Spinal Cord Ischemia-reperfusion Injury Research Articles

Protective Effect of Contralateral, Ipsilateral, and Bilateral Remote Ischemic Preconditioning on Spinal Cord Ischemia Reperfusion Injury in Rats.

To evaluate the effect of different remote ischemic preconditioning (RIPC) methods in spinal cord ischemia-reperfusion (IR) injury. A total of 36 rats were distributed to the 6 groups: sham surgery, control (only spinal cord IR), unilateral (hind limb RIPC before spinal cord IR), bilateral (hind limbs RIPC before spinal cord IR), ipsilateral (hind and fore limbs RIPC to the right before spinal cord IR), contralateral (right hind limb and left fore limb as RIPC before spinal cord IR). Thirty minutes after RIPC, the spinal cord was subjected to ischemia for 60 minutes. Seventy two hours after IR, all rats were evaluated by neurological function, histological and biochemical examinations. The mean Motor Deficit Index (MDI) scores in the ipsilateral, contralateral, and bilateral groups were lower than that of the unilateral group (p < 0.05). The mean malondialdehyde (MDA) in ipsilateral group was lower than were control group (p < 0.05). The mean total antioxidant capacity (TAC) and the mean number of normal motor neurons in the experimental groups were significantly higher than increased control group (p < 0.05). The mean plasma levels of catalase in the contralateral, ipsilateral, and bilateral groups were significantly increased compared to control group (p < 0.05). The mean scores of white matter damage in contralateral, bilateral, and unilateral groups were lower than control group (p < 0.05). The results of this study show that contralateral, ipsilateral, and bilateral limb RIPC may reduce the complications of spinal cord ischemic injury.

Neuroprotective Effects of Tocilizumab on Experimentally-Induced Spinal Cord Ischemia-Reperfusion Injury

We aimed to evaluate neuroprotective effects of tocilizumab on spinal cord ischemia-reperfusion (I/R) injury. Our study design was an experimental rabbit spinal cord I/R injury model, and the setting was at the Animal Research Laboratory, Necmettin Erbakan University, Meram School of Medicine, Konya, Turkey. Twenty-four adult New Zealand rabbits were randomly divided into 3 groups: Group 1, control group (n=8); Group 2, I/R group, and Group 3 (n= 8) I/R injury+ tocilizumab (4 mg/kg, ip) treatment group. Spinal cord I/R injury repair was performed by infrarenal aortic cross clamping. On neurologic evaluation, spinal cord tissue plasma tumor necrosis factor alpha (TNFα), total antioxidant status (TAS), total oxidant status (TOS), thiobarbituric acid reactive substances (TBARS), interleukin 6 (IL-6), interleukin 10 (IL-10) levels were analyzed. Spinal cord neuronal damage score and apoptotic cell count were also investigated. I/R injury significantly increases the plasma and spinal cord tissue TNFα, TOS, TBARS, and IL-6 levels and decreases the plasma and spinal cord tissue TAS and IL-10 levels. Tocilizumab treatment significantly reduces the plasma and spinal cord tissue TNFα, TOS, TBARS, IL-6 levels and increases plasma and tissue TAS and IL-10 levels. I/R injury significantly increases spinal cord neuronal damage score and apoptotic cell count. Tocilizumab treatment significantly reduces spinal cord neuronal damage score and apoptotic cell count. Neurologic examination scores at 24, 48, and 72 hours were significantly better in the treatment group when compared with the I/R group. This study shows significant neuroprotective effects of tocilizumab on rabbit spinal cord I/R injury.

The expression of bradykinin and its receptors in spinal cord ischemia-reperfusion injury rat model

ObjectiveTo investigate the expression and time-dependent manner of bradykinin (BK) as well as its receptors (Bradykinin receptors 1 and 2, B1R and B2R) in spinal cord ischemia-reperfusion injury (SCII) in rat model. MethodsSprague-Dawley (SD) rats were subjected to 1 h of infra-renal abdominal aorta occlusion and reperfused for 3 h to 5 d to induce SCII. The concentration of BK in serum was detected by enzyme linked immunosorbent assay (ELISA). In situ expression of BK receptors was evaluated by immunochemistry and their mRNA level was evaluated by Real time quantitative-PCR (RTq-PCR). ResultsThe concentration of BK in serum was increased right after following SCII. Both of the BK receptors were detected and up-regulated in 24 h and 48 h after injury. The levels of B1R and B2R mRNA were up-regulated after SCII, and the B1R mRNA dropped to basal level after 6 h, but B2R mRNA dropped to lower level right after injury, peaked at 3 h, then remained a lower level from 6 h till 5 day. ConclusionThis study provides the evidence of the expression of BK and its receptors in SCII in rat model, and suggests that BK and its receptors may have some physiological or pathological significance in SCII.

Rapamycin Enhances Mitophagy and Attenuates Apoptosis After Spinal Ischemia-Reperfusion Injury.

The spinal cord is extremely vulnerable to ischemia-reperfusion (I/R) injury, and the mitochondrion is the most crucial interventional target. Rapamycin can promote autophagy and exert neuroprotective effects in several diseases of the central nervous system. However, the impact of rapamycin via modulating mitophagy and apoptosis after spinal cord ischemia-reperfusion injury remains unclear. This study was undertaken to investigate the potential role of rapamycin in modulating mitophagy and mitochondria-dependent apoptosis using the spinal cord ischemia-reperfusion injury (SCIRI) mouse model. We found that rapamycin significantly (p < 0.05) enhanced mitophagy by increasing the translocation of p62 and Parkin to the damaged mitochondria in the mouse spinal cord injury model. At the same time, rapamycin significantly (p < 0.05) decreased mitochondrial apoptosis related protein (Apaf-1, Caspase-3, Caspase-9) expression by inhibiting Bax translocation to the mitochondria and the release of the cytochrome c from the mitochondria. After 24 h following SCIRI, rapamycin treatment reduced the TUNEL+ cells in the spinal cord ischemic tissue and improved the locomotor function in these mice. Our results therefore demonstrate that rapamycin can improve the locomotor function by promoting mitophagy and attenuating SCIRI -induced apoptosis, indicating its potential therapeutic application in a spinal cord injury.

Pretreatment With Diazoxide Attenuates Spinal Cord Ischemia-Reperfusion Injury Through Signaling Transducer and Activator of Transcription 3 Pathway

Delayed paraplegia remains a feared complication of thoracoabdominal aortic intervention. Pharmacologic preconditioning with diazoxide (DZ), an adenosine 5'-triphosphate-sensitive potassium channel opener, results in neuroprotection against ischemic insult. However, the effects of DZ in spinal cord ischemia-reperfusion injury have not been fully elucidated. We hypothesized that DZ attenuates spinal cord ischemia-reperfusion injury through the signaling transducer and activator of transcription (STAT) 3 pathway. Adult male C57/BL6 mice received DZ (20 mg/kg) by oral gavage. Spinal cords were harvested at 0, 12, 24, 36, 48, and 60 hours after administration of DZ. The expression of phosphorylated STAT3 was assessed by Western blot analysis. Five groups were studied: DZ (DZ pretreatment, n= 8), ischemic control (phosphate-buffered saline pretreatment, n= 11), DZ+ STAT3 inhibitor LY5 (DZ pretreatment+ LY5, n= 8), LY5 (phosphate-buffered saline pretreatment+ LY5, n= 8), and sham (without cross-clamping, n= 5). Spinal cord ischemia was induced by 4 minutes of thoracic aortic cross-clamp. Functional scoring (Basso Mouse Score) was done at 12-hour intervals until 48 hours, and spinal cords were harvested for the evaluation of B-cell lymphoma 2 expression and histologic changes. The expression of phosphorylated STAT3 was significantly upregulated 36 hours after the administration of DZ. The motor function in the DZ group was significantly preserved compared with all other groups. The expression of B-cell lymphoma 2 in the DZ group was significantly higher than in the ischemic control, DZ+ LY5, and LY5 groups 48 hours after reperfusion. DZ preserves motor function in spinal cord ischemia-reperfusion injury by the STAT3 pathway. DZ may be beneficial clinically for use in spinal protection in aortic intervention.

LncRNA MALAT1 is Neuroprotective in a Rat Model of Spinal Cord Ischemia-Reperfusion Injury Through miR-204 Regulation.

This study was to investigate the neuroprotective effect of long noncoding RNAs Metastasis associated lung adenocarcinoma transcript-1 (lncRNA MALAT-1) in Spinal Cord Ischemic/Reperfusion Injury (SCIRI). Quantitative real-time PCR (RT-qPCR) was used to examine the expressions of MALAT1, miR-204 and Bcl-2, while western blot was performed to examine Bcl-2. Besides, apoptosis was evaluated by the percentage of cell viability and apoptotic cells. Neurological evaluation was performed by measuring hindlimb locomotor function. The expression of MALAT1 and Bcl-2 was decreased, while miRNA-204 (miR-204) was up-regulated in rats SCIRI model and neurocyte lines under hypoxic conditions. Oxygen, Glucose Deprivation (OGD) promoted apoptosis of neurocytes, downregulated MALAT1 and Bcl-2 and elevated miR-204 expression, however, overexpression of MALAT1 notably reversed this trend. Nevertheless, knockdown of MALAT1 increased cell apoptosis, decreased MALAT1 and Bcl-2 but upregulated miR-204. MALAT1 overexpression-induced anti-apoptosis and knockdowninduced pro-apoptosis were obviously reversed by synchronously overexpression and knockdown of miR-204, respectively. MALAT1-treated SCIRI rats exhibited lower Motor Deficit Index (MDI) scores, higher levels of MALAT1 and Bcl-2 expression and lower miR-204 expression. Our data suggested that MALAT1 exerted neuroprotective effect in a rat model of SCIRI by regulating miR-204.

Knockdown of miR-372 Inhibits Nerve Cell Apoptosis Induced by Spinal Cord Ischemia/Reperfusion Injury via Enhancing Autophagy by Up-regulating Beclin-1.

To investigate the role of miR-372/Beclin-1 on nerve cell apoptosis induced by spinal cord ischemia/reperfusion injury (SCII). We established in vivo and in vitro SCII model. MiR-372 and Beclin-1 expressions in spinal cord tissues of SCII rats and SCII nerve cells were measured. The cell apoptosis was detected by flow cytometry. MiR-372 inhibitor was used to reduce miR-372 expression. Dual luciferase reporter assay was used to confirm the interaction between miR-372 and Beclin-1. MiR-372 expression in spinal cord tissues of SCII rats and SCII nerve cells was increased, while Beclin-1 expression was decreased. Knockdown of miR-372 could inhibit SCII nerve cell apoptosis. In addition, MiR-372 could negatively regulate Beclin-1 expression. Autophagy inhibitor could inhibit autophagy to promote the apoptosis of SCII nerve cells through decreasing Beclin-1, while interference of miR-372 changed the effect of autophagy inhibitor. Interference of miR-372 could reduce nerve cell apoptosis in SCII via increasing autophagy by up-regulating Beclin-1.

Spinal cord stimulation postconditioning reduces microglial activation through down-regulation of ERK1/2 phosphorylation during spinal cord ischemic reperfusion in rabbits.

Microglial activation plays a critical role in spinal cord ischemic reperfusion injury. Spinal cord stimulation preconditioning and postconditioning has shown spinal cord protection in ischemic reperfusion injury in animal studies. However, whether spinal cord stimulation could reduce microglial activation is still unclear. In this study, rabbits experienced 28-min infrarenal aorta occlusion and reperfusion for 8 h, 1, 3, and 7 days correspondingly. Immediately after reperfusion, rabbits received spinal cord stimulation of 2 or 50 Hz for 30 min and daily for a week. The results showed that spinal cord stimulation of 2 Hz reduced microglial activation. Microglial activation was accompanied with up-regulated p-ERK1/2, and microglial inhibition by 2 Hz spinal cord stimulation was associated with down-regulated p-ERK1/2. Spinal cord stimulation increased the expression of IL-1β. Our results revealed, for the first time, that spinal cord stimulation postconditioning suppresses microglial activation during spinal cord ischemic reperfusion by down-regulation of p-ERK1/2, which may be the protective mechanism of spinal cord stimulation.

Synergistic Reduction of Apoptosis With Diazoxide and Erythropoietin in Spinal Cord Ischemic Injury

Paraplegia remains a devastating complication of thoracoabdominal aortic intervention. Metabolic stress induces expression of beta common receptor subunit of erythropoietin (EPO) receptor (βcR) to exert a neuroprotective effect in spinal cord ischemia reperfusion injury (SCIR). Diazoxide (DZ) has been shown to induce ischemic tolerance. We previously reported that DZ upregulated βcR expression and enhanced the neuroprotective effects of EPO through the upregulation of βcR. We hypothesize that βcR expression induced by DZ before ischemia amplifies the antiapoptotic effects of EPO in a murine model of SCIR. Experimental groups included phosphate-buffered saline (PBS) pretreatment+ PBS immediately before the operation, PBS+EPO, DZ+PBS, DZ+EPO, and sham. Spinal cord ischemia was induced by a 4-minute thoracic aortic cross-clamp. Functional scoring (Basso Mouse Score) was done at 12-hour intervals for 48 hours. Spinal cords were harvested for histologic analysis, and antiapoptotic factors (caspase 3, 8, and 9, B-cell lymphoma-2, and neuroglobin) were evaluated by Western blot analysis. The motor function of DZ+EPO group was significantly preserved compared with all other groups. The levels of cleaved caspase 8 and 3 in DZ+EPO were significantly lower than in the other groups. Mice treated with DZ+EPO had significantly fewer terminal deoxynucleotide transferase-mediated deoxy uridine triphosphate nick-end labeling-positive cells than other groups. Optimized upregulation of βcR by DZ can increase the extrinsic antiapoptotic effects of EPO. Better understanding of this synergetic mechanism may serve to help prevent ischemic complications caused by aortic intervention.

Ginsenoside Rb1 protects against spinal cord ischemia-reperfusion injury in rats by downregulating the Bax/Bcl-2 ratio and caspase-3 and p-Ask-1 levels

The aim of this study was to confirm the effects of ginsenoside Rb1 on neural cell apoptosis in the spinal cord of rats with spinal cord ischemia-reperfusion injury (SCII) and to explore its potential mechanisms. A total of 100 healthy adult Sprague-Dawley (SD) rats were randomly divided into four groups: normal control (n = 10), sham-operated (n = 10), SCII model (n = 40), and ginsenoside Rb1-treated groups (n = 40). Basso, Beattie, Bresnahan (BBB) scale was used to examine rat hindlimb locomotor function. Nissl and Tunnel staining were used to observe neural cell injury and apoptosis, respectively, in the spinal cord of rats with SCII. Immunofluorescence staining was performed to detect the expression of Bax and Bcl-2. The levels of caspase-3 and phosphorylated Ask-1 (p-Ask-1) were detected by western blotting. Ginsenoside Rb1 prevented neural cell apoptosis in the spinal cord and improved hindlimb locomotor dysfunction of rats (P < .05). Moreover, SCII-induced upregulation of caspase-3 and p-Ask-1 levels and the Bax/Bcl-2 ratio were significantly decreased by ginsenoside Rb1 (P < .05). The protective effects of ginsenoside Rb1 on neural cells in the spinal cord of rats with SCII were mediated by the ginsenoside Rb1-induced downregulation of caspase-3 and p-Ask-1 levels and the Bax/Bcl-2 ratio.

The Protective Effect of Spinal Cord Stimulation Postconditioning Against Spinal Cord Ischemia/Reperfusion Injury in Rabbits

Delayed paraplegia due to spinal cord ischemia/reperfusion injury (IRI) remains one of the most severe complications of thoracoabdominal aneurysm surgery, for which effective prevention and treatment is still lacking. The current study investigates whether spinal cord stimulation (SCS) postconditioning has neuroprotective effects against spinal cord IRI. Ninety-six New Zealand white male rabbits were randomly divided into four groups as follows: a sham group and three experimental groups (C group, 2 Hz group, and 50 Hz group) n = 24/group. Spinal cord ischemia was induced by transient infrarenal aortic balloon occlusion for 28 min, after which rabbits in group C underwent no additional intervention, while rabbits in the other two experimental groups underwent 2 Hz or 50 Hz epidural SCS for 30 min at the onset of reperfusion and then daily until sacrifice. Hind limb neurologic function of rabbits was assessed using Jacob scale. Lumbar spinal cords were harvested immediately after sacrifice for histological examination and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. The number of viable α-motor neurons in ventral horn was counted and TUNEL-positive rate of α-motor neurons was calculated. Spinal cord IRI was caused by transient infrarenal aorta occlusion for 28 min. Both 2 Hz and 50 Hz SCS postconditioning had neuroprotective effects, particularly the 2 Hz SCS postconditioning. Comparing to C group and 50 Hz group, rabbits in the 2 Hz group demonstrated better hind limb motor function and a lower rate of TUNEL-positive α-motor neuron after eight hours, one day, three days, and seven days of spinal cord reperfusion. More viable α-motor neurons were preserved after one and three days of spinal cord reperfusion in 2 Hz group rabbits than in C group and 50 Hz group rabbits. SCS postconditioning at 2 Hz protected the spinal cord from IRI.

The study on pathological mechanism and solution method for spinal cord ischemia reperfusion injury.

We aimed at investigating the pathological mechanism changing of injury during reperfusion injury, reperfusion time correlation and compliance, finding the blood supply and improving the secondary damage. A total of 180 patients who underwent a surgical procedure and that received normal saline intraperitoneally immediately after the patients' aortic occlusions were investigated. Patients were divided in three groups. Experimental conditions and programs were designed for various approaches. Thirty min after the onset of ischemia, we found a decrease in the local blood flow in the lumbar spinal cord, almost -77.48% of the baseline, which was reversed partially by initial reperfusion, even exceeding the baseline level. However, 1 hour after reperfusion, the blood flow was again decreased to the level below the baseline, followed by a decline to 207.13% ± 38.25 PU for 3 h without any recovery. Attenuating this secondary damage with neuroprotective strategies requires an understanding of these pathophysiologic processes. This study showed the pathological mechanism changes during reperfusion injury and reperfusion time correlation and compliance, and analyzed some of the important pathophysiologic processes involved in secondary damage after spinal cord injury. Moreover, our research discusses a number of pharmacologic therapies that have either been studied or have future potential for this devastating injury.

Protective role of astragalus injection in spinal cord ischemia-reperfusion injury in rats.

Objectives:To investigate the neuroprotective effect of Astragalus injection in a spinal cord ischemia-reperfusion (I/R) injury model.Methods:A total of 27 Sprague Dawley rats were randomly divided into 3 groups: control group (n=3), I/R group (n=12), and Astragalus injection group (Ast group, n=12). Spinal cord ischemia was induced by occlusion of the abdominal aorta above the right renal artery for 32 min. Animals in the Ast group were administered Astragalus injection (6.42 mL/kg) at 30 min before the induction of ischemia. After reperfusion for 8, 12, 24, or 48 hours, the serum neuron-specific enolase (NSE) concentration was measured by enzyme-linked immunosorbent assay (ELISA) and the aquaporin-4 (AQP4) protein level was detected by western blotting.Results:The pathological changes, as assessed by hematoxylin and eosin (HE) staining, were milder in the spinal cords of the Ast group compared to the I/R group. Enzyme-linked immunosorbent assay demonstrated that the NSE concentration of the Ast group was significantly lower than that of the I/R group (p<0.05). However, the NSE concentrations of the I/R and Ast groups were significantly higher than that of the control group (p=0.05). Additionally, the expression of AQP4 in the Ast group was lower than that of the I/R group at each time point.Conclusion:These findings indicate that Astragalus injection has a neuroprotective effect in spinal cord I/R injury by decreasing the AQP4 expression.

The attenuation of neurological injury from the use of simvastatin after spinal cord ischemia-reperfusion injury in rats

BackgroundSpinal cord ischemic injury remains a serious complication of open surgical and endovascular aortic procedures. Simvastatin has been reported to be associated with neuroprotective effect after spinal cord ischemia-reperfusion (IR) injury. The aim of this study was to determine the therapeutic efficacy of starting simvastatin after spinal cord IR injury in a rat model.MethodsIn adult Sprague-Dawley rats, spinal cord ischemia was induced using a balloon-tipped catheter placed in the descending thoracic aorta. The animals were then randomly divided into 4 groups: group A (control); group B (0.5 mg/kg simvastatin); group C (1 mg/kg simvastatin); and group D (10 mg/kg simvastatin). Simvastatin was administered orally upon reperfusion for 5 days. Neurological function of the hind limbs was evaluated for 7 days after reperfusion and recorded using a motor deficit score (MDS) (0: normal, 5: complete paraplegia). The number of normal motor neurons within the anterior horns of the spinal cord was counted after final MDS evaluation. Then, the spinal cord was harvested for histopathological examination.ResultsGroup D showed a significantly lower MDS than the other groups at post-reperfusion day 1 and this trend was sustained throughout the study period. Additionally, a greater number of normal motor neurons was observed in group D than in other groups (group D 21.2 [3.2] vs. group A: 15.8 [4.2]; group B 15.4 [3.4]; and group C 15.5 [3.7]; P = 0.002).ConclusionsThe results of the current study suggest that 10 mg/kg can significantly improve neurologic outcome by attenuating neurologic injury and restoring normal motor neurons after spinal cord IR injury.

Optimized induction of beta common receptor enhances the neuroprotective function of erythropoietin in spinal cord ischemic injury

BackgroundParaplegia remains the most feared complication of complex thoracoabdominal aortic intervention. Although erythropoietin (EPO) has demonstrated neuroprotective effects in spinal cord ischemia, it does not work until expression of the beta common receptor subunit of the EPO receptor (βcR) is induced by ischemia. We hypothesized that the βcR can be induced by diazoxide (DZ), amplifying the neuroprotective effects of EPO in spinal cord ischemia-reperfusion injury. MethodsFor the DZ time trial, adult male C57/BL6 mice received DZ (20 mg/kg) by oral gavage. Spinal cords were harvested after 0, 12, 24, 36, and 48 hours of administration. To evaluate optimal dosing, DZ was administered at 0, 5, 10, 20, and 40 mg/kg. The expression of βcR was assessed by Western blot analysis. Five groups were studied: PBS (pretreatment)+PBS (immediately before), PBS+EPO, DZ+PBS, DZ+EPO, and sham (without cross-clamping). Spinal cord ischemia was induced by 4 minutes of thoracic aortic cross-clamping. Functional scoring (Basso Mouse Score) was done at 12-hour intervals for 48 hours, and spinal cords were harvested for histological analysis. ResultsWestern blot analysis demonstrated that optimal βcR up-regulation occurred at 36 hours after DZ administration, and the optimal DZ dosage for βcR induction was 20 mg/kg. Motor function at 48 hours after treatment was significantly better preserved in the DZ+EPO group compared with all other groups, and was significantly better preserved in the DZ only and EPO only groups compared with control (PBS+PBS). ConclusionsPharmacologic up-regulation of βcR with DZ can increase the efficacy of EPO in preventing spinal cord ischemia and reperfusion injury. Improved understanding of this synergetic mechanism may serve to further prevent ischemic complications for high-risk aortic intervention.

Protection from spinal cord ischemia-reperfusion damage with alpha-lipoic acid preconditioning in an animal model.

This study aims to investigate whether preconditioning with alpha-lipoic acid has any protective effect in neuronal damage in an experimental spinal cord ischemia-reperfusion injury model. Eighteen adult male New Zealand rabbits (2.4-3.5 kg) were equally divided into sham, control and treatment groups. The abdominal aorta was occluded for 30 min proximally 1 cm below the renal artery and distally 1 cm above the bifurcation using aneurysm clips in control and treatment groups. Treatment group received intraperitoneal 100 mg/kg lipoic acid 20 min before aortic cross-clamping. The animals were sacrificed 48 hours after the operation and spinal cord segments between L2 and L5 were removed for biochemical and histopathological analysis. Levels of glutathione, malondialdehyde, total nitrate/nitrite, advanced oxidation protein products, catalase, superoxide dismutase, and glutathione peroxidase were examined in spinal cord. Preconditioning with alpha-lipoic acid demonstrated significantly favorable effects in all measured parameters of oxidative stress. Histopathological evaluation of the tissues also demonstrated significantly decreased neuronal degeneration, axonal damage, and microglial and astrocytic infiltration in the treatment group compared to the control group. The results of this study indicate that alpha-lipoic acid administration before aortic cross-clamping has significant neuroprotective effect on spinal cord injury in rabbits.

Mesenchymal Stem Cell-Based Therapy Improves Lower Limb Movement After Spinal Cord Ischemia in Rats

Spinal cord ischemia is a devastating complication after thoracic and thoracoabdominal aortic operations. In this study, we aimed to investigate the effects of mesenchymal stem cells (MSCs), which have regenerative capability and exert paracrine actions on damaged tissues, injected into rat models of spinal cord ischemia-reperfusion injury. Forty-five Sprague-Dawley rats were divided into sham, phosphate-buffered saline (PBS), and MSC groups. Spinal cord ischemia was induced in the latter two groups by balloon occlusion of the thoracic aorta. MSCs and PBS were then immediately injected into the left carotid artery of the MSC and PBS groups, respectively. Hindlimb motor function was evaluated at 6 and 24 hours. The spinal cord was removed at 24 hours after ischemia-reperfusion injury, and histologic and immunohistochemical analyses and real-time polymerase chain reaction assessments were performed. Rats in the MSC and PBS groups showed flaccid paraparesis/paraplegia postoperatively. Hindlimb function was significantly better at 6 and 24 hours after ischemia-reperfusion injury in the MSC group than in the PBS group (p < 0.05). The number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive neuron cells in the spinal cord and the ratio of Bax to Bcl2 were significantly larger (p < 0.05) in the PBS group than in the MSC group. The injected MSCs were observed in the spinal cord 24 hours after ischemia-reperfusion injury. The MSC therapy by transarterial injection immediately after spinal cord ischemia-reperfusion injury may improve lower limb function by preventing apoptosis of neuron cells in the spinal cord.

Hydrogen sulfide upregulated lncRNA CasC7 to reduce neuronal cell apoptosis in spinal cord ischemia-reperfusion injury rat

ObjectiveHydrogen sulfide has been recognized as an important neuroprotective agent in the nervous system. The present study aimed to study the effect and the underlying mechanisms of hydrogen sulfide on spinal cord ischemia-reperfusion injury (SCII). MethodsThe gene mRNA and protein expression were examined by RT-PCR and western blot, respectively. Spinal cord infarct zone was analyzed by Triphenyltetrazolium chloride staining. Cell apoptosis was detected by MTT assay. The relationship between miR-30c and CasC7 was analyzed by RNA immunoprecipitation (RIP) and RNA pull-down. ResultsWe observed that SCII rat model have a bigger spinal cord infarct zone than the control rat, but NaSH preprocessing could reduce spinal cord infarct zone in SCII rat. OGD/R induced cell apoptosis, and NaSH preprocessing reduced the OGD/R-induced SH5Y-SY cells apoptosis. CasC7 was decreased in SCII rat and OGD/R-induced SH5Y-SY cells, while miR-30c expression was increased. NaSH preprocessing upregulated CasC7 and downregulated miR-30c in OGD/R-induced SH5Y-SY cells. In OGD/R induced SH5Y-SY cells with NaSH preprocessing, knockdown of CasC7 could upregulate miR-30c expression, promote cell apoptosis and downregulate miR-30c’s target gene expression. The RIP and RNA pull-down demonstrated that CasC7 functioned as a miR-30c decoy, and miR-30c inhibitor could reverse the effect of si-CasC7. Moreover, intrathecal injection of si-CasC7 upregulated miR-30c expression and increased spinal cord infarct zone in SCII rat with NaSH preprocessing. ConclusionHydrogen sulfide protects spinal cord by upregulating CasC7 expression in SCII rat model.

Down-regulated miR-448 relieves spinal cord ischemia/reperfusion injury by up-regulating SIRT1.

MicroRNAs play a crucial role in the progression of spinal cord ischemia/reperfusion injury (SCII). The role of miR-448 and SIRT1 in SCII was investigated in this study, to provide further insights into prevention and improvement of this disorder. In this study, expressions of miR-448 and SIRT1 protein were determined by qRT-PCR and western blot, respectively. Flow cytometry was used to analyze cell apoptosis. The endogenous expression of genes was modulated by recombinant plasmids and cell transfection. Dual-luciferase reporter assay was performed to determine the interaction between miR-448 and SIRT1. The Basso, Beattie, and Bresnahan score was used to measure the hind-limb function of rat. The spinal cord ischemia reperfusion injury model of adult rats was developed by abdominal aorta clamping, and the nerve function evaluation was completed by motor deficit index score. In SCII tissues and cells treated with hypoxia, miR-448 was up-regulated while SIRT1 was down-regulated. Hypoxia treatment reduced the expression of SIRT1 through up-regulating miR-448 in nerve cells. Up-regulation of miR-448 induced by hypoxia promoted apoptosis of nerve cells through down-regulating SIRT1. Down-regulated miR-448 improved neurological function and hind-limb motor function of rats with SCII by up-regulating SIRT1. Down-regulated miR-448 inhibited apoptosis of nerve cells and improved neurological function by up-regulating SIRT1, which contributes to relieving SCII.

Antioxidative and Antiapoptotic Effects of Delta-Opioid Peptide [D-Ala2, D-Leu5] Enkephalin on Spinal Cord Ischemia-Reperfusion Injury in Rabbits.

Background: In our previous study, we found that regional administration of delta-opioid peptide [D-Ala2, D-Leu5] enkephalin (DADLE) could provide dose-dependent protection on spinal cord ischemia-reperfusion (I/R) injury in rabbits. However, the relative protective molecular mechanisms underlying this neuroprotection remain unclear. The purpose of this study was to investigate whether DADLE provided the protection in spinal cord I/R injury through its antioxidant property by decreasing malondialdehyde (MDA) and nitric oxide (NO) levels and increasing glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) levels and through its antiapoptotic capacity by inhibiting caspase-3 and p53 expression.Methods: The rabbits were divided into three groups. The animals in Group NS and Group DADLE were administered with normal saline (NS) or DADLE via aorta during 30 min of ischemia respectively, while the one in Group Sham received no intervention. During the period of reperfusion, the rabbit's blood samples were collected for enzyme-linked immunoabsorbent assay (ELISA) examinations of MDA, NO, GSH-Px and SOD. At 48 h after reperfusion, the lumbar spinal cords were harvested for immunohistochemical, real-time polymerase chain reaction (PCR) and western blot studies to detect the caspase-3 and p53 expressions.Results: The activities of serum MDA and NO showed significant reductions in the DADLE group as compared with the control group. By contrast, the levels of serum GSH-Px and SOD were significantly higher in the DADLE group than those in the NS group. In addition, caspase-3 and p53 expression were significantly increased in the NS group, while DADLE mitigated these changes.Conclusions: The protective effects of DADLE at the dosage of 0.05 mg/kg may be related to its antioxidant and antiapoptosis properties in the rabbit model of spinal cord I/R injury.