Porcine leptin inhibits lipogenesis in porcine adipocytes.
Porcine leptin inhibits lipogenesis in porcine adipocytes.
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DOI：
10.2527/2003.81123008x
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发表时间：
2003-12
影响因子：
3.3
通讯作者：
T. Ramsay
中科院分区：
文献类型：
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作者：
T. Ramsay
本研究检验了重组猪瘦素是否改变猪脂肪细胞中的脂质合成。通过胶原酶消化、过滤和随后的离心分离新生猪皮下脂肪组织的基质血管细胞部分。将这些细胞接种在 25 cm2 组织培养瓶中，并在 Dulbecco 改良 Eagle 培养基/F12（DMEM/F12，50:50）中的 10%（vol/vol）胎牛血清中增殖至汇合。使用 2.5% 猪血清 (vol/vol)、10 nM 胰岛素、100 nM 氢化可的松对培养物进行分化。脂质填充7天后，将培养物洗去该培养基，在含有2%猪血清（vol/vol）的DMEM/F12中孵育过夜，然后用于实验。急性实验评估了暴露于猪瘦素（0 至 1,000 ng/mL 培养基）4 小时的培养物中 U-(14)C-葡萄糖或 1-(14)C-棕榈酸酯代谢。慢性实验使用的培养物与 0 至 1,000 ng 猪瘦素/mL 培养基一起孵育 44 小时，然后测量 U-(14)C-葡萄糖和 1-(14)C-棕榈酸酯氧化和掺入脂质。另一项实验检查了长期瘦素治疗是否通过将胰岛素 (10 nM) 与含有瘦素的孵育液一起改变而改变胰岛素反应性。瘦素对葡萄糖氧化或转化为脂质没有急性影响（P > 0.05）。急性瘦素治疗使瘦素将棕榈酸掺入脂质的程度降低了 45% (P < 0.05)。这些数据表明，瘦素通过间接抑制葡萄糖氧化和脂肪生成、通过减少胰岛素介导的脂肪生成刺激、以及通过刺激脂肪酸氧化同时抑制脂肪酸酯化来促进能量从猪脂肪组织内的脂质积聚中分配。
The present study examined whether recombinant porcine leptin alters lipid synthesis in porcine adipocytes. The stromal-vascular cell fraction of neonatal pig subcutaneous adipose tissue was isolated by collagenase digestion, filtration, and subsequent centrifugation. These cells were seeded on 25-cm2 tissue culture flasks and proliferated to confluency in 10% (vol/vol) fetal bovine serum in Dulbecco's modified Eagle medium/F12 (DMEM/F12, 50:50). Cultures were differentiated using 2.5% pig serum (vol/vol), 10 nM insulin, 100 nM hydrocortisone. After 7 d of lipid filling, cultures were washed free of this medium, incubated overnight in DMEM/F12 containing 2% pig serum (vol/vol), and then used for experiments. Acute experiments assessed U-(14)C-glucose or 1-(14)C-palmitate metabolism in cultures exposed to porcine leptin (0 to 1,000 ng/mL medium) for 4 h. Chronic experiments used cultures incubated with 0 to 1,000 ng porcine leptin/mL medium for 44 h before measurements of U-(14)C-glucose and 1-(14)C-palmitate oxidation and incorporation into lipid. Another experiment examined whether chronic leptin treatment alters insulin responsiveness by including insulin (10 nM) with incubations containing leptin. Leptin had no acute effects on glucose oxidation or conversion to lipid (P > 0.05). Acute leptin treatment decreased palmitate incorporation into lipids up to 45% (P 0.05) by leptin. These data indicate that leptin functions to promote partitioning of energy away from lipid accretion within porcine adipose tissue by inhibiting glucose oxidation and lipogenesis indirectly, by decreasing insulin-mediated stimulation of lipogenesis, and by stimulating fatty acid oxidation while inhibiting fatty acid esterification.