PR000661 (Project)

Description:In adult mammals, retinal ganglion cells (RGCs) fail to regenerate their axons when damaged. As a result, RGCs die after acute injury and in progressive degenerative diseases such as glaucoma; such damage can lead to permanent vision loss and blindness. Little is known about the roles of lipids in axon injury and repair despite their fundamental importance in composition of cell membranes, myelin sheaths and mediation of signaling pathways. Study of the lipidome in the biology of optic nerve (ON) regeneration has been largely neglected. A better understanding of the roles that lipids play in RGC biology may enhance understanding of RGC-related diseases and point to novel treatments. Established experimental models of ON regeneration allow exploration of molecular determinants of RGC axon regenerative success and failure. In this study, we used high-resolution liquid chromatography-tandem mass spectrometry to analyze lipidomic profiles of the ON and retina in an ON crush model with and without intravitreal Zymosan injections to enhance regeneration. Our results reveal profound remodeling of retina and ON lipidomes that occur after injury. In the retina, Zymosan treatment largely abrogates widespread lipidome alterations. In the ON, Zymosan induces lipid profiles that are distinct from those observed in naïve and vehicle-injected crush controls. We have identified a number of lipid species, classes and fatty acids that may be involved in the mechanisms of axon damage and repair. Lipids upregulated during RGC regeneration may be interesting candidates for further functional studies.