The Proteomic Landscape of Cysteine Oxidation That Underpins Retinoic Acid-Induced Neuronal Differentiation

The initial phases of neuronal differentiation
are key to neuronal
function. A particularly informative model to study these initial
phases are retinoic acid-stimulated SH-SY5Y cells. Although these
progressions are associated with redox-sensitive processes, it is
largely undefined how the cellular proteome underpins redox dynamics
and the management of reactive oxygen species. Here, we map the global
cysteine-based redox landscape of SH-SY5Y cells using quantitative
redox proteomics. We find evidence that redox alterations occurred
early in differentiation and affect the expression of neuronal marker
proteins and the extension of neurites. The spatiotemporal analysis
of reactive oxygen species suggests a NOX2-dependent peak in cytoplasmic
superoxide anions/hydrogen peroxide generation 2 h after retinoic
acid stimulation. At the same time point, 241 out of 275 proteins
with an altered cysteine redox state are reversibly oxidized in response
to retinoic acid. Our analyses pinpoint redox alterations of proteins
involved in the retinoic acid homeostasis and cytoskeletal dynamics.

神经元分化的初始阶段对于神经元功能的实现至关重要。研究这些初始阶段，视网膜酸刺激的SH-SY5Y细胞模型尤为富有启示。尽管这些进展与氧化还原敏感过程相关联，但关于细胞质蛋白组如何支撑氧化还原动力学以及活性氧种的管理，目前仍处于模糊不清的状态。在本研究中，我们利用定量氧化还原蛋白质组学技术，绘制了SH-SY5Y细胞中基于半胱氨酸的全球氧化还原景观图。研究发现，氧化还原状态的改变发生在分化早期，并影响神经元标志蛋白的表达以及神经突的延伸。活性氧种的空间时间分析表明，在视网膜酸刺激后2小时，细胞质中超氧阴离子/过氧化氢的生成达到NOX2依赖性的峰值。在同一时间点，275种半胱氨酸氧化还原状态改变的蛋白中有241种对视网膜酸刺激产生可逆的氧化反应。我们的分析揭示了参与视网膜酸稳态和细胞骨架动态的蛋白的氧化还原变化。