101
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Stefin B deficiency reduces tumor growth via sensitization of tumor cells to oxidative stress in a breast cancer model. Oncogene 2013; 33:3392-400. [DOI: 10.1038/onc.2013.314] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 05/19/2013] [Accepted: 06/17/2013] [Indexed: 12/20/2022]
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102
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Cytosolic flagellin-induced lysosomal pathway regulates inflammasome-dependent and -independent macrophage responses. Proc Natl Acad Sci U S A 2013; 110:E3321-30. [PMID: 23942123 DOI: 10.1073/pnas.1305316110] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
NAIP5/NLRC4 (neuronal apoptosis inhibitory protein 5/nucleotide oligomerization domain-like receptor family, caspase activation recruitment domain domain-containing 4) inflammasome activation by cytosolic flagellin results in caspase-1-mediated processing and secretion of IL-1β/IL-18 and pyroptosis, an inflammatory cell death pathway. Here, we found that although NLRC4, ASC, and caspase-1 are required for IL-1β secretion in response to cytosolic flagellin, cell death, nevertheless, occurs in the absence of these molecules. Cytosolic flagellin-induced inflammasome-independent cell death is accompanied by IL-1α secretion and is temporally correlated with the restriction of Salmonella Typhimurium infection. Despite displaying some apoptotic features, this peculiar form of cell death do not require caspase activation but is regulated by a lysosomal pathway, in which cathepsin B and cathepsin D play redundant roles. Moreover, cathepsin B contributes to NAIP5/NLRC4 inflammasome-induced pyroptosis and IL-1α and IL-1β production in response to cytosolic flagellin. Together, our data describe a pathway induced by cytosolic flagellin that induces a peculiar form of cell death and regulates inflammasome-mediated effector mechanisms of macrophages.
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103
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Prosperini A, Juan-García A, Font G, Ruiz MJ. Reactive oxygen species involvement in apoptosis and mitochondrial damage in Caco-2 cells induced by enniatins A, A₁, B and B₁. Toxicol Lett 2013; 222:36-44. [PMID: 23867914 DOI: 10.1016/j.toxlet.2013.07.009] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 07/04/2013] [Accepted: 07/07/2013] [Indexed: 12/31/2022]
Abstract
The cytotoxic effects, the generation of reactive oxygen species (ROS) and lipid peroxidation (LPO) as well as the cell cycle disruption, the induction of apoptosis and changes in mitochondrial membrane potential (ΔΨm) as a function of increasing time have been determined in human colorectal adenocarcinoma (Caco-2) cells after exposure to enniatins (ENs) A, A₁, B and B₁. IC₅₀ values obtained by the MTT and Neutral Red assay, after 24, 48 and 72 h of exposure ranged from 0.5±0.1 to >15 μM. A significant increase (p≤0.05) in ROS generation and LPO production, as determined by the fluorescent probe H2-DCFDA and TBARS method respectively, was observed for all mycotoxins tested at 3.0 μM concentration. The highest increase in ROS generation (2.6 fold higher than control) and LPO production (111%, as compared to control) was observed with EN A. Cell cycle was significantly arrested at G2/M phase after 24 h of exposure to EN A, A₁, B₁, whereas after 72 h of exposure an arrest in S phase was observed almost for all mycotoxins tested. Moreover, after 24 and 48 h of exposure, ENs increased the early apoptotic cells, whereas after 72h of exposure necrosis was observed. In addition the loss of ΔΨm was produced on Caco-2 cells after ENs exposure. ENs A, A₁, B and B₁ cytotoxicity involved early ROS generation that induced LPO oxidative damage, apoptosis and necrosis via the mitochondrial pathway. ENs A, A₁ and B₁ induced DNA damage. However the same effects cannot be proposed for EN B. Further studies on the toxicological effects induced by ENs A, A₁, B and B₁ are needed.
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Affiliation(s)
- A Prosperini
- Laboratori de Toxicologia, Facultat de Farmacia, Universitat de Valencia, Av. Vincent Andres Estelles, 46100 Burjassot, Valencia, Spain.
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104
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Di Michele M, Goubau C, Waelkens E, Thys C, De Vos R, Overbergh L, Schyns T, Buyse G, Casaer P, Van Geet C, Freson K. Functional studies and proteomics in platelets and fibroblasts reveal a lysosomal defect with increased cathepsin-dependent apoptosis in ATP1A3 defective alternating hemiplegia of childhood. J Proteomics 2013; 86:53-69. [DOI: 10.1016/j.jprot.2013.05.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 04/29/2013] [Accepted: 05/06/2013] [Indexed: 01/07/2023]
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105
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Bottone MG, Santin G, Aredia F, Bernocchi G, Pellicciari C, Scovassi AI. Morphological Features of Organelles during Apoptosis: An Overview. Cells 2013; 2:294-305. [PMID: 24709702 PMCID: PMC3972681 DOI: 10.3390/cells2020294] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 03/24/2013] [Accepted: 04/19/2013] [Indexed: 12/13/2022] Open
Abstract
An apoptotic program leading to controlled cell dismantling implies perturbations of nuclear dynamics, as well as changes affecting the organelle structure and distribution. In human cancer cells driven to apoptosis by different stimuli, we have recently investigated the morphological properties of several organelles, including mitochondria, lysosomes, endoplasmic reticulum and Golgi apparatus. In this review, we will discuss the body of evidence in the literature suggesting that organelles are generally relocated and/or degraded during apoptosis, irrespectively of the apoptogenic stimulus and cell type.
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Affiliation(s)
- Maria Grazia Bottone
- Laboratorio di Biologia Cellulare e Neurobiologia, Dipartimento di Biologia e Biotecnologie "L. Spallanzani", Università di Pavia, 27100 Pavia, Italy.
| | - Giada Santin
- Laboratorio di Biologia Cellulare e Neurobiologia, Dipartimento di Biologia e Biotecnologie "L. Spallanzani", Università di Pavia, 27100 Pavia, Italy.
| | | | - Graziella Bernocchi
- Laboratorio di Biologia Cellulare e Neurobiologia, Dipartimento di Biologia e Biotecnologie "L. Spallanzani", Università di Pavia, 27100 Pavia, Italy.
| | - Carlo Pellicciari
- Laboratorio di Biologia Cellulare e Neurobiologia, Dipartimento di Biologia e Biotecnologie "L. Spallanzani", Università di Pavia, 27100 Pavia, Italy.
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106
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Yamashima T. Reconsider Alzheimer's disease by the 'calpain-cathepsin hypothesis'--a perspective review. Prog Neurobiol 2013; 105:1-23. [PMID: 23499711 DOI: 10.1016/j.pneurobio.2013.02.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 02/08/2013] [Accepted: 02/28/2013] [Indexed: 01/24/2023]
Abstract
Alzheimer's disease (AD) is characterized by slowly progressive neuronal death, but its molecular cascade remains elusive for over 100 years. Since accumulation of autophagic vacuoles (also called granulo-vacuolar degenerations) represents one of the pathologic hallmarks of degenerating neurons in AD, a causative connection between autophagy failure and neuronal death should be present. The aim of this perspective review is at considering such underlying mechanism of AD that age-dependent oxidative stresses may affect the autophagic-lysosomal system via carbonylation and cleavage of heat-shock protein 70.1 (Hsp70.1). AD brains exhibit gradual but continual ischemic insults that cause perturbed Ca(2+) homeostasis, calpain activation, amyloid β deposition, and oxidative stresses. Membrane lipids such as linoleic and arachidonic acids are vulnerable to the cumulative oxidative stresses, generating a toxic peroxidation product 'hydroxynonenal' that can carbonylate Hsp70.1. Recent data advocate for dual roles of Hsp70.1 as a molecular chaperone for damaged proteins and a guardian of lysosomal integrity. Accordingly, impairments of lysosomal autophagy and stabilization may be driven by the calpain-mediated cleavage of carbonylated Hsp70.1, and this causes lysosomal permeabilization and/or rupture with the resultant release of the cell degradation enzyme, cathepsins (calpain-cathepsin hypothesis). Here, the author discusses three topics; (1) how age-related decrease in lysosomal and autophagic activities has a causal connection to programmed neuronal necrosis in sporadic AD, (2) how genetic factors such as apolipoprotein E and presenilin 1 can facilitate lysosomal destabilization in the sequential molecular events, and (3) whether a single cascade can simultaneously account for implications of all players previously reported. In conclusion, Alzheimer neuronal death conceivably occurs by the similar 'calpain-hydroxynonenal-Hsp70.1-cathepsin cascade' with ischemic neuronal death. Blockade of calpain and/or extra-lysosomal cathepsins as well as scavenging of hydroxynonenal would become effective AD therapeutic approaches.
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Affiliation(s)
- Tetsumori Yamashima
- Department of Restorative Neurosurgery, Kanazawa University Graduate School of Medical Science, Takara-machi 13-1, Kanazawa 920-8641, Japan.
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107
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Shen K, Sun L, Zhang H, Xu Y, Qian X, Lu Y, Li Q, Ni L, Liu J. A ROS-mediated lysosomal-mitochondrial pathway is induced by a novel Amonafide analogue, 7c, in human Hela cervix carcinoma cells. Cancer Lett 2013; 333:229-38. [PMID: 23376642 DOI: 10.1016/j.canlet.2013.01.038] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 01/13/2013] [Accepted: 01/22/2013] [Indexed: 12/12/2022]
Abstract
In this study, a novel naphthalimide derivative 7c was designed which is topo II inhibiting though owning weak DNA binders. It was shown that 7c could induce cancer cells apoptosis and have less cytotoxicity in normal human cell. Further investigations on Hela cells revealed that 7c could also induce ROS generation, lysosome rupture as well as cathepsin B release. Subsequent mitochondrial damages including mitochondrial membrane permeabilization and the release of cytochrome c were also found in 7c when treating with Hela cells. According to our data, 7c may act as a lead compound for potential anticancer drugs. The idea of naphthalimides modification may also provide a novel strategy for naphthalimides design.
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Affiliation(s)
- Ke Shen
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, #268, 130 Meilong Road, Shanghai 200237, PR China
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108
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Dev A, Byrne SM, Verma R, Ashton-Rickardt PG, Wojchowski DM. Erythropoietin-directed erythropoiesis depends on serpin inhibition of erythroblast lysosomal cathepsins. ACTA ACUST UNITED AC 2013; 210:225-32. [PMID: 23319700 PMCID: PMC3570101 DOI: 10.1084/jem.20121762] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Serpina3g/Spi2A inhibits cathepsins B/L to enhance erythropoietin induced red blood cell formation. Erythropoietin (EPO) and its cell surface receptor (EPOR) are essential for red blood cell production and exert important cytoprotective effects on select vascular, immune, and cancer cells. To discover novel EPO action modes, we profiled the transcriptome of primary erythroid progenitors. We report Serpina3g/Spi2A as a major new EPO/EPOR target for the survival of erythroid progenitors. In knockout mice, loss of Spi2A worsened anemia caused by hemolysis, radiation, or transplantation. EPO-induced erythropoiesis also was compromised. In particular, maturing erythroblasts required Spi2A for cytoprotection, with iron and reactive oxygen species as cytotoxic agents. Spi2A defects were ameliorated by cathepsin-B/L inhibition, and by genetic co-deletion of lysosomal cathepsin B. Pharmacological inhibition of cathepsin B/L enhanced EPO-induced red cell formation in normal mice. Overall, we define an unexpected EPO action mode via an EPOR–Spi2A serpin–cathepsin axis in maturing erythroblasts, with lysosomal cathepsins as novel therapeutic targets.
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Affiliation(s)
- Arvind Dev
- Center of Excellence in Stem Cell Biology and Regenerative Medicine (COBRE), Maine Medical Center Research Institute, Scarborough, ME 04074, USA
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109
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Abstract
The endocytic pathway is a system specialized for the uptake of compounds from the cell microenvironment for their degradation. It contains an arsenal of hydrolases, including proteases, which are normally enclosed in membrane-bound organelles, but if released to the cytosol can initiate apoptosis signaling pathways. Endogenous and exogenous compounds have been identified that can mediate destabilization of lysosomal membranes, and it was shown that lysosomal proteases are not only able to initiate apoptotic signaling but can also amplify the apoptotic pathways initiated in other cellular compartments. The endocytic pathway also receives cargo destined for degradation via the autophagic pathway. By recycling energy and biosynthetic substrates, and by degrading damaged organelles and molecules, the endocytic system assists the autophagic system in resisting apoptotic stimuli. Steps leading to lysosomal membrane permeabilization and subsequent triggering of cell death as well as the therapeutic potential of intervention in lysosomal membrane permeabilization will be discussed.
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Affiliation(s)
- Urška Repnik
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
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110
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Pereira H, Azevedo F, Rego A, Sousa MJ, Chaves SR, Côrte-Real M. The protective role of yeast Cathepsin D in acetic acid-induced apoptosis depends on ANT (Aac2p) but not on the voltage-dependent channel (Por1p). FEBS Lett 2012; 587:200-5. [DOI: 10.1016/j.febslet.2012.11.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 10/20/2012] [Accepted: 11/25/2012] [Indexed: 11/16/2022]
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111
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Zhu Y, Eaton JW, Li C. Titanium dioxide (TiO2) nanoparticles preferentially induce cell death in transformed cells in a Bak/Bax-independent fashion. PLoS One 2012. [PMID: 23185639 PMCID: PMC3503962 DOI: 10.1371/journal.pone.0050607] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
While the cytotoxic effects of titanium dioxide (TiO2) nanoparticles have been under intense investigation, the molecular mechanisms of this cytotoxicity remain unknown. Here we investigated the influence of oncogenic transformation and a major apoptotic signaling pathway on cellular responses to TiO2 nanoparticles. Isogenic wild-type (WT) and apoptosis-resistant (Bak−/−Bax−/−) cell lines with and without tumorigenic transformation were examined. TiO2 nanoparticles preferentially reduced viability of tumorigenic cells in a dose-dependent fashion compared with their untransformed counterparts. Importantly, the elevated cytotoxicity of TiO2 nanoparticles was independent of a major Bak/Bax-dependent apoptosis pathway. Because transformation does not affect cellular fluid-phase endocytosis or nanoparticle uptake, it is likely that the increased cytotoxicity in tumor cells is due to the interaction between TiO2 nanoparticles and the lysosomal compartment. Overall, our data indicate that TiO2 nanoparticles induce cytotoxicity preferentially in transformed cells independent of a major apoptotic signaling pathway.
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Affiliation(s)
- Yanglong Zhu
- Molecular Targets Program, James Graham Brown Cancer Center, Department of Medicine, Department of Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, United States of America
| | - John W. Eaton
- Molecular Targets Program, James Graham Brown Cancer Center, Department of Medicine, Department of Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, United States of America
| | - Chi Li
- Molecular Targets Program, James Graham Brown Cancer Center, Department of Medicine, Department of Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, United States of America
- * E-mail:
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112
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Development of Purkinje cell degeneration in a knockin mouse model reveals lysosomal involvement in the pathogenesis of SCA6. Proc Natl Acad Sci U S A 2012; 109:17693-8. [PMID: 23054835 DOI: 10.1073/pnas.1212786109] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disease caused by the expansion of a polyglutamine tract in the Ca(v)2.1 voltage-gated calcium channel. To elucidate how the expanded polyglutamine tract in this plasma membrane protein causes the disease, we created a unique knockin mouse model that modestly overexpressed the mutant transcripts under the control of an endogenous promoter (MPI-118Q). MPI-118Q mice faithfully recapitulated many features of SCA6, including selective Purkinje cell degeneration. Surprisingly, analysis of inclusion formation in the mutant Purkinje cells indicated the lysosomal localization of accumulated mutant Ca(v)2.1 channels in the absence of autophagic response. The lack of cathepsin B, a major lysosomal cysteine proteinase, exacerbated the loss of Purkinje cells and was accompanied by an acceleration of inclusion formation in this model. Thus, the pathogenic mechanism of SCA6 involves the endolysosomal degradation pathway, and unique pathological features of this model further illustrate the pivotal role of protein context in the pathogenesis of polyglutamine diseases.
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113
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Wang J, Gao R, Li Q, Xie S, Zhao J, Wang C. Synthesis, Cytotoxicity, and Cell Death Profile of Polyaminoanthraquinones as Antitumor Agents. Chem Biol Drug Des 2012; 80:909-17. [DOI: 10.1111/cbdd.12038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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114
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Mechanisms for ribotoxin-induced ribosomal RNA cleavage. Toxicol Appl Pharmacol 2012; 265:10-8. [PMID: 23022514 DOI: 10.1016/j.taap.2012.09.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 09/11/2012] [Accepted: 09/17/2012] [Indexed: 12/13/2022]
Abstract
The Type B trichothecene deoxynivalenol (DON), a ribotoxic mycotoxin known to contaminate cereal-based foods, induces ribosomal RNA (rRNA) cleavage in the macrophage via p38-directed activation of caspases. Here we employed the RAW 264.7 murine macrophage model to test the hypothesis that this rRNA cleavage pathway is similarly induced by other ribotoxins. Capillary electrophoresis confirmed that the antibiotic anisomycin (≥25ng/ml), the macrocylic trichothecene satratoxin G (SG) (≥10ng/ml) and ribosome-inactivating protein ricin (≥300ng/ml) induced 18s and 28s rRNA fragmentation patterns identical to that observed for DON. Also, as found for DON, inhibition of p38, double-stranded RNA-activated kinase (PKR) and hematopoietic cell kinase (Hck) suppressed MAPK anisomycin-induced rRNA cleavage, while, in contrast, their inhibition did not affect SG- and ricin-induced rRNA fragmentation. The p53 inhibitor pifithrin-μ and pan caspase inhibitor Z-VAD-FMK suppressed rRNA cleavage induced by anisomycin, SG and ricin, indicating that these ribotoxins shared with DON a conserved downstream pathway. Activation of caspases 8, 9 and 3 concurrently with apoptosis further suggested that rRNA cleavage occurred in parallel with both extrinsic and intrinsic pathways of programmed cell death. When specific inhibitors of cathepsins L and B (lysosomal cysteine cathepsins active at cytosolic neutral pH) were tested, only the former impaired anisomycin-, SG-, ricin- and DON-induced rRNA cleavage. Taken together, the data suggest that (1) all four ribotoxins induced p53-dependent rRNA cleavage via activation of cathepsin L and caspase 3, and (2) activation of p53 by DON and anisomycin involved p38 whereas SG and ricin activated p53 by an alternative mechanism.
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115
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Johnson JR, Kocher B, Barnett EM, Marasa J, Piwnica-Worms D. Caspase-activated cell-penetrating peptides reveal temporal coupling between endosomal release and apoptosis in an RGC-5 cell model. Bioconjug Chem 2012; 23:1783-93. [PMID: 22900707 PMCID: PMC3447108 DOI: 10.1021/bc300036z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Caspase-activatable cell-penetrating peptide (CPP) probes, designed for efficient cell uptake and specificity via cleavable intramolecular quenched-fluorophore strategies, show promise for identifying and imaging retinal ganglion cell apoptosis in vivo. However, initial cell uptake and trafficking events cannot be visualized because the probes are designed to be optically quenched in the intact state. To visualize subcellular activation events in real-time during apoptosis, a new series of matched quenched and nonquenched CPP probes were synthesized. In both native and staurosporine-differentiated RGC-5 cells, probe uptake was time- and concentration-dependent through clathrine-, caveolin-, and pinocytosis-mediated endocytic mechanisms. During apoptosis, KcapTR488, a novel dual fluorophore CPP probe, revealed by multispectral imaging a temporal coupling of endosomal release and effector caspase activation in RGC-5 cells. The novel CPPs described herein provide new tools to study spatial and temporal regulation of endosomal permeability during apoptosis.
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Affiliation(s)
- James R. Johnson
- Molecular Imaging Center, Mallinckrodt Institute of Radiology, BRIGHT Institute, Departments of Cell Biology & Physiology, Developmental Biology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Brandon Kocher
- Molecular Imaging Center, Mallinckrodt Institute of Radiology, BRIGHT Institute, Departments of Cell Biology & Physiology, Developmental Biology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Edward M. Barnett
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Jayne Marasa
- Molecular Imaging Center, Mallinckrodt Institute of Radiology, BRIGHT Institute, Departments of Cell Biology & Physiology, Developmental Biology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - David Piwnica-Worms
- Molecular Imaging Center, Mallinckrodt Institute of Radiology, BRIGHT Institute, Departments of Cell Biology & Physiology, Developmental Biology, Washington University School of Medicine, St. Louis, Missouri 63110
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116
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Enzenmüller S, Gonzalez P, Karpel-Massler G, Debatin KM, Fulda S. GDC-0941 enhances the lysosomal compartment via TFEB and primes glioblastoma cells to lysosomal membrane permeabilization and cell death. Cancer Lett 2012; 329:27-36. [PMID: 23000516 DOI: 10.1016/j.canlet.2012.09.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 08/17/2012] [Accepted: 09/10/2012] [Indexed: 12/20/2022]
Abstract
Since phosphatidylinositol-3-kinase (PI3K) inhibitors are primarily cytostatic against glioblastoma, we searched for new drug combinations. Here, we discover that the PI3K inhibitor GDC-0941 acts in concert with the natural compound B10, a glycosylated derivative of betulinic acid, to induce cell death in glioblastoma cells. Importantly, parallel experiments in primary glioblastoma cultures similarly show that GDC-0941 and B10 cooperate to trigger cell death, underscoring the clinical relevance of this finding. Molecular studies revealed that treatment with GDC-0941 stimulates the expression and nuclear translocation of Transcription Factor EB (TFEB), a master regulator of lysosomal biogenesis, the lysosomal membrane marker LAMP-1 and the mature form of cathepsin B. Also, GDC-0941 triggers a time-dependent increase of the lysosomal compartment in a TFEB-dependent manner, since knockdown of TFEB significantly reduces this GDC-0941-stimulated lysosomal enhancement. Importantly, GDC-0941 cooperates with B10 to trigger lysosomal membrane permeabilization, leading to increased activation of Bax, loss of mitochondrial membrane potential (MMP), caspase-3 activation and cell death. Addition of the cathepsin B inhibitor CA-074me reduces Bax activation, loss of MMP, caspase-3 activation and cell death upon treatment with GDC-0941/B10. By comparison, knockdown of caspase-3 or the broad-range caspase inhibitor zVAD.fmk inhibits GDC-0941/B10-induced DNA fragmentation, but does not prevent cell death, thus pointing to both caspase-dependent and -independent pathways. By identifying the combination of GDC-0941 and B10 as a new, potent strategy to trigger cell death in glioblastoma cells, our findings have important implications for the development of novel treatment approaches for glioblastoma.
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117
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Veeravalli KK, Dasari VR, Rao JS. Regulation of proteases after spinal cord injury. J Neurotrauma 2012; 29:2251-62. [PMID: 22709139 DOI: 10.1089/neu.2012.2460] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Spinal cord injury is a major medical problem worldwide. Unfortunately, we still do not have suitable therapeutic agents for the treatment of spinal cord injury and prevention of its devastating consequences. Scientists and physicians are baffled by the challenges of controlling progressive neurodegeneration in spinal cord injury, which has not been healed with any currently-available treatments. Although extensive work has been carried out to better understand the pathophysiology of spinal cord injury, our current understanding of the repair mechanisms of secondary injury processes is still meager. Several investigators reported the crucial role played by various proteases after spinal cord injury. Understanding the beneficial and harmful roles these proteases play after spinal cord injury will allow scientists to plan and design appropriate treatment strategies to improve functional recovery after spinal cord injury. This review will focus on various proteases such as matrix metalloproteinases, cysteine proteases, and serine proteases and their inhibitors in the context of spinal cord injury.
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Affiliation(s)
- Krishna Kumar Veeravalli
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61605, USA
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118
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Impaired protein quality control system underlies mitochondrial dysfunction in skeletal muscle of streptozotocin-induced diabetic rats. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1189-97. [DOI: 10.1016/j.bbadis.2012.04.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 04/06/2012] [Accepted: 04/13/2012] [Indexed: 11/20/2022]
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119
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Ivanova L, Egge-Jacobsen WM, Solhaug A, Thoen E, Fæste CK. Lysosomes as a possible target of enniatin B-induced toxicity in Caco-2 cells. Chem Res Toxicol 2012; 25:1662-74. [PMID: 22731695 DOI: 10.1021/tx300114x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Enniatins are cyclic hexadepsipeptidic mycotoxins with ionophoric, antibiotic, and insecticidal activity. Enniatin B (EnnB), the most important analogue, is produced by many Fusarium species and is a common contaminant in grain-based foods. The compound's cytotoxic potential has been shown in different experiments; however, the mode of action has not been detailed so far. In the present study, several mutually confirmative experiments have been performed indicating that EnnB-initiated cytotoxicity could be connected with lysosomal membrane permeabilization (LMP). Lysosomal functionality, as assessed by the Neutral Red assay, was already affected after 3 h of toxin exposure. After 24 h, cell proliferation was decreased, and there was indication for a cell cycle arrest in the G(2)/M phase leading to the initiation of apoptosis or necrosis. Intracellular ROS-production was observed. However, antioxidants did not alter the observed EnnB-induced loss of lysosomal functionality leading to the conclusion that ROS was not an initial factor but one produced later in the event cascade. The collected data suggested that lysosomal destabilization is an upstream event in EnnB-initiated cytotoxicity followed by a certain extent of translocation of cathepsins into the cytosol, which was observed using immunological and proteomic methods. It appeared that cell death induced by EnnB was delayed and occurred not as a massive lysosomal breakdown but was probably progressing and leading to partial and selective LMP, starting a nonapoptotic cell death pathway with morphological features that had been previously considered as necrotic. The molecular mechanism of EnnB-triggered lysosomal destabilization, and the cellular processes leading to mitochondrial permeabilization and cell death are still unknown. They may, however, be connected to the compound's ionophoric properties.
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Affiliation(s)
- L Ivanova
- Norwegian Veterinary Institute, Oslo, Norway.
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120
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Hudej R, Kljun J, Kandioller W, Repnik U, Turk B, Hartinger CG, Keppler BK, Miklavčič D, Turel I. Synthesis and Biological Evaluation of the Thionated Antibacterial Agent Nalidixic Acid and Its Organoruthenium(II) Complex. Organometallics 2012. [DOI: 10.1021/om300424w] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rosana Hudej
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva
c. 5, SI-1000 Ljubljana, Slovenia
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška
c. 25, SI-1000 Ljubljana, Slovenia
| | - Jakob Kljun
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva
c. 5, SI-1000 Ljubljana, Slovenia
| | - Wolfgang Kandioller
- Institute of Inorganic Chemistry, University of Vienna, Währinger
Straße 42, A-1090 Vienna, Austria
| | - Urška Repnik
- Jozef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
| | - Boris Turk
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva
c. 5, SI-1000 Ljubljana, Slovenia
- Jozef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
- CIPKEBIP Centre of Excellence, Jamova c. 39, SI-1000 Ljubljana, Slovenia
| | - Christian G. Hartinger
- Institute of Inorganic Chemistry, University of Vienna, Währinger
Straße 42, A-1090 Vienna, Austria
- School of Chemical Sciences, The University of Auckland, Private
Bag 92019, Auckland 1142, New Zealand
| | - Bernhard K. Keppler
- Institute of Inorganic Chemistry, University of Vienna, Währinger
Straße 42, A-1090 Vienna, Austria
| | - Damijan Miklavčič
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška
c. 25, SI-1000 Ljubljana, Slovenia
| | - Iztok Turel
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva
c. 5, SI-1000 Ljubljana, Slovenia
- EN→Fist Centre of Excellence, Dunajska
c. 156, SI-1000 Ljubljana, Slovenia
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121
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Fan F, Nie S, Yang D, Luo M, Shi H, Zhang YH. Labeling Lysosomes and Tracking Lysosome-Dependent Apoptosis with a Cell-Permeable Activity-Based Probe. Bioconjug Chem 2012; 23:1309-17. [DOI: 10.1021/bc300143p] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Fengkai Fan
- Britton Chance Center
for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, and ‡Key Laboratory
of Biomedical Photonics of Ministry of Education, Department of Biomedical
Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan 430074,
P. R. China
| | - Si Nie
- Britton Chance Center
for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, and ‡Key Laboratory
of Biomedical Photonics of Ministry of Education, Department of Biomedical
Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan 430074,
P. R. China
| | - Dongmei Yang
- Britton Chance Center
for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, and ‡Key Laboratory
of Biomedical Photonics of Ministry of Education, Department of Biomedical
Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan 430074,
P. R. China
| | - Meijie Luo
- Britton Chance Center
for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, and ‡Key Laboratory
of Biomedical Photonics of Ministry of Education, Department of Biomedical
Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan 430074,
P. R. China
| | - Hua Shi
- Britton Chance Center
for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, and ‡Key Laboratory
of Biomedical Photonics of Ministry of Education, Department of Biomedical
Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan 430074,
P. R. China
| | - Yu-Hui Zhang
- Britton Chance Center
for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, and ‡Key Laboratory
of Biomedical Photonics of Ministry of Education, Department of Biomedical
Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan 430074,
P. R. China
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122
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O'Leary MFN, Vainshtein A, Carter HN, Zhang Y, Hood DA. Denervation-induced mitochondrial dysfunction and autophagy in skeletal muscle of apoptosis-deficient animals. Am J Physiol Cell Physiol 2012; 303:C447-54. [PMID: 22673615 DOI: 10.1152/ajpcell.00451.2011] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Skeletal muscle undergoes remarkable adaptations in response to chronic decreases in contractile activity, such as a loss of muscle mass, decreases in both mitochondrial content and function, as well as the activation of apoptosis. Although these adaptations are well known, questions remain regarding the signaling pathways that mediated these changes. Autophagy is an organelle turnover pathway that could contribute to these adaptations. The purpose of this study was to determine whether denervation-induced muscle disuse would result in the activation of autophagy gene expression in both wild-type (WT) and Bax/Bak double knockout (DKO) animals, which display an attenuated apoptotic response. Denervation caused a reduction in muscle mass for WT and DKO animals; however, there was a 40% attenuation in muscle atrophy in DKO animals. Mitochondrial state 3 respiration was significantly reduced, and reactive oxygen species production was increased by two- to threefold in both WT and DKO animals. Apoptotic markers, including cytosolic AIF and DNA fragmentation, were elevated in WT, but not in DKO animals following denervation. Autophagy proteins including LC3II, ULK1, ATG7, p62, and Beclin1 were increased similarly following denervation for both WT and DKO. Interestingly, denervation markedly increased the localization of LC3II to subsarcolemmal mitochondria, and this was more pronounced in the DKO animals. Thus denervation-induced muscle disuse activates both apoptotic and autophagic signaling pathways in muscle, and autophagic protein expression does not exhibit a compensatory increase in the presence of attenuated apoptosis. However, the absence of Bax and Bak may represent a potential signal to trigger mitophagy in muscle.
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Affiliation(s)
- Michael F N O'Leary
- School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
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123
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Hornick JR, Vangveravong S, Spitzer D, Abate C, Berardi F, Goedegebuure P, Mach RH, Hawkins WG. Lysosomal membrane permeabilization is an early event in Sigma-2 receptor ligand mediated cell death in pancreatic cancer. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2012; 31:41. [PMID: 22551149 PMCID: PMC3414770 DOI: 10.1186/1756-9966-31-41] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Accepted: 05/02/2012] [Indexed: 01/13/2023]
Abstract
Background Sigma-2 receptor ligands have been studied for treatment of pancreatic cancer because they are preferentially internalized by proliferating cells and induce apoptosis. This mechanism of apoptosis is poorly understood, with varying reports of caspase-3 dependence. We evaluated multiple sigma-2 receptor ligands in this study, each shown to decrease tumor burden in preclinical models of human pancreatic cancer. Results Fluorescently labeled sigma-2 receptor ligands of two classes (derivatives of SW43 and PB282) localize to cell membrane components in Bxpc3 and Aspc1 pancreatic cancer cells and accumulate in lysosomes. We found that interactions in the lysosome are critical for cell death following sigma-2 ligand treatment because selective inhibition of a protective lysosomal membrane glycoprotein, LAMP1, with shRNA greatly reduced the viability of cells following treatment. Sigma-2 ligands induced lysosomal membrane permeabilization (LMP) and protease translocation triggering downstream effectors of apoptosis. Subsequently, cellular oxidative stress was greatly increased following treatment with SW43, and the hydrophilic antioxidant N-acetylcysteine (NAC) gave greater protection against this than a lipophilic antioxidant, α-tocopherol (α-toco). Conversely, PB282-mediated cytotoxicity relied less on cellular oxidation, even though α-toco did provide protection from this ligand. In addition, we found that caspase-3 induction was not as significantly inhibited by cathepsin inhibitors as by antioxidants. Both NAC and α-toco protected against caspase-3 induction following PB282 treatment, while only NAC offered protection following SW43 treatment. The caspase-3 inhibitor DEVD-FMK offered significant protection from PB282, but not SW43. Conclusions Sigma-2 ligand SW43 commits pancreatic cancer cells to death by a caspase-independent process involving LMP and oxidative stress which is protected from by NAC. PB282 however undergoes a caspase-dependent death following LMP protected by DEVD-FMK and α-toco, which is also known to stabilize the mitochondrial membrane during apoptotic stimuli. These differences in mechanism are likely dependent on the structural class of the compounds versus the inherent sigma-2 binding affinity. As resistance of pancreatic cancers to specific apoptotic stimuli from chemotherapy is better appreciated, and patient-tailored treatments become more available, ligands with high sigma-2 receptor affinity should be chosen based on sensitivities to apoptotic pathways.
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Affiliation(s)
- John R Hornick
- Department of Surgery, Washington University School of Medicine, S, Euclid Avenue, St, Louis, MO, USA
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124
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Enniatin B-induced cell death and inflammatory responses in RAW 267.4 murine macrophages. Toxicol Appl Pharmacol 2012; 261:74-87. [PMID: 22483798 DOI: 10.1016/j.taap.2012.03.014] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Revised: 03/12/2012] [Accepted: 03/19/2012] [Indexed: 12/11/2022]
Abstract
The mycotoxin enniatin B (EnnB) is predominantly produced by species of the Fusarium genera, and often found in grain. The cytotoxic effect of EnnB has been suggested to be related to its ability to form ionophores in cell membranes. The present study examines the effects of EnnB on cell death, differentiation, proliferation and pro-inflammatory responses in the murine monocyte-macrophage cell line RAW 264.7. Exposure to EnnB for 24 h caused an accumulation of cells in the G0/G1-phase with a corresponding decrease in cyclin D1. This cell cycle-arrest was possibly also linked to the reduced cellular ability to capture and internalize receptors as illustrated by the lipid marker ganglioside GM1. EnnB also increased the number of apoptotic, early apoptotic and necrotic cells, as well as cells with elongated spindle-like morphology. The Neutral Red assay indicated that EnnB induced lysosomal damage; supported by transmission electron microscopy (TEM) showing accumulation of lipids inside the lysosomes forming lamellar structures/myelin bodies. Enhanced levels of activated caspase-1 were observed after EnnB exposure and the caspase-1 specific inhibitor ZYVAD-FMK reduced EnnB-induced apoptosis. Moreover, EnnB increased the release of interleukin-1 beta (IL-1β) in cells primed with lipopolysaccharide (LPS), and this response was reduced by both ZYVAD-FMK and the cathepsin B inhibitor CA-074Me. In conclusion, EnnB was found to induce cell cycle arrest, cell death and inflammation. Caspase-1 appeared to be involved in the apoptosis and release of IL-1β and possibly activation of the inflammasome through lysosomal damage and leakage of cathepsin B.
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125
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Česen MH, Pegan K, Spes A, Turk B. Lysosomal pathways to cell death and their therapeutic applications. Exp Cell Res 2012; 318:1245-51. [PMID: 22465226 DOI: 10.1016/j.yexcr.2012.03.005] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 03/05/2012] [Accepted: 03/05/2012] [Indexed: 01/07/2023]
Abstract
Lysosomes are the major cell digestive organelles that were discovered over 50 years ago. They contain a number of hydrolases that help them to degrade intracellular and extracellular material delivered. Among the hydrolases, the cathepsins, a group of proteases enclosed in the lysosomes, have a major role. About a decade ago, the cathepsins were found to participate in apoptosis. Following their release into the cytosol, they cleave Bid and degrade antiapoptotic Bcl-2 proteins, thereby triggering the mitochondrial pathway of apoptosis, with the lysosomal membrane permeabilization being the critical step in this pathway. Lysosomal dysfunction is linked with several diseases, including cancer and neurodegenerative disorders, thereby providing a potential for therapeutic applications. In this review lysosomes and lysosomal proteases involvement in apoptosis and their possible pharmaceutical targeting are discussed.
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Affiliation(s)
- Maruša Hafner Česen
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, Ljubljana, Slovenia
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126
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Abstract
Protease research has undergone a major expansion in the last decade, largely due to the extremely rapid development of new technologies, such as quantitative proteomics and in-vivo imaging, as well as an extensive use of in-vivo models. These have led to identification of physiological substrates and resulted in a paradigm shift from the concept of proteases as protein-degrading enzymes to proteases as key signalling molecules. However, we are still at the beginning of an understanding of protease signalling pathways. We have only identified a minor subset of true physiological substrates for a limited number of proteases, and their physiological regulation is still not well understood. Similarly, links with other signalling systems are not well established. Herein, we will highlight current challenges in protease research.
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127
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Vacuole-mitochondrial cross-talk during apoptosis in yeast: a model for understanding lysosome-mitochondria-mediated apoptosis in mammals. Biochem Soc Trans 2012; 39:1533-7. [PMID: 21936847 DOI: 10.1042/bst0391533] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The yeast apoptosis field emerged with the finding that key components of the apoptotic machinery are conserved in these simple eukaryotes. Thus it became possible to exploit these genetically tractable organisms to improve our understanding of the intricate mechanisms of cell death in higher eukaryotes and of severe human diseases associated with apoptosis dysfunctions. Early on, it was recognized that a mitochondria-mediated apoptotic pathway showing similarities to the mammalian intrinsic pathway was conserved in yeast. Recently, lysosomes have also emerged as central players in mammalian apoptosis. Following LMP (lysosomal membrane permeabilization), lysosomal proteases such as cathepsins B, D and L are released into the cytosol and can trigger a mitochondrial apoptotic cascade. CatD (cathepsin D) can also have anti-apoptotic effects in some cellular types and specific contexts. Nonetheless, the mechanisms underlying LMP and the specific role of cathepsins after their release into the cytosol remain poorly understood. We have recently shown that yeast vacuoles, membrane-bound acidic organelles, which share many similarities to plant vacuoles and mammalian lysosomes, are also involved in the regulation of apoptosis and that the vacuolar protease Pep4p, orthologue of the human CatD, is released from the vacuole into the cytosol in response to acetic acid. Here, we discuss how the conservation of cell-death regulation mechanisms in yeast by the lysosome-like organelle and mitochondria may provide new insights into the understanding of the complex interplay between the mitochondria and lysosome-mediated signalling routes during mammalian apoptosis.
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128
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Chen J, Xavier S, Moskowitz-Kassai E, Chen R, Lu CY, Sanduski K, Špes A, Turk B, Goligorsky MS. Cathepsin cleavage of sirtuin 1 in endothelial progenitor cells mediates stress-induced premature senescence. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 180:973-983. [PMID: 22234173 DOI: 10.1016/j.ajpath.2011.11.033] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 11/15/2011] [Accepted: 11/22/2011] [Indexed: 12/15/2022]
Abstract
Stress-induced premature senescence (SIPS) of endothelial cells (ECs) has emerged as a contributor to global EC dysfunction. One of the cellular abnormalities mechanistically linked to SIPS is lysosomal dysfunction. In this study, we examined the impact of a range of cardiovascular risk factors on the expression of sirtuin 1 (SIRT1), SIPS, and apoptosis, and we documented the role of SIRT1 in reduced EC and endothelial progenitor cell (EPC) viability. These findings were confirmed in mice with selective endothelial SIRT1 knockout. The effects of stressors could be partially mimicked by inducing lysosomal membrane permeabilization or inhibiting autophagy, and were reversed by a cathepsin inhibitor. We provide evidence that SIRT1 is an important substrate of cysteine cathepsins B, S, and L. An antioxidant/peroxynitrite scavenger, ebselen, prevented stress-induced SIRT1 depletion and subversion of autophagy by mitigating lysosomal dysfunction. In conclusion, our data advance the concept of "stem cell aging" by establishing the critical role of lysosomal dysfunction in the development of SIPS through the cathepsin-induced proteolytic cleavage of SIRT1, a mechanism linking cell stress to apoptosis and SIPS. Ebselen potently protects lysosomal membrane integrity, preventing cathepsin-induced cleavage of SIRT 1 in EPCs and blunting SIPS and apoptotic cell death induced by relevant cardiovascular stressors. The proposed mechanism of SIRT1 depletion in stress has all of the attributes of being a paradigm of SIPS of EPCs.
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Affiliation(s)
- Jun Chen
- Departments of Medicine, Pharmacology, and Physiology, Renal Research Institute, New York Medical College, Valhalla, New York
| | - Sandhya Xavier
- Departments of Medicine, Pharmacology, and Physiology, Renal Research Institute, New York Medical College, Valhalla, New York
| | - Eliza Moskowitz-Kassai
- Departments of Medicine, Pharmacology, and Physiology, Renal Research Institute, New York Medical College, Valhalla, New York
| | - Robert Chen
- Departments of Medicine, Pharmacology, and Physiology, Renal Research Institute, New York Medical College, Valhalla, New York
| | - Connie Y Lu
- Departments of Medicine, Pharmacology, and Physiology, Renal Research Institute, New York Medical College, Valhalla, New York
| | - Kyle Sanduski
- Departments of Medicine, Pharmacology, and Physiology, Renal Research Institute, New York Medical College, Valhalla, New York
| | - Aleš Špes
- Departments of Medicine, Pharmacology, and Physiology, Renal Research Institute, New York Medical College, Valhalla, New York
| | - Boris Turk
- Department of Biochemistry and Molecular and Structural Biology, Jozef Stefan Institute, Ljubljana, Slovenia; Center of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, Ljubljana, Slovenia
| | - Michael S Goligorsky
- Departments of Medicine, Pharmacology, and Physiology, Renal Research Institute, New York Medical College, Valhalla, New York.
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130
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Repnik U, Stoka V, Turk V, Turk B. Lysosomes and lysosomal cathepsins in cell death. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1824:22-33. [PMID: 21914490 DOI: 10.1016/j.bbapap.2011.08.016] [Citation(s) in RCA: 292] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 08/24/2011] [Accepted: 08/26/2011] [Indexed: 12/30/2022]
Abstract
Lysosomes are the key degradative compartments of the cell. Lysosomal cathepsins, which are enclosed in the lysosomes, help to maintain the homeostasis of the cell's metabolism by participating in the degradation of heterophagic and autophagic material. Following the targeted lysosomal membrane's destabilization, the cathepsins can be released into the cytosol and initiate the lysosomal pathway of apoptosis through the cleavage of Bid and the degradation of the anti-apoptotic Bcl-2 homologues. Cathepsins can also amplify the apoptotic signaling, when the lysosomal membranes are destabilized at a later stage of apoptosis, initiated by other stimuli. However, the functional integrity of the lysosomal compartment during apoptosis enables efficient autophagy, which can counteract apoptosis by providing the energy source and by disposing the damaged mitochondria, which generate the ROS. Impairing autophagy by disabling the lysosome function is being investigated as an adjuvant therapeutic approach to sensitize cells to apoptosis-inducing agents. Destabilization of the lysosomal membranes by the lysosomotropic detergents seems to be a promising strategy in this context as it would not only disable autophagy, but also promote apoptosis through the initiation of the lysosomal pathway. In contrast, the impaired autophagy and lysosomal degradation linked with the increased oxidative stress underlie degenerative changes in the aging neurons. This further suggests that lysosomes and lysosomal cathepsins have a dual role in cell death. This article is part of a Special Issue entitled: Proteolysis 50 years after the discovery of lysosome.
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Affiliation(s)
- Urška Repnik
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, Jamova, Ljubljana, Slovenia
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131
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Jiang Z, Hu Z, Zeng L, Lu W, Zhang H, Li T, Xiao H. The role of the Golgi apparatus in oxidative stress: is this organelle less significant than mitochondria? Free Radic Biol Med 2011; 50:907-17. [PMID: 21241794 DOI: 10.1016/j.freeradbiomed.2011.01.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 12/30/2010] [Accepted: 01/08/2011] [Indexed: 10/18/2022]
Abstract
Reactive oxygen species (ROS)/reactive nitrogen species (RNS) and ROS/RNS-mediated oxidative stress have well-established roles in many physiological and pathological processes and are associated with the pathogenesis of many diseases, such as hypertension, ischemia/reperfusion injury, diabetes mellitus, atherosclerosis, stroke, cancer, and neurodegenerative disorders. It is generally accepted that mitochondria play an essential role in oxidative stress because they are responsible for the primary generation of superoxide radicals. Little attention, however, has been paid to the importance of the Golgi apparatus (GA) in this process. The GA is a pivotal organelle in cell metabolism and participates in modifying, sorting, and packaging macromolecules for cell secretion or use within the cell. It is inevitably involved in the process of oxidative stress, which can cause modification and damage of lipids, proteins, DNA, and other structural constituents. Here we discuss the connections between the GA and oxidative stress and highlight the role of the GA in oxidative stress-related Ca(2+)/Mn(2+) homeostasis, cell apoptosis, sphingolipid metabolism, signal transduction, and antioxidation. We also provide a novel perspective on the subcellular significance of oxidative stress and its pathological implications and present "GA stress" as a new concept to explain the GA-specific stress response.
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Affiliation(s)
- Zheng Jiang
- Department of Neurology, Second Xiangya Hospital, Central South University, Changsha 410011, China
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132
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Berndt C, Kurz T, Bannenberg S, Jacob R, Holmgren A, Brunk UT. Ascorbate and endocytosed Motexafin gadolinium induce lysosomal rupture. Cancer Lett 2011; 307:119-23. [PMID: 21492999 DOI: 10.1016/j.canlet.2011.03.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 03/21/2011] [Accepted: 03/28/2011] [Indexed: 11/25/2022]
Abstract
Motexafin gadolinium (MGd) sensitizes malignant cells to ionizing radiation, although the underlying mechanisms for uptake and sensitization are both unclear. Here we show that MGd is endocytosed by the clathrin-dependent pathway with ensuing lysosomal membrane permeabilization, most likely via formation of reactive oxygen species involving redox-active metabolites, such as ascorbate. We propose that subsequent apoptosis is a synergistic effect of irradiation and high MGd concentrations in malignant cells due to their pronounced endocytic activity. The results provide novel insights into the mode of action of this promising anti-cancer drug, which is currently under clinical trials.
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Affiliation(s)
- Carsten Berndt
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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133
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Ray SK, Samantaray S, Smith JA, Matzelle DD, Das A, Banik NL. Inhibition of cysteine proteases in acute and chronic spinal cord injury. Neurotherapeutics 2011; 8:180-6. [PMID: 21373949 PMCID: PMC3101838 DOI: 10.1007/s13311-011-0037-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Spinal cord injury (SCI) is a serious neurological disorder that debilitates mostly young people. Unfortunately, we still do not have suitable therapeutic agents for treatment of SCI and prevention of its devastating consequences. However, we have gained a good understanding of pathological mechanisms that cause neurodegeneration leading to paralysis or even death following SCI. Primary injury to the spinal cord initiates the secondary injury process that includes various deleterious factors for ultimate activation of different cysteine proteases for degradation of cellular key cytoskeleton and other crucial proteins for delayed death of neurons and glial cells at the site of SCI and its penumbra in different animal models. An important aspect of SCI is the increase in intracellular free Ca(2+) concentration within a short time of primary injury. Various studies in different laboratories demonstrate that the most important cysteine protease for neurodegeneration in SCI is calpain, which absolutely requires intracellular free Ca(2+) for its activation. Furthermore, other cysteine proteases, such as caspases and cathepsin B also make a contribution to neurodegeneration in SCI. Therefore, inhibition of cysteine proteases is an important goal in prevention of neurodegeneration in SCI. Studies showed that individual inhibitors of cysteine proteases provided significant neuroprotection in animal models of SCI. Recent studies suggest that physiological hormones, such as estrogen and melatonin, can be successfully used for prevention of neurodegeneration and preservation of motor function in acute SCI as well as in chronic SCI in rats.
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Affiliation(s)
- Swapan K. Ray
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina 29209 USA
| | - Supriti Samantaray
- Division of Neurology, Department of Neurosciences, Medical University of South Carolina, 96 Jonathan Lucas Street, Suite 309 CSB, Charleston, South Carolina 29425 USA
| | - Joshua A. Smith
- Division of Neurology, Department of Neurosciences, Medical University of South Carolina, 96 Jonathan Lucas Street, Suite 309 CSB, Charleston, South Carolina 29425 USA
| | - Denise D. Matzelle
- Division of Neurology, Department of Neurosciences, Medical University of South Carolina, 96 Jonathan Lucas Street, Suite 309 CSB, Charleston, South Carolina 29425 USA
| | - Arabinda Das
- Division of Neurology, Department of Neurosciences, Medical University of South Carolina, 96 Jonathan Lucas Street, Suite 309 CSB, Charleston, South Carolina 29425 USA
| | - Naren L. Banik
- Division of Neurology, Department of Neurosciences, Medical University of South Carolina, 96 Jonathan Lucas Street, Suite 309 CSB, Charleston, South Carolina 29425 USA
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134
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Sun XS, Bandura-Morgan L, Zacharias W. Induction of Apoptosis in Lung Cancer Cells by TRAIL and L-leucyl-L-leucine Methyl Ester. ACTA ACUST UNITED AC 2011. [DOI: 10.4236/jct.2011.23057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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