The metabolic properties of live cells are very susceptible to intra- or extra-cellular perturbations, making their measurements challenging tasks. We show that the dynamics of lipid droplets (LDs) carry information to measure the lipid metabolism of live cells. Coherent anti-Stokes Raman scattering microscopy was used to statistically quantify LD dynamics in living cells in a label-free manner. We introduce dynamic signatures of cells derived from the LD displacement, speed, travel length, and directionality, which allows for the detection of cellular changes induced by stimuli such as fluorescent labeling, temperature change, starvation, and chemical treatment. Histogram fittings of the dynamic signatures using lognormal distribution functions provide quantification of changes in cellular metabolic states. The LD dynamics also enable separation of subpopulations of LDs correlated with different functions. We demonstrate that LD dynamics are new markers to quantify the metabolic changes in live cells.

中文翻译：

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脂滴的动态特征作为量化细胞代谢变化的新标记

活细胞的代谢特性非常容易受到细胞内或细胞外扰动的影响，从而使其测量成为一项艰巨的任务。我们显示脂质滴（LDs）的动力学携带信息来测量活细胞的脂质代谢。相干抗斯托克斯拉曼散射显微镜用于以无标记的方式统计量化活细胞中的LD动态。我们介绍了从LD位移，速度，行进长度和方向性得出的细胞动态特征，它可以检测由刺激引起的细胞变化，例如荧光标记，温度变化，饥饿和化学处理。使用对数正态分布函数对动态签名进行直方图拟合，可以量化细胞代谢状态的变化。LD动态还可以实现与不同功能相关的LD亚群的分离。我们证明LD动态是量化活细胞代谢变化的新标记。