Reactive oxygen species and caspase activation mediate silica-induced apoptosis in alveolar macrophages

2001 ◽  
Vol 280 (1) ◽  
pp. L10-L17 ◽  
Author(s):  
Han-Ming Shen ◽  
Zhuo Zhang ◽  
Qi-Feng Zhang ◽  
Choon-Nam Ong
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Alveolar Macrophages ◽  
Caspase 3 ◽  
Reactive Oxygen ◽  
Parp Cleavage ◽  
Oxygen Species ◽  
Caspase Activation ◽  
Caspase 9 ◽  
Induced Apoptosis

Alveolar macrophages (AMs) are the principal target cells of silica and occupy a key position in the pathogenesis of silica-related diseases. Silica has been found to induce apoptosis in AMs, whereas its underlying mechanisms involving the initiation and execution of apoptosis are largely unknown. The main objective of the present study was to examine the form of cell death caused by silica and the mechanisms involved. Silica-induced apoptosis in AMs was evaluated by terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling assay and cell cycle/DNA content analysis. The elevated level of reactive oxygen species (ROS), caspase-9 and caspase-3 activation, and poly(ADP-ribose) polymerase (PARP) cleavage in silica-treated AMs were also determined. The results showed that there was a temporal pattern of apoptotic events in silica-treated AMs, starting with ROS formation and followed by caspase-9 and caspase-3 activation, PARP cleavage, and DNA fragmentation. Silica-induced apoptosis was significantly attenuated by a caspase-3 inhibitor, N-acetyl-Asp-Glu-Val-Asp aldehyde, and ebselen, a potent antioxidant. These findings suggest that apoptosis is an important form of cell death caused by silica exposure in which the elevated ROS level that results from silica exposure may act as an initiator, leading to caspase activation and PARP cleavage to execute the apoptotic process.

scholarly journals Bufalin Induces Reactive Oxygen Species Dependent Bax Translocation and Apoptosis in ASTC-a-1 Cells

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Lei Sun ◽  
Tongsheng Chen ◽  
Xiaoping Wang ◽  
Yun Chen ◽  
Xunbin Wei
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Temporal Dynamics ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Ros Production ◽  
Oxygen Species ◽  
Induced Apoptosis

Bufalin has been shown to induce cancer cell death through apoptotic pathways. However, the molecular mechanisms are not well understood. In this study, we used the confocal fluorescence microscopy (CFM) to monitor the spatio-temporal dynamics of reactive oxygen species (ROS) production, Bax translocation and caspase-3 activation during bufalin-induced apoptosis in living human lung adenocarcinoma (ASTC-a-1) cells. Bufalin induced ROS production and apoptotic cell death, demonstrated by Hoechst 33258 staining as well as flow cytometry analysis. Bax redistributed from cytosol to mitochondria from 12 to 48 h after bufalin treatment in living cells expressed with green fluorescent protein Bax. Treatment with the antioxidantN-acetyl-cysteine (NAC), a ROS scavenger, inhibited ROS generation and Bax translocation and led to a significant protection against bufalin-induced apoptosis. Our results also revealed that bufalin induced a prominent increase of caspase-3 activation blocked potently by NAC. Taken together, bufalin induced ROS-mediated Bax translocation, mitochondrial permeability transition and caspase-3 activation, implying that bufalin induced apoptosis via ROS-dependent mitochondrial death pathway in ASTC-a-1 cells.

z-VAD-fmk augmentation of TNFα-stimulated neutrophil apoptosis is compound specific and does not involve the generation of reactive oxygen species

Blood ◽  
2005 ◽  
Vol 105 (7) ◽  
pp. 2970-2972 ◽  
Author(s):  
Andrew S. Cowburn ◽  
Jessica F. White ◽  
John Deighton ◽  
Sarah R. Walmsley ◽  
Edwin R. Chilvers
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Broad Spectrum ◽  
Reactive Oxygen ◽  
Cell Types ◽  
Ros Generation ◽  
Neutrophil Apoptosis ◽  
Oxygen Species ◽  
Caspase Inhibitor ◽  
Induced Apoptosis

Abstract In most cell types constitutive and ligand-induced apoptosis is a caspase-dependent process. In neutrophils, however, the broad-spectrum caspase inhibitor z-VAD-fmk enhances tumor necrosis factor-α (TNFα)-induced cell death, and this has been interpreted as evidence for caspase-dependent and -independent cell death pathways. Our aim was to determine the specificity of the effect of z-VAD-fmk in neutrophils and define the potential mechanism of action. While confirming that z-VAD-fmk (> 100 μM) enhances TNFα-induced neutrophil apoptosis, lower concentrations (1-30 μM) completely blocked TNFα-stimulated apoptosis. Boc-D-fmk, a similar broad-spectrum caspase inhibitor, and z-IETD-fmk, a selective caspase-8 inhibitor, caused a concentration-dependent inhibition of only TNFα-stimulated apoptosis. Moreover, the caspase-9 inhibitor, Ac-LEHD-cmk, had no effect on TNFα-induced apoptosis, and z-VAD-fmk and Boc-D-fmk inhibited TNFα-stimulated reactive oxygen species (ROS) generation. These data suggest that TNFα-induced apoptosis in neutrophils is fully caspase dependent and uses a mitochondrial-independent pathway and that the proapoptotic effects of z-VAD-fmk are compound specific and ROS independent.

scholarly journals Generation of Cellular Reactive Oxygen Species by Activation of the EP2 Receptor Contributes to Prostaglandin E2-Induced Cytotoxicity in Motor Neuron-Like NSC-34 Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Yasuhiro Kosuge ◽  
Hiroshi Nango ◽  
Hiroki Kasai ◽  
Takuya Yanagi ◽  
Takayuki Mawatari ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Prostaglandin E2 ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Caspase 3 ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Oxygen Species ◽  
Intracellular Ros

Amyotrophic lateral sclerosis (ALS) is a devastating motor neuron disease characterized by progressive degeneration of motor neurons in the central nervous system. Prostaglandin E2 (PGE2) plays a pivotal role in the degeneration of motor neurons in human and transgenic models of ALS. We have shown previously that PGE2 directly induces neuronal death through activation of the E-prostanoid (EP) 2 receptor in differentiated NSC-34 cells, a motor neuron-like cell line. In the present study, to clarify the mechanisms underlying PGE2-induced neurotoxicity, we focused on generation of intracellular reactive oxygen species (ROS) and examined the effects of N-acetylcysteine (NAC), a cell-permeable antioxidant, on PGE2-induced cell death in differentiated NSC-34 cells. Dichlorofluorescein (DCF) fluorescence analysis of PGE2-treated cells showed that intracellular ROS levels increased markedly with time, and that this effect was antagonized by a selective EP2 antagonist (PF-04418948) but not a selective EP3 antagonist (L-798,106). Although an EP2-selective agonist, butaprost, mimicked the effect of PGE2, an EP1/EP3 agonist, sulprostone, transiently but significantly decreased the level of intracellular ROS in these cells. MTT reduction assay and lactate dehydrogenase release assay revealed that PGE2- and butaprost-induced cell death were each suppressed by pretreatment with NAC in a concentration-dependent manner. Western blot analysis revealed that the active form of caspase-3 was markedly increased in the PGE2- and butaprost-treated cells. These increases in caspase-3 protein expression were suppressed by pretreatment with NAC. Moreover, dibutyryl-cAMP treatment of differentiated NSC-34 cells caused intracellular ROS generation and cell death. Our data reveal the existence of a PGE2-EP2 signaling-dependent intracellular ROS generation pathway, with subsequent activation of the caspase-3 cascade, in differentiated NSC-34 cells, suggesting that PGE2 is likely a key molecule linking inflammation to oxidative stress in motor neuron-like NSC-34 cells.

scholarly journals In vitro Studies on Calcium Oxalate Induced Apoptosis Attenuated by Didymocarpus pedicellata

2021 ◽  
Vol 12 (6) ◽  
pp. 7342-7355
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Cell Death ◽  
Calcium Oxalate ◽  
Reactive Oxygen ◽  
Ethanolic Extract ◽  
Sem Analysis ◽  
Oxygen Species ◽  
Induced Apoptosis

The present study focuses on exploring the antilithiatic potential of Didymocarpus pedicellata, which is valuable in managing renal disorders. Urolithiasis is an idiopathic disorder with a high recurrence and an incidence rate and is of major concern worldwide due to partial and unsatisfactory relief. Calcium oxalate crystals in contact with renal epithelial cells (HK2), causing reactive oxygen species overproduction, oxidative stress, apoptosis resulting in crystal adhesion and internalization. Crystals were modulated by cotreatment with ethanolic extract of D. pedicellata. Cell toxicity assay was assessed using flow cytometry. Cell-crystal interaction, adhesion, and internalization were visualized through Scanning electron microscopy (SEM) analysis and hematoxylin-eosin staining. The lithogenic induction caused impairment of renal function due to oxidative stress, measured by ROS levels. Cell death assays were detected by dual staining methods. Fluorimeter evaluation pointed to active caspase 3 mediated cell death (apoptotic) in oxalate injured cells was attenuated by Didymocarpus pedicellata extract. Alterations in cell adhesion were observed by immunocytochemistry. The current study revealed that the Didymocarpus pedicellata was endowed with antiurolithiatic activity as it displayed increased viability, reduced oxidative stress due to lowered production of intracellular reactive oxygen species (ROS), and decreased apoptosis when oxalate injured HK2 cells were cotreated with the extract.

Sign in / Sign up

Export Citation Format

Share Document