Abstract
The aim of the present study was to examine the effect of growth-associated protein-43 (GAP-43) on bone marrow mesenchymal stem cell (BMSC) differentiation in a rat model of traumatic optic neuropathy (TON). GAP‑43 and short hairpin (sh)RNA‑GAP‑43 were inserted into pGLV5 and pGLV3 lentiviral vectors, respectively. The stable control, GAP‑43‑overexpression and GAP‑43‑knockdown cell lines (GFP/BMSCs, GAP‑43/BMSCs and shGAP‑43/BMSCs, respectively) were established. The expression of GAP‑43, neuron‑specific enolase (NSE), nestin, neurofilament (NF), neuron‑specific nuclear‑binding protein (NeuN) and βIII‑tubulin were detected in the GAP‑43/BMSCs and shGAP‑43/BMSCs with retinal cell‑conditioned differentiation medium using semi‑quantitative polymerase chain reaction (PCR), western blotting and cell immunofluorescence. In addition, the BMSCs were observed under fluorescence microscopy. The Sprague‑Dawley rat models of TON were established and identified by retrograde labeling of retinal ganglion cells (RGCs) with fluoroGold (FG). The lentiviral‑mediated GAP‑43‑modified BMSCs were then transplanted into the rat model of TON. The expression of GAP‑43 was detected in the retinal tissues using qPCR and western blotting. The histopathology of the retinal tissues was observed using hematoxylin and eosin (H&E) staining. The GAP‑43/BMSCs exhibited positive expression of NSE, NF, nestin and βIII‑tubulin, and exhibited a neuronal phenotype. The shGAP‑43/BMSCs markedly inhibited expression of NeuN, NSE, NF, nestin and βIII‑tubulin induced by retinal cell‑conditioned differentiation medium. The FG staining revealed that the number of labeled RGCs were significantly decreased in the TON model rats, compared with normal rats (P<0.05). The H&E staining revealed that the degree of pathological changes was improved in the GAP‑43/BMSC group, compared with the GFP/BMSC and shGAP‑43/BMSC groups. In conclusion, GAP‑43 promoted BMSC differentiation into neuron-like cells, and intravitreally injected GAP-43/BMSCs promoted the process of nerve repair in a rat model of TON.