Lipid organisation and dynamics in the myelin membrane sheets

摘要: Myelin is a unique lipid-enriched membrane, produced by oligodendrocytes in the central nervous system, that enwrapped around axons the multilayered fashion to ensure swift saltatory conduction of neuronal impulses. has composition. It enriched cholesterol, sphingomyelin and myelin lipids possess high number long-chain fatty acids their structure. Previous results have shown basic protein (MBP) acts as diffusion barrier within sheath, preventing majority proteins to enter sheath region. Therefore, sheaths are deprived cytoplasm proteins, do not contain cortical actin cytoskeleton. This specific composition raises question how lipid might be affected sheath. We used primary oligodendrocyte culture well-established model study To assess modes, we STED-FCS (stimulated emission depletion microscopy combined with fluorescence correlation spectroscopy). showed artificial analogs phosphatidylethanolamine, galactosylcerebroside (PE, SM GalC, respectively) introduced into cellular faster oligodendrocytes, when compared control membrane fibroblasts cell line (PtK2 cells). Moreover, could show complete absence trapping for decrease GalC oligodendrocytes. Additionally, using reconstituted sheets PtK2 cells, demonstrate MBP presence sufficient reorganize change mode behaviour, from free diffusion. In second project addressed polarised distribution phosphatidylinositols membrane. PIP2 PIP3 two distinct regions: outer rim processes PIP3. interacts masks it antibody staining, but processes. Furthermore, found highly susceptible changes levels: upon its augmentation size non-compact domains increased. an increase accompanied enlargement regions. speculate this filamentous reason would prevent zipping suggest downstream effector increased levels.