College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
National Beef Cattle Improvement Center, Northwest A&F University, Yangling, Shaanxi, China.
J Cell Biochem. 2019 Aug;120(8):13932-13943. doi: 10.1002/jcb.28667. Epub 2019 Apr 4.
The elongation of very long chain fatty acids protein 6 (ELOVL6) gene encodes a key enzyme that plays a role in lipogenesis through the catalytic elongation of both saturated and monounsaturated fatty acids. Previous studies have described the high expression of bovine ELOVL6 in adipose tissues. However, transcriptional regulation and the functional role of ELOVL6 in lipid metabolism and adipocyte proliferation remain unexplored. Here, a 1.5 kb fragment of the 5'-untranslated region promoter region of ELOVL6 was amplified from the genomic DNA of Qinchuan cattle and sequenced. The core promoter region was identified through unidirectional 5'-end deletion of the promoter plasmid vector. In silico analysis predicted important transcription factors that were then validated through site-directed mutation and small interfering RNA interference with an electrophoretic mobility shift assay. We found that the binding of KLF6 and PU.1 transcription factors occurred in the region -168/+69. Both perform a vital regulatory function in the transcription of bovine ELOVL6. Overexpression of ELOVL6 significantly upregulated the expression of peroxisome proliferator activated receptor γ (PPARγ), but inhibited the expression of fatty acid-binding protein 4 (FABP4), while silencing of ELOVL6 negatively regulated the messenger RNA expression level of PPARγ, FABP4, ACSL, and FATP1. In addition, ELOVL6 promotes adipocyte proliferation by regulating the cell-cycle genes' expression. Taken together, these findings provide useful information about the transcriptional regulation and functional mechanisms of bovine ELOVL6 in lipid metabolism and adipocyte proliferation in Qinchuan cattle.
长链脂肪酸延长酶 6（ELOVL6）基因的延长编码一种关键酶，通过催化饱和和单不饱和脂肪酸的延长，在脂肪生成中发挥作用。以前的研究描述了牛 ELOVL6 在脂肪组织中的高表达。然而，ELOVL6 在脂质代谢和脂肪细胞增殖中的转录调控和功能作用仍未被探索。在这里，从秦川牛的基因组 DNA 中扩增了 ELOVL6 的 5'-非翻译区启动子区域的 1.5kb 片段并进行了测序。通过启动子质粒载体的单向 5'-末端缺失鉴定了核心启动子区域。计算机分析预测了重要的转录因子，然后通过电泳迁移率变动分析的定点突变和小干扰 RNA 干扰进行了验证。我们发现 KLF6 和 PU.1 转录因子的结合发生在-168/+69 区域。这两个转录因子在牛 ELOVL6 的转录中都起着重要的调节作用。ELOVL6 的过表达显著上调过氧化物酶体增殖物激活受体 γ（PPARγ）的表达，但抑制脂肪酸结合蛋白 4（FABP4）的表达，而 ELOVL6 的沉默则负调控 PPARγ、FABP4、ACSL 和 FATP1 的信使 RNA 表达水平。此外，ELOVL6 通过调节细胞周期基因的表达促进脂肪细胞增殖。总之，这些发现为秦川牛 ELOVL6 在脂质代谢和脂肪细胞增殖中的转录调控和功能机制提供了有用的信息。
