Application of human embryonic stem cells overexpressing FGF2 after ventral root avulsion: neuroprotection and immunomodulation

Abstract

Traumatic injuries of the spinal cord resulting in severe neurological deficits and, in most cases, irreversible. The nerve root avulsion is a type of spinal injury that triggers a cascade of molecular events that lead to retrograde degeneration of nerve fibers and neuronal death in the spinal cord, leading to degeneration of about 80% of the motoneurons two weeks after the injury. Thus, the motor avulsion has been a reproducible experimental model of motor neuron degeneration in mice. Several studies have shown the benefits of cell therapy using stem cells in neuroprotection of injured motoneurons and, consequently, in increased neuronal survival. Other studies have shown that therapy with fibroblast growth factor 2 (FGF2) stimulates neurogenesis and neuronal plasticity in models of neurodegenerative diseases. The present study aims to investigate the neuroprotective effect of FGF2 on the spinal alpha motoneurons in Lewis rats after avulsion motor. For that, we constructed bioengineered human embryonic stem cell (hES) cells which overexpress human FGF2 in an inducible mode. The animals will be divided into the following groups: Group 1 - avulsion motor + fibrin sealant; Group 2 - avulsion motor + fibrin sealant + FGF2, Group 3 - Group 3 - avulsion motor + fibrin sealant + injection of hES-FGF2-GFP + doxycycline, Group 4 - avulsion motor + fibrin sealant + injection of hES-FGF2-GFP; Group 5 - avulsion motor + fibrin sealant + injection of mesenchymal stem cell (MSC). To evaluate the expression of GFAP, Iba-1, synaptophysin and OX-42 will use the technique of immunohistochemistry; to evaluate the survival of sensory and medullary motor neurons, we will use the Nissl staining and subsequent quantitative analysis (stereological) by light microscopy. As for the evaluation and relative quantification of gene expression TNFa, IL1², IL10, MHC-I, CD3, BDNF and GDNFwe will use the technique qRT-PC.