13C- and 15N-Labeling Strategies Combined with Mass Spectrometry Comprehensively Quantify Phospholipid Dynamics in C. elegans.
13C- and 15N-Labeling Strategies Combined with Mass Spectrometry Comprehensively Quantify Phospholipid Dynamics in C. elegans.
复制标题
DOI：
10.1371/journal.pone.0141850
复制
发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Olsen CP
中科院分区：
文献类型：
--
作者：
Dancy BC;Chen SW;Drechsler R;Gafken PR;Olsen CP
膜定义细胞和细胞器的边界，这一功能对所有生命系统都至关重要。与其他生物分子一样，膜脂质是动态维持的，但目前的方法对于监测活体动物的脂质动态非常有限。我们在C中开发了新的策略。elegans将13 C和15 N稳定同位素与质谱法相结合，以直接定量膜的单个脂肪酸和完整磷脂的补充率。使用磷脂动力学的多个测量，我们发现，磷脂池被迅速取代，其速率几乎是中性脂质群体的两倍。事实上，我们的分析表明，大多数膜脂每天都在更换。此外，我们发现，硬脂酰辅酶A去饱和酶（SCD），在多不饱和脂肪酸生产的关键酶，发挥意想不到的作用，在影响膜的整体维护率SCD消耗影响几乎所有的膜脂质的营业额。此外，如通过具有SCD RNAi的LC-MS/MS所定义的受损的膜维持导致活性磷脂重塑，我们预测这对于减轻这些动物中膜维持减少的影响至关重要。这些组合方法不仅确定了SCD对膜影响的新方面，而且它们还具有揭示许多未发现的磷脂代谢调节剂的巨大潜力。
Membranes define cellular and organelle boundaries, a function that is critical to all living systems. Like other biomolecules, membrane lipids are dynamically maintained, but current methods are extremely limited for monitoring lipid dynamics in living animals. We developed novel strategies in C. elegans combining 13C and 15N stable isotopes with mass spectrometry to directly quantify the replenishment rates of the individual fatty acids and intact phospholipids of the membrane. Using multiple measurements of phospholipid dynamics, we found that the phospholipid pools are replaced rapidly and at rates nearly double the turnover measured for neutral lipid populations. In fact, our analysis shows that the majority of membrane lipids are replaced each day. Furthermore, we found that stearoyl-CoA desaturases (SCDs), critical enzymes in polyunsaturated fatty acid production, play an unexpected role in influencing the overall rates of membrane maintenance as SCD depletion affected the turnover of nearly all membrane lipids. Additionally, the compromised membrane maintenance as defined by LC-MS/MS with SCD RNAi resulted in active phospholipid remodeling that we predict is critical to alleviate the impact of reduced membrane maintenance in these animals. Not only have these combined methodologies identified new facets of the impact of SCDs on the membrane, but they also have great potential to reveal many undiscovered regulators of phospholipid metabolism.