Neuroprotective and immunomodulatory effect of dimethyl-fumarate (DMF) after avulsion and reimplantation of spinal motor roots associated to cell-therapy

Abstract

Central Nervous System (CNS) lesions are the subject of intense research in the development of strategies that restore the morphology and functionality of the affected neural pathways. Different experimental models of injury have substantiated many of the current knowledge on neuronal regeneration and plasticity and have been instrumental in investigating the potential of different methods and treatments. In this context, avulsion of the medullary ventral roots has shown to be a reproducible model, since it results in the degeneration of 80% of the axotomized motoneurons between the second and third week after the avulsion. However, avulsed-surviving motoneurons have regenerative potential after reimplantation of nerve roots, and may serve as a model of CNS/PNS regeneration. In the present study, we will evaluate the immunomodulatory and neuroprotective potential of dimethyl-fumarate (DMF), in view of its demonstrated positive effects in the treatment of multiple sclerosis. DMF will be associated with reimplantation of spinal roots and cell therapy using adult mesenchymal stem cells (bone marrow and adipocyte-derived). Thus, animals submitted to the avulsion of the spinal motor roots L4 to L6 will be submitted to acute reimplantation, by the use of heterologous fibrin sealant, produced by the Center for the Study of Poisonous Animal Poisons (CEVAP - UNESP) together with the stem cells. In sequence, they will be treated with DMF (0, 7.5, 15, 30 and 45 mg/kg, gavage). The results, after 1, 4 or 12 weeks of treatment, will involve analysis of neuronal survival, medullary synaptic preservation and axonal regeneration in the sciatic nerve, using morphological techniques (Nissl staining, light microscopy and transmission electron microscopy), molecular (reactivity for Anexin V-Cy5, immunohistochemistry and real-time PCR) and functional (walking-track test and electronic von-Frey). (AU)