Microenvironment Imbalance of Spinal Cord Injury

Mutual regulation of microglia and astrocytes after Gas6 inhibits spinal cord injury

JOURNAL/nrgr/04.03/01300535-202502000-00032/figure1/v/2024-05-28T214302Z/r/image-tiff Invasive inflammation and excessive scar formation are the main reasons for the difficulty in repairing nervous tissue after spinal cord injury. Microglia and astrocytes play key roles in the spinal cord injury micro-environment and share a close interaction. However, the mechanisms involved remain unclear. In this study, we found that after spinal cord injury, resting microglia (M0) were polarized into pro-inflammatory phenotypes (MG1 and MG3), while resting astrocytes were polarized into reactive and scar-forming phenotypes. The expression of growth arrest-specific 6 (Gas6) and its receptor Axl were significantly down-regulated in microglia and astrocytes after spinal cord injury. In vitro experiments showed that Gas6 had negative effects on the polarization of reactive astrocytes and pro-inflammatory microglia, and even inhibited the cross-regulation between them. We further demonstrated that Gas6 can inhibit the polarization of reactive astrocytes by suppressing the activation of the Yes-associated protein signaling pathway. This, in turn, inhibited the polarization of pro-inflammatory microglia by suppressing the activation of the nuclear factor-κB/p65 and Janus kinase/signal transducer and activator of transcription signaling pathways. In vivo experiments showed that Gas6 inhibited the polarization of pro-inflammatory microglia and reactive astrocytes in the injured spinal cord, thereby promoting tissue repair and motor function recovery. Overall, Gas6 may play a role in the treatment of spinal cord injury. It can inhibit the inflammatory pathway of microglia and polarization of astrocytes, attenuate the interaction between microglia and astrocytes in the inflammatory microenvironment, and thereby alleviate local inflammation and reduce scar formation in the spinal cord.

Screening biomarkers for spinal cord injury using weighted gene co-expression network analysis and machine learning

JOURNAL/nrgr/04.03/01300535-202412000-00028/figure1/v/2024-04-08T165401Z/r/image-tiff Immune changes and inflammatory responses have been identified as central events in the pathological process of spinal cord injury. They can greatly affect nerve regeneration and functional recovery. However, there is still limited understanding of the peripheral immune inflammatory response in spinal cord injury. In this study, we obtained microRNA expression profiles from the peripheral blood of patients with spinal cord injury using high-throughput sequencing. We also obtained the mRNA expression profile of spinal cord injury patients from the Gene Expression Omnibus (GEO) database (GSE151371). We identified 54 differentially expressed microRNAs and 1656 differentially expressed genes using bioinformatics approaches. Functional enrichment analysis revealed that various common immune and inflammation-related signaling pathways, such as neutrophil extracellular trap formation pathway, T cell receptor signaling pathway, and nuclear factor-κB signal pathway, were abnormally activated or inhibited in spinal cord injury patient samples. We applied an integrated strategy that combines weighted gene co-expression network analysis, LASSO logistic regression, and SVM-RFE algorithm and identified three biomarkers associated with spinal cord injury: ANO10, BST1, and ZFP36L2. We verified the expression levels and diagnostic performance of these three genes in the original training dataset and clinical samples through the receiver operating characteristic curve. Quantitative polymerase chain reaction results showed that ANO10 and BST1 mRNA levels were increased and ZFP36L2 mRNA was decreased in the peripheral blood of spinal cord injury patients. We also constructed a small RNA-mRNA interaction network using Cytoscape. Additionally, we evaluated the proportion of 22 types of immune cells in the peripheral blood of spinal cord injury patients using the CIBERSORT tool. The proportions of naïve B cells, plasma cells, monocytes, and neutrophils were increased while the proportions of memory B cells, CD8+ T cells, resting natural killer cells, resting dendritic cells, and eosinophils were markedly decreased in spinal cord injury patients increased compared with healthy subjects, and ANO10, BST1 and ZFP26L2 were closely related to the proportion of certain immune cell types. The findings from this study provide new directions for the development of treatment strategies related to immune inflammation in spinal cord injury and suggest that ANO10, BST1, and ZFP36L2 are potential biomarkers for spinal cord injury. The study was registered in the Chinese Clinical Trial Registry (registration No. ChiCTR2200066985, December 12, 2022).

Ruxolitinib improves the inflammatory microenvironment, restores glutamate homeostasis, and promotes functional recovery after spinal cord injury

JOURNAL/nrgr/04.03/01300535-202419110-00030/figure1/v/2024-03-08T184507Z/r/image-tiff The inflammatory microenvironment and neurotoxicity can hinder neuronal regeneration and functional recovery after spinal cord injury. Ruxolitinib, a JAK-STAT inhibitor, exhibits effectiveness in autoimmune diseases, arthritis, and managing inflammatory cytokine storms. Although studies have shown the neuroprotective potential of ruxolitinib in neurological trauma, the exact mechanism by which it enhances functional recovery after spinal cord injury, particularly its effect on astrocytes, remains unclear. To address this gap, we established a mouse model of T10 spinal cord contusion and found that ruxolitinib effectively improved hindlimb motor function and reduced the area of spinal cord injury. Transcriptome sequencing analysis showed that ruxolitinib alleviated inflammation and immune response after spinal cord injury, restored EAAT2 expression, reduced glutamate levels, and alleviated excitatory toxicity. Furthermore, ruxolitinib inhibited the phosphorylation of JAK2 and STAT3 in the injured spinal cord and decreased the phosphorylation level of nuclear factor kappa-B and the expression of inflammatory factors interleukin-1β, interleukin-6, and tumor necrosis factor-α. Additionally, in glutamate-induced excitotoxicity astrocytes, ruxolitinib restored EAAT2 expression and increased glutamate uptake by inhibiting the activation of STAT3, thereby reducing glutamate-induced neurotoxicity, calcium influx, oxidative stress, and cell apoptosis, and increasing the complexity of dendritic branching. Collectively, these results indicate that ruxolitinib restores glutamate homeostasis by rescuing the expression of EAAT2 in astrocytes, reduces neurotoxicity, and effectively alleviates inflammatory and immune responses after spinal cord injury, thereby promoting functional recovery after spinal cord injury.

Ferroptosis in the neurovascular unit after spinal cord injury

The mechanisms of secondary injury following spinal cord injury are complicated. The role of ferroptosis, which is a newly discovered form of regulated cell death in the neurovascular unit(NVU), is increasingly important. Ferroptosis inhibitors have been shown to improve neurovascular homeostasis and attenuate secondary spinal cord injury(SCI). This review focuses on the mechanisms of ferroptosis in NVU cells and NVU-targeted therapeutic strategies according to the stages of SCI, and analyzes possible future research directions.

Modulatory effects of gut microbiota on innate and adaptive immune responses following spinal cord injury

Spinal cord injury (SCI) represents a highly debilitating trauma to the central nervous system, currently lacking effective therapeutic strategies. The cascade of inflammatory responses induced by secondary damage following SCI disrupts the local immune environment at the injury site, ultimately exacerbating functional impairments post-injury. With advancing research on the gut-brain axis, evidence suggests that dysbiosis of the gut microbiota post-SCI amplifies inflammatory responses and plays a pivotal role in modulating post-injury immune-inflammatory responses. In this review article, we will explore the significant role of the gut microbiota and its metabolic products in modulating the responses of central and peripheral immune cells post-SCI, as well as their potential as therapeutic interventions for SCI treatment.

Functional biomaterials for modulating the dysfunctional pathological microenvironment of spinal cord injury

Spinal cord injury (SCI) often results in irreversible loss of sensory and motor functions, and most SCIs are incurable with current medical practice. One of the hardest challenges in treating SCI is the development of a dysfunctional pathological microenvironment, which mainly comprises excessive inflammation, deposition of inhibitory molecules, neurotrophic factor deprivation, glial scar formation, and imbalance of vascular function. To overcome this challenge, implantation of functional biomaterials at the injury site has been regarded as a potential treatment for modulating the dysfunctional microenvironment to support axon regeneration, remyelination at injury site, and functional recovery after SCI. This review summarizes characteristics of dysfunctional pathological microenvironment and recent advances in biomaterials as well as the technologies used to modulate inflammatory microenvironment, regulate inhibitory microenvironment, and reshape revascularization microenvironment. Moreover, technological limitations, challenges, and future prospects of functional biomaterials to promote efficient repair of SCI are also discussed. This review will aid further understanding and development of functional biomaterials to regulate pathological SCI microenvironment.

Intercellular Mitochondrial Transfer: The Novel Therapeutic Mechanism for Diseases

Mitochondria, the dynamic organelles responsible for energy production and cellular metabolism, have the metabolic function of extracting energy from nutrients and synthesizing crucial metabolites. Nevertheless, recent research unveils that intercellular mitochondrial transfer by tunneling nanotubes, tumor microtubes, gap junction intercellular communication, extracellular vesicles, endocytosis and cell fusion may regulate mitochondrial function within recipient cells, potentially contributing to disease treatment, such as nonalcoholic steatohepatitis, glioblastoma, ischemic stroke, bladder cancer and neurodegenerative diseases. This review introduces the principal approaches to intercellular mitochondrial transfer and examines its role in various diseases. Furthermore, we provide a comprehensive overview of the inhibitors and activators of intercellular mitochondrial transfer, offering a unique perspective to illustrate the relationship between intercellular mitochondrial transfer and diseases.

Protocatechuic aldehyde promotes the functional recovery of spinal cord injury by activating the Wnt/β-catenin signaling pathway

CONTEXT/OBJECTIVE

This study aimed to explore the anti-inflammatory and neuroprotective effects of protocatechuic aldehyde (PCA) in rats with spinal cord injury (SCI) and to clarify the molecular mechanisms underlying its pharmacological effects.

DESIGN

Male Sprague Dawley rat model of moderate spinal cord contusion were established.

SETTING

Third-class first-class hospital.

OUTCOME MEASURES

The Basso, Beattie, and Bresnahan scores and performance on the inclined plane test were evaluated. Histological analyses were performed via hematoxylin and eosin staining. Apoptosis in the spinal cord and neurons was detected by 5 terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling staining. Apoptotic factors (Bax, Bcl-2, and cleaved caspase-3) were also evaluated. INOS, IL-1β, IL-10, TNF-α, Wnt-3α, β-catenin, iBA-1, and NeuN were assessed by real-time reverse transcription-polymerase chain reaction (RT-PCR), western blotting (WB), and enzyme-linked immunosorbent assay. Cell viability and the immunofluorescence of IL-1β were measured in PC-12 cells.

RESULTS

Using WB and quantitative reverse transcription-PCR, we confirmed that PCA treatment activated the Wnt/β-catenin signaling axis in vivo and in vitro. Hematoxylin and eosin staining and hindlimb motor functional evaluation revealed that treatment with PCA improved tissue protection and functional recovery via the Wnt/β-catenin axis. The upregulation of TUNEL-positive cells, downregulation of neurons, elevated apoptosis-associated factors in rats, and increased apoptotic rates were observed in microglia and PC-12 after PCA application. Finally, PCA mitigated SCI-induced inflammation by targeting the Wnt/β-catenin axis.

CONCLUSION

This study provided preliminary evidence that PCA inhibits neuroinflammation and apoptosis through the Wnt/β-catenin pathway, thereby attenuating the secondary injury after SCI and promoting the regeneration of injured spinal tissues.

The Role of Exosomes from Mesenchymal Stem Cells in Spinal Cord Injury: A Systematic Review

Spinal cord injury (SCI) is a serious nervous system disease that usually leads to the impairment of the motor, sensory, and autonomic nervous functions of the spinal cord, and it places a heavy burden on families and healthcare systems every year. Due to the complex pathophysiological mechanism of SCI and the poor ability of neurons to regenerate, the current treatment scheme has very limited effects on the recovery of spinal cord function. In addition, due to their unique advantages, exosomes can be used as carriers for cargo transport. In recent years, some studies have confirmed that treatment with mesenchymal stem cells (MSCs) can promote the recovery of SCI nerve function. The therapeutic effect of MSCs is mainly related to exosomes secreted by MSCs, and exosomes may have great potential in SCI therapy. In this review, we summarized the repair mechanism of mesenchymal stem cells-derived exosomes (MSCs-Exos) in SCI treatment and discussed the microRNAs related to SCI treatment based on MSCs-Exos and their mechanism of action, which is helpful to further understand the role of exosomes in SCI.

UAMC-3203 inhibits ferroptosis and promotes functional recovery in rats with spinal cord injury

Spinal cord injury (SCI) results in irreversible neurological impairment. After SCI, Ferritinophagy-induced free iron released from ferritin can lead to extensive lipid peroxidation and aggravate neurological damage. NRF2/HO-1 pathway is to endow cells with a protective effect against oxidative stress, and it plays an important role in the transcriptional activation of a series of antioxidant and detoxification genes. UAMC-3203 is a ferrostatin-1(Fer-1) analogue with better solubility and stability, which can more effectively inhibit ferroptosis after SCI. A rat SCI model was constructed, and the recovery of motor function was observed after treatment with UAMC-3203. ELISA was employed to assess the impact of UAMC-3203 on inflammation-related factors, while immunofluorescence was utilized to investigate the influence of UAMC-3203 on neuronal count as well as the activation of astrocytes and microglia/macrophages. Malondialdehyde (MDA) were detected to reflect the level of oxidation products. Western blot analysis was used to measure the level of ferroptosis markers and the expression of NRF2/HO-1. Our findings demonstrate that UAMC-3203 inhibits the production of reactive oxygen species (ROS) and lipid peroxides, preventing ferroptosis and reducing neuronal degeneration. Additionally, UAMC-3203 suppresses astrocyte proliferation and microglia/macrophage activation, as well as the release of ferroptosis-related inflammatory factors. These combined effects contribute to the preservation of spinal cord tissue and the facilitation of motor function recovery. UAMC-3203 maybe inhibit ferroptosis after SCI to promote functional recovery.

The anti-inflammatory and immunomodulatory effects of olfactory ensheathing cells transplantation in spinal cord injury and concomitant pathological pain

Spinal cord injury (SCI) is a serious and disabling injury that is often accompanied by neuropathic pain (NeP), which severely affects patients' motor and sensory functions and reduces their quality of life. Currently, there is no specific treatment for treating SCI and relieving the accompanying pain, and we can only rely on medication and physical rehabilitation, both of which are ineffective. Researchers have recently identified a novel class of glial cells, olfactory ensheathing cells (OECs), which originate from the olfactory system. Transplantation of OECs into damaged spinal cords has demonstrated their capacity to repair damaged nerves, improve the microenvironment at the point of injury, and They can also restore neural connectivity and alleviate the patient's NeP to a certain extent. Although the effectiveness of OECs transplantation has been confirmed in experiments, the specific mechanisms by which it repairs the spinal cord and relieves pain have not been articulated. Through a review of the literature, it has been established that the ability of OECs to repair and relieve pain is inextricably linked to its anti-inflammatory and immunomodulatory effects. In this regard, it is imperative to gain a deeper understanding of how OECs exert their anti-inflammatory and immunomodulatory effects. The objective of this paper is to provide a comprehensive overview of the mechanisms by which OECs exert anti-inflammatory and immunomodulatory effects. We aim to manipulate the immune microenvironment at the transplantation site through the intervention of cytokines and immune cells, with the goal of enhancing OECs' function or creating a conducive microenvironment for OECs' survival. This approach is expected to improve the therapeutic efficacy of OECs in clinical settings. However, numerous fundamental and clinical challenges remain to be addressed if OEC transplantation therapy is to become a standardized treatment in clinical practice.

Hypoxic-preconditioned mesenchymal stem cell-derived small extracellular vesicles inhibit neuronal death after spinal cord injury by regulating the SIRT1/Nrf2/HO-1 pathway

Background

Oxidative stress and apoptosis of neurons significantly contribute to the pathophysiological cascade of spinal cord injury (SCI). However, the role of hypoxic-preconditioned mesenchymal stem cell-derived small extracellular vesicles (H-sEVs) in promoting SCI repair remains unclear. Hence, the present study aims to investigate the regulatory effects of H-sEVs on neuronal oxidative stress and apoptotic responses following SCI.

Methods

The administration of H-sEVs of SCI rats was assessed using behavioral evaluations such as Basso-Beattie-Bresnahan (BBB) scores, neuroelectrophysiological monitoring, and Catwalk gait analysis. Indices of oxidative stress (including superoxide dismutase [SOD], total antioxidant capacity [T-AOC], and malondialdehyde [MDA]) were measured. Neuronal survival was evaluated through Nissl staining, while the expression level of sirtuin 1 (SIRT1) was examined using immunohistochemical staining. Additionally, histological evaluation of lesion size was performed using hematoxylin-eosin (HE) staining. Tunel cell apoptosis staining and analysis of apoptosis-associated proteins (B-cell lymphoma-2 [Bcl2] and BCL2-Associated X [Bax]) were conducted through immunofluorescence staining and western blot, respectively. Furthermore, the model of oxidative stress was established using PC12 cells, and apoptosis levels were assessed via flow cytometry and western blot analysis. Importantly, to ascertain the critical role of SIRT1, we performed SIRT1 knockout experiments in PC12 cells using lentivirus transfection, followed by western blot.

Results

Using those behavioral evaluations, we observed significant functional improvement after H-sEVs treatment. Nissl staining revealed that H-sEVs treatment promoted neuronal survival. Moreover, we found that H-sEVs effectively reduced oxidative stress levels after SCI. HE staining demonstrated that H-sEVs could reduce lesion area. Immunohistochemical analysis revealed that H-sEVs enhanced SIRT1 expression. Furthermore, Tunel cell apoptosis staining and western blot analysis of apoptosis-related proteins confirmed the anti-apoptotic effects of H-sEVs. The PC12 cells were used to further substantiate the neuroprotective properties of H-sEVs by significantly inhibiting neuronal death and attenuating oxidative stress. Remarkably, SIRT1 knockout in PC12 cells reversed the antioxidant stress effects induced by H-sEVs treatment. Additionally, we elucidated the involvement of the downstream Nrf2/HO-1 signaling pathway.

Conclusion

Our study provides valuable insights into the effects of H-sEVs on neuronal oxidative stress and apoptosis after SCI. These findings underscore the potential clinical significance of H-sEVs-based therapies for SCI.

The Emerging Roles of Hydrogen Sulfide in Ferroptosis

Significance: Ferroptosis, a form of regulated cell death characterized by a large amount of lipid peroxidation-mediated membrane damage, joins the evolution of multisystem diseases, for instance, neurodegenerative diseases, chronic obstructive pulmonary disease, acute respiratory distress syndrome, osteoporosis, osteoarthritis, and so forth. Since being identified as the third gasotransmitter in living organisms, the intricate role of hydrogen sulfide (H2S) in ferroptosis has emerged at the forefront of research. Recent Advances: Novel targets in the relevant metabolic pathways have been found, including transferrin receptor 1, cystine/glutamate antiporter, and others, coupled with the exploration of new signaling pathways, particularly the p53 signaling pathway, the nitric oxide/nuclear factor erythroid 2-related factor 2 signaling pathway, and so on. Many diseases such as emphysema and airway inflammation, myocardial diseases, endothelial dysfunction in aging arteries, and traumatic brain injury have recently been found to be alleviated directly by H2S inhibition of ferroptosis. Safe, effective, and tolerable novel H2S donors have been developed and have shown promising results in phase I clinical trials. Critical Issues: Complicated cross talk between the ferroptosis signaling pathway and oncogenic factors results in the risk of cancer when inhibiting ferroptosis. Notably, targeted delivery of H2S is still a challenging task. Future Directions: Discovering more reliable and stable novel H2S donors and achieving their targeted delivery will enable further clinical trials for diseases associated with ferroptosis inhibition by H2S, determining their safety, efficacy, and tolerance.

Design and preparation of hydrogel microspheres for spinal cord injury repair

A severe disorder known as spinal cord damage causes both motor and sensory impairment in the limbs, significantly reducing the patients' quality of life. After a spinal cord injury, functional recovery and therapy have emerged as critical concerns. Hydrogel microspheres have garnered a lot of interest lately because of their enormous promise in the field of spinal cord injury rehabilitation. The material classification of hydrogel microspheres (natural and synthetic macromolecule polymers) and their synthesis methods are examined in this work. This work also covers the introduction of several kinds of hydrogel microspheres and their use as carriers in the realm of treating spinal cord injuries. Lastly, the study reviews the future prospects for hydrogel microspheres and highlights their limitations and problems. This paper can offer feasible ideas for researchers to advance the application of hydrogel microspheres in the field of spinal cord injury.

Identification of coagulation diagnostic biomarkers related to the severity of spinal cord injury

BACKGROUND

Blood always shows coagulation changes after spinal cord injury (SCI), and identifying these blood changes may be helpful for diagnosis and treatment of SCI. Nevertheless, studies to date on blood coagulation changes after SCI in humans are not comprehensive. Therefore, this study aims to identify blood coagulation diagnostic biomarkers and immune changes related to SCI and its severity levels.

METHODS

Human blood sequencing datasets were obtained from public databases. Differentially expressed coagulation-related genes were analyzed (DECRGs). Enrichment analysis and assessment of immune changes were conducted. Weighted gene co-expression network analysis, least absolute shrinkage and selection operator logistic regression were used to identify biomarkers. Validation for these biomarkers was performed. The correlation between biomarkers and immune cells was evaluated. Transcription factors, miRNA, lncRNA, and drugs that can regulate biomarkers were analyzed.

RESULTS

DECRGs associated with SCI and its different grades were identified, showing enrichment in altered coagulation and immune-related signaling pathways. ADAM9, CD55, and STAT4 were identified as coagulation diagnostic biomarkers for SCI. IRF4 and PABPC4 were identified as coagulation diagnostic biomarkers for American Spinal Injury Association Impairment Scale (AIS) A grade of SCI. GP9 was designated as a diagnostic biomarker for AIS D grade of SCI. Immune changes in blood of SCI and its different grades were observed. Correlation between diagnostic biomarkers and immune cells were identified. Transcription factors, miRNA, lncRNA, and drugs that can regulate diagnostic biomarker expression were discovered.

CONCLUSION

Therefore, detecting the expression of these putative diagnostic biomarkers and related immune changes may be helpful for predicting the severity of SCI. Uncovering potential regulatory mechanisms for biomarkers may be beneficial for further research.

Metformin enhances endogenous neural stem cells proliferation, neuronal differentiation, and inhibits ferroptosis through activating AMPK pathway after spinal cord injury

BACKGROUND

Inadequate nerve regeneration and an inhibitory local microenvironment are major obstacles to the repair of spinal cord injury (SCI). The activation and differentiation fate regulation of endogenous neural stem cells (NSCs) represent one of the most promising repair approaches. Metformin has been extensively studied for its antioxidative, anti-inflammatory, anti-aging, and autophagy-regulating properties in central nervous system diseases. However, the effects of metformin on endogenous NSCs remains to be elucidated.

METHODS

The proliferation and differentiation abilities of NSCs were evaluated using CCK-8 assay, EdU/Ki67 staining and immunofluorescence staining. Changes in the expression of key proteins related to ferroptosis in NSCs were detected using Western Blot and immunofluorescence staining. The levels of reactive oxygen species, glutathione and tissue iron were measured using corresponding assay kits. Changes in mitochondrial morphology and membrane potential were observed using transmission electron microscopy and JC-1 fluorescence probe. Locomotor function recovery after SCI in rats was assessed through BBB score, LSS score, CatWalk gait analysis, and electrophysiological testing. The expression of the AMPK pathway was examined using Western Blot.

RESULTS

Metformin promoted the proliferation and neuronal differentiation of NSCs both in vitro and in vivo. Furthermore, a ferroptosis model of NSCs using erastin treatment was established in vitro, and metformin treatment could reverse the changes in the expression of key ferroptosis-related proteins, increase glutathione synthesis, reduce reactive oxygen species production and improve mitochondrial membrane potential and morphology. Moreover, metformin administration improved locomotor function recovery and histological outcomes following SCI in rats. Notably, all the above beneficial effects of metformin were completely abolished upon addition of compound C, a specific inhibitor of AMP-activated protein kinase (AMPK).

CONCLUSION

Metformin, driven by canonical AMPK-dependent regulation, promotes proliferation and neuronal differentiation of endogenous NSCs while inhibiting ferroptosis, thereby facilitating recovery of locomotor function following SCI. Our study further elucidates the protective mechanism of metformin in SCI, providing new mechanistic insights for its candidacy as a therapeutic agent for SCI.

Acellular spinal cord scaffold containing quercetin-encapsulated nanoparticles plays an anti-inflammatory role in functional recovery from spinal cord injury in rats

Inflammatory responses play a crucial role in the pathophysiology of spinal cord injury (SCI) and developing new approaches to establish an anti-inflammatory environment for the promotion of neuroregeneration holds promise as a potential approach. In this study, our aim was to investigate the potential of combining an acellular spinal cord scaffold (ASCS) with quercetin-loaded bovine serum albumin (Qu/BSA) nanoparticles (NPs) for the treatment of SCI. The ASCS was prepared using physical and chemical methods, while the Qu/BSA NPs were prepared through a desolvation technique. The NPs exhibited favorable characteristics, including a mean size of 203 nm, a zeta potential of -38, and an encapsulation efficiency of 96%. Microscopic evaluation confirmed the successful distribution of NPs on the walls of ASCS. Animal studies revealed that Qu/BSA NPs group exhibited a significant decrease in NLRP3, ASC, and Casp1 gene expression compared to the SCI group (p < 0.0001). The findings indicated a significant decrease in the NLRP3, ASC, and Casp1 protein level between the Qu/BSA/ASCS group and the SCI group (p < 0.0001). Moreover, treatment with ASCS containing either blank BSA (B/BSA) NPs or Qu/BSA NPs effectively promoted functional recovery via increasing the amount of nestin- and glial fibrillary acidic protein (GFAP)-positive cells in the site of injury. Notably, Qu/BSA/ASCS exhibited superior outcomes compared to B/BSA/ASCS. Overall, the combination of ASCS with the Qu delivery system presents a promising therapeutic approach for SCI by inhibiting inflammatory responses and promoting neuroregeneration, leading to the restoration of motor function in animals. This study demonstrates the potential of utilizing biomaterials and NPs to enhance the effectiveness of SCI treatment.

Schwann Cell-Derived Exosomes Induced Axon Growth after Spinal Cord Injury by Decreasing PTP-σ Activation on CSPGs via the Rho/ROCK Pathway

Spinal cord injury (SCI) is a severe neurological condition that involves a lengthy pathological process. This process leads to the upregulation of chondroitin sulfate proteoglycans (CSPGs) by reactive glia, which impedes repair and regeneration in the spinal cord. The role of the CSPG-specific receptor protein tyrosine phosphatase-sigma (PTP-σ) in post-SCI remains largely unexplored. Exosomes have great potential in the diagnosis, prognosis, and treatment of SCI due to their ability to easily cross the blood‒brain barrier. Schwann cell-derived exosomes (SCDEs) promote functional recovery in mice post-SCI by decreasing CSPG deposition. However, the mechanism by which SCDEs decrease CSPGs after SCI remains unknown. Herein, we observed elevated levels of PTP-σ and increased CSPG deposition during glial scar formation after SCI in vivo. After SCDEs were injected into SCI mice, CSPG deposition decreased in scar tissue at the injury site, the expression of PTP-σ increased during axonal growth around the injury site, and motor function subsequently recovered. Additionally, we demonstrated that the use of both Rho/ROCK inhibitors and SCDEs inhibited the reparative effects of SCDEs on scar tissue after SCI. In conclusion, our study revealed that treatment with SCDEs targeting the Rho/ROCK signaling pathway reduced PTP-σ activation in the CSPG post-SCI, which inhibited scar tissue formation.

Fucoidan improving spinal cord injury recovery: Modulating microenvironment and promoting remyelination

INTRODUCTION

Excessive neuroinflammation, apoptosis, glial scar, and demyelination triggered by spinal cord injury (SCI) are major obstacles to SCI repair. Fucoidan, a natural marine plant extract, possesses broad-spectrum anti-inflammatory and immunomodulatory effects and is regarded as a potential therapeutic for various diseases, including neurological disorders. However, its role in SCI has not been investigated.

METHODS

In this study, we established an SCI model in mice and intervened in injury repair by daily intraperitoneal injections of different doses of fucoidan (10 and 20 mg/kg). Concurrently, primary oligodendrocyte precursor cells (OPCs) were treated in vitro to validate the differentiation-promoting effect of fucoidan on OPCs. Basso Mouse Scale (BMS), Louisville Swim Scale (LSS), and Rotarod test were carried out to measure the functional recovery. Immunofluorescence staining, and transmission electron microscopy (TEM) were performed to assess the neuroinflammation, apoptosis, glial scar, and remyelination. Western blot analysis was conducted to clarify the underlying mechanism of remyelination.

RESULTS

Our results indicate that in the SCI model, fucoidan exhibits significant anti-inflammatory effects and promotes the transformation of pro-inflammatory M1-type microglia/macrophages into anti-inflammatory M2-type ones. Fucoidan enhances the survival of neurons and axons in the injury area and improves remyelination. Additionally, fucoidan promotes OPCs differentiation into mature oligodendrocytes by activating the PI3K/AKT/mTOR pathway.

CONCLUSION

Fucoidan improves SCI repair by modulating the microenvironment and promoting remyelination.

The role of TNF-α in osteoporosis, bone repair and inflammatory bone diseases: A review

Tumour necrosis factor alpha (TNF-α) is a pleiotropic cytokine synthesised primarily by mononuclear cells; it has a potent pro-inflammatory effect, playing a crucial role in metabolic, immune, and inflammatory diseases. This cytokine has been studied in various biological systems. In bone tissue, TNF-α plays an integral role in skeletal disorders such as osteoporosis, fracture repair and rheumatoid arthritis through its involvement in regulating the balance between osteoblasts and osteoclasts, mediating inflammatory responses, promoting angiogenesis and exacerbating synovial proliferation. The biological effect TNF-α exerts in this context is determined by a combination of the signalling pathway it activates, the type of receptor it binds, and the concentration and duration of exposure. This review summarises the participation and pathophysiological role of TNF-α in osteoporosis, bone damage repair, chronic immunoinflammatory bone disease and spinal cord injury, and discusses its main mechanisms.

ROS-responsive nanoparticle delivery of ferroptosis inhibitor prodrug to facilitate mesenchymal stem cell-mediated spinal cord injury repair

Spinal cord injury (SCI) is a traumatic condition that results in impaired motor and sensory function. Ferroptosis is one of the main causes of neural cell death and loss of neurological function in the spinal cord, and ferroptosis inhibitors are effective in reducing inflammation and repairing SCI. Although human umbilical cord mesenchymal stem cells (Huc-MSCs) can ameliorate inflammatory microenvironments and promote neural regeneration in SCI, their efficacy is greatly limited by the local microenvironment after SCI. Therefore, in this study, we constructed a drug-release nanoparticle system with synergistic Huc-MSCs and ferroptosis inhibitor, in which we anchored Huc-MSCs by a Tz-A6 peptide based on the CD44-targeting sequence, and combined with the reactive oxygen species (ROS)-responsive drug nanocarrier mPEG-b-Lys-BECI-TCO at the other end for SCI repair. Meanwhile, we also modified the classic ferroptosis inhibitor Ferrostatin-1 (Fer-1) and synthesized a new prodrug Feborastatin-1 (Feb-1). The results showed that this treatment regimen significantly inhibited the ferroptosis and inflammatory response after SCI, and promoted the recovery of neurological function in rats with SCI. This study developed a combination therapy for the treatment of SCI and also provides a new strategy for the construction of a drug-coordinated cell therapy system.

Tangeretin alleviates inflammation and oxidative response induced by spinal cord injury by activating the Sesn2/Keap1/Nrf2 pathway

Spinal cord injury (SCI) is a severe disabling disease that is characterized by inflammation and oxidative reactions. Tangeretin has been shown to possess significant antioxidant and anti-inflammatory activities. The Keap1/Nrf2 pathway, downstream of the Sesn2 gene, is involved in regulating the inflammation and oxidative response. The main objective of this study was to investigate the effect of tangeretin on SCI and its possible mechanism through cell and animal models. A T9 clamp injury was used for the mouse model and the LPS-induced stimulation of BV-2 cells was used for the cell model. The improvement of motor function after SCI was assessed by open field, swimming, and footprint experiments. The morphological characteristics of mouse spinal cord tissue and the levels of INOS, Sesn2, TNF-α, Keap1, Nrf2, IL-10, and reactive oxygen species (ROS) in vivo and in vitro were measured by several methods including western blotting, qPCR, immunofluorescence, HE, and Nissl staining. In vivo data showed that tangeretin can improve motor function recovery and reduce neuron loss and injury size in mice with SCI. Simultaneously, the in vitro findings suggested that treatment of BV-2 cells with tangeretin after LPS stimulation reduced the production of inflammatory factors and ROS, and could convert BV-2 cells from the M1 to the M2 type. Furthermore, Sesn2 knockout suppressed Keap1/Nrf2, inflammatory factors, ROS levels, and the M1 to M2 transition. Tangeretin can alleviate the inflammation and oxidative response induced by SCI by activating the Sesn2/Keap1/Nrf2 pathway.

Regulation of MicroRNAs After Spinal Cord Injury in Adult Zebrafish

Spinal cord injury (SCI) is a central nerve injury that often leads to loss of motor and sensory functions at or below the level of the injury. Zebrafish have a strong ability to repair after SCI, but the role of microRNAs (miRNAs) after SCI remains unclear. Locomotor behavior analysis showed that adult zebrafish recovered about 30% of their motor ability at 2 weeks and 55% at 3 weeks after SCI, reflecting their strong ability to repair SCI. Through miRNA sequencing, mRNA sequencing, RT-qPCR experiment verification, and bioinformatics predictive analysis, the key miRNAs and related genes in the repair of SCI were screened. A total of 38 miRNAs were significantly different, the top ten miRNAs were verified by RT-qPCR. The prediction target genes were verified by the mRNAs sequencing results at the same time point. Finally, 182 target genes were identified as likely to be networked regulated by the 38 different miRNAs. GO and KEGG enrichment analysis found that miRNAs targeted gene regulation of many key pathways, such as membrane tissue transport, ribosome function, lipid binding, and peroxidase activity. The PPI network analysis showed that miRNAs were involved in SCI repair through complex network regulation, among which dre-miR-21 may enhance cell reversibility through nop56, and that dre-miR-125c regulates axon growth through kpnb1 to repair SCI.

Re-analysis of single-cell RNA-seq data reveals the origin and roles of cycling myeloid cells

Cycling myeloid cells (CMCs) are often detected from various tissues using single-cell RNA sequencing (scRNA-seq) datasets, however, their research value was not noticed before. For the first time, our study preliminarily revealed the origin, differentiation, and roles of CMCs in physiological processes. Particularly, subgroup a of cycling myeloid cells (aCMCs) were conclusively identified as belonging to a specific cell type. In an active state, aCMCs rapidly proliferate during the early stages of an embryonic development. With an individual maturing, most aCMCs differentiate into specialized cells, while a small portion of them enter an inactive or dormant state. Under pathological conditions, aCMCs restore their proliferative and differentiation capacities via activation or revival. The present study has set the stage for future research on CMCs by linking them with progenitors of immune cells, and provided a crucial starting point to understand the origin, differentiation, and roles of CMCs in various physiological and pathological processes, particularly those related to traumatic injury, cancer, and pathogen infection, leading to develop targeted therapies or interventions.

Acid Neutralization by Composite Lysine Nanoparticles for Spinal Cord Injury Recovery through Mitigating Mitochondrial Dysfunction

After spinal cord injury (SCI), significant alterations in the tissue microenvironment lead to mitochondrial dysfunction, inducing apoptosis and inhibiting the remodeling of neural circuits, thereby impeding recovery. Although previous studies have demonstrated a marked decrease in pH at the injury site, creating an acidic microenvironment, the impact of improving this acidic microenvironment on SCI recovery has not been investigated. This study prepared a lysine@hollow mesoporous silica nanoparticle/gelatin methacrylate (GelMA) (L@H/G) composite hydrogel. The L@H/G composite hydrogel was demonstrated to release lysine and efficiently improve the acidic microenvironment slowly. Significantly, the composite hydrogel reduced cell apoptosis, promoted nerve regeneration, inhibited glial scar formation, and ultimately enhanced motor function recovery in mice with SCI. Mechanistically, the L@H/G hydrogel improved the mitochondrial tricarboxylic acid (TCA) cycle and fatty acid metabolism, restoring energy supply and facilitating mitochondrial function recovery. To the best of our knowledge, this is the first report confirming that improving the acidic microenvironment could promote SCI repair, providing a potential therapeutic strategy for SCI.

The roles of neural stem cells in myelin regeneration and repair therapy after spinal cord injury

Spinal cord injury (SCI) is a complex tissue injury that results in a wide range of physical deficits, including permanent or progressive disabilities of sensory, motor and autonomic functions. To date, limitations in current clinical treatment options can leave SCI patients with lifelong disabilities. There is an urgent need to develop new therapies for reconstructing the damaged spinal cord neuron-glia network and restoring connectivity with the supraspinal pathways. Neural stem cells (NSCs) possess the ability to self-renew and differentiate into neurons and neuroglia, including oligodendrocytes, which are cells responsible for the formation and maintenance of the myelin sheath and the regeneration of demyelinated axons. For these properties, NSCs are considered to be a promising cell source for rebuilding damaged neural circuits and promoting myelin regeneration. Over the past decade, transplantation of NSCs has been extensively tested in a variety of preclinical models of SCI. This review aims to highlight the pathophysiology of SCI and promote the understanding of the role of NSCs in SCI repair therapy and the current advances in pathological mechanism, pre-clinical studies, as well as clinical trials of SCI via NSC transplantation therapeutic strategy. Understanding and mastering these frontier updates will pave the way for establishing novel therapeutic strategies to improve the quality of recovery from SCI.

Exosomes from hypoxic ADSCs ameliorate neuronal damage post spinal cord injury through circ-Wdfy3 delivery and inhibition of ferroptosis

BACKGROUND

Exosomes generated from adipose-derived mesenchymal stem cells (Exos), and in particular hypoxia-pretreated ADSCs (HExos), possess therapeutic properties that promote spinal cord repair following spinal cord injury (SCI). Nevertheless, the regulatory mechanisms through which HExos exert their effects remain unclear.

METHODS

Here, next-generation sequencing (NGS) was utilized to examine abnormal circRNA expression comparing HExos to Exos. Bioinformatics analysis and RNA pulldown assays together with luciferase reporter assays were applied to determine interactions among miRNAs, mRNAs and circRNAs. ELISA and immunofluorescence staining were used to examine inflammatory cytokine levels, apoptosis and ROS deposition in LPS-treated HT-22 cells, respectively. The therapeutic effects of Exos and HExos on a mouse model of SCI were analyzed by immunohistochemistry and immunofluorescence staining.

RESULTS

Our findings confirmed that HExos have more significant therapeutic influences on decreasing ROS and inflammatory cytokine levels post-SCI than Exos. NGS revealed that circ-Wdfy3 expression levels were significantly higher in HExos than Exos. Downregulation of circ-Wdfy3 led to a decrease in HExo-induced therapeutic effects on spinal cord repair post-SCI, indicating that circ-Wdfy3 has a critical role in the regulation of HExo-mediated protection against SCI. Our bioinformatics, RNA pulldown and luciferase reporter data demonstrated that GPX4 and miR-423-3p were downstream targets of circ-Wdfy3. GPX4 downregulation or miR-423-3p overexpression reversed the protective effects of circ-Wdfy3 on LPS-treated HT-22 cells. Furthermore, overexpression of circ-Wdfy3 led to an in increase in the Exo-induced therapeutic effects on spinal cord repair post-SCI through the inhibition of ferroptosis.

CONCLUSIONS

circ-WDfy3-overexpressing Exos promote spinal cord repair post-SCI through mediation of ferroptosis via the miR-138-5p/GPX4 pathway.

Effect of Intermittent Theta Burst Stimulation Dual-Target Stimulation on Lower Limb Function in Patients with Incomplete Spinal Cord Injury: A Randomized, Single-Blind, Sham-Controlled Study

OBJECTIVE

To explore the influence of intermittent theta burst stimulation (iTBS) dual-target stimulation on lower limb function in patients with incomplete spinal cord injury (iSCI).

METHODS

A randomized, single -blind, sham-controlled trial was used in this study. Thirty iSCI patients with lower limb dysfunction meeting the inclusion criteria were randomly divided into a sham group and an iTBS group, with 15 cases in each group. The iTBS group received conventional rehabilitation therapy combined with iTBS dual-target stimulation on the central cerebral sulcus and the nerve root of the spinal cord injury segment. The sham group was treated with conventional rehabilitation therapy combined with iTBS dual-target sham stimulation therapy. Comprehensive functional assessment was performed on all patients before treatment, on the day 3 and day 21 of treatment. The main evaluation indicators were as follows: amplitude and latency of motor-evoked potential (MEP) in the anterior tibial muscles of both lower limbs, latency of sensory-evoked potential (SEP) of both lower limbs, knee flexor strength and knee extensor strength, lower extremity motor score (LEMS), lower extremity sensory score, spinal cord independence measure (SCIM) score, and gait parameters (stride speed, stride frequency, stride length, and ground reaction force).

RESULTS

On day 21 of treatment, in the iTBS group, the MEP amplitude of the anterior tibial muscles increased, the latency of MEP shortened, knee flexor strength and knee extensor strength increased, and the LEMS and SCIM score of both lower limbs increased. In addition, there were statistically significant differences in the muscle strength of the knee flexion muscle, knee extensor muscle, MEP amplitude, LEMS, and SCIM between the 2 groups (P < 0.05). Among the 10 patients who could walk with an assisted walker, the step length and step frequency of the iTBS group were increased compared with the sham group after treatment (P < 0.01), and the ground reaction force was increased (P < 0.05). There was no significant difference in the lower extremity sensory score of the lower limbs between the 2 groups (P > 0.05).

CONCLUSIONS

ITBS dual-target stimulation can significantly improve the motor function of both lower limbs in patients with iSCI but does not significantly improve the sensory function of both lower limbs. Therefore, this treatment mode may participate in the reconstruction and repair of some nerve circuits in patients with iSCI. In addition, iTBS dual-target stimulation can improve the ability of iSCI patients to perform daily living.

Exosomes derived from vMIP-II-Lamp2b gene-modified M2 cells provide neuroprotection by targeting the injured spinal cord, inhibiting chemokine signals and modulating microglia/macrophage polarization in mice

Inflammation is one of the key injury factors for spinal cord injury (SCI). Exosomes (Exos) derived from M2 macrophages have been shown to inhibit inflammation and be beneficial in SCI animal models. However, lacking targetability restricts their application prospects. Considering that chemokine receptors increase dramatically after SCI, viral macrophage inflammatory protein II (vMIP-II) is a broad-spectrum chemokine receptor binding peptide, and lysosomal associated membrane protein 2b (Lamp2b) is the key membrane component of Exos, we speculated that vMIP-II-Lamp2b gene-modified M2 macrophage-derived Exos (vMIP-II-Lamp2b-M2-Exo) not only have anti-inflammatory properties, but also can target the injured area by vMIP-II. In this study, using a murine contusive SCI model, we revealed that vMIP-II-Lamp2b-M2-Exo could target the chemokine receptors which highly expressed in the injured spinal cords, inhibit some key chemokine receptor signaling pathways (such as MAPK and Akt), further inhibit proinflammatory factors (such as IL-1β, IL-6, IL-17, IL-18, TNF-α, and iNOS), and promote anti-inflammatory factors (such as IL-4 and Arg1) productions, and the transformation of microglia/macrophages from M1 into M2. Moreover, the improved histological and functional recoveries were also found. Collectively, our results suggest that vMIP-II-Lamp2b-M2-Exo may provide neuroprotection by targeting the injured spinal cord, inhibiting some chemokine signals, reducing proinflammatory factor production and modulating microglia/macrophage polarization.

Zein-Based Triple-Drug Nanoparticles to Promote Anti-Inflammatory Responses for Nerve Regeneration after Spinal Cord Injury

Defects in autophagy contribute to neurological deficits and motor dysfunction after spinal cord injury. Here a nanosystem is developed to deliver autophagy-promoting, anti-inflammatory drugs to nerve cells in the injured spinal cord. Celastrol, metformin, and everolimus as the mTOR inhibitor are combined into the zein-based nanoparticles, aiming to solubilize the drugs and prolong their circulation. The nanoparticles are internalized by BV2 microglia and SH-SY5Y neuron-like cells in culture; they inhibit the secretion of inflammatory factors by BV2 cells after insult with lipopolysaccharide, and they protect SH-SY5Y cells from the toxicity of H2O2. In a rat model of spinal cord injury, the nanoparticles mitigate inflammation and promote spinal cord repair. In the in vitro and in vivo experiments, the complete nanoparticles function better than the free drugs or nanoparticles containing only one or two drugs. These results suggest that the triple-drug nanoparticles show promise for treating spinal cord injury.

Nicotinamide Riboside Promotes the Proliferation of Endogenous Neural Stem Cells to Repair Spinal Cord Injury

Activation of endogenous neural stem cells (NSC) is one of the most potential measures for neural repair after spinal cord injury. However, methods for regulating neural stem cell behavior are still limited. Here, we investigated the effects of nicotinamide riboside promoting the proliferation of endogenous neural stem cells to repair spinal cord injury. Nicotinamide riboside promotes the proliferation of endogenous neural stem cells and regulates their differentiation into neurons. In addition, nicotinamide riboside significantly restored lower limb motor dysfunction caused by spinal cord injury. Nicotinamide riboside plays its role in promoting the proliferation of neural stem cells by activating the Wnt signaling pathway through the LGR5 gene. Knockdown of the LGR5 gene by lentivirus eliminates the effect of nicotinamide riboside on the proliferation of endogenous neural stem cells. In addition, administration of Wnt pathway inhibitors also eliminated the proliferative effect of nicotinamide riboside. Collectively, these findings demonstrate that nicotinamide promotes the proliferation of neural stem cells by targeting the LGR5 gene to activate the Wnt pathway, which provides a new way to repair spinal cord injury.

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

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

Retinal transplant immunology and advancements

Several gaps and barriers remain for transplanting stem cells into the eye to treat ocular disease, especially diseases of the retina. While the eye has historically been considered immune privileged, recent thinking has identified the immune system as both a barrier and an opportunity for eye stem cell transplantation. Recent approaches leveraging scaffolds or cloaking have been considered in other tissues beyond immune suppression. This perspective paper outlines approaches for transplantation and proposes opportunities to overcome barriers of the immune system in stem cell transplantation in the eye.

Analysis and experimental validation of genes and their transcription factor prediction in contused rat spinal cord at the intermediate phase

The intermediate phase of spinal cord injury (SCI) serves as an important target site for therapeutic mediation of SCI. However, there is a lack of insight into the mechanism of the intermediate phase of SCI. The present study aimed to investigate the molecular mechanism and the feasible treatment targets in the intermediate phase of SCI. We downloaded GSE2599 from GEO and identified 416 significant differentially expressed genes (DEGs), including 206 downregulated and 210 upregulated DEGs. Further enrichment analysis of DEGs revealed that many important biological processes and signal pathways were triggered in the injured spinal cord. Furthermore, a protein-protein interaction (PPI) network was constructed and the top 10 high-degree hub nodes were identified. Furthermore, 27 predicted transcription factors (TFs) and 136 predicted motifs were identified. We then selected insulin-like growth factor 1 (IGF1) and its predicted transcription factor, transcription factor A, mitochondrial (TFAM) for further investigation. We speculated and preliminarily confirmed that TFAM may regulate gene transcription of IGF1 and effected alterations in the function recovery of rats after SCI. These findings together provide novel information that may improve our understanding of the pathophysiological processes during the intermediate phase of SCI.

Demultiplexing of single-cell RNA-sequencing data using interindividual variation in gene expression

Motivation

Pooled designs for single-cell RNA sequencing, where many cells from distinct samples are processed jointly, offer increased throughput and reduced batch variation. This study describes expression-aware demultiplexing (EAD), a computational method that employs differential co-expression patterns between individuals to demultiplex pooled samples without any extra experimental steps.

Results

We use synthetic sample pools and show that the top interindividual differentially co-expressed genes provide a distinct cluster of cells per individual, significantly enriching the regulation of metabolism. Our application of EAD to samples of six isogenic inbred mice demonstrated that controlling genetic and environmental effects can solve interindividual variations related to metabolic pathways. We utilized 30 samples from both sepsis and healthy individuals in six batches to assess the performance of classification approaches. The results indicate that combining genetic and EAD results can enhance the accuracy of assignments (Min. 0.94, Mean 0.98, Max. 1). The results were enhanced by an average of 1.4% when EAD and barcoding techniques were combined (Min. 1.25%, Median 1.33%, Max. 1.74%). Furthermore, we demonstrate that interindividual differential co-expression analysis within the same cell type can be used to identify cells from the same donor in different activation states. By analysing single-nuclei transcriptome profiles from the brain, we demonstrate that our method can be applied to nonimmune cells.

Availability and implementation

EAD workflow is available at https://isarnassiri.github.io/scDIV/ as an R package called scDIV (acronym for single-cell RNA-sequencing data demultiplexing using interindividual variations).

Optical Devices for the Diagnosis and Management of Spinal Cord Injuries: A Review

Throughout the central nervous system, the spinal cord plays a very important role, namely, transmitting sensory and motor information inwardly so that it can be processed by the brain. There are many different ways this structure can be damaged, such as through traumatic injury or surgery, such as scoliosis correction, for instance. Consequently, damage may be caused to the nervous system as a result of this. There is no doubt that optical devices such as microscopes and cameras can have a significant impact on research, diagnosis, and treatment planning for patients with spinal cord injuries (SCIs). Additionally, these technologies contribute a great deal to our understanding of these injuries, and they are also essential in enhancing the quality of life of individuals with spinal cord injuries. Through increasingly powerful, accurate, and minimally invasive technologies that have been developed over the last decade or so, several new optical devices have been introduced that are capable of improving the accuracy of SCI diagnosis and treatment and promoting a better quality of life after surgery. We aim in this paper to present a timely overview of the various research fields that have been conducted on optical devices that can be used to diagnose spinal cord injuries as well as to manage the associated health complications that affected individuals may experience.

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.

Disrupted autonomic pathways in spinal cord injury: Implications for the immune regulation

Spinal Cord Injury (SCI) disrupts critical autonomic pathways responsible for the regulation of the immune function. Consequently, individuals with SCI often exhibit a spectrum of immune dysfunctions ranging from the development of damaging pro-inflammatory responses to severe immunosuppression. Thus, it is imperative to gain a more comprehensive understanding of the extent and mechanisms through which SCI-induced autonomic dysfunction influences the immune response. In this review, we provide an overview of the anatomical organization and physiology of the autonomic nervous system (ANS), elucidating how SCI impacts its function, with a particular focus on lymphoid organs and immune activity. We highlight recent advances in understanding how intraspinal plasticity that follows SCI may contribute to aberrant autonomic activity in lymphoid organs. Additionally, we discuss how sympathetic mediators released by these neuron terminals affect immune cell function. Finally, we discuss emerging innovative technologies and potential clinical interventions targeting the ANS as a strategy to restore the normal regulation of the immune response in individuals with SCI.

Injectable Hydrogel System Incorporating Black Phosphorus Nanosheets and Tazarotene Drug for Enhanced Vascular and Nerve Regeneration in Spinal Cord Injury Repair

Spinal cord injury (SCI) often leads to cell death, vascular disruption, axonal signal interruption, and permanent functional damage. Currently, there are no clearly effective therapeutic options available for SCI. Considering the inhospitable SCI milieu typified by ischemia, hypoxia, and restricted neural regeneration, a novel injectable hydrogel system containing conductive black phosphorus (BP) nanosheets within a lipoic acid-modified chitosan hydrogel matrix (LAMC) is explored. The incorporation of tannic acid (TA)-modified BP nanosheets (BP@TA) into the LAMC hydrogel matrix significantly improved its conductivity. Further, by embedding a bicyclodextrin-conjugated tazarotene drug, the hydrogel showcased amplified angiogenic potential in vitro. In a rat model of complete SCI, implantation of LAMC/BP@TA hydrogel markedly improved the recovery of motor function. Immunofluorescence evaluations confirmed that the composite hydrogel facilitated endogenous angiogenesis and neurogenesis at the injury site. Collectively, this work elucidates an innovative drug-incorporated hydrogel system enriched with BP, underscoring its potential to foster vascular and neural regeneration.

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.

Water channels in the brain and spinal cord-overview of the role of aquaporins in traumatic brain injury and traumatic spinal cord injury

Knowledge about the mechanisms underlying the fluid flow in the brain and spinal cord is essential for discovering the mechanisms implicated in the pathophysiology of central nervous system diseases. During recent years, research has highlighted the complexity of the fluid flow movement in the brain through a glymphatic system and a lymphatic network. Less is known about these pathways in the spinal cord. An important aspect of fluid flow movement through the glymphatic pathway is the role of water channels, especially aquaporin 1 and 4. This review provides an overview of the role of these aquaporins in brain and spinal cord, and give a short introduction to the fluid flow in brain and spinal cord during in the healthy brain and spinal cord as well as during traumatic brain and spinal cord injury. Finally, this review gives an overview of the current knowledge about the role of aquaporins in traumatic brain and spinal cord injury, highlighting some of the complexities and knowledge gaps in the field.

Hspb1 and Lgals3 in spinal neurons are closely associated with autophagy following excitotoxicity based on machine learning algorithms

Excitotoxicity represents the primary cause of neuronal death following spinal cord injury (SCI). While autophagy plays a critical and intricate role in SCI, the specific mechanism underlying the relationship between excitotoxicity and autophagy in SCI has been largely overlooked. In this study, we isolated primary spinal cord neurons from neonatal rats and induced excitotoxic neuronal injury by high concentrations of glutamic acid, mimicking an excitotoxic injury model. Subsequently, we performed transcriptome sequencing. Leveraging machine learning algorithms, including weighted correlation network analysis (WGCNA), random forest analysis (RF), and least absolute shrinkage and selection operator analysis (LASSO), we conducted a comprehensive investigation into key genes associated with spinal cord neuron injury. We also utilized protein-protein interaction network (PPI) analysis to identify pivotal proteins regulating key gene expression and analyzed key genes from public datasets (GSE2599, GSE20907, GSE45006, and GSE174549). Our findings revealed that six genes-Anxa2, S100a10, Ccng1, Timp1, Hspb1, and Lgals3-were significantly upregulated not only in vitro in neurons subjected to excitotoxic injury but also in rats with subacute SCI. Furthermore, Hspb1 and Lgals3 were closely linked to neuronal autophagy induced by excitotoxicity. Our findings contribute to a better understanding of excitotoxicity and autophagy, offering potential targets and a theoretical foundation for SCI diagnosis and treatment.

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.

Conditioned medium from human dental pulp stem cells treats spinal cord injury by inhibiting microglial pyroptosis

Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury. However, whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear. In the present study, we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells. We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury, decreased expression of the microglial pyroptosis markers NLRP3, GSDMD, caspase-1, and interleukin-1β, promoted axonal and myelin regeneration, and inhibited the formation of glial scars. In addition, in a lipopolysaccharide-induced BV2 microglia model, conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1β pathway. These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1β pathway, thereby promoting the recovery of neurological function after spinal cord injury. Therefore, conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.

Mechanism of Fat Mass and Obesity-Related Gene-Mediated Heme Oxygenase-1 m6A Modification in the Recovery of Neurological Function in Mice with Spinal Cord Injury

OBJECTIVES

This study examined the mechanism of fat mass and obesity-related gene (FTO)-mediated heme oxygenase-1 (HO-1) m6A modification facilitating neurological recovery in spinal cord injury (SCI) mice. FTO/HO-1 was identified as a key regulator of SCI as well as a potential target for treatment of SCI.

METHODS

An SCI mouse was treated with pcDNA3.1-FTO/pcDNA3.1-NC/Dac51. An oxygen/glucose deprivation (OGD) cell model simulated SCI, with cells treated with pcDNA3.1-FTO/si-HO-1/Dac51. Motor function and neurobehavioral evaluation were assessed using the Basso, Beattie, and Bresnahan (BBB) scale and modified neurological severity score (mNSS). Spinal cord pathology and neuronal apoptosis were assessed. Further, FTO/HO-1 mRNA and protein levels, HO-1 mRNA stability, the interaction of YTHDF2 with HO-1 mRNA, neuronal viability/apoptosis, and HO-1 m6A modification were evaluated.

RESULTS

Spinal cord injury mice exhibited reduced BBB, elevated mNSS scores, disorganized spinal cord cells, scattered nuclei, and severe nucleus pyknosis. pcDNA3.1-FTO elevated FTO mRNA, protein expression, and BBB score; reduced the mNSS score of SCI mice; decreased neuronal apoptosis; improved the cell arrangement; and improved nucleus pyknosis in spinal cord tissues. OGD decreased FTO expression. FTO upregulation ameliorated OGD-induced neuronal apoptosis. pcDNA3.1-FTO reduced HO-1 mRNA and protein and HO-1 m6A modification, while increasing HO-1 mRNA stability and FTO in OGD-treated cells. FTO upregulated HO-1 by modulating m6A modification. HO-1 downregulation attenuated the effect of FTO. pcDNA3.1-FTO/Dac51 increased the HO-1 m6A level in mouse spinal cord tissue homogenate, reduced BBB, boosted mNSS scores of SCI mice, aggravated nucleus pyknosis, and increased neuronal apoptosis in spinal cord tissues, confirming that FTO mediated HO-1 m6A modification facilitated neurological recovery in SCI mice.

CONCLUSION

The fat mass and obesity-related gene modulates HO-1 mRNA stability by regulating m6A modification levels, thereby influencing HO-1 expression and promoting neurological recovery in SCI mice.

The potential therapeutic roles of dental pulp stem cells in spinal cord injury

Spinal cord injury (SCI) can lead to serious functional disorders, which have serious impacts on patients and society. The current traditional treatments of SCI are not effective the injured spinal cord is difficult to repair and regenerate. In recent years, stem cell transplantation for the treatment of SCI has been a hot research topic. Dental pulp stem cells have strong abilities of self-renewal and multi-directional differentiation, and have been applied for tissue engineering and regenerative medicine. And dental pulp stem cells have certain advantages in neuro-regenetation, bringing new hope to biotherapy for SCI. This article reviews the characteristics of dental pulp stem cells and their research progress in the treatment of SCI.

Reactive Oxygen Species-Responsive Composite Fibers Regulate Oxidative Metabolism through Internal and External Factors to Promote the Recovery of Nerve Function

It is challenging to sufficiently regulate endogenous neuronal reactive oxygen species (ROS) production, reduce neuronal apoptosis, and reconstruct neural networks under spinal cord injury conditions. Here, hydrogel surface grafting and microsol electrospinning are used to construct a composite biomimetic scaffold with "external-endogenous" dual regulation of ROS. The outer hydrogel enhances local autophagy through responsive degradation and rapid release of rapamycin (≈80% within a week), neutralizing extracellular ROS and inhibiting endogenous ROS production, further reducing neuronal apoptosis. The inner directional fibers continuously supply brain-derived neurotrophic factors to guide axonal growth. The results of in vitro co-culturing show that the dual regulation of oxidative metabolism by the composite scaffold approximately doubles the neuronal autophagy level, reduces 60% of the apoptosis induced by oxidative stress, and increases the differentiation of neural stem cells into neuron-like cells by ≈2.5 times. The in vivo results show that the composite fibers reduce the ROS levels by ≈80% and decrease the formation of scar tissue. RNA sequencing results show that composite scaffolds upregulate autophagy-associated proteins, antioxidase genes, and axonal growth proteins. The developed composite biomimetic scaffold represents a therapeutic strategy to achieve neurofunctional recovery through programmed and accurate bidirectional regulation of the ROS cascade response.

The beneficial effect of α-lipoic acid on spinal cord injury repair in rats is mediated through inhibition of oxidative stress: A transcriptomic analysis

BACKGROUND

Oxidative stress is a crucial factor contributing to the occurrence and development of secondary damage in spinal cord injuries (SCI), ultimately impacting the recovery process. α-lipoic acid (ALA) exhibits potent antioxidant properties, effectively reducing secondary damage and providing neuroprotective benefits. However, the precise mechanism by which ALA plays its antioxidant role remains unknown.

METHODS

We established a model of moderate spinal cord contusion in rats. Experimental rats were randomly divided into 3 distinct groups: the sham group, the model control group (SCI_Veh), and the ALA treatment group (SCI_ALA). The sham group rats were exposed only to the SC without contusion injury. Rats belonging to SCI_Veh group were not administered any treatment after SCI. Rats of SCI_ALA group were intraperitoneally injected with the corresponding volume of ALA according to body weight for three consecutive days after the surgery. Subsequently, three days after SCI, spinal cord samples were obtained from three groups of rats: the sham group, model control group, and administration group. Thereafter, total RNA was extracted from the samples and the expression of three sets of differential genes was analyzed by transcriptome sequencing technology. Real-time PCR was used to verify the sequencing results. The impact of ALA on oxidative stress in rats following SCI was assessed by measuring their total antioxidant capacity and hydrogen peroxide (H2O2) content. The effects of ALA on rat recovery following SCI was investigated through Beattie and Bresnahan (BBB) score and footprint analysis.

RESULTS

The findings from the transcriptome sequencing analysis revealed that the model control group had 2975 genes with altered expression levels when compared to the ALA treatment group. Among these genes, 1583 were found to be upregulated while 1392 were down-regulated. Gene ontology (GO) displayed significant enrichment in terms of functionality, specifically in oxidative phosphorylation, oxidoreductase activity, and signaling receptor activity. The Kyoto encyclopedia of genes and genomes (KEGG) pathway was enriched in oxidative phosphorylation, glutathione metabolism and cell cycle. ALA was found to have multiple benefits for rats after SCI, including increasing their antioxidant capacity and reducing H2O2 levels. Additionally, it was effective in improving motor function (such as 7 days after SCI, the BBB score for SCI_ALA was 8.400 ± 0.937 compared to 7.050 ± 1.141 for SCI_Veh) and promoting histological recovery after SCI (The results of HE demonstrated that the percentage of damage area in was 44.002 ± 6.680 in the SCI_ALA and 57.215 ± 3.964 in the SCI_Veh at the center of injury.). The sequence data from this study has been deposited into Sequence Read Archive (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE242507).

CONCLUSION

Overall, the findings of this study confirmed the beneficial effects of ALA on recovery in SCI rats through transcriptome sequencing, behavioral, as well histology analyses.

Synergistic effects of tetramethylpyrazine and astragaloside IV on spinal cord injury via alteration of astrocyte A1/A2 polarization through the Sirt1-NF-κB pathway

OBJECTIVE

Reactive astrocytes are hallmarks of traumatic spinal cord injury (T-SCI) and are associated with neuropathic pain (NP). Mediating the functional phenotype of reactive astrocytes helps neural repair and ameliorates NP in T-SCI. Here, we aimed to explore the role of tetramethylpyrazine (TMPZ) and astragaloside IV (AGS-IV) in astrocyte polarization and the underlying molecular mechanism in T-SCI.

METHODS

Primary cultured astrocytes from mice were treated with LPS or conditioned medium from "M1" polarized microglia (M1-CM), followed by TMPZ and/or AGS-IV administration. The expression levels of "A1" astrocyte-specific markers (including C3, GBP2, Serping1, iNOS), "A2" astrocyte-specific markers (including S100a10 and PTX3), Sirt1 and NF-κB were detected via western blotting. TNF-α and IL-1β levels were detected via ELISA. RT-PCR was used to evaluate OIP5-AS1 and miR-34a expression. si-OIP5-AS1 or the Sirt1 inhibitor EX-527 was administered to astrocytes. A spinal cord injury (SCI) model was constructed in Sprague-Dawley (SD) rats. Alterations in astrocytic "A1/A2" polarization in the spinal cord tissues were evaluated.

RESULTS

LPS and M1-CM induced "A1" polarization of primary astrocytes. TMPZ and ASG IV could substantially reduce the expression of "A1"-related biomarkers but enhance "A2"-related biomarkers. OIP5-AS1 and Sirt1 levels were reduced in "A1"-polarized astrocytes, while miR-34a and p-NF-κB p65 were elevated. TMPZ and ASG IV enhanced OIP5-AS1 and Sirt1 levels and, in contrast, attenuated the changes in miR-34a and p-NF-κB p65 levels. Notably, the TMPZ and ASG IV combination had stronger effects on astrocyte polarization than the single treatment with TMPZ or ASG IV. OIP5-AS1 knockdown and Sirt1 inhibition both reversed the regulatory effects of TMPZ and ASG IV in astrocytic polarization. According to the in vivo experiments, the expression of "A1"-associated markers was enhanced in the spinal cords of SCI rats. The TMPZ and ASG IV combination reduced astrocytic "A1" polarization and enhanced astrocytic "A2" polarization. The expression of lncRNA OIP5-AS1 and Sirt1 was enhanced by TMPZ and ASG IV, while that of miR-34a and p-NF-κB p65 was inhibited.

CONCLUSION

The combination of TMPZ and ASG IV can ameliorate dysregulated astrocytic polarization induced by spinal cord injury by affecting the lncRNA OIP5-AS1-Sirt1-NF-κB pathway.

Enhancing anti-neuroinflammation effect of X-ray-triggered RuFe-based metal-organic framework with dual enzyme-like activities

Traumatic spinal cord injury (SCI), often resulting from external physical trauma, initiates a series of complex pathophysiological cascades, with severe cases leading to paralysis and presenting significant clinical challenges. Traditional diagnostic and therapeutic approaches, particularly X-ray imaging, are prevalent in clinical practice, yet the limited efficacy and notable side effects of pharmacological treatments at the injury site continue to pose substantial hurdles. Addressing these challenges, recent advancements have been made in the development of multifunctional nanotechnology and synergistic therapies, enhancing both the efficacy and safety of radiographic techniques. In this context, we have developed an innovative nerve regeneration and neuroprotection nanoplatform utilizing an X-ray-triggered, on-demand RuFe metal-organic framework (P-RuFe) for SCI recovery. This platform is designed to simulate the enzymatic activities of catalase and superoxide dismutase, effectively reducing the production of reactive oxygen species, and to remove free radicals and reactive nitrogen species, thereby protecting cells from oxidative stress-induced damage. In vivo studies have shown that the combination of P-RuFe and X-ray treatment significantly reduces mortality in SCI mouse models and promotes spinal cord repair by inhibiting glial cell proliferation and neuroinflammation. P-RuFe demonstrates excellent potential as a safe, effective scavenger of reactive oxygen and nitrogen species, offering good stability, biocompatibility, and high catalytic activity, and thus holds promise for the treatment of inflammation-related diseases.