Inhibition Of Cell Death Research Articles

Platycodi radix aqueous extract salvages doxorubicin-induced senescence by mitochondrial reactive oxygen speciesreduction in umbilical cord matrix stem cells.

Platycodi radix is a widely used herbal medicine that contains numerous phytochemicals beneficial to health. The health and biological benefits of P. radix have been found across various diseases. The utilization of umbilical cord stromal stem cells, derived from Wharton's jelly of the human umbilical cord, has emerged as a promising approach for treating degenerative diseases. Nevertheless, growing evidence indicates that the function of stem cells declines with age, thereby limiting their regenerative capacity. The primary objective in this study is to investigate the beneficial effects of P. radix in senescent stem cells. We conducted experiments to showcase that diminished levels of Lamin B1 and Sox-2, along with an elevation in p21, which serve as indicative markers for the senescent stem cells. Our findings revealed the loss of Lamin B1 and Sox-2, coupled with an increase in p21, in umbilical cord stromal stem cells subjected to a low-dose (0.1 μM) doxorubicin (Dox) stimulation. However, P. radix restored the Dox-damage in the umbilical cord stromal stem cells. P. radix reversed the senescent conditions when the umbilical cord stromal stem cells exposed to Dox-induced reactive oxygen species (ROS) and mitochondrial membrane potential are significantly changed. In Dox-challenged aged umbilical cord stromal stem cells, P. radix reduced senescence, increased longevity, prevented mitochondrial dysfunction and ROS and protected against senescence-associated apoptosis. This study suggests that P. radix might be as a therapeutic and rescue agent for the aging effect in stem cells. Inhibition of cell death, mitochondrial dysfunction and aging-associated ROS with P. radix provides additional insights into the underlying molecular mechanisms.

Esculin induces endoplasmic reticulum stress and drives apoptosis and ferroptosis in colorectal cancer via PERK regulating eIF2α/CHOP and Nrf2/HO-1 cascades

Ethnopharmacological relevanceCortex fraxini (also known as Qinpi), the bark of Fraxinus rhynchophylla Hance and Fraxinus stylosa Lingelsh, constitutes a crucial component in several traditional Chinese formulas (e.g., Baitouweng Tang, Jinxiao Formula, etc.) and has demonstrated efficacy in alleviating intestinal carbuncle and managing diarrhea. Cortex fraxini has demonstrated commendable anticancer activity in the realm of Chinese ethnopharmacology; nevertheless, the underlying mechanisms against colorectal cancer (CRC) remain elusive. Aim of the studyEsculin, an essential bioactive compound derived from cortex fraxini, has recently garnered attention for its ability to impede viability and induce apoptosis in cancer cells. This investigation aims to assess the therapeutic potential of esculin in treating CRC and elucidate the underlying mechanisms. Materials and methodsThe impact of esculin on CRC cell viability was assessed using CCK-8 assay, Annexin V/PI staining, and Western blotting. Various cell death inhibitors, along with DCFH-DA, ELISA, biochemical analysis, and Western blotting, were employed to delineate the modes through which esculin induces HCT116 cells death. Inhibitors and siRNA knockdown were utilized to analyze the signaling pathways influenced by esculin. Additionally, an azomethane/dextran sulfate sodium (AOM/DSS)-induced in vivo CRC mouse model was employed to validate esculin's potential in inhibiting tumorigenesis and to elucidate its underlying mechanisms. ResultsEsculin significantly suppressed the viability of various CRC cell lines, particularly HCT116 cells. Investigation with diverse cell death inhibitors revealed that esculin-induced cell death was associated with both apoptosis and ferroptosis. Furthermore, esculin treatment triggered cellular lipid peroxidation, as evidenced by elevated levels of malondialdehyde (MDA) and decreased levels of glutathione (GSH), indicative of its propensity to induce ferroptosis in HCT116 cells. Enhanced protein levels of protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) and p-eIF2α suggested that esculin induced cellular endoplasmic reticulum (ER) stress, subsequently activating the Nrf2/ARE signaling pathway and initiating the transcriptional expression of heme oxygenase (HO)-1. Esculin-induced excessive expression of HO-1 could potentially lead to iron overload in HCT116 cells. Knockdown of Ho-1 significantly attenuated esculin-induced ferroptosis, underscoring HO-1 as a critical mediator of esculin-induced ferroptosis in HCT116 cells. Furthermore, utilizing an AOM/DSS-induced colorectal cancer mouse model, we validated that esculin potentially inhibits the onset and progression of colon cancer by inducing apoptosis and ferroptosis in vivo. ConclusionsThese findings provide comprehensive insights into the dual induction of apoptosis and ferroptosis in HCT116 cells by esculin. The activation of the PERK signaling pathway, along with modulation of downstream eIF2α/CHOP and Nrf2/HO-1 cascades, underscores the mechanistic basis supporting the clinical application of esculin on CRC treatment.

Therapeutic Potential of Nanomaterial-based Drug Delivery

The medical market for sophisticated therapeutic medicine delivery systems is growing at a breakneck pace. There are many benefits to using nanotechnology and nanomaterials in treating chronic human illnesses, such as the ability to target the delivery of drugs to particular areas. Improving the therapeutic effectiveness of current and future medications might be as simple as creating new drug delivery methods. The prime applications related to nanomaterial drug delivery include immunotherapeutic agents, diagnostic testing, cancer therapy and nutraceutical delivery. Nanotechnology has the capacity to collaborate with physics, biologists, chemists and pharmaceutics to form a multidisciplinary contribution in the rise of novel diagnostic and therapeutic technology. Nanomaterials can be used in specific sites targeted by drugs for brain illnesses. These nanodrugs can cause lesser immune response and maintain low inflammatory conditions compared to heavy drug particles. Along with this, nanodrugs can cause damage at the genetic level, create oxidative stress and inhibit cell death according to their particle size, shape, surface and its composition. In this current review various applications, current trends and recent developments in nanomaterials are elucidated. The detailed mechanism and cutting edge nanomaterial based drug delivery were explained along with this.

Pharmacological effects of methysticin and L-sulforaphane through the Nrf2/ARE signaling pathway in MLO-Y4 osteocytes: in vitro study

BackgroundOxidative stress plays a crucial role in the pathogenesis of many skeletal diseases by inducing osteocyte death. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulator of various antioxidant gene expressions through antioxidant response element (ARE) against cellular oxidative stress and can be induced by various stimulants, including the phytochemicals methysticin (MET) and L-sulforaphane (SFN). This study aimed to establish an osteocyte in vitro model to investigate the pharmacological effects of MET and SFN on the Nrf2/ARE pathway. MethodsMLO-Y4 murine osteocytes and the stably transduced MLO-Y4-SIN-lenti-ARE reporter gene cell line were used. MET and SFN were used as Nrf2 inducers. The cytotoxicity of MET, SFN, and hydrogen peroxide (H2O2) was evaluated using the CytoTox-Glo™ Assay. Time- and dose-dependent ARE induction was examined by Monoluciferase Assay. The mRNA and protein expressions of Nrf2 target markers, such as heme-oxygenase 1 (Ho-1), NADPH quinone dehydrogenase 1 (Nqo1), and thioredoxin reductase 1 (Txnrd1), were detected by RT-qPCR, Western Blot, and immunofluorescence staining, respectively. Osteogenesis markers, osteopontin, and osteocalcin were compared with and without treatment by immunofluorescence staining. ResultsThe experimental data showed that MET and SFN induced ARE activity in a time- and dose-dependent manner and increased the mRNA and protein expression of antioxidant markers compared to vehicle-treated controls. The protein expression of osteopontin and osteocalcin in the samples treated with SFN were significantly higher than without treatment, and the number of cell death treated with SFN was significantly lower than without treatment under H2O2-induced stress conditions. ConclusionsNrf2 inducers MET and SFN increased the mRNA expression of antioxidant genes through the Nrf2/ARE pathway in osteocytes. Notably, SFN increased the protein expression of osteocyte-associated osteogenic markers and suppressed cell death under H2O2-induced stress condition. Thus, Nrf2 stimulators can exert stress-relieving and osteogenic effects on osteocytes.

Abstract 2826: Examples of translational preclinical models to mimic cancer drug resistance

Abstract Drug resistance is becoming a major obstacle when treating patients with cancer. Cancer is characterized by an uncontrolled growth of abnormal cells with permanent genome alterations, which lead to severe mutations including resistance mechanisms. Mutations can occur in different resistance pathways, such as inhibition of drug transport, DNA damage repair, drug efflux, EMT (epithelial-mesenchymal transition), drug target alteration and cell death inhibition. Resistance mechanisms are now well studied in vitro, based on mutated cell lines for specific resistance pathways. There is however a gap in our knowledge of resistance mechanisms observed in patient tumor cells. We are challenged to discover cancer resistance treatments in patients and need predictive models of clinical situations. Animal tumor models are the best translational tools to study cancer drug resistance, especially when they closely mimic human pathologies. Such models can bridge the gap between our understanding of cancer resistance in vitro and in tumor patients. In this poster we show different pre-clinical experiments, simulating clinical translational approaches, that led to novel and unique tumor resistant models. Patient Derived Xenograft (PDX) models: Using our breast cancer PDX collection we showed that after repeated treatment with a spindle poison, tumor-bearing mice started to develop resistance and continued tumor growth under drug pressure. Following this successful approach, we initiated the development of a novel ER2-expressing PDX breast tumor model, resistant to hormone therapy by repeated Fulvestrant treatment. Using our colon cancer PDX collection we were able to recapitulate clinical situations by correlating PDX molecular profiles and drug sensitivity. We confirmed the key role of a KRAS mutation in cetuximab resistance. Syngeneic model: In this model, animals were dosed with anti-PDL1 as first line of treatment. All animals were then defined as initial responders or non-responders at the end of the dosing schedule. Following this, a new treatment protocol was initiated with a Tyrosine Kinase inhibitor to study the effect of second line drug treatment in responder and non-responder arms. Human model: In this experiment, we performed a first line Avastin treatment on human colon carcinoma tumor-bearing mice. A tumor resistance to Avastin was observed. During the second line of treatment with a tyrosine kinase inhibitor, we observed an antitumor activity on Avastin resistant animals. In each of these case studies, we developed a novel tumor-resistant mechanism model. In some tumor models, we showed the added value of treating animals with new drugs as second line treatment, after establishing resistance to the first line standard of care treatment. Citation Format: Marc Hillairet de Boisferon, Nicolas Hoffmann, Elodie Rajon, Ismahène Benzaid. Examples of translational preclinical models to mimic cancer drug resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2826.

Abstract 2060: Automation of 3D cancer spheroid assay for compound screening

Abstract Finding efficient drug combinations to treat cancer patients is critical for therapy success. Accordingly, there is a critical need to develop methods for efficient testing drug efficacy to discover new therapeutic targets. 3D cancer models are highly valuable tools for cancer research and drug development. However, the complexity of performing 3D assays remains a hurdle for adopting these methods for compound screening. To alleviate the bottlenecks that come with labor-intensive manual protocols we developed cell culture automation methods using CellXpress.ai instrument. The instrument enables automation of 2D or 3D culture for prolonged complex workflows. The CellXpress.ai provides automated plating, passaging, media exchanges, monitoring organoids, alone with compound treatment and the end point assays with high content image analysis. In the present study we describe full automation of imaging, analysis, and cell culture process which enables scaling up complex 3D cell-based assays and compound screening. As an example of 3D protocol, we automated culture and imaging of colorectal cancer 3D spheroids formed from HCT116 cell line in U-shape low attachment plates. HCT116 cells were expanded in 2D, then spheroids were formed after automated dispensing of cell suspension into U-shape 96 or 384 plates. After 48h spheroids were treated with 12 anti-cancer compounds, at multiple concentrations for 3-5 days, then stained and imaged. Cell plating, compound additions, media exchange, and staining were performed automatically by CellXpressAI instrument. During the culture spheroids were monitored using transmitted light, with immediate analysis of phenotypic changes, including inhibition of growth or spheroid disintegration. For endpoint assay spheroids were stained with combination of Hoechst nuclear stain and viability dyes Calcein AM and EtHD, then imaged, and analyzed for multiple read-outs including spheroid size, marker intensities, and live-dead cell scoring. We observed concentration-dependent inhibition of spheroid growth and cell death in response to anti-cancer compounds and evaluated effective compound concentrations for cytotoxic or cytostatic effects. Cell culture process automation for 3D assays, powered by imaging and image analysis has a potential to bring 3D biology into another level, allowing to increase throughput and reproducibility, and enabling variety of high throughput drug discovery and precision medicine applications. Citation Format: Oksana Sirenko, Angeline Lim, Astrid Michlmayr, Zhisong Tong, Emilie Keidel, Felix Spira. Automation of 3D cancer spheroid assay for compound screening [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2060.

Abstract 5944: Discovery of BH-30236: A novel macrocyclic CLK inhibitor targeting alternative splicing in cancers

Abstract Aberrant alternative splicing is a newly recognized hallmark of cancer, that has been shown to play a critical role in tumorigenesis, cancer progression, and therapeutic resistance via multiple mechanisms, including increased proliferation, decreased apoptosis, promoted migration, enhanced metastatic potential, and induced evasion of immune surveillance. Serine and arginine-rich splicing factors (SRSFs) are RNA-binding proteins (RBPs) that regulate constitutive and alternative splicing. SRSFs are often mutated or overexpressed in cancers, resulting in widespread alterations in splicing patterns. The Cdc2-like kinase (CLK) family and dual-specificity tyrosine-regulated kinase (DYRK) phosphorylate SRSFs, influencing the assembly of spliceosome machinery, exon recognition, and splicing. Therefore, targeting CLK/DYRK kinases can modulate cancer specific splicing isoforms, opening avenues for new therapeutic interventions. BH-30236 was designed as a novel orally bioavailable, ATP-competitive, macrocyclic inhibitor of CLK with IC50s of 0.134, 0.165, and 0.446 nM against CLK1, CLK2, and CLK4, respectively in enzymatic kinase assays. At clinically relevant concentrations, BH-30236 also inhibited DYRK1A/1B/2, proviral insertion site of moloney murine leukemia virus kinase 3 (PIM3), and FMS-like tyrosine kinase 3 (FLT3) with IC50s of 0.111, 0.148, 0.562, 0.115 and 0.248 nM, respectively. In cancer cells, BH-30236 impaired the phosphorylation of SRSFs, Tau and 4EBP1, the direct downstream substrates of CLK, DYRK, and PIM kinases with IC50s of 40-60 nM, ~50 nM, and ~80 nM, respectively. Furthermore, BH-30236 potently inhibited the FLT3 phosphorylation with an IC50 of 0.16 nM. Overall, BH-30236 regulated alternative splicing by primarily inducing skipped exons in favor of anti-tumor isoforms, leading to cancer cell death and growth suppression in a broad panel of cancer cell lines and in vivo efficacy studies. For example, BH-30236 potently inhibited cell proliferation with an IC50 of 0.62 nM in FLT3-ITD positive MV-4-11 cells and achieved complete tumor regression in the MV-4-11 cell-derived xenograft tumor model, even after dose cessation for 4 weeks. In MV-4-11 cells, BH-30236 increased pro-apoptosis splicing variant BCLxS, downregulated RNA expression of BCL2, MCL1, and AML stem cell markers CD33 and CD123. In addition, BH-30236 has demonstrated good human ADME and preclinical safety profiles. Collectively, the preclinical study results strongly support the clinical applications of the novel multikinase CLK inhibitor BH-30236 in hematological malignancies and solid tumors, as a single agent or in combination with other therapies. Citation Format: J. Jean Cui, Ping Jiang, Wei Deng, Dayong Zhai, Nancy Ling, Danan Li, Zhenping Wang, Yue Hu, Levan Darjania, Jeff Whitten, Evan Rogers, Eugene Rui. Discovery of BH-30236: A novel macrocyclic CLK inhibitor targeting alternative splicing in cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5944.

Abstract 3070: CDK12 is a novel therapeutic target in glioblastoma

Abstract Glioblastoma (GBM), the most common primary brain tumor in adults carries a highly unfavorable prognosis of only one to two years despite treatment with the standard of care, involving surgery, temozolomide and radiation. Patient-derived xenograft (PDX) GBM cultures were assessed for their susceptibility to loss of CDK12 function, which was either mediated genetically (shRNA) or by the novel inhibitor, SR-4835. GBM metabolism was measured by utilizing extracellular flux analysis as well as LC/MS based carbon tracing analyses. In vivo efficacy was determined by orthotopic GBM models in mice. Based on Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) and shRNA library screens in multiple GBM cell cultures we identified CDK12 as essential for the growth of GBM. Consistently, loss of function of CDK12 (genetically and pharmacologically) led to a reduction of growth of GBM patient-derived xenograft (PDX) lines in vitro. Notably, SR-4835 reduced GBM growth in the low nanomolar range and synergistically enhanced the potency of temozolomide. Extracellular flux analysis and metabolite screening analyses, including carbon tracing (U13C-Glucose, U13C-Glutamine) suggested that loss of function of CDK12 elicited a substantial inhibition of cellular respiration, causing energy deprivation with subsequent cell death with apoptotic features. On the molecular level, loss of function of CDK12 increased ATF4 along with pro-apoptotic Noxa, whereas anti-apoptotic Mcl-1 decreased. In turn, adenoviral mediated ectopic expression of Mcl-1 inhibited cell death mediated by loss of function of CDK12 in GBM cells. In an orthotopic murine PDX model of GBM animals receiving treatment with SR-4835 had a significantly longer overall survival without induction of toxicity as compared to mice treated with vehicle. In summary, these findings suggest that CDK12 is a novel treatment target for GBM and that CDK12 is an important driver of energy metabolism in GBM to partially mediate apoptotic resistance. Moreover, SR-4835 enhanced the potency of temozolomide in GBM models. Therefore, the novel CDK12 inhibitor, SR-4835 should be tested in a clinical trial in patients suffering from GBM. Citation Format: Jeong-Yeon Mun, Chang Shu, Qiuqiang Gao, Mike-Andrew Westhoff, Georg Karpel-Massler, Markus D. Siegelin. CDK12 is a novel therapeutic target in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3070.

Abstract 7598: The novel eIF4A inhibitor potently synergizes with BCL2 inhibitor in high grade B-cell lymphoma with MYC and BCL2 rearrangements through regulating UPR

Abstract Double hit lymphoma(DHL) is defined to be a chromosomal break with MYC gene combined with BCL2 or BCL6. MYC is an oncogene which proliferation the cells and BCL2 inhibit cell death. These combinations could be a cause of highly aggressive clinical features and poor survival of DLBCL. The WHO-HAEM5 renames the entity DLBCL/high-grade B-cell lymphoma with MYC and BCL2 rearrangements. Despite the dismal prognosis, no widely accepted standard treatment exists to the management of DHL. Therefore, new therapeutic approaches for these patients are urgently needed. Previously, we looked at the eIf4A inhibition was shown to downregulate MYC expression in lymphoma cell lines. Venetoclax, a highly selective inhibitor of BCL2, shows clinical activity for patients with DLBCL although there are concerns about increasing toxicity. Our hypothesis in the following: If eIF4A inhibitor preferentially inhibit the translation of oncogenes such as cMyc and venetoclax inhibit the BCL2 in DHL, then the combination of eIF4A inhibitor and BCL2 inhibitor will be highly effective for DHL and potentially safe for animals and humans. We tested the anti-lymphoma effect of CR-1-31-B, in combination with Venetoclax in lymphoma cell lines using flow cytometry. We performed cell apoptosis assays in increasing concentrations of Venetoclax, CR-1-31-B and a combination of the two drugs at 48 hours. To better understand molecular mechanisms underlying the observed synergistic effect in DLBCL-DHL, RNA-seq profiling was performed on cells treated with single drugs and their combinations, respectively. Venetoclax and CR1-31-B exhibited concentration and time dependent cytotoxicity in lymphoma cell lines at low nanomolar concentrations. Overall, the combination of eIF4A inhibitor and BCL2 inhibitor showed synergy in all kinds of DLBCL cell lines. Especially DHL cell lines were more sensitive to the drug combination and showed enhanced synergy compared to the non-DHL cell lines(p<0.0001). We analyzed RNA-seq profiling of cells treated with single drugs and their combinations and found that the transcriptional signature of the synergistic combination was unique relative to that of either constituent monotherapy. Gene set enrichment analysis was performed in the DHL and non-DHL group. The analysis demonstrates that known Unfolded protein response(UPR) part and metabolism, are enriched in DHL groups. This suggests that the UPR and metabolism pathway are closely related to the combination effect in DHL. These findings suggest that the combination of eIF4A inhibitor and BCL2 inhibitor have potent pharmacological activity in DHL lines, it was closely related with UPR. These combination is promising and novel treatment for high-grade B-cell lymphoma with MYC and BCL2 rearrangements. Further pre-clinical investigations of this combination for these patients are needed. Citation Format: So-Young Seol, Chung Hyun Park, Soo Jeong Kim, Haerim Chung, Hyunsoo Cho, Jin Seok Kim, Yu Ri Kim. The novel eIF4A inhibitor potently synergizes with BCL2 inhibitor in high grade B-cell lymphoma with MYC and BCL2 rearrangements through regulating UPR [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7598.

Interleukin 3 Inhibits Glutamate-Cytotoxicity in Neuroblastoma Cell Line.

Interleukin 3 (IL-3) is a well-known pleiotropic cytokine that regulates the proliferation and differentiation of hematopoietic progenitor cells, triggering classical signaling pathways such as JAK/STAT, Ras/MAPK, and PI3K/Akt to carry out its functions. Interestingly, the IL-3 receptor is also expressed in non-hematopoietic cells, playing a crucial role in cell survival. Our previous research demonstrated the expression of the IL-3 receptor in neuron cells and its protective role in neurodegeneration. Glutamate, a principal neurotransmitter in the central nervous system, can induce cellular stress and lead to neurotoxicity when its extracellular concentrations surpass normal levels. This excessive glutamate presence is frequently observed in various neurological diseases. In this study, we uncover the protective role of IL-3 as an inhibitor of glutamate-induced cell death, analyzing the cytokine's signaling pathways during its protective effect. Specifically, we examined the relevance of JAK/STAT, Ras/MAPK, and PI3 K signaling pathways in the molecular mechanism triggered by IL-3. Our results show that the inhibition of JAK, ERK, and PI3 K signaling pathways, using pharmacological inhibitors, effectively blocked IL-3's protective role against glutamate-induced cell death. Additionally, our findings suggest that Bcl-2 and Bax proteins may be involved in the molecular mechanism triggered by IL-3. Our investigation into IL-3's ability to protect neuronal cells from glutamate-induced damage offers a promising therapeutic avenue with potential clinical implications for several neurological diseases characterized by glutamate neurotoxicity.

Identification of candidate RXLR effectors from downy mildew of foxtail millet pathogen Sclerospora graminicola and functional analysis of SG_RXLR41

AbstractDowny mildew caused by Sclerospora graminicola is a systemic disease that affects the yield and quality of foxtail millet. This obligate biotrophic oomycete manipulates host physiology and immune processes through numerous effectors. A thorough comprehension of effector biology is crucial to unravel disease mechanisms and understand host plant resistance. In this study, bioinformatic analyses revealed 498 potentially secreted proteins in S. graminicola, of which 62 were identified as RXLR effectors; 46 RXLR‐encoding genes exhibited upregulated expression during the early stages of infection. To elucidate the functions of these secreted proteins, a heterogeneous expression system was developed using Nicotiana benthamiana. Twenty‐one RXLR effectors secreted by S. graminicola were transiently expressed in N. benthamiana, of which four could suppress INF1‐triggered cell death. Various defence responses in N. benthamiana were attenuated, including inhibition of defence gene expression, reduction of reactive oxygen species (ROS) accumulation and diminished callose deposition. The expression of SG_RXLR41 also enhanced the growth of Phytophthora capsici on N. benthamiana leaves. These findings indicate that S. graminicola facilitates infection and expansion through the secretion of multiple RXLR effectors, and SG_RXLR41 is an important virulence‐related effector that is involved in manipulating plant immunity by suppressing cell death.

Alpha1-antitrypsin improves survival in murine abdominal sepsis model by decreasing inflammation and sequestration of free heme.

Excessive inflammation, hemolysis, and accumulation of labile heme play an essential role in the pathophysiology of multi-organ dysfunction syndrome (MODS) in sepsis. Alpha1-antitrypsin (AAT), an acute phase protein with heme binding capacity, is one of the essential modulators of host responses to inflammation. In this study, we evaluate the putative protective effect of AAT against MODS and mortality in a mouse model of polymicrobial abdominal sepsis. Polymicrobial abdominal sepsis was induced in C57BL/6N mice by cecal ligation and puncture (CLP). Immediately after CLP surgery, mice were treated intraperitoneally with three different forms of human AAT-plasma-derived native (nAAT), oxidized nAAT (oxAAT), or recombinant AAT (recAAT)-or were injected with vehicle. Sham-operated mice served as controls. Mouse survival, bacterial load, kidney and liver function, immune cell profiles, cytokines/chemokines, and free (labile) heme levels were assessed. In parallel, in vitro experiments were carried out with resident peritoneal macrophages (MPMΦ) and mouse peritoneal mesothelial cells (MPMC). All AAT preparations used reduced mortality in septic mice. Treatment with AAT significantly reduced plasma lactate dehydrogenase and s-creatinine levels, vascular leakage, and systemic inflammation. Specifically, AAT reduced intraperitoneal accumulation of free heme, production of cytokines/chemokines, and neutrophil infiltration into the peritoneal cavity compared to septic mice not treated with AAT. In vitro experiments performed using MPMC and primary MPMΦ confirmed that AAT not only significantly decreases lipopolysaccharide (LPS)-induced pro-inflammatory cell activation but also prevents the enhancement of cellular responses to LPS by free heme. In addition, AAT inhibits cell death caused by free heme in vitro. Data from the septic CLP mouse model suggest that intraperitoneal AAT treatment alone is sufficient to improve sepsis-associated organ dysfunctions, preserve endothelial barrier function, and reduce mortality, likely by preventing hyper-inflammatory responses and by neutralizing free heme.

Exploring the role of disulfidptosis-related signatures in immune microenvironment, prognosis and therapeutic strategies of cervical cancer

BackgroundCervical cancer is characterized by a complex immunosuppressive tumor microenvironment (TME). Disulfidptosis is a recently identified form of programmed cell death that has emerged as a crucial factor in tumorigenesis. However, the research on the specific involvement of disulfidptosis within the TME is still in its early stages. MethodsUnder glucose starvation, SiHa and HeLa cells underwent experiments employing diverse cell death inhibitors and SLC7A11 knockdown to observe their impact on cell survival. TCGA-CESC cohort was subjected to consensus clustering for disulfidptosis-related clusters. Prognosis, function, immune infiltration, and differentially expressed genes (DEGs) evaluations among clusters were compared. A prognostic model based on DEGs and disulfidptosis regulator genes (DRGs) was constructed and internally and externally validated. The correlation between YWHAG and clinicopathological characteristics in cervical cancer patients was investigated at both the mRNA and protein levels. Proliferation and migration assays were performed to uncover the roles of YWHAG in cervical cancer. ResultsExperimental validation confirmed disulfidptosis in cervical cancer cell lines. Cervical cancer patients were classified into three clusters based on DRGs, showing notably improved prognosis and increased immune infiltration in cluster B. The developed disulfidptosis-related prognostic model effectively stratified patients into high- and low-risk groups. Low-risk patients exhibited more favorable responses to immunotherapy and improved overall prognosis. Additionally, YWHAG, recognized as a tumor-promoting gene, demonstrated active roles in enhancing the growth, migration, and invasion of cervical cancer cells. ConclusionOur research proposed a prognostic model for cervical cancer, probably contributing to tumor microenvironment traits and more potent immunotherapy strategy exploration.

Mechanism of Porphyra Yezoensis Polysaccharides in Inhibiting Hyperoxalate-Induced Renal Injury and Crystal Deposition.

Oxidative damage to the kidneys is a primary factor in the occurrence of kidney stones. This study explores the inhibitory effect of Porphyra yezoensis polysaccharides (PYP) on oxalate-induced renal injury by detecting levels of oxidative damage, expression of adhesion molecules, and damage to intracellular organelles and revealed the molecular mechanism by molecular biology methods. Additionally, we validated the role of PYP in vivo using a crystallization model of hyperoxalate-induced rats. PYP effectively scavenged the overproduction of reactive oxygen species (ROS) in HK-2 cells, inhibited the adhesion of calcium oxalate (CaOx) crystals on the cell surface, unblocked the cell cycle, restored the depolarization of the mitochondrial membrane potential, and inhibited cell death. PYP upregulated the expression of antioxidant proteins, including Nrf2, HO-1, SOD, and CAT, while decreasing the expression of Keap-1, thereby activating the Keap1/Nrf2 signaling pathway. PYP inhibited CaOx deposition in renal tubules in the rat crystallization model, significantly reduced high oxalate-induced renal injury, decreased the levels of the cell surface adhesion proteins, improved renal function in rats, and ultimately inhibited the formation of kidney stones. Therefore, PYP, which has crystallization inhibition and antioxidant properties, may be a therapeutic option for the treatment of kidney stones.

Beneficial Effects of Small-Molecule Oligopeptides Isolated from Panax Ginseng C. A. Meyer on Cellular Fates in Oxidative Stress-Induced Damaged Human Umbilical Vein Endothelial Cells and PC-12.

Cell fate instability is a crucial characteristic of aging and appears to contribute to various age-related pathologies. Exploring the connection between bioactive substances and cell fate stability may offer valuable insights into longevity. Therefore, the objective of this study was to investigate the potential beneficial effects of ginseng oligopeptides (GOPs) isolated from Panax ginseng C. A. Meyer at the cellular level. Disruption of homeostasis of human umbilical vein endothelial cells (HUVECs) and PC-12 was achieved by culturing them in the growth medium supplemented with 200 µM of H2O2, and 25, 50, and 100 µg/mL GOPs for 4 h. Then, they were cultured in a H2O2-free growth medium containing different concentration of GOPs. We found that GOP administration retards the oxidative stress-induced cell instability in HUVECs by increasing cell viability, inhibiting the cell cycle arrest, enhancing telomerase (TE) activity, suppressing oxidative stress and an inflammatory attack, and protecting mitochondrial function. Furthermore, we hypothesized that GOPs may promote mitochondrial biosynthesis by upregulating PGC-1α expression. Similarly, GOPs positively regulated cell stability in PC-12; notably, the protective effect of GOPs on PC-12 mainly occurred through the inhibition of autophagic cell death of neuronal cells, while the protective effect on mitochondria was weak. In conclusion, it is evident that GOPs demonstrate potential beneficial effects in maintaining cell fate stability, thereby potentially contributing to an enhanced health span and overall well-being.

Ferroptosis Inducers as Promising Radiosensitizer Agents in Cancer Radiotherapy.

Radiotherapy (RT) failure has historically been mostly attributed to radioresistance. Ferroptosis is a type of controlled cell death that depends on iron and is caused by polyunsaturated fatty acid peroxidative damage. Utilizing a ferroptosis inducer may be a successful tactic for preventing tumor growth and radiotherapy-induced cell death. A regulated form of cell death known as ferroptosis is caused by the peroxidation of phospholipids containing polyunsaturated fatty acids in an iron-dependent manner (PUFA-PLs). The ferroptosis pathway has a number of important regulators. By regulating the formation of PUFA-PLs, the important lipid metabolism enzyme ACSL4 promotes ferroptosis, whereas SLC7A11 and (glutathione peroxidase 4) GPX4 prevent ferroptosis. In addition to introducing the ferroptosis inducer chemicals that have recently been demonstrated to have a radiosensitizer effect, this review highlights the function and methods by which ferroptosis contributes to RT-induced cell death and tumor suppression in vitro and in vivo.

Pronecroptotic Therapy Using Ceramide Nanoliposomes Is Effective for Triple-Negative Breast Cancer Cells.

Regulated necrosis, termed necroptosis, represents a potential therapeutic target for refractory cancer. Ceramide nanoliposomes (CNLs), considered potential chemotherapeutic agents, induce necroptosis by targeting the activating protein mixed lineage kinase domain-like protein (MLKL). In the present study, we examined the potential of pronecroptotic therapy using CNLs for refractory triple-negative breast cancer (TNBC), for which there is a lack of definite and effective therapeutic targets among the various immunohistological subtypes of breast cancer. MLKL mRNA expression in tumor tissues was significantly higher in TNBC patients than in those with non-TNBC subtypes. Similarly, among the 50 breast cancer cell lines examined, MLKL expression was higher in TNBC-classified cell lines. TNBC cell lines were more susceptible to the therapeutic effects of CNLs than the non-TNBC subtypes of breast cancer cell lines. In TNBC-classified MDA-MB-231 cells, the knockdown of MLKL suppressed cell death induced by CNLs or the active substance short-chain C6-ceramide. Accordingly, TNBC cells were prone to CNL-evoked necroptotic cell death. These results will contribute to the development of CNL-based pronecroptotic therapy for TNBC.

Cancer Drug Resistance: Targeting Proliferation or Programmed Cell Death.

The development of resistance to chemotherapy is one of the main problems for effective cancer treatment. Drug resistance may result from disturbances in two important physiological processes-cell proliferation and cell death. Importantly, both processes characterize alterations in cell metabolism, the level of which is often measured using MTT/MTS assays. To examine resistance to chemotherapy, different cancer cell lines are usually used for the in vitro modulation of developing resistance. However, after the creation of resistant cell lines, researchers often have difficulty in starting investigations of the mechanisms of insensitivity. In the first stage, researchers should address the question of whether the drug resistance results from a depression of cell proliferation or an inhibition of cell death. To simplify the choice of research strategy, we have suggested a combination of different approaches which reveal the actual mechanism. This combination includes rapid and high-throughput methods such as the MTS test, the LIVE/DEAD assay, real-time cell metabolic analysis, and Western blotting. To create chemoresistant tumor cells, we used four different cancer cell lines of various origins and utilized the most clinically relevant pulse-selection approach. Applying a set of methodological approaches, we demonstrated that three of them were more capable of modulating proliferation to avoid the cytostatic effects of anti-cancer drugs. At the same time, one of the studied cell lines developed resistance to cell death, overcoming the cytotoxic action.

Regulation of NCOA4-mediated iron recycling ameliorates paraquat-induced lung injury by inhibiting ferroptosis

Paraquat (PQ) is an irreplaceable insecticide in many countries for the advantage of fast-acting and broad-spectrum. However, PQ was classified as the most prevailing poisoning substance for suicide with no specific antidote. Therefore, it is imperative to develop more effective therapeutic agents for the treatment of PQ poisoning. In the present study, both the RNA-Seq and the application of various cell death inhibitors reflected that ferroptosis exerts a crucial regulatory role in PQ poisoning. Moreover, we found PQ strengthens lipid peroxidation as evidenced by different experimental approaches. Of note, pretreatment of iron chelation agent DFO could ameliorate the ferroptotic cell death and alleviate the ferroptosis-related events. Mechanistically, PQ treatment intensively impaired mitochondrial homeostasis, enhanced phosphorylation of AMPK, accelerated the autophagy flux and triggered the activation of Nuclear receptor coactivator 4-ferritin heavy chain (NCOA4-FTH) axis. Importantly, the activation of autophagy was observed prior to the degradation of ferritin, and inhibition of autophagy could inhibit the accumulation of iron caused by the ferritinophagy process. Genetic and pharmacological inhibition of ferritinophagy could alleviate the lethal oxidative events, and rescue the ferroptotic cell death. Excitingly, in the mouse models of PQ poisoning, both the administration of DFO and adeno-associated virus-mediated FTH overexpression significantly reduced PQ-induced ferroptosis and improved the pathological characteristics of pulmonary fibrosis. In summary, the current work provides an in-depth study on the mechanism of PQ intoxication, describes a framework for the further understanding of ferroptosis in PQ-associated biological processes, and demonstrates modulation of iron metabolism may act as a promising therapeutic agent for the management of PQ toxicity.Graphical

Protective Effects on Neuronal SH-SY5Y Cells and Antioxidant Activity of Enzymatic Hydrolyzate from Silkworms Fed the Leaves of Cudrania tricuspidata

We investigated the antioxidant activity and neuroprotective effects of an enzymatic hydrolyzate from silkworms fed the leaves of Cudrania tricuspidata (ESLC) produced by enzymatic treatment. The proteins in silkworms fed the leaves of Cudrania tricuspidata (SLC) were effectively hydrolyzed using enzymatic treatment. The total polyphenols of ESLC were significantly higher, and the superoxide dismutase-like activity and 2,2′-azino-bis (3-thylbenzothiazoline-6-sulfonicacid) diammonium salt radical scavenging capacity of ESLC were significantly increased compared to the SLC group. We evaluated the properties of ESLC to protect SH-SY5Y cells from H2O2-induced oxidative stress. The viability rate of SH-SY5Y neuroblastoma cells was significantly restored when treated with ESLC at a concentration of 100 μg/mL or 250 μg/mL. Furthermore, the mitogen-activated protein kinase (MAPK) pathway was investigated, and ESLC significantly inhibited the phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38. Therefore, ESLC can potentially be used as an antioxidant. The polyphenol content increases owing to hydrolysis through enzymatic treatment, which increases the antioxidant effect and inhibits the phosphorylation of JNK, ERK, and p38 by activating the MAPK pathway, which inhibits cell death from oxidative stress and exerts cytoprotective effects.