Induction of mmp-9 expression and endothelial injury by oxidative stress after spinal cord injury

Matrix metalloproteinase-9 (MMP-9) activation plays an important role in blood-brain barrier (BBB) dysfunction after central nervous system injury. Oxidative stress is also implicated in the pathogenesis after cerebral ischemia and spinal cord injury (SCI), but the relationship between MMP-9 activation and oxidative stress after SCI has not yet been clarified. We examined MMP-9 expression after SCI using copper/zinc-superoxide dismutase (SOD1) transgenic (Tg) rats. Our results show that MMP-9 activity significantly increased after SCI in both SOD1 Tg rats and their wild-type (Wt) littermates, although the increase was less in the SOD1 Tg rats. This pattern of MMP-9 expression was further confirmed by immunostaining and Western blot analysis. In situ zymography showed that gelatinolytic activity increased after SCI in the Wt rats, while the increase was less in the Tg rats. Evans blue extravasation increased in both the Wt and Tg rats, but was less in the SOD1 Tg rats. Inhibitor studies showed that, with an intrathecal injection of SB-3CT (a selective MMP-2/MMP-9 inhibitor), the MMP activity, Evans blue extravasation, and apoptotic cell death decreased after SCI. We conclude that increased oxidative stress after SCI leads to MMP-9 upregulation, BBB disruption, and apoptosis, and that overexpression of SOD1 in Tg rats decreases oxidative stress and further attenuates MMP-9 mediated BBB disruption.     

Caspase-Independent Programmed Cell Death Following Ischemic Stroke

There is accumulating evidence that caspase-independent programs play a significant role in delayed neuronal death following ischemic stroke. Previous research has implicated mitochondrial proteins, such as apoptosis-inducing factor (AIF) and Bcl-2/adenovirus E1B 19 kDa-interacting protein (BNIP3), as players involved in this pathway. More recent work has begun to hone in on the specific interactions between these molecules and the mediators that might function upstream [e.g., poly(ADP-ribose) polymerase-1 (PARP-1)] and downstream [e.g., endonuclease G (EndoG)] of them. As the study of caspase-independent programs has expanded, it has become increasingly apparent that this pathway is not simply an alternative to apoptosis when caspases are unavailable, but a unique process, distinct from both apoptosis and necrosis. Similar caspase-independent pathways as the ones mentioned apply to organ systems outside of the central nervous system. Put together, the data suggest that caspase-independent programmed cell death is a complex and resilient death program that will likely need to be considered and countered in devising an effective drug therapy for the treatment of ischemic stroke.     

Caspase-independent programmed cell death following ischemic stroke.

There is accumulating evidence that caspase-independent programs play a significant role in delayed neuronal death following ischemic stroke. Previous research has implicated mitochondrial proteins, such as apoptosis-inducing factor (AIF) and Bcl-2/adenovirus E1B 19 kDa-interacting protein (BNIP3), as players involved in this pathway. More recent work has begun to hone in on the specific interactions between these molecules and the mediators that might function upstream [e.g., poly(ADP-ribose) polymerase-1 (PARP-1)] and downstream [e.g., endonuclease G (EndoG)] of them. As the study of caspase-independent programs has expanded, it has become increasingly apparent that this pathway is not simply an alternative to apoptosis when caspases are unavailable, but a unique process, distinct from both apoptosis and necrosis. Similar caspase-independent pathways as the ones mentioned apply to organ systems outside of the central nervous system. Put together, the data suggest that caspase-independent programmed cell death is a complex and resilient death program that will likely need to be considered and countered in devising an effective drug therapy for the treatment of ischemic stroke.     

黄连素在脊髓损伤中对线粒体的保护作用及机制

目的探讨黄连素对脊髓损伤(SCI)后线粒体氧化损伤的作用和可能机制。方法将36只C57小鼠随机分为假手术组、SCI组(伤后立即腹腔注射10 mg/kg生理盐水)和黄连素组(SCI后立即腹腔注射10 mg/kg黄连素),每组12只。使用PSI-IH脊髓打击器建立小鼠SCI模型,于损伤后24 h处死小鼠,取脊髓组织。使用全自动酶标仪检测各组小鼠脊髓组织线粒体内丙二醛(MDA)、还原型谷胱甘肽(GSH)和超氧化物歧化酶(SOD)的变化;用蛋白质印迹法检测脊髓组织caspase-3、cleaved caspase-3的表达及细胞质内和线粒体内细胞色素C(Cyt C)的表达;用免疫荧光双标染色法检测脊髓组织中神经细胞凋亡情况。结果与假手术组相比,SCI组小鼠脊髓组织线粒体内MDA水平升高,GSH、SOD水平降低;细胞质内Cyt C和脊髓组织中caspase-3、cleaved caspase-3表达水平增高,线粒体内Cyt C表达水平降低;脊髓组织中神经元凋亡比例增高;差异均有统计学意义(P 0.05)。与SCI组相比,黄连素组小鼠脊髓组织线粒体内MDA水平降低,SOD和GSH水平增高;细胞质内Cyt C和脊髓组织中caspase-3、cleaved caspase-3表达水平降低,线粒体内Cyt C表达水平增高;脊髓组织中神经细胞凋亡比例减少;差异均有统计学意义(P 0.05)。结论黄连素可减轻SCI小鼠脊髓组织中神经细胞凋亡,这可能与其抑制线粒体氧化损伤、减少Cyt C释放、降低凋亡蛋白表达有关。     

Suppressor of Cytokine Signaling 1 Inhibits Apoptosis of Islet Grafts Through Caspase 3 and Apoptosis-Inducing Factor Pathways in Rats

A significant portion of pancreatic islet grafts can be destroyed by apoptosis, failing to engraft in the early period after transplantation. Recently, we observed that overexpression of suppressor of cytokine signaling 1 (SOCS1) in islet grafts achieved an antiapoptotic effect, prolonging graft survival in a rat transplant model. Caspase 3 is the central executioner caspase that is activated by upstream cascades in a caspase-dependent apoptosis pathway. Apoptosis inducing factor (AIF) is a key protein that can be released from mitochondria, translocating to the nucleus in the caspase-independent apoptosis pathway. In this study, we investigated whether these two pathways were involved in cytoprotection afforded by SOCS1 on islet grafts. We used a chimeric adenovirus vector (Ad5F35-SOCS1) to enhance SOCS1 expression in isolated Sprague-Dawley rat islets, which were transplanted into recipients experiencing streptozotocin-induced diabetes. We analyzed the expressions of active (cleaved) caspase 3 and AIF on islets. The Ad5F35-SOCS1-infected islets with higher SOCS1 expression showed decreased levels of active caspase 3 and intranuclear AIF after treatment with tumor necrosis factor-α and cycloheximide in vitro. The diabetic recipients transplanted with Ad5F35-SOCS1-infected islets showed longer periods of normoglycemia versus recipients transplanted with mock-infected islets (P < .05) due to prolonged graft survival. A histological analysis indicated that the Ad5F35-SOCS1-infected islet grafts displayed decreased caspase 3 activation and AIF translocation (to nucleus) in the early posttransplant period. These results demonstrated that the expression of SOCS1 in islet grafts protected them from apoptosis through caspase 3 dependent and AIF caspase-independent-pathways.     

Cardiac mitochondrial damage and inflammation responses in sepsis

BACKGROUND AND PURPOSE: Studies in sepsis suggest that mitochondria mediate multiple organ dysfunction, including cardiac failure; however, the underlying molecular mechanisms remain elusive. This study examined changes in mitochondrial membrane integrity, antioxidant activities, and oxidative stress in the heart after infectious challenge (intratracheal Streptococcus pneumoniae, 4 x 10(6) colony-forming units). Inflammation responses also were examined. METHODS: Cardiac tissues were harvested from Sprague-Dawley rats 4, 8, 12, and 24 h after bacterial challenge (or intratracheal vehicle for sham-treated animals) and homogenized, followed by preparation of subcellular fractions (mitochondrial, cytosol, and nuclei) or whole-tissue lysate. We examined mitochondrial outer membrane damage and cytochrome C translocation to evaluate mitochondrial integrity, mitochondrial lipid and protein oxidation to assess oxidative stress, and mitochondrial superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities to estimate antioxidant defense. In addition, we measured nuclear factor-kappa B (NF-kappaB) activation in myocardium and cytokine production to investigate inflammatory responses to septic challenge. RESULTS: Oxidation of mitochondrial protein and lipid was evident 4 h through 24 h after bacterial challenge. Mitochondrial outer membrane damage and cytochrome C release were accompanied by down-regulation of mitochondrial SOD and GPx activity. After bacterial challenge, systemic and myocardial cytokine production increased progressively, and NF-kappaB was activated gradually. CONCLUSION: Sepsis impaired cardiac mitochondria by damaging membrane integrity, increasing oxidative stress, and altering defenses against reactive oxygen species. These alterations occur earlier than or simultaneously with inflammatory responses in myocardium after infectious challenge, suggesting that mitochondria play a role in modulating inflammation in sepsis.     

亚低温对大鼠脑缺血/再灌注海马神经元p-JNK,AIF的影响

目的 通过动态观察亚低温对SD大鼠全脑缺血海马神经元半胱氨酸蛋白激酶-3(Caspase-3),凋亡诱导因子(AIF),p-JNK表达的影响,探讨亚低温对脑保护的可能机制.方法 10～12周龄的成年雄性SD大鼠,参照Pulsinelli 等[1]的四血管阻断法制作全脑缺血模型,随机分为假手术组,全脑缺血再灌损伤组,亚低温再灌注组,每组根据再灌注不同时间点(2 h,1 d,3 d,7 d)制取海马标本,观察其组织形态学变化;免疫组化检测AIF,p-JNK;TUNEL染色检测海马区神经元凋亡;Caspase-3荧光活性检测.结果 假手术组各时间点无变化,缺血再灌注两组海马神经元凋亡在CA1区都从再灌注2 h开始,且在1 d达到高峰后回落,其中亚低温组在(1 d,3 d)明显降低了Caspase-3、AIF、p-JNK的活性,增加了存活细胞(P<0.05).结论 亚低温可显著减少SD大鼠缺血性海马神经元再灌注后凋亡的发生,其机制可能与抑制海马P-JNK的活化,减弱Caspase-3活性,同时通过非Caspase-3通路减少AIF的表达相关.     

Neural circuitry of the adult rat central nervous system after spinal cord injury: a study using fast blue and the Bartha strain of pseudorabies virus

The distribution of retrogradely and transneuronally labeled neurons in the adult rat brain and spinal cord after contusive mid-thoracic spinal cord injury (SCI) was studied using Fast Blue (FB) and the Bartha strain of pseudorabies virus (PRV), respectively. When FB was injected into the distal spinal cord at 2 days after graded SCI at the 10th vertebral level, labeled neurons were consistently found 7 days later in supraspinal areas that normally project to the spinal cord. The number of FB-labeled neurons decreased as the injury severity increased. An inverse correlation between the number of FB-labeled neurons and injury severity was seen in most investigated brain nuclei with coefficient of correlations (r) ranging from -0.84 in the red nucleus to -0.92 in the raphe nuclei. The coefficient of correlation was relatively poor in the motor cortex (r = -0.63), where a mild injury (6.25 g.cm) resulted in a 99% damage of the corticospinal tract. Such a prominent difference between the corticospinal tract and other descending pathways can be related to the difference in location of these pathways within the adult rat spinal cord. When PRV was injected into the right sciatic nerve one month after the injury, labeled cells were consistently identified 5 days later in the spinal cord rostral to the injury and in certain supraspinal regions that regulate autonomic outflow. In these nuclei, the distribution and number of PRV-labeled neurons markedly decreased after SCI as compared to the control group. In contrast, PRV-labeled neurons were inconsistently found in the supraspinal nuclei that contribute to somatic motor outflow in normal controls and no labeling was observed in these nuclei after injury. These results demonstrate that (1) a proportion of neural network across the injured spinal cord has been spared after acute contusive SCI, (2) the proportion of spared axons of a particular pathway is closely correlated to the injury severity and the position of that pathway, and (3) the transneuronal labeling method using PRV may provide a unique approach to investigate multi-synaptic neural circuitry of the central autonomic control after SCI, but its application to the somatic motor system is limited.     

Transplantation of viable mitochondria attenuates neurologic injury after spinal cord ischemia

ObjectivesSpinal cord ischemia (SCI) is one of the major concerns of postoperative paraplegia during major vascular or aortic surgery. Since mitochondrial dysfunction develops at the early stage of SCI, this study tested the neuronal protective effect of transplantation of viable mitochondria to the ischemic cord in rats.MethodsSCI was induced by crossclamping of thoracic aorta at T6 level for 25 minutes, followed by release of vascular clip to restore aortic blood flow in the anesthetized rats. Mitochondria (100 μg) were isolated from freshly harvested soleus muscle and delivered via the internal jugular vein before releasing of vascular clip. The motor function was assessed independently up to 7 days after reperfusion. Spinal cords were harvested and analyzed for molecular and histological changes.ResultsWhole-body in vivo images acquired by an in vivo imaging system confirmed the enhancement of MitoTracker fluorescence at the regions below crossclamping and in the ischemic cord. Compared with control vehicles, transplantation of mitochondria significantly improved the lower-limb locomotor function of rats subjected to cord ischemia up to 7 days after surgery. Mitochondrial transplantation suppressed the regional endoplasmic reticulum stress in the ischemic cord by attenuating CCAAT-enhancer-binding protein homologous protein expression and restoring binding immunoglobulin protein levels. In accordance, tissue levels of interleukin-6, tumor necrosis factor-α, and caspase-3 were attenuated in the mitochondrial transplanted group. Histologic examination also showed significant increase in numbers of Nissls bodies in the neurons at the ventral horn of ischemic cord following mitochondrial transplantation.ConclusionsOur study showed that transplantation of freshly isolated mitochondria during the early stage of spinal cord ischemia–reperfusion injury suppressed the oxidative stress in endoplasmic reticulum of the injured cord, thereby reducing neuroapoptosis and improving locomotor function of rats with SCI.     

凋亡诱导因子和caspase-3在结直肠腺瘤-癌序列中的表达及相关性

目的探讨非caspase依赖凋亡途径的凋亡诱导因子（AIF）与caspase依赖凋亡途径的caspase-3在结直肠腺瘤．癌序列中的表达变化及两种蛋白之间的相关性。方法采用免疫组织化学染色检测18例正常黏膜、84例结直肠腺瘤和72例结直肠癌中AIF及caspase-3的表达情况。结果结直肠腺瘤组织中AIF及caspase-3的阳性表达率均明显高于正常黏膜组织（P〈0．05）;腺瘤组织中AIF阳性表达率与腺癌之间的差异无统计学意义（P〉0．05）,而caspase-3阳性表达率则明显高于腺癌组织（P〈0．05）;腺瘤组内绒毛状腺瘤AIF阳性表达率明显低于管状腺瘤（P〈0．05）,而caspase-3阳性表达率在两种腺瘤之间的差异无统计学意义（P〉0．05）。相关分析显示,AIF表达与caspase-3表达无显著相关性（P〉0．05）。结论AIF代表的非caspase依赖凋亡途径异常发生在腺瘤向癌突变早期．而caspase依赖途径的凋亡失控可能是更重要的促进结直肠癌发生的因素之一。非caspase依赖的凋亡途径与caspase依赖的凋亡途径是肿瘤发生中两条相对独立的细胞凋亡途径。     

骨髓间充质干细胞移植对大鼠脊髓损伤后氧化应激的影响

目的研究骨髓间充质干细胞（bone marrow mesenchymal stem cells,BMSCs）移植对大鼠脊髓损伤（spinal cord injury,SCI）后氧化应激的影响。方法取大鼠股骨和胫骨骨髓培养BMSCs并传代。参照Taoka方法制作30只大鼠脊髓压迫损伤模型,随机分为3组,损伤组（SCI）、假移植组（SCI＋生理盐水）、移植组（SCI＋BMSCs）。脊髓损伤30 min时,假移植组和移植组于损伤周围相应注射生理盐水和BMSCs。在损伤后第3天、7天、14天和28天,进行BBB（Basso-Beattie-Bresnahan,BBB）行为学评价。应用MTT方法检测血清中超氧化物岐化酶（SOD）活性和丙二醛（MDA）水平。结果脊髓损伤后,BMSCs移植第14天即可观察到大鼠后肢运动功能明显改善,第28天BBB评分有明显提高。与损伤组和假移植组大鼠相比,第7天、14天和28天移植组血中MDA水平降低（P〈0.05）;血中SOD水平较高（P〈0.05）。结论 BMSCs移植对SCI神经功能恢复有促进作用,其机制可能与其抑制氧化应激有关。     

Molecular mechanisms of Fas-mediated cell death in oligodendrocytes

Oligodendrocyte cell death is a significant component of the secondary damage following spinal cord injury (SCI) and other neurodegenerative disorders. However, the mechanisms underlying oligodendroglial apoptotic cell death and the potential relationship to Fas receptor (FasR) activation require further clarification. Here, using MO3.13, a human oligodendroglial cell line, we show clear evidence of apoptosis upon exposure to soluble Fas ligand (sFasL). Apoptosis was linked to caspase-8, -9, and -3 activity and resulted in DNA fragmentation detected by deoxynucleotide transferase dUTP nick end-labeling (TUNEL). Dissipation of mitochondrial membrane potential (DeltaPsim) was an early event and temporally coincided with mitochondrial outer membrane permeability (MOMP), demonstrated by the presence of cytochrome c and apoptosis inducing factor (AIF) in cytosolic fractions. Pretreatment with 100 microM of the caspase inhibitor zVAD-fmk prior to sFasL exposure reduced caspase activation, the dissipation of DeltaPsim, MOMP, and apoptotic cell death. These data provide clear evidence that Fas activation induces apoptosis in oligodendrocytes signaling through intrinsic and extrinsic events. Moreover, we provide evidence for the first time that AIF may play a role in caspase-independent apoptotic execution following Fas activation of oligodendrocytes. These data also add to an emerging body of evidence, which strongly implicates Fas-mediated apoptosis of oligodendrocytes as a potential mediator in the pathobiology of a variety of neurological disorders, including SCI.     

Polyethylene glycol improves function and reduces oxidative stress in synaptosomal preparations following spinal cord injury

Spinal cord injury (SCI) results in rapid and significant oxidative stress. We have previously demonstrated that administration of polyethylene glycol (PEG) inhibits oxidative stress using an in vitro model of SCI. In this study we tested the effects of PEG in vivo, to elucidate the mechanism of PEG-mediated neuroprotection. We show that a compression injury at T10-11 induced diffusive oxidative stress in crude synaptosomal preparations, correlated with synaptosomal dysfunction and increased intrasynaptosomal calcium. Administration of PEG immediately post-injury produced a marked decrease in synaptosomal oxidative stress and calcium, associated with an increase in synaptosomal function. Confocal microscopy using fluorescein conjugated PEG revealed that PEG entered the cells of the injured spinal cord, placing the polymer in a position to directly interact with cellular organelles. PEG attenuates calcium-induced functional compromise of normal spinal cord synaptosomes and mitochondria in vitro. These results indicate that PEG may exert its neuroprotective effect through direct interaction with mitochondria, besides its known ability to rescue neurons and their axons by repairing the plasma membranes. We submit that PEG is likely to interfere with the cascade of secondary injury by several mechanisms of action that in concert reduce oxidative stress.     

Calpain inhibitors prevent neuronal cell death and ameliorate motor disturbances after compression-induced spinal cord injury in rats

Traumatic spinal cord injury (SCI) results in widespread neuronal cell death. Recent studies have suggested that activated calpain mediates neuronal cell death in the central nervous system. We conducted a study to determine whether calpain mediates neuronal cell death in the motor neurons of the spinal cord after SCI, and whether postinjury administration of the calpain inhibitors N-acetyl- Leu-Leu-Met-CHO (ALLM) and calpain inhibitor III (CI III) (MDL28170) reduces the motor disturbances in rats with a model of SCI. Adult male Wistar rats were subjected to SCI by application of a 20-g weight impactor probe to the spinal cord at T12 for 20 min. The rats were divided into three groups according to whether they were injected intravenously with 0.05-2.5 mg/kg ALLM, 10 mg/kg CI III, or 0.1% DMSO as a control every 24 h for 1 week after SCI. Calpain was activated in the spinal cord at 8 h, 24 h, and 5 days after SCI, and administration of ALLM inhibited its activation. ALLM, as compared to the DMSO vehicle alone, also significantly reduced the number of motor neurons in spinal-cord lesions that were positively labeled at 24 h after SCI with the terminal deoxynucleotidyl transferase-uridine nucleotide end-labeling (TUNEL) technique. Additionally, both the inclined plane test and footprint analysis showed markedly better motor activity after 4 weeks in rats injected with ALLM or CI III than in rats given vehicle only. These results suggest that activation of calpain plays a critical role in the neuronal cell death that follows SCI, and that calpain inhibitors may have benefit in treating the motor disturbances that follow SCI.     

Dexamethasone prevents podocyte apoptosis induced by puromycin aminonucleoside: role of p53 and Bcl-2-related family proteins

Nephrotic-range proteinuria is due to glomerular diseases characterized by podocyte injury. Glucocorticoids are the standard of care for most forms of nephrotic syndrome. However, the precise mechanisms underlying the beneficial effects of glucocorticoids on podocytes, beyond its general immunosuppressive and anti-inflammatory effects, are still unknown. This study tested the hypothesis that the synthetic glucocorticoid dexamethasone directly reduces podocyte apoptosis. Growth-restricted immortalized mouse podocytes in culture were exposed to puromycin aminonucleoside (PA) to induce apoptosis. Our results showed that dexamethasone significantly reduced PA-induced apoptosis by 2.81-fold. Dexamethasone also rescued podocyte viability when exposed to PA. PA-induced apoptosis was associated with increased p53 expression, which was completely blocked by dexamethasone. Furthermore, the inhibition of p53 by the p53 inhibitor pifithrin-alpha protected against PA-induced apoptosis. Dexamethasone also lowered the increase in the proapoptotic Bax, which was increased by PA, and increased expression of the antiapoptotic Bcl-xL protein. Moreover, the decrease in p53 by dexamethasone was associated with increased Bcl-xL levels. Podocyte apoptosis induced by PA was caspase-3 independent but was associated with the translocation of apoptosis-inducing factor (AIF) from the cytoplasm to nuclei. AIF translocation was inhibited by dexamethasone. These results show that PA-induced podocyte apoptosis is p53 dependent and associated with changes in Bcl-2-related proteins and AIF translocation. The protective effects of dexamethasone on PA-induced apoptosis were associated with decreasing p53, increasing Bcl-xL, and inhibition of AIF translocation. These novel findings provide new insights into the beneficial effects of corticosteroids on podocytes directly, independent of its immunosuppressive effects.     

长链非编码RNA-XIST对脊髓损伤大鼠神经元凋亡影响及其机制的实验研究

目的:探讨长链非编码核糖核酸-X染色体失活基因(lncRNA-XIST)对脊髓损伤大鼠神经元凋亡过程的影响及其作用机制。方法:将成年SD大鼠(北京中国科学院实验动物中心提供)随机分为假手术组、脊髓损伤组、观察组,假手术组接受椎板切除术,脊髓损伤组和观察组椎板切除后使用脊髓打击器损伤脊髓。假手术组和脊髓损伤组脊髓内注射空...     

Neuroprotective effects of recombinant thrombomodulin in controlled contusion spinal cord injury implicates thrombin signaling

Although the central nervous system (CNS) of mammals has had poor prospects for regeneration, recent studies suggest this might improve from blocking "secondary cell loss" or apoptosis. In this regard, intravenous activated protein C (aPC) improved neurologic outcomes in a rat compression spinal cord injury (SCI) model. Protein C activation occurs when the serine protease thrombin binds to the cell surface proteoglycan thrombomodulin (TM) forming a complex that halts coagulation. In culture, rTM blocks thrombin's activation of protease-activated receptors (PARs), that mediate thrombin killing of neurons and glial reactivity. Both PAR1 and prothrombin are rapidly upregulated after contusion SCI in rats, prior to peak apoptosis. We now report neuroprotective effects of intraperitoneal soluble recombinant human rTM on open-field locomotor rating scale (BBB) and spinal cord lesion volume when given 1 h after SCI. BBB scores from four separate experiments showed a 7.6 +/- 1.4 absolute score increase (p < 0.05) at 3 days, that lasted throughout the time course. Histological sections at 14 days were even more dramatic where a twofold reduction in lesion volume was quantified in rTM-treated rats. Thionin staining revealed significant preservation of motor neuronal profiles both at, and two segments below, the lesion epicenter. Activated caspase-3 immunocytochemistry indicated apoptosis was quite prominent in motor neurons in vehicle (saline) controls, but was dramatically reduced by rTM. Microglia, increased and activated after injury, were reduced with rTM treatment. Taken together, these and previous results support a prominent role for coagulation-inflammation signaling cascades in the subacute changes following SCI. They identify a neuroprotective role for rTM by its inhibition of thrombin generation and blockade of PAR activation.     

多聚ADP核糖聚合酶-1及其依赖性细胞死亡在神经系统疾病中的研究进展

背景多聚ADP核糖聚合酶-1（poly ADP-ribose polymerase-1,PARP-1）作为-种DNA修复酶,具有维持基因组稳定的生理作用,应激条件下介导细胞程序性死亡,即PARP．1依赖性细胞死亡（PARP-1-dependent cell death,PARthanatos）。目的研究PARP-1及其介导的细胞死亡在脑卒中和神经退行性疾病等神经系统疾病中作用,探讨PARP-1阻断对神经细胞的保护作用。内容持续氧化应激可使PARP-1过度活化,促进凋亡诱导因子（apoptosis induced factor,AIF）转位至细胞核,介导PARthanatos。缺血,再灌注以及谷氨酸兴奋性毒性作用均可产生大量氧自由基,是神经系统疾病主要致病物质。脑卒中和神经退行性疾病中存在持续氧化应激和PARP-1活化,其介导的PARthanatos是神经元死亡的主要方式之一。抑制PARP-1活化具有神经保护作用。趋向PARP-1活化介导脑卒中和神经退行性疾病的发生,阻断PARP-1有望成为治疗该类疾病的新靶点。     

Acupuncture combined with moxibustion promote the recovery of spinal cord injury in correlation with Shh/Gli-1 signaling pathway

Objective: Acupuncture combined with moxibustion (AM) therapy has been applied to treat spinal cord injury (SCI), but the underlying mechanism is unclear. The present study aimed to confirm the effect and mechanism of AM treatment on the recovery of SCI.Design: Male Sprague–Dawley rats were used to establish the SCI model by impact method. SCI rat models were subjected to AM treatment at Dazhui (GV14) and Jiaji points (T7-T12), Yaoyangguan (GV3), Zusanli (ST36) and Ciliao (BL32).Outcome measures: Motor function and cell apoptosis in rats after SCI. The mRNA and protein expression levels of Shh and Gli-1 were determined by real-time quantitative polymerase chain reaction, western blot and immunohistochemistry.Results: After AM treatment, the hindlimb motor function of SCI rats was significantly increased than the SCI group at 7, 9, 11, 14 days (P < 0.05). AM treatment 7 d and 14 d significantly preserved the nissl-stained positive neurons and significantly decreased number of apoptotic cells, compared to that of SCI 7 and 14 d groups (P < 0.05). AM treatment improved the mRNA protein levels of Shh and Gli-1 after 7 and 14 days treatment compared to the SCI group (P < 0.05).Conclusion: AM could improve the expression of Shh and Gli-1 in injured spinal cord of rats. That could be part of underlying mechanisms of AM treatment including recover motor function and preserve the neuron cells and alleviate the apoptosis of nerve cells in rats after SCI.