Poricoic acid A activates AMPK to attenuate fibroblast activation and abnormal extracellular matrix remodelling in renal fibrosis
Poricoic acid A activates AMPK to attenuate fibroblast activation and abnormal extracellular matrix remodelling in renal fibrosis
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茯苓酸 A 激活 AMPK 减弱肾纤维化过程中成纤维细胞的活化和异常细胞外基质重塑
DOI：
10.1016/j.phymed.2020.153232
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发表时间：
2020-07-01
期刊：
影响因子：
7.9
通讯作者：
Zhao, Ying-Yong
中科院分区：
文献类型：
--
作者：
Chen, Dan-Qian;Wang, Yan-Ni;Zhao, Ying-Yong
背景：在慢性肾脏疾病中，虽然预防纤维化是有益的，但很少有专门针对纤维化发生的干预措施。茯苓中分离的茯苓酸A （PAA）具有抗肾纤维化作用，但其作用机制尚不清楚。目的：分离PAA，探讨其在肾纤维化中的作用及其机制。研究设计：采用单侧输尿管梗阻（UUO）和5/6肾切除术（Nx）动物模型和tgf - β 1诱导的肾成纤维细胞（NRK-49F）研究PAA的抗纤维化活性及其机制。方法：采用Western blots、qRT-PCR、免疫荧光染色、共免疫沉淀、分子对接等方法。通过在UUO模型和培养的NRK-49F细胞中敲低和敲入腺苷单磷酸活化蛋白激酶（AMPK）来验证PAA的作用机制。结果：在Nx和UUO模型中，PAA通过特异性刺激AMPK和抑制Smad3改善肾功能，减轻纤维化。AMPK活性降低与Smad3诱导、成纤维细胞激活以及人肾穿刺样本和培养的NRK-49F细胞中细胞外基质（ECM）的积累和异常重构有关。PAA以剂量依赖的方式刺激AMPK活性并减少纤维化，从而表明AMPK是PAA发挥其抗纤维化作用所必需的。AMPK缺乏降低了PAA的抗纤维化作用，而AMPK过表达增强了其抗纤维化作用。结论：PAA激活AMPK，进一步特异性抑制Smad3，通过阻止ECM的异常积累和重塑，促进成纤维细胞的失活来抑制纤维化。
Background: In chronic kidney disease, although fibrosis prevention is beneficial, few interventions are available that specifically target fibrogenesis. Poricoic acid A (PAA) isolated from Poria cocos exhibits anti-fibrotic effects in the kidney, however the underlying mechanisms remain obscure.Purpose: We isolated PAA and investigated its effects and the underlying mechanisms in renal fibrosis.Study design: Unilateral ureteral obstruction (UUO) and 5/6 nephrectomy (Nx) animal models and TGF-beta 1-induced renal fibroblasts (NRK-49F) were used to investigate the anti-fibrotic activity of PAA and its underlying mechanisms.Methods: Western blots, qRT-PCR, immunofluorescence staining, co-immunoprecipitation and molecular docking methods were used. Knock-down and knock-in of adenosine monophosphate-activated protein kinase (AMPK) in the UUO model and cultured NRK-49F cells were employed to verify the mechanisms of action of PAA.Results: PAA improved renal function and alleviated fibrosis by stimulating AMPK and inhibiting Smad3 specifically in Nx and UUO models. Reduced AMPK activity was associated with Smad3 induction, fibroblast activation, and the accumulation and aberrant remodelling of extracellular matrix (ECM) in human renal puncture samples and cultured NRK-49F cells. PAA stimulated AMPK activity and decreased fibrosis in a dose-dependent manner, thus showing that AMPK was essential for PAA to exert its anti-fibrotic effects. AMPK deficiency reduced the anti-fibrotic effects of PAA, while AMPK overexpression enhanced its effect.Conclusion: PAA activated AMPK and further inhibited Smad3 specifically to suppress fibrosis by preventing aberrant ECM accumulation and remodelling and facilitating the deactivation of fibroblasts.