Cell death modalities: classification and pathophysiological implications

Knockdown of iPLA2γ enhances cisplatin-induced apoptosis by increasing ROS-dependent peroxidation of mitochondrial phospholipids in bladder cancer cells

Cisplatin (CDDP) is a platinum-based drug with anti-cancer activity and is widely used as a standard therapy for bladder cancer. It is well known that CDDP causes cell death by increasing the generation of reactive oxygen species (ROS) and lipid peroxidation, but the mechanism of its anti-cancer effects has not been fully elucidated. There are still some problems such as chemoresistance in CDDP therapy. In the present study, we found the expression of Ca2+-independent phospholipase A2γ (iPLA2γ), which has been reported to regulate cellular redox homeostasis by inhibiting lipid peroxide accumulation, in human bladder cancer tissues. Thus, we investigated the effect of iPLA2γ knockdown on CDDP-induced bladder cancer cell death. As a result, we found that iPLA2γ knockdown significantly enhanced CDDP-induced apoptosis, intracellular and mitochondrial ROS production, cytochrome c release and caspase activation in bladder cancer cells. Moreover, mitochondrial membrane potential was decreased and peroxidation of mitochondrial phospholipids was increased by iPLA2γ knockdown. It was also shown that co-treatment of bromoenol lactone, an iPLA2 inhibitor, increased CDDP-induced apoptosis. These results indicated that iPLA2γ plays an important role in protecting bladder cancer cells from CDDP-induced apoptosis, and that iPLA2γ inhibitors might represent a novel strategy in CDDP-based multi-drug therapy.

Current therapy in amyotrophic lateral sclerosis (ALS): A review on past and future therapeutic strategies

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that affects the first and second motoneurons (MNs), associated with muscle weakness, paralysis and finally death. The exact etiology of the disease still remains unclear. Currently, efforts to develop novel ALS treatments which target specific pathomechanisms are being studied. The mechanisms of ALS pathogenesis involve multiple factors, such as protein aggregation, glutamate excitotoxicity, oxidative stress, mitochondrial dysfunction, apoptosis, inflammation etc. Unfortunately, to date, there are only two FDA-approved drugs for ALS, riluzole and edavarone, without curative treatment for ALS. Herein, we give an overview of the many pathways and review the recent discovery and preclinical characterization of neuroprotective compounds. Meanwhile, drug combination and other therapeutic approaches are also reviewed. In the last part, we analyze the reasons of clinical failure and propose perspective on the treatment of ALS in the future.

Glutathione Depletion and Stalwart Anticancer Activity of Metallotherapeutics Inducing Programmed Cell Death: Opening a New Window for Cancer Therapy

The cellular defense system against exogenous substances makes therapeutics inefficient as intracellular glutathione (GSH) exhibits an astounding antioxidant activity in scavenging reactive oxygen species (ROS) or reactive nitrogen species (RNS) or other free radicals produced by the therapeutics. In the cancer cell microenvironment, the intracellular GSH level becomes exceptionally high to fight against oxidative stress created by the production of ROS/RNS or any free radicals, which are the byproducts of intracellular redox reactions or cellular respiration processes. Thus, in order to maintain redox homeostasis for survival of cancer cells and their rapid proliferation, the GSH level starts to escalate. In this circumstance, the administration of anticancer therapeutics is in vain, as the elevated GSH level reduces their potential by reduction or by scavenging the ROS/RNS they produce. Therefore, in order to augment the therapeutic potential of anticancer agents against elevated GSH condition, the GSH level must be depleted by hook or by crook. Hence, this Review aims to compile precisely the role of GSH in cancer cells, the importance of its depletion for cancer therapy and examples of anticancer activity of a few selected metal complexes which are able to trigger cancer cell death by depleting the GSH level.

Research progress on morphology and mechanism of programmed cell death

Programmed cell death (PCD) is a basic process of life that is closely related to the growth, development, aging and disease of organisms and is one of the hotspots of life science research today. PCD is a kind of genetic control, autonomous and orderly important cell death that involves the activation, expression, and regulation of a series of genes. In recent years, with the deepening of research in this field, new mechanisms of multiple PCD pathways have been revealed. This article reviews and summarizes the multiple PCD pathways that have been discovered, analyses and compares the morphological characteristics and biomarkers of different types of PCD, and briefly discusses the role of various types of PCD in the diagnosis and treatment of different diseases, especially malignant tumors.

The crosstalk between mitochondrial quality control and metal-dependent cell death

Mitochondria are the centers of energy and material metabolism, and they also serve as the storage and dispatch hubs of metal ions. Damage to mitochondrial structure and function can cause abnormal levels and distribution of metal ions, leading to cell dysfunction and even death. For a long time, mitochondrial quality control pathways such as mitochondrial dynamics and mitophagy have been considered to inhibit metal-induced cell death. However, with the discovery of new metal-dependent cell death including ferroptosis and cuproptosis, increasing evidence shows that there is a complex relationship between mitochondrial quality control and metal-dependent cell death. This article reviews the latest research results and mechanisms of crosstalk between mitochondrial quality control and metal-dependent cell death in recent years, as well as their involvement in neurodegenerative diseases, tumors and other diseases, in order to provide new ideas for the research and treatment of related diseases.

Exploring the role of pyroptosis in the pathogenicity of heart disease

Cell death is an essential cellular mechanism that ensures quality control and whole-body homeostasis. Various modes of cell death have been studied and detailed. Unbalanced cell death can lead to uncontrolled cell proliferation (i.e., tumors) or excessive loss of cells (i.e., ischemia injury tissue loss). Thus, it is imperative for modes of cell death to be balanced and controlled. Here, we will focus on a recent mode of cell death called pyroptosis. While extensive studies have shown the role of this route of cell death in macrophages and monocytes, evidence for pyroptosis have expanded to encompass other pathologies, including cancer and cardiac diseases. Herein, we provide a brief review on pyroptosis and discuss current gaps in knowledge and scientific advances in cardiac pyroptosis in recent years. Lastly, we provide conclusions and prospective on the relevance to various cardiac diseases.

Unraveling the genetics of arsenic toxicity with cellular morphology QTL

The health risks that arise from environmental exposures vary widely within and across human populations, and these differences are largely determined by genetic variation and gene-by-environment (gene-environment) interactions. However, risk assessment in laboratory mice typically involves isogenic strains and therefore, does not account for these known genetic effects. In this context, genetically heterogenous cell lines from laboratory mice are promising tools for population-based screening because they provide a way to introduce genetic variation in risk assessment without increasing animal use. Cell lines from genetic reference populations of laboratory mice offer genetic diversity, power for genetic mapping, and potentially, predictive value for in vivo experimentation in genetically matched individuals. To explore this further, we derived a panel of fibroblast lines from a genetic reference population of laboratory mice (the Diversity Outbred, DO). We then used high-content imaging to capture hundreds of cell morphology traits in cells exposed to the oxidative stress-inducing arsenic metabolite monomethylarsonous acid (MMAIII). We employed dose-response modeling to capture latent parameters of response and we then used these parameters to identify several hundred cell morphology quantitative trait loci (cmQTL). Response cmQTL encompass genes with established associations with cellular responses to arsenic exposure, including Abcc4 and Txnrd1, as well as novel gene candidates like Xrcc2. Moreover, baseline trait cmQTL highlight the influence of natural variation on fundamental aspects of nuclear morphology. We show that the natural variants influencing response include both coding and non-coding variation, and that cmQTL haplotypes can be used to predict response in orthogonal cell lines. Our study sheds light on the major molecular initiating events of oxidative stress that are under genetic regulation, including the NRF2-mediated antioxidant response, cellular detoxification pathways, DNA damage repair response, and cell death trajectories.

5-ALA localises to the autophagy compartment and increases its fluorescence upon autophagy enhancement through caloric restriction and spermidine treatment in human glioblastoma

Glioblastoma Multiforme (GBM) is the most invasive and prevalent Central Nervous System (CNS) malignancy. It is characterised by diffuse infiltrative growth and metabolic dysregulation that impairs the extent of surgical resection (EoR), contributing to its poor prognosis. 5-Aminolevulinic acid (5-ALA) fluorescence-guided surgical resection (FGR) takes advantage of the preferential generation of 5-ALA-derived fluorescence signal in glioma cells, thereby improving visualisation and enhancing the EoR. However, despite 5-ALA FGR is a widely used technique in the surgical management of malignant gliomas, the infiltrative tumour margins usually show only vague or no visible fluorescence and thus a significant amount of residual tumour tissue may hence remain in the resection cavity, subsequently driving tumour recurrence. To investigate the molecular mechanisms that govern the preferential accumulation of 5-ALA in glioma cells, we investigated the precise subcellular localisation of 5-ALA signal using Correlative Light and Electron Microscopy (CLEM) and colocalisation analyses in U118MG glioma cells. Our results revealed strong 5-ALA signal localisation in the autophagy compartment - specifically autolysosomes and lysosomes. Flow cytometry was employed to investigate whether autophagy enhancement through spermidine treatment (SPD) or nutrient deprivation/caloric restriction (CR) would enhance 5-ALA fluorescence signal generation. Indeed, SPD, CR and a combination of SPD/CR treatment significantly increased 5-ALA signal intensity, with a most robust increase in signal intensity observed in the combination treatment of SPD/CR. When using 3-D glioma spheroids to assess the effect of 5-ALA on cellular ultrastructure, we demonstrate that 5-ALA exposure leads to cytoplasmic disruption, vacuolarisation and large-scale mitophagy induction. These findings not only suggest a critical role for the autophagy compartment in 5-ALA engagement and signal generation but also point towards a novel and practically feasible approach to enhance 5-ALA fluorescence signal intensity. The findings may highlight that indeed autophagy control may serve as a promising avenue to promote an improved resection and GBM prognosis.

Ferroptosis and aerobic training in ageing: A review

 Ferroptosis is a form of programmed cell death that plays a significant role in causing several diseases such as heart attack and heart failure, through alterations in fat, amino acid, and iron metabolism. Comprehending the regulatory mechanisms of ferroptosis signaling is critical because it has a considerable effect on the elderly's mortality. Conversely, age-related changes in substrate metabolism and metabolite levels are recognized to give rise to obesity. Furthermore, research has proposed that aging and obesity-related changes in substrate metabolism may aggravate ferroptosis. The suppression of ferroptosis holds potential as a successful therapeutic approach for managing different diseases, including sarcopenia, cardiovascular diseases, and central nervous system diseases. However, the pathologic and biological mechanisms behind the function of ferroptosis are not fully comprehended yet. Physical activity could affect lipid, amino acid, and iron metabolism to modulate ferroptosis. The aim of this study is to showcase the current understanding of the molecular mechanisms leading to ferroptosis and discuss the role of aging and physical activity in this phenomenon.

The Mechanisms of Regulated Cell Death: Structural and Functional Proteomic Pathways Induced or Inhibited by a Specific Protein-A Narrative Review

Billions of cells die in us every hour, and our tissues do not shrink because there is a natural regulation where Cell Death (CD) is balanced with cell division. The process in which cells eliminate themselves in a controlled manner is called Programmed Cell Death (PCD). The PCD plays an important role during embryonic development, in maintaining homeostasis of the body's tissues, and in the elimination of damaged cells, under a wide range of physiological and developmental stimuli. A multitude of protein mediators of PCD have been identified and signals have been found to utilize common pathways elucidating the proteins involved. This narrative review focuses on caspase-dependent and caspase-independent PCD pathways. Included are studies of caspase-dependent PCD such as Anoikis, Catastrophe Mitotic, Pyroptosis, Emperitosis, Parthanatos and Cornification, and Caspase-Independent PCD as Wallerian Degeneration, Ferroptosis, Paraptosis, Entosis, Methuosis, and Extracellular Trap Abnormal Condition (ETosis), as well as neutrophil extracellular trap abnormal condition (NETosis) and Eosinophil Extracellular Trap Abnormal Condition (EETosis). Understanding PCD from those reported in this review could shed substantial light on the processes of biological homeostasis. In addition, identifying specific proteins involved in these processes is mandatory to identify molecular biomarkers, as well as therapeutic targets. This knowledge could provide the ability to modulate the PCD response and could lead to new therapeutic interventions in a wide range of diseases.

A novel EGFR inhibitor, HNPMI, regulates apoptosis and oncogenesis by modulating BCL-2/BAX and p53 in colon cancer

BACKGROUND AND PURPOSE

Colorectal cancer (CRC) is the second most lethal disease, with high mortality due to its heterogeneity and chemo-resistance. Here, we have focused on the epidermal growth factor receptor (EGFR) as an effective therapeutic target in CRC and studied the effects of polyphenols known to modulate several key signalling mechanisms including EGFR signalling, associated with anti-proliferative and anti-metastatic properties.

EXPERIMENTAL APPROACH

Using ligand- and structure-based cheminformatics, we developed three potent, selective alkylaminophenols, 2-[(3,4-dihydroquinolin-1(2H)-yl)(p-tolyl)methyl]phenol (THTMP), 2-[(1,2,3,4-tetrahydroquinolin-1-yl)(4-methoxyphenyl)methyl]phenol (THMPP) and N-[2-hydroxy-5-nitrophenyl(4'-methylphenyl)methyl]indoline (HNPMI). These alkylaminophenols were assessed for EGFR interaction, EGFR-pathway modulation, cytotoxic and apoptosis induction, caspase activation and transcriptional and translational regulation. The lead compound HNPMI was evaluated in mice bearing xenografts of CRC cells.

KEY RESULTS

Of the three alkylaminophenols tested, HNPMI exhibited the lowest IC50 in CRC cells and potential cytotoxic effects on other tumour cells. Modulation of EGFR pathway down-regulated protein levels of osteopontin, survivin and cathepsin S, leading to apoptosis. Cell cycle analysis revealed that HNPMI induced G0/G1 phase arrest in CRC cells. HNPMI altered the mRNA for and protein levels of several apoptosis-related proteins including caspase 3, BCL-2 and p53. HNPMI down-regulated the proteins crucial to oncogenesis in CRC cells. Assays in mice bearing CRC xenografts showed that HNPMI reduced the relative tumour volume.

CONCLUSIONS AND IMPLICATIONS

HNPMI is a promising EGFR inhibitor for clinical translation. HNPMI regulated apoptosis and oncogenesis by modulating BCL-2/BAX and p53 in CRC cell lines, showing potential as a therapeutic agent in the treatment of CRC.

Autophagy in an extruded disc compared to the remaining disc after lumbar disc herniation in the same patient

PURPOSE

The purpose of this study was to investigate autophagy in an extruded disc and to compare this activity with the activity in the remaining disc after lumbar disc herniation in the same patient.

METHODS

In total, 12 patients (females 4, males 8) with the extruded type of lumbar disc herniation (LDH) were surgically treated. Their mean age was 54.3 ± 15.8 years (range: 29 ~ 78 years). The mean interval from the occurrence of symptoms to the operation was 9.8 ± 9.4 weeks (range: 2 ~ 24 weeks). The extruded discs were excised, and the remaining disc material removed, to prevent recurrence of herniation. Immediately after specimen collection, all tissues were stored at -70 °C prior to analysis. Autophagy was assessed immunohistochemically and via Western blotting for Atg5, Atg7, Atg12, Atg12L1, and Beclin-1. And the relationship between autophagy and apoptosis was investigated by correlation analysis of caspase-3 with autophagy proteins.

RESULTS

The expression levels of autophagic markers were significantly increased in the extruded discs compared to the remaining discs within the same patients. The mean expression levels of Atg5, Atg7, Atg12, and Beclin-1 in extruded discs were statistically significantly higher than those in the remaining discs (P < 0.01, P < 0.001, P < 0.01, and P < 0.001 respectively).

CONCLUSIONS

The autophagic pathway was more active in extruded disc material than in remaining disc material within the same patient. This may explain spontaneous resorption of the extruded disc after LDH.

Ferroptosis, Metabolic Rewiring, and Endometrial Cancer

Ferroptosis is a newly discovered form of regulated cell death. The main feature of ferroptosis is excessive membrane lipid peroxidation caused by iron-mediated chemical and enzymatic reactions. In normal cells, harmful lipid peroxides are neutralized by glutathione peroxidase 4 (GPX4). When GPX4 is inhibited, ferroptosis occurs. In mammalian cells, ferroptosis serves as a tumor suppression mechanism. Not surprisingly, in recent years, ferroptosis induction has gained attention as a potential anticancer strategy, alone or in combination with other conventional therapies. However, sensitivity to ferroptosis inducers depends on the metabolic state of the cell. Endometrial cancer (EC) is the sixth most common cancer in the world, with more than 66,000 new cases diagnosed every year. Out of all gynecological cancers, carcinogenesis of EC is mostly dependent on metabolic abnormalities. Changes in the uptake and catabolism of iron, lipids, glucose, and glutamine affect the redox capacity of EC cells and, consequently, their sensitivity to ferroptosis-inducing agents. In addition to this, in EC cells, ferroptosis-related genes are usually mutated and overexpressed, which makes ferroptosis a promising target for EC prediction, diagnosis, and therapy. However, for a successful application of ferroptosis, the connection between metabolic rewiring and ferroptosis in EC needs to be deciphered, which is the focus of this review.

Cell death classification: A new insight based on molecular mechanisms

Cells tend to disintegrate themselves or are forced to undergo such destructive processes in critical circumstances. This complex cellular function necessitates various mechanisms and molecular pathways in order to be executed. The very nature of cell death is essentially important and vital for maintaining homeostasis, thus any type of disturbing occurrence might lead to different sorts of diseases and dysfunctions. Cell death has various modalities and yet, every now and then, a new type of this elegant procedure gets to be discovered. The diversity of cell death compels the need for a universal organizing system in order to facilitate further studies, therapeutic strategies and the invention of new methods of research. Considering all that, we attempted to review most of the known cell death mechanisms and sort them all into one arranging system that operates under a simple but subtle decision-making (If \ Else) order as a sorting algorithm, in which it decides to place and sort an input data (a type of cell death) into its proper set, then a subset and finally a group of cell death. By proposing this algorithm, the authors hope it may solve the problems regarding newer and/or undiscovered types of cell death and facilitate research and therapeutic applications of cell death.

PEI-Based Nanoparticles for Tumor Immunotherapy via In Situ Antigen-Capture Triggered by Photothermal Therapy

Activating a tumor antigen-specific immune response is key to the success of tumor immunotherapy and the development of personalized antitumor therapy. Nanocarriers can capture, enrich, and protect in situ produced tumor antigens due to immunogenic cell death (ICD), thus enhancing the tumor-specific immune response. Developing multifunctional nanocarriers that combine multiple antigen capturing mechanisms is crucial to the activation of tumor-specific immune responses. In this study, polyethylenimine (PEI) was employed as a main building block to construct a series of multifunctional indocyanine green (ICG)-loaded nanoparticles to capture antigens via multiple mechanisms: electrostatic interactions with PEI, hydrophobic interactions with the thermosensitive segment (POEGMA300), and covalent bonding with the pyridyl disulfide (PDS) groups, respectively. Their capacity of ICD induction, tumor antigen-capture, and antitumor immune responses were evaluated. Both the intrinsic toxicity of PEI and the ICG-mediated photothermal effect were responsible for inducing ICD. The positively charged PEI segment exhibited the best antigen-capturing ability via electrostatic interactions, promoted bone marrow-derived dendritic cell maturation and CD8+ T cell proliferation, and elicited antitumor immune responses in vivo. PDS groups bonded antigens covalently and significantly contributed to the suppression of distant tumor growth. Although the thermosensitive hydrophobic polymer segment did not contribute positively to antigen capture or tumor growth inhibition, NPs containing all of the functional modules prolonged the survival of tumor-bearing mice more than other treatments. This study provides more chemical insights into the design of polymer-based in situ nanovaccines against cancer.

Cell morphology QTL reveal gene by environment interactions in a genetically diverse cell population

Genetically heterogenous cell lines from laboratory mice are promising tools for population-based screening as they offer power for genetic mapping, and potentially, predictive value for in vivo experimentation in genetically matched individuals. To explore this further, we derived a panel of fibroblast lines from a genetic reference population of laboratory mice (the Diversity Outbred, DO). We then used high-content imaging to capture hundreds of cell morphology traits in cells exposed to the oxidative stress-inducing arsenic metabolite monomethylarsonous acid (MMAIII). We employed dose-response modeling to capture latent parameters of response and we then used these parameters to identify several hundred cell morphology quantitative trait loci (cmQTL). Response cmQTL encompass genes with established associations with cellular responses to arsenic exposure, including Abcc4 and Txnrd1, as well as novel gene candidates like Xrcc2. Moreover, baseline trait cmQTL highlight the influence of natural variation on fundamental aspects of nuclear morphology. We show that the natural variants influencing response include both coding and non-coding variation, and that cmQTL haplotypes can be used to predict response in orthogonal cell lines. Our study sheds light on the major molecular initiating events of oxidative stress that are under genetic regulation, including the NRF2-mediated antioxidant response, cellular detoxification pathways, DNA damage repair response, and cell death trajectories.

The romantic history of signaling pathway discovery in cell death: an updated review

Cell death is a fundamental physiological process in all living organisms. Processes such as embryonic development, organ formation, tissue growth, organismal immunity, and drug response are accompanied by cell death. In recent years with the development of electron microscopy as well as biological techniques, especially the discovery of novel death modes such as ferroptosis, cuprotosis, alkaliptosis, oxeiptosis, and disulfidptosis, researchers have been promoted to have a deeper understanding of cell death modes. In this systematic review, we examined the current understanding of modes of cell death, including the recently discovered novel death modes. Our analysis highlights the common and unique pathways of these death modes, as well as their impact on surrounding cells and the organism as a whole. Our aim was to provide a comprehensive overview of the current state of research on cell death, with a focus on identifying gaps in our knowledge and opportunities for future investigation. We also presented a new insight for macroscopic intracellular survival patterns, namely that intracellular molecular homeostasis is central to the balance of different cell death modes, and this viewpoint can be well justified by the signaling crosstalk of different death modes. These concepts can facilitate the future research about cell death in clinical diagnosis, drug development, and therapeutic modalities.

Characterization and expression profiling of fadd gene in response to exogenous Aeromonas hydrophila or Edwardsiella tarda challenge in the hybrid yellow catfish (Pelteobagrus fulvidraco ♀ × P. vachelli ♂)

In mammals, fas-associated protein with death domain (FADD) is involved in the process of cell apoptosis and plays a key role in innate immune signaling. Nevertheless, its detailed molecular mechanisms underlying apoptosis and immune responses to exogenous bacterial infections in teleosts remain largely unknown. In this study, a group of 60 hybrid yellow catfish (with the body weight of 25 ± 0.5 g) were used in subsequent experiments, we examined the expression profiling of fadd gene through comparative genomics and comparative immunological methods. Our results showed that fadd in the hybrid yellow catfish (hycfadd) exhibited similar gene and spatial structures to those in other vertebrates, and formed an independent clade in phylogeny. An expression pattern analysis revealed that hycfadd widely transcribed in various tissues, with the highest transcription level in the liver. Furthermore, expression profiling of hycfadd when intraperitoneally infected with 50 μL of exogenous Aeromonas hydrophila (2.0 × 107 CFU/mL) or Edwardsiella tarda (2.0 × 107 CFU/mL) within 48 h were significantly up-regulated in the kidney, spleen, liver and intestine. Important genes in the toll like receptor (tlr) 1-tlr2- myeloid differentiation primary response 88 (MyD88)-fadd-caspase (casp) 8 cascades of TLR signaling pathway in liver were significantly up-regulated after the A. hydrophila stimulation, suggesting that apoptosis through the TLR signaling pathway may have been triggered and activated, which were further verified in the liver, kidney, spleen, intestine and gill by a TUNEL assay. Overall, this study provides solid evidence for the bacterial induction of fadd-related apoptosis in teleosts.

Encapsulation of Nano-Bortezomib in Apoptotic Stem Cell-Derived Vesicles for the Treatment of Multiple Myeloma

Extracellular vesicles (EVs) are lipid bilayer nanovesicles released from living or apoptotic cells that can transport DNA, RNA, protein, and lipid cargo. EVs play critical roles in cell-cell communication and tissue homeostasis, and have numerous therapeutic uses including serving as carriers for nanodrug delivery. There are multiple ways to load EVs with nanodrugs, such as electroporation, extrusion, and ultrasound. However, these approaches may have limited drug-loading rates, poor EV membrane stability, and high cost for large-scale production. Here, it is shown that apoptotic mesenchymal stem cells (MSCs) can encapsulate exogenously added nanoparticles into apoptotic vesicles (apoVs) with a high loading efficiency. When nano-bortezomib is incorporated into apoVs in culture-expanded apoptotic MSCs, nano-bortezomib-apoVs show a synergistic combination effect of bortezomib and apoVs to ameliorate multiple myeloma (MM) in a mouse model, along with significantly reduced side effects of nano-bortezomib. Moreover, it is shown that Rab7 regulates the nanoparticle encapsulation efficiency in apoptotic MSCs and that activation of Rab7 can increase nanoparticle-apoV production. In this study, a previously unknown mechanism to naturally synthesize nano-bortezomib-apoVs to improve MM therapy is revealed.

Roles of pyroptosis in atherosclerosis pathogenesis

Pyroptosis is a pro-inflammatory type of regulated cell death (RCD) characterized by gasdermin protein-mediated membrane pore formation, cell swelling, and rapid lysis. Recent studies have suggested that pyroptosis is closely related to atherosclerosis (AS). Previous studies reported that pyroptosis involving endothelial cells (ECs), macrophages, and smooth muscle cells (SMCs) plays an important role in the formation and development of AS. Pyroptosis not only causes local inflammation but also amplifies the inflammatory response and it aggravates plaque instability, leading to plaque rupture and thrombosis, eventually resulting in acute cardiovascular events. In this review, we clarified some novel pathways and mechanics and presented some potential drugs.

Mitochondria in health, disease, and aging

Mitochondria are well known as organelles responsible for the maintenance of cellular bioenergetics through the production of ATP. Although oxidative phosphorylation may be their most important function, mitochondria are also integral for the synthesis of metabolic precursors, calcium regulation, the production of reactive oxygen species, immune signaling, and apoptosis. Considering the breadth of their responsibilities, mitochondria are fundamental for cellular metabolism and homeostasis. Appreciating this significance, translational medicine has begun to investigate how mitochondrial dysfunction can represent a harbinger of disease. In this review, we provide a detailed overview of mitochondrial metabolism, cellular bioenergetics, mitochondrial dynamics, autophagy, mitochondrial damage-associated molecular patterns, mitochondria-mediated cell death pathways, and how mitochondrial dysfunction at any of these levels is associated with disease pathogenesis. Mitochondria-dependent pathways may thereby represent an attractive therapeutic target for ameliorating human disease.

Determination of the Impact of High-Intensity Pulsed Electromagnetic Fields on the Release of Damage-Associated Molecular Pattern Molecules

High-Intensity Pulsed Electromagnetic Fields (HI-PEMF) treatment is an emerging noninvasive and contactless alternative to conventional electroporation, since the electric field inside the tissue is induced remotely by an externally applied pulsed magnetic field. Recently, HI-PEMF has been successfully used in the transfer of plasmid DNA and siRNA in vivo, with no or minimal infiltration of immune cells. In addition to gene electrotransfer, treatment with HI-PEMF has also shown potential for electrochemotherapy, where activation of the immune response contributes to the treatment outcome. The immune response can be triggered by immunogenic cell death that is characterized by the release of damage-associated molecular patterns (DAMPs) from damaged or/and dying cells. In this study, the release of the best-known DAMP molecules, i.e., adenosine triphosphate (ATP), calreticulin and high mobility group box 1 protein (HMBG1), after HI-PEMF treatment was investigated in vitro on three different cell lines of different tissue origin and compared with conventional electroporation treatment parameters. We have shown that HI-PEMF by itself does not cause the release of HMGB1 or calreticulin, whereas the release of ATP was detected immediately after HI-PEMF treatment. Our results indicate that HI-PEMF treatment causes no to minimal release of DAMP molecules, which results in minimal/limited activation of the immune response.

Seeing beyond apoptosis: ultrastructural aspects of necrosis in human atherosclerosis

In recent years, there has been an explosive growth of research to decipher the pathobiologic relevance of cell death in the development and progression of various cardiovascular disorders such as arterial remodeling and atherosclerosis. High rates of cell death have been reported in animal models, particularly following balloon catheter injury. Also, in humans there is considerable evidence indicating a close connection between cell death and atherosclerosis. In this regard, diverse biochemical and molecular analysis have suggested that intraplaque cells preferentially die by apoptosis, a mode of cell death considered to be active, highly regulated and programmed. In contrast to apoptosis, necrosis has been classically defined as an uncontrolled form of cell death that can occur in response to chemical or physical insults such as trauma, infection, toxins, or lack of blood supply. Necrosis has long been known to be present within atherosclerotic plaques but to date it is still less well understood and characterized than apoptosis. In addition, although electron microscopy (EM) remains essential in cell death research, only a very small proportion of studies deal with the ultrastructural aspects of cell death and/or include EM images to support their findings. As a consequence, many features of cell death modes in human atherosclerosis have not yet been thoroughly investigated and defined. The present study was undertaken to provide an ultrastructural description of the route/s by which intraplaque cells can die also suggesting novel insights for future research.

Functional micro-RNA drugs acting as a fate manipulator in the regulation of osteoblastic death

Bone loss is prevalent in clinical pathological phenomena such as osteoporosis, which is characterized by decreased osteoblast function and number, increased osteoclast activity, and imbalanced bone homeostasis. However, current treatment strategies for bone diseases are limited. Regulated cell death (RCD) is a programmed cell death pattern activated by the expression of specific genes in response to environmental changes. Various studies have shown that RCD is closely associated with bone diseases, and manipulating the death fate of osteoblasts could contribute to effective bone treatment. Recently, microRNA-targeting therapy drugs have emerged as a potential solution because of their precise targeting, powerful curative effect, and limited side effects. Nevertheless, their clinical application is limited by their inherent instability, easy enzymatic degradation, and poor membrane penetrability. To address this challenge, a self-assembling tetrahedral DNA nanostructure (TDN)-based microRNA (Tmi) delivery system has been proposed. TDN features excellent biocompatibility, cell membrane penetrability, serum stability, and modification versatility, making it an ideal nucleic acid carrier for miRNA protection and intracellular transport. Once inside cells, Tmi can dissociate and release miRNAs to manipulate key molecules in the RCD signaling pathway, thereby regulating bone homeostasis and curing diseases caused by abnormal RCD activation. In this paper, we discuss the impact of the miRNA network on the initiation and termination of four critical RCD programs in bone tissues: apoptosis, autophagy, pyroptosis, and ferroptosis. Furthermore, we present the Tmi delivery system as a miRNA drug vector. This provides insight into the clinical translation of miRNA nucleic acid drugs and the application of miRNA drugs in bone diseases.

ERRα protects against sepsis-induced acute lung injury in rats

BACKGROUND

Sepsis-induced acute lung injury (ALI) is associated with poor survival rates. The identification of potential therapeutic targets for preventing sepsis-induced ALI has clinical importance. This study aims to investigate the role of estrogen-related receptor alpha (ERRα) in sepsis-induced ALI.

METHODS

Lipopolysaccharide (LPS) was used to simulate sepsis-induced ALI model in rat pulmonary microvascular endothelial cells (PMVECs). The effects of ERRα overexpression and knockdown on LPS-induced endothelial permeability, apoptosis and autophagy were determined by horseradish peroxidase permeability assay, TdT-mediated dUTP Nick End Labeling (TUNEL) assay, flow cytometry, immunofluorescence staining, RT-PCR and Western Blotting. The rat model with sepsis-induced ALI was established by cecal ligation and puncture in anesthetized rats to verify the results of in vitro experiments. Animals were randomly assigned to receive intraperitoneal injection of vehicle or ERRα agonist. Lung vascular permeability, pathological injury, apoptosis and autophagy were examined.

RESULTS

Overexpression of ERRα ameliorated LPS-induced endothelial hyperpermeability, degradation of adherens junctional molecules, upregulation of bax, cleaved caspase 3 and cleaved caspase 9 levels, downregulation of anti-apoptotic protein Bcl-2 level, and promoted the formation of autophagic flux, while the knockdown of ERRα exacerbated LPS-induced apoptosis and inhibited the activation of autophagy. Administration of ERRα agonist alleviated the pathological damage of lung tissue, increased the levels of tight junction proteins and adherens junction proteins, and decreased the expression of apoptosis-related proteins. Promoting the expression of ERRα significantly enhanced the process of autophagy and reduced CLP-induced ALI. Mechanistically, ERRα is essential to regulate the balance between autophagy and apoptosis to maintain the adherens junctional integrity.

CONCLUSION

ERRα protects against sepsis-induced ALI through ERRα-mediated apoptosis and autophagy. Activation of ERRα provides a new therapeutic opportunity to prevent sepsis-induced ALI.

Mycobacterium avium subsp. paratuberculosis Candidate Vaccine Strains Are Pro-apoptotic in RAW 264.7 Murine Macrophages

Mycobacterium avium subsp. paratuberculosis (MAP) is the etiological agent of Johne's disease, a severe gastroenteritis of ruminants. This study developed a model cell culture system to rapidly screen MAP mutants with vaccine potential for apoptosis. Two wild-type strains, a transposon mutant, and two deletion mutant MAP strains (MOI of 10 with 1.2 × 10⁶ CFU) were tested in murine RAW 264.7 macrophages to determine if they induce apoptosis and/or necrosis. Both deletion mutants were previously shown to be attenuated and immunogenic in primary bovine macrophages. All strains had similar growth rates, but cell morphology indicated that both deletion mutants were elongated with cell wall bulging. Cell death kinetics were followed by a real-time cellular assay to measure luminescence (apoptosis) and fluorescence (necrosis). A 6 h infection period was the appropriate time to assess apoptosis that was followed by secondary necrosis. Apoptosis was also quantified via DAPI-stained nuclear morphology and validated via flow cytometry. The combined analysis confirmed the hypothesis that candidate vaccine deletion mutants are pro-apoptotic in RAW 264.7 cells. In conclusion, the increased apoptosis seen in the deletion mutants correlates with the attenuated phenotype and immunogenicity observed in bovine macrophages, a property associated with good vaccine candidates.

"Zombie" Macrophages for Targeted Drug Delivery to Treat Acute Pneumonia

A cell-based drug delivery system has emerged as a promising drug delivery platform. Due to their innate inflammatory tropism, natural and engineered macrophages have exhibited targeted accumulation in inflammatory tissues, which has allowed targeted delivery of medicine for the treatment of a variety of inflammatory diseases. Nevertheless, live macrophages may take up the medicine and metabolize it during preparation, storage, and in vivo delivery, sometimes causing unsatisfactory therapeutic efficacy. In addition, live macrophage-based drug delivery systems are usually freshly prepared and injected, due to the poor stability that does not allow storage. "Off-the-shelf" products would be indeed conducive to the timely therapy of acute diseases. Herein, a cryo-shocked macrophage-based drug delivery system was developed via supramolecular conjugation of cyclodextrin (CD)-modified "zombie" macrophages and adamantane (ADA)-functionalized nanomedicine. "Zombie" macrophages exhibited a much better storage stability over time than their counterpart live macrophage drug carriers and maintained cell morphology, membrane integrity, and biological functions. In an acute pneumonia mouse model, "zombie" macrophages carried quercetin-loaded nanomedicine, hand-in-hand, to the inflammatory lung tissues and effectively alleviated the inflammation in mice.

Understanding necroptosis and its therapeutic target for intervertebral disc degeneration

Intervertebral disc degeneration (IVDD) is a complex pathological condition associated with the development of low back pain. Despite numerous studies, the specific molecular mechanisms underlying IVDD remain unclear. At the cellular level, IVDD involves a series of changes, including cell proliferation, cell death, and inflammation. Of these, cell death plays a critical role in the progression of the condition. In recent years, necroptosis has been identified as a new form of programmed cell death (PCD). Necroptosis can be activated by ligands of death receptors, which then interact with RIPK1, RIPK3 and MLKL and lead to necrosome formation.. According to various previous studies, the necroptosis related pathway is activated in IVDD, and plays a significant role in the pathogenesis of IVDD. Furthermore, necroptosis may serve as a target for the IVDD treatment. Recently, several studies have reported the role of necroptosis in IVDD, but few studies have summarized the association between IVDD and necroptosis. The review gives a brief summary of the research progress of necroptosis, and discusses strategies and mechanisms that target necroptosis in IVDD. Lastly, matters needing attention in the necroptosis targeted therapy of IVDD are put forward at last. To the best of our knowledge, the review paper is the first one that integrates current research about the impact of necroptosis on IVDD, and contributes to the future therapy of IVDD from new perspectives.

An overview of programmed cell death: Apoptosis and pyroptosis-Mechanisms, differences, and significance in organism physiology and pathophysiology

Regulated cell death is an essential and heterogeneous process occurring in the life cycle of organisms, from embryonic development and aging to the regulation of homeostasis and organ maintenance. Under this term, we can distinguish many distinct pathways, including apoptosis and pyroptosis. Recently, there has been an increasing comprehension of the mechanisms governing these phenomena and their characteristic features. The coexistence of different types of cell death and the differences and similarities between them has been the subject of many studies. This review aims to present the latest literature in the field of pyroptosis and apoptosis and compare their molecular pathway's elements and significance in the physiology and pathophysiology of the organism.

Effect of Smilax spp. and Phellinus linteus combination on cytotoxicity and cell proliferation of breast cancer cells

BACKGROUND

Although the prevalence of breast cancer (BC) has been reduced in recent years, proficient therapeutic regimens should be further investigated with the aim of further reducing the mortality rate. To obtain more effective treatment, the present study aimed to observe the effects of PL synergistically combined with Smilax corbularia and S. glabra extracts (PSS) on BC cell lines, MCF7, T47D, MDA-MB-231, and MDA-MB-468.

METHODS

The half-maximal inhibition (IC₅₀) concentrations of PSS and PL were determined in a dose- and time-dependent manner using MTT assay. The activity of PSS and PL on anti-BC proliferation was evaluated using BrdU assay, and colony formation assay. Moreover, cell cycle analysis and apoptosis induction as a result of PSS and PL exposure were investigated using propidium iodide (PI) staining and co-staining of annexin V DY634 and PI combined flow cytometric analysis, respectively. Finally, changes in the mRNA expression of genes involved in proliferative and apoptotic pathways (MKI67, HER2, EGFR, MDM2, TNFα, PI3KCA, KRAS, BAX, and CASP8) were explored using RT-qPCR following PSS and PL treatment.

RESULTS

The PSS and PL extracts exhibited significant potential in BC cytotoxicity which were in were in dose- and time-dependent response. This inhibition of cell growth was due to the suppression of cell proliferation, the cell cycle arrest, and the induction of apoptosis. Additionally, an investigation of the underlying molecular mechanism revealed that PSS and PL are involved in downregulation of the MKI67, HER2, EGFR, MDM2, TNFα, and PI3KCA expression.

CONCLUSIONS

This present study has suggested that PSS and PL possess anti-BC proliferative activity mediated via the downregulation of genes participating in the relevant pathways. PSS or PL may be combined with other agents to alleviate the adverse side effects resulted from conventional chemotherapeutic drugs.

Potential anticancer properties of calotropis procera: An investigation on breast and colon cancer cells

Calotropis procera is a perennial flowering plant of the Apocynaceae family, traditionally used in medicine to treat various ailments. Recent investigations have revealed its potential therapeutic activities such as anti-inflammatory, gastroprotective, analgesic, anti-obesity, and anti-diabetic properties. RP-HPLC qualitatively and quantitatively evaluated the phenolic acids and flavonoids in the ethanolic extract at two different wavelengths, 280 and 330 nm. In addition, total phenolic and flavonoid contents were measured via spectrophotometric determination in addition to the antioxidant activity. The antiproliferative effects of C. procera were investigated on two cancer cell lines: human colon (HCT-116) and breast (MCF-7) cancer. Several methods were utilised to analyse the effectiveness of the plant extract on the cytotoxicity, apoptosis, cell cycle progression, genes involved in the cell cycle, and protein expression profiles of HCT-116 and MCF-7 cells. These included the MTT assay, Annexin V-FITC/PI, analysis of the cell cycle, and Western blot. Results indicated that ferulic and caffeic acids were the major compounds at λ_max 280 nm (1.374% and 0.561%, respectively), while the major compounds at λ_max 325 nm were kaempferol and luteolin (1.036% and 0.512%, respectively). The ethanolic extract had significantly higher antioxidant activity (80 ± 2.3%) compared to ascorbic acid (90 ± 3.1%). C. procera extract exhibited dose-dependent cell growth inhibition, with an estimated IC₅₀ of 50 μg/mL for MCF-7 and 55 μg/mL for HCT-116 cells at 24 h. Annexin V-FITC/PI confirmed the induction of apoptosis. Remarkably, cell cycle arrest occurred at the sub-G1 phase in MCF-7 cells, while in HCT-116 cells, it was observed at the G2-M phase. The sub-G1 arrest was associated with dysregulation of Akt, p-AKT, mTOR, and p-mTOR proteins, as confirmed by the Western blot analysis, while downregulation of CDK1, cyclin B1, and survivin caused G2-M arrest.

Polymeric nano-micelle of carbon monoxide donor SMA/CORM2 ameliorates acetaminophen-induced liver injury via suppressing HMGB1/TLR4 signaling pathway

Acetaminophen (APAP) overdose-induced hepatotoxicity is the most common cause of acute liver failure. Excessive generation of reactive oxygen species (ROS) and inflammatory responses are the major causes of necrosis and/or necroptosis of the liver cells. Currently, the treatment options for APAP-induced liver injury are very limited, N-acetylcysteine (NAC) is the only approved drug to treat APAP overdose patients. It is of great necessity to develop new therapeutic strategies. In a previous study, we focused on the anti-oxidative, anti-inflammatory signal molecule carbon monoxide (CO), and developed a nano-micelle encapsulating CO donor, i.e., SMA/CORM2. Administration of SMA/CORM2 to the mice exposed to APAP significantly ameliorated the liver injury and inflammatory process, in which modulating macrophage reprogramming plays a critical role. Along this line, in this study, we investigated the potential effect of SMA/CORM2 on toll-like receptor 4 (TLR4) and high mobility group protein B1 (HMGB1) signaling pathways that are known to be closely involved in many inflammatory responses and necroptosis. In a mouse APAP-induced liver injury model, similar to the previous study, SMA/CORM2 at 10 mg/kg remarkably improved the condition of the liver after injury as evidenced by histological examination and liver function. During the process of liver injury triggered by APAP, TLR4 expression gradually increased over time, and it was significantly upregulated as early as 4 h after APAP exposure, whereas, an increase of HMGB1 was a late-stage event. Notably, SMA/CORM2 treatment suppressed significantly both TLR4 and HMGB1, consequently inhibiting the progression of inflammation and liver injury. Compared to CORM2 without SMA modification (native CORM2) of 1 mg/kg that is equivalent to 10 mg/kg of SMA/CORM2 (the amount of CORM2 in SMA/CORM2 is 10% [w/w]), SMA/CORM2 exhibited a much better therapeutic effect, indicating its superior therapeutic efficacy to native CORM2. These findings revealed that SMA/CORM2 protects against APAP-induced liver injury via mechanisms involving the suppression of TLR4 and HMGB1 signaling pathways. Taking together the results in this study and previous studies, SMA/CORM2 exhibits great therapeutic potential for APAP overdose-induced liver injury, we thus anticipate the clinical application of SMA/CORM2 for the treatment of APAP overdose, as well as other inflammatory diseases.

Marine Polyether Phycotoxin Palytoxin Induces Apoptotic Cell Death via Mcl-1 and Bcl-2 Downregulation

Palytoxin is considered one of the most potent biotoxins. As palytoxin-induced cancer cell death mechanisms remain to be elucidated, we investigated this effect on various leukemia and solid tumor cell lines at low picomolar concentrations. As palytoxin did not affect the viability of peripheral blood mononuclear cells (PBMC) from healthy donors and did not create systemic toxicity in zebrafish, we confirmed excellent differential toxicity. Cell death was characterized by a multi-parametric approach involving the detection of nuclear condensation and caspase activation assays. zVAD-sensitive apoptotic cell death was concomitant with a dose-dependent downregulation of antiapoptotic Bcl-2 family proteins Mcl-1 and Bcl-xL. Proteasome inhibitor MG-132 prevented the proteolysis of Mcl-1, whereas the three major proteasomal enzymatic activities were upregulated by palytoxin. Palytoxin-induced dephosphorylation of Bcl-2 further exacerbated the proapoptotic effect of Mcl-1 and Bcl-xL degradation in a range of leukemia cell lines. As okadaic acid rescued cell death triggered by palytoxin, protein phosphatase (PP)2A was involved in Bcl-2 dephosphorylation and induction of apoptosis by palytoxin. At a translational level, palytoxin abrogated the colony formation capacity of leukemia cell types. Moreover, palytoxin abrogated tumor formation in a zebrafish xenograft assay at concentrations between 10 and 30 pM. Altogether, we provide evidence of the role of palytoxin as a very potent and promising anti-leukemic agent, acting at low picomolar concentrations in cellulo and in vivo.

Targeting multifunctional magnetic nanowires for drug delivery in cancer cell death: an emerging paradigm

Apoptosis, often known as programmed cell death is a mechanism used by numerous species to maintain tissue homeostasis. The process leading to cell death is complicated because it requires the stimulation of caspases. According to several studies, nanowires have important medical benefits, can kill cells by adhering to cancer cells, destroying them, and killing the entire cell using a triple attack that integrates vibration, heat, and drug delivery to trigger apoptosis. The sewage effluents and industrial, fertilizer and organic wastes decomposition can produce elevated levels of chemicals in the environment which may interrupt the cell cycle and activate apoptosis. The purpose of this review is to give a thorough summary of the evidence that is currently available on apoptosis. Current review discussed topics like the morphological and biochemical alterations that occur during apoptosis, as well as the various mechanisms that cause cell death, including the intrinsic (or mitochondrial), extrinsic (or death receptor), and intrinsic endoplasmic reticulum pathway. The apoptosis reduction in cancer development is mediated by (i) an imbalance between pro- and anti-apoptotic proteins, such as members of the B-cell lymphoma-2 (BCL2) family of proteins, tumour protein 53 and inhibitor of apoptosis proteins, (ii) a reduction in caspase activity, and (iii) impaired death receptor signalling. This review does an excellent task of outlining the function of nanowires in both apoptosis induction and targeted drug delivery for cancer cells. A comprehensive summary of the relevance of nanowires synthesised for the purpose of inducing apoptosis in cancer cells has been compiled collectively.

The unfolding story of dying tumor cells during cancer treatment

Generally, the demise of cancer cells in different ways enables the body to clear these harmful cells. However, cancer cells obtain unlimited replication and immortality from successful circumvention of cell death via various mechanisms. Some evidence suggests that treatment-induced dying tumor cells even promote cancer progression. Notably, therapeutic interventions to harness the immune system against tumor cells have shown complicated influences in clinics. Herein, there is an urgent need to clarify the underlying mechanisms that influence the outcome and regulation of the immune system during cancer treatment. In this review, we provide an account on the cell death modes and the relationship between dying tumor cells with tumor immune microenvironment during cancer treatment, focusing on immunotherapy, from mechanistic standpoint to emerging limitations and future directions.

Overview of the synergistic use of radiotherapy and immunotherapy in cancer treatment: current challenges and scopes of improvement

INTRODUCTION

Oncological treatments are changing rapidly due to the advent of several targeted anticancer drugs and regimens. The primary new area of research in oncological medicine is the implementation of a combination of novel therapies and standard care. In this scenario, radioimmunotherapy is one of the most promising fields, as proven by the exponential growth of publications in this context during the last decade.

AREAS COVERED

This review provides an overview of the synergistic use of radiotherapy and immunotherapy and addresses questions like the importance of this subject, aspects clinicians look for in patients to administer this combined therapy, individuals who would benefit the most from this treatment, how to achieve abscopal effect and when does radio-immunotherapy become standard clinical practice.

EXPERT OPINION

Answers to these queries generate further issues that need to be addressed and solved. The abscopal and bystander effects are not utopia, rather physiological phenomena that occur in our bodies. Nevertheless, substantial evidence regarding the combination of radioimmunotherapy is lacking. In conclusion, joining forces and finding answers to all these open questions is of paramount importance.

An Ascovirus Utilizes Different Types of Host Larval Regulated Cell Death Mechanisms To Produce and Release Vesicles

Ascoviruses are insect-specific viruses that are thought to utilize the cellular apoptotic processes of host larvae to produce numerous virion-containing vesicles. In this study, we monitored the in vivo infection processes of Heliothis virescens ascovirus 3h (HvAV-3h) to illustrate the regulated cell death (RCD) of host cells. Transmission electron microscopic observations did not reveal any morphological markers of apoptosis in the fat bodies or hemocytes of HvAV-3h-infected Helicoverpa armigera or Spodoptera exigua larvae. However, several hemocytes showed the morphological criteria for necrosis and/or pyroptosis. Further in vitro biochemical tests were performed to confirm the RCD type of host cells after infection with HvAV-3h. Different morphological characteristics were found between the early (prior to 24 hours post-infection, [hpi]) and later (48 to 120 hpi) stages in both HvAV-3h infected larval fat bodies and hemocytes. In the early stages, the virions could only be found in several adipohemocytes, and the fat bodies were cleaving their contained lipid inclusions into small lipid dots. In the later stage, both fat bodies and hemocytes were filled with numerous virions. According to the morphological characteristics of HvAV-3h infected larval fat bodies or hemocytes, the pathogenic characteristics and infection patterns of HvAV-3h in the host larvae were described, and the systematic pathogenic mode of ascovirus infection was refined in this study. This study details the complete infection process of ascoviruses, which provides insights into the relationship between a pathogenesis of an insect virus and the RCD of different host tissues at different stages of infection. IMPORTANCE Viruses and other pathogens can interrupt host cellular apoptosis to gain benefits, such as sufficient resources and a stable environment that enables them to complete their replication and assembly. It is unusual for viruses to code proteins with homology to caspases, which are commonly recognized as apoptosis regulators. Ascoviruses are insect viruses with special cytopathology, and they have been hypothesized to induce apoptosis in their host larvae via coding a caspase-like protein. This enables them to utilize the process of cellular apoptosis to facilitate vesicle formation and replication. However, our previous studies revealed different trends. The fat bodies and hemocytes of Heliothis virescens ascovirus 3h (HvAV-3h)-infected larvae did not show any morphological markers of apoptosis but did display necrosis and/or pyroptosis morphological characteristics. The pathogenic characteristics and infection patterns of HvAV-3h in the host larvae were described, which can help us understand the relationship between the pathogenesis of an insect virus and host RCD.

Circulating tumor nucleic acids: biology, release mechanisms, and clinical relevance

BACKGROUND

Despite advances in early detection and therapies, cancer is still one of the most common causes of death worldwide. Since each tumor is unique, there is a need to implement personalized care and develop robust tools for monitoring treatment response to assess drug efficacy and prevent disease relapse.

MAIN BODY

Recent developments in liquid biopsies have enabled real-time noninvasive monitoring of tumor burden through the detection of molecules shed by tumors in the blood. These molecules include circulating tumor nucleic acids (ctNAs), comprising cell-free DNA or RNA molecules passively and/or actively released from tumor cells. Often highlighted for their diagnostic, predictive, and prognostic potential, these biomarkers possess valuable information about tumor characteristics and evolution. While circulating tumor DNA (ctDNA) has been in the spotlight for the last decade, less is known about circulating tumor RNA (ctRNA). There are unanswered questions about why some tumors shed high amounts of ctNAs while others have undetectable levels. Also, there are gaps in our understanding of associations between tumor evolution and ctNA characteristics and shedding kinetics. In this review, we summarize current knowledge about ctNA biology and release mechanisms and put this information into the context of tumor evolution and clinical utility.

CONCLUSIONS

A deeper understanding of the biology of ctDNA and ctRNA may inform the use of liquid biopsies in personalized medicine to improve cancer patient outcomes.

Reverse Transfection of Functional RNA Rings into Cancer Cells Followed by in Vitro Irradiation

RNA nanoparticles are promising therapeutic platforms to improve radiotherapy since they can be functionalized with multiple small interfering RNAs (RNAi) to simultaneously silence critical radioresistance genes. Here we describe the transfer of RNA rings to mammalian cancer cells through reverse transfection, followed by in vitro irradiation and biological assays as surrogates' endpoints for radiotherapy efficacy.

Mechanisms of Myofibre Death in Muscular Dystrophies: The Emergence of the Regulated Forms of Necrosis in Myology

Myofibre necrosis is a central pathogenic process in muscular dystrophies (MD). As post-lesional regeneration cannot fully compensate for chronic myofibre loss, interstitial tissue accumulates and impairs muscle function. Muscle regeneration has been extensively studied over the last decades, however, the pathway(s) controlling muscle necrosis remains largely unknown. The recent discovery of several regulated cell death (RCD) pathways with necrotic morphology challenged the dogma of necrosis as an uncontrolled process, opening interesting perspectives for many degenerative disorders. In this review, we focus on how cell death affects myofibres in MDs, integrating the latest research in the cell death field, with specific emphasis on Duchenne muscular dystrophy, the best-known and most common hereditary MD. The role of regulated forms of necrosis in myology is still in its infancy but there is increasing evidence that necroptosis, a genetically programmed form of necrosis, is involved in muscle degenerating disorders. The existence of apoptosis in myofibre demise will be questioned, while other forms of non-apoptotic RCDs may also have a role in myonecrosis, illustrating the complexity and possibly the heterogeneity of the cell death pathways in muscle degenerating conditions.

Synergic Effect of Honey with Other Natural Agents in Developing Efficient Wound Dressings

Honey has been used for therapeutic and nutritional purposes since ancient times. It was considered one of the essential medical assets in wound healing. According to research, honeybees have significant antibacterial, antioxidant, anti-inflammatory, antitumor, and wound-healing properties. Lately, scientific researchers have focused on apitherapy, using bee products to protect and strengthen the immune system. Since honey is the most important natural product rich in minerals, proteins, and vitamins, it has been intensively used in such therapies. Honey has gained significant consideration because of the beneficial role of its antioxidant compounds, such as enzymes, proteins, amino and organic acids, polyphenols, and carotenoids, but mainly due to flavonoids and phenolic acids. It has been proven that phenolic compounds are responsible for honey's biological activity and that its physicochemical properties, antioxidants, and antimicrobial potential are significant for human health. The review also presents some mechanisms of action and the medical applications of honey, such as wound healing dressings, skin grafts, honey-based nanofibers, and cochlear implants, as the most promising wound healing tools. This extensive review has been written to highlight honey's applications in medicine; its composition with the most important bioactive compounds also illustrates its synergistic effect with other natural products having remarkable therapeutic properties in wound healing.

Material basis and action mechanism of Euryale Ferox Salisb in preventing and treating diabetic kidney disease

The aim of this study was to determine the chemical structure and mechanism of action of Euryale ferox Salisb (ES) in the prevention and treatment of diabetic kidney disease (DKD). The TCMSP, SymMap V2, CTD, DisGeNET, and GeneCards databases were searched for ES components, targets, and DKD targets using the network pharmacology method to identify common drug-disease targets. PPI analysis was used to identify hub genes, which were then followed by DKD clinical relevance, GO, KEGG analysis, and transcription factor prediction. Finally, molecular docking was performed. We discovered 24 components of ES and 72 objectives of ES, 9 of which were clinically relevant and primarily regulated by transcription factors such as HNF4A and PPARG. They are involved primarily in signal transduction, inflammatory responses, TNF regulation, apoptosis, MAPK, and other signaling pathways. The main components are oleic acid targeting the protein encoded by PPARA, LPL, FABP1, and vitamin E binding the protein encoded by MAPK1, TGFB1. In general, this approach provides an effective strategy in which ES acts primarily against DKD through oleic acid and vitamin E, targeting the protein encoded by PPARA, LPL, FABP1, MAPK1 to regulate TNF, apoptosis, MAPK, and other signaling pathways. PRACTICAL APPLICATIONS: Euryale ferox Salisb (ES) is well known for its use in medicine and food. Furthermore, ES contains many nutrients, whose pharmacological properties, including antidepressant, antioxidant, and anti-diabetic action, have been extensively demonstrated by numerous studies. In this article, through network pharmacology combined with clinical correlation analysis and molecular docking, the target and mechanism of ES in the treatment of diabetic kidney disease (DKD) were discussed, which clarified its mechanism at the molecular level. Provides a reference for the further development and utilization of ES.

Integrated bioinformatic analysis identified a novel prognostic pan-programmed cell death signature for bladder cancer

Programmed cell death (PCD) refers to a molecularly regulated form of cell death that functions as an essential anticancer defense mechanism and serves as a target of anticancer therapies. Multiple types of PCD comprehensively regulate tumorigenesis and tumor progression and metastasis. However, a systemic exploration of the multiple types of PCD in cancers, especially bladder cancer, is lacking. In this study, we evaluated the expression pattern of genes associated with multiple types of PCD in bladder cancer using the "ssGSEA" method and conceptualized the multiple types of PCD as being collectively involved in "Pan-PCD". Based on the differentially expressed genes related to Pan-PCD, we developed a Pan-PCD-related prognostic signature (PPRPS) to predict patient prognosis via univariate and multivariate Cox regression analysis. The PPRPS is an independent prognostic factor, and the AUC (Area Under Curve) for 3-year overall survival was 0.748. Combined with age and stage, PPRPS displayed excellent predictive ability. Based on the PPRPS, higher levels of immune cell infiltration, tumor microenvironment, and immune checkpoint molecules were observed in the high-PPRPS group. Furthermore, PPRPS enabled accurate risk prediction for metastatic urothelial carcinoma after anti-PD-L1 monoclonal antibody treatment. Patients in the high-PPRPS group had poor prognoses. Docetaxel, staurosporine, and luminespib were identified as potentially effective drugs for high-PPRPS bladder cancer patients. In summary, we developed the Pan-PCD signature to improve the accuracy of bladder cancer prognostic predictions and to provide a novel classification method to guide treatment selection.

Adjuvant chemoradiotherapy versus chemotherapy or radiotherapy in advanced endometrial cancer: a systematic review and meta-analysis

Background

Endometrial cancer is one of the most common gynecological cancer in the world. However, the available adjuvant therapies, chemotherapy (CT) and radiotherapy (RT), demonstrated several limitations when used alone. Therefore, we conducted a meta-analysis to investigate the clinical effectiveness of chemoradiotherapy (CRT) based on overall survival (OS) and disease-free survival (DFS).

Methods

A literature search was performed on five databases and one clinical trial registry to obtain all relevant articles. Search for studies was completed on September 9, 2021. A meta-analysis was conducted to determine the overall hazard ratio with the 95% Confidence Interval.

Results

A total of 17 articles with 23,975 patients in the CRT vs RT group and 50,502 patients in the CRT vs CT group were included. The OS Hazard Ratios (HR) of CRT compared to RT was 0.66 (95% CI [0.59-0.75]; P < 0.00001). Compared to CT, the OS HR was 0.70 (95% CI [0.64-0.78]; P < 0.00001). CRT also significantly improved the DFS compared to CT only (HR 0.79, 95% CI [0.64-0.97]; P = 0.02) However, CRT did not improve the DFS compared to RT only, with HR of 0.71 (95% CI [0.46-1.09]; P = 0.12).

Conclusion

Adjuvant CRT can significantly improve OS compared to CT or RT alone and improve the DFS compared to CT alone in patients with advanced endometrial cancer. Further research is needed to identify the optimal CRT regimen, and to whom CRT will be most beneficial.

Implications and Emerging Therapeutic Avenues of Inflammatory Response in HPV+ Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinomas (HNSCC) are a heterogeneous group of malignancies which have shown exponential incidence in the last two decades especially due to human papillomavirus (HPV) infection. The HPV family comprises more than 100 types of viruses with HPV16 and HPV18 being the most prevalent strains in HNSCC. Literature data reveal that the mutation profile as well as the response to chemotherapy and radiotherapy are distinct among HPV+ versus HPV-negative tumors. Furthermore, the presence of the virus induces activation of an immune response, in particular the recruitment of specific antiviral T lymphocytes to tumor sites. These T cells when activated produce soluble factors including cytokines and chemokines capable of modifying the local immune tumor microenvironment and impact on tumor response to the treatment. In this comprehensive review we investigated current knowledge on how the presence of an HPV can modify the inflammatory response systemically and within the tumor microenvironment's immunological responses, thereby impacting on disease prognosis and survival. We highlighted the research gaps and emerging approaches necessary to discover novel immunotherapeutic targets for HPV-associated HNSCC.

Different modalities of host cell death and their impact on Mycobacterium tuberculosis infection

Mycobacterium tuberculosis (Mtb) is the pathogen that causes tuberculosis (TB), a leading infectious disease of humans worldwide. One of the main histopathological hallmarks of TB is the formation of granulomas comprised of elaborately organized aggregates of immune cells containing the pathogen. Dissemination of Mtb from infected cells in the granulomas due to host and mycobacterial factors induces multiple cell death modalities in infected cells. Based on molecular mechanism, morphological characteristics, and signal dependency, there are two main categories of cell death: programmed and nonprogrammed. Programmed cell death (PCD), such as apoptosis and autophagy, is associated with a protective response to Mtb by keeping the bacteria encased within dead macrophages that can be readily phagocytosed by arriving in uninfected or neighboring cells. In contrast, non-PCD necrotic cell death favors the pathogen, resulting in bacterial release into the extracellular environment. Multiple types of cell death in the PCD category, including pyroptosis, necroptosis, ferroptosis, ETosis, parthanatos, and PANoptosis, may be involved in Mtb infection. Since PCD pathways are essential for host immunity to Mtb, therapeutic compounds targeting cell death signaling pathways have been experimentally tested for TB treatment. This review summarizes different modalities of Mtb-mediated host cell deaths, the molecular mechanisms underpinning host cell death during Mtb infection, and its potential implications for host immunity. In addition, targeting host cell death pathways as potential therapeutic and preventive approaches against Mtb infection is also discussed.

Pyroptosis and Its Role in the Modulation of Cancer Progression and Antitumor Immunity

Pyroptosis is a type of programmed cell death (PCD) accompanied by an inflammatory reaction and the rupture of a membrane. Pyroptosis is divided into a canonical pathway triggered by caspase-1, and a non-canonical pathway independent of caspase-1. More and more pyroptosis-related participants, pathways, and regulatory mechanisms have been exploited in recent years. Pyroptosis plays crucial roles in the initiation, progression, and metastasis of cancer and it affects the immunotherapeutic outcome by influencing immune cell infiltration as well. Extensive studies are required to elucidate the molecular mechanisms between pyroptosis and cancer. In this review, we introduce the discovery history of pyroptosis, delineate the signaling pathways of pyroptosis, and then make comparisons between pyroptosis and other types of PCD. Finally, we provide an overview of pyroptosis in different cancer types. With the progression in the field of pyroptosis, new therapeutic targets and strategies can be explored to combat cancer.

ERK inhibition reduces neuronal death and ameliorates inflammatory responses in forebrain-specific Ppp2cα knockout mice

It has been shown that PP2A is critical for apoptosis in neural progenitor cells. However, it remains unknown whether PP2A is required for neuronal survival. To address this question, we generated forebrain-specific Ppp2cα knockout (KO) mice. We show that Ppp2cα KO mice display robust neuronal apoptosis and inflammatory responses in the postnatal cortex. Previous evidence has revealed that PD98059 is a potent ERK inhibitor and may protect the brain against cell death after cardiac arrest. To study whether PD98059 may have any effects on Ppp2cα KO mice, the latter was treated with this inhibitor. We demonstrated that the total number of cleaved caspase3 positive (+) cells in the cortex was significantly reduced in Ppp2cα KO mice treated with PD98059 compared with those without PD98059 treatment. We observed that the total number of IBA1+ cells in the cortex was significantly decreased in Ppp2cα KO mice treated with PD98059. Mechanistic analysis reveals that deletion of PP2Aca causes DNA damage, which may be attenuated by PD98059. Together, this study suggests that inhibition of ERK may be an effective strategy to reduce cell death in brain diseases with abnormal neuronal apoptosis.