Mechanism Of Cell Death Research Articles

Analysis of High-Dose Ascorbate-Induced Cytotoxicity in Human Glioblastoma Cells and the Role of Dehydroascorbic Acid and Iron.

Several studies have demonstrated, both in vitro and in animal models, the anti-tumor efficacy of high-dose ascorbate treatment against a variety of tumor entities, including glioblastoma, the most common and aggressive primary malignant brain tumor. The aim of this study was to investigate the effects of high-dose ascorbate as well as dehydroascorbic acid on human glioblastoma cell lines and to evaluate different treatment conditions for the combined administration of ascorbate with magnesium (Mg2+) and iron (Fe3+). Intracellular levels of reactive oxygen species and the induction of cell death following ascorbate treatment were also investigated. We demonstrated high cytotoxicity and antiproliferative efficacy of high-dose ascorbate in human glioblastoma cells, whereas much weaker effects were observed for dehydroascorbic acid. Ascorbate-induced cell death was independent of apoptosis. Both the reduction in cell viability and the ascorbate-induced generation of intracellular reactive oxygen species could be significantly increased by incubating the cells with Fe3+ before ascorbate treatment. This work demonstrates, for the first time, an increase in ascorbate-induced intracellular ROS formation and cytotoxicity in human glioblastoma cells by pre-treatment of the tumor cells with ferric iron, as well as caspase-3 independence of cell death induced by high-dose ascorbate. Instead, the cell death mechanism caused by high-dose ascorbate in glioblastoma cells shows evidence of ferroptosis. The results of the present work provide insights into the efficacy and mode of action of pharmacological ascorbate for the therapy of glioblastoma, as well as indications for possible approaches to increase the effectiveness of ascorbate treatment.

Targeting cell death mechanisms: the potential of autophagy and ferroptosis in hepatocellular carcinoma therapy.

Ferroptosis is a type of cell death that plays a remarkable role in the growth and advancement of malignancies including hepatocellular carcinoma (HCC). Non-coding RNAs (ncRNAs) have a considerable impact on HCC by functioning as either oncogenes or suppressors. Recent research has demonstrated that non-coding RNAs (ncRNAs) have the ability to control ferroptosis in HCC cells, hence impacting the advancement of tumors and the resistance of these cells to drugs. Autophagy is a mechanism that is conserved throughout evolution and plays a role in maintaining balance in the body under normal settings. Nevertheless, the occurrence of dysregulation of autophagy is evident in the progression of various human disorders, specifically cancer. Autophagy plays dual roles in cancer, potentially influencing both cell survival and cell death. HCC is a prevalent kind of liver cancer, and genetic mutations and changes in molecular pathways might worsen its advancement. The role of autophagy in HCC is a subject of debate, as it has the capacity to both repress and promote tumor growth. Autophagy activation can impact apoptosis, control proliferation and glucose metabolism, and facilitate tumor spread through EMT. Inhibiting autophagy can hinder the growth and spread of HCC and enhance the ability of tumor cells to respond to treatment. Autophagy in HCC is regulated by several signaling pathways, such as STAT3, Wnt, miRNAs, lncRNAs, and circRNAs. Utilizing anticancer drugs to target autophagy may have advantageous implications for the efficacy of cancer treatment.

Experimental study of radioprotective properties of lithium pyruvate in vitro

Radiotoxicity is a serious problem for patients undergoing radiotherapy, so the search for new radioprotective drugs to mitigate its effects is highly relevant. Radioprotectors should have a number of properties, including direct antioxidant action, reduction of oxidative stress, ability to induce DNA repair or inhibit apoptosis, and at the same time not cause their own side effects. Antioxidants based on lithium salts look promising in terms of their properties. The aim of study was to study the radioprotective properties of lithium pyruvate in vitro. Material and Methods. Relatively radiosensitive blood mononuclear cells and relatively radioresistant fibroblasts of 3T3L1 line were used as biomodels for x-ray exposure. Cells were incubated and irradiated in 96-well plates. Lithium pyruvate was used at a final concentration of 1.2 mM. Cells were irradiated at a dose rate of 15 mGy/s in the absorbed-dose range from 0 to 5 Gy using an x-ray unit (anode voltage: 160 kV, average current: 3.5 mA). Cell viability was assessed by MTT test and resazurin test. The evaluation of cell death variants and the level of oxidative stress were determined by cytofluorimetric method. Results. The cytoprotective effect of lithium pyruvate was established. Cytoprotection was manifested in the increased cell survival and decreased oxidative stress level under lithium pyruvate after x-ray in a wide range of absorbed doses. Relatively high efficiency was shown in relation to blood mononuclear cells with an increase in the viable fraction by 5–7 % and a decrease in oxidative stress level during irradiation in the range of 1.0–3.0 Gy. Apoptosis was found to be the main mechanism of cell death after irradiation. Lithium pyruvate reduced the level of apoptosis in cell population under irradiation and chemically induced oxidative stress. Conclusion. Radioprotective effect of lithium pyruvate under x-ray irradiation in vitro has been shown. Reduction of oxidative stress under the action of pyruvate provides a pathogenetic basis for the potential use of this compound as a radioprotector, which requires further studies on in vivo models.

Small molecules targeting mitochondria as an innovative approach to cancer therapy

Cellular death evasion is a defining characteristic of human malignancies and a significant contributor to therapeutic inefficacy. As a result of oncogenic inhibition of cell death mechanisms, established therapeutic regimens seems to be ineffective. Mitochondria serve as the cellular powerhouses, but they also function as repositories of self-destructive weaponry. Changes in the structure and activities of mitochondria have been consistently documented in cancer cells. In recent years, there has been an increasing focus on using mitochondria as a targeted approach for treating cancer. Considerable attention has been devoted to the development of delivery systems that selectively aim to deliver small molecules called “mitocans” to mitochondria, with the ultimate goal of modulating the physiology of cancer cells. This review summarizes the rationale and mechanism of mitochondrial targeting with small molecules in the treatment of cancer, and their impact on the mitochondria. This paper provides a concise overview of the reasoning and mechanism behind directing treatment towards mitochondria in cancer therapy, with a particular focus on targeting using small molecules. This review also examines diverse small molecule types within each category as potential therapeutic agents for cancer.

MYC Induces Oncogenic Stress through RNA Decay and Ribonucleotide Catabolism in Breast Cancer.

Upregulation of MYC is a hallmark of cancer, wherein MYC drives oncogenic gene expression and elevates total RNA synthesis across cancer cell transcriptomes. Although this transcriptional anabolism fuels cancer growth and survival, the consequences and metabolic stresses induced by excess cellular RNA are poorly understood. Herein, we discover that RNA degradation and downstream ribonucleotide catabolism is a novel mechanism of MYC-induced cancer cell death. Combining genetics and metabolomics, we find that MYC increases RNA decay through the cytoplasmic exosome, resulting in the accumulation of cytotoxic RNA catabolites and reactive oxygen species. Notably, tumor-derived exosome mutations abrogate MYC-induced cell death, suggesting excess RNA decay may be toxic to human cancers. In agreement, purine salvage acts as a compensatory pathway that mitigates MYC-induced ribonucleotide catabolism, and inhibitors of purine salvage impair MYC+ tumor progression. Together, these data suggest that MYC-induced RNA decay is an oncogenic stress that can be exploited therapeutically. Significance: MYC is the most common oncogenic driver of poor-prognosis cancers but has been recalcitrant to therapeutic inhibition. We discovered a new vulnerability in MYC+ cancer where MYC induces cell death through excess RNA decay. Therapeutics that exacerbate downstream ribonucleotide catabolism provide a therapeutically tractable approach to TNBC (Triple-negative Breast Cancer) and other MYC-driven cancers.

Vitamin K3 derivative inhibits androgen receptor signaling in targeting aggressive prostate cancer cells.

Prostate cancer (PCa) is the second critical cause of cancer-related deaths, with African Americans dying at higher rates in the U.S. The main reasons for the higher mortality rate are ethnic differences and lack of understanding of prostate cancer biology and affordable treatments, as well as the financial burden of African American men to obtain the most effective and safe treatments. The effect of micronutrients, including Vitamin K, on various cancer cell lines has been widely studied, but the potential anticancer effect of VK3-OCH3, an analog of vitamin K3 (Menadione), on African American prostate cancer has not been evaluated. In this study, we compared the anticancer effect of VK3-OCH3 on targeting African American derived PCa cell lines namely RC77-T and MDA-PCa-2b. Our results show that VK3-OCH3 significantly inhibits the proliferation of both RC77-T and MDA-PCa-2b African American PCa cells and promotes apoptosis, and the underlying mechanism of cell death appears to be similar in both the cell lines. Notably, VK3-OCH3 inhibits colony-forming ability and induces apoptosis by blocking the cell cycle at G0 in African American PCa cells. VK3-OCH3 also acts as an anti-metastatic agent by inhibiting the migration ability of the metastatic properties of African American PCa cells. The cell death of African American PCa cells mediated by VK3-OCH3 is associated with the production of free radicals, such as intracellular and mitochondrial reactive oxygen species (ROS). Interestingly, antioxidants such as N-Acetylcysteine (NAC) and Glutathione (GSH) effectively negated the oxidative stress induced by VK3-OCH3 on PCa cell lines derived from African American patients. Of note, VK3-OCH3 reduces androgen receptor and prostate-specific antigen expression in these PCa cells. Furthermore, molecular dynamic studies reiterated that VK3-OCH3 strongly binds to the androgen receptor, suggesting that the androgen receptor is the potential molecular target of VK3-OCH3. In addition, Western blot analysis showed that VK3-OCH3 reduces the expression of androgen receptor, TRX2, and anti-apoptotic signaling molecules such as Bcl-2 and TCTP in the MDA-PCa-2b metastatic PCa cellular model. In conclusion, our results suggested that VK3-OCH3 is a promising anticancer agent that could potentially reduce the mortality rates of African American PCa patients, warranting further preclinical and translational studies.

Sequential induction of ferroptosis and pyroptosis in cancer cells by lipid droplet-targeting AIE theranostics

Aggregation-induced emission (AIE) theranostics has received considerable attention because of its potential applications in bioimaging and photodynamic therapy (PDT). Herein, we report a series of phthalimide-based AIEgens that are selectively localized in lipid droplets (LDs) in cancer cells and simultaneously generate reactive oxygen species (ROS) under light irradiation. The enhanced photostability resulting from the AIE properties of LPSP2 enabled the long-term tracking of LDs during ferroptotic cell death triggered by LPSP2 under PDT conditions. As the irradiation time increased, the lipid peroxides generated by LPSP2 were transported from the LDs to the endoplasmic reticulum (ER), where oxidative stress activates NLRP3, leading to pyroptotic cell death. The spatiotemporal control of lipid peroxidation achieved by LPSP2 revealed sequential activation of ferroptosis followed by pyroptosis, depending on the irradiation duration. Our research demonstrates novel LD-targeted theranostics with unprecedented induction of ferroptotic and pyroptotic cell death under PDT, which will enrich our understanding of cancer cell death mechanisms toward a more efficient therapeutic strategy.

Phenolic Contents, Antioxidant Activities, LCMS Profiles of Mespilus germanica Leaf Extract and Effects on mRNA Transcription Levels of Apoptotic, Autophagic, and Necrotic Genes in MCF7 and A549 Cancer Cell Lines.

Cancer, defined by the continuous, uncontrollable proliferation of cells in the human body, is a disease with a rapidly increasing incidence and mortality rate. Scientists are looking for novel ways to cure and prevent this sneaky disease because of the toxicity of contemporary chemotherapy and the cancer cells' resilience to anticancer drugs. Determining the effect of herbal medicines, which do not have as harmful side effects as synthetic drugs, on cancer cell lines is an essential preliminary study in the production of effective drugs against cancer. In this study, the phenolic acid profile, antioxidant capacity, and cytotoxicity of the medicinal plant Mespilus germanica (MG) leaf extract were determined, and its effects on the expression of some apoptotic, necrotic, and autophagic pathway genes of MCF7 (Human breast cancer line) and A549 (Human lung cancer line) and healthy HDF (Human Dermal Fibroblasts) cells were investigated for the first time. The LCMS device detected many important phenolic compounds previously reported to act against cancer cells in Mespilus germanica leaf extract. DPPH and total phenolic content showed high antioxidant capacity. The cytotoxicity of MG was determined by the MTT method. The levels of mRNA transcription for Atg5, Atg3, Rıpk1, Bcl2, Bax, Apaf1, Caspase-8, Caspase-7, Caspase-3, and Caspase-9, as well as the expression patterns of the DNA damage markers P53 and Parp-1 genes, were assessed. MG leaf extract did not cause significant toxicity against healthy HDF cells. However, it had a cytotoxic effect on A549 and MCF7 cancer cell lines, increasing the transcription levels of essential genes involved in cell death mechanisms. This research is the first to analyze the phenolic components and antioxidant capabilities of leaf extracts from Mespilus germanica. Additionally, it investigates the impact of these extracts on crucial genes involved in cell death pathways of A549 lung cancer, MCF7 breast cancer, and non-cancerous HDF (Human Dermal Fibroblasts) cells.

Tannic acid elicits differential gene regulation in prostate cancer apoptosis.

Prostate cancer is a significant global health concern that requires innovative therapeutic investigations. Here, the potential anticancer properties of tannic acid were evaluated by examining its effects on apoptosis in prostate cancer cell lines. PC-3 and LnCaP prostate adeno carcinoma cells, along with PNT1A prostate control cells, were cultured and divided into untreated and tannic acid-treated groups. Cell proliferation, cytotoxicity, and effects of tannic acid on the cell death mechanism were evaluated. mRNA expression levels of 84 genes were explored in cells following tannic acid treatment. Notably, tannic acid-induced down-regulation of several pro-survival genes, including ATM, BCL2, BCL2A1, BIK, BIRC2, BIRC3, BRE, CASP3, CASP6, CASP8, CHEK2, CRADD, PPIA, RPA3, TNFSF18, TRAF1, TRAF2, TRAF4, and TRAF5 in both cell lines. Moreover, tannic acid treatment led to the up-regulation of various pro-apoptotic genes, such as BCL10, BIRC3, BNIP3, CASP1, CASP5, CD40, CIDEB, DAPK2, FASLG, GADD45A, MYD88, RPA 3, TNFRSF10D, TNFRSF17, TNFRSF8, TNFSF13B, TNFSF4, TNFSF7, TNFSF8, TNFSF9, TP53, TRAF1, and TRAF2 in both PC-3 and LnCap cells. These findings highlight tannic acid's ability to induce apoptosis in prostate cancer cells through pro-apoptotic pathways. This study concludes that tannic acid selectively inhibits prostate cancer cell growth.

Data-driven analysis that integrates bioinformatics and machine learning uncovers PANoptosis-related diagnostic genes in early pediatric septic shock

ObjectivesSepsis is one of the leading causes of death for children worldwide. Additionally, refractory septic shock is one of the most significant groups that contributes to a high death rate. The interaction of pyroptosis, apoptosis, and necroptosis results in a unique inflammatory cell death mechanism known as PANoptosis. An increasing amount of evidence suggests that PANoptosis can be brought on by several stimuli, including cytokine storms, malignancy, and bacterial or viral infections. The goal of this study is to improve the diagnostic significance of the PANoptosis-related gene signature in early pediatric septic shock. Design and methodsWe examined children with septic shock from the GSE66099 discovery cohort and looked at differentially expressed genes (DEGs). To filter the important modules, weighted gene co-expression network analysis (WCGNA) was employed. In the end, random forest analysis and the least absolute shrinkage and selection operator (LASSO) were used to determine the PANoptosis diagnostic signature genes. To determine the PANoptosis signature genes, we also found four validation cohorts: GSE26378, GSE26440, GSE8121, and GSE13904. The area under the curve (AUC) of the receiver operating characteristic curves (ROCs), along with sensitivity, specificity, positive predictive value, and negative predictive value, were used to assess the diagnostic efficacy of these signature genes. ResultsFrom GSE66099, 1142 DEGs in total were tested. Following the WGCNA clustering of the data into 16 modules, the MEgrey module showed a significant correlation with pediatric septic shock (p < 0.0001). Following the use of LASSO and random forest algorithms to identify the PANoptosis-related signature genes, which include ANXA3, S100A9, TXN, CLEC5A, and TMEM263. These signature genes' receiver operating characteristic curves (ROCs) were confirmed in the external dataset from GSE26378, GSE26440, GSE8121, and GSE13904, and were 0.994 (95 % CI 0.987–0.999), 0.987 (95 % CI 0.974–0.997), 0.957 (95 % CI 0.927–0.981), 0.974 (95 % CI 0.954–0.988), 0.897 (95 % CI 0.846–0.941), respectively. ConclusionIn summary, the discovery of PANoptosis genes, ANXA3, S100A9, TXN, CLEC5A, and TMEM263 proved to be quite helpful in the early detection of pediatric septic shock patients. These early results, which need to be further confirmed in basic and clinical research, are extremely important for understanding immune cell infiltration in the pathophysiology of pediatric septic shock.

Role of N6-methyladenosine RNA modification in cancer.

N6-methyladenosine (m6A) is the most abundant modification of RNA in eukaryotic cells. Previous studies have shown that m6A is pivotal in diverse diseases especially cancer. m6A corelates with the initiation, progression, resistance, invasion, and metastasis of cancer. However, despite these insights, a comprehensive understanding of its specific roles and mechanisms within the complex landscape of cancer is still elusive. This review begins by outlining the key regulatory proteins of m6A modification and their posttranslational modifications (PTMs), as well as the role in chromatin accessibility and transcriptional activity within cancer cells. Additionally, it highlights that m6A modifications impact cancer progression by modulating programmed cell death mechanisms and affecting the tumor microenvironment through various cancer-associated immune cells. Furthermore, the review discusses how microorganisms can induce enduring epigenetic changes and oncogenic effect in microorganism-associated cancers by altering m6A modifications. Last, it delves into the role of m6A modification in cancer immunotherapy, encompassing RNA therapy, immune checkpoint blockade, cytokine therapy, adoptive cell transfer therapy, and direct targeting of m6A regulators. Overall, this review clarifies the multifaceted role of m6A modification in cancer and explores targeted therapies aimed at manipulating m6A modification, aiming to advance cancer research and improve patient outcomes.

Copper coordinated nano-assemblies based on photosensitizer and chemo-prodrugs for cascade-activated and enhanced apoptosis-cuproptosis

Cuproptosis is a recently discovered regulated cell death mechanism that differs from known cell death pathways, showing significant potential in tumor therapy. However, precise delivery of copper (Cu) ions to the tumor site and optimizing their therapeutic efficacy pose significant challenges. In the current study, we have developed a novel Cu-based chemotherapeutic prodrug and photosensitizer coordination polymer for synergistic therapy combining photothermal enhancement with apoptosis-cuproptosis. After internalization by cancer cells, the photothermal effect increases intracellular glutathione depletion and reactive oxygen species production, triggering the release of chemotherapeutic agents camptothecin and doxorubicin and promoting tumor cell apoptosis. Additionally, the presence of Cu2+/Cu+ triggers cuproptosis, leading to a synergistic anti-tumor effect combining apoptosis and cuproptosis. Our findings offer another perspective on potential cancer treatment through the apoptosis-cuproptosis axis and present a novel approach for designing nanomedicine based on cuproptosis.

On the binding of auranofin to Prdx6 and its potential role in cancer cell sensitivity to treatment

In this study, we demonstrate that ferroptosis is a component of the cell death mechanism induced by auranofin in HT-1080 cells, in contrast to the gold(III) compounds [Au(phen)Cl2]PF6 and [Au(bnpy)Cl2]. Additionally, we identify a potential role of Prdx6 in modulating the sensitivity of A-375 cells to auranofin treatment, whereas the gold(III) compounds evaluated here exhibit Prdx6-independent cytotoxicity. Finally, using mass spectrometry, we show that auranofin binds selectively to the catalytic Cys47 residue of Prdx6 in vitro under acidic conditions. No binding was observed with the C47S mutant or at neutral pH.

Sodium diethyldithiocarbamate trihydrate: an effective and selective compound for hematological malignancies.

Myeloid leukemias and lymphomas are among the most common and well-studied hematological malignancies. However, due to the aggressiveness and rapid progression of certain subtypes, treating these diseases remains a challenge. Considering the promising results of diethyldithiocarbamates in preclinical and clinical oncology trials, this study aimed to investigate the potential of sodium diethyldithiocarbamate trihydrate (DETC) as a prototype for developing new drugs to treat hematological malignancies. In silico analysis using SwissADME was conducted to evaluate the physicochemical characteristics and pharmacokinetic properties of DETC. An in vitro investigation utilizing the MTT assay assessed the cytotoxic effects of DETC on neoplastic and non-neoplastic cell lines. Selectivity was determined using a selectivity index and a hemolysis assay, while the mechanism of cell death in neoplastic cell lines was examined through flow cytometry analysis of pro-apoptotic and anti-apoptotic protein levels. The results demonstrated that the physicochemical characteristics of DETC are suitable for oral administration. Furthermore, the compound showed promising cytotoxic activity against human myeloid leukemia (K562) and Burkitt's lymphoma (Daudi) cell lines, with high selectivity for neoplastic cells over non-neoplastic cells of the bone marrow microenvironment (HS-5 cell line). Moreover, hemolysis was observed only at very high concentrations. The cytotoxicity mechanism of DETC against both neoplastic cell lines involved cell cycle arrest and the production of reactive oxygen species. In K562 cells, cell death was induced via apoptosis. Additional experiments are needed to confirm the exact mechanism of cell death in Daudi Burkitt's lymphoma cells.

Prognostic and immunological implications of heterogeneous cell death patterns in prostate cancer

BackgroundProstate cancer is one of the most common cancers in men with a significant proportion of patients developing biochemical recurrence (BCR) after treatment. Programmed cell death (PCD) mechanisms are known to play critical roles in tumor progression and can potentially serve as prognostic and therapeutic biomarkers in PCa. This study aimed to develop a prognostic signature for BCR in PCa using PCD-related genes.Materials and methodsWe conducted an analysis of 19 different modes of PCD to develop a comprehensive model. Bulk transcriptomic, single-cell transcriptomic, genomic, and clinical data were collected from multiple cohorts, including TCGA-PRAD, GSE58812, METABRIC, GSE21653, and GSE193337. We analyzed the expression and mutations of the 19 PCD modes and constructed, evaluated, and validated the model.ResultsTen PCD modes were found to be associated with BCR in PCa, with specific PCD patterns exhibited by various cell components within the tumor microenvironment. Through Lasso Cox regression analysis, we established a Programmed Cell Death Index (PCDI) utilizing an 11-gene signature. High PCDI values were validated in five independent datasets and were found to be associated with an increased risk of BCR in PCa patients. Notably, older age and advanced T and N staging were associated with higher PCDI values. By combining PCDI with T staging, we constructed a nomogram with enhanced predictive performance. Additionally, high PCDI values were significantly correlated with decreased drug sensitivity, including drugs such as Docetaxel and Methotrexate. Patients with lower PCDI values demonstrated higher immunophenoscores (IPS), suggesting a potentially higher response rate to immune therapy. Furthermore, PCDI was associated with immune checkpoint genes and key components of the tumor microenvironment, including macrophages, T cells, and NK cells. Finally, clinical specimens validated the differential expression of PCDI-related PCDRGs at both the gene and protein levels.ConclusionIn conclusion, we developed a novel PCD-based prognostic feature that successfully predicted BCR in PCa patients and provided insights into drug sensitivity and potential response to immune therapy. These findings have significant clinical implications for the treatment of PCa.

E-Cyanoacrylamides and 5-Imino Pyrrolones against Trypanosoma cruzi: Activity and Induced Mechanisms of Cell Death.

Chagas disease is caused by a protozoan parasite called Trypanosoma cruzi. The infection produces a first clinical phase, commonly asymptomatic or showing non-specific symptoms, and a second chronic phase characterized by cardiac and digestive dysfunctions in some individuals with the disease. This disease affects 7 million people and has been categorized by the World Health Organisation as a neglected tropical disease. In addition, the drugs used to combat it were developed in the 1970s and present major toxicity problems and limited efficacy in the chronicity of the disease. This has led to research into new active compounds that are effective against the disease, with studies on cyanoderivatives showing promising activity. In this work, eight active E-cyanoacrylamides/5-imino pyrrolones were studied. Compounds B and F showed excellent activity, while compounds C and G stood out for their lower cytotoxicity. After correlating the activity and cytotoxicity of the compounds, it was observed that compounds B, C, and G obtained the most favourable results. Various cell death studies were carried out with these compounds, and it was determined that all of them produced programmed cell death, with compound B standing out as being at a late stage in the process.

Sevoflurane promotes neuronal ferroptosis via upregulation of PLIN4 to modulate the hippo signaling pathway

BackgroundSevoflurane is a widely used inhalation anesthetic associated with neuronal damage, cognitive impairment and neurodegenerative diseases, with iron overload reported to contribute to these adverse effects. However, the mechanisms of iron-dependent cell death (ferroptosis) in sevoflurane-induced neurotoxicity remain poorly understood. MethodsThe role of PLIN4, a protein associated with neurodegeneration, in sevoflurane-induced neuronal damage was investigated using cultured mouse hippocampal neurons (HT22). PLIN4 knockdown or overexpression was performed through vector transfection, and PLIN4 transcription and expression levels after sevoflurane treatment and knockdown experiments were assessed via RT-qPCR, immunostaining, and western blot to evaluate its impact on ferroptosis. Transmission electron microscopy was used to assess cellular morphology and measure Fe2+ levels. ResultsSevoflurane treatment significantly increased PLIN4 expression in hippocampal neurons and induced ferroptosis. Silencing PLIN4 reduced ferroptosis and partially reversed sevoflurane's inhibition of the Hippo signaling pathway. Specifically, sevoflurane treatment led to a 2.9-fold increase in PLIN4 mRNA levels. Furthermore, higher PLIN4 levels upregulated ferroptosis in hippocampal neurons by inhibiting the Hippo pathway. ConclusionOur study indicates that sevoflurane promotes ferroptosis in neurons by upregulating PLIN4 and modulating the Hippo signaling pathway. These findings provide insights into the potential development of interventions to prevent anesthesia-related cognitive impairments and neurodegeneration.

Inhibition of GPR68 kills glioblastoma in zebrafish xenograft models

ObjectiveInhibition and knockdown of GPR68 negatively affects glioblastoma cell survival in vitro by inducing ferroptosis. Herein, we aimed to demonstrate that inhibition of GPR68 reduces the survival of glioblastoma cells in vivo using two orthotopic larval xenograft models in Danio rerio, using GBM cell lines U87-MG and U138-MG. In vivo survival of the cancer cells was assessed in the setting of GPR68 inhibition or knockdown.ResultsIn vitro, shRNA-mediated knockdown of GPR68 inhibition demonstrated potent cytotoxic effects against U87 and U138 glioblastoma cell lines. This effect was associated with increased intracellular lipid peroxidation, suggesting ferroptosis as the underlying mechanism of cell death. Translating these findings in vivo, we established a novel xenograft model in zebrafish by successfully grafting fluorescently labeled human glioblastoma cells, which were previously shown to overexpress GPR68. shRNA knockdown of GPR68 significantly reduced the viability of grafted GBM cells within this model. Additionally, treatment with ogremorphin (OGM), a highly specific small molecule inhibitor of GPR68, also reduced the viability of grafted GBM cells with limited toxicity to the developing zebrafish embryos. This study suggests that therapeutic targeting of GPR68 with small molecules like OGM represents a promising approach for the treatment of GBM.

Cryo-Nanocatalyst Enhances Therapeutic Efficacy of Cryo-Immunotherapy through Necroptosis and Local Delivery of Programmed Death-Ligand 1 Inhibitors.

Combining cryoablation and immunotherapy presents a promising approach to revert immunosuppressive responses to solid tumors. However, challenges such as postablated residual tumors and insufficient immune activity contribute to recurrence after cryo-immunotherapy. Herein, we investigated metallic supra-structured cryo-nanocatalyst (MSCN), which features numerous ice nucleation sites and interspace loading of therapeutic agents. MSCN elevates the freezing point and enhances ice nucleation, facilitating effective ice formation during cryotreatment. MSCN-loaded tumor cells showed a 2-fold increase in cryo-cytotoxicity and undergo osmotic-related cell damage, primarily necroptosis rather than other regulated cell death mechanisms. In prostate cancer models, RNA sequencing reveals that MSCN-cryoablation promoted antitumor inflammatory pathways, including necroptosis, compared to cryoablation alone. Additionally, following programmed death-ligand 1 (PD-L1) upregulation postcryoablation, synergistic effects with PD-L1 blockade were confirmed. Given the interspace of MSCN for aPD-L1 loading, we compared the intratumoral delivery of PD-L1 blockade against systemic injection. Enhanced necrosis and necroptosis from MSCN-cryoablation and PD-L1 blockade effectively eradicated tumors and triggered antitumor and memory immune responses locally and systemically. Lastly, a spatial landscape of tumor-infiltrating immune cells was analyzed to gain insight into heterogeneous tumor responses, leading to the limitations of conventional focal ablation techniques. Our findings highlight the potential of advanced cryo-immunotherapy using cryo-nanocatalysis to promote ice formation and necroptosis, stimulating antitumor immunogenic responses.

RCDdb: A manually curated database and analysis platform for regulated cell death

Regulated cell death is a pivotal regulatory mechanism governing the development and homeostasis of multicellular organisms. A comprehensive understanding of RCD's regulatory mechanisms is crucial for developing novel therapeutic strategies against diseases associated with cell death, such as cancer and neurodegenerative diseases. However, existing data repositories support limited types of cell death data and lack comprehensive annotation and analytical functionalities. Thus, establishing an extensive cell death database is an urgent imperative. To address this gap, we developed the Regulated Cell Death Database (RCDdb, chenyclab.com/RCDdb), the first comprehensively manually annotated database designed to support annotations and analytical capabilities across all RCD types. We compiled 3090 marker gene annotations associated with 15 RCD types from 2180 relevant articles. The RCDdb includes annotation data on these marker genes concerning diseases, drugs, pathways, proteins, and gene expressions. Furthermore, it provides 49 diverse visualization methods to present this information. More importantly, the RCDdb features three online analysis tools for identifying and analyzing RCD-related features within user-submitted data. Furthermore, the RCDdb offers a user-friendly interface for querying, browsing, analysis, and visualization of detailed information associated with each RCD category. This resource promises to significantly aid researchers in better understanding the mechanisms of cell death, thereby accelerating progress in research and therapeutic strategies aimed at combating RCD-related diseases.