Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, United States of America.
Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America.
PLoS Comput Biol. 2020 Apr 15;16(4):e1007773. doi: 10.1371/journal.pcbi.1007773. eCollection 2020 Apr.
Evolutionarily conserved mechanisms maintain homeostasis of essential elements, and are believed to be highly time-variant. However, current approaches measure elemental biomarkers at a few discrete time-points, ignoring complex higher-order dynamical features. To study dynamical properties of elemental homeostasis, we apply laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) to tooth samples to generate 500 temporally sequential measurements of elemental concentrations from birth to 10 years. We applied dynamical system and Information Theory-based analyses to reveal the longest-known attractor system in mammalian biology underlying the metabolism of nutrient elements, and identify distinct and consistent transitions between stable and unstable states throughout development. Extending these dynamical features to disease prediction, we find that attractor topography of nutrient metabolism is altered in amyotrophic lateral sclerosis (ALS), as early as childhood, suggesting these pathways are involved in disease risk. Mechanistic analysis was undertaken in a transgenic mouse model of ALS, where we find similar marked disruptions in elemental attractor systems as in humans. Our results demonstrate the application of a phenomological analysis of dynamical systems underlying elemental metabolism, and emphasize the utility of these measures in characterizing risk of disease.
进化保守机制维持必需元素的体内平衡,且被认为高度时变。然而,目前的方法在几个离散的时间点测量元素生物标志物,忽略了复杂的高阶动态特征。为了研究元素体内平衡的动力学特性,我们应用激光烧蚀电感耦合等离子体质谱(LA-ICP-MS)对牙齿样本进行分析,从出生到 10 岁,生成 500 个时间顺序的元素浓度测量值。我们应用动力系统和基于信息论的分析方法,揭示了哺乳动物生物学中已知的最长的营养元素代谢的吸引子系统,并确定了在整个发育过程中稳定和不稳定状态之间的独特而一致的转变。将这些动态特征扩展到疾病预测中,我们发现肌萎缩侧索硬化症(ALS)患者的营养代谢吸引子地形早在儿童时期就发生了改变,这表明这些途径与疾病风险有关。我们在肌萎缩侧索硬化症的转基因小鼠模型中进行了机制分析,发现人类和小鼠的元素吸引子系统都存在类似的明显破坏。我们的研究结果证明了对元素代谢基础下的动力系统的现象学分析的应用,并强调了这些方法在疾病风险特征中的效用。