Yang Yongqing, Liu Fenglan, Lu Rongsheng, Jia Junli
College of Life Science, Shanxi Normal University, The First Gongyuan Road, Linfen, Shanxi Province, 041000, People's Republic of China.
Lipids. 2019 Nov;54(11-12):667-678. doi: 10.1002/lipd.12200. Epub 2019 Nov 6.
Excessive adipogenesis in adipocytes results in obesity. Berberine, a natural isoquinoline alkaloid, has antiobesity properties. However, the underlying molecular mechanisms have remained unclear up to now. In this study, porcine adipocytes were cultured and treated with berberine. Cellular lipid content was measured by Oil Red O staining extraction. The role of an adenosine monophosphate-activated protein kinase (AMPK) signaling pathway was evaluated by the phosphorylation detection of AMPKα protein and knockdown of AMPK alpha1 (Ampka1) gene. Gene expressions were analyzed by Western blot and real-time reverse transcription-polymerase chain reaction (RT-PCR). The results showed that berberine reduced lipid accumulation in porcine adipocytes in a dose- and time-dependent manner and increased phosphorylation of AMPKα. Furthermore, berberine significantly downregulated the mRNA expression of related genes to adipogenesis including peroxisome proliferator activated receptor gamma 2 (Pparg2), CCAAT/enhancer-binding protein alpha (Cebpa), Cebp beta (Cebpb), sterol regulatory element binding transcription factor 1 (Srebf1), acetyl-CoA carboxylase-1 (Acc-1), fatty acid synthase (Fas), fatty acid binding protein 4 (Fabp4), and stearoyl-CoA desaturase 1 (Scd1). Knockdown of Ampka1 markedly reversed the inhibitory effect of berberine on lipid accumulation and mRNA expression of the above genes except Cebpb in porcine adipocytes. Meanwhile, the protein expression of these adipogenic genes in response to berberine and Ampka1 knockdown paralleled the alterations of their mRNA level. These results suggest that berberine inhibits adipogenesis in porcine adipocytes via AMPK-dependent and -independent multiple mechanisms, which would provide an important idea for the reduction of porcine body fat, as well as the prevention and treatment of human obesity.
脂肪细胞中过度的脂肪生成会导致肥胖。黄连素是一种天然异喹啉生物碱，具有抗肥胖特性。然而，其潜在的分子机制至今仍不清楚。在本研究中，培养猪脂肪细胞并用黄连素处理。通过油红O染色提取法测量细胞脂质含量。通过检测AMPKα蛋白的磷酸化以及敲低AMPKα1（Ampka1）基因来评估腺苷酸活化蛋白激酶（AMPK）信号通路的作用。通过蛋白质印迹法和实时逆转录-聚合酶链反应（RT-PCR）分析基因表达。结果表明，黄连素以剂量和时间依赖性方式减少猪脂肪细胞中的脂质积累，并增加AMPKα的磷酸化。此外，黄连素显著下调与脂肪生成相关基因的mRNA表达，包括过氧化物酶体增殖物激活受体γ2（Pparg2）、CCAAT/增强子结合蛋白α（Cebpa）、Cebpβ（Cebpb）、固醇调节元件结合转录因子1（Srebf1）、乙酰辅酶A羧化酶-1（Acc-1）、脂肪酸合酶（Fas）、脂肪酸结合蛋白4（Fabp4）和硬脂酰辅酶A去饱和酶1（Scd1）。敲低Ampka1显著逆转了黄连素对猪脂肪细胞脂质积累和上述基因（除Cebpb外）mRNA表达的抑制作用。同时，这些脂肪生成基因响应黄连素和Ampka1敲低的蛋白质表达与其mRNA水平的变化平行。这些结果表明，黄连素通过AMPK依赖性和非依赖性多种机制抑制猪脂肪细胞的脂肪生成，这将为减少猪体脂以及预防和治疗人类肥胖提供重要思路。
