USP11 regulates autophagy-dependent ferroptosis after spinal cord ischemia-reperfusion injury by deubiquitinating Beclin 1

Pyroptosis, ferroptosis, and autophagy in spinal cord injury: regulatory mechanisms and therapeutic targets

Regulated cell death is a form of cell death that is actively controlled by biomolecules. Several studies have shown that regulated cell death plays a key role after spinal cord injury. Pyroptosis and ferroptosis are newly discovered types of regulated cell deaths that have been shown to exacerbate inflammation and lead to cell death in damaged spinal cords. Autophagy, a complex form of cell death that is interconnected with various regulated cell death mechanisms, has garnered significant attention in the study of spinal cord injury. This injury triggers not only cell death but also cellular survival responses. Multiple signaling pathways play pivotal roles in influencing the processes of both deterioration and repair in spinal cord injury by regulating pyroptosis, ferroptosis, and autophagy. Therefore, this review aims to comprehensively examine the mechanisms underlying regulated cell deaths, the signaling pathways that modulate these mechanisms, and the potential therapeutic targets for spinal cord injury. Our analysis suggests that targeting the common regulatory signaling pathways of different regulated cell deaths could be a promising strategy to promote cell survival and enhance the repair of spinal cord injury. Moreover, a holistic approach that incorporates multiple regulated cell deaths and their regulatory pathways presents a promising multi-target therapeutic strategy for the management of spinal cord injury.

Natural products and ferroptosis: A novel approach for heart failure management

BACKGROUND

The discovery of ferroptosis has brought a revolutionary breakthrough in heart failure treatment, and natural products, as a significant source of drug discovery, are gradually demonstrating their extraordinary potential in regulating ferroptosis and alleviating heart failure symptoms. In addition to chemically synthesized small molecule compounds, natural products have attracted attention as an important source for discovering compounds that target ferroptosis in treating heart failure.

PURPOSE

Systematically summarize and analyze the research progress on improving heart failure through natural products' modulation of the ferroptosis pathway.

METHODS

By comprehensively searching authoritative databases like PubMed, Web of Science, and China National Knowledge Infrastructure with keywords such as "heart failure", "cardiovascular disease", "heart disease", "ferroptosis", "natural products", "active compounds", "traditional Chinese medicine formulas", "traditional Chinese medicine", and "acupuncture", we aim to systematically review the mechanism of ferroptosis and its link with heart failure. We also want to explore natural small-molecule compounds, traditional Chinese medicine formulas, and acupuncture therapies that can inhibit ferroptosis to improve heart failure.

RESULTS

In this review, we not only trace the evolution of the concept of ferroptosis and clearly distinguish it from other forms of cell death but also establish a comprehensive theoretical framework encompassing core mechanisms such as iron overload and system xc-/GSH/GPX4 imbalance, along with multiple auxiliary pathways. On this basis, we innovatively link ferroptosis with various types of heart failure, covering classic heart failure types and extending our research to pre-heart failure conditions such as arrhythmia and aortic aneurysm, providing new insights for early intervention in heart failure. Importantly, this article systematically integrates multiple strategies of natural products for interfering with ferroptosis, ranging from monomeric compounds and bioactive components to crude extracts and further to traditional Chinese medicine formulae. In addition, non-pharmacological means such as acupuncture are also included.

CONCLUSION

This study fills the gap in the systematic description of the relationship between ferroptosis and heart failure and the therapeutic strategies of natural products, aiming to provide patients with more diverse treatment options and promote the development of the heart failure treatment field.

Gallic acid protect against spinal cord ischemia-reperfusion injury in rat via activation of Nrf2/HO-1 signaling

Object

This study explores Gallic acid's (GA) neuroprotective effects against spinal cord ischemia-reperfusion injury (SCII) and its underlying mechanisms.

Methods

Spinal cord ischemia/reperfusion injury was induced in rats using the modified Zivin's method of clamping the abdominal aorta. The Basso-Beattie-Bresnahan scores, the inclined plane test, hematoxylin and eosin (HE) staining, and Nissl staining were used to measure locomotor activity and histological changes in the injured spinal cords. Proinflammatory factors (TNF-α and IL-1β) were examined using an ELISA kit. Moreover, In vitro oxidative stress model was induced by tBHP used to assess the cell survival rate, reactive oxygen species (ROS) levels, Malondialdehyde (MDA) levels. RT-qPCR and Western blot was used to detect the expression levels of mRNA and proteins.

Results

In vitro, GA inhibited tBHP-induced apoptosis in PC-12 cells, reduced ROS and MDA production, and abolished the expression of pro-apoptotic factors while enhancing the Nrf2/HO-1 signaling pathway. In vivo, GA treatment improved the behavioral and structural aspects of SCII in rats, inhibiting the production of proinflammatory factors, also reduced oxidative stress, and prevented neuronal apoptosis by enhancing the Nrf2/HO-1 signaling pathway.

Conclusions

GA exhibits neuroprotective effects against SCII, involving antioxidant, anti-inflammatory, and anti-apoptotic activities through Nrf2/HO-1 signaling pathway.

Enhanced inhibition of neuronal ferroptosis and regulation of microglial polarization with multifunctional traditional Chinese medicine active ingredients-based selenium nanoparticles for treating spinal cord injury

Spinal cord injury (SCI) is a devastating condition that results in the loss of sensory and motor functions. The complex pathogenesis of SCI contributes to the limited availability of effective therapies. Two major factors exacerbating secondary injury in SCI are neuronal ferroptosis and microglial inflammatory polarization. Tanshinone IIA (TSIIA) has demonstrated a significant anti-ferroptosis effect by inhibiting lipid peroxidation, while tetramethylpyrazine (TMP) exhibits remarkable anti-inflammatory properties by promoting the shift of microglial polarization from the M1 to the M2 phenotype. However, most drugs currently under development primarily target a single aspect of this multifaceted condition, which is insufficient for comprehensive treatment. Selenium nanoparticles have emerged as a promising therapeutic strategy due to their ability to encapsulate various agents, effectively targeting diverse pathophysiological mechanisms while offering favorable water solubility and low toxicity. In this study, we developed a novel nanocarrier functionalized with astragalus polysaccharide (APS) and loaded with TSIIA and TMP. Results from both in vitro and in vivo studies indicate that TSIIA/TMP/APS@Se NPs possess anti-ferroptosis properties and can regulate microglial polarization, potentially enhancing functional recovery following SCI. In summary, this study presents a promising alternative strategy for treating SCI, highlighting its significant potential for future clinical applications.

Small Extracellular Vesicles Orchestrate Cisplatin-Induced Ototoxicity: Potential Biomarker and Targets Discovery

Cisplatin-induced ototoxicity remains a clinical dilemma with limited mechanistic understanding and no food and drug administration (FDA)-approved therapies. Despite emerging roles of small extracellular vesicles (sEV) in drug ototoxicity, their molecular cargo profiles and causal roles to cisplatin-induced ototoxicity are unexplored. This study systematically investigates sEV derived from cochlear explants treated with cisplatin (Cis-sEV) and controls (Ctrl-sEV) using multi-omics profiling. Through small RNA sequencing, 83 differentially expressed microRNAs (miRNAs) are identified in Cis-sEV compared to Ctrl-sEV. Notably, mmu-miR-34a-5p, mmu-miR-140-5p, mmu-miR-15b-5p, mmu-miR-25-3p, and mmu-miR-339-5p are significantly upregulation in Cis-sEVs. Predicted target pathways of these differentially expressed miRNAs are enriched in apoptosis, inflammation, and cellular damage, indicating their potential involvement in cisplatin-induced cochlear damage. LC-MS/MS analysis reveals 90 upregulated and 150 downregulated proteins in Cis-sEV, with many involved in damage response. Specifically, CLTC, CCT2, ANXA6, and HSPA8 are uniquely upregulated proteins in Cis-sEV, and CLTC and ANXA6 are exclusively co-localized in hair cells (HCs) post-cisplatin exposure, suggesting that Cis-sEV originate primarily from damaged HCs. Moreover, CLTC in sEV may serve as a potential biomarker for cisplatin-induced ototoxicity as verified in both in vitro and in vivo models. This study provides novel insights into the molecular mechanisms of cisplatin-induced ototoxicity and identifies potential biomarker and therapeutic targets.

Tetrandrine Improves Severe Acute Pancreatitis by Inhibiting NCOA4 Glycosylation-Mediated Binding to FTH1 and Inducing Autophagy-Dependent Ferroptosis

Severe acute pancreatitis (SAP) is an acute abdominal disease with extremely high mortality; autophagy-dependent ferroptosis plays a crucial role in acute pancreatitis. However, the specific underlying mechanism remains unclear. To investigate the role of nuclear receptor coactivator 4 (NCOA4) in SAP and the mechanism by which tetrandrine influences it. Experimental SAP models were established using L-arginine (L-Arg) induction to observe changes in NCOA4 expression. Knockout and overexpression experiments of NCOA4 were conducted to assess the impact on SAP. Additionally, in vitro cell experiments were performed to verify these findings. Furthermore, the impact of N-glycosylation of NCOA4 on its function, particularly its binding ability with ferritin heavy chain 1 (FTH1), was studied. Finally, the effects of tetrandrine on N-glycosylation of NCOA4, the binding between NCOA4 and FTH1, and the progression of SAP were analyzed. NCOA4 expression was significantly upregulated in SAP. Knockout of NCOA4 improved the phenotype of SAP, whereas its overexpression exacerbated SAP. This was also confirmed in vitro. N-glycosylation of NCOA4 is crucial for its binding with FTH1, which in turn affects ferroptosis. Tetrandrine targets the N-glycosylation of NCOA4, weakening the interaction between NCOA4 and FTH1, thereby inhibiting the progression of SAP. This study demonstrates that tetrandrine targets the N-glycosylation of NCOA4, inhibiting autophagy-dependent ferroptosis mediated by its binding to FTH1 and thus ameliorates SAP. This finding provides us with a novel therapeutic approach for SAP and offers a new perspective on understanding the mechanism of action of tetrandrine in SAP.

GLUT1 maintains esophageal cancer stem cell-like characteristics by inhibiting autophagy-dependent ferroptosis via EGFR

Esophageal cancer, a highly malignant tumor with poor prognosis, is characterized by the presence of cancer stem cells (CSCs) that drive tumor initiation, metastasis, and recurrence. This study investigates the molecular mechanism by which glucose transporter 1 (GLUT1) maintains esophageal CSC-like properties through regulation of autophagy-dependent ferroptosis via epidermal growth factor receptor (EGFR). Using shRNA to knock down GLUT1 or EGFR and constructing a GLUT1 overexpression vector in KYSE520 cells, we employed western blotting, qRT-PCR, flow cytometry, sphere formation, Transwell assays, and xenograft models to assess stemness markers (NANOG, OCT4, SOX2), autophagic flux (LC3B, P62, Beclin1), and ferroptosis-related parameters (ROS, Fe2+, GSH, GPX4, COX2). Mechanistic analyses included co-immunoprecipitation to validate the GLUT1-EGFR interaction, chloroquine to inhibit autophagy, and cycloheximide/MG132 to evaluate EGFR protein stability. Results showed that GLUT1 depletion reduced CSC marker expression, increased ROS and Fe2+ levels, depleted GSH, and induced lipid peroxidation, sensitizing cells to ferroptosis while activating autophagy (elevated LC3 II/I, Beclin1; reduced P62); autophagy inhibition exacerbated cell death, indicating a protective role for autophagy in this context. GLUT1 directly bound to EGFR, stabilizing the receptor by blocking ubiquitin-proteasome-mediated degradation, whereas EGFR knockdown enhanced autophagic flux and reversed GLUT1-overexpression-induced ferroptosis resistance and stemness maintenance. In vivo, GLUT1 knockdown suppressed tumor growth and lung metastasis, and clinical samples revealed a positive correlation between GLUT1 and EGFR expression, linked to advanced TNM stages and poor survival. Collectively, these findings demonstrate that GLUT1 preserves esophageal CSC-like characteristics by stabilizing EGFR to inhibit autophagy-dependent ferroptosis, highlighting targeting GLUT1 as a potential therapeutic strategy to eliminate CSCs and combat esophageal cancer progression.

Mechanism of ferroptosis in heart failure: The role of the RAGE/TLR4-JNK1/2 pathway in cardiomyocyte ferroptosis and intervention strategies

The ferroptosis of cardiomyocytes has been recognized as the core pathological mechanism of heart failure. During the evolution of cardiovascular diseases, the accumulation of angiotensin II and advanced glycation end products can lead to the excessive activation of the RAGE/TLR4-JNK1/2 pathway, which subsequently triggers ferritinophagy, clockophagy, and enhanced p53 activity, ultimately leading to cardiomyocyte ferroptosis. It is evident that deeply unraveling the specific mechanisms in this field and comprehensively evaluating potential drugs and therapeutic strategies targeting this pathway is crucial for improving the status of cardiomyocyte ferroptosis. However, our current understanding of this pathway's specific molecular biological mechanisms in the process of cardiomyocyte ferroptosis remains limited. In light of this, this paper first comprehensively reviews the historical context of ferroptosis research, compares the similarities and differences between ferroptosis and other standard modes of cell death, elucidates the core mechanisms of ferroptosis and its close connection with heart failure, aiming to establish a basic cognitive framework for readers on ferroptosis and its role in heart failure. Subsequently, the paper delves into the pivotal role of the RAGE/TLR4-JNK1/2 pathway in cardiomyocyte ferroptosis and its intricate molecular biological regulatory network. Furthermore, it systematically integrates various therapeutic approaches aimed at inhibiting RAGE, TLR4, and JNK1/2 activity to alleviate cardiomyocyte ferroptosis, encompassing RNA interference technology, gene knockout techniques, small molecule inhibitors, natural active ingredients, as well as traditional Chinese and Western medicines, with the ultimate goal of forging new avenues and strategies for the prevention and treatment of heart failure.

OTUD4 inhibits ferroptosis by stabilizing GPX4 and suppressing autophagic degradation to promote tumor progression

Ferroptosis, a regulated cell demise predicated on iron metabolism and lipid peroxidation, has increasingly become a focal point in oncological therapies. Nonetheless, its governance, particularly the role of deubiquitination, is not fully delineated. This investigation concentrates on the deubiquitinase OTUD4, scrutinizing its functional and molecular implications in ferroptosis within tumor cells. By engineering OTUD4 knockout cell lines via CRISPR-Cas9, we observed that these cells exhibit heightened sensitivity to ferroptosis inducers, augmenting ferroptotic cell death and robustly diminishing tumor growth both in vitro and in vivo. Mechanistically, OTUD4 not only sustains protein stability by directly deubiquitinating GPX4 but also impedes its degradation via RHEB-mediated autophagy, collectively stalling the ferroptosis pathway. In vivo assays substantiate that OTUD4 deletion, when combined with regorafenib, drastically reduces tumor proliferation, showcasing potent synergistic antitumor activity. This study pioneers the revelation of OTUD4's bifunctional role in modulating ferroptosis through deubiquitination and autophagy, underscoring its potential as a therapeutic target in oncology.

Identification of disulfidptosis-related genes and subgroups in spinal cord injury

STUDY DESIGN

Bioinformatics analysis and experimental validation study.

OBJECTIVES

To investigate the role and expression patterns of disulfidptosis-related genes in spinal cord injury (SCI), identify potential pivotal genes, and explore possible therapeutic targets.

SETTING

Shanghai, China.

METHODS

Data acquisition and pre-processing: Screened 27 disulfidptosis-related genes based on literature and downloaded RNA-sequencing data of ASCI patients from GEO database (GSE151371); Identification of differentially expressed genes (DEGs): Used R package "limma" for differential gene expression analysis between ASCI samples and normal controls; Evaluating immune cell infiltration: Employed ssGSEA algorithm and CIBERSORT to determine immune cell abundance; Identification and functional verification of key genes: Intersected disulfidptosis-related genes with DEGs, and used machine learning techniques (Random Forest, Lasso, Support Vector Machine) to identify hub genes. Validated hub genes expression by real-time PCR; Construction of a diagnostic model: Developed a backpropagation neural network clinical prediction model based on hub genes and clinical features, and evaluated its performance using ROC curve. 6. Subcluster analysis: Performed consensus cluster analysis of ASCI samples and hub genes, and used GSVA to elucidate functional differences between subgroups.

RESULTS

Identified 7764 DEGs in ASCI, with GO and KEGG enrichment in inflammation and autophagy-related pathways; Found differences in immune cell infiltration between ASCI and control groups, and correlation between immune cells and DRGs; Determined seven hub genes (MYL6, NUBPL, CYFIP1, IQGAP1, FLNB, SLC7A11, CD2AP) through machine learning; Validated the expression of hub genes by qRT-PCR; Constructed a clinical diagnostic model with good predictive accuracy (overall dataset accuracy of 83.3%); Identified two subtypes of ASCI based on hub genes, with different immune infiltration and pathway activity.

CONCLUSION

Disulfidptosis is closely related to spinal cord injury. The identified hub genes and subtypes provide new insights for biomarker and therapeutic target research. The diagnostic model has potential for clinical application, but further studies are needed due to limitations such as small sample size.

SPONSORSHIP

This study was supported in part by the project of Youth Scientific and Technological Talents of PLA (2020QN06125), Changhong Talent Project in First affiliated hospital of Navy Medical University (Wei Xianzhao) and Basic Medical Research Project in First affiliated hospital of Navy Medical University (2023PY17). I want to reiterate that there is no prior publication of figures or tables and no conflict of interest in the submission of this manuscript. The graphical abstract is divided into two parts. The upper section sequentially illustrates the occurrence of disulfidptosis and changes in the immune microenvironment in the human body after SCI. The lower section displays the construction of a diagnostic model for SCI through the detection of changes in disulfidptosis-related genes, combined with patient clinical information.

Role of ubiquitin-specific proteases in programmed cell death of breast cancer cells

Breast cancer (BC) is the most common malignant tumor and the leading cause of cancer-related deaths among women worldwide. Great progress has been recently achieved in controlling breast cancer; however, mortality from breast cancer remains a substantial challenge, and new treatment mechanisms are being actively sought. Programmed cell death (PCD) is associated with the progression and treatment of many types of human cancers. PCD can be divided into multiple pathways including autophagy, apoptosis, mitotic catastrophe, necroptosis, ferroptosis, pyroptosis, and anoikis. Ubiquitination is a post-translational modification process in which ubiquitin, a 76-amino acid protein, is coupled to the lysine residues of other proteins. Ubiquitination is involved in many physiological events and promotes cancer development and progression. This review elaborates the role of ubiquitin-specific protease (USP) in programmed cell death, which is common in breast cancer cells, and lays the foundation for tumor diagnosis and targeted therapy.

RNF128 promotes gastric cancer progression by inhibiting autophagy-dependent ferroptosis through Beclin1 ubiquitination

As an important protein post-translational modification process, ubiquitination plays an indispensable role in the regulation of gastric cancer (GC) occurrence and development. And recent studies have demonstrated that this modification is closely related to regulated cell death. This suggests that our therapeutic approach to inhibit the malignant progression of GC by regulating the intracellular death mode through ubiquitination modification becomes possible. Although ubiquitination modification has been well described in some tumorigenesis, its potential role and specific mechanisms are still unknown. In the present study, we identified RNF128, an E3 ubiquitin ligase with a RING structural domain, whose expression was significantly increased in GC. In-depth studies showed that knockdown of RNF128 significantly inhibited GC cell proliferation and increased intracellular autophagic flux and lipid peroxidation production, and we hypothesized that autophagy-dependent ferroptosis might be the main mode of death mediated by RNF128. Mechanistically, RNF128 directly binds and ubiquitinates degradation of Beclin1 through its PA structural domain and significantly inhibits the Beclin1/solute transport family 7 member 11(SLC7A11)/glutathione peroxidase 4(GPX4) axis. Taken together, our study reports for the first time that RNF128 acts as a tumor promoter to inhibit autophagy-dependent ferroptosis in GCs by targeting Beclin1. These data provide new insights into the activation of intracellular ferroptosis to inhibit malignant tumor progression and are expected to provide a new strategy for molecular therapy in clinical GC patients.

Protein modifications in hepatic ischemia-reperfusion injury: molecular mechanisms and targeted therapy

Ischemia-reperfusion injury refers to the damage that occurs when blood supply is restored to organs or tissues after a period of ischemia. This phenomenon is commonly observed in clinical contexts such as organ transplantation and cardiac arrest resuscitation. Among these, hepatic ischemia-reperfusion injury is a prevalent complication in liver transplantation, significantly impacting the functional recovery of the transplanted liver and potentially leading to primary graft dysfunction. With the growing demand for organ transplants and the limited availability of donor organs, effectively addressing hepatic ischemia-reperfusion injury is essential for enhancing transplantation success rates, minimizing complications, and improving graft survival. The pathogenesis of hepatic ischemia-reperfusion injury is multifaceted, involving factors such as oxidative stress and inflammatory responses. This article focuses on the role of protein post-translational modifications in hepatic ischemia-reperfusion injury, including phosphorylation, ubiquitination, acetylation, ADP-ribosylation, SUMOylation, crotonylation, palmitoylation, and S-nitrosylation. Initially, we examined the historical discovery of these protein post-translational modifications and subsequently investigated their impact on cellular signal transduction, enzymatic activity, protein stability, and protein-protein interactions. The emphasis of this study is on the pivotal role of protein post-translational modifications in the progression of hepatic ischemia-reperfusion injury and their potential as therapeutic targets. This study aims to conduct a comprehensive analysis of recent advancements in research on protein modifications in hepatic ischemia-reperfusion injury, investigate the underlying molecular mechanisms, and explore future research trajectories. Additionally, future research directions are proposed, including the exploration of interactions between various protein modifications, the identification of specific modification sites, and the development of drugs targeting these modifications. These efforts aim to deepen our understanding of protein post-translational modifications in hepatic ischemia-reperfusion injury and pave the way for innovative therapeutic interventions.

The long noncoding RNA APR attenuates PPRV infection-induced accumulation of intracellular iron to inhibit membrane lipid peroxidation and viral replication

Peste des petits ruminants virus (PPRV) is an important pathogen that has long been a significant threat to small ruminant productivity worldwide. Iron metabolism is vital to the host and the pathogen. However, the mechanism underlying host-PPRV interactions from the perspective of iron metabolism and iron-mediated membrane lipid peroxidation has not been reported thus far. In this study, we identified a novel host long-noncoding RNA (lncRNA), APR, that impairs PPRV infectivity by sponging miR-3955-5p, a negative microRNA (miRNA) that directly targets the gene encoding the ferritin-heavy chain 1 (FTH1) protein. Importantly, we demonstrated that PPRV infection causes aberrant cellular iron accumulation by increasing transferrin receptor (TFRC) expression and that iron accumulation induces reticulophagy and ferroptosis, which benefits PPRV replication. Moreover, PPRV infection enhanced the localization of cellular iron on the endoplasmic reticulum (ER) and caused ER membrane damage by promoting excess lipid peroxidation to induce reticulophagy. Interestingly, APR decreased PPRV infection-induced accumulation of intracellular Fe2+ via miR-3955-5p/FTH1 axis and ultimately inhibited reticulophagy and ferroptosis. Additionally, our results indicate that interferon regulatory factor 1 promotes APR transcription by positively regulating APR promoter activity after PPRV infection. Taken together, our findings revealed a new pattern of PPRV-host interactions, involving noncoding RNA regulation, iron metabolism, and iron-related membrane lipid peroxidation, which is critical for understanding the host defense against PPRV infection and the pathogenesis of PPRV.IMPORTANCEMany viruses have been demonstrated to engage in iron metabolism to facilitate their replication and pathogenesis. However, the mechanism by which PPRV interacts with host cells from the perspective of iron metabolism, or iron-mediated membrane lipid peroxidation, has not yet been reported. Our data provide the first direct evidence that PPRV infection induces aberrant iron accumulation to promote viral replication and reveal a novel host lncRNA, APR, as a regulator of iron accumulation by promoting FTH1 protein expression. In this study, PPRV infection increased cellular iron accumulation by increasing TFRC expression, and more importantly, iron overload increased viral infectivity as well as promoted ER membrane lipid peroxidation by enhancing the localization of cellular iron on the ER and ultimately induced ferroptosis and reticulophagy. Furthermore, a host factor, the lncRNA APR, was found to decrease cellular iron accumulation by sponging miR-3955-5p, which directly targets the gene encoding the FTH1 protein, thereby attenuating PPRV infection-induced ferroptosis and reticulophagy and inhibiting PPRV infection. Taken together, the results of the present study provide new insight into our understanding of host-PPRV interaction and pathogenesis from the perspective of iron metabolism and reveal potential targets for therapeutics against PPRV infection.

Endothelial USP11 drives VEGFR2 signaling and angiogenesis via PRDX2/c-MYC axis

Angiogenesis is a crucial component of various physiological and pathological processes, including embryonic development, ischemic diseases, and tumor progression. Recent studies have highlighted the importance of ubiquitinases in angiogenesis. In this study, we utilized RNA sequencing data of the mouse retinal development model from the GEO database to identify the potential proangiogenic deubiquitinases and found USP11 was significantly upregulated. Although USP11 is known to regulate cell survival, DNA repair, and oxidative stress in cancers and ischemic conditions, its direct role in endothelial angiogenesis remains poorly understood. Here, we demonstrated that USP11 expression correlates with key pro-angiogenic genes and is significantly upregulated at both mRNA and protein levels in VEGF-treated human umbilical vein endothelial cells (HUVECs). USP11 knockout markedly inhibited angiogenesis both in vivo and in vitro, whereas USP11 overexpression promoted angiogenesis. Mechanistically, USP11 binds to PRDX2, facilitating the removal of its K63-linked polyubiquitination, which promotes its translocation into the nucleus. This facilitates the concurrent nuclear translocation of c-MYC, a PRDX2 interactor, which subsequently enhances the transcription of KDR (encoding VEGFR2) and activates the VEGFR2 signaling pathway. Our findings suggest that USP11 promotes angiogenesis by upregulating VEGFR2 expression through the PRDX2/c-MYC pathway, indicating that USP11 could serve as a potential target for clinical interventions in angiogenesis-related diseases.

Pre-treated mesenchymal stem cell-derived exosomes: A new perspective for accelerating spinal cord injury repair

Spinal cord injury (SCI) is a devastating event for the central nervous system (CNS), often resulting in the loss of sensory and motor functions. It profoundly affects both the physiological and psychological well-being of patients, reducing their quality of life while also imposing significant economic pressure on families and the healthcare system. Due to the complex pathophysiology of SCI, effective treatments for promoting recovery remain scarce. Mesenchymal stem cell-derived exosomes (MSC-Exos) offer advantages such as low immunogenicity, good biocompatibility, and the ability to cross the blood-spinal cord barrier (BSCB). In preclinical studies, they have progressively shown efficacy in promoting SCI repair and functional recovery. However, the low yield and insufficient targeting of MSC-Exos limit their therapeutic efficacy. Currently, genetic engineering and other preprocessing techniques are being employed to optimize both the yield and functional properties of exosomes, thereby enhancing their therapeutic potential. Therefore, this paper provides an overview of the pathophysiology of SCI and the biogenesis of exosomes. It also summarizes current approaches to optimizing exosome performance. Additionally, it details the mechanisms through which optimized exosomes provide neuroprotection and explores the potential of combined treatments involving MSC-Exos and hydrogels.

The inducible role of autophagy in cell death: emerging evidence and future perspectives

BACKGROUND

Autophagy is a lysosome-dependent degradation pathway for recycling intracellular materials and removing damaged organelles, and it is usually considered a prosurvival process in response to stress stimuli. However, increasing evidence suggests that autophagy can also drive cell death in a context-dependent manner. The bulk degradation of cell contents and the accumulation of autophagosomes are recognized as the mechanisms of cell death induced by autophagy alone. However, autophagy can also drive other forms of regulated cell death (RCD) whose mechanisms are not related to excessive autophagic vacuolization. Notably, few reviews address studies on the transformation from autophagy to RCD, and the underlying molecular mechanisms are still vague.

AIM OF REVIEW

This review aims to summarize the existing studies on autophagy-mediated RCD, to elucidate the mechanism by which autophagy initiates RCD, and to comprehensively understand the role of autophagy in determining cell fate.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review highlights the prodeath effect of autophagy, which is distinct from the generally perceived cytoprotective role, and its mechanisms are mainly associated with the selective degradation of proteins or organelles essential for cell survival and the direct involvement of the autophagy machinery in cell death. Additionally, this review highlights the need for better manipulation of autophagy activation or inhibition in different pathological contexts, depending on clinical purpose.

NLRP3 inflammasome promotes functional repair after spinal cord injury in mice by regulating autophagy and its mechanism

BACKGROUND

Inflammation at the injury site exacerbates tissue cell death following a spinal cord injury (SCI). Studies show that NLRP3 inflammasomes are crucial in the inflammation following Spinal Cord Injury, and NLRP3 inflammasomes have been shown to promote cells to undergo excessive autophagy in other diseases. Moreover, excessive autophagy levels could hinder functional repair post-SCI. In this regard, we hypothesized that inhibiting NLRP3 inflammasomes could reduce autophagy levels at the injury site, thus promoting functional repair post-SCI.

METHODS

Herein, a mouse SCI model was used for in vivo experiments, and an in vitro neuroinflammatory model created using LPS-activated BV2 cells was used for in vitro experiments. Histopathological staining was used to assess tissue repair. Western Blot (WB) and quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) were used to detect changes in relevant autophagy molecules, macrophage polarization-related markers and downstream inflammatory factors, and Immunofluorescence (IF) was used to detect changes in macrophage polarization.

RESULTS

Following SCI, the inhibition of NLRP3 inflammasomes resulting from intraperitoneal injection of MCC950 significantly reduced autophagy levels at the injury site, resulting in both histological and behavioral improvements. In addition, the phosphorylation of mTOR during inhibition of NLRP3 inflammasomes to reduce autophagy levels further improved the immune microenvironment at the injury site, and M2-type macrophages were significantly upregulated M2-type macrophages. Moreover, in vitro experiments yielded results consistent with those of in vivo experiments regarding changes in autophagy-related indexes and polarization-related markers.

CONCLUSIONS

Inhibition of NLRP3 inflammasomes can reduce autophagy level at the injury site to promote functional recovery and play a neuroprotective role. Moreover, phosphorylation of mTOR during the process of inhibition of NLRP3 inflammasomes to reduce autophagy, leading to reduced autophagy levels, could improve the immune microenvironment at the injury site, thus promoting functional recovery and histopathological repair post-SCI.

TRIM21 Promotes Endothelial Cell Activation via Accelerating SOCS3 Ubiquitination Degradation in Atherosclerosis

Activated endothelial cells play an important role in the beginning of atherosclerotic disease by secreting various proteins and inflammatory cytokines. Ubiquitination is one of the most common post-translational changes in cells. However, the role and mechanisms of ubiquitination in endothelial cell activation remain poorly understood. In this study, we identified TRIM21 as an E3 ubiquitin ligase with increased expression in atherosclerotic disease and activated endothelial cells. Knockdown of TRIM21 resulted in reduced secretion of inflammatory factors and attenuated the pyroptosis of endothelial cells, inhibiting the progression of atherosclerosis. Mechanistically, TRIM21 could bind and ubiquitinate SOCS3, thereby enhancing NLRP3-mediated pyroptosis. Taken together, we found that endothelial TRIM21 activated the JAK/STAT3 pathway by degrading SOCS3, which in turn promoted NLRP3-mediated pyroptosis and aggravated atherosclerosis, revealing that TRIM21 may be a promising treatment target for the medical management of atherosclerosis.

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.

Deciphering the role of TMEM164 in autophagy-mediated ferroptosis and immune modulation in non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) remains one of the most prevalent and deadly malignancies. Despite advancements in molecular therapies and diagnostic methods, the 5-year survival rate for lung adenocarcinoma patients remains unacceptably low, highlighting the urgent need for novel therapeutic strategies. Ferroptosis, a distinct form of regulated cell death, has emerged as a promising target in cancer treatment. This study investigates the role of TMEM164, a membrane protein, in promoting ferroptosis and modulating anti-tumor immunity in NSCLC, aiming to elucidate its therapeutic potential.

METHODS

Using publicly available datasets, we performed bioinformatics analyses to identify TMEM164-regulated genes involved in ferroptosis. In addition, in vitro and in vivo assays were conducted to assess the impact of TMEM164 on cellular functions in NSCLC.

RESULTS

Functional assays demonstrated that TMEM164 overexpression significantly inhibited invasion, migration, and cell proliferation in both in vitro and in vivo models. TMEM164 was also found to induce ferroptosis in NSCLC cells by promoting autophagy. Specifically, we identified a mechanism whereby TMEM164 mediates ATG5-dependent autophagosome formation, leading to the degradation of ferritin, GPX4, and lipid droplets. This degradation facilitated iron accumulation and lipid peroxidation, which triggered iron-dependent cell death. Notably, co-administration of TMEM164 upregulation and anti-PD-1 antibodies exhibited synergistic anti-tumor effects in a mouse model.

CONCLUSION

These findings suggest that targeting TMEM164 to enhance ferroptosis and stimulate anti-tumor immunity may inhibit NSCLC progression. Consequently, TMEM164 holds promise as a new therapeutic target for NSCLC treatment.

Hydrogen Sulfide Sustained Release Donor Alleviates Spinal Cord Ischemia-Reperfusion-Induced Neuron Death by Inhibiting Ferritinophagy-Mediated Ferroptosis

AIMS

Spinal cord ischemia-reperfusion injury (SCIRI) is a disastrous complication that cannot be completely prevented in thoracoabdominal aneurysm surgery, leading to sensory and motor dysfunction and even paraparesis, causing tremendous socioeconomic burden. Ferritinophagy is a form of autophagic ferroptosis, which is a contributor to SCIRI. Hydrogen sulfide (H2S) has been reported to be neuroprotective in various diseases. However, it remains unclear whether H2S alleviates SCIRI-induced neural death via regulating ferritinophagy-mediated ferroptosis. The aim of this study was to explore their relationship and interaction in SCIRI.

RESULTS

The results demonstrate that Nissl bodies and motor function were obviously lost in SCIRI rats. Meanwhile, SCIRI led to a significant increase in DHE-positive neurons, TUNEL-positive neurons, LC3-positive neurons, and ferritin-positive neurons, downregulation of GPx4, Slc7a11, p62, and ferritin expression, and upregulation of LC3 II/I and NCOA4 expression. Additionally, there was upregulation of the level of MDA, GSH, and Fe2+. Finally, we found that H2S could significantly relieve neuronal death and loss of motor function in SCIRI rats by inhibiting ferritinophagy and ferroptosis.

CONCLUSION

Ferroptosis and ferritinophagy play a crucial role in the etiopathogenesis of SCIRI, and H2S exerts neuroprotection by inhibiting ferritinophagy-mediated ferroptosis.

USP13 facilitates a ferroptosis-to-autophagy switch by activation of the NFE2L2/NRF2-SQSTM1/p62-KEAP1 axis dependent on the KRAS signaling pathway

Macroautophagy/autophagyis a lysosomal-regulated degradation process that participates incellular stress and then promotes cell survival or triggers celldeath. Ferroptosis was initially described as anautophagy-independent, iron-regulated, nonapoptotic cell death.However, recent studies have revealed that autophagy is positivelyassociated with sensitivity to ferroptosis. Nonetheless, themolecular mechanisms by which these two types of regulated cell death(RCD) modulate each other remain largely unclear. Here, we screened85 deubiquitinating enzymes (DUBs) and found that overexpression ofUSP13 (ubiquitin specific peptidase 13) could significantlyupregulate NFE2L2/NRF2 (NFE2 like bZIP transcription factor 2)protein levels. In addition, in 39 cases of KRAS-mutated lungadenocarcinoma (LUAD), we found that approximately 76% of USP13overexpression is positively correlated with NFE2L2 overexpression.USP13 interacts with and catalyzes the deubiquitination of thetranscription factor NFE2L2. Additionally, USP13 depletion promotesan autophagy-to-ferroptosis switch invitro andin xenograft tumor mouse models, through the activation of theNFE2L2-SQSTM1/p62 (sequestosome 1)-KEAP1 axis in KRAS mutant cellsand tumor tissues. Hence, targeting USP13 effectively switchedautophagy-to-ferroptosis, thereby inhibiting KRAS (KRASproto-oncogene, GTPase) mutant LUAD, suggesting the therapeuticpromise of combining autophagy and ferroptosis in the KRAS-mutantLUAD.Abbreviation: ACSL4: acyl-CoA synthetase long-chain family member 4; ACTB: actin beta; AL: autolysosomes; AP: autophagosomes; BCL2L1/BCL-xL: BCL2 like 1; CCK8: Cell Counting Kit-8; CQ: chloroquine; CUL3: cullin 3; DMSO: dimethyl sulfoxide; DOX: doxorubicin; DUB: deubiquitinating enzyme; Ferr-1: ferrostatin-1; GPX4: glutathione peroxidase 4; GSEA: gene set enrichment analysis; 4HNE: 4-hydroxynonenal; IKE: imidazole ketone erastin; KEAP1: kelch like ECH associated protein 1; KRAS: KRAS proto-oncogene, GTPase; LCSC: lung squamous cell carcinoma; IF: immunofluorescence; LUAD: lung adenocarcinoma; Lys05: Lys01 trihydrochloride; MAPK1/ERK2/p42: mitogen-activated protein kinase 1; MAPK3/ERK1/p44; MTOR: mechanistic target of rapamycin kinase; NFE2L2/NRF2: NFE2 like bZIP transcription factor, 2; NQO1: NAD(P)H quinone dehydrogenase 1; PG: phagophore; RCD: regulated cell death; RAPA: rapamycin; ROS: reactive oxygen species; SLC7A11/xCT: solute carrier family 7 member 11; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscopy; TUBB/beta-tubulin: tubulin, beta; UPS: ubiquitin-proteasome system; USP13: ubiquitin specific peptidase 13.

ISRIB facilitates post-spinal cord injury recovery through attenuation of neuronal apoptosis and modulation of neuroinflammation

Background

Neuronal apoptosis and inflammation are two critical factors that impede functional recovery post spinal cord injury (SCI). Previous studies have demonstrated the inhibitory effects of integrated stress response inhibitor (ISRIB) on neuroinflammation in brain injury. However, whether ISRIB can regulate neuron death and neuroinflammation in the context of SCI remains elusive.

Methods

We employed an oxygen-glucose deprivation/reperfusion (OGD/R) model to simulate spinal cord ischemia-reperfusion injury and utilized lipopolysaccharide (LPS) to activate microglia. We assessed cell viability and death to demonstrate the neuroprotective effect of ISRIB against neuron death, while evaluating cytokine levels and the expression of Arg1 and iNOS to elucidate the regulatory role of ISRIB in neuroinflammation. Bulk RNA-seq analysis was employed to investigate the global transcriptional changes in neurons and microglia induced by ISRIB treatment. Additionally, we validated the promoting effects of ISRIB on motor and sensory recovery in a mouse model of SCI.

Results

We observed that ISRIB exerted a suppressive effect on neuron death and neuroinflammation. RNA-seq data revealed that the ISRIB exhibited regulation of neuron apoptosis through the P53 signaling pathway, as well as modulation of neuroinflammation by the JAK2/STAT3 signaling pathway. Western blotting and immunofluorescence analyses demonstrated that ISRIB reduced P53 expression in neuronal nuclei and inhibited the phosphorylation of JAK2 and STAT3 in microglia. In addition, we validated the capacity of ISRIB to promote locomotor function recovery in a mouse model of SCI.

Conclusion

Our study confirmed the ability of ISRIB to regulate neuron apoptosis and neuroinflammation in SCI via the P53 signaling pathway and the JAK2/STAT3 signaling pathway, respectively. Treatment with ISRIB in mice with SCI promoted the recovery of neural function. This research provides new evidence and options for therapeutic strategies of SCI.

The translational potential of this article

Our study provides experimental evidence to support the application of ISRIB in the repair of spinal cord injury.

CCR1 antagonist as a potential modulator of inflammatory, autophagic, and apoptotic markers in spinal cord injury

Spinal cord injury (SCI) leads to severe and lasting impairments in motor and sensory functions. The intense inflammatory response following SCI is a significant challenge, and autophagy has emerged as a key factor in the recovery process. The C-C chemokine receptor type 1 (CCR1), a G-protein coupled receptor, plays a crucial role in managing the chemokine response under stress. BX471, a selective and potent CCR1 antagonist, has been explored in various disease contexts for its therapeutic potential. In this study, we assessed the effects of BX471 in a mouse model of SCI. The treatment was administered at doses of 3 and 10 mg/kg, 1 h and 6 h after the injury occurred. Results showed that BX471 significantly improved tissue structure by positively influencing autophagy and reducing inflammation. Inflammatory markers, including CCR1 ligands RANTES, MIP-1α, TNF-α, and IL-1β, were measured using Western blot analysis. Additionally, histological evaluations revealed that BX471 effectively decreased infiltration and reduced astrocyte and microglial activation, supporting the idea that enhancing autophagy through CCR1 inhibition could promote neuronal survival. The highest efficacy was observed at the 10 mg/kg dose, leading to optimal out-comes across the assessments. These findings suggest that CCR1 blockade with BX471 may offer a promising therapeutic strategy for SCI, addressing a critical gap in the current pharmacological treatment options.

GelMA@APPA microspheres promote chondrocyte regeneration and alleviate osteoarthritis via Fgfr2 activation

BACKGROUND

In the context of osteoarthritis (OA), a condition marked by joint degeneration, there is a notable absence of efficacious approaches to promote regenerative healing in chondrocytes. Novel therapeutic strategies like nanomicelles-hydrogel microspheres loaded with Astragalus polysaccharide (GelMA@APPA) offer promising avenues for promoting chondrocyte regeneration and mitigating OA progression.

METHODS

Astragalus polysaccharide (APS) has been shown to induce chondrocyte proliferation and promote cartilage matrix secretion, demonstrating biological activity associated with chondrocyte regeneration. However, the clinical efficacy of APS remains uncertain. Therefore, this investigation validated the beneficial impact of APS on reducing knee joint damage severity induced by destabilization of the medial meniscus (DMM) in mice. The application of bioinformatics analysis and in vitro experimentation revealed that fibroblast growth factor receptor 2 (Fgfr2) in chondrocytes is a key target protein for APS in ameliorating OA-induced cartilage injury, as the deletion of chondrocyte Fgfr2 resulted in the complete loss of the therapeutic effect of APS. To enhance the efficacy of APS, we incorporated APS into nanoparticle-laden hydrogel microspheres to further bolster its potential in chondrocyte regeneration therapy. Subsequently, we developed GelMA@APPA, which exhibited no significant cytotoxic effects on normal chondrocytes in vitro and could be efficiently internalized by chondrocytes. Following subsequent in vitro and in vivo experiments, we affirmed the beneficial effects of GelMA@APPA on OA mice and cartilage cells damaged by OA, as well as its enhancement of the therapeutic effects of APS.

RESULTS

APS significantly improved knee joint injuries in OA mice. Bioinformatics and in vitro analyses identified Fgfr2 as a critical target protein for APS's regenerative effects. Disruption of Fgfr2 negated APS's benefits. GelMA@APPA demonstrated good biocompatibility, effective internalization by chondrocytes, and enhanced the therapeutic efficacy of APS in experiments conducted both in vitro and in vivo, improving chondrocyte proliferation and reducing apoptosis.

CONCLUSIONS

This study demonstrates that GelMA@APPA microspheres effectively promote chondrocyte regeneration and OA treatment by activating Fgfr2. These findings suggest a novel therapeutic mechanism for OA and lay the groundwork for future clinical utilization of GelMA@APPA in regenerative medicine.

Ubiquitin-specific protease 25 improves myocardial ischemia-reperfusion injury by deubiquitinating NLRP3 and negatively regulating NLRP3 inflammasome activity in cardiomyocytes

BACKGROUND

Myocardial ischemia/reperfusion injury (MI/RI) restricts the effect of myocardial reperfusion therapy and lacks effective prevention and treatment methods. Deubiquitinating enzymes (DUBs), especially members of the ubiquitin-specific protease (USP) family of DUBs, are key proteins in the ubiquitination modification process and play a vital role in MI/RI. Therefore, we aimed to investigate the role of USP25, as a member of the USP family, in MI/RI and its molecular mechanism.

METHODS

Transcriptome sequencing was applied to evaluate the differential expression of USP families during hypoxia/reoxygenation (H/R) and validated in human and mouse heart samples and cardiomyocytes by performing quantitative polymerase chain reaction. Wild-type or USP25-/- mice were used to develop the MI/RI model. Co-immunoprecipitation (Co-IP) combined with liquid chromatography-tandem mass spectrometry analysis was used to screen the potential substrate protein of USP25 in H/R-induced cardiomyocyte injury. TUNEL and Hoechst/propidium iodide staining and western blot were used to detect the level of pyroptosis. In addition, cardiomyocyte-specific USP25 overexpression in NLRP3-/- mice with AAV9 vectors was used to validate the biological function of USP25 and NLRP3 interaction.

RESULTS

We found that the expression level of USP25 was significantly decreased in I/R-induced mouse heart tissues and primary cardiomyocytes in a time-dependent manner. USP25 deficiency exacerbated MI/RI and aggravated I/R-induced cardiac remodelling in mice. Mechanistically, USP25 directly binds to NLRP3 protein and K63-linkedly deubiquitinates NLRP3 at residue K243 via its active site C178, thus hindering NLRP3-ASC interaction and ASC oligomerization to inhibit NLRP3 activation and pyroptosis in cardiomyocytes. We further showed that the overexpression of USP25 in cardiomyocytes ameliorated MI/RI in mice, whereas this protective effect disappeared when NLRP3 is knocked out.

CONCLUSIONS

Our study demonstrated that USP25 ameliorates MI/RI by regulating NLRP3 activation and its mediated pyroptosis. This finding extends the protective role of USP25 in cardiovascular disease and provides an experimental basis for future USP25-based drug development for the treatment of MI/RI.

KEY POINTS

The deubiquitinating enzyme USP25 was down-regulated both in myocardial ischemia/reperfusion injury (MI/RI) myocardium tissues. The deficiency of USP25 worsened exacerbated MI/RI in mice, whereas the overexpression of USP25 in cardiomyocytes mitigated this pathological phenotype. USP25 directly interacts with the NLRP3 protein and deubiquitinates it via K63 linkage at residue K243 through its active site C178, thus affecting NLRP3-ASC interaction and ASC oligomerization to inhibit NLRP3 activation and pyroptosis in cardiomyocytes.

Transcranial alternating current stimulation inhibits ferroptosis and promotes functional recovery in spinal cord injury via the cGMP-PKG signalling pathway

AIMS

This study explores the potential of neuromodulation, specifically transcranial alternating current stimulation (tACS), as a promising rehabilitative therapy in spinal cord injury (SCI).

MAIN METHODS

By meticulously optimizing treatment parameters and durations, our objective was to enhance nerve regeneration and facilitate functional recovery. To assess the efficacy of tACS, our experiments used the rat T10 SCI model. Motor function outcomes were measured using the Basso-Beattie-Bresnahan (BBB) scoring scale and footprint analysis. To thoroughly understand the impact of tACS, we conducted a series of histological evaluations two weeks post-injury. These included q-PCR, enzyme-linked immunosorbent assays (ELISA), transmission electron microscopy (TEM), immunofluorescence staining, and Western blotting. The mechanisms underlying the role of tACS will be elucidated through comprehensive analyses.

KEY FINDINGS

Simultaneously, tACS reduced the levels of reactive oxygen species (ROS), Fe, and malondialdehyde (MDH), and increased the levels of glutathione (GSH) after SCI. Additionally, tACS significantly enhanced motor function, reduced fibrotic scar tissue formation, and provided substantial neuroprotection. It also contributed to the restoration of the blood-spinal cord barrier and supported the regeneration of essential neural components, including axons, myelin, and synapses. The cGMP-PKG signalling pathway was identified as playing a crucial role in these processes.

SIGNIFICANCE

Our findings suggest that tACS inhibits ferroptosis and necrotic degeneration by modulating the cGMP-PKG signalling pathway. This highlights the importance of tACS in promoting neural repair and functional recovery in SCI patients. Overall, tACS emerges as a highly effective and cost-efficient rehabilitative approach for SCI, offering new hope for improving patient outcomes.

Ferroptosis contributes to immunosuppression

As a novel form of cell death, ferroptosis is mainly regulated by the accumulation of soluble iron ions in the cytoplasm and the production of lipid peroxides and is closely associated with several diseases, including acute kidney injury, ischemic reperfusion injury, neurodegenerative diseases, and cancer. The term "immunosuppression" refers to various factors that can directly harm immune cells' structure and function and affect the synthesis, release, and biological activity of immune molecules, leading to the insufficient response of the immune system to antigen production, failure to successfully resist the invasion of foreign pathogens, and even organ damage and metabolic disorders. An immunosuppressive phase commonly occurs in the progression of many ferroptosis-related diseases, and ferroptosis can directly inhibit immune cell function. However, the relationship between ferroptosis and immunosuppression has not yet been published due to their complicated interactions in various diseases. Therefore, this review deeply discusses the contribution of ferroptosis to immunosuppression in specific cases. In addition to offering new therapeutic targets for ferroptosis-related diseases, the findings will help clarify the issues on how ferroptosis contributes to immunosuppression.

Redox regulation of TRIM28 facilitates neuronal ferroptosis by promoting SUMOylation and inhibiting OPTN-selective autophagic degradation of ACSL4

Ferroptosis is one of the cell death programs occurring after spinal cord injury (SCI) and is driven by iron-dependent phospholipid peroxidation. However, little is known about its underlying regulation mechanism. The present study demonstrated that lipid peroxidation was promoted in patients with SCI. Neurons affected by ferroptosis following SCI had a high expression of ferroptotic protein ACSL4. The E3 SUMOylase TRIM28 promoted neuronal ferroptosis by enhancing ACSL4 expression. Genetic deletion of Trim28 significantly attenuated neuronal ferroptosis and improved mouse hindlimb motor function following SCI. In contrast, mice with Trim28 overexpression demonstrated poor neurological function after SCI, which was attenuated by ferroptosis inhibitor Liproxstatin-1. Mechanistically, TRIM28 bound to ACSL4, promoted SUMO3 modification at lysine (K) 532, and inhibited K63-linked ACSL4 ubiquitination, thereby suppressing OPTN-dependent autophagic degradation. Additionally, SENP3 was identified as the deSUMOylation enzyme that can reverse this process and compete with TRIM28, which was transcriptionally upregulated due to excessive oxidative stress. These data unveiled a mechanism by which TRIM28-mediated SUMOylation regulated neuronal ACSL4 levels and ferroptosis, identified interactions and correlations involved in ACSL4 SUMOylation, ubiquitination, and autophagic degradation, and discovered a positive feedback loop where oxidative stress transcriptionally upregulated Trim28, and conversely TRIM28 promoted ferroptosis and oxidative stress. Notably, screening of the FDA-approved drug library revealed that pharmacological TRIM28/ACSL4 axis interventions with Rutin hydrate inhibited neuronal ferroptosis and improved hindlimb motor function in mice after SCI, thus providing a promising therapeutic strategy for its treatment.

Actl6a regulates autophagy via Sox2-dependent Atg5 and Atg7 expression to inhibit apoptosis in spinal cord injury

INTRODUCTION

Spinal cord injury (SCI) is a severe central nervous system disorder with limited treatment options. While autophagy plays a protective role in neural repair, its regulatory mechanisms in SCI remain unclear. Actin-like protein 6A (Actl6a) influences cell fate and neural development, yet its specific role in SCI repair is not well understood. This study investigates Actl6a's function in regulating autophagy and apoptosis via the transcription factor Sox2 in SCI.

OBJECTIVES

This study aims to determine if Actl6a promotes neural survival post-SCI by regulating autophagy-related genes Atg5 and Atg7 through Sox2. It also examines how the demethylase Fto modulates Actl6a mRNA stability via m6A methylation.

METHODS

In vitro experiments were conducted using primary neurons and HT-22 hippocampal cells exposed to hydrogen peroxide (H2O2)-induced oxidative stress. Actl6a expression was manipulated by knockdown or overexpression. For in vivo studies, a rat SCI model was established with AAV-Actl6a injected at the injury site to induce Actl6a overexpression. Autophagy and apoptosis markers were analyzed using immunofluorescence, Western blotting, and qPCR. Additionally, m6A dot blot and RNA immunoprecipitation (RIP) assays were performed to assess Fto's role in regulating Actl6a mRNA methylation and stability.

RESULTS

Actl6a expression significantly decreased after SCI, resulting in increased apoptosis. Overexpressing Actl6a enhanced autophagy, reduced apoptosis, and improved neurological function in SCI models. Mechanistically, Actl6a and Sox2 collaboratively upregulated Atg5 and Atg7 expression, promoting autophagy. Fto's modulation of Actl6a mRNA stability via m6A demethylation further influenced autophagy and apoptosis.

CONCLUSION

Actl6a, through interaction with Sox2, plays a critical role in modulating autophagy and reducing apoptosis in SCI, with Fto's m6A modification affecting Actl6a stability. This Fto/Actl6a/Sox2 axis is a promising therapeutic target for SCI repair.

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.

TRIM32 promotes neuronal ferroptosis by enhancing K63-linked ubiquitination and subsequent p62-selective autophagic degradation of GPX4

Ferroptosis, characterized by iron-dependent phospholipid peroxidation, is recognized as one of the cell death pathways activated following spinal cord injury (SCI). However, the precise regulatory mechanisms governing this process remain poorly understood. Here, this study identified TRIM32, an E3 ubiquitin ligase, as a key enhancer of neuronal ferroptosis. TRIM32 promoted neuronal ferroptosis by accelerating the degradation of GPX4, which is an essential inhibitor of ferroptosis. Conditional deletion of Trim32 in neurons markedly inhibited neuronal ferroptosis and promoted neuronal survival, eventually improving mouse locomotor functional recovery after SCI. However, overexpression of Trim32 showed aggravated neuronal loss and poor behavioral function, which could be attenuated by ferroptosis inhibitor Liproxstatin-1. Mechanistically, TRIM32 interacted with GPX4, promoted K63-linked ubiquitination modification of GPX4 at K107, thus enhanced p62-dependent autophagic degradation of GPX4. Moreover, ROS-ATM-Chk2 signaling pathway phosphorylates TRIM32 at S55, further contributing to GPX4 ubiquitination and degradation and subsequent neuronal ferroptosis after SCI, suggesting a positive feedback loop between ROS and TRIM32. Clinically, lipid peroxidation was significantly promoted in patients with SCI. These findings reveal that TRIM32 functions as a neuronal ferroptosis enhancer which is detrimental to neuronal survival and locomotor functional recovery in mice after SCI by promoting K63-linked ubiquitination and subsequent p62-dependent autophagic degradation of GPX4, suggesting a promising therapeutic target for SCI.

Ubiquitin specific peptidase 11 knockdown slows Huntington's disease progression via regulating mitochondrial dysfunction and neuronal damage depending on PTEN-mediated AKT pathway

BACKGROUND

Mitochondrial dysfunction and neuronal damage are major sign of cytopathology in Huntington's disease (HD), a neurodegenerative disease. Ubiquitin specific peptidase 11 (USP11) is a deubiquitinating enzyme involved in various physiological processes through regulating protein degradation. However, its specific role in HD is unclear.

METHODS

To interfere with USP11 expression, adeno-associated viruses 2 containing USP11-specific shRNA were injected into the bilateral striatum of 12-week-old R6/1 and WT mice. In vitro, the inducible PC12 cell model of HD was used in which the expression of an N-terminal truncation of huntingtin, with either wild type (Q23) or expanded polyglutamine (Q74) can be induced by the doxycycline. USP11 was knocked down to study its role in HD. The protein expression patterns in Q74 cells were quantified by label-free proteomics to further explore the target protein of USP11. Detecting the association between USP11 and Phosphatase and Tensin Homolog (PTEN) through Co-IP.

RESULTS

Herein, USP11 was found to be upregulated in the striatum of R6/1 mice (an HD model with gradual development of symptoms) in an age-dependent manner. The spontaneous HD was alleviated by silencing USP11, as evidenced by improved locomotor activity and spatial memory, attenuated striatal atrophy in R6/1 mice, reduced accumulation of mutant huntingtin protein, and restored mitochondrial function in vitro and in vivo. The results of label-free proteomics revealed a significant change in the protein expression profile. Through functional enrichment, we focused on PTEN, known as a negative regulator of the AKT pathway. We demonstrated that USP11 downregulation promoted ubiquitination modification of PTEN and activated the AKT pathway, and PTEN overexpression reversed the effects of USP11 knockdown.

CONCLUSIONS

Collectively, USP11 knockdown protects R6/1 mouse neurons from oxidative stress by alleviating mitochondrial dysfunction, thereby preventing the HD progression. This is achieved by inhibiting PTEN expression, which in turn activates the AKT pathway. This study suggests that USP11-PTEN-AKT signaling pathway may be a new attractive therapeutic target for HD.

Integrated Analysis and Validation of Ferroptosis-Related Genes Associated with Ischemia/Reperfusion Injury in Lung Transplantation

Background

Lung transplantation is the only effective therapeutic option for patients with end-stage lung disease. However, ischemia/reperfusion injury (IRI) during transplantation is a leading cause of primary graft dysfunction (PGD). Ferroptosis, a form of iron-dependent cell death driven by lipid peroxidation, has been implicated in IRI across various organs. This study aims to explore the role of ferroptosis in lung transplantation-related ischemia/reperfusion injury and to identify its potential molecular mechanisms through bioinformatics analysis.

Methods

Transcriptome data from lung transplant patients were obtained from the Gene Expression Omnibus (GEO) database. Ferroptosis-related differentially expressed genes (FRGs) were identified by analyzing gene expression profiles before and after reperfusion. Weighted gene co-expression network analysis (WGCNA) was used to identify module genes, and overlapping genes were further analyzed using two machine learning algorithms. The CIBERSORT algorithm was applied to assess immune cell infiltration, while Mendelian randomization (MR) analysis was used to investigate causal relationships between candidate genes and PGD. Finally, Consensus clustering based on FRGs was performed to identify subtypes.

Results

We identified four candidate genes associated with ferroptosis during lung reperfusion: tumor necrosis factor alpha-induced protein 3 (TNFAIP3), C-X-C motif chemokine ligand 2 (CXCL2), neural precursor cell expressed developmentally down-regulated 4-like (NEDD4L), and sestrin 2 (SESN2). These genes were closely associated with immune cell infiltration. MR analysis suggested that SESN2 might play a protective role against PGD. Additionally, consensus clustering revealed distinct immune infiltration patterns across subtypes, providing insights for personalized therapeutic approaches to lung ischemia/reperfusion injury (LIRI).

Conclusion

This study highlights TNFAIP3, CXCL2, NEDD4L, and SESN2 as candidate genes associated with ferroptosis during LIRI, with SESN2 potentially protecting against PGD. These findings offer promising therapeutic targets for preventing LIRI and improving outcomes in lung transplantation.

Crosstalk between ferroptosis and autophagy: broaden horizons of cancer therapy

Ferroptosis and autophagy are two main forms of regulated cell death (RCD). Ferroptosis is a newly identified RCD driven by iron accumulation and lipid peroxidation. Autophagy is a self-degradation system through membrane rearrangement. Autophagy regulates the metabolic balance between synthesis, degradation and reutilization of cellular substances to maintain intracellular homeostasis. Numerous studies have demonstrated that both ferroptosis and autophagy play important roles in cancer pathogenesis and cancer therapy. We also found that there are intricate connections between ferroptosis and autophagy. In this article, we tried to clarify how different kinds of autophagy participate in the process of ferroptosis and sort out the common regulatory pathways between ferroptosis and autophagy in cancer. By exploring the complex crosstalk between ferroptosis and autophagy, we hope to broaden horizons of cancer therapy.

USP38 exacerbates myocardial injury and malignant ventricular arrhythmias after ischemia/reperfusion by promoting ferroptosis through the P53/SLC7A11 pathway

INTRODUCTION

Myocardial ischemia-reperfusion (I/R) leads to myocardial injury and malignant ventricular arrhythmias (VAs). Ferroptosis is a novel form of cell death that plays a role in myocardial injury after I/R. Ubiquitin-specific protease 38 (USP38), a member of the deubiquitinating enzyme family, is involved in regulating the progression of inflammation and tumors, but its role in myocardial I/R and ferroptosis is unclear.

OBJECTIVES

Herein, we explored whether USP38 regulates myocardial I/R-induced ferroptosis and the development of malignant arrhythmias and underlying mechanisms.

METHODS

In this study, cardiac I/R mice model was established by ligating/loosening the left anterior descending artery, and the effects of USP38 on I/R-induced ferroptosis and VAs susceptibility were investigated using USP38 cardiac conditional knockout (USP38-CKO) mice and USP38 cardiac specific overexpression (USP38-TG) mice. In addition, an in vitro I/R model was constructed by hypoxia/reoxygenation (H/R) for further validation.

RESULTS

Our study showed that USP38 expression was significantly increased after I/R. USP38-CKO significantly inhibited I/R-induced iron overload, ROS production, and lipid peroxidation. In addition, USP38-CKO ameliorates post-I/R electrophysiologic abnormalities and reduces susceptibility to VAs. USP38-TG showed the opposite effect, exacerbating ferroptosis and increasing susceptibility to VAs after I/R. In vivo experiments similarly demonstrated that USP38 significantly exacerbated H/R-induced ferroptosis. Mechanistically, USP38 directly interacts with P53 and regulates the ubiquitination level of P53 and downstream SLC7A11 expression.

CONCLUSION

We found that ferroptosis was significantly associated with VAs after I/R. USP38 can modulate myocardial injury and VAs susceptibility by affecting ferroptosis, which may be related to the P53/SLC7A11 pathway.

Ferritin Hinders Ferroptosis in Non-Tumorous Diseases: Regulatory Mechanisms and Potential Consequences

Ferritin, as an iron storage protein, has the potential to inhibit ferroptosis by reducing excess intracellular free iron concentrations and lipid reactive oxygen species (ROS). An insufficient amount of ferritin is one of the conditions that can lead to ferroptosis through the Fenton reaction mediated by ferrous iron. Consequently, upregulation of ferritin at the transcriptional or posttranscriptional level may inhibit ferroptosis. In this review, we have discussed the essential role of ferritin in ferroptosis and the regulatory mechanism of ferroptosis in ferritin-deficient individuals. The description of the regulatory factors governing ferritin and its properties in regulating ferroptosis as underlying mechanisms for the pathologies of diseases will allow potential therapeutic approaches to be developed.

Mechanism by which hyperglycemia regulates precursor of brainderived neurotrophic factor expression to exacerbate neurological injury and inflammation in a mouse model of spinal cord ischemiareperfusion injury

OBJECTIVES

Spinal cord ischemia-reperfusion injury (SCIRI) remains a major challenge in the field of organ protection due to the lack of effective prevention and therapeutic strategies. Hyperglycemia, a common perioperative condition, contributes to neurological injury via multiple mechanisms. However, its role and underlying mechanism in SCIRI are still unclear. This study aims to investigate the involvement of the precursor of brain-derived neurotrophic factor (proBDNF) in hyperglycemia-induced SCIRI in mice.

METHODS

Eight-week-old male C57BL/6 mice were randomly assigned to a control group (Vehicle) or a diabetes mellitus (DM) group. The DM group was established using intraperitoneal injection of streptozotocin (STZ) combined with 10% sucrose water. The Vehicle group received an equal volume of 50 mmol/L sodium citrate buffer (pH 4.5). Fasting blood-glucose levels ≥11.1 mmol/L were considered successful DM modeling. Both Vehicle and DM groups underwent SCIRI modeling via descending aortic clamping, while the Sham group underwent a sham procedure without aortic occlusion. Lower limb motor function was assessed using the Basso Mouse Scale (BMS) and its subscale (sub-BMS). Locomotor activity was evaluated using an open field test. Immunohistochemistry was performed to detect changes in neuronal nuclear protein (NeuN) and proBDNF expression in spinal cord tissues. Real-time reverse transcription polymerase chain reaction (RT-PCR) was used to measure mRNA expression of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). To explore the effect of proBDNF inhibition, diabetic mice were divided into groups: A DM+SCIRI+monoclonal anti-proBDNF antibody (McAb-proB) group received an intraperitoneal injection of 100 μg of McAb-proB 30 minutes before SCIRI modeling, and a DM+SCIRI+Vehicle group received an equal amount of isotype immunoglobulin G. BMS and sub-BMS scores were recorded, and the gene expression of inflammatory cytokines mentioned above were evaluated.

RESULTS

Compared with the Vehicle+SCIRI group, the DM+SCIRI group showed significantly reduced BMS and sub-BMS scores, decreased NeuN expression, shorter total movement distance, slower locomotion, increased proBDNF expression, and elevated IL-1β, IL-6, and TNF-α mRNA levels (all P<0.05 or P<0.01). Compared with the DM+SCIRI+Vehicle group, the DM+SCIRI+McAb-proB group exhibited significantly improved BMS and sub-BMS scores and decreased mRNA expression of IL-1β, IL-6, and TNF-α (all P<0.05 or P<0.01).

CONCLUSIONS

Hyperglycemia exacerbates neural injury and inflammatory response in SCIRI through upregulation of proBDNF expression, delaying motor functional recovery. Antagonizing proBDNF expression can alleviate neurological damage and promote functional recovery in diabetic mice after SCIRI.

Novel Perspective on Sevoflurane-Induced Cognitive Dysfunction: Implications of Neuronal SIRPα and Microglial Synaptic Remodeling

This study aims to investigate the role of neuronal SIRPα and microglial synaptic remodeling in sevoflurane-induced cognitive dysfunction in newborn mice. Newborn mice were exposed to sevoflurane, followed by behavioral assessments and single-cell transcriptome sequencing of cortical cells. Lentivirus-mediated overexpression of neuronal SIRPα and assessment of the microglial morphology and synaptic function were conducted. Sevoflurane exposure resulted in social cognitive impairments without affecting motor coordination. Transcriptomic analysis revealed no significant changes in cortical microglial cells or neurons. However, sevoflurane inhibited nonsynaptic synapse modification by microglia. Overexpression of neuronal SIRPα enhanced microglial function, promoted neuron development, and ameliorated cognitive impairments. SCENIC analysis identified a correlation between IRF8 and SIRPα expression. This study sheds light on the involvement of neuronal SIRPα and microglial synaptic remodeling in sevoflurane-induced cognitive dysfunction. Understanding these mechanisms offers new avenues for exploring cognitive impairment pathways and potential therapeutic targets.

TMEM164 promotes ferroptosis by selectively mediating ATG5-dependent autophagosome formation to inhibit the progression of LUAD

The study focuses on lung adenocarcinoma (LUAD), a predominant type of lung cancer. Despite advancements in diagnostics and molecular therapies, treatment remains challenging due to its low five-year survival rate. This study aims to investigate the role of the transmembrane protein TMEM164 in ferroptosis and anti-tumor immunity in LUAD, and to evaluate its potential as a therapeutic target. Through cellular experiments (such as QPCR, WB, CCK-8, EdU, Transwell, flow cytometry, CO-IP) and animal model experiments (including HE staining and IHC analysis), the relationship between TMEM164 expression and LUAD progression was explored, with particular attention to its mechanisms in ferroptosis and autophagy. The results show that TMEM164 expression is downregulated in LUAD and is associated with poor prognosis. Increasing TMEM164 expression significantly inhibits cell proliferation, migration, and invasion, while promoting an autophagy process dependent on ATG5 for autophagosome formation, thus facilitating ferroptosis. In mouse models, high TMEM164 expression combined with anti-PD-1 antibodies demonstrated synergistic anti-tumor effects. These findings highlight the critical role of TMEM164 in LUAD, suggesting that modulating TMEM164 expression could open new avenues for LUAD treatment.

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.

Identification of iron metabolism-related genes in coronary heart disease and construction of a diagnostic model

Background

Coronary heart disease is a common cardiovascular disease, yferroptosiset its relationship with iron metabolism remains unclear.

Methods

Gene expression data from peripheral blood samples of patients with coronary heart disease and a healthy control group were utilized for a comprehensive analysis that included differential expression analysis, weighted gene co-expression network analysis, gene enrichment analysis, and the development of a logistic regression model to investigate the associations and differences between the groups. Additionally, the CIBERSORT algorithm was employed to examine the composition of immune cell types within the samples.

Results

Eight central genes were identified as being both differentially expressed and related to iron metabolism. These central genes are mainly involved in the cellular stress response. A logistic regression model based on the central genes achieved an AUC of 0.64-0.65 in the diagnosis of coronary heart disease. A higher proportion of M0 macrophages was found in patients with coronary heart disease, while a higher proportion of CD8T cells was observed in the normal control group.

Conclusion

The study identified important genes related to iron metabolism in the pathogenesis of coronary heart disease and constructed a robust diagnostic model. The results suggest that iron metabolism and immune cells may play a significant role in the development of coronary heart disease, providing a basis for further research.

Hydrogen sulfide plays an important role by regulating microRNA in different ischemia-reperfusion injury

MicroRNAs (miRNAs) are the short endogenous non-coding RNAs that regulate the expression of the target gene at posttranscriptional level through degrading or inhibiting the specific target messenger RNAs (mRNAs). MiRNAs regulate the expression of approximately one-third of protein coding genes, and in most cases inhibit gene expression. MiRNAs have been reported to regulate various biological processes, such as cell proliferation, apoptosis and differentiation. Therefore, miRNAs participate in multiple diseases, including ischemia-reperfusion (I/R) injury. Hydrogen sulfide (H2S) was once considered as a colorless, toxic and harmful gas with foul smelling. However, in recent years, it has been discovered that it is the third gas signaling molecule after carbon monoxide (CO) and nitric oxide (NO), with multiple important biological functions. Increasing evidence indicates that H2S plays a vital role in I/R injury through regulating miRNA, however, the mechanism has not been fully understood. In this review, we summarized the current knowledge about the role of H2S in I/R injury by regulating miRNAs, and analyzed its mechanism in detail.

Targeting USP11 regulation by a novel lithium-organic coordination compound improves neuropathologies and cognitive functions in Alzheimer transgenic mice

Alzheimer's Disease (AD), as the most common neurodegenerative disease worldwide, severely impairs patients' cognitive functions. Although its exact etiology remains unclear, the abnormal aggregations of misfolded β-amyloid peptide and tau protein are considered pivotal in its pathological progression. Recent studies identify ubiquitin-specific protease 11 (USP11) as the key regulator of tau deubiquitination, exacerbating tau aggregation and AD pathology. Thereby, inhibiting USP11 function, via either blocking USP11 activity or lowering USP11 protein level, may serve as an effective therapeutic strategy against AD. Our research introduces IsoLiPro, a unique lithium isobutyrate-L-proline coordination compound, effectively lowers USP11 protein level and enhances tau ubiquitination in vitro. Additionally, long-term oral administration of IsoLiPro dramatically reduces total and phosphorylated tau levels in AD transgenic mice. Moreover, IsoLiPro also significantly lessens β-amyloid deposition and synaptic damage, improving cognitive functions in these animal models. These results indicate that IsoLiPro, as a novel small-molecule USP11 inhibitor, can effectively alleviate AD-like pathologies and improve cognitive functions, offering promise as a potential multi-targeting therapeutic agent against AD.

Ruxolitinib improves the inflammatory microenvironment, restores glutamate homeostasis, and promotes functional recovery after spinal cord injury

JOURNAL/nrgr/04.03/01300535-202419110-00030/figure1/v/2024-03-08T184507Z/r/image-tiff The inflammatory microenvironment and neurotoxicity can hinder neuronal regeneration and functional recovery after spinal cord injury. Ruxolitinib, a JAK-STAT inhibitor, exhibits effectiveness in autoimmune diseases, arthritis, and managing inflammatory cytokine storms. Although studies have shown the neuroprotective potential of ruxolitinib in neurological trauma, the exact mechanism by which it enhances functional recovery after spinal cord injury, particularly its effect on astrocytes, remains unclear. To address this gap, we established a mouse model of T10 spinal cord contusion and found that ruxolitinib effectively improved hindlimb motor function and reduced the area of spinal cord injury. Transcriptome sequencing analysis showed that ruxolitinib alleviated inflammation and immune response after spinal cord injury, restored EAAT2 expression, reduced glutamate levels, and alleviated excitatory toxicity. Furthermore, ruxolitinib inhibited the phosphorylation of JAK2 and STAT3 in the injured spinal cord and decreased the phosphorylation level of nuclear factor kappa-B and the expression of inflammatory factors interleukin-1β, interleukin-6, and tumor necrosis factor-α. Additionally, in glutamate-induced excitotoxicity astrocytes, ruxolitinib restored EAAT2 expression and increased glutamate uptake by inhibiting the activation of STAT3, thereby reducing glutamate-induced neurotoxicity, calcium influx, oxidative stress, and cell apoptosis, and increasing the complexity of dendritic branching. Collectively, these results indicate that ruxolitinib restores glutamate homeostasis by rescuing the expression of EAAT2 in astrocytes, reduces neurotoxicity, and effectively alleviates inflammatory and immune responses after spinal cord injury, thereby promoting functional recovery after spinal cord injury.

Spexin inhibits excessive autophagy-induced ferroptosis to alleviate doxorubicin-induced cardiotoxicity by upregulating Beclin 1

BACKGROUND AND PURPOSE

Doxorubicin is widely used in the treatment of malignant tumours, but doxorubicin-induced cardiotoxicity severely limits its clinical application. Spexin is a neuropeptide that acts as a novel biomarker in cardiovascular disease. However, the effects of spexin on doxorubicin-induced cardiotoxicity is unclear.

EXPERIMENTAL APPROACH

We established a model of doxorubicin-induced cardiotoxicity both in vivo and in vitro. Levels of cardiac damage in mice was assessed through cardiac function assessment, determination of serum cardiac troponin T and CKMB levels and histological examination. CCK8 and PI staining were used to assess the doxorubicin-induced toxicity in cultures of cardiomyocytes in vitro. Ferroptosis was assessed using FerroOrange staining, determination of MDA and 4-HNE content and ferroptosis-associated proteins SLC7A11 and GPX4. Mitochondrial membrane potential and lipid peroxidation levels were measured using TMRE and C11-BODIPY 581/591 probes, respectively. Myocardial autophagy was assessed by expression of P62 and Beclin1.

KEY RESULTS

Spexin treatment improved heart function of mice with doxorubicin-induced cardiotoxicity, and attenuated doxorubicin-induced cardiotoxicity by decreasing iron accumulation, abnormal lipid metabolism and inhibiting ferroptosis. Interestingly, doxorubicin caused excessive autophagy in cardiomyocyte in culture, which could be alleviated by treatment with spexin. Knockdown of Beclin 1 eliminated the protective effects of spexin in mice with DIC.

CONCLUSION AND IMPLICATIONS

Spexin ameliorated doxorubicin-induced cardiotoxicity by inhibiting excessive autophagy-induced ferroptosis, suggesting that spexin could be a drug candidate against doxorubicin-induced cardiotoxicity. Beclin 1 might be critical in mediating the protective effect of spexin against doxorubicin-induced cardiotoxicity.

Iron homeostasis and ferroptosis in human diseases: mechanisms and therapeutic prospects

Iron, an essential mineral in the body, is involved in numerous physiological processes, making the maintenance of iron homeostasis crucial for overall health. Both iron overload and deficiency can cause various disorders and human diseases. Ferroptosis, a form of cell death dependent on iron, is characterized by the extensive peroxidation of lipids. Unlike other kinds of classical unprogrammed cell death, ferroptosis is primarily linked to disruptions in iron metabolism, lipid peroxidation, and antioxidant system imbalance. Ferroptosis is regulated through transcription, translation, and post-translational modifications, which affect cellular sensitivity to ferroptosis. Over the past decade or so, numerous diseases have been linked to ferroptosis as part of their etiology, including cancers, metabolic disorders, autoimmune diseases, central nervous system diseases, cardiovascular diseases, and musculoskeletal diseases. Ferroptosis-related proteins have become attractive targets for many major human diseases that are currently incurable, and some ferroptosis regulators have shown therapeutic effects in clinical trials although further validation of their clinical potential is needed. Therefore, in-depth analysis of ferroptosis and its potential molecular mechanisms in human diseases may offer additional strategies for clinical prevention and treatment. In this review, we discuss the physiological significance of iron homeostasis in the body, the potential contribution of ferroptosis to the etiology and development of human diseases, along with the evidence supporting targeting ferroptosis as a therapeutic approach. Importantly, we evaluate recent potential therapeutic targets and promising interventions, providing guidance for future targeted treatment therapies against human diseases.

USP24 promotes autophagy-dependent ferroptosis in hepatocellular carcinoma by reducing the K48-linked ubiquitination of Beclin1

Ubiquitination is a post-translational modification (PTM), which is critical to maintain cell homeostasis. Ubiquitin-specific protease 24 (USP24) plays roles in various diseases, the mechanisms by which USP24 regulates hepatocellular carcinoma (HCC) remain poorly understood. In this study, USP24 is found to be significantly downregulated in HCC. Knocking down USP24 promotes HCC proliferation and migration, whereas USP24 overexpression inhibits HCC in vitro and in vivo. The endogenous interaction between USP24 and Beclin1 is confirmed. Mechanically, USP24 delays Beclin1 degradation by reducing its K48-linked ubiquitination, the effects of overexpressing USP24 on HCC proliferation can be partially reversed by silencing Beclin1. We find that increased autophagy is accompanied by ferroptosis in USP24 overexpressed HCC cells and USP24 increases the susceptibility of HCC to sorafenib. Collectively, this study highlights the critical role of USP24 in regulating autophagy-dependent ferroptosis by decreasing Beclin1 ubiquitination, suggesting that targeting USP24 may be a strategy for treating HCC.

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.