过氧化物酶体增殖物激活受体-α在山羊乳腺上皮细胞中单不饱和脂肪酸合成中的作用。
Role of peroxisome proliferator-activated receptor-α on the synthesis of monounsaturated fatty acids in goat mammary epithelial cells.
机构信息
Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, China.
College of Animal Science, Zhejiang University, Hangzhou, Zhejiang, China.
出版信息
J Anim Sci. 2020 Mar 1;98(3). doi: 10.1093/jas/skaa062.
A key member of the nuclear receptor superfamily is the peroxisome proliferator-activated receptor alpha (PPARA) isoform, which in nonruminants is closely associated with fatty acid oxidation. Whether PPARA plays a role in milk fatty acid synthesis in ruminants is unknown. The main objective of the present study was to use primary goat mammary epithelial cells (GMEC) to activate PPARA via the agonist WY-14643 (WY) or to silence it via transfection of small-interfering RNA (siRNA). Three copies of the peroxisome proliferator-activated receptor response element (PPRE) contained in a luciferase reporter vector were transfected into GMEC followed by incubation with WY at 0, 10, 20, 30, 50, or 100 µM. A dose of 50 µM WY was most effective at activating PPRE without influencing PPARA mRNA abundance. Transfecting siRNA targeting PPARA decreased its mRNA abundance to 20% and protein level to 50% of basal levels. Use of WY upregulated FASN, SCD1, ACSL1, DGAT1, FABP4, and CD36 (1.1-, 1.5-, 2-, 1.4-, 1.5-, and 5-fold, respectively), but downregulated DGAT2 and PGC1A (-20% and -40%, respectively) abundance. In contrast, triacylglycerol concentration decreased and the content and desaturation index of C16:1 and C18:1 increased. Thus, activation of PPARA via WY appeared to channel fatty acids away from esterification. Knockdown of PPARA via siRNA downregulated ACACA, SCD1, AGPAT6, CD36, HSL, and SREBF1 (-43%, -67%, -16%, -56%, -26%, and -29%, respectively), but upregulated ACSL1, DGAT2, FABP3, and PGC1A (2-, 1.4-, 1.3-, and 2.5-fold, respectively) mRNA abundance. A decrease in the content and desaturation index of C16:1 and C18:1 coupled with an increase in triacylglycerol content accompanied those effects at the mRNA level. Overall, data suggest that PPARA could promote the synthesis of MUFA in GMEC through its effects on mRNA abundance of genes related to fatty acid synthesis, oxidation, transport, and triacylglycerol synthesis.
过氧化物酶体增殖物激活受体α（PPARA）同工型是核受体超家族的一个关键成员，在非反刍动物中，它与脂肪酸氧化密切相关。PPARA 是否在反刍动物的乳脂肪酸合成中发挥作用尚不清楚。本研究的主要目的是使用原代山羊乳腺上皮细胞（GMEC）通过激动剂 WY-14643（WY）激活 PPARA，或通过转染小干扰 RNA（siRNA）使其沉默。将包含 3 个过氧化物酶体增殖物激活受体反应元件（PPRE）的荧光素酶报告载体转染到 GMEC 中，然后用 0、10、20、30、50 或 100µM 的 WY 孵育。WY 的 50µM 剂量最有效地激活 PPRE，而不影响 PPARA mRNA 丰度。转染针对 PPARA 的 siRNA 将其 mRNA 丰度降低至基础水平的 20%，并将蛋白质水平降低至 50%。WY 的使用上调 FASN、SCD1、ACSL1、DGAT1、FABP4 和 CD36（分别为 1.1、1.5、2、1.4、1.5 和 5 倍），但下调 DGAT2 和 PGC1A（分别为-20%和-40%）的丰度。相比之下，三酰基甘油浓度降低，C16:1 和 C18:1 的含量和饱和度指数增加。因此，通过 WY 激活 PPARA 似乎使脂肪酸远离酯化。通过 siRNA 敲低 PPARA 下调 ACACA、SCD1、AGPAT6、CD36、HSL 和 SREBF1（分别为-43%、-67%、-16%、-56%、-26%和-29%），但上调 ACSL1、DGAT2、FABP3 和 PGC1A（分别为 2、1.4、1.3 和 2.5 倍）的 mRNA 丰度。在 mRNA 水平上，C16:1 和 C18:1 的含量和饱和度指数降低，三酰基甘油含量增加，伴随着这些变化。总的来说，数据表明，PPARA 可以通过其对与脂肪酸合成、氧化、转运和三酰基甘油合成相关基因的 mRNA 丰度的影响，促进 GMEC 中 MUFA 的合成。
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