Department of Cell Biology and Anatomy, Hamamatsu University School of Medicine, 1-20-1, Handayama, Hamamatsu 431-3192, Japan.
J Biol Chem. 2012 Feb 17;287(8):5290-300. doi: 10.1074/jbc.M111.316877. Epub 2011 Dec 29.
Phosphatidylcholine (PC) is the most abundant component of lipid bilayers and exists in various molecular forms, through combinations of two acylated fatty acids. Arachidonic acid (AA)-containing PC (AA-PC) can be a source of AA, which is a crucial mediator of synaptic transmission and intracellular signaling. However, the distribution of AA-PC within neurons has not been indicated. In the present study, we used imaging mass spectrometry to characterize the distribution of PC species in cultured neurons of superior cervical ganglia. Intriguingly, PC species exhibited a unique distribution that was dependent on the acyl chains at the sn-2 position. In particular, we found that AA-PC is enriched within the axon and is distributed across a proximal-to-distal gradient. Inhibitors of actin dynamics (cytochalasin D and phallacidin) disrupted this gradient. This is the first report of the gradual distribution of AA-PC along the axon and its association with actin dynamics.
磷脂酰胆碱（PC）是脂质双层中最丰富的成分，通过两种酰化脂肪酸的组合存在于各种分子形式中。含有花生四烯酸（AA）的 PC（AA-PC）可以作为 AA 的来源，AA 是突触传递和细胞内信号转导的关键介质。然而，神经元内 AA-PC 的分布尚未确定。在本研究中，我们使用成像质谱法来描述培养的颈上交感神经节神经元中 PC 种类的分布。有趣的是，PC 种类表现出一种独特的分布，这种分布依赖于 sn-2 位置上的酰基链。具体而言，我们发现 AA-PC 在轴突中富集，并呈近端到远端的梯度分布。肌动蛋白动力学抑制剂（细胞松弛素 D 和鬼笔环肽）破坏了这种梯度。这是 AA-PC 沿着轴突的逐渐分布及其与肌动蛋白动力学相关的首次报道。
