Data_Sheet_3_Effect of the ACAA1 Gene on Preadipocyte Differentiation in Sheep.PDF

Acetyl-CoA acyltransferase 1 (ACAA1) functions as a key regulator of fatty acid β-oxidation in peroxisomes by catalyzing the cleavage of 3-ketoacyl-CoA to acetyl-CoA and acyl-CoA, which participate in the extension and degradation of fatty acids. Thus, ACAA1 is an important regulator of lipid metabolism and plays an essential role in fatty acid oxidation and lipid metabolism. Our previous study findings revealed that ACAA1 is closely associated with the peroxisome proliferator-activated receptor (PPAR) signaling and fatty acid metabolism pathways, which are involved in fat deposition in sheep, leading to our hypothesis that ACAA1 may be involved in fat deposition by regulating lipid metabolism. However, the associated molecular mechanism remains unclear. In the present study, to assess the potential function of ACAA1 in sheep preadipocyte differentiation, we knocked down and overexpressed ACAA1 in sheep preadipocytes and evaluated the pattern of ACAA1 gene expression during preadipocyte differentiation by qRT-PCR. ACAA1 was significantly expressed in the early stage of adipocyte differentiation, and then its expression decreased. ACAA1 deficiency increased lipid accumulation and the triglyceride content and promoted sheep preadipocyte differentiation, whereas ACAA1 overexpression inhibited adipogenesis and decreased lipid accumulation and the triglyceride content. Simultaneously, we demonstrated that ACAA1 deficiency upregulated the expressions of the adipogenic marker genes PPARγ and C/EBPα in sheep preadipocytes, but ACAA1 overexpression inhibited the expressions of these markers, indicating that ACAA1 affects lipid metabolism by regulating adipogenic marker genes. Our results may promote a better understanding of the regulation of adipogenesis by ACAA1.

乙酰辅酶A酰基转移酶1（Acetyl-CoA acyltransferase 1，ACAA1）作为过氧化物酶体脂肪酸β氧化的关键调控因子，可催化3-酮酰基辅酶A裂解为乙酰辅酶A与酰基辅酶A，二者参与脂肪酸的延伸与降解过程。因此，ACAA1是脂质代谢的重要调控因子，在脂肪酸氧化及脂质代谢中发挥不可或缺的作用。我们既往的研究结果显示，ACAA1与过氧化物酶体增殖物激活受体（PPAR）信号通路及脂肪酸代谢通路密切相关，而这些通路参与绵羊脂肪沉积过程，据此我们提出假说：ACAA1可能通过调控脂质代谢参与绵羊脂肪沉积，但其具体分子机制尚未明确。本研究为探究ACAA1在绵羊前体脂肪细胞分化中的潜在功能，我们对绵羊前体脂肪细胞中的ACAA1分别进行了基因敲低与过表达处理，并通过实时荧光定量聚合酶链式反应（qRT-PCR）分析了前体脂肪细胞分化全过程中ACAA1基因的表达模式。结果显示，ACAA1在脂肪细胞分化早期呈现高表达，随后表达量逐渐降低。ACAA1基因敲低可提升脂质积累水平与甘油三酯含量，促进绵羊前体脂肪细胞分化；而ACAA1过表达则会抑制成脂过程，降低脂质积累与甘油三酯含量。同时，我们证实，ACAA1敲低可上调绵羊前体脂肪细胞中成脂标志基因PPARγ与CCAAT增强子结合蛋白α（C/EBPα）的表达，而ACAA1过表达则会抑制上述标志基因的表达，表明ACAA1可通过调控成脂标志基因的表达影响脂质代谢。本研究结果有助于进一步阐明ACAA1对脂肪生成的调控机制。