Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada.
Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, Canada.
Int J Biochem Cell Biol. 2022 Sep;150:106264. doi: 10.1016/j.biocel.2022.106264. Epub 2022 Jul 19.
Membrane phospholipids are critical components of several signaling pathways. Maintained in a variety of asymmetric distributions, their trafficking across the membrane can be induced by intra-, extra-, and intercellular events. A familiar example is the externalization of phosphatidylserine from the inner leaflet to the outer leaflet in apoptosis, inducing phagocytosis of the soma. Recently, it has been recognized that phospholipids in the axonal membrane may be a signal for axonal degeneration, regeneration, or other processes. This review focuses on key recent developments and areas for ongoing investigations. KEY FACTS: Phosphatidylserine externalization propagates along an axon after axonal injury and is delayed in the Wallerian degeneration slow (Wld) mutant. The ATP8A2 flippase mutant has spontaneous axonal degeneration. Microdomains of axonal degeneration in spheroid bodies have differential externalization of phosphatidylserine and phosphatidylethanolamine. Phospholipid trafficking could represent a mechanism for coordinated axonal degeneration and elimination, i.e. axoptosis, analogous to apoptosis of the cell body.
膜磷脂是几种信号通路的关键组成部分。它们以各种不对称分布的形式存在，其在膜内的运输可以被细胞内、细胞外和细胞间的事件所诱导。一个常见的例子是凋亡过程中磷脂酰丝氨酸从内膜向质膜外叶的外向化，从而诱导细胞体的吞噬作用。最近，人们已经认识到轴突膜中的磷脂可能是轴突退化、再生或其他过程的信号。这篇综述重点介绍了关键的最新进展和正在进行的研究领域。关键事实：轴突损伤后，磷脂酰丝氨酸的外向化沿轴突传播，并在 Wallerian 变性慢（Wld）突变体中延迟。ATP8A2 翻转酶突变体有自发的轴突退化。球体中轴突退化的微区有不同的磷脂酰丝氨酸和磷脂酰乙醇胺的外向化。脂类运输可能代表了一种协调轴突退化和消除的机制，即轴凋亡，类似于细胞体的细胞凋亡。
