Data from: Acute maneb exposure significantly alters both glycolysis and mitochondrial function in neuroblastoma cells

The pesticides paraquat (PQ) and maneb (MB) have been described as environmental risk factors for Parkinson’s disease (PD), with mechanisms associated with mitochondrial dysfunction and reactive oxygen species generation. A combined exposure of PQ and MB in murine models and neuroblastoma cells has been utilized to further advance understanding of the PD phenotype. MB acts as a redox modulator through alkylation of protein thiols and has been previously characterized to inhibit complex III of the electron transport chain and uncouple the mitochondrial proton gradient. The purpose of this study was to analyze ATP-linked respiration and glycolysis in human neuroblastoma cells utilizing the Seahorse extracellular flux platform. Employing an acute, subtoxic exposure of MB, this investigation revealed a MB-mediated decrease in mitochondrial oxygen consumption at baseline and maximal respiration, with inhibition of ATP synthesis and coupling efficiency. Additionally, MB-treated cells showed an increase in nonmitochondrial respiration and proton leak. Further investigation into mitochondrial fuel flex revealed an elimination of fuel flexibility across all 3 major substrates, with a decrease in pyruvate capacity as well as glutamine dependency. Analyses of glycolytic function showed a substantial decrease in glycolytic acidification caused by lactic acid export. This inhibition of glycolytic parameters was also observed after titrating the MB dose as low as 6 μM, and appears to be dependent on the dithiocarbamate functional group, with manganese possibly potentiating the effect. Further studies into cellular ATP and NAD levels revealed a drastic decrease in cells treated with MB. In summary, MB significantly impacted both aerobic and anaerobic energy production; therefore, further characterization of MB’s effect on cellular energetics may provide insight into the specificity of PD to dopaminergic neurons.

除草剂百草枯（paraquat, PQ）与代森锰（maneb, MB）已被认定为帕金森病（Parkinson’s disease, PD）的环境风险因素，其致病机制与线粒体功能障碍及活性氧（reactive oxygen species, ROS）生成相关。在小鼠模型与神经母细胞瘤细胞中联合暴露PQ与MB，可用于进一步加深对PD表型的理解。MB可通过对蛋白质巯基的烷基化作用充当氧化还原调节剂，此前已有研究证实其可抑制电子传递链复合体III，并解偶联线粒体质子梯度。本研究旨在利用海马细胞外通量检测平台（Seahorse extracellular flux platform），检测人神经母细胞瘤细胞中的ATP耦联呼吸与糖酵解水平。通过采用急性亚毒性剂量的MB暴露，本研究发现MB可介导基础呼吸与最大呼吸状态下的线粒体氧消耗降低，并抑制ATP合成与耦联效率。此外，经MB处理的细胞呈现非线粒体呼吸与质子渗漏水平升高的现象。针对线粒体燃料灵活性的进一步分析显示，三种主要代谢底物的燃料灵活性均被消除，同时丙酮酸代谢能力降低、谷氨酰胺依赖性下降。糖酵解功能分析结果表明，由乳酸外排介导的糖酵解酸化水平显著降低。即使将MB剂量滴定至6 μM，仍可观察到糖酵解相关参数受到抑制，且该效应似乎依赖于二硫代氨基甲酸酯官能团，锰元素可能增强这一作用。针对细胞内ATP与NAD水平的检测进一步显示，MB处理组细胞的ATP与NAD水平大幅下降。综上，MB可显著影响细胞有氧与无氧能量生成过程；因此，对MB影响细胞能量代谢的机制进行深入解析，或可为阐明PD对多巴胺能神经元的特异性损伤提供新的见解。