The Molecular Biological Mechanism of Hydrogen Therapy and Its Application in Spinal Cord Injury.

Hydrogen, which is a novel biomedical molecule, is currently the subject of extensive research involving animal experiments and in vitro cell experiments, and it is gradually being applied in clinical settings. Hydrogen has been proven to possess anti-inflammatory, selective antioxidant, and antiapoptotic effects, thus exhibiting considerable protective effects in various diseases. In recent years, several studies have provided preliminary evidence for the protective effects of hydrogen on spinal cord injury (SCI). This paper provides a comprehensive review of the potential molecular biology mechanisms of hydrogen therapy and its application in treating SCI, with an aim to better explore the medical value of hydrogen and provide new avenues for the adjuvant treatment of SCI.

[Jisuikang formula promotes spinal cord injury repair in rats by activating the YAP/PKM2 signaling axis in astrocytes].

OBJECTIVE: To investigate the effect of Jisuikang formula-medicated serum for promoting spinal cord injury (SCI) repair in rats and explore the possible mechanism. METHODS: Thirty adult SD rats were randomized into sham-operated group, SCI (induced using a modified Allen method) model group, and Jisuikang formula-medicated serum treatment group. After the operations, the rats were treated with normal saline or Jisuikang by gavage on a daily basis for 14 days, and the changes in hindlimb motor function of the rats was assessed with Basso-Beattie-Bresnahan (BBB) scores and inclined-plate test. The injured spinal cord tissues were sampled from the SCI rat models for single-cell RNA sequencing, and bioinformatics analysis was performed to identify the target genes of Jisuikang, spinal cord injury and glycolysis. In the cell experiment, cultured astrocytes from neonatal SD rat cortex were treated with SOX2 alone or in combination with Jisuikang-medicated serum for 21 days, and the protein expressions of PKM2, p-PKM2 and YAP and colocalization of PKM2 and YAP in the cells were analyzed with Western blotting and immunofluorescence staining, respectively. RESULTS: The SCI rats with Jisuikang treatment showed significantly improved BBB scores and performance in inclined-plate test. At the injury site, high PKM2 expression was detected in various cell types. Bioinformatic analysis identified the HIPPO-YAP signaling pathway as the target pathway of Jisuikang. In cultured astrocytes, SOX2 combined with the mediated serum, as compared with SOX2 alone, significantly increased PKM2, p-PKM2 and YAP expressions and entry of phosphorylated PKM2 into the nucleus, and promoted PKM2 and YAP co-localization in the cells. CONCLUSION: Jisuikang formula accelerates SCI repair in rats possibly by promoting aerobic glycolysis of the astrocytes via activating the PKM2/YAP axis to induce reprogramming of the astrocytes into neurons.

Injectable Hydrogel Loaded with CDs and FTY720 Combined with Neural Stem Cells for the Treatment of Spinal Cord Injury.

Purpose: Spinal cord injury (SCI) is an incurable and disabling event that is accompanied by complex inflammation-related pathological processes, such as the production of excessive reactive oxygen species (ROS) by infiltrating inflammatory immune cells and their release into the extracellular microenvironment, resulting in extensive apoptosis of endogenous neural stem cells. In this study, we noticed the neuroregeneration-promoting effect as well as the ability of the innovative treatment method of FTY720-CDs@GelMA paired with NSCs to increase motor function recovery in a rat spinal cord injury model. Methods: Carbon dots (CDs) and fingolimod (FTY720) were added to a hydrogel created by chemical cross-linking GelMA (FTY720-CDs@GelMA). The basic properties of FTY720-CDs@GelMA hydrogels were investigated using TEM, SEM, XPS, and FTIR. The swelling and degradation rates of FTY720-CDs@GelMA hydrogels were measured, and each group's ability to scavenge reactive oxygen species was investigated. The in vitro biocompatibility of FTY720-CDs@GelMA hydrogels was assessed using neural stem cells. The regeneration of the spinal cord and recovery of motor function in rats were studied following co-treatment of spinal cord injury using FTY720-CDs@GelMA hydrogel in combination with NSCs, utilising rats with spinal cord injuries as a model. Histological and immunofluorescence labelling were used to determine the regeneration of axons and neurons. The recovery of motor function in rats was assessed using the BBB score. Results: The hydrogel boosted neurogenesis and axonal regeneration by eliminating excess ROS and restoring the regenerative environment. The hydrogel efficiently contained brain stem cells and demonstrated strong neuroprotective effects in vivo by lowering endogenous ROS generation and mitigating ROS-mediated oxidative stress. In a follow-up investigation, we discovered that FTY720-CDs@GelMA hydrogel could dramatically boost NSC proliferation while also promoting neuronal regeneration and synaptic formation, hence lowering cavity area. Conclusion: Our findings suggest that the innovative treatment of FTY720-CDs@GelMA paired with NSCs can effectively improve functional recovery in SCI patients, making it a promising therapeutic alternative for SCI.

Injectable conductive hydrogel remodeling microenvironment and mimicking neuroelectric signal transmission after spinal cord injury.

Severe spinal cord injury (SCI) leads to dysregulated neuroinflammation and cell apoptosis, resulting in axonal die-back and the loss of neuroelectric signal transmission. While biocompatible hydrogels are commonly used in SCI repair, they lack the capacity to support neuroelectric transmission. To overcome this limitation, we developed an injectable silk fibroin/ionic liquid (SFMA@IL) conductive hydrogel to assist neuroelectric signal transmission after SCI in this study. The hydrogel can form rapidly in situ under ultraviolet (UV) light. The mechanical supporting and neuro-regenerating properties are provided by silk fibroin (SF), while the conductive capability is provided by the designed ionic liquid (IL). SFMA@IL showed attractive features for SCI repair, such as anti-swelling, conductivity, and injectability. In vivo, SFMA@IL hydrogel used in rats with complete transection injuries was found to remodel the microenvironment, reduce inflammation, and facilitate neuro-fiber outgrowth. The hydrogel also led to a notable decrease in cell apoptosis and the achievement of scar-free wound healing, which saved 45.6 ± 10.8 % of spinal cord tissue in SFMA@IL grafting. Electrophysiological studies in rats with complete transection SCI confirmed SFMA@IL's ability to support sensory neuroelectric transmission, providing strong evidence for its signal transmission function. These findings provide new insights for the development of effective SCI treatments.

Wogonoside alleviates microglia-mediated neuroinflammation via TLR4/MyD88/NF-κB signaling axis after spinal cord injury.

Wogonoside (WG) is a natural flavonoid extracted from Scutellariae Radix, recognized for its established anti-inflammatory properties. However, the role of WG in the context of neuroinflammation after spinal cord injury (SCI) remains inadequately elucidated. This study employed in silico, in vitro, and in vivo methodologies to investigate the impact of WG on microglia-mediated neuroinflammation after SCI. In the in silico experiment, we identified 15 potential target genes of WG associated with SCI. These genes were linked to the regulation of inflammatory response and immune defense. Molecular docking maps revealed toll-like receptor 4 as a molecular target for WG, demonstrating binding through a hydrogen bond (Lys263, Ser120). In lipopolysaccharide-stimulated BV2 cells and SCI mice, WG significantly attenuated microglial activation and facilitated a phenotype shift from M1 to M2. This was evidenced by the reversal of the increased expressions of Iba1, GFAP, and iNOS, as well as the decreased expression of Arg1. WG also suppressed the production of pro-inflammatory mediators (NO, TNF-α, IL-6, IL-1α, IL-1ß, C1q). WG exerted these effects by suppressing the TLR4/MyD88/NF-κB signaling axis in microglia. Furthermore, by reducing levels of TNF-α, IL-1α, and C1q in supernatant of LPS-induced microglia, WG indirectly induced astrocytes change to A2 phenotype, evidenced by transcriptome sequencing result of primary mouse astrocytes. All these events above collectively created a favorable microenvironment, contributing to a significant alleviation of weight loss and neuronal damage at the lesion site of SCI mice. Our findings substantiate the efficacy of WG in mitigating neuroinflammation after SCI, thereby warranting further exploration.

Efficacy and safety of Buyang Huanwu Decoction in patients with spinal cord injury: A meta-analysis of randomized controlled trials.

BACKGROUND: There has been growing interest in using the traditional Chinese herb Buyang Huanwu Decoction (BHD) as a potential treatment for spinal cord injury (SCI), owing to its long-used treatment for SCI in China. However, the efficacy and safety of BHD treatment for SCI remain widely skeptical. This meta-analysis aims to assess the safety and efficacy of BHD in managing SCI. METHOD: A comprehensive literature search was conducted across several databases, including PubMed, EMBASE, Cochrane Library, CNKI, Wanfang, VIP, and Sinomed, up to January 1, 2024. Randomized controlled clinical trials evaluating the safety or efficacy of BHD in SCI treatment were included. The analysis focused on 8 critical endpoints: Patient-perceived total clinical effective rate, American Spinal Cord Injury Association (ASIA) sensory score, ASIA motor score, somatosensory evoked potential, motor evoked potential, visual analog scale pain score, Japanese Orthopaedic Association score, and adverse events. RESULTS: Thirteen studies comprising 815 participants met the inclusion criteria. No significant heterogeneity or publication bias was observed across the trials. The findings revealed significant improvements in the patient-perceived total clinical effective rate (OR = 3.77; 95% confidence interval [CI] = [2.43, 5.86]; P < .001), ASIA sensory score (mean difference [MD] = 8.22; 95% CI = [5.87, 10.56]; P < .001), ASIA motor score (MD = 7.16; 95% CI = [5.15, 9.18]; P < .001), somatosensory evoked potential (MD = 0.25; 95% CI = [0.03, 0.48]; P = .02), motor evoked potential (MD = 0.30; 95% CI = [0.14, 0.46]; P = .0002), and Japanese Orthopaedic Association score (MD = 1.99; 95% CI = [0.39, 3.58]; P = .01) in the BHD combination group compared to the control group. Additionally, there was a significant reduction in visual analog scale pain scores (MD = -0.81; 95% CI = [-1.52, -0.11]; P = .02) with BHD combination treatment, without a significant increase in adverse effects (OR = 0.68; 95% CI = [0.33, 1.41]; P = .3). CONCLUSION: The current evidence suggests that BHD is effective and safe in treating SCI, warranting consideration as a complementary and alternative therapy. However, given the low methodological quality of the included studies, further rigorous research is warranted to validate these findings.

ACOD1, rather than itaconate, facilitates p62-mediated activation of Nrf2 in microglia post spinal cord contusion.

BACKGROUND: Spinal cord injury (SCI)-induced neuroinflammation and oxidative stress (OS) are crucial events causing neurological dysfunction. Aconitate decarboxylase 1 (ACOD1) and its metabolite itaconate (Ita) inhibit inflammation and OS by promoting alkylation of Keap1 to induce Nrf2 expression; however, it is unclear whether there is another pathway regulating their effects in inflammation-activated microglia after SCI. METHODS: Adult male C57BL/6 ACOD1-/- mice and their wild-type (WT) littermates were subjected to a moderate thoracic spinal cord contusion. The degree of neuroinflammation and OS in the injured spinal cord were assessed using qPCR, western blot, flow cytometry, immunofluorescence, and trans-well assay. We then employed immunoprecipitation-western blot, chromatin immunoprecipitation (ChIP)-PCR, dual-luciferase assay, and immunofluorescence-confocal imaging to examine the molecular mechanisms of ACOD1. Finally, the locomotor function was evaluated with the Basso Mouse Scale and footprint assay. RESULTS: Both in vitro and in vivo, microglia with transcriptional blockage of ACOD1 exhibited more severe levels of neuroinflammation and OS, in which the expression of p62/Keap1/Nrf2 was down-regulated. Furthermore, silencing ACOD1 exacerbated neurological dysfunction in SCI mice. Administration of exogenous Ita or 4-octyl itaconate reduced p62 phosphorylation. Besides, ACOD1 was capable of interacting with phosphorylated p62 to enhance Nrf2 activation, which in turn further promoted transcription of ACOD1. CONCLUSIONS: Here, we identified an unreported ACOD1-p62-Nrf2-ACOD1 feedback loop exerting anti-inflammatory and anti-OS in inflammatory microglia, and demonstrated the neuroprotective role of ACOD1 after SCI, which was different from that of endogenous and exogenous Ita. The present study extends the functions of ACOD1 and uncovers marked property differences between endogenous and exogenous Ita. KEY POINTS: ACOD1 attenuated neuroinflammation and oxidative stress after spinal cord injury. ACOD1, not itaconate, interacted with p-p62 to facilitate Nrf2 expression and nuclear translocation. Nrf2 was capable of promoting ACOD1 transcription in microglia.

MG53/GMs/HA-Dex neural scaffold promotes the functional recovery of spinal cord injury by alleviating neuroinflammation.

The adverse microenvironment, including neuroinflammation, hinders the recovery of spinal cord injury (SCI). Regulating microglial polarization to alleviate neuroinflammation at the injury site is an effective strategy for SCI recovery. MG53 protein exerts obvious repair ability on multiple tissues damage, but with short half-life. In this study, we composited an innovative MG53/GMs/HA-Dex neural scaffold using gelatin microspheres (GMs), hyaluronic acid (HA), and dextran (Dex) loaded with MG53 protein. This novel neural scaffold could respond to MMP-2/9 protein and stably release MG53 protein with good physicochemical properties and biocompatibility. In addition, it significantly improved the motor function of SCI mice, suppressed M1 polarization of microglia and neuroinflammation, and promoted neurogenesis and axon regeneration. Further mechanistic experiments demonstrated that MG53/GMs/HA-Dex hydrogel inhibited the JAK2/STAT3 signaling pathway. Thus, this MG53/GMs/HA-Dex neural scaffold promotes the functional recovery of SCI mice by alleviating neuroinflammation, which provides a new intervention strategy for the neural regeneration and functional repair of SCI.

SCIWORA. Una rara entidad clínica en la población pediátrica. Estudio ambispectivo / SCIWORA in children. A rare clinical entity: Ambispective study

Introducción: La lesión medular tipo SCIWORA es una entidad clínica con baja incidencia y alta repercusión funcional. El objetivo del estudio es la descripción epidemiológica de esta lesión y su evolución funcional con un seguimiento medio de 10 años. Material y métodos: Estudio analítico, longitudinal, de cohortes ambispectivo. Fueron evaluados 13 pacientes con el diagnóstico de SCIWORA en el periodo de estudio 2001-2022. Variables evaluadas: edad, sexo, días hasta la lesión medular, causa de lesión, imagen medular en la RM postraumatismo, nivel neurológico de lesión, ASIA ingreso/alta/5 años, SCIM III ingreso/alta/3 años, tipo de tratamiento empleado, empleo de terapia NASCIS III ingreso, tiempo de hospitalización, seguimiento medio. En octubre del 2022 fueron nuevamente evaluados en consultas externas mediante: cuestionario de discapacidad cervical (NDI)/Oswestry y cuestionario de calidad de vida validado en castellano para lesionados medulares (SV-QLI/SCI). Resultados: La mediana de edad fue de 4 años, 77% varones. El 54% de las lesiones corresponden a nivel cervical. El ASIA al ingreso fue del 31% A y del 31% C, nivel neurológico: C2 (22%) y T10 (15%), tráfico como causa de lesión (77%), SCIM III ingreso/alta: 28,5/42. La estancia media hospitalaria fue de 115 días. NDI: 11,6 y Oswestry: 15,3. Conclusión: El 77% de los SCIWORA se producen en menores de 8 años. Al año del alta hospitalaria un 31% de los pacientes fueron catalogados como ASIA D y a los 5 años el porcentaje se mantiene constante. No se encontraron diferencias significativas entre la causa de la lesión y tipo de alteración en RM (p = 0,872), ni entre la edad y el tipo de lesión medular objetivada en RM (p = 0,149).(AU)

Introduction: SCIWORA has a low incidence but a high functional repercussion. The aim of the present study was to characterize the epidemiology of this clinical-radiological condition and evaluate functional outcome with a mean of 10-years follow-up. Material and methods: Observational, longitudinal ambispective cohort study. Thirteen SCIWORA patients were admitted in the study period. Demographics, mechanism of injury, spinal cord MRI findings, neurological level of injury, time to SCI, neurological status (AIS) at admission/discharge/5 years, spinal cord independence measure (SCIM III) scale at admission and discharge, hospital length of stay and mean follow-up were recorded. On October 2022 patients were re-evaluated using NDI, Oswestry, and SV-QLI/SCI. Results: Median age was 4 years. The study population for this investigation was mostly men (77%). 54% of level of injury correspond to cervical spine. AIS at admission was A (31%) and C (31%). Neurological level of injury was C2 (22%) and T10 (15%). Motor vehicle-related injury was the most prevalent mechanism of injury (77%), SCIM III scale at admission and discharge: 28.5/42, hospital length of stay was 115 days. The NDI was 11.6, Oswestry: 15.3 and SV-QLI/SCI: 17. Conclusions: Seventy-seven percent of SCIWORA patients was detected under 8 years-old. At 1 year follow-up after discharge 31% patients were AIS grade D and with 5 years follow-up the percentage remain constant. No statistically significant differences in the mechanism of injury and MRI findings (P = 0.872), age and MRI spinal cord findings (P = 0.149) were found in SCIWORA patients.(AU)

The Translation of Nanomedicines in the Contexts of Spinal Cord Injury and Repair.

PURPOSE OF THIS REVIEW: Manipulating or re-engineering the damaged human spinal cord to achieve neuro-recovery is one of the foremost challenges of modern science. Addressing the restricted permission of neural cells and topographically organised neural tissue for self-renewal and spontaneous regeneration, respectively, is not straightforward, as exemplified by rare instances of translational success. This review assembles an understanding of advances in nanomedicine for spinal cord injury (SCI) and related clinical indications of relevance to attempts to design, engineer, and target nanotechnologies to multiple molecular networks. RECENT FINDINGS: Recent research provides a new understanding of the health benefits and regulatory landscape of nanomedicines based on a background of advances in mRNA-based nanocarrier vaccines and quantum dot-based optical imaging. In relation to spinal cord pathology, the extant literature details promising advances in nanoneuropharmacology and regenerative medicine that inform the present understanding of the nanoparticle (NP) biocompatibility-neurotoxicity relationship. In this review, the conceptual bases of nanotechnology and nanomaterial chemistry covering organic and inorganic particles of sizes generally less than 100 nm in diameter will be addressed. Regarding the centrally active nanotechnologies selected for this review, attention is paid to NP physico-chemistry, functionalisation, delivery, biocompatibility, biodistribution, toxicology, and key molecular targets and biological effects intrinsic to and beyond the spinal cord parenchyma. SUMMARY: The advance of nanotechnologies for the treatment of refractory spinal cord pathologies requires an in-depth understanding of neurobiological and topographical principles and a consideration of additional complexities involving the research's translational and regulatory landscapes.

Analgesic Mechanism of Dexmedetomidine and Esketamine in Rats with Spinal Cord Injury.

BACKGROUND: Spinal cord injury (SCI) is usually caused by external direct or indirect factors, and with a high morbidity and mortality rate. The aim of this study was to observe the effects of Dexmedetomidine (DEX) combined with Esketamine (ESK) on pain behavior and potential analgesic mechanisms in rats with SCI. The goal was to provide a reliable multimodal analgesic medication regimen for SCI. METHODS: Thirty rats were divided into five groups with six rats in each group: Sham group, SCI group, DEX group, ESK group, and DEX+ESK group. The SCI model in rats was constructed, and the motor function of hind limbs of rats was measured using Basso Beattie Bresnahan (BBB) locomotor rating scale and inclined plate test. The levels of interleukin 18 (IL-18), interleukin 1ß (IL-1ß), and tumor necrosis factor-α (TNF-α) in the spinal cord were determined by enzyme-linked immunosorbent assay (ELISA). The expressions of substance P (SP), neurokinin-1 receptor (NK-1R), B cell lymphoma-2 (Bcl-2), and Bcl2-associated X protein (Bax) in the rats' spinal cord were measured by Western blot assay. The viability of spinal astrocytes was evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: After 7 days, the BBB scores were significantly higher in the DEX, ESK, and DEX+ESK groups compared to the SCI group (p < 0.01). Additionally, the DEX+ESK group had significantly higher scores than both the DEX and ESK groups (p < 0.01). The maximum angle of the DEX (p < 0.05), ESK (p < 0.05), and DEX+ESK groups (p < 0.01) were higher than the SCI group, and the maximum angle of DEX+ESK group was higher than DEX and ESK groups (p < 0.05). The levels of IL-18, IL-1ß, and TNF-α in the DEX, ESK, and DEX+ESK groups were lower than the SCI group (p < 0.01), while the DEX+ESK group had significantly lower IL-18, IL-1ß, and TNF-α levels than the DEX and ESK groups (p < 0.01). The levels of SP (p < 0.01) and NK-1R (p < 0.05) were lower in the DEX, ESK, and DEX+ESK groups compared to the SCI group, and the levels of SP and NK-1R were lower in the DEX+ESK group compared to the DEX and ESK groups (p < 0.01). The DEX and ESK groups suppressed the activity of spinal astrocytes (p < 0.01), however, the DEX+ESK group had larger effects on spinal astrocytes than the ESK group (p < 0.05). CONCLUSIONS: Treatment using DEX combined with ESK improves the motor function, inhibits inflammation and astrocyte activity, and exerts analgesic effects on rats with SCI. These findings can serve as a reference for the selection of multi-modal analgesics.

Advancing Spinal Cord Injury Bioimaging and Repair with Multifunctional Gold Nanodots Tracking.

High levels of reactive oxygen species (ROS) are known to play a critical role in the secondary cascade of spinal cord injury (SCI). The scavenging of ROS has emerged as a promising approach for alleviating acute SCI. Moreover, identifying the precise location of the SCI site remains challenging. Enhancing the visualization of the spinal cord and improving the ability to distinguish the lesion site are crucial for accurate and safe treatment. Therefore, there is an urgent clinical need to develop a biomaterial that integrates diagnosis and treatment for SCI. Herein, ultra-small-sized gold nanodots (AuNDs) were designed for dual-mode imaging-guided precision treatment of SCI. The designed AuNDs demonstrate two important functions. First, they effectively scavenge ROS, inhibit oxidative stress, reduce the infiltration of inflammatory cells, and prevent apoptosis. This leads to a significant improvement in SCI repair and promotes a functional recovery after injury. Second, leveraging their excellent dual-mode imaging capabilities, the AuNDs enable rapid and accurate identification of SCI sites. The high contrast observed between the injured and adjacent uninjured areas highlights the tremendous potential of AuNDs for SCI detection. Overall, by integrating ROS scavenging and dual-mode imaging in a single biomaterial, our work on functionalized AuNDs provides a promising strategy for the clinical diagnosis and treatment of SCI.

Tetramethylpyrazine-loaded electroconductive hydrogels promote tissue repair after spinal cord injury by protecting the blood-spinal cord barrier and neurons.

Spinal cord injury (SCI) usually induces profound microvascular dysfunction. It disrupts the integrity of the blood-spinal cord barrier (BSCB), which could trigger a cascade of secondary pathological events that manifest as neuronal apoptosis and axonal demyelination. These events can further lead to irreversible neurological impairments. Thus, reducing the permeability of the BSCB and maintaining its substructural integrity are essential to promote neuronal survival following SCI. Tetramethylpyrazine (TMP) has emerged as a potential protective agent for treating the BSCB after SCI. However, its therapeutic potential is hindered by challenges in the administration route and suboptimal bioavailability, leading to attenuated clinical outcomes. To address this challenge, traditional Chinese medicine, TMP, was used in this study to construct a drug-loaded electroconductive hydrogel for synergistic treatment of SCI. A conductive hydrogel combined with TMP demonstrates good electrical and mechanical properties as well as superior biocompatibility. Furthermore, it also facilitates sustained local release of TMP at the implantation site. Furthermore, the TMP-loaded electroconductive hydrogel could suppress oxidative stress responses, thereby diminishing endothelial cell apoptosis and the breakdown of tight junction proteins. This concerted action repairs BSCB integrity. Concurrently, myelin-associated axons and neurons are protected against death, which meaningfully restore neurological functions post spinal cord injury. Hence, these findings indicate that combining the electroconductive hydrogel with TMP presents a promising avenue for potentiating drug efficacy and synergistic repair following SCI.

Caffeic acid phenethyl ester inhibits neuro-inflammation and oxidative stress following spinal cord injury by mitigating mitochondrial dysfunction via the SIRT1/PGC1α/DRP1 signaling pathway.

BACKGROUND: The treatment of spinal cord injury (SCI) has always been a significant research focus of clinical neuroscience, with inhibition of microglia-mediated neuro-inflammation as well as oxidative stress key to successful SCI patient treatment. Caffeic acid phenethyl ester (CAPE), a compound extracted from propolis, has both anti-inflammatory and anti-oxidative effects, but its SCI therapeutic effects have rarely been reported. METHODS: We constructed a mouse spinal cord contusion model and administered CAPE intraperitoneally for 7 consecutive days after injury, and methylprednisolone (MP) was used as a positive control. Hematoxylin-eosin, Nissl, and Luxol Fast Blue staining were used to assess the effect of CAPE on the structures of nervous tissue after SCI. Basso Mouse Scale scores and footprint analysis were used to explore the effect of CAPE on the recovery of motor function by SCI mice. Western blot analysis and immunofluorescence staining assessed levels of inflammatory mediators and oxidative stress-related proteins both in vivo and in vitro after CAPE treatment. Further, reactive oxygen species (ROS) within the cytoplasm were detected using an ROS kit. Changes in mitochondrial membrane potential after CAPE treatment were detected with 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine iodide. Mechanistically, western blot analysis and immunofluorescence staining were used to examine the effect of CAPE on the SIRT1/PGC1α/DRP1 signaling pathway. RESULTS: CAPE-treated SCI mice showed less neuronal tissue loss, more neuronal survival, and reduced demyelination. Interestingly, SCI mice treated with CAPE showed better recovery of motor function. CAPE treatment reduced the expression of inflammatory and oxidative mediators, including iNOS, COX-2, TNF-α, IL-1ß, 1L-6, NOX-2, and NOX-4, as well as the positive control MP both in vitro and in vivo. In addition, molecular docking experiments showed that CAPE had a high affinity for SIRT1, and that CAPE treatment significantly activated SIRT1 and PGC1α, with down-regulation of DRP1. Further, CAPE treatment significantly reduced the level of ROS in cellular cytoplasm and increased the mitochondrial membrane potential, which improved normal mitochondrial function. After administering the SIRT1 inhibitor nicotinamide, the effect of CAPE on neuro-inflammation and oxidative stress was reversed.On the contrary, SIRT1 agonist SRT2183 further enhanced the anti-inflammatory and antioxidant effects of CAPE, indicating that the anti-inflammatory and anti-oxidative stress effects of CAPE after SCI were dependent on SIRT1. CONCLUSION: CAPE inhibits microglia-mediated neuro-inflammation and oxidative stress and supports mitochondrial function by regulating the SIRT1/PGC1α/DRP1 signaling pathway after SCI. These effects demonstrate that CAPE reduces nerve tissue damage. Therefore, CAPE is a potential drug for the treatment of SCI through production of anti-inflammatory and anti-oxidative stress effects.

Tetramethylpyrazine inhibits the inflammatory response by downregulating the TNFR1/IκB-α/NF-κB p65 pathway after spinal cord injury.

Previous studies have demonstrated that tetramethylpyrazine (TMP) can enhance the recovery of motor function in spinal cord injury (SCI) rats. However, the underlying mechanism involved in this therapeutic effect remains to be elucidated. We conducted RNA sequencing with a network pharmacology strategy to predict the targets and mechanism of TMP for SCI. The modified Allen's weight-drop method was used to construct an SCI rat model. The results indicated that the nuclear transfer factor-κB (NF-κB) pathway was identified through the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and an inflammatory response was identified through the Gene Ontology (GO) enrichment analysis. Tumor necrosis factor (TNF) was identified as a crucial target. Western blotting revealed that TMP decreased the protein expression of TNF superfamily receptor 1 (TNFR1), inhibitor κB-α (IκB-α), and NF-κB p65 in spinal cord tissues. Enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) demonstrated that TMP inhibited TNF-α, interleukin-1ß (IL-1ß), reactive oxygen species (ROS), and malondialdehyde (MDA) expression and enhanced superoxide dismutase (SOD) expression. Histopathological observation and behavior assessments showed that TMP improved morphology and motor function. In conclusion, TMP inhibits inflammatory response and oxidative stress, thereby exerting a neuroprotective effect that may be related to the regulation of the TNFR1/IκB-α/NF-κB p65 signaling pathway.

Encapsulation of the growth factor neurotrophin-3 in heparinised poloxamer hydrogel stabilises bioactivity and provides sustained release.

Poloxamer-based hydrogels show promise to stabilise and sustain the delivery of growth factors in tissue engineering applications, such as following spinal cord injury. Typically, growth factors such as neurotrophin-3 (NT-3) degrade rapidly in solution. Similarly, poloxamer hydrogels also degrade readily and are, therefore, only capable of sustaining the release of a payload over a small number of days. In this study, we focused on optimising a hydrogel formulation, incorporating both poloxamer 188 and 407, for the sustained delivery of bioactive NT-3. Hyaluronic acid blended into the hydrogels significantly reduced the degradation of the gel. We identified an optimal hydrogel composition consisting of 20 % w/w poloxamer 407, 5 % w/w poloxamer 188, 0.6 % w/w NaCl, and 1.5 % w/w hyaluronic acid. Heparin was chemically bound to the poloxamer chains to enhance interactions between the hydrogel and the growth factor. The unmodified and heparin-modified hydrogels exhibited sustained release of NT-3 for 28 days while preserving the bioactivity of NT-3. Moreover, these hydrogels demonstrated excellent cytocompatibility and had properties suitable for injection into the intrathecal space, underscoring their suitability as a growth factor delivery system. The findings presented here contribute valuable insights to the development of effective delivery strategies for therapeutic growth factors for tissue engineering approaches, including the treatment of spinal cord injury.

Celastrol inhibits oligodendrocyte and neuron ferroptosis to promote spinal cord injury recovery.

BACKGROUND: Spinal cord injury (SCI) is a traumatic injury to the central nervous system and can cause lipid peroxidation in the spinal cord. Ferroptosis, an iron-dependent programmed cell death, plays a key role in the pathophysiology progression of SCI. Celastrol, a widely used antioxidant drug, has potential therapeutic value for nervous system. PURPOSE: To investigate whether celastrol can be a reliable candidate for ferroptosis inhibitor and the molecular mechanism of celastrol in repairing SCI by inhibiting ferroptosis. METHODS: First, a rat SCI model was constructed, and the recovery of motor function was observed after treatment with celastrol. The regulatory effect of celastrol on ferroptosis pathway Nrf2-xCT-GPX4 was detected by Western blot and immunofluorescence. Finally, the ferroptosis model of neurons and oligodendrocytes was constructed in vitro to further verify the mechanism of inhibiting ferroptosis by celastrol. RESULTS: Our results demonstrated that celastrol promoted the recovery of spinal cord tissue and motor function in SCI rats. Further in vitro and in vivo studies showed that celastrol significantly inhibited ferroptosis in neurons and oligodendrocytes and reduced the accumulation of ROS. Finally, we found that celastrol could inhibit ferroptosis by up-regulating the Nrf2-xCT-GPX4 axis to repair SCI. CONCLUSION: Celastrol effectively inhibits ferroptosis after SCI by upregulating the Nrf2-xCT-GPX4 axis, reducing the production of lipid ROS, protecting the survival of neurons and oligodendrocytes, and improving the functional recovery.

Alleviating Severe Cytoskeletal Destruction of Spinal Motor Neurons: Another Effect of Docosahexaenoic Acid in Spinal Cord Injury.

Spinal cord injury (SCI) treatment remains a major challenge. Spinal motor neurons (MNs) are seriously injured in the early stage after SCI, but this has not received sufficient attention. Oxidative stress is known to play a crucial role in SCI pathology. Our studies demonstrated that oxidative stress can cause severe damage to the cytoskeleton of spinal MNs. Docosahexaenoic acid (DHA) has been shown to have beneficial effects on SCI, but the mechanism remains unclear, and no study has investigated the effect of DHA on oxidative stress-induced spinal MN injury. Here, we investigated the effect of DHA on spinal MN injury through in vivo and in vitro experiments, focusing on the cytoskeleton. We found that DHA not only promoted spinal MN survival but, more importantly, alleviated the severe cytoskeletal destruction of these neurons induced by oxidative stress in vitro and in mice with SCI in vivo. In addition, the mechanisms involved were investigated and elucidated. These results not only suggested a beneficial role of DHA in spinal MN cytoskeletal destruction caused by oxidative stress and SCI but also indicated the important role of the spinal MN cytoskeleton in the recovery of motor function after SCI. Our study provides new insights for the formulation of SCI treatment.

Injectable Hydrogel To Deliver Bone Mesenchymal Stem Cells Preloaded with Azithromycin To Promote Spinal Cord Repair.

Spinal cord injury is a disease that causes severe damage to the central nervous system. Currently, there is no cure for spinal cord injury. Azithromycin is commonly used as an antibiotic, but it can also exert anti-inflammatory effects by down-regulating M1-type macrophage genes and up-regulating M2-type macrophage genes, which may make it effective for treating spinal cord injury. Bone mesenchymal stem cells possess tissue regenerative capabilities that may help promote the repair of the injured spinal cord. In this study, our objective was to explore the potential of promoting repair in the injured spinal cord by delivering bone mesenchymal stem cells that had internalized nanoparticles preloaded with azithromycin. To achieve this objective, we formulated azithromycin into nanoparticles along with a trans-activating transcriptional activator, which should enhance nanoparticle uptake by bone mesenchymal stem cells. These stem cells were then incorporated into an injectable hydrogel. The therapeutic effects of this formulation were analyzed in vitro using a mouse microglial cell line and a human neuroblastoma cell line, as well as in vivo using a rat model of spinal cord injury. The results showed that the formulation exhibited anti-inflammatory and neuroprotective effects in vitro as well as therapeutic effects in vivo. These results highlight the potential of a hydrogel containing bone mesenchymal stem cells preloaded with azithromycin and trans-activating transcriptional activator to mitigate spinal cord injury and promote tissue repair.

An updated systematic review of neuroprotective agents in the treatment of spinal cord injury.

This systematic review aims to summarize the findings from all clinical randomized trials assessing the efficacy of potential neuroprotective agents in influencing the outcomes of acute spinal cord injuries (SCI). Following the PRISMA guidelines, we conducted comprehensive searches in four electronic databases (PubMed, Scopus, Cochrane Library, and Web of Science) up to September 5th, 2023. Our analysis included a total of 30 studies. We examined the effects of 15 substances/drugs: methylprednisolone, tirilazad mesylate, erythropoietin, nimodipine, naloxone, Sygen, Rho protein antagonist, granulocyte colony-stimulating factor, autologous macrophages, autologous bone marrow cells, vitamin D, progesterone, riluzole, minocycline, and blood alcohol concentration. Notable improvements in neurological outcomes were observed with progesterone plus vitamin D and granulocyte colony-stimulating factor. In contrast, results for methylprednisolone, erythropoietin, Sygen, Rho Protein, and Riluzole were inconclusive, primarily due to insufficient sample size or outdated evidence. No significant differences were found in the remaining evaluated drugs. Progesterone plus vitamin D, granulocyte colony-stimulating factor, methylprednisolone, Sygen, Rho Protein, and Riluzole may enhance neurological outcomes in acute SCI cases. It is worth noting that different endpoints or additional subgroup analyses may potentially alter the conclusions of individual trials. Therefore, certain SCI grades may benefit more from these treatments than others, while the overall results may remain inconclusive.