-PCR法和Western-blot技术检测LPS对奶牛乳腺上皮细胞乳蛋白合成关键基因表达的影响。结果表明,LPS抑制细胞的增殖、增加LDH漏出率,当浓度大于1 000 ng·m L-1时细胞形态学与对照组相比有明显变化,并能抑制奶牛乳腺上皮细胞乳蛋白合成关键基因m TOR、S6K1、4EBP1和STAT5 m RNA转录和相关蛋白的表达,与对照组相比差异极显著(P<0.01)。研究表明,LPS可通过对奶牛乳腺上皮细胞的毒性作用而影响奶牛的泌乳功能和牛奶品质。

By culturing cow mammary epithelial cell with different concentrations of LPS, we explored the cytotoxicity of LPS and effects on key genes of milk protein signaling pathways. We studied the toxic effects of LPS on cow mammary epithelial cell using MTT, LDH activity detection and cytological observation. The effects of expression of LPS on key genes of cow mammary epithelial cell were detected by qRT-PCR and Western-blot methods. As results, LPS could inhibit cell proliferation and increase the leakage rate of LDH. When the concentration of LPS was greater than 1 000 ng. mL1, cytological observation was significant changes compared with the control group. And increasing the concentration of LPS could inhibit the transcription of key genes of milk protein synthesis, roTOR, S6K1, 4EBP1 and STAT5 mRNA, the same are the expressions of related proteins. The difference is significant compared with the control group （P〈0.01）. It showed that LPS can affect lactating function and milk quality of cow through its toxic effects on cow mammary epithelial cell.