School of Life Sciences, Beijing University of Chinese Medicine, Beijing 100029, China.
School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, China.
Phytomedicine. 2024 Oct;133:155923. doi: 10.1016/j.phymed.2024.155923. Epub 2024 Jul 29.
Hepatic ischemia-reperfusion injury (HIRI) is commonly observed in cases of extensive hepatic resection and involves complex mechanisms. Cell senescence has been recognized as a factor in liver injury including HIRI, where it presents as a pro-inflammatory phenotype called senescence-associated secretory phenotype (SASP). Radix Rehmanniae Praeparata (RRP) is a commonly utilized traditional Chinese medicine known for its hepatoprotective, anti-aging and antioxidant qualities. Despite its recognized benefits, the specific mechanisms by which RRP may impede the progression of HIRI through the regulation of cell senescence and the identification of the most potent anti-aging extracts from RRP remain unclear.
Here, we first applied different chemical analysis methods to identify the RRP aqueous extract (RRP) and active fractions of RRP. Next, we constructed a surgically established mouse model and a hypoxia-reoxygenation (HR)-stimulated liver sinusoidal endothelial cells (LSECs) model to explore the underlying mechanism of RRP against HIRI through transcriptomics and multiple molecular biology experiments.
After identifying active ingredients in RRP, we observed that RRP and its factions effectively restored LSECs fenestration and improved inflammation, cellular swelling and vascular continuity in the hepatic sinusoidal region during HIRI. Transcriptomic results revealed that RRP might reverse HIRI-induced senescence through the NOTCH signaling pathway and cell categorization further showed that the senescent cell population in HIRI liver was primarily LSECs rather than other cell types. Different RRP, especially RRP glucoside (RRP), improved LSECs senescence and suppressed the expression of pro-inflammatory SASP genes either induced by HR insult or NOTCH1 activator, which was accompanied with the inhibition of LRP1-NOTCH1-C/EBPβ pathways. Additionally, the specific inhibition of NOTCH1 by siRNA synergistically enhanced the hepatoprotective effect of RRP. The ChIP-qPCR results further showed that C/EBPβ was enriched at the promoter of a representative SASP, Il-1β, in hypoxic LSECs but was significantly inhibited by RRP.
Our study not only clarified the potential mechanism of RRP active extractions in alleviating HIRI, but also highlighted RRP was the main component of RRP that exerted anti-aging and anti-HIRI effects, providing a fresh perspective on the use of RRP to improve HIRI.
肝缺血再灌注损伤（HIRI）在广泛肝切除术中很常见，涉及复杂的机制。细胞衰老已被认为是包括 HIRI 在内的肝损伤的一个因素，其表现为一种称为衰老相关分泌表型（SASP）的促炎表型。熟地黄（RRP）是一种常用的中药，具有保肝、抗衰老和抗氧化作用。尽管它有公认的益处，但 RRP 通过调节细胞衰老来阻碍 HIRI 进展的具体机制以及从 RRP 中鉴定出最有效的抗衰老提取物仍然不清楚。
在这里，我们首先应用不同的化学分析方法来鉴定 RRP 水提物（RRP）和 RRP 的活性部分。接下来，我们构建了一种手术建立的小鼠模型和一种缺氧再复氧（HR）刺激的肝窦内皮细胞（LSEC）模型，通过转录组学和多种分子生物学实验来探讨 RRP 对 HIRI 的潜在机制。
在鉴定 RRP 的活性成分后，我们观察到 RRP 及其分数有效地恢复了 LSEC 的窗孔，并改善了 HIRI 期间肝窦区的炎症、细胞肿胀和血管连续性。转录组学结果表明，RRP 可能通过 NOTCH 信号通路逆转 HIRI 诱导的衰老，细胞分类进一步表明，HIRI 肝脏中的衰老细胞群体主要是 LSEC，而不是其他细胞类型。不同的 RRP，特别是 RRP 糖苷（RRP），改善了 LSEC 的衰老，并抑制了 HR 损伤或 NOTCH1 激活诱导的促炎 SASP 基因的表达，同时抑制了 LRP1-NOTCH1-C/EBPβ 途径。此外，通过 siRNA 特异性抑制 NOTCH1 可协同增强 RRP 的肝保护作用。ChIP-qPCR 结果进一步表明，C/EBPβ在缺氧 LSEC 中 IL-1β等代表性 SASP 的启动子处富集，但 RRP 可显著抑制其富集。
我们的研究不仅阐明了 RRP 活性提取物缓解 HIRI 的潜在机制，还强调了 RRP 是发挥抗衰老和抗 HIRI 作用的 RRP 的主要成分，为使用 RRP 改善 HIRI 提供了新的视角。
