Basso Mouse Scale for locomotion detects differences in recovery after spinal cord injury in five common mouse strains

Genetically engineered mice are used extensively to examine molecular responses to spinal cord injury (SCI). Inherent strain differences may confound behavioral outcomes; therefore, behavioral characterization of several strains after SCI is warranted. The Basso, Beattie, Bresnahan Locomotor Rating Scale (BBB) for rats has been widely used for SCI mice, but may not accurately reflect their unique recovery pattern. This study's purpose was to develop a valid locomotor rating scale for mice and to identify strain differences in locomotor recovery after SCI. We examined C57BL/6, C57BL/10, B10.PL, BALB/c, and C57BL/6x129S6 F1 strains for 42 days after mild, moderate, and severe contusive SCI or transection of the mid thoracic spinal cord. Contusions were created using the Ohio State University electromagnetic SCI device which is a displacement-driven model, and the Infinite Horizon device, which is a force-driven model. Attributes and rankings for the Basso Mouse Scale for Locomotion (BMS) were determined from frequency analyses of seven locomotor categories. Mouse recovery differed from rats for coordination, paw position and trunk instability. Disagreement occurred across six expert raters using BBB (p < 0.05) but not BMS to assess the same mice. BMS detected significant differences in locomotor outcomes between severe contusion and transection (p < 0.05) and SCI severity gradations resulting from displacement variations of only 0.1 mm (p < 0.05). BMS demonstrated significant face, predictive and concurrent validity. Novice BMS raters with training scored within 0.5 points of experts and demonstrated high reliability (0.92-0.99). The BMS is a sensitive, valid and reliable locomotor measure in SCI mice. BMS revealed significantly higher recovery in C57BL/10, B10.PL and F1 than the C57BL/6 and BALB/c strains after moderate SCI (p < 0.05). The differing behavioral response to SCI suggests inherent genetic factors significantly impact locomotor recovery and must be considered in studies with inbred or genetically engineered mouse strains.     

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。     

Secondary conditions in a community sample of people with spinal cord damage

Objective: To compare secondary conditions in people with traumatic spinal cord injury (SCI) and non-traumatic spinal cord dysfunction (SCDys).

Design: Survey; completed August 2012 – June 2013.

Setting: Community, Australia.

Participants: Adults with spinal cord damage from any cause.

Interventions: Nil.

Outcome Measures: Demographic and clinical variables and the SCI-Secondary Conditions Scale (SCI-SCS).

Results: Survey completed by 150 people: 112 (74.7%) with traumatic SCI and 38 (25.3%) with non-traumatic SCDys a median of 10 years post onset. No significant difference (t?=?–0.6, P?=?0.6) in the total SCI-SCS score between those with SCI (mean 13.7) and SCDys (mean 14.4). Except for bladder problems (SCDys mean?=?1.5, SD?=?1.1; SCI mean?=?1.0, SD=1.1; t?=?–2.6, P?=?0.01) there were no significant differences between the aetiology groups regarding the conditions comprising the SCI-SCS (all other P values >0.1). The most common significant or chronic problems from the SCI-SCS were: sexual problems 41%; chronic pain 24%; bladder dysfunction 17%; spasms 17%; joint and muscle pain 15%; bowel dysfunction 14%; circulation problems 14%; contractures 9%; urinary tract infections 9%; pressure ulcer 7% and postural hypotension 5%. A linear regression analysis found that tetraplegia and higher disability were the only variables that significantly influenced (R²?=?0.13; P?=?0.005) the total SCI-SCS score and that sex, age, years post injury and etiology of spinal cord damage had no influence.

Conclusions: Secondary conditions following spinal cord damage do not appear to be influenced by etiology. Prevention and management of secondary conditions following need to consider people with non-traumatic SCDys as well as those with traumatic SCI.     

Flexion Model Simulating Spinal Cord Injury Without Radiographic Abnormality in Patients With Ossification of the Longitudinal Ligament: The Influence of Flexion Speed on the Cervical Spine

Abstract

Background/Objective: It is suspected that the speed of the motion of the spinal cord under static compression may be the cause of spinal cord injury (SCI). However, little is known about the relationship between the speed of the motion of the spinal cord and its stress distributions. The objective was to carry out a biomechanical study of SCI in patients with ossification of the longitudinal ligament without radiologic evidence of injury.

Methods: A 3-dimensional finite element spinal cord model was established. After the application of static compression, the model underwent anterior flexion to simulate SCI in ossification of the longitudinal ligament patients without radiologic abnormality. Flexion of the spine was assumed to occur at 1 motor segment. Flexion angle was 5°, and flexion speeds were 0.5°/s, 5°/s, and 50°/s. Stress distributions inside of the spinal cord were evaluated.

Results: Stresses on the spinal cord increased slightly after the application of 5° of flexion at a speed of 0.5°/s. Stresses became much higher at a speed of 5°/s and increased further at 50°s.

Conclusions: The stress distribution of the spinal cord under static compression increased with faster flexion speed of the spinal cord. High-speed motion of the spinal cord under static compression may be one of the causes of SCI in the absence of radiologic abnormality.     

红花注射液对大鼠脊髓损伤后继发性损伤的影响

目的探讨脊髓损伤（spinal cord injury,SCI）后红花注射液对脊髓的保护效果。方法将18只SD大鼠随机分为假手术组（A组）,脊髓打击损伤组（B组）、红花溶液组（C组）,每组6只。观察3组大鼠SCI后1 h、24 h、48 h的脊髓组织病理学变化,检测这3个时间点乳酸（lactic acid,LD）含量、乳酸脱氢酶（lactate dehydrogenase,LDH）活性、超氧化物歧化酶（superoxide dismutase,SOD）活性、丙二醛（malondialdehyde,MDA）含量。结果术后C组LD含量、LDH活性比B组低,差异有统计学意义（P〈0.05）,特别是在术后48 h（P〈0.01）;与B组相比较,C组术后24 hMDA含量明显较低,SOD活性明显升高,差异具有统计学意义（P〈0.05）。结论红花注射液能减轻脊髓继发性损伤,对SCI后的脊髓神经功能具有一定的保护作用。     

Bone morphogenetic protein-2 used in spinal fusion with spinal cord injury penetrates intrathecally and elicits a functional signaling cascade

Background contextThe use of recombinant human bone morphogenetic protein-2 (rhBMP-2) and its indications for spinal fusion continue to be expanded with recent reports citing spinal trauma application. However, there are no data establishing the effects of rhBMP-2 on the injured spinal cord.PurposeThe purpose of this study was to evaluate the extent of bone morphogenetic protein (BMP)–specific intrathecal signaling after application to the spine at various time points after a spinal cord injury (SCI).Study designThis is an in vivo rat study using a combination of the dorsal hemisection SCI and the posterolateral arthrodesis animal models.MethodsSixty-five female Sprague-Dawley rats underwent either a T9–T10 dorsal hemisection SCI (n=52) or laminectomy only (n=13). Spinal cord injury animals were further subdivided into four follow-up groups (n=13/group): 30 minutes, 24 hours, 7 days, and 21 days, at which time one of two secondary surgeries were performed: Eight rats per time point received either 43 μg of rhBMP-2 per side or sterile water control over T9–T11 on absorbable collagen sponges (ACSs). Animals were perfused after 24 hours, and spinal cords were immunohistochemically analyzed. Sections of the lesion were stained with BMP-specific pSmad 1, 5, 8 antibody and costained with cell–specific markers. pSmad-positive cells were then counted around the lesion. The remaining five rats (n=5/time point) had luciferase (blood spinal cord barrier [BSCB] permeability marker) injected through the jugular vein. Subsequently, spinal cords were collected and luciferase activity was quantified around the lesion and in the cervical samples (controls) using a luminometer.ResultsAfter injury, a significant increase in the number of pSmad-positive cells was observed when rhBMP-2 was implanted at the 30-minute, 24-hour, and 7-day time points (p<.05). Costaining revealed BMP-specific signaling activation in neurons, glial cells, macrophages, and fibroblasts. Spinal cord permeability to luciferase was significantly increased at 30 minutes, 24 hours, and 7 days post lesion (p<.05). A significant linear regression was established between the extent of BSCB permeability and pSmad signaling (r²=0.66, p=.000).ConclusionsOur results indicate that rhBMP-2 use around a spinal cord lesion elicits a robust signaling response within the spinal cord parenchyma. All CNS cell types and the invading fibroblasts are activated to the extent dependent on the integrity of the meningeal and BSCB barriers. Therefore, in the presence of a SCI and/or dural tear, rhBMP-2 diffuses intrathecally and activates a signaling cascade in all major CNS cell types, which may increase glial scarring and impact neurologic recovery.     

Role of Rho-associated coiled-coil containing protein kinase in the spinal cord injury induced neuropathic pain

BACKGROUND CONTEXTSpinal cord injury (SCI) can lead to increased phosphorylation of p38 in spinal cord microglia. This is one of the main causes for the development of persistent pain. Recently, we reported our study on the activation of p38 mitogen-activated protein kinases (MAPK) in spinal microglia, which has been considered the key molecule for the onset and maintenance of neuropathic pain after peripheral nerve injury, using a rat model. We also reported that the RhoA/Rho-associated coiled-coil containing protein kinase (ROCK) pathway mediates p38 activation in spinal microglia in peripheral nerve injury. But the precise mechanisms of neuropathic pain induced by SCI are still unclear.PURPOSEThis study aimed to examine the activation of microglia and the p38 MAPK expression in the lumbar spinal cord after thoracic SCI in rats, and the correlation to the therapeutic effect of ROCK inhibitor ripasudil in rats with SCI.STUDY DESIGNMale Sprague–Dawley rats underwent thoracic (T10) spinal cord contusion injury using an Infinite Horizon impactor device. SCI rats received ROCK inhibitor ripasudil (24 nmol/day or 240 nmol/day) from just before SCI to 3 days after SCI.METHODSThe mechanical threshold in the rat's hind paws was measured over four weeks. Morphology of microglia and phosphorylation of p38 (p-p38) in the lumbar spinal cord and were analyzed using immunohistochemistry.RESULTSThe p-p38 positive cell and Iba1 (a maker of microglia) positive area were significantly increased at the lumbar spinal dorsal horn (L4–5) 3 days and 7 days after SCI compared with the sham-control (p<.05), whereas phosphorylated p38 was co-localized with microglia. Three days after SCI, the intensity of phosphorylated p38 and Iba1 immunoreactive cells in the dorsal horn was significantly lower in the ripasudil treated groups than in the saline group. However, administration of ROCK inhibitor did not affect the numbers of microglia. Moreover, the withdrawal threshold of the ripasudil-treated rats was significantly higher than that of the saline-injected rats on 14 days and 28 days after SCI.CONCLUSIONSOur results suggest that activation of ROCK in spinal cord microglia is likely to have an important role in the activation of p38 MAPK, which has been considered as a key molecule that switches on neuropathic pain after SCI. Inhibition of ROCK signaling may offer a means in developing a novel neuropathic pain treatment after SCI. It may help patients with neuropathic pain after SCI.CLINICAL SIGNIFICANCEThe findings in the present study regarding intracellular mechanisms suggest that modulation of ROCK signaling may be a focus for novel treatment for neuropathic pain after SCI.     

The pre-hospital epidemiology and management of spinal cord injuries in New South Wales: 2004-2008

ContextPatients who have sustained a traumatic spinal cord injury require appropriate management in the immediate post-injury period for both survival and to reduce the chances of costly and disabling permanent neurological deficits. Emerging time-critical neuroprotective therapies require the prompt recognition and transfer of patients to a specialised centre for early intervention.MethodsThe Ambulance Research Institute, with the New South Wales State Spinal Cord Injury Service retrospectively linked prehospital data to spinal cord injury unit (SCIU) outcome data for all 324 patients transported by ambulance and subsequently admitted to a SCIU with a persisting traumatic spinal cord injury (SCI) between January 2004 and June 2008, with the aim of identifying factors that impact on the provision of timely and appropriate care.ResultsParamedics appropriately managed 88% of SCI patients. Only 4.9% of patients had initial vital signs potentially indicative of neurological injury. The median time to a SCIU was 12 h, with 60% of patients undergoing multiple transfers. The odds of reaching a SCIU in over 24 h were 1.71 times greater for patients injured in a major city (95% CI 1.00–2.90) in comparison to other areas of NSW. More SCI patients with multiple trauma experienced delays in reaching a SCIU (59%), compared to patients with isolated SCI (40%; p = 0.039). Patients initially transported to a designated major trauma centre were more likely to be delayed in reaching a SCIU, regardless of whether their injury was an isolated SCI or associated with multiple trauma, compared with other patients. Patients who took greater than 24 h to reach a SCIU were 2.5 times more likely to develop a secondary complication (95% CI 1.51–4.17, p = 0.0004). Patients who sustained their SCI as a result of a low fall were older and less likely to have their SCI identified and treated early, with less than half of this group reaching a SCIU within 24 h compared with other SCI patients (OR 0.42, 95% CI 0.19–0.93, p = 0.004).ConclusionEarly recognition, appropriate prehospital management, triage, timely and appropriate interfacility transfers of all SCI patients are critical for access to specialised care and reducing preventable complications. Elderly fallers present particular challenges to early identification.     

Comparison of functional and histological outcomes after intralesional, intracisternal, and intravenous transplantation of human bone marrow-derived mesenchymal stromal cells in a rat model of spinal cord injury

Background

Few studies have compared methods of stem cell transplantation. The aim of the present study was to determine the optimal method of delivery of therapeutic stem cells in spinal cord injury (SCI). We compared functional and histologic outcomes after administration of human bone marrow stromal cells (BMSCs) by intralesional (ILT), intracisternal (ICT), and intravenous transplantation (IVT).

Method

A rat model of spinal cord injury was produced by dropping a 10-g weight, 2 mm in diameter, onto the exposed spinal cords of animals from a height of 25 mm. In each treatment group, 24 animals were randomly assigned for functional assessment and 24 for histologic examination. BMSCs (3?×?10⁵, ILT; 1?×?10⁶, ICT; 2?×?10⁶, IVT) were transplanted 1 week after SCI in numbers determined in previous studies. Basso-Beattie-Bresnahan scoring was performed in all animals weekly for 6 weeks. Spinal cord specimens were obtained from eight animals in each group 2, 4, and 6 weeks after SCI. Viable BMSCs were counted in six sagittal sections from each spinal cord.

Results

All three treatment groups showed improved functional recovery compared to controls beginning 2 weeks after stem cell injection (P?<?0.01). The ICT group showed the best functional recovery, followed by the ILT and IVT groups, respectively (P?<?0.01). Histological analysis showed the largest number of viable BMSCs in the ILT group, followed by the ICT and IVT groups, respectively (P?<?0.01).

Conclusions

ICT may be the safest and most effective method for delivering stem cells and improving functional outcome in SCI when no limits are placed on the number of cells transplanted. As research on enhancing engraftment rates advances, further improvement of functional outcome can be expected.     

脊髓损伤后脂质蓄积对损伤灶自发荧光强度的影响

目的 :研究小鼠脊髓损伤后损伤灶的脂质蓄积与自发荧光强度之间的关系,探索硫酸铜能否消除脊髓损伤灶的自发荧光。方法:选取鼠龄8~12周,体重18~24 g的野生型小鼠36只,随机分为正常对照组(4只)与脊髓损伤组(32只)。脊髓损伤组于损伤后1、2、4、8周分别随机抽取8只处死,以损伤灶为中心取脊髓组织标本行冰冻切片(正常对照组取相同节段的脊髓,标本放入4%多聚甲醛溶液进行后固定),在荧光显微镜的绿色通道下观察自发荧光,进行油红O染色显示损伤灶的脂质蓄积,并分析自发荧光强度与脂质蓄积量的相关性。配制硫酸铜缓冲液处理切片以消除自发荧光,并优化硫酸铜浓度与作用时间。结果:正常脊髓组织切片未发现明显自发荧光或脂质染色,而脊髓损伤后在损伤灶出现自发荧光,并且强度随损伤后时间延长而增强。油红O染色显示损伤灶的脂质同样随伤后时间延长而蓄积,并且增长趋势与自发荧光的增强趋势呈正相关。应用硫酸铜缓冲液后,自发荧光强度显著降低,优化硫酸铜浓度与作用时间后效果更好。结论:脊髓损伤后损伤灶脂质蓄积可能在决定自发荧光的强度上起重要作用,自发荧光强度可以作为评估脂质过氧化损害的简便指标;优化的硫酸铜法能够显著消除脊髓损伤后损伤灶的自发荧光,有利于免疫荧光染色技术在脊髓损伤研究中的应用。     

Necroptosis,a novel type of programmed cell death,contributes to early neural cells damage after spinal cord injury in adult mice

Abstract

Background

Necroptosis is an emerging programmed necrosis other than traditional necrosis and apoptosis. Until recently, there have not been studies that have investigated a relationship between necroptosis and pathogenesis of cell death after spinal cord injury (SCI).

Objective

To investigate whether necroptosis takes part in the early pathophysiological processes of traumatic SCI in mice.

Methods

Female ICR mice were randomized equally into three groups: the sham, the vehicle-treated + SCI group, and the Nec-1-treated + SCI group. To induce SCI, the mice were subjected to a laminectomy at T9 and compression with a vascular clip. After mice were sacrificed 24 hours post-SCI, propidium iodide (PI)-positive cells were detected using in vivo PI labeling. Morphological analyses were performed by hematoxylin and eosin staining and Nissl staining. The samples were evaluated for apoptosis by the in situ TUNEL assay. The expression of caspase-3 was assessed by western blot. Locomotor behavior of hindlimb was evaluated by BMS (Basso mouse scale) score at 1, 3, 5, 7, and 14 days post-injury.

Results

Compared with dimethyl sulfoxide -treated mice, necrostatin-1-treated mice showed decreased PI-positive cells (P < 0.05), alleviated tissue damage, more surviving neuron at 24 hours after SCI (P < 0.05), and improved functional recovery from days 7 to 14 (P < 0.05). Necrostatin-1 did not reduce the expression of caspase-3 and the number of TUNEL-positive cells at 24 hours after SCI (P > 0.05).

Conclusions

Necroptosis contributes to necroptotic cell death and influences functional outcome after SCI in adult mice. The inhibition of necroptosis by necrostatin-1 may have therapeutic potential for patients with SCI.     

Synergistic neuroprotective effects of hyperbaric oxygen and methylprednisolone following contusive spinal cord injury in rat

ObjectiveRecent studies revealed the neuroprotective effects of hyperbaric oxygen (HBO) on spinal cord injury (SCI). Meanwhile, the use of methylprednisolone (MP) is one of the current protocols with limited effects in SCI patients. Accordingly, the aim of the present study was to investigate the effect of combined HBO and MP treatment on SCI.DesignThe present study was conducted on five groups of rats each as follows: Sham group (underwent laminectomy alone at T9 level vertebra); SCI group (underwent moderate contusive SCI); MP group (underwent SCI and received MP); HBO group (underwent SCI and received HBO); HBO + MP group (underwent SCI and simultaneously received MP and HBO). Blood serum and Spinal cord tissue samples were taken 48 h after SCI for analysis of serum ferric reducing antioxidant power (FRAP) and tissue malodialdehyde (MDA) levels as well as immunohistochemistry of caspase-3 and tumor necrosis factor-alpha (TNF-α). Neurological function was evaluated by the Basso–Beattie–Bresnehan (BBB) locomotion scores until the end of experiments. Additionally, histopathology was assessed at the end of the study.SettingMazandaran University of Medical Sciences, Sari, Iran.ResultsCombination therapy with HBO and MP in the HBO + MP group significantly decreased MDA as well as increased FRAP levels compared to other treatment groups. Meanwhile, attenuated TNF-α and Caspase-3 expression could be significantly detected in the HBO + MP group. At the end of treatment, the neurological outcome was significantly improved and the extent of injured spinal tissue was also significantly reduced in the HBO + MP compared to other treatment groups.ConclusionThe results suggest that combined therapy with MP and HBO has synergistic effects on SCI treatment.     

Curcumin modulates TLR4/NF-κB inflammatory signaling pathway following traumatic spinal cord injury in rats

Abstract

Background

Curcumin, a polyphenolic compound extracted from the plant turmeric, has protective effects on spinal cord injury (SCI) through attenuation of inflammatory response. This study was designed to detect whether curcumin modulates toll-like receptor 4 (TLR4) and the nuclear factor-kappa B (NF-κB) inflammatory signaling pathway in the injured rat spinal cord following SCI.

Methods

Adult male Sprague–Dawley rats were subjected to laminectomy at T8–T9 and compression with a vascular clip. There were three groups: (a) sham group; (b) SCI group; and (g) SCI + curcumin group. We measured TLR4 gene and protein expression by real-time polymerase chain reaction and western blot analysis; NF-κB activity by electrophoretic mobility shift assay, inflammatory cytokines tumor necrosis factor-α, interleukin-1β, and interleukin-6 levels by enzyme-linked immunosorbent assay, hindlimb locomotion function by Basso, Beattie, and Bresnahan rating, spinal cord edema by wet/dry weight method, and apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) analysis.

Results

The results showed that SCI induced the up-regulation of TLR4, NF-κB, and inflammatory cytokines in the injured rat spinal cord. Treatment with curcumin following SCI markedly down-regulated the levels of these agents related to the TLR4/NF-κB inflammatory signaling pathway. Administration of curcumin also significantly ameliorated SCI induced hind limb locomotion deficits, spinal cord edema, and apoptosis.

Conclusions

Post-SCI curcumin administration attenuates the TLR4/NF-κB inflammatory signaling pathway in the injured spinal cord, and this may be a mechanism whereby curcumin improves the outcome following SCI.     

Patterns of cognitive deficits in persons with spinal cord injury as compared with both age-matched and older individuals without spinal cord injury

Context/Objective: Cognitive deficits can impact as many as 60% of individuals with spinal cord injury (SCI). In an effort to identify the nature of cognitive deficits in SCI, we examined neuropsychological test performance in individuals with SCI, age matched healthy controls and older healthy controls.

Design: Participants completed a motor-free neuropsychological test battery assessing attention, working memory, information processing speed, new learning /memory and executive control.

Setting: Outpatient rehabilitation research facility.

Participants: Participants included 60 individuals with chronic spinal cord injury [SCI; 32 with paraplegia (T2-T12) and 28 with tetraplegia (C3-T1)], 30 age-matched healthy controls (AMHC; 30–40 years old) and 20 older healthy controls (OHC; 50–60 years old).

Outcome Measures: Wechsler Intelligence Scale – 3^rd edition (WAIS-III) Digit Span and Letter-Number Sequencing; Symbol Digit Modalities Test (SDMT) – oral version; California Verbal Learning Test-II; Paced Auditory Serial Addition Test (PASAT); Wechsler Abbreviated Scale of Intelligence (WASI); Delis-Kaplan Executive Function System; Verbal Fluency subtest.

Results: Significant differences were noted between the SCI and AMHC groups on measures of information processing speed, new learning and memory, and verbal fluency. No significant differences were noted between the groups on tests of attention or working memory.

Conclusion: The current study documented differences in specific realms of cognitive functioning between a chronic SCI sample and AMHC. Implications for cognitive rehabilitation and overall quality of life are discussed. Additional research is needed utilizing a more comprehensive battery of motor-free neuropsychological tests that avoid the confound of upper limb motor limitations on cognitive performance.     

Caveolin-1 Deficiency Inhibits the Basolateral K+ Channels in the Distal Convoluted Tubule and Impairs Renal K+ and Mg2+ Transport

Kcnj10 encodes the inwardly rectifying K⁺ channel Kir4.1 in the basolateral membrane of the distal convoluted tubule (DCT) and is activated by c-Src. However, the regulation and function of this K⁺ channel are incompletely characterized. Here, patch-clamp experiments in Kcnj10-transfected HEK293 cells demonstrated that c-Src–induced stimulation of Kcnj10 requires coexpression of caveolin-1 (cav-1), and immunostaining showed expression of cav-1 in the basolateral membrane of parvalbumin-positive DCT. Patch-clamp experiments detected a 40-pS inwardly rectifying K⁺ channel, a heterotetramer of Kir4.1/Kir5.1, in the basolateral membrane of the early DCT (DCT1) in both wild-type (WT) and cav-1-knockout (KO) mice. However, the activity of this basolateral 40-pS K⁺ channel was lower in KO mice than in WT mice. Moreover, the K⁺ reversal potential (an indication of membrane potential) was less negative in the DCT1 of KO mice than in the DCT1 of WT mice. Western blot analysis demonstrated that cav-1 deficiency decreased the expression of the Na⁺/Cl^– cotransporter and Ste20-proline-alanine-rich kinase (SPAK) but increased the expression of epithelial Na⁺ channel-α. Furthermore, the urinary excretion of Mg²⁺ and K⁺ was significantly higher in KO mice than in WT mice, and KO mice developed hypomagnesemia, hypocalcemia, and hypokalemia. We conclude that disruption of cav-1 decreases basolateral K⁺ channel activity and depolarizes the cell membrane potential in the DCT1 at least in part by suppressing the stimulatory effect of c-Src on Kcnj10. Furthermore, the decrease in Kcnj10 and Na⁺/Cl^– cotransporter expression induced by cav-1 deficiency may underlie the compromised renal transport of Mg²⁺, Ca²⁺, and K⁺.     

Spinal motor neurite outgrowth over glial scar inhibitors is enhanced by coculture with bone marrow stromal cells

Background contextTransplantation of bone marrow cells into spinal cord lesions promotes functional recovery in animal models, and recent clinical trials suggest possible recovery also in humans. The mechanisms responsible for these improvements are still unclear.PurposeTo characterize spinal cord motor neurite interactions with human bone marrow stromal cells (MSCs) in an in vitro model of spinal cord injury (SCI).Study design/settingPreviously, we have reported that human MSCs promote the growth of extending sensory neurites from dorsal root ganglia (DRG), in the presence of some of the molecules present in the glial scar, which are attributed with inhibiting axonal regeneration after SCI. We have adapted and optimized this system replacing the DRG with a spinal cord culture to produce a central nervous system (CNS) model, which is more relevant to the SCI situation.MethodsWe have developed and characterized a novel spinal cord culture system. Human MSCs were cocultured with spinal motor neurites in substrate choice assays containing glial scar–associated inhibitors of nerve growth. In separate experiments, MSC-conditioned media were analyzed and added to spinal motor neurites in substrate choice assays.ResultsAs has been reported previously with DRG, substrate-bound neurocan and Nogo-A repelled spinal neuronal adhesion and neurite outgrowth, but these inhibitory effects were abrogated in MSC/spinal cord cocultures. However, unlike DRG, spinal neuronal bodies and neurites showed no inhibition to substrates of myelin-associated glycoprotein. In addition, the MSC secretome contained numerous neurotrophic factors that stimulated spinal neurite outgrowth, but these were not sufficient stimuli to promote spinal neurite extension over inhibitory concentrations of neurocan or Nogo-A.ConclusionsThese findings provide novel insight into how MSC transplantation may promote regeneration and functional recovery in animal models of SCI and in the clinic, especially in the chronic situation in which glial scars (and associated neural inhibitors) are well established. In addition, we have confirmed that this CNS model predominantly comprises motor neurons via immunocytochemical characterization. We hope that this model may be used in future research to test various other potential interventions for spinal injury or disease states.     

油红O染色在大鼠脊髓损伤中的应用

目的:探讨油红O染色在评价大鼠脊髓损伤中的应用价值。方法:选取体重220～260 g的SD雄鼠24只,编号后简单随机抽样分为正常对照组与脊髓横断组,正常对照组6只,脊髓横断组18只。脊髓横断组于T₁₀节段横断脊髓。于术后1、2、4周在脊髓横断组分别随机各抽取6只处死,以横断部位为中心取脊髓组织标本。正常组取相同部位脊髓组织标本,行冰冻切片,进行油红O染色观察。结果:正常对照组大鼠脊髓白质均匀着色,与灰质有较明显的区分。脊髓横断组在术后1、2、4周时白质着色不均匀,断端液化坏死灶呈进行性扩大,油红O染色逐渐明显。结论:油红O染色能够较明显的区分白质及灰质,在一定程度上反映了白质的完整程度。断端坏死灶内油红O染色随脊髓损伤时间的延长逐渐明显反映了脂质在脊髓损伤过程中起着重要作用。     

Curcumin inhibits the increase of labile zinc and the expression of inflammatory cytokines after traumatic spinal cord injury in rats

Background

The present study aimed to investigate the effects of curcumin on the levels of spinal cord labile zinc (Zn) and inflammatory cytokines in rats after traumatic spinal cord injury (SCI).

Methods

Adult male Sprague–Dawley rats were subjected to laminectomy at T8-T9 and compression with a vascular clip. There were three groups: (a) sham group; (b) SCI group; and (c) SCI + curcumin group. We measured spinal labile Zn by N-(6-methoxy-8-quinolinyl)-4-methylbenzenesulfonamide (TSQ) fluorescence staining, inflammatory cytokines such as interleukin 1β, interleukin-6, and tumor necrosis factor α by enzyme-linked immunosorbent assay, hindlimb locomotion function by Basso, Beattie, and Bresnahan rating, spinal cord edema by wet dry weight method, and apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling analysis.

Results

The results showed that SCI caused a significant increase in labile Zn and inflammatory cytokines in the injured rat spinal cord. Treatment with curcumin after SCI markedly downregulated the levels of these agents and ameliorated SCI-induced hindlimb locomotion deficits, spinal cord edema, and apoptosis.

Conclusions

Curcumin treatment attenuates the increase of labile Zn and the expression of inflammatory cytokines in the injured spinal cord, and this may be a mechanism whereby curcumin improves the outcome after SCI.     

A Review of the Neuropathology of Human Spinal Cord Injury with Emphasis on Special Features

Abstract

A judicious understanding of the basic neuropathology of spinal cord injuries (SCI) is essential knowledge for the clinician responsible for SCI management. An appreciation of the nature of human SCI is also necessary for the neuroscientist searching for a cure. The neuropathology of human SCI described here is derived from the study of 564 cases of spinal cord trauma held in a tissue bank and database of the Department of Neuropathology, Royal Perth Hospital in Australia. The main features of SCI neuropathology are reviewed and special aspects such as early axonal lesions, traumatic demyelination-remyelination, and quantification of white matter tracts are reported in more detail. One of the remarkable outcomes of this work is the finding that the majority of SCI patients have a proportion of spinal corcJ white matter maintained across the level of the lesion, an observation that has important therapeutic implications. (J Spinal Cord Med 1999;22:119–124)     

The combined effect of granulocyte-colony stimulating factor (G-CSF) treatment and exercise in rats with spinal cord injury

Objective: To identify that the combined G-CSF and treadmill exercise is more effective in functional recovery after spinal cord injury (SCI).

Design: Rats were divided into 4 groups: a SCI group treated with G-CSF (G-CSF group, n?=?6), a SCI group treated with treadmill exercise plus G-CSF (G-CSF/exercise group, n?=?6), a SCI group with treadmill exercise (exercise group, n?=?6), and a SCI group without treatments (control group, n?=?6). We performed laminectomy at the T8–10 spinal levels with compression injury of the spinal cord in all rats. G-CSF (20?μg/ml) was administered intraperitoneally for 5 consecutive days after SCI in G-CSF and G-CSF/exercise groups. From one week after surgery, animals in G-CSF/exercise and exercise groups received 30?min of exercise 5 days per week for 4 weeks. Functional recoveries were assessed using the Basso, Beattie, and Bresnahan (BBB) scale and the inclined plane test. Five weeks after SCI, hematoxylin and eosin staining for cavity size and immunohistochemistry for glial scar formation and neuro-regeneration factor expression were conducted.

Setting: Inha University School of medicine, Incheon, Korea

Results: Rats in G-CSF/exercise group showed the most effective functional recovery in the BBB scale and the inclined plane test, and spinal cord cavity size by injury were the smallest, and immunohistochemistry revealed expression of higher BDNF (brain-derived neurotrophic factor) and VEGF (vascular endothelial growth factor) and lower GFAP (glial fibrillary acidic protein) than others.

Conclusion: Combined treatment provided more effective neuroplasty and functional recovery than individual treatments.