Beneficial Effects of Myo-Inositol Oxygenase Deficiency in Cisplatin-Induced AKI
Beneficial Effects of Myo-Inositol Oxygenase Deficiency in Cisplatin-Induced AKI
复制标题
DOI：
10.1681/asn.2016070744
复制
发表时间：
2017-05-01
影响因子：
13.6
通讯作者：
Kanwart, Yashpal S.
中科院分区：
文献类型：
--
作者：
Dutta, Rajesh K.;Kondeti, Vinay K.;Kanwart, Yashpal S.
近端小管酶肌醇加氧酶（MIOX）的过表达在体外诱导氧化应激。然而，MIOX与肾小管病理学的相关性仍然是个谜。为了研究MIOX在顺铂诱导的肾小管阿基中的作用，我们分别产生了肾小管特异性MIOX过表达或敲除的条件性MIOX过表达转基因（MIOX-TG）小鼠和MIOX敲除（MIOX-/-）小鼠。与顺铂治疗的野生型（WT）小鼠相比，顺铂治疗的MIOX-TG小鼠的尿素，肌酐和KIM-1水平增加更大，肾小管损伤和凋亡更多，但这些影响在顺铂治疗的MIOX-/-小鼠中减弱。类似地，在顺铂处理后，MIOX-TG小鼠具有最高的Bax、裂解的半胱天冬酶-3和NADPH氧化酶-4表达和活性氧（ROS）产生的肾水平，而MIOX-/-小鼠具有最低的肾水平。在体外，顺铂剂量依赖性地增加LLC-PK 1细胞中的ROS生成。此外，MIOX在这些细胞中的过表达加重顺铂诱导的ROS产生和GSH与氧化型GSH的比例的扰动，而MIOX-siRNA或N-乙酰半胱氨酸处理减弱了这些作用。此外，顺铂诱导的WT小鼠中p53活化、NF-κ B与DNA结合和NF-κ B核转位的增强在MIOX-TG小鼠中加剧，但在MIOX-/-小鼠中不存在。在体外，MIOX-siRNA或NAC处理减少了顺铂诱导的p53表达的剂量依赖性增加。我们还观察到顺铂处理的MIOX-TG小鼠肾脏中炎性细胞的显著流入和细胞因子的上调。最后，WT小鼠基因组DNA分析显示顺铂诱导的MIOX启动子低甲基化。这些数据表明，MIOX过表达加剧，而MIOX基因破坏保护免受顺铂诱导的阿基。
Overexpression of the proximal tubular enzyme myo-inositol oxygenase (MIOX) induces oxidant stress in vitro. However, the relevance of MIOX to tubular pathobiology remains enigmatic. To investigate the role of MIOX in cisplatin-induced tubular AKI, we generated conditional MIOX-overexpressing transgenic (MIOX-TG) mice and MIOX-knockout (MIOX-/-) mice with tubule-specific MIOX overexpression or knockout, respectively. Compared with cisplatin-treated wild-type (WT) mice, cisplatin-treated MIOX-TG mice had even greater increases in urea, creatinine, and KIM-1 levels and more tubular injury and apoptosis, but these effects were attenuated in cisplatin-treated MIOX-/- mice. Similarly, MIOX-TG mice had the highest and MIOX-/- mice had the lowest renal levels of Bax, cleaved caspase-3, and NADPH oxidase-4 expression and reactive oxygen species (ROS) generation after cisplatin treatment. In vitro, cisplatin dose dependently increased ROS generation in LLC-PK1 cells. Furthermore, MIOX overexpression in these cells accentuated cisplatin-induced ROS generation and perturbations in the ratio of GSH to oxidized GSH, whereas MIOX-siRNA or N-acetyl cysteine treatment attenuated these effects. Additionally, the cisplatin-induced enhancement of p53 activation, NF-kappa B binding to DNA, and NF-kappa B nuclear translocation in WT mice was exacerbated in MIOX-TG mice but absent in MIOX-/- mice. In vitro, MIOX-si RNA or NAC treatment reduced the dose-dependent increase in p53 expression induced by cisplatin. We also observed a remarkable influx of inflammatory cells and upregulation of cytokines in kidneys of cisplatin-treated MIOX-TG mice. Finally, analysis of genomic DNA in WT mice revealed cisplatin-induced hypomethylation of the MIOX promoter. These data suggest that MIOX overexpression exacerbates, whereas MIOX gene disruption protects against, cisplatin-induced AKI.