Gene expression was analyzed using quantitative real-time polymerase chain reaction or transcriptome sequencing. CRISPR/Cas9 technology was employed to generate nkx1.2 knockout zebrafish and nkx1.2-deleted 3T3-L1 cells. Lipid droplet production in zebrafish larvae was visually quantified using Nile red staining, whereas lipid droplets in 3T3-L1 cells were stained with Oil red O. The binding of Nkx1-2 to the promoter was verified through an electrophoretic mobility shift assay experiment.
Nkx1-2 plays crucial roles in the regulation of fat production in zebrafish. Knockout of nkx1.2 in zebrafish leads to weight loss, accompanied by significantly reduced lipid droplet production and decreased visceral and liver fat content. Furthermore, genes related to lipid biosynthesis are significantly downregulated. In 3T3-L1 preadipocytes, Nkx1-2 induces differentiation into mature adipocytes by binding to the cebpa promoter, thereby activating its transcription. Additionally, the expression of nkx1.2 is regulated by the p38 MAPK, JNK, or Smad2/3 signaling pathways in 3T3-L1 cells.
Our findings suggest that Nkx1-2 functions as a positive regulator of fat production, playing a critical role in adipocyte differentiation and lipid biosynthesis.
方法:使用定量实时聚合酶链反应或转录组测序分析基因表达。CRISPR/Cas9技术用于产生nkx1.2敲除斑马鱼和nkx1.2缺失的3T3-L1细胞。使用尼罗河红染色对斑马鱼幼虫中的脂滴产生进行视觉定量,而3T3-L1细胞中的脂滴被油红O染色。通过电泳迁移率变化实验验证了Nkx1-2与启动子的结合。
结果:Nkx1-2在斑马鱼脂肪生产的调节中起着至关重要的作用。在斑马鱼中敲除nkx1.2会导致体重减轻,伴随着脂滴的产生显着减少,内脏和肝脏脂肪含量降低。此外,与脂质生物合成相关的基因显著下调。在3T3-L1前脂肪细胞中,Nkx1-2通过与cebpa启动子结合诱导分化为成熟脂肪细胞,从而激活其转录。此外,nkx1.2的表达受p38MAPK调控,JNK,或Smad2/3信号通路在3T3-L1细胞。
结论:我们的研究结果表明,Nkx1-2作为脂肪产生的正调节因子,在脂肪细胞分化和脂质生物合成中起关键作用。