Hepatic sinusoidal obstruction syndrome (HSOS) is a death-dealing liver disease with a fatality rate of up to 67%. In the study present, we explored the efficacy of andrographolide (Andro), a diterpene lactone from Andrographis Herba, in ameliorating the monocrotaline (MCT)-induced HSOS and the underlying mechanism. The alleviation of Andro on MCT-induced rats HSOS was proved by biochemical index detection, electron microscope observation, and liver histological evaluation. Detection of hepatic ATP content, mitochondrial DNA (mtDNA) copy number, and protein expression of nuclear respiratory factor-1 (NRF1) and peroxisome proliferator–activated receptor gamma coactivator 1 alpha (PPARGC1A) demonstrated that Andro strengthened mitochondrial biogenesis in livers from MCT-treated rats. Chromatin immunoprecipitation assay exhibited that Andro enhanced the occupation of nuclear factor erythroid 2-related factor 2 (NFE2L2, also known as NRF2) in the promoter regions of both PPARGC1A and NRF1. Andro also activated the NRF2-dependent anti-oxidative response and alleviated liver oxidative injury. In Nrf2 knock-out mice, MCT induced more severe liver damage, and Andro showed no alleviation in it. Furthermore, the Andro-activated mitochondrial biogenesis and anti-oxidative response were reduced in Nrf2 knock-out mice. Contrastingly, knocking out Kelch-like ECH-associated protein 1 (Keap1), a NRF2 repressor, reduced MCT-induced liver damage. Results from co-immunoprecipitation, molecular docking analysis, biotin-Andro pull-down, cellular thermal shift assay, and surface plasmon resonance assay showed that Andro hindered the NRF2-KEAP1 interaction via directly binding to KEAP1. In conclusion, our results revealed that NRF2-dependent liver mitochondrial biogenesis and anti-oxidative response were essential for the Andro-provided alleviation of the MCT-induced HSOS.

Graphical abstract

Graphical Headlights:

1. Andro alleviated MCT-induced HSOS via activating antioxidative response and promoting mitochondrial biogenesis.

2. Andro-activated antioxidative response and mitochondrial biogenesis were NRF2-dependent.

3. Andro activated NRF2 via binding to KEAP1.

中文翻译：

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穿心莲内酯通过调节 NRF2 启动的线粒体生物合成和抗氧化反应来减弱 MCT 诱导的 HSOS

肝窦阻塞综合征（HSOS）是一种致命性肝脏疾病，死亡率高达 67%。在本研究中，我们探讨了穿心莲内酯 (Andro)（一种来自穿心莲的二萜内酯）在改善野百合碱 (MCT) 诱导的 HSOS 方面的功效及其潜在机制。通过生化指标检测、电镜观察和肝脏组织学评价证明Andro对MCT诱导的大鼠HSOS有改善作用。检测肝 ATP 含量、线粒体 DNA (mtDNA) 拷贝数以及核呼吸因子 1 (NRF1) 和过氧化物酶体增殖物激活受体 γ 共激活剂 1 α (PPARGC1A) 的蛋白表达，表明 Andro 增强了 MCT-肝脏中线粒体的生物合成。治疗大鼠。染色质免疫沉淀分析表明，Andro 增强了 PPARGC1A 和 NRF1 启动子区域中核因子红细胞 2 相关因子 2（NFE2L2，也称为 NRF2）的占据。Andro 还激活 NRF2 依赖性抗氧化反应，减轻肝脏氧化损伤。在Nrf2敲除小鼠中，MCT 引起更严重的肝损伤，而 Andro 没有显示出缓解作用。此外， Nrf2敲除小鼠中 Andro 激活的线粒体生物发生和抗氧化反应均减少。相比之下，敲除 Kelch 样 ECH 相关蛋白 1 ( Keap1 )（一种 NRF2 阻遏蛋白）可减少 MCT 引起的肝损伤。免疫共沉淀、分子对接分析、生物素-Andro Pull-down、细胞热位移测定和表面等离子共振测定的结果表明，Andro 通过直接结合 KEAP1 阻碍 NRF2-KEAP1 相互作用。总之，我们的结果表明，NRF2 依赖性肝脏线粒体生物合成和抗氧化反应对于 Andro 缓解 MCT 诱导的 HSOS 至关重要。

图形概要

图形车头灯：

1. Andro 通过激活抗氧化反应和促进线粒体生物合成减轻 MCT 诱导的 HSOS。

2. Andro激活的抗氧化反应和线粒体生物发生是NRF2依赖性的。

3.Andro通过与KEAP1结合激活NRF2。