Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo 657-8501, Japan.
Lipids Health Dis. 2012 Mar 12;11:36. doi: 10.1186/1476-511X-11-36.
Fatty acid-induced insulin resistance and impaired glucose uptake activity in muscle cells are fundamental events in the development of type 2 diabetes and hyperglycemia. There is an increasing demand for compounds including drugs and functional foods that can prevent myocellular insulin resistance.
In this study, we established a high-throughput assay to screen for compounds that can improve myocellular insulin resistance, which was based on a previously reported non-radioisotope 2-deoxyglucose (2DG) uptake assay. Insulin-resistant muscle cells were prepared by treating rat L6 skeletal muscle cells with 750 μM palmitic acid for 14 h. Using the established assay, the impacts of several fatty acids on myocellular insulin resistance were determined.
In normal L6 cells, treatment with saturated palmitic or stearic acid alone decreased 2DG uptake, whereas unsaturated fatty acids did not. Moreover, co-treatment with oleic acid canceled the palmitic acid-induced decrease in 2DG uptake activity. Using the developed assay with palmitic acid-induced insulin-resistant L6 cells, we determined the effects of other unsaturated fatty acids. We found that arachidonic, eicosapentaenoic and docosahexaenoic acids improved palmitic acid-decreased 2DG uptake at lower concentrations than the other unsaturated fatty acids, including oleic acid, as 10 μM arachidonic acid showed similar effects to 750 μM oleic acid.
We have found that polyunsaturated fatty acids, in particular arachidonic and eicosapentaenoic acids prevent palmitic acid-induced myocellular insulin resistance.
脂肪酸诱导的胰岛素抵抗和肌肉细胞葡萄糖摄取活性受损是 2 型糖尿病和高血糖发展的基本事件。人们对包括药物和功能性食品在内的能够预防肌细胞胰岛素抵抗的化合物的需求日益增加。
在这项研究中，我们建立了一种高通量筛选化合物的方法，以改善肌细胞胰岛素抵抗，该方法基于先前报道的非放射性 2-脱氧葡萄糖（2DG）摄取测定法。通过用 750 μM 棕榈酸处理大鼠 L6 骨骼肌细胞 14 小时来制备胰岛素抵抗的肌肉细胞。使用建立的测定法，确定了几种脂肪酸对肌细胞胰岛素抵抗的影响。
在正常的 L6 细胞中，单独用饱和棕榈酸或硬脂酸处理会降低 2DG 的摄取，而不饱和脂肪酸则不会。此外，油酸的共同处理取消了棕榈酸诱导的 2DG 摄取活性的降低。使用开发的用于棕榈酸诱导的胰岛素抵抗的 L6 细胞的测定法，我们确定了其他不饱和脂肪酸的作用。我们发现，花生四烯酸、二十碳五烯酸和二十二碳六烯酸在较低浓度下改善了棕榈酸降低的 2DG 摄取，而其他不饱和脂肪酸，包括油酸，在 10 μM 花生四烯酸的作用与 750 μM 油酸相似。
我们发现多不饱和脂肪酸，特别是花生四烯酸和二十碳五烯酸，可以预防棕榈酸诱导的肌细胞胰岛素抵抗。
