Occurrence Of Necroptosis Research Articles

The traditional herb Sargentodoxa cuneata alleviates DSS-induced colitis by attenuating epithelial barrier damage via blocking necroptotic signaling

Ethnopharmacological relevanceThe traditional Chinese herb, Sargentodoxa cuneata, is primarily utilized as a crucial herb for managing ulcerative colitis (UC), also known as “Da Xue Teng (DXT)” or “Hong Teng” in Chinese. Nevertheless, the chemical composition, prototype, and metabolite constituents of DXT and its pharmacological mechanism of treatment for UC remain unclear. Aim of the studyNecroptosis, a caspase-independent form of programmed cell death, plays a crucial role in the inflammatory pathogenesis of UC. The occurrence of necroptosis in intestinal epithelial cells triggers a robust inflammatory response and disrupts the integrity of both the mucinous barrier and tight junction construction. The objective of our study was to determine the chemical composition of DXT, identify its absorbed active ingredients and metabolites in rat serum, and investigate whether DXT possesses epithelial barrier protective effects by inhibiting necroptosis. Materials and methodsFirst, the UPLC-Q-TOF/MS was applied to identify the chemical composition of DXT, as well as the absorption components and metabolites of DXT in rat serum. Second, the network pharmacology analysis was further investigated to elucidate the potential targets for treating UC. Finally, the mechanism of action was validated by necroptosis-based experiment in vitro and an in vivo model of colitis. ResultsA comprehensive analysis revealed the presence of 31 phytochemicals derived from DXT herb, as well as a total of 39 components in rat serum. Network pharmacology analysis indicated that TNF, EGFR, HSP90, etc. are the potential targets. Experimental in vitro and in vivo verified that the DXT could improve disease activity index, body weight, colon length and intestinal barrier permeability in mice with colitis by inhibiting necroptosis of intestinal epithelial cells. ConclusionsIn this study, the phytochemicals derived from DXT herb and absorption active ingredients and metabolites of DXT in rat serum were analyzed. The biological mechanism of treatment for UC can be elucidated by combining network pharmacology investigation with experimental in vitro and in vivo studies. The findings offered a theoretical basis for comprehending the bioactive substances and the pharmacological process of DXT.

Major adverse cardiovascular events are associated with necroptosis during severe COVID-19

BackgroundThe mechanisms used by SARS-CoV-2 to induce major adverse cardiac events (MACE) are unknown. Thus, we aimed to determine if SARS-CoV-2 can induce necrotic cell death to promote MACE in patients with severe COVID-19.MethodsThis observational prospective cohort study includes experiments with hamsters and human samples from patients with severe COVID-19. Cytokines and serum biomarkers were analysed in human serum. Cardiac transcriptome analyses were performed in hamsters' hearts.ResultsFrom a cohort of 70 patients, MACE was documented in 26% (18/70). Those who developed MACE had higher Log copies/mL of SARS-CoV-2, troponin-I, and pro-BNP in serum. Also, the elevation of IP-10 and a major decrease in levels of IL-17ɑ, IL-6, and IL-1rɑ were observed. No differences were found in the ability of serum antibodies to neutralise viral spike proteins in pseudoviruses from variants of concern. In hamster models, we found a stark increase in viral titters in the hearts 4 days post-infection. The cardiac transcriptome evaluation resulted in the differential expression of ~ 9% of the total transcripts. Analysis of transcriptional changes in the effectors of necroptosis (mixed lineage kinase domain-like, MLKL) and pyroptosis (gasdermin D) showed necroptosis, but not pyroptosis, to be elevated. An active form of MLKL (phosphorylated MLKL, pMLKL) was elevated in hamster hearts and, most importantly, in the serum of MACE patients.ConclusionSARS-CoV-2 identification in the systemic circulation is associated with MACE and necroptosis activity. The increased pMLKL and Troponin-I indicated the occurrence of necroptosis in the heart and suggested necroptosis effectors could serve as biomarkers and/or therapeutic targets.Trial registration Not applicable.

Abstract 6726: Effectiveness of irinotecan plus trabectedin in a desmoplastic small round cell tumor patient-derived xenograft

Abstract Desmoplastic small round cell tumor (DSRCT) is a ultra-rare pediatric scarcoma with poor overall survival. This tumor is dependent on the continued expression and activity of its pathognomonic molecular lesion, the EWS-WT1 transcription factor. DSRCT is often treated with multimodal approach of chemotherapy, surgery, and radiotherapy. Given the rarity of the disease, there have not been clinical studies to establish an effective therapeutic regimen. Indeed, the development of fully characterized preclinical models, able to reproduce the molecular characteristics of clinical tumors, appears instrumental for testing novel therapeutic strategies and accelerating the translation of preclinical findings to the clinical practice. In this study we exploited a novel DSRCT patient-derived xenograft (PDX), which reproduces histomorphological, genomic (CNV) and transcriptomic characteristics of the paired clinical tumor, to comparatively assess the activity of cytotoxic and targeted anticancer agents. Anti-tumor effect was moderate for single-agent doxorubicin, pazopanib and larotrectenib [maximum tumor volume inhibition (max TVI): 55-66%], trabectedin had a higher effect (max TVI: 82%) while irinotecan and eribulin almost complete inhibited tumor growth (max TVI: 96% and 98%, respectively). Interestingly, combination of irinotecan with either eribulin or trabectedin resulted in complete responses which were maintained until the end of the experiment for irinotecan + trabectedin. The trabectedin + irinotecan combination markedly reduced the expression of anti-apoptotic proteins and caused caspase-3 cleavage, consistent with an apoptotic response, and also induced the accumulation of phospho-RIP1 (Ser166) and phospho-RIP3 (Ser227), indicating the occurrence of necroptosis, a type of programmed cell death with necrotic morphology. In line with these findings, transcriptomic profile analysis of ex-vivo tumor samples obtained from mice exposed to trabectedin ± irinotecan revealed a reduced expression of the biological pathways related to apoptosis and cell proliferation in tumor exposed to the drug combination. Mechanistically, we found that these effects were mediated, at least in part, by the down-regulation of EWS-WT1 chimeric protein and its downstream targets, as assessed by PCR and western blotting. Overall, this study emphasizes the importance of patient-derived pre-clinical models to explore new treatments in DSRCT and fosters clinical investigation in the activity of irinotecan plus trabectedin, providing a step forward for developing more effective trabectedin-based combinations for DSRCT to be tested in clinical trials. Citation Format: Valentina Zuco, Sandro Pasquali, Monica Tortoreto, Stefano Percio, Valentina Doldi, Marta Barisella, Paola Collini, Gianpaolo Dagrada, Silvia Brich, Patrizia Gasparini, Marco Fiore, Michela Casanova, Anna Maria Frezza, Alessandro Gronchi, Silvia Stacchiotti, Andrea Ferrari, Nadia Zaffaroni. Effectiveness of irinotecan plus trabectedin in a desmoplastic small round cell tumor patient-derived xenograft. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6726.

Some Macrophages With High Expression of CHOP Undergo Necroptosis in Chronic Rhinosinusitis.

Endoplasmic reticulum stress (ER stress) is activated in chronic sinusitis with nasal polyps (CRSwNP) and leads to increased expression of C/EBP homologous protein (CHOP). However, the role of CHOP in the pathogenesis of CRSwNP remains unclear. CHOP expression was detected by immunohistochemistry staining in nasal mucosa of control and CRSwNP patients. Co-localization of CHOP and cleaved caspase3, p-MLKL, and CD68 was detected by immunofluorescence staining in CRSwNP patients. TNFα, IFNγ, IL1β, LPS, and tunicamycin were added to primary dispersed nasal polyp cells (DNPCs) to explore their roles in cell death. Western blot, CCK8 assay, and flow cytometry were employed to detect cell death. CHOP was specifically activated in CRSwNP compared to controls. It was mainly macrophages that highly expressed CHOP, some of which underwent apoptosis and the other underwent necroptosis. IL1β induced increased CHOP and apoptosis, and a slight p-MLKL. In addition, ER stress could also promote p-MLKL expression. Whereas classical TNFα plus IFNγ and LPS did not induce increased necroptosis in DNPCs. IL1β induced the apoptotic pathway and minor necroptosis. And ER stress also plays a role in the occurrence of necroptosis in CRSwNP.

The Anti-Tumor and Immunomodulatory Effects of PLGA-Based Docetaxel Nanoparticles in Lung Cancer: The Potential Involvement of Necroptotic Cell Death through Reactive Oxygen Species and Calcium Build-Up.

Taxanes, microtubule stabilizing agents, are extensively used in the treatment of non-small cell lung cancer (NSCLC). However, their clinical effectiveness remains restricted owing to significant adverse effects and drug resistance. Nanotechnology may guide chemotherapeutic drugs directly and selectively to malignant cells, improving their therapeutic efficiency. In the present study, we synthesized polylactic-co-glycolic acid (PLGA) based nanoparticles encapsulating docetaxel and evaluated their efficacy in non-small cell lung carcinoma (A549) cells and primary immune cells derived from humans. Docetaxel-PLGA nanoparticles (PLGA-Dtx) were synthesized and characterized using distinct methods. Moreover, the cytotoxicity of free docetaxel (Dtx) and Dtx-conjugated nanoparticles (PLGA-Dtx) was studied in A549 cells and peripheral blood mononuclear cells derived from humans. Furthermore, annexin V-FITC/PI staining was used to assess the mode of cell death. Additionally, human peripheral blood mononuclear cells (PBMCs) were used for assessing the associated immune response and cytokine profile following PLGA-Dtx treatment. Spherical PLGA-Dtx nanoparticles with a 150 ± 10 nm diameter and 70% encapsulation efficiency (EE) were synthesized. The MTT assay showed that the IC50 of PLGA-Dtx nanoparticles was significantly lower than free docetaxel in A549 cells. Cytotoxicity data also revealed the selective nature of PLGA-Dtx with no significant effects in normal human bronchial epithelial cells (BEAS-2B) and PBMCs derived from healthy donors. Interestingly, PLGA-Dtx exerted an improved effect and tempted both apoptosis and necroptosis, as evidenced by annexin V and propidium iodide-positive cells. Further, PLGA-Dtx-exposed A549 cells showed increased Cas-3, Cas-9, RIP-1, and RIP-3, indicating apoptosis and necroptosis. An increased pro-inflammatory response manifested from the enhancement of IFN-γ and TNF-α in PLGA-Dtx-exposed PBMCs, posed by the occurrence of necroptosis and the immune stimulatory effect of PLGA-Dtx. In conclusion, PLGA-Dtx has a selective anticancer potential and better immunostimulatory potential. Therefore, PLGA-Dtx may be useful for the treatment of non-small cell lung carcinoma.

The myth of cobra venom cytotoxin: More than just direct cytolytic actions.

Cobra venom cytotoxin (CTX) is a non-enzymatic three-finger toxin that constitutes 40–60% of cobra venom. Thus, it plays an important role in the pathophysiology of cobra envenomation, especially in local dermonecrosis. The three-finger hydrophobic loops of CTX determine the cytotoxicity. Nevertheless, the actual mechanisms of cytotoxicity are not fully elucidated as they involve not only cytolytic actions but also intracellular signalling-mediated cell death pathways. Furthermore, the possible transition cell death pattern remains to be explored. The actual molecular mechanisms require further studies to unveil the relationship between different CTXs from different cobra species and cell types which may result in differential cell death patterns. Here, we discuss the biophysical interaction of CTX with the cell membrane involving four binding modes: electrostatic interaction, hydrophobic partitioning, isotropic phase, and oligomerisation. Oligomerisation of CTX causes pore formation in the membrane lipid bilayer. Additionally, the CTX-induced apoptotic pathway can be executed via death receptor-mediated extrinsic pathways and mitochondrial-mediated intrinsic pathways. We also discuss lysosomal-mediated necrosis and the occurrence of necroptosis following CTX action. Collectively, we provided an insight into concentration-dependent transition of cell death pattern which involves different mechanistic actions. This contributes a new direction for further investigation of cytotoxic pathways activated by the CTXs for future development of biotherapeutics targeting pathological effects caused by CTX.

Interplay of Oxidative Stress and Necrosis-like Cell Death in Cardiac Ischemia/Reperfusion Injury: A Focus on Necroptosis.

Extensive research work has been carried out to define the exact significance and contribution of regulated necrosis-like cell death program, such as necroptosis to cardiac ischemic injury. This cell damaging process plays a critical role in the pathomechanisms of myocardial infarction (MI) and post-infarction heart failure (HF). Accordingly, it has been documented that the modulation of key molecules of the canonical signaling pathway of necroptosis, involving receptor-interacting protein kinases (RIP1 and RIP3) as well as mixed lineage kinase domain-like pseudokinase (MLKL), elicit cardioprotective effects. This is evidenced by the reduction of the MI-induced infarct size, alleviation of myocardial dysfunction, and adverse cardiac remodeling. In addition to this molecular signaling of necroptosis, the non-canonical pathway, involving Ca2+/calmodulin-dependent protein kinase II (CaMKII)-mediated regulation of mitochondrial permeability transition pore (mPTP) opening, and phosphoglycerate mutase 5 (PGAM5)–dynamin-related protein 1 (Drp-1)-induced mitochondrial fission, has recently been linked to ischemic heart injury. Since MI and HF are characterized by an imbalance between reactive oxygen species production and degradation as well as the occurrence of necroptosis in the heart, it is likely that oxidative stress (OS) may be involved in the mechanisms of this cell death program for inducing cardiac damage. In this review, therefore, several observations from different studies are presented to support this paradigm linking cardiac OS, the canonical and non-canonical pathways of necroptosis, and ischemia-induced injury. It is concluded that a multiple therapeutic approach targeting some specific changes in OS and necroptosis may be beneficial in improving the treatment of ischemic heart disease.

Antidepressant Mechanism of Traditional Chinese Medicine Formula Xiaoyaosan in CUMS-Induced Depressed Mouse Model via RIPK1-RIPK3-MLKL Mediated Necroptosis Based on Network Pharmacology Analysis.

Background: Depression is a stress-related disorder that seriously threatens people’s physical and mental health. Xiaoyaosan is a classical traditional Chinese medicine formula, which has been used to treat mental depression since ancient times. More and more notice has been given to the relationship between the occurrence of necroptosis and the pathogenesis of mental disorders. Objective: The purpose of present study is to explore the potential mechanism of Xiaoyaosan for the treatment of depression using network pharmacology and experimental research, and identify the potential targets of necroptosis underlying the antidepressant mechanism of Xiaoyaosan. Methods: The mice model of depression was induced by chronic unpredictable mild stress (CUMS) for 6 weeks. Adult C57BL/6 mice were randomly divided into five groups, including control group, chronic unpredictable mild stress group, Xiaoyaosan treatment group, necrostatin-1 (Nec-1) group and solvent group. Drug intervention performed from 4th to 6th week of modeling. The mice in Xiaoyaosan treatment group received Xiaoyaosan by intragastric administration (0.254 g/kg/d), and mice in CUMS group received 0.5 ml physiological saline. Meanwhile, the mice in Nec-1 group were injected intraperitoneally (i.p.) with Nec-1 (10 mg/kg/d), and the equivalent volume of DMSO/PBS (8.3%) was injected into solvent group mice. The behavior tests such as sucrose preference test, forced swimming test and novelty-suppressed feeding test were measured to evaluate depressive-like behaviors of model mice. Then, the active ingredients in Xiaoyaosan and the related targets of depression and necroptosis were compiled through appropriate databases, while the “botanical drugs-active ingredients-target genes” network was constructed by network pharmacology analysis. The expressions of RIPK1, RIPK3, MLKL, p-MLKL were detected as critical target genes of necroptosis and the potential therapeutic target compounds of Xiaoyaosan. Furthermore, the levels of neuroinflammation and microglial activation of hippocampus were measured by detecting the expressions of IL-1β, Lipocalin-2 and IBA1, and the hematoxylin and eosin (H&E) stained was used to observe the morphology in hippocampus sections. Results: After 6-weeks of modeling, the behavioral data showed that mice in CUMS group and solvent group had obvious depressive-like behaviors, and the medication of Xiaoyaosan or Nec-1 could improve these behavioral changes. A total of 96 active ingredients in Xiaoyaosan which could regulate the 23 key target genes were selected from databases. Xiaoyaosan could alleviate the core target genes in necroptosis and improve the hippocampal function and neuroinflammation in depressed mice. Conclusion: The activation of necroptosis existed in the hippocampus of CUMS-induced mice, which was closely related to the pathogenesis of depression. The antidepressant mechanism of Xiaoyaosan included the regulation of multiple targets in necroptosis. It also suggested that necroptosis could be a new potential target for the treatment of depression.

The Role of Nuclear Factor of Activated T Cells 5 in Hyperosmotic Stress-Exposed Human Lens Epithelial Cells.

We investigated the role of nuclear factor of activated T cells 5 (NFAT5) under hyperosmotic conditions in human lens epithelial cells (HLECs). Hyperosmotic stress decreased the viability of human lens epithelial B-3 cells and significantly increased NFAT5 expression. Hyperosmotic stress-induced cell death occurred to a greater extent in NFAT5-knockout (KO) cells than in NFAT5 wild-type (NFAT5 WT) cells. Bcl-2 and Bcl-xl expression was down-regulated in NFAT5 WT cells and NFAT5 KO cells under hyperosmotic stress. Pre-treatment with a necroptosis inhibitor (necrostatin-1) significantly blocked hyperosmotic stress-induced death of NFAT5 KO cells, but not of NFAT5 WT cells. The phosphorylation levels of receptor-interacting protein kinase 1 (RIP1) and RIP3, which indicate the occurrence of necroptosis, were up-regulated in NFAT5 KO cells, suggesting that death of these cells is predominantly related to the necroptosis pathway. This finding is the first to report that necroptosis occurs when lens epithelial cells are exposed to hyperosmolar conditions, and that NFAT5 is involved in this process.

RIP1-dependent linear and nonlinear recruitments of caspase-8 and RIP3 respectively to necrosome specify distinct cell death outcomes

There remains a significant gap in our quantitative understanding of crosstalk between apoptosis and necroptosis pathways. By employing the SWATH-MS technique, we quantified absolute amounts of up to thousands of proteins in dynamic assembling/de-assembling of TNF signaling complexes. Combining SWATH-MS-based network modeling and experimental validation, we found that when RIP1 level is below ~1000 molecules/cell (mpc), the cell solely undergoes TRADD-dependent apoptosis. When RIP1 is above ~1000 mpc, pro-caspase-8 and RIP3 are recruited to necrosome respectively with linear and nonlinear dependence on RIP1 amount, which well explains the co-occurrence of apoptosis and necroptosis and the paradoxical observations that RIP1 is required for necroptosis but its increase down-regulates necroptosis. Higher amount of RIP1 (>~46,000 mpc) suppresses apoptosis, leading to necroptosis alone. The relation between RIP1 level and occurrence of necroptosis or total cell death is biphasic. Our study provides a resource for encoding the complexity of TNF signaling and a quantitative picture how distinct dynamic interplay among proteins function as basis sets in signaling complexes, enabling RIP1 to play diverse roles in governing cell fate decisions.

Shikonin Overcomes Drug Resistance and Induces Necroptosis By Regulating the Mir-92a-1-5p/Mlkl Axis in Chronic Myeloid Leukemia Cells

BACKGROUND: Resistance to cell death and metabolic reprogramming are common features of tumor cells. Although the introduction of selective BCR/ABL tyrosine kinase inhibitors (TKIs) has dramatically improved the outcomes and survival rates of chronic myeloid leukemia (CML) patients, some patients (20-30%) develop TKI resistance. The most aggressive and treatment-resistant CML is the subtype harboring BCR/ABL with the T315I mutation, and this subtype is refractory to nearly all TKI-induced apoptosis. Thus, alternative approaches that induce apoptosis-independent cell death are thought to compensate for apoptotic-resistant cells. Recently, necroptosis (also called programmed necrosis), which is generally driven by RIPK1/RIPK3/MLKL activation, has been demonstrated to be a new type of programmed cell death mode that is different from apoptosis. Thus, a deeper understanding of the molecular mechanisms regulating necroptosis might lead to the development of new therapeutic strategies that could remarkably improve the treatment-responses and outcomes of patients with TKI-resistant CML. RESULTS: Shikonin, a compound purified from traditional Chinese medicine, has been reported to induce cell death in various tumor cell lines via a wide range of mechanisms. In our current study, we found that shikonin can effectively inhibit proliferation and induce necrosis-like morphological alterations (Fig. A and B) accompanied by RIPK1/RIPK3/MLKL signaling activation ((Fig. C) in CML cell lines, including the T315I mutant type (32Dp210-T315I). The effects of shikonin can be attenuated by the necroptosis-specific inhibitor (essentially a RIPK1 inhibitor) Nec-1, but not by the pan-apoptosis inhibitor z-VAD-fmk, indicating the occurrence of necroptosis in these cells ((Fig. B and C). Our data also show that shikonin has in vivo anti-CML activity via necroptosis induction in 32Dp210-T315I cells xenografted into NOD/SCID mice via subcutaneous injection ((Fig. D). miRNAs play an important role in tumorigenesis mainly via regulation of gene expression. Our next generation sequencing-based microRNA expression profiling showed significant dysregulation of miR-92a-1-5p expression in a shikonin-treated CML cell line (K562) (Fig. E). We then measured the miR-92a-1-5p expression levels in bone marrow samples from CML patients and patients with nonhematologic malignant diseases. The data showed that the miR-92a-1-5p expression level was higher in primary cells obtained from CML-BC patients than in those from non-CML-CP patients, suggesting that miR-92a-1-5p upregulation is correlated with poor outcomes (Fig. F). Bioinformatics analyses and a dual luciferase reporter gene assay proved that MLKL, a downstream factor in the necroptosis pathway that usually acts as the necroptosis executor, is a direct target of miR-92a-1-5p (Fig. G). Overexpression of miR-92a-1-5p in vitro led to decreased MLKL protein abundance in CML cells (Fig. G). Inhibition of miR-92a-1-5p via use of a specific antago-miRNA could inhibit CML xenograft tumor growth and induce necroptosis via MLKL upregulation in vivo (Fig. H). Hence, we believe that miR-92a-1-5p plays a role in promoting the proliferation and survival of CML via downregulating the abundance of MLKL, the necroptosis executor. CONCLUSIONS: In conclusion, our study proves that shikonin can overcome TKI resistance and induce necroptosis in CML cells, mainly via a mechanism involving RIPK1/RIPK3/MLKL activation. Our study also suggests that miR-92a-1-5p is frequently overexpressed in CML patients with poor outcomes and that it can promote tumor survival by inhibiting MLKL expression. For the first time, we demonstrated that miR-92a-1-5p inhibition via antago-miRNA can potentially be used to treat CML via necroptosis induction. Since necroptosis has not yet been considered to be a therapeutic strategy for tumor treatment, our research confirms that it might indeed serve as a new modality to better control drug-resistant CML. Figure Disclosures No relevant conflicts of interest to declare.