Bone marrow mesenchymal stem cells repair spinal cord ischemia/reperfusion injury by promoting axonal growth and anti-autophagy

Bone marrow mesenchymal stem cells can differentiate into neurons and astrocytes after trans- plantation in the spinal cord of rats with ischemia/reperfusion injury. Although bone marrow mesenchymal stem cells are known to protect against spinal cord ischemia/reperfusion injury through anti-apoptotic effects, the precise mechanisms remain unclear. In the present study, bone marrow mesenchymal stem cells were cultured and proliferated, then transplanted into rats with ischemia/reperfusion injury via retro-orbital injection. Immunohistochemistry and immunofluorescence with subsequent quantification revealed that the expression of the axonal regeneration marker, growth associated protein-43, and the neuronal marker, microtubule-as- sociated protein 2, significantly increased in rats with bone marrow mesenchymal stem cell transplantation compared with those in rats with spinal cord ischemia/reperfusion injury. Fur- thermore, the expression of the autophagy marker, microtubule-associated protein light chain 3B, and Beclin 1, was significantly reduced in rats with the bone marrow mesenchymal stem cell transplantation compared with those in rats with spinal cord ischemia/reperfusion injury. Western blot analysis showed that the expression of growth associated protein-43 and neuro- filament-H increased but light chain 3B and Beclin 1 decreased in rats with the bone marrow mesenchymal stem cell transplantation. Our results therefore suggest that bone marrow mes- enchymal stem cell transplantation promotes neurite growth and regeneration and prevents autophagy. These responses may likely be mechanisms underlying the protective effect of bone marrow mesenchymal stem cells against spinal cord ischemia/reperfusion injury.     

Ginsenoside Rd inhibits apoptosis following spinal cord ischemia/reperfusion injury

Ginsenoside Rd has a clear neuroprotective effect against ischemic stroke. We aimed to verify the neuroprotective effect of ginsenoside Rd in spinal cord ischemia/reperfusion injury and explore its anti-apoptotic mechanisms. We established a spinal cord ischemia/reperfusion injury model in rats through the occlusion of the abdominal aorta below the level of the renal artery for 1 hour. Successfully established models were injected intraperitoneally with 6.25, 12.5, 25 or 50 mg/kg per day ginsenoside Rd. Spinal cord morphology was observed at 1, 3, 5 and 7 days after spinal cord ischemia/reperfusion injury. Intraperitoneal injection of ginsenoside Rd in ischemia/reperfusion injury rats not only improved hindlimb motor function and the morphology of motor neurons in the anterior horn of the spinal cord, but it also reduced neuronal apoptosis. The optimal dose of ginsenoside Rd was 25 mg/kg per day and the optimal time point was 5 days after ischemia/ reperfusion. Immunohistochemistry and western blot analysis showed ginsenoside Rd dose-de- pendently inhibited expression of pro-apoptotic Caspase 3 and down-regulated the expression of the apoptotic proteins ASK1 and JNK in the spinal cord of rats with spinal cord ischemia/reper- fusion injury. These findings indicate that ginsenoside Rd exerts neuroprotective effects against spinal cord ischemia/reperfusion injury and the underlying mechanisms are achieved through the inhibition of ASK1-JNK pathway and the down-regulation of Caspase 3 expression.     

丹参酮对大鼠脊髓缺血再灌注损伤NMDAR1蛋白表达的影响

BACKGROUND： Tanshinone has been previously shown to be involved in the prevention and treatment of cerebral ischemia/reperfusion injury. In addition, excitatory amino acid-mediated neu- rotoxicity may induce neuronal damage following spinal cord ischemia/reperfusion injury.
OBJECTIVE： To explore the interventional effect of tanshinone on N-methyl-D-aspartate receptor 1 （NMDAR1） protein expression in a rat model of spinal cord ischemia/reperfusion injury.
DESIGN, TIME AND SETTING： A randomized molecular biology experiment was conducted at the Traumatology ＆ Orthopedics Laboratory of Fujian Hospital of Traditional Chinese Medicine （Key Laboratory of State Administration of Traditional Chinese Medicine） between September 2007 and May 2008. MATERIALS： A total of 88 Sprague Dawley rats were randomly divided into a sham operation （n = 8）, model （n = 40）, and tanshinone （n = 40） groups. Thirty minutes after ischemia, rats in the model and tanshinone groups were observed at hour 0.5, 1, 4, 8, and 12 following perfusion, with eight rats for each time point. METHODS： Abdominal aorta occlusion was performed along the right renal arterial root using a Scoville-Lewis clamp to induce spinal cord ischemia. Blood flow was recovered 30 minutes following occlusion to establish models of spinal cord ischemia/reperfusion injury. Abdominal aorta occlusion was not performed in the sham operation group. An intraperitoneal injection of tanshinone ⅡA sulfonic sodium solution （0.2 L/g） was administered to rats in the tanshinone group, preoperatively. In addition, rats in the sham operation and model groups were treated with an intraperitoneal injection of the same concentration of saline, preoperatively.
MAIN OUTCOME MEASURES： NMDAR1 protein expression in the anterior horn of the spinal cord, accumulative absorbance, average absorbance, and area of positive cells were detected in the three groups through immunohistochemistry.
RESULTS： All 88 rats were included in the final analysis. （1） NMDAR1 protein expression increased following 30-minute ischemia/1-hour reperfusion injury to the spinal cord, and reached a peak 4 hours after reperfusion. （2） Accumulative absorbance and average absorbance of NMDAR1, as well as area of positive cells in the model group, were significantly greater than the sham operation group at each time point （P 〈 0.05）. However, values in the tanshinone group were significantly less than the model group （P 〈 0.05）.
CONCLUSION： NMDAR1 protein expression was rapidly increased following spinal cord ischemia/reperfusion injury and reached a peak 4 hours following reperfusion. In addition, tanshinone downregulated NMDAR1 protein expression in the anterior horn of the spinal cord.     

Oxidative phosphorylated neurofilament protein M protects spinal cord against ischemia/reperfusion injury

Previous studies have shown that neurofilament protein M expression is upregulated in the early stage of spinal cord ischemia/reperfusion injury, indicating that this protein may play a role in the injury process. In the present study, we compared protein expression in spinal cord tissue of rabbits after 25 minutes of ischemia followed by 0, 12, 24, or 48 hours of reperfusion with that of sham operated rabbits, using proteomic two-dimensional gel electrophoresis and mass spec- trometry. In addition, the nerve repair-related neurofilament protein M with the unregulated expression was detected with immunohistochemistry and western blot analysis. Two-dimen- sional gel electrophoresis and mass spectrometry showed that, compared with the sham group, upregulation of protein expression was most significant in the spinal cords of rabbits that had undergone ischemia and 24 hours of reperfusion. Immunohistochemical analysis revealed that neurofilament protein M was located in the membrane and cytoplasm of neuronal soma and axons at each time point after injury. Western blot analysis showed that neurofilament protein M expression increased with reperfusion time until it peaked at 24 hours and returned to baseline level after 48 hours. Furthermore, neurofilament protein M is phosphorylated under oxidative stress, and expression changes were parallel for the phosphorylated and non-phosphorylated forms. Neurofilament protein M plays an important role in spinal cord ischemia/reperfusion injury, and its functions are achieved through oxidative phosphorylation.     

Stress protein expression in early phase spinal cord ischemia/reperfusion injury*

Spinal cord ischemia/reperfusion injury is a stress injury to the spinal cord. Our previous studies using differential proteomics identified 21 differentially expressed proteins (n > 2) in rabbits with spinal cord ischemia/reperfusion injury. Of these proteins, stress-related proteins included protein disulfide isomerase A3, stress-induced-phosphoprotein 1 and heat shock cognate protein 70. In this study, we established New Zealand rabbit models of spinal cord ischemia/reperfusion injury by abdominal aorta occlusion. Results demonstrated that hind limb function initially improved after spinal cord ischemia/reperfusion injury, but then deteriorated. The pathological morphology of the spinal cord became aggravated, but lessened 24 hours after reperfusion. However, the numbers of motor neurons and interneurons in the spinal cord gradually decreased. The expression of protein disulfide isomerase A3, stress-induced-phosphoprotein 1 and heat shock cognate protein 70 was induced by ischemia/reperfusion injury. The expression of these proteins increased within 12 hours after reperfusion, and then decreased, reached a minimum at 24 hours, but subsequently increased again to similar levels seen at 6-12 hours, showing a characterization of induction-inhibition-induction. These three proteins were expressed only in cytoplasm but not in the nuclei. Moreover, the expression was higher in interneurons than in motor neurons, and the survival rate of interneurons was greater than that of motor neurons. It is assumed that the expression of stress-related proteins exhibited a protective effect on neurons.     

Key genes expressed in different stages of spinal cord ischemia/reperfusion injury

The temporal expression of microRNA atfer spinal cord ischemia/reperfusion injury is not yet fully understood. In the present study, we established a model of spinal cord ischemia in Sprague-Dawley rats by clamping the abdominal aorta for 90 minutes, before allowing reperfusion for 24 or 48 hours. A sham-operated group underwent surgery but the aorta was not clamped. The damaged spinal cord was removed for hematoxylin-eosin staining and RNA extraction. Neuronal degeneration and tissue edema were the most severe in the 24-hour reperfusion group, and milder in the 48-hour reperfusion group. RNA ampliifcation, labeling, and hybridization were used to obtain the microRNA expression proifles of each group. Bioinformatics analysis conifrmed four differentially expressed microRNAs (miR-22-3p, miR-743b-3p, miR-201-5p and miR-144-5p) and their common target genes (Tmem69 and Cxcl10). Compared with the sham group, miR-22-3p was continuously upregulated in all three ischemia groups but was highest in the group with no reperfusion, whereas miR-743b-3p, miR-201-5p and miR-144-5p were downregulated in the three ischemia groups. We have successfully identiifed the key genes expressed at different stages of spinal cord ischemia/reperfusion injury, which provide a reference for future investigations into the mechanism of spinal cord injury.     

脊髓缺血性损害时检测血糖、丙二醛、神经源性胞浆酶的意义

目的 观察家兔脊髓缺血性损害时血糖、丙二醛(MDA)、神经源性胞浆酶的变化,探讨其临床意义。方法 16只家兔随机分为二组:假手术组和缺血再灌注组,缺血再灌注组分缺血40min和再灌注后1h两时点采血。分别检测各组血糖、MDA、血清肌酸激酶(CK)、肌酸激酶脑型同工酶(CK-BB)、乳酸脱氢酶(LDH)及天门冬氨酸氨基转移酶(AST)等的含量。结果 缺血期血糖、CK、CK-BB及MDA均增高。再灌注后血糖下降,MDA持续增高,CK、CK-BB较缺血期进一步升高。结论 脊髓缺血再灌注损伤时CK、CK-BB明显增高,实时检测CK-BB的变化可反映脊髓损伤的程度。     

Edaravone promotes functional recovery after mechanical peripheral nerve injury

Edaravone has been shown to reduce ischemia/reperfusion-induced peripheral nerve injury. However, the therapeutic effect of edaravone on peripheral nerve injury caused by mechanical factors is unknown. In the present study, we established a peripheral nerve injury model by crushing the sciatic nerve using hemostatic forceps, and then administered edaravone 3 mg/kg intraperitoneally. The sciatic functional index and superoxide dismutase activity of the sciatic nerve were increased, and the malondialdehyde level was decreased in animals in the edaravone group compared with those in the model group. Bcl-2 expression was increased, but Bax expression was decreased in anterior horn cells of the L4–6 spinal cord segments. These results indicated that edaravone has a neuroprotective effect following peripheral nerve injury caused by mechanical factors through alleviating free radical damage to cells and inhibiting lipid peroxidation, as well as regulating apoptosis-related protein expression.     

丙泊酚可调节缺血再灌注损伤脊髓Ca2+, Mg2+, Cu2+，Zn2+的平衡

检测血清和脊髓匀浆中Ca2+、Mg2+、Cu2+、Zn2+的变化规律，揭示丙泊酚对缺血再灌注损伤脊髓保护作用的可能机制。结果发现，随着缺血再灌注损伤时间的延长，兔血清Ca2+，Cu2+浓度逐渐升高，Mg2+，Zn2+浓度逐渐下降，至脊髓损伤后7d，以上离子变化最明显；缺血再灌注损伤7 d，兔缺血脊髓匀浆中的各离子浓度变化与血清中相一致。给予丙泊酚干预后，缺血再灌注期间兔血清和脊髓匀浆中Ca2+、Mg2+、Cu2+、Zn2+浓度均无显著的波动。提示丙泊酚可通过稳定或恢复脊髓缺血再灌注损伤区金属离子的平衡发挥对脊髓缺血再灌注损伤的保护作用。     

Key genes expressed in different stages of spinal cord ischemia/reperfusion injury ischemia/reperfusion injury

The temporal expression of microRNA after spinal cord ischemia/reperfusion injury is not yet fully understood.In the present study,we established a model of spinal cord ischemia in Sprague-Dawley rats by clamping the abdominal aorta for 90 minutes,before allowing reperfusion for 24 or 48 hours.A sham-operated group underwent surgery but the aorta was not clamped.The damaged spinal cord was removed for hematoxylin-eosin staining and RNA extraction.Neuronal degeneration and tissue edema were the most severe in the 24-hour reperfusion group,and milder in the 48-hour reperfusion group.RNA amplification,labeling,and hybridization were used to obtain the microRNA expression profiles of each group.Bioinformatics analysis confirmed four differentially expressed microRNAs(miR-22-3p,miR-743b-3p,miR-201-5p and miR-144-5p) and their common target genes(Tmem69 and CxcllO).Compared with the sham group,miR-22-3p was continuously upregulated in all three ischemia groups but was highest in the group with no reperfusion,whereas miR-743b-3p,miR-201-5p and miR-144-5p were downregulated in the three ischemia groups.We have successfully identified the key genes expressed at different stages of spinal cord ischemia/reperfusion injury,which provide a reference for future investigations into the mechanism of spinal cord injury.     

异丙酚及缺血预处理联合对主动脉阻断致脊髓损伤的保护

目的 探讨缺血预处理(ischemic preconditioning,IPC)和异丙酚（Propofol）预处理对兔主动脉阻断所致脊髓损伤的防治作用其可能作用机制。 方法 本实验有二处理因素：缺血预处理及异丙酚预处理。采用2×2析因实验设计,分四个实验组：缺血再灌注损伤组（A组,空白组）、缺血预处理组（B组）、异丙酚组（C组）及缺血预处理和异丙酚联合预处理组（D组）。雄性日本大白兔32只,随机分为4组,每组8只。各组阻断腹主动脉40min,再灌注7d。B组IPC5min,再灌注30min后阻断腹主动脉40min,再灌注7d;C组静注异丙酚5mg/kg 10min后阻断腹主动脉40min,再灌注7d;D组IPC5min,,再灌注20min时静注异丙酚5mg/kg,再灌注30min时阻断腹主动脉血流40分钟,再灌注7天。分别测定阻断前10min（C-10）、开放前即刻（C40）、再灌注60min（R60）及7d（R7d）血清MDA、SOD;观察术后后肢神经功能;脊髓病理学观察;脊髓凋亡神经元。 结果 ①缺血再灌注后B、C、D组MDA值明显高于C-10值及A组相应时点值（p<0.05）, SOD值变化同MDA变化相反（p<0.05）; B组缺血后各时点MDA值明显低于C组(P<0.05), D组缺血后各时点MDA值明显低于B、C组(P<0.05),SOD值变化同MDA变化相反（p<0.05）。②B、C、D组凋亡细胞数明显少于A组(P<0.05); B组明显少于C组(P<0.05),D组明显少于B、C组(P<0.05)。③B、C、D组瘫痪发生率明显低于A组(P<0.05),B组瘫痪发生率明显低于C组(P<0.05),D组瘫痪发生率明显低于B、C组(P<0.05);B、C、D组后肢神经功能评分明显高于A组(P<0.05), B组后肢神经功能评分高于C组(P<0.05),D后肢神经功能评分高于B、C组(P<0.05)。④ D组脊髓病理变化明显轻于A、B、C组(P<0.05)。结论 缺血预处理和异丙酚预处理对兔主动脉阻断所致脊髓损伤都有良好的防治作用;缺血预处理对脊髓缺血再灌注损伤的作用明显好于异丙酚;缺血预处理和异丙酚联合应用对脊髓缺血再灌注损伤有更加良好的防治作用,表现出一定的交互作用。缺血预处理和异丙酚联合预处理对兔主动脉阻断所致脊髓损伤其机制可能与其抗氧化反应作用有关。     

Curcumin protects against ischemic spinal cord injury The pathway effect

Inducible nitric oxide synthase and N-methyI-D-aspartate receptors have been shown to participate in nerve cell injury during spinal cord ischemia. This study observed a protective effect of curcumin on ischemic spinal cord injury. Models of spinal cord ischemia were established by ligating the lumbar artery from the left renal artery to the bifurcation of the abdominal aorta. At 24 hours after model establishment, the rats were intraperitoneally injected with curcumin, Reverse transcrip- tion-polymerase chain reaction and immunohistochemical results demonstrated that after spinal cord ischemia, inducible nitric oxide synthase and N-methyI-D-aspartate receptor mRNA and protein expression significantly increased. However, curcumin significantly decreased inducible nitric oxide synthase and N-methyI-D-aspartate receptor mRNA and protein expression in the ischemic spinal cord. Tadov scale results showed that curcumin significantly improved motor function of the rat hind limb after spinal cord ischemia. The results demonstrate that curcumin exerts a neuroprotective ef- fect against ischemic spinal cord injury by decreasing inducible nitric oxide synthase and N-methyI-D-aspartate receptor expression.     

Nischarin-siRNA delivered by polyethylenimine-alginate nanoparticles accelerates motor function recovery after spinal cord injury

A previous study by our group found that inhibition of nischarin promotes neurite outgrowth and neuronal regeneration in Neuro-2 a cells and primary cortical neurons.In recent years,more and more studies have shown that nanomaterials have good prospects in treatment of spinal cord injury.We proposed that small interfering RNA targeting nischarin(Nis-si RNA) delivered by polyethyleneimine-alginate(PEIALG) nanoparticles promoted motor function recovery in rats with spinal cord injury.Direct microinjection of 5 μL PEI-ALG/Nis-si RNA into the spinal cord lesion area of spinal cord injury rats was performed.From day 7 after surgery,Basso,Beattie and Bresnahan score was significantly higher in rats from the PEI-ALG/Nis-si RNA group compared with the spinal cord injury group and PEI-ALG/Control-si RNA group.On day 21 after injection,hematoxylin-eosin staining showed that the necrotic area was reduced in the PEI-ALG/Nis-si RNA group.Immunohistochemistry and western blot assay results confirmed successful inhibition of nischarin expression and increased protein expression of growth-associated protein-43 in the PEI-ALG/Nis-si RNA group.These findings suggest that a complex of PEI-ALG nanoparticles and Nis-si RNA effectively suppresses nischarin expression,induces expression of growth-associated protein-43,and accelerates motor function recovery after spinal cord injury.     

Neuroprotective effect of angiotensin Ⅱ type 2 receptor during cerebral ischemia/reperfusion

Angiotensin Ⅱ type 2 receptor(AT2R) activation has been shown to protect against stroke,but its precise mechanism remains poorly understood.We investigated whether the protective effect of AT2 R against ischemia/reperfusion injury is mediated by the suppression of immune and inflammatory responses.Rat models of middle cerebral artery occlusion were intraperitoneally injected with physiological saline,the AT2 R agonist CGP42112(1 mg/kg per day) or antagonist PD123319(1 mg/kg per day).In the CGP42112 group,AT2 R expression increased,the infarct area decreased,interleukin-1β and tumor necrosis factor-α expression decreased,and interleukin-10 expression increased compared with the saline group.Antagonisin AT2 R using PD123319 produced the opposite effects.These results indicate that AT2 R activation suppresses immune and inflammatory responses,and protects against cerebral ischemia/reperfusion injury.     

丹参酮IIa拮抗脊髓缺血再灌注损伤：干预谷氨酸释放的上游因素

目的：探讨丹参酮调控谷氨酸转运体功能对脊髓缺血再灌注损伤的作用。方法：88只SD 大鼠结扎腹主动脉,制作脊髓缺血再灌注损伤模型。按随机数字表法将动物分为假手术组（n=8）,模型组（n=40）和丹参酮组（n=40）。分别在脊髓缺血再灌注损伤后0.5h、1h、4h、8h、12h相应时点检测各组谷氨酸转运体功能和Na+-K+−ATP酶活性。结果： ①大鼠脊髓组织谷氨酸转运体功能及Na+-K+−ATP酶活性在脊髓缺血再灌注损伤后0.5h后开始下降,4h后降到最低点,其后活性逐渐恢复,但12h后仍未及正常水平。②丹参酮组各观测点脊髓组织谷氨酸转运体功能及Na+-K+−ATP酶活性均较其它两组高。结论：①大鼠脊髓缺血再灌注损伤时脊髓谷氨酸转运体功能和Na+-K+−ATP酶活性均下降;②丹参酮可能通过保护脊髓谷氨酸转运体功能和Na+-K+−ATP酶活性的下降,从而减轻大鼠脊髓缺血再灌注损伤。     

Neuroprotective effects of the immunodepressant FTY720 on caspase-3 expression and neural apoptosis in a rat model of acute spinal cord injury

BACKGROUND:Studies on the immunodepressant FTY720 have primarily focused on organ transplantation and autoimmune disease therapy.However,the effects on caspase-3 expression and neural apoptosis following acute spinal cord injury remain uncertain.OBJECTIVE:To elucidate the underlying mechanism of the immunodepressant FTY720 to alleviate spinal cord injury by inhibiting expression of caspase-3 and neural apoptosis.DESIGN,TIME AND SETTING:A randomized,controlled,animal experiment was performed at Central Laboratory of the Second Affiliated Hospital of Dalian Medical University from April to July 2009.MATERIALS:FTY720 was provided by Wuhan Yuancheng Technology Developing,China.METHODS:A total of 120 Sprague Dawley rats were randomly assigned to sham-surgery,model,and FTY720 groups.Spinal cord injury at the T9-10 segment was induced in model groups using the free-fall method.Following establishment of spinal cord injury at the T9-10 segment in the FTY720 group,rats were treated with an intragastric injection of 0.3 mL saline-diluted FTY720 (3 mg/kg).MAIN OUTCOME MEASURES:At 6,12,24,48,and 72 hours following spinal cord injury,caspase-3 expression was detected using streptavidin-peroxidase immunohistochemistry,and neural apoptosis was detected using the TUNEL method.RESULTS:Positive caspase-3 expression and neural apoptosis was not observed in the sham-surgery group at the various time points.The number of apoptotic cells increased with time after acute spinal cord injury,peaked at 24 hours following injury,and then gradually reduced.However,neural apoptosis remained at a high level.Caspase-3 expression positively correlated with neural apoptosis (r= 0.864,P< 0.05).Caspase-3 expression and neural apoptosis significantly decreased following FTY720 therapy (P< 0.05).CONCLUSION:FTY720 significantly reduced caspase-3 expression and neural apoptosis in a rat model of acute spinal cord injury.     

Propofol application combined with ischemic preconditioning for aortic occlusion-induced spinal cord injury

BACKGROUND:Propofol combined with ischemic preconditioning(IPC)could prevent spinal ischemia/reperfusion injury,However,the effect of this combination remains poorly understood.OBJECTIVE:To measure neuroprotection of IPC in combination with propofol in a rabbit model of aorta occlusion-induced spinal injury.DESIGN,TIME AND SETTING:A randomized,controlled,animal experiment was performed at the Laboratory of Anesthesiology,Wuhan University and Central Laboratory of the First Clinical Medical College,China Three Gorges University,from October 2006 to April 2008.MATERIALS:Propofol was purchased from AstraZeneca,UK; malondialdehyde(MDA)and superoxide dismutase(SOD)kits were purchased from Nanjing Jiancheng Bioengineering Institute,China.METHODS:A total of 32 male,Japanese White rabbits,were randomly assigned to model,IPC,propofol,and combination groups,with eight rabbits in each group,using 2 × 2 factorial experimental design.Spinal ischemia/reperfusion injury was induced by abdominal aorta occlusion for 40 minutes and reperfusion for 7 days.The IPC group was subjected to IPC treatment for 30 minutes prior to occlusion; the propofol group was treated with propofol for 10minutes before occlusion; and the combination group underwent IPC treatment for 30 minutes and propofol for 10 minutes prior to occlusion.MAIN OUTCOME MEASURES:Serum MDA levels and SOD activity were detected 35 minutes prior to occlusion,immediately after reperfusion,and 60 minutes and 7 days after reperfusion,respectively.Rabbit hind limb nerve function and spinal pathological changes following injury were observed,and spinal neuronal apoptosis was determined using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling method.RESULTS:Serum MDA levels,spinal neuronal apoptosis,and palsy incidence following injury were greatest in the propofol group,followed by the IPC and combination groups(P < 0.01),while SOD activity and hind limb neurological scores were greatest in the combination group,followed by the IPC and propofol groups.Spinal cord injury in the combination group was slight(P < 0.01).CONCLUSION:IPC and propofol treatment resulted in a synergistic effect for treating spinal ischemia/reperfusion injury.Combined application was superior to IPC or propofol treatment,suggesting that the protection of spinal cord injury may relate with anti-peroxidation.     

Influence of Tanshinone IIa on heat shock protein 70, Bcl-2 and Bax expression in rats with spinal ischemia/reperfusion injury

Tanshinone lla is an effective monomer component of Danshen, which is a traditional Chinese medicine for activating blood circulation to dissipate blood stasis. Tanshinone lla can effectively improve brain tissue ischemia/hypoxia injury. The present study established a rat model of spinal cord ischemia/reperfusion injury and intraperitoneally injected Tanshinone IIa, 0.5 hour prior to model establishment. Results showed that Tanshinone lla promoted heat shock protein 70 and Bcl-2 protein expression, but inhibited Bax protein expression in the injured spinal cord after ischemia/reperfusion injury. Furthermore, Nissl staining indicated a reduction in nerve cell apoptosis and fewer pathological lesions in the presence of Tanshinone lla, compared with positive control Danshen injection.     

Serine-threonine protein kinase activation may be an effective target for reducing neuronal apoptosis after spinal cord injury

The signaling mechanisms underlying ischemia-induced nerve cell apoptosis are poorly understood. We investigated the effects of apoptosis-related signal transduction pathways following ischemic spinal cord injury, including extracellular signal-regulated kinase (ERK), serine-threonine protein kinase (Akt) and c-Jun N-terminal kinase (JNK) signaling pathways. We established a rat model of acute spinal cord injury by inserting a catheter balloon in the left subclavian artery for 25 minutes. Rat models exhibited notable hindlimb dysfunction. Apoptotic cells were abundant in the anterior horn and central canal of the spinal cord. The number of apoptotic neurons was highest 48 hours post injury. The expression of phosphorylated Akt (p-Akt) and phosphorylated ERK (p-ERK) increased immediately after reperfusion, peaked at 4 hours (p-Akt) or 2 hours (p-ERK), decreased at 12 hours, and then increased at 24 hours. Phosphorylated JNK expression reduced after reperfusion, increased at 12 hours to near normal levels, and then showed a downward trend at 24 hours. Pearson linear correlation analysis also demonstrated that the number of apoptotic cells negatively correlated with p-Akt expression. These findings suggest that activation of Akt may be a key contributing factor in the delay of neuronal apoptosis after spinal cord ischemia, particularly at the stage of reperfusion, and thus may be a target for neuronal protection and reduction of neuronal apoptosis after spinal cord injury.