Oxidized Phosphatidylserine: Production and Bioactivities

Recent development of analytical methods for lipid hydroperoxides and preparation of highly pure lipid hydroperoxideshave revealed the important new pathophysiological roles of oxidized phospholipids. Generation of reactive oxygen speciesand subsequent oxidative stress leads to random oxidation of membrane phospholipids. However, recent studies havereported that anionic phospholipid molecules such as phosphatidylserine (PS) and cardiolipin are preferentiallyoxidized during apoptosis, resulting in efficient apoptosis execution and apoptotic cell clearance by phagocytes.This review is exclusively focused on selective production of oxidized PS (oxPS) during apoptosis as well as the novelroles of oxPS under pathophysiological conditions.     

Decreased Cytochrome c Oxidase Subunit VIIa in Aged Rat Heart Mitochondria: Immunocytochemistry

Aging decreases oxidative phosphorylation through cytochrome oxidase (COX) in cardiac interfibrillar mitochondria (IFM) in 24‐month old (aged) rats compared to 6‐month old adult Fischer 344 rats, whereas subsarcolemmal mitochondria (SSM) located beneath the plasma membrane remain unaffected. Immunoelectron microscopy (IEM) reveals in aged rats a 25% reduction in cardiac COX subunit VIIa in cardiac IFM, but not in SSM. In contrast, the content of subunit IV remains unchanged in both SSM and IFM, irrespective of age. These subunits are localized mainly on cristae membranes. In contrast, semi‐quantitative immunoblotting, which detects denatured protein, indicates that the content of COX VIIa is similar in IFM and SSM from both aged and adult hearts. IEM provides a sensitive method for precise localizing and quantifying specific mitochondrial proteins. The lack of immunoreaction of COX VIIa subunit by IEM in aged IFM is not explained by a reduction in protein, but rather by a masking phenomenon or by an in situ change in protein structure affecting COX activity. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.     

Apoptosis and the Receptor Specificity of Its Mechanisms During the Neurotoxic Action of Glutamate

The ratio of necrosis to apoptosis and the mechanisms of apoptosis were studied during neurodegeneration induced by glutamate and selective agonists of glutamate receptors – N-methyl-D-aspartate (NMDA) and kainate. Experiments were performed on primary cultures (seven days in vitro) of rat cerebral cortex neurons. Apoptosis and necrosis were identified using a vital fluorescence rapid test with staining with acridine orange and ethidium bromide. Immunocytochemistry in combination with confocal microscopy was used to visualize apoptotic proteins. Agonists (240 min) caused neuron death via both processes, though the proportion of necrotic cells when neurodegeneration was induced by NMDA and kainate was significantly less than when neurodegeneration was induced with glutamate. The neurotoxic effect of 3 mM glutamate was mediated via α-amino-3-(3-hydroxy-5-methylisoxazole-4-yl)propionate (AMPA) and kainate receptors, as it was blocked by 6-cyano-7-nitroquinoxalin-2,3-dione (CNQX). Activation of NMDA receptors led to the development of apoptosis without involvement of caspases, due to the direct action of apoptosis-inducing factor (AIF) on neuron nuclei. Activation of AMPA-kainate receptors was accompanied by the development of apoptosis via the caspase-dependent pathway. Thus, these data identified the receptor dependence of the mechanisms of apoptosis during the neurotoxic action of glutamate. Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 94, No. 4, pp. 380–393, April, 2008.     

Apoptosis and its relation with clinical course in patients with Crimean-Congo hemorrhagic fever

Crimean-Congo hemorrhagic fever (CCHF) is a tick-mediated viral infection. Patients with CCHF may show various clinical presentations. The cause of this difference in the clinical course is not completely understood. Apoptosis is programmed cell death and plays an important role in regulating the immune system. Our knowledge of the role of apoptosis in CCHF disease is limited. We investigated the role of apoptosis and their relationship with the severity of the disease in CCHF. Thus, in 30 patients with CCHF and 30 healthy individuals, we analyzed the serum levels of cytochrome C, apoptotic protease activating factor-1 (Apaf 1), caspase 3, caspase 8, caspase 9, sFas, sFasL, perforin, granzyme B, and CK18 by enzyme-linked immunosorbent assay. This is the first study that research the serum levels of the mentioned apoptosis markers in adult patients with CCHF. We found that the serum levels of sFasL, cytochrome C, Apaf 1, caspase 3, caspase 8, caspase 9, perforin, granzyme B, and M30 were statistically significantly different in the acute phase of the disease compared with healthy individuals and patients in convalescent period. There was no association between the clinical severity of the disease and apoptosis markers. In conclusion, the results of our study suggested that the extrinsic and intrinsic apoptosis pathway play an important role in CCHF.     

Mechanisms of Apoptosis in the Heart

Apoptosis is a complex and highly regulated form of cell death, and believed to contribute to the continuous decline of ventricular function in heart failure. Apoptotic cell death is observed in a variety of cardiovascular diseases, including myocardial infarction, ischemia-reperfusion injury, end-stage heart failure, arrhythmias, and adriamycin cardiomyopathy. There are several pathways leading to programmed cell death. Apoptosis can be initiated by extracellular or intracellular stimuli, leading to the activation of caspases and subsequent cell death. A better understanding of the process of apoptosis in the heart is clearly important as it may lead to the identification of novel therapies for cardiovascular disease. This review is focused on the basic cellular mechanisms of apoptosis, as well as our current understanding of this process in the heart.     

Apoptosis in Buruli ulcer: a clinicopathological study of 45 cases

Zavattaro E, Boccafoschi F, Borgogna C, Conca A, Johnson R C, Sopoh G E, Dossou A D, Colombo E, Clemente C, Leigheb G & Valente G
(2012) Histopathology  61, 224–236 Apoptosis in Buruli ulcer: a clinicopathological study of 45 cases Aims: To investigate the presence and pathogenetic role of apoptosis in Buruli ulcer (BU), a highly destructive skin disease caused by Mycobacterium ulcerans. Methods and results: Forty‐five skin biopsies obtained from 30 Beninese patients affected by BU, in different clinical and therapeutic periods, were analysed for the main histopathological features (inflammatory infiltration, necrosis, sclerosis, oedema, granulomas and nerve damage). Immunofluorescent detection of antigens (anti‐Bax, anti‐caspases‐3 and ‐8), together with deoxyuridine, 5′‐triphosphate (dUTP) nick end labelling (TUNEL) assay, were also performed. A significant decrease in inflammatory infiltration (P = 0.0001) was detected between the beginning and end of antibiotic treatment. Neutrophils predominated in the first phase, while lymphocytes and plasma cells were increased at the end of the therapy. An inverse correlation between tissue necrosis and sclerosis was observed (P = 0.001). In 11 cases, inflammatory and regressive changes involved the nerve bundles with axonal degeneration and disruption of nerve fibres. TUNEL assay detected apoptotic bodies within nerve bundles, and these decreased from beginning to end of therapy. Bax, caspase‐3 and ‐8 were down‐regulated over the course of antibiotic therapy. Conclusions: In BU, apoptosis plays a role in promoting and sustaining the destructive changes and is implicated in the neural pathology that is associated with clinically detected anaesthesia.     

The role of mitochondria,cytochrome c and caspase-9 in embryonic lens fibre cell denucleation

During the differentiation of secondary lens fibre cells from the lens epithelium, the fibre cells lose all of their cytoplasmic organelles as well as their nuclei. The fibre cells, containing crystallins, which confer optical clarity, then persist in the adult lens. The process of denucleation of these cells has been likened to an apoptotic event which is not followed by the plasma membrane changes that are characteristic of apoptosis. We have examined the expression and subcellular translocation of molecules of the apoptotic cascade in differentiating lens epithelial cells in culture. In this culture system, the epithelial cells differentiate into lentoids composed of lens fibre cells. We find that caspase-9, which is expressed and activated before embryonic day 12 in intact lenses, is localized in the cytosol outside mitochondria in non-differentiating cultured cells. In lentoid cells, caspase-9 migrates into mitochondria after the latter undergo a membrane permeability transition that is characteristic of apoptotic cells. At the same time, caspase-9 co-localizes with cytochrome c in the cytosol. The cytochrome c is apparently released from the mitochondria in lentoid cells after the mitochondrial membrane permeability transition and during the period of nuclear shrinkage. Also during this time, the mitochondria aggregate around the degenerating nuclei. Cytochrome c disappears rapidly, while mitochondrial breakdown occurs approximately coincident with the disappearance of the nuclei, but mitochondrial remnants persist together with cytochrome c oxidase, which is a mitochondrial marker protein. Apaf-1, another cytosolic protein of the apoptotic cascade, also migrates to the permeabilized mitochondria and also co-localizes with caspase-9 and cytochrome c in the cytosol or mitochondria of denucleating cells, thus providing evidence for the formation of an 'apoptosome' in these cells, as in apoptotic cells. At no time did we observe the translocation of molecules between cytoplasmic compartments and the nucleus in differentiating lentoid cells. We suggest that the uncoupling of nuclear and membrane apoptotic events in these cells may be due to the early permeability changes in the mitochondria, resulting in the loss of mitochondrial signalling molecules, or to the failure of molecules to migrate to the nucleus in these cells, thus failing to activate nuclear-plasma membrane signalling pathways.     

Somatic cell apoptosis markers and pathways in human ejaculated sperm: potential utility as indicators of sperm quality

In this study we extended earlier work to determine whether sperm respond to somatic cell apoptotic stimuli and whether apoptotic phenotypes are significant indicators of human sperm quality. We evaluated ejaculated sperm from fertile donors and subfertile patients following purification of fractions of high and low motility. In unstimulated conditions, caspase enzymatic activity was higher in motile fractions from subfertile patients than in donors, and was higher in low motility fractions from both groups. Staurosporine, but not a Fas ligand or H2O2, significantly increased caspase activity, but only in high motility fractions. Procaspase-3, -7 and -9 and low levels of active caspase-3, -7 and -9 were identified by immunoblot analysis. Apoptosis-inducing factor (AIF) was present in all samples but poly ADP-ribose polymerase-1 (PARP-1) was not detected. Phosphatidylserine translocation was significantly increased only with H2O2 treatment. In ejaculates of both subfertile and fertile men, we demonstrated the presence and activation of several proteins that are key constituents of apoptosis-related pathways in somatic cells, which may serve as markers for sperm quality.     

Caspase-3在脑出血后神经细胞凋亡中的作用

目的:探讨Caspase-3表达与大鼠脑出血后神经元凋亡的关系。方法:应用立体定向技术,将自体不凝血注入大鼠尾状核制备脑出血模型,将动物随机分为假手术组、脑出血组,分别在不同时间点断头取脑,连续切片作TUNEL染色和Caspase-3免疫组化染色。结果:脑出血后6h血肿内部及周边组织出现TUNEL阳性细胞, 72h达高峰, 2w时仍有少量表达;Caspase-3在脑出血后6h表达明显增高, 24h达到高峰,各组与假手术组之间差异显著(P<0 05 )。脑出血后的TUNEL阳性细胞与Caspase-3的表达呈正相关(r=0. 547,P<0 01),且Caspase-3的高峰时间早于凋亡的发生。结论:脑出血后的细胞凋亡与Caspase-3的表达有关。     

Mechanism of Fibroblast‐Like Synoviocyte Apoptosis Induced by Recombinant Human Endostatin in Rats with Adjuvant Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by pronounced synovial hyperplasia, in which there may be an imbalance between the growth and death of fibroblast‐like synoviocytes (FLS). The present study was undertaken to examine the effect of recombinant human endostatin (rhEndostatin) on FLS apoptosis in experimental RA. Adjuvant arthritis (AA) was induced in male Sprague Dawley (SD) rats. Using cultured AA FLS obtained from these rats, the apoptosis process was measured by terminal deoxyribonucleotidyl transferase‐mediated dUTP nick‐end labeling (TUNEL) as well as Annexin V‐fluorescein isothiocyanate (FITC) and propidium iodide (PI) labeling methods. In addition, the expression levels of the Fas, c‐jun, NFκB, and caspase‐3 gene products in synovial tissues were quantified by quantitative real‐time polymerase chain reaction (qPCR) and/or Western blotting assays. Our data revealed that rhEndostatin induced apoptosis in AA FLS. The number and signal density of TUNEL‐positive cells were significantly increased in rats treated with rhEndostatin (2.5 mg/kg). The percentage of Annexin V‐FITC‐positive cells was 6.67% after treatment with rhEndostatin at 25 μg/mL for 48 hr, compared with only 3.32% among untreated control cells. There were significant increases in Fas mRNA, c‐jun mRNA, c‐Jun protein, and caspase‐3 (p20) protein in AA synovial tissues treated with rhEndostatin (2.5 mg/kg), whereas no significant difference in NFκB expression was detected between treated and untreated tissues. These findings indicate that rhEndostatin has a therapeutic effect on RA by inducing FLS apoptosis, which is strongly associated with increased expression of Fas, c‐jun, and caspase‐3, but not NFκB. Anat Rec, 291:1029–1037, 2008. © 2008 Wiley‐Liss, Inc.     

Fibrinogen and Its Oxidized Form Induce Interleukin-2 Production in Cultured Endothelial Cells of Human Vessels

Oxidized fibrinogen was more potent than native fibrinogen in inducing interleukin-8 production in primary culture of human endothelial cells. The optimal concentration of oxidized fibrinogen was 3 mg/ml. The optimal time of UV irradiation was 17 min. Secretion of interleukin-8 was maximum during culturing of endothelial cells in a serum-free medium.     

柯萨奇病毒B3通过caspase依赖途径诱导HeLa细胞凋亡

目的 评价柯萨奇病毒B3（CVB3）致HeLa细胞死亡的方式及分子机制。方法 用CVB3作用于HeLa细胞,在不同时间收集细胞,通过相差显微镜、电子显微镜、流式细胞仪以及分子生物学手段,HeLa细胞的病变及caspase-3基因mRNA和蛋白质的表达。结果 CVB3作用于HeLa细胞后,细胞很快发生变性和坏死,24h后较多细胞凋亡;caspase基因在病毒作用早期即被活化,表现在caspase-3 mRNA在病毒作用后6h内,迅速增高达峰值。在24h内,又降至接近病毒作用前的水平。caspase-3蛋白表达在42h内逐渐增高。结论CVB3可诱导HeLa细胞发生坏死和凋亡两种反应,坏死早于凋亡,细胞凋亡与caspase-3的表达密切相关。     

Caspase activation in the absence of mitochondrial changes in granulocyte apoptosis

Eosinophils and neutrophils are two different types of granulocytes evolved from a common haematopoetic precursor in the bone marrow. Eosinophils are mainly involved in parasitic infection and allergic inflammation while neutrophils mainly participate in the defence against bacterial infections. Prolongation of granulocyte life span by inhibition of apoptosis may lead to tissue load of cells, and this has been detected in different inflammatory reactions. The molecular mechanisms and the potential role of the mitochondria in granulocyte apoptosis are poorly understood. In the present study we have characterized further the role of the mitochondria in granulocyte-apoptosis by studying the sequence of mitochondrial permeability transition (MPT) induction, loss of mitochondrial membrane potential (Deltapsim) and release of cytochrome c. This was made possible by applying tributyltin (TBT), a well-characterized apoptotic stimulus and MPT-inducer. We also studied potential differences in apoptosis-susceptibility between eosinophils and neutrophils. Ten minutes of TBT-exposure resulted in a substantial caspase-3 activity in both eosinophils and neutrophils, followed by phosphatidylserine (PS)-exposure after 30-120 min. Interestingly, caspase-3 activity was not preceded by MPT-induction, loss of Deltapsim or by cytochrome c-release in either eosinophils or neutrophils. In conclusion, we have demonstrated an extremely rapid induction of caspase-3 activity and apoptosis in human blood granulocytes without prior mitochondrial changes, including loss of mitochondrial membrane potential and release of cytochrome c. Our results open the possibility for a mitochondrial-independent activation of caspase 3 and subsequent apoptosis in granulocytes.     

Mechanisms of Apoptosis of T-Cells in Human Tuberculosis

The role of TGF-β TNF-α FasL and Bcl-2 in apoptosis of CD4 T-cells during active TB was studied. Coculture of PBMC from TB patients with neutralizing antibodies to TGF-β or TNF-α decreased spontaneous (P ≤ 0.05) and MTB-induced (P≤ 0.02) T-cell apoptosis by 50–90%, but effects were not additive. Interestingly, only levels of TGF-β in supernatants correlated with rates of spontaneous and MTB-induced apoptosis. FasL surface and mRNA expression were higher in unstimulated and MTB-stimulated PBMC from patients than controls, and neutralization of FasL abrogated apoptosis of T-cells from patients only. Intracellular Bcl-2 protein was lower among unstimulated CD4 T-cells from patients than those from controls (P ≤ 0.02), and MTB stimulation reduced intracellular Bcl-2 content in CD4 T-cells from patients only (P ≤ 0.001). These findings may indicate that, during TB, predisposition of CD4 T-cells to apoptosis may involve both low expression of Bcl-2, and excessive expression of TGF-β TNF-α and FasL.     

Induction of Apoptosis in Thymocytes by Prostaglandin E2 In Vivo

In vivo administration in mice of a synthetic analog of prostaglandin E₂ (PGE₂) caused a selective and dramatic decrease of CD4⁺CD8⁺ double-positive, CD3/T-cell-receptor-αb¹⁰ cells in the thymus. This loss was corticosteroid-independent and not affected by Cyclosporin A. The disappearance of CD4⁺CD8⁺ thymocytes was strictly correlated with the induction of apoptosis inside the thymus as shown by morphological studies and by the induction of intracellular transglutaminase expression. Considering that PGE₂ has been found to be produced by different cell populations inside the thymus, these results indicate that PGE₂ may act as endogenous signals for apoptosis during T-cell differentiation.     

Differential Gene Expression in Apoptosis: Identification of Ribosomal Protein 23K, a Cell Proliferation Inhibitor

Gene expression during the camptothecin-induced apoptotic death of human leukemic U937 cells and mouse T-cell hybridoma QW4.1 cells was studied by the mRNA differential display technique. Ten clones were confirmed to be differentially expressed, nine of which encoded novel sequences. One clone, U3.2, was induced approximately 10-fold in camptothecin-treated cells and was found to be identical to a highly basic 23-kDa human protein which contains basic leucine zipper-like motifs and has recently been identified as the human homologue of the rat ribosomal protein L13a. Northern blot analysis revealed a major mRNA of 0.9 kb and a minor mRNA of 1.3 kb. Overexpression of a full-length 23K cDNA, tagged with a FLAG sequence, in COS-7 cells revealed a predominantly nucleolar localization and the absence of any 23K protein from the cytoplasm. Subsequent transfection studies, using antisense phosphorothioate-modified oligonucleotides, revealed that inhibition of 23K expression results in an increased cell proliferation and greater sensitivity of U937 cells to the effects of camptothecin-induced cell death. Upregulation of 23K expression using a cDNA construct resulted in a decrease in cell proliferation and growth arrest, suggesting a role for 23K protein as a proliferation checkpoint following a cellular insult.     

Involvement of miR-30c in resistance to doxorubicin by regulating YWHAZ in breast cancer cells

MicroRNAs (miRNAs) are small RNA molecules that modulate gene expression implicated in cancer, which play crucial roles in diverse biological processes, such as development, differentiation, apoptosis, and proliferation. The aim of this study was to investigate whether miR-30c mediated the resistance of breast cancer cells to the chemotherapeutic agent doxorubicin (ADR) by targeting tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ). miR-30c was downregulated in the doxorubicin-resistant human breast cancer cell lines MCF-7/ADR and MDA-MB-231/ADR compared with their parental MCF-7 and MDA-MB-231 cell lines, respectively. Furthermore, we observed that transfection of an miR-30c mimic significantly suppressed the ability of MCF-7/ADR to resist doxorubicin. Moreover, the anti-apoptotic gene YWHAZ was confirmed as a target of miR-30c by luciferase reporter assay, and further studies indicated that the mechanism for miR-30c on the sensitivity of breast cancer cells involved YWHAZ and its downstream p38 mitogen-activated protein kinase (p38MAPK) pathway. Together, our findings provided evidence that miR-30c was one of the important miRNAs in doxorubicin resistance by regulating YWHAZ in the breast cancer cell line MCF-7/ADR.     

Nonthermal Plasma Induces Apoptosis in ATC Cells: Involvement of JNK and p38 MAPK-Dependent ROS

Purpose

To determine the effects of nonthermal plasma (NTP) induced by helium (He) alone or He plus oxygen (O₂) on the generation of reactive oxygen species (ROS) and cell death in anaplastic thyroid cancer cells.

Materials and Methods

NTP was generated in He alone or He plus O₂ blowing through a nozzle by applying a high alternating current voltage to the discharge electrodes. Optical emission spectroscopy was used to identify various excited plasma species. The apoptotic effect of NTP on the anaplastic thyroid cancer cell lines, such as HTH83, U-HTH 7, and SW1763, was verified with annexin V/propidium staining and TUNEL assay. ROS formation after NTP treatment was identified with fluorescence-activated cell sorting with DCFDA staining. The mitogen-activated protein kinase pathways and caspase cascade were investigated to evaluate the molecular mechanism involved and cellular targets of plasma.

Results

NTP induced significant apoptosis in all three cancer cell lines. The plasma using He and O₂ generated more O₂-related species, and increased apoptosis and intracellular ROS formation compared with the plasma using He alone. NTP treatment of SW1763 increased the expression of phosphor-JNK, phosphor-p38, and caspase-3, but not phosphor-ERK. Apoptosis of SW1763 as well as expressions of elevated phosphor-JNK, phosphor-p38, and caspase-3 induced by NTP were effectively inhibited by intracellular ROS scavengers.

Conclusion

NTP using He plus O₂ induced significant apoptosis in anaplastic cancer cell lines through intracellular ROS formation. This may represent a new promising treatment modality for this highly lethal disease.     

Apoptosis and apoptosis-associated perturbations of peripheral blood lymphocytes during HIV infection: comparison between AIDS patients and asymptomatic long-term non-progressors

This study was designed to compare the degree of lymphocyte apoptosis and Fas-Fas ligand (FasL) expression in AIDS patients and long-term non-progressors (LTNPs) and correlate these parameters with apoptosis-associated perturbations in lymphocyte function. LTNPs had a lower frequency of apoptotic CD4+ and CD8+ T cells compared with subjects with AIDS. This correlated with a lower frequency of cells expressing Fas and FasL. The frequency of selected lymphocyte populations exhibiting a disrupted mitochondrial transmembrane potential (DeltaPsim) and increased superoxide generation was lower in LTNPs than in patients with AIDS; these abnormalities were associated with lower levels of caspase-1 activation in LTNPs. The results indicate a significantly reduced level of apoptosis and apoptosis-associated parameters in LTNPs than in patients developing AIDS. Based on these findings, a crucial role for mitochondria can be predicted in the process of lymphocyte apoptosis during the evolution of AIDS.     

2‐(Pro‐1‐ynyl)‐5‐(5,6‐dihydroxypenta‐1,3‐diynyl) Thiophene Induces Apoptosis Through Reactive Oxygen Species‐Mediated JNK Activation in Human Colon Cancer SW620 Cells

2‐(Pro‐1‐ynyl)?5‐(5,6‐dihydroxypenta‐1,3‐diynyl) thiophene (PYDDT) is a naturally occurring thiophene isolated from the roots of Echinops grijsii, a Chinese herbal medicine used to treat colon cancer, breast cancer, and lung cancer. There are many reports on the clinical use of Echinops grijsii alone or in combination with other herbs to treat malignant tumors. We previously reported that the expression and activity of phase II enzymes including GSTs and NQO1 could be induced through the activation of Keap1‐Nrf2 pathway by the treatment of PYDDT. In this study, we reported the anticancer effect and mechanism of PYDDT against human colon cancer SW620 cells. Our results demonstrate that treatment of SW620 cells with PYDDT leads to induction of mitochondrial‐mediated apoptosis, which is characterized by the cleavage of PARP, activation of caspase 9 and caspase 3, release of cytochrome c from mitochondria, loss of mitochondrial membrane potential, down‐regulation of Bcl‐2, and mitochondrial translocation of Bax. The PYDDT treatment caused the production of reactive oxygen species (ROS), and the activation of JNK but not p38 mitogen‐activated protein kinases and ERK1/2. Specific JNK inhibitor SP600125 prevented the PYDDT‐induced down‐regulation of Bcl‐2, mitochondrial translocation of Bax, activation of caspase 3, and apoptosis of SW620 cells. Moreover, PYDDT‐induced apoptosis as well as activation of JNK was abrogated by the pretreatment with antioxidant N‐acetylcysteine. Taken together, these findings suggest that PYDDT induces apoptosis in SW620 cells through a ROS/JNK‐mediated mitochondrial pathway. Anat Rec, 298:376–385, 2015. © 2014 Wiley Periodicals, Inc.