Contusive Spinal Cord Injury In Rats Research Articles

Blood-spinal cord barrier in spinal cord injury: a scientific review based on own experimental trial

Objective. To analyze the mechanisms of the blood-spinal cord barrier permeability violation after spinal cord injury and to assess its impact on the development of secondary injuries, including those in the areas significantly remote from the epicenter of injury.Material and Methods. The article is an analysis of 45 publications supplemented by our own experimental data. The search for articles was conducted in databases such as PubMed, Scopus and Web of Science on the topic under study. Experimental data were obtained using confocal microscopy and bioluminescence detection on a rat spinal cord contusion injury model.Results. The problem of barrier disintegration in a region remote from the injury epicenter is considered. It is shown that spinal cord injury significantly increases the permeability of the blood-spinal cord barrier, which promotes enhanced transmigration of immune cells and release of cytotoxic molecules. The results of our own studies on a model of dosed contusion injury in the thoracic spinal cord of a rat show that the permeability of the barrier increases not only in the injury epicenter, but also along the entire length of the organ. This circumstance is especially significant for the lumbar spinal cord, where neural networks that are critical for the maintenance and restoration of motor function are localized.Conclusion. Potential causes of remote barrier disruption have been discussed, including the possible influence of damage biomarker molecules that travel from the injury epicenter to remote regions of the spinal cord via the bloodstream or cerebrospinal fluid. The promising clinical application of effective experimental approaches to contain barrier disruption and restore the blood-spinal cord barrier and the lack of translational research in this direction are highlighted.

Human induced pluripotent stem cell/embryonic stem cell-derived pyramidal neuronal precursors show safety and efficacy in a rat spinal cord injury model

Nerve regeneration and circuit reconstruction remain a challenge following spinal cord injury (SCI). Corticospinal pyramidal neurons possess strong axon projection ability. In this study, human induced pluripotent stem cells (iPSCs) were differentiated into pyramidal neuronal precursors (PNPs) by addition of small molecule dorsomorphin into the culture. iPSC-derived PNPs were transplanted acutely into a rat contusion SCI model on the same day of injury. Following engraftment, the SCI rats showed significantly improved motor functions compared with vehicle control group as revealed by behavioral tests. Eight weeks following engraftment, the PNPs matured into corticospinal pyramidal neurons and extended axons into distant host spinal cord tissues, mostly in a caudal direction. Host neurons rostral to the lesion site also grew axons into the graft. Possible synaptic connections as a bridging relay may have been formed between host and graft-derived neurons, as indicated by pre- and post-synaptic marker staining and the regulation of chemogenetic regulatory systems. PNP graft showed an anti-inflammatory effect at the injury site and could bias microglia/macrophages towards a M2 phenotype. In addition, PNP graft was safe and no tumor formation was detected after transplantation into immunodeficient mice and SCI rats. The potential to reconstruct a neuronal relay circuitry across the lesion site and to modulate the microenvironment in SCI makes PNPs a promising cellular candidate for treatment of SCI.

Microchip encapsulation and microRNA-7 overexpression of trabecular meshwork mesenchymal stem/stromal cells improve motor function after spinal cord injury.

Manipulation of stem cells and microencapsulation through microfluidic chips has shown more promising results in treating complex conditions, such as spinal cord injury (SCI), than traditional treatments. This study aimed to investigate the potency of neural differentiation and its therapeutic role in SCI animal model of trabecular meshwork mesenchymal stem/stromal cells (TMMSCs) via miR-7 overexpression and microchip-encapsulated. TMMSCs are transduced with miR-7 via a lentiviral vector (TMMSCs-miR-7[+]) and encapsulated in alginate-reduced graphene oxide (alginate-rGO) hydrogel via a microfluidic chip. Neuronal differentiation of transduced cells in hydrogel (3D) and tissue cultures plate (2D) was assessed by expressing specific mRNAs and proteins. Further evaluation is being carried out through 3D and 2D TMMSCs-miR-7(+ and -) transplantation into the rat contusion SCI model. TMMSCs-miR-7(+) encapsulated in the microfluidic chip (miR-7-3D) increased nestin, β-tubulin III, and MAP-2 expression compared with 2D culture. Moreover, miR-7-3D could improve locomotor behavior in contusion SCI rats, decrease cavity size, and increase myelination. Our results revealed that miR-7 and alginate-rGO hydrogel were involved in the neuronal differentiation of TMMSCs in a time-dependent manner. In addition, the microfluidic-encapsulated miR-7 overexpression TMMSCs represented a better survival and integration of the transplanted cells and the repair of SCI. Collectively, the combination of miR-7 overexpression and encapsulation of TMMSCs in hydrogels may represent a promising new treatment for SCI.

Restoration of Motor Function through Delayed Intraspinal Delivery of Human IL-10-Encoding Nucleoside-Modified mRNA after Spinal Cord Injury.

Efficient invivo delivery of anti-inflammatory proteins to modulate the microenvironment of an injured spinal cord and promote neuroprotection and functional recovery is a great challenge. Nucleoside-modified messenger RNA (mRNA) has become a promising new modality that can be utilized for the safe and efficient delivery of therapeutic proteins. Here, we used lipid nanoparticle (LNP)-encapsulated human interleukin-10 (hIL-10)-encoding nucleoside-modified mRNA to induce neuroprotection and functional recovery following rat spinal cord contusion injury. Intralesional administration of hIL-10 mRNA-LNP to rats led to a remarkable reduction of the microglia/macrophage reaction in the injured spinal segment and induced significant functional recovery compared to controls. Furthermore, hIL-10 mRNA treatment induced increased expression in tissue inhibitor of matrix metalloproteinase 1 and ciliary neurotrophic factor levels in the affected spinal segment indicating a time-delayed secondary effect of IL-10 5 d after injection. Our results suggest that treatment with nucleoside-modified mRNAs encoding neuroprotective factors is an effective strategy for spinal cord injury repair.

LC-MS/MS-based arachidonic acid metabolomics in acute spinal cord injury reveals the upregulation of 5-LOX and COX-2 products.

Arachidonic acid (AA) plays a critical role in inflammatory regulation and secondary injury after spinal cord injury (SCI). However, the overall AA metabolism profile in the acute phase of SCI remains elusive. Here we quantified AA metabolomics by High Performance Liquid Chromatography-Tandem Mass Spectrometry-Based Method (LC-MS/MS) using spinal cord tissue collected at 4h, 24h and 48h after contusive SCI in rats. Remarkably, Prostaglandin E2 (PGE2) and Leukotriene B4 (LTB4) were significantly increased throughout the acute SCI. Cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX), the key enzymes involved in the production of PGE2 and LTB4, were elevated in the lesioned spinal cord tissue, validated by both western blot and immunofluorecnce. The spatial-temporal changes of COX-2 and 5-LOX mainly occurs in neurons both in epicenter and rostral and caudal spinal cord segments after SCI. Our study sheds light on the dynamic microenvironment changes in acute SCI by characterizing the profile of AA metabolism. The COX-2 and 5-LOX may be promising therapeutic target for SCI.

P.122 Unbiased whole brain circuit interrogation reveals neurons restoring walking after spinal cord injury

Background: There is presently no cure for locomotor deficits after spinal cord injury (SCI). Very few therapies effectively target the brain due to poor understanding of the brain’s role post-SCI. Newly developed tissue clearing techniques have permitted unbiased three-dimensional circuit analysis, opening new opportunities for SCI-related brain interrogation. Methods: We established a novel brain interrogation pipeline by optimizing mouse brain clearing, imaging, and atlas registration. We leveraged a spontaneous recovery lateral hemisection model to analyze whole brain cell activity and connectivity with the lumbar cord using cFos immunolabelling and virus-mediated projection tracing. We identified a functionally and anatomically dynamic region correlating with recovery and interrogated its locomotor role with optogenetics. We assessed deep brain electrical stimulation (DBS) of this region in a more clinically relevant rat contusion SCI using an established bipedal robotic interface. Results: We unexpectedly uncovered the lateral hypothalamus (LH) to functionally and anatomically correlate with recovery. LHVglut2 optogenetic stimulation significantly augmented locomotor function. LH DBS in rats acutely robustly augmented bipedal locomotion post-SCI. Conclusions: This is the first demonstration of the LH’s role in locomotion post-SCI and is a novel DBS target that robustly augmented locomotor function, dependent on LH glutamatergic cells. LH DBS may be a promising intervention in humans.

A modified impactor for establishing a graded contusion spinal cord injury model in rats.

BackgroundGiven the indispensable role of animal models in preclinical studies of spinal cord injury (SCI) and the current state of available impactors, we designed a modified impactor for establishing contusion SCI in rats. The major improvement is the replacement of the impactor rod with a weight and an impactor tip.MethodsPreoperatively, radiographs of 8-week-old female Wistar rats were taken to establish a protocol for locating the target spinal segment. A total of 72 rats were randomly divided into 4 groups: the sham, 12.5-, 25- and 50-mm groups. Within 35 days postinjury (dpi), the Basso, Beattie, and Bresnahan locomotor rating scale (BBB) was used to evaluate the hindlimb motor function of the rats. At 7 dpi, the rats were sacrificed, and the spinal cord tissue was fixed. Hematoxylin-eosin (HE) staining was used to assess histological changes. Subsequently, immunofluorescence staining was performed to visualize the expression and distribution of GFAP, CD68, MBP, and NeuN. Additionally, rats were sacrificed, and their tissues were extracted for relevant protein assays. At 3 and 7 dpi, electrophysiological function was evaluated by measuring motor evoked potentials (MEPs) and sensory evoked potentials (SEPs).ResultsThe behavioral results revealed that higher strike heights were associated with lower BBB scores. Over time, the BBB scores of the SCI rats exhibited an improving trend. Quantitative analysis of the lesions indicated that as the impact height increased, the area of histological destruction, GFAP-negative area, CD68-positive cell count, and MBP-positive destruction area increased, and the number of NeuN-positive cells decreased. Western blot analysis further verified relevant protein changes. Electrophysiology confirmed that the MEP and SEP amplitudes decreased as the strike height increased.ConclusionsThus, these results confirm that this modified impactor can be used to establish a graded SCI model in rats. The model is clinically relevant, reproducible, stable, accessible, and affordable, providing a practical tool with which to elucidate the pathophysiological mechanisms and potential therapies for contusive SCI.

200 Unbiased Interrogation of Whole Brain Circuits Identifies Neurons That Restore Walking After Spinal Cord Injury

INTRODUCTION: Currently, there is no cure for locomotor deficits after spinal cord injury (SCI). Despite advances in spinal cord modulation with epidural electrical stimulation, there remains a paucity of therapies targeting the brain due to a poor understanding of the brain’s role post-SCI. Recently developed tissue clearing and light sheet imaging techniques have permitted unbiased three-dimensional interrogation of whole brain circuits, which has opened unexplored avenues for SCI-related brain interrogation. METHODS: We established a novel brain interrogation pipeline for SCI by optimizing mouse whole brain clearing, imaging, and atlas registration after a spontaneous recovery lateral hemisection model. We examined both whole brain cell activity and connectivity with the lumbar cord using cFos immunolabelling and virus-mediated projection tracing, respectively, to identify a functionally and anatomically dynamic region correlating with recovery. We interrogated the locomotor role of this region with optogenetics and chemogenetics. In a more clinically relevant rat contusion SCI, we assessed the translatability of deep brain electrical stimulation (DBS) of this region by leveraging an established bipedal robotic interface and rehabilitation paradigm. RESULTS: We unexpectedly uncovered the lateral hypothalamus (LH) to be a functionally and anatomically dynamic region post-SCI correlating with recovery. Optogenetic stimulation of mouse LHVglut2 neurons significantly augmented locomotor function, which required medullary reticular formation (MRF) Vglut2-positive neurons. In line with previously demonstrated sparing of MRF-to-spinal cord projections after contusion SCI, we found that LH DBS in rats post-contusion SCI could acutely robustly augment bipedal rat locomotor function. CONCLUSION: This is the first demonstration of the LH's role in locomotion post-SCI. The LH is a novel DBS target that robustly augmented locomotor function, dependent on LH and brainstem glutamatergic cells.

SV2A PET Imaging Is a Noninvasive Marker for the Detection of Spinal Damage in Experimental Models of Spinal Cord Injury.

Traumatic spinal cord injury (SCI) is a neurologic condition characterized by long-term motor and sensory neurologic deficits as a consequence of an external physical impact damaging the spinal cord. Anatomic MRI is considered the gold-standard diagnostic tool to obtain structural information for the prognosis of acute SCI; however, it lacks functional objective information to assess SCI progression and recovery. In this study, we explored the use of synaptic vesicle glycoprotein 2A (SV2A) PET imaging to detect spinal cord lesions noninvasively after SCI. Methods: Mice (n = 7) and rats (n = 8) subjected to unilateral moderate cervical (C5) contusion were euthanized 1 wk after SCI for histologic and autoradiographic (3H-labeled (4R)-1-[(3-methylpyridin-4-yl)methyl]-4-(3,4,5-trifluorophenyl)pyrrolidin-2-one [UCB-J]) investigation of SV2A levels. Longitudinal 11C-UCB-J PET/CT imaging was performed in sham (n = 7) and SCI rats (n = 8) 1 wk and 6 wk after SCI. Animals also underwent an 18F-FDG PET scan during the latter time point. Postmortem tissue SV2A analysis to corroborate invivo PET findings was performed 6 wk after SCI. Results: A significant SV2A loss (ranging from -70.3% to -87.3%; P < 0.0001) was measured at the epicenter of the impact invitro in both mouse and rat contusion SCI models. Longitudinal 11C-UCB-J PET imaging detected SV2A loss in SCI rats (-49.0% ± 8.1% at 1 wk and -52.0% ± 12.9% at 6 wk after SCI), with no change observed in sham rats. In contrast, 18F-FDG PET imaging measured only subtle hypometabolism (-17.6% ± 14.7%). Finally, postmortem 3H-UCB-J autoradiography correlated with the invivo SV2A PET findings (r = 0.92, P < 0.0001). Conclusion:11C-UCB-J PET/CT imaging is a noninvasive marker for SV2A loss after SCI. Collectively, these findings indicate that SV2A PET may provide an objective measure of SCI and thus represent a valuable tool to evaluate novel therapeutics. Clinical assessment of SCI with SV2A PET imaging is highly recommended.

Результаты применения противоспаечного геля после моделирования контузионного повреждения спинного мозга у крыс

Objective was to investigate an effect of anti-adhesion hyaluronic-containing resorbable gel on the course of traumatic spinal cord disease caused by a simulated contusion spinal cord injury (SCI) in rats. Material and methods A moderate spinal cord injury was simulated at the Th9 level of 40 female Wistar rats that were randomly divided into 2 groups. Group I received hyaluronic-containing absorbable antiadhesion gel Antiadgezin® that was intraoperatively applied to the dura mater of experimental rats; Group II of control rats received no gel. The BBB locomotor rating scale was used to evaluate the extent of recovered pelvic limb function. The animals were sacrificed on days 5, 15, 30, 60 and 90. Paraffin and epoxy semi-thin 1 μm sections were used for morphological examination of the spinal cord using light microscopy. Results The gel used for contusion SCI in rats caused neither significant changes during postoperative period nor local infectious and inflammatory complications, and showed no negative impact on functional results. Morphological examination revealed pathomorphological changes that were identical for both groups and characteristic of contusion SCI showing softening, necrosis of the nervous tissue, tissue and cell detritus of gray and white matter, small cysts in the early stages of the experiment; progression of syringomyelia and formation of large cysts primarily seen in the gray matter and the onset of regenerative processes in the white matter at 60 and 90 days of the experiment. Conclusion The absence of a negative effect of the anti-adhesion hyaluronic-containing resorbable gel on the functional results, and morphological characteristics of the spinal cord offer the opportunity of the further experimental use as a carrier of substance composition initiating beneficial metabolic and neuroprotective action for transdural delivery in simulated SCI.

The Application of an Omentum Graft or Flap in Spinal Cord Injury.

Background: Spinal cord injury (SCI) causes a primary injury at the lesion site and triggers a secondary injury and prolonged inflammation. There has been no definitive treatment till now. Promoting angiogenesis is one of the most important strategies for functional recovery after SCI. The omentum, abundant in blood and lymph vessels, possesses the potent ability of tissue regeneration. Methods: The present work examines the efficacy of autologous omentum, either as a flap (with vascular connection intact) or graft (severed vascular connection), on spinal nerve regeneration. After contusive SCI in rats, a thin sheath of omentum was grafted to the injured spinal cord. Results: Omental graft improved behavior scores significantly from the 3rd to 6th week after injury (6th week, 5.5 ± 0.5 vs. 8.6 ± 1.3, p < 0.05). Furthermore, the reduction in cavity and the preservation of class III β-tubulin-positive nerve fibers in the injury area was noted. Next, the free omental flap was transposed to a completely transected SCI in rats through a pre-implanted tunnel. The flap remained vascularized and survived well several weeks after the operation. At 16 weeks post-treatment, SCI rats with omentum flap treatment displayed the preservation of significantly more nerve fibers (p < 0.05) and a reduced injured cavity, though locomotor scores were similar. Conclusions: Taken together, the findings of this study indicate that treatment with an omental graft or transposition of an omental flap on an injured spinal cord has a positive effect on nerve protection and tissue preservation in SCI rats. The current data highlight the importance of omentum in clinical applications.

Overexpression of miR-338-5p in exosomes derived from mesenchymal stromal cells provides neuroprotective effects by the Cnr1/Rap1/Akt pathway after spinal cord injury in rats

Growing evidence has shown that microRNAs (miRNAs) play crucial roles in the physiopathology of spinal cord injury (SCI). Recent studies have confirmed that miR-338-5p regulates myelination, suggesting a potential role in the treatment of SCI. However, the molecular mechanism of miR-338-5p on SCI is still unknown. Recently, exosomes have emerged as an ideal vector to deliver therapeutic molecules such as miRNAs. Here, we explored the effects of miR-338-5p-overexpressing exosomes derived from bone marrow-derived mesenchymal stromal cells (BMSCs) on SCI. In vivo, a model of contusion SCI in rats was established, and we observed that overexpression of miR-338-5p in exosomes profoundly increased the expression levels of neurofilament protein-M and growth-associated protein-43 and decreased those of myelin-associated glycoprotein and glial fibrillary acidic protein, which provided neuroprotective effects after acute SCI. In an in vitro study, we found that overexpression of miR-338-5p in exosomes repressed cell apoptosis following H2O2-induced oxidative stress injury in PC12 cells. Additionally, we confirmed that cannabinoid receptor 1 (Cnr1) was the target gene of miR-338-5p by dual-luciferase reporter assays and that Rap1 was the downstream gene by the KEGG pathway analysis. We found that miR-338-5p increased cAMP accumulation as a consequence of downregulated expression of the target gene Cnr1, and then, Rap1 was activated by cAMP. Eventually, the activation of the PI3K/Akt pathway attenuated cell apoptosis and promoted neuronal survival by cAMP-mediated Rap1 activation. In brief, these findings showed that exosomes overexpressing miR-338-5p were a promising treatment strategy for SCI.

Whole body measurements using near-infrared spectroscopy in a rat spinal cord contusion injury model

Background Spinal cord injuries cause great damage to the central nervous system as well as the peripheral vasculature. While treatments for spinal cord injury typically focus on the spine itself, improvements in the function of the peripheral vasculature after spinal cord injury have shown to improve overall neurological recovery. Objective This study focused on the use of near-infrared spectroscopy (NIRS) as a mode to monitor cerebral and peripheral vascular condition non-invasively during the recovery process. Design Animal research study. Methods Rats underwent spinal contusion or sham injury and relative concentrations of de-/oxyhemoglobin (Δ[HbO]/Δ[Hb]) over time were measured over the cerebral, spinal, and pedal regions via NIRS. Correlational relationships across the body were determined. Rats received 1 NIRS measurement before injury and 3 after injury: 4, 7, and 14 days post. Results Correlational relationships between signals across the body, between animals with and without spinal cord injury, indicate that NIRS was able to detect patterns of vascular change in the spine and the periphery occurring secondary to spinal cord injury and evolving during subsequent recovery. Additionally, NIRS determined an overall correlational decrease within the central nervous system, between spinal and cerebral measurements. Conclusion NIRS was able to closely reflect physiologic changes in the rat during recovery, demonstrating a promising method to monitor whole body hemodynamics after spinal cord injury.

Fluence as a Function of Weight: A Photobiomodulation Therapy (PBMT) Spinal Cord Injury (SCI) Rat Model—A Computational Study

A spinal cord injury (SCI) is caused by damage to neurons in the spinal cord, which interrupts neural signal conduction via axonal tracts, causing either total or partial paralysis. Researchers have proven that photobiomodulation therapy (PBMT) can affect nerve repair, causing enhanced functionality. Many PBMT studies have examined contusion SCIs in rats by employing a fixed fluence applied to the skin over the course of the treatment without considering the animal weight, which could affect the fluence delivered to the SCI site. This study performed Monte Carlo simulations using four computer-simulated rat models, all 11 weeks of age but each one having a different weight, and used various irradiation parameters to assess the impact of these factors on the fluence delivery at the SCI site. When the weight of the rat decreased, the fluence delivered to the SCI site increased. The findings also demonstrated that the greatest percentage rise in the fluence delivered to the SCI site occurred when employing a 660 nm Gaussian beam. The rat weight and irradiation parameters had a significant effect on the fluence delivered to the SCI site in rats. Thus, when assessing the effectiveness of PBMT, researchers must consider how much fluence reaches the injury site rather than how much fluence is applied to the skin.

Isobaric Tagging for Relative and Absolute Protein Quantification (iTRAQ)-Based Quantitative Proteomics Analysis of Differentially Expressed Proteins 1 Week After Spinal Cord Injury in a Rat Model.

BackgroundSpinal cord injury (SCI) is a devastating trauma of the central nervous system (CNS), with high levels of morbidity, disability, and mortality. One week after SCI may be a critical time for treatment. Changes in protein expression have crucial functions in nervous system diseases, although the effects of changes occurring 1 week after SCI on patient outcomes are unclear.Material/MethodsProtein expression was examined in a rat contusive SCI model 1 week after SCI. Differentially expressed proteins (DEPs) were identified by isobaric tagging for relative and absolute protein quantification (iTRAQ)-coupled liquid chromatography tandem-mass spectrometry (LC-MS/MS) proteomics analysis. Gene Ontology (GO) analysis was performed to identify the biological processes, molecular functions, and cellular component terms of the identified DEPs, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) was used to identify key enriched pathways. Protein–protein interaction (PPI) networks were analyzed to identify the top 10 high-degree core proteins.ResultsOf the 295 DEPs identified, 204 (69.15%) were upregulated and 91 (30.85%) were downregulated 1 week after injury. The main cellular components, molecular functions, biological processes, and pathways identified may be crucial mechanisms involved in SCI. The top 10 high-degree core proteins were complement component C3 (C3), alpha-2-HS-glycoprotein (Ahsg), T-kininogen 1 (Kng1), Serpinc1 protein (Serpinc1), apolipoprotein A-I (Apoa1), serum albumin (Alb), disulfide-isomerase protein (P4hb), transport protein Sec61 subunit alpha isoform 1 (Sec61a1), serotransferrin (Tf), and 60S ribosomal protein L15 (Rpl15).ConclusionsThe proteins identified in this study may provide potential targets for diagnosis and treatment 1 week after SCI.

Improvement of lower urinary tract function by a selective serotonin 5-HT1A receptor agonist, NLX-112, after chronic spinal cord injury

Spinal cord injury (SCI) above the lumbosacral level results in lower urinary tract dysfunction, including (1) detrusor hyperreflexia, wherein bladder compliance is low, and (2) a lack of external urethral sphincter (EUS) control, leading to detrusor-sphincter dyssynergia (DSD) with poor voiding efficiency. Experimental studies in animals have shown a dense innervation of serotonergic (5-HT) fibers and multiple 5-HT receptors in the spinal reflex circuits that control voiding function. Here, we investigated the efficacy of NLX-112 (a.k.a. befiradol or F13640), in regulating lower urinary tract function after T8 contusive SCI in rats. NLX-112 is a very potent, highly-selective, and fully efficacious 5-HT1A receptor agonist, which has been developed for the treatment of L-DOPA-induced dyskinesia in Parkinson's disease patients. We performed urodynamics tests and external urethral sphincter electromyogram recordings to assess lower urinary tract function while NLX-112 was infused through the femoral vein in rats with chronic complete SCI or contusive SCI. The dose response studies indicated that NLX-112 was able to improve voiding behavior by regulating both detrusor and EUS activity. These included improvements in voiding efficiency, reduction of detrusor hyperactivity, and phasic activity of EUS during the micturition period. In addition, the application of a selective 5-HT1A receptor antagonist, WAY100635, reversed the improved detrusor and EUS activity elicited by NLX-112. In summary, the current data suggest that pharmacological activation of 5-HT1A receptors by NLX-112 may constitute a novel therapeutic strategy to treat neurogenic bladder after SCI.

Transplantation of human urine-derived neural progenitor cells after spinal cord injury in rats

Spinal cord injury (SCI) is a worldwide problem and transplantation of neural progenitor cells (NPCs) represents a promising treatment strategy. Urine derived induced pluripotent stem cells (UiPSCs) which enable the generation of patient-specific NPCs, provide an invaluable source of autologous cells for future therapeutic applications after SCI. However, the fate and potential contribution of transplanted human UiPSCs-derived NPCs (UiPSC-NPCs) into injured spinal cords remain largely unknown. In this study, using a rat contusive SCI model, we evaluated the survival, migration and differentiation of UiPSC-NPCs after transplantation at subacute phase. Transplanted cells survived and migrated from the site of grafting towards the lesion epicenter. More than 25 % cells survived over 4 weeks post transplantation, with a few of them differentiated into neurons and astrocytes. Cytokine and chemokine levels within the injured spinal cord tissues were measured using multiplex immunoassays to evaluate the immune response. Pro-inflammatory factors and chemokines were significantly decreased at 3 days after UiPSC-NPCs transplantation. At 7 days post transplantation, a lower level of pro-inflammatory factor IFN-γ and a higher level of pro-inflammatory IL-2 were found in UiPSC-NPCs group than in the control. Transplantation of UiPSC-NPCs showed little effect on microglia activation at the lesion epicenter. However, the number of microglia cells at 4 mm rostral to the injury site was significantly decreased. The size of lesion cavity was reduced after transplantation of UiPSC-NPCs. In conclusions, the UiPSC-NPCs transplanted at the subacute phase of SCI showed a beneficial effect on tissue repairing.

Neuroglia in rat spinal cord contusion injury with cell-mediated delivery of a combination of VEGF165, GDNF, and NCAM1 genes in combination with epidural electrical stimulation

Neural networks disturbed due to spinal cord injury are capable to restore that is largely determined by post-traumatic remodeling. It is known that information exchange between neurons is carried out by electrical impulse, which ensures the transmission of excitation in synapses, that is realized through neurotrophic factors according to the concept of neurotrophic interactions. Objective: to study the effect of a combination of epidural electrostimulation above and below the site of neurotrauma during training on the treadmill and intrathecal administration of human umbilical cord blood mononuclear cells, which simultaneously delivered three therapeutic genes encoding vascular endothelial growth factor (VEGF165), glial neurotrophic factor (GDNF) and neuronal cell adhesion molecule (NCAM1), to post-traumatic reorganization of neuroglia cells in a model of dosed concussion injury of rat spinal cord at the Th8-Th9 level. 30 days after the simulation of neurotrauma by the immunofluorescence method, a change in the number of macro- and microglia cells in the segment caudal from the damage epicenter was revealed. Electrostimulation did not affect the number of GFAP+-cells in the gray matter, but the combined effect of gene and electrotherapy restrained the increase in their number. Differences were found in the reactions of astrocytes in white and gray matter in response to electrical stimulation. In the zones of gray matter, the supporting effect of the combination of gene and electrotherapy on the number of Olig2+-cells was most clearly manifested. In this group of animals, the inhibition of the increase in the number of Iba1+-microglia cells in the gray matter can also be interpreted as a positive factor contributing to neuroregeneration.

Relationship (?) Between Histological and Functional Measures in Moderate Contusion SCI in Adult Rat

To create a spinal cord injury (SCI), most laboratories implement a standardized method; however, considerable variability in injury size and associated functional deficits can occur across subjects. The present study was initiated to explore relationships between the histological features of spinal cord (SC) lesion and the associated functional deficits in locomotor, respiratory, and lower urinary tract (LUT) function in a widely used rat contusion SCI model that is generated using an Infinite Horizon impactor. To this end, adult female rats (n=8) received a moderate mid‐thoracic contusion SCI (200 kdyn, T8), and the impact displacement and force were recorded. Indices of functional recovery included: (1) BBB open field locomotor scoring at 1‐week post SCI, (2) total volume of expressed urine during the first 2‐weeks post SCI, and (3) diaphragm EMG activity and reflex micturition behavior and residual urine volume recorded during an acute cystometry experiment at 4‐weeks post SCI, after which the bladder was removed and weighed. Following fixation (4% PFA) and cryoprotection of the SC, 20 μm thick horizonal sections were obtained and counterstained with cresyl violet and Cyanine R / FeCl3 to visualize cell bodies and myelin, respectively, and the section at the level of the central canal was used as the site for preliminary analysis of the extent of lesion damage and degree of white matter sparing. The lesion area ranged from 27–49% and was measured by outlining the perimeter of the lesion site using a threshold tool and then normalized (%) to the area of a standardized 7 mm rostral‐caudal length region of SC that included the injury site. Myelin thickness was measured at 3 sites at the level of the injury and at the rostral and caudal ends of the tissue (uninjured) on each side of the SC, and the injury site measurements were normalized to the average myelin thickness of the corresponding uninjured side. A spared myelin index (%) using the larger minimum myelin thickness from the right or left side of the SC was then determined and ranged from 19–91%. For generation of the SCI, impactor displacement varied from 1287 to 1728 μm, with larger displacements being associated with larger injury sites and less myelin sparing. The lesion area, however, was not a strong predictor of myelin sparing, particularly in cases with asymmetrical lesions (n=2). Both lesion area and spared myelin index were reasonable predictors of post SCI recovery of locomotor (BBB scores) and LUT (expressed urine volume) function but not in predicting the degree of dysfunction in reflex micturition (increased residual volume) and bladder hypertrophy or inspiratory burst measures and their variability. These preliminary results suggest that factors in addition to the histological characteristics of the lesion site contribute to the degree of functional deficits/recovery following SCI.Support or Funding InformationDOD CDMRP W81XWH‐17‐1‐0260; NIH NS096514; NYS DOH SCIRB C32088GG

Repositioning Flubendazole for Spinal Cord Injury

We previously reported the serendipitous observation that fenbendazole, a benzimidazole anthelmintic, improved functional and pathological outcomes following thoracic spinal cord contusion injury in mice when administered pre-injury. Fenbendazole is widely used in veterinary medicine. However, it is not approved for human use and it was uncertain if only post-injury administration would offer similar benefits. In the present study we evaluated post-injury administration of a closely related, human anthelmintic drug, flubendazole, using a rat spinal cord contusion injury model. Flubendazole, administered i.p. 5 or 10 mg/kg day, beginning 3 h post-injury and daily thereafter for 2 or 4 weeks, resulted in improved locomotor function after contusion spinal cord injury (SCI) compared with vehicle-treated controls. Histological analysis of spinal cord sections showed that such treatment with flubendazole also reduced lesion volume and improved total tissue sparing, white matter sparing, and gray matter sparing. Flubendazole inhibited the activation of glial fibrillary acidic protein (GFAP); suppressed cyclin B1 expression and Bruton tyrosine kinase activation, markers of B cell activation/proliferation and inflammation; and reduced B cell autoimmune response. Together, these results suggest the use of the benzimidazole anthelmintic flubendazole as a potential therapeutic for SCI.