Up-regulation of thioredoxin system by puerarin inhibits lipid uptake in macrophages
Up-regulation of thioredoxin system by puerarin inhibits lipid uptake in macrophages
复制标题
葛根素上调硫氧还蛋白系统抑制巨噬细胞的脂质摄取。
DOI：
10.1016/j.freeradbiomed.2020.11.011
复制
发表时间：
2021-02-13
影响因子：
7.4
通讯作者：
Ou, Hailong
中科院分区：
文献类型：
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作者：
Li, Wenchao;Xu, Xiaoting;Ou, Hailong
动脉粥样硬化形成过程中细胞氧化应激促进巨噬细胞脂质蓄积。葛根素是一种天然植物，具有抗氧化和抗动脉粥样硬化的作用。在这项研究中，我们研究了葛根素对脂质摄取的影响，并探讨了潜在的分子调控。我们发现葛根素上调硫氧还蛋白-1（Trx 1）和Trx还原酶-1（TrxR 1）的表达;它增加TrxR 1活性，细胞巯基含量和减少氧化形式的Trx 1，从而抑制细胞ROS的产生。共聚焦显微镜和流式细胞仪分析显示葛根素显著抑制RAW264.7细胞以及原代骨髓源性巨噬细胞和腹腔巨噬细胞摄取荧光标记的Dil-oxLDL。当用Trx 1抑制剂PX-12或Trx 1 siRNA抑制Trx 1时，这种作用被逆转。我们还发现，清道夫受体，如SR-A和Lox-1，而不是CD 36参与Trx 1介导的脂质摄取抑制。此外，测量主动脉根部切片中的泡沫细胞积累和ROS产生显示，葛根素减少了这些，但当apoE-/-小鼠中使用PX-12或Trx 1 siRNA进行额外治疗时，这些增加了，这表明葛根素减少脂质摄取需要体内Trx 1抑制。此外，我们分析了上游调控，发现葛根素诱导Nrf 2的活性，Nrf 2和ATF 4之间的协同作用促进了葛根素的作用。检测到PERK磷酸化被葛根素增加，而PERK抑制减少细胞Trx 1，TrxR 1，核Nrf 2和ATF 4。总而言之，葛根素调节与ATF 4协调的PERK/Nrf 2以激活Trx 1，这导致巨噬细胞中SR-A和Lox-1减少和脂质摄取抑制。提示Trx 1可能是葛根素预防动脉粥样硬化的有效靶点。
Cellular oxidative stress promotes lipid accumulation in macrophages during atherogenesis. Puerarin is a natural isoflavone with beneficial effects against oxidation and atherosclerosis. In this study, we investigated the effects of puerarin on lipid uptake and explored the underlying molecular regulation. We found puerarin up-regulated thioredoxin-1 (Trx1) and Trx reductase-1 (TrxR1) expression; it increased TrxR1 activity, cellular thiols contents and decreased oxidized form of Trx1, thus inhibiting cellular ROS generation. Confocal microscope and flow cytometry analysis showed fluorescence labeled Dil-oxLDL uptake was dramatically inhibited by puerarin in RAW264.7 cells as well as in primary bone marrow derived macrophages and peritoneal macrophages. The effects were reversed when Trx1 was inhibited by treatment with Trx1 inhibitor PX-12 or Trx1 siRNA. We also found scavenger receptors such as SR-A and Lox-1, but not CD36 were involved in the Trx1-mediated lipid uptake inhibition. Moreover, measurements of foam cell accumulation and ROS production in sections of aortic roots showed those were reduced by puerarin but raised when additional treatment with PX-12 or Trx1 siRNA in apoE-/- mice, which demonstrates the lipid uptake reduction by puerarin requires Trx1 inhibition in vivo. In addition, we analyzed the upstream regulation and found puerarin induced Nrf2 activity; cooperation between Nrf2 and ATF4 facilitated the puerarin effects. PERK phosphorylation was detected to be increased by puerarin, while PERK inhibition reduced cellular Trx1, TrxR1, nuclear Nrf2 and ATF4. Altogether, puerarin modulates PERK/Nrf2 that coordinates with ATF4 to active Trx1, which causes SR-A and Lox-1 reduction and lipid uptake inhibition in macrophages. This suggests Trx1 could be an effective target by puerarin in the prevention of atherosclerosis.