Course Of Apoptosis Research Articles

Post-Transcriptional Modifications of RNA as Regulators of Apoptosis in Glioblastoma.

This review is devoted to changes in the post-transcriptional maturation of RNA in human glioblastoma cells, which leads to disruption of the normal course of apoptosis in them. The review thoroughly highlights the latest information on both post-transcriptional modifications of certain regulatory RNAs, associated with the process of apoptosis, presents data on the features of apoptosis in glioblastoma cells, and shows the relationship between regulatory RNAs and the apoptosis in tumor cells. In conclusion, potential target candidates are presented that are necessary for the development of new drugs for the treatment of glioblastoma.

Microtubule Cytoskeleton Remodeling by Nanosecond Pulsed Electric Fields

Remodeling of nanoscopic structures is not just crucial for cell biology, but it is also at the core of bioinspired materials. While the microtubule cytoskeleton in cells undergoes fast adaptation, adaptive materials still face this remodeling challenge. Moreover, the guided reorganization of the microtubule network and the correction of its abnormalities is still a major aim. This work reports new findings for externally triggered microtubule network remodeling by nanosecond electropulses (nsEPs). At first, a wide range of nsEP parameters, applied in a low conductivity buffer, is explored to find out the minimal nsEP dosage needed to disturb microtubules in various cell types. The time course of apoptosis and microtubule recovery in the culture medium is thereafter assessed. Application of nsEPs to cells in culture media result in modulation of microtubule binding properties to end-binding (EB1) protein, quantified by newly developed image processing techniques. The microtubules in nsEP-treated cells in the culture medium have longer EB1 comets but their density is lower than that of the control. The nsEP treatment represents a strategy for microtubule remodeling-based nano-biotechnological applications, such as engineering of self-healing materials, and as a manipulation tool for the evaluation of microtubule remodeling mechanisms during various biological processes in health and disease.

Changes in Apoptosis-Related Proteins in The Urothelium of Rat Bladder Following Partial Bladder Outlet Obstruction and Subsequent Relief.

Partial bladder outlet obstruction (PBOO) induces sustained bladder over-distension, leading to ischemia/reperfusion (I/R)-related oxidative damage of the urothelium via apoptosis. The present study aimed to investigate the sequential course of apoptosis in the urothelium of rat bladder and identify the changes in apoptosis-related proteins during PBOO and subsequent relief. Materials and Methods: The study was conducted using 60 female Sprague-Dawley rats divided into three groups: sham-operated, PBOO only, and PBOO plus subsequent relief. PBOO was induced for 2 weeks, and then the obstruction was relieved by removal of the ligature. The urothelium was assessed by a histological analysis, and expression levels of apoptosis-related proteins were detected by quantitative PCR and immunoblotting. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells were significantly increased in the PBOO only group when compared with the sham-operated group, and decreased in the PBOO relief group when compared with the PBOO group (P < 0.001). From the quantitative PCR and the western blot analyses, expression of Bax, caspase-3, P38, and Jnk was significantly increased in the PBOO group (P < 0.001). However, expression of Erk, Bcl-2 significantly decreased in the PBOO group (P < 0.001). The expression of Erk and Bcl-2 significantly increased in the PBOO relief group when compared with the PBOO group (P < 0.001). In comparison to the sham-operated group, expression levels of survivin significantly increased in both the PBOO and PBOO plus relief groups (P < 0.001). In addition, the expression levels were significantly different between the PBOO and PBOO plus relief groups (P < 0.001). PBOO induced apoptosis of urothelium is related to alterations in the MAPK signaling pathways and apoptosis-related protein change. These results may also suggest that the pro-survival Erk signaling cascade and the expression survivin are activated in response to ischemic bladder injury and associated with initiation of bladder restoration in PBOO and subsequent relief. However, the mechanism of survivin as anti-apoptotic protein in ischemic bladder injuries remains unclear.

Analysis and Identification of Active Compounds from Salviae miltiorrhizae Radix Toxic to HCT-116 Human Colon Cancer Cells

Colorectal cancer is one of the most frequently diagnosed cancers worldwide. The aim of the present study was to simultaneously analyze compounds of Salviae miltiorrhizae Radix (SMR) and determine their cytotoxic effects on HCT-116 human colorectal cancer cells. We established a simultaneous analysis method of five compounds (salvianic acid A, salvianolic acid B, caffeic acid, tanshinone IIA, and rosmarinic acid) contained in SMR, and found that among the various compounds in SMR, tanshinone IIA significantly decreased cell viability in a concentration-dependent manner. Hoechst staining also showed that both SMR and tanshinone IIA increased nuclear condensation, suggesting induction of apoptosis. By Western blotting, we found that tanshinone IIA induced apoptotic cell death, significantly increased Bax, but decreased Bcl-2 in the course of apoptosis. Tanshinone IIA increased the expression of cleaved caspases-7 and -8. Tanshinone IIA was shown to be an active ingredient of SMR that may be a useful chemotherapeutic strategy for patients with colorectal cancer.

Apoptosis and eryptosis: Striking differences on biomembrane level

The cell plasma membrane plays an essential role in programmed cell death of nucleated cells (apoptosis) and erythrocytes (eryptosis), and its changes due to loss of transmembrane asymmetry are quite similar. However, nucleated cells possess the network of intracellular membranes, which are missing in erythrocytes. Providing comparative studies with series of molecular probes, we observe dramatic differences in membrane lipid order in the course of apoptosis and eryptosis. In contrast to nucleated cells, in which a significant drop of the lipid order in the plasma membrane is observed, the erythrocyte membrane retains the relatively high level of the lipid order. Observation in nucleated cells of significant differences between inner and plasma membranes and detection of apoptotic bodies with different organization suggest that the decrease in the lipid order of their plasma membrane could be at least partially explained by the phospholipid and/or cholesterol exchange between membranes. Such features are absent in erythrocytes.

Apoptosis in the cochlear nucleus and inferior colliculus upon repeated noise exposure.

The time course of apoptosis and the corresponding neuronal loss was previously shown in central auditory pathway of mice after a single noise exposure. However, repeated acoustic exposure is a major risk factor for noise-induced hearing loss. The present study investigated apoptosis by terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling (TUNEL) assay after a second noise trauma in the ventral and dorsal cochlear nucleus and central nucleus of the inferior colliculus. Mice [Naval Medical Research Institute (NMRI) strain] were noise exposed [115 dB sound pressure level, 5–20 kHz, 3 h) at day 0. A double group received the identical noise exposure a second time at day 7 post-exposure and apoptosis was either analyzed immediately (7-day group-double) or 1 week later (14-day group-double). Corresponding single exposure groups were chosen as controls.No differences in TUNEL were seen between 7-day or 14-day single and double-trauma groups. Interestingly, independent of the second noise exposure, apoptosis increased significantly in the 14-day groups compared to the 7-day groups in all investigated areas.It seems that the first noise trauma has a long-lasting effect on apoptotic mechanisms in the central auditory pathway that were not largely influenced by a second trauma. Homeostatic mechanisms induced by the first trauma might protect the central auditory pathway from further damage during a specific time slot. These results might help to understand the underlying mechanisms of different psychoacoustic phenomena in noise-induced hearing loss.

Apoptotic Effects of Temozolomide and Naturopathic Agents upon Glioblastoma Cells

Temozolomide (TMZ), thymoquinone (TMQ), epigallocatechin gallate (EPIGAL) and staurosporine (STAURO) were used as apoptotic inducing agents acting upon the U87-MG (ATCC, HTB15), LN18 (ATCC, CRL2610) and U118-MG (ATCC, HTB14) glioblastoma multiforme (GBM) cell lines. TMZ is the current drug of choice for primary treatment and adjuvant therapy for recurrent GBM. TMQ and EPIGAL are naturopathic agents, while STAURO is a well-studied apoptotic-inducing agent. The degree and time course of apoptosis were measured by flow cytometry techniques capable of detecting changes in mitochondrial function using the fluorescent dye MitoTracker Deep Red. Phosphatidylserine exposure and plasma membrane permeability were detected simultaneously using violet fluorescent reactive dye (VFRD) in combination with AnnexinV-488. The apoptotic effectiveness of the inducing agents TMZ, TMQ, EPIGAL and STAURO were compared with their ability to inhibit invasiveness and degrade Class I major histocompatibility complex (MHC) determinants. Invasiveness was measured in vitro by the 3D matrigel spheroid invasion assay. The density of the class 1 MHC determinants was measured by flow cytometry. Although TMZ is widely used for the chemotherapeutic treatment of GBM, it was determined that the time course for TMZ induced apoptosis was slower than those of TMQ, EPIGAL and STAURO. Unexpectedly, TMZ was ineffective in its ability to inhibit in vitro invasiveness and did not degrade the class I MHC determinants as effectively as the other apoptotic inducing agents. The findings raise the question of whether in vitro assays of apoptosis and invasiveness are the best measures of the effectiveness of chemotherapeutic agents for the primary treatment and adjuvant therapy of recurrent GBM. The findings also point to the in vivo complexity of the efficacy of chemotherapeutic agents whereby preserving the components of natural and acquired immune mechanisms may be more important than the rapid apoptotic effects of the chemotherapeutic agent.

Nitric Oxide Production in the Striatum and Cerebellum of a Rat Model of Preterm Global Perinatal Asphyxia

Encephalopathy due to perinatal asphyxia (PA) is a major cause of neonatal morbidity and mortality in the period around birth. Preterm infants are especially at risk for cognitive, attention and motor impairments. Therapy for this subgroup is limited to supportive care, and new targets are thus urgently needed. Post-asphyxic excitotoxicity is partially mediated by excessive nitric oxide (NO) release. The aims of this study were to determine the timing and distribution of nitric oxide (NO) production after global PA in brain areas involved in motor regulation and coordination. This study focused on the rat striatum and cerebellum, as these areas also affect cognition or attention, in addition to their central role in motor control. NO/peroxynitrite levels were determined empirically with a fluorescent marker on postnatal days P5, P8 and P12. The distributions of neuronal NO synthase (nNOS), cyclic guanosine monophosphate (cGMP), astroglia and caspase-3 were determined with immunohistochemistry. Apoptosis was additionally assessed by measuring caspase-3-like activity from P2-P15. On P5 and P8, increased intensity of NO-associated fluorescence and cGMP immunoreactivity after PA was apparent in the striatum, but not in the cerebellum. No changes in nNOS immunoreactivity or astrocytes were observed. Modest changes in caspase-3-activity were observed between groups, but the overall time course of apoptosis over the first 11 days of life was similar between PA and controls. Altogether, these data suggest that PA increases NO/peroxynitrite levels during the first week after birth within the striatum, but not within the cerebellum, without marked astrogliosis. Therapeutic benefits of interventions that reduce endogenous NO production would likely be greater during this time frame.

Programmed cell self-liquidation (apoptosis)

Abstract Brief characteristic of self-liquidation phenomenon (apoptosis) encoded (programmed) in living cell genome is presented. Great resemblance in course of apoptosis in plant and animal cells is shown. In both cases, sequence of single components of this complex process may be even interchangeable. For instance, a gene, similar to animal DAD-1 protecting cell from apoptosis, is found in plants. Upon plant aging or seed dehydratation, gene activity and resistance to apoptosis decrease dramatically. During development of apoptosis, first, proteolytic enzymes are activated. Among them, cysteine proteinases, particularly, caspases hydrolyzing great number of structural proteins and protein enzymes acquire special importance. Mitochondria-dependent apoptosis (mitoptosis) is discussed in the review. At this time, changes in mitochondrial membrane permeability occur. Reactive oxygen species (mainly, superoxide anion-radicals), generated in respiratory chain, participate there. Upon increase in concentrations, ATP/ADP antiporter is converted into gigantic channel, by means of which cytochrome c starts entering cytosol. AIF, capable of activating cytosolic proteinases, also leaves mitochondria. After entering cytosol, cytochrome c with cytoplasmic APAF-1, participates in activation of caspase-9. At this time, APAF-1, which contains CARD-domain, together with cytochrome c binds procaspase-9, also containing CARD-domain, and so apoptosome complex is formed. Procaspase-9 undergoes conformational changes, and obtained in such a way caspase-9, by-turn converts procaspase-3 into caspase-3. The latter plays a leading role of effector in apoptosis. In plants, apoptosis is controlled directly by the ratio of cysteine proteinases and corresponding inhibitors, which can modulate apoptosis.

Computational Systems Biology Approach Predicts Regulators and Targets of microRNAs and Their Genomic Hotspots in Apoptosis Process.

Novel computational systems biology tools such as common targets analysis, common regulators analysis, pathway discovery, and transcriptomic-based hotspot discovery provide new opportunities in understanding of apoptosis molecular mechanisms. In this study, after measuring the global contribution of microRNAs in the course of apoptosis by Affymetrix platform, systems biology tools were utilized to obtain a comprehensive view on the role of microRNAs in apoptosis process. Network analysis and pathway discovery highlighted the crosstalk between transcription factors and microRNAs in apoptosis. Within the transcription factors, PRDM1 showed the highest upregulation during the course of apoptosis, with more than 9-fold expression increase compared to non-apoptotic condition. Within the microRNAs, MIR1208 showed the highest expression in non-apoptotic condition and downregulated by more than 6 fold during apoptosis. Common regulators algorithm showed that TNF receptor is the key upstream regulator with a high number of regulatory interactions with the differentially expressed microRNAs. BCL2 and AKT1 were the key downstream targets of differentially expressed microRNAs. Enrichment analysis of the genomic locations of differentially expressed microRNAs led us to the discovery of chromosome bands which were highly enriched (p<0.01) with the apoptosis-related microRNAs, such as 13q31.3, 19p13.13, and Xq27.3 This study opens a new avenue in understanding regulatory mechanisms and downstream functions in the course of apoptosis as well as distinguishing genomic-enriched hotspots for apoptosis process.

MOLECULAR APOPTOSIS MECHANISMS WITH UNDERLYING EXPERIMENTAL ACUTE LUNG INJURY

&lt;p&gt;Background. Current data suggest systemic autoimmune activation in the pathogenesis of bronchopulmonary&lt;br /&gt;diseases. The imbalance in the system of pro- and anti-inflammatory cytokines is very important in&lt;br /&gt;immunopathogenesis.&lt;br /&gt;Objective. The aim of our research was to determine the caspase-3 rate in the dynamics of experimental&lt;br /&gt;acute lung injury and to study the relationship between their level and the number of cells carrying membrane&lt;br /&gt;binding TNF receptor type 1 to define the main mechanisms of cell death.&lt;br /&gt;Results. The analysis of the results of caspase-3 rate in lung homogenate showed that this cysteine proteinase&lt;br /&gt;was uniformly increasing in all experimental groups during simulating of ALI induced by administration of&lt;br /&gt;hydrochloric acid (p&amp;lt;0.001). When comparing the results of caspase course of apoptosis it was defined that,&lt;br /&gt;despite the progressive increase in caspase-3 rate in lung homogenate, cysteine proteinase rate in plasma did&lt;br /&gt;not change.&lt;br /&gt;The receptor mechanism of apoptosis was studied by establishing correlation relationships with the number&lt;br /&gt;of cells carrying membrane binding TNF type 1 (TNF-R1) receptor. A strong positive correlation relationship&lt;br /&gt;between the number of neutrophils with TNF-R1 and caspase-3 rate in lungs of all research groups was&lt;br /&gt;determined.&lt;br /&gt;Conclusions. The implementation of neutrophils death by apoptosis is caused by change of activity of&lt;br /&gt;caspase cascade effector components, such as caspase-3, in cases of ALI induced by intratracheal administration&lt;br /&gt;of hydrochloric acid. One of the potential mechanisms responsible for the activation of caspase course is excessive&lt;br /&gt;generation of active forms of oxygen and increase in the number of neutrophils carrying membrane binding TNF&lt;br /&gt;receptor type 1.&lt;br /&gt;KEY WORDS: caspase-3, tumour necrosis factor alpha receptor 1, acute lung injury&lt;/p&gt;

Time course of apoptosis induced by photodynamic therapy with PsD007 in LT12 acute myeloid leukemia cells.

Apoptosis is one of the major mechanisms of photodynamic therapy (PDT) that leads to tumor degradation. Apoptosis-related genes and proteins function in a certain order and timing in the complex network of apoptosis. To further understanding of the apoptotic mechanism of PDT, this research examined the time course of apoptosis from PsD007 (a second-generation photosensitizer developed in China) induced PDT on the rat acute myeloid leukemia cell line LT12. MTT was used to detect the temporal dynamic of PDT killing effects and identified the "apoptotic window" of 2-24h. Apoptosis showed a basal peak at 2h, and the duration of apoptosis depended on PDT dose, which disappeared quickly at low concentrations but lasted to higher levels to 6 or 12h at high concentrations as detected by flow cytometry. High-content imaging confirmed these results. An 84-gene apoptosis PCR array identified 15 genes with an expression level change of over twofold at 6h post-PDT. Nine apoptosis-related genes showed changes in expression at 2-12h after PDT. TNF family genes TNF and FASLG showed a maximal change of 3.47- and 4.42-fold from baseline. Key apoptosis proteins such as activated caspases showed strong up-regulation after PDT, with the expression peaks of cleaved caspase-7, caspase-9 and PARP at 4-6h, and cleaved caspase-3 delayed to 6-12h. Our findings help clarify the time course of apoptosis events in response to PDT treatment in a leukemia cell line and may help contribute to the clinical application of PDT in leukemia treatment.

Nuclease Activity Associated with Secreting Granules by Lymphocytes in Patients with Bronchial Asthma

Background: We know, through recent studies, the existence of some morpho-biochemical peculiarities in the process of type 1 programmed death of patients’ lymphocytes suffering from bronchial asthma, but little convincing data exist on the activity of enzymes involved in this physiological process. Therefore, the aim of our research was to study the enzymatic activity of secreting granules of patients’ lymphocytes with bronchial asthma, according to the degree of severity. Method: The study was based on the role of granular extracts in the process of programmed death isolated lymphocytes from peripheral blood of relatively healthy individuals and asthmatic patients with different severity. The immunological characteristics of lymphocytes was done with the radial immune-diffusion method and ELISA test but the method of agarose gel electrophoresis help us to detect the catalytic activity of protein extracts of secreting granules of lymphocytes. Results: The results obtained showed that lymphocytes from asthmatic patients with severe severity are characterized by a decrease in cytotoxic T lymphocytes content balanced by an increase in T-Helper lymphocytes. We also noticed the enzymatic activity at all the groups studied but this activity was relatively high in asthmatics with severe severity. Furthermore, the study of the cationic dependence has allowed to establish an increase in enzymatic activity in all the groups studied after incubation of DNA in a medium containing Ca2+ with a pH of 7.5 unlike ions Mn2+ which seem to reduce the enzymatic activity. The expression of enzymatic activity in the presence of zinc allows us to suggest the presence of DNase acid in granules, which activity is not necessarily associated with divalent metal ions. Conclusion: Based on the above results, one might conclude that the secreting granules have a high enzymatic activity but with a strong cationic dependence. This not only allows a better understanding of the morphological changes observed during the course of apoptosis in lymphocytes of patients but also brings more to the knowledge of the enzymatic influence in the process of type 1 programmed death.

Proliferative events and apoptotic remodelling in retinal development of common toad (Bufo bufo).

Proliferation and apoptosis are fundamental processes in the development of the retina, and a proper balance of the two phenomena is crucial to correct development of the organ. Despite intense investigation in different vertebrates, only a few studies have analyzed the cell death and the cell division quantitatively in the same species during development. Here we studied the time course of apoptosis and proliferation in the retina of common toad, Bufo bufo, and discuss the findings in an evolutionary perspective. We found cells that were dividing first scattered throughout the retina, then, in later stages, proliferation was confined to the ciliary marginal zone. This pattern was confirmed by the expression of the proliferative marker PCNA. Both proliferation and apoptosis occurred in successive waves, and two apoptotic peaks were detected: one at premetamorphosis 1 and the second at prometamorphosis. PARP-1, a known molecular marker of apoptosis, was used to confirm the data obtained by counting pyknotic nuclei. In summary, proliferative and apoptotic waves display an inverse time-relationship through development, with apoptotic peaks coinciding with low proliferation phases. In a comparative perspective, amphibians follow a developmental pattern similar to other vertebrates, although with different timing.

Low temperature-induced circulating triiodothyronine accelerates seasonal testicular regression.

In temperate zones, animals restrict breeding to specific seasons to maximize the survival of their offspring. Birds have evolved highly sophisticated mechanisms of seasonal regulation, and their testicular mass can change 100-fold within a few weeks. Recent studies on Japanese quail revealed that seasonal gonadal development is regulated by central thyroid hormone activation within the hypothalamus, depending on the photoperiodic changes. By contrast, the mechanisms underlying seasonal testicular regression remain unclear. Here we show the effects of short day and low temperature on testicular regression in quail. Low temperature stimulus accelerated short day-induced testicular regression by shutting down the hypothalamus-pituitary-gonadal axis and inducing meiotic arrest and germ cell apoptosis. Induction of T3 coincided with the climax of testicular regression. Temporal gene expression analysis over the course of apoptosis revealed the suppression of LH response genes and activation of T3 response genes involved in amphibian metamorphosis within the testis. Daily ip administration of T3 mimicked the effects of low temperature stimulus on germ cell apoptosis and testicular mass. Although type 2 deiodinase, a thyroid hormone-activating enzyme, in the brown adipose tissue generates circulating T3 under low-temperature conditions in mammals, there is no distinct brown adipose tissue in birds. In birds, type 2 deiodinase is induced by low temperature exclusively in the liver, which appears to be caused by increased food consumption. We conclude that birds use low temperature-induced circulating T3 not only for adaptive thermoregulation but also to trigger apoptosis to accelerate seasonal testicular regression.

Abstract 4393: miR-138 overexpression most effectively enhanced efficacy of apigenin to impair cell cycle progression and induce apoptosis in human malignant neuroblastoma SK-N-DZ and SK-N-BE2 cells in vivo

Abstract Malignant neuroblastoma, which mostly occurs in children, remains incurable with conventional chemotherapeutic agents. Innovative therapeutic strategies must be developed to control the growth of this childhood malignancy. Inhibition of cyclin D3 may induce cell cycle arrest and apoptosis in human malignant neuroblastoma. Also, inhibition of the catalytic component of human telomerase reverse transcriptase (hTERT) may induce apoptosis in many human cancers including malignant neuroblastoma. Decrease in expression of the tumor suppressor microRNA-138 (miR-138) is often associated with increases in expression of hTERT and cyclin D3. We hypothesized that miR-138 overexpression could be a better therapeutic strategy than hTERT knockdown to potentiate pro-apoptotic effect of apigenin (APG), a plant-derived flavonoid, in human malignant neuroblastoma. We found that transfection of miR-138 mimics was more powerful than transfection of hTERT shRNA plasmid in potentiating efficacy of APG for decreasing cell viability in human neuroblastoma SK-N-DZ and SK-N-BE2 cells. We then examined comparative effectiveness of different treatment strategies in reducing tumor growth and inducing apoptosis in SK-N-DZ and SK-N-BE2 xenografts in athymic nude mice. Combination of miR-138 overexpression and APG treatment showed better efficacy than combination of hTERT knockdown and APG treatment in reducing tumor growth and inducing cell death in both neuroblastoma xenograft models. According to the microRNA database (miRDB), miR-138 may target and inhibit expression of cyclin D3 so as to impair cell cylce progression. Combination of miR-138 overexpression and APG treatment caused the highest inhibition of expression of cyclin D3, CDK4, and CDK6, which were required for G1/S transition in cell cycle. Down regulation of cyclin D3 could inhibit phosphorylation of the tumor suppressor Rb and impair cell cycle progression. We delineated that apoptosis occurred with induction of molecular components of extrinsic and intrinsic pathways in the xenografts. Combination of miR-138 overexpression and APG treatment most effectively activated caspase-8 and cleaved Bid to tBid to induce extrinsic pathway of apoptosis and also raised Bax:Bcl-2 ratio to trigger intrinsic pathway of apoptosis with mitochondrial release of Smac into the cytosol to neutralize a set of endogenous inhibitor-of-apoptosis proteins such as Survivin so as to facilitate activation of caspase-3. Activation of both calpain and caspase-3 caused proteolysis of α-spectrin to generate calpain-specific 145 kD SBDP and caspase-3-specific 120 kD SBDP, respectively, in course of apoptosis in the xenografts. In conclusion, miR-138 overexpression was more powerful than hTERT knockdown in enhancing pro-apoptotic effect of APG for controlling growth of human malignant neuroblastomas in vivo. Citation Format: Mrinmay Chakrabarti, Walden Ai, Swapan K. Ray. miR-138 overexpression most effectively enhanced efficacy of apigenin to impair cell cycle progression and induce apoptosis in human malignant neuroblastoma SK-N-DZ and SK-N-BE2 cells in vivo. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4393. doi:10.1158/1538-7445.AM2014-4393

Essential versus accessory aspects of cell death: recommendations of the NCCD 2015.

Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death' (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death' (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death.

Efeito de anti-inflamatórios não esteroidais na apoptose de células epidermais lamelares de equinos com laminite

O objetivo deste trabalho foi avaliar a influência da administração dos anti-inflamatórios não esteroidais (AINEs) cetoprofeno, fenilbutazona e flunixin meglumine sobre o índice apoptótico de células epiteliais do tecido lamelar de cavalos com laminite induzida por administração de amido. Foram empregados 20 equinos hígidos, divididos em quatro grupos experimentais (n=5): solução salina, cetoprofeno, fenilbutazona e flunixin meglumine. O tecido lamelar foi coletado por biópsia, fixado e corado pela técnica de TUNEL. À marcação positiva por essa técnica adicionou-se a avaliação morfológica celular para identificação da apoptose. Não houve diferença significativa no índice apoptótico entre os grupos tratados com anti-inflamatórios e o controle (P&gt;0,05). Os anti-inflamatórios não interferiram sobre o índice apoptótico possivelmente porque foram administrados após a fase prodrômica da laminite e/ou porque não são eficazes em alterar a dinâmica da apoptose. Concluiu-se que a administração de anti-inflamatórios não esteroidais após a fase prodrômica da laminite não contribui para uma intervenção no curso da apoptose no tecido lamelar de cavalos com laminite quando comparados ao grupo controle não tratado. Outros estudos, com diferentes períodos de avaliação, são necessários para esclarecer os efeitos dos anti-inflamatórios não esteroidais na fisiopatologia da laminite em equinos, especialmente no que concerne à participação da apoptose.

Cardioprotective C-kit+ Bone Marrow Cells Attenuate Apoptosis after Acute Myocardial Infarction in Mice - In-vivo Assessment with Fluorescence Molecular Imaging

Cardiomyocyte loss via apoptosis plays a crucial role in ventricular remodeling following myocardial infarction (MI). Cell-based therapy approaches using bone marrow derived c-kit+ pluripotent cells may attenuate apoptosis following ischemic injury. We therefore thought to examine the early course of apoptosis following myocardial infarction - in-vivo - and non-invasively determine the effect of c-kit+ bone marrow cells on post-MI remodeling. We studied apoptosis in wild-type Kit+/+, c-kit mutant KitW/KitW-v and KitW/KitW-v mice after cell therapy with bone-marrow derived c-kit+ cells after ischemia-reperfusion injury. Mice were followed by hybrid Fluorescence Molecular Tomography/X-ray Computed Tomography (FMT-XCT) at 6h, 24h and 7 days after ischemia-reperfusion injury using an Annexin V-based fluorescent nanosensor targeting phosphatidylserine. KitW/KitW-v mice showed increased and prolonged apoptosis compared to control Kit+/+ mice while c-kit cell therapy was able to attenuate the altered apoptosis rates. Increased apoptosis was accompanied by severe decline in heart function, determined by cardiac Magnetic Resonance Imaging, and cell therapy was able to rescue the animals from deleterious heart failure. Post-mortem cryoslicing and immunohistochemistry localized the fluorescence signal of the Annexin V sensor within the infarcted myocardium. Flow cytometry of digested infarct specimens identified apoptotic cardiomyocytes as the major source for the in-vivo Annexin V signal.In-vivo molecular imaging using hybrid FMT-XCT reveals increased cardiomyocyte apoptosis in KitW/KitW-v mice and shows that c-kit+ cardioprotective cells are able to attenuate post-MI apoptosis and rescue mice from progressive heart failure.

Stabilization of MAPO1 by specific binding with folliculin and AMP-activated protein kinase in O6-methylguanine-induced apoptosis

When DNA is damaged by alkylating agents, apoptosis is induced to exclude cells carrying DNA lesions in order to prevent mutations and cancer. MAPO1, identified as a component involved in the induction of apoptosis, interacts with AMP-activated protein kinase (AMPK) and folliculin (FLCN). We herein report that MAPO1 is stabilized during the course of apoptosis, triggered by alkylation-induced O6-methylguanine in DNA. An immunoblotting analysis revealed that the amount of MAPO1 increased gradually after treatment with N-methyl-N-nitrosourea (MNU), although the level of mRNA for MAPO1 was unchanged. When cells were exposed to a proteasome inhibitor, MG132, the MAPO1 level significantly increased. On the other hand, application of a protein synthesis inhibitor, cycloheximide, caused a decrease in the MAPO1 content, implying that proteasome-mediated degradation is involved. In FLCN-knockdown cells, the MAPO1 level decreased, and no increases occurred even after MNU treatment. In contrast, stabilization of MAPO1 occurred in AMPKα-knockdown cells even without MNU treatment. While MAPO1 retains its ability to stably bind to FLCN, it dissociates gradually from AMPK after exposure to MNU. It seems that the proapoptotic function of MAPO1 may be regulated by AMPK and FLCN through stabilization of MAPO1 itself.