Major Pathways of Polymyxin-Induced Apoptosis in Rat Kidney Proximal Tubular Cells
Major Pathways of Polymyxin-Induced Apoptosis in Rat Kidney Proximal Tubular Cells
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DOI：
10.1128/aac.04869-14
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发表时间：
2015-04-01
影响因子：
4.9
通讯作者：
Li, Jian
中科院分区：
文献类型：
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作者：
Azad, Mohammad A. K.;Akter, Jesmin;Li, Jian
确定与多粘菌素引起的肾毒性相关的凋亡细胞死亡的相关途径，对于制定改善这种剂量限制性副作用的策略和开发新的更安全的多粘菌素至关重要。本研究的主要目的是确定多粘菌素诱导培养大鼠肾近端小管细胞（NRK-52E）凋亡的主要途径。Caspase-3、-8和-9在多粘菌素B处理下呈浓度依赖性激活。多粘菌素B处理后，FasL的表达和线粒体形态的变形呈浓度和时间依赖性。1.0 mM多粘菌素B作用8 h后，丝状线粒体（形态规则）细胞的比例为56.2% +/- 9.7% （n = 3）。当多粘菌素B浓度增加到2.0 mM时，这一比例下降到30.7% +/- 7.5%。与未处理的对照组相比，1.0 mM多粘菌素B处理24 h （n = 3）的细胞线粒体膜电位（类似于psi(m)）下降到14.1% +/- 2.9%。同时，还观察到线粒体超氧化物的浓度和时间依赖性生产。本研究首次证明了多粘菌素诱导的肾小管细胞凋亡是通过死亡受体和线粒体途径介导的。它不仅为改善多粘菌素引起的肾毒性提供了关键信息，而且为发现新的更安全的抗革兰氏阴性“超级细菌”的多粘菌素类抗生素提供了关键信息。
Identifying the pathways involved in the apoptotic cell death that is associated with polymyxin-induced nephrotoxicity is crucial for the development of strategies to ameliorate this dose-limiting side effect and for the development of novel safer polymyxins. The primary aim of this study was to identify the major pathways which lead to polymyxin-induced apoptosis in cultured rat kidney proximal tubular cells (NRK-52E). Caspase-3, -8, and -9 were activated by polymyxin B treatment in a concentration-dependent manner. Concentration-and time-dependent expression of FasL and deformation of mitochondrial morphology were revealed following polymyxin B treatment. The proportion of cells with filamentous mitochondria (regular morphology) following an 8-h treatment with 1.0 mM polymyxin B was 56.2% +/- 9.7% (n = 3). This was decreased to 30.7% +/- 7.5% when the polymyxin B concentration was increased to 2.0 mM. The mitochondrial membrane potential (similar to psi(m)) decreased to 14.1% +/- 2.9% in the cells treated with 1.0 mM polymyxin B for 24 h (n = 3) compared to that in the untreated control group. Concomitantly, concentration-and time-dependent production of mitochondrial superoxide was also observed. This study is the first to have demonstrated that polymyxin-induced apoptosis is mediated through both the death receptor and mitochondrial pathways in cultured renal tubular cells. It provides key information not only for the amelioration of polymyxin-induced nephrotoxicity but also for the discovery of novel safer polymyxin-like antibiotics against Gram-negative "superbugs."