Liu Lei, Li Xinwei, Li Yu, Guan Yuan, Song Yuxiang, Yin Liheng, Chen Hui, Lei Liancheng, Liu Juxiong, Li Xiaobing, Wang Zhe, Yang Xiaoyu, Liu Guowen
Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, Jilin, 130062, China.
College of Animal Science, Jilin University, 5333 Xi'an Road, Changchun, Jilin, 130062, China.
J Dairy Sci. 2014 Mar;97(3):1328-35. doi: 10.3168/jds.2013-6654. Epub 2013 Dec 28.
High serum concentrations of nonesterified fatty acids (NEFA), which may affect the synthesis and assembly of very low density lipoproteins (VLDL), are associated with fatty liver during the early lactation period. Therefore, the objective of this study was to investigate the effects of NEFA on the synthesis and assembly of VLDL in bovine hepatocytes. Bovine hepatocytes were cultured and treated with different concentrations of NEFA. The mRNA expression of apolipoprotein B100 (ApoB100) and apolipoprotein E (ApoE) was significantly lower in the NEFA treatment groups than in the control group (0mM NEFA). The abundance of mRNA from microsomal triglyceride transfer protein (MTP) and the low density lipoprotein receptor (LDLR) was significantly lower in the medium- and high-dose NEFA treatment groups. The protein expression of ApoB100, ApoE, MTP, and LDLR was found to be significantly and dose-dependently decreased in groups of NEFA-treated hepatocytes. The VLDL content was also significantly decreased in the NEFA-treated hepatocytes. Large amounts of triglycerides accumulated in the hepatocytes. These results indicate that NEFA significantly inhibits the expression of ApoB100, ApoE, MTP, and LDLR, thereby decreasing the synthesis and assembly of VLDL and inducing TG accumulation in bovine hepatocytes.
高血清浓度的非酯化脂肪酸（NEFA）可能会影响极低密度脂蛋白（VLDL）的合成和组装，在泌乳早期与脂肪肝有关。因此，本研究的目的是探讨NEFA对牛肝细胞中VLDL合成和组装的影响。培养牛肝细胞并用不同浓度的NEFA处理。NEFA处理组中载脂蛋白B100（ApoB100）和载脂蛋白E（ApoE）的mRNA表达明显低于对照组（0mM NEFA）。中、高剂量NEFA处理组微粒体甘油三酯转移蛋白（MTP）和低密度脂蛋白受体（LDLR）的mRNA丰度明显较低。在NEFA处理的肝细胞组中，发现ApoB100、ApoE、MTP和LDLR的蛋白表达显著且呈剂量依赖性降低。NEFA处理的肝细胞中VLDL含量也显著降低。大量甘油三酯在肝细胞中积累。这些结果表明，NEFA显著抑制ApoB100、ApoE、MTP和LDLR的表达，从而减少VLDL的合成和组装，并诱导牛肝细胞中TG积累。
