转录因子NF-E2相关因子2-氧化反应元件通路在抗心肌再灌注损伤中的作用

背景 转录因子NF-E2相关因子2(Nf-E2 related factor-2,Nrf2)抗氧化反应元件(antioxidant response element,ARE)通路广泛分布于机体心血管系统中,激活后可上调内源性抗氧化系统减轻心肌的氧化损伤. 目的 阐述Nrf2-ARE通路作为抗心肌缺血/再灌注损伤(ischemia/reperfusion injury,I/RI)的潜在靶点,并探讨其可能的保护机制.内容 Nrf2-ARE通路处于氧化应激、炎症反应的中心地位,介导编码抗氧化蛋白和二项解毒酶基因的基础表达和诱导表达;多种外源性化合物可以激活Nrf2-ARE通路,在转录水平上调节抗氧化蛋白及二项解毒酶基因的表达,增强内源性抗氧化系统的能力从而在减少氧自由基产生、抗炎症反应、减轻钙超载、抗心肌细胞凋亡等方面减轻心肌I/RI.趋向 激活Nrf2-A RE通路可为临床抗I/RI提供新的策略.     

坐骨神经损伤对背根节细胞凋亡及细胞凋亡相关蛋白表达的影响

目的：观察大鼠坐骨神经条件性损伤后对背根节细胞凋亡及细胞凋亡相关蛋白表达的影响。方法：将45只成年Wistar大鼠,按手术的不同随机分为3组;正常对照组（A组,n=5）;坐骨神经压榨伤组（B组,n=20);坐骨神经切断组（C组,n=20)。B、C两组又按术后3d,2周,1个月和2个月取材时间分为4个时间组,每组5只大鼠。各时间组取鼠的L5背根神经节后,以TUNEL法检测细胞的凋亡数,以免疫组化技术检测Bcl-2和Bax的表达。结果：正常组及B、C两组伤后3d时未检出凋亡细胞;B、C两组的细胞凋亡率在伤后2周达到高峰,以后随时间的推移而逐渐降低。C组的细胞凋亡率明显高于B组。背根节细胞凋亡相关蛋白Bcl-2及Bax的表达,伤后2周达到高峰。B组中Bcl-2和Bax的表达呈现从低到高而后逐渐恢复正常的规律;而C组的表达始终保持在高水平。结论：细胞凋亡相关蛋白Bcl-2和Bax参与外周神经损伤后背根节细胞凋亡的调节。外周神经的不同损伤方式对背根节细胞凋亡及细胞凋亡相关蛋白的表达影响不同。     

人参皂甙Rb1在核因子NF-E2相关因子2/血红素氧合酶-1通路减轻肠缺血再灌注致急性肺损伤中的分子机制

目的 探讨人参皂甙Rb1对肠缺血/再灌注致急性肺损伤的保护效应及核因子NF-E2相关因子2(Nrf2)/血红素氧合酶-1(HO-1)通路参与该效应的分子机制.方法 成年雄性C57BL/6J小鼠随机分为5组:假手术组(S组);肠缺血/再灌注组(I/R组);再灌注+Rb1组(I/R +Rb1组);全反式维甲酸(ATRA)+再灌注组(ATRA+ I/R组);ATRA+再灌注+Rb1组(ATRA+ I/R+Rb1组).采用肠缺血/再灌注模型,Western blot检测肺组织Nrf2、HO-1表达变化;酶联免疫吸附试验(ELISA)法检测肺组织肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6、IL-10水平;检测超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量;检测肺湿/干比及肺组织病理损伤评分.结果 与S组比较,其他4组Nrf2、HO-1蛋白表达,TNF-α、IL-6、MDA含量,肺组织湿/干重比及肺组织病理评分增高(P＜0.05);与1/R组比较,1/R+ Rb1组Nrf2,HO-1蛋白表达,TNF-α,IL-6,MDA含量,肺组织湿/干重比及肺组织病理评分降低(P＜0.05);与I/R+ Rb1组比较,ATRA+ I/R组,ATRA+ I/R+ Rb1组Nrf2、HO-1蛋白表达,NF-α、IL-6、MDA含量,肺组织湿/干重比及肺组织病理评分增高(P＜0.05).SOD活性、IL-10水平与上述变化相反.结论 肠缺血/再灌注可引起急性肺损伤,人参皂甙Rb1后处理能通过激活Nrf2/HO-1通路减轻肠缺血/再灌注所致肺损伤.     

Thermal hyperalgesia assessment for rats after spinal cord injury: developing a valid and useful pain index

Background contextOngoing research to understand the mechanism behind pain is heavily dependent on animal testing. However, unlike humans, animal subjects cannot directly communicate with researchers to express the degree of pain they are experiencing. Therefore, measuring the presence of pain in animal studies is based on behavioral tests. The use of arbitrary values for determining the presence of pain in animal studies is an oversimplification of a complex and cortically dependent process.PurposeThe purpose of the present study was to identify a statistically supported latency time indicator that can be used as an accurate index for hyperalgesia to thermal stimuli in Sprague-Dawley rats subjected to T9 contusive spinal cord injury (SCI).Study designA statistical analysis of latency of withdrawal from stimulus-mediated spinal reflex in 979 Sprague-Dawley rats that had been subjected to a T9 contusive SCI was performed.MethodsThis is a retrospective review of a large research database derived from a series of studies performed evaluating thermal hyperalgesia in rats after SCI. Sprague-Dawley rats underwent a T9 contusive SCI and were tested for withdrawal latency from a heat stimulus. Assessment was done preinjury and on Postinjury Days 21, 28, 35, and 42 of the chronic phase of injury via a plantar withdrawal test.ResultsThe baseline test results of the 979 rats showed a significant resemblance to the normal distribution. The observed change in withdrawal showed mean latency drops of 0.42 second (standard error of the mean [SEM], 0.18; p=.026), 0.57 second (SEM, 0.19; p=.004), 0.63 second (SEM, 0.19; p=.002), and 0.69 second (SEM, 0.19; p=.0003). The standard deviation from the mean at all four postsurgical assessments was between 2.8 and 2.9 seconds.ConclusionsInterpretation of withdrawal latency times as a marker for thermal hyperalgesia must be based on an appreciation for the normal distribution of pain scores. Recognizing that withdrawal latency is normally distributed both before and after injury allows for rational assignment of animals to groups designated as hyperalgesic and nonhyperalgesic. Two point nine seconds faster than the mean latency time is a statistically reliable indicator of thermal hyperalgesia in Sprague-Dawley rats subjected to contusive SCI. Repeated testing of animals to establish the presence or absence of thermal hyperalgesia beyond 21 days is not necessary in the absence of intervention.     

Loss of Type A neuronal cells in the dorsal root ganglion after a non-severe full-thickness burn injury in a rodent model

Burn scars can be associated with significant loss of cutaneous sensation, paresthesia and chronic pain. Long-term systemic changes in cutaneous innervation may contribute to these symptoms and dorsal root ganglia have been implicated in the development of chronic neuropathic pain. Therefore we hypothesized that changes in cutaneous innervation after burn injury may be mediated at the level of the dorsal root ganglia. Burn group rats (n = 20) were subjected to a unilateral burn injury while 12 control rats underwent sham procedure. The DRGs dermatomally related to the site of burn (Thoracic 13, lumbar 1 and lumbar 2), ipsilateral and contralateral to the injury, were compared for Type A, Type B and total cell number with sham control DRGs, at 4 and 6 weeks after injury. There was a significant decrease in Type A cell count (cell bodies of nerve fibres mediating touch-pressure-vibration sensation) in the 4 week time-point group (p = 0.0124) ipsilateral to the burn injury. Total DRG cell count and Type B DRG cell count (cell bodies of fibres mediating pain and itch) on the ipsilateral side was not significantly altered. On the side contralateral to the burn injury, there was no statistically significant change in the total cell count, Type A cell count or Type B cell count. This data showed a decrease in Type A cell number in DRGs after a burn injury, suggesting cell death may mediate some changes observed in cutaneous innervation after a burn. Type B cells constituted a greater proportion of the viable cell population in the ipsilateral DRG after a burn injury. This change may be important in the induction of signalling related to pain and itch and has important implications for the restoration of normal cutaneous innervation after burn injury. Investigating whether neuro-protective or neuro-restorative approaches can ameliorate damage to the DRG will be important to improve sensory outcomes for burn patients.     

神经生长因子对大鼠脊髓损伤后神经元凋亡的影响

目的探讨神经生长因子(NGF)对脊髓损伤保护作用的分子机制.方法采用Allen's法以25 gcm力致伤大鼠T8脊髓,经蛛网膜下腔导管于术后即刻、2、4、8、12、24 h各注入NGF溶液,并与生理盐水组(NS组)和正常对照组作对照,采用免疫组织化学方法和末端单位标记法(TUNEL)原位末端标记法分别检测bcl-2、bax蛋白在脊髓神经元的表达及神经元凋亡情况.结果正常组中脊髓灰质bax蛋白阳性细胞吸光度(A)值为34.51±4.47,NS组中bax蛋白表达增加,以2 h及12 h最为显著,而NGF组与NS组相比,bax蛋白表达明显减少(P＜0.01).正常组中脊髓灰质bcl-2蛋白表达的A值为19.72±2.92,NS组中bcl-2表达下降,而NGF组与NS组相比较,bcl-2蛋白表达明显增多(P＜0.01).TUNEL检测结果显示,正常对照组中未见神经元凋亡,NS组中自2 h后可见神经元凋亡,NGF组与NS组相比,神经元凋亡指数明显减少(P＜0.01).结论NGF能通过抑制bax蛋白的表达,促进bcl-2表达抑制脊髓损伤后神经元凋亡,从而保护损伤的脊髓组织,这可能是NGF对脊髓损伤具有保护作用的机制之一.     

星状神经节阻滞对瓣膜置换术患者颅内静脉血炎性因子及氧化应激指标的影响

目的 观察星状神经节阻滞(SGB)对心脏瓣膜置换术患者颅内静脉血炎症因子氧化应激指标的影响.方法 择期心肺转流(CPB)下心脏瓣膜置换术患者40例,随机均分为两组,SGB组和对照组.SGB组以0.25%罗哌卡因10 ml行右侧SGB,对照组不行SGB,SGB 10 min后开始麻醉诱导.分别于左颈内静脉逆行置管后即刻(T0)、主动脉开放后10 min(T1)、术后2 h(T2)、6 h(T3)及24 h(T4)抽取颈内静脉球部血5 ml,检测血浆肿瘤坏死因子-α(TNF-α)、白细胞介素-8(IL-8)、白细胞介素-10(IL-10)、丙二醛(MDA)浓度、超氧化物歧化酶(SOD)活性.结果 与T0时比较,两组血浆TNF-α、IL-8、IL-10及MDA浓度在T1～T4时升高,血浆SOD活性对照组在T1～T4时降低(P＜0.05),SGB组在T1～T2时降低(P＜0.05);与对照组比较,SGB组血浆TNF-α、IL-8、MDA浓度在T1～T4时降低(P＜0.05),IL-10浓度及SOD活性在T1～T4时升高(P＜0.05).结论 SGB可以减轻心脏瓣膜置换术患者围CPB期颅内过度炎症反应及脂质过氧化损伤,对减轻脑损伤具有一定积极意义.     

坐骨神经损伤及神经生长因子对背根神经节中TrkA及其mRNA表达的调控

目的 研究周围神经损伤、神经再生及外源性神经生长因子对脊神经背根神经节中TrkA及TrkA mRNA表达的影响。方法 将24只SD大鼠坐骨神经从神经中段切断后，外膜缝合修复神经。实验组动物的胫后肌内每日注射NGF200U，术后3、7、14、28d，采用免疫组织化学及原位杂交方法，检查大鼠坐骨神经损伤、神经再生及外源性NGF靶肌肉注射后脊神经背根神经节中TrkA及TrkA mRNA表达。结果 正常背根神经节中有大量的神经元表达TrkA及TrkA mRNA；坐骨神经损伤后，背根神经节中TrkA的表达下降，术后7d组最低，28d接近正常；NGF靶肌肉注射后，背根神经节中TrkA的表达明显增高。结论 神经损伤后背根神经节中TrkA的表达降低，靶肌肉注射外源性NGF背根神经节中TrkA的表达增加，表明靶肌肉注射可作为NGF的有效给药途径.     

Trehalose attenuates spinal cord injury through the regulation of oxidative stress,inflammation and GFAP expression in rats

Objective: Inflammation and oxidative stress are implicated in pathogenesis of spinal cord injury (SCI). Trehalose, a nonreducing disaccharide, exhibits anti-inflammatory and antioxidant effects. The present study investigated the therapeutic efficacy of trehalose in the SCI model.

Design and setting: An experimental study was designed using 120 male Wistar rats which were randomly divided into three groups including SCI, SCI?+?phosphate buffer saline (vehicle) and SCI?+?trehalose. All rats were subjected to SCI. Immediately after SCI, vehicle and trehalose groups received intrathecal injection of buffer and trehalose, respectively.

Outcome measures: The level of tissue TNFα, IL-1β, nitric oxide, malondialdehyde, myeloperoxidase, glial fibrillary acidic protein (GFAP) as well as hindlimb function were assessed at 4 hours, 1, 3 and 7 days post-SCI.

Results: Data indicated an early significant decrease in inflammatory and oxidative responses following SCI in trehalose treated group. Moreover, trehalose reduced GFAP expression as soon as 1-day post-trauma. Furthermore, trehalose treatment increased the score of hindlimb function.

Conclusion: Our results indicated that treatment with trehalose reduces the development of secondary injury associated with SCI. This effect likely underlies improved neurological function.     

结缔组织生长因子在周围神经慢性卡压损伤中的表达及其意义

目的 探讨大鼠坐骨神经慢性卡压损伤后其卡压神经段内结缔组织生长因子(CTGF)表达变化及其意义. 方法 2010年7月到2010年9月,将50只成年雄性SD大鼠随机分成:A组(假手术组),仅分离暴露坐骨神经;B组(卡压组),采用Mackinnon建立的坐骨神经卡压模型方法对大鼠右侧后腿坐骨神经行硅胶管卡压术.于卡压术后2、4、6、8、10周时间点,随机取A、B组大鼠各5只,取其卡压段坐骨神经行组织形态学、免疫组织化学观察及RT-PCR、Western blot定量测定CTGF及Ⅰ、Ⅲ型胶原蛋白(COL-Ⅰ、Ⅲ)含量. 结果 坐骨神经慢性卡压损伤后,有髓神经纤维发生瓦勒变性,胶原纤维增生,CTGF表达上调,并伴有COL-I、Ⅲ表达升高,与假手术组比较差异有统计学意义(P＜0.05).结论 慢性卡压损伤可致周围神经发生纤维化病变,CTGF参与了这一病理生理改变过程,提示CTGF在周围神经纤维化过程中具有一定作用.     

Nerve injury and recovery after lateral lumbar interbody fusion with and without bone morphogenetic protein-2 augmentation: a cohort-controlled study

Background contextDespite common use of intraoperative electrophysiologic neuromonitoring, injuries to the lumbar plexus during lateral lumbar interbody fusion (LLIF) have been reported. Emerging data suggest that recombinant human bone morphogenetic protein-2 (rhBMP-2) use during an anterior or transforaminal lumbar interbody fusion may be associated with an increased risk of neurological deficit. Clinical data on the sequelae of rhBMP-2 implantation in close proximity to the lumbosacral plexus during LLIF remains to be understood.PurposeThe purpose of this study was to compare the incidence of neurologic deficits and pain in patients undergoing LLIF with and without rhBMP-2.Study design/settingRetrospective outcome analysis in controlled cohorts undergoing the lateral exposure technique for LLIF with and without rhBMP-2.MethodsThe electronic medical records of patients undergoing LLIF with and without supplemental posterior fusion for degenerative spinal conditions were retrospectively reviewed over a 6-year period. Patients with previous lumbar spine surgery or follow-up of less than 6 months were excluded. Patients were divided into 2 groups, Group 1 (rhBMP-2 use; n=72) and Group 2 (autograft/allograft use; n=72), and were matched according to the age at the time of surgery, gender, weight, body mass index, side of approach, total number of treated spinal segments, use of supplemental posterior fusion, and length of follow-up.ResultsImmediately after surgery, a sensory deficit was recorded in 33 patients in Group 1 and 35 patients in Group 2 (odds ratio [OR] 0.895; 90% confidence interval [CI] 0.516–1.550; p=.739). At last follow-up, a persistent sensory deficit was identified in 29 patients whose LLIF procedure was supplemented by rhBMP-2 and 20 patients in whom autograft/allograft was used (OR 1.754; 90% CI 0.976–3.151; p=.115). A motor deficit was recorded in 37 patients immediately after the rhBMP-2 procedure and 28 patients treated with autograft/allograft (OR 1.661; 90% CI 0.953–2.895; p=.133). A persistent motor deficit was recorded in 35 and 17 patients in Groups 1 and 2, respectively, at last follow-up (OR 3.060; 90% CI 1.681–5.571; p=.002). During the first postoperative examination, 37 patients in Group 1 and 25 patients in Group 2 complained of anterior thigh or groin pain (OR 1.987; 90% CI 1.133–3.488; p=.045). At last follow-up, there was a significantly higher number of patients in Group 1 who complained of persistent anterior thigh or groin pain than Group 2 (8 vs. 0 patients) (OR 16.470; 90% CI 1.477–183.700; p=.006).ConclusionsOur results provide evidence of an increased rate of postoperative neurologic deficit and anterior thigh/groin pain after LLIF using rhBMP-2, when compared with matched controls without rhBMP-2 exposure. This study suggests a potential direct deleterious effect of rhBMP-2 on the lumbosacral plexus.     

髓核对背根节神经元GDNF表达影响及其与痛觉过敏的关系

目的:探讨腰神经根周围髓核组织移植对背根节胶质细胞源性神经营养因子(glialcellline-derivedneurotrophicfactor,GDNF)表达的影响及其与痛觉过敏之间的关系。方法:从鼠尾椎间盘取髓核组织移植到腰神经根周围,采用神经行为学观察痛觉过敏的出现规律,免疫荧光染色的方法计数背根节内GDNF免疫反应阳性神经元百分比,分析其与痛觉过敏之间的关系。结果:在髓核组织刺激下,背根节内GDNF免疫反应阳性细胞明显增多(P<0.01),这种变化与痛觉过敏有显著的正相关性(P<0.05)。结论:内源性GDNF很可能参与了痛觉过敏的调控。     

p27kip1和Skp2在大鼠坐骨神经切断后脊髓中的表达

目的 观察坐骨神经切断后大鼠脊髓中p27^kip1和Skp2的表达变化。方法 将成年SD大鼠随机分为正常对照组和实验组。对实验组实行坐骨神经切断术。用Western blot和免疫组织化学技术检测脊髓中p27^kip1和Skp2的表达变化。结果 Western blot结果表明坐骨神经切断后脊髓中p27^kip1表达持续下降，Skp2表达上调。免疫组织化学结合免疫荧光双标技术显示，在正常组和实验组，p27^kip1和Skp2在脊髓神经元和胶质细胞均有表达。在腹角神经元，损伤后p27^kip1 免疫染色减弱，Skp2增强。坐骨神经损伤前后脊髓腹角p27^kip1和Skp2阳性细胞数目改变呈负相关（r=-0．6892，P〈0．01）。结论 坐骨神经损伤可影响脊髓中p27^kip1和Skp2的表达水平及亚细胞定位，两者改变呈负相关。     

脊髓损伤后促红细胞生成素对bcl-2的影响

目的 探讨促红细胞生成素（EPO）对大鼠脊髓损伤后伤区脊髓细胞凋亡和神经功能恢复的影响。方法 Wistar大鼠210只，随机分为4组：假手术组、脊髓损伤组、脊髓损伤加重组人EPO治疗组、脊髓损伤加生理盐水治疗组。采用原位末端脱氧核糖核苷酸转移酶介导dUTP标记（TUNEL标记法）检测神经元和少突胶质细胞凋亡，Western blot免疫印迹法和免疫组化染色检测bcl-2表达，免疫组化染色和图像分析方法观察对白质内神经纤维（NF-200染色）的保护作用，通过感觉诱发电位（SSEP）、运动诱发电位（MEP）和大鼠BBB后肢运动功能评分，观察损伤脊髓传导功能的恢复。结果 EPO保护组bcl-2在各时相点的表达明显增高，8h和7d时神经元和少突胶质细胞的TUNEL阳性细胞数明显减少；在7d时白质中NF-200阳性神经纤维明显增多；SSEP和MEP的平均潜伏期和波幅以及BBB功能评分明显提高，与损伤组和生理盐水治疗相比，差异有统计学意义（P〈0．01）。结论 EPO通过上调bcl-2的表达，在抑制脊髓损伤后神经元和少突胶质细胞的凋亡中起到神经保护作用。