Chandler T L, Erb S J, Myers William A, Deme Pragney, Haughey Norman J, McFadden J W, White H M
Department of Dairy Science, University of Wisconsin-Madison, Madison, WI, 53706, USA.
Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
Sci Rep. 2020 Nov 5;10(1):19078. doi: 10.1038/s41598-020-75956-z.
Choline and methionine may serve unique functions to alter hepatic energy metabolism. Our objective was to trace carbon flux through pathways of oxidation and glucose metabolism in bovine hepatocytes exposed to increasing concentrations of choline chloride (CC) and D,L-methionine (DLM). Primary hepatocytes were isolated from 4 Holstein calves and maintained for 24 h before treatment with CC (0, 10, 100, 1000 μmol/L) and DLM (0, 100, 300 μmol/L) in a factorial design. After 21 h, [1-C]C16:0 or [2-C]pyruvate was added to measure complete and incomplete oxidation, and cellular glycogen. Reactive oxygen species (ROS), cellular triglyceride (TG), and glucose and ß-hydroxybutyrate (BHB) export were quantified. Exported very-low density lipoprotein particles were isolated for untargeted lipidomics and to quantify TG. Interactions between CC and DLM, and contrasts for CC (0 vs. [10, 100, 1000 μmol/L] and linear and quadratic contrast 10, 100, 1000 μmol/L) and DLM (0 vs. [100, 300 μmol/L] and 100 vs. 300 μmol/L) were evaluated. Presence of CC increased complete oxidation of [1-C]C16:0 and decreased BHB export. Glucose export was decreased, but cellular glycogen was increased by the presence of CC and increasing CC. Presence of CC decreased ROS and marginally decreased cellular TG. No interactions between CC and DLM were detected for these outcomes. These data suggest a hepato-protective role for CC to limit ROS and cellular TG accumulation, and to alter hepatic energy metabolism to support complete oxidation of FA and glycogen storage regardless of Met supply.
胆碱和蛋氨酸可能具有独特的功能来改变肝脏能量代谢。我们的目标是追踪在暴露于浓度不断增加的氯化胆碱（CC）和D,L-蛋氨酸（DLM）的牛肝细胞中，碳通过氧化和葡萄糖代谢途径的通量。从4头荷斯坦犊牛中分离出原代肝细胞，并在以析因设计用CC（0、10、100、1000 μmol/L）和DLM（0、100、300 μmol/L）处理前维持24小时。21小时后，添加[1-C]C16:0或[2-C]丙酮酸以测量完全和不完全氧化以及细胞糖原。对活性氧（ROS）、细胞甘油三酯（TG）、葡萄糖和β-羟基丁酸（BHB）的输出进行定量。分离出输出的极低密度脂蛋白颗粒用于非靶向脂质组学分析并定量TG。评估了CC和DLM之间的相互作用，以及CC（0与[10、100、1000 μmol/L]以及10、100、1000 μmol/L的线性和二次对比）和DLM（0与[100、300 μmol/L]以及100与300 μmol/L）的对比。CC的存在增加了[1-C]C16:0的完全氧化并减少了BHB的输出。葡萄糖输出减少，但CC的存在以及CC浓度增加会使细胞糖原增加。CC的存在降低了ROS，并略微降低了细胞TG。在这些结果中未检测到CC和DLM之间的相互作用。这些数据表明CC具有肝脏保护作用，可限制ROS和细胞TG积累，并改变肝脏能量代谢以支持脂肪酸的完全氧化和糖原储存，而与蛋氨酸供应无关。
