https://ror.org/03mstc592 Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
Faculty of Biosciences, Candidate for Joint PhD Degree Between EMBL and Heidelberg University, Heidelberg, Germany.
Life Sci Alliance. 2024 Feb 28;7(5). doi: 10.26508/lsa.202402622. Print 2024 May.
During development, different tissues acquire distinct lipotypes that are coupled to tissue function and homeostasis. In the brain, where complex membrane trafficking systems are required for neural function, specific glycerophospholipids, sphingolipids, and cholesterol are highly abundant, and defective lipid metabolism is associated with abnormal neural development and neurodegenerative disease. Notably, the production of specific lipotypes requires appropriate programming of the underlying lipid metabolic machinery during development, but when and how this occurs is unclear. To address this, we used high-resolution MS lipidomics to generate an extensive time-resolved resource of mouse brain development covering early embryonic and postnatal stages. This revealed a distinct bifurcation in the establishment of the neural lipotype, whereby the canonical lipid biomarkers 22:6-glycerophospholipids and 18:0-sphingolipids begin to be produced in utero, whereas cholesterol attains its characteristic high levels after birth. Using the resource as a reference, we next examined to which extent this can be recapitulated by commonly used protocols for in vitro neuronal differentiation of stem cells. Here, we found that the programming of the lipid metabolic machinery is incomplete and that stem cell-derived cells can only partially acquire a neural lipotype when the cell culture media is supplemented with brain-specific lipid precursors. Altogether, our work provides an extensive lipidomic resource for early mouse brain development and highlights a potential caveat when using stem cell-derived neuronal progenitors for mechanistic studies of lipid biochemistry, membrane biology and biophysics, which nonetheless can be mitigated by further optimizing in vitro differentiation protocols.
在发育过程中，不同的组织获得与组织功能和内稳态相关的独特脂质类型。在大脑中，复杂的膜运输系统是神经功能所必需的，特定的甘油磷脂、鞘脂和胆固醇含量非常丰富，脂质代谢缺陷与异常的神经发育和神经退行性疾病有关。值得注意的是，特定脂质类型的产生需要在发育过程中适当规划潜在的脂质代谢机制，但这是何时以及如何发生的尚不清楚。为了解决这个问题，我们使用高分辨率 MS 脂质组学生成了一个广泛的时间分辨的小鼠大脑发育资源，涵盖了早期胚胎和出生后阶段。这揭示了神经脂质类型建立的明显分叉，其中典型的脂质生物标志物 22:6-甘油磷脂和 18:0-鞘脂开始在子宫内产生，而胆固醇在出生后达到其特征性的高水平。利用该资源作为参考，我们接下来检查了这在干细胞体外神经元分化的常用方案中可以在多大程度上被重现。在这里，我们发现脂质代谢机制的编程是不完整的，当细胞培养基中补充大脑特异性脂质前体时，干细胞衍生的细胞只能部分获得神经脂质类型。总的来说，我们的工作为早期小鼠大脑发育提供了广泛的脂质组学资源，并强调了当使用干细胞衍生的神经元祖细胞进行脂质生物化学、膜生物学和生物物理学的机制研究时存在潜在的注意事项，但通过进一步优化体外分化方案可以减轻这种情况。
