Abstract

Fibroblast growth factor 21 (FGF21) plays a critical role in the regulation of lipid metabolism; however, its function in goat intramuscular fat (IMF) deposition remains unknown. To explore the role of FGF21 for goat IMF deposition, we performed gain and loss function of FGF21 in intramuscular adipocyte. Our results showed that overexpression of FGF21 mediated by adenovirus inhibits lipid accumulation of goat intramuscular adipocyte, accompanied by down-regulating the mRNA levels of peroxisome proliferator activated receptor γ (PPARγ), adipocyte fatty acid-binding protein 2 (aP2) and sterol regulatory element-binding protein 1 (SREBP1), but up-regulating counterpart of preadipocyte factor1 (Pref1). Conversely, siRNAs knocking down FGF21 promotes the expression of PPARγ and CCAAT/enhancer binding protein-α (C/EBPα) but suppressed that of lipoprotein lipase (LPL) and Pref1. Meanwhile, we found that FGF21 regulates the expression of many KLFs transcription factors, such as KLF3, 7, 9, 11, 14, and 16. These findings demonstrate a key role of FGF21 as a negative factor in the regulation of adipogenic differentiation in goat intramuscular preadipocyte.

摘要

成纤维细胞生长因子 21 (FGF21) 在脂质代谢的调节中起关键作用；然而，其在山羊肌肉内脂肪 (IMF) 沉积中的功能仍然未知。为了探索 FGF21 在山羊 IMF 沉积中的作用，我们在肌内脂肪细胞中进行了 FGF21 的增益和丢失功能。我们的研究结果表明，腺病毒介导的 FGF21 过表达抑制山羊肌肉内脂肪细胞的脂质积累，同时下调过氧化物酶体增殖物激活受体 γ (PPARγ)、脂肪细胞脂肪酸结合蛋白 2 (aP2) 和甾醇调节元件的 mRNA 水平结合蛋白 1 (SREBP1)，但上调前脂肪细胞因子 1 (Pref1) 的对应物。反过来，siRNA 敲低 FGF21 促进 PPARγ 和 CCAAT/增强子结合蛋白-α (C/EBPα) 的表达，但抑制脂蛋白脂肪酶 (LPL) 和 Pref1 的表达。同时，我们发现 FGF21 调节许多 KLFs 转录因子的表达，如 KLF3、7、9、11、14 和 16。这些发现表明 FGF21 作为调节山羊脂肪分化的负因子的关键作用肌内前脂肪细胞。