Wogonin induces apoptosis in macrophages by exhibiting cytotoxic and genotoxic effects

Macrophages play an important role in defending the body against invading pathogens. In the face of pathogens, macrophages become activated and release toxic materials that disrupt the pathogens. Macrophage overactivation can lead to severe illness and inflammation. Wogonin has several therapeutic effects, including anti-inflammatory, anticancer, antioxidant, and neuroprotective effects. No studies have investigated the cytotoxic effects of wogonin at concentrations of more than 0.1 mM in RAW264.7 cells. In this study, RAW 264.7 cells were treated with wogonin, which, at concentrations of more than 0.1 mM, had cytotoxic and genotoxic effects in the RAW264.7 cells, leading to apoptosis and necrosis. Further, wogonin at concentrations of more than 0.1 mM induced caspase-3, caspase-8, and caspase-9 activation and mitochondrial dysfunction and death receptor expression. These results suggest that wogonin induces apoptosis through upstream intrinsic and extrinsic pathways by exhibiting cytotoxic and genotoxic effects.

A Non-Apoptotic Pattern of Caspase-9/Caspase-3 Activation During Differentiation of Human Embryonic Stem Cells into Cardiomyocytes

In vitro studies have demonstrated that the differentiation of embryonic stem cells (ESCs) into cardiomyocytes requires activation of caspases through the mitochondrial pathway. These studies have relied on synthetic substrates for activity measurements, which can be misleading due to potential none-specific hydrolysis of these substrates by proteases other than caspases. Hence, caspase-9 and caspase-3 activation are investigated during the differentiation of human ESCs (hESCs) by directly assessing caspase-9 and -3 cleavage. Western blot reveals the presence of the cleaved caspase-9 prior to and during the differentiation of human ESCs (hESCs) into cardiomyocytes at early stages, which diminishes as the differentiation progresses, without cleavage and activation of endogenous procaspase-3. Activation of exogenous procaspase-3 by endogenous caspase-9 and subsequent cleavage of chromogenic caspase-3 substrate i.e. DEVD-pNA during the course of differentiation confirmes that endogenous caspase-9 has the potency to recognize and activate procaspase-3, but for reasons that are unknown to us fails to do so. These observations suggest the existence of distinct mechanisms of caspase regulation in differentiation as compared to apoptosis. Bioinformatics analysis suggests the presence of caspase-9 regulators, which may influence proteolytic function under specific conditions.

Lentivirus-Mediated BCL-XL Overexpression Inhibits Stem Cell Apoptosis during Ex Vivo Expansion and Provides Competitive Advantage Following Xenotransplantation

Hematopoietic reconstitution after hematopoietic stem cell transplantation (HSCT) is influenced by the number of transplanted cells. However, under certain conditions donor cell counts are limited and impair clinical outcome. Hematopoietic stem and progenitor cell (HSPC) expansion prior to HSCT is a widely used method to achieve higher donor cell counts and minimize transplantation-related risks such as graft failure or delayed engraftment. Still, expansion in a non-physiological environment can trigger cell death mechanisms and hence counteract the desired effect. We have shown earlier that during HSCT a relevant amount of HSPCs were lost due to apoptosis and that cell death inhibition in donor HSPCs improved engraftment in xenotransplantation experiments. Here, we assessed the effect of combined ex vivo expansion and cell death inhibition on HSPC yield and their reconstitution potential in vivo. During expansion with cytokines and the small molecule inhibitor StemRegenin 1, concomitant lentiviral overexpression of antiapoptotic BCL-XL resulted in an increased yield of transduced HSPCs. Importantly, BCL-XL overexpression enhanced the reconstitution potential of HSPCs in xenotransplantation experiments in vivo. In contrast, treatment with caspase and necroptosis inhibitors had no favorable effects on HSPC yields nor on cell viability. We postulate that overexpression of antiapoptotic BCL-XL, both during ex vivo expansion and transplantation, is a promising approach to improve the outcome of HSCT in situations with limited donor cell numbers. However, such apoptosis inhibition needs to be transient to avoid long-term sequelae like leukemia.

Phyto-therapeutic potential of Withania somnifera: Molecular mechanism and health implications

Withania somnifera, the plant named Indian ginseng, Ashwagandha, or winter cherry, has been used since ancient times to cure various health ailments. Withania somnifera is rich in constituents belonging to chemical classes like alkaloids, saponins, flavonoids, phenolic acids, and withanolides. Several chemotypes were identified based on their phytochemical composition and credited for their multiple bioactivities. Besides, exhibiting neuroprotective, immunomodulatory, adaptogenic, anti-stress, bone health, plant has shown promising anti-cancer properties. Several withanolides have been reported to play a crucial role in cancer; they target cancer cells by different mechanisms such as modulating the expression of tumor suppressor genes, apoptosis, telomerase expression, and regulating cell signaling pathway. Though, many treatments are available for cancer; however, to date, no assured reliable cure for cancer is made available. Additionally, synthetic drugs may lead to development of resistance in time; therefore, focus on new and natural drugs for cancer therapeutics may prove a longtime effective alternative. This current report is a comprehensive combined analysis upto 2023 with articles focused on bio-activities of plant Withania somnifera from various sources, including national and international government sources. This review focuses on understanding of various mechanisms and pathways to inhibit uncontrolled cell growth by W. somnifera bioactives, as reported in literature. This review provides a recent updated status of the W. somnifera on pharmacological properties in general and anti-cancer in particular and may provide a guiding resource for researchers associated with natural product-based cancer research and healthcare management.

Pyroptosis in health and disease

The field of cell death has witnessed significant advancements since the initial discovery of apoptosis in the 1970s. This review delves into the intricacies of pyroptosis, a more recently identified form of regulated, lytic cell death, and explores the roles of pyroptotic effector molecules, with a strong emphasis on their mechanisms and relevance in various diseases. Pyroptosis, characterized by its proinflammatory nature, is driven by the accumulation of large plasma membrane pores comprised of gasdermin family protein subunits. In different contexts of cellular homeostatic perturbations, infections, and tissue damage, proteases, such as caspase-1 and caspase-4/5, play pivotal roles in pyroptosis by cleaving gasdermins. Gasdermin-D (GSDMD), the most extensively studied member of the gasdermin protein family, is expressed in various immune cells and certain epithelial cells. Upon cleavage by caspases, GSDMD oligomerizes and forms transmembrane pores in the cell membrane, leading to the release of proinflammatory cytokines. GSDMD-N, the NH2-terminal fragment, displays an affinity for specific lipids, contributing to its role in pore formation in pyroptosis. While GSDMD is the primary focus, other gasdermin family members are also discussed in detail. These proteins exhibit distinct tissue-specific functions and contribute to different facets of cell death regulation. Additionally, genetic variations in some gasdermins have been linked to diseases, underscoring their clinical relevance. Furthermore, the interplay between GSDM pores and the activation of other effectors, such as ninjurin-1, is elucidated, providing insights into the complexity of pyroptosis regulation. The findings underscore the molecular mechanisms that govern pyroptosis and its implications for various physiological and pathological processes.

CRISPR-controlled proteases

With the discovery of CRISPR-controlled proteases, CRISPR-Cas has moved beyond mere nucleic acid targeting into the territory of targeted protein cleavage. Here, we review the understanding of Craspase, the best-studied member of the growing CRISPR RNA-guided protease family. We recollect the original bioinformatic prediction and early experimental characterizations; evaluate some of the mechanistic structural intricacies and emerging biotechnology; discuss open questions and unexplained mysteries; and indicate future directions for the rapidly moving field of the CRISPR proteases.

Harnessing Pyroptosis for Cancer Immunotherapy

Cancer immunotherapy is a novel pillar of cancer treatment that harnesses the immune system to fight tumors and generally results in robust antitumor immunity. Although immunotherapy has achieved remarkable clinical success for some patients, many patients do not respond, underscoring the need to develop new strategies to promote antitumor immunity. Pyroptosis is an immunostimulatory type of regulated cell death that activates the innate immune system. A hallmark of pyroptosis is the release of intracellular contents such as cytokines, alarmins, and chemokines that can stimulate adaptive immune activation. Recent studies suggest that pyroptosis promotes antitumor immunity. Here, we review the mechanisms by which pyroptosis can be induced and highlight new strategies to induce pyroptosis in cancer cells for antitumor defense. We discuss how pyroptosis modulates the tumor microenvironment to stimulate adaptive immunity and promote antitumor immunity. We also suggest research areas to focus on for continued development of pyroptosis as an anticancer treatment. Pyroptosis-based anticancer therapies offer a promising new avenue for treating immunologically 'cold' tumors.

Understanding Developmental Cell Death Using Drosophila as a Model System

Cell death plays an essential function in organismal development, wellbeing, and ageing. Many types of cell deaths have been described in the past 30 years. Among these, apoptosis remains the most conserved type of cell death in metazoans and the most common mechanism for deleting unwanted cells. Other types of cell deaths that often play roles in specific contexts or upon pathological insults can be classed under variant forms of cell death and programmed necrosis. Studies in Drosophila have contributed significantly to the understanding and regulation of apoptosis pathways. In addition to this, Drosophila has also served as an essential model to study the genetic basis of autophagy-dependent cell death (ADCD) and other relatively rare types of context-dependent cell deaths. Here, we summarise what is known about apoptosis, ADCD, and other context-specific variant cell death pathways in Drosophila, with a focus on developmental cell death.

Synthesis and Characterization of Graphene Oxide/Polyethylene Glycol/Folic Acid/Brucine Nanocomposites and Their Anticancer Activity on HepG2 Cells

Background

Liver cancer is the sixth most prevalent form of cancer and the second major cause of cancer-associated mortalities worldwide. Cancer nanotechnology has the ability to fundamentally alter cancer treatment, diagnosis, and detection.

Objective

In this study, we explained the development of graphene oxide/polyethylene glycol/folic acid/brucine nanocomposites (GO/PEG/Bru-FA NCs) and evaluated their antimicrobial and anticancer effect on the liver cancer HepG2 cells.

Methodology

The GO/PEG/Bru-FA NCs were prepared using the co-precipitation technique and characterized using various techniques. The cytotoxicity of the GO/PEG/Bru-FA NCs was tested against both liver cancer HepG2 and non-malignant Vero cells using an MTT assay. The antimicrobial activity of the GO/PEG/Bru-FA NCs was tested against several pathogens using the well diffusion technique. The effects of GO/PEG/Bru-FA NCs on endogenous ROS accumulation, apoptosis, and MMP levels were examined using corresponding fluorescent staining assays, respectively. The apoptotic protein expressions, such as Bax, Bcl-2, and caspases, were studied using the corresponding kits.

Results

The findings of various characterization assays revealed the development of GO/PEG/Bru-FA NCs with face-centered spherical morphology and an agglomerated appearance with an average size of 197.40 nm. The GO/PEG/Bru-FA NCs treatment remarkably inhibited the growth of the tested pathogens. The findings of the MTT assay evidenced that the GO/PEG/Bru-FA NCs effectively reduced the HepG2 cell growth while not showing toxicity to the Vero cells. The findings of the fluorescent assay proved that the GO/PEG/Bru-FA NCs increased ROS generation, reduced MMP levels, and promoted apoptosis in the HepG2 cells. The levels of Bax, caspase-9, and -3 were increased, and Bcl-2 was reduced in the GO/PEG/Bru-FA NCs-treated HepG2 cells.

Conclusion

The results of this work demonstrate that GO/PEG/Bru-FA NCs suppress viability and induce apoptosis in HepG2 cells, indicating their potential as an anticancer candidate.

Neosetophomone B induces apoptosis in multiple myeloma cells via targeting of AKT/SKP2 signaling pathway

Multiple myeloma (MM) is a hematologic malignancy associated with malignant plasma cell proliferation in the bone marrow. Despite the available treatments, drug resistance and adverse side effects pose significant challenges, underscoring the need for alternative therapeutic strategies. Natural products, like the fungal metabolite neosetophomone B (NSP-B), have emerged as potential therapeutic agents due to their bioactive properties. Our study investigated NSP-B's antitumor effects on MM cell lines (U266 and RPMI8226) and the involved molecular mechanisms. NSP-B demonstrated significant growth inhibition and apoptotic induction, triggered by reduced AKT activation and downregulation of the inhibitors of apoptotic proteins and S-phase kinase protein. This was accompanied by an upregulation of p21Kip1 and p27Cip1 and an elevated Bax/BCL2 ratio, culminating in caspase-dependent apoptosis. Interestingly, NSP-B also enhanced the cytotoxicity of bortezomib (BTZ), an existing MM treatment. Overall, our findings demonstrated that NSP-B induces caspase-dependent apoptosis, increases cell damage, and suppresses MM cell proliferation while improving the cytotoxic impact of BTZ. These findings suggest that NSP-B can be used alone or in combination with other medicines to treat MM, highlighting its importance as a promising phytoconstituent in cancer therapy.

Aloe-emodin exhibits growth-suppressive effects on androgen-independent human prostate cancer DU145 cells via inhibiting the Wnt/β-catenin signaling pathway: an in vitro and in silico study

At the molecular level, several developmental signaling pathways, such as Wnt/β-catenin, have been associated with the initiation and subsequent progression of prostate carcinomas. The present report elucidated the anti-cancerous attributes of an anthraquinone, aloe-emodin (AE), against androgen-independent human prostate cancer DU145 cells. The cytotoxicity profiling of AE showed that it exerted significant cytotoxic effects and increased lactose dehydrogenase levels in DU145 cells (p < 0.01 and p < 0.001). AE also induced considerable reactive oxygen species (ROS)-mediated oxidative stress, which escalated at higher AE concentrations of 20 and 25 μM. AE also efficiently instigated nuclear fragmentation and condensation concomitantly, followed by the activation of caspase-3 and -9 within DU145 cells. AE further reduced the viability of mitochondria with increased cytosolic cytochrome-c levels (p < 0.01 and p < 0.001) in DU145 cells. Importantly, AE exposure was also correlated with reduced Wnt2 and β-catenin mRNA levels along with their target genes, including cyclin D1 and c-myc. Furthermore, the molecular mechanism of AE was evaluated by performing molecular docking studies with Wnt2 and β-catenin. Evidently, AE exhibited good binding energy scores toward Wnt2 and β-catenin comparable with their respective standards, CCT036477 (Wnt2 inhibitor) and FH535 (β-catenin inhibitor). Thus, it may be considered that AE was competent in exerting anti-growth effects against DU145 androgen-independent prostate cancer cells plausibly by modulating the expression of Wnt/β-catenin signaling.

Osmundacetone Inhibits Angiogenesis of Infantile Hemangiomas through Inducing Caspases and Reducing VEGFR2/MMP9

AIM

This study aims to explore the potential of Osmundacetone (OSC) as a new treatment for infantile hemangiomas (IH), the most common benign tumors in infancy. Currently, propranolol serves as the primary treatment for IH, but its effectiveness is limited, and it poses challenges of drug resistance and side effects. Therefore, there is a pressing need to identify alternative therapies for IH.

METHODS

The effects of OSC on the proliferation and apoptosis of HemECs (endothelial cells from hemangiomas) were assessed using CCK-8 assay, colony formation assay, HOCHEST 33342 staining, and flow cytometry. Western blot analysis was performed to investigate OSC's influence on Caspases and angiogenesis-related proteins. Animal models were established using HemECs and BALB/c mice, and histological and immunohistochemical staining were conducted to evaluate the impact of OSC on mouse hemangiomas, VEGFR2, and MMP9 expression.

RESULTS

OSC treatment significantly reduced HemECs' viability and colony-forming ability, while promoting apoptosis, as indicated by increased HOCHEST 33342 staining. OSC upregulated the protein expression of Bax, PARP, Caspase9, Caspase3, AIF, Cyto C, FADD, and Caspase8 in HemECs. In animal models, OSC treatment effectively reduced hemangioma size and improved histopathological changes. OSC also suppressed VEGFR2 and MMP9 expression while elevating Caspase3 levels in mouse hemangiomas.

CONCLUSION

OSC demonstrated promising results in inhibiting HemECs' proliferation, inducing apoptosis, and ameliorating pathological changes in hemangiomas in mice. Moreover, it influenced the expression of crucial caspases and angiogenesis-related proteins. These findings suggest that OSC holds potential as a novel drug for clinical treatment of IH.

Combined RhoA morpholino and ChABC treatment protects identified lamprey neurons from retrograde apoptosis after spinal cord injury

Previously, we reported that RhoA knockdown by morpholino antisense oligonucleotides (MOs), and enzymatic digestion of chondroitin sulfate proteoglycans (CSPGs) at the site of injury with chondroitinase ABC (ChABC), each can reduce retrograde neuronal apoptosis after spinal cord transection in the lamprey. To elucidate the mechanisms in neuronal survival and axon regeneration, we have investigated whether these two effects are additive in vivo. We used lampreys as a spinal cord injury model. MOs were used to knockdown RhoA and Chondroitinase ABC (ChABC) was used to digest CSPGs in vivo. Retrograde labeling, fluorochrome-labeled inhibitor of caspase activity (FLICA), immunohistochemistry, and western blots were performed to assess axonal regeneration, neuronal apoptotic signaling and Akt activation. Four treatment combinations were evaluated at 2-, 4-, and 10-weeks post-transection: (1) Control MO plus enzyme buffer (Ctrl); (2) control MO plus ChABC; (3) RhoA MO plus enzyme buffer (RhoA MO); and (4) RhoA MO plus ChABC (RhoA MO + ChABC). Consistent with our previous findings, at 4-weeks post-transection, there was less caspase activation in the ChABC and RhoA MO groups than in the Ctrl group. Moreover, the RhoA MO plus ChABC group had the best protective effect on identified reticulospinal (RS) neurons among the four treatment combinations. At 2 weeks post-transection, when axons have retracted maximally in the rostral stump and are beginning to regenerate back toward the lesion, the axon tips in the three treatment groups each were closer to the transection than those in the Ctr MO plus enzyme buffer group. Long-term axon regeneration also was evaluated for the large, individually identified RS neurons at 10 weeks post-transection by retrograde labeling. The percent regenerated axons in the RhoA MO plus ChABC group was greater than that in any of the other groups. Akt phosphorylation levels at threonine 308 was quantified in the identified RS neurons by western blots and immunofluorescence. The RhoA MO plus ChABC treatment enhanced pAkt-308 phosphorylation more than any of the other treatment groups. Although some of the effects of CSPGs are mediated through RhoA activation, some growth-inhibiting mechanisms of RhoA and CSPGs are independent of each other, so combinatorial therapies may be warranted.

Anti-Proliferative and Apoptotic Activities of Rumex crispus

Colorectal cancer is the fourth leading cause of cancer death and the third most common cancer diagnosed in the United States. Several anticancer compounds from natural products have been of great interest in cancer chemotherapy and are currently in clinical trials. Natural products that present the targeted killing of cancerous cell and are soluble in water with minimal side effects are ideal candidates. In this study, water-soluble compounds from Rumex crispus plants were screened for anti-proliferative and apoptotic activity against human colorectal adenocarcinoma (DLD-1) cells. The most potent fraction with the highest cell killing and caspase fold change rates was selected for further experiments. The observed changes were further validated by measuring the caspase fold change using RT-qPCR. Furthermore, gene transcript levels were evaluated using an RT2 Profiler assay and a microarray experiment. Our results showed that the most potent L19 fraction exhibits anti-proliferative activity in a dose-dependent manner. The L19 fraction was found to induce apoptotic pathways by triggering different caspases and inflammatory pathways through the activation of non-apoptotic genes. Our study identified and validated the anticancer property of the L19 fraction, which can serve as a strong lead compound for the synthesis of other novel potent analogues.

Discriminating Between Apoptosis, Necrosis, Necroptosis, and Ferroptosis by Microscopy and Flow Cytometry

Apoptosis is a mode of programmed cell death that plays important roles in tissue sculpting during development, in the maintenance of tissue homeostasis in the adult, and in the eradication of injured or infected cells during pathological processes. Numerous physiological as well as pathological stimuli trigger apoptosis, such as engagement of plasma-membrane-associated Fas, TRAIL, or TNF receptors, growth factor deprivation, hypoxia, radiation, and exposure to diverse cytotoxic drugs. Apoptosis is coordinated by members of the caspase family of cysteine proteases, which, upon activation, trigger a series of dramatic morphological and biochemical changes including retraction from the substratum, cell shrinkage, extensive and protracted plasma membrane blebbing, chromatin condensation, DNA hydrolysis, nuclear fragmentation, and proteolytic cleavage of numerous caspase substrates. These dramatic structural and biochemical alterations result not only in the controlled dismantling of the cell, but also in the rapid recognition and removal of apoptotic cells by phagocytes through the cell surface display of phagocytotic triggers such as phosphatidylserine. Necrosis, which is typically nonprogrammed or imposed upon the cell by overwhelming membrane or organelle damage, is characterized by high-amplitude cell swelling, followed by rapid plasma membrane rupture and release of cellular contents into the extracellular space. Necrosis is often provoked by infectious agents or severe departure from physiological conditions due to toxins, temperature extremes, or physical injury. However, forms of programmed necrosis (necroptosis, pyroptosis, ferroptosis) can also occur in specific circumstances. Nonprogrammed and programmed necrosis can be distinguished from apoptosis by morphological features, based on the rapid uptake of vital dyes, and through the application of specific inhibitors of key molecules associated with the latter modes of cell death. This unit describes protocols for the measurement of apoptosis and necrosis and for distinguishing apoptosis from programmed as well as conventional necrosis. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Analysis of cell morphology by phase-contrast microscopy Alternative Protocol 1: Assessment of morphological changes using eosin-methylene blue staining Alternative Protocol 2: Analysis of nuclear morphology by fluorescence microscopy Support Protocol: Preparation of cytospins Basic Protocol 2: Measurement of plasma membrane composition with annexin V and propidium iodide Basic Protocol 3: Measurement of DNA fragmentation by flow cytometry Alternative Protocol 3: Analysis of DNA fragmentation by the TUNEL assay Basic Protocol 4: Measurement of caspase activation by flow cytometry Basic Protocol 5: Discriminating between apoptosis, necrosis, necroptosis, and ferroptosis.

An oral caspase inhibitor as monotherapy or with antibiotics eradicates MRSA skin infections in mice

Staphylococcus aureus is the leading cause of skin and soft tissue infections. With the emergence of antibiotic-resistant bacteria, there is an unmet clinical need to develop immune-based therapies to treat skin infections. Previously, we have shown pan-caspase inhibition as a potential host-directed immunotherapy against community-acquired methicillin-resistant S aureus (CA-MRSA) and other bacterial skin infections. Here, we evaluated the role of irreversible pan-caspase inhibitor emricasan as a monotherapy and an adjunctive with a standard-of-care antibiotic, doxycycline, as potential host-directed immunotherapies against S. aureus skin infections in vivo. We used the established CA-MRSA strain USA300 on the dorsum of WT C57BL/6J mice and monitored lesion size and bacterial burden noninvasively, and longitudinally over 14 days with in vivo bioluminescence imaging (BLI). Mice in four groups placebo (0.5% carboxymethyl cellulose [CMC] solution), placebo plus doxycycline (100 mg/kg), emricasan (40 mg/kg) plus doxycycline, and emricasan only were treated orally twice daily by oral gavage for 7 days, starting at 4 h after injection of S aureus. When compared with placebo, all three groups, placebo plus doxycycline, emricasan plus doxycycline, and emricasan treated group, exhibited biological effect, with reduction of both the lesion size (*p = .0277, ****p < .0001, ****p < .0001, respectively) and bacterial burden (***p = .003, ****p < .0001, ****p < .0001, respectively). Importantly, the efficacy of emricasan against S. aureus was not due to direct antibacterial activity. Collectively, pan-caspase inhibitor emricasan and emricasan plus doxycycline reduced both the lesion size and bacterial burden in vivo, and emricasan is a potential host-directed immunotherapy against MRSA skin infections in a preclinical mouse model.

Embelin inhibits viability of cutaneous T cell lymphoma cell lines HuT78 and H9 by targeting inhibitors of apoptosis

Cutaneous T cell lymphoma (CTCL) is a varied group of neoplasms that affects the skin. Acquired resistance against chemotherapeutic drugs and associated toxic side effects are limitations that warrant search for novel drugs against CTCL. Embelin (EMB) is a naturally occurring benzoquinone derivative that has gained attention owing to its anticancer pharmacological actions and nontoxic nature. We assessed the anticancer activity of EMB against CTCL cell lines, HuT78, and H9. EMB inhibited viability of CTCL cells in a dose-dependent manner. EMB activated extrinsic and intrinsic pathways of apoptosis as shown by the activation of initiator and executioner caspases. EMB-induced apoptosis also involved suppression of inhibitors of apoptosis, XIAP, cIAP1, and cIAP2. PARP cleavage and upregulation of pH2AX indicated DNA damage induced by EMB. In conclusion, we characterized a novel apoptosis-inducing activity of EMB against CTCL cells, implicating EMB as a potential therapeutic agent against CTCL.

Streptococcus pyogenes emm98.1 variants activate inflammatory caspases in human neutrophils

ABBREVIATIONS

CovRS, control of virulence regulatory system; GAS, Group A Streptococcus; PMN, polymorphonuclear leukocyte.

Recent updates on pyroptosis in tumors of the digestive tract

Pyroptosis is an inflammasome-dependent form of programmed cell death that is mediated by caspases-1, -4, -5, and -11, and the gasdermin protein family. It is characterized by the rupture of cell membrane and the subsequent release of cell contents and interleukins, leading to inflammatory reaction and activation of the immune system. Recent studies have suggested that pyroptosis plays a role in the development of gastrointestinal tumors, impeding tumor generation and progression as well as providing a favorable microenvironment for tumor growth. In this review we outlined the current knowledge regarding the implications of pyroptosis in gastrointestinal cancers.

In Vitro Cytotoxic Effects of Ferruginol Analogues in Sk-MEL28 Human Melanoma Cells

Ferruginol is a promising abietane-type antitumor diterpene able to induce apoptosis in SK-Mel-28 human malignant melanoma. We aim to increase this activity by testing the effect of a small library of ferruginol analogues. After a screening of their antiproliferative activity (SRB staining, 48 h) on SK-Mel-28 cells the analogue 18-aminoferruginol (GI50 ≈ 10 µM) was further selected for mechanistic studies including induction of apoptosis (DAPI staining, p < 0.001), changes in cell morphology associated with the treatment (cell shrinkage and membrane blebbing), induction of caspase-3/7 activity (2.5 at 48 h, 6.5 at 72 h; p < 0.0001), changes in the mitochondrial membrane potential (not significant) and in vitro effects on cell migration and cell invasion (Transwell assays, not significant). The results were compared to those of the parent molecule (ferruginol, GI50 ≈ 50 µM, depolarisation of mitochondrial membrane p < 0.01 at 72 h; no caspases 3/7 activation) and paclitaxel (GI50 ≈ 10 nM; caspases 3/7 activation p < 0.0001) as a reference drug. Computational studies of the antiproliferative activity of 18-aminoferruginol show a consistent improvement in the activity over ferruginol across a vast majority of cancer cells in the NCI60 panel. In conclusion, we demonstrate here that the derivatisation of ferruginol into 18-aminoferruginol increases its antiproliferative activity five times in SK-MEL-28 cells and changes the apoptotic mechanism of its parent molecule, ferruginol.

Placentas from Women with Late-Onset Preeclampsia Exhibit Increased Expression of the NLRP3 Inflammasome Machinery

Pre-eclampsia is a harmful and potentially lethal medical condition during pregnancy clinically diagnosed by hypertension and commonly accompanied by proteinuria and multiorgan affections. According to the time of diagnosis, it is differentiated between early-onset (EO-PE) and late-onset preeclampsia (LO-PE). Despite being less dangerous and presenting distinct pathophysiological signatures, LO-PE has a greater prevalence than EO-PE, both having significant consequences on the placenta. Previous works have evidenced that exacerbated inflammation in this organ might play a potential pathogenic role in the development of pre-eclampsia, and there is some preliminary evidence that the hyperactivation of inflammasomes can be related to the altered immunoinflammatory responses observed in the placentas of these patients. However, the precise role of inflammasomes in the placentas of women with LO-PE remains to be fully understood. In this work, we have studied the gene and protein expression of the main components related to the canonical and non-canonical pathways of the inflammasome NLRP3 (NLRP3, ASC, caspase 1, caspase 5, caspase 8, interleukin 1β, and interleukin 18) in the placental tissue of women with LO-PE. Our results show a marked increase in all these components in the placentas of women who have undergone LO-PE, suggesting that NLRP3 inflammasome plays a potentially pathophysiological role in the development of this entity. Future works should aim to evaluate possible translational approaches to this dysregulation in these patients.

[Corrigendum] Antiproliferative effect of alpinetin in BxPC-3 pancreatic cancer cells

Following the publication of the above article, an interested reader drew to the authors' attention that, for the western blots shown in Fig. 4 on p. 610, the two leftmost bands shown for the Bax data in Fig. 4A were strikingly similar to the two rightmost Mito Cyt C bands featured in Fig. 4C. The authors have checked their original data, and realized that these data were assembled incorrectly in this figure. The revised version of Fig. 4 is shown below, now featuring the correct Bax data in Fig. 4A. The authors confirm that the errors associated with this figure did not have any significant impact on either the results or the conclusions reported in this study, and are grateful to the Editor of International Journal of Molecular Medicine for allowing them the opportunity to publish this Corrigendum. Furthermore, they apologize to the readership of the Journal for any inconvenience caused. [International Journal of Molecular Medicine 29: 607-612, 2012; DOI: 10.3892/ijmm.2012.884].

Cell organelles are retained inside pyroptotic corpses during inflammatory cell death

Many proinflammatory proteins are released via the necrotic form of cell death known as pyroptosis. Sometimes known as gasdermin D (GSDMD) dependent cell death, pyroptosis results from the formation of pores in the plasma membrane leading to eventual cell lysis. Seeking to understand the magnitude of this cell lysis we measured the size of proteins released during pyroptosis. We demonstrate that there is no restriction on the size of soluble proteins released during pyroptosis even at early timepoints. However, even though large molecules can exit the dying cell, organelles are retained within it. This observation indicates that complete cell rupture may not be a consequence of pyroptosis, and that plasma membrane architecture is retained.

Methotrexate-conjugated zinc oxide nanoparticles exert a substantially improved cytotoxic effect on lung cancer cells by inducing apoptosis

In the current study, we report the synthesis of methotrexate-conjugated zinc oxide nanoparticles (MTX-ZnONPs) and their high efficacy against lung cancer cells. Conjugation of MTX with ZnONPs was authenticated by UV-vis spectroscopy, dynamic light scattering (DLS), Fourier-transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). This drug-nanoconjugate also showed high drug-loading efficiency. The therapeutic efficacy of MTX-ZnONPs was further tested in vitro against A549 cells, and the results of MTT and LDH release assays showed that MTX-ZnONPs, in addition to free MTX, were efficient in exerting cytotoxic effect on A549 cells; however, the effectiveness of MTX-ZnONPs was found to be considerably enhanced at very low doses compared to that of free MTX. Moreover, ZnONPs alone significantly inhibited the cell viability of A549 cells at a much higher concentration compared to MTX-ZnONPs and MTX. Furthermore, the cytomorphology of A549 cells was characterized by cellular shrinkage and detachment from the surface in all the treatment groups. Similarly, A549 cells, in all the treatment groups, showed fragmented and condensed nuclei, indicating the initiation of apoptosis. Mitochondrial membrane potential (ψm) in A549 cells showed a gradual loss in all the treatment groups. Results of the qualitative and quantitative analyses depicted increased reactive oxygen species (ROS) levels in A549 cells. The results of the caspase activity assay showed that MTX-ZnONPs andfree MTX caused significant activation of caspase-9, -8, and -3 in A549 cells; however, the effect of MTX-ZnONPs was more profound at very low doses compared to that of free MTX. Thus, our results showed high efficacy of MTX-ZnONPs, suggesting efficient intracellular delivery of the drug by ZnONPs as nanocarriers.

6-Hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline Demonstrates Anti-Inflammatory Properties and Reduces Oxidative Stress in Acetaminophen-Induced Liver Injury in Rats

We examined the effects of 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline on markers of liver injury, oxidative status, and the extent of inflammatory and apoptotic processes in rats with acetaminophen-induced liver damage. The administration of acetaminophen caused the accumulation of 8-hydroxy-2-deoxyguanosine and 8-isoprostane in the liver and serum, as well as an increase in biochemiluminescence indicators. Oxidative stress resulted in the activation of pro-inflammatory cytokine and NF-κB factor mRNA synthesis and increased levels of immunoglobulin G, along with higher activities of caspase-3, caspase-8, and caspase-9. The administration of acetaminophen also resulted in the development of oxidative stress, leading to a decrease in the level of reduced glutathione and an imbalance in the function of antioxidant enzymes. This study discovered that 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline reduced oxidative stress by its antioxidant activity, hence reducing the level of pro-inflammatory cytokine and NF-κB mRNA, as well as decreasing the concentration of immunoglobulin G. These changes resulted in a reduction in the activity of caspase-8 and caspase-9, which are involved in the activation of ligand-induced and mitochondrial pathways of apoptosis and inhibited the effector caspase-3. In addition, 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline promoted the normalization of antioxidant system function in animals treated with acetaminophen. As a result, the compound being tested alleviated inflammation and apoptosis by decreasing oxidative stress, which led to improved liver marker indices and ameliorated histopathological alterations.

Molecular mechanism of Enteroaggregative Escherichia coli induced apoptosis in cultured human intestinal epithelial cells

Background. Enteroaggregative Escherichia coli (EAEC) is an evolving etiological agent of acute and persistent diarrhoea worldwide. The previous study from our laboratory has reported the apoptosis-inducing activity of EAEC in human small intestinal and colonic epithelial cell lines. In the present investigation, we have explored the underlying mechanism of EAEC-induced apoptosis in human intestinal epithelial cell lines.Methods. INT-407 and HCT-15 cells were infected with EAEC-T8 and EAEC-pT8 (plasmid cured strain of EAEC-T8) separately. Cells cultured in the absence of bacteria served as a negative control in all the experiments. For the subsequent experiments, the molecular mechanism(s) of epithelial cell aposptosis was measured in EAEC infecting both the cell lines by flow cytometry, real-time PCR and Western blotting.Results and conclusions. EAEC was found to activate the intrinsic/mitochondrial apoptotic pathway in both the cell lines through upregulation of pro-apoptotic Bax and Bak, un-alteration/reduction in the level of anti-apoptotic Bcl-2 and Bcl-XL, decrease in mitochondrial transmembrane potential, accumulation of cytosolic cytochrome c leading to activation of procaspase-9 and procaspase-3, which ultimately resulted in DNA fragmentation and apoptosis. Further, an increased expression of Fas, activation of procaspase-8 and upregulation of pro-apoptotic Bid in the EAEC-infected cells indicated the involvement of extrinsic apoptotic pathway too in this process. Our finding has undoubtedly led to an increased understanding of EAEC pathogenesis, which may be helpful to develop an improved strategy to combat the infection.

Dual-targeting peptides@PMO, a mimetic to the pro-apoptotic protein Smac/DIABLO for selective activation of apoptosis in cancer cells

The refractoriness of tumor cells to apoptosis represents the main mechanism of resistance to chemotherapy. Smac/DIABLO mimetics proved to be effective in overcoming cancer-acquired resistance to apoptosis as a consequence of overexpression of the anti-apoptotic proteins XIAP, cIAP1, and cIAP2. In this work, we describe a dual-targeting peptide capable of selectively activating apoptosis in cancer cells. The complex consists of a fluorescent periodic mesoporous organosilica nanoparticle that carries the short sequences of Smac/DIABLO bound to the αvβ3-integrin ligand. The dual-targeting peptide @PMO shows significantly higher toxicity in αvβ3-positive HeLa cells with respect to αvβ3-negative Ht29 cells. @PMO exhibited synergistic effects in combination with oxaliplatin in a panel of αvβ3-positive cancer cells, while its toxicity is overcome by XIAP overexpression or integrin β3 silencing. The successful uptake of the molecule by αvβ3-positive cells makes @PMO promising for the re-sensitization to apoptosis of many cancer types.

Research Progress of Pyroptosis in Fatty Liver Disease

Fatty liver disease (FLD) is a clinical and pathological syndrome characterized by excessive fat deposition and even steatosis in hepatocytes. It has been proven that liver inflammation induced by fat and its derivatives are involved in the pathogenesis of FLD, while the precise mechanism still remains poorly understood. Pyroptosis is programmed inflammatory cell death driving cell swelling and membrane rupture. Pyroptosis is initiated by the activation of inflammasomes and caspases, which further cleaves and activates various gasdermins, leading to pores forming on the cell membrane and the release of pro-inflammatory factors such as interleukin (IL)-1β and IL-18. Recent studies demonstrate that pyroptosis occurs in hepatocytes, and inhibiting pyroptosis could effectively reduce fat deposition in the liver and could ameliorate inflammation from FLD, attracting our prime focus on the role of pyroptosis in FLD. In this manuscript, we reviewed the current understanding of pyroptosis in FLD development, aiming to provide new insights and potential research targets for the clinical diagnosis and intervention of FLD.

Cytotoxicity Analysis and In Silico Studies of Three Plant Extracts with Potential Application in Treatment of Endothelial Dysfunction

Endothelial dysfunction is the basis of the physiopathological mechanisms of vascular diseases. In addition to the therapeutic activity of plant extracts, cytotoxicity is significant. This research evaluates the cytotoxicity of three vegetal extracts (Calendulae flos extract-CE, Ginkgo bilobae folium extract-GE, and Sophorae flos extract-SE). In vitro evaluation was performed using an endothelial cell line model (Human Pulmonary Artery Endothelial Cells-HPAEC) when a dose-dependent cytotoxic activity was observed after 72 h. The IC50 values were calculated for all extracts: Calendulae flos extract (IC50 = 91.36 μg/mL), Sophorae flos extract (IC50 = 68.61 μg/mL), and Ginkgo bilobae folium extract (IC50 = 13.08 μg/mL). Therefore, at the level of HPAEC cells, the cytotoxicity of the extracts follows the order GE > SE > CE. The apoptotic mechanism implied in cell death was predicted for several phytocompounds using the PASS algorithm and molecular docking simulations, highlighting potential interactions with caspases-3 and -8. In vivo analysis was performed through brine shrimp lethality assay (BSLA) when lethal, behavioral, and cytological effects were evaluated on Artemia salina larvae. The viability examined after 24 h (assessment of lethal effects) follows the same sequence: CE > SE > GE. In addition, the predicted cell permeability was observed mainly for GE constituents through in silico studies. However, the extracts can be considered nontoxic according to Clarckson's criteria because no BSL% was registered at 1200 µg/mL. The obtained data reveal that all three extracts are safe for human use and suitable for incorporation in further pharmaceutical formulations.

Ultraviolet Radiation-Induced Mitochondrial Disturbances Are Attenuated by Metabolites of Melatonin in Human Epidermal Keratinocytes

Melatonin (N-acetyl-5-methoxytryptamine) is recognized as an effective antioxidant produced by the pineal gland, brain and peripheral organs, which also has anti-inflammatory, immunomodulatory, and anti-tumour capacities. Melatonin has been reported as a substance that counteracts ultraviolet radiation B (UVB)-induced intracellular disturbances. Nevertheless, the mechanistic actions of related molecules including its kynurenic derivatives (N1-acetyl-N2-formyl-5-methoxykynurenine (AFMK)), its indolic derivatives (6-hydroxymelatonin (6(OH)MEL) and 5-methoxytryptamine (5-MT)) and its precursor N-acetylserotonin (NAS) are only poorly understood. Herein, we treated human epidermal keratinocytes with UVB and assessed the protective effect of the studied substances in terms of the maintenance of mitochondrial function or their radical scavenging capacity. Our results show that UVB caused the significant elevation of catalase (CAT) and superoxide dismutase (Mn-SOD), the dissipation of mitochondrial transmembrane potential (mtΔΨ), a reduction in ATP synthesis, and the enhanced release of cytochrome c into cytosol, leading subsequently to UVB-mediated activation of the caspases and apoptosis (appearance of sub-G1 population). Our findings, combined with data reported so far, indicate the counteracting and beneficial actions of melatonin and its molecular derivatives against these deleterious changes within mitochondria. Therefore, they define a path to the development of novel strategies delaying mitochondrial aging and promoting the well-being of human skin.

A Potential Effect of Circadian Rhythm in the Delivery/Therapeutic Performance of Paclitaxel-Dendrimer Nanosystems

The circadian clock controls behavior and physiology. Presently, there is clear evidence of a connection between this timing system and cancer development/progression. Moreover, circadian rhythm consideration in the therapeutic action of anticancer drugs can enhance the effectiveness of cancer therapy. Nanosized drug delivery systems (DDS) have been demonstrated to be suitable engineered platforms for drug targeted/sustained release. The investigation of the chronobiology-nanotechnology relationship, i.e., timing DDS performance according to a patient's circadian rhythm, may greatly improve cancer clinical outcomes. In the present work, we synthesized nanosystems based on an octa-arginine (R8)-modified poly(amidoamine) dendrimer conjugated with the anticancer drug paclitaxel (PTX), G4-PTX-R8, and its physicochemical properties were revealed to be appropriate for in vitro delivery. The influence of the circadian rhythm on its cellular internalization efficiency and potential therapeutic effect on human cervical cancer cells (HeLa) was studied. Cell-internalized PTX and caspase activity, as a measure of induced apoptosis, were monitored for six time points. Higher levels of PTX and caspase-3/9 were detected at T8, suggesting that the internalization of G4-PTX-R8 into HeLa cells and apoptosis are time-specific/-regulated phenomena. For a deeper understanding, the clock protein Bmal1-the main regulator of rhythmic activity, was silenced by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technology. Bmal1 silencing was revealed to have an impact on both PTX release and caspase activity, evidencing a potential role for circadian rhythm on drug delivery/therapeutic effect mediated by G4-PTX-R8.

Regulators mount up: the metabolic roles of apoptotic proteins

The induction of apoptosis, a programmed cell death pathway governed by activation of caspases, can result in fundamental changes in metabolism that either facilitate or restrict the execution of cell death. In addition, metabolic adaptations can significantly impact whether cells in fact initiate the apoptotic cascade. In this mini-review, we will highlight and discuss the interconnectedness of apoptotic regulation and metabolic alterations, two biological outcomes whose regulators are intertwined.

In Vitro Assessment of the Synergistic Effect of Aspirin and 5-Fluorouracil in Colorectal Adenocarcinoma Cells

Although remarkable progress has been made, colorectal cancer remains a significant global health issue. One of the most challenging aspects of cancer treatment is the resistance of tumor cells to classical chemotherapy. Conventional therapy for colorectal cancer often involves the use of 5-fluorouracil as a chemotherapeutic agent. Aspirin, a drug used primarily to prevent cardiovascular complications, became a focus of attention due to its potential use as an antitumor agent. The purpose of the study was to evaluate the potential synergistic cytotoxic effects of aspirin and 5-fluorouracil on colorectal adenocarcinoma cells. The viability of cells, the impact on the morphology and nuclei of cells, the potential antimigratory effect, and the impact on the expression of the major genes associated with cell apoptosis (Bcl-2, Bax, Bad), as well as caspases 3 and 8, were evaluated. The results indicated that the two compounds exerted a synergistic effect, causing a reduction in cell viability accompanied by changes characteristic of the apoptosis process-the condensation of nuclei and the reorganization of actin filaments in cells, the reduction in the expression of the Bcl-2 gene, and the increase in the expression of Bax and Bad genes, along with caspases 3 and 8. Considering all these findings, it appears that aspirin may be investigated in depth in order to be used in conjunction with 5-fluorouracil to increase antitumor activity.

Cell death checkpoints in the TNF pathway

Tumor necrosis factor (TNF) plays a central role in orchestrating mammalian inflammatory responses. It promotes inflammation either directly by inducing inflammatory gene expression or indirectly by triggering cell death. TNF-mediated cell death-driven inflammation can be beneficial during infection by providing cell-extrinsic signals that help to mount proper immune responses. Uncontrolled cell death caused by TNF is instead highly detrimental and is believed to cause several human autoimmune diseases. Death is not the default response to TNF sensing. Molecular brakes, or cell death checkpoints, actively repress TNF cytotoxicity to protect the organism from its detrimental consequences. These checkpoints therefore constitute essential safeguards against inflammatory diseases. Recent advances in the field have revealed the existence of several new and unexpected brakes against TNF cytotoxicity and pathogenicity.

Perezone and its phenyl glycine derivative induce cytotoxicity via caspases on human glial cancer cells

The new phenyl glycine derivative of perezone was obtained in a single reaction step in ca. 80% yield which showed remarkable cytotoxic activity against the astrocytoma U-251 cell line. After 24 h of exposure, both perezone (IC₅₀ = 6.83 ± 1.64 µM) and its phenyl glycine derivative (2.60 ± 1.69 µM) showed cytotoxic effect on U-251 cells but were five times less cytotoxic on the non-tumoral SVGp12 cell line (IC₅₀ = 28.54 ± 1.59 and 31.87 ± 1.54 µM respectively). Both compounds induced cellular morphological changes (pyknosis or cytoplasmic vacuolization) and increased the expression of caspases 3, 8, and 9 genes related to apoptosis. In the acute toxicity study, phenyl glycine perezone (DL₅₀ = 2000 mg/Kg) demonstrated to be less toxic than perezone (DL₅₀ = 500 mg/Kg). Phenylglycine-perezone can envisage a beneficial therapeutic potential.

Non-apoptotic caspase activation ensures the homeostasis of ovarian somatic stem cells

Current evidence has associated caspase activation with the regulation of basic cellular functions without causing apoptosis. Malfunction of non-apoptotic caspase activities may contribute to specific neurological disorders, metabolic diseases, autoimmune conditions and cancers. However, our understanding of non-apoptotic caspase functions remains limited. Here, we show that non-apoptotic caspase activation prevents the intracellular accumulation of the Patched receptor in autophagosomes and the subsequent Patched-dependent induction of autophagy in Drosophila follicular stem cells. These events ultimately sustain Hedgehog signalling and the physiological properties of ovarian somatic stem cells and their progeny under moderate thermal stress. Importantly, our key findings are partially conserved in ovarian somatic cells of human origin. These observations attribute to caspases a pro-survival role under certain cellular conditions.

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.

Pro-Apoptotic Activity and Cell Cycle Arrest of Caulerpa sertularioides against SKLU-1 Cancer Cell in 2D and 3D Cultures

Cancer is a disease with the highest mortality and morbidity rate worldwide. First-line drugs induce several side effects that drastically reduce the quality of life of people with this disease. Finding molecules to prevent it or generate less aggressiveness or no side effects is significant to counteract this problem. Therefore, this work searched for bioactive compounds of marine macroalgae as an alternative treatment. An 80% ethanol extract of dried Caulerpa sertularioides (CSE) was analyzed by HPLS-MS to identify the chemical components. CSE was utilized through a comparative 2D versus 3D culture model. Cisplatin (Cis) was used as a standard drug. The effects on cell viability, apoptosis, cell cycle, and tumor invasion were evaluated. The IC₅₀ of CSE for the 2D model was 80.28 μg/mL versus 530 μg/mL for the 3D model after 24 h of treatment exposure. These results confirmed that the 3D model is more resistant to treatments and complex than the 2D model. CSE generated a loss of mitochondrial membrane potential, induced apoptosis by extrinsic and intrinsic pathways, upregulated caspases-3 and -7, and significantly decreased tumor invasion of a 3D SKLU-1 lung adenocarcinoma cell line. CSE generates biochemical and morphological changes in the plasma membrane and causes cell cycle arrest at the S and G2/M phases. These findings conclude that C. sertularioides is a potential candidate for alternative treatment against lung cancer. This work reinforced the use of complex models for drug screening and suggested using CSE's primary component, caulerpin, to determine its effect and mechanism of action on SKLU-1 in the future. A multi-approach with molecular and histological analysis and combination with first-line drugs must be included.

In Vitro Cytotoxic Effect of Aqueous Extracts from Leaves and Rhizomes of the Seagrass Posidonia oceanica (L.) Delile on HepG2 Liver Cancer Cells: Focus on Autophagy and Apoptosis

Aqueous extracts from Posidonia oceanica's green and brown (beached) leaves and rhizomes were prepared, submitted to phenolic compound and proteomic analysis, and examined for their potential cytotoxic effect on HepG2 liver cancer cells in culture. The chosen endpoints related to survival and death were cell viability and locomotory behavior, cell-cycle analysis, apoptosis and autophagy, mitochondrial membrane polarization, and cell redox state. Here, we show that 24 h exposure to both green-leaf- and rhizome-derived extracts decreased tumor cell number in a dose-response manner, with a mean half maximal inhibitory concentration (IC₅₀) estimated at 83 and 11.5 μg of dry extract/mL, respectively. Exposure to the IC₅₀ of the extracts appeared to inhibit cell motility and long-term cell replicating capacity, with a more pronounced effect exerted by the rhizome-derived preparation. The underlying death-promoting mechanisms identified involved the down-regulation of autophagy, the onset of apoptosis, the decrease in the generation of reactive oxygen species, and the dissipation of mitochondrial transmembrane potential, although, at the molecular level, the two extracts appeared to elicit partially differentiating effects, conceivably due to their diverse composition. In conclusion, P. oceanica extracts merit further investigation to develop novel promising prevention and/or treatment agents, as well as beneficial supplements for the formulation of functional foods and food-packaging material with antioxidant and anticancer properties.

Caspases help to spread the message via extracellular vesicles

Cell-cell communication is an essential aspect of multicellular life, key for coordinating cell proliferation, growth, and death in response to environmental changes. Whilst caspases are well-known for facilitating apoptotic and pyroptotic cell death, several recent investigations are uncovering new roles for these enzymes in biological scenarios requiring long-range intercellular signalling mediated by extracellular vesicles (EVs). EVs are small membrane-bound nanoparticles released from cells that may carry and deliver cargo between distant cells, thus helping to coordinate their behaviour. Intriguingly, there is emerging evidence indicating a key contribution of caspases in the biogenesis of EVs, the selection of their cargo content, and EV uptake/function in recipient cells. Here, we discuss the latest findings supporting the interplay between caspases and EVs, and the biological relevance of this molecular convergence for cellular signalling, principally in non-apoptotic scenarios.

Inula viscosa (L.) Aiton Ethanolic Extract Inhibits the Growth of Human AGS and A549 Cancer Cell Lines

The present study shows the chemical profile and cytotoxic properties of the ethanolic extracts of Inula viscosa from Northeast Algeria. The extract was obtained by maceration using ethanol. Its phenolic profile was determined using ultra-high-performance liquid chromatography coupled with a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI/MS), which allowed the identification and quantification of 17 compounds, 1,5-O-caffeoylquinic acid being the most abundant. The cytotoxic activity was assessed against human gastric cancer (AGS) and human non-small-cell lung cancer (A549) cell lines, whereas ethanolic extract elicited nearly 60 % and 40 % viability loss toward AGS and A549 cancer cells, respectively. Results also showed that cell death is caspase-independent and confirmed the involvement of RIPK1 and the necroptosis pathway in the toxicity induced by the I. viscosa extract. In addition, the ethanolic extract would not provoke morphological traits in the cancer cells. These findings suggest that I. viscosa can be a source of new antiproliferative drugs or used in preparation plant-derived pharmaceuticals.

MLKL-Driven Inflammasome Activation and Caspase-8 Mediate Inflammatory Cell Death in Influenza A Virus Infection

Influenza A virus (IAV) triggers multiple programmed cell death pathways, including MLKL-dependent necroptosis, caspase-8-dependent apoptosis, and caspase-1-dependent pyroptosis in myeloid cells. All three pathways share common upstream regulators, namely, ZBP1 and RIPK3. Yet, the molecular mechanism underlying IAV-induced inflammasome activation remains unclear. Here, we demonstrate that MLKL promotes inflammasome activation and IL-1β processing in IAV-infected macrophages. MLKL drives NLRP3 inflammasome activation through potassium efflux. In the absence of the MLKL-inflammasome axis, caspase-8 coordinates the maturation and secretion of IL-1β. MLKL alone is dispensable for host inflammatory responses to IAV in vivo. Taken together, MLKL and caspase-8 serve as redundant mechanisms by which to drive an inflammatory form of cell death in response to an IAV infection. IMPORTANCE Influenza A virus (IAV) induces multiple types of cell death, which play important roles in the host antiviral responses but can also cause unwanted inflammation and tissue damage. In this study, we dissect the interplay of cell death pathways and demonstrate that macrophages utilize redundant mechanisms to drive an inflammatory form of cell death upon IAV infection. MLKL, the executor of necroptosis, promotes inflammasome activation and pyroptotic cell death. When the MLKL-inflammasome axis is inhibited, cells divert to caspase-8-dependent inflammatory cell death. Our findings advance the current understanding of the innate immune response to IAV infection as well as broader contexts involving multifaceted cell death.

Apoptotic Mechanisms of Quercetin in Liver Cancer: Recent Trends and Advancements

Due to rising incidence rates of liver cancer and worries about the toxicity of current chemotherapeutic medicines, the hunt for further alternative methods to treat this malignancy has escalated. Compared to chemotherapy, quercetin, a flavonoid, is relatively less harmful to normal cells and is regarded as an excellent free-radical scavenger. Apoptotic cell death of cancer cells caused by quercetin has been demonstrated by many prior studies. It is present in many fruits, vegetables, and herbs. Quercetin targets apoptosis, by upregulating Bax, caspase-3, and p21 while downregulating Akt, PLK-1, cyclin-B1, cyclin-A, CDC-2, CDK-2, and Bcl-2. Additionally, it has been reported to increase STAT3 protein degradation in liver cancer cells while decreasing STAT3 activation. Quercetin has a potential future in chemoprevention, based on substantial research on its anticancer effects. The current review discusses quercetin's mechanisms of action, nanodelivery strategies, and other potential cellular effects in liver cancer.

Mechanisms of Arachidonic Acid In Vitro Tumoricidal Impact

To promote the potential of arachidonic acid (ARA) for cancer prevention and management, experiments were implemented to disclose the mechanisms of its tumoricidal action. Hepatocellular, lung, and breast carcinoma and normal hepatocytes cell lines were exposed to 0 or 50 μM ARA for 30 min and then assessed for proliferative capacity, surface membrane-associated sphingomyelin (SM) content, neutral sphingomyelinase (nSMase) activity, beta 2 microglobulin (β2 m) expression, and ceramide (Cer) levels. Reactive oxygen species (ROS) content and caspase 3/7 activity were evaluated. Exposure to ARA for 30 min led to impairment of the tumor cells' proliferative capacity and revealed that the different cell lines display remarkably similar surface membrane SM content but diverse responses to ARA treatment. Arachidonic acid tumoricidal impact was shown to be associated with nSMase activation, exposure of cell surface membrane β2 m to antibody binding, and hydrolysis of SM to Cer, which accumulated on the cell surface and in the cytosol. The ARA and Cer-mediated inhibition of tumor cell viability appeared to be independent of ROS generation or caspase 3/7 activation. The data were compared and contrasted to findings reported in the literature on ARA tumoricidal mechanisms.

Impact of Enniatin B and Beauvericin on Lysosomal Cathepsin B Secretion and Apoptosis Induction

Enniatin B (ENN B) and Beauvericin (BEA) are cyclohexadepsipeptides that can be isolated from Fusarium and Beauveria bassiana, respectively. Both compounds are cytotoxic and ionophoric. In the present study, the mechanism of cell death induced by these compounds was investigated. Epidermal carcinoma-derived cell line KB-3-1 cells were treated with different concentrations of these compounds. The extracellular secretion of cathepsin B increased in a concentration-dependent manner, and the lysosomal staining by lysotracker red was reduced upon the treatment with any of the compounds. However, the extracellular secretion of cathepsin L and cathepsin D were not affected. Inhibition of cathepsin B with specific inhibitor CA074 significantly reduced the cytotoxic effect of both compounds, while inhibition of cathepsin D or cathepsin L did not influence the cytotoxic activities of both compounds. In vitro labelling of lysosomal cysteine cathepsins with Ethyl (2S, 3S)-epoxysuccinate-Leu-Tyr-Acp-Lys (Biotin)-NH2 (DCG04) was not affected in case of cathepsin L upon the treatment with both compounds, while it was significantly reduced in case of cathepsin B. In conclusion, ENN B and BEA increase lysosomal Ph, which inhibits delivery of cathepsin B from Golgi to lysosomes, thereby inducing cathepsin B release in cytosol, which activates caspases and hence the apoptotic pathway.

Anticancer agents incorporating the N-acylhydrazone scaffold: Progress from 2017 to present

The N-acylhydrazone motif has been shown to be particularly adaptable and promising in the area of medicinal chemistry and drug development, due to its significant biological and pharmacological characteristics. Moreover, N-acylhydrazones are appealing synthetic and biological tools because of their simple and straightforward synthesis. This scaffold has emerged as a fundamental building block for the synthesis of bioactive compounds. Particularly, the N-acylhydrazone scaffold served as a base for the synthesis of a number of potent anticancer agents acting via different mechanisms. An updated summary of the anticancer activity of N-acylhydrazone derivatives described in the literature (from 2017 to 2022) is provided in the current review. It discusses the structure-activity relationship (SAR) of N-acylhydrazone derivatives exhibiting anticancer potential, which could be helpful in designing and developing new derivatives as effective antiproliferative candidates in the future.

Making the head: Caspases in life and death

The term apoptosis, as a way of programmed cell death, was coined a half century ago and since its discovery the process has been extensively investigated. The anatomy and physiology of the head are complex and thus apoptosis has mostly been followed in separate structures, tissues or cell types. This review aims to provide a comprehensive overview of recent knowledge concerning apoptosis-related molecules involved in the development of structures of head with a particular focus on caspases, cysteine proteases having a key position in apoptotic pathways. Since many classical apoptosis-related molecules, including caspases, are emerging in several non-apoptotic processes, these were also considered. The largest organ of the head region is the brain and its development has been extensively investigated, including the roles of apoptosis and related molecules. Neurogenesis research also includes sensory organs such as the eye and ear, efferent nervous system and associated muscles and glands. Caspases have been also associated with normal function of the skin and hair follicles. Regarding mineralised tissues within craniofacial morphogenesis, apoptosis in bones has been of interest along with palate fusion and tooth development. Finally, the role of apoptosis and caspases in angiogenesis, necessary for any tissue/organ development and maintenance/homeostasis, are discussed. Additionally, this review points to abnormalities of development resulting from improper expression/activation of apoptosis-related molecules.

A Mixture of Dietary Plant Sterols at Nutritional Relevant Serum Concentration Inhibits Extrinsic Pathway of Eryptosis Induced by Cigarette Smoke Extract

Cell death program of red blood cells (RBCs), called eryptosis, is characterized by activation of caspases and scrambling of membrane phospholipids with externalization of phosphatidylserine (PS). Excessive eryptosis confers a procoagulant phenotype and is implicated in impairment of microcirculation and increased prothrombotic risk. It has recently been reported that cigarette smokers have high levels of circulating eryptotic erythrocytes, and a possible contribution of eryptosis to the vaso-occlusive complications associated to cigarette smoke has been postulated. In this study, we demonstrate how a mixture of plant sterols (MPtS) consisting of β-sitosterol, campesterol and stigmasterol, at serum concentration reached after ingestion of a drink enriched with plant sterols, inhibits eryptosis induced by cigarette smoke extract (CSE). Isolated RBCs were exposed for 4 h to CSE (10-20% v/v). When RBCs were co-treated with CSE in the presence of 22 µM MPtS, a significant reduction of the measured hallmarks of apoptotic death like assembly of the death-inducing signaling complex (DISC), PS outsourced, ceramide production, cleaved forms of caspase 8/caspase 3, and phosphorylated p38 MAPK, was evident. The new beneficial properties of plant sterols on CSE-induced eryptosis presented in this work open new perspectives to prevent the negative physio-pathological events caused by the eryptotic red blood cells circulating in smokers.

Vacuolar Processing Enzymes in Plant Programmed Cell Death and Autophagy

Vacuolar processing enzymes (VPEs) are plant cysteine proteases that are subjected to autoactivation in an acidic pH. It is presumed that VPEs, by activating other vacuolar hydrolases, are in control of tonoplast rupture during programmed cell death (PCD). Involvement of VPEs has been indicated in various types of plant PCD related to development, senescence, and environmental stress responses. Another pathway induced during such processes is autophagy, which leads to the degradation of cellular components and metabolite salvage, and it is presumed that VPEs may be involved in the degradation of autophagic bodies during plant autophagy. As both PCD and autophagy occur under similar conditions, research on the relationship between them is needed, and VPEs, as key vacuolar proteases, seem to be an important factor to consider. They may even constitute a potential point of crosstalk between cell death and autophagy in plant cells. This review describes new insights into the role of VPEs in plant PCD, with an emphasis on evidence and hypotheses on the interconnections between autophagy and cell death, and indicates several new research opportunities.

CcGSDMEa functions the pore-formation in cytomembrane and the regulation on the secretion of IL-lβ in common carp (Cyprinus carpio haematopterus)

GSDME is the only direct executor of caspase-dependent pyroptosis in both canonical and non-canonical inflammasomes known to date in fish, and plays an important role in anti-bacterial infection and inflammatory response. In order to determine the regulation of GSDMEa on antibacterial infection in innate immune response, the CcGSDMEa gene in common carp (Cyprinus carpio haematopterus) was first identified and characterized, and then its function related to immune defense was investigated. Our results showed that the expressions of CcGSDMEa at the mRNA and protein levels were both significantly increased after Aeromonas hydrophila intraperitoneal infection at the early stage than that in the control group. We found that CcGSDMEa could be cleaved by inflammatory caspase (CcCaspase-1b) and apoptotic caspases (CcCaspase-3a/b and CcCaspase-7a/b). Interestingly, only the CcGSDMEa-NT (1-252 aa) displayed bactericidal activity to Escherichia coli and could punch holes in the membrane of HEK293T cells, whereas CcGSDMEa-FL (1-532 aa) and CcGSDMEa-CT (257-532 aa) showed no above activity and pore-forming ability. Overexpression of CcGSDMEa increased the secretion of CcIL-1β and the release of LDH, and could reduce the A. hydrophila burdens in fish. On the contrary, knockdown of CcGSDMEa reduced the secretion of CcIL-1β and the release of LDH, and could increase the A. hydrophila burdens in fish. Taken together, the elevated expression of CcGSDMEa was a positive immune response to A. hydrophila challenge in fish. CcGSDMEa could perform the pore-formation in cell membrane and the regulation on the secretion of IL-lβ, and further regulate the bacterial clearance in vivo. These results suggested that CcGSDMEa played an important role in immune defense against A. hydrophila and could provide a new insight into understanding the immune mechanism to resist pathogen invasion in teleost.