Cord Ischemia-reperfusion Injury In Rats Research Articles

Effect of captopril on paraplegia caused by spinal cord ischemia-reperfusion injury in rats.

This study investigated the effect of captopril (Cap) on spinal cord ischemia-reperfusion injury (SCII) in rats. Twenty-four adults male Wistar rats were randomly divided into four groups of six animals each: spinal cord ischemia-reperfusion (SCI-R) with Cap (SCI-R + Cap), SCI-R, sham-operated with Cap (SHAM + Cap), and SHAM. The 24 hr and 90 min before ischemia induction, Cap was administered intragastrically (100 mg kg-1) to the SHAM + Cap and SCI-R + Cap groups. Abdominal aortic clamping was performed in the SCI-R and SCI-R + Cap groups for 40 min. Hindlimb motor function was evaluated using the Tarlov Scale at 4, 6, 12, 24, 48, and 60 hr after SCII. The malondialdehyde (MDA), the ferric-reducing ability of plasma (FRAP) and prooxidant-antioxidant balance (PAB) values were also measured. Throughout the study period, the SCI-R group had significantly lower motor function scores compared to the other groups. The MDA and PAB levels were higher and the FRAP value was lower in the SCI-R group compared to in the SHAM group. The SCI-R + Cap had higher motor function scores compared to the SCI-R group at all time points. There were no significant differences in MDA concentration, FRAP and PAB values between the SCI-R + Cap and SCI-R groups. Captopril may act as a protective agent against SCII in rats based on hind limb motor function assessment.

Protective Effect of Gum Arabic on Spinal Cord Ischemia-reperfusion Injury in Rats

Protective Effect of Gum Arabic on Spinal Cord Ischemia-reperfusion Injury in Rats

Identification of key genes involved in neural regeneration and the repairing effect of BDNF-overexpressed BMSCs on spinal cord ischemia-reperfusion injury in rats

Bone marrow mesenchymal stem cells (BMSCs) can repair spinal cord ischemia-reperfusion injury (SCII); however, only a few BMSCs are usually located in the injured spinal cord. Since the brain-derived neurotrophic factor (BDNF) can promote neural development and maturation, we hypothesised that BDNF-overexpressed BMSCs can ameliorate SCII more effectively than BMSCs alone. To determine the effect of BDNF overexpression on SCII repair, BDNF-overexpressed BMSCs and BMSCs were transplanted into SCII rats. Our results revealed that BDNF-overexpressed BMSCs can better promote the recovery of damaged spinal cords than BMSCs alone. Gene chip detection of spinal cord tissues showed 803 differentially expressed genes in all groups. BTG anti-proliferation factor 2 (Btg2), FOS like 2 (Fosl2), early growth response protein 1 (Egr1), and serpin family E member 1 (Serpine1) were identified as key interrelated genes based on their expression trends, as validated via quantitative PCR and protein–protein interaction network analysis. A co-expression network was constructed to further explore the role of the candidate key genes using Pearson correlation analysis. Cluster 5 was identified as the key cluster using community discovery algorithms. Functional analysis of Cluster 5 genes revealed that this cluster was mainly involved in the stress-activated MAPK cascade, p38MAPK cascade, and apoptosis. Notably, Egr1 may play an important role in SCII repair as the top hub gene in Cluster 5. Therefore, the repair activity of transplanted BDNF-overexpressed BMSCs in SCII rats is better than that of BMSCs alone, which may be regulated by the interactions between Btg2, Fosl2, Egr1, Serpine1, and BDNF.

MiR-872-5p/FOXO3a/Wnt signaling feed-forward loop promotes proliferation of endogenous neural stem cells after spinal cord ischemia-reperfusion injury in rats.

The activation of endogenous neural stem cells (NSCs) is considered an important mechanism of neural repair after mechanical spinal cord injury; however, whether endogenous NSC proliferation can also occur after spinal cord ischemia-reperfusion injury (SCIRI) remains unclear. In this study, we aimed to verify the existence of endogenous NSC proliferation after SCIRI and explore the underlying molecular mechanism. NSC proliferation was observed after SCIRI in vivo and oxygen-glucose deprivation and reperfusion (OGD/R) in vitro, accompanied by a decrease in forkhead box protein O 3a (FOXO3a) expression. This downward trend was regulated by the increased expression of microRNA-872-5p (miR-872-5p). miR-872-5p affected NSC proliferation by targeting FOXO3a to increase the expression of β-catenin and T-cell factor 4 (TCF4). In addition, TCF4 in turn acted as a transcription factor to increase the expression level of miR-872-5p, and knockdown of FOXO3a enhanced the binding of TCF4 to the miR-872-5p promoter. In conclusion, SCIRI in vivo and OGD/R in vitro stimulated the miR-872-5p/FOXO3a/β-catenin-TCF4 pathway, thereby promoting NSC proliferation. At the same time, FOXO3a affected TCF4 transcription factor activity and miR-872-5p expression, forming a positive feedback loop that promotes NSC proliferation.

Xenon post-conditioning protects against spinal cord ischemia-reperfusion injury in rats by downregulating mTOR pathway and inhibiting endoplasmic reticulum stress-induced neuronal apoptosis

The purpose of this study was to determine whether xenon post-conditioning affects mTOR signaling as well as endoplasmic reticulum stress (ERS)-apoptosis pathway in rats with spinal cord ischemia/reperfusion injury. Fifty male rats were randomized equally into sham-operated group (Sham group), I/R model group (I/R group), I/R model+ xenon post-conditioning group (Xe group), I/R model+rapamycin (a mTOR signaling pathway inhibitor) treatment group (I/R+ Rapa group), and I/R model + xenon post- conditioning with rapamycin treatment group (Xe + Rapa group).. In the latter 4 groups, SCIRI was induced by clamping the abdominal aorta for 85 min followed by reperfusion for 4 h. Rapamycin (or vehicle) was administered by daily intraperitoneal injection (4 mg/kg) for 3 days before SCIRI, and xenon post-conditioning by inhalation of 1∶1 mixture of xenon and oxygen for 1 h at 1 h after initiation of reperfusion; the rats without xenon post-conditioning were given inhalation of nitrogen and oxygen (1∶ 1). After the reperfusion, motor function and histopathologic changes in the rats were examined. Western blotting and real-time PCR were used to detect the protein and mRNA expressions of GRP78, ATF6, IRE1α, PERK, mTOR, p-mTOR, Bax, Bcl-2 and caspase-3 in the spinal cord. The rats showed significantly lowered hind limb motor function following SCIRI (P < 0.01) with a decreased count of normal neurons, increased mRNA and protein expressions of GRP78, ATF6, IRE1α, PERK, and caspase-3, and elevated p-mTOR/mTOR ratio and Bax/Bcl-2 ratio (P < 0.01). Xenon post-conditioning significantly decreased the mRNA and protein levels of GRP78, ATF6, IRE1α, PERK and caspase-3 (P < 0.05 or 0.01) and reduced p-mTOR/mTOR and Bax/Bcl-2 ratios (P < 0.01) in rats with SCIRI; the mRNA contents and protein levels of GRP78 and ATF6 were significantly decreased in I/R+Rapa group (P < 0.01). Compared with those in Xe group, the rats in I/R+Rapa group and Xe+Rapa had significantly lowered BBB and Tarlov scores of the hind legs (P < 0.01), and caspase-3 protein level and Bax/Bcl-2 ratio were significantly lowered in Xe+Rapa group (P < 0.05 or 0.01). By inhibiting ERS and neuronal apoptosis, xenon post- conditioning may have protective effects against SCIRI in rats. The mTOR signaling pathway is partially involved in this process.

Protective Effect of Catechin Hydrate on Spinal Cord Ischemia-reperfusion Injury in Rats

Background: Aortic artery stenosis leads to Ischemia-Reperfusion (I-R) injury, which can cause certain clinical expressions, such as paraplegia. Objectives: To appraise the effect of Catechin Hydrate (CH) against spinal cord I-R injury. Materials &amp; Methods: A total of 35 male rats (250-300 g) were divided randomly into five groups: intact, sham surgery, dimethyl sulfoxide (I-R+DMSO), low-dose CH (I-R+10 mg/kg CH), and high-dose CH (I-R+20 mg/kg CH). Abdominal aorta clamping was done for 60 min. Seventy-two hours after I-R, animals were evaluated for neurologic function, biochemical analysis, and histology. The data analysis was conducted by SPSS v. 16 using ANOVA and Kruskal-Wallis and Mann-Whitney U tests. Results: The mean Motor Deficit Index (MDI) score and white matter damage in the CH (20 mg/kg) group were lower than in the DMSO group (P=0.032). The mean plasma levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in the CH groups were lower than that of the DMSO group (P&lt;0.05). The plasma level of Total Antioxidant Capacity (TAC) in the CH (20 mg/kg) group was higher than in the DMSO group (P=0.032). In addition, the plasma level of catalase in the CH (20 mg/kg) group was higher than in the DMSO and CH (10 mg/kg) groups (P&lt;0.001). The average number of normal motor neurons in the experimental groups was lower than in the sham surgery group (P&lt;0.001).

Identification of key microRNAs and the underlying molecular mechanism in spinal cord ischemia-reperfusion injury in rats.

Spinal cord ischemia-reperfusion injury (SCII) is a pathological process with severe complications such as paraplegia and paralysis. Aberrant miRNA expression is involved in the development of SCII. Differences in the experimenters, filtering conditions, control selection, and sequencing platform may lead to different miRNA expression results. This study systematically analyzes the available SCII miRNA expression data to explore the key differently expressed miRNAs (DEmiRNAs) and the underlying molecular mechanism in SCII. A systematic bioinformatics analysis was performed on 23 representative rat SCII miRNA datasets from PubMed. The target genes of key DEmiRNAs were predicted on miRDB. The DAVID and TFactS databases were utilized for functional enrichment and transcription factor binding analyses. In this study, 19 key DEmiRNAs involved in SCII were identified, 9 of which were upregulated (miR-144-3p, miR-3568, miR-204, miR-30c, miR-34c-3p, miR-155-3p, miR-200b, miR-463, and miR-760-5p) and 10 downregulated (miR-28-5p, miR-21-5p, miR-702-3p, miR-291a-3p, miR-199a-3p, miR-352, miR-743b-3p, miR-125b-2-3p, miR-129-1-3p, and miR-136). KEGG enrichment analysis on the target genes of the upregulated DEmiRNAs revealed that the involved pathways were mainly the cGMP-PKG and cAMP signaling pathways. KEGG enrichment analysis on the target genes of the downregulated DEmiRNAs revealed that the involved pathways were mainly the Chemokine and MAPK signaling pathways. GO enrichment analysis indicated that the target genes of the upregulated DEmiRNAs were markedly enriched in biological processes such as brain development and the positive regulation of transcription from RNA polymerase II promoter. Target genes of the downregulated DEmiRNAs were mainly enriched in biological processes such as intracellular signal transduction and negative regulation of cell proliferation. According to the transcription factor analysis, the four transcription factors, including SP1, GLI1, GLI2, and FOXO3, had important regulatory effects on the target genes of the key DEmiRNAs. Among the upregulated DEmiRNAs, miR-3568 was especially interesting. While SCII causes severe neurological deficits of lower extremities, the anti-miRNA oligonucleotides (AMOs) of miR-3568 improve neurological function. Cleaved caspase-3 and Bax was markedly upregulated in SCII comparing to the sham group, and miR-3568 AMO reduced the upregulation. Bcl-2 expression levels showed a opposite trend as cleaved caspase-3. The expression of GATA6, GATA4, and RBPJ decreased after SCII and miR-3568 AMO attenuated this upregulation. In conclusion, 19 significant DEmiRNAs in the pathogenesis of SCII were identified, and the underlying molecular mechanisms were validated. The DEmiRNAs could serve as potential intervention targets for SCII. Moreover, inhibition of miR-3568 preserved hind limb function after SCII by reducing apoptosis, possibly through regulating GATA6, GATA4, and RBPJ in SCII.

Identification of the biological function of miR-9 in spinal cord ischemia-reperfusion injury in rats.

Spinal cord ischemia–reperfusion injury (SCII) is still a serious problem, and the mechanism is not fully elaborated. In the rat SCII model, qRT-PCR was applied to explore the altered expression of miR-9 (miR-9a-5p) after SCII. The biological function of miR-9 and its potential target genes based on bioinformatics analysis and experiment validation in SCII were explored next. Before the surgical procedure of SCII, miR-9 mimic and inhibitor were intrathecally infused. miR-9 mimic improved neurological function. In addition, miR-9 mimic reduced blood-spinal cord barrier (BSCB) disruption, inhibited apoptosis and decreased the expression of IL-6 and IL-1β after SCII. Gene Ontology (GO) analysis demonstrated that the potential target genes of miR-9 were notably enriched in several biological processes, such as “central nervous system development”, “regulation of growth” and “response to cytokine”. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the potential target genes of miR-9 were significantly enriched in several signaling pathways, including “Notch signaling pathway”, “MAPK signaling pathway”, “Focal adhesion” and “Prolactin signaling pathway”. We further found that the protein expression of MAP2K3 and Notch2 were upregulated after SCII while miR-9 mimic reduced the increase of MAP2K3 and Notch2 protein. miR-9 mimic or MAP2K3 inhibitor reduced the release of IL-6 and IL-1β. miR-9 mimic or si-Notch2 reduced the increase of cleaved-caspase3. Moreover, MAP2K3 inhibitor and si-Notch2 reversed the effects of miR-9 inhibitor. In conclusion, overexpression of miR-9 improves neurological outcomes after SCII and might inhibit BSCB disruption, neuroinflammation, and apoptosis through MAP2K3-, or Notch2-mediated signaling pathway in SCII.

Dexmedetomidine postconditioning alleviates spinal cord ischemia-reperfusion injury in rats via inhibiting neutrophil infiltration, microglia activation, reactive gliosis and CXCL13/CXCR5 axis activation

Purpose Spinal cord ischemia-reperfusion (I/R) injury is an unresolved complication and its mechanisms are still not completely understood. Here, we studied the neuroprotective effects of dexmedetomidine (DEX) postconditioning against spinal cord I/R injury in rats and explored the possible mechanisms. Materials and methods In the study, rats were randomly divided into five groups: sham group, I/R group, DEX0.5 group, DEX2.5 group, and DEX5 group. I/R injury was induced in experimental rats; 0.5 μg/kg, 2.5 μg/kg, 5 μg/kg DEX were intravenously injected upon reperfusion respectively. Neurological function, histological assessment, and the disruption of blood-spinal cord barrier (BSCB) were evaluated via the BBB scoring, hematoxylin and eosin staining, Evans Blue (EB) extravasation and spinal cord edema, respectively. Neutrophil infiltration was evaluated via Myeloperoxidase (MPO) activity. Microglia activation and reactive gliosis was evaluated via ionized calcium-binding adapter molecule-1(IBA-1) and glial fibrillary acidic protein (GFAP) immunofluorescence, respectively. The expression of C-X-C motif ligand 13 (CXCL13), C-X-C chemokine receptor type 5(CXCR5), caspase-3 was determined by western blotting. The expression levels of interleukin 6(IL-6), tumor necrosis factor-α(TNF-α), IL-1β were determined by ELISA assay. Results DEX postconditioning preserved neurological assessment scores, improved histological assessment scores, attenuated BSCB leakage after spinal cord I/R injury. Neutrophil infiltration, microglia activation and reactive gliosis were also inhibited by DEX postconditioning. The expression of CXCL13, CXCR5, caspase-3, IL-6, TNF-α, IL-1β were reduced by DEX postconditioning. Conclusions DEX postconditioning alleviated spinal cord I/R injury, which might be mediated via inhibition of neutrophil infiltration, microglia activation, reactive gliosis and CXCL13/CXCR5 axis activation.

Fe3O4 methylprednisolone plus calpain inhibitor protects against spinal cord ischemia-reperfusion injury in rats

To investigate the neuroprotective effects of pretreatment with Fe3O4 methylprednisolone plus calpain inhibitor against spinal cord ischemia-reperfusion injury (SCI) in rats. A total of 18 male Sprague Dawley rats were randomly divided into sham operation, model, and pretreatment + SCI groups (receiving 25 mg/kg Fe3O4 methylprednisolone plus calpain inhibitor) (n = 6 each). The SCI model was established by clamping the left renal inferior abdominal aorta. Hindlimb motor function was evaluated 6, 12, 24, and 48 hours after reperfusion. At 48 hours after reperfusion, spinal cord tissues were collected for histopathological examination, measurement of oxidation product accumulation (malondialdehyde, MDA), and antioxidant enzyme activity assays [superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX)]. Motor function scores were compared using non-parametric rank sum (Kruskal-Wallis) test, and mean tissue MDA content and antioxidant enzyme activities were compared using one-way analysis of variance. Compared with the sham operation group, the model group showed significantly increased MDA content (2.95 vs. 5.90 g mg; P = 0.023); significantly increased GSH-Px activity (0.31 vs. 0.78 U/mg; P = 0.001); significantly decreased SOD (16.03 vs. 8.37 U/mg; P = 0.001) and CAT (1.24 vs. 0.54 U/mg; P = 0.002) activities; and significantly decreased hindlimb motor function score at 6 hours (21 to 15.5; P =0.001). Compared with the model group, the pretreatment + SCI group showed significantly decreased MDA content (5.90 vs. 3.27 mg; P = 0.0355); significantly decreased GSH-Px activity (0.78 vs. 0.36 U/mg; P = 0.001); and significantly increased SOD (8.37 vs. 14.79 U/mg; P = 0.001) and CAT (0.54 vs. 0.89 U/mg; P = 0.043) activities. Histopathological changes were significantly less severe in the pretreatment + SCI group than in the model and sham operation groups (P &lt; 0.05). Pretreatment with Fe3O4 methylprednisolone plus calpain inhibitor can prevent SCI by improving the balance between oxidation and antioxidant systems.

Assessment of the neuroprotective effects of (-)-epigallocatechin-3-gallate on spinal cord ischemia-reperfusion injury in rats

Objective: Paraplegia or paraparesis due to spinal cord ischemia is one of the complications following thoracoabdominal aortic surgery. Recent studies revealed the neuroprotective effects of (-)-epigallocatechin-3-gallate (EGCG) on a variety of neurological disorders. The purpose of this study was to determine the neuroprotective effects of EGCG following spinal cord ischemia-reperfusion injury (IRI). Design: The present study was conducted on four groups of rats each as follows: Sham-operated group (laparotomy alone); Control group (with IRI); EGCGI group (50-mg/kg, i.p., before IRI), and EGCGII group (50-mg/kg, i.p., after IRI). Neurological function evaluated with motor deficit index (MDI) test. Spinal cord samples were taken 48 h after IRI and studied for determination of malodialdehyde (MDA) level, histopathology, and immunohistochemistry of caspase-3, TNF-α, and iNOS. Setting: Mazandaran University of Medical Sciences, Sari, Iran. Results: The level of MDA was significantly decreased in EGCG-treated rats. Attenuated caspase-3, TNF-α, and iNOS expression could be significantly detected in the EGCG-treated rats. Also, EGCG reduced the extent of degeneration of the spinal cord neurons, in addition to a significant reduction of MDI. Conclusion: The results suggest that pre- and post-treatment with EGCG may be effective in protecting spinal cord from IRI.

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.

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.

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.

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.

Protective effect of Crocus sativus L. (Saffron) extract on spinal cord ischemia-reperfusion injury in rats.

Objective(s):Ischemia/reperfusion (I/R) injury of spinal cord is leading to the paraplegia observed. In this study, we investigated the protective effect of the saffron extract on spinal cord I/R injury.Materials and Methods:Thirty five male Sprague-Dawley rats were divided into 5 groups: intact, sham surgery, normal saline (NS), low dose saffron aqua extract, high dose saffron aqua extract.Results:The mean motor deficit index (MDI) scores were significantly lower in the saffron extract groups than in the NS group at 48 hr after spinal cord ischemia (P<0.001). Saffron extract groups significantly decreased plasma level of malondialdehyde than in the NS Group (P<0.05). The number of motor normal neurons was significantly greater in the high saffron extract group than in the NS and low saffron group (P<0.05).Conclusion:These data suggest that a saffron extract may protect spinal cord neurons from I/R injury.

Methane ameliorates spinal cord ischemia-reperfusion injury in rats: Antioxidant, anti-inflammatory and anti-apoptotic activity mediated by Nrf2 activation

Methane is reported to have antioxidant, anti-inflammatory and anti-apoptotic properties. We investigated the potential neuroprotective effects of methane-rich saline (MS) on spinal cord ischemia-reperfusion injury and determined that its therapeutic benefits are associated with the activation of nuclear factor erythroid 2-related factor 2 (Nrf2). Rats received 9min of spinal cord ischemia induced by occlusion of the descending thoracic aorta plus systemic hypotension followed by a single MS treatment (10ml/kg, ip) and 72h reperfusion. MS treatment attenuated motor sensory deficits and produced high concentrations of methane in spinal cords during reperfusion, which increased Nrf2 expression and transcriptional activity in neurons, microglia and astrocytes in the ventral, intermediate and dorsal gray matter of lumbar segments. Heme oxygenase-1, superoxide dismutase, catalase and glutathione were upregulated; and glutathione disulfide, superoxide, hydrogen peroxide, malondialdehyde, 8-hydroxy-2-deoxyguanosine and 3-nitrotyrosine were downregulated in MS-treated spinal cords. MS treatment reduced neuronal apoptosis in gray matter zones, which was consistent with the suppression of cytochrome c release to the cytosol from the mitochondria and the activation of caspase-9 and -3. Throughout the gray matter, the activation of microglia and astrocytes was inhibited; the nuclear accumulation of phosphorylated nuclear factor-kappa B p65 was reduced; and tumor necrosis factor α, interleukin 1β, chemokine (C-X-C motif) ligand 1, intercellular adhesion molecule 1 and myeloperoxidase were decreased. MS treatment attenuated blood-spinal cord barrier dysfunction by preventing the expression and activity of matrix metallopeptidase-9 and disrupting tight junction proteins. Consecutive intrathecal injection of specific siRNAs targeting Nrf2 at 24-h intervals 3 days before ischemia reduced the beneficial effects of MS. Our data indicate that MS treatment prevents IR-induced spinal cord damage via antioxidant, anti-inflammatory and anti-apoptotic activities that involve the activation of Nrf2 signaling. Thus, methane may serve as a novel promising therapeutic agent for treating ischemic spinal cord injury.

Neuroprotective Effects of Pregabalin Against Spinal Cord Ischemia-Reperfusion Injury in Rats.

To evaluate the effect of pregabalin pre-treatment on spinal cord ischemia-reperfusion (I/R) injury and compare with methylprednisolone (MP). Thirty-two rats were randomly divided into four groups as follow: Group 1 (sham)(n=8), group 2 (ischemia only)(n=8), group 3 (30 mg/kg pregabalin)(n=8), and group 4 (30 mg/kg methylprednisolone)(n=8). Laparotomy was performed without aortic clamp in the sham group. All animals were sacrificed 24 hours after surgery. The spinal cord tissue samples were harvested and caspase-3 activity, tumor necrosis factor-alpha (TNF-α) and Interleukin-1 Beta (IL-1β) levels, catalase (CAT) activity, glutathione peroxidase (GPx) activity, superoxide dismutase (SOD) levels malondialdehyde (MDA) levels and nitric oxide (NO) levels were analyzed to investigate the effects of different excitatory and inflammatory pathways in mechanism of I/R injury. Ultrastructural and histopathological examinations were carried out. Neurological recovery was measured by Basso, Beattie, Bresnahan (BBB) test and Inclined Plane Test. Decresead caspase-3 activity and decreased inflammatory markers like TNF-α, IL-1β, and decresaed excitotatory pathways like CAT, GPx, MDA, NO and SOD were observed in both pregabalin pre-treatment and MP treatment groups. Pregabalin pre-treatment produced better ultrastructural results compared to MP treatment, as with histopathological examination. Pregabalin group showed better recovery compared to MP treament group according to BBB scoring system. Pregabalin pre-treatmet and MP treatment both has neuroprotective effect on I/R injury by decreasing caspase dependant apoptosis, and inflammatory and oxidative stress markers. In addition, pregabalin pre-treatment had better clinical effects compared to MP treatment.