AAV2-mediated and hypoxia response element-directed expression of bFGF in neural stem cells showed therapeutic effects on spinal cord injury in rats

Abstract

Neural stem cell (NSCs) transplantation has been one of the hot topics in the repair of spinal cord injury (SCI). Fibroblast growth factor (FGF) is considered a promising nerve injury therapy after SCI. However, owing to a hostile hypoxia condition in SCI, there remains a challenging issue in implementing these tactics to repair SCI. In this report, we used adeno-associated virus 2 (AAV2), a prototype AAV used in clinical trials for human neuron disorders, basic FGF (bFGF) gene under the regulation of hypoxia response element (HRE) was constructed and transduced into NSCs to yield AAV2-5HRE-bFGF-NSCs. Our results showed that its treatment yielded temporally increased expression of bFGF in SCI, and improved scores of functional recovery after SCI compared to vehicle control (AAV2-5HRE-NSCs) based on the analyses of the inclined plane test, Basso–Beattie–Bresnahan (BBB) scale and footprint analysis. Mechanistic studies showed that AAV2-5HRE-bFGF-NSCs treatment increased the expression of neuron-specific neuronal nuclei protein (NeuN), neuromodulin GAP43, and neurofilament protein NF200 while decreased the expression of glial fibrillary acidic protein (GFAP) as compared to the control group. Further, the expressions of autophagy-associated proteins LC3-II and Beclin 1 were decreased, whereas the expression of P62 protein was increased in AAV2-5HRE-bFGF-NSCs treatment group. Taken together, our data indicate that AAV2-5HRE-bFGF-NSCs treatment improved the recovery of SCI rats, which is accompanied by evidence of nerve regeneration, and inhibition of SCI-induced glial scar formation and cell autophagy. Thus, this study represents a step forward towards the potential use of AAV2-5HRE-bFGF-NSCs for future clinical trials of SCI repair.

Water Treadmill Training Ameliorates Neurite Outgrowth Inhibition Associated with NGR/RhoA/ROCK by Inhibiting Astrocyte Activation following Spinal Cord Injury

“…Focusing on the paralysis of lower limbs after spinal cord injury, we combined swimming with a treadmill to allow rats to perform active rehabilitation training through the synergistic effect of water flow and the conveyor belt. The current experimental results show that the motor function of rats was significantly improved after treadmill training for 14 d. In addition, GAP43 and NF200 were used to evaluate neuronal and axonal injury [ 27 – 29 ]. As expected, we found that the expression of GAP43 and NF200 significantly decreased due to neuronal injury.…”

Spinal Cord Injury Management through the Combination of Stem Cells and Implantable 3D Bioprinted Platforms

“…The results of MRI tests proved the migration of transplanted cells toward the injury site of the spinal cord that could functionally connect to host neurons and substantially enhance locomotor functions while expressing neural lineage markers. These results imply that the transplantation of these cells could regulate inflammatory cells and glia activation and improve the hyperalgesia that occurred after SCI [45]. Moreover, the combination transplantation of NSCs and human olfactory ensheathing mucosa cells has shown effectiveness in preclinical trials to treat post-traumatic cysts of spinal cord injuries.…”

“…According to a mechanistic study, this therapy could increase the expression of basic FGF and enhance total functional recovery compared to the control group (AAV2-5HRE-NSCs) by increasing the expression of specific neuronal proteins and reducing the expression of the glial fibrillary acidic protein and autophagy-associated proteins (Figure 2). Overall, AAV2-5HRE-bFGF-NSCs treatment could upgrade the recovery of SCI in rats by enhancing successful nerve regeneration as well as inhibiting cell autophagy and glial scar formation [45].…”

The role of hypoxia in stem cell regulation of the central nervous system: From embryonic development to adult proliferation

“…Together, these findings have important implications for potential therapeutic strategies for CNS diseases. 147 At present, NSC transplantation is a hot topic in the treatment of stroke, 148 spinal cord injury, 149 traumatic brain injury, 150 and other CNS diseases. Indeed, NSCs were shown to induce the release of Mir‐133b in BMSCs to promote the survival of neurons, thus further improving the therapeutic effect of NSC transplantation on cardiac arrest‐induced brain injury.…”