Department of Nutrition, Dietetics and Hospitality Management, Auburn University, Auburn, AL, USA.
Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA.
Lipids Health Dis. 2017 Sep 25;16(1):181. doi: 10.1186/s12944-017-0574-7.
Increased consumption of omega-3 (ω-3) fatty acids found in cold-water fish and fish oil has been reported to protect against obesity. A potential mechanism may be through reduction in adipocyte differentiation. Stearidonic acid (SDA), a plant-based ω-3 fatty acid, has been targeted as a potential surrogate for fish-based fatty acids; however, its role in adipocyte differentiation is unknown. This study was designed to evaluate the effects of SDA on adipocyte differentiation in 3T3-L1 cells.
3T3-L1 preadipocytes were differentiated in the presence of SDA or vehicle-control. Cell viability assay was conducted to determine potential toxicity of SDA. Lipid accumulation was measured by Oil Red O staining and triglyceride (TG) quantification in differentiated 3T3-L1 adipocytes. Adipocyte differentiation was evaluated by adipogenic transcription factors and lipid accumulation gene expression by quantitative real-time polymerase chain reaction (qRT-PCR). Fatty acid analysis was conducted by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS).
3T3-L1 cells treated with SDA were viable at concentrations used for all studies. SDA treatment reduced lipid accumulation in 3T3-L1 adipocytes. This anti-adipogenic effect by SDA was a result of down-regulation of mRNA levels of the adipogenic transcription factors CCAAT/enhancer-binding proteins alpha and beta (C/EBPα, C/EBPβ), peroxisome proliferator-activated receptor gamma (PPARγ), and sterol-regulatory element binding protein-1c (SREBP-1c). SDA treatment resulted in decreased expression of the lipid accumulation genes adipocyte fatty-acid binding protein (AP2), fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD-1), lipoprotein lipase (LPL), glucose transporter 4 (GLUT4) and phosphoenolpyruvate carboxykinase (PEPCK). The transcriptional activity of PPARγ was found to be decreased with SDA treatment. SDA treatment led to significant EPA enrichment in 3T3-L1 adipocytes compared to vehicle-control.
These results demonstrated that SDA can suppress adipocyte differentiation and lipid accumulation in 3T3-L1 cells through down-regulation of adipogenic transcription factors and genes associated with lipid accumulation. This study suggests the use of SDA as a dietary treatment for obesity.
有报道称，增加冷水鱼和鱼油中ω-3（ω-3）脂肪酸的摄入可以预防肥胖。一种潜在的机制可能是通过减少脂肪细胞分化。硬脂酸（SDA），一种植物性ω-3 脂肪酸，已被作为鱼类脂肪酸的潜在替代品进行研究；然而，其在脂肪细胞分化中的作用尚不清楚。本研究旨在评估 SDA 对 3T3-L1 细胞脂肪细胞分化的影响。
在 SDA 或对照载体存在的情况下，将 3T3-L1 前体脂肪细胞分化。通过细胞活力测定来确定 SDA 的潜在毒性。通过油红 O 染色和分化的 3T3-L1 脂肪细胞中的三酰基甘油（TG）定量来测量脂质积累。通过定量实时聚合酶链反应（qRT-PCR）评估脂肪细胞分化和脂质积累基因表达。通过液相色谱-质谱/质谱（LC-MS/MS）进行脂肪酸分析。
在用于所有研究的浓度下，用 SDA 处理的 3T3-L1 细胞存活。SDA 处理减少了 3T3-L1 脂肪细胞中的脂质积累。SDA 的这种抗脂肪生成作用是由于脂肪生成转录因子 CCAAT/增强子结合蛋白-α和-β（C/EBPα、C/EBPβ）、过氧化物酶体增殖物激活受体γ（PPARγ）和固醇调节元件结合蛋白-1c（SREBP-1c）的 mRNA 水平下调所致。SDA 处理导致脂肪细胞脂肪酸结合蛋白（AP2）、脂肪酸合酶（FAS）、硬脂酰辅酶 A 去饱和酶（SCD-1）、脂蛋白脂肪酶（LPL）、葡萄糖转运蛋白 4（GLUT4）和磷酸烯醇丙酮酸羧激酶（PEPCK）等脂质积累基因的表达减少。发现 SDA 处理后 PPARγ 的转录活性降低。与对照载体相比，SDA 处理导致 3T3-L1 脂肪细胞中 EPA 显著富集。
这些结果表明，SDA 通过下调脂肪生成转录因子和与脂质积累相关的基因，可抑制 3T3-L1 细胞中的脂肪细胞分化和脂质积累。本研究表明，SDA 可作为肥胖的饮食治疗方法。
