Role of pyroptosis in spinal cord injury and its therapeutic implications

HSPA1A inhibits pyroptosis and neuroinflammation after spinal cord injury via DUSP1 inhibition of the MAPK signaling pathway

BACKGROUND

Inflammation and proinflammatory programmed cell death, referred to as pyroptosis, are important causes of poor functional recovery after traumatic spinal cord injury (TSCI). Heat shock protein family A member 1A (HSPA1A) is a molecular chaperone protein that is highly expressed after TSCI and is thought to be neuroprotective. However, the mechanisms underlying the protective effects of HSPA1A after TSCI are unclear.

METHODS

The levels of pyroptosis and inflammation after TSCI were determined by enzyme-linked immunosorbent assay (ELISA) and western blotting analysis. The role of HSPA1A in regulating pyroptosis and inflammation in TSCI was verified by in vivo and in vitro experiments. The molecular mechanism of the effects of HSPA1A in TSCI was elucidated by bioinformatics and coimmunoprecipitation analyses.

RESULTS

Pyroptosis and inflammation are significantly increased after TSCI. HSPA1A overexpression in microglia attenuated nigericin- and lipopolysaccharide (LPS)-induced pyroptosis and inflammation in vitro, whereas knockdown of HSPA1A aggravated pyroptosis and inflammation. In vivo, overexpression of HSPA1A reduced tissue damage, nerve cell death, pyroptosis, and inflammation in TSCI rats and promoted functional recovery. Mechanistically, we identified that HSPA1A interacts with dual specificity phosphatase 1 (DUSP1) and inhibits activation of the mitogen-activated protein kinase (MAPK) pathway, thereby attenuating pyroptosis and inflammation.

CONCLUSION

HSPA1A reduces pyroptosis and inflammation after TSCI by upregulating DUSP1 and inhibiting MAPK pathway activation. HSPA1A activation has potential as a therapeutic approach to promote functional recovery after TSCI.

Mechanism of effect and therapeutic potential of NLRP3 inflammasome in spinal cord injury

Spinal cord injury (SCI) is a serious and disabling central nervous system injury that can trigger various neuropathological conditions, resulting in neuronal damage and release of various pro-inflammatory mediators, leading to neurological dysfunction. Currently, surgical decompression, drugs and rehabilitation are primarily used to relieve symptoms and improve endogenous repair mechanisms; however, they cannot directly promote nerve regeneration and functional recovery. SCI can be divided into primary and secondary injuries. Secondary injury is key to determining the severity of injury, whereas inflammation and cell death are important pathological mechanisms in the process of secondary SCI. The activation of the inflammasome complex is thought to be a necessary step in neuro-inflammation and a key trigger for neuronal death. The NLRP3 inflammasome is a cytoplasmic multiprotein complex that is considered an important factor in the development of SCI. Once the NLRP3 inflammasome is activated after SCI, NLRP3 nucleates the assembly of an inflammasome, leading to caspase 1-mediated proteolytic activation of the interleukin-1β (IL-1β) family of cytokines, and induces an inflammatory, pyroptotic cell death. Inhibition of inflammasomes can effectively inhibit inflammation and cell death in the body and promote the recovery of nerve function after SCI. Therefore, inhibition of NLRP3 inflammasome activation may be a promising approach for the treatment of SCI. In this review, we describe the current understanding of NLRP3 inflammasome activation in SCI pathogenesis and its subsequent impact on SCI and summarize drugs and other potential inhibitors based on NLRP3 inflammasome regulation. The objective of this study was to emphasize the role of the NLRP3 inflammasome in SCI, and provide a new therapeutic strategy and theoretical basis for targeting the NLRP3 inflammasome as a therapy for SCI.

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

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

O-GlcNAc transferase mediates O-GlcNAcylation of NLRP3 regulates pyroptosis in spinal cord injury

BACKGROUND

Spinal cord injury (SCI) represents a severe disorder of the nervous system, imposing significant physical, psychological, and socioeconomic burdens on affected individuals and society.

OBJECTIVE

We investigated the implication of O-linked β-N-acetylglucosamine (O-GlcNAcylation) in regulating pyroptosis related proteins at the posttranslational level.

MATERIALS AND METHODS

PC12 cells were stimulated with lipopolysaccharide (LPS). The O-GlcNAcylation pathway was modified by manipulating the expression of O-GlcNAc transferase (OGT) or O-GlcNAcase (OGA). Pro-inflammatory cytokine levels and cell pyroptosis were assessed. Co-immunoprecipitation (Co-IP) assays were employed to investigate the interaction between NLRP3 and OGT. For in vivo studies, an established SCI rat model was utilized. Levels of pro-inflammatory factors, NLRP3 inflammasome components, and proteins associated with pyroptosis were measured.

RESULTS

Both O-GlcNAc levels and OGT expression were significantly elevated in the SCI model cells. Inhibition of OGT led to a marked reduction in the levels of pro-inflammatory cytokines and a suppression of pyroptosis. Furthermore, inhibition of OGT resulted in downregulation of NLRP3 and its O-GlcNAcylation, while overexpression of OGT produced the opposite effect. We verified the endogenous and exogenous interactions between NLRP3 and OGT. Importantly, knockout of OGT mitigated the progression of SCI in an animal model, suggesting a protective role of OGT inhibition in SCI.

DISCUSSION AND CONCLUSION

This study preliminarily proved that the mechanism of OGT mediated O-GlcNAcylation of NLRP3 participates in the action of pyroptosis in SCI. Targeting OGT and NLRP3 may be novel therapy method in SCI.

E3 Ubiquitin Ligase TRIM7 Alleviates LPS-Induced Acute Lung Injury via Inhibiting NLRP3 Inflammasome Activation

Acute lung injury (ALI) is a clinically common disease with high mortality, characterized by tissue damage caused by excessive activation of inflammation. TRIM7 is an E3 ligase that plays an important role in regulating viral infection, tumor progression, and innate immune response. Its function in ALI is unclear, however. In this study, lipopolysaccharide (LPS) was used to stimulate C57BL/6j mice and HULEC-5a cells to establish ALI models in vivo and in vitro. The results showed that TRIM7 expression was down-regulated during ALI. Furthermore, overexpressing TRIM7 in HULEC-5a cells relieved cell damage and inflammatory activation induced by LPS stimulation. TRIM7 knockdown has the opposite effect. Trim7-overexpressing mice were established by endotracheal injection of adeno-associated virus 6-Trim7 virus in vivo; the ALI model was then induced by LPS stimulation. We showed that overexpression of TRIM7 could alleviate lung tissue injury, pulmonary interstitial hemorrhage, increased alveolar and vascular permeability, inflammatory cell infiltration, and secretion of inflammatory factors induced by LPS stimulation. Mechanistically, TRIM7 has been shown to inhibit the expression of NOD-, LRR- and pyrin domain-containing 3 (NLRP3) and activation of the NLRP3 inflammasome. The regulatory effect of TRIM7 on ALI depends on the NLRP3 inflammasome. This investigation for the first time shows the inhibitory effect of TRIM7 on ALI and activation of the NLRP3 inflammasome, providing new targets and ideas for the mechanism research and treatment of ALI.

Novel pyroptosis-immune-related lncRNA signature exhibits a distinct immune cell infiltration landscape in breast cancer

Introduction

This study investigated pyroptosis- and immunity-related long non-coding RNAs (lncRNAs) to identify promising therapeutic targets for breast cancer (BC), and constructed lncRNA signatures to determine the prognosis and immunotherapy responses of BC patients.

Methods

Pearson's correlation coefficient was used to identify pyroptosis- and immune-related differentially expressed lncRNAs (DE-pyrolncRNAs and DE-ImmlncRNAs, respectively). The Cancer Genome Atlas dataset was allocated to training and testing subsets. Prognostic lncRNA signatures were derived based on the training subset using univariate Cox regression analysis and Least Absolute Shrinkage and Selection Operator methods. Stepwise Cox regression was used to refine these signatures and to select the optimal lncRNA signature. The median risk score of the training subset was applied as a threshold to divide patients into high-risk (HR) and low-risk (LR) groups. The Wilcoxon test was used to reveal differences in immune scores, cell types, functions, and checkpoint genes between these groups. Single-cell sequencing data from GSE176078 were used to validate the immune cell infiltration landscape of the identified lncRNA signatures.

Results

We identified a six-lncRNA pyroptosis-immune signature comprising MAPT.AS1, CTA.384, D8.34, RP11.561, I11.3, HID1.AS1, AC097713.3, and USP2.AS1. Patients in the HR group demonstrated inferior prognoses in the training, testing, and full datasets (P=3.622e-07, P=3.736e-03, and P=1.151e-08, respectively). Immune scores were significantly enhanced in the LR group, whereas tumor purity was elevated in the HR group. Fifty-eight immune scores showed significant differences between the groups (P<0.05). Immune function (APC coinhibition, CCR, and checkpoints) more significantly impaired in the HR group. Expression levels of 38 immune checkpoint genes, including KIR2DS4, KIR3DL2, CD40LG, KIR3DL1, and PDCD1, were significantly higher in the LR group. Conversely, the TDO2, PVR, and CD276 levels were elevated in the HR group. Single-cell sequencing data from GSE176078 showed sparse T cell, B cell, myeloid, and plasmablast clusters in the HR group, whereas the LR group displayed significant clustering of B cells, myeloids, and plasmablasts.

Conclusion

The six-lncRNA pyroptosis-immune signature effectively predicted BC prognosis and highlighted distinct immune cell infiltration patterns. This holds promise for evaluating immunotherapy responses and guiding therapeutic target identification in BC.

Exploring Ubiquitination in Spinal Cord Injury Therapy: Multifaceted Targets and Promising Strategies

Spinal cord injury (SCI) is a severely debilitating neurological condition that often results in significant functional impairment and is associated with poor long-term prognosis. Edema, oxidative stress, inflammatory responses, and cell death are the primary factors contributing to secondary injury following spinal cord damage. Ubiquitination is a crucial intracellular mechanism for protein regulation that has garnered significant attention as a therapeutic target in a variety of diseases. Numerous studies have shown that ubiquitination plays a key role in modulating processes such as inflammatory responses, apoptosis, and nerve regeneration following SCI, thereby influencing injury repair. Accordingly, targeting ubiquitination has the potential for mitigating harmful inflammatory responses, inhibiting dysregulated programmed cell death, and protecting the integrity of the blood-spinal cord barrier, thereby providing a novel therapeutic strategy for SCI. In this review, we discuss the role of ubiquitination and its potential as a therapeutic target in SCI, aiming to offer a foundation for developing ubiquitination-targeted therapies for this condition.

Urolithin A alleviates NLRP3 inflammasome activation and pyroptosis by promoting microglial mitophagy following spinal cord injury

Spinal cord injury (SCI) is a potentially fatal condition that often results in loss of motor and sensory functions, thereby significantly burdening global health initiatives. Urolithin A (UA), an intestinal microbial metabolite of ellagic acid, is known for its potent anti-inflammatory properties in chronic inflammation contexts. UA treatment in humans induces a molecular signature of improved mitochondrial and cellular health. Yet, its effects on acute inflammation following SCI remain unclear. In this study, we developed an impact-induced mouse model for SCI and treated the injured mice with UA (50 mg/kg/d, till 8 weeks) via intragastric administration. Furthermore, we subjected BV2 cells to lipopolysaccharide and adenosine 5'-triphosphate to simulate the post-injury inflammatory response. Our results demonstrated that pre-treatment with UA (10 μM) effectively inhibited NLRP3 inflammasome activation in LPS-primed BV2 cells. This inhibition was evidenced by reduced cleaved Caspase-1 and mature IL-1β release, diminished ASC speck formation, and decreased gasdermin D (GSDMD)-mediated pyroptosis. Additionally, UA treatment restored mitochondrial activity and ROS production attenuated by NLRP3 activation, increased LC3-II expression, and enhanced LC3 co-localization with mitochondria. 3-Methyladenine (3-MA), an autophagy inhibitor, can partially reverse the stimulatory effect of UA on mitophagy, as well as the inhibitory effect of UA on pyroptosis. This study highlighted the protective role of UA against SCI through its promotion of mitophagy, which in turn inhibits NLRP3 inflammasome activation and pyroptosis.

Global trends and emerging insights in BRAF and MEK inhibitor resistance in melanoma: a bibliometric analysis

Objective

This study aims to perform a comprehensive bibliometric analysis of global research on BRAF and MEK inhibitor resistance in melanoma, identifying key research trends, influential contributors, and emerging themes from 2003 to 2024.

Methods

A systematic search was conducted in the Web of Science Core Collection (WoSCC) database to retrieve publications related to BRAF and MEK inhibitor resistance from 1 January 2003, to 1 September 2024. Bibliometric analyses, including publication trends, citation networks, and keyword co-occurrence patterns, were performed using VOSviewer and CiteSpace. Collaborative networks, co-cited references, and keyword burst analyses were mapped to uncover shifts in research focus and global cooperation.

Results

A total of 3,503 documents, including 2,781 research articles and 722 review papers, were analyzed, highlighting significant growth in this field. The United States, China, and Italy led in publication volume and citation impact, with Harvard University and the University of California System among the top contributing institutions. Research output showed three phases of growth, peaking in 2020. Keyword and co-citation analyses revealed a transition from early focus on BRAF mutations and MAPK pathway activation to recent emphasis on immunotherapy, combination therapies, and non-apoptotic cell death mechanisms like ferroptosis and pyroptosis. These trends reflect the evolving priorities and innovative approaches shaping the field of resistance to BRAF and MEK inhibitors in melanoma.

Conclusion

Research on BRAF and MEK inhibitor resistance has evolved significantly. This analysis provides a strategic framework for future investigations, guiding the development of innovative, multi-modal approaches to improve treatment outcomes for melanoma patients.

Molecular characterization of PANoptosis-related genes as novel signatures for peripheral nerve injury based on time-series transcriptome sequencing

Programmed cell death (PCD) pathways play pivotal roles in the development and progression of peripheral nerve injury (PNI). PANoptosis, as a novel form of PCD pathway with key features of pyroptosis, apoptosis and necroptosis, is implicated in the pathogenesis of multiple neurologic diseases. This study aimed to identify PANoptosis-related biomarkers and characterize their molecular roles and immune landscape in PNI. PANoptosis-related genes (PRGs) were retrieved from Reactome pathway database and previous literatures. Differentially expressed PANoptosis-related genes (DEPRGs) were identified based on a time-series transcriptome sequencing dataset. DEPRGs were predicted to be enriched in inflammatory response, inflammatory complex, PCD and NOD-like receptor signaling pathway through GO, KEGG, Reactome and GSEA analysis. Hub genes, including Ripk3, Pycard and Il18, were then recognized through PPI network and multiple algorithms. The molecular regulatory mechanisms of hub genes were elucidated by transcription factor network and competing endogenous RNA network. Moreover, the immune cell landscape of hub genes was analyzed. Eventually, the expression levels of hub genes were verified through external dataset and animal model. Ripk3, Pycard and Il18 were remarkably upregulated in PNI samples, which were in consistent with the results of bioinformatic analysis. This study uncovered the molecular characterization of PANoptosis-related genes in PNI and illustrated the novel PANoptosis biomarkers for PNI.

Natural products target pyroptosis for ameliorating neuroinflammation: A novel antidepressant strategy

BACKGROUND

Depression is a common mental disorder characterized by prolonged loss of interest and low mood, accompanied by symptoms such as sleep disturbances and cognitive impairments. In severe cases, there may be a tendency toward suicide. Depression can be caused by a series of highly complex pathological mechanisms; However, its key pathogenic mechanism remains unclear. As a novel programmed cell death (PCD) pathway and inflammatory cell death mode, pyroptosis involves a series of tightly regulated gene expression events. It may play a significant role in the pathogenesis and management of depression by modulating neuroinflammatory processes. In addition, a large number of studies have shown that various pharmacologically active natural products can regulate pyroptosis through multiple targets and pathways, demonstrating significant potential in the treatment of depression. These natural products offer advantages such as low costs and minimal side effects, making them a viable supplement or alternative to traditional antidepressants. In this review, we summarized recent research on natural products that regulate pyroptosis and neuroinflammation to improve depression. The aim of this review was to contribute to a scientific basis for the discovery and development of more natural antidepressants in the future.

METHODS

To review the antidepressant effects of natural products targeting pyroptosis-mediated neuroinflammation, data were collected from the Web of Science, ScienceDirect databases, and PubMed to classify and summarize the relationship between pyroptosis and neuroinflammation in depression, as well as the pharmacological mechanisms of natural products.

RESULTS

Multiple researches have revealed that pyroptosis-mediated neuroinflammation serves as a pivotal contributory factor in the pathological process of depression. Natural products, such as terpenoids, terpenes, phenylethanol glycosides, and alkaloids, have antidepressant effects by regulating pyroptosis to alleviate neuroinflammation.

CONCLUSION

We comprehensively reviewed the regulatory effects of natural products in depression-related pyroptosis pathways, providing a uniquely insightful perspective for the research, development, and application of natural antidepressants. However, future research should further explore the modulatory mechanisms of natural products in regulating pyroptosis, which is of great importance for the genration of effective antidepressants.

Resveratrol Upregulates miR-124-3p Expression to Target DAPK1, Regulating the NLRP3/Caspase-1/GSDMD Pathway to Inhibit Pyroptosis and Alleviate Spinal Cord Injury

Currently, an effective treatment for spinal cord injury (SCI) is not available. Due to the irreversible primary injury associated with SCI, the prevention and treatment of secondary injury are very important. In the secondary injury stage, pyroptosis exacerbates the deterioration of the spinal cord injury, and inhibiting pyroptosis is beneficial for recovery from SCI. The aim of this study was to clarify the role of resveratrol (RES) and the antipyroptotic mechanisms of RES and miR-124-3p in SCI to lay a theoretical foundation for the clinical treatment of SCI and provide new therapeutic approaches. Using cell staining and related molecular protein detection techniques to assess DAPK1, the effects of miR-124-3p and RES on pyroptosis were investigated, and the effects of RES on injured spinal cord repair in rats were evaluated using tissue staining and related functional recovery experiments. In vitro, DAPK1 interacts with NLRP3, exerting a pyroptotic effect through the NLRP3/Caspase-1/GSDMD pathway and DAPK1 knockdown inhibits pyroptosis. miR-124-3P negatively regulates the level of DAPK1 and reduced cell pyroptosis. RES increased miR-124-3p expression and reduces DAPK1 expression, affecting the NLRP3/Caspase-1/GSDMD pathway and inhibiting pyroptosis. In vivo, RES reduces GSDMD-N levels in rats with SCI, promotes functional recovery, and thus promotes recovery from SCI. Therefore, we concluded that RES increases the level of miR-124-3p, which targets DAPK1, regulates the NLRP3/Caspase-1/GSDMD pathway, inhibits pyroptosis and alleviates SCI.

Gasdermin D-mediated neutrophil pyroptosis drives inflammation in psoriasis

Psoriasis is a multifactorial immune-mediated inflammatory disease. Its pathogenesis involves abnormal accumulation of neutrophils and T-cell-related abnormalities. Pyroptosis is a type of regulated cell death associated with innate immunity, but its role in psoriasis is unclear. In this study, we found that gasdermin D (GSDMD) is higher in human psoriatic skin than that in normal skin, and in imiquimod-induced psoriasis-like mouse skin, the expression of Gsdmd was most significantly altered in neutrophils and Il1b was also mainly expressed in neutrophils. Immunohistochemical staining of serial sections of skin lesions from psoriasis patients and healthy control also showed that GSDMD expression is higher in psoriasis lesion, especially in neutrophils. Gsdmd deficiency mitigates psoriasis-like inflammation in mice. GSDMD in neutrophils contributes to psoriasis-like inflammation, while Gsdmd depletion in neutrophils attenuates the development of skin inflammation in psoriasis and reduces the release of the inflammatory cytokines. We found that neutrophil pyroptosis is involved in and contributes to psoriasis inflammation, which provides new insights into the treatment of psoriasis by targeting neutrophil pyroptosis.

Dynamic changes in pyroptosis following spinal cord injury and the identification of crucial molecular signatures through machine learning and single-cell sequencing

The pathological cascade of spinal cord injury (SCI) is highly intricate. The onset of neuroinflammation can exacerbate the extent of damage. Pyroptosis is a form of inflammation-linked programmed cell death (PCD), the inhibition of pyroptosis can partially mitigate neuroinflammation. It is imperative to delineate the principal cell types susceptible to pyroptosis and concomitantly identify key genes associated with this process. We initially defined the pyroptosis-related genes (PRGs) and analyzed their expression at different time points post SCI. The results demonstrate a substantial upregulation of differentially expressed genes (DEGs) related to pyroptosis on the 7 days post-injury (dpi), these DEGs in the 7 dpi are closely related to the inflammatory response. Subsequently, immune infiltration analysis revealed a predominant presence of inflammatory microglia. Through correlation analysis, we postulated that pyroptosis primarily manifested within the inflammatory microglia. Employing machine learning algorithms, we identified four pyroptosis-related molecular signatures, which were experimentally validated using BV2 cells and spinal cord tissue samples. The robustness of the identified molecular signatures was further confirmed through single-cell sequencing data analysis. Overall, our study elucidates the temporal dynamics of pyroptosis and identifies key molecular signatures following SCI. These findings can provide novel evidence for therapeutic interventions in SCI.

Crocin facilitates osteogenesis and angiogenesis by moderating oxidative stress and ferroptosis via Nrf2/GPX4 pathway

Bone formation is a complex multi-factor process of bone defect healing. Oxidative stress (OS) is predisposed to induce regulatory cell death (RCD), such as ferroptosis. At present, the antioxidant effects of Crocin on erastin induced oxidative damage were studied. The activity of bone marrow mesenchymal stem cells (BMSCs) and human umbilical vein endothelial cells (HUVECs) was detected by CCK-8 and EdU staining. The production of reactive oxygen species (ROS), MDA, SOD and GSH were evaluated. Western blotting assay was used to detect ferroptosis-related proteins. The osteogenic function of BMSCs was determined by alkaline phosphatase (ALP) activity, ALP staining and alizarin red S (ARS) staining. Western blotting and RT-PCR assays were used to detect the expression of osteogenic proteins and genes. Angiogenesis of HUVECs was evaluated by tube formation, RT-PCR, scratch test and Transwell assay. The results showed that Crocin can promote the osteogenic function of BMSCs and angiogenesis of HUVECs. In addition, Crocin protects cells from erastin-induced oxidative injury and inhibits ferroptosis via the Nrf2/GPX4 pathway. These findings suggest that Crocin can promote bone defect healing by regulating OS and inhibiting ferroptosis through the Nrf2/GPX4 pathway.

Crosstalk Between Cell Death and Spinal Cord Injury: Neurology and Therapy

Spinal cord injury (SCI) often leads to neurological dysfunction, and neuronal cell death is one of the main causes of neurological dysfunction. After SCI, in addition to necrosis, programmed cell death (PCD) occurs in nerve cells. At first, studies recognized only necrosis, apoptosis, and autophagy. In recent years, researchers have identified new forms of PCD, including pyroptosis, necroptosis, ferroptosis, and cuproptosis. Related studies have confirmed that all of these cell death modes are involved in various phases of SCI and affect the direction of the disease through different mechanisms and pathways. Furthermore, regulating neuronal cell death after SCI through various means has been proven to be beneficial for the recovery of neural function. In recent years, emerging therapies for SCI have also provided new potential methods to restore neural function. Thus, the relationship between SCI and cell death plays an important role in the occurrence and development of SCI. This review summarizes and generalizes the relevant research results on neuronal necrosis, apoptosis, autophagy, pyroptosis, necroptosis, ferroptosis, and cuproptosis after SCI to provide a new understanding of neuronal cell death after SCI and to aid in the treatment of SCI.

A new strategy for the treatment of intracerebral hemorrhage: Ferroptosis

Intracerebral hemorrhage, is a cerebrovascular disease with high morbidity, mortality, and disability. Due to the lack of effective clinical treatments, the development of new drugs to treat intracerebral hemorrhage is necessary. In recent years, ferroptosis has been found to play an important role in the pathophysiological process of intracerebral hemorrhage, which can be treated by inhibiting ferroptosis and thus intracerebral hemorrhage. This article aims to explain the mechanism of ferroptosis and its relationship to intracerebral hemorrhage. In the meantime, it briefly discusses the molecules identified to alleviate intracerebral hemorrhage by inhibiting ferroptosis, along with other clinical agents that are expected to treat intracerebral hemorrhage through this mechanism. In addition, a brief overview of the morphological alterations of different forms of cell death and their role in ICH is provided. Finally, the challenges that may arise in translating ferroptosis inhibitors from basic research to clinical use are presented. This article serves as a reference and provides insights to aid in the treatment of intracerebral hemorrhage in the clinic.

Genetic deletion of the apoptosis associated speck like protein containing a card in LysM+ macrophages attenuates spinal cord injury by regulating M1/M2 polarization through ASC-dependent inflammasome signaling axis

Apoptosis associated speck like protein containing a card (ASC), the key adaptor protein of the assembly and activation of canonical inflammasomes, has been found to play a significant role in neuroinflammation after spinal cord injury (SCI). The previous studies indicated that widely block or knockout ASC can ameliorate SCI. However, ASC is ubiquitously expressed in infiltrated macrophages and local microglia, so further exploration is needed on which type of cell playing the key role. In this study, using the LysMcre;Ascflox/flox mice with macrophage-specifc ASC conditional knockout (CKO) and contusive SCI model, we focus on evaluating the specific role of ASC in lysozyme 2 (LysM)+ myeloid cells (mainly infiltrated macrophages) in this pathology. The results revealed that macrophage-specifc Asc CKO exhibited the follow effects: (1) A significant reduction in the numbers of infiltrated macrophages in the all phases of SCI, and activated microglia in the acute and subacute phases. (2) A significant reduction in ASC, caspase-1, interleukin (IL)-1β, and IL-18 compared to control mice. (3) In the acute and subacute phases of SCI, M1 subset differentiation was inhibited, and M2 differentiation was increased. (4) Histology and hindlimb motor recoveries were improved. In conclusion, this study elucidates that macrophage-specific ASC CKO can improve nerve function recovery after SCI by regulating M1/M2 polarization through inhibiting ASC-dependent inflammasome signaling axis. This indicates that ASC in peripheral infiltrated macrophages may play an important role in SCI pathology, at least in mice, could be a potential target for treatment.

Moderate-intensity aerobic exercise inhibits cell pyroptosis to improve myocardial ischemia-reperfusion injury

BACKGROUND

Myocardial ischemia-reperfusion injury (MI/RI) significantly impacts the patients with acute myocardial infarction (AMI), with the NLRP3-mediated necrosis exacerbates the pathological progression of myocardial infarction. Exercise, recognized as a crucial approach for both disease prevention and treatment, is widely utilized in clinical practice worldwide and has demonstrated broad effectiveness in cardiovascular disease (CVD) prevention.

PURPOSE

To explore the cardio protective effect of exercise preconditioning and the mechanism by which exercise modulation of NLRP3 improves myocardial ischemia and reperfusion injury.

METHODS AND RESULTS

In this study, C57BL/6 N mice were employed to establish an exercise preconditioning model and a MI/RI model. The exercise intervention involved moderate-intensity aerobic exercise on a treadmill (50-70% VO2max) for small animals. Our research findings indicate that moderate-intensity aerobic exercise intervention improved cardiac function, reduced myocardial injury and inflammatory response, decreased myocardial infarction area and degree of cell apoptosis in mice compared to those raised under conventional conditions. Additionally, the expression of NLRP3 in the myocardial tissue of mice with MI/RI was reduced after exercise intervention. Moreover, exercise inhibited the activation of apoptosis related proteins such as Caspase-1 and GSDMD, while reducing the levels of inflammatory factors such as IL-1β and IL-18.

CONCLUSIONS

This study found that moderate-intensity aerobic exercise can reduce the inflammatory response, reduce the degree of cell pyroptosis, reduce myocardial ischemia and reperfusion injury, and achieve endogenous protective effects on the myocardium.

Synthesis and Anti-Inflammatory Bowel Disease Activity of Pterostilbene Derivatives

The aberrant activation of NLRP3 inflammasomes is intricately linked to various inflammatory diseases. In this study, we present the discovery and optimization of a series of NLRP3 inflammasome inhibitors based on the pterostilbene skeleton. All compounds underwent screening to evaluate their inhibitory effects on LPS/Nigericin-induced IL-1β secretion and anti-cellular pyroptosis. Most compounds exhibit good biological activity and cellular safety, with compound D20 showing the most prominent activity. Preliminary mechanism studies suggest that compound D20 may affect the assembly of NLRP3 inflammasomes by targeting the NLRP3 protein, thereby inhibiting the activation of NLRP3 inflammasomes. The in vivo anti-inflammatory activity demonstrated significant therapeutic effect of compound D20 on DSS-induced acute colitis model in mice. This work has important reference significance for the development of drugs targeting NLRP3 inflammasomes.

Cynarin inhibits microglia-induced pyroptosis and neuroinflammation via Nrf2/ROS/NLRP3 axis after spinal cord injury

BACKGROUND

Spinal cord injury (SCI) elicits excess neuroinflammation and resident microglial pyroptosis, leading further terrible neurological collapse and locomotor dysfunction. However, the current clinical therapy is useless and a feasible treatment is urgent to be explored. Cynarin is a natural component in artichoke playing anti-inflammatory and anti-aging roles in hepatoprotection and cardioprotection, but it is unclear that the pharmacologic action and underlying mechanism of Cynarin in neuropathy.

METHODS

Using the SCI mouse model and the BV2 cell line, we here investigated whether Cynarin reduces neuroinflammation and pyroptosis to promote neurological recovery after SCI.

RESULTS

Our results showed that treatment with Cynarin reduces the level of neuroinflammation and microglial pyroptosis. Moreover, the mice treated with Cynarin exhibited lower level of reactive oxygen species (ROS) and cell death, less damage of neurohistology and better locomotor improvement of hindlimbs than the untreated mice and the nuclear factor erythroid 2-related factor 2 (Nrf2)-inhibited mice. Mechanically, Cynarin inhibited the assembly of NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome by Nrf2-dependent expression to attenuate microglial pyroptosis and neuroinflammation.

CONCLUSIONS

To sum up, the current study suggested that administration of Cynarin is a promising compound for anti-neuroinflammation and anti-pyroptosis after SCI. It may be an efficient Nrf2 activator and a NLRP3 inhibitor for microglia in neuropathies.

Heterophyllin B enhances transcription factor EB-mediated autophagy and alleviates pyroptosis and oxidative stress after spinal cord injury

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.

From apoptosis to pyroptosis: A two-decade analysis of spinal cord injury systematic review

BACKGROUND

Spinal cord injury has a significant impact on patients' physical and mental health, with cell death playing a key role in the pathology.

METHODS

The Web of Science Core Collection database was searched and screened according to inclusion criteria for publications between January 1, 2000 and December 31, 2023. Bibliometric analysis was conducted using bibliomatrix R-package, CiteSpace, and VOSviewer software.

RESULTS

A total of 2309 publications were identified, with a stable growth in the first 13 years and accelerated growth in the past decade, indicating an increasing trend in this field. These publications on cell death after spinal cord injury originated from 251 countries/regions. China contributed the most publications, with funding support primarily from China, and Wenzhou Medical University in China being the leading institution with the highest number of publications. Salvatore Cuzzocrea was the most influential author. The research direction in this field after 2000 mainly focused on topics such as apoptosis, autophagy, mesenchymal stem cells, mammalian target of rapamycin pathway, ferroptosis, functional recovery, neuronal regeneration, and NOD-like receptor protein 3.Current hot topics and future research trends revolve around extracellular vesicles including exosomes, extracellular vesicle-mediated mesenchymal stem cells, microRNA, autophagy, NOD-like receptor protein 3 inflammasome-mediated cell pyroptosis, and mechanisms of glial scar formation.

CONCLUSION

Publications in this field have grown rapidly in the past 2 decades and are expected to keep increasing. Current hot topics include mesenchymal stem cells, apoptosis, autophagy, and ferroptosis. Future research will focus on extracellular vesicle-mediated mesenchymal stem cells, autophagy, inflammasome-mediated cell pyroptosis, and glial scar formation.

Role of Pyroptosis in Endometrial Cancer and Its Therapeutic Regulation

Pyroptosis is an inflammatory cell death induced by inflammasomes that release several pro-inflammatory mediators such as interleukin-18 (IL-18) and interleukin-1β (IL-1β). Pyroptosis, a type of programmed cell death, has recently received increased interest both as a therapeutic and immunological mechanism. Numerous studies have provided substantial evidence supporting the involvement of inflammasomes and pyroptosis in a variety of pathological conditions including cancers, nerve damage, inflammatory diseases and metabolic conditions. Researchers have demonstrated that dysregulation of pyroptosis and inflammasomes contribute to the progression of endometriosis and gynecological malignancies. Current research also indicates that inflammasome and pyroptosis-dependent signaling pathways may further induce the progression of endometrial cancer (EC). More specifically, dysregulation of NLR family pyrin domain 3 (NLRP3) and caspase-1-dependent pyroptosis play a contributory role in the pathogenesis and development of EC. Therefore, pyroptosis-regulated protein gasdermin D (GSDMD) may be an independent prognostic biomarker for the detection of EC. This review presents the molecular mechanisms of pyroptosis-dependent signaling pathways and their contributory role and function in advancing EC. Moreover, this review offers new insights into potential future applications and innovative approaches in utilizing pyroptosis to develop effective anti-cancer therapies.

Jun-activated SOCS1 enhances ubiquitination and degradation of CCAAT/enhancer-binding protein β to ameliorate cerebral ischaemia/reperfusion injury

This study investigates the molecular mechanisms behind ischaemia/reperfusion (I/R) injury in the brain, focusing on neuronal apoptosis. It scrutinizes the role of the Jun proto-oncogene in apoptosis, involvement of SOCS1 in neural precursor cell accumulation in ischaemic regions, and the upregulation of C-EBPβ in the hippocampus following I/R. Key to the study is understanding how Jun controls C-EBPβ degradation via SOCS1, potentially offering new clinical treatment avenues for I/R. Techniques such as mRNA sequencing, KEGG enrichment analysis and protein-protein interaction (PPI) in mouse models have indicated involvement of Jun (AP-1) in I/R-induced cerebral damage. The study employs middle cerebral artery occlusion in different mouse models and oxygen-glucose deprivation/reoxygenation in cortical neurons to examine the impacts of Jun and SOCS1 manipulation on cerebral I/R injury and neuronal damage. The findings reveal that I/R reduces Jun expression in the brain, but its restoration lessens cerebral I/R injury and neuron death. Jun activates SOCS1 transcriptionally, leading to C-EBPβ degradation, thereby diminishing cerebral I/R injury through the SOCS1/C-EBPβ pathway. These insights provide a deeper understanding of post-I/R cerebral injury mechanisms and suggest new therapeutic targets for cerebral I/R injury. KEY POINTS: Jun and SOCS1 are poorly expressed, and C-EBPβ is highly expressed in ischaemia/reperfusion mouse brain tissues. Jun transcriptionally activates SOCS1. SOCS1 promotes the ubiquitination-dependent C-EBPβ protein degradation. Jun blunts oxygen-glucose deprivation/reoxygenation-induced neuron apoptosis and alleviates neuronal injury. This study provides a theoretical basis for the management of post-I/R brain injury.

Chitosan oligosaccharides alleviate macrophage pyroptosis and protect sepsis mice via activating the Nrf2/GPX4 pathway

In the process of sepsis, excessive occurrence of pyroptosis, a form of programmed cell death acting as a defense mechanism against pathogens, can disrupt immune responses, thus leading to tissue damage and organ dysfunction. Chitosan oligosaccharide (COS), derived from chitosan degradation, has demonstrated diverse beneficial effects. However, its impact on sepsis-induced pyroptosis remains unexplored. In the present study, ATP/LPS was utilized to induce canonical-pyroptosis in THP-1 cells, while bacterial outer membrane vesicles (OMV) were employed to trigger non-canonical pyroptosis in RAW264.7 cells. Our results revealed a dose-dependent effect of COS on both types of pyroptosis. This was evidenced by a reduction in the expression of pro-inflammatory cytokines, as well as crucial regulatory proteins involved in pyroptosis. In addition, COS inhibited the cleavage of caspase-1 and GSDMD, and reduced ASC oligomerization. The underlying mechanism revealed that COS acts an antioxidant, reducing the release of pyroptosis-induced ROS and malondialdehyde (MDA) by upregulation the expression and promoting the nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2), which led to an elevation of glutathione peroxidase 4 (GPX4) and superoxide dismutase (SOD). Notably, the actions of COS were completely reversed by the Nrf2 inhibitor. Consequently, COS intervention increased the survival rate of sepsis.

Epigenetic modifications of inflammation in spinal cord injury

Spinal cord injury (SCI) is a central nervous system injury that leads to neurological dysfunction or paralysis, which seriously affects patients' quality of life and causes a heavy social and economic burden. The pathological mechanism of SCI has not been fully revealed, resulting in unsatisfactory clinical treatment. Therefore, more research is urgently needed to reveal its precise pathological mechanism. Numerous studies have shown that inflammation is closely related to various pathological processes in SCI. Inflammatory response is an important pathological process leading to secondary injury, and sustained inflammatory response can exacerbate the injury and hinder the recovery of neurological function after injury. Epigenetic modification is considered to be an important regulatory mechanism in the pathological process of many diseases. Epigenetic modification mainly affects the function and characteristics of genes through the reversibility of mechanisms such as DNA methylation, histone modification, and regulation of non-coding RNA, thus having a significant impact on the pathological process of diseases and the survival state of the body. Recently, the role of epigenetic modification in the inflammatory response of SCI has gradually entered the field of view of researchers, and epigenetic modification may be a potential means to treat SCI. In this paper, we review the effects and mechanisms of different types of epigenetic modifications (including histone modifications, DNA methylation, and non-coding RNAs) on post-SCI inflammation and their potential therapeutic effects on inflammation to improve our understanding of the secondary SCI stage. This review aims to help identify new markers, signaling pathways and targeted drugs, and provide theoretical basis and new strategies for the diagnosis and treatment of SCI.

Overview of pyroptosis mechanism and in-depth analysis of cardiomyocyte pyroptosis mediated by NF-κB pathway in heart failure

The pyroptosis of cardiomyocytes has become an essential topic in heart failure research. The abnormal accumulation of these biological factors, including angiotensin II, advanced glycation end products, and various growth factors (such as connective tissue growth factor, vascular endothelial growth factor, transforming growth factor beta, among others), activates the nuclear factor-κB (NF-κB) signaling pathway in cardiovascular diseases, ultimately leading to pyroptosis of cardiomyocytes. Therefore, exploring the underlying molecular biological mechanisms is essential for developing novel drugs and therapeutic strategies. However, our current understanding of the precise regulatory mechanism of this complex signaling pathway in cardiomyocyte pyroptosis is still limited. Given this, this study reviews the milestone discoveries in the field of pyroptosis research since 1986, analyzes in detail the similarities, differences, and interactions between pyroptosis and other cell death modes (such as apoptosis, necroptosis, autophagy, and ferroptosis), and explores the deep connection between pyroptosis and heart failure. At the same time, it depicts in detail the complete pathway of the activation, transmission, and eventual cardiomyocyte pyroptosis of the NF-κB signaling pathway in the process of heart failure. In addition, the study also systematically summarizes various therapeutic approaches that can inhibit NF-κB to reduce cardiomyocyte pyroptosis, including drugs, natural compounds, small molecule inhibitors, gene editing, and other cutting-edge technologies, aiming to provide solid scientific support and new research perspectives for the prevention and treatment of heart failure.

Carbon monoxide-releasing molecule-3 exerts neuroprotection effects after cardiac arrest in mice: A randomized controlled study

Background

Post-cardiac arrest brain injury (PCABI) is the leading cause of death in survivors of cardiac arrest (CA). Carbon monoxide-releasing molecule (CORM-3) is a water-soluble exogenous carbon monoxide that has been shown to have neuroprotection benefits in several neurological disease models. However, the effects of CORM-3 on PCABI is still unclear.

Methods

A mice model combined asystole with hemorrhage was used. Mice were anesthetized and randomized into 4 groups (n = 12/group) and underwent either 9.5 min CA followed by cardiopulmonary resuscitation (CPR) or sham surgery. CORM-3 (30 mg/kg) or vehicle (normal saline) were administered at 1 h after return of spontaneous circulation or sham surgery. Survival, neurologic deficits, alterations in the permeability of the brain-blood barrier and cerebral blood flow, changes of oxidative stress level, level of neuroinflammation and neuronal degeneration, and the activation of Nrf2/HO-1 signaling pathway were measured.

Results

In CORM-3 treated mice that underwent CA/CPR, significantly improved survival (75.00% vs. 58.33%, P = 0.0146 (24 h) and 66.67% vs. 16.67%, P < 0.0001 (72 h)) and neurological function were observed at 24 h and 72 h after ROSC (P < 0.05 for each). Additionally, increased cerebral blood flow, expression of tight junctions, and reduced reactive oxygen species generation at 24 h after ROSC were observed (P < 0.05 for each). CORM-3 treated mice had less neuron death and alleviated neuroinflammation at 72 h after ROSC (P < 0.05 for each). Notably, the Nrf2/HO-1 signaling pathway was significantly activated in mice subjected to CA/CPR with CORM-3 treatment.

Conclusions

CORM-3 could improve survival and exert neuroprotection after CA/CPR in mice. CORM-3 may be a novel and promising pharmacological therapy for PCABI.

Non-coding RNAs as key regulators of Gasdermin-D mediated pyroptosis in cancer therapy

Pyroptosis is an inflammatory programed cell death process that plays a crucial role in cancer therapeutic, while Gasdermin-D is a critical effector protein for pyroptosis execution. This review discusses the intricate interactions between Gasdermin-D and some non-coding RNAs (lncRNA, miRNA, siRNA) and their potential application in the regulation of pyroptosis as an anticancer therapy. Correspondingly, these ncRNAs significantly implicate in Gasdermin-D expression and function regarding the pyroptosis pathway. Functioning as competing endogenous RNAs (ceRNAs), these ncRNAs might regulate Gasdermin-D at the molecular level, underlying fatal cell death caused by cancer and tumor propagation. Therefore, these interactions appeal to therapeutics, offering new avenues for cancer treatment. It address this research gap by discussing the possible roles of ncRNAs as mediators of gasdermin-D regulation. It suggest therapeutic strategies based on the current research findings to ensure the interchange between the ideal pyroptosis and cancer cell death.

The Role of Exosomes from Mesenchymal Stem Cells in Spinal Cord Injury: A Systematic Review

Spinal cord injury (SCI) is a serious nervous system disease that usually leads to the impairment of the motor, sensory, and autonomic nervous functions of the spinal cord, and it places a heavy burden on families and healthcare systems every year. Due to the complex pathophysiological mechanism of SCI and the poor ability of neurons to regenerate, the current treatment scheme has very limited effects on the recovery of spinal cord function. In addition, due to their unique advantages, exosomes can be used as carriers for cargo transport. In recent years, some studies have confirmed that treatment with mesenchymal stem cells (MSCs) can promote the recovery of SCI nerve function. The therapeutic effect of MSCs is mainly related to exosomes secreted by MSCs, and exosomes may have great potential in SCI therapy. In this review, we summarized the repair mechanism of mesenchymal stem cells-derived exosomes (MSCs-Exos) in SCI treatment and discussed the microRNAs related to SCI treatment based on MSCs-Exos and their mechanism of action, which is helpful to further understand the role of exosomes in SCI.

Exploring the relationship between pyroptosis and inflammatory bone loss: Evidence from a cigarette smoke-induced osteoporosis mouse model

Smoking is by far one of the greatest public health threats and is recognized as an important predisposing factor for osteoporosis. Exposure to cigarette smoke (CS) has been reported to be associated with inflammation-associated diseases through the induction of pyroptosis. Nevertheless, the correlation between pyroptosis and bone loss induced by CS remains uninvestigated. Here, a mouse model of mainstream smoke exposure-induced osteoporosis was established. μCT, biomechanical testing, and immunohistochemical staining of bone tissue were used to assess the deleterious effects of CS on bone metabolism. In vitro, the effects of cigarette smoke extracts (CSE) on mouse primary bone marrow-derived mesenchymal stem cells (BMSCs) were tested by cell viability assays, gene and protein expression assays, and alizarin red staining. The utilization of the pyroptosis inhibitor MCC950 served to confirm the critical role of BMSCs pyroptosis in CS-induced osteoporosis. Our results indicated that exposure to mainstream smoke led to a notable decrease in the quantity of osteoblasts and hindered the process of osteogenic differentiation in mice. Additionally, there was a significant increase in the expression of pyroptosis-related proteins in the bone marrow. The inhibitory effects of CSE on cell viability and osteogenic differentiation of BMSCs were found to be dose-dependent in vitro. However, the presence of the pyroptosis inhibitor MCC950 significantly improved the impaired osteogenic differentiation and bone mineralization caused by CSE. These results highlight the crucial involvement of BMSCs pyroptosis in the development of bone loss induced by CS. In summary, the findings of this study provide novel evidence that CS exerts a detrimental effect on the process of osteogenesis in BMSCs through the induction of pyroptosis, ultimately leading to bone loss. Inhibition of pyroptosis effectively attenuated the toxicological effects of CS on BMSCs, providing a new target for preventing inflammatory osteoporosis.

Lupenone improves motor dysfunction in spinal cord injury mice through inhibiting the inflammasome activation and pyroptosis in microglia via the nuclear factor kappa B pathway

JOURNAL/nrgr/04.03/01300535-202408000-00034/figure1/v/2023-12-16T180322Z/r/image-tiff Spinal cord injury-induced motor dysfunction is associated with neuroinflammation. Studies have shown that the triterpenoid lupenone, a natural product found in various plants, has a remarkable anti-inflammatory effect in the context of chronic inflammation. However, the effects of lupenone on acute inflammation induced by spinal cord injury remain unknown. In this study, we established an impact-induced mouse model of spinal cord injury, and then treated the injured mice with lupenone (8 mg/kg, twice a day) by intraperitoneal injection. We also treated BV2 cells with lipopolysaccharide and adenosine 5'-triphosphate to simulate the inflammatory response after spinal cord injury. Our results showed that lupenone reduced IκBα activation and p65 nuclear translocation, inhibited NLRP3 inflammasome function by modulating nuclear factor kappa B, and enhanced the conversion of proinflammatory M1 microglial cells into anti-inflammatory M2 microglial cells. Furthermore, lupenone decreased NLRP3 inflammasome activation, NLRP3-induced microglial cell polarization, and microglia pyroptosis by inhibiting the nuclear factor kappa B pathway. These findings suggest that lupenone protects against spinal cord injury by inhibiting inflammasomes.

The effects of hyaluronan and proteoglycan link protein 1 (HAPLN1) in ameliorating spinal cord injury mediated by Nrf2

Excessive inflammatory response and oxidative stress (OS) play an important role in the pathogenesis of spinal cord injury (SCI). Balance of inflammation and prevention of OS have been considered an effective strategy for the treatment of SCI. Hyaluronan and proteoglycan link protein 1 (HAPLN1), also known as cartilage link protein, has displayed a wide range of biological and physiological functions in different types of tissues and cells. However, whether HAPLN1 regulates inflammation and OS during SCI is unknown. Therefore, we aimed to examine whether HAPLN1 can have a protective effect on SCI. In this study, both in vitro and in vivo SCI models were established. Nissl staining and terminal deoxynucleotidyl transferase dUTP nick end labeling staining assays were used. Western blotting and enzyme-linked immunosorbent assay were employed to assess the expression of proteins. Our results demonstrate that the administration of HAPLN1 promoted the recovery of motor neurons after SCI by increasing the Basso mouse scale score, increasing the numbers of motor neurons, and preventing apoptosis of spinal cord cells. Additionally, HAPLN1 mitigated OS in spinal cord tissue after SCI by increasing the content of superoxide dismutase SOD and the activity of glutathione peroxidase but reducing the levels of malondialdehyde. Importantly, we found that HAPLN1 stimulated the activation of the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway and stimulated the expression of heme oxygenase-1 and nicotinamide adenine dinucleotide phosphate quinone oxidoreductase-1, which mediated the attenuation of HAPLN1 in activation of the NOD-like receptor protein 3 (NLRP3) inflammasome by reducing the levels of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), caspase-1, and interleukin-1β. Correspondingly, in vitro experiments show that the presence of HAPLN1 suppressed the NLRP3 inflammasome and prevented cell injury against H2O2 in PC12 cells. These effects were mediated by the Nrf2/ARE pathway, and inhibition of Nrf2 with ML385 abolished the beneficial effects of HAPLN1. Based on these findings, we conclude that HAPLN1 inhibits the NLRP3 inflammasome through the stimulation of the Nrf2/ARE pathway, thereby suppressing neuroinflammation, enhancing motor neuronal survival, and improving the recovery of nerve function after SCI.

Ginkgolide B effectively mitigates neuropathic pain by suppressing the activation of the NLRP3 inflammasome through the induction of mitophagy in rats

Neuropathic pain is a pathological state induced by the aberrant generation of pain signals within the nervous system. Ginkgolide B(GB), an active component found of Ginkgo. biloba leaves, has neuroprotective properties. This study aimed to explore the effects of GB on neuropathic pain and its underlying mechanisms. In the in vivo study, we adopted the rat chronic constriction injury model, and the results showed that GB(4 mg/kg) treatment effectively reduced pain sensation in rats and decreased the expressions of Iba-1 (a microglia marker), NLRP3 inflammasome, and inflammatory factors, such as interleukin (IL)-1β, in the spinal cord 7 days post-surgery. In the in vitro study, we induced microglial inflammation using lipopolysaccharide (500 ng/mL) / adenosine triphosphate (5 mM) and treated it with GB (10, 20, and 40 μM). GB upregulated the expression of mitophagy proteins, such as PINK1, Parkin, LC3 II/I, Tom20, and Beclin1, and decreased the cellular production of reactive oxygen species. Moreover, it lowered the expression of inflammation-related proteins, such as Caspase-1, IL-1β, and NLRP3 in microglia. However, this effect was reversed by Parkin shRNA/siRNA or the autophagy inhibitor 3-methyladenine (5 mM). These findings reveal that GB alleviates neuropathic pain by mitigating neuroinflammation through the activation of PINK1-Parkin-mediated mitophagy.

Platelet-rich plasma-derived exosomes promote blood-spinal cord barrier repair and attenuate neuroinflammation after spinal cord injury

Spinal cord injury (SCI) compromises the blood-spinal cord barrier (BSCB) and induces neuroinflammation, potentially exacerbating neuronal damage. This underscores the importance of maintaining BSCB integrity and mitigating neuroinflammation in SCI treatment. Our study explores an innovative approach to treating SCI by utilizing platelet-rich plasma-derived exosomes (PRP-Exos) to stabilize BSCB function and alleviate neuroinflammation. We successfully isolated exosomes from platelet-rich plasma and conducted both in vivo and in vitro experiments to assess the therapeutic effects of PRP-Exos and explore their potential mechanisms in stabilizing the BSCB, reducing neuroinflammation, and promoting neural functional recovery.In vitro results demonstrate that PRP-Exos significantly reduce the permeability of bEnd.3 cells under hypoxic-hypoglycemic conditions, thereby restoring the integrity of tight junctions. Additionally, our study elucidates the critical role of the NF-κB signaling pathway in the amelioration of neuroinflammation by PRP-Exos. In the SCI model, local injection of hydrogel-encapsulated PRP-Exos reduced Evans blue dye leakage, enhanced the expression of tight junction proteins, alleviated the inflammatory environment in the damaged area, and improved neural functional recovery. In conclusion, PRP-Exos presents a promising and effective treatment option for SCI.

Ginsenoside-Rh2 Promotes Functional Recovery after Spinal Cord Injury by Enhancing TFEB-Mediated Autophagy

Background: Following spinal cord injury (SCI), autophagy plays a positive role in neuronal protection, whereas pyroptosis triggers an inflammatory response. Ginsenoside-Rh2 (GRh2), known for its neuroprotective effects, is considered a promising drug. However, the exact molecular mechanisms underlying these protective effects remain unclear. Aim of the Study: Explore the therapeutic value of GRh2 in SCI and its potential mechanisms of action. Materials and Methods: An SCI mouse model was established, followed by random grouping and drug treatments under different conditions. Subsequently, the functional recovery of SCI mice after GRh2 treatment was assessed using hematoxylin and eosin, Masson's trichrome, and Nissl staining, footprint analysis, Basso Mouse Scale scoring, and inclined plane tests. The expression levels of relevant indicators in the mice were detected using Western blotting, immunofluorescence, and a quantitative polymerase chain reaction. Network pharmacology analysis was used to identify the relevant signaling pathways through which GRh2 exerts its therapeutic effects. Results: GRh2 promoted functional recovery after SCI. GRh2 significantly inhibits pyroptosis by enhancing autophagy in SCI mice. Simultaneously, the neuroprotective effect of GRh2, achieved through the inhibition of pyroptosis, is partially reversed by 3-methyladenine, an autophagy inhibitor. Additionally, the increase in autophagy induced by GRh2 is mediated by the promotion of transcription factor EB (TFEB) nuclear translocation and dephosphorylation. Partial attenuation of the protective effects of GRh2 was observed after TFEB knockdown. Additionally, GRh2 can modulate the activity of TFEB in mice post-SCI through the EGFR-MAPK signaling pathway, and NSC228155 (an EGFR activator) can partially reverse the effect of GRh2 on the EGFR-MAPK signaling pathway. Conclusions: GRh2 improves functional recovery after SCI by upregulating TFEB-mediated autophagic flux and inhibiting pyroptosis, indicating its potential clinical applicability.

Picein alleviates oxidative stress and promotes bone regeneration in osteoporotic bone defect by inhibiting ferroptosis via Nrf2/HO-1/GPX4 pathway

Osteoporosis (OP) can result in slower bone regeneration than the normal condition due to abnormal oxidative stress and high levels of reactive oxygen species (ROS), a condition detrimental for bone formation, making the OP-related bone healing a significant clinical challenge. As the osteogenic differentiation ability of bone marrow mesenchymal stem cells (BMSCs) is closely related to bone regeneration; currently, this study assessed the effects of Picein on BMSCs in vitro and bone regeneration in osteoporotic bone defect in vivo. Cell viability was determined by CCK-8 assay. The production of (ROS), malonaldehyde, superoxide dismutase activities, and glutathione was evaluated by using commercially available kits, and a flow cytometry analysis was adopted to detect macrophage polarization. Osteogenic capacity of BMSCs was evaluated by alkaline phosphatase (ALP) activity, ALP staining, and Alizarin red S staining. The expression of osteogenic-related proteins (OPN, Runx-2, OCN) and osteogenic-related genes (ALP, BMP-4, COL-1, and Osterix) were evaluated by Western blotting and real-time PCR (RT-PCR). In addition, proliferation, migration ability, and angiogenic capacity of human umbilical vein endothelial cells (HUVECs) were evaluated by EdU staining, scratch test, transwell assay, and tube formation assay, respectively. Angiogenic-related genes (VEGF, vWF, CD31) were also evaluated by RT-PCR. Results showed that Picein alleviated erastin-induced oxidative stress, enhanced osteogenic differentiation capacity of BMSCs, angiogenesis of HUVECs, and protects cells against ferroptosis through Nrf2/HO-1/GPX4 axis. Moreover, Picein regulate immune microenvironment by promoting the polarization of M2 macrophages in vitro. In addition, Picein also reduce the inflammation levels and promotes bone regeneration in osteoporotic bone defect in OP rat models in vivo. Altogether, these results suggested that Picein can promote bone regeneration and alleviate oxidative stress via Nrf2/HO-1/GPX4 pathway, offering Picein as a novel antioxidant agent for treating osteoporotic bone defect.

Exogenous NADPH could mitigate pyroptosis-induced brain injury in fetal mice exposed to gestational intermittent hypoxia

OBJECTIVE

Obstructive Sleep Apnea (OSA) during pregnancy is characterized by intermittent hypoxia (IH) during sleep and will lead to the rise of oxidative stress in the fetal body. Pyroptosis, a type of inflammatory and programmable cell death mediated by Gasdermin D (GSDMD), plays a substantial role in oxygen deprivation's contribution to neural system damage. Existing research shows that Nicotinamide Adenine Dinucleotide Phosphate (NADPH) plays a protective role in alleviating brain tissue pyroptosis. We speculate that exogenous NADPH may play a protective role in OSA during pregnancy.

METHODS

A model of GIH group was established to simulate the pathophysiological mechanisms of OSA during pregnant and AIR group was established by giving the same frequency. Sham group was established by injecting NS and the NADPH group was established and given exogenous NADPH. We utilized the Morris Water Maze to assess cognitive function impairment, Luxol Fast Blue (LBF) staining to confirm myelin sheath formation, TUNEL staining to examine cell death in fetal mice brain tissue, and Western blotting to detect pertinent protein expressions.

RESULTS

The GIH group offspring exhibited decreases in spatial learning and memory abilities, reduced numbers of oligodendrocytes and formed myelin, as well as increased expression of pyroptosis-related proteins. The NADPH group offspring showed restoration in spatial learning and memory abilities increased counts of oligodendrocytes and formed myelin sheaths, in addition to decreased expression of pyroptosis-related.

CONCLUSIONS

This study demonstrates that early injection of exogenous NADPH can alleviate the damage to fetal brain development caused by gestational intermittent hypoxia (GIH).

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.

New strategy to treat spinal cord injury: Nafamostat mesilate suppressed NLRP3-mediated pyroptosis during acute phase

Spinal cord injury (SCI) is a devastating condition for which effective clinical treatment is currently lacking. During the acute phase of SCI, myriad pathological changes give rise to subsequent secondary injury. The results of our previous studies indicated that treating rats post-SCI with nafamostat mesilate (NM) protected the blood-spinal cord barrier (BSCB) and exerted an antiapoptotic effect. However, the optimal dosage for mice with SCI and the underlying mechanisms potentially contributing to recovery, especially during the acute phase of SCI, have not been determined. In this study, we first determined the optimal dosage of NM for mice post-SCI (5 mg/kg/day). Subsequently, our RNA-seq findings revealed that NM has the potential to inhibit pyroptosis after SCI. These findings were further substantiated by subsequent Western blot (WB) and Immunofluorescence (IF) analyses in vivo. These results indicate that NM can alleviate NLRP3 (NOD-like receptor thermal protein domain associated protein 3)-mediated pyroptosis by modulating the NF-κB signaling pathway and reducing the protein expression levels of NIMA-related kinase 7 (NEK7) and cathepsin B (CTSB). In vitro experimental results supported our in vivo findings, revealing the effectiveness of NM in suppressing pyroptosis induced by adenosine triphosphate (ATP) and lipopolysaccharide (LPS) in BV2 cells. These results underscore the potential of NM to regulate NLRP3-mediated pyroptosis following SCI. Notably, compared with other synthetic compounds, NM exhibits greater versatility, suggesting that it is a promising clinical treatment option for SCI.

Neurological recovery and neurogenesis by curcumin sustained-release system cross-linked with an acellular spinal cord scaffold in rat spinal cord injury: Targeting NLRP3 inflammasome pathway

In the context of treating spinal cord injury (SCI), the modulation of inflammatory responses, and the creation of a suitable region for tissue regeneration may present a promising approach. This study aimed to evaluate the effects of curcumin (Cur)-loaded bovine serum albumin nanoparticles (Cur-BSA NPs) cross-linked with an acellular spinal cord scaffold (ASCS) on the functional recovery in a rat model of SCI. We developed an ASCS using chemical and physical methods. Cur-BSA, and blank (B-BSA) NPs were fabricated and cross-linked with ASCS via EDC-NHS, resulting in the production of Cur-ASCS and B-ASCS. We assessed the properties of scaffolds and NPs as well as their cross-links. Finally, using a male rat hemisection model of SCI, we investigated the consequences of the resulting scaffolds. The inflammatory markers, neuroregeneration, and functional recovery were evaluated. Our results showed that Cur was efficiently entrapped at the rate of 42% ± 1.3 in the NPs. Compared to B-ASCS, Cur-ASCS showed greater effectiveness in the promotion of motor recovery. The implantation of both scaffolds could increase the migration of neural stem cells (Nestin- and GFAP-positive cells) following SCI with the superiority of Cur-ASCS. Cur-ASCS was successful to regulate the gene expression and protein levels of NLRP3, ASC, and Casp1in the spinal cord lesion. Our results indicate that using ASCS can lead to the entrance of cells into the scaffold and promote neurogenesis. However, Cur-ASCS had greater effects in terms of inflammation relief and enhanced neurogenesis.

Neuroprotective effects of chaperone-mediated autophagy in neurodegenerative diseases

ABSTRACT

Chaperone-mediated autophagy is one of three types of autophagy and is characterized by the selective degradation of proteins. Chaperone-mediated autophagy contributes to energy balance and helps maintain cellular homeostasis, while providing nutrients and support for cell survival. Chaperone-mediated autophagy activity can be detected in almost all cells, including neurons. Owing to the extreme sensitivity of neurons to their environmental changes, maintaining neuronal homeostasis is critical for neuronal growth and survival. Chaperone-mediated autophagy dysfunction is closely related to central nervous system diseases. It has been shown that neuronal damage and cell death are accompanied by chaperone-mediated autophagy dysfunction. Under certain conditions, regulation of chaperone-mediated autophagy activity attenuates neurotoxicity. In this paper, we review the changes in chaperone-mediated autophagy in neurodegenerative diseases, brain injury, glioma, and autoimmune diseases. We also summarize the most recent research progress on chaperone-mediated autophagy regulation and discuss the potential of chaperone-mediated autophagy as a therapeutic target for central nervous system diseases.

Elevated microRNA-214-3p level ameliorates neuroinflammation after spinal cord ischemia-reperfusion injury by inhibiting Nmb/Cav3.2 pathway

BACKGROUND

Neuromedin B (Nmb) plays a pivotal role in the transmission of neuroinflammation, particularly during spinal cord ischemia-reperfusion injury (SCII). However, the detailed molecular mechanisms underlying this process remain elusive.

METHODS

The SCII model was established by clamping the abdominal aorta of male Sprague-Dawley (SD) rats for 60 min. The protein expression levels of Nmb, Cav3.2, and IL-1β were detected by Western blotting, while miR-214-3p expression was quantified by qRT-PCR. The targeted regulation between miR-214-3p and Nmb was investigated using a dual-luciferase reporter gene assay. The cellular localization of Nmb and Cav3.2 with cell-specific markers was visualized by immunofluorescence staining. The specific roles of miR-214-3p on the Nmb/Cav3.2 interactions in SCII-injured rats were explored by intrathecal injection of Cav3.2-siRNA, PD168368 (a specific NmbR inhibitor) and synthetic miR-214-3p agomir and antagomir in separate experiments. Additionally, hind-limb motor function was evaluated using the modified Tarlov scores.

RESULTS

Compared to the Sham group, the protein expression levels of Nmb, Cav3.2, and the proinflammatory factor Interleukin(IL)-1β were significantly elevated at 24 h post-SCII. Intrathecal injection of PD168368 and Cav3.2-siRNA significantly suppressed the expression of Cav3.2 and IL-1β compared to the SCII group. The miRDB database and dual-luciferase reporter gene assay identified Nmb as a direct target of miR-214-3p. As expected, in vivo overexpression of miR-214-3p by agomir-214-3p pretreatment significantly inhibited the increases in Nmb, Cav3.2 and IL-1β expression and improved lower limb motor function in SCII-injured rats, while antagomiR-214-3p pretreatment reversed these effects.

CONCLUSIONS

Nmb protein levels positively correlated with Cav3.2 expression in SCII rats. Upregulating miR-214-3p ameliorated hind-limb motor function and protected against neuroinflammation via inhibiting the aberrant Nmb/Cav3.2 interactions and downstream IL-1β release. These findings provide novel therapeutic targets for clinical prevention and treatment of SCII.

Conditioned medium from human dental pulp stem cells treats spinal cord injury by inhibiting microglial pyroptosis

Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury. However, whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear. In the present study, we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells. We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury, decreased expression of the microglial pyroptosis markers NLRP3, GSDMD, caspase-1, and interleukin-1β, promoted axonal and myelin regeneration, and inhibited the formation of glial scars. In addition, in a lipopolysaccharide-induced BV2 microglia model, conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1β pathway. These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1β pathway, thereby promoting the recovery of neurological function after spinal cord injury. Therefore, conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.

Galectin-3 Plays a Role in Neuroinflammation in the Visual Pathway in Experimental Optic Neuritis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) featuring numerous neuropathologies, including optic neuritis (ON) in some patients. However, the molecular mechanisms of ON remain unknown. Galectins, β-galactoside-binding lectins, are involved in various pathophysiological processes. We previously showed that galectin-3 (gal-3) is associated with the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. In the current study, we investigated the expression of gal-3 in the visual pathway in EAE mice to clarify its role in the pathogenesis of ON. Immunohistochemical analysis revealed upregulation of gal-3 in the visual pathway of the EAE mice during the peak stage of the disease, compared with naïve and EAE mice during the chronic stage. Gal-3 was detected mainly in microglia/macrophages and astrocytes in the visual pathway in EAE mice. In addition, gal-3+/Iba-1+ cells, identified as phagocytic by immunostaining for cathepsin D, accumulated in demyelinating lesions in the visual pathway during the peak disease stage of EAE. Moreover, NLRP3 expression was detected in most gal-3+/Iba-1+ cells. These results strongly suggest that gal-3 regulates NLRP3 signaling in microglia/macrophages and neuroinflammatory demyelination in ON. In astrocytes, gal-3 was expressed from the peak to the chronic disease stages. Taken together, our findings suggest a critical role of gal-3 in the pathogenesis of ON. Thus, gal-3 in glial cells may serve as a potential therapeutic target for ON.

Non-stem cell-derived exosomes: a novel therapeutics for neurotrauma

Neurotrauma, encompassing traumatic brain injuries (TBI) and spinal cord injuries (SCI) impacts a significant portion of the global population. While spontaneous recovery post-TBI or SCI is possible, recent advancements in cell-based therapies aim to bolster these natural reparative mechanisms. Emerging research indicates that the beneficial outcomes of such therapies might be largely mediated by exosomes secreted from the administered cells. While stem cells have garnered much attention, exosomes derived from non-stem cells, including neurons, Schwann cells, microglia, and vascular endothelial cells, have shown notable therapeutic potential. These exosomes contribute to angiogenesis, neurogenesis, and axon remodeling, and display anti-inflammatory properties, marking them as promising agents for neurorestorative treatments. This review provides an in-depth exploration of the current methodologies, challenges, and future directions regarding the therapeutic role of non-stem cell-derived exosomes in neurotrauma.

BMSCs-derived exosomes inhibit macrophage/microglia pyroptosis by increasing autophagy through the miR-21a-5p/PELI1 axis in spinal cord injury

Spinal cord injury (SCI) results in a diverse range of disabilities and lacks effective treatment options. In recent years, exosomes derived from bone mesenchymal stem cells (BMSCs) have emerged as a promising cell-free therapeutic approach for treating ischemic brain injury and other inflammatory conditions. Macrophage/microglial pyroptosis has been identified as a contributing factor to neuroinflammation following SCI. The therapeutic potential of BMSC-derived exosomes in macrophage/microglia pyroptosis-induced neuroinflammation, however, has to be determined. Our findings demonstrate that exosomes derived from BMSCs can enhance motor function recovery and mitigate neuroinflammation subsequent to SCI by upregulating the expression of autophagy-related proteins and inhibiting the activation of NLRP3 inflammasomes in macrophage/microglia. Moreover, miR-21a-5p is markedly increased in BMSCs-derived exosomes, and knocking down miR-21a-5p in BMSCs-derived exosomes eliminates the beneficial effects of administration; upregulation of miR-21a-5p in BMSCs-derived exosomes enhances the beneficial effects of administration. Mechanistically, miR-21a-5p positively regulates the autophagy of macrophage/microglia by reducing PELI1 expression, which in turn inhibits their pyroptosis. This research provides novel evidence that exosomes derived from BMSCs can effectively suppress macrophage/microglia pyroptosis through the miR-21a-5p/PELI1 axis-mediated autophagy pathway, ultimately facilitating functional restoration following SCI. In particular, our constructed miR-21a-5p overexpression exosomes greatly improved the efficacy of BMSCs-derived exosomes in treating spinal cord injury. These results establish a foundation for the prospective utilization of exosomes derived from BMSCs as a novel biological intervention for spinal cord injury.

The Role of Pyroptosis and Autophagy in the Nervous System

Autophagy is a conservative self-degradation system, which includes the two major processes of enveloping abnormal proteins, organelles and other macromolecules, and transferring them into lysosomes for the subsequent degradation. It holds the stability of the intracellular environment under stress. So far, three types of autophagy have been found: microautophagy, chaperone-mediated autophagy and macroautophagy. Many diseases have the pathological process of autophagy dysfunction, such as nervous system diseases. Pyroptosis is one kind of programmed cell death mediated by gasdermin (GSDM). In this process of pyroptosis, the activated caspase-3, caspase-4/5/11, or caspase-1 cleaves GSDM into the N-terminal pore-forming domain (PFD). The oligomer of PFD combines with the cell membrane to form membrane holes, thus leading to pyroptosis. Pyroptosis plays a key role in multiple tissues and organs. Many studies have revealed that autophagy and pyroptosis participate in the nervous system, but the mechanisms need to be fully clarified. Here, we focused on the recent articles on the role and mechanism of pyroptosis and autophagy in the pathological processes of the nervous system.

Ezrin inhibition alleviates oxidative stress and pyroptosis via regulating TRPML1-calcineurin axis mediated enhancement of autophagy in spinal cord injury

Spinal cord injury (SCI) presents profound ramifications for patients, leading to diminished motor and sensory capabilities distal to the lesion site. Once SCI occurs, it not only causes great physical and psychological problems for patients but also imposes a heavy economic burden. Ezrin is involved in various cellular processes, including signal transduction, cell death, inflammation, chemotherapy resistance and the stress response. However, whether Ezrin regulates functional repair after SCI and its underlying mechanism has not been elucidated. Here, our results showed that there is a marked augmentation of Ezrin levels within neurons and Ezrin inhibition markedly diminished glial scarring and bolstered functional recuperation after SCI. RNA sequencing indicated the potential involvement of pyroptosis, oxidative stress and autophagy in the enhancement of functional recovery upon reduced Ezrin expression. Moreover, the inhibition of Ezrin expression curtailed pyroptosis and oxidative stress by amplifying autophagy. Our studies further demonstrated that Ezrin inhibition promoted autophagy by increasing TFEB activity via the Akt-TRPML1-calcineurin pathway. Finally, we concluded that inhibiting Ezrin expression alleviates pyroptosis and oxidative stress by enhancing TFEB-driven autophagy, thereby promoting functional recovery after SCI, which may be a promising therapeutic target for SCI treatment.