Glucose enhances catecholamine-stimulated lipolysis via increased glycerol-3-phosphate synthesis in 3T3-L1 adipocytes and rat adipose tissue.
Glucose enhances catecholamine-stimulated lipolysis via increased glycerol-3-phosphate synthesis in 3T3-L1 adipocytes and rat adipose tissue.
复制标题
葡萄糖通过增加 3T3-L1 脂肪细胞和大鼠脂肪组织中甘油-3-磷酸的合成来增强儿茶酚胺刺激的脂肪分解。
DOI：
10.1007/s11033-021-06617-1
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Nakai N.
中科院分区：
文献类型：
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作者：
Takeuchi N;Higashida K;Li X;Nakai N.
背景在脂肪分解过程中，甘油三酯（TG）在脂肪细胞中水解成甘油和脂肪酸。很大一部分脂肪酸被重新酯化成TG，这是促进脂肪分解的关键步骤。尽管 3-磷酸甘油 (G3P) 是哺乳动物细胞中甘油三酯合成所必需的，但活性脂解过程中 G3P 合成的底物尚不清楚。最近的一项研究表明，抑制葡萄糖摄取会减少儿茶酚胺刺激的脂肪分解，这表明葡萄糖的可用性在脂肪细胞的脂肪分解中很重要。我们假设葡萄糖可能在生成 G3P 从而促进脂肪细胞中儿茶酚胺刺激的脂肪分解中发挥重要作用。因此，我们确定了葡萄糖利用率对 3T3-L1 脂肪细胞和大鼠脂肪组织中儿茶酚胺刺激的脂肪分解的影响。方法和结果在异丙肾上腺素刺激期间，在含有/不含葡萄糖的培养基中培养 3T3-L1 脂肪细胞和大鼠附睾脂肪垫。当脂肪细胞在含葡萄糖的培养基中培养时，甘油释放量高于在不含葡萄糖的培养基中培养的甘油释放量。在儿茶酚胺刺激的脂肪分解过程中对葡萄糖摄取的测量显示葡萄糖摄取有轻微但显着的增加。我们还比较了在主动脂肪分解中起关键作用的脂肪组织之间的葡萄糖代谢相关蛋白，如葡萄糖转运蛋白4、己糖激酶、3-磷酸甘油脱氢酶和脂肪酶的含量。由于脂肪酶和葡萄糖代谢相关蛋白含量较高，附睾脂肪比腹股沟脂肪表现出更高的脂肪分解活性。结论我们证明，儿茶酚胺刺激的脂肪分解在葡萄糖存在下增强，并表明葡萄糖是活性脂肪分解过程中脂肪细胞中 G3P 的主要底物之一。
BackgroundDuring lipolysis, triglyceride (TG) are hydrolyzed into a glycerol and fatty acids in adipocyte. A significant portion of the fatty acids are re-esterificated into TG, and this is a critical step in promoting lipolysis. Although glycerol-3-phosphate (G3P) is required for triglyceride synthesis in mammalian cell, the substrate for G3P synthesis during active lipolysis is not known. A recent study showed that the inhibition of glucose uptake reduces catecholamine-stimulated lipolysis, suggesting that glucose availability is important in lipolysis in adipocytes. We hypothesized that glucose might play an essential role in generating G3P and thereby promoting catecholamine-stimulated lipolysis in adipocytes. Therefore, we determined the effect of glucose availability on catecholamine-stimulated lipolysis in 3T3-L1 adipocytes and rat adipose tissue.Methods and Results3T3-L1 adipocytes and rat epididymal fat pads were cultured in a medium with/without glucose during stimulation by isoproterenol. Glycerol release was higher when adipocytes were cultured in a glucose-containing medium than that in a medium without glucose. Measurement of glucose uptake during catecholamine-stimulated lipolysis showed a slight, but significant increase in glucose uptake. We also compared glucose metabolism-related protein, such as glucose transporter 4, hexokinase, glycerol-3-phosphate dehydrogenase and lipase contents between fat tissues that play a critical role in active lipolysis. Epididymal fat exhibited higher lipolytic activity than inguinal fat because of higher lipase and glucose metabolism-related protein contents.ConclusionWe demonstrated that catecholamine-stimulated lipolysis is enhanced in the presence of glucose, and suggests that glucose is one of the primary substrates for G3P in adipocytes during active lipolysis.