scholarly journals A Triazole Hybrid of Neolignans as a Potential Antileishmanial Agent by Triggering Mitochondrial Dysfunction

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 37 ◽  
Author(s):  
Carla Cardozo Pinto de Arruda ◽  
Daiana de Jesus Hardoim ◽  
Yasmin Silva Rizk ◽  
Celeste da Silva Freitas de Souza ◽  
Tânia Zaverucha do Valle ◽  
...  
Keyword(s):  
Cell Death ◽  
Direct Action ◽  
Flow Cytometric Analysis ◽  
Tem Analysis ◽  
Methylenedioxy Group ◽  
Highly Active ◽  
Flow Cytometric ◽  
Transmission Electron ◽  
New Compounds ◽  
Intracellular Amastigote

In the search for new compounds with antileishmanial activity, we synthesized a triazole hybrid analogue of the neolignans grandisin and machilin G (LASQUIM 25), which was previously found highly active against both promastigotes and intracellular amastigote forms of Leishmania amazonensis. In this work, we investigated the leishmanicidal effects of LASQUIM 25 to identify the mechanisms involved in the cell death of L. amazonensis promastigotes. Transmission electron microscopy (TEM) analysis showed marked effects of LASQUIM 25 (IC50 = 7.2 µM) on the morphology of promastigote forms, notably on mitochondria. The direct action of the triazole derivative on the parasite was noticed over time from 2 h to 48 h, and cells displayed several ultrastructural alterations characteristic of apoptotic cells. Also, flow cytometric analysis (FACS) after TMRE staining detected changes in mitochondrial membrane potential after LASQUIM 25 treatment (64.83% labeling versus 83.38% labeling in nontreated cells). On the other hand, FACS after PI staining in 24 h-treatment showed a slight alteration in the integrity of the cell membrane, a necrotic event (16.76% necrotic cells versus 3.19% staining in live parasites). An abnormal secretion of lipids was observed, suggesting an exocytic activity. Another striking finding was the presence of autophagy-related lysosome-like vacuoles, suggesting an autophagic cell death that may arise as consequence of mitochondrial stress. Taken together, these results suggest that LASQUIM 25 leishmanicidal mechanisms involve some degree of mitochondrial dysregulation, already evidenced by the treatment with the IC50 of this compound. This effect may be due to the presence of a methylenedioxy group originated from machilin G, whose toxicity has been associated with the capacity to generate electrophilic intermediates.

Flow Cytometric Analysis of Hyperglycemia-Induced Cell Death in

2021 ◽  
pp. 259-270
Author(s):  
Ravichandra Shivalingappa Davargaon ◽  
M. V. V. Subramanyam ◽  
S. Asha Devi
Keyword(s):  
Cell Death ◽  
Flow Cytometric Analysis ◽  
Flow Cytometric

scholarly journals Cytolethal Distending Toxin Induces Caspase-Dependent and -Independent Cell Death in MOLT-4 Cells

2008 ◽  
Vol 76 (10) ◽  
pp. 4783-4791 ◽  
Author(s):  
Masaru Ohara ◽  
Tomonori Hayashi ◽  
Yoichiro Kusunoki ◽  
Kei Nakachi ◽  
Tamaki Fujiwara ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Population ◽  
Apoptotic Cell ◽  
Flow Cytometric Analysis ◽  
Annexin V ◽  
Membrane Disruption ◽  
Classical Pathway ◽  
Cytolethal Distending Toxin ◽  
Flow Cytometric ◽  
General Caspase Inhibitor

ABSTRACT Cytolethal distending toxin (CDT) induces apoptosis using the caspase-dependent classical pathway in the majority of human leukemic T cells (MOLT-4). However, we found the process to cell death is only partially inhibited by pretreatment of the cells with a general caspase inhibitor, z-VAD-fmk. Flow cytometric analysis using annexin V and propidium iodide showed that a 48-h CDT treatment decreased the living cell population by 35% even in the presence of z-VAD-fmk. z-VAD-fmk completely inhibited caspase activity in 24 h CDT-intoxicated cells. Further, CDT with z-VAD-fmk treatment clearly increased the cell population that had a low level of intracellular reactive oxygen. This is a characteristic opposite to that of caspase-dependent apoptosis. Overexpression of bcl2 almost completely inhibited cell death using CDT treatment in the presence of z-VAD-fmk. The data suggest there are at least two different pathways used in CDT-induced cell death: conventional caspase-dependent (early) apoptotic cell death and caspase-independent (late) death. Both occur via the mitochondrial membrane disruption pathway.

scholarly journals Flow-cytometric method for simultaneous analysis of mouse lung epithelial, endothelial, and hematopoietic lineage cells

2016 ◽  
Vol 310 (9) ◽  
pp. L796-L801 ◽  
Author(s):  
Benjamin D. Singer ◽  
Jason R. Mock ◽  
Franco R. D'Alessio ◽  
Neil R. Aggarwal ◽  
Pooja Mandke ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Death ◽  
Lung Tissue ◽  
Flow Cytometric Analysis ◽  
Mouse Lung ◽  
Tissue Preparation ◽  
Pulmonary Vascular Permeability ◽  
Flow Cytometric ◽  
Hematopoietic Lineage ◽  
Cellular Compartments

Flow cytometry is a powerful tool capable of simultaneously analyzing multiple parameters on a cell-by-cell basis. Lung tissue preparation for flow cytometry requires creation of a single-cell suspension, which often employs enzymatic and mechanical dissociation techniques. These practices may damage cells and cause cell death that is unrelated to the experimental conditions under study. We tested methods of lung tissue dissociation and sought to minimize cell death in the epithelial, endothelial, and hematopoietic lineage cellular compartments. A protocol that involved flushing the pulmonary circulation and inflating the lung with Dispase, a bacillus-derived neutral metalloprotease, at the time of tissue harvest followed by mincing, digestion in a DNase and collagenase solution, and filtration before staining with fluorescent reagents concurrently maximized viable yields of epithelial, endothelial, and hematopoietic lineage cells compared with a standard method that did not use enzymes at the time of tissue harvest. Flow cytometry identified each population—epithelial (CD326+CD31−CD45−), endothelial (CD326−CD31+CD45−), and hematopoietic lineage (CD326−CD31−CD45+)—and measured cellular viability by 7-aminoactinomycin D (7-AAD) staining. The Dispase method permitted discrimination of epithelial vs. endothelial cell death in a systemic lipopolysaccharide model of increased pulmonary vascular permeability. We conclude that application of a dissociative enzyme solution directly to the cellular compartments of interest at the time of tissue harvest maximized viable cellular yields of those compartments. Investigators could employ this dissociation method to simultaneously harvest epithelial, endothelial, and hematopoietic lineage and other lineage-negative cells for flow-cytometric analysis.

scholarly journals Cork cells in cork oak periderms undergo programmed cell death and proanthocyanidin deposition

2021 ◽  
Author(s):  
Vera Inácio ◽  
Carolina Lobato ◽  
José Graça ◽  
Leonor Morais-Cecílio
Keyword(s):  
Cell Death ◽  
Cell Wall ◽  
Programmed Cell Death ◽  
Secondary Growth ◽  
Cork Oak ◽  
Comprehensive Overview ◽  
Highly Active ◽  
Transmission Electron ◽  
Traumatic Wound ◽  
The Impact

Abstract Vascular plants with secondary growth develop a periderm mostly composed of dead suberized cork cells to face environmental hostile conditions. Cork oak has a highly active and long-living phellogen forming a remarkably thick periderm that is periodically debarked for industrial purposes. This wounding originates the quick formation of a new traumatic periderm, making cork oak an exceptional model to study the first periderm differentiation during normal development in young sprigs and traumatic (wound) periderm formation after debarking. Here, we studied the poorly known first periderm differentiation steps that involve cell wall suberization, polyphenolic accumulation and programmed cell death (PCD) by combining transmission electron microscopy, histochemical and molecular methods in periderms from young sprigs. These processes were further compared with traumatic periderms formed after wounding using molecular and histochemical techniques, such as the polyphenolic accumulation. In the first periderms from young sprigs, four distinct differentiation stages were defined according to the presence of PCD morphological features. First young and traumatic periderms showed an upregulation of genes related to suberin biosynthesis, proanthocyanidins biosynthesis and transport, autophagy, and PCD. Traumatic periderms revealed an overall upregulation of these genes, likely resulting from ontogeny differences and distinct phellogen origin associated with a faster metabolism, highlighting the impact of wounding on phellogen activity after debarking. First periderms from young sprigs showed gradual accumulation of proanthocyanidins in the vacuoles throughout PCD stages until total filled lumens, whereas in traumatic periderms, these compounds were found cell wall linked in already empty cells. This work enabled a comprehensive overview of the cork cells differentiation processes contributing to deepening the knowledge of the fundamental ontogenic program of this protective tissue, which is also a unique forest product, constituting the basis of a sustainable and profitable industry.

Insights into Nano-Photo-Thermal Therapy of Cancer: The Kinetics of Cell Death and Effect on Cell Cycle

2020 ◽  
Vol 20 (5) ◽  
pp. 612-621
Author(s):  
Mousa Tabei ◽  
Elham Zeinizade ◽  
Jaber Beik ◽  
S. Kamran Kamrava ◽  
Zahra Nasiri ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Cancer Cells ◽  
Signaling Pathway ◽  
Flow Cytometric Analysis ◽  
Thermal Therapy ◽  
Normal Fibroblast ◽  
Cycle Phase ◽  
Flow Cytometric ◽  
Kinetics Of

Background: Despite considerable advances in nano-photo-thermal therapy (NPTT), there have been a few studies reporting in-depth kinetics of cell death triggered by such a new modality of cancer treatment. Objective: In this study, we aimed to (1) investigate the cell death pathways regulating the apoptotic responses to NPTT; and (2) ascertain the effect of NPTT on cell cycle progression. Methods: Folate conjugated gold nanoparticle (F-AuNP) was firstly synthesized, characterized and then assessed to determine its potentials in targeted NPTT. The experiments were conducted on KB nasopharyngeal cancer cells overexpressing folate receptors (FRs), as the model, and L929 normal fibroblast cells with a low level of FRs, as the control. Cytotoxicity was evaluated by MTT assay and the cell death mode (i.e., necrosis or apoptosis) was determined through AnnexinV/FITC-propidium iodide staining. Next, the gene expression profiles of some key apoptotic factors involved in the mitochondrial signaling pathway were investigated using RT-qPCR. Finally, cell cycle phase distribution was investigated at different time points post NPTT using flow cytometric analysis. Results: The obtained results showed that KB cell death following targeted NPTT was greater than that observed for L929 cells. The majority of KB cell death following NPTT was related to apoptosis. RT-qPCR analysis indicated that the elevated expression of Bax along with the depressed expression of Bcl-xL, Survivin and XIAP may involve in the regulation of apoptosis in response to NPTT. Flow cytometric analysis manifested that 16-24 hours after NPTT, the major proportion of KB cells was in the most radiosensitive phases of the cell cycle (G2/M). Conclusion: This study extended the understanding of the signaling pathway involved in the apoptotic response to NPTT. Moreover, the potential effect of NPTT on sensitizing cancer cells to subsequent radiation therapy was highlighted.

scholarly journals Selective and Efficient Olefin Epoxidation by Robust Magnetic Mo Nanocatalysts

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 380
Author(s):  
Cristina I. Fernandes ◽  
Pedro D. Vaz ◽  
Carla D. Nunes
Keyword(s):  
Electron Microscopy ◽  
Silica Layer ◽  
Olefin Epoxidation ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Highly Active ◽  
Transmission Electron ◽  
Tert Butyl Hydroperoxide ◽  
Iron Oxide Magnetic Nanoparticles ◽  
The Stöber Method

Iron oxide magnetic nanoparticles were synthesized with different sizes (11 and 30 nm). Subsequently they were shelled with a silica layer allowing grafting of an organic phosphine ligand that coordinated to the [MoI2(CO)3] organometallic core. The silica layer was prepared by the Stöber method using either mechanical (both 11 and 30 nm nanoparticles) or ultrasound (30 nm only) stirring. The latter nanoparticles once coated with silica were obtained with less aggregation, which was beneficial for the final material holding the organometallic moiety. The Mo loadings were found to be 0.20, 0.18, and 0.34 mmolMo·g−1 for MNP30-Si-phos-Mo,MNP11-Si-phos-Mo, and MNP30-Sius-phos-Mo, respectively, with the ligand-to-metal ratio reaching 4.6, 4.8, and 3.2, by the same order, confirming coordination of the Mo moieties to two phos ligands. Structural characterization obtained from powder X-ray diffraction (XRD), scanning electron microscopy (SEM)/ transmission electron microscopy (TEM) analysis, and Fourier-transform infrared (FTIR) spectroscopy data confirmed the successful synthesis of all nanomaterials. Olefin epoxidation of several substrates catalyzed by these organometallic nano-hybrid materials using tert-butyl hydroperoxide (tbhp) as oxidant, achieved very good results. Extensive testing of the catalysts showed that they are highly active, selective, recyclable, and efficient concerning oxidant consumption.

Hepatotoxic effects of melamine exposure from the weaning period in rats: a flow cytometric, electron microscopic, and histopathologic study

2021 ◽  
Author(s):  
Zuleyha Erisgin ◽  
Hasan Serdar Mutlu ◽  
Yavuz Tekelioglu ◽  
Engin Deveci ◽  
Ugur Seker
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Periodic Acid ◽  
Flow Cytometric Analysis ◽  
Control Group ◽  
Albino Rats ◽  
Histopathological Analysis ◽  
Periodic Acid Schiff ◽  
Flow Cytometric ◽  
Transmission Electron

Abstract This study aims to investigate the effects of melamine exposure from the weaning period (21st postnatal days in rats) on liver tissue. Female Wistar albino rats (n = 18) were divided into three groups. About 0.1-ml saline was applied to the control group by gavage for 21 days from the postnatal 21st day. The second group was taken 50-mg/kg melamine (in 0.1-ml saline) and the third group was taken 75-mg/kg melamine (in 0.1-ml saline) p.o. On the postnatal 45th day, all rats were sacrificed under anesthesia. Then, liver tissues were cut into three parts and two of them placed in neutral formalin for histopathological and flow cytometric analysis, and one of them placed in 2.5% glutaraldehyde. Histopathological analysis was performed with hematoxylin & eosin, Masson trichrome, periodic acid Schiff stained sections, and also with transmission electron microscopy. Apoptosis (Annexin V positivity) was analyzed by flow cytometry. According to histopathological analysis, hepatocyte damage, sinusoidal dilatation, and inflammatory cell infiltration significantly increased in both melamine groups compared with the control group. Apoptosis significantly increased in the 50 and 75-mg melamine groups compared with the control group. In the results of transmission electron microscopy analysis, there was abnormal chromatin distribution in the hepatocyte nuclei, loss in the cristae of the mitochondria, and organelle loss in large areas in the cytoplasm in both melamine exposure groups. As result, melamine exposure from the weaning period causes liver damage with increasing doses.

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