The molecular assembly of cells depends not only on the balance between anabolism and catabolism, but to a large degree on the building blocks available in the environment. For cultured mammalian cells, this is largely determined by the composition of the applied growth medium. Here we study the impact of lipids in the medium on mitochondrial membrane architecture and function by combining LC-MS/MS lipidomics and functional tests with lipid supplementation experiments in an otherwise serum- and lipid-free cell culture model. We demonstrate that the composition of mitochondrial cardiolipins strongly depends on the lipid environment in cultured cells and favours the incorporation of essential linoleic acid over other fatty acids. Simultaneously, the mitochondrial respiratory Complex I activity was altered, whereas the matrix-localized enzyme citrate synthase was unaffected. This raises the question on a link between membrane composition and respiratory control. In summary, we found a strong dependency of central mitochondrial features on the type of lipids contained in the growth medium. This underlines the importance of considering these factors when using and establishing cell culture models in biomedical research.

中文翻译：

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脂肪酰基可用性调节 HeLa 细胞中的心磷脂组成并改变线粒体功能。

细胞的分子组装不仅取决于合成代谢和分解代谢之间的平衡，而且在很大程度上取决于环境中可用的构建模块。对于培养的哺乳动物细胞，这很大程度上取决于所用生长培养基的成分。在这里，我们通过将 LC-MS/MS 脂质组学和功能测试与脂质补充实验相结合，在无血清和无脂质的细胞培养模型中研究培养基中的脂质对线粒体膜结构和功能的影响。我们证明，线粒体心磷脂的组成强烈依赖于培养细胞中的脂质环境，并且与其他脂肪酸相比，有利于必需亚油酸的掺入。同时，线粒体呼吸复合物 I 活性发生改变，而基质定位酶柠檬酸合酶不受影响。这就提出了膜成分与呼吸控制之间联系的问题。总之，我们发现中央线粒体特征对生长培养基中所含脂质的类型有很强的依赖性。这强调了在生物医学研究中使用和建立细胞培养模型时考虑这些因素的重要性。