Xie Tao, Liu Yinuo, Lu Huixian, Iqbal Ambreen, Ruan Mengru, Jiang Ping, Yu Haibin, Meng Jilun, Zhao Zhihui
Department of Animal Sciences, College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, China.
Zhejiang Institute of Freshwater Fisheries, Huzhou 313000, China.
Animals (Basel). 2022 May 28;12(11):1389. doi: 10.3390/ani12111389.
Agouti signalling protein (ASIP) is a coat colour-related protein and also is a protein-related to lipid metabolism, which had first been found in agoutis. According to our previous study, ASIP is a candidate gene that affects the lipid metabolism in bovine adipocytes. However, its effect on milk lipid has not been reported yet. This study focused on the effect of the ASIP gene on the lipid metabolism of mammary epithelial cells in cattle. The ASIP gene was knocked out in bMECs by using CRISPR/Cas9 technology. The result of transcriptome sequencing showed that the differentially expressed genes associated with lipid metabolism were mainly enriched in the fatty acids metabolism pathways. Furthermore, the contents of intracellular triglycerides were significantly increased (p < 0.05), and cholesterol tended to rise (p > 0.05) in bMECs with the knockout of the ASIP gene. Fatty acid assays showed a significant alteration in medium and long-chain fatty acid content. Saturated and polyunsaturated fatty acids were significantly up-regulated (p < 0.05), and monounsaturated fatty acids were significantly decreased in the ASIP knockout bMECs (p < 0.05). The Q-PCR analysis showed that knockout of ASIP resulted in a significant reduction of gene expressions like PPARγ, FASN, SCD, and a significant up-regulation of genes like FABP4, ELOVL6, ACSL1, HACD4 prompted increased mid-to long-chain fatty acid synthesis. Overall, ASIP plays a pivotal role in regulating lipid metabolism in bMECs, which could further influence the component of lipid in milk.
刺鼠信号蛋白（ASIP）是一种与毛色相关的蛋白质，也是一种与脂质代谢相关的蛋白质，最初在刺鼠中被发现。根据我们之前的研究，ASIP是影响牛脂肪细胞脂质代谢的候选基因。然而，其对乳脂的影响尚未见报道。本研究聚焦于ASIP基因对奶牛乳腺上皮细胞脂质代谢的影响。利用CRISPR/Cas9技术在牛乳腺上皮细胞（bMECs）中敲除ASIP基因。转录组测序结果表明，与脂质代谢相关的差异表达基因主要富集在脂肪酸代谢途径中。此外，敲除ASIP基因的bMECs中细胞内甘油三酯含量显著增加（p<0.05），胆固醇有升高趋势（p>0.05）。脂肪酸检测显示中长链脂肪酸含量有显著变化。在敲除ASIP基因的bMECs中，饱和脂肪酸和多不饱和脂肪酸显著上调（p<0.05），单不饱和脂肪酸显著降低（p<0.05）。Q-PCR分析表明，敲除ASIP导致PPARγ、FASN、SCD等基因表达显著降低，FABP4、ELOVL6、ACSL1、HACD4等基因显著上调，促使中长链脂肪酸合成增加。总体而言，ASIP在调节bMECs脂质代谢中起关键作用，这可能进一步影响乳脂成分。
