Acute Phase Of Spinal Cord Injury Research Articles

New strategy to treat spinal cord injury: Nafamostat mesilate suppressed NLRP3-mediated pyroptosis during acute phase

Spinal cord injury (SCI) is a devastating condition for which effective clinical treatment is currently lacking. During the acute phase of SCI, myriad pathological changes give rise to subsequent secondary injury. The results of our previous studies indicated that treating rats post-SCI with nafamostat mesilate (NM) protected the blood–spinal cord barrier (BSCB) and exerted an antiapoptotic effect. However, the optimal dosage for mice with SCI and the underlying mechanisms potentially contributing to recovery, especially during the acute phase of SCI, have not been determined. In this study, we first determined the optimal dosage of NM for mice post-SCI (5 mg/kg/day). Subsequently, our RNA-seq findings revealed that NM has the potential to inhibit pyroptosis after SCI. These findings were further substantiated by subsequent Western blot (WB) and Immunofluorescence (IF) analyses in vivo. These results indicate that NM can alleviate NLRP3 (NOD-like receptor thermal protein domain associated protein 3)-mediated pyroptosis by modulating the NF-κB signaling pathway and reducing the protein expression levels of NIMA-related kinase 7 (NEK7) and cathepsin B (CTSB). In vitro experimental results supported our in vivo findings, revealing the effectiveness of NM in suppressing pyroptosis induced by adenosine triphosphate (ATP) and lipopolysaccharide (LPS) in BV2 cells. These results underscore the potential of NM to regulate NLRP3-mediated pyroptosis following SCI. Notably, compared with other synthetic compounds, NM exhibits greater versatility, suggesting that it is a promising clinical treatment option for SCI.

Balloon compression-induced spinal cord injury in canines: a large animal model for spinal cord injury research.

Spinal cord injury (SCI) is a life-altering condition that severely impacts an individual's functional capabilities and has significant implications for both the individual and society. Large animal models are crucial for understanding the pathology and biomechanics of SCI. Dogs (Canis lupus familiaris) are promising models for SCI research due to their anatomical and histopathological similarities to humans. Balloon compression is an established method for inducing controlled SCI in canines. In this study, we optimized a balloon compression procedure for inducing SCI in dogs, aiming to develop a reliable model for future in vivo studies. Our methodology successfully induced total motoric loss in canines, observed for seven days, a critical period for therapeutic interventions. Histopathological examinations using Luxol fast blue (LFB) staining revealed total demyelination in intralesional samples, confirming the structural damage caused by balloon compression. We concluded that a balloon compression model at the T10-T11 vertebral level, with an inflated balloon volume of 1.0 ml, induced SCI while minimizing the risk of balloon rupture. Longer duration of compression ensures total paralysis in this model, providing a platform for testing therapeutic interventions during the acute phase of SCI. The canine model generated consistent data and facilitated straightforward observational findings.

Intrathecal injection of human placental mesenchymal stem cells derived exosomes significantly improves functional recovery in spinal cord injured rats.

Spinal cord injury (SCI) due to lack of restoration of damaged neuronal cells is associated with sensorimotor impairment. This study was focused on using the human placental mesenchymal stem cells- exosome (HPMSCs- Exosomes) in an animal model of severe SCI under myelogram procedure. Intrathecal injection of exosomes was performed in the acute phase of SCI in female rats. The improved functional recovery of the animals was followed for 6 weeks in control (saline, n = 6) and HPMSCs- EXO (HPMSCs-Exosomes, n = 6) groups. Pathological changes and glial scar size were evaluated. The Immunohistochemistry (IHC) of GFAP and NF200 factors as well as the apoptosis assay was investigated in the tissue samples from the injury site. The results demonstrated that HPMSCs-exosomes can improve motor function by attenuating apoptosis of neurons at the injury site, decreasing GFAP expression and increasing NF200 in the HPMSCs-EXO group. Also, HPMSCs-exosomes by preventing the formation of cavities causes preservation of tissue in SCI rats. These findings demonstrate the effectiveness of HPMSC-Exosomes as a therapeutic method to improve functional recovery, reduce pathological changes associated with injury, and prevent chronicity after SCI. The neuroprotective and anti-apoptotic potential of HPMSCs- Exosomes may be a promising therapeutic approach for SCI. Another result was the importance of intrathecal injection of exosomes in the acute phase, which accelerated the healing process. Furthermore, the myelogram can be a feasible and suitable method to confirm the accuracy of intrathecal injection and examine the subarachnoid space in the laboratory animals.

Chemogenetic Attenuation of Acute Nociceptive Signaling Enhances Functional Outcomes Following Spinal Cord Injury.

Identifying novel therapeutic approaches to promote recovery of neurological functions following spinal cord injury (SCI) remains a great unmet need. Nociceptive signaling in the acute phase of SCI has been shown to inhibit recovery of locomotor function and promote the development of chronic neuropathic pain. We therefore hypothesized that inhibition of nociceptive signaling in the acute phase of SCI might improve long-term functional outcomes in the chronic phase of injury. To test this hypothesis, we took advantage of a selective strategy utilizing AAV6 to deliver inhibitory (hM4Di) Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) to nociceptors of the L4-L6 dorsal root ganglia to evaluate the effects of transient nociceptor silencing on long-term sensory and motor functional outcomes in a rat thoracic contusion SCI model. Following hM4Di-mediated nociceptor inhibition from 0-14 days post-SCI, we conducted behavioral assessments until 70 days post-SCI, then performed histological assessments of lesion severity and axon plasticity. Our results show highly selective expression of hM4Di within small diameter nociceptors including calcitonin gene-related peptide (CGRP)+ and IB4-binding neurons. Expression of hM4Di in less than 25% of nociceptors was sufficient to increase hindlimb thermal withdrawal latency in naïve rats. Compared with subjects who received AAV-yellow fluorescent protein (YFP; control), subjects who received AAV-hM4Di exhibited attenuated thermal hyperalgesia, greater coordination, and improved hindlimb locomotor function. However, treatment did not impact the development of cold allodynia or mechanical hyperalgesia. Histological assessments of spinal cord tissue suggested trends toward reduced lesion volume, increased neuronal sparing and increased CGRP+ axon sprouting in hM4Di-treated animals. Together, these findings suggest that nociceptor silencing early after SCI may promote beneficial plasticity in the acute phase of injury that can impact long-term functional outcomes, and support previous work highlighting primary nociceptors as possible therapeutic targets for pain management after SCI.

Transcriptome Profiling after Early Spinal Cord Injury in the Axolotl and Its Comparison with Rodent Animal Models through RNA-Seq Data Analysis.

Traumatic spinal cord injury (SCI) is a disabling condition that affects millions of people around the world. Currently, no clinical treatment can restore spinal cord function. Comparison of molecular responses in regenerating to non-regenerating vertebrates can shed light on neural restoration. The axolotl (Ambystoma mexicanum) is an amphibian that regenerates regions of the brain or spinal cord after damage. In this study, we compared the transcriptomes after SCI at acute (1-2 days after SCI) and sub-acute (6-7 days post-SCI) periods through the analysis of RNA-seq public datasets from axolotl and non-regenerating rodents. Genes related to wound healing and immune responses were upregulated in axolotls, rats, and mice after SCI; however, the immune-related processes were more prevalent in rodents. In the acute phase of SCI in the axolotl, the molecular pathways and genes associated with early development were upregulated, while processes related to neuronal function were downregulated. Importantly, the downregulation of processes related to sensorial and motor functions was observed only in rodents. This analysis also revealed that genes related to pluripotency, cytoskeleton rearrangement, and transposable elements (e.g., Sox2, Krt5, and LOC100130764) were among the most upregulated in the axolotl. Finally, gene regulatory networks in axolotls revealed the early activation of genes related to neurogenesis, including Atf3/4 and Foxa2. Immune-related processes are upregulated shortly after SCI in axolotls and rodents; however, a strong immune response is more noticeable in rodents. Genes related to early development and neurogenesis are upregulated beginning in the acute stage of SCI in axolotls, while the loss of motor and sensory functions is detected only in rodents during the sub-acute period of SCI. The approach employed in this study might be useful for designing and establishing regenerative therapies after SCI in mammals, including humans.

Administration of Tamoxifen Can Regulate Changes in Gene Expression during the Acute Phase of Traumatic Spinal Cord Injury.

Traumatic spinal cord injury (SCI) causes irreversible damage leading to incapacity. Molecular mechanisms underlying SCI damage are not fully understood, preventing the development of novel therapies. Tamoxifen (TMX) has emerged as a promising therapy. Our aim was to identify transcriptome changes in the acute phase of SCI and the effect of Tamoxifen on those changes in a rat model of SCI. Four groups were considered: (1) Non-injured without TMX (Sham/TMX-), (2) Non-injured with TMX (Sham/TMX+), (3) injured without TMX (SCI/TMX-), and (4) injured with TMX (SCI/TMX+). Tamoxifen was administered intraperitoneally 30 min after injury, and spinal cord tissues were collected 24 h after injury. Clariom S Assays Array was used for transcriptome analysis. After comparing Sham/TMX- versus SCI/TMX-, 708 genes showed differential expression. The enriched pathways were the SCI pathway and pathways related to the inflammatory response. When comparing SCI/TMX- versus SCI/TMX+, only 30 genes showed differential expression, with no pathways enriched. Our results showed differential expression of genes related to the inflammatory response after SCI, and Tamoxifen seems to regulate gene expression changes in Ccr2 and Mmp12. Our study contributes data regarding the potential value of tamoxifen as a therapeutic resource for traumatic SCI during the acute phase.

Mesoporous polydopamine delivering 8-gingerol for the target and synergistic treatment to the spinal cord injury

In the treatment of spinal cord injury (SCI), the complex process of secondary injury is mainly responsible for preventing SCI repair or even exacerbating the injury. In this experiment, we constructed the 8-gingerol (8G)-loaded mesoporous polydopamine (M-PDA), M@8G, as the in vivo targeting nano-delivery platform, and investigated the therapeutic effects of M@8G in secondary SCI and its related mechanisms. The results indicated that M@8G could penetrate the blood-spinal cord barrier to enrich the spinal cord injury site. Mechanism research has shown that all of the M-PDA,8G and M@8G displayed the anti-lipid peroxidation effect, and then M@8G can inhibit the secondary SCI by suppressing the ferroptosis and inflammation. In vivo assays showed that M@8G significantly diminished the local injury area, reduced axonal and myelin loss, thus improving the neurological and motor recovery in rats. Based on the analysis of cerebrospinal fluid samples from patients, ferroptosis occurred locally in SCI and continued to progress in patients during the acute phase of SCI as well as the stage after their clinical surgery. This study showcases effective treatment of SCI through the aggregation and synergistic effect of M@8G in focal areas, providing a safe and promising strategy for the clinical treatment of SCI.

Comparison of the Anti-Inflammatory Effects of Mouse Adipose- and Bone-Marrow-Derived Multilineage-Differentiating Stress-Enduring Cells in Acute-Phase Spinal Cord Injury.

Abstract Spinal cord injury (SCI) is a serious neurological disorder, with the consequent disabilities conferred by this disorder typically persisting for life. Multilineage-differentiating stress-enduring (Muse) cells are endogenous stem cells that can be collected from various tissues as well as from mesenchymal stem cells (MSCs); additionally, these Muse cells are currently being used in clinical trials. The anti-inflammatory effect of stem cell transplantation prevents secondary injuries of SCI; however, its effect on Muse cells remains unclear. In this study, we aimed to compare the anti-inflammatory effects of adipose (AD)- and bone marrow (BM)-Muse cells that were isolated from mice (6-week-old C57BL/6J) following intralesional administration during the acute phase of SCI. Flow cytometry was used to isolate Muse cells from AD and BM MSCs. The percentage of Muse cells was 3.9 and 2.7% for AD and BM MSCs, respectively. To examine cell viability, Muse cells were incubated under H2O2-induced oxidative stress conditions. Overall, AD-Muse cells exhibited higher viability than BM-Muse cells (p = 0.032). In enzyme-linked immunosorbent assay analysis, AD-Muse cells displayed greater secretion of brain-derived neurotrophic factor (BDNF; p = 0.008), vascular endothelial growth factor (p = 0.032), and hepatocyte growth factor (p = 0.016). DNA microarray analysis revealed higher expression of Bdnf, neurotrophin-3 (Ntf3), nerve growth factor (Ngf), pleiotrophin (Ptn), and midkine (Mdk) in AD-Muse cells than in BM-Muse cells. To assess their anti-inflammatory effects in vitro, Muse cells and macrophages were co-cultured, and the levels of cytokines (tumor necrosis factor [TNF] α and interleukin [IL] 10) were measured in the medium. Consequently, we found that TNFα levels were lower in AD-Muse cells than in BM-Muse cells (p = 0.009), and IL10 levels were higher in AD-Muse cells than in BM-Muse cells (p = 0.008). Further, we induced moderate injuries via contusion of the spinal cord at the T10 level; Muse cells were transplanted intralesionally 7 days post-SCI. The number of surviving cells, alongside the number of CD86+ (M1 inflammatory effect), and CD206+ (M2 anti-inflammatory effect) macrophages in the spinal cord were measured 7 days post-transplantation. The number of surviving AD-Muse cells was higher than the number of surviving BM-Muse cells (ratio of AD-Muse/BM-Muse = 2.5, p > 0.05). The M1/M2 ratio in the AD-Muse cell-group (0.37) was lower than that in the control (phosphate-buffered saline) group (3.60, p = 0.008). The lesion area in the AD-Muse cell group was smaller than that in the BM-non-Muse (p = 0.049) and control groups (p = 0.012). As AD-Muse cells conferred a higher cell survival and neurotrophic factor secretion ability in vitro, AD-Muse cells demonstrated reduced inflammation after SCI. Overall, intralesional AD-Muse cell therapy is a potential therapeutic candidate that is expected to exhibit anti-inflammatory effects following acute SCI.

The neuro-protective role of telomerase via TERT/TERF-2 in the acute phase of spinal cord injury.

To investigate the interaction of telomerase activity and telomere length on neuro-protection or neuro-degeneration effects after spinal cord injury (SCI). A contusive SCI model was developed using 56 Sprague-Dawley rats. Seven rats were allocated into acute injury phase groups (1, 3, 8, 24, and 48h), and sub-acute and chronic injury phase groups (1, 2, and 4weeks). Telomerase activity was assessed by telomerase reverse transcriptase (TERT) and telomeric repeat binding factor-2 (TERF-2). Differentiation of activated neural stem cells was investigated by co-expression of neuronal/glial cell markers. Apoptosis expression was also investigated by caspase-3, 8, and 9 using terminal deoxynucleotidyl transferase dUTP nick end labelling staining. Immunofluorescence staining and western blotting were performed for quantitative analyses. Expression of TERT increased gradually until 24h post-injury, and was decreased following SCI (P < 0.05). TERF-2 also was increased following SCI until 24h post-injury and then decreased with time (P < 0.05). Co-localization of TERT and TERF-2 was higher at 24h post-injury. High expression of TERT was seen in neurons (Neu N Ab), however, expression of TERT was relatively lower in astrocytes and oligodendrocytes. Apoptosis analysis showed persistent high expression of caspases-3, -9, and -8 during the observation period. Increased TERT and TERF-2 activity were noted 24h post-injury in the acute phase of SCI with TERF-2 maintaining telomeric-repeat length. Our results suggest that increased activity of telomere maintenance may be related to neuro-protective mechanisms against subsequent apoptosis resulting from DNA damage after acute SCI.

Role of Neutrophils to Determine the Outcome in Traumatic Spinal Cord Injury: a Systematic Review

Background: Based to the National Spinal Cord Injury Statistical Center (NSCISC) of the University of Alabama at Birmingham, USA, there are 15 to 40 cases of Spinal Cord Injury (SCI) per one million population each year (approximately 4,125 to 11,000 new cases) in the world. Neutrophils in SCI have two roles, namely beneficial and detrimental. These roles can be an outcome indicator in Traumatic Spinal Cord Injury, especially in the acute phase of SCI. Therefore, this study aimed to analyze neutrophils role in SCI outcome indicators. Methods: This systematic review used secondary data in the form of animal trial studies that were found in the last five years. Five databases were searched, including PubMed, Science Direct, Scopus, Web of Science, and Springer Link, using keywords spinal cord injury, neutrophil, inflammation, and outcome. Results: There were six studies reviewed in which all studies explained the detrimental role of neutrophils in SCI. Five studies explained that the role could be inhibited by proinflammatory cytokines and chemokines, while four studies explained an increase in locomotor function after observation until the remodeling phase. Conclusion: The dominant role of neutrophils in SCI is detrimental. This role can be affected by two factors that become resolutions: direct and indirect. These two factors also affect the improvement in the locomotor function of SCI.

Administration of C5a Receptor Antagonist Improves the Efficacy of Human Induced Pluripotent Stem Cell-Derived Neural Stem/Progenitor Cell Transplantation in the Acute Phase of Spinal Cord Injury.

Human-induced pluripotent stem cell-derived neural stem/progenitor cell (hiPSC-NS/PC) transplantation during the acute phase of spinal cord injury (SCI) is not effective due to the inflammatory response occurring immediately after SCI, which negatively impacts transplanted cell survival. Therefore, we chose to study the powerful chemoattractant complement C5a as a method to generate a more favorable transplantation environment. We hypothesized that suppression of the inflammatory response immediately after SCI by C5a receptor antagonist (C5aRA) would improve the efficacy of hiPSC-NS/PCs transplantation for acute phase SCI. Here, we evaluated the influence of C5aRA on the inflammatory reaction during the acute phase after SCI, and observed significant reductions in several inflammatory cytokines, macrophages, neutrophils, and apoptotic markers. Next, we divided the SCI mice into four groups: 1) phosphate-buffered saline (PBS) only; 2) C5aRA only; 3) PBS + transplantation (PBS+TP); and 4) C5aRA + transplantation (C5aRA+TP). Immediately after SCI, C5aRA or PBS was injected once a day for 4 consecutive days, followed by hiPSC-NS/PC transplantation or PBS into the lesion epicenter on Day 4. The C5aRA+TP group had better functional improvement compared with the PBS only group. The C5aRA+TP group also had a significantly higher cell survival rate compared with the PBS+TP group. This study demonstrates that administration of C5aRA can suppress the inflammatory response during the acute phase of SCI, while improving the survival rate of transplanted hiPSC-NS/PCs, as well as enhancing motor functional restoration. Human-induced pluripotent stem cell-derived neural stem/progenitor cell transplantation with C5aRA is a promising treatment during the acute injury phase for SCI patients.

Diffusional kurtosis imaging as a possible prognostic marker of cervical incomplete spinal cord injury outcome: a prospective pilot study.

Spinal cord injury (SCI) is associated with substantial chronic morbidity and mortality. Routine imaging techniques such as T1- and T2-weighted magnetic resonance imaging (MRI) are not effective in predicting neurological deficiency grade or outcome. Diffusional kurtosis imaging (DKI) is an MR imaging technique that provides microstructural information about biological tissue. There are no longitudinal prospective studies assessing DKI metrics in acute traumatic SCI. Therefore, the purpose of this study was to establish a DKI protocol for acute SCI and correlate the DKI metrics to the functional neurological outcome of the patients. Eight consecutive SCI patients referred to our institution with cervical SCI were included in the study. An acute diagnostic MRI scan was supplemented with a novel fast, mean kurtosis DKI protocol, which describes the average deviation from Gaussian diffusional along nine different directions. Mean kurtosis values were measured at the injury site and normalized to the mean kurtosis values of a non-injured site. At discharge form specialized rehabilitation, patients were evaluated using the Spinal Cord Independence Measure-III (SCIM-III). The DKI metrics and SCIM-III were analysed using Spearman's rank correlation. This pilot study found a significant correlation between decreasing mean kurtosis values at the injury site of the spinal cord and higher grade of disability measured by the SCIM-III (p = 0.002). This pilot study found that DKI may be a valuable tool as a prognostic marker in the acute phase of SCI.

MANAGEMENT OF RECURRENT BRADYCARDIA WITH THEOPHYLLINE IN THE SETTING OF SPINAL CORD INJURY

TOPIC: Cardiovascular Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Cardiovascular complications are common in patients with cervical or high thoracic spinal cord injury (SCI) including autonomic dysreflexia and cardiac arrhythmias. Cardiac instability is a result of disruption of the descending sympathetic pathways and lack of compensation to parasympathetic responses via the vagus nerve for supraspinal control of the heart. We present a rare case of a 49-year-old male with recurrent episodes of bradycardia and subsequent complete heart block post SCI responding to theophylline. CASE PRESENTATION: 49-year-old male with a history significant for T5 fracture and spinal cord injury resulting in paraplegia was found to have brief episodes of bradycardia two months post accident during prolonged ventilator weaning. He was initially treated with and titrated off chronotropic agents (dopamine and isoproterenol). A month later, he began having recurrent episodes of transient complete heart block with the absence of ventricular activity for up to 30 seconds. After the period of heart block, he would progress to sinus bradycardia for about 30 seconds before transitioning to normal sinus rhythm. After specialty consultation, the patient was started on theophylline 100 mg three times daily with complete resolution of his symptoms for nine days. Then, during manual disimpaction, he had re-emergence of his transient complete heart block and had a brief cardiac arrest with pulseless electrical activity, which led to the implantation of a leadless pacemaker. DISCUSSION: This patient is unique in that cardiac dysrhythmias and cardiac arrest are more common in the acute phase of SCIs (2-6 weeks post injury), whereas this patient was 3 months post injury. Chronotropic and inotropic infusions are the primary treatment strategy for bradyarrhythmias. Dopamine and isoproterenol were trialed in the patient but stopped due to transient improvement in the symptoms. Minimizing vagal stimulation is important for the prevention of bradycardia associated with SCIs. Theophylline has been found to have anti-bradyarrhythmia effects and may be used for prevention of recurrent bradycardia. The mechanism is thought to be through antagonism of adenosine receptors, which is a crucial pathway in patients with high SCIs with unopposed vagal tone. In this case, initiation of oral theophylline prevented recurrent bradycardia and complete heart block for 9 days before a pacemaker was implanted. CONCLUSIONS: Routine use of theophylline to prevent cardiovascular complications in spinal cord injuries is not well known. Methylxanthine therapy may prevent recurrent bradyarrhythmias from occurring and avert or delay implantation of a pacemaker. REFERENCE #1: Furlan JC, Fehlings MG. Cardiovascular complications after acute spinal cord injury: pathophysiology, diagnosis, and management. Neurosurg Focus. 2008;25(5):E13. doi: 10.3171/FOC.2008.25.11.E13. REFERENCE #2: Alboni P, Rossi P, Ratto B, Pedroni P, Gatto E, Antonioli GE. Electrophysiologic effects of oral theophylline in sinus bradycardia. Am J Cardiol.1990; 65:1037-1039. REFERENCE #3: Whitman CB, Schroeder WS, Ploch PJ, Raghavendran K. Efficacy of aminophylline for treatment of recurrent symptomatic bradycardia after spinal cord injury. Pharmacotherapy. 2008 Jan;28(1):131-5. doi: 10.1592/phco.28.1.131. DISCLOSURES: No relevant relationships by Kirsten McGrew, source=Web Response No relevant relationships by Lindsay Saum, source=Web Response No relevant relationships by Adam Smalley, source=Web Response

Ibrutinib reduces neutrophil infiltration, preserves neural tissue and enhances locomotor recovery in mouse contusion model of spinal cord injury.

Following acute spinal cord injury (SCI), excessive recruitment of neutrophils can result in inflammation, neural tissue loss and exacerbation of neurological outcomes. Ibrutinib is a bruton’s tyrosine kinase inhibitor in innate immune cells such as the neutrophils that diminishes their activation and influx to the site of injury. The present study evaluated the efficacy of ibrutinib administration in the acute phase of SCI on neural tissue preservation and locomotor recovery. Ibrutinib was delivered intravenously at 3.125 mg/kg either immediately, 12 hours after, or both immediately and 12 hours after SCI induction in adult male C57BL/6 mice. Neutrophil influx into the lesion area was evaluated 24 hours following SCI using light microscopy and immunohistochemistry methods. Animals’ body weight changes were recorded, and their functional motor recovery was assessed based on the Basso mouse scale during 28 days after treatment. Finally, spinal cord lesion volume was estimated by an unbiased stereological method. While animals’ weight in the control group started to increase one week after injury, it stayed unchanged in treatment groups. However, the double injection of ibrutinib led to a significantly lower body weight compared to the control group at 4 weeks post-injury. Mean neutrophil counts per visual field and the lesion volume were significantly decreased in all ibrutinib-treated groups. In addition, ibrutinib significantly improved locomotor functional recovery in all treated groups, especially in immediate and double-injection groups. Neural tissue protection and locomotor functional recovery suggest ibrutinib treatment as a potent immunotherapeutic intervention for traumatic SCI that warrants clinical testing.

Local delivery of fingolimod through PLGA nanoparticles and PuraMatrix-embedded neural precursor cells promote motor function recovery and tissue repair in spinal cordinjury.

Spinal cord injury (SCI) is a devastating clinical problem that can lead to permanent motor dysfunction. Fingolimod (FTY720) is a sphingosine structural analogue, and recently, its therapeutic benefits in SCI have been reported. The present study aimed to evaluate the therapeutic efficacy of fingolimod-incorporated poly lactic-co-glycolic acid (PLGA) nanoparticles (nanofingolimod) delivered locally together with neural stem/progenitor cells (NS/PCs) transplantation in a mouse model of contusive acute SCI. Fingolimod was encapsulated in PLGA nanoparticles by the emulsion-evaporation method. Mouse NS/PCs were harvested and cultured from embryonic Day 14 (E14) ganglionic eminences. Induction of SCI was followed by the intrathecal delivery of nanofingolimod with and without intralesional transplantation of PuraMatrix-encapsulated NS/PCs. Functional recovery, injury size and the fate of the transplanted cells were evaluated after 28 days. The nanofingolimod particles represented spherical morphology. The entrapment efficiency determined by UV-visible spectroscopy was approximately 90%, and the drug content of fingolimod loaded nanoparticles was 13%. About 68% of encapsulated fingolimod was slowly released within 10 days. Local delivery of nanofingolimod in combination with NS/PCs transplantation led to a stronger improvement in neurological functions and minimized tissue damage. Furthermore, co-administration of nanofingolimod and NS/PCs not only increased the survival of transplanted cells but also promoted their fate towards more oligodendrocytic phenotype. Our data suggest that local release of nanofingolimod in combination with three-dimensional (3D) transplantation of NS/PCs in the acute phase of SCI could be a promising approach to restore the damaged tissues and improve neurological functions.

Bioinformatic Analysis of the Proteome in Exosomes Derived From Plasma: Exosomes Involved in Cholesterol Metabolism Process of Patients With Spinal Cord Injury in the Acute Phase.

Spinal cord injury (SCI) is a common but severe disease caused by traffic accidents. Coronary atherosclerotic heart disease (CHD) caused by dyslipidemia is known as the leading cause of death in patients with SCI. However, the quantitative analysis showed that the cholesterol and lipoprotein concentrations in peripheral blood (PB) did not change significantly within 48 h after SCI. Due to the presence of the Blood spinal cord barrier (BSCB), there are only few studies concerning the plasma cholesterol metabolism in the acute phase of SCI. Exosomes have a smaller particle size, which enables them relatively less limitation of BSCB. This study uses exosomes derived from the plasma of 43 patients in the acute phase of SCI and 71 patients in the control group as samples. MS proteomics and bioinformatics analysis found 590 quantifiable proteins, in which 75 proteins were upregulated and 153 proteins were downregulated, and the top 10 differentially expressed proteins are those including downregulating proteins: HIST1H4A, HIST2H3A, HIST2H2BE, HCLS1, S100A9, HIST1H2BM, S100A8, CALM3, YWHAH, and SFN, and upregulating proteins: SERPIND1, C1QB, SPTLC3, IGHV4-28, C4A, IGHV4-38-2, IGHV4-30-2, SLC15A1, C4B, and ACTG2. Enrichment analysis showed that the largest part of proteins was related to cholesterol metabolism among the downregulated proteins. The main components of cholesterol [ApoB-48 and ApoB-100 increased, ApoA-I, ApoA-II, ApoA-IV, ApoC, ApoE, and Apo(a) decreased] were changed in exosomes derived from plasma of patients. ELISA analysis showed that some components were disordered in the acute phase of SCI. These results suggested that the exosomes might be involved in cholesterol metabolism regulation in the acute phase of SCI.

Hippocampal neurodegeneration and rhythms mirror each other during acute spinal cord injury in male rats

Spinal Cord Injury (SCI), triggers neurodegenerative changes in the spinal cord, and simultaneously alters oscillatory manifestations of motor cortex. However, these disturbances may not be limited to motor areas and other parts such as hippocampus, which is vital in the neurogenesis and cognitive function, may be affected in the neurogenic and oscillatory manners. Addressing this remarkable complication of SCI, we evaluated the hippocampal neurogenesis and rhythms through acute phase of SCI. In the present study, we used 40 male rats (Sham.W1 = 10, SCI.W1 = 10, Sham.W2 = 10, SCI.W2 = 10), and findings revealed that contusive SCI declines hippocampal rhythms (Delta, Theta, Beta, Gamma) power and max-frequency. Also, there was a significant decrease in the DCX + and BrdU + cells of the dentate gyrus; correlated significantly with rhythms power decline. Considering the TUNEL assay analysis, there were significantly greater apoptotic cells, in the CA1, CA3, and DG regions of injured animals. Furthermore, according to the western blotting analysis, the expression of receptors (NMDA, GABAA, Muscarinic1), which are essential in the neurogenesis and generation of rhythms significantly attenuated following SCI. Our study demonstrated that acute SCI, alters the power and max-frequency of hippocampal rhythms parallel with changes in the hippocampal neurogenesis, apoptosis, and receptors expression.

Identification of four genes and biological characteristics associated with acute spinal cord injury in rats integrated bioinformatics analysis.

Spinal cord injury (SCI) is a serious condition that can cause physical disability and sensory dysfunction. Cytokines play an extremely important role in the acute phase of SCI. Clarifying the cytokine expression profile is of great importance. Cytokine array analysis was used to explore the changes in 67 different proteins at 0 hours, 2 hours, 1 day, 3 days, and 7 days after acute SCI in rats. The differentially expressed cytokines in the various periods were analyzed and compared. The biological processes related to the differentially expressed proteins were examined using Gene Ontology (GO) analysis. Immediately after SCI (0 hours), only ciliary neurotrophic factor (CNTF) was slightly up-regulated, while 23 other proteins were down-regulated. At 2 hours after SCI, there were 3 upregulated and 21 downregulated proteins. At 1 day after SCI, there were 5 upregulated and 6 downregulated proteins. At 3 days after SCI, there were 6 upregulated and 4 downregulated proteins. At 7 days after SCI, there were 4 upregulated and 9 downregulated proteins. Erythropoietin (EPO) and Fms related tyrosine kinase 3 ligand (Flt-3L) were downregulated at all time points. CD48 was decreased at 2 hours to 7 days after SCI. Monocyte chemotactic protein-1 (MCP-1) was the only protein that was upregulated at 2 hours to 7 days. The GO and pathway analyses revealed that the cytokine-related pathways, cell death, and proliferation might play a key role during secondary SCI. This study identified 3 downregulated proteins during SCI, that being EPO, Flt-3L, and CD48. MCP-1 was the only upregulated protein, and its expression was upregulated till day 7 following SCI. These 4 identified genes may be potential therapeutic targets for the treatment of SCI.

Comparison of systemic and localized carrier-mediated delivery of methylprednisolone succinate for treatment of acute spinal cord injury.

Localized carrier-mediated administration of drugs is a promising approach to treatment of acute phase of spinal cord injury (SCI) as it allows enhanced and/or sustained drug delivery to damaged tissues along with minimization of systemic side effects. We studied the effect of locally applied self-assembling micellar formulation of methylprednisolone succinate (MPS) with trifunctional block copolymer of ethylene oxide and propylene oxide (TBC) on functional recovery and tissue drug content after SCI in rats in comparison with local and systemic administration of MPS alone. Variations in the amplitude of motor evoked responses in the hindlimb muscles induced by epidural stimulation during acute phase of SCI and restoration of movements during chronic period after local vs. systemic application of MPS were evaluated in this study. Results demonstrate that local delivery of MPS in combination with TBC facilitates spinal cord sensorimotor circuitry, increasing the excitability. In addition, this formulation was found to be more effective in improvement of locomotion after SCI compared to systemic administration. LC-MS/MS data shows that the use of TBC carrier increases the glucocorticoid content in treated spinal cord by more than four times over other modes of treatment. The results of this study demonstrate that the local treatment of acute SCI with MPS in the form of mixed micelles with TBC can provide improved therapeutic outcome by promoting drug accumulation and functional restoration of the spinal cord.

The Value of MicroRNAs as an Indicator of the Severity and the Acute Phase of Spinal Cord Injury.

ObjectiveTo assess the role of miRNA-21 and miRNA-223 in a balloon-compression model of spinal cord injury (SCI).MethodsA total of 50 male Wistar rats (n=50) were divided into the three groups: the group A (n=15, insertion of the unflated Fogarty balloon catheter), the group B (n=15, insertion of the Fogarty balloon catheter at a volume of 20 μL) and the group C (n=15, insertion of the Fogarty balloon catheter at a volume of 50 μL). After the behavioral test, RNA isolation, microRNA expression profiling using microarrays and quantitative polymerase chain reaction, measurements were compared between the three groups.ResultsDespite a lack of significant differences in time-dependent changes in miRNA-21 expression levels between the three groups at 4 hours, there were significant differences in them at 1, 3, and 7 days (p<0.05). Moreover, there were significant differences in time-dependent changes in miRNA-223 expression levels between the three groups at 4 hours and 1, 3, and 7 days (p<0.05). Furthermore, miRNA-223 expression levels reached the highest at 1 day but were decreased with time thereafter in all the three groups.ConclusionExpression levels of miRNA-21 and miRNA-223 might be associated with the severity and acute phase of SCI, respectively. It is mandatory, however, to analyze changes in levels of inflammatory markers and the relevant biological pathways.