Post-traumatic inflammation following spinal cord injury

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.

Galectin-3 absence alters lymphocytes populations dynamics behavior and promotes functional recovery after spinal cord injury in mice

Spinal cord injury (SCI) results from various mechanisms that damage the nervous tissue and the blood-brain barrier, leading to sensory and motor function loss below the injury site. Unfortunately, current therapeutic approaches for SCI have limited efficacy in improving patients outcomes. Galectin-3, a protein whose expression increases after SCI, influences the neuroinflammatory response by favoring pro-inflammatory M1 macrophages and microglia, while inhibiting pro-regenerative M2 macrophages and microglia, which are crucial for inflammation resolution and tissue regeneration. Previous studies with Galectin-3 knock-out mice demonstrated enhanced motor recovery after SCI. The M1/M2 balance is strongly influenced by the predominant lymphocytic profiles (Th1, Th2, T Reg, Th17) and cytokines and chemokines released at the lesion site. The present study aimed to investigate how the absence of galectin-3 impacts the adaptive immune system cell population dynamics in various lymphoid spaces following a low thoracic spinal cord compression injury (T9-T10) using a 30 g vascular clip for one minute. It also aimed to assess its influence on the functional outcome in wild-type (WT)and Galectin-3 knock-out (GALNEG) mice. Histological analysis with hematoxylin-eosin and Luxol Fast Blue staining revealed that WT and GALNEG animals exhibit similar spinal cord morphology. The absence of galectin-3 does not affect the common neuroanatomy shared between the groups prompting us to analyze outcomes between both groups. Following our crush model, both groups lost motor and sensory functions below the lesion level. During a 42-day period, GALNEG mice demonstrated superior locomotor recovery in the Basso Mouse Scale (BMS) gait analysis and enhanced motor coordination performance in the ladder rung walk test (LRW) compared to WT mice. GALNEG mice also exhibited better sensory recovery, and their electrophysiological parameters suggested a higher number of functional axons with faster nerve conduction. Seven days after injury, flow cytometry of thymus, spleen, and blood revealed an increased number of T Reg and Th2 cells, accompanied by a decrease in Th1 and Th17 cells in GALNEG mice. Immunohistochemistry conducted on the same day exhibited an increased number of Th2 and T Reg cells around the GALNEG's spinal cord lesion site. At 42-day dpi immunohistochemistry analyses displayed reduced astrogliosis and greater axon preservation in GALNEG's spinal cord seem as a reduction of GFAP immunostaining and an increase in NFH immunostaining, respectively. In conclusion, GALNEG mice exhibited better functional recovery attributed to the milder pro-inflammatory influence, compensated by a higher quantity of T Reg and Th2 cells. These findings suggest that galectin-3 plays a crucial role in the immune response after spinal cord injury and could be a potential target for clinical therapeutic interventions.

The effects of acteoside on locomotor recovery after spinal cord injury - The role of autophagy and apoptosis signaling pathway

In the current study, we investigated the effects of acteoside as a phenylpropanoid glycoside on interaction with neurons to assesses locomotor recovery after spinal cord injury (SCI) in rats by focusing on evaluating the factors involved in autophagy, apoptosis, inflammation and oxidative stress processes. 49 Spargue-Dawley rats were prepared and divided into seven healthy and SCI groups receiving different concentrations of acteoside. After 28 days of disease induction and treatment with acteoside, a BBB score test was used to evaluate locomotor activity. Then, by preparing spinal cord cell homogenates, the expression levels of MAP1LC3A, MAP-2, glial fibrillary acidic protein (GFAP), Nrf2, Keap-1, Caspase 3 (Casp3), Bax, Bcl-2, TNF-a, IL-1B, reactive oxygen species (ROS), and malondialdehyde (MDA) were measured. Improvement of locomotor activity in SCI rats receiving acteoside was observed two weeks after the beginning of the experiment and continued until the fourth week. Both MAP1LC3A and MAP-2 were significantly up-regulated in SCI rats treated with acteoside compared to untreated SCI rats, and GFAP levels were significantly decreased in these animals. Pro-apoptotic proteins Bax and Casp3 and anti-apoptotic protein Bcl-2 were down-regulated and up-regulated, respectively, in SCI rats receiving acteoside. In addition, a significant downregulation of iNOS, TNF-α, and IL-1β and a decrease in contents of both ROS and MDA as well as increases in Nrf2 and Keap-1 were seen in rats receiving acteoside. Furthermore, acteoside strongly interacted with MAP1LC3A, TNF-α, and Casp3 targets with binding affinities of -8.3 kcal/mol, -8.3 kcal/mol, and -8.5 kcal/mol, respectively, determined by molecular docking studies. In general, it can be concluded that acteoside has protective effects in SCI and can be considered as an adjuvant therapy in the treatment of this disease. However, more studies, especially clinical studies, are needed in this field.

The role of small extracellular vesicles and microRNA as their cargo in the spinal cord injury pathophysiology and therapy

Spinal cord injury (SCI) is a devastating condition with a complex pathology that affects a significant portion of the population and causes long-term consequences. After primary injury, an inflammatory cascade of secondary injury occurs, followed by neuronal cell death and glial scar formation. Together with the limited regenerative capacity of the central nervous system, these are the main reasons for the poor prognosis after SCI. Despite recent advances, there is still no effective treatment. Promising therapeutic approaches include stem cells transplantation, which has demonstrated neuroprotective and immunomodulatory effects in SCI. This positive effect is thought to be mediated by small extracellular vesicles (sEVs); membrane-bound nanovesicles involved in intercellular communication through transport of functional proteins and RNA molecules. In this review, we summarize the current knowledge about sEVs and microRNA as their cargo as one of the most promising therapeutic approaches for the treatment of SCI. We provide a comprehensive overview of their role in SCI pathophysiology, neuroprotective potential and therapeutic effect.

α-Gal Nanoparticles in CNS Trauma: II. Immunomodulation Following Spinal Cord Injury (SCI) Improves Functional Outcomes

BACKGROUND

Previous investigations have shown that local application of nanoparticles presenting the carbohydrate moiety galactose-α-1,3-galactose (α-gal epitopes) enhance wound healing by activating the complement system and recruiting pro-healing macrophages to the injury site. Our companion in vitro paper suggest α-gal epitopes can similarly recruit and polarize human microglia toward a pro-healing phenotype. In this continuation study, we investigate the in vivo implications of α-gal nanoparticle administration directly to the injured spinal cord.

METHODS

α-Gal knock-out (KO) mice subjected to spinal cord crush were injected either with saline (control) or with α-gal nanoparticles immediately following injury. Animals were assessed longitudinally with neurobehavioral and histological endpoints.

RESULTS

Mice injected with α-gal nanoparticles showed increased recruitment of anti-inflammatory macrophages to the injection site in conjunction with increased production of anti-inflammatory markers and a reduction in apoptosis. Further, the treated group showed increased axonal infiltration into the lesion, a reduction in reactive astrocyte populations and increased angiogenesis. These results translated into improved sensorimotor metrics versus the control group.

CONCLUSIONS

Application of α-gal nanoparticles after spinal cord injury (SCI) induces a pro-healing inflammatory response resulting in neuroprotection, improved axonal ingrowth into the lesion and enhanced sensorimotor recovery. The data shows α-gal nanoparticles may be a promising avenue for further study in CNS trauma.

Identification of Anoikis-Related Genes in Spinal Cord Injury: Bioinformatics and Experimental Validation

Spinal cord injury (SCI) is a serious disease without effective therapeutic strategies. To identify the potential treatments for SCI, it is extremely important to explore the underlying mechanism. Current studies demonstrate that anoikis might play an important role in SCI. In this study, we aimed to identify the key anoikis-related genes (ARGs) providing therapeutic targets for SCI. The mRNA expression matrix of GSE45006 was downloaded from the Gene Expression Omnibus (GEO) database, and the ARGs were downloaded from the Molecular Signatures Database (MSigDB database). Then, the potential differentially expressed ARGs were identified. Next, correlation analysis, gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and protein-protein interaction (PPI) analysis were employed for the differentially expressed ARGs. Moreover, miRNA-gene networks were constructed by the hub ARGs. Finally, RNA expression of the top ten hub ARGs was validated in the SCI cell model and rat SCI model. A total of 27 common differentially expressed ARGs were identified at different time points (1, 3, 7, and 14 days) following SCI. The GO and KEGG enrichment analysis of these ARGs indicated several enriched terms related to proliferation, cell cycle, and apoptotic process. The PPI results revealed that most of the ARGs interacted with each other. Ten hub ARGs were further screened, and all the 10 genes were validated in the SCI cell model. In the rat model, only seven genes were validated eventually. We identified 27 differentially expressed ARGs of the SCI through bioinformatic analysis. Seven real hub ARGs (CCND1, FN1, IGF1, MYC, STAT3, TGFB1, and TP53) were identified eventually. These results may expand our understanding of SCI and contribute to the exploration of potential SCI targets.

The prognostic utility of neutrophil-lymphocyte ratio in spinal surgery: A systematic review and meta-analysis

PURPOSE

Neutrophil-lymphocyte ratio (NLR) is reportedly an effective prognostic tool across various medical and surgical fields, but its value in spinal surgery is unestablished. We aim to investigate the relationship between elevated baseline/postoperative NLR and patient outcomes in spinal surgery.

MATERIALS AND METHODS

We performed a systematic search in PubMed, EMBASE, and SCOPUS databases for studies investigating the prognostic value of NLR in spine patients.Odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were analysed on the RevMan 5.4 software. Where meta-analysis was not possible, we vote-counted the direction of the effect of elevated NLR. The GRADE framework for prognostic factor research was utilised to assess the certainty of the evidence for each outcome measure.

RESULTS

Five outcome measures (overall survival, mortality, disease-free survival, functional recovery and complications) were assessed across 16 studies involving 5471 patients. Elevated baseline NLR was associated with reduced overall survival (HR: 1.63, 95 % CI: 1.05 - 2.54) (GRADE: low) and worsened functional recovery (OR: 0.93, 95 % CI: 0.87 - 0.98) (GRADE: low). There was no association between baseline NLR and disease-free survival (HR: 2.42, 95 % CI: 0.49 - 11.83) (GRADE: very low) or mortality (OR: 1.39, 95 % CI: 0.41 - 4.75) (GRADE: very low). Elevated NLR levels measured on days 3-4 and days 6-7 postoperatively, but not NLR measured at baseline or on days 1-2 postoperatively, were associated with greater risks of complications (GRADE: low).

CONCLUSIONS

NLR is an objective tool with the potential to identify the patients that would benefit from surgery and facilitate shared decision-making.

Role of NLRP3 Inflammasome in Post-Spinal-Cord-Injury Anxiety and Depression: Molecular Mechanisms and Therapeutic Implications

The majority of research on the long-term effects of spinal cord injury (SCI) has primarily focused on neuropathic pain (NP), psychological issues, and sensorimotor impairments. Among SCI patients, mood disorders, such as anxiety and depression, have been extensively studied. It has been found that chronic stress and NP have negative consequences and reduce the quality of life for individuals living with SCI. Our review examined both human and experimental evidence to explore the connection between mood changes following SCI and inflammatory pathways, with a specific focus on NLRP3 inflammasome signaling. We observed increased proinflammatory factors in the blood, as well as in the brain and spinal cord tissues of SCI models. The NLRP3 inflammasome plays a crucial role in various diseases by controlling the release of proinflammatory molecules like interleukin 1β (IL-1β) and IL-18. Dysregulation of the NLRP3 inflammasome in key brain regions associated with pain processing, such as the prefrontal cortex and hippocampus, contributes to the development of mood disorders following SCI. In this review, we summarized recent research on the expression and regulation of components related to NLRP3 inflammasome signaling in mood disorders following SCI. Finally, we discussed potential therapeutic approaches that target the NLRP3 inflammasome and regulate proinflammatory cytokines as a way to treat mood disorders following SCI.

The combination treatment of methylprednisolone and growth factor-rich serum ameliorates the structural and functional changes after spinal cord injury in rat

STUDY DESIGN

Preclinical pharmacology.

OBJECTIVES

Our study aims to evaluate the combined effect of Methylprednisolone (MP) and growth factor-rich serum (GFRS) on structural and functional recovery in rats following spinal cord injury (SCI).

SETTING

Shiraz University of Medical Sciences, Shiraz, Iran METHODS: Male Sprague-Dawley rats were randomly assigned to five groups: sham group (laminectomy); SCI group (the spinal cord clip compression model); SCI-MP group (30 mg/kg MP was administrated intraperitoneally (IP) immediately after SCI); SCI-GFRS group (GFRS (200 µl, IP) was administrated for six consecutive days); and SCI-MP + GFRS group (the rats received MP (30 mg/kg, IP) immediately after SCI, and GFRS (200 µl, IP) for six consecutive days). Motor function was assessed weekly using the Basso, Beattie, and Bresnahan (BBB) scale. After 4 weeks, we conducted the rotarod test, then removed and prepared the spinal cords (including the epicenter of injury) for stereological and histological estimation, and biochemical assays.

RESULTS

The results showed that MP and GFRS combining treatment enhanced functional recovery, which was associated with a decrement in lesion volume, increased spared white and gray matter volume, reduced neuronal loss, as well as decreased necrosis and hemorrhage after SCI. Moreover, administration of MP and GFRS inhibited lipid peroxidation (malondialdehyde (MDA) content), and increased antioxidant enzymes including glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) after rat SCI.

CONCLUSIONS

We suggests that the combination treatment of MP and GFRS may ameliorate the structure and functional changes following SCI by reducing oxidative stress, and increasing the level of antioxidants enzymes.

Cell Transplantation for Repair of the Spinal Cord and Prospects for Generating Region-Specific Exogenic Neuronal Cells

Spinal cord injury (SCI) is associated with currently irreversible consequences in several functional components of the central nervous system. Despite the severity of injury, there remains no approved treatment to restore function. However, with a growing number of preclinical studies and clinical trials, cell transplantation has gained significant potential as a treatment for SCI. Researchers have identified several cell types as potential candidates for transplantation. To optimize successful functional outcomes after transplantation, one key factor concerns generating neuronal cells with regional and subtype specificity, thus calling on the developmental transcriptome patterning of spinal cord cells. A potential source of spinal cord cells for transplantation is the generation of exogenic neuronal progenitor cells via the emerging technologies of gene editing and blastocyst complementation. This review highlights the use of cell transplantation to treat SCI in the context of relevant developmental gene expression patterns useful for producing regionally specific exogenic spinal cells via in vitro differentiation and blastocyst complementation.

PI3K signaling promotes formation of lipid-laden foamy macrophages at the spinal cord injury site

After spinal cord injury (SCI), infiltrating macrophages undergo excessive phagocytosis of myelin and cellular debris, forming lipid-laden foamy macrophages. To understand their role in the cellular pathology of SCI, investigation of the foamy macrophage phenotype in vitro revealed a pro-inflammatory profile, increased reactive oxygen species (ROS) production, and mitochondrial dysfunction. Bioinformatic analysis identified PI3K as a regulator of inflammation in foamy macrophages, and inhibition of this pathway decreased their lipid content, inflammatory cytokines, and ROS production. Macrophage-specific inhibition of PI3K using liposomes significantly decreased foamy macrophages at the injury site after a mid-thoracic contusive SCI in mice. RNA sequencing and in vitro analysis of foamy macrophages revealed increased autophagy and decreased phagocytosis after PI3K inhibition as potential mechanisms for reduced lipid accumulation. Together, our data suggest that the formation of pro-inflammatory foamy macrophages after SCI is due to the activation of PI3K signaling, which increases phagocytosis and decreases autophagy.

The Comparative Effects of Schwann Cells and Wharton's Jelly Mesenchymal Stem Cells on the AIM2 Inflammasome Activity in an Experimental Model of Spinal Cord Injury

Inflammasome activation and the consequent release of pro-inflammatory cytokines play a crucial role in the development of sensory/motor deficits following spinal cord injury (SCI). Immunomodulatory activities are exhibited by Schwann cells (SCs) and Wharton's jelly mesenchymal stem cells (WJ-MSCs). In this study, we aimed to compare the effectiveness of these two cell sources in modulating the absent in melanoma 2 (AIM2) inflammasome complex in rats with SCI. The Basso, Beattie, Bresnahan (BBB) test, Nissl staining, and Luxol fast blue (LFB) staining were performed to evaluate locomotor function, neuronal survival, and myelination, respectively. Real-time polymerase chain reaction (RT-PCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA) were employed to analyze the gene and protein expressions of inflammasome components, including AIM2, ASC, caspase-1, interleukin-1β (IL-1β), and IL-18. Both gene and protein expressions of all evaluated factors were decreased after SC or WJ-MSC treatment, with a more pronounced effect observed in the SCs group (P < 0.05). Additionally, SCs promoted neuronal survival and myelination. Moreover, the administration of 3 × 105 cells resulted in motor recovery improvement in both treatment groups (P < 0.05). Although not statistically significant, these effects were more prominent in the SC-treated animals. In conclusion, SC therapy demonstrated greater efficacy in targeting AIM2 inflammasome activation and the associated inflammatory pathway in SCI experiments compared to WJ-MSCs.

Shinbaro2 enhances axonal extension beyond the glial scar for functional recovery in rats with contusive spinal cord injury

Spinal cord injury (SCI) is a devastating event that often results in the inflammatory condition of glial scar tissue formation, impeding neural regeneration and recovery. Reducing the inflammatory response and inhibiting glial formation are promising strategies for improving SCI outcomes. Here, we introduce a new role for Shinbaro2 (Sh2), known for its anti-inflammatory and pain-reducing effects, in ameliorating glial scars formed in the damaged spinal cord and promoting axon growth after SCI. Sh2 was applied at various concentrations to cultivate primary spinal cord neurons. Concentrations of 1 and 2 mg/mL effectively enhanced cell viability and axonal outgrowth in spinal cord neurons subjected to hydrogen peroxide or laceration injury. Sh2 helped reduce neuroinflammation by increasing anti-inflammatory M2 macrophages (arginase 1) and decreasing inflammatory cells, ultimately reducing lesion size. In scar formation, Sh2 inhibited the expression of β-catenin and nestin in reactive astrocytes in the injured spinal cord. Moreover, Sh2 suppressed the expression of chondroitin sulfate proteoglycans and SOX9, which are involved in scar formation. Furthermore, Sh2 promoted the sprouting of serotonergic axons and the growth of neurofibrillary tangles, enhancing motor function recovery in SCI. These findings highlight the potential of Sh2 as an SCI therapeutic intervention, offering hope for neural and functional restoration in individuals with this debilitating condition.

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.

Utility of Brain Injury Biomarkers in Children With Congenital Heart Disease Undergoing Cardiac Surgery

BACKGROUND

Congenital heart disease (CHD) affects roughly 40,000 children annually. Despite advancements, children undergoing surgery for CHD are at an increased risk for adverse neurological outcomes. At present, there is no gold standard for the diagnosis of cerebral injury during the perioperative period.

OBJECTIVE

To determine the utility of brain injury biomarkers in children undergoing cardiac surgery.

METHODS

We searched PUBMED, EMBASE, LILACS, EBSCO, ClinicalTrials.gov, Cochrane Databases, and OVID interface to search MEDLINE through July 2021 and assessed the literature following the snowball method. The search terms used were "congenital heart disease," "cardiopulmonary bypass," "biomarkers," "diagnosis," "prognosis," and "children." No language or publication date restrictions were used. Papers studying inflammatory and imaging biomarkers were excluded. The risk of bias, strengths, and limitations of the study were reported. Study was registered in PROSPERO ID: CRD42021258385.

RESULTS

A total of 1449 articles were retrieved, and 27 were included. Eight neurological biomarkers were examined. Outcomes assessed included prognosis of poor neurological outcome, mortality, readmission, and diagnosis of brain injury. Results from these studies support that significant perioperative elevations in brain injury biomarkers in cerebrospinal fluid and serum, including S100B, GFAP, NSE, and activin A, may be diagnostic of real-time brain injury and serve as an independent predictor of adverse neurological outcomes in patients with CHD undergoing cardiopulmonary bypass.

CONCLUSIONS

There are limited homogeneous data in the field, limiting the generalizability and comparability of the results. Further large-scale longitudinal studies addressing neurological biomarkers in children undergoing CHD corrective surgery are required to support the routine use of neuronal biomarkers in this population.

The research landscape of immunology research in spinal cord injury from 2012 to 2022

Background

Spinal cord injury (SCI) is defined as traumatic damage to the spinal cord, affecting over three million patients worldwide, and there is still no treatment for the injured spinal cord itself. In recent years, immunology research on SCI has been published in various journals.

Methods

To systematically analyze the research hotspots and dynamic scientific developments of immunology research in SCI, we conducted a bibliometric and knowledge map analysis to help researchers gain a global perspective in this research field.

Results

The bibliometric study we completed included 1788 English-language papers published in 553 journals by 8861 authors from 1901 institutions in 66 countries/regions. Based on the references and keyword analysis, researchers in the past 10 years have mainly focused on the research directions of "monocyte chemoattractor protein 1," "nitric oxide," "pain," and "nitric oxide synthase" related to immunological research in SCI. However, with the development of other new directions such as "extracellular vesicles" (2019-2022), "Regenerative medicine" (2019-2022), "stromal cells" (2018-2022), "motor recovery" (2019-2022), and "glial activation" (2019-2022). Researchers prefer to study the application of regenerative strategies in SCI, the mechanism of extracellular vesicles in the development of SCI, the activation of spinal glial cells in SCI, and the pathways of motor recovery. This bibliometric analysis of immunology research in SCI summarizes the current status of this research field. The relationship between extracellular vesicles, regenerative medicine, stromal cells, motor recovery, and glial activation is currently a major research frontier. Further research and cooperation worldwide need to be enhanced.

Conclusion

We believe that our research can help researchers quickly grasp the current hotspot of immunology research in SCI and determine a new direction for future research.

Neutrophil biology in injuries and diseases of the central and peripheral nervous systems

The role of inflammation in nervous system injury and disease is attracting increased attention. Much of that research has focused on microglia in the central nervous system (CNS) and macrophages in the peripheral nervous system (PNS). Much less attention has been paid to the roles played by neutrophils. Neutrophils are part of the granulocyte subtype of myeloid cells. These cells, like macrophages, originate and differentiate in the bone marrow from which they enter the circulation. After tissue damage or infection, neutrophils are the first immune cells to infiltrate into tissues and are directed there by specific chemokines, which act on chemokine receptors on neutrophils. We have reviewed here the basic biology of these cells, including their differentiation, the types of granules they contain, the chemokines that act on them, the subpopulations of neutrophils that exist, and their functions. We also discuss tools available for identification and further study of neutrophils. We then turn to a review of what is known about the role of neutrophils in CNS and PNS diseases and injury, including stroke, Alzheimer's disease, multiple sclerosis, amyotrophic lateral sclerosis, spinal cord and traumatic brain injuries, CNS and PNS axon regeneration, and neuropathic pain. While in the past studies have focused on neutrophils deleterious effects, we will highlight new findings about their benefits. Studies on their actions should lead to identification of ways to modify neutrophil effects to improve health.

Pediatric Spinal Cord Injury: A Review

A spinal cord injury (SCI) can be a devastating condition in children, with profound implications for their overall health and quality of life. In this review, we aim to provide a concise overview of the key aspects associated with SCIs in the pediatric population. Firstly, we discuss the etiology and epidemiology of SCIs in children, highlighting the diverse range of causes. We explore the unique anatomical and physiological characteristics of the developing spinal cord that contribute to the specific challenges faced by pediatric patients. Next, we delve into the clinical presentation and diagnostic methods, emphasizing the importance of prompt and accurate diagnosis to facilitate appropriate interventions. Furthermore, we approach the multidisciplinary management of pediatric SCIs, encompassing acute medical care, surgical interventions, and ongoing supportive therapies. Finally, we explore emerging research as well as innovative therapies in the field, and we emphasize the need for continued advancements in understanding and treating SCIs in children to improve their functional independence and overall quality of life.

Multimodal therapy strategy based on a bioactive hydrogel for repair of spinal cord injury

Traumatic spinal cord injury results in permanent and serious neurological impairment, but there is no effective treatment yet. Tissue engineering approaches offer great potential for the treatment of SCI, but spinal cord complexity poses great challenges. In this study, the composite scaffold consists of a hyaluronic acid-based hydrogel, decellularized brain matrix (DBM), and bioactive compounds such as polydeoxyribonucleotide (PDRN), tumor necrosis factor-α/interferon-γ primed mesenchymal stem cell-derived extracellular vesicles (TI-EVs), and human embryonic stem cell-derived neural progenitor cells (NPC). The composite scaffold showed significant effects on regenerative prosses including angiogenesis, anti-inflammation, anti-apoptosis, and neural differentiation. In addition, the composite scaffold (DBM/PDRN/TI-EV/NPC@Gel) induced an effective spinal cord regeneration in a rat spinal cord transection model. Therefore, this multimodal approach using an integrated bioactive scaffold coupled with biochemical cues from PDRN and TI-EVs could be used as an advanced tissue engineering platform for spinal cord regeneration.

Adipose-Derived Mesenchymal Stromal Cell Transplantation for Severe Spinal Cord Injury: Functional Improvement Supported by Angiogenesis and Neuroprotection

Mesenchymal stromal cell transplantation alone is insufficient when motor dysfunction is severe; combination therapy with rehabilitation could improve motor function. Here, we aimed to analyze the characteristics of adipose-derived MSCs (AD-MSCs) and determine their effectiveness in severe spinal cord injury (SCI) treatment. A severe SCI model was created and motor function were compared. The rats were divided into AD-MSC-transplanted treadmill exercise-combined (AD-Ex), AD-MSC-transplanted non-exercise (AD-noEx), PBS-injected exercise (PBS-Ex), and no PBS-injected exercise (PBS-noEx) groups. In cultured cell experiments, AD-MSCs were subjected to oxidative stress, and the effects on the extracellular secretion of AD-MSCs were investigated using multiplex flow cytometry. We assessed angiogenesis and macrophage accumulation in the acute phase. Spinal cavity or scar size and axonal preservation were assessed histologically in the subacute phase. Significant motor function improvement was observed in the AD-Ex group. Vascular endothelial growth factor and C-C motif chemokine 2 expression in AD-MSC culture supernatants increased under oxidative stress. Enhanced angiogenesis and decreased macrophage accumulation were observed at 2 weeks post-transplantation, whereas spinal cord cavity or scar size and axonal preservation were observed at 4 weeks. Overall, AD-MSC transplantation combined with treadmill exercise training improved motor function in severe SCI. AD-MSC transplantation promoted angiogenesis and neuroprotection.

Toward discovering a novel family of peptides targeting neuroinflammatory states of brain microglia and astrocytes

Microglia are immune-derived cells critical to the development and healthy function of the brain and spinal cord, yet are implicated in the active pathology of many neuropsychiatric disorders. A range of functional phenotypes associated with the healthy brain or disease states has been suggested from in vivo work and were modeled in vitro as surveying, reactive, and primed sub-types of primary rat microglia and mixed microglia/astrocytes. It was hypothesized that the biomolecular profile of these cells undergoes a phenotypical change as well, and these functional phenotypes were explored for potential novel peptide binders using a custom 7 amino acid-presenting M13 phage library (SX7) to identify unique peptides that bind differentially to these respective cell types. Surveying glia were untreated, reactive were induced with a lipopolysaccharide treatment, recovery was modeled with a potent anti-inflammatory treatment dexamethasone, and priming was determined by subsequently challenging the cells with interferon gamma. Microglial function was profiled by determining the secretion of cytokines and nitric oxide, and expression of inducible nitric oxide synthase. After incubation with the SX7 phage library, populations of SX7-positive microglia and/or astrocytes were collected using fluorescence-activated cell sorting, SX7 phage was amplified in Escherichia coli culture, and phage DNA was sequenced via next-generation sequencing. Binding validation was done with synthesized peptides via in-cell westerns. Fifty-eight unique peptides were discovered, and their potential functions were assessed using a basic local alignment search tool. Peptides potentially originated from proteins ranging in function from a variety of supportive glial roles, including synapse support and pruning, to inflammatory incitement including cytokine and interleukin activation, and potential regulation in neurodegenerative and neuropsychiatric disorders.

Human Adipose-Derived Stem Cells Reduce Cellular Damage after Experimental Spinal Cord Injury in Rats

Traumatic spinal cord injury (SCI) is a devastating condition without an effective therapy. Cellular therapies are among the promising treatment strategies. Adult stem cells, such as mesenchymal stem cells, are often used clinical research for their immunomodulatory and regenerative potential. This study aimed to evaluate the effect of human adipose tissue-derived stem cells (ADSC) infusion through the cauda equina in rats with SCI. The human ADSC from bariatric surgery was isolated, expanded, and characterized. Wistar rats were subjected to blunt SCI and were divided into four groups. Two experimental groups (EG): EG1 received one ADSC infusion after SCI, and EG2 received two infusions, the first one after SCI and the second infusion seven days after the injury. Control groups (CG1 and CG2) received infusion with a culture medium. In vivo, cell tracking was performed 48 h and seven days after ADSC infusion. The animals were followed up for 40 days after SCI, and immunohistochemical quantification of myelin, neurons, and astrocytes was performed. Cellular tracking showed cell migration towards the injury site. ADSC infusion significantly reduced neuronal loss, although it did not prevent the myelin loss or enhance the area occupied by astrocytes compared to the control group. The results were similar when comparing one or two cell infusions. The injection of ADSC distal to the injured area was shown to be a safe and effective method for cellular administration in spinal cord injury.

Effects of Whole-Body Vibration and Manually Assisted Locomotor Therapy on Neurotrophin-3 Expression and Microglia/Macrophage Mobilization Following Thoracic Spinal Cord Injury in Rats

Microglial cells play an important role in neuroinflammation and secondary damages after spinal cord injury (SCI). Progressive microglia/macrophage inflammation along the entire spinal axis follows SCI, and various factors may determine the microglial activation profile. Neurotrophin-3 (NT-3) is known to control the survival of neurons, the function of synapses, and the release of neurotransmitters, while also stimulating axon plasticity and growth. We examined the effects of whole-body vibration (WBV) and forms of assisted locomotor therapy, such as passive flexion-extension (PFE) therapy, at the neuronal level after SCI, with a focus on changes in NT-3 expression and on microglia/macrophage reaction, as they play a major role in the reconstitution of CNS integrity after injury and they may critically account for the observed structural and functional benefits of physical therapy. More specifically, the WBV therapy resulted in the best overall functional recovery when initiated at day 14, while inducing a decrease in Iba1 and the highest increase in NT-3. Therefore, the WBV therapy at the 14th day appeared to be superior to the PFE therapy in terms of recovery. Functional deficits and subsequent rehabilitation depend heavily upon the inflammatory processes occurring caudally to the injury site; thus, we propose that increased expression of NT-3, especially in the dorsal horn, could potentially be the mediator of this favorable outcome.

The potential effects of polyunsaturated ω-3 fatty acids on spinal cord injury: A systematic review & meta-analysis of preclinical evidence

Polyunsaturated fatty acids (PUFAs) have received attention for their anti-inflammatory and antioxidant properties. Preclinical studies have investigated the efficacy of PUFAs in animal models of spinal cord injury (SCI) to determine if these properties can translate to neuroprotection and locomotor recovery. Findings from such studies have been promising, suggesting PUFAs as potential treatments against the neurological dysfunction induced by SCI. This systematic review and meta-analysis sought to investigate the efficacy of PUFAs for promoting locomotor recovery in animal models of SCI. PubMed, Web of Science and Embase (Ovid) were searched for relevant papers and those that examined the restorative effects of PUFAs on locomotor recovery in preclinical SCI models were included in our analysis. A random effects meta-analysis (restricted maximum likelihood estimator) was employed. A total of 28 studies were included and the results showed the claim that PUFAs have a beneficial therapeutic effect for promoting locomotor recovery (SMD = 1.037, 95% CI = 0.809-1.2644, p = <0.001) and cell survival (SMD = 1.101, 95% CI = 0.889-1.313, p = <0.001) in animal models of SCI. No significant differences for the secondary outcomes of neuropathic pain and lesion volume. Moderate asymmetry was observed in the funnel plots for locomotor recovery, cell survival and neuropathic pain measures, suggesting publication bias. Trim-and-fill analysis estimated 13, 3, 0 and 4 missing studies for locomotor recovery, cell survival, neuropathic pain, and lesion volume, respectively. A modified CAMARADES checklist was also used to assess risk of bias, showing that the median score for all included papers was 4 out of a possible 7.

Moonlighting chromatin: when DNA escapes nuclear control

Extracellular chromatin, for example in the form of neutrophil extracellular traps (NETs), is an important element that propels the pathological progression of a plethora of diseases. DNA drives the interferon system, serves as autoantigen, and forms the extracellular scaffold for proteins of the innate immune system. An insufficient clearance of extruded chromatin after the release of DNA from the nucleus into the extracellular milieu can perform a secret task of moonlighting in immune-inflammatory and occlusive disorders. Here, we discuss (I) the cellular events involved in the extracellular release of chromatin and NET formation, (II) the devastating consequence of a dysregulated NET formation, and (III) the imbalance between NET formation and clearance. We include the role of NET formation in the occlusion of vessels and ducts, in lung disease, in autoimmune diseases, in chronic oral disorders, in cancer, in the formation of adhesions, and in traumatic spinal cord injury. To develop effective therapies, it is of utmost importance to target pathways that cause decondensation of chromatin during exaggerated NET formation and aggregation. Alternatively, therapies that support the clearance of extracellular chromatin are conceivable.

Xeomin®, a Commercial Formulation of Botulinum Neurotoxin Type A, Promotes Regeneration in a Preclinical Model of Spinal Cord Injury

Xeomin® is a commercial formulation of botulinum neurotoxin type A (BoNT/A) clinically authorized for treating neurological disorders, such as blepharospasm, cervical dystonia, limb spasticity, and sialorrhea. We have previously demonstrated that spinal injection of laboratory purified 150 kDa BoNT/A in paraplegic mice, after undergoing traumatic spinal cord injury (SCI), was able to reduce excitotoxic phenomena, glial scar, inflammation, and the development of neuropathic pain and facilitate regeneration and motor recovery. In the present study, as proof of concept in view of a possible clinical application, we studied the efficacy of Xeomin® in the same preclinical SCI model in which we highlighted the positive effects of lab-purified BoNT/A. Data comparison shows that Xeomin® induces similar pharmacological and therapeutic effects, albeit with less efficacy, to lab-purified BoNT/A. This difference, which can be improved by adjusting the dose, can be attributable to the different formulation and pharmacodynamics. Although the mechanism by which Xeomin® and laboratory purified BoNT/A induce functional improvement in paraplegic mice is still far from being understood, these results open a possible new scenario in treatment of SCI and are a stimulus for further research.

Multifunctional Integrated Nanozymes Facilitate Spinal Cord Regeneration by Remodeling the Extrinsic Neural Environment

High levels of reactive oxygen species (ROS) and inflammation create a complicated extrinsic neural environment that dominates the initial post-injury period after spinal cord injury (SCI). The compensatory pathways between ROS and inflammation limited the efficacy of modulating the above single treatment regimen after SCI. Here, novel "nanoflower" Mn₃ O₄ integrated with "pollen" ^IRF-5 SiRNA was designed as a combination antioxidant and anti-inflammatory treatment after SCI. The "nanoflower" and "pollen" structure was encapsulated with a neutrophil membrane for protective and targeted delivery. Furthermore, valence-engineered nanozyme Mn₃ O₄ imitated the cascade response of antioxidant enzymes with a higher substrate affinity compared to natural antioxidant enzymes. Nanozymes effectively catalyzed ROS to generate O₂ , which is advantageous for reducing oxidative stress and promoting angiogenesis. The screened "pollen" ^IRF-5 SiRNA could reverse the inflammatory phenotype by reducing interferon regulatory factors-5 (IRF-5) expression (protein level: 73.08% and mRNA level: 63.10%). The decreased expression of pro-inflammatory factors reduced the infiltration of inflammatory cells, resulting in less neural scarring. In SCI rats, multifunctional nanozymes enhanced the proliferation of various neuronal subtypes (motor neurons, interneurons, and sensory neurons) and the recovery of locomotor function, demonstrating that the remodeling of the extrinsic neural environment is a promising strategy to facilitate nerve regeneration.

GDNF-Loaded Polydopamine Nanoparticles-Based Anisotropic Scaffolds Promote Spinal Cord Repair by Modulating Inhibitory Microenvironment

Spinal cord injury (SCI) is a devastating injury that causes permanent loss of sensation and motor function. SCI repair is a significant challenge due to the limited regenerating ability of adult neurons and the complex inflammatory microenvironment. After SCI, the oxidative stress induced by excessive reactive oxygen species (ROS) often leads to prolonged neuroinflammation that results in sustained damage to the spinal cord tissue. Polydopamine (PDA) shows remarkable capability in scavenging ROS to treat numerous inflammatory diseases. In this study, glial cell-derived neurotrophic factor (GDNF)-loaded PDA nanoparticle-based anisotropic scaffolds for spinal cord repair are developed. It is found that mesoporous PDA nanoparticles (mPDA NPs) in the scaffolds efficiently scavenge ROS and promote microglia M2 polarization, thereby inhibiting inflammatory response at the injury site and providing a favorable microenvironment for nerve cell survival. Furthermore, the GDNF encapsulated in mPDA NPs promotes corticospinal tract motor axon regeneration and its locomotor functional recovery. Together, findings from this study reveal that the GDNF-loaded PDA/Gelatin scaffolds hold potential as an effective artificial transplantation material for SCI treatment.

Mesenchymal stem cells in the treatment of spinal cord injury: Mechanisms, current advances and future challenges

Spinal cord injury (SCI) has considerable impact on patient physical, mental, and financial health. Secondary SCI is associated with inflammation, vascular destruction, and subsequent permanent damage to the nervous system. Mesenchymal stem cells (MSCs) have anti-inflammatory properties, promoting vascular regeneration and the release neuro-nutrients, and are a promising strategy for the treatment of SCI. Preclinical studies have shown that MSCs promote sensory and motor function recovery in rats. In clinical trials, MSCs have been reported to improve the American Spinal Injury Association (ASIA) sensory and motor scores. However, the effectiveness of MSCs in treating patients with SCI remains controversial. MSCs promote tumorigenesis and ensuring the survival of MSCs in the hostile environment of SCI is challenging. In this article we examine the evidence on the pathophysiological changes occurring after SCI. We then review the underlying mechanisms of MSCs in the treatment of SCI and summarize the potential application of MSCs in clinical practice. Finally, we highlight the challenges surrounding the use of MSCs in the treatment of SCI and discuss future applications.

Paired associates learning is disrupted after unilateral parietal lobe controlled cortical impact in rats: A trial-by-trial behavioral analysis

Approximately 60-70 million people suffer from traumatic brain injury (TBI) each year. Animal models continue to be paramount in understanding mechanisms of cellular dysfunction and testing new treatments for TBI. Enhancing the translational potential of novel interventions therefore necessitates testing pre-clinical intervention strategies with clinically relevant cognitive assays. This study used a unilateral parietal lobe controlled cortical impact (CCI) model of TBI and tested rats on a touchscreen-based Paired Associates Learning (PAL) task, which is part of the Cambridge Neuropsychological Test Automated Battery. In humans, the PAL task has been used to assess cognitive deficits in the ability to form stimulus-location associations in a multitude of disease states, including TBI. Although the use of PAL in animal models could be important for understanding the clinical severity of cognitive impairment post-injury and throughout intervention, to date, the extent to which a rat model of TBI produces deficits in PAL task performance has not yet been reported. This study details the behavioral consequences of the CCI injury model with a Trial-by-Trial analysis of PAL performance that enables behavioral strategy use to be inferred. Following behavior, the extent of the injury was quantified with histology and staining for the presence of glial fibrillary acid protein and ionized calcium-binding adapter molecule 1. Rats that received unilateral CCI were impaired on the PAL task and showed more aberrant response-driven behavior. The magnitude of PAL impairment was also correlated with Iba1 staining in the thalamus. These observations suggest that PAL could be useful for pre-clinical assessments of novel interventions for treating TBI.

3D Gelatin Microsphere Scaffolds Promote Functional Recovery after Spinal Cord Hemisection in Rats

Spinal cord injury (SCI) damages signal connections and conductions, with the result that neuronal circuits are disrupted leading to neural dysfunctions. Such injuries represent a serious and relatively common central nervous system condition and current treatments have limited success in the reconstruction of nerve connections in injured areas, especially where sizeable gaps are present. Biomaterial scaffolds have become an effective alternative to nerve transplantation in filling these gaps and provide the foundation for simulating the 3D structure of solid organs. However, there remain some limitations with the application of 3D bioprinting for preparation of biomaterial scaffolds. Here, the approach in constructing and testing mini-tissue building blocks and self-assembly, solid 3D gelatin microsphere (GM) scaffolds with multiple voids as based on the convenient preparation of gelatin microspheres by microfluidic devices is described. These 3D GM scaffolds demonstrate suitable biocompatibility, biodegradation, porosity, low preparation costs, and relative ease of production. Moreover, 3D GM scaffolds can effectively bridge injury gaps, establish nerve connections and signal transductions, mitigate inflammatory microenvironments, and reduce glial scar formation. Accordingly, these 3D GM scaffolds can serve as a novel and effective bridging method to promote nerve regeneration and reconstruction and thus recovery of nerve function after SCI.

Mechanism of traditional Chinese medicine in treating overactive bladder

Overactive bladder syndrome (OAB) has made increasing progress in mechanism and treatment research. Traditional Chinese medicine (TCM) is a common complementary therapy for OAB, and it has been found to be effective. However, the intervention mechanism of TCM in the treatment of OAB is still unclear. The aim of this review is to consolidate the current knowledge about the mechanism of TCM: acupuncture, moxibustion, herbs in treating OAB, and the animal models of OAB commonly used in TCM. Finally, we put forward the dilemma of TCM treatment of OAB and discussed the insufficiency and future direction of TCM treatment of OAB.

Canine bone marrow peri-adipocyte cells could therapeutically benefit acute spinal cord injury through migration and secretion of hepatocyte growth factor to inflammatory milieu

Spinal cord injury (SCI) is a common neurological disorder in dogs. A secondary injury that occurs in the acute phase causes expansion of inflammation, resulting in lesion extension and further loss of function. Mesenchymal stem cells (MSCs) have trophic effects and the ability to migrate toward injured tissues; therefore, MSC-based therapy is considered promising for the treatment of canine SCI. We recently reported that bone marrow peri-adipocyte cells (BM-PACs) can be obtained from canine bone marrow and have stem cell potential superior to that of conventional bone marrow MSCs (BMMSCs). However, their therapeutic potential for SCI have been still unknow. Here, we first evaluated the ability of BM-PACs to secrete hepatocyte growth factor (HGF) and their migration ability toward inflammatory milieu in vitro. BM-PACs can secrete HGF in response to pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α and IL-1β, and exhibit migration ability toward these cytokines. Next, BM-PACs were intravenously administered into nude mice with acute SCI to analyze the homing ability and therapeutic effects of HGF secreted by BM-PACs. BM-PACs homed to the injured spinal cord, where the HGF expression level increased 7 days after administration. Intravenous administration of BM-PACs induced functional recovery and pathological improvement, indicated by less demyelinating area, more preserved axons, and less glial scar formation compared with the mice only received vehicle. These findings suggest that the intravenous administration of BM-PACs can be a novel therapeutic intervention for acute canine SCI.

Equilibrative Nucleoside Transporter 1 is a Target to Modulate Neuroinflammation and Improve Functional Recovery in Mice with Spinal Cord Injury

Neuroinflammation plays a critical role in the neurological recovery of spinal cord injury (SCI). Adenosine can modulate neuroinflammation, whose uptake is mediated by nucleoside transporters. This study aimed to investigate the roles of equilibrative nucleoside transporter 1 (Ent1) in the inflammatory responses and functional recovery of SCI. Spinal cord contusion at the T10 dorsal portion was induced in mice to cause partial paralysis of the hindlimbs. Genetic deletion and pharmacological inhibition of Ent1 were used to evaluate the role of Ent1 in SCI. The outcomes were evaluated in terms of the Basso Mouse Scale (BMS), gait analysis, astrogliosis, microgliosis, and cytokine levels on day 14 post-injury. As a result, Ent1 deletion reduced neuroinflammation and improved the BMS score (4.88 ± 0.35 in Ent1^-/- vs. 3.78 ± 1.09 in Ent1^+/+) and stride length (3.74 ± 0.48 cm in Ent1^-/- vs. 2.82 ± 0.78 cm in Ent1^+/+) of mice with SCI. Along with the reduced lesion size, more preserved neurons were identified in the perilesional area of mice with Ent1 deletion (102 ± 23 in Ent1^-/- vs. 73 ± 10 in Ent1^+/+). The results of pharmacological inhibition were consistent with the findings of genetic deletion. Moreover, Ent1 inhibition decreased the protein level of complement 3 (an A1 marker), but increased the levels of S100 calcium-binding protein a10 (an A2 marker) and transforming growth factor-β, without changing the levels of inducible nitric oxide synthase (a M1 marker) and arginase 1 (a M2 marker) at the injured site. These findings indicate the important role of Ent1 in the pathogenesis and treatment of SCI.

The Reibergram for immunoglobulin A in dogs: Evaluation of intrathecal IgA synthesis using a quotient graph in dogs with neurological diseases

BACKGROUND

Increased cerebrospinal fluid (CSF) protein concentration is a common finding in neurological diseases of dogs. Distinguishing between intrathecally-produced proteins and proteins that have passed the blood-CSF barrier because of barrier disruption facilitates diagnosis. Albumin is a microprotein mainly produced extrathecally that can be used as a reference marker for blood-CSF barrier dysfunction.

OBJECTIVES

Develop a quotient graph based on the CSF/serum quotient of albumin and immunoglobulin A (IgA; Reibergram) to visualize intrathecal IgA synthesis and blood-CSF barrier dysfunction.

ANIMALS AND METHODS

Retrospective single-center cohort study. A hyperbolic function was developed using data from 6 healthy Beagles and 38 dogs with neurological diseases in which an isolated blood-CSF barrier dysfunction was expected. The function was validated using data from 10 dogs with expected intrathecal IgA synthesis and was visualized as a quotient graph. Finally, the graph was used to evaluate data of 118 dogs with various neurological diseases.

RESULTS

Within the Reibergram, the function QLim IgA = 0.13 QAlb 2 + 11.9 · 10 - 6 - 1.01 · 10 - 3 describes the upper values of physiological IgA quotients. It detects diseases with expected intrathecal IgA synthesis with higher sensitivity (85%) and specificity (89%) than the IgA index. The upper value of the physiological albumin quotient is 2.22 and detects diseases with expected blood-CSF barrier dysfunction (sensitivity: 81%; specificity: 88%).

CONCLUSION AND CLINICAL IMPORTANCE

The canine Reibergram can detect blood-CSF barrier dysfunction and intrathecal IgA synthesis in the majority of cases. The graphical visualization simplifies data evaluation and makes it a feasible tool in routine CSF diagnostic testing.

CRISPRi screens in human iPSC-derived astrocytes elucidate regulators of distinct inflammatory reactive states

Astrocytes become reactive in response to insults to the central nervous system by adopting context-specific cellular signatures and outputs, but a systematic understanding of the underlying molecular mechanisms is lacking. In this study, we developed CRISPR interference screening in human induced pluripotent stem cell-derived astrocytes coupled to single-cell transcriptomics to systematically interrogate cytokine-induced inflammatory astrocyte reactivity. We found that autocrine-paracrine IL-6 and interferon signaling downstream of canonical NF-κB activation drove two distinct inflammatory reactive signatures, one promoted by STAT3 and the other inhibited by STAT3. These signatures overlapped with those observed in other experimental contexts, including mouse models, and their markers were upregulated in human brains in Alzheimer's disease and hypoxic-ischemic encephalopathy. Furthermore, we validated that markers of these signatures were regulated by STAT3 in vivo using a mouse model of neuroinflammation. These results and the platform that we established have the potential to guide the development of therapeutics to selectively modulate different aspects of inflammatory astrocyte reactivity.

Neuroprotective effects of lovastatin against traumatic spinal cord injury in rats

BACKGROUND

Lovastatin, as a drug of statins subgroup, has been conceptualized to have anti-inflammatory, antioxidant, and anti-apoptotic properties. Accordingly, the present study aimed to investigate the neuroprotective ramification of lovastatin on spinal cord injury (SCI).

MATERIAL AND METHODS

Seventy-five female adult Wistar rats were divided into five groups (n = 15). In addition to non-treated (Control group) and laminectomy alone (Sham group), SCI animals were randomly assigned to non-treated spinal cord injury (SCI group), treated with 2 mg/kg of lovastatin (Lova 2 group), and treated with 5 mg/kg of lovastatin (Lova 5 group). At the end of the study, to evaluate the treatments, MDA, CAT, SOD, and GSH factors were evaluated biochemically, apoptosis and gliosis were assessed by immunohistochemical while measuring caspase-3 and GFAP antibodies, and inflammation was estimated by examining the expression of IL-10, TNF-α, and IL-1β genes. The stereological method was used to appraise the total volume of the spinal cord at the site of injury, the volume of the central cavity created, and the density of neurons and glial cells in the traumatic area. In addition, Basso-Beattie-Bresnehan (BBB) and narrow beam test (NBT) were utilized to rate neurological functions.

RESULTS

Our results exposed the fact that biochemical factors (except MDA), stereological parameters, and neurological functions were significantly ameliorated in both lovastatin-treated groups, especially in Lova 5 ones, compared to the SCI group. The expression of the IL-10 gene was significantly upregulated in both lovastatin-treated groups compared to the SCI group and was considerably heighten in Lova 5 group. Expression of TNF-α and IL-1β, as well as the rate of apoptosis and GFAP positive cells significantly decreased in both lovastatin treated groups compared to the SCI group, and it was more pronounced in the Lova 5 ones.

CONCLUSION

Overall, using lovastatin, especially at a dose of 5 mg/kg, has a dramatic neuroprotective impact on SCI treatment.

MiR-487b suppressed inflammation and neuronal apoptosis in spinal cord injury by targeted Ifitm3

Spinal cord injury (SCI) was a serious nerve injury, which involves complex genetic changes. This paper was intended to investigate the function and mechanism of differentially expressed genes in SCI. The three datasets GSE92657, GSE93561 and GSE189070 of SCI from GEO database were used to identify differentially expressed genes (DEGs). We identified the common DEGs in the three datasets GSE92657, GSE93561 and GSE189070 of SCI from GEO database. Next, a protein-protein interaction (PPI) network of DEGs was constructed. Subsequently, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that DEGs were significantly enriched in immune response, inflammatory response. The expression level of immune-related genes (Arg1, Ccl12, Ccl2, Ifitm2, Ifitm3, and et al.) at different time points of SCI were analyzed in GSE189070 dataset. Next, differentially expressed miRNAs (DE-miRNAs) were identified in SCI compared with normal based on GSE158194 database. DE-miRNA and targeted immune-related genes were predicted by miRwalk, including miR-487b-5p targeted Ifitm3, miR-3072-5p targeted Ccl3, and et al. What's more, the miR-487b was identified and verified to be down-regulated in Lipopolysaccharide (LPS)-induced BV-2 cell model. Further, the miR-487b inhibited cell inflammation and apoptosis in LPS-induced BV2 cell by targeted Ifitm3. For the first time, our results revealed that miR-487b may play an important regulatory role in SCI by targeted Ifitm3 and provide further evidence for SCI research.

Neuroprotective effect of the Nrf2/ARE/miRNA145-5p signaling pathway in the early phase of spinal cord injury

AIMS

Spinal cord injury (SCI) is a debilitating neurological condition often associated with chronic neuroinflammation and redox imbalance. Oxidative stress is one of the main hallmark of secondary injury of SCI which is tightly regulated by nuclear factor E2-related factor 2/antioxidant response element (Nrf2/ARE) signaling. In this study, we aimed at investigating the interplay between inflammation-related miRNAs and the Nrf2 pathway in animal model of SCI.

MATERIALS AND METHODS

The expression of selected four validated miRNA-target pairs (miRNA223-3p, miRNA155-5p, miRNA145-5p, and miRNA124-3p) was examined at different time points (6 h, 12 h, 1 day, 3 day and 7 day) after SCI. Further, using GFAP-specific kelch-like ECH-associated protein 1 deletion (Keap1-/-) and whole-body Nrf2-/- knockout mice, we investigated the potential interplay between each miRNA and the Keap1/Nrf2 signaling system.

KEY FINDINGS

The expression of all miRNAs except miRNA155-5p significantly increased 24 h after SCI and decreased after 7 days. Interestingly, Keap1-/- mice only showed significant increase in the miRNA145-5p after 24 h SCI compared to the WT group. In addition, Keap1-/- mice showed significant decrease in CXCL10/12 (CXCL12 increased in Nrf2-/- mice), and TNF-α, and an increase in Mn-SOD and NQO-1 (Mn-SOD and NQO-1 decreased in Nrf2-/- mice) compared to WT mice.

SIGNIFICANCE

Our results suggest that astrocytic hyperactivation of Nrf2 exert neuroprotective effects at least in part through the upregulation of miRNA145-5p, a negative regulator of astrocyte proliferation, and induction of ARE in early phase of SCI. Further studies are needed to investigate the potential interplay between Nrf2 and miRNA145-5p in neuroinflammatory condition.

Polyphenols Targeting Oxidative Stress in Spinal Cord Injury: Current Status and Future Vision

A spinal cord injury (SCI) occurs when the spinal cord is deteriorated or traumatized, leading to motor and sensory functions lost even totally or partially. An imbalance within the generation of reactive oxygen species and antioxidant defense levels results in oxidative stress (OS) and neuroinflammation. After SCI, OS and occurring pathways of inflammations are significant strenuous drivers of cross-linked dysregulated pathways. It emphasizes the significance of multitarget therapy in combating SCI consequences. Polyphenols, which are secondary metabolites originating from plants, have the promise to be used as alternative therapeutic agents to treat SCI. Secondary metabolites have activity on neuroinflammatory, neuronal OS, and extrinsic axonal dysregulated pathways during the early stages of SCI. Experimental and clinical investigations have noted the possible importance of phenolic compounds as important phytochemicals in moderating upstream dysregulated OS/inflammatory signaling mediators and axonal regeneration's extrinsic pathways after the SCI probable significance of phenolic compounds as important phytochemicals in mediating upstream dysregulated OS/inflammatory signaling mediators. Furthermore, combining polyphenols could be a way to lessen the effects of SCI.

Traumatic spinal cord injury and the contributions of the post-injury microbiome

Spinal cord injuries are an enormous burden on injured individuals and their caregivers. The pathophysiological effects of injury are not limited to the spine and limb function, but affect numerous body systems. Growing observations in human studies and experimental models suggest that the gut microbiome is altered following spinal cord injury. Given the importance of signals derived from the gut microbiome for host physiology, it is possible that injury-triggered dysbiosis subsequently affects aspects of recovery. Here, we review emerging literature on the role of the microbiome following spinal cord injury. Specifically, we highlight findings from both human and experimental studies that correlate taxonomic changes to aspects of injury recovery. Examination of both observational and emerging interventional studies supports the notion that future therapeutic avenues for spinal cord injury pathologies may lie at the interface of the host and indigenous microbes.

Curcumin as a Promising Neuroprotective Agent for the Treatment of Spinal Cord Injury: A Review of the Literature

Curcumin is a polyphenolic chemical derived from the rhizomes of Curcuma longa. It has been used throughout the Indian subcontinent for medicinal purposes, religious events, and regional cuisine. It has various pharmacological benefits owing to its anti-inflammatory and antioxidant properties. Its neuroprotective effects on the brain and peripheral nerves have been demonstrated in several in vivo neuronal tissue studies. Because of these functional properties of curcumin, it is considered to have great potential for use in the treatment of spinal cord injuries (SCIs). Numerous immunopathological and biochemical studies have reported that curcumin can help prevent and alleviate subsequent secondary injuries, such as inflammation, edema, free radical damage, fibrosis, and glial scarring, after a primary SCI. Furthermore, following SCI, curcumin administration resulted in better outcomes of neurological function recovery as per the Basso, Beattie, and Bresnahan locomotor rating scale. However, to date, its utility in treating SCIs has only been reported in laboratories. More studies on its clinical applications are needed in the future for ensuring its bioavailability across the blood-brain barrier and for verifying the safe dose for treating SCIs in humans.

Mitochondrial function in spinal cord injury and regeneration

Many people around the world suffer from some form of paralysis caused by spinal cord injury (SCI), which has an impact on quality and life expectancy. The spinal cord is part of the central nervous system (CNS), which in mammals is unable to regenerate, and to date, there is a lack of full functional recovery therapies for SCI. These injuries start with a rapid and mechanical insult, followed by a secondary phase leading progressively to greater damage. This secondary phase can be potentially modifiable through targeted therapies. The growing literature, derived from mammalian and regenerative model studies, supports a leading role for mitochondria in every cellular response after SCI: mitochondrial dysfunction is the common event of different triggers leading to cell death, cellular metabolism regulates the immune response, mitochondrial number and localization correlate with axon regenerative capacity, while mitochondrial abundance and substrate utilization regulate neural stem progenitor cells self-renewal and differentiation. Herein, we present a comprehensive review of the cellular responses during the secondary phase of SCI, the mitochondrial contribution to each of them, as well as evidence of mitochondrial involvement in spinal cord regeneration, suggesting that a more in-depth study of mitochondrial function and regulation is needed to identify potential targets for SCI therapeutic intervention.

Mitochondrial Transplantation Attenuates Neural Damage and Improves Locomotor Function After Traumatic Spinal Cord Injury in Rats

Mitochondrial dysfunction is a hallmark of secondary neuroinflammatory responses and neuronal death in spinal cord injury (SCI). Even though mitochondria-based therapy is an attractive therapeutic option for SCI, the efficacy of transplantation of allogeneic mitochondria in the treatment of SCI remains unclear. Herein, we determined the therapeutic effects of mitochondrial transplantation in the traumatic SCI rats. Compressive SCI was induced by applying an aneurysm clip on the T10 spinal cord of rats. A 100-μg bolus of soleus-derived allogeneic mitochondria labeled with fluorescent tracker was transplanted into the injured spinal cords. The results showed that the transplanted mitochondria were detectable in the injured spinal cord up to 28 days after treatment. The rats which received mitochondrial transplantation exhibited better recovery of locomotor and sensory functions than those who did not. Both the expression of dynamin-related protein 1 and severity of demyelination in the injured cord were reduced in the mitochondrial transplanted groups. Mitochondrial transplantation also alleviated SCI-induced cellular apoptosis and inflammation responses. These findings suggest that transplantation of allogeneic mitochondria at the early stage of SCI reduces mitochondrial fragmentation, neuroapoptosis, neuroinflammation, and generation of oxidative stress, thus leading to improved functional recovery following traumatic SCI.

Staying active after rehab: Physical activity perspectives with a spinal cord injury beyond functional gains

Lifestyle physical activity following spinal cord injury (SCI) is critical for functional independence, mental wellness, and social participation, yet nearly 50% of individuals with SCI report no regular exercise. The objective of this study was to better understand factors leading to this participation gap by capturing the physical activity perspectives of individuals living with SCI. We completed small group interviews with nine individuals living with SCI across the United States. Iterative thematic analysis systematically revealed meaningful core concepts related to physical activity engagement with SCI. Emergent themes revealed challenges to lifestyle physical activity behavior including gaps in physical activity education, isolation during psychological adjustment, and knowledge limitations in community exercise settings. A secondary theme related to the COVID-19 pandemic emerged, highlighting additional environmental constraints affecting participation. Our findings suggest that most physical activity education is delivered during inpatient rehabilitation and is related to physical function. Lifetime physical activity strategies are achieved through self-education and peer networking. Personal motivators for physical activity include secondary condition prevention, while social and emotional barriers prevent regular adherence. These findings can inform the development and delivery of physical activity programs to maximize physical activity engagement in individuals living with chronic SCI.

Molecular Pharmacology and Novel Potential Therapeutic Applications of Fingolimod

Fingolimod is a well-tolerated, highly effective disease-modifying therapy successfully utilized in the management of multiple sclerosis. The active metabolite, fingolimod-phosphate, acts on sphingosine-1-phosphate receptors (S1PRs) to bring about an array of pharmacological effects. While being initially recognized as a novel agent that can profoundly reduce T-cell numbers in circulation and the CNS, thereby suppressing inflammation and MS, there is now rapidly increasing knowledge on its previously unrecognized molecular and potential therapeutic effects in diverse pathological conditions. In addition to exerting inhibitory effects on sphingolipid pathway enzymes, fingolimod also inhibits histone deacetylases, transient receptor potential cation channel subfamily M member 7 (TRMP7), cytosolic phospholipase A2α (cPLA2α), reduces lysophosphatidic acid (LPA) plasma levels, and activates protein phosphatase 2A (PP2A). Furthermore, fingolimod induces apoptosis, autophagy, cell cycle arrest, epigenetic regulations, macrophages M1/M2 shift and enhances BDNF expression. According to recent evidence, fingolimod modulates a range of other molecular pathways deeply rooted in disease initiation or progression. Experimental reports have firmly associated the drug with potentially beneficial therapeutic effects in immunomodulatory diseases, CNS injuries, and diseases including Alzheimer's disease (AD), Parkinson's disease (PD), epilepsy, and even cancer. Attractive pharmacological effects, relative safety, favorable pharmacokinetics, and positive experimental data have collectively led to its testing in clinical trials. Based on the recent reports, fingolimod may soon find its way as an adjunct therapy in various disparate pathological conditions. This review summarizes the up-to-date knowledge about molecular pharmacology and potential therapeutic uses of fingolimod.

Administration of C5a receptor antagonist improves the efficacy of human iPSCs-derived NS/PC transplantation in the acute phase of spinal cord injury

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

Myelin and non-myelin debris contribute to foamy macrophage formation after spinal cord injury

Tissue damage after spinal cord injury (SCI) elicits a robust inflammatory cascade that fails to resolve in a timely manner, resulting in impaired wound healing and cellular regeneration. This inflammatory response is partly mediated by infiltrating immune cells, including macrophages. As professional phagocytes, macrophages initially play an important role in debris clearance at the injury site, which would be necessary for proper tissue regeneration. After SCI, most macrophages become filled with lipid droplets due to excessive uptake of lipid debris, assuming a "foamy" phenotype that is associated with a proinflammatory state. Myelin has been assumed to be the main source of lipid that induces foamy macrophage formation after injury given its abundance in the spinal cord. This assumption has led to the widespread use of purified myelin treatment to model foamy macrophage formation in vitro. However, the assumption that myelin is necessary for foamy macrophage formation remains untested. To this end, we developed a novel foamy macrophage assay utilizing total spinal cord homogenate to include all sources of lipid present at the injury site. Using the myelin basic protein knockout (MBP KO, i.e., Shiverer) mice that lack myelin, we investigated lipid accumulation in foamy macrophages. Primary macrophages treated with myelin-deficient spinal cord homogenate still formed large lipid droplets typically observed in foamy macrophages, although to a lesser degree than cells treated with normal homogenate. Similarly, MBP KO mice subjected to contusive spinal cord injury also formed foamy macrophages that exhibited reduced lipid content and associated with improved histological outcomes and reduced immune cell infiltration. Therefore, the absence of myelin does not preclude foamy macrophage formation, indicating that myelin is not the only major source of lipid that contributes this pathology, even though myelin may alter certain aspects of its inflammatory profile.