Role Of Necroptosis Research Articles

Parkin deficiency exacerbates particulate matter-induced injury by enhancing airway epithelial necroptosis

Exposure to fine particulate matter (PM) disrupts the function of airway epithelial barriers causing cellular stress and damage. However, the precise mechanisms underlying PM-induced cellular injury and the associated molecular pathways remain incompletely understood. In this study, we used intratracheal instillation of PM in C57BL6 mice and PM treatment of the BEAS-2B cell line as in vivo and in vitro models, respectively, to simulate PM-induced cellular damage and inflammation. We collected lung tissues and bronchoalveolar lavage fluids to assess histopathological changes, necroptosis, and airway inflammation. Our findings reveal that PM exposure induces necroptosis in mouse airway epithelial cells. Importantly, concurrent administration of a receptor interacting protein kinases 3 (RIPK3) inhibitor or the deletion of the necroptosis effector mixed-lineage kinase domain-like protein (MLKL) effectively attenuated PM-induced airway inflammation. PM exposure dose-dependently induces the expression of Parkin, an E3 ligase we recently reported to play a pivotal role in necroptosis through regulating necrosome formation. Significantly, deletion of endogenous Parkin exacerbates inflammation by enhancing epithelial necroptosis. These results indicate that PM-induced Parkin expression plays a crucial role in suppressing epithelial necroptosis, thereby reducing airway inflammation. Overall, these findings offer valuable mechanistic insights into PM-induced airway injury and identify a potential target for clinical intervention.

Discovery of 5-(1-benzyl-1H-imidazol-4-yl)-1,2,4-oxadiazole derivatives as novel RIPK1 inhibitors via structure-based virtual screening.

RIPK1 plays a key role in necroptosis and is associated with various inflammatory diseases. Using structure-based virtual screening, a novel hit with 5-(1-benzyl-1H-imidazol-4-yl)-1,2,4-oxadiazole scaffold was identified as an RIPK1 inhibitor with an IC50 value of 1.3 μM. Further structure-activity relationship study was performed based on similarity research and biological evaluation. The molecular dynamics simulation of compound 2 with RIPK1 indicated that it may act as a type II kinase inhibitor. This study provides a highly efficient way to discover novel scaffold RIPK1 inhibitors for further development.

Necroptosis in recurrent implantation failure: A bioinformatics analysis of key genes and therapeutic targets.

Recurrent implantation failure (RIF), a major issue in assisted reproductive technology (ART), may be influenced by necroptosis, a form of cell death linked to several diseases. This study was aimed at investigating the involvement of necroptosis in RIF. Using RNA-sequencing data from the Gene Expression Omnibus database, we identified differentially expressed necroptosis-related genes (DENRGs) in RIF patients compared with those in controls. Functional enrichment, protein-protein interaction (PPI) networks, and transcription factor (TF) regulatory networks were analyzed to identify key genes. Immune cell infiltration was analyzed using the single-sample gene set enrichment analysis (ssGSEA) algorithm. Finally, potential therapeutic drugs targeting key genes were explored using a Drug Gene Interaction Database. In total, 20 DENRGs associated with RIF were identified, with a focus on 6 key genes (MLKL, FASLG, XIAP, CASP1, BIRC3, and TLR3) implicated in necroptosis and immune processes. These genes were used to develop a predictive model for RIF, which was validated in 2 datasets. The model and TF network analysis underscored the importance of TLR3. Immune infiltration analysis showed reduced levels of 16 immune cells in RIF patients, highlighting immune system alterations. Several drugs targeting CASP1, such as nivocasan and emricasan, were identified as potential treatments. The study sheds light on the role of necroptosis in RIF, identifying key genes and immune alterations that could serve as biomarkers and therapeutic targets. These findings pave the way for future experimental research and clinical applications targeting necroptosis in RIF treatment.

Bioinformatics reveals the potential mechanisms and biomarkers of necroptosis in neuroblastoma.

Neuroblastoma (NB) is a malignant tumor primarily found in children, presenting significant challenges in its development and prognosis. The role of necroptosis in the pathogenesis of NB has been acknowledged as crucial for treatment. This study aimed to investigate the key genes and functional pathways associated with necroptosis, as well as immune infiltration analysis, in NB. Furthermore, we aimed to evaluate the diagnostic significance of these genes for prognostic assessment and explore their potential immunological characteristics. The NB dataset (GSE19274, GSE73517, and GSE85047) was obtained from the Gene Expression Omnibus (GEO) database, and genes associated with necroptosis were collected from GeneCards and previous literature. First, we conducted differential expression analysis and performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). We employed gene set enrichment analysis (GSEA) to identify overlapping enriched functional pathways from the NB dataset. In addition, we constructed a protein-protein interaction (PPI) network, predicting relevant microRNAs (miRNAs) and transcription factors (TFs), as well as their corresponding drug predictions. Furthermore, the diagnostic value was assessed using receiver operating characteristic (ROC) curves. Finally, an immune infiltration analysis was performed. We identified six necroptosis-related differentially expressed genes (NRDEGs) closely associated with necroptosis in NB. They were enriched in Tuberculosis, Apoptosis-multiple species, Salmonella infection, legionellosis, and platinum drug resistance. GSEA and PPI network analyses, along with mRNA-drug interaction network, revealed 38 potential drugs corresponding to BIRC2, CAMK2G, CASP3, and IL8. ROC curve analysis showed that in GSE19274, FLOT2 with area under the ROC curve (AUC) of 0.850 and DAPK1 with AUC of 0.789. Our study elucidates the key genes and functional pathways associated with necroptosis in NB, offering valuable insights to enhance our comprehension of the pathogenesis of NB, and improve prognosis assessment.

GSK’872 Improves Prognosis of Traumatic Brain Injury by Switching Receptor-Interacting Serine/Threonine-Protein Kinase 3-dependent Necroptosis to Cysteinyl Aspartate Specific Proteinase-8-Dependent Apoptosis

Traumatic brain injury (TBI) is an important health concern in the society. Previous studies have suggested that necroptosis occurs following TBI. However, the underlying mechanisms and roles of necroptosis are not well understood. In this study, we aimed to assess the role of receptor-interacting serine/threonine-protein kinase 3 (RIP3)-mediated necroptosis after TBI both invitro and invivo. We established a cell-stretching injury and mouse TBI model by applying a cell injury controller and controlled cortical impactor to evaluate the relationships among necroptosis, apotosis, inflammation, and TBI both invitro and invivo. The results revealed that necroptosis mediated by RIP1, RIP3, and mixed lineage kinase domain-like protein was involved in secondary TBI. Additionally, protein kinase B (Akt), phosphorylated Akt, mammalian target of rapamycin (mTOR), and phosphorylated mTOR potentially contribute to necroptosis. The inhibition of RIP3 by GSK'872 (a specific inhibitor) blocked necroptosis and reduced the activity of Akt/mTOR, leading to the alleviation of inflammation by reducing the levels of NOD-, LRR- and pyrin domain-containing protein 3. Moreover, the inhibition of RIP3 by GSK'872 promoted the activity of cysteinyl aspartate specific proteinase-8, an enzyme involved in apoptosis and inflammation. These data demonstrate that RIP3 inhibition could improve the prognosis of TBI, based on the attenuation of inflammation by switching RIP3-dependent necroptosis to cysteinyl aspartate specific proteinase-8-dependent apoptosis.

The Role of Microvascular Obstruction and Intra-Myocardial Hemorrhage in Reperfusion Cardiac Injury. Analysis of Clinical Data.

Microvascular obstruction (MVO) of coronary arteries promotes an increase in mortality and major adverse cardiac events in patients with acute myocardial infarction (AMI) and percutaneous coronary intervention (PCI). Intramyocardial hemorrhage (IMH) is observed in 41-50% of patients with ST-segment elevation myocardial infarction and PCI. The occurrence of IMH is accompanied by inflammation. There is evidence that microthrombi are not involved in the development of MVO. The appearance of MVO is associated with infarct size, the duration of ischemia of the heart, and myocardial edema. However, there is no conclusive evidence that myocardial edema plays an important role in the development of MVO. There is evidence that platelets, inflammation, overload, neuropeptide Y, and endothelin-1 could be involved in the pathogenesis of MVO. The role of endothelial cell damage in MVO formation remains unclear in patients with AMI and PCI. It is unclear whether nitric oxide production is reduced in patients with MVO. Only indirect evidence on the involvement of inflammation in the development of MVO has been obtained. The role of reactive oxygen species (ROS) in the pathogenesis of MVO is not studied. The role of necroptosis and pyroptosis in the pathogenesis of MVO in patients with AMI and PCI is also not studied. The significance of the balance of thromboxane A2, vasopressin, angiotensin II, and prostacyclin in the formation of MVO is currently unknown. Conclusive evidence regarding the role of coronary artery spasm in the development of MVhasn't been established. Correlation analysis of the neuropeptide Y, endothelin-1 levels and the MVO size in patients with AMI and PCI has not previously been performed. It is unclear whether epinephrine aggravates reperfusion necrosis of cardiomyocytes. Dual antiplatelet therapy improves the efficacy of PCI in prevention of MVO. It is unknown whether epinephrine or L-type channel blockers result in the long-term improvement of coronary blood flow in patients with MVO.

Cigarette tar accelerates atherosclerosis progression via RIPK3-dependent necroptosis mediated by endoplasmic reticulum stress in vascular smooth muscle cells

BackgroundTar is the main toxic of cigarettes, and its effect on atherosclerosis progression and the underlying mechanisms remain largely unknown. Vascular smooth muscle cells (VSMCs) play a key role in atherogenesis and plaque vulnerability. The present study sought to investigate the mechanism of atherosclerosis progression through tar-induced VSMC necroptosis, a recently described form of necrosis.MethodsThe effect of tar on atherosclerosis progression and VSMC necroptosis was examined in ApoE−/− mice and cultured VSMCs. The role of necroptosis in tar-induced plaque development was evaluated in RIPK3-deletion mice (ApoE−/−RIPK3−/−). The key proteins of necroptosis in carotid plaques of smokers and non-smokers were also examined. Quantitative proteomics of mice aortas was conducted to further investigate the underlying mechanism. Pharmacological approaches were then applied to modulate the expression of targets to verify the regulatory process of tar-induced necroptosis.ResultsTar administration led to increased atherosclerotic plaque area and reduced collagen and VSMCs in ApoE−/− mice. The expression of RIPK1、RIPK3、and MLKL in VSMCs of plaques were all increased in tar-exposed mice and smokers. RIPK3 deletion protected against VSMC loss and plaque progression stimulated by tar. In mechanistic studies, quantitative proteomics analysis of ApoE−/− mice aortas suggested that tar triggered endoplasmic reticulum (ER) stress. PERK-eIF2α-CHOP axis was activated in tar-treated VSMCs and atherosclerotic plaque. Inhibition of ER stress using 4PBA significantly reduced plaque progression and VSMC necroptosis. Further study revealed that ER stress resulted in calcium (Ca2+) release into mitochondria and cytoplasm. Elevated Ca2+ levels lead to mitochondrial dysfunction and excessive reactive oxygen species (ROS) production, which consequently promote RIPK3-dependent necroptosis. In addition, Ca2+/calmodulin-dependent protein kinase II (CaMKII) activated by cytosolic Ca2+ overload binds to RIPK3, accounting for necroptosis.ConclusionThe findings revealed that cigarette tar promoted atherosclerosis progression by inducing RIPK3-dependent VSMC necroptosis and identified novel avenues of ER stress and Ca2+ overload.

MLKL Protects Pulmonary Endothelial Cells in Acute Lung Injury.

The role of autophagy in pulmonary microvascular endothelial cells (PMVECs) is controversial in LPS-induced acute lung injury (ALI). Mixed lineage kinase domain-like pseudokinase (MLKL) has recently been reported to maintain cell survival by facilitating autophagic flux in response to starvation rather than its well-recognized role in necroptosis. Using a mouse PMVEC and LPS-induced ALI model, we showed that in PMVECs, MLKL was phosphorylated (p-MLKL) and autophagic flux was accelerated at the early stage of LPS stimulation (1-3 h), manifested by increases in concentrations of lipidated MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 β; LC3-II), decreases in concentrations of SQSTM1/p62 (sequestosome 1), and fusion of the autophagosome and lysosome by pHluorin-mKate2-human LC3 assay, which were all reversed by either MLKL inhibitor or siRNA MLKL. In mice, the inhibition of MLKL increased vascular permeability and aggravated mouse ALI upon 3-hour LPS stimulation. The p-MLKL induced by short-term LPS formed multimers to facilitate the closure of the phagophore by HaloTag-LC3 autophagosome completion assay. The charged multivesicular body protein 2A (CHMP2A) is essential in the process of phagophore closure into the nascent autophagosome. In agreement with the p-MLKL change, CHMP2A concentrations markedly increased during 1-3-hour LPS stimulation. CHMP2A knockdown blocked autophagic flux upon LPS stimulation, whereas CHMP2A overexpression boosted autophagic flux and attenuated mouse ALI even in the presence of MLKL inhibitor. We propose that the activated MLKL induced by short-term LPS facilitates autophagic flux by accelerating the closure of the phagophore via CHMP2A, thus protecting PMVECs and alleviating LPS-induced ALI.

Inhibition of the RIP3/MLKL/TRPM7 necroptotic pathway ameliorates diabetes mellitus-induced erectile dysfunction by reducing cell death, fibrosis, and inflammation.

Diabetes mellitus-induced erectile dysfunction (DMED) is a common complication in patients with diabetes mellitus. Necroptosis is regarded as a form of cell death that is intimately associated with the inflammatory response, which is not only initiated by inflammatory factors such as TNF-α, but also triggers the inflammatory cascade through the rupture of the dying cell. There is no definitive study on the role of necroptosis in the pathological process of DMED. In light of the pathological features of high inflammation levels in DMED patients, we assessed whether the necroptosis plays an important role in the course of DMED. Our study revealed that penile tissues of DMED rats showed high levels of key necroptosis factors such as receptor-interacting protein kinase 3 (RIP3), mixed-lineage kinase domain-like protein (MLKL), and transient receptor potential melatonin 7 (TRPM7). Furthermore, the inhibition of necroptosis with a receptor-interacting protein kinase 3 (RIP3) inhibitor or Yimusake (a common herbal remedy for ED) effectively rescued damage to corpus cavernosum smooth muscle cells (CCSMC) under high glucose conditions. Our findings suggest that inhibition of the RIP3/MLKL/TRPM7 necroptotic pathway could effectively ameliorate CCSMCs fibrosis and death induced by high glucose and inhibited the inflammatory response.

Identification and Validation of a Necroptosis-Related Prognostic Model in Tumor Recurrence and Tumor Immune Microenvironment in Breast Cancer Management.

Breast cancer is the leading cause of cancer-related death in women. Necroptosis, a form of programmed necrotic cell death, occurs in many solid tumors, including breast cancer, and influences anti-tumor immunity. The role of necroptosis in managing breast cancer recurrence remains unclear. Gene expression profiles and clinical data of breast cancer patients were obtained from the GEO (GSE20685, GSE21653, GSE25055) and TCGA databases. Data analysis and visualization were performed using R. Unsupervised Consensus Clustering and LASSO-COX regression stratified breast cancer patients. GO, KEGG, GSVA, ESTIMATE, and ROC analyses were used to investigate necroptotic signatures. In vitro and in vivo experiments validated necroptosis's role in breast cancer immunity. The potential function of necroptotic signature in immunity was first indicated with GO analysis in BRCA cohort. Next, two prognostic models based on the necroptotic profiles both suggested a link between low-risk group with a particular necroptotic immune signature. And a variety of immune cells and immune pathways were shown to be positively associated with a patient's risk score. As an altered immune checkpoint pattern was observed after regulating necroptotic genes, where TIM-3 and LAGLS9 elevated significantly in low-risk group, further validation in vitro and in vivo demonstrated that manipulating a subset of necroptotic gene set could sensitize tumor response to the co-blockade immunotherapy of anti-TIM-3 and anti-PD-1. We demonstrated two strategies to stratify breast cancer patients based on their necroptotic profiles and showed that necroptotic signature could assign patients with different tumor immune microenvironment patterns and different recurrence-related prognosis. A subset of necroptotic gene set, composed of TLR3, RIPK3, NLRP3, CASP1, ALDH2 and EZH2, was identified as a biomarker set for predicting immunotherapy-response and recurrence-related prognosis. Targeting necroptosis could helpfacilitate the development of novel breast cancer treatments and tailor personalized medical treatment.

Is death a living being?

The death process begins with the loss of function of one or more of the three classic vital organs: the heart, the brain, and/or the lungs. Failure to resuscitate the function of the affected primary organ leads to the cessation of the function of other organs. The cell carries death factors or elements such as caspases and some mitochondrial secretions - At the same time the mitochondria represent the basic source of energy and life in the cell. Death occurs only when activating the molecules and factors of cell annihilation. Apoptosis is a type of cell death mechanism, controlled by interactions between several molecules - and is responsible for removing unwanted cells from the body. Apoptosis can be induced by signals from inside the cell or by death signals coming from outside the cell via cosmic energy waves. Caspases are cysteine aspartate-specific proteases that are essential for the initiation and execution of apoptosis. As one of the initiator and executor caspases, caspase-2 is the most evolutionally conserved caspase, exerting both apoptotic and non-apoptotic functions. Caspases also have a role in inflammation, whereby they directly process proinflammatory cytokines such as pro-IL1β. These are signaling molecules that allow recruitment of immune cells to an infected cell or tissue. In addition to apoptosis, caspases play a role in necroptosis, pyroptosis, and autophagy, which are non-apoptotic cell death processes. Mitochondria coordinate cell stress responses, such as autophagy, and control nonapoptotic cell death routines, such as regulated necrosis. Mitochondrial permeabilization leads to release of these proteins, which then interfere with the IAP-inhibition of caspases, resulting in potentiation of cell death. Initiators of mitochondrial-driven inflammation include the release of mitochondrial dsRNA and mt DNA thereby initiating type I interferons. It is concluded that mitochondria not only power the metabolic cell activities with energy but also power the cell death with both energy and signaling molecules denoting that cell death is an active living being.

Role of the RIP3-PGAM5-Drp1 pathway in aluminum-induced PC12 cells necroptosis

Epidemiological studies from diverse global regions suggest a correlation between the accumulation of aluminum in the brain and the onset of various neurodegenerative diseases, including Alzheimer's disease, of which, neuronal cells death happen. Our previous research has found the potential of aluminum to induce neuronal cell death. A comprehensive exploration of the regulatory pathways influenced by aluminum in neuronal cell death could contribute to the development of strategies aimed at preventing the detrimental impact of aluminum on neuronal cells. This study is dedicated to exploring the impact of aluminum on mitochondrial homeostasis through the RIP3-PGAM5-Drp1 pathway, with a specific focus on its potential role in necroptosis. We observed that the inhibition of RIP3 function and the reduction in PGAM5 protein expression both mitigate aluminum-induced necroptosis in PC12 cells and enhance mitochondrial function. However, the inhibition of PGAM5 protein expression does not exert an impact on the expression of RIP3 and MLKL proteins. In summary, our study posits that aluminum can induce necroptosis in PC12 cells through the RIP3-PGAM5-Drp1 pathway.

Dynamic landscape of the intracellular termini of acid-sensing ion channel 1a.

Acid-sensing ion channels (ASICs) are trimeric proton-gated sodium channels. Recent work has shown that these channels play a role in necroptosis following prolonged acidic exposure like occurs in stroke. The C-terminus of ASIC1a is thought to mediate necroptotic cell death through interaction with receptor interacting serine threonine kinase 1 (RIPK1). This interaction is hypothesized to be inhibited at rest via an interaction between the C- and N-termini which blocks the RIPK1 binding site. Here, we use two transition metal ion FRET methods to investigate the conformational dynamics of the termini at neutral and acidic pH. We do not find evidence that the termini are close enough to be bound while the channel is at rest and find that the termini may modestly move closer together during acidification. At rest, the N-terminus adopts a conformation parallel to the membrane about 10 Å away. The distal end of the C-terminus may also spend time close to the membrane at rest. After acidification, the proximal portion of the N-terminus moves marginally closer to the membrane whereas the distal portion of the C-terminus swings away from the membrane. Together these data suggest that a new hypothesis for RIPK1 binding during stroke is needed.

Dynamic landscape of the intracellular termini of acid-sensing ion channel 1a

Acid-sensing ion channels (ASICs) are trimeric proton-gated sodium channels. Recent work has shown that these channels play a role in necroptosis following prolonged acidic exposure like occurs in stroke. The C-terminus of ASIC1a is thought to mediate necroptotic cell death through interaction with receptor interacting serine threonine kinase 1 (RIPK1). This interaction is hypothesized to be inhibited at rest via an interaction between the C- and N-termini which blocks the RIPK1 binding site. Here, we use two transition metal ion FRET methods to investigate the conformational dynamics of the termini at neutral and acidic pH. We do not find evidence that the termini are close enough to be bound while the channel is at rest and find that the termini may modestly move closer together during acidification. At rest, the N-terminus adopts a conformation parallel to the membrane about 10 Å away. The distal end of the C-terminus may also spend time close to the membrane at rest. After acidification, the proximal portion of the N-terminus moves marginally closer to the membrane whereas the distal portion of the C-terminus swings away from the membrane. Together these data suggest that a new hypothesis for RIPK1 binding during stroke is needed.

The Role of Necroptosis in Cerebral Ischemic Stroke.

Cerebral ischemia, also known as ischemic stroke, accounts for nearly 85% of all strokes and is the leading cause of disability worldwide. Due to disrupted blood supply to the brain, cerebral ischemic injury is trigged by a series of complex pathophysiological events including excitotoxicity, oxidative stress, inflammation, and cell death. Currently, there are few treatments for cerebral ischemia owing to an incomplete understanding of the molecular and cellular mechanisms. Accumulated evidence indicates that various types of programmed cell death contribute to cerebral ischemic injury, including apoptosis, ferroptosis, pyroptosis and necroptosis. Among these, necroptosis is morphologically similar to necrosis and is mediated by receptor-interacting serine/threonine protein kinase-1 and -3 and mixed lineage kinase domain-like protein. Necroptosis inhibitors have been shown to exert inhibitory effects on cerebral ischemic injury and neuroinflammation. In this review, we will discuss the current research progress regarding necroptosis in cerebral ischemia as well as the application of necroptosis inhibitors for potential therapeutic intervention in ischemic stroke.

Nocardia seriolae mediates granulomatous chronic inflammation of spleen in Micropterus salmoides through necroptosis

Granulomatous chronic inflammation is a typical pathological characteristic of largemouth bass (Micropterus salmoides) infected by Nocardia seriolae, and it is also an important breakthrough to solve the problem of pathogen prevention and treatment.Spleen, the target organ of N. seriolae infection, is significant for studying pathogenic mechanism. However, histopathological characteristics and immunological molecular mechanisms of the development of splenic granulomas in fish have not been extensively studied. In the initial process of exploring the molecular mechanism of N. seriolae infectious splenic granuloma formation, we accidentally found positive signals of necroptosis-related gene by immunohistochemical staining, suggesting that necroptosis may be involved in the formation of granulomas.Nevertheless, the role of necroptosis in the formation of splenic granuloma is still unclear. In this study, we established a granuloma model in the spleen of largemouth bass infected by N. seriolae. Through multiple tissue staining, we compared splenic granulomas with hepatic and renal granulomas, and preliminarily clarified the histopathological characteristics of splenic granulomas and the formation pattern of fibrosis, calcium salt deposition and other lesions. Notably, we found that the expression of inflammatory factors and necroptosis-related molecules in spleen were significantly upregulated during N. seriolae infection. Further immunohistochemical staining showed that the splenic granulomas were accompanied by extensive and intense p-MLKL-positive signals in the peripheral tissue. In addition, western blot and immunofluorescence results showed that N. seriolae could induce necroptosis in primary spleen cells of largemouth bass in vitro. Our data indicated that necroptosis is closely related to the formation of splenic granulomas in largemouth bass, and provide some ideas for the study of the formation mechanism of fish granuloma.

Role of Necroptosis in Intervertebral Disc Degeneration.

Apoptosis has historically been considered the primary form of programmed cell death (PCD) and is responsible for regulating cellular processes during development, homeostasis, and disease. Conversely, necrosis was considered uncontrolled and unregulated. However, recent evidence has unveiled the significance of necroptosis, a regulated form of necrosis, as an important mechanism of PCD alongside apoptosis. The activation of necroptosis leads to cellular membrane disruption, inflammation, and vascularization. This process is crucial in various pathological conditions, including intervertebral disc degeneration (IVDD), neurodegeneration, inflammatory diseases, multiple cancers, and kidney injury. In recent years, extensive research efforts have shed light on the molecular regulation of the necroptotic pathway. Various stimuli trigger necroptosis, and its regulation involves the activation of specific proteins such as receptor-interacting protein kinase 1 (RIPK1), RIPK3, and the mixed lineage kinase domain-like (MLKL) pseudokinase. Understanding the intricate mechanisms governing necroptosis holds great promise for developing novel therapeutic interventions targeting necroptosis-associated IVDD. The objective of this review is to contribute to the growing body of scientific knowledge in this area by providing a comprehensive overview of necroptosis and its association with IVDD. Ultimately, these understandings will allow the development of innovative drugs that can modulate the necroptotic pathway, offering new therapeutic avenues for individuals suffering from necroptosis.

Role of Necroptosis, a Regulated Cell Death, in Seizure and Epilepsy.

Epilepsy is a chronic neurological disease that is characterized by spontaneous and recurrent seizures. Regulated cell death is a controlled process and has been shown to be involved in neurodegenerative diseases. Necroptosis is a type of regulated cell death, and its association with epilepsy has been documented. Necroptosis signaling can be divided into two pathways: canonical and non-canonical pathways. Inhibition of caspase-8, dimerization of receptor-interacting protein kinase 1 (RIP1) and RIP3, activation of mixed-lineage kinase domain-like protein (MLKL), movement of MLKL to the plasma membrane, and cell rupture occurred in these pathways. Through literature review, it has been revealed that there is a relationship between seizure, neuroinflammation, and oxidative stress. The seizure activity triggers the activation of various pathways within the central nervous system, including TNF-α/matrix metalloproteases, Neogenin and Calpain/ Jun N-terminal Kinase 1, which result in distinct responses in the brain. These responses involve the activation of neurons and astrocytes, consequently leading to an increase in the expression levels of proteins and genes such as RIP1, RIP3, and MLKL in a time-dependent manner in regions such as the hippocampus (CA1, CA3, dentate gyrus, and hilus), piriform cortex, and amygdala. Furthermore, the imbalance in calcium ions, depletion of adenosine triphosphate, and elevation of extracellular glutamate and potassium within these pathways lead to the progression of necroptosis, a reduction in seizure threshold, and increased susceptibility to epilepsy. Therefore, it is plausible that therapeutic targeting of these pathways could potentially provide a promising approach for managing seizures and epilepsy.

RIP3/MLKL regulates necroptosis via activating 4EBP1-eIF4E pathway.

Necroptosis is a cell death type mediated by receptor interacting protein 3 (RIP3)/mixed lineage kinase domain-like protein (MLKL). It has been reported that mammalian target of rapamycin plays a regulatory role in necroptosis. Eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1)-eukaryotic initiation factor 4E (eIF4E) pathway is a key down streamer of mammalian target of rapamycin. However, whether 4EBP1-eIF4E pathway is involved in necroptosis is still unknown. This study aims to investigate the changes of 4EBP1-eIF4E pathway in necroptosis. TNF-α/SM-164/Z-VAD-FMK (TSZ), a necroptosis inducer, was used to induce necroptosis in murine fibroblastoid cell line L929. Cell necrosis was observed under an optical microscope. Then, TSZ was added to L929 cells with RIP3 and MLKL gene knockout. Propidium iodide (PI) staining was used to observe cell necrosis. Real-time fluorescence quantitative PCR and Western blotting were used to determine the mRNA and protein expression of 4EBP1 and eIF4E, respectively. After treating L929 cells with TSZ, the number of necrotic cells was increased, the mRNA and protein expression levels of 4EBP1 were significantly downregulated, and the ratio of phosphorylated 4EBP1 (p-4EBP1) to 4EBP1 was increased (P<0.05 or P<0.01); the mRNA expression level of eIF4E was significantly upregulated, and the ratio of phosphorylated eIF4E (p-eIF4E) to eIF4E was increased (both P<0.01). After knocking out RIP3 and MLKL in L929 cells, PI positive necrotic cells were significantly reduced, the mRNA and protein expression levels of 4EBP1 were significantly upregulated, and the ratio of p-4EBP1 to 4EBP1 was decreased (P<0.05 or P<0.01); the mRNA expression level of eIF4E was significantly downregulated, and the ratio of p-eIF4E to eIF4E was decreased (both P<0.01). 4EBP1-eIF4E pathway is activated in the RIP3/MLKL mediated-necroptosis.

Pharmaceutical Therapies for Necroptosis in Myocardial Ischemia-Reperfusion Injury.

Cardiovascular disease morbidity/mortality are increasing due to an aging population and the rising prevalence of diabetes and obesity. Therefore, innovative cardioprotective measures are required to reduce cardiovascular disease morbidity/mortality. The role of necroptosis in myocardial ischemia-reperfusion injury (MI-RI) is beyond doubt, but the molecular mechanisms of necroptosis remain incompletely elucidated. Growing evidence suggests that MI-RI frequently results from the superposition of multiple pathways, with autophagy, ferroptosis, and CypD-mediated mitochondrial damage, and necroptosis all contributing to MI-RI. Receptor-interacting protein kinases (RIPK1 and RIPK3) as well as mixed lineage kinase domain-like pseudokinase (MLKL) activation is accompanied by the activation of other signaling pathways, such as Ca2+/calmodulin-dependent protein kinase II (CaMKII), NF-κB, and JNK-Bnip3. These pathways participate in the pathological process of MI-RI. Recent studies have shown that inhibitors of necroptosis can reduce myocardial inflammation, infarct size, and restore cardiac function. In this review, we will summarize the molecular mechanisms of necroptosis, the links between necroptosis and other pathways, and current breakthroughs in pharmaceutical therapies for necroptosis.