Han Lingling, Li Jia, Chen Ying, Wang Wei, Zhang Dan, Liu Guoliang
Department of Endocrinology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, China.
Department of Endocrinology, The Fourth Hospital of China Medical University, Shenyang, Liaoning 110032, China.
Int J Endocrinol. 2015;2015:635863. doi: 10.1155/2015/635863. Epub 2015 Dec 2.
This study aimed to study the effects of acylated ghrelin on glucose and triglyceride metabolism in rat myoblasts under palmitic acid- (PA-) induced high fat conditions. Rat myoblasts were treated with 0, 10(-11), 10(-9), or 10(-7) M acylated ghrelin and 0.3 mM PA for 12 h. Triglyceride accumulation was determined by Oil-Red-O staining and the glycerol phosphate dehydrogenase-peroxidase enzymatic method, and glucose uptake was determined by isotope tracer. The glucose transporter 4 (GLUT4), AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), and uncoupling protein 3 (UCP3) were assessed by RT-PCR and western blot. Compared to 0.3 mM PA, ghrelin at 10(-9) and 10(-7) M reduced triglyceride content (5.855 ± 0.352 versus 5.030 ± 0.129 and 4.158 ± 0.254 mM, P < 0.05) and prevented PA-induced reduction of glucose uptake (1.717 ± 0.264 versus 2.233 ± 0.333 and 2.333 ± 0.273 10(-2) pmol/g/min, P < 0.05). The relative protein expression of p-AMPKα/AMPKα, UCP3, and p-ACC under 0.3 mM PA was significantly reduced compared to controls (all P < 0.05), but those in the 10(-9) and 10(-7) M ghrelin groups were significantly protected from 0.3 mM PA (all P < 0.05). In conclusion, acylated ghrelin reduced PA-induced triglyceride accumulation and prevented the PA-induced decrease in glucose uptake in rat myoblasts. These effects may involve fatty acid oxidation.
本研究旨在探讨在棕榈酸（PA）诱导的高脂条件下，酰化胃饥饿素对大鼠成肌细胞葡萄糖和甘油三酯代谢的影响。将大鼠成肌细胞分别用0、10⁻¹¹、10⁻⁹或10⁻⁷ M的酰化胃饥饿素以及0.3 mM PA处理12小时。通过油红O染色和磷酸甘油脱氢酶-过氧化物酶酶法测定甘油三酯积累，通过同位素示踪法测定葡萄糖摄取。采用RT-PCR和蛋白质免疫印迹法评估葡萄糖转运蛋白4（GLUT4）、AMP激活的蛋白激酶（AMPK）、乙酰辅酶A羧化酶（ACC）和解偶联蛋白3（UCP3）。与0.3 mM PA相比，10⁻⁹和10⁻⁷ M的胃饥饿素降低了甘油三酯含量（5.855±0.352对5.030±0.129和4.158±0.254 mM，P<0.05），并防止了PA诱导的葡萄糖摄取减少（1.717±0.264对2.233±0.333和2.333±0.273×10⁻² pmol/g/min，P<0.05）。与对照组相比，0.3 mM PA处理组中p-AMPKα/AMPKα、UCP3和p-ACC的相对蛋白表达显著降低（均P<0.05），但10⁻⁹和10⁻⁷ M胃饥饿素组的上述指标受0.3 mM PA的影响得到显著保护（均P<0.05）。总之，酰化胃饥饿素减少了PA诱导的大鼠成肌细胞甘油三酯积累，并防止了PA诱导的葡萄糖摄取减少。这些作用可能涉及脂肪酸氧化。
