Antioxidant therapies for acute spinal cord injury

Nrf2 Signaling Pathway: Focus on Oxidative Stress in Spinal Cord Injury

Spinal cord injury (SCI) is a serious, disabling injury to the central nervous system that can lead to motor, sensory, and autonomic dysfunction below the injury plane. SCI can be divided into primary injury and secondary injury according to its pathophysiological process. Primary injury is irreversible in most cases, while secondary injury is a dynamic regulatory process. Secondary injury involves a series of pathological events, such as ischemia, oxidative stress, inflammatory events, apoptotic pathways, and motor dysfunction. Among them, oxidative stress is an important pathological event of secondary injury. Oxidative stress causes a series of destructive events such as lipid peroxidation, DNA damage, inflammation, and cell death, which further worsens the microenvironment of the injured site and leads to neurological dysfunction. The nuclear factor erythrocyte 2-associated factor 2 (Nrf2) is considered to be a key pathway of antioxidative stress and is closely related to the pathological process of SCI. Activation of this pathway can effectively inhibit the oxidative stress process and promote the recovery of nerve function after SCI. Therefore, the Nrf2 pathway may be a potential therapeutic target for SCI. This review deeply analyzed the generation of oxidative stress in SCI, the role and mechanism of Nrf2 as the main regulator of antioxidant stress in SCI, and the influence of cross-talk between Nrf2 and related pathways that may be involved in the pathological regulation of SCI on oxidative stress, and summarized the drugs and other treatment methods based on Nrf2 pathway regulation. The objective of this paper is to provide evidence for the role of Nrf2 activation in SCI and to highlight the important role of Nrf2 in alleviating SCI by elucidating the mechanism, so as to provide a theoretical basis for targeting Nrf2 pathway as a therapy for SCI.

Advancements in Antioxidant-Based Therapeutics for Spinal Cord Injury: A Critical Review of Strategies and Combination Approaches

Spinal cord injury (SCI) initiates a cascade of secondary damage driven by oxidative stress, characterized by the excessive production of reactive oxygen species and other reactive molecules, which exacerbate cellular and tissue damage through the activation of deleterious signaling pathways. This review provides a comprehensive and critical evaluation of recent advancements in antioxidant-based therapeutic strategies for SCI, including natural compounds, RNA-based therapies, stem cell interventions, and biomaterial applications. It emphasizes the limitations of single-regimen approaches, particularly their limited efficacy and suboptimal delivery to injured spinal cord tissue, while highlighting the synergistic potential of combination therapies that integrate multiple modalities to address the multifaceted pathophysiology of SCI. By analyzing emerging trends and current limitations, this review identifies key challenges and proposes future directions, including the refinement of antioxidant delivery systems, the development of multi-targeted approaches, and strategies to overcome the structural complexities of the spinal cord. This work underscores the pressing need for innovative and integrative therapeutic approaches to advance the clinical translation of antioxidant-based interventions and improve outcomes for SCI patients.

Bibliometric analysis of the inflammation expression after spinal cord injury: current research status and emerging frontiers

STUDY DESIGN

Bibliometric analysis.

OBJECTIVE

To analyze literature on inflammatory expression following spinal cord injury, highlighting development trends, current research status, and potential emerging frontiers.

SETTING

Not applicable.

METHODS

Articles were retrieved using terms related to spinal cord injury and inflammatory responses from the Web of Science Core Collection, covering January 1, 1980, to May 23, 2024. Tools like CiteSpace and VOSviewer assessed the research landscape, evaluating core authors, journals, and contributing countries. Keyword co-occurrence analyses identified research trends.

RESULTS

A total of 2504 articles were retrieved, showing a consistent increase in publications. The Journal of Neurotrauma had the highest publication volume and influence. The most prolific author was Cuzzocrea S, with Popovich PG having the highest H-index. China led in the number of publications, followed closely by the United States, which had the highest impact and extensive international collaboration. Research mainly focused on nerve function recovery, glial scar formation, and oxidative stress. Future research is expected to investigate cellular autophagy, vesicular transport, and related signaling pathways.

CONCLUSION

The growing interest in inflammation caused by spinal cord injury is evident, with current research focusing on oxidative stress, glial scar, and neurological recovery. Future directions include exploring autophagy and extracellular vesicles for new therapies. Interdisciplinary research and extensive clinical trials are essential for validating new treatments. Biomarker discovery is crucial for diagnosis and monitoring, while understanding autophagy and signaling pathways is vital for drug development. Global cooperation is needed to accelerate the application of scientific findings, improving spinal cord injury treatment.

Constructing Electron-Rich Ru Clusters on Non-Stoichiometric Copper Hydroxide for Superior Biocatalytic ROS Scavenging to Treat Inflammatory Spinal Cord Injury

Traumatic spinal cord injury (SCI) represents a complex neuropathological challenge that significantly impacts the well-being of affected individuals. The quest for efficacious antioxidant and anti-inflammatory therapies is both a compelling necessity and a formidable challenge. Here, in this work, the innovative synthesis of electron-rich Ru clusters on non-stoichiometric copper hydroxide that contain oxygen vacancy defects (Ru/def-Cu(OH)2), which can function as a biocatalytic reactive oxygen species (ROS) scavenger for efficiently suppressing the inflammatory cascade reactions and modulating the endogenous microenvironments in SCI, is introduced. The studies reveal that the unique oxygen vacancies promote electron redistribution and amplify electron accumulation at Ru clusters, thus enhancing the catalytic activity of Ru/def-Cu(OH)2 in multielectron reactions involving oxygen-containing intermediates. These advancements endow the Ru/def-Cu(OH)2 with the capacity to mitigate ROS-mediated neuronal death and to foster a reparative microenvironment by dampening inflammatory macrophage responses, meanwhile concurrently stimulating the activity of neural stem cells, anti-inflammatory macrophages, and oligodendrocytes. Consequently, this results in a robust reparative effect on traumatic SCI. It is posited that the synthesized Ru/def-Cu(OH)2 exhibits unprecedented biocatalytic properties, offering a promising strategy to develop ROS-scavenging and anti-inflammatory materials for the management of traumatic SCI and a spectrum of other diseases associated with oxidative stress.

Advances in Novel Biomaterial-Based Strategies for Spinal Cord Injury Treatment

Spinal cord injury (SCI) is a highly disabling neurological disorder. Its pathological process comprises an initial acute injury phase (primary injury) and a secondary injury phase (subsequent chronic injury). Although surgical, drug, and cell therapies have made some progress in treating SCI, there is no exact therapeutic strategy for treating SCI and promoting nerve regeneration due to the complexity of the pathological SCI process. The development of novel drug delivery systems to treat SCI is expected to significantly impact the individualized treatment of SCI due to its unique and excellent properties, such as active targeting and controlled release. In this review, we first describe the pathological progression of the SCI response, including primary and secondary injuries. Next, we provide a concise overview of newly developed nanoplatforms and their potential application in regulating and treating different pathological processes of SCI. Then, we introduce the existing potential problems and future clinical application perspectives of biomedical engineering-based therapies for SCI.

The role of nitric oxide and hydrogen sulfide in spinal cord injury: an updated review

Medical gases play an important role in the pathophysiology of human diseases and have received extensive attention for their role in neuroprotection. Common pathological mechanisms of spinal cord injury include excitotoxicity, inflammation, cell death, glial scarring, blood-spinal cord barrier disruption, and ischemia/reperfusion injury. Nitric oxide and hydrogen sulfide are important gaseous signaling molecules in living organisms; their pathological role in spinal cord injury models has received more attention in recent years. This study reviews the possible mechanisms of spinal cord injury and the role of nitric oxide and hydrogen sulfide in spinal cord injury.

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.

Enhancing mitophagy by ligustilide through BNIP3-LC3 interaction attenuates oxidative stress-induced neuronal apoptosis in spinal cord injury

Mitophagy selectively eliminates damaged or dysfunctional mitochondria, playing a crucial role in maintaining mitochondrial quality control. However, it remains unclear whether mitophagy can be fully activated and how it evolves after SCI. Our RNA-seq analysis of animal samples from sham and 1, 3, 5, and 7 days post-SCI indicated that mitophagy was indeed inhibited during the acute and subacute early stages. In vitro experiments showed that this inhibition was closely related to excessive production of reactive oxygen species (ROS) and the downregulation of BNIP3. Excessive ROS led to the blockage of mitophagy flux, accompanied by further mitochondrial dysfunction and increased neuronal apoptosis. Fortunately, ligustilide (LIG) was found to have the ability to reverse the oxidative stress-induced downregulation of BNIP3 and enhance mitophagy through BNIP3-LC3 interaction, alleviating mitochondrial dysfunction and ultimately reducing neuronal apoptosis. Further animal experiments demonstrated that LIG alleviated oxidative stress and mitophagy inhibition, rescued neuronal apoptosis, and promoted tissue repair, ultimately leading to improved motor function. In summary, this study elucidated the state of mitophagy inhibition following SCI and its potential mechanisms, and confirmed the effects of LIG-enhanced mitophagy through BNIP3-LC3, providing new therapeutic targets and strategies for repairing SCI.

Management of traumatic spinal cord injury: A current concepts review of contemporary and future treatment

Spinal Cord Injury (SCI) is a condition leading to inflammation, edema, and dysfunction of the spinal cord, most commonly due to trauma, tumor, infection, or vascular disturbance. Symptoms include sensory and motor loss starting at the level of injury; the extent of damage depends on injury severity as detailed in the ASIA score. In the acute setting, maintaining mean arterial pressure (MAP) higher than 85 mmHg for up to 7 days following injury is preferred; although caution must be exercised when using vasopressors such as phenylephrine due to serious side effects such as pulmonary edema and death. Decompression surgery (DS) may theoretically relieve edema and reduce intraspinal pressure, although timing of surgery remains a matter of debate. Methylprednisolone (MP) is currently used due to its ability to reduce inflammation but more recent studies question its clinical benefits, especially with inconsistency in recommending it nationally and internationally. The choice of MP is further complicated by conflicting evidence for optimal timing to initiate treatment, and by the reported observation that higher doses are correlated with increased risk of complications. Thyrotropin-releasing hormone may be beneficial in less severe injuries. Finally, this review discusses many options currently being researched and have shown promising pre-clinical results.

Bioactivities of morroniside: A comprehensive review of pharmacological properties and molecular mechanisms

Morroniside (MOR) is an iridoid glycoside and the main active principle of the medicinal plant, Cornus officinalis Sieb. This phytochemical is associated with numerous health benefits due to its antioxidant properties. The primary objective of the present study was to assess the pharmacological effects and underlying mechanisms of MOR, utilizing published data obtained from literature databases. Data collection involved accessing various sources, including PubMed/Medline, Scopus, Science Direct, Google Scholar, Web of Science, and SpringerLink. Our findings demonstrate that MOR can be utilized for the treatment of several diseases and disorders, as numerous studies have revealed its significant therapeutic activities. These activities encompass anti-inflammatory, antidiabetic, lipid-lowering capability, anticancer, trichogenic, hepatoprotective, gastroprotective, osteoprotective, renoprotective, and cardioprotective effects. MOR has also shown promising benefits against various neurological ailments, including Alzheimer's disease, Parkinson's disease, spinal cord injury, cerebral ischemia, and neuropathic pain. Considering these therapeutic features, MOR holds promise as a lead compound for the treatment of various ailments and disorders. However, further comprehensive preclinical and clinical trials are required to establish MOR as an effective and reliable therapeutic agent.

In Situ Reaction-Generated Aldehyde-Scavenging Polypeptides-Curcumin Conjugate Nanoassemblies for Combined Treatment of Spinal Cord Injury

The microenvironment after traumatic spinal cord injury (SCI) involves complex pathological processes, including elevated oxidative stress, accumulated reactive aldehydes from lipid peroxidation, excessive immune cell infiltration, etc. Unfortunately, most of current neuroprotection therapies cannot cope with the intricate pathophysiology of SCI, leading to scant treatment efficacies. Here, we developed a facile in situ reaction-induced self-assembly method to prepare aldehyde-scavenging polypeptides (PAH)-curcumin conjugate nanoassemblies (named as PFCN) for combined neuroprotection in SCI. The prepared PFCN could release PAH and curcumin in response to oxidative and acidic SCI microenvironment. Subsequently, PFCN exhibited an effectively neuroprotective effect through scavenging toxic aldehydes as well as reactive nitrogen and oxygen species in neurons, modulating microglial M1/M2 polarization, and down-regulating the expression of inflammation-related cytokines to inhibit neuroinflammation. The intravenous administration of PFCN could significantly ameliorate the malignant microenvironment of injured spinal cord, protect the neurons, and promote the motor function recovery in the contusive SCI rat model.

Research Progress of Antioxidants in Oxidative Stress Therapy after Spinal Cord Injury

Spinal cord injury (SCI) is a serious problem in the central nervous system resulting in high disability and mortality with complex pathophysiological mechanisms. Oxidative stress is one of the main secondary reactions of SCI, and its main pathophysiological marker is the production of excess reactive oxygen species. The overproduction of reactive oxygen species and insufficient antioxidant capacity lead to the occurrence of oxidative stress and neuroinflammation, and the dysregulation of oxidative stress and neuroinflammation leads to further aggravation of damage. Oxidative stress can initiate a variety of inflammatory and apoptotic pathways, and targeted antioxidant therapy can greatly reduce oxidative stress and reduce neuroinflammation, which has a certain positive effect on rehabilitation and prognosis in SCI. This article reviewed the research on different types of antioxidants and related treatments in SCI, focusing on the mechanisms of oxidative stress.

Catalytic antioxidant nanoparticles mitigate secondary injury progression and promote functional recovery in spinal cord injury model

Traumatic spinal cord injury exacerbates disability with time due to secondary injury cascade triggered largely by overproduction of reactive oxygen species (ROS) at the lesion site, causing oxidative stress. This study explored nanoparticles containing antioxidant enzymes (antioxidant NPs) to neutralize excess ROS at the lesion site and its impact. When tested in a rat contusion model of spinal cord injury, a single dose of antioxidant NPs, administered intravenously three hours after injury, effectively restored the redox balance at the lesion site, interrupting the secondary injury progression. This led to reduced spinal cord tissue inflammation, apoptosis, cavitation, and inhibition of syringomyelia. Moreover, the treatment reduced scar tissue forming collagen at the lesion site, protected axons from demyelination, and stimulated lesion healing, with further analysis indicating the formation of immature neurons. The ultimate effect of the treatment was improved motor and sensory functions and rapid post-injury weight loss recovery. Histological analysis revealed activated microglia in the spinal cord displaying rod-shaped anti-inflammatory and regenerative phenotype in treated animals, contrasting with amoeboid inflammatory and degenerative phenotype in untreated control. Overall data suggest that restoring redox balance at the lesion site shifts the dynamics in the injured spinal cord microenvironment from degenerative to regenerative, potentially by promoting endogenous repair mechanisms. Antioxidant NPs show promise to be developed as an early therapeutic intervention in stabilizing injured spinal cord for enhanced recovery.

Neuronal NADPH oxidase is required for neurite regeneration of Aplysia bag cell neurons

NADPH oxidase (Nox), a major source of reactive oxygen species (ROS), is involved in neurodegeneration after injury and disease. Nox is expressed in both neuronal and non-neuronal cells and contributes to an elevated ROS level after injury. Contrary to the well-known damaging effect of Nox-derived ROS in neurodegeneration, recently a physiological role of Nox in nervous system development including neurogenesis, neuronal polarity, and axonal growth has been revealed. Here, we tested a role for neuronal Nox in neurite regeneration following mechanical transection in cultured Aplysia bag cell neurons. Using a novel hydrogen peroxide (H2 O2 )-sensing dye, 5'-(p-borophenyl)-2'-pyridylthiazole pinacol ester (BPPT), we found that H2 O2 levels are elevated in regenerating growth cones following injury. Redistribution of Nox2 and p40phox in the growth cone central domain suggests Nox2 activation after injury. Inhibiting Nox with the pan-Nox inhibitor celastrol reduced neurite regeneration rate. Pharmacological inhibition of Nox is correlated with reduced activation of Src2 tyrosine kinase and F-actin content in the growth cone. Taken together, these findings suggest that Nox-derived ROS regulate neurite regeneration following injury through Src2-mediated regulation of actin organization in Aplysia growth cones.

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.

Bioactive role of vitamins as a key modulator of oxidative stress, cellular damage and comorbidities associated with spinal cord injury (SCI)

Introduction: Spinal cord injury (SCI) cause significant disability and impact the quality of life of those affected by it. The nutritional status and diet are fundamental to diminish the progression of complications; vitamins modulate the inflammatory response and oxidative stress, promote blood-spinal cord barrier preservation and the prompt recovery of homeostasis. A deep knowledge of the benefits achieved from vitamins in patients with SCI are summarized. Information of dosage, time, and effects of vitamins in these patients are also displayed. Vitamins have been extensively investigated; however, more clinical trials are needed to clarify the scope of vitamin supplementation.Objective: The objective of this review was to offer relevant therapeutic information based on vitamins supplementation for SCI patients.Methods: Basic and clinical studies that have implemented the use of vitamins in SCI were considered. They were selected from the year 2000-2022 from three databases: PubMed, Science Direct and Google Scholar.Results: Consistent benefits in clinical trials were shown in those who were supplemented with vitamin D (prevents osteoporosis and improves physical performance variables), B3 (improves lipid profile) and B12 (neurological prophylaxis of chronic SCI damage) mainly. On the other hand, improvement related to neuroprotection, damage modulation (vitamin A) and its prophylaxis were associated to B complex vitamins supplementation; the studies who reported positive results are displayed in this review.Discussion: Physicians should become familiar with relevant information that can support conventional treatment in patients with SCI, such as the use of vitamins, a viable option that can improve outcomes in patients with this condition.

Revert total protein normalization method offers a reliable loading control for mitochondrial samples following TBI

Owing to evidence that mitochondrial dysfunction plays a dominant role in the traumatic brain injury (TBI) pathophysiology, the Western blot (WB) based immunoblotting method is widely employed to identify changes in the mitochondrial protein expressions after neurotrauma. In WB method, the housekeeping proteins (HKPs) expression is routinely used as an internal control for sample normalization. However, the traditionally employed HKPs can be susceptible to complex cascades of TBI pathogenesis, leading to their inconsistent expression. Remarkably, our data illustrated here that mitochondrial HKPs, including Voltage-dependent anion channels (VDAC), Complex-IV, Cytochrome C and Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) yielded altered expressions following penetrating TBI (PTBI) as compared to Sham. Therefore, our goal was to identify more precise normalization procedure in WB. Adult male Sprague Dawley rats (N = 6 rats/group) were used to perform PTBI, and the novel REVERT Total Protein (RTP) method was used to quantify mitochondrial protein load consistency between samples at 6 h and 24 h post-injury. Notably, the RTP method displayed superior protein normalization compared to HKPs method with higher sensitivity at both time-points between experimental groups. Our data favors application of RTP based normalization to accurately quantify protein expression where inconsistent HKPs may be evident in neuroscience research.

Mesenchymal Stem Cell Transplantation: Neuroprotection and Nerve Regeneration After Spinal Cord Injury

Spinal Cord Injury (SCI), with its morbidity characteristics of high disability rate and high mortality rate, is a disease that is highly destructive to both the physiology and psychology of the patient, and for which there is still a lack of effective treatment. Following spinal cord injury, a cascade of secondary injury reactions known as ischemia, peripheral inflammatory cell infiltration, oxidative stress, etc. create a microenvironment that is unfavorable to neural recovery and ultimately results in apoptosis and necrosis of neurons and glial cells. Mesenchymal stem cell (MSC) transplantation has emerged as a more promising therapeutic options in recent years. MSC can promote spinal cord injury repair through a variety of mechanisms, including immunomodulation, neuroprotection, and nerve regeneration, giving patients with spinal cord injury hope. In this paper, it is discussed the neuroprotection and nerve regeneration components of MSCs' therapeutic method for treating spinal cord injuries.

Oxidative stress following spinal cord injury: From molecular mechanisms to therapeutic targets

Spinal cord injury (SCI) is a medical condition that results from severe trauma to the central nervous system; it imposes great psychological and economic burdens on affected patients and their families. The dynamic balance between reactive oxygen species (ROS) and antioxidants is essential for maintaining normal cellular physiological functions. As important intracellular signaling molecules, ROS regulate numerous physiological activities, including vascular reactivity and neuronal function. However, excessive ROS can cause damage to cellular macromolecules, including DNA, lipids, and proteins; this damage eventually leads to cell death. This review discusses the mechanisms of oxidative stress in SCI and describes some signaling pathways that regulate oxidative injury after injury, with the aim of providing guidance for the development of novel SCI treatment strategies.

Neuroprotective effect and possible mechanism of edaravone in rat models of spinal cord injury: a protocol for a systematic review and meta-analysis

BACKGROUND

Spinal cord injury (SCI) is one of the most disabling neurological conditions, afflicting thousands of human beings. Edaravone, a well-known reactive oxygen species scavenger, is expanding its new scope in field of SCI. The objective of this systematic review is to determine the neuroprotective effects and discuss the underlying mechanism of edaravone in management of SCI.

METHODS

The systematic review will include the controlled studies evaluating the neurological roles of edaravone on experiment rat models following SCI. The primary outcome will be the 21-point Basso, Beattie, and Bresnahan locomotor rating scale. The secondary outcomes will include the preservation of white matter areas and malondialdehyde levels. Two researchers will independently search PubMed, Embase, Web of Science, Scopus and Cochrane Library from their inception date. Following study selection, data extraction, and assessment of methodological quality in included studies using the SYRCLE's RoB tool, data from eligible studies will be pooled and analyzed using random-effects models with RevMan 5.3 software. In case of sufficient data, subgroup analyses with respect to species, age, gender, injury characteristics, or administration details will be carried out to explore the factors modifying efficacy of edaravone. For exploring the appropriate dose of edaravone, a network meta-analysis approach will be conducted based on the Bayesian method. Importantly, the proposed mechanisms and changes of related molecules will be also extracted from included studies for comprehensively investigating the mechanisms underlying the neuroprotective effects of edaravone.

DISCUSSION

In this study, we aim to quantitatively analyze the role of edaravone in locomotor recovery and tissue damage in SCI rat model. The efficacy of edaravone in distinct scenarios will be investigated by subgroup analyses, and we expect to predict the candidate dose that offers a superior treatment effect using network meta-analyses. Moreover, a comprehensive framework regarding the neuroprotective mechanisms behind edaravone will be constructed via a combination of systematic and traditional review. This study will bring implications for future preclinical studies and clinical applications of SCI. Nonetheless, in light of the anticipated limitations in animal experimental design and methodological quality, the results in this review should be interpreted with caution.

Coaxial 3D printing of hierarchical structured hydrogel scaffolds for on-demand repair of spinal cord injury

After spinal cord injury (SCI), endogenous neural stem cells (NSCs) near the damaged site are activated, but few NSCs migrate to the injury epicenter and differentiate into neurons because of the harsh microenvironment. It has demonstrated that implantation of hydrogel scaffold loaded with multiple cues can enhance the function of endogenous NSCs. However, programming different cues on request remains a great challenge. Herein, a time-programmed linear hierarchical structure scaffold is developed for spinal cord injury recovery. The scaffold is obtained through coaxial 3D printing by encapsulating a dual-network hydrogel (composed of hyaluronic acid derivatives and N-cadherin modified sodium alginate, inner layer) into a temperature responsive gelatin/cellulose nanofiber hydrogel (Gel/CNF, outer layer). The reactive species scavenger, metalloporphyrin, loaded in the outer layer is released rapidly by the degradation of Gel/CNF, inhibiting the initial oxidative stress at lesion site to protect endogenous NSCs; while the inner hydrogel with appropriate mechanical support, linear topology structure and bioactive cues facilitates the migration and neuronal differentiation of NSCs at the later stage of SCI treatment, thereby promoting motor functional restorations in SCI rats. This study offers an innovative strategy for fabrication of multifunctional nerve regeneration scaffold, which has potential for clinical treatment of SCI. STATEMENT OF SIGNIFICANCE: Two major challenges facing the recovery from spinal cord injury (SCI) are the low viability of endogenous neural stem cells (NSCs) within the damaged microenvironment, as well as the difficulty of neuronal regeneration at the injured site. To address these issues, a spinal cord-like coaxial scaffold was fabricated with free radical scavenging agent metalloporphyrin Mn (III) tetrakis (4-benzoic acid) porphyrin and chemokine N-cadherin. The scaffold was constructed by 3D bioprinting for time-programmed protection and modulation of NSCs to effectively repair SCI. This 3D coaxially bioprinted biomimetic construct enables multi-factor on-demand repair and may be a promising therapeutic strategy for SCI.

Hydralazine Promotes Central Nervous System Recovery after Spinal Cord Injury by Suppressing Oxidative Stress and Inflammation through Macrophage Regulation

OBJECTIVE

This study aims to investigate the effects of hydralazine on inflammation induced by spinal cord injury (SCI) in the central nervous system (CNS) and its mechanism in promoting the structural and functional recovery of the injured CNS.

METHODS

A compressive SCI mouse model was utilized for this investigation. Immunofluorescence and quantitative real-time polymerase chain reaction were employed to examine the levels of acrolein, acrolein-induced inflammation-related factors, and macrophages at the injury site and within the CNS. Western blotting was used to evaluate the activity of the phosphoinositide 3-kinase (PI3K)/AKT pathway to study macrophage regulation. The neuropathic pain and motor function recovery were evaluated by glutamic acid decarboxylase 65/67 (GAD65/67), vesicular glutamate transporter 1 (VGLUT1), paw withdrawal response, and Basso Mouse Scale score. Nissl staining and Luxol Fast Blue (LFB) staining were performed to investigate the structural recovery of the injured CNS.

RESULTS

Hydralazine downregulated the levels of acrolein, IL-1β, and TNF-α in the spinal cord. The downregulation of acrolein induced by hydralazine promoted the activation of the PI3K/AKT pathway, leading to M2 macrophage polarization, which protected neurons against SCI-induced inflammation. Additionally, hydralazine promoted the structural recovery of the injured spinal cord area. Mitigating inflammation and oxidative stress by hydralazine in the animal model alleviated neuropathic pain and altered neurotransmitter expression. Furthermore, hydralazine facilitated motor function recovery following SCI. Nissl staining and LFB staining indicated that hydralazine promoted the structural recovery of the injured CNS.

CONCLUSION

Hydralazine, an acrolein scavenger, significantly mitigated SCI-induced inflammation and oxidative stress in vivo, modulated macrophage activation, and consequently promoted the structural and functional recovery of the injured CNS.

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

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

A mechanistic overview of spinal cord injury, oxidative DNA damage repair and neuroprotective therapies

Despite substantial development in medical treatment strategies scientists are struggling to find a cure against spinal cord injury (SCI) which causes long term disability and paralysis. The prime rationale behind it is the enlargement of primary lesion due to an initial trauma to the spinal cord which spreads to the neighbouring spinal tissues It begins from the time of traumatic event happened and extends to hours and even days. It further causes series of biological and functional alterations such as inflammation, excitotoxicity and ischemia, and promotes secondary lesion to the cord which worsens the life of individuals affected by SCI. Oxidative DNA damage is a stern consequence of oxidative stress linked with secondary injury causes oxidative base alterations and strand breaks, which provokes cell death in neurons. It is implausible to stop primary damage however it is credible to halt the secondary lesion and improve the quality of the patient's life to some extent. Therefore it is crucial to understand the hidden perspectives of cell and molecular biology affecting the pathophysiology of SCI. Thus the focus of the review is to connect the missing links and shed light on the oxidative DNA damages and the functional repair mechanisms, as a consequence of the injury in neurons. The review will also probe the significance of neuroprotective strategies in the present scenario. HIGHLIGHTSSpinal cord injury, a pernicious condition, causes excitotoxicity and ischemia, ultimately leading to cell death.Oxidative DNA damage is a consequence of oxidative stress linked with secondary injury, provoking cell death in neurons.Base excision repair (BER) is one of the major repair pathways that plays a crucial role in repairing oxidative DNA damages.Neuroprotective therapies curbing SCI and boosting BER include the usage of pharmacological drugs and other approaches.

Multiple mechanisms of curcumin targeting spinal cord injury

Spinal cord injury (SCI) is an irreversible disease process with a high disability and mortality rate. After primary spinal cord injury, the secondary injury may occur in sequence, which is composed of ischemia and hypoxia, excitotoxicity, calcium overload, oxidative stress and inflammation, resulting in massive death of parenchymal cells in the injured area, followed by the formation of syringomyelia. Effectively curbing the process of secondary injury can promote nerve repair and improve functional prognosis. As the main active ingredient in turmeric, curcumin can play an important role in reducing inflammation and oxidation, protecting the neurons, and ultimately reducing spinal cord injury. This article reviews the effects of curcumin on the repair of nerve injury, with emphasis on the various mechanisms by which curcumin promotes the treatment of spinal cord injury.

Co-Administration of Nanowired Monoclonal Antibodies to Inducible Nitric Oxide Synthase and Tumor Necrosis Factor Alpha Together with Antioxidant H-290/51 Reduces SiO2 Nanoparticles-Induced Exacerbation of Pathophysiology of Spinal Cord Trauma

Military personnel are often exposed to silica dust during combat operations across the globe. Exposure to silica dust in US military or service personnel could cause Desert Strom Pneumonitis also referred to as Al Eskan disease causing several organs damage and precipitate autoimmune dysfunction. However, the effects of microfine particles of sand inhalation-induced brain damage on the pathophysiology of traumatic brain or spinal cord injury are not explored. Previously intoxication of silica nanoparticles (50-60 nm size) is shown to exacerbates spinal cord injury induces blood-spinal cord barrier breakdown, edema formation and cellular changes. However, the mechanism of silica nanoparticles-induced cord pathology is still not well known. Spinal cord injury is well known to alter serotonin (5-hydroxytryptamine) metabolism and induce oxidative stress including upregulation of nitric oxide synthase and tumor necrosis factor alpha. This suggests that these agents are involved in the pathophysiology of spinal cord injury. In this review, we examined the effects of combined nanowired delivery of monoclonal antibodies to neuronal nitric oxide synthase (nNOS) together with tumor necrosis factor alpha (TNF-α) antibodies and a potent antioxidant H-290/51 to induce neuroprotection in spinal cord injury associated with silica nanoparticles intoxication. Our results for the first time show that co-administration of nanowired delivery of antibodies to nNOS and TNF-α with H-290/51 significantly attenuated silica nanoparticles-induced exacerbation of spinal cord pathology, not reported earlier.

Molecular approaches for spinal cord injury treatment

Injuries to the spinal cord result in permanent disabilities that limit daily life activities. The main reasons for these poor outcomes are the limited regenerative capacity of central neurons and the inhibitory milieu that is established upon traumatic injuries. Despite decades of research, there is still no efficient treatment for spinal cord injury. Many strategies are tested in preclinical studies that focus on ameliorating the functional outcomes after spinal cord injury. Among these, molecular compounds are currently being used for neurological recovery, with promising results. These molecules target the axon collapsed growth cone, the inhibitory microenvironment, the survival of neurons and glial cells, and the re-establishment of lost connections. In this review we focused on molecules that are being used, either in preclinical or clinical studies, to treat spinal cord injuries, such as drugs, growth and neurotrophic factors, enzymes, and purines. The mechanisms of action of these molecules are discussed, considering traumatic spinal cord injury in rodents and humans.

Recent advances in nanomaterials for the treatment of spinal cord injury

Spinal cord injuries (SCIs) are devastating. In SCIs, a powerful traumatic force impacting the spinal cord results in the permanent loss of nerve function below the injury level, leaving the patient paralyzed and wheelchair-bound for the remainder of his/her life. Unfortunately, clinical treatment that depends on surgical decompression appears to be unable to handle damaged nerves, and high-dose methylprednisolone-based therapy is also associated with problems, such as infection, gastrointestinal bleeding, femoral head necrosis, obesity, and hyperglycemia. Nanomaterials have opened new avenues for SCI treatment. Among them, performance-based nanomaterials derived from a variety of materials facilitate improvements in the microenvironment of traumatic injury and, in some cases, promote neuron regeneration. Nanoparticulate drug delivery systems enable the optimization of drug effects and drug bioavailability, thus contributing to the development of novel treatments. The improved efficiency and accuracy of gene delivery will also benefit the exploration of SCI mechanisms and the understanding of key genes and signaling pathways. Herein, we reviewed different types of nanomaterials applied to the treatment of SCI and summarized their functions and advantages to provide new perspectives for future clinical therapies.

A tannic acid doped hydrogel with small extracellular vesicles derived from mesenchymal stem cells promotes spinal cord repair by regulating reactive oxygen species microenvironment

Spinal cord injury (SCI) is a serious disease of the central nervous system that is associated with a poor prognosis; furthermore, existing clinical treatments cannot restore nerve function in an effective manner. Inflammatory responses and the increased production of reactive oxygen species (ROS) in the microenvironment of the lesion are major obstacles that inhibit the recovery of SCI. Small extracellular vesicles (sEVs), derived from mesenchymal stem cells, are suitable options for cell-free therapy and have been shown to exert therapeutic effects in SCI, thus providing a potential strategy for microenvironment regulation. However, the effective retention, controlled release, and integration of small extracellular vesicles into injured spinal cord tissue are still a major challenge. Herein, we fabricated an N-acryloyl glycinamide/gelatin methacrylate/Laponite/Tannic acid (NAGA/GelMA/LPN/TA, NGL/T) hydrogel with sustainable sEV release (sEVs-NGL/T) to promote the recovery of motor function after SCI. The newly developed functional sEVs-NGL/T hydrogel exhibited excellent antioxidant properties in an H₂O₂-simulated peroxidative microenvironment in vitro. Implantation of the functional sEVs-NGL/T hydrogel in vivo could encapsulate sEVs, exhibiting efficient retention and the sustained release of sEVs, thereby synergistically inducing significant restoration of motor function and urinary tissue preservation. These positive effects can be attributed to the effective mitigation of the inflammatory and ROS microenvironment. Therefore, sEVs-NGL/T therapy provides a promising strategy for the sEV-based therapy in the treatment of SCI by comprehensively regulating the pathological microenvironment.

Spinal Obstruction-Related vs. Craniocervical Junction-Related Syringomyelia: A Comparative Study

Background

No prior reports have focused on spinal cord injury (SCI) characteristics or inflammation after destruction of the blood–spinal cord barrier by syringomyelia. This study aimed to determine the differences in syringomyelia-related central SCI between craniocervical junction (CCJ) syringomyelia and post-traumatic syringomyelia (PTS) before and after decompression.

Methods

In all, 106 CCJ, 26 CCJ revision and 15 PTS patients (mean history of symptoms, 71.5 ± 94.3, 88.9 ± 85.5, and 32.3 ± 48.9 months) between 2015 and 2019 were included. The symptom course was analyzed with the American Spinal Injury Association ASIA and Klekamp–Samii scoring systems, and neurological changes were analyzed by the Kaplan–Meier statistics. The mean follow-up was 20.7 ± 6.2, 21.7 ± 8.8, and 34.8 ± 19.4 months.

Results

The interval after injury was longer in the PTS group, but the natural history of syringomyelia was shorter (p = 0.0004 and 0.0173, respectively). The initial symptom was usually paraesthesia (p = 0.258), and the other main symptoms were hypoesthesia (p = 0.006) and abnormal muscle strength (p = 0.004), gait (p < 0.0001), and urination (p < 0.0001). SCI associated with PTS was more severe than that associated with the CCJ (p = 0.003). The cavities in the PTS group were primarily located at the thoracolumbar level, while those in the CCJ group were located at the cervical-thoracic segment at the CCJ. The syrinx/cord ratio of the PTS group was more than 75% (p = 0.009), and the intradural adhesions tended to be more severe (p < 0.0001). However, there were no significant differences in long-term clinical efficacy or peripheral blood inflammation markers (PBIMs) except for the red blood cell (RBC) count (p = 0.042).

Conclusion

PTS tends to progress faster than CCJ-related syringomyelia. Except for the RBC count, PBIMs showed no value in distinguishing the two forms of syringomyelia. The predictive value of the neutrophil-to-lymphocyte ratio for syringomyelia-related inflammation was negative except in the acute phase.

Citric acid cross-linked chitosan for inhibiting oxidative stress after nerve injury

Scaffold design is particularly important and necessary for soft tissue repair such as nerve tissue repair. In this article, we designed and manufactured a macroporous chitosan-based hydrogel with excellent cell compatibility and antioxidant properties. Here, the chitosan (CS) based hydrogel is obtained by repeated freezing and thawing using citric acid (CA) as a cross-linking agent. We have evaluated the effects of citric acid content on the physical and chemical properties of hydrogels through mechanical properties and scanning electron microscopy. CA-CS hydrogel shows a macroporous structure, as the citric acid increases, the mechanical strength increases and the pore size decreases. In vitro cell experiments show that CA-CS hydrogel partakes positive effects on cell survival, adhesion and proliferation, as well as antioxidant properties. All results provide a basis for the construction of porous chitosan-based hydrogels, while demonstrating a promising approach to deal with oxidative stress in nerve injury.

Can chlorogenic acid reduce oxidative stress and in an experimental spinal cord injury?

BACKGROUND

We aimed to investigate antioxidant and neuroprotective properties of chlorogenic acid in spinal cord injury (SCI).

METHODS

Twenty-one rats were divided into three groups. Laminectomy was performed in group L (n=7), spinal cord trauma was induced in group T (n=7), and spinal cord trauma was induced and chlorogenic acid treatment was started in group C (n=7). Blood samples were collected to analyze baseline values and the 12th h, 1st day, 3rd day, and 5th day catalase, native thiol (NT), total thiol (TT), disulfide (SS), SS/TT, SS/NT, and NT/TT levels. Functional analysis with Basso-Beattie and Bresnahan scores was performed at the same time points. Total antioxidant status (TAS), total oxidative stress, oxidative stress index, and cyclooxygenase-2 (Cox-2) were examined in the spinal cord of rats euthanized on day 7; results were statistically analyzed.

RESULTS

On day 7, catalase levels in Group C were significantly higher than baseline levels, whereas those in Group T were significantly lower than baseline levels; Group L showed no significant difference (p=0.008). SS values on day 7 were lower in Group T than in Groups C and L. Group C showed the lowest decrease in NT/TT level after trauma. On day 7, SS/TT level was high in Group T but stable in Groups C and L (p=0.04). Histopathological examination revealed significantly lower Cox-2 and TAS levels in Group C than in Group T (p=0.003, p=0.017, respectively).

CONCLUSION

In this study, SCI was primarily examined through thiol-SS balance, and it was demonstrated by experimental models that chlorogenic acid has antioxidant and neuroprotective effects in SCI.

Supplementation With Vitamin E, Zinc, Selenium, and Copper Re-Establishes T-Cell Function and Improves Motor Recovery in a Rat Model of Spinal Cord Injury

Spinal cord injury (SCI) causes a dysfunction of sympathetic nervous system innervation that affects the immune system, leading to immunosuppression syndrome (ISS) and contributing to patient degeneration and increased risk of several infections. A possible therapeutic strategy that could avoid further patient deterioration is the supplementation with Vitamin E or trace elements, such as Zinc, Selenium, and Copper, which individually promotes T-cell differentiation and proliferative responses. For this reason, the aim of the present study was to evaluate whether Vitamin E, Zinc, Selenium, and Copper supplementation preserves the number of T-lymphocytes and improves their proliferative function after traumatic SCI. Sprague–Dawley female rats were subjected to moderate SCI and then randomly allocated into three groups: (1) SCI + supplements; (2) SCI + vehicle (olive oil and phosphate-buffered saline); and (3) sham-operated rats. In all rats, the intervention was initiated 15 min after SCI and then administered daily until the end of study. Locomotor recovery was assessed at 7 and 15 days after SCI. At 15 days after supplementation, the quantification of the number of T-cells and its proliferation function were examined. Our results showed that the SCI + supplements group presented a significant improvement in motor recovery at 7 and 15 days after SCI. In addition, this group showed a better T-cell number and proliferation rate than that observed in the group with SCI + vehicle. Our findings suggest that Vitamin E, Zinc, Selenium, and Copper supplementation could be part of a therapy for patients suffering from acute SCI, helping to preserve T-cell function, avoiding complications, and promoting a better motor recovery. All procedures were approved by the Animal Bioethics and Welfare Committee (Approval No. 201870; CSNBTBIBAJ 090812960).

Anti-inflammatory and antioxidative effects of genistein in a model of spinal cord injury in rats

Background

Neurological damage from spinal cord injury (SCI) is a result of primary mechanical injury and secondary damage from oxidative stress and neuroinflammation. Although genistein has been shown to have potent antioxidant and anti-inflammatory effects in studies of brain injury, its effect on secondary damage in SCI has remained unknown.

Objective

To determine effects of genistein in a model of SCI in rats.

Methods

We divided 21 rats evenly into 3 groups, a control group, in which only a laminectomy was performed; a trauma group in which SCI was induced; and a genistein group in which genistein was administered subcutaneously after SCI. The rats were assessed using a Basso-Beattie and Bresnahan functional score at the 12th hour and on the 1st, 3rd, 5th, and 7th days. Biochemical analyses were conducted at the same time points to determine the serum levels of catalase, ischemia-modified albumin (IMA), disulfide (SS), total thiol (TT), native thiol (NT), disulfide/total thiol (SS/TT), and native thiol/total thiol (NT/TT). Total oxidant and antioxidant capacity, and oxidative stress index were determined in spinal cord tissue obtained on the 7th day together with immunohistochemistry for cyclooxygenase-2 levels.

Result

Catalase activity on the 7th day was significantly (P = 0.001) higher in the genistein-treated rats than in other groups, and IMA levels became stable earlier (3rd day) in the genistein group. SS values were significantly (P = 0.004) lower in the genistein group. NT/TT ratio were significantly (P = 0.049) higher in the genistein-treated rats on the 7th day.

Conclusion

Genistein has antioxidant, anti-inflammatory, and protective effects in a model of SCI in rats and warrants further study.

Acute spinal cord injury: Pathophysiology and pharmacological intervention (Review)

Spinal cord injury (SCI) is one of the most debilitating of all the traumatic conditions that afflict individuals. For a number of years, extensive studies have been conducted to clarify the molecular mechanisms of SCI. Experimental and clinical studies have indicated that two phases, primary damage and secondary damage, are involved in SCI. The initial mechanical damage is caused by local impairment of the spinal cord. In addition, the fundamental mechanisms are associated with hyperflexion, hyperextension, axial loading and rotation. By contrast, secondary injury mechanisms are led by systemic and cellular factors, which may also be initiated by the primary injury. Although significant advances in supportive care have improved clinical outcomes in recent years, a number of studies continue to explore specific pharmacological therapies to minimize SCI. The present review summarized some important pathophysiologic mechanisms that are involved in SCI and focused on several pharmacological and non‑pharmacological therapies, which have either been previously investigated or have a potential in the management of this debilitating injury in the near future.

Methylprednisolone Induces Neuro-Protective Effects via the Inhibition of A1 Astrocyte Activation in Traumatic Spinal Cord Injury Mouse Models

Traumatic spinal cord injury (TSCI) leads to pathological changes such as inflammation, edema, and neuronal apoptosis. Methylprednisolone (MP) is a glucocorticoid that has a variety of beneficial effects, including decreasing inflammation and ischemic reaction, as well as inhibiting lipid peroxidation. However, the efficacy and mechanism of MP in TSCI therapy is yet to be deciphered. In the present study, MP significantly attenuated the apoptotic effects of H₂O₂ in neuronal cells. Western blot analysis demonstrated that the levels of apoptotic related proteins, Bax and cleaved caspase-3, were reduced while levels of anti-apoptotic Bcl-2 were increased. In vivo TUNEL assays further demonstrated that MP effectively protected neuronal cells from apoptosis after TSCI, and was consistent with in vitro studies. Furthermore, we demonstrated that MP could decrease expression levels of IBA1, Il-1α, TNFα, and C3 and suppress A1 neurotoxic reactive astrocyte activation in TSCI mouse models. Neurological function was evaluated using the Basso Mouse Scale (BMS) and Footprint Test. Results demonstrated that the neurological function of MP-treated injured mice was significantly increased. In conclusion, our study demonstrated that MP could attenuate astrocyte cell death, decrease microglia activation, suppress A1 astrocytes activation, and promote functional recovery after acute TSCI in mouse models.

IL-10 lentivirus-laden hydrogel tubes increase spinal progenitor survival and neuronal differentiation after spinal cord injury

A complex cellular cascade characterizes the pathophysiological response following spinal cord injury (SCI) limiting regeneration. Biomaterial and stem cell combination therapies together have shown synergistic effects, compared to the independent benefits of each intervention, and represent a promising approach towards regaining function after injury. In this study, we combine our polyethylene glycol (PEG) cell delivery platform with lentiviral-mediated overexpression of the anti-inflammatory cytokine interleukin (IL)-10 to improve mouse embryonic Day 14 (E14) spinal progenitor transplant survival. Immediately following injury in a mouse SCI hemisection model, five PEG tubes were implanted followed by direct injection into the tubes of lentivirus encoding for IL-10. Two weeks after tube implantation, mouse E14 spinal progenitors were injected directly into the integrated tubes, which served as a soft substrate for cell transplantation. Together, the tubes with the IL-10 encoding lentivirus improved E14 spinal progenitor survival, assessed at 2 weeks posttransplantation (4 weeks postinjury). On average, 8.1% of E14 spinal progenitors survived in mice receiving IL-10 lentivirus-laden tubes compared with 0.7% in mice receiving transplants without tubes, an 11.5-fold difference. Surviving E14 spinal progenitors gave rise to neurons when injected into tubes. Axon elongation and remyelination were observed, in addition to a significant increase in functional recovery in mice receiving IL-10 lentivirus-laden tubes with E14 spinal progenitor delivery compared to the injury only control by 4 weeks postinjury. All other conditions did not exhibit increased stepping until 8 or 12 weeks postinjury. This system affords increased control over the transplantation microenvironment, offering the potential to improve stem cell-mediated tissue regeneration.

Biomaterials reinforced MSCs transplantation for spinal cord injury repair

Due to the complex pathophysiological mechanism, spinal cord injury (SCI) has become one of the most intractable central nervous system (CNS) diseases to therapy. Stem cell transplantation, mesenchymal stem cells (MSCs) particularly, appeals to more and more attention along with the encouraging therapeutic results for the functional regeneration of SCI. However, traditional cell transplantation strategies have some limitations, including the unsatisfying survival rate of MSCs and their random diffusion from the injection site to ambient tissues. The application of biomaterials in tissue engineering provides a new horizon. Biomaterials can not only confine MSCs in the injured lesions with higher cell viability, but also promote their therapeutic efficacy. This review summarizes the strategies and advantages of biomaterials reinforced MSCs transplantation to treat SCI in recent years, which are clarified in the light of various therapeutic effects in pathophysiological aspects of SCI.

Hormetic Effects of Bioactive Compounds from Foods, Beverages, and Food Dressing: The Potential Role in Spinal Cord Injury

Spinal cord injury (SCI) is a damage or trauma to the spinal cord resulting in a total or partial loss of motor and sensory function. SCI is characterized by a disequilibrium between the production of reactive oxygen species and the levels of antioxidant defences, causing oxidative stress and neuroinflammation. This review is aimed at highlighting the hormetic effects of some compounds from foods, beverages, and food dressing that are able to reduce oxidative stress in patients with SCI. Although curcumin, ginseng, and green tea have been proposed for SCI management, low levels of antioxidant vitamins have been reported in individuals with SCI. Mediterranean diet includes food rich in vitamins and antioxidants. Moreover, food dressing, including spices, herbs, and extra virgin olive oil (EVOO), contains multiple components with hormetic effects. The latter involves the activation of the nuclear factor erythroid-derived 2, consequently increasing the antioxidant enzymes and decreasing inflammation. Furthermore, EVOO improves the bioavailability of carotenoids and could be a delivery system for bioactive compounds. In conclusion, Mediterranean dressing in addition to plant foods can have an important effect on redox balance in individuals with SCI.

4-Hydroxynonenal is An Oxidative Degradation Product of Polysorbate 80

INTRODUCTION

Polysorbates (PS) are used in biopharmaceuticals to stabilize therapeutic proteins. Oxidative degradation of (poly)unsaturated fatty acids (PUFAs) contained in PS was shown to lead to α,β-unsaturated carbonyls.

AIM

The n-6-PUFA linoleic acid accounts for up to 18% of all FAs contained in multi-compendial grade PS80. 4-Hydroxynonenal (HNE) is highly reactive towards nucleophilic amino acids, potentially leading to covalent protein modifications. This study tests whether HNE may be a pharmaceutically relevant PS80 peroxidation product.

METHODS

Since HNE was not directly detectable in the PS80 matrix by UV and MS, a new quantification method was established. After derivatization with 2,4-dinitrophenyl hydrazine (DNPH) and extraction of the formed hydrazone with a salting-out assisted liquid-liquid extraction, the HNE-DNPH adduct was analyzed by multiple reaction monitoring. Kinetic oxidation studies were conducted incubating PS80 in presence and absence of the antioxidant butylhydroxytoluene (BHT).

RESULTS

HNE was confirmed as PS80 degradant in oxidatively stressed samples. BHT was shown to prevent its formation.

CONCLUSION

HNE is a detectable PS80 degradation product raising questions about the potential impact on critical quality attributes of biopharmaceuticals formulated with PS80. Addition of BHT prevented HNE formation under oxidative stress. Consequently, BHT might be a valuable additive in PS used in biopharmaceuticals.

Role of melatonin in the dynamics of acute spinal cord injury in rats

Melatonin is well‐documented to have the ability of reducing nerve inflammation and scavenging free radicals. However, the therapeutic effect of melatonin on spinal cord injury has not been fully described. In this study, we assessed the effect of melatonin on T9 spinal cord injury established by Allen method in rats. Melatonin deficiency significantly delayed the recovery of sensory and motor functions in SCI rats. Treatment with melatonin significantly alleviated neuronal apoptosis and accelerated the recovery of spinal cord function. These results suggest that melatonin is effective to ameliorate spinal cord injury through inhibition of neuronal apoptosis and promotion of neuronal repair.

Macrophage migration inhibitory factor as a therapeutic target after traumatic spinal cord injury: a systematic review

PURPOSE

Macrophages play an important role in mediating damage after Spinal cord injury (SCI) by secreting macrophage migration inhibitory factor (MMIF) as a secondary injury mediator. We aimed to systematically review the role of MMIF as a therapeutic target after traumatic SCI.

METHODS

Our systematic review has been performed according to the PRISMA 2009 Checklist. A systematic search in the scientific databases was carried out for studies published before 20 February 2019 from major databases. Two researchers independently screened titles. The risk of bias of eligible articles was assessed, and data were extracted. Finally, we systematically analyzed and interpreted related data.

RESULTS

785 papers were selected for the title and abstract screening. 12 papers were included for data extraction. Eight animal studies were of high quality and the remaining two were of medium quality. One of the two human studies was of poor quality and the other was of fair quality. MMIF as a pro-inflammatory mediator can cause increased susceptibility to glutamate-related neurotoxicity, increased nitrite production, increased ERK activation, and increased COX2/PGE2 signaling pathway activation and subsequent stimulation of CCL5-related chemotaxis. Two human studies and six animal studies demonstrated that MMIF level increases after SCI. MMIF inhibition might be a potential therapeutic target in SCI by multiple different mechanisms (6/12 studies).

CONCLUSION

Most animal studies demonstrate significant neurologic improvement after administration of MMIF inhibitors, but these inhibitors have not been studied in humans yet. Further clinical trials are need to further understand MMIF inhibitor utility in acute or chronic SCI.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Identification of potential oxidative stress biomarkers for spinal cord injury in erythrocytes using mass spectrometry

Oxidative stress is a hallmark of secondary injury associated with spinal cord injury. Identifying stable and specific oxidative biomarkers is of important significance for studying spinal cord injury-associated secondary injury. Mature erythrocytes do not contain nuclei and mitochondria and cannot be transcribed and translated. Therefore, mature erythrocytes are highly sensitive to oxidative stress and may become a valuable biomarker. In the present study, we revealed the proteome dynamics of protein expression in erythrocytes of beagle dogs in the acute and subacute phases of spinal cord injury using mass spectrometry-based approaches. We found 26 proteins that were differentially expressed in the acute (0-3 days) and subacute (7-21 days) phases of spinal cord injury. Bioinformatics analysis revealed that these differentially expressed proteins were involved in glutathione metabolism, lipid metabolism, and pentose phosphate and other oxidative stress pathways. Western blot assays validated the differential expression of glutathione synthetase, transaldolase, and myeloperoxidase. This result was consistent with mass spectrometry results, suggesting that erythrocytes can be used as a novel sample source of biological markers of oxidative stress in spinal cord injury. Glutathione synthetase, transaldolase, and myeloperoxidase sourced from erythrocytes are potential biomarkers of oxidative stress after spinal cord injury. This study was approved by the Experimental Animal Centre of Ningxia Medical University, China (approval No. 2017-073) on February 13, 2017.

Spinal Cord Injury: Pathophysiology, Multimolecular Interactions, and Underlying Recovery Mechanisms

Spinal cord injury (SCI) is a destructive neurological and pathological state that causes major motor, sensory and autonomic dysfunctions. Its pathophysiology comprises acute and chronic phases and incorporates a cascade of destructive events such as ischemia, oxidative stress, inflammatory events, apoptotic pathways and locomotor dysfunctions. Many therapeutic strategies have been proposed to overcome neurodegenerative events and reduce secondary neuronal damage. Efforts have also been devoted in developing neuroprotective and neuro-regenerative therapies that promote neuronal recovery and outcome. Although varying degrees of success have been achieved, curative accomplishment is still elusive probably due to the complex healing and protective mechanisms involved. Thus, current understanding in this area must be assessed to formulate appropriate treatment modalities to improve SCI recovery. This review aims to promote the understanding of SCI pathophysiology, interrelated or interlinked multimolecular interactions and various methods of neuronal recovery i.e., neuroprotective, immunomodulatory and neuro-regenerative pathways and relevant approaches.

Biomarkers of oxidative stress and inflammation in people witha physical disability treated with a standardized extract of Nasturtium officinale: A randomized, double-blind, and placebo-controlled trial

It is well established that plants from the Brassicaceae family, particularly watercress, have been associated to reduce oxidative DNA damage. Nasturtium officinale R. Br (watercress) contains glucosinolates, with anti-inflammatory action and protective effect on human health against oxidative stress. We aimed to evaluate whether the standardized extract of Nasturtium officinale (SENO) is capable of changing biomarkers of oxidative stress and inflammation in people with physical disabilities. 65 people enrolled this study: as a control group composed by; 15 people with no physical disability assessed once, 25 people with physical disabilities using 750 mg/kg/day of SENO, and 25 people with physical disabilities using 750 mg/kg/day of placebo-control for 5 weeks. Biomarkers of oxidative stress and inflammation were analyzed on day 0 and 36. The results indicated that SENO was associated with decreasing levels of lipid peroxidation, protein carbonyl, catalase, superoxide dismutase, and C-reactive protein. Furthermore, the cytokine kit demonstrated below and out of invertible range, which was impossible to detect the inflammatory process. Despite the cytokine kit was not able to detect the inflammation; these data might provide supportive evidence that SENO, have affected positively people with physical disabilities decreasing their biomarkers of oxidative stress and C-reactive protein. Further studies are required.