Spinal Cord Injury In Rats Research Articles

Extracellular vesicles loaded with ApoB-100 protein affect the occurrence of coronary heart disease in patients after injury of spinal cord

Spinal cord injury (SCI) patients have an increased susceptibility to coronary heart disease (CHD) due to dysregulated lipid deposition. We conducted a comprehensive investigation to gain insights into the specific roles of Apolipoprotein B-100 (APOB-100) in the development of CHD in patients suffering from SCI. First, we established an SCI rat model through semitransection. APOB-100 expression in plasma exosomes obtained from patients were determined. Subsequently, we found APOB-100 affected macrophage polarization when treating co-cultured neurons/macrophages lacking Sortilin with extracellular vesicles derived from SCI rats, where APOB-100 co-immunoprecipitated with Sortilin. Moreover, APOB-100 upregulation reduced neuronal cell viability and triggered apoptosis by upregulating Sortilin, leading to a decline in the Basso, Beattie, and Bresnahan (BBB) scale, exacerbation of neuron injury, increased macrophage infiltration, and elevated blood lipid-related indicators in SCI rats, which could be reversed by silencing Sortilin. In conclusion, APOB-100 from post-SCI patients' extracellular vesicles upregulates Sortilin, thereby endangering those patients to CHD.

Human induced pluripotent stem cell/embryonic stem cell-derived pyramidal neuronal precursors show safety and efficacy in a rat spinal cord injury model

Nerve regeneration and circuit reconstruction remain a challenge following spinal cord injury (SCI). Corticospinal pyramidal neurons possess strong axon projection ability. In this study, human induced pluripotent stem cells (iPSCs) were differentiated into pyramidal neuronal precursors (PNPs) by addition of small molecule dorsomorphin into the culture. iPSC-derived PNPs were transplanted acutely into a rat contusion SCI model on the same day of injury. Following engraftment, the SCI rats showed significantly improved motor functions compared with vehicle control group as revealed by behavioral tests. Eight weeks following engraftment, the PNPs matured into corticospinal pyramidal neurons and extended axons into distant host spinal cord tissues, mostly in a caudal direction. Host neurons rostral to the lesion site also grew axons into the graft. Possible synaptic connections as a bridging relay may have been formed between host and graft-derived neurons, as indicated by pre- and post-synaptic marker staining and the regulation of chemogenetic regulatory systems. PNP graft showed an anti-inflammatory effect at the injury site and could bias microglia/macrophages towards a M2 phenotype. In addition, PNP graft was safe and no tumor formation was detected after transplantation into immunodeficient mice and SCI rats. The potential to reconstruct a neuronal relay circuitry across the lesion site and to modulate the microenvironment in SCI makes PNPs a promising cellular candidate for treatment of SCI.

BMSC-derived exosomal miR-219-5p alleviates ferroptosis in neuronal cells caused by spinal cord injury via the UBE2Z/NRF2 pathway

ObjectiveThe aim of this study was to investigate the molecular mechanism of exosomal miR-219-5p derived from bone marrow mesenchymal stem cells (BMSCs) in the treatment of spinal cord injury (SCI). MethodsBasso Beattie Bresnahan (BBB) score and tissue staining were used to assess SCI and neuronal survival in rats. The contents of Fe2+, malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD) were detected by a kit. The expression levels of ubiquitin-conjugating enzyme E2 Z (UBE2Z), nuclear factor erythroid 2-related Factor 2 (NRF2) and ferroptosis-related proteins were detected by Western blotting. In addition, the ability of BMSC-derived exosomes to inhibit ferroptosis in neuronal cells in rats with SCI was validated by in vivo injection of ferroptosis inhibitors/inducers. ResultsIn this study, we found that miR-219-5p-rich BMSC-derived exosomes inhibited ferroptosis in SCI rats and that the alleviating effect of BMSC-Exos on SCI was achieved by inhibiting the ferroptosis signaling pathway and that NRF2 played a key role in this process. Our study confirmed that BMSC exosome-specific delivery of miR-219-5p can target UBE2Z to regulate its stability and that overexpression of UBE2Z reverses miR-219-5p regulation of NRF2. In addition, in vivo experiments showed that BMSC exosomes alleviated ferroptosis in neuronal SCI progression, and inhibiting the expression of miR-219-5p in BMSCs reduced the alleviating effect of exosomes on ferroptosis in neuronal cells and SCI. ConclusionmiR-219-5p in BMSC-derived exosomes can repair the injured spinal cord. In addition, miR-219-5p alleviates ferroptosis in neuronal cells induced by SCI through the UBE2Z/NRF2 pathway.

Optical imaging detection of extracellular vesicles of miR-146 modified bone marrow mesenchymal stem cells promoting spinal cord injury repair

Bone Marrow mesenchymal Stem Cells (BMSCs) are considered as an important source of cells for regenerative medicine, In particular, Bone Marrow mesenchymal Stem Cells Exosomes (BMSCs-EXO) have the most significant effect in the treatment of Spinal Cord Injury (SCI), but the mechanism of action is still unknown. This study found that compared with other SCI groups, BMSCs-EXO loaded with miR-146a could significantly improve the functional recovery of the hind limbs of SCI rats. Hematoxylin and eosin (H&E) indicated that the lesion area of spinal cord injury was less, nissl staining indicated that the number of nissl bodies remained more; the mechanism may be through inhibiting the expression of IRAK1 and TRAF6, blocking the activation of NF-κB p65, reducing the expression of TNF-α, IL-1β and IL-6 inflammatory factors and oxidative stress, improving the SCI microenvironment, and promoting the repair of neural function. In general, we found that BMSCs-EXO loaded with miR-146a could reduce the inflammatory response and oxidative stress in SCI by inhibiting the activation of IRAK1/TRAF6/NF-κB p65 signaling pathway, and promote the recovery of neurological function in SCI rats.

Epidermal Neural Crest Stem Cell Conditioned Medium Enhances Spinal Cord Injury Recovery via PI3K/AKT-Mediated Neuronal Apoptosis Suppression

This study aimed to assess the impact of conditioned medium from epidermal neural crest stem cells (EPI-NCSCs-CM) on functional recovery following spinal cord injury (SCI), while also exploring the involvement of the PI3K-AKT signaling pathway in regulating neuronal apoptosis. EPI-NCSCs were isolated from 10-day-old Sprague-Dawley rats and cultured for 48 h to obtain EPI-NCSC-CM. SHSY-5Y cells were subjected with H2O2 treatment to induce apoptosis. Cell viability and survival rates were evaluated using the CCK-8 assay and calcein-AM/PI staining. SCI contusion model was established in adult Sprague-Dawley rats to assess functional recovery, utilizing the Basso, Beattie and Bresnahan (BBB) scoring system, inclined test, and footprint observation. Neurological restoration after SCI was analyzed through electrophysiological recordings. Histological analysis included hematoxylin and eosin (H&E) staining and Nissl staining to evaluate tissue organization. Apoptosis and oxidative stress levels were assessed using TUNEL staining and ROS detection methods. Additionally, western blotting was performed to examine the expression of apoptotic markers and proteins related to the PI3K/AKT signaling pathway. EPI-NCSC-CM significantly facilitated functional and histological recovery in SCI rats by inhibiting neuronal apoptosis through modulation of the PI3K/AKT pathway. Administration of EPI-NCSCs-CM alleviated H2O2-induced neurotoxicity in SHSY-5Y cells in vitro. The use of LY294002, a PI3K inhibitor, underscored the crucial role of the PI3K/AKT signaling pathway in regulating neuronal apoptosis. This study contributes to the ongoing exploration of molecular pathways involved in spinal cord injury (SCI) repair, focusing on the therapeutic potential of EPI-NCSC-CM. The research findings indicate that EPI-NCSC-CM exerts a neuroprotective effect by suppressing neuronal apoptosis through activation of the PI3K/AKT pathway in SCI rats. These results highlight the promising role of EPI-NCSC-CM as a potential treatment strategy for SCI, emphasizing the significance of the PI3K/AKT pathway in mediating its beneficial effects.Graphical

USP7 alleviates neuronal inflammation and apoptosis in spinal cord injury via deubiquitinating NRF1/KLF7 axis

ABSTRACT Background Ubiquitin-specific protease 7 (USP7) has been found to be associated with motor function recovery after spinal cord injury (SCI). Therefore, its role and mechanism in SCI process need further exploration. Methods SCI rat models were established via performing laminectomy at the T9-T11 spinal vertebrae and cutting spinal cord tissues. SCI cell models were constructed by inducing PC12 cells with lipopolysaccharide (LPS). The protein levels of USP7, nuclear respiratory factor 1 (NRF1), Krüppel-like factor 7 (KLF7) and apoptosis-related markers were detected by western blot. Cell viability and apoptosis were tested by cell counting kit-8 assay and flow cytometry. The contents of inflammatory factors were examined using ELISA. The interaction between NRF1 and USP7 or KLF7 was analyzed by co-immunoprecipitation assay, chromatin immunoprecipitation assay and dual-luciferase reporter assay, respectively. Results USP7 was downregulated in SCI rat models and LPS-induced PC12 cells. Overexpressed USP7 promoted viability, while repressed apoptosis and inflammation in LPS-induced PC12 cells. USP7 could stabilize NRF1 protein expression via deubiquitination, and NRF1 knockdown reversed the protective effect of USP7 against LPS-induced PC12 cell injury. NRF1 is bound to KLF7 promoter to enhance its transcription. NRF1 overexpression inhibited LPS-induced PC12 cell inflammation and apoptosis via increasing KLF7 expression. Conclusion USP7 alleviated inflammation and apoptosis in LPS-induced PC12 cells via NRF1/KLF7 axis, indicating that targeting of USP7/NRF1/KLF7 axis might be a promising treatment strategy for SCI.

Inhibition of Ferroptosis by Mesenchymal Stem Cell-Derived Exosomes in Acute Spinal Cord Injury: Role of Nrf2/GCH1/BH4 Axis.

The therapeutic benefits of exosomes obtained from mesenchymal stem cells (MSCs) in acute spinal cord injury (SCI) have been demonstrated in recent years, but the precise mechanisms remain unknown. In this study, the efficacy and mechanisms of MSC-derived exosomes (MSC-Exo) in acute SCI were investigated. By utilizing a BV2 ferroptosis cellular model and an SCI rat model, we investigated the effects of MSC-Exo on iron death related indicators and NF-E2 related factor 2 (Nrf2)/GTP cyclolase I (GCH1)/5,6,7,8-tetrahydrobiopterin (BH4) signaling axis, as well as their therapeutic effects on SCI rats. The results revealed that MSC-Exo effectively inhibited the production of ferrous iron, lipid peroxidation products malonaldehyde and reactive oxygen species, and ferroptosis-promoting factor prostaglandin-endoperoxide synthase 2. Concurrently, they upregulated ferroptosis suppressors FTH-1 (ferritin heavy chain 1), SLC7A11 (solute carrier family 7 member 11), FSP1 (ferroptosis suppressor protein 1), and GPX4 (glutathione peroxidase 4), contributing to enhanced neurological recovery in SCI rats. Further analysis showed the Nrf2/GTP/BH4 signaling pathway's critical role in suppressing ferroptosis. Additionally, MSC-Exo was found to inhibit lipopolysaccharide-induced ferroptosis in BV2 cells and SCI rats by activating the Nrf2/GCH1/BH4 axis. In summary, the study demonstrates that MSC-Exo mitigates microglial cell ferroptosis via the Nrf2/GCH1/BH4 axis, showing potential for preserving and restoring neurological function post-SCI.

Therapeutic effect and mechanism of piracetam for the treatment of spinal cord injury in rats through MAPK pathway

To explore mechanism of piracetam for the treatment of spinal cord injury in rats through mitogen-activated protein kinase (MAPK) pathway. Fifty-four healthy 6-week-old SD female rats with body weight of 80 to 100 g were divided into sham operation group, spinal cord injury group and piracetam group by random number table method, with 18 rats in each group. Spinal cord injury model was established in spinal cord injury group and piracetam group using percussion apparatus, while sham operation group did not damage spinal cord. Piracetam group was injected with piracetam injection through tail vein according to 5 ml·kg-1 standard, once a day for 3 days;the other two groups were injected with normal saline at the same dose, the same frequency and the same duration. The rats were sacrificed at 1, 3, and 7 days after surgery, and changes of Basso, Beattie and Bresnahan (BBB) locomotor rating scale was observed and compared. Enzyme-linked immunosorbent assay (ELISA) was used to detect spinal cord inflammatory factors, such as interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-1β (interleukin-1β), necrosis factor-α (IL-1β) and tumor necrosis factor-α (TNF-α);HE staining was used to observe morphological changes of rats with spinal cord injury, and immunohistochemistry was used to observe expression level of aquaporin 4 (AQP4). The activation of MAPK signaling pathway in spinal cord of rats after spinal cord injury was observed by western blotting (WB). BBB scores of sham operation group on 1, 3 and 7 day were 21 points. In spinal cord injury group, the scores were (1±1), (4±1) and (7±2);piracetam group was (1±1), (5±1), (9±2), respectively;the difference between spinal cord injury group and sham operation group was statistically significant (P<0.05). HE staining showed that no abnormality was found in sham operation group. In spinal cord injury group, bleeding and degeneration of spinal cord tissue appeared at 1 day after operation; flaky necrotic areas were appeared in spinal cord at 3 days after surgery, and spinal cord tissue began to slowly repair at 7 days after surgery. In piracetam group, the bleeding area was less than that of spinal cord injury group at 1 day after surgery;at 3 days after operation, the necrotic area was reduced and the range of nuclear disappearance was reduced; and the spinal cord began to recover slowly at 7 days after surgery. AQP4 staining of spinal cord of rats in sham operation group was weak at 1, 3 and 7 days after modeling, AQP4 staining was deepened and area increased in spinal cord injury group, AQP4 staining of piracetam group was lighter than that of spinal cord injury group, and the positive cells were slightly increased and the staining was slightly darker than that of sham operation group. At 1, 3 and 7 days, the level of IL-6, IL-10, IL-1β and TNF-α in spinal cord injury group were higher than those in sham operation group and piracetam group(P<0.05). Compared with spinal cord injury group, the area of spinal cord bleeding and necrosis were decreased by HE staining in piracetam group, and AQP4 staining was decreased by immunohistochemistry. WB results showed that P-ERK, P-JNK and P-P38 levels in spinal cord injury group at 3 days were higher than those in sham operation group and piracetam group(P<0.05). Piracetam not only showed significant effect in promoting motor function recovery after spinal cord injury, but also showed positive therapeutic potential in reducing lesion area, regulating AQP4 expression to reduce edema, and reducing inflammatory response by regulating MAPK signaling pathway.

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

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

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

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

Combination of induced pluripotent stem cell-derived motor neuron progenitor cells with irradiated brain-derived neurotrophic factor over-expressing engineered mesenchymal stem cells enhanced restoration of axonal regeneration in a chronic spinal cord injury rat model

BackgroundSpinal cord injury (SCI) is a disease that causes permanent impairment of motor, sensory, and autonomic nervous system functions. Stem cell transplantation for neuron regeneration is a promising strategic treatment for SCI. However, selecting stem cell sources and cell transplantation based on experimental evidence is required. Therefore, this study aimed to investigate the efficacy of combination cell transplantation using the brain-derived neurotrophic factor (BDNF) over-expressing engineered mesenchymal stem cell (BDNF-eMSC) and induced pluripotent stem cell-derived motor neuron progenitor cell (iMNP) in a chronic SCI rat model.MethodA contusive chronic SCI was induced in Sprague-Dawley rats. At 6 weeks post-injury, BDNF-eMSC and iMNP were transplanted into the lesion site via the intralesional route. At 12 weeks post-injury, differentiation and growth factors were evaluated through immunofluorescence staining and western blot analysis. Motor neuron differentiation and neurite outgrowth were evaluated by co-culturing BDNF-eMSC and iMNP in vitro in 2-dimensional and 3-dimensional.ResultsCombination cell transplantation in the chronic SCI model improved behavioral recovery more than single-cell transplantation. Additionally, combination cell transplantation enhanced mature motor neuron differentiation and axonal regeneration at the injured spinal cord. Both BDNF-eMSC and iMNP played a critical role in neurite outgrowth and motor neuron maturation via BDNF expression.ConclusionsOur results suggest that the combined transplantation of BDNF- eMSC and iMNP in chronic SCI results in a significant clinical recovery. The transplanted iMNP cells predominantly differentiated into mature motor neurons. Additionally, BDNF-eMSC exerts a paracrine effect on neuron regeneration through BDNF expression in the injured spinal cord.Graphical

Assessing Functional Recovery of Eupneic Diaphragm Activity Following Unilateral Cervical Spinal Cord Injury in Rats

Assessing Functional Recovery of Eupneic Diaphragm Activity Following Unilateral Cervical Spinal Cord Injury in Rats

20-Deoxyingenol Activates Mitophagy Through TFEB and Promotes Functional Recovery After Spinal Cord Injury.

Spinal cord injury (SCI) can lead to permanent paralysis and various motor, sensory and autonomic nervous system dysfunction. The complex pathophysiological processes limit the effectiveness of many clinical treatments. Mitochondria has been reported to play a key role in the pathogenesis of SCI; while mitophagy is a protective mechanism against mitochondrial dysfunction. However, there is recently little drugs that may targeted activate mitophagy to treat SCI. In this study, we evaluated the role of 20-Deoxyingenol (20-DOI) in SCI and explored its potential mechanisms. We used a SCI rat model and evaluated the functional outcomes after the injury. Western blotting and immunofluorescence techniques were used to analyze the levels of mitophagy, apoptosis, and TFEB-related signaling pathways. Our research results show that 20-DOI significantly improves the apoptosis of neural cells after TBHP stimulation and functional recovery after spinal cord injury. In addition, mitophagy, TFEB levels, and apoptosis are related to the mechanism of 20-DOI treatment for spinal cord injury. Specifically, our research results indicate that 20-DOI restored the autophagic flux after injury, thereby inducing mitophagy, eliminating the accumulation of Cyto C, and inhibiting apoptosis. Further mechanism research suggests that 20-DOI may regulate mitophagy by promoting TFEB nuclear translocation. These results indicate that 20-DOI can significantly promote recovery after spinal cord injury, which may be a promising treatment method for spinal cord injury.

Targeted-delivery of nanomedicine-enabled methylprednisolone to injured spinal cord promotes neuroprotection and functional recovery after acute spinal cord injury in rats

To date, no therapy has been proven to be efficacious in fully restoring neurological functions after spinal cord injury (SCI). Systemic high-dose methylprednisolone (MP) improves neurological recovery after acute SCI in both animal and human. MP therapy remains controversial due to its modest effect on functional recovery and significant adverse effects. To overcome the limitation of MP therapy, we have developed a N-(2-hydroxypropyl) methacrylamide copolymer-based MP prodrug nanomedicine (Nano-MP) that can selectively deliver MP to the SCI lesion when administered systemically in a rat model of acute SCI. Our in vivo data reveal that Nano-MP is significantly more effective than free MP in attenuating secondary injuries and neuronal apoptosis. Nano-MP is superior to free MP in improving functional recovery after acute SCI in rats. These data support Nano-MP as a promising neurotherapeutic candidate, which may provide potent neuroprotection and accelerate functional recovery with improved safety for patients with acute SCI.

Retraction: Spermatogonial stem-cell-derived neural-like cell transplantation enhances the functional recovery of a rat spinal cord injury model: characterization of evoked potentials.

[This retracts the article DOI: 10.3389/fnins.2023.1289581.].

Spinal cord injury-induced metabolic impairment and steatohepatitis develops in non-obese rats and is exacerbated by premorbid obesity

Impaired sensorimotor functions are prominent complications of spinal cord injury (SCI). A clinically important but less obvious consequence is development of metabolic syndrome (MetS), including increased adiposity, hyperglycemia/insulin resistance, and hyperlipidemia. MetS predisposes SCI individuals to earlier and more severe diabetes and cardiovascular disease compared to the general population, which trigger life-threatening complications (e.g., stroke, myocardial infarcts). Although each comorbidity is known to be a risk factor for diabetes and other health problems in obese individuals, their relative contribution or perceived importance in propagating systemic pathology after SCI has received less attention. This could be explained by an incomplete understanding of MetS promoted by SCI compared with that from the canonical trigger diet-induced obesity (DIO). Thus, here we compared metabolic-related outcomes after SCI in lean rats to those of uninjured rats with DIO. Surprisingly, SCI-induced MetS features were equal to or greater than those in obese uninjured rats, including insulin resistance, endotoxemia, hyperlipidemia, liver inflammation and steatosis. Considering the endemic nature of obesity, we also evaluated the effect of premorbid obesity in rats receiving SCI; the combination of DIO + SCI exacerbated MetS and liver pathology compared to either alone, suggesting that obese individuals that sustain a SCI are especially vulnerable to metabolic dysfunction. Notably, premorbid obesity also exacerbated intraspinal lesion pathology and worsened locomotor recovery after SCI. Overall, these results highlight that normal metabolic function requires intact spinal circuitry and that SCI is not just a sensory-motor disorder, but also has significant metabolic consequences.

Repeated trans-spinal magnetic stimulation promotes microglial phagocytosis of myelin debris after spinal cord injury through LRP-1

Spinal cord injury (SCI) is a serious trauma of the central nervous system. The clearance of myelin debris is a critical step in the functional recovery following spinal cord injury (SCI). Recent studies have begun to reveal critical roles for professional phagocytes in the central nervous system, microglia, and their receptors in the control of myelin debris in neurodegenerative disease. Repeated trans-spinal magnetic stimulation (rTSMS) has been demonstrated as a noninvasive SCI treatment that enhances tissue repair and functional recovery. In this study, we investigated the role and molecular mechanism of rTSMS on microglial phagocytosis of myelin debris in a rat SCI model. In our studies, we found that rTSMS significantly promoted the motor function recovery of SCI rats associated with the inhibition the neuroinflammation and glia scar formation. Immunofluorescence results further showed that the rTSMS promotes the clearance of myelin debris by microglia in vivo and in vitro. Additionally, receptor-associated protein (RAP), a Low-density lipoprotein receptor-related protein-1 (LRP-1) inhibitor, could cancel the accelerated microglial phagocytosis of myelin debris after rTSMS in vitro experiments. Simultaneously, Elisa's results and western blotting respectively showed that rTSMS significantly decreased the levels of soluble LRP-1(sLRP-1) and the LRP-1 splicing enzyme of ADAM17. In conclusion, rTSMS could promote the clearance of myelin debris by microglia through LRP-1 to improve the functional recovery of SCI rats.

Dysregulated MiR-223-5p Modulates Inflammation and Oxidative Stress in Traumatic Spinal Cord Injury

ABSTRACT Aim This study aimed to evaluate the miR-223-5p expression in patients with spinal cord injury (SCI) and to determine its role in the pathogenesis of SCI. Methods The serum miR-223-5p levels were analyzed using quantitative real-time polymerase chain reaction. The diagnostic accuracy of miR-223-5p was evaluated using the receiving operating characteristic curves. LPS-induced PC12 cells were established as an in vitro inflammatory cell model. Cell apoptosis, inflammation and oxidative stress were examined. The SCI rat model was constructed to evaluate the effects of miR-223-5p on inflammatory response and motor function in rats. Results MiR-223-5p expression was upregulated in SCI patients. MiR-223-5p expression in the complete SCI group was significantly higher than that in incomplete SCI group. ROC analysis showed that miR-223-5p can distinguish SCI patients from healthy volunteers. In vitro experiments demonstrated that LPS upregulated apoptosis and inflammation in PC12 cells. Treatment with miR-223-5p inhibitor alleviated the changes in LPS-induced PC12 cells . Inhibition of miR-223-5p can alleviate the activation of inflammatory response and the effects of SCI on the motor function in rats. Conclusions MiR-223-5p is a potential diagnostic marker for SCI, and it can promote the SCI progression by regulating nerve cell survival, inflammation, and oxidative stress.

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

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

Protective effects of orientin against spinal cord injury in rats.

We aimed to study the reparative effects of orientin against spinal cord injury (SCI) in rats and explore its potential mechanisms. Sprague-Dawley rats were divided into Sham, SCI, Orientin, and SB203580 [an inhibitor of p38 mitogen-activated protein kinase (p38MAPK)] groups. In the SCI group, rats underwent Allen's beat. SCI animals in Orientin and SB203580 groups were respectively treated with 40 mg kg-1 orientin and 3 mg kg-1 SB203580 once daily. Functional recovery was evaluated based on Basso, Beattie, and Bresnahan scoring. Histopathological analysis was performed using hematoxylin-eosin and Nissl staining. Cell apoptosis was examined by TUNEL staining. The relative quantity of apoptosis-related proteins, glial fibrillary acidic protein (GFAP), neurofilament 200 (NF200), and brain derived neurotrophic factor (BDNF) was detected via western blotting. The indices related to inflammation and oxidation were measured using agent kits. The p38MAPK/inducible nitric oxide synthase (iNOS) signaling activity was detected using real-time quantitative PCR, western blotting, and immunohistochemical staining. Orientin was revealed to effectively mitigate cell apoptosis, neuroinflammation, and oxidative stress in impaired tissues. Meanwhile, orientin exerted great neuroprotective effects by abating GFAP expression, and up-regulating the expression of NF200 and BDNF, and significantly suppressed the p38MAPK/iNOS signaling. Orientin application could promote the repair of secondary SCI through attenuating oxidative stress and inflammatory response, reducing cell apoptosis and suppressing p38MAPK/iNOS signaling.