Apoptosis: A Programme of Cell Death or Cell Disposal?

Targeted pathophysiological treatment of ischemic stroke using nanoparticle-based drug delivery system

Ischemic stroke poses significant challenges in terms of mortality and disability rates globally. A key obstacle to the successful treatment of ischemic stroke lies in the limited efficacy of administering therapeutic agents. Leveraging the unique properties of nanoparticles for brain targeting and crossing the blood-brain barrier, researchers have engineered diverse nanoparticle-based drug delivery systems to improve the therapeutic outcomes of ischemic stroke. This review provides a concise overview of the pathophysiological mechanisms implicated in ischemic stroke, encompassing oxidative stress, glutamate excitotoxicity, neuroinflammation, and cell death, to elucidate potential targets for nanoparticle-based drug delivery systems. Furthermore, the review outlines the classification of nanoparticle-based drug delivery systems according to these distinct physiological processes. This categorization aids in identifying the attributes and commonalities of nanoparticles that target specific pathophysiological pathways in ischemic stroke, thereby facilitating the advancement of nanomedicine development. The review discusses the potential benefits and existing challenges associated with employing nanoparticles in the treatment of ischemic stroke, offering new perspectives on designing efficacious nanoparticles to enhance ischemic stroke treatment outcomes.

Exploring the cytotoxicity of dinuclear Ru(II) p-cymene complexes appended N,N'-bis(4-substituted benzoyl)hydrazines: insights into the mechanism of apoptotic cell death

Cancer is a perilous life-threatening disease, and attempts are constantly being made to create multinuclear transition metal complexes that could lead to the development of potential anticancer medications and administration procedures. Hence, this work aims to design, synthesize, characterize, and assess the anticancer efficacy of ruthenium p-cymene complexes incorporating N,N'-bis(4-substituted benzoyl)hydrazine ligands. The formation of the new complexes (Ru2H1-Ru2H3) has been thoroughly established by elemental analysis, and FT-IR, UV-vis, NMR, and HR-MS spectral techniques. The solid-state molecular structures of the complexes Ru2H1 and Ru2H3 have been determined using the SC-XRD study, which confirms the N, O, and Cl-legged piano stool pseudo-octahedral geometry of each ruthenium(II) ion. The stability of these complexes in the solution state and their lipophilicity profile have been determined. Furthermore, the title complexes were tested for their in vitro anticancer activity against cancerous H460 (lung cancer cells), SkBr3 (breast cancer cells), HepG2 (liver cancer cells), and HeLa (cervical cancer cells) along with non-cancerous (HEK-293) cells. The IC50 results revealed that complex Ru2H3 exhibits potent activity against the proliferation of all four cancer cells and outscored the effect of the standard metallodrug cisplatin. This may be attributed to the presence of a couple of lipophilic electron-donating methoxy groups in the ligand scaffold and also the ruthenium(II) p-cymene motifs. Advantageously, all the complexes (Ru2H1-Ru2H3) displayed cytotoxic specificity only towards cancerous cells by leaving the off-target non-cancerous cells undamaged. Acridine orange/ethidium bromide (AO/EB) staining, Hoechst 33342, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) staining assays were used to investigate the apoptotic pathway and ROS levels in mitochondria. The results of western blot analysis confirmed that the complexes triggered apoptosis through an intrinsic mitochondrial pathway by upregulating Bax and downregulating Bcl-2 proteins. Finally, the extent of apoptosis triggered by the complex Ru2H3 was quantified with the aid of flow cytometry using the Annexin V-FITC/propidium iodide (PI) double-staining technique.

Phenolic-rich extracts from toasted white and tannin sorghum flours have distinct profiles influencing their antioxidant, antiproliferative, anti-adhesive, anti-invasive, and antimalarial activities

Sorghum is a gluten-free cereal commonly used in foods, and its consumption has been associated with the prevention of human chronic conditions such as obesity and cancer, due to the presence of dietary fiber and phenolic compounds. This study aimed to evaluate, for the first time, the antiproliferative, antioxidant, anti-adhesion, anti-invasion, and antimalarial activities of phenolic extracts from toasted white and tannin sorghum flours to understand how different phenolic profiles contribute to sorghum biological activities. Water and 70 % ethanol/water (v/v), eco-friendly solvents, were used to obtain the phenolic extracts of toasted sorghum flours, and their phenolic profile was analyzed by UPLC-MSE. One hundred forty-five (145) phenolic compounds were identified, with 23 compounds common to all extracts. The solvent type affected the phenolic composition, with aqueous extract of both white sorghum (WSA) and tannin sorghum (TSA) containing mainly phenolic acids. White sorghum (WSE) and tannin sorghum (TSE) ethanolic extracts exhibited a higher abundance of flavonoids. WSE demonstrated the lowest IC50 on EA.hy926 (IC50 = 46.6 µg/mL) and A549 cancer cells (IC50 = 33.1 µg/mL), while TSE showed the lowest IC50 (IC50 = 70.8 µg/mL) on HCT-8 cells (human colon carcinoma). Aqueous extracts also demonstrated interesting results, similar to TSE, showing selectivity for cancer cells at higher IC50 concentrations. All sorghum extracts also reduced the adhesion and invasion of HCT-8 cells, suggesting antimetastatic potential. WSE, rich in phenolic acids and flavonoids, exhibited greater toxicity to both the W2 (chloroquine-resistant) and 3D7 (chloroquine-sensitive) strains of Plasmodium falciparum (IC50 = 8 µg GAE/mL and 22.9 µg GAE/mL, respectively). These findings underscore the potential health benefits of toasted sorghum flours, suggesting diverse applications in the food industry as a functional ingredient or even as an antioxidant supplement. Moreover, it is suggested that, besides the phenolic concentration, the phenolic profile is important to understand the health benefits of sorghum flours.

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.

BH3 mimetics and TKI combined therapy for Chronic Myeloid Leukemia

Chronic myeloid leukemia (CML) was considered for a long time one of the most hostile leukemia that was incurable for most of the patients, predominantly due to the extreme resistance to chemotherapy. Part of the resistance to cell death (apoptosis) is the result of increased levels of anti-apoptotic and decreased levels of pro-apoptotic member of the BCL-2 family induced by the BCR-ABL1 oncoprotein. BCR-ABL1 is a constitutively active tyrosine kinase responsible for initiating multiple and oncogenic signaling pathways. With the development of specific BCR-ABL1 tyrosine kinase inhibitors (TKIs) CML became a much more tractable disease. Nevertheless, TKIs do not cure CML patients and a substantial number of them develop intolerance or become resistant to the treatment. Therefore, novel anti-cancer strategies must be developed to treat CML patients independently or in combination with TKIs. Here, we will discuss the mechanisms of BCR-ABL1-dependent and -independent resistance to TKIs and the use of BH3-mimetics as a potential tool to fight CML.

BCR-ABL1 Tyrosine Kinase Complex Signaling Transduction: Challenges to Overcome Resistance in Chronic Myeloid Leukemia

The constitutively active BCR-ABL1 tyrosine kinase, found in t(9;22)(q34;q11) chromosomal translocation-derived leukemia, initiates an extremely complex signaling transduction cascade that induces a strong state of resistance to chemotherapy. Targeted therapies based on tyrosine kinase inhibitors (TKIs), such as imatinib, dasatinib, nilotinib, bosutinib, and ponatinib, have revolutionized the treatment of BCR-ABL1-driven leukemia, particularly chronic myeloid leukemia (CML). However, TKIs do not cure CML patients, as some develop TKI resistance and the majority relapse upon withdrawal from treatment. Importantly, although BCR-ABL1 tyrosine kinase is necessary to initiate and establish the malignant phenotype of Ph-related leukemia, in the later advanced phase of the disease, BCR-ABL1-independent mechanisms are also in place. Here, we present an overview of the signaling pathways initiated by BCR-ABL1 and discuss the major challenges regarding immunologic/pharmacologic combined therapies.

Programmed Cell Death in SARS-CoV-2 Infection: A Short Review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the latest variant in the coronavirus family, causing COVID-19, has resulted in global pandemic since early 2020 leading to severe public health concern. So far, the pandemic has caused more than 200 million infections and 4 million deaths worldwide. Most of the studies are focused on developing prevention, intervention, and therapeutic strategies. However, underlying pathophysiology of the disease is important as well, which needs further attention. Cell death is one of the major causative mechanisms that leads to severe inflammation, and it is also an a posteriori consequence of the hyperinflammatory storm that renders poor prognosis of the disease. Substantial cell death has been reported in biopsy samples from post mortem patients. Among the distinct cell death pathways, apoptosis, the regulated programmed cell death plays an important role in the pathogenesis of the disease. Understanding the role of SARS-CoV-2 infection in apoptosis is critical to linearize the pathogenesis of the virus as well as the resultant disease, that may uncover novel therapeutic targets in treatment of COVID-19 patients. Here, we review the current progress on the underlying molecular mechanism(s) of SARS-CoV-2-induced apoptosis, not only at the level of the virus but also at its individual proteins.

Cell Death in Coronavirus Infections: Uncovering Its Role during COVID-19

Cell death mechanisms are crucial to maintain an appropriate environment for the functionality of healthy cells. However, during viral infections, dysregulation of these processes can be present and can participate in the pathogenetic mechanisms of the disease. In this review, we describe some features of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and some immunopathogenic mechanisms characterizing the present coronavirus disease (COVID-19). Lymphopenia and monocytopenia are important contributors to COVID-19 immunopathogenesis. The fine mechanisms underlying these phenomena are still unknown, and several hypotheses have been raised, some of which assign a role to cell death as far as the reduction of specific types of immune cells is concerned. Thus, we discuss three major pathways such as apoptosis, necroptosis, and pyroptosis, and suggest that all of them likely occur simultaneously in COVID-19 patients. We describe that SARS-CoV-2 can have both a direct and an indirect role in inducing cell death. Indeed, on the one hand, cell death can be caused by the virus entry into cells, on the other, the excessive concentration of cytokines and chemokines, a process that is known as a COVID-19-related cytokine storm, exerts deleterious effects on circulating immune cells. However, the overall knowledge of these mechanisms is still scarce and further studies are needed to delineate new therapeutic strategies.

Bothrops moojeni L-amino acid oxidase induces apoptosis and epigenetic modulation on Bcr-Abl+ cells

Background:

Resistance to apoptosis in chronic myeloid leukemia (CML) is associated with constitutive tyrosine kinase activity of the Bcr-Abl oncoprotein. The deregulated expression of apoptosis-related genes and alteration in epigenetic machinery may also contribute to apoptosis resistance in CML. Tyrosine kinase inhibitors target the Bcr-Abl oncoprotein and are used in CML treatment. The resistance of CML patients to tyrosine kinase inhibitors has guided the search for new compounds that may induce apoptosis in Bcr-Abl⁺ leukemic cells and improve the disease treatment.

Methods:

In the present study, we investigated whether the L-amino acid oxidase isolated from Bothrops moojeni snake venom (BmooLAAO-I) (i) was cytotoxic to Bcr-Abl⁺ cell lines (HL-60.Bcr-Abl, K562-S, and K562-R), HL-60 (acute promyelocytic leukemia) cells, the non-tumor cell line HEK-293, and peripheral blood mononuclear cells (PBMC); and (ii) affected epigenetic mechanisms, including DNA methylation and microRNAs expression in vitro.

Results:

BmooLAAO-I induced ROS production, apoptosis, and differential DNA methylation pattern of regulatory apoptosis genes. The toxin upregulated expression of the pro-apoptotic genes BID and FADD and downregulated DFFA expression in leukemic cell lines, as well as increased miR-16 expression - whose major predicted target is the anti-apoptotic gene BCL2 - in Bcr-Abl⁺ cells.

Conclusion:

BmooLAAO-I exerts selective antitumor action mediated by H₂O₂ release and induces apoptosis, and alterations in epigenetic mechanisms. These results support future investigations on the effect of BmooLAAO-I on in vivo models to determine its potential in CML therapy.

Apoptosis in Autoimmunological Diseases, with Particular Consideration of Molecular Aspects of Psoriasis

Apoptosis is a natural physiological process involving programmed cell death. Thanks to this process, it is possible to maintain the homeostasis of the body and the immune system. Dysfunctions of this mechanism lead to development of autoimmune diseases such as psoriasis; these diseases are chronic and treatment is extremely difficult. In psoriasis (a skin disease), apoptosis disorders are manifested by keratinocyte proliferation dysfunction. Autoimmune diseases coexisting with psoriasis include multiple sclerosis, autoimmune thyroid disease, and diabetes, but the common pathogenesis of these diseases is not fully understood. Given the heterogenous nature and chronic and recurrent course of psoriasis, the selection of an effective therapeutic strategy is still a problem. This literature review was focused on the process of apoptosis as a factor in the development of autoimmune diseases, with particular emphasis on psoriasis. The work also includes a review of therapeutic methods of psoriasis based on the latest literature.

Potential Molecular Mechanisms of Zhibai Dihuang Wan in Systemic Lupus Erythematosus Based on Network Biology

Systemic lupus erythematosus (SLE) is a refractory autoimmune disease. Zhibai Dihuang Wan (ZDW) has frequently been used for treating SLE in China and been proved to have a prominent role in decreasing SLE patients’ morality rate. However, the active substances in ZDW and the molecular mechanisms of ZDW in SLE remain unclear. This study identified the bioactive compounds and delineated the molecular targets and potential pathways of ZDW by using a network biology approach. First, we collected putative targets of ZDW based on TCMSP, GeneCards, and STITCH databases and built a network containing the interactions between the putative targets of ZDW and known therapeutic targets of SLE. Then, the key hubs were imported to DAVID Bioinformatics Resources 6.7 to perform gene ontology biological process (GOBP) and pathway enrichment analysis. A total of 95 nodes including 73 putative targets of ZDW were determined as major hubs in terms of their node degree. The results of GOBP and pathway enrichment analysis indicated that putative targets of ZDW mostly were involved in various pathways associated with inflammatory response and apoptosis. More importantly, eleven putative targets of ZDW (CASP3, BCL2, BAX, CYCS, NFKB1, NFKBIA, IL-6, IL-1β, PTGS2, CCL2, and TNF-α) were recognized as active factors involved in the main biological functions of treatment, implying the underlying mechanisms of ZDW acting on SLE. This study provides novel insights into the mechanisms of ZDW in SLE, from the molecular level to the pathway level.

Apoptosis and proliferation during human salivary gland development

Human salivary gland (SG) branching morphogenesis is an intricate mechanism divided into stages, prebud, initial bud, pseudoglandular, canalicular, and terminal bud, to form the final lobular structure of the organ. The coordination of molecular cascades, including cell proliferation and apoptosis, are fundamental to this process. The intrinsic apoptosis pathway appears to be important in the early phases of ductal cavitation and luminisation; however, the role of the extrinsic apoptosis pathway has still to be determined. Questions remain as to whether the latter mechanism participates in the maintenance of the ductal lumen; therefore, the present study investigated the expression of proteins Prostate apoptosis response-4 (Par-4), Fas cell surface death receptor (Fas), Fas ligand (FasL), pleckstrin homology-like domain family A member 1 (PHLDA1), caspase-3, B-cell CLL/lymphoma 2 (Bcl-2), survivin, Ki-67, mucin 1 (MUC1), and secreted protein acidic and cysteine-rich (SPARC) during distinct phases of human SG development (50 specimens). This strategy aimed to draw an immunomorphological map of the proteins involved in apoptosis, cell proliferation, and tissue maturation during the SG branching morphogenesis process. Par-4 was positive at all stages except the pre-acinar phase. Fas and FasL were expressed in few cells. PHLDA1 was expressed in all phases but not in the terminal bud. Bcl-2 expression was mainly negative (expressed in few cells). Survivin showed a cytoplasmic expression pattern in the early phases of development, which changed to a predominantly nuclear expression during development into more differentiated structures. Ki-67 was expressed mainly at the pseudoglandular stage. MUC1 was positive in the pseudoglandular stage with a cytoplasmic pattern in regions of early luminal opening. Immunostaining for SPARC and caspase-3 was negative. Our results suggest that proteins associated with the regulation of extrinsic and intrinsic apoptosis contribute to apoptosis during specific phases of the early formation of SGs in humans.

Adenovirus-Mediated CRM197 Sensitizes Human Glioma Cells to Gemcitabine by the Mitochondrial Pathway

PURPOSE

The cross-reacting material 197 (CRM197) is a mutation of the diphtheria toxin. The protein of CRM197 was used successfully for the therapy of various tumors in the recent studies. In this study, the recombinant adenoviruses containing the CRM197gene(AdCRM197) were used to enhance the cellar toxicity of gemcitabine in human glioma U87, U251, and H4 cells.

PROCEDURES

MTT assay and flow cytometric analysis were performed to test the apoptosis of the U87, U251 and H4 cells with the combined treatment of AdCRM197 plus gemcitabine. Western blotting analyses were carried out to detect the cell apoptosis of the mitochondrial pathway. And the xenograft nude mice were used to observe the enhanced antitumor effect of AdCRM197 in vivo.

RESULTS

AdCRM197 sensitizes human glioma cells to gemcitabine in vitro by the mitochondrial pathway. Tumor volume was inhibited and survival time was prolonged in the U251 or U87 xenografted nude mice with gemcitabine plus AdCRM197. The enhanced antitumor effect of AdCRM197 was also detected by the immunohistochemical analyses and TUNEL staining.

CONCLUSION

The authors found that AdCRM197 sensitized the human glioma to gemcitabine not only in vitro but also in vivo. They provide the first evidence that adenovirus-mediated CRM197 may be a potential chemosensitizing agent for the treatment of cancer. The diphtheria toxin is of great toxicity that even one molecule of diphtheria toxin is enough to kill one cell. However, because of the high toxicity, the diphtheria toxin would kill the packing cells when it is being packaged into the recombinant viruses. Therefore, the diphtheria toxin is hard to be used in the gene therapy for virus vectors. The cross-reacting material 197 (CRM197) is a mutation of the diphtheria toxin. Unlike DTA, CRM197 exhibit a weak toxicity. The week toxicity of CRM197 is a good feature for the virus packaging. In the present study, we used a recombinant adenovirus which carried a CRM197 gene (AdCRM197) to enhance the cellar toxicity of gemcitabine in human glioma cells.

Cytotoxic and pro-apoptotic action of MjTX-I, a phospholipase A2 isolated from Bothrops moojeni snake venom, towards leukemic cells

Background

Chronic myeloid leukemia (CML) is a BCR-ABL1⁺ myeloproliferative neoplasm marked by increased myeloproliferation and presence of leukemic cells resistant to apoptosis. The current first-line therapy for CML is administration of the tyrosine kinase inhibitors imatinib mesylate, dasatinib or nilotinib. Although effective to treat CML, some patients have become resistant to this therapy, leading to disease progression and death. Thus, the discovery of new compounds to improve CML therapy is still challenging. Here we addressed whether MjTX-I, a phospholipase A₂ isolated from Bothrops moojeni snake venom, affects the viability of imatinib mesylate-resistant Bcr-Abl⁺ cell lines.

Methods

We examined the cytotoxic and pro-apoptotic effect of MjTX-I in K562-S and K562-R Bcr-Abl⁺ cells and in the non-tumor HEK-293 cell line and peripheral blood mononuclear cells, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and the hypotonic fluorescent solution methods, associated with detection of caspases 3, 8, and 9 activation and poly (ADP-ribose) polymerase (PARP) cleavage. We also analyzed the MjTX-I potential to modulate the expression of apoptosis-related genes in K562-S and K562-R cells.

Results

MjTX-I decreased the viability of K562-S and K562-R cells by 60 to 65%, without affecting the viability of the non-tumor cells, i.e. it exerted selective cytotoxicity towards Bcr-Abl⁺ cell lines. In leukemic cell lines, the toxin induced apoptosis, activated caspases 3, 8, and 9, cleaved PARP, downregulated expression of the anti-apoptotic gene BCL-2, and upregulated expression of the pro-apoptotic gene BAD.

Conclusion

The antitumor effect of MjTX-I is associated with its potential to induce apoptosis and cytotoxicity in Bcr-Abl positive cell lines sensitive and resistant to imatinib mesylate, indicating that MjTX-I is a promising candidate drug to upgrade the CML therapy.

Pattern Recognition Receptors and the Host Cell Death Molecular Machinery

Pattern Recognition Receptors (PRRs) are proteins capable of recognizing molecules frequently found in pathogens (the so-called Pathogen-Associated Molecular Patterns—PAMPs), or molecules released by damaged cells (the Damage-Associated Molecular Patterns—DAMPs). They emerged phylogenetically prior to the appearance of the adaptive immunity and, therefore, are considered part of the innate immune system. Signals derived from the engagement of PRRs on the immune cells activate microbicidal and pro-inflammatory responses required to eliminate or, at least, to contain infectious agents. Molecularly controlled forms of cell death are also part of a very ancestral mechanism involved in key aspects of the physiology of multicellular organism, including the elimination of unwanted, damaged or infected cells. Interestingly, each form of cell death has its particular effect on inflammation and on the development of innate and adaptive immune responses. In this review article, we discuss some aspects of the molecular interplay between the cell death machinery and signals initiated by the activation of PRRs by PAMPs and DAMPs.

p53 Plays a Key Role in the Apoptosis of Human Ovarian Cancer Cells Induced by Adenovirus-Mediated CRM197

Cross-reacting material 197 (CRM197) is a mutant form of the diphtheria toxin. Recent studies have found that CRM197 exerts an experimental antitumor effect on several types of tumors. This study applied a novel treatment of adenovirus-mediated CRM197 (AdCRM197) to human ovarian cancer cells. Interestingly, it was found that A2780 cells were sensitive to AdCRM197, but SKOV3 cells were resistant to it. Since SKOV3 cells are p53 deletion cells, while A2780 cells are p53 wild-type cells, it was postulated that p53 might play a key role in AdCRM197-induced apoptosis. This presumption was demonstrated by means of knockdown of p53 of the A2780 cells through lentivirus-mediated RNA interference. This knockdown resulted in the A2780 cells becoming resistant to AdCRM197. To verify this presumption further, the wild-type p53 gene in the SKOV3 cells was replaced with adenovirus-mediated p53 (Adp53). As expected, AdCRM197 plus Adp53 resulted in apoptosis of the SKOV3 cells. The combined treatment of AdCRM197 plus Adp53 also showed a good antitumor effect in the in vivo experiment on nude mice with xenograft tumors. Taking these results together, it is concluded that AdCRM197 induces apoptosis of human ovarian cancer cells via the p53 pathway. Moreover, it was found that Adp53 can reverse the resistance of p53-deletion human ovarian cancer cells to AdCRM197. The combination of AdCRM197 and Adp53 may be a potentially effective method for overcoming the resistance of p53-deficient human ovarian cancer to AdCRM197.

Oxidative stress regulates cellular bioenergetics in esophageal squamous cell carcinoma cell

The aim of the present study was to explore the effects of oxidative stress induced by CoCl₂ and H₂O₂ on the regulation of bioenergetics of esophageal squamous cell carcinoma (ESCC) cell line TE-1 and analyze its underlying mechanism. Western blot results showed that CoCl₂ and H₂O₂ treatment of TE-1 cells led to significant reduction in mitochondrial respiratory chain complex subunits expression and increasing intracellular reactive oxygen species (ROS) production. We further found that TE-1 cells treated with CoCl₂, a hypoxia-mimicking reagent, dramatically reduced the oxygen consumption rate (OCR) and increased the extracellular acidification rate (ECAR). However, H₂O₂ treatment decreased both the mitochondrial respiration and aerobic glycolysis significantly. Moreover, we found that H₂O₂ induces apoptosis in TE-1 cells through the activation of PARP, Caspase 3, and Caspase 9. Therefore, our findings indicate that CoCl₂ and H₂O₂ could cause mitochondrial dysfunction by up-regulation of ROS and regulating the cellular bioenergy metabolism, thus affecting the survival of tumor cells.

Antioxidative, membrane protective and antiapoptotic effects of melatonin, in silico study of physico-chemical profile and efficiency of nanoliposome delivery compared to betaine

Hepatoprotective effects of melatonin mediated by the inhibition of apoptotic and oxidative processes and activation of survival pathways, in comparison with betaine, were studied in mouse hepatocytes undergone Fas-ligand apoptosis.

MicroRNA134 Mediated Upregulation of JNK and Downregulation of NFkB Signalings Are Critically Involved in Dieckol Induced Antihepatic Fibrosis

Though Dieckol, a phlorotannin of Ecklonia cava, was known to have antioxidant, anticancer, antidiabetic, and anti-inflammatory effects, the underlying antifibrotic mechanism of Dieckol still remains unclear until now. Thus, in the current study, the inhibitory mechanism of Dieckol on liver fibrosis was elucidated mainly in hepatic stellate cells (HSCs). Dieckol exerted cytotoxicity in LX-2, HSC-T6, and HepG2 cells with the reduced fibrosis features of large, spread out, and flattened polygonal shapes in LX-2 cells compared to untreated control. Dieckol attenuated the expression of α-SMA and TGF-β1, increased sub-G1 phase population, and induced caspase-3 activation and cleavages of PARP in HSCs. Furthermore, Dieckol decreased phosphorylation of ERK, p38, AKT, NF-kB, and IkB and activated the microRNA(miR)134 level and JNK phosphorylation in HSCs. Conversely, JNK inhbitor SP600125 reversed the effect of Dieckol on PARP, p-NF-kB, α -SMA, and p-JNK in LX-2 cells. Likewise, miR134 overexpression mimic enhanced phosphorylation of JNK and NF-kB and reduced the expression of α-SMA and PARP cleavage, while miR134 inhibitor reversed the ability of Dieckol to cleave PARP and attenuate the expression of α-SMA in LX-2 cells. Overall, our findings suggest that Dieckol suppresses liver fibrosis via caspase activation and miR134 mediated JNK activation and NF-kB inhibition.

Tumor neovasculature-targeted cationic PEGylated liposomes of gambogic acid for the treatment of triple-negative breast cancer

Gambogic acid (GA) is a naturally derived potent anticancer agent with extremely poor aqueous solubility. In the present study, positively charged PEGylated liposomal formulation of GA (GAL) was developed for parenteral delivery for the treatment of triple-negative breast cancer (TNBC). The GAL was formulated with a particle size of 107.3 ± 10.6 nm with +32 mV zeta potential. GAL showed very minimal release of GA over 24 h period confirming the non-leakiness and stability of liposomes. In vitro cytotoxicity assays showed similar cell killing with GA and GAL against MDA-MB-231 cells but significantly higher inhibition of HUVEC growth was observed with GAL. Furthermore, GAL significantly (p < 0.05) inhibited the MDA-MB-231 orthotopic xenograft tumor growth with >50% reduction of tumor volume and reduction in tumor weight by 1.7-fold and 2.2-fold when compared to GA and controls, respectively. Results of western blot analysis indicated that GAL significantly suppressed the expression of apoptotic markers, bcl2, cyclinD1, survivin and microvessel density marker-CD31 and increased the expression of p53 and Bax compared to GA and control. Collectively, these data provide further support for the potential applications of cationic GAL in its intravenous delivery and its significant role in inhibiting angiogenesis against TNBC.

CR-LAAO antileukemic effect against Bcr-Abl(+) cells is mediated by apoptosis and hydrogen peroxide

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by the presence of the Bcr-Abl tyrosine kinase protein, which confers resistance to apoptosis in leukemic cells. Tyrosine kinase inhibitors (TKIs) are effectively used to treat CML; however, CML patients in the advanced (CML-AP) and chronic (CML-CP) phases of the disease are usually resistant to TKI therapy. Thus, it is necessary to seek for novel agents to treat CML, such as the enzyme l-amino acid oxidase from Calloselasma rhodostoma (CR-LAAO) snake venom. We examined the antitumor effect of CR-LAAO in Bcr-Abl(+) cell lines and peripheral blood mononuclear cells (PBMC) from healthy subjects and CML patients. CR-LAAO was more cytotoxic towards Bcr-Abl(+) cell lines than towards healthy subjects' PBMC. The H2O2 produced during the enzymatic action of CR-LAAO mediated its cytotoxic effect. The CR-LAAO induced apoptosis in Bcr-Abl(+) cells, as detected by caspases 3, 8, and 9 activation, loss of mitochondrial membrane potential, and DNA damage. CR-LAAO elicited apoptosis in PBMC from CML-CP patients without TKI treatment more strongly than in PBMC from healthy subjects and TKI-treated CML-CP and CML-AP patients. The antitumor effect of CR-LAAO against Bcr-Abl(+) cells makes this toxin a promising candidate to CML therapy.

Disturbances in apoptosis of lamina propria lymphocytes in Crohn's disease

INTRODUCTION

The aim of this study was to assess the potential mechanisms providing resistance to apoptosis of lamina propria lymphocytes (LPL) directlyin intestinal tissues from patients with Crohn's disease (CD).

MATERIAL AND METHODS

Fifty CD patients were enrolled in the study. The control group consisted of healthy patients who underwent surveillance colonoscopy after endoscopic polypectomy. Each CD patient underwent colonoscopy with tissue sampling from inflamed areas of the colon with the assessment of immunohistochemical expression of active caspase 3, Fas, tumour necrosis factor receptor 1 (TNFR1), Bcl-2, Bax, CD4 and CD8. This was compared with healthy intestinal mucosa.

RESULTS

The expression of active caspase 3 was significantly lower in LPL in CD (0.4 ±0.3 vs. 2.8 ±1.5; p = 0.0002). A statistically significant increase of CD4 and CD8 positive cells was noted in CD (2.3 ±0.5 vs. 1.2 ±0.2, p < 0.0001; 2.1 ±0.3 vs. 1.1 ±0.3, p < 0.0001, respectively). It was associated with a significant increase of the Bcl-2 (6.7 ±2.7 vs. 2.9 ±0.8; p < 0.0001) and a decrease of the Bax protein expression (3.4 ±2.1 vs. 5.5 ±1.8; p < 0.0001) in CD. The expression of Fas and TNFR1 did not differ between the study groups.

CONCLUSIONS

LPL in CD are resistant to apoptosis when compared with physiological conditions. This is probably due to an imbalance in Bcl-2 family proteins. TNFR1-related pathway is probably not involved in disturbances of LPL apoptosis in CD.

Impact of anemia treatment with methoxy polyethylene glycol-epoetin beta on polymorphonuclear cells apoptosis in predialysis patients with chronic kidney disease

BACKGROUND

Some data in literature indicate increased apoptosis of polymorphonuclear cells (PMNs) in chronic kidney disease (CKD), what seems to be connected with anemia. Erythropoiesis-stimulating agents, used in anemia treatment in CKD may affect cells apoptosis. Aim of this study was to investigate impact of anemia treatment with methoxy polyethylene glycol-epoetin beta (CERA) on PMNs apoptosis in predialysis patients with CKD.

METHODS

Percentage of early and late apoptotic PMNs was measured by flow cytometry based on annexin V and propidium iodide binding. CD90 (Fas), CD95L (FasL), CD16 and CD11b expression on PMNs were evaluated by flow cytometry after incubation with respective monoclonal antibody.

RESULTS

Percentage of PMNs in early and late apoptosis in CKD patients before CERA treatment was significantly higher to control group, which was accompanied by significantly higher Fas and Fas-L expression and significantly lower expression of CD16. CERA treatment downregulated significantly percentage of early, apoptotic PMNs but percentage of late apoptotic cells did not change and was still significantly higher to control group. In all investigated groups we observed a significant negative correlation between hemoglobin concentration and percentage of apoptotic PMNs, as well as Fas and FasL expression and significant positive correlation between Hb and CD16 expression.

CONCLUSIONS

Our results indicate that PMNs apoptosis is increased in predialysis patients with CKD and anemia treatment with CERA may diminish readiness of PMNs to undergo apoptosis. This antiapoptotic impact of anemia treatment with CERA seems to concern early apoptotic PMNs before they undergo to late, irreversible stage of apoptosis.

Therapeutic applications of TRAIL receptor agonists in cancer and beyond

TRAIL/Apo-2L is a member of the TNF superfamily first described as an apoptosis-inducing cytokine in 1995. Similar to TNF and Fas ligand, TRAIL induces apoptosis in caspase-dependent manner following TRAIL death receptor trimerization. Because tumor cells were shown to be particularly sensitive to this cytokine while normal cells/tissues proved to be resistant along with being able to synthesize and release TRAIL, it was rapidly appreciated that TRAIL likely served as one of our major physiologic weapons against cancer. In line with this, a number of research laboratories and pharmaceutical companies have attempted to exploit the ability of TRAIL to kill cancer cells by developing recombinant forms of TRAIL or TRAIL receptor agonists (e.g., receptor-specific mAb) for therapeutic purposes. In this review article we will describe the biochemical pathways used by TRAIL to induce different cell death programs. We will also summarize the clinical trials related to this pathway and discuss possible novel uses of TRAIL-related therapies. In recent years, the physiological importance of TRAIL has expanded beyond being a tumoricidal molecule to one critical for a number of clinical settings - ranging from infectious disease and autoimmunity to cardiovascular anomalies. We will also highlight some of these conditions where modulation of the TRAIL/TRAIL receptor system may be targeted in the future.

Expression of selected proteins of the extrinsic and intrinsic pathways of apoptosis in human leukocytes exposed to N-nitrosodimethylamine

N-nitrosodimethylamine (NDMA) is a xenobiotic widespread in human environment capable of regulating the lifespan of immune cells. In this study, we examined the roles of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/death receptor 5 (DR5) complex and the Fas molecule in the induction of the extrinsic apoptosis pathway in human neutrophils (polymorphonuclear neutrophils (PMNs)) and peripheral blood mononuclear cells (PBMCs) exposed to NDMA. Also we assessed these proteins ability to trigger the intrinsic apoptosis pathway in those cells. For this purpose, we examined the expression of Fas-associated protein with death domain, truncated Bid (tBid) proteins, and apoptogenic factors such as apoptosis-inducing factor, Smac/Diablo, Omi/HtrA2, and caspase-3 as an indication of accomplished apoptosis phenomenon. PMNs and PBMCs were isolated from whole blood by density gradient centrifugation using Polymorphrep. Apoptotic cells were assessed with flow cytometry using a ready-made kit. The expression of proapoptotic molecules was investigated by Western blot analysis of PMNs and PBMCs treated with NDMA and/or rhTRAIL. The obtained results confirm the proapoptotic effects of NDMA on the examined human leukocytes and indicate an active participation of the TRAIL/DR5 complex and Fas protein in the process of apoptosis. Moreover, the research revealed distinct mechanisms of intrinsic apoptosis pathway activation between PMNs and PBMCs exposed to NDMA, as confirmed by the different levels of tBid, Smac/Diablo, Omi/HtrA2, and caspase-3 expression in those cells.

Long-term aerobic exercise protects against cisplatin-induced nephrotoxicity by modulating the expression of IL-6 and HO-1

Nephrotoxicity is substantial side effect for 30% of patients undergoing cancer therapy with cisplatin and may force them to change or even abandon the treatment. Studies regarding aerobic exercise have shown its efficacy for the treatment of many types of diseases and its capacity to reduce tumors. However, little is known about the impact of physical exercise on cisplatin-induced acute kidney injury (AKI). In the present study, our aim was to investigate the role of physical exercise in AKI induced by cisplatin. We submitted C57Bl6 male mice to seven weeks of chronic exercise on a training treadmill and treated them with single i.p. injection of cisplatin (20 mg/kg) in the last week. Exercise efficacy was confirmed by an increased capillary-to-fiber ratio in the gastrocnemius muscle of exercised groups (EX and CIS-EX). The group submitted to exercise before cisplatin administration (CIS-EX) exhibited less weight loss and decreased serum urea levels compared to the cisplatin group (CIS). Exercise also showed a protective role against cisplatin-induced cell death in the kidney. The CIS-EX group showed a lower inflammatory response, with less TNF and IL-10 expression in the kidney and serum. In the same group, we observed an increase of IL-6 and HO-1 expression in the kidney. Taken together, our results indicate that chronic aerobic exercise is able to attenuate AKI by inducing IL-6 and HO-1 production, which results in lower inflammatory and apoptotic profiles in the kidney.

Snake venom L-amino acid oxidases: an overview on their antitumor effects

The L-amino acid oxidases (LAAOs) constitute a major component of snake venoms and have been widely studied due to their widespread presence and various effects, such as apoptosis induction, cytotoxicity, induction and/or inhibition of platelet aggregation, hemorrhage, hemolysis, edema, as well as antimicrobial, antiparasitic and anti-HIV activities. The isolated and characterized snake venom LAAOs have become important research targets due to their potential biotechnological applications in pursuit for new drugs of interest in the scientific and medical fields. The current study discusses the antitumor effects of snake venom LAAOs described in the literature to date, highlighting the mechanisms of apoptosis induction proposed for this class of proteins.

The influence of infliximab and adalimumab on the expression of apoptosis-related proteins in lamina propria mononuclear cells and enterocytes in Crohn's disease - an immunohistochemical study

BACKGROUND AND AIMS

The aim of this study was to assess the influence of anti-TNF agents on the expression of apoptosis-related proteins in Crohn's disease (CD) patients.

METHODS

The clinical, biochemical and endoscopic activity of CD was assessed with the use of tissue sampling before the initiation of therapy and after induction doses of infliximab and adalimumab. Additionally, the immunohistochemical expression of active caspase 3, TNFR1, Fas, Bcl-2, Bax, CD4 and CD8 proteins was estimated. Patients achieving deep remission were considered as responders.

RESULTS

Of the 35 patients qualified for the study, 60% achieved deep remission. In those patients, a significant decrease in the number of CD4 and CD8 positive cells was noted. Also observed was a significant increase in the expression of active caspase 3 in lamina propria mononuclear cells, which correlated with an increase of the pro-apoptotic Bax/Bcl-2 ratio. No change in Fas and TNFR1 expression was observed in those cells. Moreover, there was a significant decrease in active caspase 3 expression in enterocytes, observed independently of the Bax/Bcl-2 ratio. This correlated with a change in TNFR1 expression. No significant changes in the expression of the investigated proteins were noted in non-responders group.

CONCLUSIONS

The efficacy of anti-TNF antibodies is, at least partly, dependent on apoptosis modulation. In lamina propria mononuclear cells, the increase of apoptosis is probably the result of the induction of the intrinsic pathway mediated by Bcl-2 family proteins. In enterocytes - the decrease of apoptosis is mediated by the extrinsic pathway, probably via TNFR1.

Cytosolic flagellin-induced lysosomal pathway regulates inflammasome-dependent and -independent macrophage responses

NAIP5/NLRC4 (neuronal apoptosis inhibitory protein 5/nucleotide oligomerization domain-like receptor family, caspase activation recruitment domain domain-containing 4) inflammasome activation by cytosolic flagellin results in caspase-1-mediated processing and secretion of IL-1β/IL-18 and pyroptosis, an inflammatory cell death pathway. Here, we found that although NLRC4, ASC, and caspase-1 are required for IL-1β secretion in response to cytosolic flagellin, cell death, nevertheless, occurs in the absence of these molecules. Cytosolic flagellin-induced inflammasome-independent cell death is accompanied by IL-1α secretion and is temporally correlated with the restriction of Salmonella Typhimurium infection. Despite displaying some apoptotic features, this peculiar form of cell death do not require caspase activation but is regulated by a lysosomal pathway, in which cathepsin B and cathepsin D play redundant roles. Moreover, cathepsin B contributes to NAIP5/NLRC4 inflammasome-induced pyroptosis and IL-1α and IL-1β production in response to cytosolic flagellin. Together, our data describe a pathway induced by cytosolic flagellin that induces a peculiar form of cell death and regulates inflammasome-mediated effector mechanisms of macrophages.

Sensitive and visible detection of apoptotic cells on Annexin-V modified substrate using aminophenylboronic acid modified gold nanoparticles (APBA-GNPs) labeling

A new strategy for sensitive detection of early stage apoptosis was proposed based on silver-enhanced gold nanoparticle (GNP) label method. Annexin-V modified substrate was constructed via layer-by-layer (LBL) method for specific capture of early stage apoptotic Jurkat cells. A new kind of aminophenylboronic acid modified gold nanoparticle (APBA-GNP) was synthesized and utilized for labeling cells, followed by silver enhancement. Anodic stripping voltammetry (ASV) was applied to sensitive detection of Ag(+) dissolved from the deposited silver particles, which reflected the number of cells. A good linear range from 1 × 10(2) to 3.5 × 10(3) cells was achieved, with a detection limit of 38 apoptotic cells. Moreover, the gray color of silver enhancement could be observed by the naked eye, which could be used to tell apoptotic cells apart from normal cells. Therefore, using the silver-enhanced GNP label method, apoptotic cells could not only be sensitively detected via electrochemical technique, but also can be discriminated from normal cells by the naked eye.

Stimulatory Toll-like receptor 2 suppresses restraint stress-induced immune suppression

Stress can enhance or suppress immune functions depending on a variety of factors. Our previous studies observed that Toll-like receptor 2 (TLR2) participates in chronic restraint stress-induced immune dysfunction. However, the mechanism by which TLR2 prevents immune suppression remains elusive. Our investigation found that stimulation of TLR2 by peptidoglycan (PGN) significantly attenuates splenocyte apoptosis and markedly blocks alterations of anti-apoptotic and apoptotic proteins. Activation of TLR2 inhibits chronic stress-reduced phosphorylation of c-Jun N-terminal kinase (JNK) and diminishes chronic stress-induced up-regulation of corticosterone production. Additionally, our data show that chronic stress causes a dramatic decrease of cytokine IL-2 level but an increase of IL-4 and IL-17 in CD4(+) T cells. Interestingly, PGN could block these alterations of cytokine levels. Collectively, our studies demonstrate that stimulation of TLR2 attenuates chronic stress-induced immune suppression by modulating apoptosis-related proteins and immunoregulatory agents.

Apigenin and its impact on gastrointestinal cancers

Apigenin (4',5,7-trihydroxyflavone, 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one) is a flavonoid found in many fruits, vegetables, and herbs, the most abundant sources being the leafy herb parsley and dried flowers of chamomile. Present in dietary sources as a glycoside, it is cleaved in the gastrointestinal lumen to be absorbed and distributed as apigenin itself. For this reason, the epithelium of the gastrointestinal tract is exposed to higher concentrations of apigenin than tissues at other locations. This would also be true for epithelial cancers of the gastrointestinal tract. We consider the evidence for actions of apigenin that might hinder the ability of gastrointestinal cancers to progress and spread. Apigenin has been shown to inhibit cell growth, sensitize cancer cells to elimination by apoptosis, and hinder the development of blood vessels to serve the growing tumor. It also has actions that alter the relationship of the cancer cells with their microenvironment. Apigenin is able to reduce cancer cell glucose uptake, inhibit remodeling of the extracellular matrix, inhibit cell adhesion molecules that participate in cancer progression, and oppose chemokine signaling pathways that direct the course of metastasis into other locations. As such, apigenin may provide some additional benefit beyond existing drugs in slowing the emergence of metastatic disease.

Characterization of a programmed necrosis process in 3-dimensional cultures of dental pulp fibroblasts

AIM

To analyse and compare the expression of necrosis markers in human lung and dental pulp fibroblasts and to determine whether this process differs by the type of mesenchymal cell.

METHODS

Human dental pulp fibroblasts were obtained from unerupted third molars. Sound lung and pulpal fibroblasts were cultured in vitro as spheroids to determine the expression of the necrosis hallmark cyclooxygenase-2 (COX-2) mRNA using RT-PCR and the concentrations of vascular endothelial growth factor (VEGF) and hepatocyte growth factor/scatter factor (HGF/SF) proteins using an ELISA test. Cell viability within spheroids was also compared with spheroid diameters over time.

RESULTS

Increased expression of COX-2 and VEGF was found in all spheroids compared with corresponding monolayers. Although HGF/SF was highly expressed in MRC5 cells, dental pulp fibroblasts aggregates maintained only a basal level compared with monolayer cultures. Further, the observed progressive loss of viable cells explained the decreased diameters of spheroids over time. The results demonstrate that necrosis occurs in sound lung and pulpal fibroblasts. This cell death also displays differences between these two different cell types, as they do not produce the same growth factors quantity release.

CONCLUSIONS

The necrosis process occurred in human dental pulp fibroblasts and is different between the two cell types studied. This in vitro experimental necrosis model could become an interesting inflammatory tool. More investigations are needed to compare necrosis process in dental pulp fibroblast and inflammation during pulpitis.

Immunopathological events initiated and maintained by pathogenic IgG autoantibodies in an experimental autoimmune kidney disease

The experimental models of Heymann nephritis (HN) and slowly progressive Heymann nephritis (SPHN) give us rare opportunities to investigate the etiologies and pathogenesis of two immunopathological processes in rats leading to: (1) autoimmune disease, where the autoimmune disease HN and SPHN is initiated and maintained by cross-reactive pathogenic IgG autoantibodies (aabs) directed against the renal proximal convoluted tubules' brush border (BB) cells - where the nephritogenic antigen (ag) is produced and localized - damaging and releasing BB associated nephritogenic ag into the circulation which in turn contributes to continuation of the autoimmune disease; and (2) immune complex glomerulonephritis, where the glomerular injury is initiated, proceeding into a chronic progressive disease by depositing immune complexes (ICs) - made up of a glomerular epithelial cell produced endogenous nephritogenic ag and the developing pathogenic IgG aab directed against the nephritogenic ag, and complement components - on the epithelial side of the glomerular basement membrane. We also observed how the normally functioning immune system is able to avert autoimmune disease developments by circulating specific non-pathogenic IgM aabs clearing the system of intracytoplasmic ags released from cells at the end of their life spans or following damage by toxic agents. We also described how an autoimmune disease SPHN can be prevented and when present terminated by the implementation of a new vaccination technique we have developed and call modified vaccination technique. By increasing the specific IgM aab production against the native nephritogenic ag - by injecting ICs made up of: [nephritogenic ag X homologous anti-nephritogenic ag IgM ab] in slight ag excess into SPHN rats - pathogenic IgG aab producing native and modified nephritogenic ags were removed from the circulation and termination of the autoimmune disease causing immune events was achieved. Even though HN and SPHN are not well-known disease models, their studies are important because the etiologies and pathogenesis of two conditions - that can also occur in humans, namely autoimmune diseases and membranous glomerulonephritis - can be simultaneously investigated.

Quantitative proteome analysis reveals RNA processing factors as modulators of ionizing radiation-induced apoptosis in the C. elegans germline

The nematode Caenorhabditis elegans is an organism most recognized for forward and reverse genetic and functional genomic approaches. Proteomic analyses of DNA damage-induced apoptosis have not been shown because of a limited number of cells undergoing apoptosis. We applied mass spectrometry-based quantitative proteomics to evaluate protein changes induced by ionizing radiation (IR) in isolated C. elegans germlines. For this purpose, we used isobaric peptide termini labeling (IPTL) combined with the data analysis tool IsobariQ, which utilizes MS/MS spectra for relative quantification of peak pairs formed during fragmentation. Using stringent statistical critera, we identified 48 proteins to be significantly up- or down-regulated, most of which are part of a highly interconnected protein-protein interaction network dominated by proteins involved in translational control. RNA-mediated depletion of a selection of the IR-regulated proteins revealed that the conserved CAR-1/CGH-1/CEY-3 germline RNP complex acts as a novel negative regulator of DNA-damage induced apoptosis. Finally, a central role of nucleolar proteins in orchestrating these responses was confirmed as the H/ACA snRNP protein GAR-1 was required for IR-induced apoptosis in the C. elegans germline.

Beyond annexin V: fluorescence response of cellular membranes to apoptosis

Dramatic changes in the structure of cell membranes on apoptosis allow easy, sensitive and non-destructive analysis of this process with the application of fluorescence methods. The strong plasma membrane asymmetry is present in living cells, and its loss on apoptosis is commonly detected with the probes interacting strongly and specifically with phosphatidylserine (PS). This phospholipid becomes exposed to the cell surface, and the application of annexin V labeled with fluorescent dye is presently the most popular tool for its detection. Several methods have been suggested recently that offer important advantages over annexin V assay with the ability to study apoptosis by spectroscopy of cell suspensions, flow cytometry and confocal or two-photon microscopy. The PS exposure marks the integrated changes in the outer leaflet of cell membrane that involve electrostatic potential and hydration, and the attempts are being made to provide direct probing of these changes. This review describes the basic mechanisms underlying the loss of membrane asymmetry during apoptosis and discusses, in comparison with the annexin V-binding assay, the novel fluorescence techniques of detecting apoptosis on cellular membrane level. In more detail we describe the detection method based on smart fluorescent dye F2N12S incorporated into outer leaflet of cell membrane and reporting on apoptotic cell transformation by easily detectable change of the spectral distribution of fluorescent emission. It can be adapted to any assay format.