In the present study, we searched for possible candidates that can prevent ischemic damage in the rabbit spinal cord. For this study, we used two-dimensional gel electrophoresis followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, in sham- and ischemia-operated animals. As the level of protein disulfide-isomerase A3 (PDIA3) significantly decreased 3 h after ischemia/reperfusion, we further investigated its possible role against ischemic damage using an in vitro spinal cord cell line and in vivo spinal cord ischemic model. The administration of Tat-PDIA3 significantly reduced the hydrogen peroxide-induced formation of reactive oxygen species and cell death, based on terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick end labeling and a colorimetric WST-1 assay. Further, Tat-PDIA3 significantly ameliorated the ischemia-induced deficits in motor function, based on Tarlov’s criteria, 24–72 h after ischemia/reperfusion, as well as the degeneration of motor neurons in the ventral horn 72 h after ischemia/reperfusion. Tat-PDIA3 administration also reduced the ischemia-induced activation of microglia and lipid peroxidation in the motor neurons 72 h after ischemia/reperfusion. PDIA3 also potentially ameliorated the ischemia-induced increase in oxidative markers in serum and decreased the activity of Cu,Zn-superoxide dismutase, Mn-superoxide dismutase, and glutathione peroxidase in spinal cord homogenates, 24 h and 72 h after ischemia/reperfusion. These results suggest that Tat-PDIA3 could be used to protect spinal cord neurons from ischemic damage, due to its modulatory action on the oxidative/anti-oxidative balance. Tat-PDIA3 could be applicable to protects neurons from the ischemic damage induced by thoracoabdominal aorta obstruction.

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In the present study, we investigated the ability of Cu, Zn-superoxide dismutase (SOD1) to improve the therapeutic potential of adipose tissue-derived mesenchymal stem cells (Ad-MSCs) against ischemic damage in the spinal cord. Animals were divided into four groups: the control group, vehicle (PEP-1 peptide and artificial cerebrospinal fluid)-treated group, Ad-MSC alone group, and Ad-MSC-treated group with PEP-1-SOD1. The abdominal aorta of the rabbit was occluded for 30 min in the subrenal region to induce ischemic damage, and immediately after reperfusion, artificial cerebrospinal fluid or Ad-MSCs (2 × 10) were administered intrathecally. In addition, PEP-1 or 0.5 mg/kg PEP-1-SOD1 was administered intraperitoneally to the Ad-MSC-treated rabbits. Motor behaviors and NeuN-immunoreactive neurons were significantly decreased in the vehicle-treated group after ischemia/reperfusion. Administration of Ad-MSCs significantly ameliorated the changes in motor behavior and NeuN-immunoreactive neuronal survival. In addition, the combination of PEP-1-SOD1 and Ad-MSCs further increased the ameliorative effects of Ad-MSCs in the spinal cord after ischemia. Furthermore, the administration of Ad-MSCs with PEP-1-SOD1 decreased lipid peroxidation and maintained levels of antioxidants such as SOD1 and glutathione peroxidase compared to the Ad-MSC alone group. These results suggest that combination therapy using Ad-MSCs and PEP-1-SOD1 strongly protects neurons from ischemic damage by modulating the balance of lipid peroxidation and antioxidants.