ShRNA-mediated gene silencing of lipoprotein lipase improves insulin sensitivity in L6 skeletal muscle cells.
ShRNA-mediated gene silencing of lipoprotein lipase improves insulin sensitivity in L6 skeletal muscle cells.
复制标题
ShRNA 介导的脂蛋白脂肪酶基因沉默可改善 L6 骨骼肌细胞的胰岛素敏感性。
DOI：
10.1016/j.bbrc.2015.04.098
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发表时间：
2015
影响因子：
3.1
通讯作者：
Medh,JheemD
中科院分区：
文献类型：
--
作者：
Jan,Majib;Medh,JheemD
在以前的研究中，我们证明了L 6肌细胞中脂蛋白脂酶的下调增加了胰岛素刺激的葡萄糖摄取。在本研究中，我们利用RNA干扰技术沉默L 6细胞中的LPL基因，并产生LPL-knock-down（LPL-KD）细胞系。shRNA转染的细胞显示LPL表达水平降低88%。在野生型（WT）和LPL-KD细胞中比较了对胰岛素的代谢反应。胰岛素刺激的糖原合成和葡萄糖氧化在LPL-KD细胞中分别是WT细胞的2.4倍和2.6倍。与WT细胞相比，即使在不存在胰岛素的情况下，LPL-KD细胞中油酸的氧化也减少了50%。通过向LPL-KD细胞的培养基中回加纯化的LPL来证实LPL在调节燃料代谢中的贡献。10 μg/mL LPL的存在导致LPL-KD细胞恢复到较低的糖原合成和葡萄糖氧化以及增加的脂肪酸氧化。因此，LPL耗竭似乎模拟胰岛素的作用。这些发现表明肌肉LPL水平与胰岛素刺激的燃料稳态之间存在负相关性。
In previous studies, we demonstrated that down-regulation of lipoprotein lipase in L6 muscle cells increased insulin-stimulated glucose uptake. In the current study, we used RNA interference technology to silence the LPL gene in L6 cells and generate a LPL-knock-down (LPL-KD) cell line. ShRNA transfected cells showed a 88% reduction in the level of LPL expression. The metabolic response to insulin was compared in wild-type (WT) and LPL-KD cells. Insulin-stimulated glycogen synthesis and glucose oxidation were respectively, 2.4-fold and 2.6-fold greater in LPL-KD cells compared to WT cells. Oxidation of oleic acid was reduced by 50% in LPL-KD cells compared to WT cells even in the absence of insulin. The contribution of LPL in regulating fuel metabolism was confirmed by adding back purified LPL to the culture media of LPL-KD cells. The presence of 10 μg/mL LPL resulted in LPL-KD cells reverting back to lower glycogen synthesis and glucose oxidation and increased fatty acid oxidation. Thus, LPL depletion appeared to mimic the action of insulin. These finding suggests an inverse correlation between muscle LPL levels and insulin-stimulated fuel homeostasis.