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1.
Propyl gallate (PG) as a synthetic antioxidant exerts a variety of effects on tissue and cell functions. Here, we investigated
the effects of MAPK (MEK, JNK and p38) inhibitors on PG-treated HeLa cells in relation to cell death, ROS and GSH levels.
PG induced cell growth inhibition and apoptosis in HeLa cells, which was accompanied by the loss of mitochondrial membrane
potential (MMP; ΔΨm). ROS levels were increased or decreased in PG-treated HeLa cells depending on the incubation times. PG also increased GSH
depleted cell numbers in HeLa cells. All the MAPK inhibitors slightly enhanced cell growth inhibition, death and MMP (ΔΨm) loss, and increased ROS levels in PG-treated HeLa cells. However, MAPK inhibitors did not significantly affect GSH depletion
in PG-treated cells. In conclusion, the enhanced effect of MAPK inhibitors on PG-induced HeLa cell death was accompanied by
increasing ROS levels but the effect was not related to changes of GSH level. 相似文献
2.
Among other mitochondrial functions, energy production and Ca2+ uptake are crucial for maintaining neuronal viability. Both of these functions are critically dependent on mitochondrial
membrane potential (ΔΨm). Mitochondrial Ca2+ overload causing a dissipation of ΔΨm is a key component of several neuronal pathologies. However, the mechanism of Ca2+-induced depolarization in neuronal mitochondria remains unclear. Typically, ΔΨm has been evaluated as a single overall estimate from all mitochondria present in a given cell or tissue. However, recent
data showed that the population of mitochondria isolated from tissues is not homogeneous, and averaged parameters from the
whole population do not necessarily reflect the processes taking place in a single organelle. This review summarizes our recent
studies of Ca2+-induced depolarization in individual mitochondria isolated from rat forebrain and immobilized to coverslips. Fluorescence
imaging techniques and potentiometric fluorescent dyes were effectively used to study ΔΨm changes. The data have shown that Ca2+ triggers ΔΨm oscillations in brain mitochondria followed by a complete depolarization. Further investigation of this phenomenon led us
to suggest that Ca2+-induced ΔΨm oscillations can represent an intermediate unstable state that may lead to irreversible mitochondrial dysfunction. Therefore,
further study of this phenomenon would help to understand what causes the irreversible damage of mitochondria during cytosolic/mitochondrial
Ca2+ overload. Here we discuss the effects of different modulators of the mitochondrial permeability transition pore on Ca2+-induced depolarization in brain mitochondria and in liver mitochondria, where the mechanism of Ca2+-depolarization is better understood. A comparison of these effects in brain and liver mitochondria led us to conclude that
Ca2+ can induce reversible “low conductance” permeability transition in brain mitochondria, the phenomenon which requires a transient
conformational change of the adenine nucleotide translocator from a specific transporter to a non-specific pore.
The article is published in the original. 相似文献
3.
Resveratrol, a natural polyphenolic antioxidant, has been reported to possess the cancer chemopreventive potential in wide
range by means of triggering tumor cells apoptosis through various pathways. It induced apoptosis through the activation of
the mitochondrial pathway in some kinds of cells. In the present reports, we showed that resveratrol-induced HepG2 cell apoptosis
and mitochondrial dysfunction was dependent on the induction of the mitochondrial permeability transition (MPT), because resveratrol
caused the collapse of the mitochondrial membrane potential (ΔΨm) with the concomitant release of cytochrome c (Cyt.c). In addition, resveratrol induced a rapid and sustained elevation of
intracellular [Ca2+], which compromised the mitochondrial ΔΨm and triggered the process of HepG2 cell apoptosis. In permeabilized HepG2 cells, we further demonstrated that the effect
of the resveratrol was indeed synergistic with that of Ca2+ and Ca2+ is necessary for resveratrol-induced MPT opening. Calcium-induced calcium release from mitochondria (mCICR) played a key
role in mitochondrial dysfunction and cell apoptosis: (1) mCICR inhibitor, ruthenium red (RR), prevent MPT opening and Cyt.c
release; and (2) RR attenuated resveratrol-induced HepG2 cell apoptotic death. Furthermore, resveratrol promotes MPT opening
by lowering Ca2+-threshold. These data suggest modifying mCICR and Ca2+ threshold to modulate MPT opening may be a potential target to control cell apoptosis induced by resveratrol.
Xuemei Tian—Foundation item: Chinese National Natural Science Foundation (No.30300455). 相似文献
4.
Studies on animal material have revealed that changes in the mitochondrial permeability transition pore (PTP), which cause a reduction in the mitochondrial transmembrane potential (m) followed by release of cytochrome c, belong to the earliest manifestations of some types of apoptosis. We have attempted to monitor the m of mitochondria during programmed cell death (PCD) of the secretory tapetum using JC-1, a fluorochrome dye that detects mitochondrial membrane potential and to relate changes in this potential to mitochondrial ultrastructure. Analysis of tapetal cells isolated from Ornithogalum virens anthers revealed that the m of mitochondria in the tapetal cells alters during development; the change, however, is not uniform in the mitochondrial population within a single tapetal cell. In young tapetal cells, at the tetrad stage, we detected only the red fluorescence of JC-1 aggregates in all tapetal mitochondria, which indicates highly negative m. In an advanced stage of PCD at the late microspore stage, in each tapetal cell we detected both mitochondria with red (as formerly) and mitochondria with green fluorescence. The green fluorescence of JC-1 monomers indicates mitochondria with depolarised membranes. These changes in m are related to observed changes in mitochondria ultrastructure. This is the first documentation of intracellular heterogeneity of m during anther tapetum development. Alteration in m suggests a relationship between mitochondrial function and PCD processes in tapetal cells. 相似文献
5.
Luis A. Flores-López Margarita Díaz-Flores Rebeca García-Macedo Alejandro Ávalos-Rodríguez Marcela Vergara-Onofre Miguel Cruz Alejandra Contreras-Ramos Mina Konigsberg Clara Ortega-Camarillo 《Molecular biology reports》2013,40(8):4947-4958
Pancreatic β-cell death in type 2 diabetes has been related to p53 subcellular localisation and phosphorylation. However, the mechanisms by which p53 is phosphorylated and its activation in response to oxidative stress remain poorly understood. Therefore, the aim of this study was to investigate mitochondrial p53 phosphorylation, its subcellular localisation and its relationship with apoptotic induction in RINm5F cells cultured under high glucose conditions. Our results show that p53 phosphorylation in the mitochondrial fraction was greater at ser392 than at ser15. This increased phosphorylation correlated with an increase in reactive oxygen species, a decrease in the Bcl-2/Bax ratio, a release of cytochrome c and an increase in the rate of apoptosis. We also observed a decline in ERK 1/2 phosphorylation over time, which is an indicator of cell proliferation. To identify the kinase responsible for phosphorylating p53, p38 mitogen-activated protein kinase (MAPK) activation was analysed. We found that high glucose induced an increase in p38 MAPK phosphorylation in the mitochondria after 24–72 h. Moreover, the phosphorylation of p53 (ser392) by p38 MAPK in mitochondria was confirmed by colocalisation studies with confocal microscopy. The addition of a specific p38 MAPK inhibitor (SB203580) to the culture medium during high glucose treatment blocked p53 mobilisation to the mitochondria and phosphorylation; thus, the release of cytochrome c and the apoptosis rate in RINm5F cells decreased. These results suggest that mitochondrial p53 phosphorylation by p38 MAPK plays an important role in RINm5F cell death under high glucose conditions. 相似文献
6.
Torres F Quintana J Díaz JG Carmona AJ Estévez F 《Apoptosis : an international journal on programmed cell death》2008,13(5):716-728
In the present study we demonstrated that the flavonoid derivative trifolin acetate (TA), obtained by acetylation of naturally
occurring trifolin, induces apoptosis. Associated downstream signaling events were also investigated. TA-induced cell death
was prevented by the non-specific caspase inhibitor z-VAD-fmk and reduced by the presence of the selective caspase inhibitors
z-LEHD-fmk (caspase-9), z-DEVD-fmk (caspase-3) and z-VEID-fmk (caspase-6). The apoptotic effect of TA was associated with
(i) the release of cytochrome c from mitochondria which was not accompanied by dissipation of the mitochondrial membrane potential (ΔΨm), (ii) the activation of the mitogen-activated protein kinases (MAPKs) pathway and (iii) abrogated by the over-expression
of Bcl-2 or Bcl-xL. TA-induced cell death was attenuated by inhibition of extracellular signal-regulated kinases (ERK) 1/2 with U0126 and inhibition
of p38MAPK with SB203580. In contrast, inhibition of c-Jun NH2-terminal kinase (JNK) by SP600125 significantly enhanced apoptosis. Although reactive oxygen species (ROS) increased in response
to TA, this did not seem to play a pivotal role in the apoptotic process since different anti-oxidants were unable to provide
cell protection. The present study demonstrates that TA-induced cell death is mediated by an intrinsic-dependent apoptotic
event involving mitochondria and MAPK, and through a mechanism independent of ROS generation. 相似文献
7.
Summary. Analysis of the mitochondrial transmembrane potential (m) with the help of the JC-1 fluorochrome (5,5,6,6-tetrachloro-1,1,3,3-tetraethylbenzimidazolcarbocyanine iodide) during mesophyll leaf senescence was performed in order to determine whether a reduction of m takes place during mesophyll senescence and whether plant mitochondria, like mammalian ones, might be involved in the induction of programmed cell death. Fluorescence analysis of mesophyll protoplasts of Pisum sativum in a confocal microscope, fluorescent spectra analysis and time dependence of fluorescence intensity of monomers and of J-aggregates revealed that JC-1 is incorporated and accumulated specifically in plant mitochondria. Analysis of m during mesophyll protoplast senescence revealed that two subpopulations of mitochondria which differ in m exist in all analyzed stages of leaf senescence. The first subpopulation contains mitochondria with red fluorescence of J-aggregates due to an unperturbed high m. The second subpopulation comprises mitochondria with green fluorescence of monomers due to a low m, proving total depolarization of mitochondrial membranes. Fluorescence analysis demonstrated that even in the latest analyzed stages of leaf senescence, mitochondria with a high m still exist. Fluorometric measurements revealed that the fluorescence intensity of J-aggregates decreases with the age of plants, which indicates that a reduction of m during the mesophyll senescence process takes place; however, it does not take place within the whole population of mitochondria of the same protoplast. The reason of this can be due to a dramatic reorganization of mitochondria in mesophyll cells and the appearance of large mitochondria with local heterogeneity of m in the oldest analyzed stages. All mitochondria in every stage of senescence maintained their membrane organization even when their size, distribution, and spatial organization in protoplasts changed dramatically. We stated that the reduction of m does not directly induce programmed cell death in mesophyll cells, as opposed to animal apoptosis.Correspondence and reprints: Department of Plant Anatomy and Cytology, Institute of Experimental Biology of Plants, Warsaw University, Miecznikowa 1, 02-096 Warszawa, Poland. 相似文献
8.
Lasfer M Vadrot N Aoudjehane L Conti F Bringuier AF Feldmann G Reyl-Desmars F 《Cell biology and toxicology》2008,24(1):55-62
The heavy metal cadmium, an environmental pollutant, has been widely demonstrated to be toxic, in particular for liver. In
murines, cadmium induces apoptosis of hepatocytes and hepatomas. In human cells, apoptosis induced by cadmium has been exclusively
demonstrated in tumoral cell lines. Nothing was known in normal liver, in vitro or in vivo. In the present study, we examined the effects of cadmium in nonmalignant human hepatocytes. For that purpose, we investigated
whether cadmium was able to induce apoptosis of normal human hepatocytes (NHH) in primary culture and of a SV40-immortalized
human hepatocyte (IHH) cell line. Treatment of IHH and NHH with cadmium induced the presence of a sub-G1 population at 10 and 100 μmol/L, respectively. DAPI staining of both cell types treated with cadmium 100 μmol/L revealed
the induction of nuclear apoptotic bodies, supporting the hypothesis of apoptosis. In IHH and NHH, cadmium 100 μmol/L induced
PARP cleavage into a 85 kDa fragment. In order to investigate the involvement of mitochondria in cadmium-induced apoptosis,
we measured the mitochondrial membrane potential (ΔΨm). We observed that in IHH and NHH, cadmium 100 μmol/L induced a decrease of ΔΨm. As expected, cadmium under the same conditions enhanced caspase-9 and caspase-3 activities. In addition, cadmium from 1
to 100 μmol/L induced the expression of p53 and phosphorylation of its Ser15 in IHH and NHH. In conclusion, we showed in this
study that human hepatocytes were sensitive to cadmium and apoptosis induced at concentrations suggested in the literature
to inhibit p53 DNA-binding and DNA repair. 相似文献
9.
Galluzzi L Zamzami N de La Motte Rouge T Lemaire C Brenner C Kroemer G 《Apoptosis : an international journal on programmed cell death》2007,12(5):803-813
Mitochondrial membrane permeabilization (MMP) is considered as the “point-of-no-return” in numerous models of programmed cell
death. Indeed, mitochondria determine the intrinsic pathway of apoptosis, and play a major role in the extrinsic route as
well. MMP affects the inner and outer mitochondrial membranes (IM and OM, respectively) to a variable degree. OM permeabilization
culminates in the release of proteins that normally are confined in the mitochondrial intermembrane space (IMS), including
caspase activators (e.g. cytochrome c) and caspase-independent death effectors (e.g. apoptosis-inducing factor). Partial IM permeabilization disrupts mitochondrial ion and volume homeostasis and dissipates
the mitochondrial transmembrane potential (ΔΨm). The assessment of early mitochondrial alterations allows for the identification of cells that are committed to die but
have not displayed yet the apoptotic phenotype. Several techniques to measure MMP by cytofluorometry and fluorescence microscopy
have been developed. Here, we summarize the currently available methods for the detection of MMP, and provide a comparative
analysis of these techniques. 相似文献
10.
In this study, the release of mitochondrial proapoptotic intermembrane space proteins induced by ex-ogenous C2-ceramide in human colon carcinoma (HT-29) cell line was investigated. HT-29 cells were treated with 12.5, 25 and 50 μmol/L C2-ceramide in vitro. Flow cytometer was used to detect the mito-chondrial membrane potential (ΔΨm). Subcellular fractions were extracted by Mitochondrial/Cytosol Fractionation Kit after C2-ceramide treatment for 24 h. SDS-PAGE was used to determine the level of cytochrome c (Cyt c), high temperature requirement A2 (HtrA2) and second mitochondrial-derived ac-tivator of caspases (Smac) released from mitochondria, the expression of X-linked inhibitor of apop-tosis protein (XIAP) and caspase-3 for 24 h. The results showed that ΔΨm began to decrease from 6 h after 25 and 50 μmol/L C2-ceramide treatment (P<0.05) and cyclosporin A (CsA) could inhibit the col-lapse of ΔΨm through regulating mitochondrial membrane permeability transition pore. There was no effect of C2-ceramide on the expression of Cyt c, HtrA2 and Smac in the total levels. 12.5, 25 and 50 μmol/L C2-ceramide could induce Cyt c, HtrA2 and Smac to release from mitochondria to cytosol and down-regulate the expression of XIAP (P<0.05). Also there was expression of cleaved caspase-3 with C2-ceramide treatment. After the treatment with caspase inhibitor, C2-ceramide still induced the release of Cyt c and HtrA2, but Smac did not. Therefore, C2-ceramide could induce apoptosis of HT-29 cells through the mitochondria pathway. The release of Cyt c, HtrA2 and Smac from mitochondria did not occur via the same mechanism, the release of Cyt c and HtrA2 was caspase-independent and the re-lease of Smac was caspase-dependent. 相似文献
11.
In order to explore the role of mitochondria in proliferation promotion and/or apoptosis induction of lanthanum, the mutual
influences between La3+ and Ca2+ on mitochondrial permeability transition pore (PTP) opening were investigated with isolated mitochondria from rat liver.
The experimental results revealed that La3+ influence the state of mitochondria in a concentration-dependent biphasic manner. La3+ in nanomolar concentrations, acting as a Ca2+ analog, entered mitochondrial matrix via the RuR sensitive Ca2+ channel and elevated ROS level, leading to opening of PTP indicated by mitochondrial swelling, reduction of ΔΨm and cytochrome c release. Inhibition of PTP with 10 μM CsA attenuated the effects of La3+. However, micromolar concentrations La3+ acted mainly as a Ca2+ antagonist, inhibiting PTP opening induced by Ca2+. We postulated that this action of La3+ on mitochondria through interaction with Ca2+ might be involved in the proliferation-promoting and apoptosis induction by La3+. 相似文献
12.
In mitochondria, oxidative phosphorylation and enzymatic oxidation of biogenic amines by monoamine oxidase produce reactive
oxygen and nitrogen species, which are proposed to cause neuronal cell death in neurodegenerative disorders, including Parkinson’s
and Alzheimer’s disease. In these disorders, mitochondrial dysfunction, increased oxidative stress, and accumulation of oxidation-modified
proteins are involved in cell death in definite neurons. The interactions among these factors were studied by use of a peroxynitrite-generating
agent, N-morpholino sydnonimine (SIN-1) and an inhibitor of complex I, rotenone, in human dopaminergic SH-SY5Y cells. In control cells,
peroxynitrite nitrated proteins, especially the subunits of mitochondrial complex I, as 3-nitrotyrosine, suggesting that neurons
are exposed to constant oxidative stress even under physiological conditions. SIN-1 and an inhibitor of proteasome, carbobenzoxy-l-isoleucyl-γ-t-butyl-l-analyl-l-leucinal (PSI), increased markedly the levels of nitrated proteins with concomitant induction of apoptosis in the cells.
Rotenone induced mitochondrial dysfunction and accumulation and aggregation of proteins modified with acrolein, an aldehyde
product of lipid peroxidation in the cells. At the same time, the activity of the 20S β-subunit of proteasome was reduced
significantly, which degrades oxidative-modified protein. The mechanism was proved to be the result of the modification of
the 20S β-subunit with acrolein and to the binding of other acrolein-modified proteins to the 20S β-subunit.
Increased oxidative stress caused by SIN-1 treatment induced a decline in the mitochondrial membrane potential, ΔΨm, and activated
mitochondrial apoptotic signaling and induced cell death in SH-SY5Y cells. As another pathway, p38 mitogen-activated protein
(MAP) kinase and exracellular signal-regulated kinase (ERK) mediated apoptosis induced by SIN-1. On the other hand, a series
of neuroprotective propargylamine derivatives, including rasagiline [N-propargyl-1(R)aminoindan]and (−)deprenyl, intervened in the activation of apoptotic cascade by reactive oxygen species-reactive nitrogen
species in mitochondria through stabilization of the membrane potential, ΔΨm. In addition, rasagiline induced antiapoptotic
Bcl-2 and glial cell line-derived neurotrophic factor (GDNF) in SH-SY5Y cells, which was mediated by the ERK-nuclear factor
(NF)-κB pathway. These results are discussed in relation to the interaction of oxidative stress and mitochondria in the regulation
of neuronal death and survival in neurodegenerative diseases. 相似文献
13.
Bioenergetic aspects of apoptosis, necrosis and mitoptosis 总被引:6,自引:2,他引:4
Skulachev VP 《Apoptosis : an international journal on programmed cell death》2006,11(4):473-485
In this review I summarize interrelations between bioenergetic processes and such programmed death phenomena as cell suicide
(apoptosis and necrosis) and mitochondrial suicide (mitoptosis). The following conclusions are made. (I) ATP and rather often
mitochondrial hyperpolarization (i.e. an increase in membrane potential, ΔΨ) are required for certain steps of apoptosis and necrosis. (II) Apoptosis, even if
it is accompanied by ΔΨ and [ATP] increases at its early stage, finally results in a ΔΨ collapse and ATP decrease. (III) Moderate
(about three-fold) lowering of [ATP] for short and long periods of time induces apoptosis and necrosis, respectively. In some
types of apoptosis and necrosis, the cell death is mediated by a ΔΨ-dependent overproduction of ROS by the initial (Complex
I) and the middle (Complex III) spans of the respiratory chain. ROS initiate mitoptosis which is postulated to rid the intracellular
population of mitochondria from those that are ROS overproducing. Massive mitoptosis can result in cell death due to release
to cytosol of the cell death proteins normally hidden in the mitochondrial intermembrane space. 相似文献
14.
Kamp David W. Panduri Vijayalakshmi Weitzman Sigmund A. Chandel Navdeep 《Molecular and cellular biochemistry》2002,(1):153-160
Asbestos causes asbestosis and malignancies by mechanisms that are not fully understood. Alveolar epithelial cell (AEC) injury by iron-derived reactive oxygen species (ROS) is one important mechanism implicated. We previously showed that iron-catalyzed ROS in part mediate asbestos-induced AEC DNA damage and apoptosis. Mitochondria have a critical role in regulating apoptosis after exposure to agents causing DNA damage but their role in regulating asbestos-induced apoptosis is unknown. To determine whether asbestos causes AEC mitochondrial dysfunction, we exposed A549 cells to amosite asbestos and assessed mitochondrial membrane potential changes (m) using a fluorometric technique involving tetremethylrhodamine ethyl ester (TMRE) and mitotracker green. We show that amosite asbestos, but not an inert particulate, titanium dioxide, reduces m after a 4 h exposure period. Further, the m after 4 h was inversely proportional to the levels of apoptosis noted at 24 h as assessed by nuclear morphology as well as by DNA nucleosome formation. A role for iron-derived ROS was suggested by the finding that phytic acid, an iron chelator, blocked asbestos-induced reductions in A549 cell m and attenuated apoptosis. Finally, overexpression of Bcl-xl, an anti-apoptotic protein that localizes to the mitochondria, prevented asbestos-induced decreases in A549 cell m after 4 h and diminished apoptosis. We conclude that asbestos alters AEC mitochondrial function in part by generating iron-derived ROS, which in turn can result in apoptosis. This suggests that the mitochondrial death pathway is important in regulating pulmonary toxicity from asbestos. 相似文献
15.
M. P. Fernandes N. M. Inada M. R. Chiaratti F. F. B. Araújo F. V. Meirelles M. T. S. Correia L. C. B. B. Coelho M. J. M. Alves F. R. Gadelha A. E. Vercesi 《Journal of bioenergetics and biomembranes》2010,42(1):69-78
Incubation of T. cruzi epimastigotes with the lectin Cramoll 1,4 in Ca2+ containing medium led to agglutination and inhibition of cell proliferation. The lectin (50 μg/ml) induced plasma membrane
permeabilization followed by Ca2+ influx and mitochondrial Ca2+ accumulation, a result that resembles the classical effect of digitonin. Cramoll 1,4 stimulated (five-fold) mitochondrial
reactive oxygen species (ROS) production, significantly decreased the electrical mitochondrial membrane potential (ΔΨm) and impaired ADP phosphorylation. The rate of uncoupled respiration in epimastigotes was not affected by Cramoll 1,4 plus
Ca2+ treatment, but oligomycin-induced resting respiration was 65% higher in treated cells than in controls. Experiments using
T. cruzi mitochondrial fractions showed that, in contrast to digitonin, the lectin significantly decreased ΔΨm by a mechanism sensitive to EGTA. In agreement with the results showing plasma membrane permeabilization and impairment of
oxidative phosphorylation by the lectin, fluorescence microscopy experiments using propidium iodide revealed that Cramoll
1,4 induced epimastigotes death by necrosis. 相似文献
16.
17.
Palmitate induces apoptosis via a direct effect on mitochondria 总被引:1,自引:0,他引:1
de Pablo MA Susin SA Jacotot E Larochette N Costantini P Ravagnan L Zamzami N Kroemer G 《Apoptosis : an international journal on programmed cell death》1999,4(2):81-87
The fatty acid palmitate can induce apoptosis. Here we show that the palmitate-induced dissipation of the mitochondrial transmembrane potential (
m
), which precedes nuclear apoptosis, is not prevented by inhibitors of mRNA synthesis, protein synthesis, caspases, or pro-apoptotic ceramide signaling. However, the mitochondrial and nuclear effects of palmitate are inhibited by overexpression of anti-apoptotic proto-oncogene product Bcl-2 and exacerbated by 2-bromo-palmitate as well as by carnitine. The cytoprotective actions of Bcl-2, respectively, is not antagonized by etomoxir, an inhibitor of carnitine palmitoyl transferase 1 (CPT1), suggesting that the recently described physical interaction between CPT1 and Bcl-2 is irrelevant to Bcl-2-mediated inhibition of palmitate-induce apoptosis. When added to purified mitochondria, palmitate causes the release of soluble factors capable of stimulating the apoptosis of isolated nuclei in a cell-free system. Mitochondria purified from Bcl-2 over-expressing cells are protected against the palmitate-stimulated release of such factors. These data suggest that palmitate causes apoptosis via a direct effect on mitochondria. 相似文献
18.
Yano T Itoh Y Matsuo M Kawashiri T Egashira N Oishi R 《Apoptosis : an international journal on programmed cell death》2007,12(10):1901-1909
We previously reported that necrosis occurs predominantly in porcine renal tubular LLC-PK1 cells, when the cells were exposed transiently to a high concentration of cisplatin. Moreover, we demonstrated that generation
of reactive oxygen species and subsequent production of tumor necrosis factor-α (TNF-α) through phosphorylation of p38 MAPK
are implicated in the pathogenesis of cisplatin-induced renal cell injury. However, some TUNEL-positive cells appeared in
renal proximal tubules of rats after systemic injection of cisplatin, suggesting an involvement of apoptosis. In the present
study, we found in LLC-PK1 cells that both apoptosis and necrosis were elicited when the cells were exposed to 200 μM cisplatin for 1 h followed by
incubation for 24 h in the presence of 20 μM cisplatin. The cisplatin-induced necrosis was largely attenuated by the antioxidant
N-acetylcysteine, while apoptosis was prevented by the specific inhibitors for caspases-2, -8, and -3 and a p53 inhibitor
pifithrin-α but not by the p38 MAPK inhibitor SB203580. On the other hand, SB203580 attenuated the cisplatin-induced increase
in TNF-α production. These findings suggest that p53-mediated activations of caspases-2, -8 and -3 play a key role in cisplatin-induced
renal cell apoptosis, while oxidative stress-induced TNF-α synthesis via p38 MAPK phosphorylation contributed to the necrosis. 相似文献
19.
Cytofluorometric quantitation of apoptosis-driven inner mitochondrial membrane permeabilization 总被引:3,自引:1,他引:2
Poncet D Boya P Métivier D Zamzami N Kroemer G 《Apoptosis : an international journal on programmed cell death》2003,8(5):521-530
The mitochondrial matrix can be specifically labeled by loading cells with calcein and simultaneous quenching of the non-mitochondrial calcein fluorescence with cobalt (Co2+). Positive staining of mitochondria thus requires that the inner mitochondrial membrane functions as a barrier separating calcein (within the matrix) from Co2+ (outside of the matrix). Upon induction of apoptosis, such calcein/Co2+-labeled cells, demonstrate a decrease in the overall calcein fluorescence resulting from inner mitochondrial membrane permeabilization. This decrease can be quantified by cytofluorometry and can be dissociated from other apoptosis-associated mitochondrial perturbations such as the loss of the mitochondrial transmembrane potential (
m
), the local overproduction of reactive oxygen species, and the mitochondrial release of cytochrome c. In some paradigms of apoptosis the loss of calcein/Co2+ (CC) staining can be dissociated from the
m
loss, both of which may occur in a caspase-dependent or caspase-independent fashion, depending on the apoptosis inducer. Importantly, inner membrane permeabilization to CC may occur without a permanent
m
dissipation in apoptosis, suggesting that transient permeabilization events could participate at the apoptotic cascade. Altogether, our data demonstrate that inner mitochondrial membrane permeabilization constitutes an early event in the apoptotic cascade. 相似文献
20.
Arsenic trioxide (ATO; As2O3) can induce apoptotic cell death in various cancer cells including lung cancer cells. However, little is known about the
toxicological effects of ATO on normal primary lung cells. In this study, we investigated the cellular effects of ATO on human
pulmonary fibroblast (HPF) cells in relation to cell growth inhibition and death. ATO inhibited HPF cell growth with an IC50 of approximately 30–40 μM at 24 h and induced cell death accompanied by the loss of mitochondrial membrane potential (MMP;
ΔΨm). Thus, HPF cells were considered to be very resistant to ATO insults. ATO increased the expression of p53 protein and decreased
that of Bcl-2 protein. This agent activated caspase-8 but not caspase-3 in HPF cells. Z-VAD (a pan-caspase inhibitor; 15 μM)
did not significantly decrease cell growth inhibition, death and MMP (ΔΨm) loss by ATO. Moreover, administration of Bax or casase-8 siRNA attenuated HPF cell death by ATO whereas p53 or caspase-3
siRNAs did not affect cell death. In conclusion, HPF cells were resistant to ATO and higher doses of ATO induced the growth
inhibition and death in HPF cells via the regulation of Bcl-2 family and caspase-8. 相似文献