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Spinal cord injury (SCI) is a debilitating condition characterized by significant sensory, motor, and autonomic dysfunctions, leading to severe physical, psychological, and financial burdens. The current therapeutic approaches for SCI show limited effectiveness, highlighting the urgent need for innovative treatments. MicroRNAs (miRNAs) like miR-10b-5p are known to play pivotal roles in gene expression regulation and have been implicated in various neurodegenerative diseases, including SCI. Polypyrimidine tract binding protein 1 (PTBP1) has also been associated with neural injury responses and recovery. This study aims to explore the interaction between miR-10b-5p and PTBP1 in the context of SCI, hypothesizing that miR-10b-5p regulates PTBP1 to influence SCI pathogenesis and recovery using a rat model of SCI and lipopolysaccharide (LPS)-induced PC12 cells. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to measure miR-10b-5p levels, revealing its low expression in SCI rats. We then assessed neurological function, histopathological changes, and spinal cord water content. We found that administering the agomiR-10b-5p significantly improved neurological function and decreased the spinal cord water content and normal motor neuron loss in SCI rats. Additionally, we explored the functions of miR-10b-5p in LPS-treated PC12 cells. Our results showed that miR-10b-5p repressed LPS-stimulated apoptosis, inflammation, and oxidative stress in PC12 cells. PTBP1 was predicted as a potential target gene of miR-10b-5p using the TargetScan database. Pulldown and luciferase reporter assays further demonstrated that miR-10b-5p binds to the 3' untranslated region (UTR) of PTBP1. RT-qPCR revealed that miR-10b-5p negatively modulated PTBP1 expression both in vivo and in vitro. Furthermore, rescue assays indicated that miR-10b-5p alleviated SCI in rats and LPS-triggered injury in PC12 cells by downregulating PTBP1. We also investigated the regulation of miR-10b-5p and PTBP1 on the transforming growth factor-beta 1 (TGF-β1)/small mother against decapentaplegic (Smad3) pathway. We found that miR-10b-5p targeted PTBP1 to repress TGF-β1 decay and facilitated TGF-β1/Smad3 pathway activation. In conclusion, our results demonstrate that miR-10b-5p alleviates SCI by repressing TGF-β1 decay and inducing TGF-β1/Smad3 pathway activation through PTBP1 downregulation. This study provides novel insights into potential targeted therapy plans for SCI., Competing Interests: Declarations Ethics approval and consent to participate All experiments and procedures were conducted in compliance with the ethical principles and received ethical approval from the Animal Ethics Committee of the Southeast University, Nanjing, China (approval number: 20210228037). Informed consent Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Electrical motor cortex stimulation can produce corticospinal system plasticity and enhance motor function after injury. We investigate molecular mechanisms of structural and physiological plasticity following electrical neuromodulation, focusing on identifying molecular predictors, or biomarkers, for durable plasticity. We used two neuromodulation protocols, repetitive multipulse stimulation (rMPS) and patterned intermittent theta burst stimulation (iTBS), incorporating different stimulation durations and follow-up periods. We compared neuromodulation efficacy in promoting corticospinal tract (CST) sprouting, motor cortex muscle evoked potential (MEP) LTP-like plasticity, and their associated molecular underpinnings. Only iTBS produced CST sprouting after short-term neuromodulation (1 d of stimulation; 9-d survival for sprouting expression); both iTBS and rMPS produced sprouting with long-term (10-d) neuromodulation. Significant mTOR signaling activation and phosphatase and tensin homolog (PTEN) protein deactivation predicted axon growth across all neuromodulation conditions that produced significant sprouting. Both neuromodulation protocols, regardless of duration, were effective in producing MEP enhancement. However, persistent LTP-like enhancement of MEPs at 30 d was only produced by long-term iTBS. Statistical modeling suggests that Stat3 signaling is the key mediator of MEP enhancement. Cervical spinal cord injury (SCI) alone did not affect baseline molecular signaling. Whereas iTBS and rMPS after SCI produced strong mTOR activation and PTEN deactivation, only iTBS produced Stat3 activation. Our findings support differential molecular biomarkers for neuromodulation-dependent structural and physiological plasticity and show that motor cortex epidural neuromodulation produces molecular changes in neurons that support axonal growth after SCI. iTBS may be more suitable for repair after SCI because it promotes molecular signaling for both CST growth and MEP plasticity., Competing Interests: Competing interests statement:The authors declare no competing interest.

Thoracic spinal cord injury (SCI) profoundly impairs motor and sensory functions, significantly reducing life quality without currently available effective treatments for neuroprotection or full functional regeneration. This study investigated the neurotrophic and synaptic recovery potential of gonadotropin-releasing hormone (GnRH) and growth hormone (GH) treatments in ovariectomized rats subjected to thoracic SCI. Employing a multidisciplinary approach, we evaluated the effects of these hormones upon gene expression of classical neurotrophins (NGF, BDNF, and NT3) as well as indicative markers of synaptic function (Nlgn1, Nxn1, SNAP25, SYP, and syntaxin-1), together with morphological assessments of myelin sheath integrity (Klüver-Barrera staining and MBP immunoreactivity) and synaptogenic proteins (PSD95, SYP) by immunohystochemistry (IHC) , and also on the neuromotor functional recovery of hindlimbs in the lesioned animals. Results demonstrated that chronic administration of GnRH and GH induced notable upregulation in the expression of several neurotrophic and synaptogenic activity genes. Additionally, the treatment showed a significant impact on the restoration of functional synaptic markers and myelin integrity. Intriguingly, while individual GnRH application induced certain recovery benefits, the combined treatment with GH appeared to inhibit neuromotor recovery, suggesting a complex interplay in hormonal regulation post-SCI. GnRH and GH are bioactive and participate in modulating neurotrophic responses and synaptic restoration under neural damage conditions, offering insights into novel therapeutic approaches for SCI. However, the intricate effects of combined hormonal treatment accentuate the necessity for further investigation that conduce to optimal and novel therapeutic strategies for patients with spinal cord lesions., (© 2024. The Author(s).)

Aim: To investigate the regulation of ginsenoside Rg1 on the PI3K/AKT pathway through the lncRNA-Malat1/miR-124-3p/ Laminin gamma1 (Lamc1) axis, activating astrocytes (As) to promote the repair of spinal cord injury (SCI)., Methods: Bioinformatics analysis was used to predict miRNA targeting Lamc1 and lncRNA targeting miR-124-3p, which were then validated through a dual-luciferase assay. Following transfection, the relationships between Malat1, miR-124-3p, and Lamc1 expression levels were assessed by qRT-PCR and Western blot (WB). Immunofluorescence staining and immunohistochemistry were utilized to measure Lamc1 expression, while changes in cavity area were observed through hematoxylin-eosin (HE) staining. Basso-Beattie-Bresnahan (BBB) scale and footprint analysis were used to evaluate functional recovery. WB was performed to assess the expression of PI3K/AKT pathway-related protein., Results: Rg1 was found to upregulate Malat1 expression, which in turn modulated the Malat1/miR-124-3p/Lamc1 axis. Furthermore, Rg1 activated the PI3K/Akt signaling pathway, significantly reducing the SCI cavity area and improving hind limb motor function. However, knockout of Malat1 hindered these effects, and inhibition of miR-124-3p reversed the silencing effects of Malat1., Conclusions: Rg1 can induce Malat1 expression to activate the Lamc1/PI3K/AKT signaling pathway by sponging with miR-124-3p, thereby regulating As activity to repair SCI., (© 2024 The Author(s). CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)

Microglia polarization is crucial for neuroinflammatory response after spinal cord injury (SCI). Small molecule compounds and hub genes play an important role in regulating microglia polarization, reducing neuroinflammatory response and oligodendrocyte demyelination after SCI. In this study, suitable data sets were used to screen hub genes, and Western blot and Immunofluorescence (IF) experiments were used to confirm the expressions of proteins related to SDAD1, RRP9 and NF-κB pathways under LPS/SCI conditions. Engeletin (ENG) reduced microglia polarization and inflammation in vivo and in vitro via the SDAD1, RRP9 or NF-κB signaling pathways. In addition, ENG binds to the membrane receptor Toll-like receptor 4 (TLR4) through small molecule-protein docking. COIP experiment and protein-protein docking revealed protein-protein interaction (PPI) between RRP9 and SDAD1. By gene knock-down (KD) / overexpression (OE) and Western blot experiments, RRP9 and SDAD1 can regulate inflammatory response through NF-κB signaling and ribosome biogenesis pathway. Western blot analysis showed that CU increased the expression of SDAD1, RRP9 and NF-κB pathway related proteins through TLR1/2, while C34 decreased the expression of SDAD1 and RRP9 proteins through TLR4. These results suggest that ENG can reduce inflammation through TLR4/RRP9(SDAD1)/NF-κB signaling pathway. In addition, we demonstrated that oligodendrocyte apoptosis and demyelination could be influenced by the regulation of microglia and tissue inflammation. In conclusion, this study found the gene Rrp9/Sdad1 and the small molecule compound ENG, which control the inflammatory response of microglia, and further explored the related mechanism of oligodendrocyte demyelination, which has important theoretical significance., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Reconstruction of the neurovascular unit is essential for the repair of spinal cord injury (SCI). Nonetheless, detailed documentation of specific vascular changes following SCI and targeted interventions for vascular treatment remains limited. This study demonstrates that traumatic pathological vascular remodeling occurs during the chronic phase of injury, characterized by enlarged vessel diameter, disruption of blood-spinal cord barrier, endothelial-to-mesenchymal transition (EndoMT), and heightened extracellular matrix deposition. After SCI, osteopontin (OPN), a critical factor secreted by immune cells, is indispensable for early vascular regeneration but also contributes to traumatic pathological vascular remodeling. This work further elucidates the mechanism by which OPN influences spinal cord microvascular endothelial cells, involving Akt-mediated Foxo1 phosphorylation. This process facilitates the extranuclear transport of Foxo1 and decreases Smad7 expression, leading to excessive activation of the TGF-β signaling pathway, which ultimately results in EndoMT and fibrosis. Targeted inhibition of Foxo1 phosphorylation through an endothelium-specific aptamer-liposome small molecule delivery system significantly mitigates vascular remodeling, thereby enhancing axon regeneration and neurological function recovery following SCI. The findings offer a novel perspective for drug therapies aimed at specifically targeting pathological vasculature after SCI., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Spinal cord injury (SCI) is a severe injury to the central nervous system, and its treatment is always a major medical challenge. Proinflammatory cell death is considered an important factor affecting neuroinflammation and the prognosis after injury. PANoptosis, a newly discovered type of proinflammatory cell death, regulates the activation of executioner molecules of apoptosis, pyroptosis and necroptosis through the PANoptosome, providing a new target for therapeutic intervention after SCI. However, its role and regulatory mechanism in SCI are not yet elucidated. Here, based on proteomic data, YBX1 expression is significantly increased in neurons after SCI. Guided by RIP-seq, subsequent experiments reveal that YBX1 promotes ZBP1 expression by stabilizing the Zbp1 mRNA, thereby aggravating ZBP1-mediated PANoptosis. Furthermore, the E3 ubiquitin ligase TRIM56 is identified as an endogenous inhibitor of YBX1 via molecular docking and IP/MS analysis. Mechanistically, TRIM56 bound to YBX1 and promoted its ubiquitination, thereby accelerating its degradation. Taken together, these findings reveal a novel function of YBX1 in regulating ZBP1-mediated PANoptosis in the pathogenesis of SCI and verified that TRIM56 functions as an endogenous inhibitor to promote the ubiquitin-proteasomal degradation of YBX1, providing new insights into SCI treatment strategies., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Reactive astrogliosis is the main cause of secondary injury to the central nerves. Biomaterials can effectively suppress astrocyte activation, but the mechanism remains unclear. Herein, Differentially Expressed Genes (DEGs) are identified through whole transcriptome sequencing in a mouse model of spinal cord injury, revealing the VIM gene as a pivotal regulator in the reactive astrocytes. Moreover, DEGs are predominantly concentrated in the extracellular matrix (ECM). Based on these, 3D injectable electrospun short fibers are constructed to inhibit reactive astrogliosis. Histological staining and functional analysis indicated that fibers with unique 3D network spatial structures can effectively constrain the reactive astrocytes. RNA sequencing and single-cell sequencing results reveal that short fibers downregulate the expression of the VIM gene in astrocytes by modulating the "ECM receptor interaction" pathway, inhibiting the transcription of downstream Vimentin protein, and thereby effectively suppressing reactive astrogliosis. Additionally, fibers block the binding of Vimentin protein with inflammation-related proteins, downregulate the NF-κB signaling pathway, inhibit neuron apoptosis, and consequently promote the recovery of spinal cord neural function. Through mechanism elucidation-material design-feedback regulation, this study provides a detailed analysis of the mechanism chain by which short fibers constrain the abnormal spatial expansion of astrocytes and promote spinal cord neural function., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Purpose: Spinal cord injury (SCI) is an irreversible neurological disease that can result in severe neurological dysfunction. The Bu Shen Huo Xue Formula (BSHXF) has been clinically shown to assist in the recovery of limb function in patients with SCI. However, the underlying mechanisms of BSHXF's therapeutic effects remain unclear. This study aimed to evaluate the effects of BSHXF in a mouse model of SCI and to identify potential therapeutic targets., Methods: The composition of BSHXF was analyzed using high-performance liquid chromatography (HPLC). In vivo, SCI was induced in mice following established protocols, followed by administration of BSHXF. Motor function was assessed using the Basso-Beattie-Bresnahan (BBB) and footprint tests. Levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were quantified with specific assay kits. Protein expression analysis was performed using Western blot and immunofluorescence. Additionally, reactive oxygen species (ROS) levels and apoptosis rates were evaluated with dedicated staining kits. In vitro, neurons were exposed to lipopolysaccharide (LPS) to investigate the effects of BSHXF on neuronal oxidative stress. The protective effects of BSHXF against LPS-induced neuronal injury were examined through RT-PCR, Western blot, and immunofluorescence., Results: The eight primary bioactive constituents of BSHXF were identified using HPLC. BSHXF significantly reduced tissue damage and enhanced functional recovery following SCI. Meanwhile, BSHXF treatment led to significant reductions in oxidative stress and apoptosis rates. It also reversed neuronal loss and reduced glial scarring after SCI. LPS exposure induced neuronal apoptosis and axonal degeneration; however, after intervention with BSHXF, neuronal damage was reduced, and the protective effects of BSHXF were mediated by the activation of the Nrf2 pathway., Conclusion: BSHXF decreased tissue damage and enhanced functional recovery after SCI by protecting neurons against oxidative stress and apoptosis. The effects of BSHXF on SCI may be related to the activation of the Nrf2 pathway., Competing Interests: The authors report no conflicts of interest in this work., (© 2024 Luo et al.)

Pyroptosis, an inflammatory programmed cell death, has recently been found to play an important role in spinal cord injury (SCI). C-type lectin domain family 5 member A (CLEC5A), triggering receptor expressed on myeloid cells 1 (TREM1), and NLR-family CARD-containing protein 4 (NLRC4) have been reported to be associated with neuronal pyroptosis, but few studies have clarified their functions and regulatory mechanisms in SCI. In this study, CLEC5A, TREM1, and NLRC4 were highly expressed in lidocaine-induced SCI rat models, and their knockdown alleviated lidocaine-induced SCI. The elevation of pyroptosis-related indicators LDH, ASC, GSDMD-N, IL-18, caspase-1, and IL-1β levels in SCI rats was attenuated after silencing of CLEC5A, TREM1, or NLRC4. Lidocaine-induced decrease in cell viability and the elevation in cell death were partly reversed after CLEC5A, TREM1, or NLRC4 silencing. Lidocaine-mediated effects on the levels of LDH, ASC, GSDMD-N, IL-18, caspase-1, and IL-1β in lidocaine-induced PC12 cells were weakened by downregulating CLEC5A, TREM1, or NLRC4. CLEC5A could interact with TREM1 to mediate NLRC4 expression, thus accelerating neuronal pyroptosis, ultimately leading to SCI exacerbation. In conclusions, CLEC5A interacted with TREM1 to increase NLRC4 expression, thus promoting neuronal pyroptosis in rat SCI models, providing new insights into the role of neuronal pyroptosis in SCI., Competing Interests: The authors declare no competing financial interests., (Copyright © 2024 Tan et al.)

Spinal cord injury creates an inflammatory microenvironment that regulates the capacity of transplanted human Neural Stem Cells (hNSC) to migrate, differentiate, and repair injury. Despite similarities in gene expression and markers detected by immunostaining, hNSC populations exhibit heterogeneous therapeutic potential. This heterogeneity derives in part from the epigenetic landscape in the hNSC genome, specifically methylation (5mC) and hydroxymethylation (5hmC) state, which may affect the response of transplanted hNSC in the injury microenvironment and thereby modulate repair capacity. We demonstrate a significant up-regulation of methylcytosine dioxygenase 2 gene (TET2) expression in undifferentiated hNSC derived from human embryonic stem cells (hES-NSC), and report that this is associated with hES-NSC competence for differentiation marker expression. TET2 protein catalyzes active demethylation and TET2 upregulation could be a signature of pluripotent exit, while shaping the epigenetic landscape in hES-NSC. We determine that the inflammatory environment overrides epigenetic programming in vitro and in vivo by directly modulating TET2 expression levels in hES-NSC to change cell fate. We also report the effect of cell fate and microenvironment on differential methylation 5mC/5hmC balance. Understanding how the activity of epigenetic modifiers changes within the transplantation niche in vivo is crucial for assessment of hES-NSC behavior for potential clinical applications., (© 2024. The Author(s).)

Injuries to the central nervous system (CNS) can cause severe neurological deficits. Axonal regrowth is a fundamental process for the reconstruction of compensatory neuronal networks after injury; however, it is extremely limited in the adult mammalian CNS. In this study, we conducted a loss-of-function genetic screen in cortical neurons, combined with a Web resource-based phenotypic screen, and identified synaptotagmin 4 (Syt4) as a novel regulator of axon elongation. Silencing Syt4 in primary cultured cortical neurons inhibits neurite elongation, with changes in gene expression involved in signaling pathways related to neuronal development. In a spinal cord injury model, inhibition of Syt4 expression in cortical neurons prevented axonal sprouting of the corticospinal tract, as well as neurological recovery after injury. These results provide a novel therapeutic approach to CNS injury by modulating Syt4 function., Competing Interests: The authors declare no competing financial interests., (Copyright © 2024 Higuchi et al.)

Spinal cord injury (SCI) pathology and pathophysiology can be attributed to both primary physical injury and secondary injury cascades. Secondary injury cascades involve dysregulated metabolism and energetic deficits directly linked to compromised mitochondrial bioenergetics. Rescuing mitochondrial function and reducing oxidative stress are associated with neuroprotection. In this regard, ketosis after traumatic brain injury (TBI), or after SCI, improves secondary neuropathology by decreasing oxidative stress, increasing antioxidants, reducing inflammation, and improving mitochondrial bioenergetics. Here, we follow up on our previous study and have used an exogenous ketone monoester, (R)-3-hydroxybutyl (R)-3-hydroxybutyrate (KE), as an alternative to a ketogenic diet, focusing on mitochondrial function between 1 and 14 days after injury. Starting 3 h following a cervical level 5 (C5) hemi-contusion injury, animals were fed either a standard control diet (SD) or a ketone ester diet (KED) combined with KE administered orally (OKE). We found that mitochondrial function was reduced after SCI at all times post-SCI, accompanied by reduced expression of most of the components of the electron transport chain (ETC). The KE rescued some of the bioenergetic parameters 1 day after SCI when D-β-Hydroxybutyrate (BHB) concentrations were ~2 mM. Still, most of the beneficial effects were observed 14 days after injury, with BHB concentrations reaching values of 4-6 mM. To our knowledge, this is the first report to show the beneficial effects of KE in rescuing mitochondrial function after SCI and demonstrates the suitability of KE in ameliorating the metabolic dysregulation that occurs after traumatic SCI without requiring a restrictive dietary regime.

Spinal cord injury (SCI) triggers a cascade of intricate molecular and cellular changes that determine the outcome. In this study, we resolve the spatiotemporal organization of the injured mouse spinal cord and quantitatively assess in situ cell-cell communication following SCI. By analyzing existing single-cell RNA sequencing datasets alongside our spatial data, we delineate a subpopulation of Igfbp2-expressing astrocytes that migrate from the white matter (WM) to gray matter (GM) and become reactive upon SCI, termed Astro-GMii. Further, Igfbp2 upregulation promotes astrocyte migration, proliferation, and reactivity, and the secreted IGFBP2 protein fosters neurite outgrowth. Finally, we show that IGFBP2 significantly reduces neuronal loss and remarkably improves the functional recovery in a mouse model of SCI in vivo. Together, this study not only provides a comprehensive molecular atlas of SCI but also exemplifies how this rich resource can be applied to endow cells and genes with functional insight and therapeutic potential., Competing Interests: Declaration of interests Y.F., Z.W., and T.L., from the Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, have filed a Patent Cooperation Treaty (PCT) application (PCT/CN2024/092024) on the use of the IGFBP2 protein and bio-material composition for treating neural injury and neurodegeneration., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Since their initial recognition, miRNAs have been the subject of rising scientific interest. Especially in recent years, miRNAs have been recognized to play an important role in the mediation of various diseases, and further, their potential as biomarkers was recognized. Rising attention has also been given to miRNA-21, which has proven to play an ambivalent role as a biomarker. Responding to the demand for biomarkers in the trauma field, the present review summarizes the contrary roles of miRNA-21 in acute organ damage after trauma with a specific focus on the role of miRNA-21 in traumatic brain injury, spinal cord injury, cardiac damage, lung injury, and bone injury. This review is based on a PubMed literature search including the terms "miRNA-21" and "trauma", "miRNA-21" and "severe injury", and "miRNA-21" and "acute lung respiratory distress syndrome". The present summary makes it clear that miRNA-21 has both beneficial and detrimental effects in various acute organ injuries, which precludes its utility as a biomarker but makes it intriguing for mechanistic investigations in the trauma field.

In individuals with a spinal cord injury (SCI), rapid skeletal muscle atrophy and metabolic dysfunction pose profound rehabilitation challenges, often resulting in substantial loss of muscle mass and function. This study evaluates the effect of combined neuromuscular electrical stimulation (Comb-NMES) on skeletal muscle cross-sectional area (CSA) and inflammatory signaling within the acute phase of SCI. We applied a novel Comb-NMES regimen, integrating both high-frequency resistance and low-frequency aerobic protocols on the vastus lateralis muscle, to participants early post-SCI. Muscle biopsies were analyzed for CSA and inflammatory markers pre- and post-intervention. The results suggest a potential preservation of muscle CSA in the Comb-NMES group compared to a control group. Inflammatory signaling proteins such as TLR4 and Atrogin-1 were downregulated, whereas markers associated with muscle repair and growth were modulated beneficially in the Comb-NMES group. The study's findings suggest that early application of Comb-NMES post-SCI may attenuate inflammatory pathways linked to muscle atrophy and promote muscle repair. However, the small sample size and variability in injury characteristics emphasize the need for further research to corroborate these results across a more diverse and extensive SCI population.

Microglia, the primary immune cells in the central nervous system, play a critical role in regulating neuronal function and fate through their interaction with neurons. Despite extensive research, the specific functions and mechanisms of microglia-neuron interactions remain incompletely understood. In this study, we demonstrate that microglia establish direct contact with myelinated axons at Nodes of Ranvier in the spinal cord of mice. The contact associated with neuronal activity occurs in a random scanning pattern. In response to axonal injury, microglia rapidly transform their contact into a robust wrapping form, preventing acute axonal degeneration from extending beyond the nodes. This wrapping behavior is dependent on the function of microglial P2Y12 receptors, which may be activated by ATP released through axonal volume-activated anion channels at the nodes. Additionally, voltage-gated sodium channels (NaV) and two-pore-domain potassium (K2P) channels contribute to the interaction between nodes and glial cells following injury, and inhibition of NaV delays axonal degeneration. Through in vivo imaging, our findings reveal a neuroprotective role of microglia during the acute phase of single spinal cord axon injury, achieved through neuron-glia interaction., (© 2024. The Author(s).)

Many central nervous system (CNS) disorders lack approved treatment options. Previous research demonstrated that peptide CAQK can bind to chondroitin sulfate proteoglycans (CSPGs) in the extracellular matrix of the CNS. In vivo studies have investigated CAQK conjugated to nanoparticles containing therapeutic agents with varying methodologies/outcomes. This paper presents the first systematic review assessing its properties, applications, and outcomes secondary to its use. Following PRISMA guidelines, a comprehensive search was performed across multiple databases. Studies utilizing CAQK as a therapeutic agent/homing molecule in animal/human models were selected. Sixteen studies met the inclusion criteria. Mice and rats were the predominant animal models. All studies except one used CAQK to deliver a therapeutic agent. The reviewed studies mostly included models of brain and spinal cord injuries. Most studies had intravenous administration of CAQK. All studies demonstrated various benefits and that CAQK conjugation facilitated localization to target tissues. No studies directly evaluated the effects of CAQK alone. The data are limited by the heterogeneity in study methodologies and the lack of direct comparison between CAQK and conjugated agents. Overall, these findings present CAQK utilization to deliver a therapeutic agent as a promising targeting strategy in the management of disorders where CSPGs are upregulated.

Spinal cord injury (SCI) is a debilitating central nervous system (CNS) disorder that leads to significant motor and sensory impairments. Given the limited regenerative capacity of adult mammalian neurons, this study presents an innovative strategy to enhance axonal regeneration and functional recovery by identifying a novel factor that markedly promotes axonal regeneration. Employing a zebrafish model with targeted single axon injury in Mauthner cells (M-cells) and utilizing the Tg (Tol056: EGFP) transgenic line for in vivo monitoring, we investigate the intrinsic mechanisms underlying axonal regeneration. This research specifically examines the role of amino acid transport, emphasizing the role of the solute carrier 1A4 amino acid transporter in axonal regeneration. Our findings demonstrate that Slc1a4 overexpression significantly enhances axonal regeneration in M-cells, whereas Slc1a4 deficiency impedes this process, which is concomitant with the downregulation of the P53/Gap43 signaling pathway. By elucidating the fundamental role of Slc1a4 in axonal regeneration and uncovering its underlying mechanisms, this study thus provides novel insights into therapeutic strategies for SCI.

Neural degeneration is a hallmark of spinal cord injury (SCI). Multipotent neural precursor cells (NPCs) have the potential to reconstruct the damaged neuron-glia network due to their tri-lineage capacity to generate neurons, astrocytes, and oligodendrocytes. However, astrogenesis is the predominant fate of resident or transplanted NPCs in the SCI milieu adding to the abundant number of resident astrocytes in the lesion. How NPC-derived astrocytes respond to the inflammatory milieu of SCI and the mechanisms by which they contribute to the post-injury recovery processes remain largely unknown. Here, we uncover that activated NPC-derived astrocytes exhibit distinct molecular signature that is immune modulatory and foster neurogenesis, neuronal maturity, and synaptogenesis. Mechanistically, NPC-derived astrocytes perform regenerative matrix remodeling by clearing inhibitory chondroitin sulfate proteoglycans (CSPGs) from the injury milieu through LAR and PTP-σ receptor-mediated endocytosis and the production of ADAMTS1 and ADAMTS9, while most resident astrocytes are pro-inflammatory and contribute to the pathologic deposition of CSPGs. These novel findings unravel critical mechanisms of NPC-mediated astrogenesis in SCI repair., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Traumatic spinal cord injury (SCI) has devastating physical, psychosocial, and vocational implications for patients and caregivers. Heterophyllin B (HB) is a brain-permeable cyclopeptide from Pseudostellaria heterophylla that promotes axonal regeneration and neuroinflammation. However, the efficacy of HB in improving functional recovery following SCI and the underlying mechanisms remain unclear. This study utilized a murine model for SCI assessment to evaluate the therapeutic effects of HB. following HB intervention, functional recovery post-SCI, was assessed through the Basso Mouse Scale, gait analysis, and the detection of motor-evoked potentials (MEPs). RNA sequencing was used to study the roles of pyroptosis, oxidative stress, and autophagy in HB's impact on SCI. Techniques such as Western blot, immunofluorescence, and enzyme-linked immunosorbent assay were used to evaluate pyroptosis, oxidative stress, and autophagy markers. Associated virus vectors were used to suppress transcription factor EB (TFEB), an autophagy regulator, in a living organism. HB promoted autophagy by enhancing TFEB nuclear translocation. In contrast, it inhibited pyroptosis and oxidative stress. Based on using the adenosine monophosphate-activated protein kinase (AMPK) inhibitor Compound C, the AMPK-TRPML1-calcineurin pathway was involved in HB's regulation of TFEB. In summary, this study demonstrated that HB facilitated functional recuperation by stimulating TFEB-driven autophagy while simultaneously suppressing pyroptosis and oxidative stress after SCI, indicating its potential for clinical application., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Study Design: Longitudinal observational study. Measurements were undertaken between weeks 4-6 post-spinal cord injury (SCI), repeated at week 8 and every 4 weeks thereafter until week 20 or rehabilitation discharge, whichever occurred first., Objectives: Observe variation in measured resting energy expenditure (REE) and body composition in males undergoing SCI rehabilitation, compare REE with SCI-specific prediction equations incorporating fat-free mass (FFM), and explore the prevalence of clinical factors that may influence individual REE., Setting: Spinal Injuries Unit, Brisbane, Queensland, Australia., Methods: Indirect calorimetry was used to measure REE and bioimpedance spectroscopy to assess body composition. Four SCI-specific FFM-based REE and basal metabolic rate (BMR) prediction equations were compared to measured REE. A clinically significant change in REE was defined as +/- 10% difference from the week 4-6 measurement. Clinical factors that may affect REE variations were collected including infection, pressure injuries, autonomic dysreflexia, spasticity, and medications., Results: Fifteen people participated (mean age 35 ± 13 years, 67% paraplegic). There was no statistically significant change in mean REE, weight, or body composition, and the Chun and Nightingale BMR prediction equations performed best (r c  > 0.8 at all time points). One-third of participants had >10% change in REE on 11 occasions, with clinical factors not consistently associated with the observed changes., Conclusion: During SCI rehabilitation, mean REE, weight, and body composition remain unchanged, and FFM-based BMR prediction equations may be an acceptable alternative to indirect calorimetry. Future research designs should avoid single indirect calorimetry measures as snapshot data may not represent typical REE in this population., (© 2024. Crown.)

Background: A spinal cord injury (SCI) can result in severe impairment and fatality as well as significant motor and sensory abnormalities. Exosomes produced from IPSCs have demonstrated therapeutic promise for accelerating spinal cord injury recovery, according to a recent study., Objective: This study aims to develop engineered IPSCs-derived exosomes (iPSCs-Exo) capable of targeting and supporting neurons, and to assess their therapeutic potential in accelerating recovery from spinal cord injury (SCI)., Methods: iPSCs-Exo were characterized using Transmission Electron Microscopy (TEM), Nanoparticle Tracking Analysis (NTA), and western blot. To enhance neuronal targeting, iPSCs-Exo were bioengineered, and their uptake by neurons was visualized using PKH26 labeling and fluorescence microscopy. In vitro, the anti-inflammatory effects of miRNA-loaded engineered iPSCs-Exo were evaluated by exposing neurons to LPS and IFN-γ. In vivo, biodistribution of engineered iPSC-Exo was monitored using a vivo imaging system. The therapeutic efficacy of miRNA-loaded engineered iPSC-Exo in a SCI mouse model was assessed by Basso Mouse Scale (BMS) scores, H&E, and Luxol Fast Blue (LFB) staining., Results: The results showed that engineered iPSC-Exo loaded with miRNA promoted the spinal cord injure recovery. Thorough safety assessments using H&E staining on major organs revealed no evidence of systemic toxicity, with normal organ histology and biochemistry profiles following engineered iPSC-Exo administration., Conclusion: These results suggest that modified iPSC-derived exosomes loaded with miRNA have great potential as a cutting-edge therapeutic approach to improve spinal cord injury recovery. The observed negligible systemic toxicity further underscores their potential safety and efficacy in clinical applications., (© 2024. The Author(s).)

After injury, mammalian spinal cords develop scars to confine the lesion and prevent further damage. However, excessive scarring can hinder neural regeneration and functional recovery 1,2 . These competing actions underscore the importance of developing therapeutic strategies to dynamically modulate scar progression. Previous research on scarring has primarily focused on astrocytes, but recent evidence has suggested that ependymal cells also participate. Ependymal cells normally form the epithelial layer encasing the central canal, but they undergo massive proliferation and differentiation into astroglia following certain injuries, becoming a core scar component 3-7 . However, the mechanisms regulating ependymal proliferation in vivo remain unclear. Here we uncover an endogenous κ-opioid signalling pathway that controls ependymal proliferation. Specifically, we detect expression of the κ-opioid receptor, OPRK1, in a functionally under-characterized cell type known as cerebrospinal fluid-contacting neuron (CSF-cN). We also discover a neighbouring cell population that expresses the cognate ligand prodynorphin (PDYN). Whereas κ-opioids are typically considered inhibitory, they excite CSF-cNs to inhibit ependymal proliferation. Systemic administration of a κ-antagonist enhances ependymal proliferation in uninjured spinal cords in a CSF-cN-dependent manner. Moreover, a κ-agonist impairs ependymal proliferation, scar formation and motor function following injury. Together, our data suggest a paracrine signalling pathway in which PDYN + cells tonically release κ-opioids to stimulate CSF-cNs and suppress ependymal proliferation, revealing an endogenous mechanism and potential pharmacological strategy for modulating scarring after spinal cord injury., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

A short peptide termed NEMO-binding domain (NBD) peptide has an inhibitory effect on nuclear factor kappa-B (NF-κB). Despite its efficacy in inhibiting inflammatory responses, the precise neuroprotective mechanisms of NBD peptide in spinal cord injury (SCI) remain unclear. This study aims to determine whether the pyroptosis-related aspects involved in the neuroprotective effects of NBD peptide post-SCI.Using RNA sequencing, the molecular mechanisms of NBD peptide in SCI are explored. The evaluation of functional recovery is performed using the Basso mouse scale, Nissl staining, footprint analysis, Masson's trichrome staining, and HE staining. Western blotting, enzyme-linked immunosorbent assays, and immunofluorescence assays are used to examine pyroptosis, autophagy, lysosomal membrane permeabilization (LMP), acid sphingomyelinase (ASMase), and the NF-κB/p38-MAPK related signaling pathway.NBD peptide mitigated glial scar formation, reduced motor neuron death, and enhanced functional recovery in SCI mice. Additionally, NBD peptide inhibits pyroptosis, ameliorate LMP-induced autophagy flux disorder in neuron post-SCI. Mechanistically, NBD peptide alleviates LMP and subsequently enhances autophagy by inhibiting ASMase through the NF-κB/p38-MAPK/Elk-1/Egr-1 signaling cascade, thereby mitigating neuronal death. NBD peptide contributes to functional restoration by suppressing ASMase-mediated LMP and autophagy depression, and inhibiting pyroptosis in neuron following SCI, which may have potential clinical application value., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

A literature review showed that Atg7 biological role was associated with the development and pathogenesis of nervous system, but very few reports focused on Atg7 role on neurogenesis at the region of spinal cord, so that we are committed to explore the subject. Atg7 expression in neural tube is incrementally increased during neurogenesis. Atg7 neural-specific knockout mice demonstrated the impaired motor function and imbalance of neuronal and glial cell differentiation during neurogenesis, which was similarly confirmed in primary neurosphere culture and reversely verified by Atg7 overexpression in unilateral neural tubes of gastrula chicken embryos. Furthermore, activating autophagy in neural stem cells (NSCs) of neurospheres did not rescue Atg7 deficiency-suppressed neuronal differentiation, but Atg7 overexpression on the basis of autophagy inhibition could reverse Atg7 deficiency-suppressed neuronal differentiation, which provides evidence for the existence of Atg7 role of autophagy-independent function. The underlying mechanism is that Atg7 deficiency directly caused the alteration of cell cycle length of NSCs, which is controlled by Atg7 through specifically binding Mdm2, thereby affecting neuronal differentiation during neurogenesis. Eventually, the effect of overexpressing Atg7-promoting neuronal differentiation was proved in spinal cord injury model as well. Taken together, this study revealed that Atg7 was involved in regulating neurogenesis by a non-autophagic signaling process, and this finding also shed light on the potential application in regenerative medicine., (© 2024. The Author(s), under exclusive licence to ADMC Associazione Differenziamento e Morte Cellulare.)

Spinal cord injury (SCI) leads to secondary neuronal death, which severely impedes recovery of motor function. Therefore, prevention of neuronal cell death after SCI is an important strategy. Ferroptosis, a new form of cell death discovered in recent years, has been shown to be involved in the regulation of SCI. However, the role and potential mechanisms of ferroptosis in secondary SCI are not fully understood. In this study, we report that the E3 ubiquitin ligase Syvn1 suppresses ferroptosis and promotes functional recovery from SCI in vitro and in vivo. Mechanistically, screened with bioinformatics, immunoprecipitation, and mass spectrometry, we identified Stat3, a transcription factor that induces the expression of the ferroptosis inhibitor Gpx4, as a substrate of Syvn1. Furthermore, we identified neurons as the primary cellular source of Syvn1 signalling. Moreover, we determined the binding domains of Syvn1 and Stat3 in HEK 293 T cells using full-length proteins and a series of truncated Flag-tagged and Myc-tagged fragments. Furthermore, we created the cell and animal models with silencing or overexpression of Syvn1 and Stat3 and found that Syvn1 inhibits neuronal ferroptosis by stabilizing Stat3, which subsequently activates the ferroptosis regulator Gpx4 in SCI. In summary, the Syvn1-mediated Stat3/Gpx4 signalling axis attenuates neuronal ferroptosis, reduces neuronal death, and promotes SCI repair. Therefore, our findings provide potential new targets and intervention strategies for the treatment of SCI., (© 2024 The Authors. Cell Proliferation published by Beijing Institute for Stem Cell and Regenerative Medicine and John Wiley & Sons Ltd.)

Patients with spinal cord injury (SCI) have permanent devastating motor and sensory disabilities. Secondary SCI is known for its complex progression and presents with sophisticated aberrant inflammation, vascular changes, and secondary cellular dysfunction, which aggravate the primary damage. Since their initial discovery, the potent neuroprotective effects and powerful delivery abilities of exosomes (Exos) have been reported in different research fields, including SCI. In this study, we summarize therapeutic advances related to the application of Exos in preclinical animal studies. Subsequently, we discuss the mechanisms of action of Exos derived from diverse cell types, including neurogenesis, angiogenesis, blood-spinal cord barrier preservation, anti-apoptosis, and anti-inflammatory potential. We also evaluate the relationship between the Exo delivery cargo and signaling pathways. Finally, we discuss the challenges and advantages of using Exos to offer innovative insights regarding the development of efficient clinical strategies for SCI., (© 2024. The Author(s).)

Astrocytes act as immune cells that can produce a series of chemokines to attract large numbers of leucocytes to the lesion site, where they contribute to excessive inflammation following spinal cord injury (SCI). However, the relevant regulatory mechanism involved in chemokine production by astrocytes has not been fully elucidated. In the present study, we examined the correlation between C-C motif chemokine ligand 5 (CCL5) and high mobility group box-1 protein (HMGB1) in a T8-T10 spinal cord contusion model. Our results revealed that SCI-induced CCL5 protein levels increased synchronously with the increase in HMGB1. Administration of an HMGB1-neutralizing antibody significantly reduced the protein expression of CCL5 in the context of SCI. An in vitro study revealed that HMGB1 binding with TLR2/4 receptors potently facilitates the production of CCL5 by astrocytes by activating the intracellular ERK/JNK-mediated NF-κB pathway. Furthermore, the HMGB1-induced release of CCL5 from astrocytes is involved in promoting microglia/macrophage accumulation and M1 polarization. The inhibition of HMGB1 activity reduces microglia/macrophage infiltration by decreasing the expression of CCL5 and improves motor functional recovery following SCI. Our results provide insights into the new functions of HMGB1-mediated astrocytic CCL5 production, which elicits inflammatory cell recruitment to the site of injury; this recruitment is associated with excessive inflammation activation. These data may provide a new therapeutic strategy for central nervous system (CNS) inflammation., (© 2024. The Author(s).)

Adult central nervous system (CNS) neurons down-regulate growth programs after injury, leading to persistent regeneration failure. Coordinated lipids metabolism is required to synthesize membrane components during axon regeneration. However, lipids also function as cell signaling molecules. Whether lipid signaling contributes to axon regeneration remains unclear. In this study, we showed that lipin1 orchestrates mechanistic target of rapamycin (mTOR) and STAT3 signaling pathways to determine axon regeneration. We established an mTOR-lipin1-phosphatidic acid/lysophosphatidic acid-mTOR loop that acts as a positive feedback inhibitory signaling, contributing to the persistent suppression of CNS axon regeneration following injury. In addition, lipin1 knockdown (KD) enhances corticospinal tract (CST) sprouting after unilateral pyramidotomy and promotes CST regeneration following complete spinal cord injury (SCI). Furthermore, lipin1 KD enhances sensory axon regeneration after SCI. Overall, our research reveals that lipin1 functions as a central regulator to coordinate mTOR and STAT3 signaling pathways in the CNS neurons and highlights the potential of lipin1 as a promising therapeutic target for promoting the regeneration of motor and sensory axons after SCI., Competing Interests: Competing interests statement:The authors declare no competing interest.

People with a spinal cord injury are at an increased risk of metabolic dysfunction due to skeletal muscle atrophy and the transition of paralyzed muscle to a glycolytic, insulin-resistant phenotype. Providing doses of exercise through electrical muscle stimulation may provide a therapeutic intervention to help restore metabolic function for people with a spinal cord injury, but high-frequency and high-force electrically induced muscle contractions increase fracture risk for the underlying osteoporotic skeletal system. Therefore, we investigated the acute molecular responses after a session of either a 3 Hz or 1 Hz electrically induced exercise program. Ten people with a complete spinal cord injury completed a 1 h (3 Hz) or 3 h (1 Hz) unilateral electrically induced exercise session prior to a skeletal muscle biopsy of the vastus lateralis. The number of pulses was held constant. Tissue samples were analyzed for genomic and epigenomic expression profiles. There was a strong acute response after the 3 Hz exercise leading to the upregulation of early response genes (NR4A3, PGC-1α, ABRA, IRS2, EGR1, ANKRD1, and MYC), which have prominent roles in regulating molecular pathways that control mitochondrial biogenesis, contractile protein synthesis, and metabolism. Additionally, these genes, and others, contributed to the enrichment of pathways associated with signal transduction, cellular response to stimuli, gene expression, and metabolism. While there were similar trends observed after the 1 Hz exercise, the magnitude of gene expression changes did not reach our significance thresholds, despite a constant number of stimuli delivered. There were also no robust acute changes in muscle methylation after either form of exercise. Taken together, this study supports that a dose of low-force electrically induced exercise for 1 h using a 3 Hz stimulation frequency is suitable to trigger an acute genomic response in people with chronic paralysis, consistent with an expression signature thought to improve the metabolic and contractile phenotype of paralyzed muscle, if performed on a regular basis.

Spinal cord injury (SCI) triggers microglial/monocytes activation with distinct pro-inflammatory or inflammation-resolving phenotypes, which potentiate tissue damage or facilitate functional repair, respectively. The major integrin Mac-1 (CD11b/CD18), a heterodimer consisting of CD11b and CD18 chains, is expressed in multiple immune cells of the myeloid lineage. Here, we examined the effects of CD11b gene ablation in neuroinflammation and functional outcomes after SCI. qPCR analysis of C57BL/6 female mice showed upregulation of CD11b mRNA starting from 1 d after injury, which persisted up to 28 d. CD11b knockout (KO) mice and their wildtype littermates were subjected to moderate SCI. At 1 d post-injury, qPCR showed increased expression of genes involved with inflammation-resolving processes in CD11b KO mice. Flow cytometry analysis of CD45 int Ly6C - CX3CR1 + microglia, CD45 hi Ly6C + Ly6G - monocytes, and CD45 hi Ly6C + Ly6G + neutrophils revealed significantly reduced cell counts as well as reactive oxygen species (ROS) production in CD11b KO mice at d3 post-injury. Further examination with NanoString and RNA-seq showed upregulation of pro-inflammatory genes, but downregulation of the ROS pathway. Importantly, CD11b KO mice exhibited significantly improved locomotor function, reduced cutaneous mechanical/thermal hypersensitivity, and limited tissue damage at 8 weeks post-injury. Collectively, our data suggest an important role for CD11b in regulating tissue inflammation and functional outcome following SCI.

Spinal cord injury (SCI) often results in permanent loss of motor and sensory function. After SCI, the blood-spinal cord barrier (BSCB) is disrupted, causing the infiltration of neutrophils and macrophages, which secrete several kinds of cytokines, as well as matrix metalloproteinases (MMPs). MMPs are proteases capable of degrading various extracellular matrix (ECM) proteins, as well as many non-matrix substrates. The tissue inhibitor of MMPs (TIMP)-1 is significantly upregulated post-SCI and operates via MMP-dependent and MMP-independent pathways. Through the MMP-dependent pathway, TIMP-1 directly reduces inflammation and destruction of the ECM by binding and blocking the catalytic domains of MMPs. Thus, TIMP-1 helps preserve the BSCB and reduces immune cell infiltration. The MMP-independent pathway involves TIMP-1's cytokine-like functions, in which it binds specific TIMP surface receptors. Through receptor binding, TIMP-1 can stimulate the proliferation of several types of cells, including keratinocytes, aortic smooth muscle cells, skin epithelial cells, corneal epithelial cells, and astrocytes. TIMP-1 induces astrocyte proliferation, modulates microglia activation, and increases myelination and neurite extension in the central nervous system (CNS). In addition, TIMP-1 also regulates apoptosis and promotes cell survival through direct signaling. This review provides a comprehensive assessment of TIMP-1, specifically regarding its contribution to inflammation, ECM remodeling, and scar formation after SCI.

Sacral spinal cord injury (SSCI) can disrupt bladder neuromodulation and impair detrusor function. Current studies provide limited information on the histologic and genetic changes associated with SSCI-related neurogenic lower urinary tract dysfunction (NLUTD), resulting in few treatment options. This study aimed to establish a simple animal model of SSCI to better understand the disease progression. Ninety 8-week-old Sprague-Dawley (SD) rats were randomly separated into sham operation and SSCI groups. The SSCI group underwent sacral spinal cord injury, while the sham group did not. Urodynamic and histological assessments were conducted at various intervals (1, 2, 3, 4, and 6 weeks) post-injury to elucidate the disease process. Urodynamic examinations revealed significant bladder dysfunction in the SSCI group compared to the sham group, stabilizing around 3-4 weeks post-injury. Histological examination, including hematoxylin-eosin and Masson's trichrome staining, correlated these functional changes with bladder microstructural alterations. RNA-seq was performed on bladder tissues from the sham group and SSCI group at 6 weeks to identify differentially expressed genes and pathways. Selected genes were further analyzed using polymerase chain reaction (PCR). The findings indicated a pronounced inflammatory response in the first 2 weeks post-SSCI, progressing to bladder fibrosis at 3-4 weeks. In conclusion, this study presents a reliable, reproducible, and straightforward SSCI model, providing insights into bladder functional and morphological alterations post-SSCI and laying the groundwork for future therapeutic research.

Rationale: Spinal cord injury (SCI)-induced vascular damage causes ischemia and hypoxia at the injury site, which, in turn, leads to profound metabolic disruptions. The effects of these metabolic alterations on neural tissue remodeling and functional recovery have yet to be elucidated. The current study aimed to investigate the consequences of the SCI-induced hypoxic environment at the epicenter of the injury. Methods: This study employed metabolomics to assess changes in energy metabolism after SCI. The use of a lactate sensor identified lactate shuttle between endothelial cells (ECs) and neurons. Reanalysis of single-cell RNA sequencing data demonstrated reduced MCT1 expression in ECs after SCI. Additionally, an adeno-associated virus (AAV) overexpressing MCT1 was utilized to elucidate its role in endothelial-neuronal interactions, tissue repair, and functional recovery. Results: The findings revealed markedly decreased monocarboxylate transporter 1 (MCT1) expression that facilitates lactate delivery to neurons to support their energy metabolism in ECs post-SCI. This decreased expression of MCT1 disrupts lactate transport to neurons, resulting in a metabolic imbalance that impedes axonal regeneration. Strikingly, our results suggested that administering adeno-associated virus specifically to ECs to restore MCT1 expression enhances axonal regeneration and improves functional recovery in SCI mice. These findings indicate a novel link between lactate shuttling from endothelial cells to neurons following SCI and subsequent neural functional recovery. Conclusion: In summary, the current study highlights a novel metabolic pathway for therapeutic interventions in the treatment of SCI. Additionally, our findings indicate the potential benefits of targeting lactate transport mechanisms in recovery from SCI., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Abstract: Zhenbao pill (ZBP) has been shown to improve outcomes in spinal cord injury (SCI). However, its potential regulatory mechanisms in SCI remain to be elucidated. This study aimed to define the role of ZBP and its underlying molecular mechanisms in SCI, both in vitro and in vivo. Our findings indicated that ZBP ameliorated SCI by inhibiting neuronal apoptosis and the inflammatory response through the enhancement of miR-214-5p in vivo. In vitro, ZBP significantly reduced the levels of inflammatory factors, increased cell viability, and decreased apoptosis induced by oxygen-glucose deprivation (OGD)-activated microglia via miR-214-5p. Furthermore, the addition of miR-214-5p diminished the inflammatory response, enhanced cell viability, and suppressed apoptosis in OGD-treated microglia. We identified SRY-box transcription factor 4 (SOX4) as a potential target of miR-214-5p. Overexpression of SOX4 negated the effects of miR-214-5p on the inflammatory response, cell viability, and apoptosis in OGD-activated microglia. ZBP inhibited SOX4/β-catenin activation and reduced pro-inflammatory cytokine secretion by enhancing miR-214-5p in activated microglia. In summary, our findings demonstrate that ZBP mitigates SCI by inhibiting neuronal damage caused by activated microglia through the miR-214-5p/SOX4/β-catenin axis, providing valuable insights into the molecular basis of ZBP as a therapeutic agent for SCI., (Copyright © 2024 Copyright: © 2024 Journal of Physiological Investigation.)

Aim: We aimed to explore whether the combination of CLP290 and bumetanide maximally improves neuropathic pain following spinal cord injury (SCI) and its possible molecular mechanism., Methods: Rats were randomly divided into five groups: Sham, SCI + vehicle, SCI + CLP290, SCI + bumetanide, and SCI + combination (CLP290 + bumetanide). Drug administration commenced on the 7th day post-injury (7 dpi) and continued for 14 days. All rats underwent behavioral assessments for 56 days to comprehensively evaluate the effects of interventions on mechanical pain, thermal pain, cold pain, motor function, and other relevant parameters. Electrophysiological assessments, immunoblotting, and immunofluorescence detection were performed at different timepoints post-injury, with a specific focus on the expression and changes of KCC2 and NKCC1 proteins in the lumbar enlargement of the spinal cord., Results: CLP290 and bumetanide alleviated SCI-associated hypersensitivity and locomotor function, with the combination providing enhanced recovery. The combined treatment group exhibited the most significant improvement in restoring Rate-Dependent Depression (RDD) levels. In the combined treatment group and the two individual drug administration groups, the upregulation of potassium chloride cotransporter 2 (K + -Cl - cotransporter 2, KCC2) expression and downregulation of sodium potassium chloride cotransporter 1 (Na + -K + -Cl - cotransporter 1, NKCC1) expression in the lumbar enlargement area resulted in a significant increase in the KCC2/NKCC1 ratio compared to the SCI + vehicle group, with the most pronounced improvement seen in the combined treatment group. Compared to the SCI + vehicle group, the SCI + bumetanide group showed no significant paw withdrawal thermal latency (PWTL) improvement at 21 and 35 dpi, but a notable enhancement at 56 dpi. In contrast, the SCI + CLP290 group significantly improved PWTL at 21 days, with non-significant changes at 35 and 56 days. At 21 dpi, KCC2 expression was marginally higher in monotherapy groups versus SCI + vehicle, but not significantly. At 56 dpi, only the SCI + bumetanide group showed a significant difference in KCC2 expression compared to the control group., Conclusion: Combined application of CLP290 and bumetanide effectively increases the ratio of KCC2/NKCC1, restores RDD levels, enhances GABA A receptor-mediated inhibitory function in the spinal cord, and relieves neuropathic pain in SCI; Bumetanide significantly improves neuropathic pain in the long term, whereas CLP290 demonstrates a notable short-term effect., (© 2024 The Author(s). CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)

Background and Objectives: Spinal cord injury (SCI) results in significant neurological deficits, and microglia play the critical role in regulating the immune microenvironment and neurological recovery. Protein lactylation has been found to modulate the function of immune cells. Therefore, this study aimed to elucidate the effects of glycolysis-derived lactate on microglial function and its potential neuroprotective mechanisms via lactylation after SCI., Methods: Single-cell RNA sequencing (scRNA-seq) data were obtained from figshare to analyze cellular and molecular alterations within the spinal cord post-SCI, further focusing on the expression of microglia-related genes for cell sub-clustering, trajectory analysis, and glycolysis function analysis. We also evaluated the expression of lactylation-related genes in microglia between day 7 after SCI and sham group. Additionally, we established the mice SCI model and performed the bulk RNA sequencing in a time-dependent manner. The expression of glycolysis- and lactylation-related genes was evaluated, as well as the immune infiltration analysis based on the lactylation-related genes. Then, we investigated the bio-effects of lactate on the inflammation and polarization phenotype of microglia. Finally, adult male C57BL/6 mice were subjected to exercise first to increase lactate level, before SCI surgery, aiming to evaluate the protective effects of lactate-mediated lactylation of microglia-related proteins on SCI., Results: scRNA-seq identified a subcluster of microglia, recombinant chemokine C-X3-C-motif receptor 1 + (CX3CR1 + ) microglia, which is featured by M1-like phenotype and increased after SCI. KEGG analysis revealed the dysfunctional glycolysis in microglia after SCI surgery, and AUCell analysis suggested that the decreased glycolysis an increased oxidative phosphorylation in CX3CR1 + microglia. Differential gene analysis suggested that several lactylation-related genes (Fabp5, Lgals1, Vim, and Nefl) were downregulated in CX3CR1 + microglia at day 7 after SCI, further validated by the results from bulk RNA sequencing. Immunofluorescence staining indicated the expression of lactate dehydrogenase A (LDHA) in CX3CR1 + microglia also decreased at day 7 after SCI. Cellular experiments demonstrated that the administration of lactate could increase the lactylation level and inhibit the pro-inflammatory phenotype in microglia. Functionally, exercise-mediated lactate production resulted in improved locomotor recovery and decreased inflammatory markers in SCI mice compared to SCI alone., Conclusions: In the subacute phase of SCI, metabolic remodeling in microglia may be key therapeutic targets to promote nerve regeneration, and lactate contributed to neuroprotection after SCI by influencing microglial lactylation and inflammatory phenotype, which offered a novel approach for therapeutic intervention., (© 2024 The Author(s). CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)

Background: Spinal cord injury (SCI) is a devastating neurological disease characterized by neuroinflammation and neuronal apoptosis. The PI3K/AKT signaling pathway is related to the pathological process of SCI. Hematopoietic growth factor inducible neurokinin-1 type (HGFIN) is a transmembrane glycoprotein that exerts neuroprotective actions in various neurodegenerative diseases. However, the potential role and mechanism of HGFIN in the development of SCI are still unclear., Objectives: To investigate the effect of HGFIN on inflammation and neuronal apoptosis as well as the underlying mechanism in SCI., Material and Methods: A rat model of SCI was established, and Basso-Beattie-Bresnahan (BBB) motor function assay was performed to detect motor function. Expression of HGFIN was measured at 7 days after injury by western blot and immunofluorescence. An HGFIN-shRNA-carrying lentivirus was injected into the injury site to block the expression of HGFIN. The effects of HGFIN on neuronal apoptosis and the PI3K/AKT pathway were analyzed by TUNEL staining and immunofluorescence. The Iba-1 expression and the levels of pro-inflammatory cytokines were measured in spinal cord tissues by immunofluorescence staining and real-time polymerase chain reaction (PCR) analysis., Results: The SCI rats showed increased expression of HGFIN in spinal cord tissues. The HGFIN deficiency aggravated SCI lesions, as evidenced by decreased BBB scores. At 7 days post-injury, HGFIN knockdown promoted neuronal apoptosis, accompanied by the increased expression level of the apoptosis effector cleaved caspase-3 and cleaved PARP, and decreased anti-apoptotic protein Bcl-2 expression. Moreover, HGFIN knockdown aggravated the inflammation process, indicated by increased Iba1-positive cells. The HGFIN knockdown increased the production of pro-inflammatory cytokines including IL-1β, TNF-α and IL-6. Further analysis revealed that HGFIN deficiency reduced the activation of the PI3K/AKT pathway in spinal cord tissue after injury., Conclusions: Lentivirus-mediated downregulation of HGFIN exacerbates inflammation and neuronal apoptosis in SCI by regulating the PI3K/AKT pathway, and provides clues for developing novel therapeutic approaches and targets against SCI.

Spinal cord contusion injury results in Wallerian degeneration of spinal cord axonal tracts, which are necessary for locomotor function. Axonal swelling and loss of axonal density at the contusion site, characteristic of Wallerian degeneration, commence within hours of injury. Tempol, a superoxide dismutase mimetic, was previously shown to reduce the loss of spinal cord white matter and improve locomotor function in an experimental model of spinal cord contusion, suggesting that tempol treatment might inhibit Wallerian degeneration of spinal cord axons. Here, we report that tempol partially inhibits Wallerian degeneration, resulting in improved locomotor recovery. We previously reported that Wallerian degeneration is reduced by inhibitors of aldose reductase (AR), which converts glucose to sorbitol in the polyol pathway. We observed that tempol inhibited sorbitol production in the injured spinal cord to the same extent as the AR inhibitor, sorbinil. Tempol also prevented post-contusion upregulation of AR (AKR1B10) protein expression within degenerating axons, as previously observed for AR inhibitors. Additionally, we hypothesized that tempol inhibits axonal degeneration by preventing loss of the glutathione pool due to polyol pathway activity. Consistent with our hypothesis, tempol treatment resulted in greater glutathione content in the injured spinal cord, which was correlated with increased expression and activity of gamma glutamyl cysteine ligase (γGCL; EC 6.3.2.2), the rate-limiting enzyme for glutathione synthesis. Administration of the γGCL inhibitor buthionine sulfoximine abolished all observed effects of tempol administration. Together, these results support a pathological role for polyol pathway activation in glutathione depletion, resulting in Wallerian degeneration after spinal cord injury (SCI). Interestingly, methylprednisolone, oxandrolone, and clenbuterol, which are known to spare axonal tracts after SCI, were equally effective in inhibiting polyol pathway activation. These results suggest that prevention of AR activation is a common target of many disparate post-SCI interventions.

Disruption of the blood-spinal cord barrier (BSCB) is a critical event in the secondary injury following spinal cord injury (SCI). Mertk has been reported to play an important role in regulating inflammation and cytoskeletal dynamics. However, the specific involvement of Mertk in BSCB remains elusive. Here, we demonstrated a distinct role of Mertk in the repair of BSCB. Mertk expression is decreased in endothelial cells following SCI. Overexpression of Mertk upregulated tight junction proteins (TJs), reducing BSCB permeability and subsequently inhibiting inflammation and apoptosis. Ultimately, this led to enhanced neural regeneration and functional recovery. Further experiments revealed that the RhoA/Rock1/P-MLC pathway plays a key role in the effects of Mertk. These findings highlight the role of Mertk in promoting SCI recovery through its ability to mitigate BSCB permeability and may provide potential targets for SCI repair., (© 2024. Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences.)

Purpose: This study aims to determine the anti-inflammatory, antioxidant, and anti-apoptotic effects of valproic acid (VPA) on rat spinal cord tissue in ischemia-reperfusion (IR) injury model created by abdominal aorta occlusion., Materials and Methods: Sprague Dawley rat (male sex) weighing 190-260 g divided into four experimental groups: control only underwent laparotomy, sham group, pre-IR injury (200 mg/kg dose), and post-IR injury (300 mg/kg) VPA. We measured serum levels of TNF- α , IL-6, IL-1 β , IL-18, Total Oxidant Status (TOS) and Total Antioxidant Status (TAS), and serum Oxidative Stress Index (OSI) ratio, and tissue expression of Bax and Bcl2, Caspase3, and Bax/Bcl2 ratio., Results: Serum IL-18 was higher in the sham than the control group( P  = 0.001), and there were declines in the pre-IR treatment ( P  = 0.002) and the post-IR treatment when compared to sham ( P  = 0.001). Despite these reductions, IL-18 expression levels in both the pre- and post-IR treatment groups were higher than in the control group ( P  = 0.001 & P  = 0.003). The favorable effects of pre-IR VPA administration on immunohistochemical biomarkers were superior to post-IR VPA administration., Conclusions: Comparative analyses between prophylactic VPA administration and post-IR interventions revealed congruence in their anti-inflammatory and anti-apoptotic ramifications. VPA can reduce spinal cord IR injury in an aortic occlusion model of rats.

Objective: Persons with spinal cord injury (SCI) are unable to efficiently dissipate heat via thermoregulatory vasodilation as efficiently as able-bodied persons during whole body passive heat stress (PHS). Skin blood flow (SkBF) is controlled by dual sympathetic vasomotor systems: noradrenergic vasoconstrictor (VC) nerves and cholinergic vasodilator (VD) nerves. Thus, impaired vasodilation could result from inappropriate increases in noradrenergic VC tone that compete with cholinergic vasodilation or diminished cholinergic tone. To address this issue, we used bretylium (BR) which selectively blocks neural release of norepinephrine, thereby reducing noradrenergic VC tone. If impaired vasodilation during PHS is due to inappropriate increase in VC tone, BR treatment will improve SkBF responses during PHS., Design: Prospective interventional trial., Setting: laboratory., Participants: 22 veterans with SCI., Interventions: Skin surface areas with previously defined intact vs. impaired thermoregulatory vasodilation were treated with BR iontophoresis with a nearby untreated site serving as control/CON. Participants underwent PHS until core temperature rose 1°C., Outcome Measures: Laser doppler flowmeters measured SkBF over BR and CON sites in areas with impaired and intact thermoregulatory vasodilation. Cutaneous vascular conductance (CVC) was calculated for all sites. Peak-PHS CVC was normalized to baseline (BL): (CVC peak-PHS/CVC BL) to quantify SkBF change., Results: CVC rise in BR sites was significantly less than CON sites in areas with intact ( P  = 0.03) and impaired ( P  = 0.04) thermoregulatory vasodilation., Conclusion: Cutaneous blockade of neural release of noradrenergic neurotransmitters affecting vasoconstriction did not enhance thermoregulatory vasodilation during PHS in persons with SCI; rather BR attenuated the response. Cutaneous blockade of neural release of noradrenergic neurotransmitters affecting vasoconstriction did not restore cutaneous active vasodilation during PHS in persons with SCI.

Context/objective: This study aimed to explore the anti-inflammatory and neuroprotective effects of protocatechuic aldehyde (PCA) in rats with spinal cord injury (SCI) and to clarify the molecular mechanisms underlying its pharmacological effects., Design: Male Sprague Dawley rat model of moderate spinal cord contusion were established., Setting: Third-class first-class hospital., Outcome Measures: The Basso, Beattie, and Bresnahan scores and performance on the inclined plane test were evaluated. Histological analyses were performed via hematoxylin and eosin staining. Apoptosis in the spinal cord and neurons was detected by 5 terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling staining. Apoptotic factors (Bax, Bcl-2, and cleaved caspase-3) were also evaluated. INOS, IL-1β, IL-10, TNF-α, Wnt-3α, β-catenin, iBA-1, and NeuN were assessed by real-time reverse transcription-polymerase chain reaction (RT-PCR), western blotting (WB), and enzyme-linked immunosorbent assay. Cell viability and the immunofluorescence of IL-1β were measured in PC-12 cells., Results: Using WB and quantitative reverse transcription-PCR, we confirmed that PCA treatment activated the Wnt/β-catenin signaling axis in vivo and in vitro. Hematoxylin and eosin staining and hindlimb motor functional evaluation revealed that treatment with PCA improved tissue protection and functional recovery via the Wnt/β-catenin axis. The upregulation of TUNEL-positive cells, downregulation of neurons, elevated apoptosis-associated factors in rats, and increased apoptotic rates were observed in microglia and PC-12 after PCA application. Finally, PCA mitigated SCI-induced inflammation by targeting the Wnt/β-catenin axis., Conclusion: This study provided preliminary evidence that PCA inhibits neuroinflammation and apoptosis through the Wnt/β-catenin pathway, thereby attenuating the secondary injury after SCI and promoting the regeneration of injured spinal tissues.

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., (Copyright © 2024 Copyright: © 2024 Medical Gas Research.)

Background: Spinal cord injury (SCI) poses a challenge due to limited treatment options. Recently, the effect and mechanism of Exo-loaded cannabinoid receptor type 2 (CB2) agonist AM1241(Exo + AM1241) have been applied in other inflammatory diseases but not in SCI., Methods: The SCI model was set up using C57BL/6 mice, followed by the treatment of Exo, AM1241, and Exo + AM1241. We assessed the effects of the following treatments on motor function recovery using BMS, and evaluated histological changes, apoptosis activity, inflammation, and oxidative stress in the SCI mice model. Additionally, the effect of following treatments on spinal cord neural stem cells (NSCs) was evaluated under lipopolysaccharides (LPS) induced inflammatory and oxidative models and, glutamate (Gluts) induced cell apoptosis models., Result: Our results demonstrated that Exo + AM1241 treatment significantly improved motor function recovery, after SCI by decreasing proinflammatory cytokines, and suppressing astrocyte/microglia (GFAP/Iba1) activation in the injury zone. Additionally, this treatment reduces pro-apoptotic proteins (Bax and caspase 3), increases the levels of the anti-apoptotic protein Bcl-2, enhances antioxidant defenses by boosting SOD and GSH, and lowers oxidative stress markers such as MDA. It also activates the Nuclear factor erythroid-2 (Nrf2) related factor 2 signaling pathway, thereby enhancing tissue protection against damage and cell death.

Spinal cord injury (SCI) is a primary lesion of the spinal cord that results from external forces or diseases, accompanied by a cascade of secondary events. Nitric oxide, an endogenous gas that functions as a signaling molecule in the human body, plays a crucial role in vasodilation of smooth muscles, regulation of blood flow and pressure, and inflammatory response. This article provides a comprehensive overview of the involvement of nitric oxide in SCI and highlights recent advances in basic research on pharmacological agents that inhibit nitric oxide elevation after SCI, offering valuable insights for future therapeutic interventions targeting SCI., (Copyright © 2024 Copyright: © 2024 Medical Gas Research.)

In mammals, the molecular mechanisms underlying transgenerational inheritance of phenotypic traits in serial generations of progeny after ancestral environmental exposures, without variation in DNA sequence, remain elusive. We've recently described transmission of a beneficial trait in rats and mice, in which F0 supplementation of methyl donors, including folic acid, generates enhanced axon regeneration after sharp spinal cord injury in untreated F1 to F3 progeny linked to differential DNA methylation levels in spinal cord tissue. To test whether the transgenerational effect of folic acid is transmitted via the germline, we performed whole-genome methylation sequencing on sperm DNA from F0 mice treated with either folic acid or vehicle control, and their F1, F2, and F3 untreated progeny. Transgenerational differentially methylated regions (DMRs) are observed in each consecutive generation and distinguish folic acid from untreated lineages, predominate outside of CpG islands and in regions of the genome that regulate gene expression, including promoters, and overlap at both the differentially methylated position (DMP) and gene levels. These findings indicate that molecular changes between generations are caused by ancestral folate supplementation. In addition, 29,719 DMPs exhibit serial increases or decreases in DNA methylation levels in successive generations of untreated offspring, correlating with a serial increase in the phenotype across generations, consistent with a 'wash-in' effect. Sibship-specific DMPs annotate to genes that participate in axon- and synapse-related pathways.

Spinal cord injury (SCI) results in irreversible neurological impairment. After SCI, Ferritinophagy-induced free iron released from ferritin can lead to extensive lipid peroxidation and aggravate neurological damage. NRF2/HO-1 pathway is to endow cells with a protective effect against oxidative stress, and it plays an important role in the transcriptional activation of a series of antioxidant and detoxification genes. UAMC-3203 is a ferrostatin-1(Fer-1) analogue with better solubility and stability, which can more effectively inhibit ferroptosis after SCI. A rat SCI model was constructed, and the recovery of motor function was observed after treatment with UAMC-3203. ELISA was employed to assess the impact of UAMC-3203 on inflammation-related factors, while immunofluorescence was utilized to investigate the influence of UAMC-3203 on neuronal count as well as the activation of astrocytes and microglia/macrophages. Malondialdehyde (MDA) were detected to reflect the level of oxidation products. Western blot analysis was used to measure the level of ferroptosis markers and the expression of NRF2/HO-1. Our findings demonstrate that UAMC-3203 inhibits the production of reactive oxygen species (ROS) and lipid peroxides, preventing ferroptosis and reducing neuronal degeneration. Additionally, UAMC-3203 suppresses astrocyte proliferation and microglia/macrophage activation, as well as the release of ferroptosis-related inflammatory factors. These combined effects contribute to the preservation of spinal cord tissue and the facilitation of motor function recovery. UAMC-3203 maybe inhibit ferroptosis after SCI to promote functional recovery., (© 2024. The Author(s).)

Traumatic spinal cord injury (tSCI) is a severe injury to the central nervous system that is categorized into primary and secondary injuries. Among them, the local microenvironmental imbalance in the spinal cord caused by secondary spinal cord injury includes accumulation of cytokines and chemokines, reduced angiogenesis, dysregulation of cellular energy metabolism, and dysfunction of immune cells at the site of injury, which severely impedes neurological recovery from spinal cord injury (SCI). In recent years, single-cell techniques have revealed the heterogeneity of multiple immune cells at the genomic, transcriptomic, proteomic, and metabolomic levels after tSCI, further deepening our understanding of the mechanisms underlying tSCI. However, spatial information about the tSCI microenvironment, such as cell location and cell-cell interactions, is lost in these approaches. The application of spatial multi-omics technology can solve this problem by combining the data obtained from immunohistochemistry and multiparametric analysis to reveal the changes in the microenvironment at different times of secondary injury after SCI. In this review, we systematically review the progress of spatial multi-omics techniques in the study of the microenvironment after SCI, including changes in the immune microenvironment and discuss potential future therapeutic strategies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Peng, Zhang, Xie, Guo, Cao and Yang.)