Dynamic 13C Flux Analysis Captures the Reorganization of Adipocyte Glucose Metabolism in Response to Insulin
Dynamic 13C Flux Analysis Captures the Reorganization of Adipocyte Glucose Metabolism in Response to Insulin
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DOI：
10.1016/j.isci.2020.100855
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发表时间：
2020-02-21
期刊：
影响因子：
5.8
通讯作者：
Kuroda, Shinya
中科院分区：
文献类型：
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作者：
Quek, Lake-Ee;Krycer, James R.;Kuroda, Shinya
细胞代谢是动态的，但通过稳定同位素示踪剂量化非稳定代谢通量提出了独特的计算挑战。在这里，我们开发了一个高效的c -13示踪剂动态代谢通量分析（13C-DMFA）框架，用于模拟随时间变化的中心碳通量。利用6样条对通量参数化系统进行了推广，提高了优化算法的稳定性。为了证明这一概念，我们研究了3T3-L1培养的脂肪细胞如何在胰岛素的作用下急性代谢葡萄糖。胰岛素迅速刺激葡萄糖摄取，但细胞内通路的反应速度和幅度不同。低糖酵解的通量比上糖酵解的增加快。与三羧酸循环相比，糖酵解通量不成比例地增大和加快，乳酸是葡萄糖的主要最终产物。未发现的一系列通量动力学表明，葡萄糖分解代谢在摄取之外还受到额外的调节，以帮助将葡萄糖分流到适当的途径。这项工作证明了使用动态细胞内通量来了解代谢功能和途径调节的价值。
Cellular metabolism is dynamic, but quantifying non-steady metabolic fluxes by stable isotope tracers presents unique computational challenges. Here, we developed an efficient C-13-tracer dynamic metabolic flux analysis (13C-DMFA) framework for modeling central carbon fluxes that vary over time. We used 6-splines to generalize the flux parameterization system and to improve the stability of the optimization algorithm. As proof of concept, we investigated how 3T3-L1 cultured adipocytes acutely metabolize glucose in response to insulin. Insulin rapidly stimulates glucose uptake, but intracellular pathways responded with differing speeds and magnitudes. Fluxes in lower glycolysis increased faster than those in upper glycolysis. Glycolysis fluxes rose disproportionally larger and faster than the tricarboxylic acid cycle, with lactate a primary glucose end product. The uncovered array of flux dynamics suggests that glucose catabolism is additionally regulated beyond uptake to help shunt glucose into appropriate pathways. This work demonstrates the value of using dynamic intracellular fluxes to understand metabolic function and pathway regulation.