scholarly journals Electrochemical Response of Saccharomyces cerevisiae Corresponds to Cell Viability upon Exposure to Dioclea reflexa Seed Extracts and Antifungal Drugs

Biosensors ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 45
Author(s):  
Patrick Arthur ◽  
Anthony Yeboah ◽  
Ibrahim Issah ◽  
Srinivasan Balapangu ◽  
Samuel Kwofie ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Death ◽  
Cell Growth ◽  
Cell Viability ◽  
Bioactive Compounds ◽  
Electrochemical Behavior ◽  
Peak Current ◽  
Water Extracts ◽  
Anodic Peak Current ◽  
Seed Extracts

Dioclea reflexa bioactive compounds have been shown to contain antioxidant properties. The extracts from the same plant are used in traditional medical practices to treat various diseases with impressive outcomes. In this study, ionic mobility in Saccharomyces cerevisiae cells in the presence of D. reflexa seed extracts was monitored using electrochemical detection methods to link cell death to ionic imbalance. Cells treated with ethanol, methanol, and water extracts were studied using cyclic voltammetry and cell counting to correlate electrochemical behavior and cell viability, respectively. The results were compared with cells treated with pore-forming Amphotericin b (Amp b), as well as Fluconazole (Flu) and the antimicrobial drug Rifampicin (Rif). The D. reflexa seed water extract (SWE) revealed higher anodic peak current with 58% cell death. Seed methanol extract (SME) and seed ethanol extract (SEE) recorded 31% and 22% cell death, respectively. Among the three control drugs, Flu revealed the highest cell death of about 64%, whereas Amp b and Rif exhibited cell deaths of 35% and 16%, respectively, after 8 h of cell growth. It was observed that similar to SWE, there was an increase in the anodic peak current in the presence of different concentrations of Amp b, which also correlated with enhanced cell death. It was concluded from this observation that Amp b and SWE might follow similar mechanisms to inhibit cell growth. Thus, the individual bioactive compounds from the water extracts of D. reflexa seeds could further be purified and tested to validate their potential therapeutic application. The strategy to link electrochemical behavior to biochemical responses could be a simple, fast, and robust screening technique for new drug targets and to understand the mechanism of action of such drugs against disease models.

scholarly journals Regulation of survivin expression through Bcr-Abl/MAPK cascade: targeting survivin overcomes imatinib resistance and increases imatinib sensitivity in imatinib-responsive CML cells

Blood ◽  
2006 ◽  
Vol 107 (4) ◽  
pp. 1555-1563 ◽  
Author(s):  
Bing Z. Carter ◽  
Duncan H. Mak ◽  
Wendy D. Schober ◽  
Maria Cabreira-Hansen ◽  
Miloslav Beran ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Growth ◽  
Cell Viability ◽  
Blast Crisis ◽  
Philadelphia Chromosome ◽  
Survivin Expression ◽  
Annexin V ◽  
Mapk Cascade ◽  
Myelogenous Leukemia ◽  
Imatinib Resistance

KBM5 cells, derived from a patient with blast crisis Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML), and imatinib-resistant KBM5 (KBM5-STI571) cells were found to express high levels of survivin. Inhibition of Bcr-Abl by imatinib significantly decreased survivin expression and cell viability in KBM5, but much less so in KBM5-STI571 cells. Inhibition of MEK, downstream of the Bcr-Abl signaling cascade decreased survivin expression and cell viability in both KBM5 and KBM5-STI571 cells. In addition, down-regulation of survivin by a survivin antisense oligonucleotide (Sur-AS-ODN) inhibited cell growth and induced maximal G2M block at 48 hours, whereas cell death was observed only at 72 hours in both KBM5 and KBM5-STI571 cells as shown by annexin V staining. Further, the combination of Sur-AS-ODN and imatinib induced more cell death in KBM5 cells than did either treatment alone. Down-regulating survivin also decreased colony-forming units (CFUs) in blast crisis CML patient samples. Our data therefore suggest that survivin is regulated by the Bcr-Abl/MAPK cascade in Ph+ CML. The facts that down-regulating survivin expression induced cell-growth arrest and subsequent cell death regardless of the cell response to imatinib and enhanced the sensitivity to imatinib suggest the potential therapeutic utility of this strategy in patients with CML, both imatinib sensitive and resistant.

Reactive Oxygen Species Regulate Spontaneous and Fas-Mediated Apoptosis in SBDS-Deficient Cells.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2036-2036
Author(s):  
Chhaya Ambekar ◽  
Bikul Das ◽  
Herman Yeger ◽  
Yigal Dror
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Cell Death ◽  
Cell Growth ◽  
Cell Viability ◽  
Cell Survival ◽  
Annexin V ◽  
Necrotic Cell Death ◽  
Oxygen Species ◽  
Necrotic Cell

Abstract Background and hypotheses: Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterized by bone marrow failure, pancreatic insufficiency, and a marked propensity for myelodysplastic syndrome and leukemia. Approximately 90% of the patients have mutations in the SBDS gene, but the function of the gene is unknown. We previously showed that marrow cells from SDS patients and SBDS-deficient HeLa Cells are characterized by accelerated apoptosis, overexpression of Fas and hypersensitive to Fas stimulation. Involvement of reactive oxygen species (ROS; oxidative stress) have been shown to be related to Fas hypersensitivity and overexpression in a variety of cell types. Therefore, we hypothesized that functional deficiency in SBDS in cells that express Fas could lead to impaired ROS generation and a subsequent increase in spontaneous and Fas-mediated apoptosis and decrease in cell growth. Methods: We used shRNA-mediated SBDS-knockdown HeLa cells as a model. We investigated whether SBDS-deficiency increases ROS levels and if antioxidants can rescue the cell growth and apoptosis phenotype. To measure ROS formation cells were incubated with DCFH-DA and fluorescence measured in Gemini Spectra MAX microplate reader. Staining with annexin V and propidium iodide was done to determine apoptosis and necrotic cell death. MTT assay was used to measure cell viability. Results: ROS levels in SBDS knockdown cells were significantly increased compared to control. Apoptosis analysis by annexin V and propidium iodide showed a marked decrease in cell viability in the SBDS-knockdown cells. NAC treatment decreased ROS levels, enhanced ERK phosphorylation (pERK), improved cell viability, and decreased apoptotic and necrotic cell death. Stimulation of the Fas signaling pathway by CH-11 (activating anti-Fas antibody) and Fas ligand showed increased ROS production in SBDS Knockdown cells. CH-11 treatment showed a marked increase in apoptotic and necrotic cell death after 24 and 48hrs incubation. Cell viability decreased by 40% and 80% after 24 and 48hrs incubation with CH-11. Treatment with NAC lowered ROS levels, enhanced pERK expression, protected the cells from Fas-mediated early apoptosis and improved cell survival. Conclusion: We have demonstrated that stable loss of SBDS results in increased ROS levels, leading to apoptotic and necrotic cell death. Thus, increased baseline and Fas-stimulated ROS could result in increased sensitivity to apoptosis and necrotic cell death. NAC appeared to reverse the ROS-mediated decrease in cell survival and apoptotic cell death. Our data support the novel concept that SBDS may be a homeostatic regulator of oxidative stress

scholarly journals INOSITOL-REQUIRING MUTANTS OF SACCHAROMYCES CEREVISIAE

Genetics ◽  
1975 ◽  
Vol 80 (1) ◽  
pp. 23-40
Author(s):  
Michael R Culbertson ◽  
Susan A Henry
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Death ◽  
Cell Viability ◽  
Cellular Localization ◽  
Physiological Role ◽  
Membrane Phospholipids ◽  
Tetrad Analysis ◽  
Unbalanced Growth ◽  
Liquid Cultures ◽  
And Function

ABSTRACT Fifty-two inositol-requiring mutants of Saccharomyces cerevisiae were isolated following mutagenesis with ethyl methanesulfonate. Complementation and tetrad analysis revealed ten major complementation classes, representing ten independently segregating loci (designated in01 through inol0) which recombined freely with their respective centromeres. Members of any given complementation class segregated as alleles of a single locus. Thirteen complementation subclasses were identified among thirty-six mutants which behaved as alleles of the inol locus. The complementation map for these mutants was circular.—Dramatic cell viability losses indicative of unbalanced growth were observed in liquid cultures of representative mutants under conditions of inositol starvation. Investigation of the timing, kinetics, and extent of cell death revealed that losses in cell viability in the range of 2-4 log orders could be prevented by the addition of inositol to the medium or by disruption of protein synthesis with cycloheximide. Mutants defective in nine of the ten loci identified in this study displayed these unusual characteristics. The results suggest an important physiological role for inositol that may be related to its cellular localization and function in membrane phospholipids. The possibility is discussed that inositol deficiency initiates the process of unbalanced growth leading to cell death through the loss of normal assembly, function, or integrity of biomembranes—Part of this work has been reported in preliminary form (CULBERTSON and HENRY1 974).

Stew in its Own Juice: Protein Homeostasis Machinery Inhibition Reduces Cell Viability in Multiple Myeloma Cell Lines

2019 ◽  
Vol 19 (2) ◽  
pp. 112-119 ◽  
Author(s):  
Mariana B. de Oliveira ◽  
Luiz F.G. Sanson ◽  
Angela I.P. Eugenio ◽  
Rebecca S.S. Barbosa-Dantas ◽  
Gisele W.B. Colleoni
Keyword(s):  
Multiple Myeloma ◽  
Cell Death ◽  
Cell Viability ◽  
Cell Lines ◽  
Treatment Options ◽  
Compensatory Mechanism ◽  
Protein Homeostasis ◽  
Protein Response ◽  
Rpmi 8226

Introduction:Multiple myeloma (MM) cells accumulate in the bone marrow and produce enormous quantities of immunoglobulins, causing endoplasmatic reticulum stress and activation of protein handling machinery, such as heat shock protein response, autophagy and unfolded protein response (UPR).Methods:We evaluated cell lines viability after treatment with bortezomib (B) in combination with HSP70 (VER-15508) and autophagy (SBI-0206965) or UPR (STF- 083010) inhibitors.Results:For RPMI-8226, after 72 hours of treatment with B+VER+STF or B+VER+SBI, we observed 15% of viable cells, but treatment with B alone was better (90% of cell death). For U266, treatment with B+VER+STF or with B+VER+SBI for 72 hours resulted in 20% of cell viability and both treatments were better than treatment with B alone (40% of cell death). After both triplet combinations, RPMI-8226 and U266 presented the overexpression of XBP-1 UPR protein, suggesting that it is acting as a compensatory mechanism, in an attempt of the cell to handle the otherwise lethal large amount of immunoglobulin overload.Conclusion:Our in vitro results provide additional evidence that combinations of protein homeostasis inhibitors might be explored as treatment options for MM.

scholarly journals CBIO-07. CELL DEATH INDUCED BY AN OSCILLATING MAGNETIC FIELD IN PATIENT DERIVED GLIOBLASTOMA CELLS IS MEDIATED BY REACTIVE OXYGEN SPECIES

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii17-ii17
Author(s):  
Shashank Hambarde ◽  
Martyn Sharpe ◽  
David Baskin ◽  
Santosh Helekar
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Cell Viability ◽  
Cortical Neurons ◽  
Reactive Oxygen ◽  
Great Promise ◽  
Antioxidant Vitamin ◽  
Ros Generation ◽  
Oxygen Species ◽  
Novel Therapy

Abstract Noninvasive cancer therapy with minimal side effects would be ideal for improving patient outcome in the clinic. We have developed a novel therapy using strong rotating magnets mounted on a helmet. They generate oscillating magnetic fields (OMF) that penetrate through the skull and cover the entire brain. We have demonstrated that OMF can effectively kill patient derived glioblastoma (GBM) cells in cell culture without having cytotoxic effects on cortical neurons and normal human astrocytes (NHA). Exposure of GBM cells to OMF reduced the cell viability by 33% in comparison to sham-treated cells (p< 0.001), while not affecting NHA cell viability. Time lapse video-microscopy for 16 h after OMF exposure showed a marked elevation of mitochondrial reactive oxygen species (ROS), and rapid apoptosis of GBM cells due to activation of caspase 3. Addition of a potent antioxidant vitamin E analog Trolox effectively blocked OMF-induced GBM cell death. Furthermore, OMF significantly potentiated the cytotoxic effect of the pro-oxidant Benzylamine. The results of our studies demonstrate that OMF-induced cell death is mediated by ROS generation. These results demonstrate a potent oncolytic effect on GBM cells that is novel and unrelated to any previously described therapy, including a very different mechanism of action and different technology compared to Optune therapy. The effect is very powerful, and unlike Optune, can be seen within hours after initiation of treatment. We believe that this technology holds great promise for new, effective and nontoxic treatment of glioblastoma.

scholarly journals Translation machinery reprogramming in programmed cell death in Saccharomyces cerevisiae

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Francesco Monticolo ◽  
Emanuela Palomba ◽  
Maria Luisa Chiusano
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Death ◽  
Acetic Acid ◽  
Programmed Cell Death ◽  
Differential Expression ◽  
Ribosomal Proteins ◽  
Relative Proportion ◽  
Duplication Event ◽  
Genome Duplication Event ◽  
Cell Death Pathway

AbstractProgrammed cell death involves complex molecular pathways in both eukaryotes and prokaryotes. In Escherichia coli, the toxin–antitoxin system (TA-system) has been described as a programmed cell death pathway in which mRNA and ribosome organizations are modified, favoring the production of specific death-related proteins, but also of a minor portion of survival proteins, determining the destiny of the cell population. In the eukaryote Saccharomyces cerevisiae, the ribosome was shown to change its stoichiometry in terms of ribosomal protein content during stress response, affecting the relative proportion between ohnologs, i.e., the couple of paralogs derived by a whole genome duplication event. Here, we confirm the differential expression of ribosomal proteins in yeast also during programmed cell death induced by acetic acid, and we highlight that also in this case pairs of ohnologs are involved. We also show that there are different trends in cytosolic and mitochondrial ribosomal proteins gene expression during the process. Moreover, we show that the exposure to acetic acid induces the differential expression of further genes coding for products related to translation processes and to rRNA post-transcriptional maturation, involving mRNA decapping, affecting translation accuracy, and snoRNA synthesis. Our results suggest that the reprogramming of the overall translation apparatus, including the cytosolic ribosome reorganization, are relevant events in yeast programmed cell death induced by acetic acid.

scholarly journals LONP1 and ClpP cooperatively regulate mitochondrial proteostasis for cancer cell survival

Oncogenesis ◽  
2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Yu Geon Lee ◽  
Hui Won Kim ◽  
Yeji Nam ◽  
Kyeong Jin Shin ◽  
Yu Jin Lee ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Growth ◽  
Cell Survival ◽  
Cancer Cell ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Tca Cycle ◽  
Mitochondrial Matrix ◽  
Mitochondrial Functions ◽  
Cancer Cell Survival

AbstractMitochondrial proteases are key components in mitochondrial stress responses that maintain proteostasis and mitochondrial integrity in harsh environmental conditions, which leads to the acquisition of aggressive phenotypes, including chemoresistance and metastasis. However, the molecular mechanisms and exact role of mitochondrial proteases in cancer remain largely unexplored. Here, we identified functional crosstalk between LONP1 and ClpP, which are two mitochondrial matrix proteases that cooperate to attenuate proteotoxic stress and protect mitochondrial functions for cancer cell survival. LONP1 and ClpP genes closely localized on chromosome 19 and were co-expressed at high levels in most human cancers. Depletion of both genes synergistically attenuated cancer cell growth and induced cell death due to impaired mitochondrial functions and increased oxidative stress. Using mitochondrial matrix proteomic analysis with an engineered peroxidase (APEX)-mediated proximity biotinylation method, we identified the specific target substrates of these proteases, which were crucial components of mitochondrial functions, including oxidative phosphorylation, the TCA cycle, and amino acid and lipid metabolism. Furthermore, we found that LONP1 and ClpP shared many substrates, including serine hydroxymethyltransferase 2 (SHMT2). Inhibition of both LONP1 and ClpP additively increased the amount of unfolded SHMT2 protein and enhanced sensitivity to SHMT2 inhibitor, resulting in significantly reduced cell growth and increased cell death under metabolic stress. Additionally, prostate cancer patients with higher LONP1 and ClpP expression exhibited poorer survival. These results suggest that interventions targeting the mitochondrial proteostasis network via LONP1 and ClpP could be potential therapeutic strategies for cancer.

scholarly journals Pyrrolizidine Alkaloids Induce Cell Death in Human HepaRG Cells in a Structure-Dependent Manner

2020 ◽  
Vol 22 (1) ◽  
pp. 202
Author(s):  
Josephin Glück ◽  
Julia Waizenegger ◽  
Albert Braeuning ◽  
Stefanie Hessel-Pras
Keyword(s):  
Cell Death ◽  
Cell Viability ◽  
Pyrrolizidine Alkaloids ◽  
Defense Mechanism ◽  
Hepatoma Cell ◽  
Hepatoma Cell Line ◽  
Dependent Manner ◽  
Human Hepatoma Cell

Pyrrolizidine alkaloids (PAs) are a group of secondary metabolites produced in various plant species as a defense mechanism against herbivores. PAs consist of a necine base, which is esterified with one or two necine acids. Humans are exposed to PAs by consumption of contaminated food. PA intoxication in humans causes acute and chronic hepatotoxicity. It is considered that enzymatic PA toxification in hepatocytes is structure-dependent. In this study, we aimed to elucidate the induction of PA-induced cell death associated with apoptosis activation. Therefore, 22 structurally different PAs were analyzed concerning the disturbance of cell viability in the metabolically competent human hepatoma cell line HepaRG. The chosen PAs represent the main necine base structures and the different esterification types. Open-chained and cyclic heliotridine- and retronecine-type diesters induced strong cytotoxic effects, while treatment of HepaRG with monoesters did not affect cell viability. For more detailed investigation of apoptosis induction, comprising caspase activation and gene expression analysis, 14 PA representatives were selected. The proapoptotic effects were in line with the potency observed in cell viability studies. In vitro data point towards a strong structure–activity relationship whose effectiveness needs to be investigated in vivo and can then be the basis for a structure-associated risk assessment.

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