乙酸钠对LPS诱导的奶牛乳腺上皮细胞脂肪变性的影响及机制分析

Effect and mechanism analysis of sodium acetate on steatosis of dairy mammary epithelial cells induced by LPS

试验向牛乳腺上皮细胞系(MAC-T)脂肪变性模型中添加不同浓度乙酸钠,探讨乙酸钠对MAC-T细胞脂肪变性模型的改善机制及炎症损伤的保护效果。使用脂多糖(LPS)刺激MAC-T细胞建立MAC-T细胞脂肪变性模型,设立对照组、LPS处理组(使用1000μg/L LPS刺激细胞9 h)及不同浓度的乙酸钠+LPS处理组(在LPS处理组基础上分别加入2、4、8 mmol/L乙酸钠),测定细胞甘油三酯(TG)含量及脂合成代谢关键基因乙酰CoA羧化酶(ACC)、脂肪酸合成酶(FAS)、硬脂酰辅酶A去饱和酶-1(SCD-1)以及分解代谢关键基因肉碱脂酰转移酶Ⅰ(CPT-1)、肉碱脂酰转移酶Ⅱ(CPT-2)以及脂酰辅酶A氧化酶(ACO)表达水平,检测肿瘤坏死因子-α(TNF-α)、白细胞介素IL-6(IL-6)、白细胞介素IL-8(IL-8)含量。结果显示,LPS刺激MAC-T细胞9 h后,细胞TG含量极显著下降(P<0.01),总脂滴面积显著下降(P<0.05)。与对照组相比,LPS处理组细胞TG含量显著下降(P<0.05),脂合成代谢相关基因ACC、FAS、SCD-1 mRNA表达水平均极显著下降(P<0.01),脂分解代谢相关基因CPT-1、CPT-2以及ACO mRNA表达水平均显著上调(P<0.05),炎症因子TNF-α、IL-6和IL-8含量均显著上升(P<0.05)。与LPS处理组相比,添加4 mmol/L乙酸钠后细胞ACC、FAS、SCD-1 mRNA表达水平均显著上调(P<0.05),CPT-1显著下调(P<0.05),TNF-α、IL-6含量显著降低(P<0.05),TG含量显著上升(P<0.05);添加8 mmol/L乙酸钠后,细胞ACC、FAS mRNA表达水平显著上调(P<0.05),CPT-1、CPT-2 mRNA表达水平显著下调(P<0.05),TNF-α、IL-6和IL-8含量均显著降低(P<0.05),TG含量显著上升(P<0.05)。研究表明,4、8 mmol/L乙酸钠会促进MAC-T细胞脂合成代谢,促进TG合成,并且对MAC-T细胞的炎症损伤具有一定的保护作用。

The experiment was to investigate the mechanism of improvement and protective effect of sodium acetate on MAC-T cell steatosis by adding different concentrations of sodium acetate to bovine MAC-T cell steatosis model.MAC-T cells were stimulated by LPS to establish a steatosis model of MAC-T cells.Control group,LPS treatment group(cells were stimulated by 1000μg/L LPS for 9 h)and sodium acetate+LPS treatment group with different concentrations(2,4 and 8 mmol/L sodium acetate were added to LPS treatment group,respectively)were established.The content of TG and the expression levels of ACC,FAS,SCD-1,CPT-1,CPT-2 and ACO of key genes of lipid anabolic metabolism were determined,and the content of TNF-α,IL-6 and IL-8 were detected.The results showed that after LPS stimulation for 9 h,the TG content of MAC-T cells was extremely decreased(P<0.01),and the total lipid drop area was significantly decreased(P<0.05).Compared with control group,the TG content of cells in LPS treatment group was significantly decreased(P<0.05),and the mRNA expression levels of ACC,FAS and SCD-1 genes related to lipid anabolic metabolism were extremely decreased(P<0.01).The mRNA expression levels of CPT-1,CPT-2 and ACO related to lipid catabolism were significantly up-regulated(P<0.05),the content of inflammatory factors TNF-α,IL-6 and IL-8 were significantly increased(P<0.05).Compared with LPS treatment group,the mRNA expression levels of ACC,FAS and SCD-1 were significantly up-regulated after adding 4 mmol/L sodium acetate(P<0.05),CPT-1 was significantly down-regulated(P<0.05),and the content of TNF-αand IL-6 were significantly decreased(P<0.05).TG content was significantly increased(P<0.05).After adding 8 mmol/L sodium acetate,the mRNA expression levels of ACC and FAS were significantly up-regulated(P<0.05),the mRNA expression levels of CPT-1 and CPT-2 were significantly down-regulated(P<0.05),and the content of TNF-α,IL-6 and IL-8 were significantly decreased(P<0.05).TG content was significantly increased(P<0.05).The study indicates that 4,8 mmol/L sodium acetate can promote the lipid anabolic metabolism of MAC-T cells,promote TG synthesis,and have a certain protective effect on the inflammatory damage of MAC-T cells.