Integration of engrafted Schwann cells into injured peripheral nerve: Axonal association and nodal formation on regenerated axons

• Published in: Neuroscience letters Vol. 387; no. 2; pp. 85 - 89
• Main Authors: Radtke, Christine, Akiyama, Yukinori, Lankford, Karen L., Vogt, Peter M., Krause, Diane S., Kocsis, Jeffery D.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 21.10.2005; Elsevier
• Subjects: Animals; Axotomy; Biological and medical sciences; Cell Adhesion Molecules, Neuronal - metabolism; Cell Compartmentation - physiology; Cytoplasm - metabolism; Cytoplasm - ultrastructure; Disease Models, Animal; Female; Fundamental and applied biological sciences. Psychology; Green Fluorescent Proteins - metabolism; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Microscopy, Electron, Transmission; Myelin Sheath - physiology; Myelin Sheath - ultrastructure; NAV1.6 Voltage-Gated Sodium Channel; Nerve Regeneration - physiology; Nerve Tissue Proteins - metabolism; Peripheral nerve; Peripheral Nerve Injuries; Peripheral Nerves - surgery; Peripheral Nerves - ultrastructure; Ranvier's Nodes - physiology; Ranvier's Nodes - ultrastructure; Schwann cells; Schwann Cells - physiology; Schwann Cells - transplantation; Schwann Cells - ultrastructure; Sciatic Neuropathy - metabolism; Sciatic Neuropathy - physiopathology; Sciatic Neuropathy - therapy; Sodium Channels - metabolism; Transplantation; Vertebrates: nervous system and sense organs; Y Chromosome - genetics; Y Chromosome - metabolism; Peripheral nerve; Transplantation; Schwann cells; Integration; Schwann cell; Neuroglia; Axon
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2005.06.073

Transplantation of myelin-forming cells can remyelinate axons, but little is known of the sodium channel organization of axons myelinated by donor cells. Sciatic nerve axons of female wild type mice were transected by a crush injury and Schwann cells (SCs) from green fluorescence protein (GFP)-expressing male mice were transplanted adjacent to the crush site. The male donor cells were identified by GFP fluorescence and fluorescence in situ hybridization (FISH) for Y chromosome. In nerves of GFP-expressing mice, GFP was observed in the axoplasm and in the cytoplasmic compartments of the Schwann cells, but not in the myelin. Following transplantation of GFP-SCs into crushed nerve of wild type mice, immuno-electron microscopic analysis indicated that GFP was observed in the cytoplasmic compartments of engrafted Schwann cells which formed myelin. Nodal and paranodal regions of the axons myelinated by the GFP-SCs were identified by Na v1.6 sodium channel and Caspr immunostaining, respectively. Nuclear identification of the Y chromosome by FISH confirmed the donor origin of the myelin-forming cells. These results indicate that engrafted GFP-SCs participate in myelination of regenerated peripheral nerve fibers and that Na v1.6 sodium channel, which is the dominant sodium channel at normal nodes, is reconstituted on the regenerated axons.