Neuroprotection and immunomodulation by dimethyl fumarate and a heterologous fibrin biopolymer after ventral root avulsion and reimplantation

• Autor(a) principal: Kempe, Paula R.G.
• Data de Publicação: 2020
• Outros Autores: Chiarotto, Gabriela Bortolança, Barraviera, Benedito [UNESP], Ferreira, Rui Seabra [UNESP], de Oliveira, Alexandre L.R.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1590/1678-9199-JVATITD-2019-0093; http://hdl.handle.net/11449/200754
• topic: Dimethyl-fumarate; Fibrin sealant; Immunomodulation; Neuroprotection; Ventral root avulsion

Background: Ventral root avulsion (VRA) is an experimental approach in which there is an abrupt separation of the motor roots from the surface of the spinal cord. As a result, most of the axotomized motoneurons degenerate by the second week after injury, and the significant loss of synapses and increased glial reaction triggers a chronic inflammatory state. Pharmacological treatment associated with root reimplantation is thought to overcome the degenerative effects of VRA. Therefore, treatment with dimethyl fumarate (DMF), a drug with neuroprotective and immunomodulatory effects, in combination with a heterologous fibrin sealant/biopolymer (FS), a biological glue, may improve the regenerative response. Methods: Adult female Lewis rats were subjected to VRA of L4-L6 roots followed by reimplantation and daily treatment with DMF for four weeks. Survival times were evaluated 1, 4 or 12 weeks after surgery. Neuronal survival assessed by Nissl staining, glial reactivity (anti-GFAP for astrocytes and anti-Iba-1 for microglia) and synapse preservation (anti-VGLUT1 for glutamatergic inputs and anti-GAD65 for GABAergic inputs) evaluated by immunofluorescence, gene expression (pro- and anti-inflammatory molecules) and motor function recovery were measured. Results: Treatment with DMF at a dose of 15 mg/kg was found to be neuroprotective and immunomodulatory because it preserved motoneurons and synapses and decreased astrogliosis and microglial reactions, as well as downregulated the expression of pro-inflammatory gene transcripts. Conclusion: The pharmacological benefit was further enhanced when associated with root reimplantation with FS, in which animals recovered at least 50% of motor function, showing the efficacy of employing multiple regenerative approaches following spinal cord root injury.