Zhang Yue, Li Chenyu, Guan Chen, Zhou Bin, Wang Lin, Yang Chengyu, Zhen Li, Dai Jie, Zhao Long, Jiang Wei, Xu Yan
Department of Nephrology, The Affiliated Hospital of Qingdao University, Qingdao, China.
Nephrologisches Zentrum, Ludwig Maximilian University of Munich, Munich, Germany.
Front Physiol. 2020 May 27;11:510. doi: 10.3389/fphys.2020.00510. eCollection 2020.
Renal tubular epithelial cell (RTEC) death and renal interstitial inflammation are the most crucial pathophysiological changes in acute kidney ischemia/reperfusion injury (IRI). The microRNA (miR)-181d family plays diverse roles in cell proliferation, apoptosis and inflammation, but its renal target and potential role in IRI are unknown. Here, we showed that the expression of miR-181d-5p decreased and Krueppel-like factor 6 (KLF6) increased in a renal cell (HK-2) model of hypoxia/reoxygenation (H/R) injury and a mouse model of renal IRI. They were mainly distributed in the renal tubules. After renal IRI, miR-181d-5p overexpression significantly inhibited inflammatory mediators, reduced apoptosis and further improved renal function. KLF6 exacerbated RTEC damage and acted as a NF-κB co-activator to aggravate the renal IRI inflammatory response. Mechanistically, KLF6 was predicted as a new potential target gene of miR-181d-5p through bioinformatic analysis and luciferase reporter assay verification. After overexpressing miR-181d-5p and inhibiting KLF6, the role of miR-181d-5p was weakened on the renal damage improvement. In conclusion, miR-181d-5p upregulation produced protective antiapoptotic and anti-inflammatory effects against IRI in kidneys and H/R injury in HK-2 cells , and these effects were achieved by targeted inhibition of KLF6. Thus, our results provide novel insights into the molecular mechanisms associated with IRI and a potential novel therapeutic target.
肾小管上皮细胞(RTEC)死亡和肾间质炎症是急性肾缺血/再灌注损伤(IRI)中最关键的病理生理变化。微小RNA(miR)-181d家族在细胞增殖、凋亡和炎症中发挥多种作用,但其在肾脏中的靶点及在IRI中的潜在作用尚不清楚。在此,我们发现,在缺氧/复氧(H/R)损伤的肾细胞(HK-2)模型和肾IRI小鼠模型中,miR-181d-5p表达降低,而Krüppel样因子6(KLF6)表达增加。它们主要分布在肾小管中。肾IRI后,miR-181d-5p过表达显著抑制炎症介质,减少细胞凋亡,并进一步改善肾功能。KLF6加剧RTEC损伤,并作为NF-κB共激活因子加重肾IRI炎症反应。机制上,通过生物信息学分析和荧光素酶报告基因检测验证,KLF6被预测为miR-181d-5p的一个新的潜在靶基因。过表达miR-181d-5p并抑制KLF6后,miR-181d-5p对肾损伤改善的作用减弱。总之,miR-181d-5p上调对肾脏IRI和HK-2细胞H/R损伤产生保护性抗凋亡和抗炎作用,这些作用是通过靶向抑制KLF6实现的。因此,我们的结果为与IRI相关的分子机制提供了新的见解以及一个潜在的新型治疗靶点。