Spinal cord injury models: neurophysiology.

Methylprednisolone in Spinal Cord Injury: The Possible Mechanism of Action

Protective effect of deferoxamine on experimental spinal cord injury in rat

Neuroprotective effects of Nigella sativa on experimental spinal cord injury in rats

Purpose: To investigate the effectiveness of tetrahydropalmatine (THP) in the treatment of spinal cord injury (SCI) in rats.
 Methods: Adult Sprague Dawley rats were divided into 3 groups: normal control group, SCI group, and SCI group treated with THP (100 mg kg-1). The effect of THP on spinal cord water content, levels of inflammatory mediators, oxidative stress and apoptosis were determined. Locomotor activity in rats was measured using Basso, Beattie and Bresnahan (BBB) scores. Various oxidative stress markers as well as cytokine levels (NF-ĸB, IL-6, IL-1β and TNF-α were determined. Apoptotic index was measured using TUNEL assay.
 Results: After 72 h of treatment with THP, BBB scores in SCI group of rats significantly increased from 4.19 ± 0.41 to 8.89 ± 0.47 (p < 0.05). Tunel assay revealed a higher apoptotic index (42.50 ± 3.19) in the tissues of SCI rats than in SCI rats treated with THP (31.48 ± 1.19, p < 0.01). Expressions of inflammatory cytokines were significantly upregulated in SCI rats. However, THP administration resulted in significant downregulation of the expressions (p < 0.01).
 Conclusion: These results indicate that THP attenuates traumatic SCI in rats via modulation of the levels of anti-inflammatory mediators. Thus, THP has a promising potential for the management of SCI.

Recent evidence indicates that estrogen exerts neuroprotective effects in both brain injury and neurodegenerative diseases. We examined the protective effect of estrogen on functional recovery after spinal cord injury (SCI) in rats. 17beta-estradiol (3, 100, or 300 microg/kg) was administered intravenously 1-2 h prior to injury (pre-treatment), and animals were then subjected to a mild, weight-drop spinal cord contusion injury. Estradiol treatment significantly improved hind limb motor function as determined by the Basso-Beattie-Bresnahan (BBB) locomotor open field behavioral rating test. Fifteen to 30 days after SCI, BBB scores were significantly higher in estradiol-treated (100 microg/kg) rats when compared to vehicle-treated rats. Morphological analysis showed that lesion sizes increased progressively in either vehicle-treated or 17beta-estradiol-treated spinal cords. However, in response to treatment with 17beta-estradiol, the lesion size was significantly reduced 18-28 days after SCI when compared to vehicle-treated controls. Terminal deoxynucleotidyl transferase-mediated UTP nickend labeling (TUNEL) staining and DNA gel electrophoresis revealed that apoptotic cell death peaked 24-48 h after injury. Also, SCI induced a marked increase in activated caspase-3 in the spinal cord, evident by 4 h after injury. However, administration of 17beta-estradiol significantly reduced the SCI-induced increase in apoptotic cell death and caspase-3 activity after SCI. Furthermore, 17beta-estradiol significantly increased expression of the anti-apoptotic genes, bcl-2 and bcl-x, after SCI while expression of the pro-apoptotic genes, bad and bax, was not affected by drug treatment. Finally, intravenous administration of 17beta-estradiol (100 microg/kg) immediately after injury (post-treatment) also significantly improved hind limb motor function 19-30 days after SCI compared to vehicle-treated controls. These data suggest that after SCI, 17 beta-estradiol treatment improved functional recovery in the injured rat, in part, by reducing apoptotic cell death.

Journal of NeurotraumaVol. 9, No. 2 NIH Workshop on Experimental Spinal Cord Injury: Modeling and CriteriaDOUGLAS K. ANDERSON, CHUNG Y. HSU, MARY ELLEN MICHEL, and BRADFORD T. STOKESDOUGLAS K. ANDERSONSearch for more papers by this author, CHUNG Y. HSUSearch for more papers by this author, MARY ELLEN MICHELSearch for more papers by this author, and BRADFORD T. STOKESSearch for more papers by this authorPublished Online:26 Mar 2009https://doi.org/10.1089/neu.1992.9.113AboutSectionsPDF/EPUB ToolsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail FiguresReferencesRelatedDetailsCited byAcute Cellular and Functional Changes With a Combinatorial Treatment of Ion Channel Inhibitors Following Spinal Cord Injury25 June 2020 | Frontiers in Molecular Neuroscience, Vol. 13Granzyme-b mediated cell death in the spinal cord-injured rat modelNeuropathology, Vol. 29, No. 3Injury in the spinal cord may produce cell death in the brainBrain Research, Vol. 1020, No. 1-2Alterações vesicais na lesão medular experimental em ratosActa Cirurgica Brasileira, Vol. 18, No. 3Animal and Culture Models of Glaucoma for Studying Neuroprotection18 January 2018 | European Journal of Ophthalmology, Vol. 11, No. 2_supplBehavioral and Histological Outcomes Following Graded Spinal Cord Contusion Injury in the C57Bl/6 MouseExperimental Neurology, Vol. 169, No. 2Modeling axonal injury in vitro: injury and regeneration following acute neuritic traumaJournal of Neuroscience Methods, Vol. 102, No. 1Spinal cord injury in the ratProgress in Neurobiology, Vol. 56, No. 3Chapter 23 Influence of dynorphin A antibodies on the formation of edema and cell changes in spinal cord traumaAn Electromechanical Spinal Injury Technique with Dynamic Sensitivity BRADFORD T. STOKES, DAVID H. NOYES, and DONALD L. BEHRMANN26 March 2009 | Journal of Neurotrauma, Vol. 9, No. 3Protective Effect of Methylprednisolone on Vascular Injury in Rat Spinal Cord Injury J. XU, Z.X. QU, E.L. HOGAN, and P.L. PEROT26 March 2009 | Journal of Neurotrauma, Vol. 9, No. 3 Volume 9Issue 2Jan 1992 To cite this article:DOUGLAS K. ANDERSON, CHUNG Y. HSU, MARY ELLEN MICHEL, and BRADFORD T. STOKES.NIH Workshop on Experimental Spinal Cord Injury: Modeling and Criteria.Journal of Neurotrauma.Jan 1992.113-116.http://doi.org/10.1089/neu.1992.9.113Published in Volume: 9 Issue 2: March 26, 2009PDF download

JOURNAL/nrgr/04.03/01300535-202410000-00027/figure1/v/2024-02-06T055622Z/r/image-tiff Spinal cord injury is a disabling condition with limited treatment options. Multiple studies have provided evidence suggesting that small extracellular vesicles (SEVs) secreted by bone marrow mesenchymal stem cells (MSCs) help mediate the beneficial effects conferred by MSC transplantation following spinal cord injury. Strikingly, hypoxia-preconditioned bone marrow mesenchymal stem cell-derived SEVs (HSEVs) exhibit increased therapeutic potency. We thus explored the role of HSEVs in macrophage immune regulation after spinal cord injury in rats and their significance in spinal cord repair. SEVs or HSEVs were isolated from bone marrow MSC supernatants by density gradient ultracentrifugation. HSEV administration to rats via tail vein injection after spinal cord injury reduced the lesion area and attenuated spinal cord inflammation. HSEVs regulate macrophage polarization towards the M2 phenotype in vivo and in vitro. MicroRNA sequencing and bioinformatics analyses of SEVs and HSEVs revealed that miR-146a-5p is a potent mediator of macrophage polarization that targets interleukin-1 receptor-associated kinase 1. Reducing miR-146a-5p expression in HSEVs partially attenuated macrophage polarization. Our data suggest that HSEVs attenuate spinal cord inflammation and injury in rats by transporting miR-146a-5p, which alters macrophage polarization. This study provides new insights into the application of HSEVs as a therapeutic tool for spinal cord injury.

To investigate the changes of autophagy after spinal cord injury (SCI) in rats and its relationship with multisite phosphorylation of B-cell lymphoma-2 (Bcl-2) protein. Forty male Sprague-Dawley rats aged 8 weeks were used to prepare SCI models by modified Allen method, and the SCI model were prepared successfully in 36 rats. The 36 SCI models were randomly divided into SCI group, autophagy inhibitor group, and autophagy promoter group, with 12 rats in each group. Another 12 rats were selected as sham operation group with only laminectomy and no spinal cord injury. At the end of modeling, the autophagy inhibitor group and the autophagy promoter group were intrathecally injected with 20 μL of 600 nmol/L 3-methyladenine and 25 nmol/L rapamycin, respectively, once a day for 4 weeks. The sham operation group and the SCI group were injected with only 20 μL of normal saline at the same time point. The motor function of rat in each group was evaluated by the Basso-Beattie-Bresnahan (BBB) score at 1 day and 1, 2, 4 weeks after modeling. The rats in each group were sacrificed at 24 hours after the last injection and the spinal cord tissues were taken. ELISA assay was used to detect the levels of inflammatory factors in spinal cord tissues, including myeloperoxidase (MPO), tumor necrosis factor α (TNF-α), and interleukin 1β (IL-1β); the morphological changes of spinal cord were observed by HE staining; the autophagy of mitochondria in spinal cord tissues was observed by transmission electron microscopy; the expressions of Beclin1 and microtubule-associated protein light chain 3 (LC3) were detected by immunofluorescence staining; neuronal apoptosis in spinal cord tissues were observed by TUNEL staining; LC3/TUNEL positive cells were calculated by immunofluorescence double staining; the expressions of Bcl-2 associated X protein (Bax), Bcl-2, p-Bcl-2 (Ser87), and p-Bcl-2 (Ser70) were detected by Western blot. Compared with sham operation group, BBB score of SCI group decreased at each time point, while the levels of MPO, TNF-α, and IL-1β increased; peripheral space of nerve cells enlarged, cells swelled, vacuoles appeared, and autophagic bodies appeared in mitochondria; the positive rates of Beclin1 and LC3 proteins, and apoptotic rate of neurons significantly increased; the LC3/TUNEL positive cells significantly increased; the expressions of Bax, p-Bcl-2 (Ser87), and p-Bcl-2 (Ser70) proteins increased, while the expression of Bcl-2 protein decreased; all showing significant differences ( P<0.05). Compared with SCI group, BBB score in autophagy inhibitor group decreased at each time point, while the levels of MPO, TNF-α, and IL-1β increased; a few autophagic vesicles appeared in mitochondria; the positive rates of Beclin1 and LC3 proteins decreased and the apoptotic rate of neurons increased significantly; the LC3 positive cells decreased and the TUNEL positive cells increased; the expressions of Bax, p-Bcl-2 (Ser87), and p-Bcl-2 (Ser70) proteins increased, while the expression of Bcl-2 protein decreased. The results of autophagy promoter group were opposite to those of autophagy inhibitor group; all showing significant differences between groups ( P<0.05). Induction of autophagy after SCI in rats can reduce neuronal apoptosis and protect spinal cord function, which may be related to the inhibition of Bcl-2 protein multisite phosphorylation.

Demyelination contributes to loss of function following spinal cord injury. We have shown previously that transplantation of human embryonic stem cell-derived oligodendrocyte progenitors into adult rat 200 kD contusive spinal cord injury sites enhances remyelination and promotes recovery of motor function. Previous studies using oligodendrocyte lineage cells have noted a correlation between the presence of demyelinating pathology and the survival and migration rate of the transplanted cells. The present study compared the survival and migration of human embryonic stem cell-derived oligodendrocyte progenitors injected 7 days after a 200 or 50 kD contusive spinal cord injury, as well as the locomotor outcome of transplantation. Our findings indicate that a 200 kD spinal cord injury induces extensive demyelination, whereas a 50 kD spinal cord injury induces no detectable demyelination. Cells transplanted into the 200 kD injury group survived, migrated, and resulted in robust remyelination, replicating our previous studies. In contrast, cells transplanted into the 50 kD injury group survived, exhibited limited migration, and failed to induce remyelination as demyelination in this injury group was absent. Animals that received a 50 kD injury displayed only a transient decline in locomotor function as a result of the injury. Importantly, human embryonic stem cell-derived oligodendrocyte progenitor transplants into the 50 kD injury group did not cause a further decline in locomotion. Our studies highlight the importance of a demyelinating pathology as a prerequisite for the function of transplanted myelinogenic cells. In addition, our results indicate that transplantation of human embryonic stem cell-derived oligodendrocyte progenitor cells into the injured spinal cord is not associated with a decline in locomotor function.

Chrysin (CH), a natural plant flavonoid, has shown a variety of beneficial effects. Our present study was conducted to evaluate the therapeutic potential of CH three days after spinal cord injury (SCI) in rats and to probe the underlying neuroprotective mechanisms. SCI was induced using the modified weight-drop method in Wistar rats. Then, they were treated with saline or CH by doses of 30 and 100 mg/kg for 26 days. Neuronal function was assessed with the Basso Beattle Bresnahan locomotor rating scale (BBB). The water content of spinal cord was determined after traumatic SCI. The NF-κB p65 unit, TNF-α, IL-1β and IL-6 in serums, as well as the apoptotic marker, caspase-3, of spinal cord tissues were measured using commercial kits. The protein level and activity of inducible nitric oxide synthase (iNOS) were detected by western blot and a commercial kit, respectively. NO (nitric oxide) production was evaluated by the determination of nitrite concentration. The rats with SCI showed marked reductions in BBB scores, coupled with increases in the water content of spinal cord, the NF-κB p65 unit, TNF-α, IL-1β, IL-6, iNOS, NO production and caspase-3. However, a CH supplement dramatically promoted the recovery of neuronal function and suppressed the inflammatory factors, as well as the iNOS pathway in rats with SCI. Our findings disclose that CH improved neural function after SCI in rats, which might be linked with suppressing inflammation and the iNOS pathway.

Study DesignThis study investigated the effects of transplantation of alginate encapsulated neural stem cells (NSCs) on spinal cord injury in Sprague-Dawley male rats. The neurological functions were assessed for 6 weeks after transplantation along with a histological study and measurement of caspase-3 levels.PurposeThe aim of this study was to discover whether NSCs cultured in alginate transplantation improve recovery from spinal cord injury.Overview of LiteratureSpinal cord injury is one of the leading causes of disability and it has no effective treatment. Spinal cord injury can also cause sensory impairment. With an impetus on using stem cells therapy in various central nervous system settings, there is an interest in using stem cells for addressing spinal cord injury. Neural stem cell is one type of stem cells that is able to differentiate to all three neural lineages and it shows promise in spinal injury treatment. Furthermore, a number of studies have shown that culturing NSCs in three-dimensional (3D) scaffolds like alginate could enhance neural differentiation.MethodsThe NSCs were isolated from 14-day-old rat embryos. The isolated NSCs were cultured in growth media containing basic fibroblast growth factor and endothelial growth factor. The cells were characterized by differentiating to three neural lineages and they were cultured in an alginate scaffold. After 7 days the cells were encapsulated and transplanted in a rat model of spinal cord injury.ResultsOur data showed that culturing in an alginate 3D scaffold and transplantation of the NSCs could improve neurological outcome in a rat model of spinal cord injury. The inflammation scores and lesion sizes and also the activity of caspase-3 (for apoptosis evaluation) were less in encapsulated neural stem cell transplantation cases.ConclusionsTransplantation of NSCs that were cultured in an alginate scaffold led to a better clinical and histological outcome for recovery from spinal cord injury in a rat model.

A previous study from our team found that hyperbaric oxygen (HBO) pretreatment attenuated decompression sickness (DCS) spinal cord injury by upregulating heat shock protein 32 (HSP32) via the ROS/p38 MAPK pathway. Meanwhile, a MEK1/2-negative regulatory pathway was also activated to inhibit HSP32 overexpression. The purpose of this study was to determine if normobaric oxygen (NBO) might effectively induce HSP32 while concurrently inhibiting MEK1/2 and to observe any protective effects on spinal cord injury in DCS rats. The expression of HSP32 in spinal cord tissue was measured at 6, 12, 18, and 24 h following NBO and MEK1/2 inhibitor U0126 pretreatment. The peak time of HSP32 was observed at 12 h after simulated air diving. Subsequently, signs of DCS, hindlimb motor function, and spinal cord and serum injury biomarkers were recorded. NBO-U0126 pretreatment significantly decreased the incidence of DCS, improved motor function, and attenuated oxidative stress, inflammatory response, and apoptosis in both the spinal cord and serum. These results suggest that pretreatment with NBO and U0126 combined can effectively alleviate DCS spinal cord injury in rats by upregulating HSP32. This may lead to a more convenient approach for DCS injury control, using non-pressurized NBO instead of HBO.

Complement Plays an Important Role in Spinal Cord Injury and Represents a Therapeutic Target for Improving Recovery following Trauma

OBJECTIVES:The intrathecal route has not yet been thoroughly standardized and evaluated in an experimental model of spinal cord injury (SCI) in Wistar rats. The objective of this study was to standardize and evaluate the effect of intradural injection in this animal model.METHOD:The animals were divided into 6 groups: 1) laminectomy and intradural catheter; 2) laminectomy, intradural catheter and infusion; 3) only SCI; 4) SCI and intradural catheter; 5) SCI, intradural catheter and infusion; and 6) control (laminectomy only). Motor evaluations were performed using the Basso, Beattie and Bresnahan (BBB) scale and the horizontal ladder test; motor evoked potentials were measured for functional evaluation, and histological evaluation was performed as well. All experimental data underwent statistical analysis.RESULTS:Regarding motor evoked potentials, the groups with experimental SCI had worse results than those without, but neither dural puncture nor the injection of intrathecal solution aggravated the effects of isolated SCI. Regarding histology, adverse tissue effects were observed in animals with SCI. On average, the BBB scores had the same statistical behaviour as the horizontal ladder results, and at every evaluated timepoint, the groups without SCI presented scored significantly better than those with SCI (p<0.05). The difference in performance on motor tests between rats with and without experimental SCI persisted from the first to the last test.CONCLUSIONS:The present work standardizes the model of intradural injection in experimental SCI in rats. Intrathecal puncture and injection did not independently cause significant functional or histological changes.

OBJECTIVES:The intrathecal route has not yet been thoroughly standardized and evaluated in an experimental model of spinal cord injury (SCI) in Wistar rats. The objective of this study was to standardize and evaluate the effect of intradural injection in this animal model.METHOD:The animals were divided into 6 groups: 1) laminectomy and intradural catheter; 2) laminectomy, intradural catheter and infusion; 3) only SCI; 4) SCI and intradural catheter; 5) SCI, intradural catheter and infusion; and 6) control (laminectomy only). Motor evaluations were performed using the Basso, Beattie and Bresnahan (BBB) scale and the horizontal ladder test; motor evoked potentials were measured for functional evaluation, and histological evaluation was performed as well. All experimental data underwent statistical analysis.RESULTS:Regarding motor evoked potentials, the groups with experimental SCI had worse results than those without, but neither dural puncture nor the injection of intrathecal solution aggravated the effects of isolated SCI. Regarding histology, adverse tissue effects were observed in animals with SCI. On average, the BBB scores had the same statistical behaviour as the horizontal ladder results, and at every evaluated timepoint, the groups without SCI presented scored significantly better than those with SCI (p<0.05). The difference in performance on motor tests between rats with and without experimental SCI persisted from the first to the last test.CONCLUSIONS:The present work standardizes the model of intradural injection in experimental SCI in rats. Intrathecal puncture and injection did not independently cause significant functional or histological changes.