Long-term changes of Th17 and regulatory T cells in peripheral blood of dogs with spinal cord injury after intervertebral disc herniation.

BACKGROUND: Intervertebral disc herniation (IVDH) is one of the most common causes of spinal cord injury (SCI) in dogs. As a result of acute SCI, a complex inflammatory response occurs in the spinal cord. Th17 cells (Th17) produce pro-inflammatory cytokines, while regulatory T cells (Treg) have opposite effects producing anti-inflammatory cytokines. Therefore, the aim of this study was to determine whether Th17- and Treg cells are involved in the pathogenesis of SCI or whether cellular changes occur due to coexisting inflammatory diseases. We hypothesized that chronic alterations in the Th17/Treg ratio are associated with a worse outcome after SCI. METHODS: Twenty-six paretic or plegic dogs with IVDH with and without coexisting inflammatory disease were investigated in the acute stage of the disease and after recovery of SCI. In addition, a healthy control group was included (n = 14). Quantification of Th17 and Treg cells, from peripheral blood samples, was performed by multicolor flow cytometry and IL17 was measured using an enzyme-linked immunosorbent assay (ELISA). RESULTS: After recovery significantly higher levels of Th17 (p = 0.0265) and Treg cells (p = 0.00025) were detected compared to acute IVDH but Th17/Treg ratio did not differ significantly. Recovered dogs and the control group did not differ significantly from each other. No association between an imbalance in the ratio and neurologic severity or underlying inflammatory diseases was found. CONCLUSION: This study demonstrated that altered Th17 and Treg levels in peripheral blood are altered in the acute stage of IVDH, preexisting inflammatory diseases seem not to influence these cell populations. Th17 and Treg cells could be considered when evaluating new treatment strategies for SCI.

Molecular evolution of the BRINP and ASTN genes and expression profles in response to pathogens and spinal cord injury repair in lamprey (Lethenteron reissneri).

Bone morphogenic protein/retinoic acid inducible neural-specific proteins (BRINPs) and astrotactins (ASTNs) are two members of membrane attack complex/perforin-like (MACPF) superfamily proteins that present high expression in the growing and mature vertebrate neurons. Lamprey has a unique evolutionary status as a representative of the oldest jawless vertebrates, making it an ideal animal model for understanding vertebrate evolution. The evolutionary origins of BRINPs and ASTNs genes in vertebrates, however, have not been shown in lampreys. Here, BRINP and ASTN genes were found in lamprey genomes and the evolutionary relationships of them were investigated by phylogenetic analysis. Protein domains, motifs, genetic structure, and crystal structure analysis revealed that the features of BRINP and ASTN appear to be conserved in vertebrates. Genomic synteny analysis indicated that lamprey BRINP and ASTN neighbor genes differed dramatically from jawed vertebrate. Real-time quantitative results illustrated that the BRINP and ASTN genes family might take part in immune defence and spinal cord injury repair. This study not only enriches a better understanding of the evolution of the BRINP and ASTN genes but also offers a foundation for exploring their roles in the development of the vertebrate central nervous system (CNS).

Evaluation of body surface temperature variations in dogs affected by spinal cord injuries during physiotherapy exercise in a water treadmill.

The aim this study was to evaluate variation in body surface temperature (BST) in healthy and spinal cord injured (SCI) dogs, and to outline temperature variation at rest (T0), during (T1) and after (T2) water-treadmill physiotherapy sessions in SCI using infrared thermography (IRT). Sixty-seven dogs of different sex, breed, body weight and age were enrolled: 14 healthy dogs and 53 dogs affected by disc pathologies. The study examined three regions of interest (ROIs): the total image of the spine (IMAGE), the spinal cord area from 1st thoracic vertebra to the last lumbar vertebra (AR01) and the surgery wound or spinal cord lesion area (AR02). Significant BST variations between healthy and SCI were reported in T°max and T°max-min (ΔT) values in IMAGE (P < 0.05). In SCI group, AR01 and AR02 assessment showed an increase in temperature ate the sited of the injured area and adjacent body structures. In SCI, a significant effect of water-treadmill exercise in AR01 and AR02 was reported. In fact, both AR01 and AR02 reported higher BST (T°max, T°mean, T°min and ΔT) during the physical exercise (T1), representing the response to physical activity of the spine vascularization, muscles and column contiguous tissues. Furthermore, in T2, the same areas reported a significant lower BST (T°max, T°mean, and ΔT), related to a decrease in tissue inflammation on the target area of the water treadmill physiotherapy. This study highlights how IRT can detect BST variations associated with injured areas. In addition, IRT revealed a positive effect of water-treadmill exercise on the injured spinal cord areas, thus it could be a viable non-invasive and rapid method to support both clinical examination and assessment of the effectiveness of medical treatment in SCI.

Traumatic Nervous System Injury.

Mechanisms of traumatic nervous system injury to a degree are similar, but differences exist in etiology, pathophysiology, and treatment of brain, spinal cord, and peripheral nerve injury. The most common clinical abnormalities seen in the horse are abnormal level of consciousness, abnormal behavior, seizures, cranial nerve deficits, vestibular disease, tetra- and paraparesis or paraplegia, cauda equina syndrome, specific gait deficits, and muscle atrophy. Treatments are directed toward reducing inflammation and swelling, halting secondary injury, and promoting mechanisms of neuroregeneration and plasticity. Prognosis depends on the severity of primary injury and the neuroanatomic location and extent of nervous tissue damage.

Acute Central Nervous System Trauma in the Field.

Acute central nervous system (CNS) trauma in the field is best approached by a systematic and thorough physical and neurologic examination that allows the practitioner to localize the brain or spinal cord injury. The skull and vertebral canal are complex 3-dimensional structures, and orthogonal radiographic views are necessary for an accurate diagnosis. Therapeutics aimed at decreasing pain, inflammation, and edema or increased intracranial pressure in the case of traumatic brain injury should be administered. Survival and return to athleticism can be achieved even in moderate-to-severe traumatic CNS injury with appropriate medical management.

Outcomes of extensive hemilaminectomy with durotomy on dogs with presumptive progressive myelomalacia: a retrospective study on 34 cases.

BACKGROUND: Progressive myelomalacia (PMM) is a fatal complication of progressive ascending and descending necrosis of the spinal cord after acute spinal cord injury. A recent study suggested that extensive hemilaminectomy with durotomy (EHLD) at the intramedullary T2-hyperintense region which performed immediately after magnetic resonance imaging (MRI) improved the survival rate in dogs with presumptive PMM. The objective of this retrospective study was to evaluate the effects of EHLD on halting the progression of PMM in dogs presumptively diagnosed with PMM which had the interval between MRI and surgery. RESULTS: Thirty-four dogs with presumptive PMM which had undergone EHLD with the delay following MRI examination (range, 0 to 3 days) were included. The cranial side of EHLD was set depending on the delay time after MRI, MRI findings, neurological examination and intraoperative macroscopic appearance. Two weeks after surgery, the perioperative survival rate was 97% (33/34). During follow-up with a median time period of 82.5 weeks (range, 0-290 weeks), the postoperative survival rate was 91% (31/34). At the end of the follow-up period, 31 out of 34 dogs were alive without severe postoperative complications while the remaining 2 dogs died from causes not directly attributable to the surgery. There was no improvement in the pelvic limb function of all dogs. CONCLUSIONS: EHLD appears to be effective in halting the progression of presumptive PMM and preventing morbidity even in dogs which had the interval between MRI and EHLD. Our algorithm of determining the range of EHLD may enable to set the appropriate ranges of EHLD in the cases which develop signs consistent with PMM after MRI examination.

Quantitative Proteomics After Spinal Cord Injury (SCI) in a Regenerative and a Nonregenerative Stage in the Frog Xenopus laevis.

The capacity to regenerate the spinal cord after an injury is a coveted trait that only a limited group of nonmammalian organisms can achieve. In Xenopus laevis, this capacity is only present during larval or tadpole stages, but is absent during postmetamorphic frog stages. This provides an excellent model for comparative studies between a regenerative and a nonregenerative stage to identify the cellular and molecular mechanisms that explain this difference in regenerative potential. Here, we used iTRAQ chemistry to obtain a quantitative proteome of the spinal cord 1 day after a transection injury in regenerative and nonregenerative stage animals, and used sham operated animals as controls. We quantified a total of 6,384 proteins, with 172 showing significant differential expression in the regenerative stage and 240 in the nonregenerative stage, with an overlap of only 14 proteins. Functional enrichment analysis revealed that although the regenerative stage downregulated synapse/vesicle and mitochondrial proteins, the nonregenerative stage upregulated lipid metabolism proteins, and downregulated ribosomal and translation control proteins. Furthermore, STRING network analysis showed that proteins belonging to these groups are highly interconnected, providing interesting candidates for future functional studies. Data are available via ProteomeXchange with identifier PXD006993.

Directional axonal regrowth induced by an aligned fibrin nanofiber hydrogel contributes to improved motor function recovery in canine L2 spinal cord injury.

Spinal cord injuries (SCI) normally disrupt the long axonal tracts of the spinal cord and cause permanent neurological deficits, for which there is currently a lack of effective therapeutic methods. Biomaterial-based regenerative medicine is a pivotal strategy to induce axonal regeneration through delivery of biophysical and/or biochemical regulatory cues by biomaterials. We previously fabricated a hierarchically aligned fibrin hydrogel (AFG) that could promote neurogenic differentiation of stem cells in vitro and has been successfully applied for peripheral nerve and spinal cord regeneration in rats. In this study, AFG was used to repair a canine lumbar segment 2 hemisection spinal cord injury, and the consistency of histological, imageological and behavioral results was compared. AFG was used to construct an aligned fiber bridge that supported cell adhesion in vitro and rapidly facilitated tissue invasion along the long axis of fibers in vivo, Moreover, in vivo results demonstrated regrowth of axons in an oriented pattern connecting the rostral and caudal stumps. Consistent results were confirmed by diffusion tensor imaging, which allowed successful tracing of reconnected nerve fibers across the defect. As a result, directional axonal regrowth contributed to significantly improved recovery of motor functional behavior of SCI canines with AFG implantation. Our results suggest that AFG has great promise for rapidly directing axonal regrowth for nerve regeneration.

Stem Cell Conditioned Medium Treatment for Canine Spinal Cord Injury: Pilot Feasibility Study.

Spinal cord injury (SCI) involves nerve damage and often leads to motor, sensory and autonomic dysfunctions. In the present study, we have designed a clinical protocol to assess the feasibility of systemic delivery of allogenic canine bone marrow tissue-derived mesenchymal stem cell conditioned medium (BMMSC CM) to dogs with SCI. Four client-owned dogs with chronic SCI lasting more than six months underwent neurological and clinical evaluation, MRI imaging and blood tests before being enrolled in this study. All dogs received four intravenous infusions with canine allogenic BMMSC CM within one month. Between the infusions the dogs received comprehensive physiotherapy, which continued for three additional months. No adverse effects or complications were observed during the one, three and six months follow-up periods. Neither blood chemistry panel nor hematology profile showed any significant changes. All dogs were clinically improved as assessed using Olby locomotor scales after one, three and six months of BMMSC CM treatment. Furthermore, goniometric measurements revealed partial improvement in the range of joint motion. Bladder function improved in two disabled dogs. We conclude that multiple delivery of allogenic cell-derived conditioned medium to dogs with chronic SCI is feasible, and it might be clinically beneficial in combination with physiotherapy.

Extended durotomy to treat severe spinal cord injury after acute thoracolumbar disc herniation in dogs.

OBJECTIVE: To report recovery of ambulation of dogs treated with extended thoracolumbar durotomy for severe spinal cord injury caused by intervertebral disc herniation. STUDY DESIGN: Descriptive cohort. ANIMALS: Twenty-six consecutive paraplegic dogs presented with loss of deep pain sensation after acute thoracolumbar intervertebral disc herniation. METHODS: Each dog underwent routine diagnostic assessment and surgery for removal of extradural herniated intervertebral disc, followed by a four-vertebral body length durotomy centered on the herniated disc. Each dog was followed up until it was able to walk 10 steps without assistance or until 6 months after surgery. RESULTS: Sixteen of 26 dogs recovered to walk unaided (all but one also recovered fecal and urinary continence), and six dogs did not; four dogs were lost to follow-up. One dog was euthanized because of signs consistent with progressive myelomalacia. There was no evidence of detrimental effects of durotomy within the period of study. Using Bayesian analysis, we found a point estimate of successful outcome of 71% with 95% credible interval from 52% to 87%. CONCLUSION: Extended durotomy seemed to improve the outcome of dogs in our case series without increase in morbidity. CLINICAL SIGNIFICANCE: Extended durotomy appears safe and may improve the outcome of dogs with severe thoracolumbar mixed contusion and compressive injuries associated with acute intervertebral disc extrusion.

Image correction for diffusion tensor imaging of Rhesus monkey thoracic spinal cord.

BACKGROUND: The relatively tiny spinal cord of non-human primate (NHP) causes increased challenge in diffusion tensor imaging (DTI) post-processing. This study aimed to establish a reliable correction strategy applied to clinical DTI images of NHP. METHODS: Six normal and partial spinal cord injury (SCI) rhesus monkeys underwent 3T MR scanning. A correction strategy combining multiple iterations and non-rigid deformation was used for DTI image post-processing. Quantitative evaluations were then conducted to investigate effects of distortion correction. RESULTS: After correction, longitudinal geometric distortion, global distortion, and residual distance errors were all significantly decreased (P < 0.05). Fractional anisotropy at the injured site was remarkably lower than that at the contralateral site (P = 0.0488) and was substantially lower than those at the adjacent superior (P = 0.0157) and inferior (P = 0.0128) areas at the same side. CONCLUSIONS: Our image correction strategy can improve the quality of the DTI images of NHP thoracic cords, contributing to the development of SCI preclinical research.

Therapeutic efficacy of microtube-embedded chondroitinase ABC in a canine clinical model of spinal cord injury.

See Moon and Bradbury (doi:10.1093/brain/awy067) for a scientific commentary on this article.Many hundreds of thousands of people around the world are living with the long-term consequences of spinal cord injury and they need effective new therapies. Laboratory research in experimental animals has identified a large number of potentially translatable interventions but transition to the clinic is not straightforward. Further evidence of efficacy in more clinically-relevant lesions is required to gain sufficient confidence to commence human clinical trials. Of the many therapeutic candidates currently available, intraspinally applied chondroitinase ABC has particularly well documented efficacy in experimental animals. In this study we measured the effects of this intervention in a double-blinded randomized controlled trial in a cohort of dogs with naturally-occurring severe chronic spinal cord injuries that model the condition in humans. First, we collected baseline data on a series of outcomes: forelimb-hindlimb coordination (the prespecified primary outcome measure), skin sensitivity along the back, somatosensory evoked and transcranial magnetic motor evoked potentials and cystometry in 60 dogs with thoracolumbar lesions. Dogs were then randomized 1:1 to receive intraspinal injections of heat-stabilized, lipid microtube-embedded chondroitinase ABC or sham injections consisting of needle puncture of the skin. Outcome data were measured at 1, 3 and 6 months after intervention; skin sensitivity was also measured 24 h after injection (or sham). Forelimb-hindlimb coordination was affected by neither time nor chondroitinase treatment alone but there was a significant interaction between these variables such that coordination between forelimb and hindlimb stepping improved during the 6-month follow-up period in the chondroitinase-treated animals by a mean of 23%, but did not change in controls. Three dogs (10%) in the chondroitinase group also recovered the ability to ambulate without assistance. Sensitivity of the dorsal skin increased at 24 h after intervention in both groups but subsequently decreased to normal levels. Cystometry identified a non-significant improvement of bladder compliance at 1 month in the chondroitinase-injected dogs but this did not persist. There were no overall differences between groups in detection of sensory evoked potentials. Our results strongly support a beneficial effect of intraspinal injection of chondroitinase ABC on spinal cord function in this highly clinically-relevant model of chronic severe spinal cord injury. There was no evidence of long-term adverse effects associated with this intervention. We therefore conclude that this study provides strong evidence in support of initiation of clinical trials of chondroitinase ABC in humans with chronic spinal cord injury.

Mesenchymal Stem Cell-Derived Exosomes Reduce A1 Astrocytes via Downregulation of Phosphorylated NFκB P65 Subunit in Spinal Cord Injury.

BACKGROUND/AIMS: Neurotoxic A1 astrocytes are induced by inflammation after spinal cord injury (SCI), and the inflammation-related Nuclear Factor Kappa B (NFκB) pathway may be related to A1-astrocyte activation. Mesenchymal stem cell (MSC) transplantation is a promising therapy for SCI, where transplanted MSCs exhibit anti-inflammatory effects by downregulating proinflammatory factors, such as Tumor Necrosis Factor (TNF)-α and NFκB. MSC-exosomes (MSC-exo) reportedly mimic the beneficial effects of MSCs. Therefore, in this study, we investigated whether MSCs and MSC-exo exert inhibitory effects on A1 astrocytes and are beneficial for recovery after SCI. METHODS: The effects of MSC and MSC-exo on SCIinduced A1 astrocytes, and the potential mechanisms were investigated in vitro and in vivo using immunofluorescence and western blot. In addition, we assessed the histopathology, levels of proinflammatory cytokines and locomotor function to verify the effects of MSC and MSC-exo on SCI rats. RESULTS: MSC or MSC-exo co-culture reduced the proportion of SCIinduced A1 astrocytes. Intravenously-injected MSC or MSC-exo after SCI significantly reduced the proportion of A1 astrocytes, the percentage of p65 positive nuclei in astrocytes, and the percentage of TUNEL-positive cells in the ventral horn. Additionally, we observed decreased lesion area and expression of TNFα, Interleukin (IL)-1α and IL-1ß, elevated expression of Myelin Basic Protein (MBP), Synaptophysin (Syn) and Neuronal Nuclei (NeuN), and improved Basso, Beattie & Bresnahan (BBB) scores and inclined-plane-test angle. In vitro assay showed that MSC and MSC-exo reduced SCI-induced A1 astrocytes, probably via inhibiting the nuclear translocation of the NFκB p65. CONCLUSION: MSC and MSC-exo reduce SCI-induced A1 astrocytes, probably via inhibiting nuclear translocation of NFκB p65, and exert antiinflammatory and neuroprotective effects following SCI, with the therapeutic effect of MSCexo comparable with that of MSCs when applied intravenously.

miR-136-5p Regulates the Inflammatory Response by Targeting the IKKß/NF-κB/A20 Pathway After Spinal Cord Injury.

BACKGROUND/AIMS: miR-136-5p participates in recovery after spinal cord injury (SCI) via an unknown mechanism. We investigated the mechanism underlying the involvement of miR-136-5p in the inflammatory response in a rat model of SCI. METHODS: Sprague-Dawley rat astrocytes were cultured in vitro to construct a reporter plasmid. Luciferase assays were used to detect the ability of miR-136-5p to target the IKKß and A20 genes. Next, recombinant lentiviral vectors were constructed, which either overexpressed miR-136-5p or inhibited its expression. The influence of miR-136-5p overexpression and miR-136-5p silencing on inflammation was observed in vivo in an SCI rat model. The expression of IL-1ß, IL-6, TNF-α, IFN-α, and related proteins (A20, IKKß, and NF-κB) was detected. RESULTS: In vitro studies showed that luciferase activity was significantly activated in the presence of the 3' untranslated region (UTR) region of the IKKß gene after stimulation of cells with miR-136-5p. However, luciferase activity was significantly inhibited in the presence of the 3'UTR region of the A20 gene. Thus, miR-136-5p may act directly on the 3'UTR regions of the IKKß and A20 genes to regulate their expression. miR-136-5p overexpression promoted the production of related cytokines and NF-κB in SCI rats and inhibited the expression of A20 protein. CONCLUSION: Overexpression of miR-136-5p promotes the generation of IL-1ß, IL-6, TNF-α, IFN-α, IKKß, and NF-κB in SCI rats but inhibits the expression of A20. Under these conditions, inflammatory cell infiltration into the rat spinal cord increases and injury is significantly aggravated. Silencing of miR-136-5p significantly reduces the protein expression results described after miR-136-5p overexpression and ameliorates the inflammatory cell infiltration and damage to the spinal cord. Therefore, miR-136-5p might be a new target for the treatment of SCI.

Local Delivery of ß-Elemene Improves Locomotor Functional Recovery by Alleviating Endoplasmic Reticulum Stress and Reducing Neuronal Apoptosis in Rats with Spinal Cord Injury.

BACKGROUND/AIMS: Spinal cord injury (SCI) is a serious global problem that leads to permanent motor and sensory deficits. This study explores the anti-apoptotic and neuroprotective effects of the natural extract ß-elemene in vitro and in a rat model of SCI. METHODS: CCK-8 assay was used to evaluate cell viability and lactate dehydrogenase assay was used to evaluate cytotoxicity. A model of cell injury was established using cobalt chloride. Apoptosis was evaluated using a fluorescence-activated cell sorting assay of annexin V-FITC and propidium iodide staining. A rat SCI model was created via the modified Allen's method and Basso, Beattie, and Bresnahan (BBB) scores were used to assess locomotor function. Inflammatory responses were assessed via enzyme-linked immunosorbent assay (ELISA). Apoptotic and surviving neurons in the ventral horn were respectively observed via terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and Nissl staining. Western blotting was used to measure protein expression. RESULTS: ß-elemene (20 µg/ml) promoted cell viability by activating phosphorylation of the PI3K-AKT-mTOR pathway. ß-elemene reduced CoCl2-induced cellular death and apoptosis by suppressing the expression levels of CHOP, cleaved-caspase 12, 78-kilodalton glucose-regulated protein, cleaved-caspase 3, and the Bax/Bcl-2 ratio. In the rat model of SCI, Nissl and TUNEL staining showed that ß-elemene promoted motor neuron survival and reduced neuronal apoptosis in the spinal cord ventral horn. BBB scores showed that ß-elemene significantly promoted locomotor behavioral recovery after SCI. In addition, ß-elemene reduced the ELISA-detected secretion of interleukin (IL)-6 and IL-1ß. CONCLUSION: ß-elemene reduces neuronal apoptosis by alleviating endoplasmic reticulum stress in vitro and in vivo. In addition, ß-elemene promotes locomotor function recovery and tissue repair in SCI rats. Thus, our study provides a novel encouraging strategy for the potential treatment of ß-elemene in SCI patients.

Isolation and characterization of canine placenta-derived mesenchymal stromal cells for the treatment of neurological disorders in dogs.

Spinal cord injury (SCI) is a devastating disorder that affects humans and dogs. The prognosis of SCI depends on the severity of the injury and can include varying levels of motor and sensory deficits including devastating paraplegia and quadriplegia. Placental mesenchymal stromal cells (PMSCs) have been shown to improve wound healing and possess neuroprotective and immunomodulatory capabilities, but have not yet been clinically tested for the treatment of SCI. This study established a protocol to isolate fetal PMSCs from canine placentas and characterized their paracrine secretion profile and ability to stimulate neurons in vitro to assess their potential as a treatment option for neurological disorders in dogs. Canine PMSCs (cPMSCs) were plastic adherent and capable of trilineage differentiation. cPMSCs expressed typical MSC markers and did not express hematopoietic or endothelial cell markers. Genotyping of cPMSCs revealed fetal rather than maternal origin of the cells. cPMSCs were viable and mitotically expansive in a collagen hydrogel delivery vehicle, and they secreted the immunomodulatory and neurotrophic paracrine factors interleukin (IL)-6, IL-8, monocyte chemoattractant protein 1 (MCP-1), and vascular endothelial growth factor (VEGF). cPMSCs also stimulated the growth of complex neural networks when co-cultured with SH-SY5Y cells, a neuroblastoma cell line used to model neuron growth in vitro. cPMSCs are analogous to human PMSCs. They meet the criteria to be defined as MSCs and represent a potential regenerative therapy option for neurological disorders in dogs with their robust growth in collagen hydrogel, stimulation of neural network formation, and secretion of potent paracrine factors. © 2017 International Society for Advancement of Cytometry.

Magnetic resonance imaging features of dogs with incomplete recovery after acute, severe spinal cord injury.

STUDY DESIGN: Retrospective case series. OBJECTIVES: Describe the magnetic resonance imaging (MRI) features of dogs chronically impaired after severe spinal cord injury (SCI) and investigate associations between imaging variables and residual motor function. SETTING: United States of America. METHODS: Thoracolumbar MRI from dogs with incomplete recovery months to years after clinically complete (paralysis with loss of pain perception) thoracolumbar SCI were reviewed. Lesion features were described and quantified. Gait was quantified using an ordinal, open field scale (OFS). Associations between imaging features and gait scores, duration of injury (DOI), or SCI treatment were determined. RESULTS: Thirty-five dogs were included. Median OFS was 2 (0-6), median DOI was 13 months (3-83), and intervertebral disk herniation was the most common diagnosis (n = 27). Myelomalacia was the most common qualitative feature followed by cystic change; syringomyelia and fibrosis were uncommon. Lesion length corrected to L2 length (LL:L2) was variable (median LL:L2 = 3.5 (1.34-11.54)). Twenty-nine dogs had 100% maximum cross-sectional spinal cord compromise (MSCC) at the lesion epicenter and the length of 100% compromised area varied widely (median length 100% MSCC:L2 = 1.29 (0.39-7.64)). Length 100% MSCC:L2 was associated with OFS (p = 0.012). OFS was not associated with any qualitative features. DOI or treatment type were not associated with imaging features or lesion quantification. CONCLUSIONS: Lesion characteristics on MRI in dogs with incomplete recovery after severe SCI were established. Length of 100% MSCC was associated with hind limb motor function. Findings demonstrate a spectrum of injury severity on MRI among severely affected dogs, which is related to functional status.

Development of an International Canine Spinal Cord Injury observational registry: a collaborative data-sharing network to optimize translational studies of SCI.

STUDY DESIGN: Prospective cross-sectional cohort study. OBJECTIVES: The canine spontaneous model of spinal cord injury (SCI) is as an important pre-clinical platform as it recapitulates key facets of human injury in a naturally occurring context. The establishment of an observational canine SCI registry constitutes a key step in performing epidemiologic studies and assessing the impact of therapeutic strategies to enhance translational research. Further, accumulating information on dogs with SCI may contribute to current "big data" approaches to enhance understanding of the disease using heterogeneous multi-institutional, multi-species datasets from both pre-clinical and human studies. SETTING: Multiple veterinary academic institutions across the United States and Europe. METHODS: Common data elements recommended for experimental and human SCI studies were reviewed and adapted for use in a web-based registry, to which all dogs presenting to member veterinary tertiary care facilities were prospectively entered over ~1 year. RESULTS: Analysis of data accumulated during the first year of the registry suggests that 16% of dogs with SCI present with severe, sensorimotor-complete injury and that 15% of cases are seen by a tertiary care facility within 8 h of injury. Similar to the human SCI population, 34% were either overweight or obese. CONCLUSIONS: Severity of injury and timing of presentation suggests that neuroprotective studies using the canine clinical model could be conducted efficiently using a multi-institutional approach. Additionally, pet dogs with SCI experience similar comorbidities to people with SCI, in particular obesity, and could serve as an important model to evaluate the effects of this condition.

Molecular Mechanism of MiR-136-5p Targeting NF-κB/A20 in the IL-17-Mediated Inflammatory Response after Spinal Cord Injury.

BACKGROUND/AIMS: The pathophysiology of spinal cord injury (SCI) results in serious damage to the human body via an increase in the secondary biological processes imposed by activated astrocytes. Abnormal expression of microRNAs after SCI has become a potential research focus. However, the underlying mechanisms are poorly understood. METHODS: SCI models were established in rats using Allen's method, and the BBB scoring method was employed to assess locomotor function. Lentivirus was used to infect rat astrocytes and SCI rats. Real-time PCR and antibody chip were used to measure gene expression and cytokine secretion. Western blot analysis was employed to detect protein expression. HE staining was used to assess the histological changes in SCI. The immunohistochemical staining of A20 and p-NF-κB in SCI was also analyzed. RESULTS: The in vitro experiment showed that miR-136-5p up-regulated the expression of p-NF-κB by down-regulating the expression of A20 so that astrocytes produced inflammatory factors and chemokines. The in vivo experiment indicated that overexpressed miR-136-5p promoted the production of inflammatory factors, chemokines and p-NF-κB in SCI rats, whereas it inhibited the expression of A20 protein and increased inflammatory cell infiltration and injuries in the spinal cord. CONCLUSION: The current findings indicate that silencing miR-136-5p effectively decreased inflammatory factors and chemokines and protected the spinal cord via NF-κB/A20 signaling in vivo and in vitro. In contrast, overexpression of miR-136-5p had the opposite effect.

Spontaneous acute and chronic spinal cord injuries in paraplegic dogs: a comparative study of in vivo diffusion tensor imaging.

STUDY DESIGN: Prospective observational-analytical study. OBJECTIVES: Description of diffusion tensor imaging (DTI) metrics obtained from the spinal cord (SC) of dogs with severe acute or chronic spontaneous, non-experimentally induced spinal cord injury (SCI) and correlation of DTI values with lesion extent of SCI measured in T2-weighted (T2W) magnetic resonance imaging sequences. SETTING: Hannover, Germany. METHODS: Forty-seven paraplegic dogs, 32 with acute and 15 with chronic SCI, and 6 disease controls were included. T2W and DTI sequences of the thoracolumbar spinal cord were performed. Values of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were obtained from the epicentre of the lesion and one SC segment cranially and caudally and compared between groups. Pearson's correlation coefficient was calculated between DTI and T2W metrics. RESULTS: During acute SCI, FA values were increased (P=0.0065) and ADC values were decreased (P=0.0099) at epicentres compared to disease controls. FA values obtained from dogs with chronic SCI were lower (P<0.0001 epicentres and caudally; P=0.0002 cranially) and ADC showed no differences compared to disease control values. Dogs with chronic SCI revealed lower FA and higher ADC compared to dogs with acute SCI (P<0.0001 for both values at all localisations). FA values from epicentre and cranially to the lesion during chronic SCI correlated with extent of lesion (r=0.5517; P=0.0052 epicentres and r=0.6810; P=0.0408 cranially). CONCLUSION: Using DTI, differences between acute and chronic stages of spontaneous canine SCI were detected and correlations between T2W and DTI sequences were found in chronic SCI, supporting canine SCI as a useful large animal model.