Search

The crosstalk between clathrin-mediated endocytosis (CME) and the autophagy pathway has been reported in mammals; however, the interconnection of CME with autophagy has not been established in plants. Here, we report that the Arabidopsis CLATHRIN LIGHT CHAIN (CLC) subunit 2 and 3 double mutant, clc2-1 clc3-1, phenocopies Arabidopsis AUTOPHAGY-RELATED GENE (ATG) mutants in both autoimmunity and nutrient sensitivity. Accordingly, the autophagy pathway is significantly compromised in the clc2-1 clc3-1 mutant. Interestingly, multiple assays demonstrate that CLC2 directly interacts with ATG8h/ATG8i in a domain-specific manner. As expected, both GFP-ATG8h/GFP-ATG8i and CLC2-GFP are subjected to autophagic degradation, and degradation of GFP-ATG8h is significantly reduced in the clc2-1 clc3-1 mutant. Notably, simultaneous knockout of ATG8h and ATG8i by CRISPR-Cas9 results in enhanced resistance against Golovinomyces cichoracearum, supporting the functional relevance of the CLC2-ATG8h/8i interactions. In conclusion, our results reveal a link between the function of CLCs and the autophagy pathway in Arabidopsis.

RNase R (encoded by the rnr gene) is a highly processive 3' → 5' exoribonuclease essential for the growth of the psychrotrophic bacterium P. syringae Lz4W at low temperature. The cell death of a rnr deletion mutant at low temperature has been previously attributed to the processing defects in 16S rRNA, defective ribosomal assembly and inefficient protein synthesis. We recently showed that RNase R is required to protect P. syringae Lz4W from DNA damage and oxidative stress, independent of its exoribonuclease activity. Here, we show that the processing defect in 16S rRNA does not cause cell death of the rnr mutant of P. syringae at low temperature. Our results demonstrate that the rnr mutant of P. syringae Lz4W, complemented with a RNase R deficient in exoribonuclease function (RNase RD284A) is defective in 16S rRNA processing but can grow at 4 oC. This suggested that the processing defect in ribosomal RNAs is not a cause of the cold sensitivity of the rnr mutant. We further show that the rnr mutant accumulates copies of the indigenous plasmid of P. syringae Lz4W, pLz4W, that bears a type II toxin-antitoxin system (psA-psT). This phenotype was rescued by over-expressing antitoxin psA in the rnr mutant, suggesting that activation of the type II toxin-antitoxin system leads to cold sensitivity of the rnr mutant of P. syringae Lz4W. Here, we report a previously unknown functional relationship between the cold sensitivity of the rnr mutant and a type II toxin-antitoxin system in P. syringae Lz4W.

Peroxiredoxin 6 (Prdx6) repairs peroxidized membranes by reducing oxidized phospholipids, and by replacing oxidized sn-2 fatty acyl groups through hydrolysis/reacylation by its phospholipase A2 (aiPLA2) and lysophosphatidylcholine acyltransferase activities. Prdx6 is highly expressed in the lung, and intact lungs and cells null for Prdx6 or with single-point mutations that inactivate either Prdx6-peroxidase or aiPLA2 activity alone exhibit decreased viability, increased lipid peroxidation, and incomplete repair when exposed to paraquat, hyperoxia, or organic peroxides. Ferroptosis is form of cell death driven by the accumulation of phospholipid hydroperoxides. We studied the role of Prdx6 as a ferroptosis suppressor in the lung. We first compared the expression Prdx6 and glutathione peroxidase 4 (GPx4) and visualized Prdx6 and GPx4 within the lung. Lung Prdx6 mRNA levels were five times higher than GPx4 levels. Both Prdx6 and GPx4 localized to epithelial and endothelial cells. Prdx6 knockout or knockdown sensitized lung endothelial cells to erastin-induced ferroptosis. Cells with genetic inactivation of either aiPLA2 or Prdx6-peroxidase were more sensitive to ferroptosis than WT cells, but less sensitive than KO cells. We then conducted RNA-seq analyses in Prdx6-depleted cells to further explore how the loss of Prdx6 sensitizes lung endothelial cells to ferroptosis. Prdx6 KD upregulated transcriptional signatures associated with selenoamino acid metabolism and mitochondrial function. Accordingly, Prdx6 deficiency blunted mitochondrial function and increased GPx4 abundance whereas GPx4 KD had the opposite effect on Prdx6. Moreover, we detected Prdx6 and GPx4 interactions in intact cells, suggesting that both enzymes cooperate to suppress lipid peroxidation. Notably, Prdx6-depleted cells remained sensitive to erastin-induced ferroptosis despite the compensatory increase in GPx4. These results show that Prdx6 suppresses ferroptosis in lung endothelial cells and that both aiPLA2 and Prdx6-peroxidase contribute to this effect. These results also show that Prdx6 supports mitochondrial function and modulates several coordinated cytoprotective pathways in the pulmonary endothelium.

Ferroptosis is a pervasive non-apoptotic form of cell death highly relevant in various degenerative diseases and malignancies. The hallmark of ferroptosis is uncontrolled and overwhelming peroxidation of polyunsaturated fatty acids contained in membrane phospholipids, which eventually leads to rupture of the plasma membrane. Ferroptosis is unique in that it is essentially a spontaneous, uncatalyzed chemical process based on perturbed iron and redox homeostasis contributing to the cell death process, but that it is nonetheless modulated by many metabolic nodes that impinge on the cells susceptibility to ferroptosis. Among the various nodes affecting ferroptosis sensitivity, several have emerged as promising candidates for pharmacological intervention, rendering ferroptosis-related proteins attractive targets for the treatment of numerous currently incurable diseases. Herein, the current members of a Germany-wide research consortium focusing on ferroptosis research, as well as key external experts in ferroptosis who have made seminal contributions to this rapidly growing and exciting field of research, have gathered to provide a comprehensive, state-of-the-art review on ferroptosis. Specific topics include: basic mechanisms, in vivo relevance, specialized methodologies, chemical and pharmacological tools, and the potential contribution of ferroptosis to disease etiopathology and progression. We hope that this article will not only provide established scientists and newcomers to the field with an overview of the multiple facets of ferroptosis, but also encourage additional efforts to characterize further molecular pathways modulating ferroptosis, with the ultimate goal to develop novel pharmacotherapies to tackle the various diseases associated with - or caused by - ferroptosis.

Mitochondrial Ca2+ overload can mediate mitochondria-dependent cell death, a major contributor to several human diseases. Indeed, Duchenne muscular dystrophy (MD) is driven by dysfunctional Ca2+ influx across the sarcolemma that causes mitochondrial Ca2+ overload, organelle rupture, and muscle necrosis. The mitochondrial Ca2+ uniporter (MCU) complex is the primary characterized mechanism for acute mitochondrial Ca2+ uptake. One strategy for preventing mitochondrial Ca2+ overload is deletion of the Mcu gene, the pore forming subunit of the MCU-complex. Conversely, enhanced MCU-complex Ca2+ uptake is achieved by deleting the inhibitory Mcub gene. Here we show that myofiber-specific Mcu deletion was not protective in a mouse model of Duchenne MD. Specifically, Mcu gene deletion did not reduce muscle histopathology, did not improve muscle function, and did not prevent mitochondrial Ca2+ overload. Moreover, myofiber specific Mcub gene deletion did not augment Duchenne MD muscle pathology. Interestingly, we observed MCU-independent Ca2+ uptake in dystrophic mitochondria that was sufficient to drive mitochondrial permeability transition pore (MPTP) activation and skeletal muscle necrosis, and this same type of activity was observed in heart, liver, and brain mitochondria. These results demonstrate that mitochondria possess an uncharacterized MCU-independent Ca2+ uptake mechanism that is sufficient to drive MPTP-dependent necrosis in MD in vivo.

The vast majority of membrane phospholipids (PLs) include two asymmetrically positioned fatty acyls: oxidizable polyunsaturated fatty acids (PUFA) attached predominantly at the sn2 position, and non-oxidizable saturated/monounsaturated acids (SFA/MUFA) localized at the sn1 position. The peroxidation of PUFA-PLs, particularly sn2-arachidonoyl(AA)- and sn2-adrenoyl(AdA)-containing phosphatidylethanolamines (PE), has been associated with the execution of ferroptosis, a program of regulated cell death. There is a minor subpopulation (≈1-2 mol %) of doubly PUFA-acylated phospholipids (di-PUFA-PLs) whose role in ferroptosis remains enigmatic. Here we report that 15-lipoxygenase (15LOX) exhibits unexpectedly high pro-ferroptotic peroxidation activity towards di-PUFA-PEs. We revealed that peroxidation of several molecular species of di-PUFA-PEs occurred early in ferroptosis. Ferrostatin-1, a typical ferroptosis inhibitor, effectively prevented peroxidation of di-PUFA-PEs. Furthermore, co-incubation of cells with di-AA-PE and 15LOX produced PUFA-PE peroxidation and induced ferroptotic death. The decreased contents of di-PUFA-PEs in ACSL4 KO A375 cells was associated with lower levels of di-PUFA-PE peroxidation and enhanced resistance to ferroptosis. Thus, di-PUFA-PE species are newly identified phospholipid peroxidation substrates and regulators of ferroptosis, representing a promising therapeutic target for many diseases related to ferroptotic death.

Alcohol-associated liver disease (ALD) is a substantial cause of morbidity and mortality worldwide and represents a spectrum of liver injury beginning with hepatic steatosis (fatty liver) progressing to inflammation and culminating in cirrhosis. Multiple factors contribute to ALD progression and disease severity. Here, we overview several crucial mechanisms related to ALD end-stage outcome development, such as epigenetic changes, cell death, hemolysis, hepatic stellate cells activation, and hepatic fatty acid binding protein 4. Additionally, in this review, we also present two clinically relevant models using human precision-cut liver slices and hepatic organoids to examine ALD pathogenesis and progression.

Spliceosomal GTPase elongation factor Tu GTP binding domain containing 2 (EFTUD2) is a causative gene for mandibulofacial dysostosis with microcephaly (MFDM) syndrome comprising cerebellar hypoplasia and motor dysfunction. How EFTUD2 deficiency contributes to these symptoms remains elusive. Here, we demonstrate that specific ablation of Eftud2 in cerebellar Purkinje cells (PCs) in mice results in severe ferroptosis, PC degeneration, dyskinesia, and cerebellar atrophy, which recapitulates phenotypes observed in patients with MFDM. Mechanistically, Eftud2 promotes Scd1 and Gch1 expression, upregulates monounsaturated fatty acid phospholipids, and enhances antioxidant activity, thereby suppressing PC ferroptosis. Importantly, we identified transcription factor Atf4 as a downstream target to regulate anti-ferroptosis effects in PCs in a p53-independent manner. Inhibiting ferroptosis efficiently rescued cerebellar deficits in Eftud2 cKO mice. Our data reveal an important role of Eftud2 in maintaining PC survival, showing that pharmacologically or genetically inhibiting ferroptosis may be a promising therapeutic strategy for EFTUD2 deficiency-induced disorders. [Display omitted] • Spliceosomal GTPase Eftud2 is essential for Purkinje cell development and survival • Eftud2 deficiency in PCs induces ferroptosis via a p53-independent manner • Eftud2 deficiency induces Scd1 and Gch1 downregulation through mis-splicing of Atf4 • Inhibition of ferroptosis efficiently rescues Eftud2 loss-induced PC death in vivo Alternative splicing critically regulates brain development. Yang et al. found that spliceosomal factor Eftud2 is essential for Purkinje cell (PC) development, survival, and cerebellar integrity by preventing ferroptosis. Inhibition of ferroptosis efficiently rescues PC death in Eftud2-deficient mice. These findings provide a promising therapeutic strategy for EFTUD2 deficiency-induced diseases. [ABSTRACT FROM AUTHOR]

In recent decades, cancer has posed a challenging obstacle that humans strive to overcome. While phototherapy and immunotherapy are two emerging therapies compared to traditional methods, they each have their advantages and limitations. These limitations include easy metastasis and recurrence, low response rates, and strong side effects. To address these issues, researchers have increasingly focused on combining these two therapies by utilizing a nano-drug delivery system due to its superior targeting effect and high drug loading rate, yielding remarkable results. The combination therapy demonstrates enhanced response efficiency and effectiveness, leading to a preparation that is highly targeted, responsive, and with low recurrence rates. This paper reviews several main mechanisms of anti-tumor effects observed in combination therapy based on the nano-drug delivery system over the last five years. Furthermore, the challenges and future prospects of this combination therapy are also discussed. [ABSTRACT FROM AUTHOR]

Ubiquitination functions as an important posttranslational modification for orchestrating inflammatory immune responses and cell death during pathogenic infection. The ubiquitination machinery is a major target hijacked by pathogenic bacteria to promote their survival and proliferation. Type I interferon (IFN-I) plays detrimental roles in host defense against Francisella novicida (F. novicida) infection. The effects of IFN-I on the ubiquitination of host proteins during F. novicida infection remain unclear. Herein, we delineate the dynamic ubiquitinome alterations in both wild-type (WT) and interferon-alpha receptor-deficient (Ifnar–/–) primary bone marrow-derived macrophages (BMDMs) during F. novicida infection. Using diGly proteomics and stable isotope labeling (SILAC), we quantified ubiquitination sites in proteins from primary WT and Ifnar–/– BMDMs with and without F. novicida infection. Our mass spectrometry analysis identified 2,491 ubiquitination sites in 1,077 endogenous proteins. Our study revealed that F. novicida infection induces dynamic changes in the ubiquitination of proteins involved in the cell death, phagocytosis, and inflammatory response pathways. IFN-I signaling is essential for both the increase and reduction in ubiquitination in response to F. novicida infection. We identified IFN-I-dependent ubiquitination in proteins involved in glycolysis and vesicle transport processes and highlighted key hub proteins modified by ubiquitination within cell death pathways. These findings underscore the significant influence of IFN-I signaling on modulating ubiquitination during F. novicida infection and provide valuable insights into the complex interplay between the host and F. novicida. [ABSTRACT FROM AUTHOR]

Background: Normal cells express functional tumor suppressor WW domain-containing oxidoreductase (WWOX), designated WWOXf. UV irradiation induces WWOXf cells to undergo bubbling cell death (BCD) — an event due to the accumulation of nuclear nitric oxide (NO) gas that forcefully pushes the nuclear and cell membranes to form one or two bubbles at room temperature (22 °C) and below. In contrast, when WWOX-deficient or -dysfunctional (WWOXd) cells are exposed to UV and/or cold shock, the cells undergo nuclear pop-out explosion death (POD). We aimed to determine the morphological and biochemical changes in WWOXf cells during BCD versus apoptosis. Methods: WWOXf and WWOXd cells were exposed to UV followed by measuring BCD or POD by time-lapse microscopy and/or time-lapse holographic microscopy at 4, 22, or 37 °C to visualize morphological changes. Live cell stains were used to measure the kinetics of nitric oxide (NO) production and Ca2+ influx. Extent of cell death was measured by uptake of propidium iodide and by internucleosomal DNA fragmentation using agarose gel electrophoresis. Results: WWOXf cells were exposed to UV and then cold shock, or cold shock and then UV, and cultured at 4, 10, and 22 °C, respectively. Initially, UV induced calcium influx and NO production, which led to nuclear bubbling and final death. Cold shock pretreatment completely suppressed UV-mediated bubbling at 37 °C, so the UV/cold shock-treated cells underwent apoptosis. Without cold shock, UV only induced bubbling at all temperatures, whereas the efficiency of bubbling at 37 °C was reduced by greater than 50%. Morphologically, the WWOXf cell height or thickness was significantly increased during cell division or apoptosis, but the event did not occur in BCD. In comparison, when WWOXd cancer cells received UV or UV/cold shock, these cells underwent NO-independent POD. UV/cold shock effectively downregulated the expression of many proteins such as the housekeeping α-tubulin (> 70%) and β-actin (< 50%), and cortactin (> 70%) in WWOXf COS7 cells. UV/cold shock induced relocation of α-tubulin to the nucleus and nuclear bubbles in damaged cells. UV induced co-translocation of the WWOX/TRAF2 complex to the nuclei, in which the prosurvival TRAF2 blocked the proapoptotic WWOX via its zinc finger domain. Without WWOX, TRAF2 did not relocate to the nuclei. Cold shock caused the dissociation of the WWOX/TRAF2 complex in the nucleus needed for BCD. In contrast, the formation of the WWOX/TRAF2 complex, plus p53, was strengthened at 37 °C required for apoptosis. Conclusions: The temperature-sensitive nuclear WWOX/TRAF2 complex acts as a molecular switch, whose dissociation favors BCD at low temperatures, and the association supports apoptosis at 37 °C in UV-treated WWOXf cells. [ABSTRACT FROM AUTHOR]

Summary Radiation, a universal component of Earth's environment, is categorized into non‐ionizing and ionizing forms. While non‐ionizing radiation is relatively harmless, ionizing radiation possesses sufficient energy to ionize atoms and disrupt DNA, leading to cell damage, mutation, cancer, and cell death. The extensive use of radionuclides and ionizing radiation in nuclear technology and medical applications has sparked global concern for their capacity to cause acute and chronic illnesses. Ionizing radiation induces DNA damage either directly through strand breaks and base change or indirectly by generating reactive oxygen species (ROS) and reactive nitrogen species (RNS) via radiolysis of water. This damage triggers a complex cellular response involving recognition of DNA damage, cell cycle arrest, DNA repair mechanisms, release of pro‐inflammatory cytokines, and cell death. This review focuses on the mechanisms of radiation‐induced cellular damage, recognition of DNA damage and subsequent activation of repair processes, and the critical role of the innate immune response in resolution of the injury. Emphasis is placed on pattern recognition receptors (PRRs) and related receptors that detect damage‐associated molecular patterns (DAMPs) and initiate downstream signaling pathways. Radiation‐induced cell death pathways are discussed in detail. Understanding these processes is crucial for developing strategies to mitigate the harmful effects of radiation and improve therapeutic outcomes. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H₂S), a metabolite of the transsulfuration pathway, has been implicated in ferroptosis, a unique form of cell death caused by lipid peroxidation. While the exact mechanisms controlling ferroptosis remain unclear, our study reveals that H₂S sensitizes human non-small cell lung cancer (NSCLC) cells to this process, particularly when cysteine levels are low. Combining H₂S with cystine depletion significantly enhances the effectiveness of ferroptosis-based cancer therapy. Mechanistically, H₂S persulfidates the 195th cysteine on S-adenosyl homocysteine hydrolase (SAHH), reducing its enzymatic activity. This leads to decreased homocysteine levels, subsequently lowering cysteine and glutathione concentrations under cystine depletion conditions. These changes ultimately increase the vulnerability of NSCLC cells to ferroptosis. Our findings establish H₂S as a key regulator of homocysteine metabolism and a critical factor in determining NSCLC cell susceptibility to ferroptosis. These results highlight the potential of H₂S-based therapies to improve the efficacy of ferroptosis-targeted cancer treatments for NSCLC. [Display omitted] • H 2 S promotes ferroptosis induced by cystine depletion in non-small cell lung cancer • H 2 S inhibits the transsulfuration pathway by decreasing homocysteine levels • H 2 S inhibits S-adenosyl homocysteine hydrolase activity through cysteine persulfidation • H 2 S enhances ferroptosis-based cancer therapies for NSCLC Zheng et al. show that H₂S sensitizes NSCLC cells to ferroptosis through cysteine persulfidation of S-adenosyl homocysteine hydrolase, reducing its activity. This leads to decreased levels of homocysteine, cysteine, and glutathione, promoting ferroptosis, particularly in low-cystine conditions. These results suggest H₂S enhances ferroptosis-based treatments for NSCLC. [ABSTRACT FROM AUTHOR]

BCL-w is a BCL-2 family protein that promotes cell survival in tissue- and disease-specific contexts. The canonical anti-apoptotic functionality of BCL-w is mediated by a surface groove that traps the BCL-2 homology 3 (BH3) α-helices of pro-apoptotic members, blocking cell death. A distinct N-terminal portion of BCL-w, termed the BCL-2 homology 4 (BH4) domain, selectively protects axons from paclitaxel-induced degeneration by modulating IP3 receptors, a noncanonical BCL-2 family target. Given the potential of BCL-w BH4 mimetics to prevent or mitigate chemotherapy-induced peripheral neuropathy, we sought to characterize the interaction between BCL-w BH4 and the IP3 receptor, combining "staple" and alanine scanning approaches with molecular dynamics simulations. We generated and identified stapled BCL-w BH4 peptides with optimized IP3 receptor binding and neuroprotective activities. Point mutagenesis further revealed the sequence determinants for BCL-w BH4 specificity, providing a blueprint for therapeutic targeting of IP3 receptors to achieve neuroprotection. [Display omitted] • Hydrocarbon staple scanning yielded optimal BCL-w BH4 domain binders of IP3R1 • Molecular dynamics simulations identified a BH4-binding site in ARM2 of IP3R1 • Point mutagenesis revealed the binding determinants for BH4 interaction • A lead stapled BCL-w BH4 peptide protects axons from chemo-induced degeneration Tang et al. report that staple and alanine scanning of the BCL-w BH4 domain revealed binding determinants for targeting IP3R1 by interaction with a surface groove on ARM2, as predicted by molecule dynamics simulations. A lead construct protected axons from paclitaxel-induced degeneration, with point mutagenesis impairing IP3R1 interaction and neuroprotection. [ABSTRACT FROM AUTHOR]

The Ribosomal S6 Kinase (RSK) family of serine/threonine kinases function as key downstream effectors of the MAPK signaling cascade. In the nervous system, RSK signaling plays crucial roles in neuronal development and contributes to activity-dependent neuronal plasticity. This study examined the role of RSK signaling in cell viability during neuronal development and in neuroprotection in the mature nervous system. Using neuronal cell-culture-based profiling, we found that suppressing RSK signaling led to significant cell death in developing primary neuronal cultures. To this end, treatment with the RSK inhibitors BiD1870 or SL0101 on the first day of culturing resulted in over 80% cell death. In contrast, more mature cultures showed attenuated cell death upon RSK inhibition. Inhibition of RSK signaling during early neuronal development also disrupted neurite outgrowth and cell growth. In maturing hippocampal explant cultures, treatment with BiD1870 had minimal effects on cell viability, but led to a striking augmentation of NMDA-induced cell death. Finally, we used the endothelin 1 (ET-1) model of ischemia to examine the neuroprotective effects of RSK signaling in the mature hippocampus in vivo. Notably, in the absence of RSK inhibition, the granule cell layer (GCL) was resistant to the effects of ET-1; However, disruption of RSK signaling (via the microinjection of BiD1870) prior to ET-1 injection triggered cell death within the GCL, thus indicating a neuroprotective role for RSK signaling in the mature nervous system. Together these data reveal distinct, developmentally-defined, roles for RSK signaling in the nervous system. [ABSTRACT FROM AUTHOR]

VEXAS syndrome is a newly described autoinflammatory entity characterized by somatic mutations in the UBA1 X-linked gene in hematopoietic progenitor cells. Several studies have demonstrated that the presence of vacuoles in progenitor cells from bone marrow aspirates is a hallmark finding for this syndrome. Therefore, this study aimed to characterize leukocytes from VEXAS patients versus patients with ANCA-associated vasculitis (AAV), familial Mediterranean fever (FMF), and healthy donors (HD) to define a specific cytological pattern that can support VEXAS diagnosis. Twelve VEXAS patients were included in the study. Blood samples from FMF (n = 16), AAV (n = 16) and HDs (n = 20) acted as controls. May-Grünwald Giemsa (MGG) staining was used for studying cellular morphology, including cytoplasm, granules, and vacuoles and to performa cytogenic evaluation of leucocytes. Plasma IL-1b, IL-1a, TNFa, IL-18 and IL-8 were measured using ELISA assay. The cytological analysis fromblood smears confirmed the presence of immature neutrophils in VEXAS patients. We found a greater number of vacuoles in VEXAS patients vs. FMF, AAV and HD. Micronuclei (MNi) and cell death rate were higher in VEXAS patients vs. HD. Cell death correlated with IL-1b and IL-8 levels. MNi were positively associated with IL-8 and IL-1b levels, and with the percentage of immature neutrophils and vacuoles. In conclusion, our findings suggested that cytological testmay be supportive for VEXAS diagnosis, despite genetical analysis is mandatory for confirming the disease. Finally, we identified several cytological hallmarks that may distinguish the VEXAS "cytotype" not only from HD but also from other inflammatory diseases. [ABSTRACT FROM AUTHOR]

Introduction: Ewing Sarcoma (EWS) has been reported in seven children with Down syndrome (DS). To date, a detailed assessment of this solid tumour in DS patients is yet to be made. Methods: Here,we characterise a chemo-resistantmediastinal EWS in a 2-year-old DS child, the youngest ever reported case, by exploiting sequencing approaches. Results: The tumour showed a neuroectodermal development driven by the EWSR1-FLI1 fusion. The inherited myeloperoxidase deficiency of the patient caused failure of neutrophil-mediated cell death and promoted genomic instability. Discussion: In this context, the tumour underwent genome-wide near haploidisation resulting in a massive overexpression of pro-inflammatory cytokines. Recruitment of defective neutrophils fostered rapid evolution of this EWS. [ABSTRACT FROM AUTHOR]

Summary: The integrity of wheat (Triticum aestivum) production is increasingly jeopardized by the fungal pathogen Blumeria graminis f. sp. tritici (Bgt), particularly amid the vicissitudes of climate change.Here, we delineated the role of a wheat transcription factor, TaNAC1, which precipitates cellular apoptosis and fortifies resistance against Bgt. Utilizing BiFC, co‐immunoprecipitation, protein quantification, luciferase report assays, we determined that cytoplasmic TaNAC1‐7A undergoes phosphorylation at the S184/S258 sites by TaCDPK20, facilitating its nuclear translocation. This migration appears to prime further phosphorylation by TaMPK1, thereby enhancing transcriptional regulatory activity. Notably, the apoptotic activity of phosphorylated TaNAC1‐7A is negatively modulated by the nuclear protein phosphatase PP2Ac.Furthermore, activation of TaNAC1 phosphorylation initiates transcription of downstream genes TaSec1a and TaCAMTA4, through binding to the C[T/G]T[N7]A[A/C]G nucleic acid motif. Suppression of TaNAC1, TaCDPK20, and TaMPK1 in wheat compromises its resistance to Bgt strain E09, whereas overexpression of TaNAC1 and silencing of PP2Ac markedly elevate resistance levels.Our results reveal the pivotal role of TaNAC1 in basal resistance which is mediated by its effects on homotypic fusion, vacuolar protein sorting, and the expression of defense‐related genes. The findings highlight the potential through targeting TaNAC1 and its regulators as a strategy for improving wheat's resistance to fungal pathogens. [ABSTRACT FROM AUTHOR]

Ferroptosis, an iron‐ and reactive oxygen species (ROS)‐dependent cell death, holds significant promise for tumor therapy due to its ability to induce lipid peroxidation (LPO) and trigger antitumor immune responses. However, elevated cholesterol levels in cancer cells impede ferroptosis and compromise immune function. Here, a novel nanozyme, Fe‐MOF/CP, composed of iron metal‐organic framework (Fe‐MOF) nanoparticles loaded with cholesterol oxidase and PEGylation for integrated ferroptosis and immunotherapy is introduced. Fe‐MOF/CP depletes cholesterol and generates hydrogen peroxide, enhancing ROS levels and inducing LPO, thereby promoting ferroptosis. This process disrupts lipid raft integrity and downregulates glutathione peroxidase 4 and ferroptosis suppressor protein 1, further facilitating ferroptosis. Concurrently, Fe‐MOF/CP augments immunogenic cell death, reduces programmed death‐ligand 1 expression, and revitalizes exhausted CD8+ T cells. In vivo studies demonstrate significant therapeutic efficacy in abscopal, metastasis, and recurrent tumor models, highlighting the robust antitumor immune responses elicited by Fe‐MOF/CP. This study underscores the potential of Fe‐MOF/CP as a multifunctional therapeutic agent that combines ferroptosis and immunotherapy, offering a promising strategy for effective and durable cancer treatment. [ABSTRACT FROM AUTHOR]

Neurodegenerative diseases are global health challenges characterized by the progressive degeneration of nerve cells, leading to cognitive and motor impairments. The brain–gut–bone axis, a complex network that modulates multiple physiological systems, has gained increasing attention owing to its profound effects on the occurrence and development of neurodegenerative diseases. No comprehensive review has been conducted to clarify the triangular relationship involving the brain–gut–bone axis and its potential for innovative therapies for neurodegenerative disorders. In light of this, a new perspective is aimed to propose on the interplay between the brain, gut, and bone systems, highlighting the potential of their dynamic communication in neurodegenerative diseases, as they modulate multiple physiological systems, including the nervous, immune, endocrine, and metabolic systems. Therapeutic strategies for maintaining the balance of the axis, including brain health regulation, intestinal microbiota regulation, and improving skeletal health, are also explored. The intricate physiological interactions within the brain–gut–bone axis pose a challenge in the development of effective treatments that can comprehensively target this system. Furthermore, the safety of these treatments requires further evaluation. This review offers a novel insights and strategies for the prevention and treatment of neurodegenerative diseases, which have important implications for clinical practice and patient well‐being. [ABSTRACT FROM AUTHOR]

Burkholderia pseudomallei (Bpm) is the causative agent of the disease melioidosis. As a facultative intracellular pathogen, Bpm has a complex lifestyle that culminates in cell-to-cell fusion and multinucleated giant cells (MNGCs) formation. The virulence factor responsible for MNGC formation is the type 6 secretion system (T6SS), a contractile nanomachine. MNGC formation is a cell-to-cell spread strategy that allows the bacteria to avoid the extracellular immune system and our previous data highlighted cell death, apoptosis, and inflammation as pathways significantly impacted by T6SS activity. Thusly, we investigated how the T6SS influences these phenotypes within the macrophage and pulmonary models of infection. Here we report that the T6SS is responsible for exacerbating apoptotic cell death during infection in both macrophages and the lungs of infected mice. We also demonstrate that although the T6SS does not influence differential macrophage polarization, the M2 polarization observed is potentially beneficial for Bpm pathogenesis and replication. Finally, we show that the T6SS contributes to the severity of inflammatory nodule formation in the lungs, which might be potentially connected to the amount of apoptosis that is triggered by the bacteria. Author summary: Burkholderia pseudomallei (Bpm) is an intracellular pathogen and is the etiological agent of melioidosis. This neglected tropical disease results in an estimated 89,000 fatalities a year, however, this number is believed to be severely underreported. The complex intracellular lifestyle and host response to infection is poorly understood, basic cell interactions and responses are critical to defense against infection. Bpm utilizes an array of virulence factors to successfully replicate and disseminate cell-to-cell, one of these is the T6SS which is responsible for MNGC formation and cell-to-cell spread. In this work, we characterized how macrophages respond to infection in the presence or absence of the critical T6SS virulence factor. Macrophages are a primary replicative niche for Bpm but how intracellular replication disrupts macrophages response to infection is poorly understood. By understanding macrophage cell death patterns and polarization, we can dissect responses that are triggered by T6SS activity with the expectation of finding exploitable responses for host directed therapies. [ABSTRACT FROM AUTHOR]

The hypertrophic scar (HS) is a prevalent cutaneous fibrotic disorder that impacts both the aesthetic and functional aspects of the skin, there is an urgent need for a highly safe and effective approach to address the challenge of HS with thick and deep types. Inspired by the superior deep tissue penetrative ability of near-infrared-II (NIR-II) light and potential mitochondria ROS inducing effect of Chinese medicine lycorine (LYC), we fabricated a Cu2Se@LYC (CL) composite by encapsulating LYC on polyvinyl pyrrolidone (PVP) modified Cu2Se nanoparticles. After NIR-II irradiation, CL could induce the generation of reactive oxygen species (ROS) and mitochondrial damage in hypertrophic scar fibroblasts (HSFs). The subsequent release of cytochrome C (cyt-c) from mitochondria into the cytoplasm and upregulation of beclin1 leads to the activation of endogenous apoptosis and autophagy-mediated cell death. The CL + NIR-II treatment exhibited a pronounced anti-scarring effect in both in vitro and in vivo rabbit ear scar models, leading to a significant reduction in the fibrotic markers including Collagen I/III and α-smooth muscle actin (α-SMA). This study comprehensively investigated the crucial role of HSFs' autophagy in scar management and proposed a safe and effective therapy based on NIR-II laser for clinical application. [ABSTRACT FROM AUTHOR]

Disulfidptosis is a novel discovered form of programmed cell death (PCD) that diverges from apoptosis, necroptosis, ferroptosis, and cuproptosis, stemming from disulfide stress-induced cytoskeletal collapse. In cancer cells exhibiting heightened expression of the solute carrier family 7 member 11 (SLC7A11), excessive cystine importation and reduction will deplete nicotinamide adenine dinucleotide phosphate (NADPH) under glucose deprivation, followed by an increase in intracellular disulfide stress and aberrant disulfide bond formation within actin networks, ultimately culminating in cytoskeletal collapse and disulfidptosis. Disulfidptosis involves crucial physiological processes in eukaryotic cells, such as cystine and glucose uptake, NADPH metabolism, and actin dynamics. The Rac1-WRC pathway-mediated actin polymerization is also implicated in this cell death due to its contribution to disulfide bond formation. However, the precise mechanisms underlying disulfidptosis and its role in tumors are not well understood. This is probably due to the multifaceted functionalities of SLC7A11 within cells and the complexities of the downstream pathways driving disulfidptosis. This review describes the critical roles of SLC7A11 in cells and summarizes recent research advancements in the potential pathways of disulfidptosis. Moreover, the less-studied aspects of this newly discovered cell death process are highlighted to stimulate further investigations in this field. [ABSTRACT FROM AUTHOR]

Development of novel therapeutic strategies that reactivate latent HIV and sensitize reactivated cells to apoptosis is crucial towards elimination of the latent viral reservoir. Among the clinically relevant latency reversing agents (LRA) under investigation, the γc-cytokine IL-15 and the superagonist N-803 have been shown to reactivate latent HIV ex vivo and in vivo. However, their clinical benefit can be hindered by IL-15 promoting survival of infected cells. We previously identified a small molecule, HODHBt, that sensitizes latently infected cells to death upon reactivation with γc-cytokines through a STAT-dependent pathway. In here, we aimed to identify and evaluate FDA-approved compounds that could also sensitize HIV-infected cells to apoptosis. Using the Connectivity Map (CMap), we identified the retinol derivative 13-cis-retinoic acid (Isotretinoin) causes similar transcriptional changes as HODHBt. Isotretinoin enhances IL-15-mediated latency reversal without inducing proliferation of memory CD4 T cells. Ex vivo analysis of PBMCs from ACTG A5325, where Isotretinoin was administered to ART-suppressed people with HIV, showed that Isotretinoin treatment enhances IL-15-mediated latency reversal. Furthermore, we showed that a combination of IL-15 with Isotretinoin promotes the reduction of translation-competent reservoirs ex vivo. Mechanistically, combination of IL-15 and Isotretinoin increases caspase-3 activation specifically in HIV-infected cells but not uninfected cells. Our results suggest that Isotretinoin can be a novel approach to target and eliminate translation-competent HIV reservoirs. Author summary: Even with the development and rapid advancement of antiretroviral therapies (ART) against HIV in the past three decades, there is still no generalized cure for HIV. Identification of novel therapeutic interventions that target the latent reservoir could provide new avenues to find a cure. In this work, we evaluated the ability of the FDA-approved compound Isotretinoin to reactivate latent HIV and promote a reduction of the latent reservoir ex vivo. Our studies found that Isotretinoin can enhance the ability of IL-15 to reactivate latent reservoirs. Furthermore, using samples from clinical trial ACTG A5325 (NCT01969058) we show that Isotretinoin sensitizes latent HIV to reactivation by IL-15. Finally, we demonstrate that Isotretinoin can sensitize reactivated cells to death via apoptosis. Overall, this study demonstrate that Isotretinoin could be used in combinatorial strategies towards the development of an HIV cure to promote reduction of latent reservoirs. [ABSTRACT FROM AUTHOR]

Epithelial tissues undergo cell turnover both during development and for homeostatic maintenance. Removal of cells is coordinated with the increase in number of newly dividing cells to maintain barrier function of the tissue. In Drosophila metamorphosis, larval epidermal cells (LECs) are replaced by adult precursor cells called histoblasts. Removal of LECs must counterbalance the exponentially increasing adult histoblasts. Previous work showed that the LEC removal accelerates as endocytic activity decreases throughout all LECs. Here, we show that the acceleration is accompanied by a mode switching from isolated single-cell apoptosis to clustered ones induced by the endocytic activity reduction. We identify the epidermal growth factor receptor (EGFR) pathway via extracellular-signal regulated kinase (ERK) activity as the main components downstream of endocytic activity in LECs. The reduced ERK activity, caused by the decrease in endocytic activity, is responsible for the apoptotic mode switching. Initially, ERK is transiently activated in normal LECs surrounding a single apoptotic LEC in a ligand-dependent manner, preventing clustered cell death. Following the reduction of endocytic activity, LEC apoptosis events do not provoke these transient ERK up-regulations, resulting in the acceleration of the cell elimination rate by frequent clustered apoptosis. These findings contrasted with the common perspective that clustered apoptosis is disadvantageous. Instead, switching to clustered apoptosis is required to accommodate the growth of neighboring tissues. Epithelial tissues undergo remodelling during development and to maintain homeostasis, and cell elimination rate must be coordinated with cell proliferation. This study shows that cell removal acceleration is associated with switching from isolated to clustered apoptosis, induced by the reduction of endocytosis and EGFR signalling. [ABSTRACT FROM AUTHOR]

Summary Macrophages, neutrophils, and epithelial cells are pivotal components of the host's immune response against bacterial infections. These cells employ inflammasomes to detect various microbial stimuli during infection, triggering an inflammatory response aimed at eradicating the pathogens. Among these inflammatory responses, pyroptosis, a lytic form of cell death, plays a crucial role in eliminating replicating bacteria and recruiting immune cells to combat the invading pathogen. The immunological function of pyroptosis varies across macrophages, neutrophils, and epithelial cells, aligning with their specific roles within the innate immune system. This review centers on elucidating the role of pyroptosis in resisting gram‐negative bacterial infections, with a particular focus on the mechanisms at play in macrophages, neutrophils, and intestinal epithelial cells. Additionally, we underscore the cell type‐specific roles of pyroptosis in vivo in these contexts during defense. [ABSTRACT FROM AUTHOR]

Background: Nanoparticles are increasingly being used in medicine, cosmetics, food, and manufacturing. However, potential toxicity may limit the use of newly engineered nanoparticles. Prior studies have identified particle characteristics that are predictive of toxicity, although the mechanisms responsible for toxicity remain largely unknown. Nanoparticle treatment in cell culture, combined with high-throughput chemical screen allows for systematic perturbations of thousands of molecular targets against potential pathways of toxicity. The resulting data matrix, called chemical compendium, can provide insights into the mechanism of toxicity as well as help classify nanoparticles based on toxicity pathway. Results: We performed unbiased screens of 1280 bioactive chemicals against a panel of four particles, searching for inhibitors of macrophage toxicity. Our hit compounds clustered upon inhibitors of kinases involved in phagocytosis, including focal adhesion kinase (FAK), with varying specificity depending on particles. Interestingly, known inhibitors of cell death including NLRP3 inflammasome inhibitor were unable to suppress particle-induced macrophage death for many of the particles. By searching for upstream receptors of kinases, we identified Cd11b as one of the receptors involved in recognizing a subset of particles. We subsequently used these hit compounds and antibodies to further characterize a larger panel of particles and identified hydrodynamic size as an important particle characteristic in Cd11b-mediated particle uptake and toxicity. Conclusions: Our chemical compendium and workflow can be expanded across cell types and assays to characterize the toxicity mechanism of newly engineered nanoparticles. The data in their current form can also be analyzed to help design future high-throughput screening for nanoparticle toxicity. [ABSTRACT FROM AUTHOR]

Background: Lung cancer (LC) occupies an important position in the lethality of cancer patients. Acquired resistance to gefitinib in lung adenocarcinoma (LUAD) seriously affects the therapeutic efficacy of LC. Thus, it is of major scientific and clinical significance to probe the mechanism of gefitinib resistance in LUAD for ameliorating the prognosis of patients. Methods: The expression of miRNAs in gefitinib-resistant LUAD cells was validated using qRT-PCR. Cell viability was assessed through CCK-8, whereas cell death was examined through PI staining. Changes in the ferroptosis process were evaluated by detecting the intracellular Glutathione (GSH), Malondialdehyde (MDA), and Reactive Oxygen Species (ROS) levels. Downstream targets of miR-138-5p were verified via luciferase reporter and RNA pull-down assays. RIP and qRT-PCR were employed to evaluate pri-miR-138-5p binding to DiGeorge critical region 8 (DGCR8) and the pri-miR-138-5p m6A modification level. Additionally, the impact of fat mass and obesity-associated protein (FTO) on LUAD gefitinib sensitivity was assessed in vivo by constructing a xenograft model. Results: We observed that miR-138-5p was notably diminished in gefitinib-resistant cells. Overexpression of miR-138-5p suppressed viability while facilitated cell death and intracellular ferroptosis in gefitinib-resistant cells. Moreover, lipocalin 2 (LCN2) was the downstream target of miR-138-5p. The biological functions of miR-138-5p on gefitinib-resistant cells was reversed by introduction of LCN2. FTO suppressed the binding of DGCR8 to pri-miR-138-5p through m6A modification, thereby restraining the processing of miR-138-5p. Meanwhile, silencing of FTO enhanced the sensitivity of LUAD to gefitinib treatment. Conclusion: FTO suppressed the processing of miR-138-5p and then modulated the proliferation, death, and ferroptosis of gefitinib-resistant cells through the miR-138-5p/LCN2 pathway, which may put forward novel insights for clinically ameliorating the therapeutic effect of gefitinib in LUAD. [ABSTRACT FROM AUTHOR]

The regulation of intracellular ionic homeostasis to trigger antigen-specific immune responses has attracted extensive interest in tumor therapy. In this study, we developed a dual-pathway nanoreactor, Au-Cu 2-x Se@ZIF-8@P18 NPs (ACS-Z-P NPs), which targets danger-associated molecular patterns (DAMPs) and releases Zn2+ and reactive oxygen species (ROS) within the tumor microenvironment (TME). Zn2+ released from the metal–organic frameworks (MOFs) was deposited in the cytoplasm, leading to aberrant transcription levels of intracellular zinc-regulated proteins and DNA damage, thereby inducing pyroptosis and immunogenic cell death (ICD) dependent on caspase1/gasdermin D (GSDMD) pathway. Furthermore, upon laser irradiation, ACS-Z-P NPs could break through the limitations of inherent defects of immunosuppression in TME, enhance ROS generation through a Fenton-like reaction cascade, which subsequently triggered the activation of inflammatory vesicles and the release of damage-associated molecular patterns (DAMPs). This cascade effect led to the amplification of pyroptosis and immunogenic cell death (ICD), thereby remodeling the immunosuppressed TME. Consequently, this process improved dendritic cell (DC) antigen presentation and augmented anti-tumor T-cell responses, effectively initiating antigen-specific immune responses and further enhancing pyroptosis and ICD. This study explores the therapeutic properties of these mechanisms in detail. The synthesized Au-Cu 2-x Se@ZIF-8@P18 nanoparticles (ACS-Z-Ps) can effectively enhance the bodyʼs immune response by regulating zinc ion levels within cells. This regulation leads to abnormal levels of zinc-regulated protein transcription and DNA damage, which induces cellular pyroptosis. As a result, antigen presentation to dendritic cells (DCs) is improved, and anti-tumor T-cell responses are enhanced. The ACS-Z-P NPs overcome the limitations of ROS deficiency and immunosuppression in the tumor microenvironment by using H 2 O 2 in the tumor microenvironment through a Fenton-like reaction. This leads to an increased production of ROS and O 2 , remodeling of the immunosuppressed tumor microenvironment, and enhanced induction of cell pyroptosis and immunogenic cell death. ACS-Z-P NPs targeted B16 cells using the photosensitizer P18 in combination with PDT treatment. This approach significantly inhibited the proliferation of B16 cells and effectively inhibited tumor growth. [Display omitted] [ABSTRACT FROM AUTHOR]

How the lung achieves immune homeostasis after a pulmonary infection is not fully understood. Here, we analyzed the spatiotemporal changes in the lungs over a 2-week natural recovery from severe pneumonia in a Syrian hamster model of SARS-CoV-2 infection. We find that SARS-CoV-2 infects multiple cell types and causes massive cell death at the early stage, including alveolar macrophages. We identify a group of monocyte-derived Slamf9+ macrophages, which are induced after SARS-CoV-2 infection and resistant to impairment caused by SARS-CoV-2. Slamf9+ macrophages contain SARS-CoV-2, recruit and interact with Isg12+Cst7+ neutrophils to clear the viruses. After viral clearance, Slamf9+ macrophages differentiate into Trem2+ and Fbp1+ macrophages, contributing to inflammation resolution at the late stage, and finally replenish alveolar macrophages. These findings are validated in a SARS-CoV-2-infected hACE2 mouse model and confirmed with publicly available human autopsy single-cell RNA-seq data, demonstrating the potential role of Slamf9+ macrophages and their coordination with neutrophils in post-injury tissue repair and inflammation resolution. [ABSTRACT FROM AUTHOR]

Uveal melanoma (UM) is the most common primary intraocular tumour in adults. Local resection, radiation therapy, and enucleation are the current first-line, primary UM treatments. However, regardless of the treatment received, around 50% of UM patients will develop metastatic disease within five to 7 years. In the largest published series of unselected patients with metastatic UM (mUM), the median survival time after diagnosis of metastasis was 3.6 months, with less than 1% of patients surviving beyond 5 years. Approved drugs for treatment of mUM include systemic treatment with tebentafusp-tebn or isolated hepatic perfusion (IHP) with melphalan. However, these drugs are only available to a subset of patients and improve survival by only a few months, highlighting the urgent need for new mUM treatments. Accurately predicting which patients are at high risk for metastases is also crucial. Researchers are developing gene expression signatures in primary UM to create reliable prognostic models aimed at improving patient follow-up and treatment strategies. In this review we discuss the evidence supporting ferroptosis, a non-apoptotic form of cell death, as a potential novel treatment target and prognosticator for UM. [ABSTRACT FROM AUTHOR]

Cisplatin is widely used to treat various solid tumors. However, its toxicity to normal tissues limits its clinical application, particularly due to its ototoxic effects, which can result in hearing loss in patients undergoing chemotherapy. While significant progress has been made in preclinical studies to elucidate the cellular and molecular mechanisms underlying cisplatin-induced ototoxicity (CIO), the precise mechanisms remain unclear. Moreover, the optimal protective agent for preventing or mitigating cisplatin-induced ototoxicity has yet to be identified. This review summarizes the current understanding of the roles of apoptosis, autophagy, ferroptosis, pyroptosis, and protective agents in cisplatin-induced ototoxicity. A deeper understanding of these cell death mechanisms in the inner ear, along with the protective agents, could facilitate the translation of these agents into clinical therapeutics, help identify new therapeutic targets, and provide novel strategies for cisplatin-based cancer treatment. [ABSTRACT FROM AUTHOR]

Copper is an important mineral, and moderate copper is required to maintain physiological processes in nervous system including cerebral ischemia/reperfusion (I/R) injury. Over the past few decades, copper induced cell death, named cuprotosis, has attracted increasing attention. Several lines of evidence have confirmed cuprotosis exerts pivotal role in diverse of pathological processes, such as cancer, neurodegenerative diseases, and I/R injury. Therefore, an in-depth understanding of the interaction mechanism between copper-mediated cell death and I/R injury may reveal the significant alterations about cellular copper-mediated homeostasis in physiological and pathophysiological conditions, as well as therapeutic strategies deciphering copper-induced cell death in cerebral I/R injury. [ABSTRACT FROM AUTHOR]

Death receptor (DR) networks are controlled by the assembly of the Death-Inducing Signaling Complex (DISC) and complex II. The family of small molecules FLIPins (FLIP interactors) were developed to target the caspase-8/c-FLIPL heterodimer. FLIPin compounds were shown to promote apoptosis and caspase-8 activation at the DISC upon stimulation with death ligands (DLs) such as CD95L and TRAIL. To further investigate the role of FLIPin compounds in the DL-mediated cell death response, we analyzed their effects in combination with DLs and SMAC mimetics treatment. FLIPins were found to enhance cell viability loss and cell death induced by DL and SMAC mimetics in acute myeloid leukemia (AML), colon and pancreatic cancer cells. FLIPins enhanced both DL/BV6-induced apoptosis and DL/BV6/zVAD-fmk-induced necroptosis via an increase in complex II formation. Our results indicate that targeting the caspase-8/c-FLIPL heterodimer plays a prominent role in enhancing cell death induced by co-stimulation of DL/SMAC mimetics and opens new therapeutic strategies for targeting DR networks. [ABSTRACT FROM AUTHOR]

Breast cancer continues to be one of the most commonly diagnosed cancers around the world. Despite the decrease in mortality, there has been a steady increase in its incidence. There is much evidence that naturally occurring phytochemicals could prove to be safer alternatives aimed at prevention and development of breast cancer. In the present review, we discuss important phytochemicals, namely capsaicin, alpha-santalol and diallyl trisulphide that are shown to have chemopreventive and anti-tumour properties against breast cancer development. We examined current knowledge of their bioavailability, safety and modulation of molecular mechanisms including their ability to induce apoptotic cell death, promote cell cycle arrest, and inhibit cellular proliferation in different breast cancer cell lines and in vivo models. This review emphasises the importance of these naturally occurring phytochemicals and their potential of becoming therapeutic options in the arsenal against breast cancer development provided further scientific and clinical validation. [ABSTRACT FROM AUTHOR]

Neuronal cytotoxic edema is implicated in neuronal injury and death, yet mitigating brain edema with osmotic and surgical interventions yields poor clinical outcomes. Importantly, neuronal swelling and its downstream consequences during early brain development remain poorly investigated, and new treatment approaches are needed. We explored Ca2+-dependent downstream effects after neuronal cytotoxic edema caused by diverse injuries in mice of both sexes using multiphoton Ca2+ imaging in vivo [Postnatal Day (P)12-17] and in acute brain slices (P8-12). After different excitotoxic insults, cytosolic GCaMP6s translocated into the nucleus after a few minutes in a subpopulation of neurons, persisting for hours. We used an automated morphology-detection algorithm to detect neuronal soma and quantified the nuclear translocation of GCaMP6s as the nuclear to cytosolic intensity (N/C ratio). Elevated neuronal N/C ratios occurred concurrently with persistent elevation in Ca2+ loads and could also occur independently from neuronal swelling. Electron microscopy revealed that the nuclear translocation was associated with the increased nuclear pore size. The nuclear accumulation of GCaMP6s in neurons led to neocortical circuit dysfunction, mitochondrial pathology, and increased cell death. Inhibiting calpains, a family of Ca2+-activated proteases, prevented elevated N/C ratios and neuronal swelling. In summary, in the developing brain, we identified a calpain-dependent alteration of nuclear transport in a subpopulation of neurons after disease-relevant insults leading to long-term circuit dysfunction and cell death. The nuclear translocation of GCaMP6 and other cytosolic proteins after acute excitotoxicity can be an early biomarker of brain injury in the developing brain. [ABSTRACT FROM AUTHOR]

PT-112 is a novel immunogenic cell death (ICD)-inducing small molecule currently under Phase 2 clinical development, including in metastatic castration-resistant prostate cancer (mCRPC), an immunologically cold and heterogeneous disease state in need of novel therapeutic approaches. PT-112 has been shown to cause ribosome biogenesis inhibition and organelle stress followed by ICD in cancer cells, culminating in anticancer immunity. In addition, clinical evidence of PT-112-driven immune effects has been observed in patient immunoprofiling. Given the unmet need for immune-based therapies in prostate cancer, along with a Phase I study (NCT#02266745) showing PT-112 activity in mCRPC patients, we investigated PT-112 effects in a panel of human prostate cancer cell lines. PT-112 demonstrated cancer cell selectivity, inhibiting cell growth and leading to cell death in prostate cancer cells without affecting the non-tumorigenic epithelial prostate cell line RWPE-1 at the concentrations tested. PT-112 also caused caspase-3 activation, as well as stress features in mitochondria including ROS generation, compromised membrane integrity, altered respiration, and morphological changes. Moreover, PT-112 induced damage-associated molecular pattern (DAMP) release, the first demonstration of ICD in human cancer cell lines, in addition to autophagy initiation across the panel. Taken together, PT-112 caused selective stress, growth inhibition and death in human prostate cancer cell lines. Our data provide additional insight into mitochondrial stress and ICD in response to PT-112. PT-112 anticancer immunogenicity could have clinical applications and is currently under investigation in a Phase 2 mCRPC study. [ABSTRACT FROM AUTHOR]

Background: Immunoglobulin derived AL amyloidosis and transthyretin derived ATTR amyloidosis are the most common forms of cardiac amyloidosis. Both may present with cardiac arrhythmias, heart failure, and extracardiac symptoms. Disease outcome is often fatal. Recently, it was proposed that amyloid may cause cardiac inflammation. Here we tested the hypothesis that immune cell infiltration in cardiac tissue correlates with clinicopathological patient characteristics. Patients and methods: Myocardial biopsies from 157 patients with cardiac amyloidosis (46.5% AL, 53.3% ATTR) were immunohistochemically assessed for the presence and amount of T lymphocytes (CD3), macrophages (CD68) and neutrophils (MPO). Amyloid load, cardiomyocyte diameter, apoptosis (Caspase 3), necrosis (complement 9), and various clinical parameters were assessed and correlated with immune cell density. Results: Myocardial tissue was infiltrated with T lymphocytes (CD3), macrophages (CD68) and neutrophils (MPO) with variable amounts. Significant correlations were found between the number of macrophages and NYHA class. No correlations were found between the presence and amount of T lymphocytes, neutrophils and clinicopathological patient characteristics. Conclusion: The significant correlation between cardiac macrophage density and heart failure points towards a significant role of macrophages in disease pathology. [ABSTRACT FROM AUTHOR]

Alzheimer disease (AD) is among the most prevalent neurodegenerative diseases globally, marked by cognitive and behavioral disruptions. Ferroptosis is a form of controlled cell death characterized by intracellular iron accumulation associated with lipid peroxide formation, which subsequently promotes AD initiation and progression. We hypothesized that targeting the ferroptosis pathway may help in AD management. Therefore, our study aimed to evaluate the potential neuroprotective effect of the antifungal Ciclopirox olamine (CPX-O) that acts through iron chelation. We employed CPX-O separately or in combination with the JNK inhibitor (SP600125) in a mice model of AlCl3-induced AD. Animals underwent examination for behavioral, biochemical, histological, and immunohistochemical findings. Our results revealed that AlCl3 was associated with disruptions in learning and memory parameters, neuronal degeneration in the hippocampus, increased immunoreactivity of amyloid-β and tau proteins, a significant rise in iron, nitric oxide (NO), malondialdehyde (MDA), JNK, and P53 levels, along with the significant decrease in glutathione peroxidase activity. Interestingly, the administration of CPX-O alone or in combination with SP600125 in the AlCl3-induced AD model caused an improvement in the previously described examination findings. Therefore, CPX-O may be a promising candidate for AD treatment, and future clinical trials will be required to confirm these preclinical findings. [ABSTRACT FROM AUTHOR]

Background: Liquid biopsy based on cell-free DNA (cfDNA) analysis holds significant promise as a minimally invasive approach for the diagnosis, genotyping, and monitoring of solid malignancies. Human tumors release cfDNA in the bloodstream through a combination of events, including cell death, active and passive release. However, the precise mechanisms leading to cfDNA shedding remain to be characterized. Addressing this question in patients is confounded by several factors, such as tumor burden extent, anatomical and vasculature barriers, and release of nucleic acids from normal cells. In this work, we exploited cancer models to dissect basic mechanisms of DNA release. Methods: We measured cell loss ratio, doubling time, and cfDNA release in the supernatant of a colorectal cancer (CRC) cell line collection (N = 76) representative of the molecular subtypes previously identified in cancer patients. Association analyses between quantitative parameters of cfDNA release, cell proliferation, and molecular features were evaluated. Functional experiments were performed to test the impact of modulating DNA methylation on cfDNA release. Results: Higher levels of supernatant cfDNA were significantly associated with slower cell cycling and increased cell death. In addition, a higher cfDNA shedding was found in non-CpG Island Methylator Phenotype (CIMP) models. These results indicate a positive correlation between lower methylation and increased cfDNA levels. To explore this further, we exploited methylation microarrays to identify a subset of probes significantly associated with cfDNA shedding and derive a methylation signature capable of discriminating high from low cfDNA releasers. We applied this signature to an independent set of 176 CRC cell lines and patient derived organoids to select 14 models predicted to be low or high releasers. The methylation profile successfully predicted the amount of cfDNA released in the supernatant. At the functional level, genetic ablation of DNA methyl-transferases increased chromatin accessibility and DNA fragmentation, leading to increased cfDNA release in isogenic CRC cell lines. Furthermore, in vitro treatment of five low releaser CRC cells with a demethylating agent was able to induce a significant increase in cfDNA shedding. Conclusions: Methylation status of cancer cell lines contributes to the variability of cfDNA shedding in vitro. Changes in methylation pattern are associated with cfDNA release levels and might be exploited to increase sensitivity of liquid biopsy assays. [ABSTRACT FROM AUTHOR]

Cell death plays an important role in the determination of secondary xylem cell functions. Tracheary elements (TEs), such as vessel elements and tracheids, lose their organelles due to rapid autolysis after the completion of secondary wall thickening and lignification, and play an important role in water movement along the stem. In contrast, xylem axial and ray parenchyma cells (xylem parenchyma cells) remain alive for several years or longer and retain their organelles even after maturation. As a result, xylem parenchyma cells play important roles in nutrient storage, axial and radial transportation of materials, and defense responses in the stem. In addition, they are involved in the formation of heartwood, which contributes to increases in the resistance of the tree trunk to decay, as they synthesize heartwood components such as polyphenols prior to their death. The present review focuses on changes in long-lived ray parenchyma cells during heartwood formation, such as morphology and contents of organelles, gene expression, and survival rate in sapwood. This review also summarizes the differences in cell death characteristics between TEs and ray parenchyma cells. The elucidation of the cell death mechanism of ray parenchyma cells is expected to provide useful information for controlling the properties of heartwood. [ABSTRACT FROM AUTHOR]

AbstractDamaged 2’-deoxyribonucleotides cause mutations, cancer, cell death, and aging. The Escherichia coli Orf135 (NudG) protein catalyzes the hydrolysis of various 2’-deoxyribonucleotides including an oxidized form of dATP, 2-oxo-1,2-dihydro-2’-deoxyadenosine 5’-triphosphate (dAOTP, 2-hydroxy-2’-deoxyadenosine 5’-triphosphate). The best substrate is 5-methyl-2’-deoxycytidine 5’-triphosphate (dCmTP), and the protein prefers dCmTP over dAOTP by ∼200-fold in vitro. To make the enzyme specific for the mutagenic nucleotide dAOTP, a double mutant protein (E33A plus D118E) was designed and produced in E. coli. The purified mutant protein showed one order of magnitude higher dAOTP preference over dCmTP. The split protein based on this mutant may potentially be used to detect dAOTP in living cells. [ABSTRACT FROM AUTHOR]

AbstractOsteoarthritis (OA) is a chronic degenerative disease caused by various factors such as aging, obesity, trauma, and genetics. It is a challenging condition faced by orthopedic doctors in clinical practice and places a heavy burden on patients and their families. Currently, the treatment of OA primarily focuses on symptomatic relief and lacks ideal therapeutic methods. Resveratrol is a natural polyphenolic compound with anti-inflammatory and antioxidant properties, and in recent years, it has gained attention as a candidate drug for OA treatment. This article provides an overview of the research status on the role and mechanisms of resveratrol in treating OA. It has been found that resveratrol can prevent the development of OA by inhibiting inflammatory responses, protecting chondrocytes, maintaining cartilage homeostasis, promoting autophagy, and has shown certain therapeutic effects. This process may be related to the regulation of signaling pathways such as nuclear factor-kappa B (NF-κB), Toll-like receptor 4 (TLR4), and silent information regulator 1 (SIRT1). We summarize the current molecular mechanisms of resveratrol in treating OA, hoping to provide a reference for further research and application of resveratrol in OA treatment. [ABSTRACT FROM AUTHOR]

Ferroptosis, distinct from apoptosis, necrosis, and autophagy, is a unique type of cell death driven by iron-dependent phospholipid peroxidation. Since ferroptosis was defined in 2012, it has received widespread attention from researchers worldwide. From a biochemical perspective, the regulation of ferroptosis is strongly associated with cellular metabolism, primarily including iron metabolism, lipid metabolism, and redox metabolism. The distinctive regulatory mechanism of ferroptosis holds great potential for overcoming drug resistance—a major challenge in treating cancer. The considerable role of nanobiotechnology in disease treatment has been widely reported, but further and more systematic discussion on how nanobiotechnology enhances the therapeutic efficacy on ferroptosis-associated diseases still needs to be improved. Moreover, while the exciting therapeutic potential of ferroptosis in cancer has been relatively well summarized, its applications in other diseases, such as neurodegenerative diseases, cardiovascular and cerebrovascular diseases, and kidney disease, remain underreported. Consequently, it is necessary to fill these gaps to further complete the applications of nanobiotechnology in ferroptosis. In this review, we provide an extensive introduction to the background of ferroptosis and elaborate its regulatory network. Subsequently, we discuss the various advantages of combining nanobiotechnology with ferroptosis to enhance therapeutic efficacy and reduce the side effects of ferroptosis-associated diseases. Finally, we analyze and discuss the feasibility of nanobiotechnology and ferroptosis in improving clinical treatment outcomes based on clinical needs, as well as the current limitations and future directions of nanobiotechnology in the applications of ferroptosis, which will not only provide significant guidance for the clinical applications of ferroptosis and nanobiotechnology but also accelerate their clinical translations. [ABSTRACT FROM AUTHOR]

Neutrophils rapidly infiltrate sites of infection and possess several microbicidal strategies, such as neutrophil extracellular traps release and phagocytosis. Enhanced neutrophil infiltration is associated with higher susceptibility to Leishmania infection, but neutrophil effector response contribution to this phenotype is uncertain. Here, we show that neutrophils from susceptible BALB/c mice (B/c) produce more NETs in response to Leishmania major than those from resistant C57BL/6 mice (B6), which are more phagocytic. The absence of neutrophil elastase contributes to phagocytosis regulation. Microarray analysis shows enrichment of genes involved in NET formation (mpo, pi3kcg, il1b) in B/c, while B6 shows upregulation of genes involved in phagocytosis and cell death (Arhgap12, casp9, mlkl, FasL). scRNA-seq in L. major-infected B6 showed heterogeneity in the pool of intralesional neutrophils, and we identified the N1 subset as the putative subpopulation involved with phagocytosis. In vivo, imaging validates NET formation in infected B/c ears where NETing neutrophils were mainly uninfected cells. NET digestion in vivo augmented parasite lymphatic drainage. Hence, a balance between NET formation and phagocytosis in neutrophils may contribute to the divergent phenotype observed in these mice. Author summary: Leishmaniasis is a complex of vector-borne diseases transmitted by infected sandflies carrying Leishmania. Clinical manifestations range from cutaneous lesions to visceral disease, which can be fatal if not treated. Cutaneous Leishmaniasis is the most common clinical manifestation. Experimental models built in the early 70s have established susceptible (BALB/c) and resistant (C57BL/6) strains to Leishmania major infection. Neutrophils comprise the first line of defense against microbial invaders. Neutrophils possess powerful microbicidal tools, which can thwart most pathogens. Accordingly, genetic disorders that lead to neutropenia enhance patients' susceptibility to infections. Counterintuitively, neutrophilia is associated with enhanced susceptibility to cutaneous Leishmaniasis. Although these cells used to be considered transcriptionally rudimental, currently neutrophils have emerged as functionally plastic cells. Here, we deepened the understanding of why neutrophils are associated with susceptibility to infection in the murine model by showing that not just the influx, but the functional profile of these cells likely impacts the early response to infection and affects parasite retention in the primary site of infection, which likely contributes to shaping disease outcome. Our results provide mechanistic insights to assist in the development of target-based therapies. [ABSTRACT FROM AUTHOR]

Background: Gastric cancer is a prevalent form of malignancy among many common carcinoma cases globally. This study was designed to assess the anticancer potential of the crude ethanolic seed extract from Mucuna pruriens against the gastric cancer cell line (AGS). Various assays were employed to assess the anticancer properties, including examinations of cell viability, nuclear morphology, apoptosis using AO/EB staining, changes in mitochondrial membrane potential, lactate dehydrogenase activity, DNA fragmentation, and cell cycle arrest. Results: The crude extract exhibited significant anticancer activity against the human gastric cancer cell line (AGS), as determined by the MTT assay, with an inhibition concentration (IC50) of 600 µg/mL at 24 h. Distinct cellular and nuclear morphological changes were observed with different concentrations of crude ethanolic seed extract. The LDH release assay reveals cell death in AGS cells, as evidenced by a significant increase in the release of LDH enzyme. DNA fragmentation analysis and flow cytometry results indicate that the extract induces chromatin condensation, apoptotic cell death, and cell cycle arrest at the G0/G1 phase in the AGS cancer cell line. These results highlight the potential therapeutic advantages of Mucuna pruriens seed extract against gastric cancer cells. Conclusion: This study could pave the way for identifying diverse natural bioactive compounds sourced from Mucuna pruriens seed, leading to the development of novel drug with potential anticancer properties. [ABSTRACT FROM AUTHOR]

Background: Neuroinflammation reportedly plays a critical role in the pathogenesis of sepsis-associated encephalopathy (SAE). We previously reported that circulating plasma extracellular vesicles (EVs) from septic mice are proinflammatory. In the current study, we tested the role of sepsis plasma EVs in neuroinflammation. Methods: To track EVs in cells and tissues, HEK293T cell-derived EVs were labeled with the fluorescent dye PKH26. Cecal ligation and puncture (CLP) was conducted to model polymicrobial sepsis in mice. Plasma EVs were isolated by ultracentrifugation and their role in promoting neuronal inflammation was tested following intracerebroventricular (ICV) injection. miRNA inhibitors (anti-miR-146a, -122, -34a, and -145a) were applied to determine the effects of EV cargo miRNAs in the brain. A cytokine array was performed to profile microglia-released protein mediators. TLR7- or MyD88-knockout (KO) mice were utilized to determine the underlying mechanism of EVs-mediated neuroinflammation. Results: We observed the uptake of fluorescent PKH26-EVs inside the cell bodies of both microglia and neurons. Sepsis plasma EVs led to a dose-dependent cytokine release in cultured microglia, which was partially attenuated by miRNA inhibitors against the target miRNAs and in TLR7-KO cells. When administered via the ICV, sepsis plasma EVs resulted in a marked increase in the accumulation of innate immune cells, including monocyte and neutrophil and cytokine gene expression, in the brain. Although sepsis plasma EVs had no direct effect on cytokine production or neuronal injury in vitro, the conditioned media (CM) of microglia treated with sepsis plasma EVs induced neuronal cell death as evidenced by increased caspase-3 cleavage and Annexin-V staining. Cytokine arrays and bioinformatics analysis of the microglial CM revealed multiple cytokines/chemokines and other factors functionally linked to leukocyte chemotaxis and migration, TLR signaling, and neuronal death. Moreover, sepsis plasma EV-induced brain inflammation in vivo was significantly dependent on MyD88. Conclusions: Circulating plasma EVs in septic mice cause a microglial proinflammatory response in vitro and a brain innate immune response in vivo, some of which are in part mediated by TLR7 in vitro and MyD88 signaling in vivo. These findings highlight the importance of circulating EVs in brain inflammation during sepsis. [ABSTRACT FROM AUTHOR]

The efficacy of anthracycline, such as doxorubicin (DOX), is facilitated by cancer cell‐intrinsic type I interferon (IFN‐I) signaling through the induction of immune responses. However, weak and chronic IFN‐I responses from rounds of chemotherapy lead to resistance against DNA damage and acquired resistance to the therapy. An exogenous supply of IFN‐I can improve the chemotherapeutic responses. Herein, a library of cationic liposomes is developed for the optimization of 1, 2‐dioleoyl‐3‐trimethylammonium‐propane (DOTAP) proportions to enhance the lysosome escape and tumor distribution of the stimulator of interferon genes (STING) agonist 2′,3′‐cyclic guanosine monophosphate‐adenosine monophosphate (cGAMP) and DOX. The cationic liposomes with 8% DOTAP release cGAMP into the cytoplasm and increase the concentration of DOX in the tumor by 1.5 times compared with the free drug. Upon accumulation at the tumor site, the optimized liposomes induce immunogenic cell death (ICD) and stimulate the STING signaling, thereby improving the production of endogenous IFN‐I and promoting dendritic cell maturation to mobilize T cell immunity. The tumor growth inhibition rate is 86%, and the median survival time is 1.6‐fold prolonged. This study offers a strategy to enhance the DOX‐induced immune response by activating the STING pathway to supply IFN‐I. [ABSTRACT FROM AUTHOR]

High‐fat diet (HFD)‐induced obesity induces peripheral inflammation and hypothalamic pathogenesis linking the activation of astrocytes and microglia. Clinical evidence indicates a positive correlation between obesity and psychiatric disorders, such as depression. The connectivity of the frontal‐striatal (FS) circuit, involving the caudate putamen (CPu) and anterior cingulate cortex (ACC) within the prefrontal cortex (PFC), is known for its role in stress‐induced depression. Thus, there is a need for a thorough investigation into whether chronic obesity‐induced gliosis, characterized by the activation of astrocytes and microglia, in these brain regions of individuals with chronic obesity. The results revealed increased S100β+ astrocytes and Iba1+ microglia in the CPu and ACC of male obese mice, along with immune cell accumulation in meningeal lymphatic drainage. Activated GFAP+ astrocytes and Iba1+ microglia were observed in the corpus callosum of obese mice. Gliosis in the CPu and ACC was linked to elevated cleaved caspase‐3 levels, indicating potential neural cell death by chronic HFD feeding. There was a loss of myelin and adenomatous polyposis coli (APC)+ oligodendrocytes (OLs) in the corpus callosum, an area known to be linked with injury to the CPu. Additionally, reduced levels of aquaporin‐4 (AQP4), a protein associated within the glymphatic systems, were noted in the CPu and ACC, while ciliary neurotrophic factor (CNTF) gene expression was upregulated in these brain regions of obese mice. The in vitro study revealed that high‐dose CNTF causing a trend of reduced astrocytic AQP4 expression, but it significantly impaired OL maturation. This pathological evidence highlights that prolonged HFD consumption induces persistent FS gliosis and demyelination in the corpus callosum. An elevated level of CNTF appears to act as a potential regulator, leading to AQP4 downregulation in the FS areas and demyelination in the corpus callosum. This cascade of events might contribute to neural cell damage within these regions and disrupt the glymphatic flow. [ABSTRACT FROM AUTHOR]

Various types of cell death program are needed for cells to respond to changes in physiological conditions. In this collection of Voices, we asked scientists to tell the story behind their contributions to the identification and mechanistic dissection of cell death pathways and to discuss future directions for such research. [ABSTRACT FROM AUTHOR]