Novosibirsk State University, Novosibirsk, 630090, Russia; Institute of Cytology and Genetics, Russian Academy of Sciences, Novosibirsk, 630090, Russia; Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk, 630090, Russia.
Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk, 630090, Russia.
Arch Biochem Biophys. 2020 Oct 15;692:108532. doi: 10.1016/j.abb.2020.108532. Epub 2020 Aug 11.
Fatty acid uptake and accumulation in lipid droplets are essential processes of lipid metabolism. Oocyte in vitro culture in media enriched with fatty acid is used to modify the lipid content and composition, aiming to study the consequences of obesity and enhance cell cryotolerance. We applied Raman spectroscopy and deuterium labeling approach to quantify stearic acid uptake and investigate its incorporation within oocytes. Our data suggest that deuterium labeling does not affect oocyte maturation rates. The efficiency of deuterated stearic acid (dSA) uptake was shown to decrease with the increase of its concentration in culture medium and the duration of in vitro culture. The molar ratio between dSA and bovine serum albumin has no significant effect on the dSA uptake for 200 μM but modifies concentration dependence of the lipid uptake. dSA accumulates in all the lipid droplets inside oocytes. Different lipid droplets within the same oocyte exhibit different concentrations of dSA. The scatter in the dSA concentration in lipid droplets decreases with the culture time. Using dSA as an example, we provide a comprehensive description of how fatty acid concentration, its molar ratio versus bovine serum albumin, and culture time affect the uptake of the fatty acids in oocytes. Raman microspectroscopy of deuterium-labeled fatty acids is a nondestructive tool providing information about fatty acid uptake and heterogeneity of their accumulation between lipid droplets within the single oocyte.
脂肪酸摄取和在脂滴中的积累是脂质代谢的基本过程。在富含脂肪酸的培养基中进行体外培养卵母细胞，旨在改变脂质含量和组成，以研究肥胖的后果并增强细胞的抗冻能力。我们应用拉曼光谱和氘标记方法来定量硬脂酸摄取并研究其在卵母细胞内的掺入。我们的数据表明，氘标记不会影响卵母细胞成熟率。在体外培养过程中，随着培养基中硬脂酸浓度的增加和培养时间的延长，氘化硬脂酸（dSA）的摄取效率降低。对于 200μM 的 dSA，dSA 与牛血清白蛋白的摩尔比对 dSA 的摄取没有显著影响，但会改变脂质摄取的浓度依赖性。dSA 积累在卵母细胞内的所有脂滴中。同一卵母细胞内的不同脂滴显示不同浓度的 dSA。脂滴中 dSA 浓度的分散度随着培养时间的延长而降低。以 dSA 为例，我们全面描述了脂肪酸浓度、其与牛血清白蛋白的摩尔比以及培养时间如何影响卵母细胞中脂肪酸的摄取。氘标记脂肪酸的拉曼微光谱是一种非破坏性工具，可提供有关脂肪酸摄取及其在单个卵母细胞内的脂滴之间的不均匀积累的信息。
