Wang Yan, Zhu Peng, Ni Jiahui, Mo Qilang, Luo Wei, Du Zongjun, Jiang Jun, Yang Song, Zhao Liulan, Gong Quan
College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, Sichuan, People's Republic of China.
Fisheries Institute, Sichuan Academy of Agricultural Sciences, Chengdu, 611713, Sichuan, People's Republic of China.
Fish Physiol Biochem. 2022 Apr;48(2):449-459. doi: 10.1007/s10695-022-01060-w. Epub 2022 Mar 1.
Retinol-binding protein 4 (RBP4) protein is a kind of adipokines synthesized and secreted by the liver, which has been verified to play important roles in liver metabolism and energy homeostasis. However, the effects of RBP4 on hepatic lipid accumulation are still elusive in fish. In the present study, we cloned and characterized the RBP4 gene in Schizothorax prenanti (S. prenanti). RBP4 gene was specifically expressed in the liver and abdominal adipose tissue. Palmitic acid (PA; 400 μM) can significantly increase lipid deposition in primary hepatocytes after 12 h of treatment. Furthermore, RBP4 knockdown can relieve the excessive lipid deposition and endoplasmic reticulum stress in the hepatocytes caused by PA. The inhibition of RBP4 abolished the ability of PA to induce the expression of genes involved in lipogenesis and endoplasmic reticulum stress. These results demonstrate that RBP4 inhibition attenuated PA-induced lipid deposition and endoplasmic reticulum stress in hepatocytes of S. prenanti. This study could contribute to improve the understanding of RBP4 functions in the PA-induced lipid deposition in hepatocytes of fish.
视黄醇结合蛋白4（RBP4）是一种由肝脏合成并分泌的脂肪因子，已证实其在肝脏代谢和能量稳态中发挥重要作用。然而，RBP4对鱼类肝脏脂质积累的影响仍不明确。在本研究中，我们克隆并鉴定了齐口裂腹鱼（S. prenanti）中的RBP4基因。RBP4基因在肝脏和腹部脂肪组织中特异性表达。棕榈酸（PA；400 μM）处理12小时后可显著增加原代肝细胞中的脂质沉积。此外，敲低RBP4可减轻PA引起的肝细胞中过多的脂质沉积和内质网应激。抑制RBP4消除了PA诱导参与脂肪生成和内质网应激的基因表达的能力。这些结果表明，抑制RBP4可减轻PA诱导的齐口裂腹鱼肝细胞中的脂质沉积和内质网应激。本研究有助于增进对RBP4在鱼类肝细胞PA诱导的脂质沉积中功能的理解。
