Enhancing Membrane Repair in Neuronal Cell Types as a Potential Therapeutic for Neurodegenerative Diseases

Abstract

Cell membrane repair is an essential cellular process to repair damage to the membrane and maintain the integrity of the cell membrane. Impaired membrane resealing kinetics can potentially lead to neurodegenerative diseases. Enhancing membrane repair via therapeutic intervention could minimize neurodegeneration in neuronal disease states. Recombinant human MG53 (rhMG53) and poloxamers have been an effective therapeutic to enhance membrane repair in muscle and non‐muscle cell types. Here, we aimed to assess if the membrane repair response is active and the efficacy of enhancing membrane resealing in neuronal cells. To assess if neuronal cells have an active membrane repair response, mouse neuroblastoma N2a cells were transfected with GFP or GFP‐MG53. MG53 localization was tracked following multiphoton infrared laser injury. N2a cells were transfected with GFP or GFP‐MG53, and subjected to multiphoton infrared laser injury to investigate if MG53 expression enhances membrane resealing following damage. An infrared laser was used to damage the cell membrane of N2a cells and primary mouse dorsal root ganglion neurons (DRG) in the presence of FM4‐64 dye. To test the efficacy of therapeutics, N2as and DRGs were treated with 1μM rhMG53 or 100μM Poloxamer 188 (P188) and challenged with the multiphoton laser injury. Lastly, the therapeutic potential of rhMG53 was tested in vivo with a sciatic nerve crush injury model. C57Bl/6 mice sciatic nerves were mechanically crushed for 10 seconds and then injected with 1μL rhMG53 (1mg/mL) or saline. The sciatic nerves were harvested and immunostained with an axonal regeneration marker, SCG10. SCG10 staining intensity was measured to calculate the regeneration index. Overall, we observed MG53 trafficking to the injury site which indicates there is an activate membrane repair mechanism within neuronal cells. Therapeutic levels of rhMG53 and P188 increased membrane resealing in both N2as and DRGs. Lastly, rhMG53‐treated sciatic nerves displayed a two‐fold increase in regenerative capacity following sciatic nerve crush injury compared to the saline vehicle control. These results illustrate an active membrane repair process in neuronal cells and potential for therapeutic intervention in the context of neuronal diseases, specifically neurodegenerative diseases.