CRID3, a blocker of apoptosis associated speck like protein containing a card, ameliorates murine spinal cord injury by improving local immune microenvironment

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

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

Kaempferol Alleviates Hepatic Injury in Nonalcoholic Steatohepatitis (NASH) by Suppressing Neutrophil-Mediated NLRP3-ASC/TMS1-Caspase 3 Signaling

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a significant hepatic condition that has gained worldwide attention. Kaempferol (Kae), renowned for its diverse biological activities, including anti-inflammatory, antioxidant, anti-aging, and cardio-protective properties, has emerged as a potential therapeutic candidate for non-alcoholic steatohepatitis (NASH). Despite its promising therapeutic potential, the precise underlying mechanism of Kae's beneficial effects in NASH remains unclear. Therefore, this study aims to clarify the mechanism by conducting comprehensive in vivo and in vitro experiments.

RESULTS

In this study, a murine model of non-alcoholic steatohepatitis (NASH) was established by feeding C57BL/6 female mice a high-fat diet for 12 weeks. Kaempferol (Kae) was investigated for its ability to modulate systemic inflammatory responses and lipid metabolism in this model (20 mg/kg per day). Notably, Kae significantly reduced the expression of NLRP3-ASC/TMS1-Caspase 3, a crucial mediator of liver tissue inflammation. Additionally, in a HepG2 cell model induced with palmitic acid/oleic acid (PA/OA) to mimic NASH conditions, Kae demonstrated the capacity to decrease lipid droplet accumulation and downregulate the expression of NLRP3-ASC/TMS1-Caspase 3 (20 µM and the final concentration to 20 nM). These findings suggest that Kae may hold therapeutic potential in the treatment of NASH by targeting inflammatory and metabolic pathways.

CONCLUSIONS

These findings suggest that kaempferol holds potential as a promising therapeutic intervention for ameliorating non-alcoholic fatty liver disease (NAFLD).

Identification of key autophagy-related genes and pathways in spinal cord injury

Spinal cord injury (SCI) can cause a range of functional impairments, and patients with SCI have limited potential for functional recovery. Previous studies have demonstrated that autophagy plays a role in the pathological process of SCI, but the specific mechanism of autophagy in this context remains unclear. Therefore, we explored the role of autophagy in SCI by identifying key autophagy-related genes and pathways. This study utilized the GSE132242 expression profile dataset, which consists of four control samples and four SCI samples; autophagy-related genes were sourced from GeneCards. R software was used to screen differentially expressed genes (DEGs) in the GSE132242 dataset, which were then intersected with autophagy-related genes to identify autophagy-related DEGs in SCI. Subsequently, the expression levels of these genes were confirmed and analyzed with gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). A protein-protein interaction (PPI) analysis was conducted to identify interaction genes, and the resulting network was visualized with Cytoscape. The MCODE plug-in was used to build gene cluster modules, and the cytoHubba plug-in was applied to screen for hub genes. Finally, the GSE5296 dataset was used to verify the reliability of the hub genes. We screened 129 autophagy-related DEGs, including 126 up-regulated and 3 down-regulated genes. GO and KEGG pathway enrichment analysis showed that these 129 genes were mainly involved in the process of cell apoptosis, angiogenesis, IL-1 production, and inflammatory reactions, the TNF signaling pathway and the p53 signaling pathway. PPI identified 10 hub genes, including CCL2, TGFB1, PTGS2, FN1, HGF, MYC, IGF1, CD44, CXCR4, and SERPINEL1. The GSE5296 dataset revealed that the control group exhibited lower expression levels than the SCI group, although only CD44 and TGFB1 showed significant differences. This study identified 129 autophagy-related genes that might play a role in SCI. CD44 and TGFB1 were identified as potentially important genes in the autophagy process after SCI. These findings provide new targets for future research and offer new perspectives on the pathogenesis of SCI.

Complanatuside A improves functional recovery after spinal cord injury through inhibiting JNK signaling-mediated microglial activation

BACKGROUND AND AIMS

Complanatuside A (ComA) is a flavonoid-rich compound in Astragalus membranaceus that has anti-inflammatory and neuroprotective effects. In this study, we focused on the effect of ComA on spinal cord injury (SCI) in mice and explored its possible mechanisms.

METHODS

The SCI model was constructed using C57BL/6J mice, and the effect of ComA on motor function recovery in SCI mice was evaluated through the BMS (Basso Mouse Scale) and footprint test. The histological effects of ComA on SCI mice were evaluated by hematoxylin-eosin (H&E) staining, Luxol-fast blue (LFB) staining, and Nissl staining. In both in vivo and in vitro experiments, we detected the activation of microglia and the release of inflammatory factors through molecular experiments. Immunofluorescence and Western blotting confirmed that ComA can prevent neuronal apoptosis caused by activated microglia through the c-Jun N-terminal kinase (JNK) pathway.

RESULTS

Our research results confirm that ComA can improve motor function in mice after SCI. Our in vitro results indicate that ComA can inhibit the activation of BV2 cells and the release of proinflammatory mediators. In addition, ComA can prevent neuronal cell apoptosis caused by activated BV2 cells. Finally, we found that ComA works through the JNK signaling pathway.

CONCLUSIONS

ComA can accelerate the restoration of motor function in mice after SCI, possibly by reducing neuronal apoptosis via inhibition of JNK-related signaling pathways, a reduction in microglial activation, and inhibition of inflammatory factor release. Our data indicate that ComA is a promising drug candidate for improving functional recovery in patients with SCI.

Serum apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) is a novel stroke biomarker

BACKGROUND

Apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) is a promising stroke biomarker. However, a large study of human serum ASC has not yet to be reported; additionally, the diagnostic value of prehospital concentration and practicality of ASC remains unknown.

METHODS

We recruited 774 Chinese stroke patients, including 523 with ischemic stroke (IS) and 251 with hemorrhagic stroke (HS) within 14 days following symptom onset in the emergency department, alongside 481 healthy individuals and 64 cognitive impairment patients as controls. Serum ASC concentrations were determined using automated chemiluminescence immunoassay, exploring the relationship between serum ASC concentration and subtypes, severity, and sampling timepoints of stroke.

RESULTS

ASC concentrations were significantly higher in stroke patients compared with all controls (P < 0.001). HS patients had greater ASC concentrations than IS patients (P < 0.05). With increasing ASC concentration, the proportion of severe cases increased. The area under the receiver operating characteristic curve (AUC) for differentiating between healthy individuals and stroke patients in the hyperacute phase was 0.78; this markedly improved (0.90) when considering samples from healthy individuals and patients with subarachnoid hemorrhage (SAH) ≤ 3  h from last-known-well (LKW).

CONCLUSIONS

Serum ASC is a valuable biomarker for stroke differentiation and aids in the clinical diagnosis of stroke severity and subtypes.

Esculentoside A ameliorates BSCB destruction in SCI rat by attenuating the TLR4 pathway in vascular endothelial cells

BACKGROUND AND AIMS

Overexpressed MMP-9 in vascular endothelial cells is involved in blood spinal cord barrier (BSCB) dysfunction in spinal cord injury (SCI). Esculentoside A (EsA) has anti-inflammatory and cell protective effects. This study aimed to evaluate its effects on neuromotor function in SCI rats, as well as the potential mechanisms.

METHODS

The therapeutic effect of EsA in SCI rats was investigated using Basso-Beattie-Bresnahan (BBB) scores, a grid walk test and histological analyses. To assess the protective role of EsA in the BSCB and in oxygen glucose deprivation/reoxygenation (OGD/R)-induced hBMECs, the BSCB function, tight junctions (TJ) protein (ZO-1 and claudin-5) expression, structure of the BSCB and Matrix metalloproteinase-9 (MMP-9) expression were observed via Evans blue (EB) detection, immunofluorescence analyses and western blotting. Molecular docking simulations and additional experiments were performed to explore the potential mechanisms by which EsA maintains the function of the BSCB in vivo and in vitro.

RESULTS

EsA treatment improved BBB scores, reduced cavity formation and the loss of neuronal cells, demonstrating an improvement in motor function in SCI rats. In vivo experiments showed that EsA decreased the infiltration of blood cells and inflammatory mediators (IL-1β, IL-6 and TNF-α) and protected the structure of TJs in the rat spinal cord and in OGD/R-induced hBMECs. EsA inhibited the activation of Toll-like receptor 4 (TLR4) signalling, which may be related to the protective effect of EsA against MMP-9-induced BSCB damage.

CONCLUSIONS

EsA downregulated MMP-9 expression in vascular endothelial cells, protected BSCB function in SCI rats and attenuated TLR4 signalling and thus provide new options for the treatment of SCI.

Proteomic profile of Trichinella spiralis infected mice with acute spinal cord injury: A 4D label-free quantitative analysis

Spinal cord injury (SCI) can cause severe loss of locomotor and sensory activities, with no ideal treatment. Emerging reports suggest that the helminth therapy is highly effective in relieving numerous inflammatory diseases. Proteomic profiling is often used to elucidate the underlying mechanism behind SCI. Herein, we systematically compared the protein expression profiles of murine SCI spinal cord and Trichinella spiralis treated murine SCI spinal cord, using a 4D label-free technique known for its elevated sensitivity. Relative to the SCI mice, the T. spiralis-treated mice exhibited marked alterations in 91 proteins (31 up- and 60 down-regulated). Based on our Gene Ontology (GO) functional analysis, the differentially expressed proteins (DEPs) were primarily enriched in the processes of metabolism, biological regulation, cellular process, antioxidant activity, and other cell functions. In addition, according to the Clusters of Orthologous Groups of protein/EuKaryotic Orthologous Groups (COG/KOG) functional stratification, proteins involved in signaling transduction mechanisms belonged to the largest category. Over-expressed DEPs were also enriched in the "NADPH oxidase complex", "superoxide anion generation", "other types of O-glycan biosynthesis", and "HIF-1 signaling pathway". Furthermore, the protein-protein interaction (PPI) network identified the leading 10 hub proteins. In conclusion, we highlighted the dynamic proteomic profiling of T. spiralis-treated SCI mice. Our findings provide significant insight into the molecular mechanism behind T. spiralis regulation of SCI.

Involvement of inflammasomes in tumor microenvironment and tumor therapies

Inflammasomes are macromolecular platforms formed in response to damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns, whose formation would cause maturation of interleukin-1 (IL-1) family members and gasdermin D (GSDMD), leading to IL-1 secretion and pyroptosis respectively. Several kinds of inflammasomes detecting different types of dangers have been found. The activation of inflammasomes is regulated at both transcription and posttranscription levels, which is crucial in protecting the host from infections and sterile insults. Present findings have illustrated that inflammasomes are involved in not only infection but also the pathology of tumors implying an important link between inflammation and tumor development. Generally, inflammasomes participate in tumorigenesis, cell death, metastasis, immune evasion, chemotherapy, target therapy, and radiotherapy. Inflammasome components are upregulated in some tumors, and inflammasomes can be activated in cancer cells and other stromal cells by DAMPs, chemotherapy agents, and radiation. In some cases, inflammasomes inhibit tumor progression by initiating GSDMD-mediated pyroptosis in cancer cells and stimulating IL-1 signal-mediated anti-tumor immunity. However, IL-1 signal recruits immunosuppressive cell subsets in other cases. We discuss the conflicting results and propose some possible explanations. Additionally, we also summarize interventions targeting inflammasome pathways in both preclinical and clinical stages. Interventions targeting inflammasomes are promising for immunotherapy and combination therapy.

The polarization of microglia and infiltrated macrophages in the injured mice spinal cords: a dynamic analysis

Background

Following spinal cord injury (SCI), a large number of peripheral monocytes infiltrate into the lesion area and differentiate into macrophages (Mø). These monocyte-derived Mø are very difficult to distinguish from the local activated microglia (MG). Therefore, the term Mø/MG are often used to define the infiltrated Mø and/or activated MG. It has been recognized that pro-inflammatory M1-type Mø/MG play "bad" roles in the SCI pathology. Our recent research showed that local M1 cells are mainly CD45^-/lowCD68⁺CD11b⁺ in the subacute stage of SCI. Thus, we speculated that the M1 cells in injured spinal cords mainly derived from MG rather than infiltrating Mø. So far, their dynamics following SCI are not yet entirely clear.

Methods

Female C57BL/6 mice were used to establish SCI model, using an Infinite Horizon impactor with a 1.3 mm diameter rod and a 50 Kdynes force. Sham-operated (sham) mice only underwent laminectomy without contusion. Flow cytometry and immunohistofluorescence were combined to analyze the dynamic changes of polarized Mø and MG in the acute (1 day), subacute (3, 7 and 14 days) and chronic (21 and 28 days) phases of SCI.

Results

The total Mø/MG gradually increased and peaked at 7 days post-injury (dpi), and maintained at high levels 14, 21 and 28 dpi. Most of the Mø/MG were activated, and the Mø increased significantly at 1 and 3 dpi. However, with the pathological process, activated MG increased nearly to 90% at 7, 14, 21 and 28 dpi. Both M1 and M2 Mø were increased significantly at 1 and 3 dpi. However, they decreased to very low levels from 7 to 28 dpi. On the contrary, the M2-type MG decreased significantly following SCI and maintained at a low level during the pathological process.

The role of immune cells and associated immunological factors in the immune response to spinal cord injury

Spinal cord injury (SCI) is a devastating neurological condition prevalent worldwide. Where the pathological mechanisms underlying SCI are concerned, we can distinguish between primary injury caused by initial mechanical damage and secondary injury characterized by a series of biological responses, such as vascular dysfunction, oxidative stress, neurotransmitter toxicity, lipid peroxidation, and immune-inflammatory response. Secondary injury causes further tissue loss and dysfunction, and the immune response appears to be the key molecular mechanism affecting injured tissue regeneration and functional recovery from SCI. Immune response after SCI involves the activation of different immune cells and the production of immunity-associated chemicals. With the development of new biological technologies, such as transcriptomics, the heterogeneity of immune cells and chemicals can be classified with greater precision. In this review, we focus on the current understanding of the heterogeneity of these immune components and the roles they play in SCI, including reactive astrogliosis and glial scar formation, neutrophil migration, macrophage transformation, resident microglia activation and proliferation, and the humoral immunity mediated by T and B cells. We also summarize findings from clinical trials of immunomodulatory therapies for SCI and briefly review promising therapeutic drugs currently being researched.

Atractylenolide III ameliorates spinal cord injury in rats by modulating microglial/macrophage polarization

Background

Inflammatory reactions induced by spinal cord injury (SCI) are essential for recovery after SCI. Atractylenolide III (ATL‐III) is a natural monomeric herbal bioactive compound that is mainly derived in Atractylodes macrocephala Koidz and has anti‐inflammatory and neuroprotective effects.

Objective

Here, we speculated that ATL‐III may ameliorate SCI by modulating microglial/macrophage polarization. In the present research, we focused on investigating the role of ATL‐III on SCI in rats and explored the potential mechanism.

Methods

The protective and anti‐inflammatory effects of ATL‐III on neuronal cells were examined in a rat SCI model and lipopolysaccharide (LPS)‐stimulated BV2 microglial line. The spinal cord lesion area, myelin integrity, and surviving neurons were assessed by specific staining. Locomotor function was evaluated by the Basso, Beattie, and Bresnahan (BBB) scale, grid walk test, and footprint test. The activation and polarization of microglia/macrophages were assessed by immunohistofluorescence and flow cytometry. The expression of corresponding inflammatory factors from M1/M2 and the activation of relevant signaling pathways were assessed by Western blotting.

Results

ATL‐III effectively improved histological and functional recovery in SCI rats. Furthermore, ATL‐III promoted the transformation of M1 into M2 and attenuated the activation of microglia/macrophages, further suppressing the expression of corresponding inflammatory mediators. This effect may be partly mediated by inhibition of neuroinflammation through the NF‐κB, JNK MAPK, p38 MAPK, and Akt pathways.

Conclusion

This study reveals a novel effect of ATL‐III in the regulation of microglial/macrophage polarization and provides initial evidence that ATL‐III has potential therapeutic benefits in SCI rats.

Selenium Nanoparticles derived from Proteus mirabilis YC801 alleviate Oxidative Stress and Inflammatory Response to Promote Nerve Repair in Rats with Spinal Cord Injury

Microbial biotransformation and detoxification of biotoxic selenite into selenium nanoparticles (SeNPs) has emerged as an efficient technique for the utilization of selenium. SeNPs are characterized by high bioavailability and have several therapeutic effects owing to their antioxidant, anti-inflammatory, and neuroprotective activities. However, their influence on microenvironment disturbances and neuroprotection after spinal cord injury (SCI) is yet to be elucidated. This study aimed to assess the influence of SeNPs on SCI and explore the underlying protective mechanisms. Overall, the proliferation and differentiation of neural stem cells (NSCs) were facilitated by SeNPs derived from Proteus mirabilis YC801 via the Wnt/β-catenin signaling pathway. The SeNPs increased the number of neurons to a greater extent than astrocytes after differentiation and improved nerve regeneration. A therapeutic dose of SeNPs remarkably protected the integrity of the spinal cord to improve the motor function of the hind limbs after SCI, and decreased the expression of several inflammatory factors such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in vivo and enhanced the production of M2-type macrophages by regulating their polarization, indicating the suppressed inflammatory response. Besides, SeNPs reversed the SCI-mediated production of reactive oxygen species. In conclusion, SeNPs treatment holds the potential to improve the disturbed microenvironment and promote nerve regeneration, representing a promising therapeutic approach for SCI.

Neuroprotective Effects of the Pannexin-1 Channel Inhibitor: Probenecid on Spinal Cord Injury in Rats

Proinflammatory immune cell subsets constitute the majority in the local microenvironment after spinal cord injury (SCI), leading to secondary pathological injury. Previous studies have demonstrated that inflammasomes act as an important part of the inflammatory process after SCI. Probenecid, an inhibitor of the Pannexin-1 channel, can inhibit the activation of inflammasomes. This article focuses on the effects of probenecid on the local immune microenvironment, histopathology, and behavior of SCI. Our data show that probenecid inhibited the expression and activation of nucleotide-binding oligomerization domain receptor pyrindomain-containing 1 (NLRP1), apoptosis-associated speck-like protein containing a CARD (ASC) and caspase-1, interleukin-1β (IL-1β), and caspase-3 proteins associated with inflammasomes, thereby suppressing the proportion of M1 cells. And consequently, probenecid reduced the lesion area and demyelination in SCI. Moreover, the drug increased the survival of motor neurons, which resulted in tissue repair and improved locomotor function in the injured SC. Altogether, existing studies indicated that probenecid can alleviate inflammation by blocking Pannexin-1 channels to inhibit the expression of caspase-1 and IL-1β, which in turn restores the balance of immune cell subsets and exerts neuroprotective effects in rats with SCI.

Extracellular vesicles derived from CD73 modified human umbilical cord mesenchymal stem cells ameliorate inflammation after spinal cord injury

BACKGROUND

Spinal cord injury (SCI) is an inflammatory condition, and excessive adenosine triphosphate (ATP) is released into the extracellular space, which can be catabolized into adenosine by CD73. Extracellular vesicles have been designed as nano drug carriers in many diseases. However, their impacts on delivery of CD73 after SCI are not yet known. We aimed to construct CD73 modified extracellular vesicles and explore the anti-inflammatory effects after SCI.

METHODS

CD73 engineered extracellular vesicles (CD73+ hucMSC-EVs) were firstly established, which were derived from human umbilical cord mesenchymal stem cells (hucMSCs) transduced by lentiviral vectors to upregulate the expression of CD73. Effects of CD73+ hucMSC-EVs on hydrolyzing ATP into adenosine were detected. The polarization of M2/M1 was verified by immunofluorescence. Furthermore, A2aR and A_2bR inhibitors and A2bR knockdown cells were used to investigate the activated adenosine receptor. Biomarkers of microglia and levels of cAMP/PKA were also detected. Repetitively in vivo study, morphology staining, flow cytometry, cytokine analysis, and ELISA assay, were also applied for verifications.

RESULTS

CD73+ hucMSC-EVs reduced concentration of ATP and promoted the level of adenosine. In vitro experiments, CD73+ hucMSC-EVs increased macrophages/microglia M2:M1 polarization, activated adenosine 2b receptor (A2bR), and then promoted cAMP/PKA signaling pathway. In mice using model of thoracic spinal cord contusion injury, CD73+ hucMSC-EVs improved the functional recovery after SCI through decreasing the content of ATP in cerebrospinal fluid and improving the polarization from M1 to M2 phenotype. Thus, the cascaded pro-inflammatory cytokines were downregulated, such as TNF-α, IL-1β, and IL-6, while the anti-inflammatory cytokines were upregulated, such as IL-10 and IL-4.

CONCLUSIONS

CD73+ hucMSC-EVs ameliorated inflammation after spinal cord injury by reducing extracellular ATP, promoting A2bR/cAMP/PKA pathway and M2/M1 polarization. CD73+ hucMSC-EVs might be promising nano drugs for clinical application in SCI therapy.

Unknown/enigmatic functions of extracellular ASC

Apoptosis-associated speck-like protein containing a caspase recruit domain (ASC), encoded by PYCARD gene, is a 22 kDa small molecule, which aggregates into ASC specks during inflammasome activation. ASC protein is an adaptor protein present in several inflammasome complexes that performs several intra- and extracellular functions, in monomeric form or as ASC specks, during physiological and pathological processes related to inflammation and adaptive immunity. Extracellular ASC specks (eASC specks) released during cell death by pyroptosis can contribute as a danger signal to the propagation of inflammation via phagocytosis and activation of surrounding cells. ASC specks are found in the circulation of patients with chronic inflammatory diseases and have been considered as relevant blood biomarkers of inflammation. eASC amplifies the inflammatory signal, may induce the production of autoantibodies, transports molecules that bind to this complex, contributing to the generation of antibodies, and can induce the maturation of cytokines promoting the modelling of the adaptive immunity. Although several advances have been registered in the last 21 years, there are numerous unknown or enigmatic gaps in the understanding of the role of eASC specks in the organism. Here, we provide an overview about the ASC protein focusing on the probable roles of eASC specks in several diseases, up to the most recent studies concerning COVID-19.

VX-765 reduces neuroinflammation after spinal cord injury in mice

Inflammation is a major cause of neuronal injury after spinal cord injury. We hypothesized that inhibiting caspase-1 activation may reduce neuroinflammation after spinal cord injury, thus producing a protective effect in the injured spinal cord. A mouse model of T9 contusive spinal cord injury was established using an Infinite Horizon Impactor, and VX-765, a selective inhibitor of caspase-1, was administered for 7 successive days after spinal cord injury. The results showed that: (1) VX-765 inhibited spinal cord injury-induced caspase-1 activation and interleukin-1β and interleukin-18 secretion. (2) After spinal cord injury, an increase in M1 cells mainly came from local microglia rather than infiltrating macrophages. (3) Pro-inflammatory Th1Th17 cells were predominant in the Th subsets. VX-765 suppressed total macrophage infiltration, M1 macrophages/microglia, Th1 and Th1Th17 subset differentiation, and cytotoxic T cells activation; increased M2 microglia; and promoted Th2 and Treg differentiation. (4) VX-765 reduced the fibrotic area, promoted white matter myelination, alleviated motor neuron injury, and improved functional recovery. These findings suggest that VX-765 can reduce neuroinflammation and improve nerve function recovery after spinal cord injury by inhibiting caspase-1/interleukin-1β/interleukin-18. This may be a potential strategy for treating spinal cord injury. This study was approved by the Animal Care Ethics Committee of Bengbu Medical College (approval No. 2017-037) on February 23, 2017.

Changes in transcriptome profiling during the acute/subacute phases of contusional spinal cord injury in rats

Background

Spinal cord injuries (SCIs), along with subsequent secondary injuries, often result in irreversible damage to both sensory and motor functions. However, a thorough view of the underlying pathological mechanisms of SCIs, especially in a temporal-spatial manner, is still lacking.

Methods

To obtain a comprehensive, real-time view of multiple subsets of the cellular mechanisms involved in SCIs, we applied RNA-sequencing technology to characterize the temporal changes in gene expression around the lesion site of contusion SCI in rats. First, we identified the differentially expressed genes (DEGs) in contrast to sham controls at 1, 4, and 7 days post SCI. Through bioinformatics analysis, including Pathway analysis, Gene-act-net, and Pathway-act-net, we screened and verified potential key pathways and genes associated with either the acute or subacute stages of SCI pathology.

Results

The top three overrepresented pathways were associated with cytokine-cytokine receptor interaction, TNF signaling pathway, and cell cycle at day 1; lysosome, cytokine-cytokine receptor interaction, phagosome at day 4; and phagosome, lysosome, cytokine-cytokine receptor interaction at day 7 post injury. Further, we identified uniquely enriched genes at each time point, such as Ccr1 and Nos2 at day 1; as well as Mgst2, and Pla2g3 at 4 and 7 days post-injury.

Conclusions

Our pathway analysis suggested a transition from inflammatory responses to multiple forms of cell death processes from the acute to subacute stages of SCI. Further, our results revealed a continuous transformation from a more inflammatory to an apoptotic/self-repairing transcriptome following the time-course of SCIs. Our research provides novel insights into the molecular mechanisms of SCI pathophysiology and identifies potential targets for therapeutic intervention after SCI.