Modern Medical Management of Spinal Cord Injury

Ginsenoside Rg1 regulates astrocytes to promote angiogenesis in spinal cord injury via the JAK2/STAT3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ginseng (Panax ginseng C. A. Mey) is a common traditional Chinese medicine used for anti-inflammation, anti-apoptosis, anti-oxidative stress, and neuroprotection. Ginsenosides Rg1, the main active components isolated from ginseng, may be a feasible therapy for spinal cord injury (SCI).

AIMS OF THE STUDY

SCI causes endothelial cell death and blood vessel rupture, ultimately resulting in long-term neurological impairment. As a result, encouraging spinal angiogenesis may be a feasible therapy for SCI. This investigation aimed to validate the capacity of ginsenoside Rg1 in stimulating angiogenesis within the spinal cord.

MATERIALS AND METHODS

Rats with SCI were injected intraperitoneally with ginsenoside Rg1. The effectiveness of ginsenoside Rg1 was assessed using the motor function score and the motor-evoked potential (MEP). Immunofluorescence techniques were applied to identify the spinal cord's angiogenesis. Angiogenic factors were examined through Western Blot (WB) and Immunohistochemistry. Oxygen-glucose deprivation (OGD) was employed to establish the hypoxia-ischemia model in vitro, and astrocytes (As) were given ginsenoside Rg1 and co-cultured with spinal cord microvascular endothelial cells (SCMECs). Immunofluorescence, wound healing test, and tube formation assay were used to identify the co-cultured SCMECs' activity. Finally, network pharmacology analysis and siRNA transfection were applied to verify the mechanism of ginsenoside Rg1 promoting angiogenesis.

RESULTS

The rats with SCI treated with ginsenoside Rg1 indicated more significant functional recovery, more pronounced angiogenesis, and higher levels of angiogenic factor expression. In vitro, the co-culture system with ginsenoside Rg1 intervention improved SCMECs' capacity for proliferating, migrating, and forming tubes, possibly by promoting the expression of vascular endothelial growth factor (VEGF) in As via the janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway.

CONCLUSION

Ginsenoside Rg1 can regulate As to promote angiogenesis, which may help to understand the mechanism of promoting SCI recovery.

Ginsenoside-Rh2 Promotes Functional Recovery after Spinal Cord Injury by Enhancing TFEB-Mediated Autophagy

Background: Following spinal cord injury (SCI), autophagy plays a positive role in neuronal protection, whereas pyroptosis triggers an inflammatory response. Ginsenoside-Rh2 (GRh2), known for its neuroprotective effects, is considered a promising drug. However, the exact molecular mechanisms underlying these protective effects remain unclear. Aim of the Study: Explore the therapeutic value of GRh2 in SCI and its potential mechanisms of action. Materials and Methods: An SCI mouse model was established, followed by random grouping and drug treatments under different conditions. Subsequently, the functional recovery of SCI mice after GRh2 treatment was assessed using hematoxylin and eosin, Masson's trichrome, and Nissl staining, footprint analysis, Basso Mouse Scale scoring, and inclined plane tests. The expression levels of relevant indicators in the mice were detected using Western blotting, immunofluorescence, and a quantitative polymerase chain reaction. Network pharmacology analysis was used to identify the relevant signaling pathways through which GRh2 exerts its therapeutic effects. Results: GRh2 promoted functional recovery after SCI. GRh2 significantly inhibits pyroptosis by enhancing autophagy in SCI mice. Simultaneously, the neuroprotective effect of GRh2, achieved through the inhibition of pyroptosis, is partially reversed by 3-methyladenine, an autophagy inhibitor. Additionally, the increase in autophagy induced by GRh2 is mediated by the promotion of transcription factor EB (TFEB) nuclear translocation and dephosphorylation. Partial attenuation of the protective effects of GRh2 was observed after TFEB knockdown. Additionally, GRh2 can modulate the activity of TFEB in mice post-SCI through the EGFR-MAPK signaling pathway, and NSC228155 (an EGFR activator) can partially reverse the effect of GRh2 on the EGFR-MAPK signaling pathway. Conclusions: GRh2 improves functional recovery after SCI by upregulating TFEB-mediated autophagic flux and inhibiting pyroptosis, indicating its potential clinical applicability.

Therapeutic effects of exendin-4 on spinal cord injury via restoring autophagy function and decreasing necroptosis in neuron

AIMS

Necroptosis is one of programmed death that may aggravate spinal cord injury (SCI). We aimed to investigate the effect and mechanism of exendin-4 (EX-4) on the recovery of motor function and necroptosis after SCI.

METHODS

The SD rats with left hemisection in the T10 spinal cord as SCI model were used. The behavior tests were measured within 4 weeks. The effects of EX-4 on necroptosis-associated proteins and autophagy flux were explored. In addition, the SHSY5Y cell model was introduced to explore the direct effect of EX-4 on neurons. The effect of lysosome was explored using mTOR activator and AO staining.

RESULTS

EX-4 could improve motor function and limb strength, promote the recovery of autophagy flux, and accelerate the degradation of necroptosis-related protein at 3 d after injury in rats. EX-4 reduced lysosome membrane permeability, promoted the recovery of lysosome function and autophagy flux, and accelerated the degradation of necroptosis-related proteins by inhibiting the phosphorylation level of mTOR in the SHSY5Y cell model.

CONCLUSION

Our results demonstrated that EX-4 may improve motor function after SCI via inhibiting mTOR phosphorylation level and accelerating the degradation of necroptosis-related proteins in neurons. Our findings may provide new therapeutic targets for clinical treatment after SCI.

Targeted Therapy of Spinal Cord Injury: Inhibition of Apoptosis Is a Promising Therapeutic Strategy

Spinal cord injury (SCI) is a serious disabling central nervous system injury that can lead to motor, sensory, and autonomic dysfunction below the injury level. SCI can be divided into primary injury and secondary injury according to pathological process. Primary injury is mostly irreversible, while secondary injury is a dynamic regulatory process. Apoptosis is an important pathological event of secondary injury and has a significant effect on the recovery of nerve function after SCI. Nerve cell death can further aggravate the microenvironment of the injured site, leading to neurological dysfunction and thus affect the clinical outcome of patients. Therefore, apoptosis plays a crucial role in the pathological progression of secondary SCI, while inhibiting apoptosis may be a promising therapeutic strategy for SCI. This review will summarize and explore the factors that lead to cell death after SCI, the influence of cross talk between signaling pathways and pathways involved in apoptosis and discuss the influence of apoptosis on SCI, and the therapeutic significance of targeting apoptosis on SCI. This review helps us to understand the role of apoptosis in secondary SCI and provides a theoretical basis for the treatment of SCI based on apoptosis.

Injectable, Electroconductive, Free Radical Scavenging Silk Fibroin/Black Phosphorus/Glycyrrhizic Acid Nanocomposite Hydrogel for Enhancing Spinal Cord Repair

Spinal cord injury (SCI) often leads to a severe permanent disability. A poor inflammatory microenvironment and nerve electric signal conduction block are the main reasons for difficulty in spinal cord nerve regeneration. In this study, black phosphorus (BP) and glycyrrhizic acid (GA) are integrated into methacrylate-modified silk fibroin (SF) to construct a bifunctional injectable hydrogel (SF/BP/GA) with appropriate conductivity and the ability to inhibit inflammation to promote neuronal regeneration after SCI. This work discovers that the SF/BP/GA hydrogel can reduce the oxidative damage mediated by oxygen free radicals, promote the polarization of macrophages toward the anti-inflammatory M2 phenotype, reduce the expression of inflammatory factors, and improve the inflammatory microenvironment. Moreover, it induces neural stem cell (NSC) differentiation and neurosphere formation, restores signal conduction at the SCI site in vivo, and ameliorates motor function in mice with spinal cord hemisection, revealing a significant neural repair effect. An injectable, electroconductive, free-radical-scavenging hydrogel is a promising therapeutic strategy for SCI repair.

Microneedle-mediated drug delivery for neurological diseases

Neurological disorders, including brain injury, brain tumors, and neurodegenerative diseases, rank as the second leading cause of death worldwide. Exploring effective new treatments for neurological disorders has long been a hot research issue in clinical practice. Recently, microneedles (MNs) have attracted much attention due to their designation as a "painless and non-invasive" novel transdermal delivery method, characterized by their biocompatibility and sustainability. The advantages of MNs open an avenue for potential therapeutic interventions targeting neurological disorders. This review presents a concise overview of progress in the field of MNs, with highlights on the application in the treatment of neurological disorders. Notably, trends in the development of MNs and future challenges are also discussed.

Characterization of the Expressions and m6A Methylation Modification Patterns of mRNAs and lncRNAs in a Spinal Cord Injury Rat Model

Spinal cord injury (SCI) is a serious central nervous system disease with no effective treatment strategy presently due to its complex pathogenic mechanism. N6-methyladenosine (m6A) methylation modification plays an important role in diverse physiological and pathological processes. However, our understanding of the potential mechanisms of messenger RNA (mRNA) and long non-coding RNAs (lncRNA) m6A methylation in SCI is currently limited. Here, comprehensive m6A profiles and gene expression patterns of mRNAs and lncRNAs in spinal cord tissues after SCI were identified using microarray analysis of immunoprecipitated methylated RNAs. A total of 3745 mRNAs (2343 hypermethylated and 1402 hypomethylated) and 738 lncRNAs (488 hypermethylated and 250 hypomethylated) were differentially methylated with m6A modifications in the SCI and sham rats. Functional analysis revealed that differentially m6A-modified mRNAs were mainly involved in immune inflammatory response, nervous system development, and focal adhesion pathway. In contrast, differentially m6A-modified lncRNAs were mainly related to antigen processing and presentation, the apoptotic process, and the mitogen-activated protein kinases (MAPKs) signaling pathway. In addition, combined analysis of m6A methylation and RNA expression results revealed that 1636 hypermethylated mRNAs and 262 hypermethylated lncRNAs were up-regulated, and 1571 hypomethylated mRNAs and 204 lncRNAs were down-regulated. Furthermore, we validated the altered levels of m6A methylation and RNA expression of five mRNAs (CD68, Gpnmb, Lilrb4, Lamp5, and Snap25) and five lncRNAs (XR_360518, uc.393 + , NR_131064, uc.280 - , and XR_597251) using MeRIP-qPCR and qRT-PCR. This study expands our understanding of the molecular mechanisms underlying m6A modification in SCI and provides novel insights to promote functional recovery after SCI.

Identification and bioinformatics analysis of genes associated with pyroptosis in spinal cord injury of rat and mouse

The mechanism of spinal cord injury (SCI) is highly complex, and an increasing number of studies have indicated the involvement of pyroptosis in the physiological and pathological processes of secondary SCI. However, there is limited bioinformatics research on pyroptosis-related genes (PRGs) in SCI. This study aims to identify and validate differentially expressed PRGs in the GEO database, perform bioinformatics analysis, and construct regulatory networks to explore potential regulatory mechanisms and therapeutic targets for SCI. We obtained high-throughput sequencing datasets of SCI in rats and mice from the GEO database. Differential analysis was conducted using the "limma" package in R to identify differentially expressed genes (DEGs). These genes were then intersected with previously reported PRGs, resulting in a set of PRGs in SCI. GO and KEGG enrichment analyses, as well as correlation analysis, were performed on the PRGs in both rat and mouse models of SCI. Additionally, a protein-protein interaction (PPI) network was constructed using the STRING website to examine the relationships between proteins. Hub genes were identified using Cytoscape software, and the intersection of the top 5 hub genes in rats and mice were selected for subsequent experimentally validated. Furthermore, a competing endogenous RNA (ceRNA) network was constructed to explore potential regulatory mechanisms. The gene expression profiles of GSE93249, GSE133093, GSE138637, GSE174549, GSE45376, GSE171441_3d and GSE171441_35d were selected in this study. We identified 10 and 12 PRGs in rats and mice datasets respectively. Six common DEGs were identified in the intersection of rats and mice PRGs. Enrichment analysis of these DEGs indicated that GO analysis was mainly focused on inflammation-related factors, while KEGG analysis showed that the most genes were enriched on the NOD-like receptor signaling pathway. We constructed a ceRNA regulatory network that consisted of five important PRGs, as well as 24 miRNAs and 34 lncRNAs. This network revealed potential regulatory mechanisms. Additionally, the three hub genes obtained from the intersection were validated in the rat model, showing high expression of PRGs in SCI. Pyroptosis is involved in secondary SCI and may play a significant role in its pathogenesis. The regulatory mechanisms associated with pyroptosis deserve further in-depth research.

Micro/nanomotors for neuromodulation

Micro-nanomotors (MNMs) are micro/nanoscale intelligent devices with vast potential in the fields of drug delivery, precision medicine, biosensing, and environmental remediation. Their primary advantage lies in their ability to convert various forms of external energy (such as magnetic, ultrasonic, and light energy) into their own propulsive force. Additionally, MNMs offer high controllability and modifiability, enabling them to navigate in the microscopic world. Importantly, recent research has harnessed the unique advantages of MNMs to synergize their capabilities in neuromodulation. This mini-review presents the significant progress and pioneering achievements in the use of MNMs for neuromodulation, with the aim of inspiring readers to explore the broader biomedical applications of these MNMs. Through continuous innovation and diligent exploration, MNMs show promise to have a profound impact on the field of biomedicine.

Targeted Repair of Spinal Cord Injury Based on miRNA-124-3p-Loaded Mesoporous Silica Camouflaged by Stem Cell Membrane Modified with Rabies Virus Glycoprotein

Spinal cord injury (SCI) has no effective treatment modalities. It faces a significant global therapeutical challenge, given its features of poor axon regeneration, progressive local inflammation, and inefficient systemic drug delivery due to the blood-spinal cord barrier (BSCB). To address these challenges, a new nano complex that achieves targeted drug delivery to the damaged spinal cord is proposed, which contains a mesoporous silica nanoparticle core loaded with microRNA and a cloaking layer of human umbilical cord mesenchymal stem cell membrane modified with rabies virus glycoprotein (RVG). The nano complex more readily crosses the damaged BSCB with its exosome-resembling properties, including appropriate size and a low-immunogenic cell membrane disguise and accumulates in the injury center because of RVG, where it releases abundant microRNAs to elicit axon sprouting and rehabilitate the inflammatory microenvironment. Culturing with nano complexes promotes axonal growth in neurons and M2 polarization in microglia. Furthermore, it showed that SCI mice treated with this nano complex by tail vein injection display significant improvement in axon regrowth, microenvironment regulation, and functional restoration. The efficacy and biocompatibility of the targeted delivery of microRNA by nano complexes demonstrate their immense potential as a noninvasive treatment for SCI.

Combination use of human menstrual blood stem cell- derived exosomes and hyperbaric oxygen therapy, synergistically promote recovery after spinal cord injury in rats

Traumatic spinal cord injury (TSCI) is one of the catastrophic events in the nervous system that leads to the loss of sensory and motor function of the spinal cord at the site of injury. Considering that several factors such as apoptosis, inflammation, and oxidative stress play a role in the spread of damage caused by trauma, therefore, the treatment should also be based on multifactorial approaches. Currently, we investigated the effects of human menstrual blood stem cells (MenSCs)-derived exosomes in combination with hyperbaric oxygen therapy (HBOT) in the recovery of TSCI in rats. Ninety male mature Sprague-Dawley (SD) rats were planned into five equal groups, including; control group, TSCI group, Exo group (underwent TSCI and received MenSCs -derived exosomes), HBOT group (underwent TSCI and received HBOT), and Exo+HBOT group (underwent TSCI and received MenSCs -derived exosomes plus HBOT). After the behavioral evaluation, tissue samples were obtained for stereological, immunohistochemical, biochemical, and molecular assessments. Our results showed that the numerical density of neurons, the concentrations of antioxidative biomarkers (CAT, GSH, and SOD), and neurological function scores were significantly greater in the treatments group than in the TSCI group, and these changes were more obvious in the Exo+HBOT ones (P<0.05). This is while the numerical densities of apoptotic cells and glial cells, the levels of an oxidative factor (MDA) and proinflammatory cytokines (IL-1β and TNF-α) were considerably decreased in the treatment groups, specially the Exo+HBOT group, compared to the TSCI group (P<0.05). We conclude that the co-administration of exosomes derived from MenSCs and HBOT has more neuroprotective effects in animals with TSCI.

HSP70 protects PC12 cells against TBHP-induced apoptosis and oxidative stress by activating the Nrf2/HO-1 signaling pathway

HSP70 exhibits neuroprotective, antioxidant, and anti-apoptotic properties, which are crucial in preventing spinal cord injury (SCI) induced by oxidative stress and apoptosis. In this study, we assessed the potential protective effects and underlying mechanisms of HSP70 on tert-butyl hydroperoxide (TBHP)-damaged PC12 cells in an in vitro model of SCI. To establish the model, PC12 cells were subjected to oxidative damage induced by TBHP, followed by overexpression of HSP70. Cell viability was assessed using the CCK8 kit, intracellular reactive oxygen species level was evaluated using a commercial kit, cell apoptosis was detected using the Annexin V-APC/7-ADD Apoptosis Detection Kit, and the oxidative stress level was determined using SOD and MDA assay kits. Western blot analysis was used to detect the expression levels of Bax, cleaved caspase-3, and Bcl-2 proteins. Furthermore, immunofluorescence staining and Western bolt were used to detect the expression levels of proteins associated with the Nrf2/HO-1 signaling pathway. We found that HSP70 overexpression reduced apoptosis and oxidative stress in TBHP-induced PC12 cells. Furthermore, it activated the Nrf2/HO-1 signaling pathway. In addition, the Nrf2 inhibitor ML385 attenuated the protective effects of HSP70 on TBHP-induced PC12 cells. In conclusion, HSP70 can partially alleviate TBHP-induced apoptosis and oxidative stress in PC12 cells by promoting the Nrf2/HO-1 signaling pathway.

Transplantation of Wnt5a-modified Bone Marrow Mesenchymal Stem Cells Promotes Recovery After Spinal Cord Injury via the PI3K/AKT Pathway

Spinal cord injury (SCI) is a severe neurological condition that can lead to paralysis or even death. This study explored the potential benefits of bone marrow mesenchymal stem cell (BMSC) transplantation for repairing SCI. BMSCs also differentiate into astrocytes within damaged spinal cord tissues hindering the cell transplantation efficacy, therefore it is crucial to enhance their neuronal differentiation rate to facilitate spinal cord repair. Wnt5a, an upstream protein in the non-classical Wnt signaling pathway, has been implicated in stem cell migration, differentiation, and neurite formation but its role in the neuronal differentiation of BMSCs remains unclear. Thus, this study investigated the role and underlying mechanisms of Wnt5a in promoting neuronal differentiation of BMSCs both in vivo and in vitro. Wnt5a enhanced neuronal differentiation of BMSCs in vitro while reducing astrocyte differentiation. Additionally, high-throughput RNA sequencing revealed a correlation between Wnt5a and phosphoinositide 3-kinase (PI3K)/protein kinase B(AKT) signaling, which was confirmed by the use of the PI3K inhibitor LY294002 to reverse the effects of Wnt5a on BMSC neuronal differentiation. Furthermore, transplantation of Wnt5a-modified BMSCs into SCI rats effectively improved the histomorphology (Hematoxylin and eosin [H&E], Nissl and Luxol Fast Blue [LFB] staining), motor function scores (Footprint test and Basso-Beattie-Bresnahan [BBB]scores)and promoted neuron production, axonal formation, and remodeling of myelin sheaths (microtubule associated protein-2 [MAP-2], growth-associated protein 43 [GAP43], myelin basic protein [MBP]), while reducing astrocyte production (glial fibrillary acidic protein [GFAP]). Therefore, targeting the Wnt5a/PI3K/AKT pathway could enhance BMSC transplantation for SCI treatment.

Long non-coding RNA DANCR increases spinal cord neuron apoptosis and inflammation of spinal cord injury by mediating the microRNA-146a-5p/MAPK6 axis

OBJECTIVE

This research was to unravel the impact of the lncRNA differentiation antagonizing non-protein coding RNA (DANCR)/microRNA (miR)-146a-5p/mitogen-activated protein kinase 6 (MAPK6) axis on spinal cord injury (SCI).

METHODS

SCI mouse models were established and injected with si-DANCR or miR-146a-5p agomir. The recovery of motor function was assessed by Basso Mouse Scale. SCI was pathologically evaluated, and serum inflammatory factors were measured in SCI mice. Mouse spinal cord neurons were injured by H2O2 and transfected, followed by assessment of proliferation and apoptosis. DANCR, miR-146a-5p, and MAPK6 in tissues and cells were detected, as well as their relationship.

RESULTS

DANCR increased and miR-146a-5p decreased in SCI. Silencing DANCR or enhancing miR-146a-5p stimulated the proliferation of mouse spinal cord neurons and reduced apoptosis. DANCR was bound to miR-146a-5p to target MAPK6. DANCR affected the proliferation and apoptosis of spinal cord neurons by mediating the miR-146a-5p/MAPK6 axis. Downregulating DANCR or upregulating miR-146a-5p improved inflammation, the destruction of spinal cord tissue structure, and apoptosis in SCI mice.

CONCLUSION

DANCR affects spinal cord neuron apoptosis and inflammation of SCI by mediating the miR-146a-5p/MAPK6 axis.

Electrical Stimulation and Motor Function Rehabilitation in Spinal Cord Injury: A Systematic Review

Spinal cord injury (SCI) often leads to devastating motor impairments, significantly affecting the quality of life of affected individuals. Over the last decades, spinal cord electrical stimulation seems to have encouraging effects on the motor recovery of impacted patients. This review aimed to identify clinical trials focused on motor function recovery through the application of epidural electrical stimulation, transcutaneous electrical stimulation, and functional electrical stimulation. Several clinical trials met these criteria, focusing on the impact of the aforementioned interventions on walking, standing, swimming, trunk stability, and upper extremity functionality, particularly grasp. After a thorough PubMed online database research, 37 clinical trials were included in this review, with a total of 192 patients. Many of them appeared to have an improvement in function, either clinically assessed or recorded through electromyography. This review outlines the various ways electrical stimulation techniques can aid in the motor recovery of SCI patients. It stresses the ongoing need for medical research to refine these techniques and ultimately enhance rehabilitation results in clinical settings.

Application of"Spinal cord fusion" in spinal cord injury repair and its neurological mechanism

Spinal cord injury (SCI) is a severely disabling and catastrophic condition that poses significant global clinical challenges. The difficulty of SCI repair results from the distinctive pathophysiological mechanisms, which are characterised by limited regenerative capacity and inadequate neuroplasticity of the spinal cord. Additionally, the formation of cystic cavities and astrocytic scars after SCI further obstructs both the ascending and descending neural conduction pathways. Consequently, the urgent challenge in post-SCI recovery lies in repairing the damaged spinal cord to reconstruct a functional and intact neural conduction circuit. In recent years, significant advancements in biological tissue engineering technology and novel therapies have resulted in a transformative shift in the field of SCI repair. Currently, SCI treatment primarily involves drug therapy, stem cell therapy, the use of biological materials, growth factors, and other approaches. This paper comprehensively reviews the progress in SCI research over the years, with a particular focus on the concept of "Spinal Cord Fusion" as a promising technique for SCI reconstruction. By discussing this important research progress and the neurological mechanisms involved, our aim is to help solve the problem of SCI repair as soon as possible and to bring new breakthroughs in the treatment of paraplegia after SCI.

Sp1 Regulates the M1 Polarization of Microglia Through the HuR/NF-κB Axis after Spinal Cord Injury

The M1 polarization of microglia, followed by the production of pro-inflammatory mediators, hinders functional recovery after spinal cord injury (SCI). Our previous study has illuminated that specificity protein 1 (Sp1) expression is increased following SCI, whereas the function and regulatory mechanism of Sp1 during M1 polarization of microglia following SCI remain unknown. RNA binding protein, HuR, has been shown to be up-regulated in the injured spinal cord through analysis of the GEO database. Further investigation using Chip-Atlas data suggests a binding between Sp1 and HuR. Emerging evidence indicates that HuR plays a pivotal role in neuroinflammation after SCI. In this research, Sp1 and HuR levels in mice with SCI and BV2 cells treated with lipopolysaccharide (LPS) was determined by using quantitative real-time polymerase chain reaction and Western blotting techniques. A series of in vitro assays were performed to investigate the function of Sp1 during M1 polarization of microglia. The association between Sp1 and its target gene HuR was confirmed through gene transfection and luciferase reporter assay. Enhanced expression of HuR was observed in both SCI mice and LPS-treated BV2 cells, while Sp1 knockdown restrained M1 polarization of microglia and its associated inflammation by inhibiting the NF-κB signaling pathway. Silencing Sp1 also suppressed microglia activation and its mediated inflammatory response, which could be reversed by overexpression of HuR. In conclusion, silencing Sp1 restrains M1 polarization of microglia through the HuR/NF-κB axis, leading to neuroprotection, and thus promotes functional restoration following SCI.

Hypothermia effects on neuronal plasticity post spinal cord injury

BACKGROUND

SCI is a time-sensitive debilitating neurological condition without treatment options. Although the central nervous system is not programmed for effective endogenous repairs or regeneration, neuroplasticity partially compensates for the dysfunction consequences of SCI.

OBJECTIVE AND HYPOTHESIS

The purpose of our study is to investigate whether early induction of hypothermia impacts neuronal tissue compensatory mechanisms. Our hypothesis is that although neuroplasticity happens within the neuropathways, both above (forelimbs) and below (hindlimbs) the site of spinal cord injury (SCI), hypothermia further influences the upper limbs' SSEP signals, even when the SCI is mid-thoracic.

STUDY DESIGN

A total of 30 male and female adult rats are randomly assigned to four groups (n = 7): sham group, control group undergoing only laminectomy, injury group with normothermia (37°C), and injury group with hypothermia (32°C +/-0.5°C).

METHODS

The NYU-Impactor is used to induce mid-thoracic (T8) moderate (12.5 mm) midline contusive injury in rats. Somatosensory evoked potential (SSEP) is an objective and non-invasive procedure to assess the functionality of selective neuropathways. SSEP monitoring of baseline, and on days 4 and 7 post-SCI are performed.

RESULTS

Statistical analysis shows that there are significant differences between the SSEP signal amplitudes recorded when stimulating either forelimb in the group of rats with normothermia compared to the rats treated with 2h of hypothermia on day 4 (left forelimb, p = 0.0417 and right forelimb, p = 0.0012) and on day 7 (left forelimb, p = 0.0332 and right forelimb, p = 0.0133) post-SCI.

CONCLUSION

Our results show that the forelimbs SSEP signals from the two groups of injuries with and without hypothermia have statistically significant differences on days 4 and 7. This indicates the neuroprotective effect of early hypothermia and its influences on stimulating further the neuroplasticity within the upper limbs neural network post-SCI. Timely detection of neuroplasticity and identifying the endogenous and exogenous factors have clinical applications in planning a more effective rehabilitation and functional electrical stimulation (FES) interventions in SCI patients.

TP53INP2 knockdown inhibits inflammatory response and apoptosis after spinal cord injury

BACKGROUND

Spinal cord injury (SCI) is a traumatic neurological disorder with limited therapeutic options. Tumor protein p53-inducible nuclear protein 2 (TP53INP2) is involved in the occurrence and development of various diseases, and it may play a role during SCI via affecting inflammation and neuronal apoptosis. This study investigated the associated roles and mechanisms of TP53INP2 in SCI.

METHODS

Mouse and lipopolysaccharide (LPS)-induced SCI BV-2 cell models were constructed to explore the role of TP53INP2 in SCI and the associated mechanisms. Histopathological evaluation of spinal cord tissue was detected by hematoxylin and eosin staining. The Basso, Beattie, and Bresnahan score was used to measure the motor function of the mice, while the spinal cord water content was used to assess spinal cord edema. The expression of TP53INP2 was measured using RT-qPCR. In addition, inflammatory factors in the spinal cord tissue of SCI mice and LPS-treated BV-2 cells were measured using enzyme-linked immunosorbent assay. Apoptosis and related protein expression levels were detected by flow cytometry and western blot analysis, respectively.

RESULTS

TP53INP2 levels increased in SCI mice and LPS-treated BV-2 cells. The results of in vivo and in vitro experiments showed that TP53INP2 knockdown inhibited the inflammatory response and neuronal apoptosis in mouse spinal cord tissue or LPS-induced BV-2 cells.

CONCLUSIONS

After spinal cord injury, TP53INP2 was upregulated, and TP53INP2 knockdown inhibited the inflammatory response and apoptosis.

Long Non-Coding RNA MALAT1 Protects Against Spinal Cord Injury via Suppressing microRNA-125b-5p Mediated Microglial M1 Polarization, Neuroinflammation, and Neural Apoptosis

Our previous studies have discovered that long non-coding RNA (lncRNA) MALAT1 and its target microRNA-125b-5p (miR-125b-5p) are implicated in neurological diseases via regulating neuroinflammation and neuronal injury. This study aimed to further explore the relationship between lncRNA MALAT1 and miR-125b-5p, as well as their effect on microglial activation, neuroinflammation, and neural apoptosis in spinal cord injury (SCI). Primary microglia from Sprague Dawley rats were stimulated with lipopolysaccharide (LPS). Then, microglia were transfected with lncRNA MALAT1 overexpression or knock-down adenovirus-associated virus with or without miR-125b-5p mimic. The culture medium of microglia was incubated with primary neurons. SCI rats were established for in vivo validation. LncRNA MALAT1 expression was reduced by LPS treatment in a dose-dependent manner. LncRNA MALAT1 overexpression suppressed the microglial M1 polarization (decreased iNOS but increased ARG1), neuroinflammation (declined PTGS2, TNF-α, IL-1β, and IL-6), and microglia-induced neural apoptosis (lower TUNEL positive cells and C-caspase3 but higher BCL2) under LPS treatment; its knock-down displayed the opposite trend. Moreover, lncRNA MALAT1 directly bound to and negatively regulated miR-125b-5p. MiR-125b-5p mimic promoted microglial M1 polarization, neuroinflammation, and microglia-induced neural apoptosis following LPS treatment; also, it could attenuate the effect of lncRNA MALAT1. Further in vivo study displayed that lncRNA MALAT1 overexpression elevated the Basso-Beattie-Bresnahan motor function score and improved neural injury. Also, in vivo validation indicated a similar effect of lncRNA MALAT1 on microglial polarization and neuroinflammation as in vitro. LncRNA MALAT1 improves SCI recovery via miR-125b-5p mediated microglial M1 polarization, neuroinflammation, and neural apoptosis.

Spinal Cord Injury: Emerging Technologies

The mainstay of treatment for spinal cord injury includes decompressive laminectomy and elevation of mean arterial pressure. However, outcomes often remain poor. Extensive research and ongoing clinical trials seek to design new treatment options for spinal cord injury, including stem cell therapy, scaffolds, brain-spine interfaces, exoskeletons, epidural electrical stimulation, ultrasound, and cerebrospinal fluid drainage. Some of these treatments are targeted at the initial acute window of injury, during which secondary damage occurs; others are designed to help patients living with chronic injuries.

Influence of Blood Pressure on Acute Cervical Spinal Cord Injury Without Fracture and Dislocation: Results From a Retrospective Analysis

OBJECTIVE

The objective of this study was to investigate the influence of blood pressure on the severity and functional recovery of patients with acute cervical spinal cord injury (SCI) without fracture and dislocation.

METHODS

A retrospective case control study analyzed the data of 40 patients admitted to our orthopedics department (Beijing Tiantan Hospital, Capital Medical University) from January 2013 to February 2021. They were diagnosed as acute cervical SCI without fracture and dislocation. Gender, age, height, weight, history of hypertension, postinjury American Spinal Injury Association grade, postinjury modified Japanese Orthopaedic Association (mJOA) score, postoperative mJOA score, 1-year follow-up mJOA score, preoperative mean arterial pressure (MAP), intramedullary T2 hyperintensity, and hyponatremia were collected. The patients were divided into groups and subgroups based on their history of hypertension and preoperative MAP. The effects of history of hypertension and preoperative MAP on the incidence of T2 hyperintensity, hyponatremia, the improvement rate of the postoperative mJOA and 1-year follow-up mJOA scores were analyzed.

RESULTS

Patients with history of hypertension had a lower incidence of intramedullary T2 hyperintensity than patients without history of hypertension (P < 0.05). Patients with history of hypertension and patients with a higher preoperative MAP had better neurological recovery at 1 year of follow-up (P < 0.05).

CONCLUSIONS

Blood pressure has great influence on acute cervical SCI without fracture and dislocation. Maintaining a higher preoperative MAP is advantageous for better recovery after SCI. Attention should be paid to the dynamic management of blood pressure to avoid the adverse effects of hypotension after SCI.

Care needs of adults with spinal trauma in the prehospital and hospital setting from the perspective of patient care team: A qualitative research

BACKGROUND

Appropriate care of patients with definite spinal cord injury or at risk of it in the prehospital and hospital stages requires comprehensive planning in the health system. It is also the requirement of any successful program to explain the needs from the perspective of its stakeholders. Thus, this study aimed to discover the care needs of adults with spinal trauma in prehospital and hospital settings from the perspective of the patient care team.

MATERIALS AND METHODS

This qualitative study was conducted with the participation of urban and rural prehospital emergency personnel and emergency departments of educational and therapeutic hospitals affiliated to Isfahan, Tehran, Shiraz, Kermanshah, Ahvaz, and Yasuj Universities of Medical Sciences, through conducting 36 in-depth semi-structured interviews from September to December 2021. Using purposive sampling method, the participants were selected considering the maximum variation. The data saturation was reached after conducting interviews and group discussions with 36 subjects. Data were analyzed using conventional content analysis approach. Lundman and Graneheim approach were used for the study rigour. Data were simultaneously analyzed using MAXQDA software version 10.

RESULT

During the data analysis, two themes of prehospital care with two main categories (emergency care and management of secondary complications of spinal trauma) and hospital care with two main categories (emergency care and management of secondary complications of spinal trauma) emerged.

CONCLUSION

Emergency care and management of secondary complications of spinal cord injury in the prehospital and hospital stages can affect treatment results, improve quality of life, and reduce mortality rate, secondary injuries, and healthcare costs. Thus, identification of the care needs of the adults with spinal trauma from the perspective of the patient care team can help the authorities to plan appropriate interventions.

Non-stem cell-derived exosomes: a novel therapeutics for neurotrauma

Neurotrauma, encompassing traumatic brain injuries (TBI) and spinal cord injuries (SCI) impacts a significant portion of the global population. While spontaneous recovery post-TBI or SCI is possible, recent advancements in cell-based therapies aim to bolster these natural reparative mechanisms. Emerging research indicates that the beneficial outcomes of such therapies might be largely mediated by exosomes secreted from the administered cells. While stem cells have garnered much attention, exosomes derived from non-stem cells, including neurons, Schwann cells, microglia, and vascular endothelial cells, have shown notable therapeutic potential. These exosomes contribute to angiogenesis, neurogenesis, and axon remodeling, and display anti-inflammatory properties, marking them as promising agents for neurorestorative treatments. This review provides an in-depth exploration of the current methodologies, challenges, and future directions regarding the therapeutic role of non-stem cell-derived exosomes in neurotrauma.

Role of dendritic cells in spinal cord injury

BACKGROUND

Inflammation can worsen spinal cord injury (SCI), with dendritic cells (DCs) playing a crucial role in the inflammatory response. They mediate T lymphocyte differentiation, activate microglia, and release cytokines like NT-3. Moreover, DCs can promote neural stem cell survival and guide them toward neuron differentiation, positively impacting SCI outcomes.

OBJECTIVE

This review aims to summarize the role of DCs in SCI-related inflammation and identify potential therapeutic targets for treating SCI.

METHODS

Literature in PubMed and Web of Science was reviewed using critical terms related to DCs and SCI.

RESULTS

The study indicates that DCs can activate microglia and astrocytes, promote T-cell differentiation, increase neurotrophin release at the injury site, and subsequently reduce secondary brain injury and enhance functional recovery in the spinal cord.

CONCLUSIONS

This review highlights the repair mechanisms of DCs and their potential therapeutic potential for SCI.

Pediatric non-Hodgkin lymphoma as a rare cause of spinal cord injury: When lymphoma hides in the canal

Key Clinical Message

Spinal cord compression from non-Hodgkin lymphoma (NHL) should be considered as a potential diagnosis in cases of acute signs of myelopathy in pediatric patients.

Abstract

Spinal cord compression in pediatric non-Hodgkin lymphoma (NHL) is a rare presentation with potential diagnostic challenges. We report on two pediatric patients with NHL who exhibited myelopathy signs as initial presentation. Considering NHL as a differential diagnosis in pediatric patients presenting with spinal cord compression is crucial for optimizing the outcome of these patients.

microRNA-143 targets SIRT2 to mediate the histone acetylation of PLAUR and modulates functions of astrocytes in spinal cord injury

This study aimed to explore effects of microRNA (miR)-143 on the proliferation, apoptosis, and cytokine secretion in astrocytes after spinal cord injury (SCI). After gain- and loss-of-function assays and transforming growth factor (TGF)-β stimulation in astrocytes, the cell viability, proliferation, and apoptosis were examined. The expression of miR-143, SIRT2, and PLAUR and levels of astrocyte-related glial fibrillary acidic protein (GFAP), Vimentin, chondroitin sulfate proteoglycan (CSPG), and connective tissue growth factor (CTGF) were also measured. The binding relationship between miR-143 and SIRT2 was assessed, as well as the correlation of PLAUR with SIRT2. In established SCI rat models, the locomotion function and astrocyte hyperplasia were detected. The TGF-β stimulation decreased miR-143 but increased SIRT2 expression in astrocytes. Mechanistically, miR-143 negatively targeted SIRT2 and SIRT2 down-regulation inhibited the H3K27 deacetylation of PLAUR promoter to increase PLAUR expression. miR-143 up-regulation inhibited TGF-β stimulated-proliferation, promoted cell apoptosis, and reduced GFAP, Vimentin, CSPG, and CTGF expression in astrocytes, which was counterweighed by SIRT2 overexpression. SIRT2 silencing reduced the proliferation and GFAP, Vimentin, CSPG, and CTGF expression while augmenting the apoptosis in TGF-β stimulated astrocytes, which was abrogated by PLAUR silencing. The injection of miR-143 agomir improved the locomotion function and reduced the astrocyte hyperplasia in SCI rats, which was reversed by silencing PLAUR. miR-143 targeted SIRT2 to affect PLAUR expression via the regulation of histone acetylation, which repressed the astrocyte activation in vivo and in vitro to improve the locomotion function in SCI rats.

Therapeutic Potential of Natural Compounds from Herbs and Nutraceuticals in Alleviating Neurological Disorders: Targeting the Wnt Signaling Pathway

As an important signaling pathway in multicellular eukaryotes, the Wnt signaling pathway participates in a variety of physiological processes. Recent studies have confirmed that the Wnt signaling pathway plays an important role in neurological disorders such as stroke, Alzheimer's disease, and Parkinson's disease. The regulation of Wnt signaling by natural compounds in herbal medicines and nutraceuticals has emerged as a potential strategy for the development of new drugs for neurological disorders. Purpose: The aim of this review is to evaluate the latest research results on the efficacy of natural compounds derived from herbs and nutraceuticals in the prevention and treatment of neurological disorders by regulating the Wnt pathway in vivo and in vitro. A manual and electronic search was performed for English articles available from PubMed, Web of Science, and ScienceDirect from the January 2010 to February 2023. Keywords used for the search engines were "natural products,″ "plant derived products,″ "Wnt+ clinical trials,″ and "Wnt+,″ and/or paired with "natural products″/″plant derived products", and "neurological disorders." A total of 22 articles were enrolled in this review, and a variety of natural compounds from herbal medicine and nutritional foods have been shown to exert therapeutic effects on neurological disorders through the Wnt pathway, including curcumin, resveratrol, and querctrin, etc. These natural products possess antioxidant, anti-inflammatory, and angiogenic properties, confer neurovascular unit and blood-brain barrier integrity protection, and affect neural stem cell differentiation, synaptic formation, and neurogenesis, to play a therapeutic role in neurological disorders. In various in vivo and in vitro studies and clinical trials, these natural compounds have been shown to be safe and tolerable with few adverse effects. Natural compounds may serve a therapeutic role in neurological disorders by regulating the Wnt pathway. This summary of the research progress of natural compounds targeting the Wnt pathway may provide new insights for the treatment of neurological disorders and potential targets for the development of new drugs.

Neuroprotective effects of tetramethylpyrazine on spinal cord injury-Related neuroinflammation mediated by P2X7R/NLRP3 interaction

OBJECTIVE

The inflammatory response is acknowledged as a crucial pathological aspect of spinal cord injury (SCI). Tetramethylpyrazine (TMP) has been demonstrated to possess neuroprotective properties within the central nervous system via its anti-inflammatory mechanisms. This study aims to investigate the molecular mechanism by which TMP alleviates SCI from an anti-inflammatory standpoint.

METHODS

The SCI model was established using the MASCIS impactor device. The Basso-Beattie-Bresnahan (BBB) locomotor rating scale was utilised to assess rat locomotion. Nissl and Golgi staining were used to observe neuron and dendritic spine morphology, respectively. A transmission electron microscope was used to observe the microcosmic morphology of the axon. ELISA kits were used to measure the concentrations of IL-1β and IL-18 in the spinal cord. Immunofluorescence staining was used to detect P2X7R+/IBA-1+ cells, and Western blot and RT-qPCR were used to analyze the protein and mRNA expression of P2X7R in the spinal cord. Additionally, Western blot was used to detect NLRP3 and Cleaved-Caspase-1 (p20), the critical proteins in the NLRP3 inflammasome pathway.

RESULTS

TMP ameliorated the microcosmic morphology of the axon and had an inhibitory effect on the concentrations of IL-1β and IL-18 after SCI. Furthermore, TMP inhibited the expression of both P2X7R and critical proteins of the NLRP3 inflammasome pathway on microglia after SCI. The aforementioned effects of TMP exhibit similarities to those of BBG (P2X7R antagonist); however, they can be effectively reversed by BzATP (P2X7R activator).

CONCLUSION

TMP alleviated SCI via reducing tissue damage, neuroinflammation, and the expression of P2X7R, NLRP3, IL-1β, and IL-18.

Transcriptome profile analysis in spinal cord injury rats with transplantation of menstrual blood-derived stem cells

Introduction

Menstrual blood-derived stem cells (MenSCs) are vital in treating many degenerative and traumatic disorders. However, the underlying molecular mechanisms remain obscure in MenSCs-treating spinal cord injury (SCI) rats.

Methods

MenSCs were adopted into the injured sites of rat spinal cords at day 7 post surgery and the tissues were harvested for total RNA sequencing analysis at day 21 after surgery to investigate the expression patterns of RNAs. The differentially expressed genes (DEGs) were analyzed with volcano and heatmap plot. DEGs were sequentially analyzed by weighted gene co-expression network, functional enrichment, and competitive endogenous RNAs (ceRNA) network analysis. Next, expression of selected miRNAs, lncRNAs, circRNAs and mRNAs were validated by quantitative real-time polymerase chain reaction (qRT-PCR). Bioinformatics packages and extra databases were enrolled to scoop the genes functions and their interaction relationships.

Results

A total of 89 lncRNAs, 65 circRNAs, 120 miRNAs and 422 mRNAs were significantly upregulated and 65 lncRNAs, 72 circRNAs, 74 miRNAs, and 190 mRNAs were significantly downregulated in the MenSCs treated rats compared to SCI ones. Current investigation revealed that MenSCs treatment improve the recovery of the injured rats and the most significantly involved pathways in SCI regeneration were cell adhesion molecules, nature killer cell mediated cytotoxicity, primary immunodeficiency, chemokine signaling pathway, T cell receptor signaling pathway and B cell receptor signaling pathway. Moreover, the lncRNA-miRNA-mRNA and circRNA-miRNA-mRNA ceRNA network of SCI was constructed. Finally, the protein-protein interaction (PPI) network was constructed using the top 100 DE mRNAs. The constructed PPI network included 47 nodes and 70 edges.

Discussion

In summary, the above results revealed the expression profile and potential functions of differentially expressed (DE) RNAs in the injured spinal cords of rats in the MenSCs-treated and SCI groups, and this study may provide new clues to understand the mechanisms of MenSCs in treating SCI.

METTL3 promotes microglial inflammation via MEF2C in spinal cord injury

Spinal cord injury (SCI) is a significant contributor to disability in contemporary society, resulting in substantial psychological and economic burdens for patients and their family. Microglia-mediated inflammation is an important factor affecting the nerve repair of SCI patients. N6-methyladenosine (m6A) is a prevalent epigenetic modification in mammals, which shows a strong association with inflammation. However, the mechanism of m6A modification regulating microglia-mediated inflammation is still unclear. Here, we observed that METTL3, a m6A methylase, was increased in SCI mice and lipopolysaccharide (LPS)-exposed BV2 cells. Knockdown of METTL3 inhibited the increased expression of iNOS and IL-1β induced by LPS in vitro. Subsequently, MEF2C, myocyte-specific enhancer factor 2C, was decreased in SCI mice and LPS-exposed BV2 cells. Knockdown of MEF2C promoted the expression of iNOS and IL-1β. Sequence analysis showed that there were multiple highly confident m6A modification sites on the MEF2C mRNA. METTL3 antibody could pull down a higher level of MEF2C mRNA than the IgG in RNA binding protein immunoprecipitation assay. Knockdown of METTL3 promoted MEF2C protein expression and MEF2C mRNA expression, accompanied by a reduced m6A modification level on the MEF2C mRNA. Knockdown of MEF2C inhibited the anti-inflammatory effect of METTL3 siRNA. Our results suggest that METTL3 promotes microglia inflammation via regulating MEF2C mRNA m6A modification induced by SCI and LPS treatment.

Combined effect of trifluoperazine and sodium cromoglycate on reducing acute edema and limiting lasting functional impairments after spinal cord injury in rats

Edema formation is one of the very first events to occur after spinal cord injury (SCI) leading to an increase of the intrathecal pressure and consequently to serious spinal tissue and functional impairments. Current edema treatments are still symptomatic and/or non-specific. Since edema formation mechanisms are mainly described as vasogenic and cytotoxic, it becomes crucial to understand the interplay between these two subtypes. Acting on key targets to inhibit edema formation may reduce secondary damage and related functional impairments. In this study, we characterize the edema kinetic after T9-10 spinal contusion. We use trifluoperazine (TFP) to block the expression and the functional subcellular localization of aquaporin-4 supposed to be implicated in the cytotoxic edema formation. We also use sodium cromoglycate (SCG) to deactivate mast cell degranulation known to be implicated in the vasogenic edema formation. Our results show a significant reduction of edema after TFP treatment and after TFP-SCG combined treatment compared to control. This reduction is correlated with limited onset of initial sensorimotor impairments particularly after combined treatment. Our results highlight the importance of potential synergetic targets in early edema therapy after SCI as part of tissue sparing strategies.

Effects of Valproic Acid Therapy on Rats with Spinal Cord Injury: A Systematic Review and Meta-Analysis

OBJECTIVE

To systematically evaluate the efficacy of valproic acid (VPA) in rats with spinal cord injury (SCI) to reduce the risk of clinical conversion and provide a valuable reference for future animal and clinical studies.

METHODS

We searched scientific databases, including PubMed, Ovid-Embase, Web of Science, and Scopus databases. The relevant literature was searched from the establishment date of the database to June 28, 2023. The search results were screened, data were extracted, and the quality of the literature was evaluated independently by 2 reviewers.

RESULTS

Among 656 nonduplicated references, 14 articles were included for meta-analysis. The summary results showed that the overall Basso, Beattie and Bresnahan scores of the VPA intervention group were significantly higher than those in the control group at 1-6 weeks after VPA intervention. Subgroup analysis showed that the injury model, administration dose, rat strain, country of study, or follow-up duration had no significant effect on the efficacy of VPA on rats with SCI. In addition, mesh analysis showed that high doses of the VPA group had a better effect on SCI rats, compared with the low dose group and the medium dose group.

CONCLUSIONS

To date, this is the first systematic evaluation of the potential effects of VPA on motor recovery in rats with SCI. We concluded that VPA can promote motor recovery in rats with SCI, and higher doses of VPA seem to be more effective in rats with SCI. However, the limited quality and sample of included studies reduced the application of this meta-analysis. In the future, more high-quality, direct comparative studies are needed to explore this issue in depth.

Small Extracellular Vesicles Released from miR-211-5p-Overexpressed Bone Marrow Mesenchymal Stem Cells Ameliorate Spinal Cord Injuries in Rats

Spinal cord injury (SCI) has become one of the common and serious diseases affecting patients' motor functions. The small extracellular vesicles secreted by bone marrow mesenchymal stem cells (BMSCs) have shown a promising prospect for the treatment of neurological diseases. BMSCs were collected from rat bones. Osteogenic and adipogenic differentiation of BMSCs was further determined. Small extracellular vesicles were obtained by high-speed centrifugation. Dual-luciferase reporter assay was performed to demonstrate the targeting of miR-211-5p to the cyclooxygenase 2 (COX2) mRNA. qRT-PCR and Western blot assay were used for the detection of the mRNA and protein expression. ELISA was performed to estimate the levels of proinflammatory factors in spinal cord tissues. Our results showed that miR-211-5p targeted COX2 mRNA and regulated the protein expression of COX2 in BMSCs. Extracellular vesicles released from miR-211-5p-overexpressed BMSCs ameliorated SCI-induced motor dysfunction and motor evoked potential impairments. Extracellular vesicles released from miR-211-5p-overexpressed BMSCs ameliorated SCI-induced COX2 expression and related inflammatory responses. In conclusion, small extracellular vesicles released from miR-211-5p-overexpressed BMSCs ameliorate spinal cord injuries in rats.

Microarray analysis of lncRNAs and mRNAs in spinal cord contusion rats with iPSC-derived A2B5+ oligodendrocyte precursor cells transplantation

Spinal cord injury (SCI) is a severe complication of spinal trauma with high disability and mortality rates. Effective therapeutic methods to alleviate neurobehavioural deficits in patients with SCI are still lacking. In this study, we established a spinal cord contusion (SCC) model in adult Sprague Dawley rats. Induced pluripotent stem cell-derived A2B5+ oligodendrocyte precursor cells (iP-A2B5+OPCs) were obtained from mouse embryonic fibroblasts and injected into the lesion sites of SCC rats. Serological testing and magnetic resonance imaging were employed to determine the effect of iP-A2B5+OPCs cell therapy. The Basso-Beattie-Bresnahan score and inclined plane test were performed on days 1, 3, 7, and 14 after cell transplantation, respectively. Differentially expressed long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) were detected by microarray analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed to analyse the biological functions of these lncRNAs and mRNAs. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to verify variations in the expression of crucial target genes. The results demonstrated that induced pluripotent stem cells exhibited embryonic stem cell-like morphology and could differentiate into diverse neural cells dominated by oligodendrocytes. The neurobehavioural performance of rats treated with iP-A2B5+OPCs transplantation was better than that of rats with SCC without cell transplantation. Notably, we found that 22 lncRNAs and 42 mRNAs were concurrently altered after cell transplantation, and the key lncRNA (NR_037671) and target gene (Cntnap5a) were identified in the iP-A2B5+OPCs group. Moreover, RT-qPCR revealed that iP-A2B5+OPCs transplantation reversed the downregulation of NR_037671 induced by SCC. Our findings indicated that iP-A2B5+OPCs transplantation effectively improves neurological function recovery after SCC, and the mechanism might be related to alterations in the expression of lncRNAs and mRNAs, such as NR_037671 and Cntnap5a.

Circular RNA HIPK2 Promotes A1 Astrocyte Activation after Spinal Cord Injury through Autophagy and Endoplasmic Reticulum Stress by Modulating miR-124-3p-Mediated Smad2 Repression

Glial scarring formed by reactive astrocytes after spinal cord injury (SCI) is the primary obstacle to neuronal regeneration within the central nervous system, making them a promising target for SCI treatment. Our previous studies have demonstrated the positive impact of miR-124-3p on neuronal repair, but it remains unclear how miR-124-3p is involved in autophagy or ER stress in astrocyte activation. To answer this question, the expression of A1 astrocyte-related markers at the transcriptional and protein levels after SCI was checked in RNA-sequencing data and verified using quantitative polymerase chain reaction (qPCR) and Western blotting in vitro and in vivo. The potential interactions among circHIPK2, miR-124-3p, and Smad2 were analyzed and confirmed by bioinformatics analyses and a luciferase reporter assay. In the end, the role of miR-124-3p in autophagy, ER stress, and SCI was investigated by using Western blotting to measure key biomarkers (C3, LC3, and Chop) in the absence or presence of corresponding selective inhibitors (siRNA, 4-PBA, TG). As a result, SCI caused the increase of A1 astrocyte markers, in which the upregulated circHIPK2 directly targeted miR-124-3p, and the direct downregulating effect of Smad2 by miR-124-3p was abolished, while Agomir-124 treatment reversed this effect. Injury caused a significant change of markers for ER stress and autophagy through the circHIPK2/miR-124-3p/Smad2 pathway, which might activate the A1 phenotype, and ER stress might promote autophagy in astrocytes. In conclusion, circHIPK2 may play a functional role in sequestering miR-124-3p and facilitating the activation of A1 astrocytes through regulating Smad2-mediated downstream autophagy and ER stress pathways, providing a new perspective on potential targets for functional recovery after SCI.

Exosome-mediated repair of spinal cord injury: a promising therapeutic strategy

Spinal cord injury (SCI) is a catastrophic injury to the central nervous system (CNS) that can lead to sensory and motor dysfunction, which seriously affects patients' quality of life and imposes a major economic burden on society. The pathological process of SCI is divided into primary and secondary injury, and secondary injury is a cascade of amplified responses triggered by the primary injury. Due to the complexity of the pathological mechanisms of SCI, there is no clear and effective treatment strategy in clinical practice. Exosomes, which are extracellular vesicles of endoplasmic origin with a diameter of 30-150 nm, play a critical role in intercellular communication and have become an ideal vehicle for drug delivery. A growing body of evidence suggests that exosomes have great potential for repairing SCI. In this review, we introduce exosome preparation, functions, and administration routes. In addition, we summarize the effect and mechanism by which various exosomes repair SCI and review the efficacy of exosomes in combination with other strategies to repair SCI. Finally, the challenges and prospects of the use of exosomes to repair SCI are described.

Folic acid-functionalized chitosan nanoparticles with bioenzyme activity for the treatment of spinal cord injury

Spinal cord injury (SCI) is a central system disease with a high rate of disability. Pathological changes such as ischemia and hypoxia of local tissues, oxidative stress and apoptosis could lead to limb pain, paralysis and even life-threatening. It was reported that catalase (CAT) was the main antioxidant in organisms, which could remove reactive oxygen species (ROS) and release oxygen (O2). However, the efficacy of the drug is largely limited due to its poor stability, low bioavailability and inability to cross the blood spinal cord barrier (BSCB). Therefore, in this study, we prepared folic acid-functionalized chitosan nanoparticles to deliver CAT (FA-CSNCAT) for solving this problem. In vivo small animal imaging results showed that FA-CSN could carry CAT across the BSCB and target to the inflammatory site. In addition, Immunofluorescence, ROS assay and JC-1 probe were used to detect the therapeutic effect of FA-CSNCAT in vitro and in vivo. The results showed that FA-CSNCAT could alleviate the hypoxic environment at the injured site and remove ROS, thereby inhibiting oxidative stress and protecting neurons, which may provide a new idea for clinical medication of SCI.

Spinal cord injury: Olfactory ensheathing cell-based therapeutic strategies

Spinal cord injury (SCI) is a highly disabling neurological disorder that is difficult to treat due to its complex pathophysiology and nerve regeneration difficulties. Hence, effective SCI treatments are necessary. Olfactory ensheathing cells (OECs), glial cells derived from the olfactory bulb or mucosa, are ideal candidates for SCI treatment because of their neuroprotective and regenerative properties, ample supply, and convenience. In vitro, animal model, and human trial studies have reported discoveries on OEC transplantation; however, shortcomings have also been demonstrated. Recent studies have optimized various OEC transplantation strategies, including drug integration, biomaterials, and gene editing. This review aims to introduce OECs mechanisms in repairing SCI, summarize the research progress of OEC transplantation-optimized strategies, and provide novel research ideas for SCI treatment.

An Insight into the Prospects and Drawbacks of Stem Cell Therapy for Spinal Cord Injuries: Ongoing Trials and Future Directions

Spinal cord injury (SCI) is a devastating neurological disorder that has a substantial detrimental impact on a person's quality of life. The estimated global incidence of SCI is 40 to 80 cases per million people and around 90% of cases are traumatic. Various etiologies can be recognized for SCI, and post-traumatic SCI represents the most common of these. Patients worldwide with SCI suffer from a persistent loss of motor and sensory function, which affects every aspect of their personal and social lives. Given the lack of effective treatments, many efforts have been made to seek a cure for this condition. In recent years, thanks to their ability to regenerate tissue and repair lost or damaged cells, much attention has been directed toward the use of stem cells (embryonic, induced pluripotent, mesenchymal, hematopoietic), aimed at restoring the functional integrity of the damaged spinal cord and improving a functional recovery including sensory and motor function. In this paper, we offer an overview of the benefits and drawbacks of stem cell therapy for SCI based on clinical evidence. This report also addresses the characteristics of various stem cell treatments, as well as the field's likely future. Each cell type targets specific pathological characteristics associated with SCI and demonstrates therapeutic effects via cell replacement, nutritional support, scaffolds, and immunomodulation pathways. SCI accompanied by complex pathological processes cannot be resolved by single treatment measures. Stem cells are associated with the adjustment of the expression of neurotrophic factors that help to achieve better nutrition to damaged tissue. Single-cell treatments have been shown in some studies to provide very minor benefits for SCI in multiple preclinical studies and a growing number of clinical trials. However, SCI damage is complex, and many studies are increasingly recognizing a combination approach such as physical therapy, electrical stimulation, or medication therapy to treatment.

Advances in Conductive Hydrogel for Spinal Cord Injury Repair and Regeneration

Spinal cord injury (SCI) treatment represents a major challenge in clinical practice. In recent years, the rapid development of neural tissue engineering technology has provided a new therapeutic approach for spinal cord injury repair. Implanting functionalized electroconductive hydrogels (ECH) in the injury area has been shown to promote axonal regeneration and facilitate the generation of neuronal circuits by reshaping the microenvironment of SCI. ECH not only facilitate intercellular electrical signaling but, when combined with electrical stimulation, enable the transmission of electrical signals to electroactive tissue and activate bioelectric signaling pathways, thereby promoting neural tissue repair. Therefore, the implantation of ECH into damaged tissues can effectively restore physiological functions related to electrical conduction. This article focuses on the dynamic pathophysiological changes in the SCI microenvironment and discusses the mechanisms of electrical stimulation/signal in the process of SCI repair. By examining electrical activity during nerve repair, we provide insights into the mechanisms behind electrical stimulation and signaling during SCI repair. We classify conductive biomaterials, and offer an overview of the current applications and research progress of conductive hydrogels in spinal cord repair and regeneration, aiming to provide a reference for future explorations and developments in spinal cord regeneration strategies.

Spinal cord injury: global burden from 1990 to 2019 and projections up to 2030 using Bayesian age-period-cohort analysis

Background

Spinal cord injuries, often resulting from spine fractures, can lead to severe lifelong symptoms such as paraplegia and even mortality. Over the past few decades, there has been a concerning increase in the annual incidence and mortality rates of spinal cord injuries, which has also placed a growing financial strain on healthcare systems. This review aims to offer a comprehensive overview of spinal cord injuries by estimating their global incidence, prevalence, and the impact in terms of years lived with disability, using data obtained from the 2019 Global Burden of Disease Study.

Method

In this study, we utilized data from the 2019 Global Burden of Disease Study, a widely recognized source for global health data. Our methodology involved estimating the global incidence and prevalence of spinal cord injuries while also assessing the impact on years lived with a disability. We analyzed this data comprehensively to identify patterns and trends and made predictions.

Finding

This research delved into the evolving trends in the global burden of spinal cord injuries, identified key risk factors, and examined variations in incidence and disability across different Socio-demographic Index (SDI) levels and age groups. Briefly, in 2019, the global incidence and burden of YLDs of SCI significantly increased compared to 1990. While males had higher incidence rates compared to females. Falls were identified as the primary cause of SCI. Trend projections up to 2030 revealed a slight decrease in ASIR for males, an upward trend in age-specific incidence rates for both sexes and a similar pattern in age-standardized YLD rates. Additionally, our findings provided crucial groundwork for shaping future policies and healthcare initiatives, with the goal of mitigating the burden of spinal cord injuries, enhancing patient outcomes, and fortifying prevention efforts.

Interpretation

Understanding the global burden of spinal cord injuries is essential for designing effective healthcare policies and prevention strategies. With the alarming increase in prevalence rates and their significant impact on individuals and healthcare systems, this research contributes vital insights to guide future efforts in reducing the incidence of spinal cord injuries, improving the quality of life for affected individuals, and reducing the economic burden on healthcare systems worldwide.

Tanshinone IIA protects motor neuron-like NSC-34 cells against lipopolysaccharide-induced cell injury by the regulation of the lncRNA TCTN2/miR-125a-5p/DUSP1 axis

Background

Tanshinone IIA (TSIIA) exerts a protective role in spinal cord injury (SCI). However, the mechanism of TSIIA activity in SCI remains to be elucidated.

Methods

Cell viability and apoptosis were gauged by CCK-8 assay and flow cytometry, respectively. The expression levels of lncRNA TCTN2, miR-125a-5p and DUSP1 were detected by qRT-PCR and western blot. Direct relationship between miR-125a-5p and TCTN2 or DUSP1 was verified by dual-luciferase reporter assay.

Results

In mouse NSC-34 cells, LPS reduced the expression of TCTN2. TSIIA alleviated cell injury induced by LPS and increased TCTN2 expression in LPS-exposed NSC-34 cells. TCTN2 was a downstream mediator of TSIIA activity. TCTN2 targeted miR-125a-5p, and TCTN2 over-expression attenuated LPS-induced cell damage in NSC-34 cells by down-regulating miR-125a-5p. TCTN2 functioned as a post-transcriptional regulator of DUSP1 expression through miR-125a-5p. DUSP1 was a functional target of miR-125a-5p in controlling NSC-34 cell injury induced by LPS. TSIIA inhibited miR-125a-5p expression and increased the level of DUSP1 protein in LPS-exposed NSC-34 cells.

Conclusion

Our study establishes a novel mechanism, the TCTN2/miR-125a-5p/DUSP1 axis, at least in part, for the protective activity of TSIIA in cell injury induced by LPS.

TRIM32 Inhibits NEK7 Ubiquitylation-Dependent Microglia Pyroptosis After Spinal Cord Injury

Spinal cord injury (SCI) is a disabling disease associated with microglial activation. Tripartite motif containing 32 (TRIM32) is an E3 ubiquitin ligase that plays a role in SCI. This study aimed to explore the role of TRIM32 in SCI and its potential mechanisms. We established an SCI mouse model to assess the function of TRIM32 using quantitative real-time polymerase chain reaction (qPCR), and hematoxylin and eosin staining. Additionally, a lipopolysaccharides (LPS)-induced cell injury model was generated to explore the impact of TRIM32 on pyroptosis using qPCR, propidium iodide staining, and western blotting. The ubiquitylation of NEK7 was analyzed using western blotting, co-immunoprecipitation, and immunofluorescence staining. The results showed that TRIM32 expression was increased in SCI mice and LPS-induced BV-2 cells. Overexpression of TRIM32 ameliorated SCI in mice and suppressed pyroptosis in LPS-treated BV-2 cells. Additionally, the E3 ligase TRIM32 promoted the ubiquitylation of NEK7 at the K64 site, leading to the downregulation of NEK7 levels. Inhibiting NEK7 ubiquitylation reversed the suppression of pyroptosis by TRIM32. In conclusion, TRIM32 inhibits microglia pyroptosis by facilitating the ubiquitylation of NEK7 at the K64 site, thereby alleviating the progression of SCI. The findings suggest that TRIM32 has the potential to be a therapeutic target of SCI.

Application of Injectable Hydrogels as Delivery Systems in Spinal Cord Injury

Spinal cord injury (SCI) is a severe neurological injury caused by traffic accidents, trauma, or falls, which leads to significant loss of sensory, motor, and autonomous functions and seriously affects the patient's life quality. Although considerable progress has been made in mitigating secondary injury and promoting the regeneration/repair of SCI, the therapeutic effects need to be improved due to drug availability. Given their good biocompatibility, biodegradability, and low immunogenicity, injectable hydrogels can be used as delivery systems to achieve controlled release of drugs and other substances (cells and proteins, etc.), offering new hope for SCI repair. In this article, we summarized the types of injectable hydrogels, analyzed their application as delivery systems in SCI, and further discussed the mechanisms of hydrogels in the treatment of SCI, such as anti-inflammatory, antioxidant, anti-apoptosis, and pro-neurogenesis. Moreover, we highlighted the potential benefits of hydrogels in the treatment of SCI in combination with therapies, including the recent advances and achievements of these promising tools. Our review may offer new strategies for the development of SCI treatments based on injectable hydrogels as delivery systems.

Serum glucose/potassium ratio as a clinical risk factor for predicting the severity and prognosis of acute traumatic spinal cord injury

OBJECTIVE

Acute traumatic Spinal cord injury (TSCI) is a devastating event that causes severe sensory and motor impairments as well as autonomic dysfunction in patients, yet relevant clinical biomarkers have not been established. This study aimed to determine the significance of the serum glucose/potassium ratio (GPR) in evaluating TSCI severity and predicting prognosis.

METHODS

An analysis of 520 clinical records of acute TSCI patients from January 2012 to June 2022 was conducted. The relationships between serum GPR and The American Spinal Injury Association Impairment Scale (AIS) grade 6-month post-trauma prognosis and the admission AIS grade were analyzed. To evaluate the discriminatory ability, a receiver operating characteristic curve (ROC) analysis was used. All methods were performed in accordance with the relevant guidelines and regulations.

RESULTS

Based on the initial assessment of AIS grade, 256 (49.2%) patients were categorized into the severe TSCI group (AIS A-B), and there was a significant correlation between the severe TSCI group and serum GPR (p < 0.001). Serum GPR was reduced in an AIS grade-dependent manner (R = - 0.540, p < 0.001). Of the 520 patients, 262 (50.4%) patients were classified as having a poor prognosis according to the AIS grade at discharge. Serum GPR was also reduced in an AIS grade at discharge-dependent manner (R = - 0.599, p < 0.001), and was significantly higher in the poor prognosis group compared to the good prognosis group (p < 0.001). Poor prognosis was significantly associated with sex (p = 0.009), severity of TSCI (p < 0.001), location of TSCI (p < 0.001), surgical decompression (p < 0.018), body temperature (p < 0.001), heart rate (p < 0.001), systolic arterial pressure (SAP) (p < 0.001), diastolic arterial pressure (DAP) (p < 0.001), serum GPR (p < 0.001), serum glucose (p < 0.001), serum potassium (p < 0.001), and white blood cell count (p = 0.003). Multivariate logistic regression analysis showed a significant correlation between poor prognosis and serum GPR (p = 0.023). The ROC analysis showed the area under the curve of serum GPR to be a poor predictor of prognosis in TSCI patients at 0.842 (95% confidence interval, 0.808-0.875).

CONCLUSION

There was a significant relationship between serum GPR and admission injury severity and the 6-month prognosis of acute TSCI patients. Serum GPR serves as a readily available clinical risk factor for predicting the severity and 6-month prognosis of acute traumatic spinal cord injury, which holds potential clinical significance for patients with TSCI.

Pregnane X receptor (PXR) deficiency protects against spinal cord injury by activating NRF2/HO-1 pathway

INTRODUCTION

As a devastating neurological disease, spinal cord injury (SCI) results in severe tissue loss and neurological dysfunction. Pregnane X receptor (PXR) is a ligand-activated nuclear receptor with a major regulatory role in xenobiotic and endobiotic metabolism and recently has been implicated in the central nervous system. In the present study, we aimed to investigate the role and mechanism of PXR in SCI.

METHODS

The clip-compressive SCI model was performed in male wild-type C57BL/6 (PXR+/+ ) and PXR-knockout (PXR-/- ) mice. The N2a H2 O2 -induced injury model mimicked the pathological process of SCI in vitro. Pregnenolone 16α-carbonitrile (PCN), a mouse-specific PXR agonist, was used to activate PXR in vivo and in vitro. The siRNA was applied to knock down the PXR expression in vitro. Transcriptome sequencing analysis was performed to discover the relevant mechanism, and the NRF2 inhibitor ML385 was used to validate the involvement of PXR in influencing the NRF2/HO-1 pathway in the SCI process.

RESULTS

The expression of PXR decreased after SCI and reached a minimum on the third day. In vivo, PXR knockout significantly improved the motor function of mice after SCI, meanwhile, inhibited apoptosis, inflammation, and oxidative stress induced by SCI. On the contrary, activation of PXR by PCN negatively influenced the recovery of SCI. Mechanistically, transcriptome sequencing analysis revealed that PXR activation downregulated the mRNA level of heme oxygenase-1 (HO-1) after SCI. We further verified that PXR deficiency activated the NRF2/HO-1 pathway and PXR activation inhibited this pathway in vitro.

CONCLUSION

PXR is involved in the recovery of motor function after SCI by regulating NRF2/HO-1 pathway.

A Novel Magnetic Responsive miR-26a@SPIONs-OECs for Spinal Cord Injury: Triggering Neural Regeneration Program and Orienting Axon Guidance in Inhibitory Astrocytic Environment

Addressing the challenge of promoting directional axonal regeneration in a hostile astrocytic scar, which often impedes recovery following spinal cord injury (SCI), remains a daunting task. Cell transplantation is a promising strategy to facilitate nerve restoration in SCI. In this research, a pro-regeneration system is developed, namely miR-26a@SPIONs-OECs, for olfactory ensheathing cells (OECs), a preferred choice for promoting nerve regeneration in SCI patients. These entities show high responsiveness to external magnetic fields (MF), leading to synergistic multimodal cues to enhance nerve regeneration. First, an MF stimulates miR-26a@SPIONs-OECs to release extracellular vesicles (EVs) rich in miR-26a. This encourages axon growth by inhibiting PTEN and GSK-3β signaling pathways in neurons. Second, miR-26a@SPIONs-OECs exhibit a tendency to migrate and orientate along the direction of the MF, thereby potentially facilitating neuronal reconnection through directional neurite elongation. Third, miR-26a-enriched EVs from miR-26a@SPIONs-OECs can interact with host astrocytes, thereby diminishing inhibitory cues for neurite growth. In a rat model of SCI, the miR-26a@SPIONs-OECs system led to significantly improved morphological and motor function recovery. In summary, the miR-26a@SPIONS-OECs pro-regeneration system offers innovative insights into engineering exogenous cells with multiple additional cues, augmenting their efficacy for stimulating and guiding nerve regeneration within a hostile astrocytic scar in SCI.

Electroacupuncture Relieves HuR/KLF9-Mediated Inflammation to Enhance Neurological Repair after Spinal Cord Injury

Electroacupuncture (EA) is widely applied in clinical therapy for spinal cord injury (SCI). However, the associated molecular mechanism has yet to be elucidated. The current study aimed to investigate the underlying mechanism of EA in neurologic repair after SCI. First, we investigated the role of EA in the neurologic repair of the SCI rat model. The expression levels of human antigen R (HuR) and Krüppel-like factor 9 (KLF9) in spinal cord tissues were quantified after treatment. Second, we conducted bioinformatics analysis, RNA pull-down assays, RNA immunoprecipitation, and luciferase reporter gene assay to verify the binding of HuR and KLF9 mRNA for mRNA stability. Last, HuR inhibitor CMLD-2 was used to verify the enhanced effect of EA on neurologic repair after SCI via the HuR/KLF9 axis. Our data provided convincing evidence that EA facilitated the recovery of neuronal function in SCI rats by reducing apoptosis and inflammation of neurons. We found that EA significantly diminished the SCI-mediated upregulation of HuR, and HuR could bind to the 3' untranslated region of KLF9 mRNA to protect its decay. In addition, a series of in vivo experiments confirmed that CMLD-2 administration increased EA-mediated pain thresholds and motor function in SCI rats. Collectively, the present study showed that EA improved pain thresholds and motor function in SCI rats via impairment of HuR-mediated KLF9 mRNA stabilization, thus providing a better understanding of the regulatory mechanisms regarding EA-mediated neurologic repair after SCI.