Spinal Cord Ischemia-reperfusion Research Articles

Effects of ligustrazine on autophagy-related proteins after spinal cord ischemia-reperfusion injury

Objective To investigate the effect of ligustrazine on autophagy-related proteins Beclin l, LC3 and P62 after spinal cord ischemia-reperfusion injury. Methods A total of 48 SD rats were randomly divided into sham operation group, model group, ligustrazine group and 3-MA group. The rats were intraperitoneally injected with ligustrazine injection 0.16 mg/kg in the Ligustrazine group, the rats were intraperitoneally injected with 3-methyladenine injection 0.015 mg/kg in the inhibitor group, and the rats were intraperitoneally injected with normal saline of equal volume in the sham operation group and model group. Spinal cord ischemia-reperfusion model was established in all groups except sham-operated group after administration. After molding behavioral scores were scored after 3 and 6 hours of ischemia, and the expression of Beclin l, LC3 and P62 was detected by immunohis-tochemistry. Results After 3 and 6 hours, compared with the model group, the behavioral score (3 h: 2.33 ± 0.58 vs. 0.67 ± 0.58, 6 h: 3.33 ± 0.58 vs. 1.33 ± 0.58) of the rats in ligustrazine group significantly increased (P<0.05). Compared with the model group, the expression of Beclinl (3 h: 348.00×104 ± 0.27×104vs. 659.00×104 ± 0.11×104; 6 h: 38.00×104 ± 0.19×104vs. 557.00×104 ± 0.26×104), LC3 (3 h: 357.00×104 ± 0.48×104vs. 686.00×104 ± 0.33×104; 6 h: 334.00×104 ± 0.51×104vs. 673.00×104 ± 0.22×104), P62 (3 h: 357.00×104 ± 0.48×104vs. 830.00×104 ± 0.48×104; 6 h: 315.00×104 ± 0.12×104vs. 591.00×104 ± 0.36×104) in ligustrazine group were significantly decreased (P<0.05). Conclusions The ligustrazine may regulate autophagy in two directions and protect nerve cells. Key words: Chuanxiongzine; Spinal cord ischemia; Reperfusion injury; Beclin-1; Rats

Role of ERK signaling pathway in intrathecal dexmedetomidine-induced reduction of spinal cord ischemia-reperfusion injury in rats

Objective To evaluate the role of extracellular signal-regulated kinase (ERK) signaling pathway in intrathecal dexmedetomidine-induced reduction of spinal cord ischemia-reperfusion (I/R) injury in rats. Methods Eighty clean-grade male Sprague-Dawley rats, aged 9-10 weeks, weighing 300-350 g, were divided into 4 groups (n=20 each) using a random number table method: sham operation group (group S), spinal cord I/R group (group I/R), dexmedetomidine group (group D), and dexmedetomidine plus ERK signaling pathway blocker PD98059 group (group P). Spinal cord ischemia was produced by cross-clamping of the abdominal aorta distal to the left renal artery for 25 min followed by reperfusion to establish the model of spinal cord I/R injury.Dexmedetomidine 1 μg/kg was intrathecally injected at 20 min before establishing the model in D and P groups, PD98059 2 mg/kg was given via the tail vein at the same time in group P, and the equal volume of normal saline was given instead in S and I/R groups.Five rats were selected at 6, 8, 10 and 12 h of reperfusion, and the modified Basso, Beattie, Bresnahan (BBB) scale was used to assess the hindlimb locomotor function.Five rats were sacrificed after assessing the locomotor function at 6 h of reperfusion, and the L3-5 segments of the spinal cord were taken for determination of cell apoptosis (by TUNEL) and expression of phosphorylated ERK (p-ERK) (by Western blot). The apoptosis index was calculated. Results Compared with group S, the BBB scores were significantly decreased at each time point of reperfusion, the apoptosis index was increased, and the expression of p-ERK was up-regulated in the other three groups (P 0.05). Compared with group D, the BBB scores were significantly decreased at each time point of reperfusion, the apoptosis index was increased, and the expression of p-ERK was down-regulated in group P (P<0.05). Conclusion The mechanism by which intrathecal dexmedetomidine reduces spinal cord I/R injury is related to activating ERK signaling pathway in rats. Key words: Dexmedetomidine; Reperfusion injury; Spinal cord; Extracellular signal-regulated MAP kinases

Effects of ginsenoside Rb1 on spinal cord ischemia-reperfusion injury in rats

BackgroundThe aim of this study was to evaluate the effects of different doses of ginsenoside Rb1 (GRb1) pretreatment on spinal cord ischemia-reperfusion (SCII) in rats and explore the potential mechanisms about the expression of survivin protein after the intervention.MethodsA total of 90 healthy adult Sprague-Dawley (SD) rats were randomly divided into six groups: sham-operated (n = 15), SCII model (n = 15), and GRb1-treated groups (n = 60). The GRb1-treated group was divided into four subgroups: 10 mg/kg, 20 mg/kg, 40 mg/kg, and 80 mg/kg (n = 15). The corresponding dose of GRb1 was injected intraperitoneally 30 min before operation and every day after operation. Forty-eight hours after model establishment, the neurological function of hind limbs was measured with Basso, Beattie, and Bresnahan (BBB) scale. The superoxide dismutase (SOD) and malondialdehyde (MDA) levels in serum and spinal cord tissue were detected respectively. The expression of survivin protein was observed by immunofluorescence staining. HE and TUNEL staining were used to observe neural cell injury and apoptosis, respectively, in the spinal cord of rats with SCII.ResultsThe intervention of different doses of GRb1 could increase SOD activity and decrease MDA content in serum and spinal cord tissue, increase survivin protein expression, and decrease neuronal apoptosis. It was dose-dependent, but there was no significant change between 40 mg/kg and 80 mg/kg.ConclusionsGRb1 could reduce the cell apoptosis induced by SCII through inhibiting oxidative stress. It can also inhibit apoptosis by promoting the expression of Survivin protein. Ginsenoside Rb1 had a dose-dependent protective effect on SCII in the dose range of 10 mg/kg–40 mg/kg.

The Pathway of Let-7a-1/2-3p and HMGB1 Mediated Dexmedetomidine Inhibiting Microglia Activation in Spinal Cord Ischemia-Reperfusion Injury Mice.

Microglial cell activation after spinal cord ischemia-reperfusion injury (SCIRI) commonly causes the secondary nerve motion function injury. This study aims to study the mechanism by which the drug dexmedetomidine (DEX) inhibits microglial cell activation and improves motion function of SCIRI mice. Mice SCIRI model was established, and microglia from spinal cord were isolated and cultured for subsequent molecule analysis of let-7a-1-3p, let-7a-2-3p, HMGB1, TNF-α, and IL-6. DEX was given by intraperitoneal injection. Mice motion function was evaluated by Basso mouse score. In vitro microglial cells were subjected to oxygen and glucose deprivation/reoxygenation (OGD/R) to imitate ischemia-reperfusion injury stimulation. DEX injection improves the mouse motion function in SCIRI model and upregulates let-7a-1/2-3p expression in the isolated activated microglia from SCIRI mice. In OGD/R-stimulated microglia, DEX treatment also caused the inactivation of cells, the upregulation of let-7a-1/2-3p expression, and the downregulation of HMGB1 expression. While the co-silencing of let-7a-1/2-3p in microglia in addition to DEX treatment restored the activation of microglia. HMGB1 is a targeted gene for let-7a-1/2-3p and negatively regulated by them. HMGB1 knockdown abrogates the pro-activation impact on microglial cell by let-7a-1/2-3p silencing. DEX inhibits the activation of microglial cell in the spinal cord of SCIRI mice, mediated by the let-7a-1/2-3p/HMGB1 pathway.

Protective Effect of Combined Melatonin and &amp;#945;-Tocopherol Administration in Spinal Cord Ischemia-Reperfusion Injury in Rat

Protective Effect of Combined Melatonin and &amp;#945;-Tocopherol Administration in Spinal Cord Ischemia-Reperfusion Injury in Rat

MLN4924 Exerts a Neuroprotective Effect against Oxidative Stress via Sirt1 in Spinal Cord Ischemia-Reperfusion Injury.

Oxidative stress is a leading contributor to spinal cord ischemia-reperfusion (SCIR) injury. Recently, MLN4924, a potent and selective inhibitor of the NEDD8-activating enzyme, was shown to exert a neuroprotective effect against oxidative stress in vitro. However, it is unknown whether MLN4924 plays a protective role against SCIR injury. In the present study, we found that MLN4924 treatment significantly attenuated oxidative stress and neuronal cell death induced by H2O2 in SH-SY-5Y neural cells and during rat SCIR injury. Furthermore, MLN4924 administration restored neurological and motor functions in rats with SCIR injury. Mechanistically, we found that MLN4924 protects against H2O2- and SCIR injury-induced neurodegeneration by regulating sirtuin 1 (Sirt1) expression. Collectively, these findings demonstrate the neuroprotective role of MLN4924 against oxidative stress in SCIR injury via Sirt1.

Neuroprotective effect of neuregulin-1β on spinal cord ischemia reperfusion injury

Objective: This study was designed to see if neuregulin-1β (NRG-1β) plays a protective role in spinal cord ischemia and reperfusion injury (SCII). Design: Animal research. Setting: China. Participants: NA. Interventions: Forty-eight SD rats were randomly divided into control group (n = 16), SCII model group (n = 16) and NRG-1β-treated group (n = 16). In control group, the abdominal aorta was isolated but not clipped. The rats in NRG-1β-treated group were treated with 10μg/kg NRG-1β during developing SCII model. Outcome Measures: Neurological scores were evaluated. At 3, 6, 12 and 24 h after the reperfusion, rats were killed. Pathological changes of spinal cord were assessed with HE staining, and immunohistochemical staining of matrix metalloproteinases-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1). MMP-9 and TIMP-1 mRNA levels were assessed using real-time PCR. Results: NRG-1β reduced the damage of SCII in the rats. The expression of MMP-9 protein and mRNA in NRG-1β treatment group was significantly lower than the model group (P < 0.05) at 6 h, 12 h and 24 h after the perfusion. The expression of TIMP-1 protein and mRNA in the treatment group was significantly higher than the model group at 12 h and 24 h after the perfusion. Conclusion: NRG-1β reduced the reperfusion damage in rat model of SCII, in which process MMP-9 and TIMP-1 were probably involved.

Activation of SK/KCa Channel Attenuates Spinal Cord Ischemia-Reperfusion Injury via Anti-oxidative Activity and Inhibition of Mitochondrial Dysfunction in Rabbits.

Spinal cord ischemia-reperfusion injury (SCI/R) is a rare but devastating disorder with a poor prognosis. Small conductance calcium-activated K+ (SK/KCa) channels are a family of voltage-independent potassium channels that are shown to participate in the pathological process of several neurological disorders. The aim of this study was to investigate the role of SK/KCa channels in experimental SCI/R in rabbits. The expression of SK/KCa1 protein significantly decreased in both cytoplasm and mitochondria in spinal cord tissues after SCI/R. Treatment with 2 mg/kg NS309, a pharmacological activator for SK/KCa channel, attenuated SCI/R-induced neuronal loss, spinal cord edema and neurological dysfunction. These effects were still observed when the administration was delayed by 6 h after SCI/R initiation. NS309 decreased the levels of oxidative products and promoted activities of antioxidant enzymes in both serum and spinal cord tissues. The results of ELISA assay showed that NS309 markedly decreased levels of pro-inflammatory cytokines while increased anti-inflammatory cytokines levels after SCI/R. In addition, treatment with NS309 was shown to preserve mitochondrial respiratory complexes activities and enhance mitochondrial biogenesis. The results of western blot analysis showed that NS309 differentially regulated the expression of mitochondrial dynamic proteins. In summary, our results demonstrated that the SK/KCa channel activator NS309 protects against SCI/R via anti-oxidative activity and inhibition of mitochondrial dysfunction, indicating a therapeutic potential of NS309 for SCI/R.

Protective effect of lutein on spinal cord ischemia-reperfusion injury in rats.

Objective(s):Paraplegia is deterioration in motor or sensory function of the lower limbs that can occur after modification of a thoracoabdominal aortic aneurysm. The purpose of this survey was to determine the protective action of lutein on spinal cord ischemia-reperfusion (I-R) damage. Materials and Methods:Thirty-five male rats were distributed into five groups: intact, sham, dimethyl sulfoxide (I-R+DMSO), low dose lutein (I-R+0.2 mg/kg lutein), and high dose lutein (I-R + 0.4 mg/kg lutein). Thirty minutes before surgery, a single dose lutein or DMSO was administered to rats of experimental groups. Next, the abdominal aorta was clamped exactly under the left renal artery and proximal to the abdominal aortic bifurcation for 60 min. All animals were evaluated by neurological function and histological and biochemical examinations at 72 hr after I-R.Results:The mean motor deficit index (MDI) scores in lutein groups were lower compared with the DMSO group (P<0.001). Plasma level of malondialdehyde in lutein groups decreased compared with the DMSO group (P<0.05). Plasma level of total antioxidative capacity was increased in the high lutein group compared with low dose lutein and sham groups (P<0.05). Mean number of normal motor neurons in lutein groups was greater compared with the DMSO group (P<0.001). There was a significant negative correlation between MDI scores and the number of normal neurons (r= -0.764, P<0.001).Conclusion:Findings of the present study demonstrate that lutein may support spinal cord neurons from I-R damage.

Abdominal Aortic Transplantation of Bone Marrow Mesenchymal Stem Cells Regulates the Expression of Ciliary Neurotrophic Factor and Inflammatory Cytokines in a Rat Model of Spinal Cord Ischemia-Reperfusion Injury.

BackgroundThis study aimed to investigate the effects of abdominal aortic transplantation of bone marrow mesenchymal stem cells (BMMSCs) on the expression of inflammatory cytokines in a rat model of spinal cord ischemia-reperfusion injury.Material/MethodsAdult female Sprague-Dawley rats (N=160) were divided into five groups: the sham operation group (N-32); the control group (N=32); the BMMSC transplanted group (N=32); the anti-ciliary neurotrophic factor (CNTF)-treated BMMSC transplanted group (N=32); and the CNTF small interfering RNA (siRNA)-treated BMMSC transplanted group (N=32). Motor behavior was assessed using the Basso, Beattie, and Bresnahan (BBB) locomotor scale. Motor evoked potentials (MEPs) and cortical somatosensory evoked potentials (CSEPs) were measured. Immunohistochemistry, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot analysis evaluated the expression of spinal inflammatory cytokines.ResultsFollowing surgery, compared with the control group the findings in the BMMSC transplant groups included significantly increased BBB scores; the latency and the amplitude of MEP and CSEP were reduced and increased, respectively; spinal neuronal necrosis was reduced; the number of normal neurons increased; CNTF mRNA and protein expression levels increased; expression levels of interleukin-6 (IL-6) were reduced and IL-10 levels were significantly increased (P<0.05). The effects of abdominal aortic BMMSC transplantation were at least partially reversed by both anti-CNTF and CNTF siRNA treatment.ConclusionsIn a rat model of spinal cord ischemia-reperfusion injury, abdominal aortic transplantation of BMMSCs increased the expression of CNTF, which improved hindlimb locomotor recovery by regulating the expression of IL-6 and IL-10 to reduce inflammation of the spinal cord.

MicroRNA-30c abrogation protects against spinal cord ischemia reperfusion injury through modulating SIRT1

Spinal cord ischemia/reperfusion (I/R) injury is a severe complication in many surgeries. Although microRNAs (miRNAs) are involved in I/R-caused spinal cord injury (SCI), the mechanism that underlies miR-30c interacted with SCI remains elusive. In this study, I/R surgery or oxygen-glucose deprivation (OGD) were performed to establish SCI model in vivo or in vitro, respectively. Basso, Beattie and Bresnahan (BBB) score, spinal cord infarct, terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) staining, flow cytometry and enzyme linked immunosorbent assays (ELISA) were used to investigate SCI. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to examine the abundances of miR-30c and sirtuin 1 (SIRT1) either in spinal cord or PC12 cells. Luciferase assay and RNA immunoprecipitation (RIP) were performed to probe the interaction between miR-30c and SIRT1. Western blot and immunofluorescence assays were used to analyze SIRT1 protein expression. Our results showed that I/R increased miR-30c expression and induced SCI, revealed by decreasing BBB score, enhancing apoptosis, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expression. However, miR-30c knockdown attenuated I/R-induced SCI in vivo. Moreover, depletion of miR-30c protected PC12 cells against OGD-caused apoptosis and inflammatory response. In addition, SIRT1 was limited by miR-30c, silencing of which reversed anti-miR-30c-mediated inhibitory effect on apoptosis and secretion of inflammatory cytokines in PC12 cells after OGD treatment. Collectively, abrogation of miR-30c inhibited spinal cord ischemia reperfusion injury through targeting SIRT1, providing a promising biomarker of prognosis and therapeutic for SCI.

Downregulation of LncRNA TUG1 Inhibited TLR4 Signaling Pathway-Mediated Inflammatory Damage After Spinal Cord Ischemia Reperfusion in Rats via Suppressing TRIL Expression.

Toll-like receptor 4 (TLR4) and TLR4 interactor with leucine-rich repeats (TRIL) play a crucial role in the inflammatory response. This study investigated the role of long noncoding RNA taurine-upregulated gene 1 (lncRNA TUG1) in TRIL/TLR4 signaling in spinal cord ischemia reperfusion (IR) injury. IR injury was induced in experimental rats; knockdown of TUG1 and TRIL was induced by intrathecal injection of siRNAs and overexpression of TRIL was induced by pcDNA3.3-TRIL. The results showed that the mRNA levels of TUG1 were increased at 12 hours after IR; this was accompanied by increased expression of the TRIL- and TLR4-mediated NF-κB/IL-1β signaling pathway. Activated microglia, detected with increased ionized calcium-binding adapter molecule 1 as a marker, exacerbated the hind-limb neurological impairment and blood-spinal cord barrier (BSCB) leakage after IR. TUG1 knockdown inhibited expression of TRIL and TLR4 signaling proinflammatory cytokines and microglial activation, and attenuated neurological deficit and BSCB leakage. TRIL knockdown inhibited the TLR4-mediated inflammatory response, while TRIL expression reversed the inhibited inflammatory effect caused by TUG1 knockdown. These data suggest that TUG1 knockdown inhibited inflammatory damage of the TLR4-mediated NF-κB/IL-1β signaling pathway after IR via suppressing TRIL expression.

Dexmedetomidine Preconditioning Ameliorates Inflammation and Blood-Spinal Cord Barrier Damage After Spinal Cord Ischemia-Reperfusion Injury by Down-Regulation High Mobility Group Box 1-Toll-Like Receptor 4-Nuclear Factor κB Signaling Pathway.

To evaluate the effect of Dexmedetomidine (Dex) on the inflammatory response and the integrity of blood-spinal cord barrier (BSCB) after spinal cord ischemia-reperfusion injury (SCIRI). To investigate the role of Dex in spinal cord I/R, particularly in the high mobility group box 1-toll-like receptor 4-nuclear factor κB (HMGB1-TLR4-NF-κB) pathway and the integrity of BSCB. High mobility group box 1 (HMGB1) has been identified as a key mediator for the inflammatory response after spinal cord injury. Toll-like receptor 4-nuclear factor κB (TLR4-NF-κB) signaling pathway is the downstream of HMGB1. Dex preconditioning could protect the spinal cord from I/R injury by inhibiting HMGB1 and stabilizing the integrity of BSCB. But its underlying mechanism is not fully understood. Forty-eight male Japanese white rabbits were randomly assigned to three groups (16 rabbits/group): sham, I/R, and Dex + I/R. The hind-limb motor function was assessed at 12 hours intervals for 48 hours after reperfusion using the modified Tarlov scale score. The expression of HMGB1, TLR4, NF-κB, and tumor necrosis factor α (TNF-α) was evaluated by real-time polymerase chain reaction (RT-PCR) and Western blot. The permeability of BSCB was examined via Evans blue (EB) extravasation. Compared with sham group, spinal cord I/R increased the expression of HMGB1, TLR4, NF-κB, and TNF-α as well as the permeability of BSCB (P < 0.05). Spinal cord I/R induced the decline of the score of hind-limb motor function (P < 0.01). Preconditioning with Dex attenuated the up-regulation of the express of HMGB1, TLR4, NF-κB, TNF-α, and stabilized the permeability of BSCB (P < 0.05). Dex preconditioning also improved the hiatopathological outcome and the motor function (P < 0.01). Dex preconditioning may inhibit the inflammatory response and stabilize the integrity of BSCB at least partially by inhibiting the HMGB1-TLR4-NF-κB signaling pathway to protect spinal cord from ischemia/reperfusion injury. 2.

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.

Antioxidative and anti-inflammatory effects of Cichorium intybus L. seed extract in ischemia/reperfusion injury model of rat spinal cord

Objectives: The antioxidant and anti-inflammatory effects of aqueous extract of chicory seed (CSE, Cichorium intybus L. seed) following spinal cord ischemia/reperfusion (SCI/R) injury in rat model were evaluated. Methods: In this study 36 male Wistar rats were randomly divided to six groups: control (Co), sham (Sh), CSE, SCI/R, CSE+SCI/R (7 days pretreatment with CSE group+inducing I/R injury), SCI/R +CSE (induced I/R injury group+3 days treatment with CSE). SCI/R injury was induced by creating a longitudinal incision on the midline of abdominal region and clamping the aorta just below renal artery for 30 minutes. After 3 days, SC was removed and used for evaluation of antioxidant enzymes (including Superoxide dismutase [SOD] and catalase [CAT]), oxidative stress markers (malondialdehyde [MDA]), inflammatory factors (IL1β, IL18 &amp; TNFα) and histopathological changes. Before sacrificing the animals, the motional score were assessed. Results: Our results demonstrated that, in the SCI/R group, the mean levels of SOD, and CAT were significantly decreased (P&lt;0.05), while the mean level of MDA was significantly increased (P&lt;0.05) in comparison to Co and Sh groups. Also, the mean levels of SOD and CAT in the treatment group were higher than the SCI/R group (P&lt;0.05), while, the mean MDA content in the treatment group was significantly less than the SCI/R group (P &lt;0.05). In addition, comparison between SCI/R and treatment groups demonstrated a significant decrease in tissue damage in the treatment group. Conclusions: Our study demonstrated that, the neuroprotective effects of aqueous extract of Cichorium intybus L. seed on SCI/R injury in rat by anti-oxidative and anti-inflammatory activities. Additionally, comparing the treatment and pretreatment groups shows that the pretreatment usage of the extract is more effective than treatment group.

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.