Suppression of Astroglial Scar Formation and Enhanced Axonal Regeneration Associated with Functional Recovery in a Spinal Cord Injury Rat Model by the Cell Cycle Inhibitor Olomoucine

Objective：To determine if a cell cycle inhibitior, olomoucine, would decrease neuronal cell death, limit astroglial proliferation and production of inhibitory CSPGs, and eventually enhance the functional compensation after SCI in rats. Methods： Three were used as un-operated controls and twelve as sham operated controls. Follow- ing spinal cord injury, 48 rats were randomly and blindly assigned to either olomoucine （n=24） or vehicle treatment （n=24） groups. Results： Up-regulations of cell cycle components were closely associated with neuronal ceil death and astroglial proliferation as well as the production of CSPGs after SCI. Meanwhile, administration of olomoucine, a selective cell cycle kinase （CDK） inhibitor, has remarkably reduced the up-regulated cell cycle proteins and then decreased neuronal cell death, astroglial proliferation as well as accumulation of CSPGs. More importantly, the treatment with olomoucine has also increased expression of growth-associated proteins-43 （GAP-43）, reduced the cavity formation, and improved functional deficits. Conclusion： Suppressing astroglial cell cycle in acute spinal cord injuries is beneficial to axonal growth, in turn, the future therapeutic strategies can be designed to achieve efficient axonal regeneration and functional compensation after traumatic CNS injury.     

Tamoxifen对大鼠脊髓损伤后炎症反应的影响

目的：探讨tamoxifen对大鼠脊髓损伤（SCI）后炎症反应的影响。方法：60只SD大鼠采用改良Allen法建立大鼠SCI模型,并随机分为假手术组、对照组和干预组各20只,采用免疫荧光和免疫印迹探讨各组小胶质细胞活化以及炎性因子白介素-1β（IL—1β）的表达情况,采用伊文思蓝定量测定法观察SCI后血脊髓屏障通透性（BSCB）的变化。结果：SCI后小胶质细胞明显活化,并产生大量的炎性因子IL-16,BSCB的通透性也显著升高;干预组大鼠给予tamoxifen干预后,与对照组比较小胶质细胞活化受到抑制,IL-1β的产生有所减少,BSCB的破坏也得到明显改善（均P〈0．05）。结论：Tamoxifen可以减轻大鼠SCI后炎症反应,促进血脊髓屏障的恢复。     

细胞周期依赖的蛋白激酶抑制剂Olomoucine对脊髓损伤后硫酸软骨素蛋白多糖表达的影响

目的探讨细胞周期抑制剂Olomoucine对脊髓损伤后硫酸软骨素蛋白多糖(CSPGs)表达的影响及意义。方法建立大鼠脊髓半切损伤模型,随机分为假手术组、损伤对照组和Olomoucine干预组,采用免疫印迹分析脊髓损伤后CSPGs的表达;应用免疫荧光技术检测损伤区域胶质纤维酸性蛋白(GFAP)和CSPGs的表达;采用改良Gale联合评分法对大鼠瘫痪后肢进行运动功能评估。结果脊髓损伤后星形胶质细胞明显活化增殖,GFAP和CSPGs的表达显著高于假手术组(P<0.05),010moucine干预可有效下调GFAP和CSPGs的表达(P相似文献   

Intrathecal cannabilactone CB(2)R agonist, AM1710, controls pathological pain and restores basal cytokine levels

Spinal glial and proinflammatory cytokine actions are strongly implicated in pathological pain. Spinal administration of the anti-inflammatory cytokine interleukin (IL)-10 abolishes pathological pain and suppresses proinflammatory IL-1β and tumor necrosis factor alpha (TNF-α). Drugs that bind the cannabinoid type-2 receptor (CB(2)R) expressed on spinal glia reduce mechanical hypersensitivity. To better understand the CB(2)R-related anti-inflammatory profile of key anatomical nociceptive regions, we assessed mechanical hypersensitivity and protein profiles following intrathecal application of the cannabilactone CB(2)R agonist, AM1710, in 2 animal models; unilateral sciatic nerve chronic constriction injury (CCI), and spinal application of human immunodeficiency virus-1 glycoprotein 120 (gp120), a model of peri-spinal immune activation. In CCI animals, lumbar dorsal spinal cord and corresponding dorsal root ganglia (DRG) were evaluated by immunohistochemistry for expression of IL-10, IL-1β, phosphorylated p38-mitogen-activated-kinase (p-p38MAPK), a pathway associated with proinflammatory cytokine production, glial cell markers, and degradative endocannabinoid enzymes, including monoacylglycerol lipase (MAGL). AM1710 reversed bilateral mechanical hypersensitivity. CCI revealed decreased IL-10 expression in dorsal spinal cord and DRG, while AM1710 resulted in increased IL-10, comparable to controls. Adjacent DRG and spinal sections revealed increased IL-1β, p-p38MAPK, glial markers, and/or MAGL expression, while AM1710 suppressed all but spinal p-p38MAPK and microglial activation. In spinal gp120 animals, AM1710 prevented bilateral mechanical hypersensitivity. For comparison to immunohistochemistry, IL-1β and TNF-α protein quantification from lumbar spinal and DRG homogenates was determined, and revealed increased DRG IL-1β protein levels from gp120, that was robustly prevented by AM1710 pretreatment. Cannabilactone CB(2)R agonists are emerging as anti-inflammatory agents with pain therapeutic implications.     

olomoucine对星形胶质细胞增殖的影响及机制研究

目的:观察细胞周期抑制剂olomoucine对培养星形胶质细胞(AS)机械损伤后增殖的影响,并探讨其作用机制。方法:建立体外培养大鼠纯化的AS物理损伤模型(划痕损伤模型),随机分为对照组、划痕组和干预组,划痕组和干预组均继续培养,干预组给予olomoucine干预。利用免疫荧光细胞化学方法观察损伤后BrdU表达;利用Westernblot印迹分析损伤后PCNA、p27的表达。结果:划痕损伤刺激12h开始出现损伤边缘区AS胞体肥大、数目增加,BrdU阳性细胞比率和PCNA表达水平较对照组增高(P<0.05),p27表达水平较对照组下降(P<0.05);干预组的BrdU阳性细胞比率和PCNA表达水平较划痕组明显减少(P<0.05),p27表达上调(P<0.05)。结论:损伤刺激可促使AS发生反应性胶质增生,CDK选择性细胞周期抑制剂olomoucine可以通过调控细胞周期抑制其反应性增生。     

Effect of Cell Cycle Inhibitor Olomoucine on Astroglial Proliferation and Scar Formation after Focal Cerebral Infarction in Rats

Background:Astrocytes become reactive following many types of CNS injuries.Excessive astrogliosis is detrimental and contributes to neuronal damage.We sought to determine whether inhibition of cell cycle could decrease the proliferation of astroglial cells and therefore reduce excessive gliosis and glial scar formation after focal ischemia.Methods:Cerebral infarction model was induced by photothrombosis method.Rats were examined using MRI,and lesion volumes were estimated on day 3 post-infarction.The expression of glial fibrillary acidic protein(GFAP) and proliferating cell nuclear antigen(PCNA) was observed by immunofluorescence staining.Protein levels for GFAP,PCNA,Cyclin A and Cyclin B1 were determined by Western blot analysis from the ischemic and sham animals sacrificed at 3,7,30 days after operation.Results:Cell cycle inhibitor olomoucine significantly suppressed GFAP and PCNA expression and reduced lesion volume after cerebral ischemia.In parallel studies,we found dense astroglial scar in boundary zone of vehicle-treated rats at 7 and 30 days.Olomoucine can markedly attenuate astroglial scar formation.Western blot analysis showed increased protein levels of GFAP,PCNA,Cyclin A and Cyclin B1 after ischemia,which was reduced by olomoucine treatment.Conclusion: Our results suggested that astroglial activation,proliferation and subsequently astroglial scar formation could be partially inhibited by regulation of cell cycle.Cell cycle modulation thereby provides a potential promising strategy to treat cerebral ischemia.     

脊髓损伤后星形胶质细胞增生动态变化分析

目的:分析脊髓损伤(SCI)后星形胶质细胞(Ast)增生动态变化。方法:建立Ast划痕损伤模型及大鼠SCI模型,在多个时间点(0、6、12、24、48、72 h)观察Ast划痕损伤后细胞形态、增殖及迁徙的变化,并设立对照组应用ELISA法检测划痕损伤后各个时间点Ast分泌致炎因子TNF-α、IL-1β、IL-6表达量;应用免疫荧光染色及Western blot分析不同时间点(0、1、3、7、14、28 d)大鼠SCI后GFAP的表达量变化。结果:划痕损伤后12 h划痕边缘已出现部分细胞增生及增殖细胞(Brdu染色阳性细胞),损伤后24 h细胞已明显增生并大量增殖,损伤后48 h细胞体普遍增大,突起明显增多,同时有大量细胞已迁徙至划痕中央处,损伤后72 h增生的细胞及迁徙至划痕的细胞几乎已覆盖划痕,部分形成瘢痕;与对照组比较,损伤后12 h TNF-α、IL-1β、IL-6均明显增加(P<0.05),24、48及72 h TNF-α、IL-1β、IL-6表达量增加更加明显(P<0.01)。大鼠SCI模型显示SCI后1 d GFAP表达量增加不明显,3 d后明显增加,而且一直呈增加趋势,14²8 d后形成表达高峰。结论:Ast活化增生是SCI后一个持续且普遍的标志性病理生理过程。     

Clinical correlates of elevated serum concentrations of cytokines and autoantibodies in patients with spinal cord injury

Davies AL, Hayes KC, Dekaban GA. Clinical correlates of elevated serum concentrations of cytokines and autoantibodies in patients with spinal cord injury.

Objective

To determine the serum cytokine profiles of patients with spinal cord injury (SCI) and varying clinical presentations relative to healthy, able-bodied, age-matched control subjects.

Design

Cross-sectional study.

Setting

Clinical research unit.

Participants

People with SCI (N=56) and different clinical presentations, and healthy, able-bodied, age-matched control subjects (N=35).

Interventions

Not applicable.

Main Outcome Measures

Serum levels of the proinflammatory cytokines interleukin (IL) 1β, IL-6, tumor necrosis factor alpha (TNF-α), the anti-inflammatory cytokines IL-4 and IL-10, the regulatory cytokine IL-2, the IL-1 receptor antagonist (IL-1RA), and autoantibodies against myelin-associated glycoprotein and GM₁ ganglioside (anti-GM₁) immunoglobulin (IgG and IgM), as determined by enzyme-linked immunosorbent assay. The relationship between elevated serum cytokine levels and clinical variables was also studied.

Results

SCI subjects exhibited serum concentrations of IL-6, TNF-α, IL-1RA, and anti-GM₁ (IgG) that were greater (P<.05) than control group values. Elevated cytokine concentrations were not associated with high white blood cell counts, level of injury, or American Spinal Injury Association classification; they were evident in SCI subjects who were asymptomatic for medical complications, but were further elevated in subjects with pain, urinary tract infection (UTI), and pressure ulcers.

Conclusions

Elevated levels of circulating proinflammatory cytokines and autoantibodies are present in the serum of SCI subjects without medical complications, and are further elevated in SCI subjects with neuropathic pain, UTI, or pressure ulcers, relative to healthy, able-bodied control subjects. These findings may be indicative of a protective autoimmunity, simply a consequence of occult or evident infection, or evidence of cytokine dysregulation that may contribute to an immune-mediated impairment of axonal conduction.     

Effect of fasudil, a selective inhibitor of rho kinase activity, in the secondary injury associated with the experimental model of spinal cord trauma

Rho kinase (ROK) may play an important role in regulating the biological events of cells, including proliferation, differentiation, and survival/death. Blockade of ROK promotes axonal regeneration and neuron survival in vivo and in vitro, thereby exhibiting potential clinical applications in spinal cord damage and stroke. The aim of this experimental study was to determine the role of ROK signaling pathways in the inflammatory response, in particular in the secondary injury associated with the experimental model of spinal cord trauma. The injury was induced by application of vascular clips to the dura via a four-level T5 to T8 laminectomy in mice. Fasudil was administered in mice (10 mg/kg i.p.) 1 and 6 h after the trauma. The treatment with fasudil significantly decreased 1) histological damage; 2) motor recovery; 3) nuclear factor-κB (NF-κB) expression; 4) ROK activity; 5) inflammasome activation (caspase-1 and NOD-like receptor family, pyrin domain-containing 3 expression); 6) production of proinflammatory cytokine such as tumor necrosis factor and interleukin-1β (IL-1β); 7) neutrophil infiltration; 8) nitrotyrosine and poly-ADP-ribose formation; 9) glial fibrillary acidic protein expression; 10) apoptosis (terminal deoxynucleotidyl transferase dUTP nick-end labeling staining, FAS ligand expression, and Bax and Bcl-2 expression); and 11) mitogen-activated protein kinase activation (phospho-extracellular signal-regulated kinase and phospho-c-Jun NH(2)-terminal kinase expression). Our results indicate that inhibition of ROK by fasudil may represent a useful therapeutic perspective in the treatment of inflammation associated with spinal cord trauma.     

SIRT1对大鼠急性脊髓损伤炎症反应的影响

目的 观察大鼠急性脊髓损伤后SIRT1对局部组织炎症反应的影响.方法 采用改良Allen′s法,建立大鼠脊髓钝挫伤模型(T10),100只SD大鼠被随机分成4组:假手术组(n=4,SHAM),模型组(n=32,SCI),白藜芦醇组(n=32,RES),对照剂组(n=32,SOL).脊髓损伤术后立即给予腹腔注射白藜芦醇(RES)100 mg/kg和聚乙二醇硬脂酸酯15(SOL)100 mg/kg,在脊髓损伤后4 h,8 h,24 h,36 h取材,用QT-PCR的方法检测4组中SIRT1的动态表达情况,采用酶联免疫吸附法(ELISA试剂盒)测定脊髓损伤后4 h,8 h,12 h,24 h,36 h各组组织中炎症因子(IL-1β,IL-6,IL-10,TNF-α)水平.结果 RES组SIRT1表达在4 h明显增加,在8 h达到高峰,与其他两组(SCI组,SOL组)比较差异有统计学意义(P<0.01).SCI组大鼠损伤脊髓组织在损伤后4 h各炎症性细胞因子表达即明显升高,其中TNF-α和IL-6于损伤后8 h达峰值,IL-10在观察时间内呈持续性增高,IL-1β在24 h达峰值.SOL组各炎症因子的变化规律与SCI组基本一致,RES组与前两组相比,浓度差异均有统计学意义(P<0.01).结论 SIRT1对大鼠急性脊髓损伤后炎症反应有明显抑制作用.     

孕酮对大鼠脊髓损伤后早期细胞凋亡的影响

目的:探讨孕酮对大鼠脊髓损伤后早期细胞凋亡的影响。方法:60只雄性SD大鼠随机分成假手术组、损伤组、孕酮组,采用改良的Allen’s撞击法制作脊髓损伤模型。孕酮组在造模成功后1、6、24、487、2 h腹腔注射16 mg/kg孕酮。术后6、24、48、75 h取材,采用HE染色观察脊髓形态学的变化,免疫组织化学法检测Caspase-3的表达,原位末端标记法(TUNEL染色)检测细胞凋亡。结果:假手术组大鼠脊髓形态正常,偶见凋亡细胞及Caspase-3阳性细胞;与损伤组相比,孕酮组术后各时间点的凋亡指数下降,Caspase-3阳性细胞数显著减少,差异有统计学意义。结论:抑制脊髓损伤后的细胞凋亡可能是孕酮的神经保护作用机制之一。     

N-Methyl-d-aspartate receptor (NMDAR) independent maintenance of inflammatory pain

Following peripheral inflammation, NMDA receptor (NMDAR) activation in spinal cord dorsal horn neurons facilitates the generation of pain in response to low threshold inputs (allodynia) and signals the phosphorylation of protein kinase C (pPKC) and extracellular signal-regulated kinase 2 (pERK2). Intraplantar complete Freund’s adjuvant (CFA) induces inflammatory nociception (allodynic pain) at 24 hours (h) with a concurrent increase in neuronal pPKCγ and pERK2 but not glial pERK2. These effects are attenuated in a spatial knockout of the NMDAR (NR1 KO) confined to SCDH neurons. Although glia and proinflammatory cytokines are implicated in the maintenance of inflammatory pain and neuronal activation, the role of NMDARs and neuronal–glial–cytokine interactions that initiate and maintain inflammatory pain are not well defined. In the maintenance phase of inflammatory pain at 96 h after CFA the NR1 KO mice are no longer protected from allodynia and the SCDH expression of pPKCγ and pERK2 are increased. At 96 h the expression of the proinflammatory cytokine, IL-1β, and pERK2 are increased in astrocytes. Intrathecal IL-1 receptor antagonist (IL-1ra), acting on neuronal IL-1 receptors, completely reverses the allodynia at 96 h after CFA. Deletion of NMDAR-dependent signaling in neurons protects against early CFA-induced allodynia. Subsequent NMDAR-independent signaling that involves neuronal expression of pPKCγ and the induction of pERK2 and IL-1β in activated astrocytes contributes to the emergence of NMDAR-independent inflammatory pain behavior at 96 h after CFA. Effective reduction of the initiation and maintenance of inflammatory pain requires targeting the neuron–astrocyte–cytokine interactions revealed in these studies.     

IL-1β促进脐带间充质干细胞的造血支持作用

本研究旨在探讨IL-1β对人脐带间充质干细胞(hUC-MSC)的造血支持的影响。将分离得到的hUC-MSC以2×106接种于75 cm2培养瓶中,贴壁2 h后,加入10 ng/ml IL-1β培养36 h后收集培养上清和细胞。观察有/无IL-1β的条件培养液对CD34+细胞造血支持的影响;real time PCR检测加/不加IL-1βMSC的造血相关因子mRAN的变化;ELISA法检测造血相关因子的差异。结果表明,含有IL-1β的MSC条件培养液能明显增强CD34+细胞集落形成能力,且以粒系和粒-单核集落形成单位为主。IL-1β促进了MSC GM-CSF、G-CSF、IL-6的mRNA的表达,促进GM-CSF、G-CSF、IL-6蛋白自脐带MSC的分泌。结论:IL-1β能够增强MSC的造血支持能力,尤其是向髓系分化的能力。     

Minocycline attenuates mechanical allodynia and proinflammatory cytokine expression in rat models of pain facilitation

Activated glial cells (microglia and astroglia) in the spinal cord play a major role in mediating enhanced pain states by releasing proinflammatory cytokines and other substances thought to facilitate pain transmission. In the present study, we report that intrathecal administration of minocycline, a selective inhibitor of microglial cell activation, inhibits low threshold mechanical allodynia, as measured by the von Frey test, in two models of pain facilitation. In a rat model of neuropathic pain induced by sciatic nerve inflammation (sciatic inflammatory neuropathy, SIN), minocycline delayed the induction of allodynia in both acute and persistent paradigms. Moreover, minocycline was able to attenuate established SIN-induced allodynia 1 day, but not 1 week later, suggesting a limited role of microglial activation in more perseverative pain states. Our data are consistent with a crucial role for microglial cells in initiating, rather than maintaining, enhanced pain responses. In a model of spinal immune activation by intrathecal HIV-1 gp120, we show that the anti-allodynic effects of minocycline are associated with decreased microglial activation, attenuated mRNA expression of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), IL-1beta-converting enzyme, TNF-alpha-converting enzyme, IL-1 receptor antagonist and IL-10 in lumbar dorsal spinal cord, and reduced IL-1beta and TNF-alpha levels in the CSF. In contrast, no significant effects of minocycline were observed on gp120-induced IL-6 and cyclooxygenase-2 expression in spinal cord or CSF IL-6 levels. Taken together these data highlight the importance of microglial activation in the development of exaggerated pain states.     

Effects of Etanercept and Minocycline in a rat model of spinal cord injury

Loss of function is usually considered the major consequence of spinal cord injury (SCI). However, pain severely compromises the quality of life in nearly 70% of SCI patients. The principal aim of this study was to assess the contribution of Tumor necrosis factor α (TNF‐α) to SCI pain. TNF‐α blockers have already been successfully used to treat inflammatory disorders but there are few studies on its effect on neuropathic pain, especially following SCI. Following T13 spinal cord hemisection, we examined the effects on mechanical allodynia and microglial activation of immediate and delayed chronic intrathecal treatment with etanercept, a fusion protein blocker of TNF‐α. Immediate treatment (starting at the time of injury) with etanercept resulted in markedly reduced mechanical allodynia 1, 2, 3 and 4 weeks after SCI. Delayed treatment had no effect. Immediate etanercept treatment also reduced spinal microglial activation assessed by OX‐42 immunostaining, a putative marker of activated microglia. To assess whether the effects of etanercept were mediated via decreased microglial activation, we examined the effects of the microglial inhibitor, minocycline which significantly reduced the development of pain behaviours at 1 and 2 weeks after SCI compared to saline treatment. Minocycline also significantly reduced microglial OX‐42 expression. Furthermore, minocycline decreased the expression of noxious‐stimulation‐induced c‐Fos, suggesting an effect on evoked neuronal activity. This study demonstrates that TNF‐α plays an important role in the establishment of neuropathic pain following SCI, seemingly dependent on microglial activation. Pharmacological targeting of TNF‐α may offer therapeutic opportunities for treating SCI pain.     

Ginger extract inhibits beta-amyloid peptide-induced cytokine and chemokine expression in cultured THP-1 monocytes

INTRODUCTION: Neuritic plaques, a neuropathologic hallmark of Alzheimer's disease, are extracellular deposits of beta-amyloid peptides (Abeta). In the central nervous system neuritic plaques are surrounded by activated microglial cells expressing proinflammatory cytokines, chemokines, and neurotoxic mediators. Long-term activation of microglial cells is suspected to contribute to the neuron loss in Alzheimer's disease. OBJECTIVE: This study was conducted to determine whether a ginger (Zingiber officinale and Alpinia galanga) extract (GE) can dampen the activation of THP-1 cells by lipopolysaccharide, proinflammatory cytokines, and fibrillar amyloid peptide Abeta(1-42), a major component of neuritic plaques. METHODS: THP-1 cells, a human monocytic cell line with properties similar to human microglial cells, were incubated with GE or control medium alone for 1 hour, and then with reincubated lipopolysaccharide (LPS), tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) or fibrillar Abeta(1-42) for an additional hour. The extent of THP-1 cell activation was determined by measuring mRNA levels of TNF-alpha and IL-1beta, cyclooxygenase-2 (COX-2), macrophage inflammatory protein 1alpha (MIP-1alpha), monocyte chemoattractant protein-1 (MCP-1), and interferon-gamma inducible protein 10 (IP-10). RESULTS: The results document that the GE used in this study inhibits LPS, cytokine, and amyloid Abeta peptide-induced expression of the proinflammatory genes TNF-alpha, IL-1beta, COX-2, MIP-alpha, MCP-1, and IP-10. The data provide experimental evidence that ginger can inhibit the activation of human monocytic THP-1 cells by different proinflammatory stimuli and reduce the expression of a wide range of inflammation-related genes in these microglial-like cells. CONCLUSIONS: The findings suggest that GE may be useful in delaying the onset and the progression of neurodegenerative disorders involving chronically activated microglial cells in the central nervous system.     

Pulsed ultrasound and dimethylsulfoxide gel treatment reduces the expression of pro-inflammatory molecules in an animal model of muscle injury

Studies have shown an exacerbated increase in proinflammatory markers during and after muscle injury. In this way, interventions that reduce inflammatory activation appear to be of great interest in muscle injury therapy. Thus, the preset study evaluated the effect of low-intensity pulsed ultrasound (LIPUS) and dimethylsulfoxide (DMSO) on the proinflammatory molecules in an animal model of traumatic muscle injury. Forty-eight 3-month old male Wistar rats were divided into six groups (n = 8/group): sham; muscle injury without treatment; muscle injury and gel-saline (0.9%); muscle injury and gel-DMSO (15 mg/kg); muscle injury and LIPUS plus gel-saline; and muscle injury and LIPUS plus gel-DMSO. Two, 12, 24 and 48 h after trauma, four groups received one of the treatments described. One hour after, Western blot was performed to quantify proinflammatory protein levels. We observed greater protein levels of TNFα (3.9 times), IL-1β (3.6 times), JNK phosphorylation (4.2 times) and NFκB (3.8 times) in muscle injury group. However, the combined LIPUS with DMSO resulted in significantly lower levels of TNFα (2.2 times), IL-1β (2.1 times), JNK phosphorylation (2.4 times), and NFκB (2.1 times). The results demonstrate that LIPUS associated with DMSO gel can attenuate TNFα, IL-1β, NFκB protein levels and JNK phosphorylation in traumatic muscle injury.     

Effect of 17beta-estradiol on signal transduction pathways and secondary damage in experimental spinal cord trauma

Because studies have shown that 17beta-estradiol (E2) produces anti-inflammatory effects after various adverse circulatory conditions, we examined whether administration of E2 before spinal cord injury (SCI) has any salutary effects in reducing SCI. Spinal cord injury was induced by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy. To gain a better insight into the mechanism of action of the anti-inflammatory effects of E2, the following end points of the inflammatory process were evaluated: (1) spinal cord inflammation and tissue injury (histological score); (2) neutrophil infiltration (myeloperoxidase activity); (3) expression of iNOS, nitrotyrosine, and COX-2; (4) apoptosis (terminal deoxynucleotidyltransferase-mediated UTP end labeling staining and Bax and Bcl-2 expression); and (5) tissue TNF-alpha, IL-6, IL-1beta, and monocyte chemoattractant protein 1 levels. In another set of experiments, the pretreatment or posttreatment with E2 significantly ameliorates the recovery of limb function (evaluated by motor recovery score). To elucidate whether the protective effects of E2 were mediated via the estrogen receptors, we investigated the effect of an estrogen receptor antagonist, ICI 182,780, on the protective effects of E2. ICI 182,780 (500 microg/kg, s.c., 1 h before treatment with E2) significantly antagonized the effect of the E2 and abolished the protective effect against SCI. Taken together, our results clearly demonstrate that administration of E2 before SCI reduces the development of inflammation and tissue injury associated with spinal cord trauma.     

Beneficial effects of ethyl pyruvate in a mouse model of spinal cord injury

The aim of the present study was to evaluate in a mouse model of spinal cord injury (SCI) the effect of the treatment with ethyl pyruvate (EP). Spinal cord injury was induced by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy in mice. Treatment with EP (75, 25, or 8.5 mg/kg) 1 and 6 h after the SCI significantly decreased (a) the degree of spinal cord inflammation and tissue injury (histological score), (b) neutrophil infiltration (myeloperoxidase activity), (c) nitrotyrosine formation and iNOS expression, (d) proinflammatory cytokines expression, (e) nuclear factor kappaB activation, (f) extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase phosphorylation, and (g) apoptosis (TUNEL staining, Fas ligand, Bax, and Bcl-2 expression). Moreover, EP (75, 25, or 8.5 mg/kg) significantly ameliorated in a dose-dependent manner the loss of limb function (evaluated by motor recovery score). Taken together, our results demonstrate that EP treatment reduces the development of inflammation and tissue injury associated with spinal cord trauma.