Zhou Ziang, Wang Yumeng, Xing Yu, Pan Shuman, Wang Wanru, Yang Jie, Wu Wenyuan, Zhou Jie, Huang Luyi, Liang Qiongdan, Zhang Dongmei, Kong Lingdong
State Key Laboratory of Pharmaceutical Biotechnology, Institute of Chinese Medicine, Nanjing Drum Tower Hospital, School of Life Sciences, Nanjing University, Nanjing 210023, China.
Pharmaceuticals (Basel). 2024 Oct 23;17(11):1416. doi: 10.3390/ph17111416.
BACKGROUND/OBJECTIVES: High fructose has been implicated as an important trigger of kidney inflammation in patients and experimental models. Magnolol, isolated from , has an anti-inflammatory effect, but its protective role in podocytes remains underexplored. This study explored the protective effects and underlying mechanism of magnolol against high fructose-induced podocyte inflammation.
The effects of magnolol on high fructose-induced podocyte inflammation were assessed in male Sprague Dawley rats administered 10% (/) fructose water for 12 weeks and heat-sensitive human podocyte cell lines (HPCs) exposed to 5 mM fructose. Podocyte foot processes were examined using transmission electron microscopy. The expression levels of nephrin, podocin, tumor necrosis factor-α (TNF-α), Notch1 intracellular domain (NICD1), triokinase/FMN cyclase (TKFC), specificity protein 1 (Sp1) and histone deacetylase 4 (HDAC4) were determined by Western blot, immunofluorescence and real-time quantitative polymerase chain reaction (qRT-PCR). The chromatin immunoprecipitation (ChIP) assay was performed to evaluate the interaction between Sp1 and the promoter region of HDAC4.
Magnolol mitigated the impairment of glomerular filtration function in high fructose-fed rats. Besides, it significantly alleviated the inflammatory responses in glomeruli and HPCs, evidenced by decreased protein levels of TNF-α and NICD1. Increased protein levels of TKFC, Sp1 and HDAC4 were observed in high fructose-stimulated HPCs and rat glomeruli. TMP195, an HDAC4 inhibitor, reduced TNF-α and NICD1 protein levels in high fructose-exposed HPCs. The increased Sp1 was shown to associate with the promoter region of HDAC4, promoting HDAC4 protein expression in high fructose-exposed HPCs. The knockdown of TKFC in HPCs by siRNA decreased Sp1, HDAC4 and NICD1 protein levels, alleviating podocyte inflammatory response. Furthermore, magnolol inhibited TKFC/Sp1/HDAC4/Notch1 activation in vivo and in vitro.
Magnolol attenuated high fructose-induced podocyte inflammation possibly through the suppression of TKFC/Sp1/HDAC4/Notch1 activation, providing new evidence for its potential role in podocyte protection.
背景/目的：在患者和实验模型中，高果糖已被认为是肾脏炎症的一个重要触发因素。从[来源未提及]中分离出的厚朴酚具有抗炎作用，但其在足细胞中的保护作用仍未得到充分研究。本研究探讨了厚朴酚对高果糖诱导的足细胞炎症的保护作用及其潜在机制。
在给予10%（/）果糖水12周的雄性Sprague Dawley大鼠以及暴露于5 mM果糖的热敏性人足细胞系（HPCs）中，评估厚朴酚对高果糖诱导的足细胞炎症的影响。使用透射电子显微镜检查足细胞足突。通过蛋白质印迹法、免疫荧光法和实时定量聚合酶链反应（qRT-PCR）测定nephrin、podocin、肿瘤坏死因子-α（TNF-α）、Notch1细胞内结构域（NICD1）、三联激酶/FMN环化酶（TKFC）、特异性蛋白1（Sp1）和组蛋白去乙酰化酶4（HDAC4）的表达水平。进行染色质免疫沉淀（ChIP）分析以评估Sp1与HDAC4启动子区域之间的相互作用。
厚朴酚减轻了高果糖喂养大鼠的肾小球滤过功能损害。此外，它显著减轻了肾小球和HPCs中的炎症反应，TNF-α和NICD1蛋白水平降低证明了这一点。在高果糖刺激的HPCs和大鼠肾小球中观察到TKFC、Sp1和HDAC4蛋白水平升高。HDAC4抑制剂TMP195降低了高果糖暴露的HPCs中TNF-α和NICD1蛋白水平。结果显示，升高的Sp1与HDAC4的启动子区域相关联，促进了高果糖暴露的HPCs中HDAC4蛋白的表达。通过小干扰RNA敲低HPCs中的TKFC可降低Sp1、HDAC4和NICD1蛋白水平，减轻足细胞炎症反应。此外，厚朴酚在体内和体外均抑制TKFC/Sp1/HDAC4/Notch1的激活。
厚朴酚可能通过抑制TKFC/Sp1/HDAC4/Notch1的激活减轻高果糖诱导的足细胞炎症，为其在足细胞保护中的潜在作用提供了新的证据。
