Myricetin activates the Caspase-3/GSDME pathway via ER stress induction of pyroptosis in lung cancer cells

The Heterogeneity in the Response of A549 Cells to Toyocamycin Observed Using Hopping Scanning Ion Conductance Microscopy

Scanning ion conductance microscopy (SICM) is a noninvasive topographic mapping technique used in imaging live cells, unlike electron microscopy and certain applications of fluorescence microscopy, which can disrupt cell integrity. In this study, we used SICM to track the morphological changes of the same A549 cells to uncover the cell-to-cell heterogeneity in their response to the drug. We found that toyocamycin (TOY) induced rapid reorganization of the actin cytoskeleton in A549 cells, causing them to become circular, irregular, or ellipsoidal in shape. Mapping of the dynamic changes in morphology revealed membrane blebbing and a significant decrease in volume over time. Using high-throughput SICM, we mapped the morphology of multiple single cells treated with TOY, which revealed that A549 showed characteristics of apoptosis and necrosis. The drug treatment does not significantly change the average root-mean-square (RMS) roughness of the cells. However, the drug leads to an increase in membrane height, possibly indicating early apoptotic changes. Plotting the individual RMS roughness of the cells showed a cell with an increase in roughness and the presence of pores, which is also an indication of necrosis behavior. Our results demonstrate that SICM is an effective technique for revealing the evolution of heterogeneity in single cells in their responses to anticancer drugs over time.

Pyroptosis was suppressed by 20-hydroxyecdysone through Lin28b-mediated let-7d in vascular endothelial cells

20-hydroxyecdysone (20E), a natural polyhydroxylated steroid, has exhibited anti-inflammatory effects across various diseases. This study investigates the potential connection between 20E's anti-inflammatory properties and the RNA-binding protein Lin28b, which is notably upregulated in TNF-α-stimulated endothelial cells. Herein, we discovered that 20E can selectively downregulate Lin28b expression without affecting its paralog Lin28a. Notably, 20E treatment could significantly attenuate pyroptosis, an inflammatory form of programmed cell death, as evidenced by reduced IL-1β and LDH release, and fewer propidium iodide (PI)-positive cells. Subsequent protein analysis revealed that 20E inhibited the enhanced expressions of key pyroptosis-associated proteins, GSDMD, GSDMD-N, and GSDME-N. Besides, this suppression of Lin28b and pyroptosis may be partially mediated through TNFR1. Additionally, 20E upregulated let-7 miRNA, particularly let-7d, a critical downstream target of Lin28b. To elucidate the role of Lin28b in 20E-mediated pyroptosis attenuation, we performed Lin28b overexpression and silencing experiments. Overexpressing Lin28b negated 20E's inhibition of LDH release and PI-related fluorescence, exacerbating GSDMD and GSDME cleavage. Conversely, Lin28b knockdown augmented the suppressive effect of 20E on pyroptosis, which was reversed by a let-7d inhibitor. Co-transfection with let-7d mimic and Lin28b plasmid demonstrated let-7d's role in mitigating pyroptosis aggravated by Lin28b overexpression. Overall, this study demonstrates that 20E may mitigate GSDMD and GSDME-mediated pyroptosis in HUVECs through the Lin28b/let-7d-dependent signaling pathway. These results highlight the potential of 20E as a promising inhibitor of pyroptosis, offering new insights into its anti-inflammatory mechanisms.

Triggering Pyroptosis in Cancer

Pyroptosis is an inflammatory programmed cell death recently identified as a crucial cellular process in various diseases, including cancers. Unlike other forms of cell death, canonical pyroptosis involves the specific cleavage of gasdermin by caspase-1, resulting in cell membrane damage and the release of the pro-inflammatory cytokines IL-1β and IL-18. Initially observed in innate immune cells responding to external pathogens or internal death signals, pyroptotic cell death has now been observed in numerous cell types. Recent studies have extensively explored different ways to trigger pyroptotic cell death in solid tumors, presenting a promising avenue for cancer treatment. This review outlines the mechanisms of both canonical and noncanonical pyroptosis pertinent to cancer and primarily focuses on various biomolecules that can induce pyroptosis in malignancies. This strategy aims not only to eliminate cancer cells but also to promote an improved tumor immune microenvironment. Furthermore, emerging research indicates that targeting pyroptotic pathways may improve the effectiveness of existing cancer treatments, making them more potent against resistant tumor types, offering new hope for overcoming treatment resistance in aggressive malignancies.

Hypericin photoactivation induces triple-negative breast cancer cells pyroptosis by targeting the ROS/CALR/Caspase-3/GSDME pathway

INTRODUCTION

Hypericin (HP), a natural photosensitizer, has demonstrated great efficacy in photodynamic therapy (PDT) for cancer treatment. In addition to the induction of apoptosis and necrosis through reactive oxygen species (ROS) generation, the therapeutic mechanisms and targets of PDT-HP remain unknown.

OBJECTIVES

To investigate the direct targets and mechanisms of action of photoactivated hypericin in the inhibition of triple-negative breast cancer (TNBC).

METHODS

Cell pyroptosis was examined via LDH release, SYTOX Green staining, and ELISA. RNA sequencing, network pharmacology, drug affinity target stability (DARTS)-tandem mass spectrometry (MS/MS), and molecular docking were employed to identify drug targets. Furthermore, immunoblotting and flow cytometry were utilized to elucidate the mechanisms of drug action.

RESULTS

Our research revealed that PDT-HP can induce pyroptosis in TNBC cells. Further investigation revealed that PDT-HP induces endoplasmic reticulum stress, activating Caspase-3 and gasdermin E (GSDME) to trigger TNBC cell pyroptosis. RNA-seq, network pharmacology, and DARTS-MS/MS proteomic analyses revealed that the endoplasmic reticulum protein calreticulin (CALR) is a potential HP target and that interfering with CALR inhibited PDT-HP-induced pyroptosis. During PDT-HP treatment, the interaction between CALR and SERCA2 inactivates SERCA2, increasing the susceptibility of cells to increased intracellular Ca2+ levels under oxidative stress. This triggered endoplasmic reticulum stress and activated Caspase3, which further cleaved GSDME, releasing GSDME-N and ultimately leading to pyroptosis in TNBC cells.

CONCLUSION

In this study, we provide insight into the antitumor mechanism by examining the pharmacological mechanism by which PDT-HP regulates TNBC cell pyroptosis via the ROS/CALR/Caspase-3/GSDME signaling axis.

Caspase inhibitors: a review on recently patented compounds (2016-2023)

INTRODUCTION

Caspases are a family of protease enzymes that play a crucial role in apoptosis. Dysregulation of caspase activity has been implicated in various pathological conditions, making caspases an important focus of research in understanding cell death mechanisms and developing therapeutic strategies for diseases associated with abnormal apoptosis.

AREAS COVERED

It is a comprehensive review of caspase inhibitors that have been comprising recently granted patents from 2016 to 2023. It includes peptide and non-peptide caspase inhibitors with their application for different diseases.

EXPERT OPINION

This review categorizes and analyses recently patented caspase inhibitors on various diseases. Diseases linked to caspase dysregulation, including neurodegenerative disorders, and autoimmune conditions, are highlighted to accentuate the therapeutic relevance of the patented caspase inhibitors. This paper serves as a valuable resource for researchers, clinicians, and pharmaceutical developers seeking an up-to-date understanding of recently patented caspase inhibitors. The integration of recent patented compounds, structural insights, and mechanistic details provides a holistic view of the progress in caspase inhibitor research and its potential impact on addressing various diseases.

UHPLC-ESI-ms/ms-based characterisation of phenolics and flavonoids in hydroalcoholic extract of Clitoria ternatea seeds and their cytotoxic potential against breast and pancreatic cancer

Fourteen known phenolics (1-14) and ten known flavonoids (15-24) were identified in the hydroalcoholic extract of Clitoria ternatea seeds. Phenolics such as gentisic acid (3), protocatechuic acid (5), o-coumaric acid (12) and p-coumaric acid (13) and among flavonoids, myricetin (16) were detected as the major compounds. The compounds were determined simultaneously in a multiple reaction monitoring (MRM) mode using the Acquity UPLC-H class coupled with TQD-MS/MS with an ESI source. The total phenolic and flavonoid contents were also determined. The hydroalcoholic extract evaluated for its cytotoxic effect against breast (MDA-MB-231) and pancreatic (PANC-1) cancer cells showed significant (p < 0.05) cytotoxicity with IC50 values of 45.4 and 96.5 µg/mL respectively. In addition, the cancer cells treated with the crude extract also showed elevated reactive oxygen species (ROS), upregulated caspase -8/-9/-3 activities and apoptosis of cells treated with C. ternatea extracts compared to control suggesting the pharmacological importance of this herb.

Synthesis, isolation, characterization of C3-C11 bridge-bond isomer of paclitaxel and its antitumor effect via inducing A549 cells pyroptosis

During the chemical manufacturing control processing of new paclitaxel formulations, a photodegradation impurity called C3-C11 bridge-bond isomer appeared. Our work describes the synthesis, isolation, purification, and structural characterization methods using four spectroscopies: FT-IR, UV, NMR (1H and 13 C), and LC-MS. In addition, we discovered that the C3-C11 bridge-bond isomer can promote A549 cells pyroptosis, and increase pyroptosis-related proteins, including cleaved-caspase 3, cleaved-PARP, GSDME-N, and lactate dehydrogenase, thus making it anti-tumor effects. The study offered data suggesting that the C3-C11 bridge bond isomer may be used as an anti-tumour drug in the future.

The clinical significance of endoplasmic reticulum stress related genes in non-small cell lung cancer and analysis of single nucleotide polymorphism for CAV1

In recent years, protein homeostasis imbalance caused by endoplasmic reticulum stress has become a major hallmark of cancer. Studies have shown that endoplasmic reticulum stress is closely related to the occurrence, development, and drug resistance of non-small cell lung cancer, however, the role of various endoplasmic reticulum stress-related genes in non-small cell lung cancer is still unclear. In this study, we established an endoplasmic reticulum stress scores based on the Cancer Genome Atlas for non-small cell lung cancer to reflect patient features and predict prognosis. Survival analysis showed significant differences in overall survival among non-small cell lung cancer patients with different endoplasmic reticulum stress scores. In addition, endoplasmic reticulum stress scores was significantly correlated with the clinical features of non-small cell lung cancer patients, and can be served as an independent prognostic indicator. A nomogram based on endoplasmic reticulum stress scores indicated a certain clinical net benefit, while ssGSEA analysis demonstrated that there was a certain immunosuppressive microenvironment in high endoplasmic reticulum stress scores. Gene Set Enrichment Analysis showed that scores was associated with cancer pathways and metabolism. Finally, weighted gene co-expression network analysis displayed that CAV1 was closely related to the occurrence of non-small cell lung cancer. Therefore, in order to further analyze the role of this gene, Chinese non-smoking females were selected as the research subjects to investigate the relationship between CAV1 rs3779514 and susceptibility and prognosis of non-small cell lung cancer. The results showed that the mutation of rs3779514 significantly reduced the risk of non-small cell lung cancer in Chinese non-smoking females, but no prognostic effect was found. In summary, we proposed an endoplasmic reticulum stress scores, which was an independent prognostic factor and indicated immune characteristics in the microenvironment of non-small cell lung cancer. We also validated the relationship between single nucleotide polymorphism locus of core genes and susceptibility to non-small cell lung cancer.

Insight into the structure, function and the tumor suppression effect of gasdermin E

Gasdermin E (GSDME), which is also known as DFNA5, was first identified as a deafness-related gene that is expressed in cochlear hair cells, and mutation of this gene causes autosomal dominant neurogenic hearing loss. Later studies revealed that GSDME is mostly expressed in the kidney, placenta, muscle and brain cells, but it is expressed at low levels in tumor cells. The GSDME gene encodes the GSDME protein, which is a member of the gasdermin (GSDM) family and has been shown to participate in the induction of apoptosis and pyroptosis. The current literature suggests that Caspase-3 and Granzyme B (Gzm B) can cleave GSDME to generate the active N-terminal fragment (GSDME-NT), which integrates with the cell membrane and forms pores in this membrane to induce pyroptosis. Furthermore, GSDME also forms pores in mitochondrial membranes to release apoptosis factors, such as cytochrome c (Cyt c) and high-temperature requirement protein A2 (HtrA2/Omi), and subsequently activates the intrinsic apoptosis pathway. In recent years, GSDME has been shown to exert tumor-suppressive effects, suggesting that it has potential therapeutic effects on tumors. In this review, we introduce the structure and function of GSDME and the mechanism by which it induces cell death, and we discuss its tumor suppressive effect.

Crosstalk between hypoxia-induced pyroptosis and immune escape in cancer: From mechanisms to therapy

Pyroptosis can be triggered through both canonical and non-canonical inflammasome pathways, involving the cleavage of gasdermin (GSDM) protein family members, like GSDMD and GSDME. The impact of pyroptosis on tumors is nuanced, because its role in regulating cancer progression and anti-tumor immunity may vary depending on the tumor type, stage, location, and immune status. However, pyroptosis cannot be simply categorized as promoting or inhibiting tumors based solely on whether it is acute or chronic in nature. The interplay between pyroptosis and cancer is intricate, with some evidence suggesting that chronic pyroptosis may facilitate tumor growth, while the acute induction of pyroptosis could stimulate anti-cancer immune responses. Tumor hypoxia activates hypoxia inducible factor (HIF) signaling to modulate pyroptosis and immune checkpoint expression. Targeting this hypoxia-pyroptosis-immune escape axis could be a promising therapeutic strategy. This review highlights the complex crosstalk between hypoxia, pyroptosis, and immune evasion in the TME.

Selected Flavonols Targeting Cell Death Pathways in Cancer Therapy: The Latest Achievements in Research on Apoptosis, Autophagy, Necroptosis, Pyroptosis, Ferroptosis, and Cuproptosis

The complex and multi-stage processes of carcinogenesis are accompanied by a number of phenomena related to the potential involvement of various chemopreventive factors, which include, among others, compounds of natural origin such as flavonols. The use of flavonols is not only promising but also a recognized strategy for cancer treatment. The chemopreventive impact of flavonols on cancer arises from their ability to act as antioxidants, impede proliferation, promote cell death, inhibit angiogenesis, and regulate the immune system through involvement in diverse forms of cellular death. So far, the molecular mechanisms underlying the regulation of apoptosis, autophagy, necroptosis, pyroptosis, ferroptosis, and cuproptosis occurring with the participation of flavonols have remained incompletely elucidated, and the results of the studies carried out so far are ambiguous. For this reason, one of the therapeutic goals is to initiate the death of altered cells through the use of quercetin, kaempferol, myricetin, isorhamnetin, galangin, fisetin, and morin. This article offers an extensive overview of recent research on these compounds, focusing particularly on their role in combating cancer and elucidating the molecular mechanisms governing apoptosis, autophagy, necroptosis, pyroptosis, ferroptosis, and cuproptosis. Assessment of the mechanisms underlying the anticancer effects of compounds in therapy targeting various types of cell death pathways may prove useful in developing new therapeutic regimens and counteracting resistance to previously used treatments.

Cholestane-3β,5α,6β-triol Induces Multiple Cell Death in A549 Cells via ER Stress and Autophagy Activation

Cholestane-3β,5α,6β-triol (CT) and its analogues are abundant in natural sources and are reported to demonstrate cytotoxicity toward different kinds of tumor cells without a deep probe into their mechanism of action. CT is also one of the major metabolic oxysterols of cholesterol in mammals and is found to accumulate in various diseases. An extensive exploration of the biological roles of CT over the past few decades has established its identity as an apoptosis inducer. In this study, the effects of CT on A549 cell death were investigated through cell viability assays. RNA-sequencing analysis and western blot of CT-treated A549 cells revealed the role of CT in inducing endoplasmic reticulum (ER) stress response and enhancing autophagy flux, suggesting a putative mechanism of CT-induced cell-death activation involving reactive oxygen species (ROS)-mediated ER stress and autophagy. It is reported for the first time that the upregulation of autophagy induced by CT can serve as a cellular cytotoxicity response in accelerating CT-induced cell death in A549 cells. This research provides evidence for the effect of CT as an oxysterol in cell response to oxidative damage and allows for a deep understanding of cholesterol in its response in an oxidative stress environment that commonly occurs in the progression of various diseases.

Engineering materials for pyroptosis induction in cancer treatment

Cancer remains a significant global health concern, necessitating the development of innovative therapeutic strategies. This research paper aims to investigate the role of pyroptosis induction in cancer treatment. Pyroptosis, a form of programmed cell death characterized by the release of pro-inflammatory cytokines and the formation of plasma membrane pores, has gained significant attention as a potential target for cancer therapy. The objective of this study is to provide a comprehensive overview of the current understanding of pyroptosis and its role in cancer treatment. The paper discusses the concept of pyroptosis and its relationship with other forms of cell death, such as apoptosis and necroptosis. It explores the role of pyroptosis in immune activation and its potential for combination therapy. The study also reviews the use of natural, biological, chemical, and multifunctional composite materials for pyroptosis induction in cancer cells. The molecular mechanisms underlying pyroptosis induction by these materials are discussed, along with their advantages and challenges in cancer treatment. The findings of this study highlight the potential of pyroptosis induction as a novel therapeutic strategy in cancer treatment and provide insights into the different materials and mechanisms involved in pyroptosis induction.

Pyroptotic cell death: an emerging therapeutic opportunity for radiotherapy

Pyroptotic cell death, an inflammatory form of programmed cell death (PCD), is emerging as a potential therapeutic opportunity for radiotherapy (RT). RT is commonly used for cancer treatment, but its effectiveness can be limited by tumor resistance and adverse effects on healthy tissues. Pyroptosis, characterized by cell swelling, membrane rupture, and release of pro-inflammatory cytokines, has been shown to enhance the immune response against cancer cells. By inducing pyroptotic cell death in tumor cells, RT has the potential to enhance treatment outcomes by stimulating anti-tumor immune responses and improving the overall efficacy of RT. Furthermore, the release of danger signals from pyroptotic cells can promote the recruitment and activation of immune cells, leading to a systemic immune response that may target distant metastases. Although further research is needed to fully understand the mechanisms and optimize the use of pyroptotic cell death in RT, it holds promise as a novel therapeutic strategy for improving cancer treatment outcomes. This review aims to synthesize recent research on the regulatory mechanisms underlying radiation-induced pyroptosis and to elucidate the potential significance of this process in RT. The insights gained from this analysis may inform strategies to enhance the efficacy of RT for tumors.

Caspase-3/GSDME dependent pyroptosis contributes to offspring lung injury induced by gestational PFOS exposure via PERK/ATF4 signaling

Perfluorooctane sulfonate (PFOS) is widely used in industry and consumer products. Previous studies have showed that PFOS gestational exposure is associated with offspring lung damage in rat. However, the underlying mechanisms remain poorly understood. In this study, we investigated the role of gasdermin E (GSDME) in lung injury of offspring and its underlying mechanisms using in vivo and in vitro approaches. Pregnant SD rats were exposed to PFOS (1 mg/kg BW/d) between gestational day 12-18, and the lung tissue of the offspring was evaluated on postnatal day 7. PFOS treated animals exhibited alveolar septal thickening and inflammation-related damages, with an increased expression of GSDME in alveolar type II epithelial cells (AECII). Furthermore, in vitro experiments demonstrated that PFOS exposure (with 225 μM and up) upregulated the caspase-3/GSDME signaling pathway in AECII. Also, ultrastructure analysis revealed significant changes in the endoplasmic reticulum (ER) structure in PFOS-induced pyroptotic cells, which is consistent with the ER stress detected in these cells. Additionally, PFOS exposure led to increased expression of ER stress-related proteins, including p-PERK, p-eIF2α, ATF4, and CHOP. Subsequently, using specific inhibitors, we found that the PERK/ATF4 pathway acted as an upstream signal regulating GSDME-dependent pyroptosis. Overall, our findings show that GSDME-dependent pyroptosis plays a crucial role in the lung injury induced by gestational PFOS exposure, and the PERK/ATF4 pathway may function as a possible mediator of this process.

Flavonoid Myricetin as Potent Anticancer Agent: A Possibility towards Development of Potential Anticancer Nutraceuticals

Good nutrition plays a crucial role in maintaining a balanced lifestyle. The beneficial effects of nutrition have been found to counteract nutritional disturbances with the expanded use of nutraceuticals to treat and manage cardiovascular diseases, cancer, and other developmental defects over the last decade. Flavonoids are found abundantly in plant-derived foods such as fruits, vegetables, tea, cocoa, and wine. Fruits and vegetables contain phytochemicals like flavonoids, phenolics, alkaloids, saponins, and terpenoids. Flavonoids can act as anti-inflammatory, anti-allergic, anti-microbial (antibacterial, antifungal, and antiviral) antioxidant, anti-cancer, and anti-diarrheal agents. Flavonoids are also reported to upregulate apoptotic activity in several cancers such as hepatic, pancreatic, breast, esophageal, and colon. Myricetin is a flavonol which is naturally present in fruits and vegetables and has shown possible nutraceutical value. Myricetin has been portrayed as a potent nutraceutical that may protect against cancer. The focus of the present review is to present an updated account of studies demonstrating the anticancer potential of myricetin and the molecular mechanisms involved therein. A better understanding of the molecular mechanism(s) underlying its anticancer activity would eventually help in its development as a novel anticancer nutraceutical having minimal side effects.

The multifaceted roles of GSDME-mediated pyroptosis in cancer: therapeutic strategies and persisting obstacles

Pyroptosis is a novel regulated cell death (RCD) mode associated with inflammation and innate immunity. Gasdermin E (GSDME), a crucial component of the gasdermin (GSDM) family proteins, has the ability to convert caspase-3-mediated apoptosis to pyroptosis of cancer cells and activate anti-tumor immunity. Accumulating evidence indicates that GSDME methylation holds tremendous potential as a biomarker for early detection, diagnosis, prognosis, and treatment of tumors. In fact, GSDME-mediated pyroptosis performs a dual role in anti-tumor therapy. On the one side, pyroptotic cell death in tumors caused by GSDME contributes to inflammatory cytokines release, which transform the tumor immune microenvironment (TIME) from a 'cold' to a 'hot' state and significantly improve anti-tumor immunotherapy. However, due to GSDME is expressed in nearly all body tissues and immune cells, it can exacerbate chemotherapy toxicity and partially block immune response. How to achieve a balance between the two sides is a crucial research topic. Meanwhile, the potential functions of GSDME-mediated pyroptosis in anti-programmed cell death protein 1 (PD-1) therapy, antibody-drug conjugates (ADCs) therapy, and chimeric antigen receptor T cells (CAR-T cells) therapy have not yet been fully understood, and how to improve clinical outcomes persists obscure. In this review, we systematically summarize the latest research regarding the molecular mechanisms of pyroptosis and discuss the role of GSDME-mediated pyroptosis in anti-tumor immunity and its potential applications in cancer treatment.

ER stress induces caspase-2-tBID-GSDME-dependent cell death in neurons lytically infected with herpes simplex virus type 2

Neurotropic viruses, including herpes simplex virus (HSV) types 1 and 2, have the capacity to infect neurons and can cause severe diseases. This is associated with neuronal cell death, which may contribute to morbidity or even mortality if the infection is not controlled. However, the mechanistic details of HSV-induced neuronal cell death remain enigmatic. Here, we report that lytic HSV-2 infection of human neuron-like SH-SY5Y cells and primary human and murine brain cells leads to cell death mediated by gasdermin E (GSDME). HSV-2-induced GSDME-mediated cell death occurs downstream of replication-induced endoplasmic reticulum stress driven by inositol-requiring kinase 1α (IRE1α), leading to activation of caspase-2, cleavage of the pro-apoptotic protein BH3-interacting domain death agonist (BID), and mitochondria-dependent activation of caspase-3. Finally, necrotic neurons released alarmins, which activated inflammatory responses in human iPSC-derived microglia. In conclusion, lytic HSV infection in neurons activates an ER stress-driven pathway to execute GSDME-mediated cell death and promote inflammation.

Inflammatory cell death induced by 5-aminolevulinic acid-photodynamic therapy initiates anticancer immunity

Background

Inflammatory cell death is a form of programmed cell death (PCD) that induces inflammatory mediators during the process. The production of inflammatory mediators during cell death is beneficial in standard cancer therapies as it can break the immune silence in cancers and induce anticancer immunity. Photodynamic therapy (PDT) is a cancer therapy with photosensitizer molecules and light sources to destroy cancer cells, which is currently used for treating different types of cancers in clinical settings. In this study, we investigated if PDT using 5-aminolevulinic (5-ALA-PDT) causes inflammatory cell death and, subsequently, increases the immunogenicity of cancer cells.

Methods

Mouse breast cancer (4T1) and human colon cancer (DLD-1) cells were treated with 5-ALA for 4 hours and then irradiated with a light source. PCD induction was measured by western blot analysis and FACS. Morphological changes were determined by transmission electron microscopy (TEM). BALB/c mice were injected with cell-free media, supernatant of freeze/thaw cells or supernatant of PDT cells intramuscular every week for 4 weeks and then challenged with 4T1 cells at the right hind flank of BALB/c. Tumor growth was monitored for 12 days.

Results

We found that 5-ALA-PDT induces inflammatory cell death, but not apoptosis, in 4T1 cells and DLD-1 cells in vitro. Moreover, when mice were pretreated with 5-ALA-PDT culture supernatant, the growth of 4T1 tumors was significantly suppressed compared to those pretreated with freeze and thaw (F/T) 4T1 culture supernatant.

Conclusion

These results indicate that 5-ALA-PDT induces inflammatory cell death which promotes anticancer immunity in vivo.

Cloning, expression of porcine GSDME and identification of its site cleaved by caspase-3

As a member of the gasdermin family, gasdermin E (GSDME) is specifically cleaved by caspase-3, resulting in pyroptosis. To date, the biological characteristics and functions of human and mouse GSDME have been extensively studied; however, little is known of porcine GSDME (pGSDME). In this study, the full-length pGSDME-FL was cloned, which encodes 495 amino acids (aa) that have closely evolutionary relationships to the homolog of camelus, aquatic mammals, cattle and goat. Moreover, pGSDME was detected at different levels of expression in 21 tissues and 5 pig-derived cell lines tested by qRT-PCR, with the highest expression levels in mesenteric lymph nodes and PK-15 cell lines. Anti-pGSDME polyclonal antibody (pAb) with good specificity was generated by expressing the truncated recombinant protein pGSDME-1-208 and immunizing the rabbits. By western blot analysis using highly specific anti-pGSDME polyclonal antibody (pAb) prepared as primary antibody, it was not only confirmed that paclitaxel and cisplatin were positive stimuli to pGSDME cleavage and caspase-3 activation, but also identified the aspartate (D268) at position 268th of pGSDME as a cleavage site of caspase-3, and the overexpressed pGSDME-1-268 possesses cytotoxicity to HEK-293T cells, indicating that pGSDME-1-268 may contain active domains and involve pGSDME-mediated pyroptosis. These results lay a foundation for further investigating the function of pGSDME, especially its role in pyroptosis and its interaction with pathogens.

Fu-Zheng-Xuan-Fei formula promotes macrophage polarization and Th17/Treg cell homeostasis against the influenza B virus (Victoria strain) infection

ETHNOPHARMACOLOGICAL RELEVANCE

Fu-Zheng-Xuan-Fei formula (FF) is a prescription that has been clinically used through the basic theory of traditional Chinese medicine (TCM) for treating viral pneumonia. Although FF possesses a prominent clinical therapeutic effect, seldom pharmacological studies have been reported on its anti-influenza B virus (IBV) activity.

AIM OF THE STUDY

Influenza is an acute infectious respiratory disease caused by the influenza virus, which has high annual morbidity and mortality worldwide. With a global decline in the COVID-19 control, the infection rate of influenza virus is gradually increasing. Therefore, it is of great importance to develop novel drugs for the effective treatment of influenza virus. Apart from conventional antiviral drugs, TCM has been widely used in the clinical treatment of influenza in China. Therefore, studying the antiviral mechanism of TCM can facilitate the scientific development of TCM.

MATERIALS AND METHODS

Madin-Darby canine kidney cells (MDCK) and BALB/c mice were infected with IBV, and FF was added to evaluate the anti-IBV effects of FF both in vitro and in vivo by Western blotting, immunofluorescence, flow cytometry, and pathological assessment.

RESULTS

It was found that FF exhibited anti-viral activity against IBV infection both in vivo and in vitro, while inducing macrophage activation and promoting M1 macrophage polarization. In addition, FF effectively regulated the signal transducer and activator of transcription (STAT) signaling pathway-mediated Th17/Treg balance to improve the lung tissue damage caused by IBV infection-induced inflammation. The findings provided the scientific basis for the antiviral mechanism of FF against IBV infection.

CONCLUSIONS

This study shows that FF is a potentially effective antiviral drug against IBV infection.

Myricetin: A Significant Emphasis on Its Anticancer Potential via the Modulation of Inflammation and Signal Transduction Pathways

Cancer is a major public health concern worldwide and main burden of the healthcare system. Regrettably, most of the currently used cancer treatment approaches such as targeted therapy, chemotherapy, radiotherapy and surgery usually cause adverse complications including hair loss, bone density loss, vomiting, anemia and other complications. However, to overcome these limitations, there is an urgent need to search for the alternative anticancer drugs with better efficacy as well as less adverse complications. Based on the scientific evidences, it is proven that naturally occurring antioxidants present in medicinal plants or their bioactive compounds might constitute a good therapeutic approach in diseases management including cancer. In this regard, myricetin, a polyhydroxy flavonol found in a several types of plants and its role in diseases management as anti-oxidant, anti-inflammatory and hepato-protective has been documented. Moreover, its role in cancer prevention has been noticed through modulation of angiogenesis, inflammation, cell cycle arrest and induction of apoptosis. Furthermore, myricetin plays a significant role in cancer prevention through the inhibition of inflammatory markers such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (Cox-2). Moreover, myricetin increases the chemotherapeutic potential of other anticancer drugs through modulation of cell signaling molecules activity. This review elaborates the information of myricetin role in cancer management through modulating of various cell-signaling molecules based on in vivo and in vitro studies. In addition, synergistic effect with currently used anticancer drugs and approaches to improve bioavailability are described. The evidences collected in this review will help different researchers to comprehend the information about its safety aspects, effective dose for different cancers and implication in clinical trials. Moreover, different challenges need to be focused on engineering different nanoformulations of myricetin to overcome the poor bioavailability, loading capacity, targeted delivery and premature release of this compound. Furthermore, some more derivatives of myricetin need to be synthesized to check their anticancer potential.

The pyroptotic role of Caspase-3/GSDME signalling pathway among various cancer: A Review

Cytotoxic drugs have long been recognised to kill cancer cells through apoptosis. According to a current study, pyroptosis inhibits cell proliferation and shrinks tumors. Pyroptosis and apoptosis are caspase-dependent programmed cell death (PCD) processes. Inflammasomes activate caspase-1 and latent cytokines, including IL-1β and IL-18, to cleave gasdermin E (GSDME) and induce pyroptosis. Gasdermin proteins activate caspase-3 to induce pyroptosis, which is associated with tumour genesis, development, and therapy response. These proteins may serve as therapeutic biomarkers for cancer detection, and their antagonists may be a new target. Caspase-3, a crucial protein in both pyroptosis and apoptosis, governs tumour cytotoxicity when activated, and GSDME expression modulates this. Once active caspase-3 cleaves GSDME, its N-terminal domain punches holes in the cell membrane, causing it to expand, burst, and die. To understand the cellular and molecular mechanisms of PCD mediated by caspase-3 and GSDME, we focused on pyroptosis. Hence, caspase-3 and GSDME may be promising targets for cancer treatment.

Why Do Dietary Flavonoids Have a Promising Effect as Enhancers of Anthracyclines? Hydroxyl Substituents, Bioavailability and Biological Activity

Anthracyclines currently play a key role in the treatment of many cancers, but the limiting factor of their use is the widespread phenomenon of drug resistance and untargeted toxicity. Flavonoids have pleiotropic, beneficial effects on human health that, apart from antioxidant activity, are currently considered small molecules-starting structures for drug development and enhancers of conventional therapeutics. This paper is a review of the current and most important data on the participation of a selected series of flavonoids: chrysin, apigenin, kaempferol, quercetin and myricetin, which differ in the presence of an additional hydroxyl group, in the formation of a synergistic effect with anthracycline antibiotics. The review includes a characterization of the mechanism of action of flavonoids, as well as insight into the physicochemical parameters determining their bioavailability in vitro. The crosstalk between flavonoids and the molecular activity of anthracyclines discussed in the article covers the most important common areas of action, such as (1) disruption of DNA integrity (genotoxic effect), (2) modulation of antioxidant response pathways, and (3) inhibition of the activity of membrane proteins responsible for the active transport of drugs and xenobiotics. The increase in knowledge about the relationship between the molecular structure of flavonoids and their biological effect makes it possible to more effectively search for derivatives with a synergistic effect with anthracyclines and to develop better therapeutic strategies in the treatment of cancer.