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Terzani F, Belhattab S, Le Guern A, Guitot K, Monasson O, Zanato C, Chelain E, Leroy-Dudal J, Pytkowicz J. Synthesis and biological evaluation of selective Pepstatin based trifluoromethylated inhibitors of Cathepsin D. Eur J Med Chem 2024; 267:116178. [PMID: 38295686 DOI: 10.1016/j.ejmech.2024.116178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/25/2024]
Abstract
Cathepsin D (CD) is overexpressed in several types of cancer and constitutes an important biological target. Pepstatin A, a pentapeptide incorporating two non-proteinogenic statin residues, is among the most potent inhibitor of CD but lacks selectivity and suffers from poor bioavailability. Eight analogues of Pepstatin A, were synthesized, replacing residues in P3 or P1 position by non-canonical (S)- and (R)-α-Trifluoromethyl Alanine (TfmAla), (S)- and (R)-Trifluoromethionine (TFM) or non-natural d-Valine. The biological activities of those analogues were quantified on isolated CD and Pepsin by fluorescence-based assay (FRET) and cytotoxicity of the best fluorinated inhibitors was evaluated on SKOV3 ovarian cancer cell line. (R)-TFM based analog of Pepstatin A (compound 6) returned a sub-nanomolar IC50 against CD and an increased selectivity. Molecular Docking experiments could partially rationalize these results. Stabilized inhibitor 6 in the catalytic pocket of CD showed strong hydrophobic interactions of the long and flexible TFM side chain with lipophilic residues of S1 and S3 sub-pockets of the catalytic pocket. The newly synthesized inhibitors returned no cytotoxicity at IC50 concentrations on SKOV3 cancer cells, however the compounds derived from (S)-TfmAla and (R)-TFM led to modifications of cells morphologies, associated with altered organization of F-actin and extracellular Fibronectin.
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Affiliation(s)
- Francesco Terzani
- CY Cergy Paris Université, CNRS, BIOCIS UMR 8076, 95000, Cergy Pontoise, France; Université Paris-Saclay, CNRS, BioCIS UMR 8076, 91400, Orsay, France.
| | - Sherazade Belhattab
- CY Cergy Paris Université, CNRS, BIOCIS UMR 8076, 95000, Cergy Pontoise, France; Université Paris-Saclay, CNRS, BioCIS UMR 8076, 91400, Orsay, France.
| | - Aurore Le Guern
- CY Cergy Paris Université, CNRS, BIOCIS UMR 8076, 95000, Cergy Pontoise, France; Université Paris-Saclay, CNRS, BioCIS UMR 8076, 91400, Orsay, France.
| | - Karine Guitot
- CY Cergy Paris Université, CNRS, BIOCIS UMR 8076, 95000, Cergy Pontoise, France; Université Paris-Saclay, CNRS, BioCIS UMR 8076, 91400, Orsay, France.
| | - Olivier Monasson
- CY Cergy Paris Université, CNRS, BIOCIS UMR 8076, 95000, Cergy Pontoise, France; Université Paris-Saclay, CNRS, BioCIS UMR 8076, 91400, Orsay, France.
| | - Chiara Zanato
- CY Cergy Paris Université, CNRS, BIOCIS UMR 8076, 95000, Cergy Pontoise, France; Université Paris-Saclay, CNRS, BioCIS UMR 8076, 91400, Orsay, France.
| | - Evelyne Chelain
- CY Cergy Paris Université, CNRS, BIOCIS UMR 8076, 95000, Cergy Pontoise, France; Université Paris-Saclay, CNRS, BioCIS UMR 8076, 91400, Orsay, France.
| | - Johanne Leroy-Dudal
- Equipe de Recherche sur les Relations Matrice Extracellulaire-Cellules, ERRMECe, (EA1391), Groupe Matrice Extracellulaire et Physiopathologie (MECuP), CY Cergy Paris Université, Neuville sur Oise, France.
| | - Julien Pytkowicz
- CY Cergy Paris Université, CNRS, BIOCIS UMR 8076, 95000, Cergy Pontoise, France; Université Paris-Saclay, CNRS, BioCIS UMR 8076, 91400, Orsay, France.
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Secomandi E, Salwa A, Vidoni C, Ferraresi A, Follo C, Isidoro C. High Expression of the Lysosomal Protease Cathepsin D Confers Better Prognosis in Neuroblastoma Patients by Contrasting EGF-Induced Neuroblastoma Cell Growth. Int J Mol Sci 2022; 23:ijms23094782. [PMID: 35563171 PMCID: PMC9101173 DOI: 10.3390/ijms23094782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/22/2022] [Accepted: 04/25/2022] [Indexed: 01/21/2023] Open
Abstract
Neuroblastoma is a malignant extracranial solid tumor arising from the sympathoadrenal lineage of the neural crest and is often associated with N-MYC amplification. Cathepsin D has been associated with chemoresistance in N-MYC-overexpressing neuroblastomas. Increased EGFR expression also has been associated with the aggressive behavior of neuroblastomas. This work aimed to understand the mechanisms linking EGFR stimulation and cathepsin D expression with neuroblastoma progression and prognosis. Gene correlation analysis in pediatric neuroblastoma patients revealed that individuals bearing a high EGFR transcript level have a good prognosis only when CTSD (the gene coding for the lysosomal protease Cathepsin D, CD) is highly expressed. Low CTSD expression was associated with poor clinical outcome. CTSD expression was negatively correlated with CCNB2, CCNA2, CDK1 and CDK6 genes involved in cell cycle division. We investigated the biochemical pathways downstream to EGFR stimulation in human SH-SY5Y neuroblastoma cells engineered for overexpressing or silencing of CD expression. Cathepsin D overexpression decreased the proliferative potential of neuroblastoma cells through downregulation of the pro-oncogenic MAPK signaling pathway. EGFR stimulation downregulated cathepsin D expression, thus favoring cell cycle division. Our data suggest that chemotherapeutics that inhibit the EGFR pathway, along with stimulators of cathepsin D synthesis and activity, could benefit neuroblastoma prognosis.
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Affiliation(s)
| | | | | | | | | | - Ciro Isidoro
- Correspondence: ; Tel.: +39-032-166-0507; Fax: +39-032-162-0421
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Cathepsin D-Managing the Delicate Balance. Pharmaceutics 2021; 13:pharmaceutics13060837. [PMID: 34198733 PMCID: PMC8229105 DOI: 10.3390/pharmaceutics13060837] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 12/11/2022] Open
Abstract
Lysosomal proteases play a crucial role in maintaining cell homeostasis. Human cathepsin D manages protein turnover degrading misfolded and aggregated proteins and favors apoptosis in the case of proteostasis disruption. However, when cathepsin D regulation is affected, it can contribute to numerous disorders. The down-regulation of human cathepsin D is associated with neurodegenerative disorders, such as neuronal ceroid lipofuscinosis. On the other hand, its excessive levels outside lysosomes and the cell membrane lead to tumor growth, migration, invasion and angiogenesis. Therefore, targeting cathepsin D could provide significant diagnostic benefits and new avenues of therapy. Herein, we provide a brief overview of cathepsin D structure, regulation, function, and its role in the progression of many diseases and the therapeutic potentialities of natural and synthetic inhibitors and activators of this protease.
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The FTLD Risk Factor TMEM106B Regulates the Transport of Lysosomes at the Axon Initial Segment of Motoneurons. Cell Rep 2021; 30:3506-3519.e6. [PMID: 32160553 DOI: 10.1016/j.celrep.2020.02.060] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 10/21/2019] [Accepted: 02/13/2020] [Indexed: 12/13/2022] Open
Abstract
Genetic variations in TMEM106B, coding for a lysosomal membrane protein, affect frontotemporal lobar degeneration (FTLD) in GRN- (coding for progranulin) and C9orf72-expansion carriers and might play a role in aging. To determine the physiological function of TMEM106B, we generated TMEM106B-deficient mice. These mice develop proximal axonal swellings caused by drastically enlarged LAMP1-positive vacuoles, increased retrograde axonal transport of lysosomes, and accumulation of lipofuscin and autophagosomes. Giant vacuoles specifically accumulate at the distal end and within the axon initial segment, but not in peripheral nerves or at axon terminals, resulting in an impaired facial-nerve-dependent motor performance. These data implicate TMEM106B in mediating the axonal transport of LAMP1-positive organelles in motoneurons and axonal sorting at the initial segment. Our data provide mechanistic insight into how TMEM106B affects lysosomal proteolysis and degradative capacity in neurons.
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Jeger JL. Endosomes, lysosomes, and the role of endosomal and lysosomal biogenesis in cancer development. Mol Biol Rep 2020; 47:9801-9810. [PMID: 33185829 DOI: 10.1007/s11033-020-05993-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/02/2020] [Accepted: 11/06/2020] [Indexed: 12/19/2022]
Abstract
Endosomes and lysosomes are membrane-bound organelles crucial for the normal functioning of the eukaryotic cell. The primary function of endosomes relates to the transportation of extracellular material into the intracellular domain. Lysosomes, on the other hand, are primarily involved in the degradation of macromolecules. Endosomes and lysosomes interact through two distinct pathways: kiss-and-run and direct fusion. In addition to the internalization of particles, endosomes also play an important role in cell signaling and autophagy. Disruptions in either of these processes may contribute to cancer development. Lysosomal proteins, such as cathepsins, can play a role in both tumorigenesis and cancer cell apoptosis. Since endosomal and lysosomal biogenesis and signaling are important components of normal cellular growth and proliferation, proteins involved in these processes are attractive targets for cancer research and, potentially, therapeutics. This literature review provides an overview of the endocytic pathway, endolysosome formation, and the interplay between endosomal/lysosomal biogenesis and carcinogenesis.
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Methionine aminopeptidase 2 is a key regulator of apoptotic like cell death in Leishmania donovani. Sci Rep 2017; 7:95. [PMID: 28273904 PMCID: PMC5427942 DOI: 10.1038/s41598-017-00186-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 02/13/2017] [Indexed: 01/11/2023] Open
Abstract
We investigate the role of methionine aminopeptidase 2 (MAP2) in miltefosine induced programmed cell death (PCD) in promastigote form of L. donovani. We report that TNP-470, an inhibitor of MAP2, inhibits programmed cell death in miltefosine treated promastigotes. It inhibits the biochemical features of metazoan apoptosis, including caspase3/7 protease like activity, oligonucleosomal DNA fragmentation, collapse of mitochondrial transmembrane potential, and increase in cytosolic pool of calcium ions but did not prevent the cell death and phosphatidyl serine externalization. The data suggests that the MAP2 is involved in the regulation of PCD in parasite. Moreover, TNP-470 shows the leishmanicidal activity (IC50 = 15 µM) and in vitro inhibition of LdMAP2 activity (Ki = 13.5 nM). Further studies on MAP2 and identification of death signaling pathways provide valuable information that could be exploited to understand the role of non caspase proteases in PCD of L. donovani.
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Li Y, Sun Y, Jing L, Wang J, Yan Y, Feng Y, Zhang Y, Liu Z, Ma L, Diao A. Lysosome Inhibitors Enhance the Chemotherapeutic Activity of Doxorubicin in HepG2 Cells. Chemotherapy 2016; 62:85-93. [PMID: 27764836 DOI: 10.1159/000448802] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 07/29/2016] [Indexed: 11/19/2022]
Abstract
The lysosome inhibitors bafilomycin A1 and chloroquine have both lysosomotropic properties and autophagy inhibition ability, and are promising clinical agents to be used in combination with anticancer drugs. In order to investigate this combination effect, HepG2 cells were treated with bafilomycin A1, chloroquine, or/and doxorubicin, and their proliferative ability, induction of apoptosis, and the changes of lysosomal membrane permeabilization and mitochondrial membrane potential were studied. The results demonstrate that treatment with bafilomycin A1 or chloroquine alone at a relatively low concentration promotes the inhibitory effect of doxorubicin on cell growth and apoptosis. Further studies reveal that bafilomycin A1 and chloroquine promote lysosomal membrane permeabilization and the reduction of mitochondrial membrane potential induced by doxorubicin. Our findings suggest that bafilomycin A1 and chloroquine potentiate the anticancer effect of doxorubicin in hepatic cancer cells and that supplementation of conventional chemotherapy with lysosome inhibitors may provide a more efficient anticancer therapy.
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Affiliation(s)
- Yuyin Li
- School of Biotechnology, Tianjin University of Science and Technology, Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin, China
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Löser R, Pietzsch J. Cysteine cathepsins: their role in tumor progression and recent trends in the development of imaging probes. Front Chem 2015; 3:37. [PMID: 26157794 PMCID: PMC4477214 DOI: 10.3389/fchem.2015.00037] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 05/29/2015] [Indexed: 12/16/2022] Open
Abstract
Papain-like cysteine proteases bear an enormous potential as drug discovery targets for both infectious and systemic human diseases. The considerable progress in this field over the last two decades has also raised interest in the visualization of these enzymes in their native context, especially with regard to tumor imaging. After a short introduction to structure and general functions of human cysteine cathepsins, we highlight their importance for drug discovery and development and provide a critical update on the current state of knowledge toward their involvement in tumor progression, with a special emphasis on their role in therapy response. In accordance with a radiopharmaceutical point of view, the main focus of this review article will be the discussion of recently developed fluorescence and radiotracer-based imaging agents together with related molecular probes.
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Affiliation(s)
- Reik Löser
- Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf Dresden, Germany ; Department of Chemistry and Food Chemistry, Technische Universität Dresden Dresden, Germany
| | - Jens Pietzsch
- Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf Dresden, Germany ; Department of Chemistry and Food Chemistry, Technische Universität Dresden Dresden, Germany
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Lysosomal ceramide generated by acid sphingomyelinase triggers cytosolic cathepsin B-mediated degradation of X-linked inhibitor of apoptosis protein in natural killer/T lymphoma cell apoptosis. Cell Death Dis 2015; 6:e1717. [PMID: 25855965 PMCID: PMC4650549 DOI: 10.1038/cddis.2015.82] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 02/20/2015] [Accepted: 02/23/2015] [Indexed: 02/07/2023]
Abstract
We previously reported that IL-2 deprivation induced acid sphingomyelinase-mediated (ASM-mediated) ceramide elevation and apoptosis in an NK/T lymphoma cell line KHYG-1. However, the molecular mechanism of ASM–ceramide-mediated apoptosis during IL-2 deprivation is poorly understood. Here, we showed that IL-2 deprivation induces caspase-dependent apoptosis characterized by phosphatidylserine externalization, caspase-8, -9, and -3 cleavage, and degradation of X-linked inhibitor of apoptosis protein (XIAP). IL-2 re-supplementation rescued apoptosis via inhibition of XIAP degradation without affecting caspase cleavage. However, IL-2 deprivation induced ceramide elevation via ASM in lysosomes and activated lysosomal cathepsin B (CTSB) but not cathepsin D. A CTSB inhibitor CA-074 Me and knockdown of CTSB inhibited ceramide-mediated XIAP degradation and apoptosis. Inhibition of ceramide accumulation in lysosomes using an ASM inhibitor, desipramine, decreased cytosolic activation of CTSB by inhibiting its transfer into cytosol from the lysosome. Knockdown of ASM also inhibited XIAP degradation and apoptosis. Furthermore, cell permeable N-acetyl sphingosine (C2-ceramide), which increases mainly endogenous d18:1/16:0 and d18:1/24:1 ceramide-like IL-2 deprivation, induced caspase-dependent apoptosis with XIAP degradation through CTSB. These findings suggest that lysosomal ceramide produced by ASM mediates XIAP degradation by activation of cytosolic CTSB and caspase-dependent apoptosis. The ASM–ceramide–CTSB signaling axis is a novel pathway of ceramide-mediated apoptosis in IL-2-deprived NK/T lymphoma cells.
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Lingaiah HB, Natarajan N, Thamaraiselvan R, Srinivasan P, Periyasamy BM. Myrtenal ameliorates diethylnitrosamine-induced hepatocarcinogenesis through the activation of tumor suppressor protein p53 and regulation of lysosomal and mitochondrial enzymes. Fundam Clin Pharmacol 2012; 27:443-54. [PMID: 22436021 DOI: 10.1111/j.1472-8206.2012.01039.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Myrtenal is a novel class of compound belongs to monoterpenes found predominantly in mint, pepper, etc., and it was shown to have excellent pharmacological activities against many diseases among which cancer is imperative. Hepatocellular carcinoma is a primary malignancy of the hepatocytes, which rapidly leads to death in short periods. The aim of this study was to investigate the possible therapeutic efficiency of myrtenal against diethylnitrosamine-induced experimental hepatocarcinogenesis by analyzing the key enzymes of carbohydrate metabolism, lysosomal and mitochondrial TCA cycle enzymes, and also the possible role of tumor suppressor protein p53, and scanning electron microscopic studies. The results revealed that myrtenal significantly ameliorated the altered enzymes of carbohydrate metabolism, lysosomal and mitochondrial enzymes, and interestingly the tumor suppressor protein p53 was found to be significantly accumulated in myrtenal-treated animals, which inevitably confirms that myrtenal has a prominent role in preventing the liver cancer during treatment. Furthermore, the antineoplastic property was well evidenced by the mRNA expression of p53 protein by the reverse-transcriptase polymerase chain reaction and immunoblot analysis. The observed anticancer property of myrtenal may be due to the involvement and expression of p53 and influence in the mitochondrial and lysosomal membrane integrity and also interference in the gluconeogenesis process of cancer cells. Our results suggest that myrtenal is very efficient and useful compound in the treatment of liver cancer in future.
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Affiliation(s)
- Hari Babu Lingaiah
- Dr. ALM Post Graduate Institute of Basic Medical Sciences, Department of Pharmacology and Environmental Toxicology, University of Madras, Tharamani Campus, Chennai - 600113, Tamil Nadu, India
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KUCHTA ANNAM, KELLY PHILIPM, STANTON CATHERINE, DEVERY ROSALEENA. Milk fat globule membrane - a source of polar lipids for colon health? A review. INT J DAIRY TECHNOL 2012. [DOI: 10.1111/j.1471-0307.2011.00759.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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12
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Depletion of cathepsin D by transglutaminase 2 through protein cross-linking promotes cell survival. Amino Acids 2011; 44:73-80. [DOI: 10.1007/s00726-011-1089-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 09/15/2011] [Indexed: 11/26/2022]
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Cathepsin D plays a crucial role in the trimethyltin-induced hippocampal neurodegeneration process. Neuroscience 2011; 174:160-70. [DOI: 10.1016/j.neuroscience.2010.11.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 10/21/2010] [Accepted: 11/11/2010] [Indexed: 11/20/2022]
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Abstract
OBJECTIVES The role of proteases in the regulation of apoptosis is becoming increasingly apparent. Whilst many of these proteases are already characterised, some have yet to be identified. Traditionally caspases held the traditional role as the prime mediators of apoptosis; however, attention is now turning towards the contribution made by serine proteases. KEY FINDINGS As unregulated apoptosis is implicated in various disease states, the emergence of this proteolytic family as apoptotic regulators offers novel and alterative opportunities for therapeutic targets. SUMMARY This review presents a brief introduction and overview of proteases in general with particular attention given to those involved in apoptotic processing.
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Affiliation(s)
- Kelly L Moffitt
- Biomolecular Sciences Group, School of Pharmacy, Queen's University of Belfast, Belfast BT97BL, Northern Ireland, UK.
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Masson O, Bach AS, Derocq D, Prébois C, Laurent-Matha V, Pattingre S, Liaudet-Coopman E. Pathophysiological functions of cathepsin D: Targeting its catalytic activity versus its protein binding activity? Biochimie 2010; 92:1635-43. [DOI: 10.1016/j.biochi.2010.05.009] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Accepted: 05/14/2010] [Indexed: 11/27/2022]
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Abstract
The hepatocyte is especially vulnerable to injury due to its central role in xenobiotic metabolism including drugs and alcohol, participation in lipid and fatty acid metabolism, its unique role in the enterohepatic circulation of bile acids, the widespread prevalence of hepatotropic viruses, and its existence within a milieu of innate immune responding cells. Apoptosis and necrosis are the most widely recognized forms of hepatocyte cell death. The hepatocyte displays many unique features regarding cell death by apoptosis. It is quite susceptible to death receptor-mediated injury, and its death receptor signaling pathways involve the mitochondrial pathway for efficient cell killing. Also, death receptors can trigger lysosomal disruption in hepatocytes which further promote cell and tissue injury. Interestingly, hepatocytes are protected from cell death by only two anti-apoptotic proteins, Bcl-x(L) and Mcl-1, which have nonredundant functions. Endoplasmic reticulum stress or the unfolded protein response contributes to hepatocyte cell death during alterations of lipid and fatty acid metabolism. Finally, the current information implicating RIP kinases in necrosis provides an approach to more fully address this mode of cell death in hepatocyte injury. All of these processes contributing to hepatocyte injury are discussed in the context of potential therapeutic strategies.
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Affiliation(s)
- Harmeet Malhi
- Division of Gastroenterology and Hepatology, College of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
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Sheikh A, Li X, Wen G, Tauqeer Z, Brown W, Malik M. Cathepsin D and apoptosis related proteins are elevated in the brain of autistic subjects. Neuroscience 2010; 165:363-70. [DOI: 10.1016/j.neuroscience.2009.10.035] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 10/15/2009] [Accepted: 10/19/2009] [Indexed: 10/20/2022]
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Khatchadourian A, Maysinger D. Lipid droplets: their role in nanoparticle-induced oxidative stress. Mol Pharm 2009; 6:1125-37. [PMID: 19445477 DOI: 10.1021/mp900098p] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Lipid droplets are cytoplasmic organelles found in almost all cells under physiological or pathological conditions. Certain nanoparticles can induce lipid droplet formation under oxidative stress conditions. Small metallic nanoparticles such as cadmium telluride (CdTe) nanoparticles, particularly those with incompletely protected surfaces, induce oxidative stress and may inflict damages to several intracellular organelles. The objective of this study was to assess formation of lipid droplets in cells treated with CdTe nanoparticles and relate their status to cell function (mitochondrial activity and cell viability). Multicolor labeling of cellular organelles (lipid droplets and lysosomes) showed that lipid droplets formed in pheochromocytoma (PC12) cells following nanoparticle or oleic acid treatment. Some lipid droplets were found closely apposed to lysosomes suggesting possible communication between these organelles during severe oxidative stress. Combination of microscopy of living cells with cell viability assays showed that oleic acid-induced lipid droplets not only serve as intracellular lipid storage sites but also play a protective role in starving stressed cells. Results from these studies suggest that oleic acid-induced LD in PC12 cells are dynamic and adaptive organelles, which provide energy to starving cells and facilitate their rescue under starvation and exposure to metallic nanoparticles.
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Affiliation(s)
- Armen Khatchadourian
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
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Benes P, Vetvicka V, Fusek M. Cathepsin D--many functions of one aspartic protease. Crit Rev Oncol Hematol 2008; 68:12-28. [PMID: 18396408 PMCID: PMC2635020 DOI: 10.1016/j.critrevonc.2008.02.008] [Citation(s) in RCA: 436] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Revised: 02/05/2008] [Accepted: 02/22/2008] [Indexed: 12/11/2022] Open
Abstract
For years, it has been held that cathepsin D (CD) is involved in rather non-specific protein degradation in a strongly acidic milieu of lysosomes. Studies with CD knock-out mice revealed that CD is not necessary for embryonal development, but it is indispensable for postnatal tissue homeostasis. Mutation that abolishes CD enzymatic activity causes neuronal ceroid lipofuscinosis (NCL) characterized by severe neurodegeneration, developmental regression, visual loss and epilepsy in both animals and humans. In the last decade, however, an increasing number of studies demonstrated that enzymatic function of CD is not restricted solely to acidic milieu of lysosomes with important consequences in regulation of apoptosis. In addition to CD enzymatic activity, it has been shown that apoptosis is also regulated by catalytically inactive mutants of CD which suggests that CD interacts with other important molecules and influences cell signaling. Moreover, procathepsin D (pCD), secreted from cancer cells, acts as a mitogen on both cancer and stromal cells and stimulates their pro-invasive and pro-metastatic properties. Numerous studies found that pCD/CD level represents an independent prognostic factor in a variety of cancers and is therefore considered to be a potential target of anti-cancer therapy. Studies dealing with functions of cathepsin D are complicated by the fact that there are several simultaneous forms of CD in a cell-pCD, intermediate enzymatically active CD and mature heavy and light chain CD. It became evident that these forms may differently regulate the above-mentioned processes. In this article, we review the possible functions of CD and its various forms in cells and organisms during physiological and pathological conditions.
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Affiliation(s)
- Petr Benes
- Laboratory of Cell Differentiation, Department of Experimental Biology, Faculty of Science, Masaryk University, ILBIT A3, Kamenice 3, Brno 625 00, Czech Republic.
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Cathepsin D overexpressed by cancer cells can enhance apoptosis-dependent chemo-sensitivity independently of its catalytic activity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 617:453-61. [PMID: 18497069 DOI: 10.1007/978-0-387-69080-3_44] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
The aspartic protease cathepsin D (CD) is a key mediator of induced-apoptosis and its proteolytic activity has been generally involved in this event. During apoptosis, CD is translocated to the cytosol. Since CD is one of the lysosomal enzymes that requires a more acidic pH to be proteolytically-active relative to the cysteine lysosomal enzymes such as cathepsin-B and cathepsin-L, it is therefore open to question whether cytosolic CD might be able to cleave substrate(s) implicated in the apoptotic cascade. Here, we have investigated the role of (wild-type) wt CD and its proteolytically inactive counterpart overexpressed by 3Y1-Ad12 cancer cells during chemotherapeutic-induced cytotoxicity and apoptosis, as well as the relevance of CD catalytic function. We demonstrate that wt or mutated catalytically inactive CD strongly enhances chemo-sensitivity and apoptotic response to etoposide. Both wt and mutated inactive CD are translocated to the cytosol, increasing the release of cytochrome c, the activation of caspases-9 and caspases-3 and the induction of a caspase-dependent apoptosis. In addition, pretreatment of cells with the aspartic protease inhibitor, pepstatin A, does not prevent apoptosis. Interestingly, therefore, the stimulatory effect of CD on cell death is independent of its catalytic activity. Overall, our results imply that cytosolic CD stimulates apoptotic pathways by interacting with a member of the apoptotic machinery rather than by cleaving specific substrate(s).
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Abstract
Autophagy contributes to ischemic brain injury, but it is not clear if autophagy occurs after intracerebral hemorrhage (ICH). This study examined whether ICH-induced cell death is partly autophagic. It then examined the role of iron in inducing this form of cell death after ICH. Male, adult Sprague-Dawley rats received an infusion of autologous whole blood or ferrous iron into the right basal ganglia. Control rats (sham) had a needle insertion. The rats were killed at 1, 3, 7, or 28 days later. Some rats were treated with either deferoxamine or vehicle after ICH. Microtubule-associated protein light chain-3 (LC3), a biomarker of autophagosome, and cathepsin D, a lysosomal biomarker, were measured by Western blot analysis and immunohistochemistry. Immunofluorescent double-labeling was used to identify the cell types expressing cathepsin D. Electron microscopy was performed to examine the cellular ultrastructure changes after ICH. We found that conversion of LC3-I to LC3-II, cathepsin D expression, and vacuole formation are increased in the ipsilateral basal ganglia after ICH. Intracerebral infusion of iron also resulted in enhanced conversion of LC3-I to LC3-II and increased cathepsin D levels. Deferoxamine (an iron chelator) treatment significantly reduced the conversion of LC3-I to LC3-II and cathepsin D levels after ICH. Our results demonstrated that autophagy occurs after ICH, and iron has a key role in ICH-induced autophagy. This also suggests that iron-induced autophagy may play a role in brain injury in other diseases associated with iron overload.
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Affiliation(s)
- Yangdong He
- Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan 48109-2200, USA
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Uchiyama Y, Shibata M, Koike M, Yoshimura K, Sasaki M. Autophagy-physiology and pathophysiology. Histochem Cell Biol 2008; 129:407-20. [PMID: 18320203 PMCID: PMC2668654 DOI: 10.1007/s00418-008-0406-y] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2008] [Indexed: 12/19/2022]
Abstract
"Autophagy" is a highly conserved pathway for degradation, by which wasted intracellular macromolecules are delivered to lysosomes, where they are degraded into biologically active monomers such as amino acids that are subsequently re-used to maintain cellular metabolic turnover and homeostasis. Recent genetic studies have shown that mice lacking an autophagy-related gene (Atg5 or Atg7) cannot survive longer than 12 h after birth because of nutrient shortage. Moreover, tissue-specific impairment of autophagy in central nervous system tissue causes massive loss of neurons, resulting in neurodegeneration, while impaired autophagy in liver tissue causes accumulation of wasted organelles, leading to hepatomegaly. Although autophagy generally prevents cell death, our recent study using conditional Atg7-deficient mice in CNS tissue has demonstrated the presence of autophagic neuron death in the hippocampus after neonatal hypoxic/ischemic brain injury. Thus, recent genetic studies have shown that autophagy is involved in various cellular functions. In this review, we introduce physiological and pathophysiological roles of autophagy.
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Affiliation(s)
- Yasuo Uchiyama
- Department of Cell Biology and Neuroscience, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Reisenauer A, Eickelberg O, Wille A, Heimburg A, Reinhold A, Sloane BF, Welte T, Bühling F. Increased carcinogenic potential of myeloid tumor cells induced by aberrant TGF-beta1-signaling and upregulation of cathepsin B. Biol Chem 2007; 388:639-50. [PMID: 17552911 DOI: 10.1515/bc.2007.072] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The TGF-beta signaling pathways are implicated in cancer. Cysteine cathepsins can contribute to the carcinogenic potential of tumor cells. The aim of this study was to investigate the regulation of cysteine cathepsin expression by TGF-beta1 and the functional implications in tumor cells. We found an upregulation of cathepsin B (CathB, 2- to 5-fold) in different myeloid tumor cells (THP-1, MonoMac-1, MonoMac-6) after incubation with TGF-beta1. No upregulation was found in monocytes, and there was suppression of CathB expression in epithelial tumor cells (A549). Increased cathepsin B activity led to enhanced carcinogenic potential, which was reflected by increased migration and invasion of the cells and resistance to inhibitor-induced apoptosis. Analysis of the TGF-beta signaling pathways showed no alterations in TGF-beta/BMP receptor expression or SMAD2/3 phosphorylation, and no influence of MAP kinase pathways. However, a reduction in SMAD1 expression was detected. The lack of BMP action on cysteine cathepsin expression in myeloid tumor cells, but not in epithelial tumor cells, suggests a defect in the Smad1/Smad5 pathway. We located a related TGF-beta1-responsive element within the first intron of the CathB gene. In conclusion, alterations in the TGF-beta1 signaling pathway lead to upregulation of CathB, which contributes to the carcinogenic potential of tumor cells.
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Lee DC, Mason CW, Goodman CB, Holder MS, Kirksey OW, Womble TA, Severs WB, Palm DE. Hydrogen peroxide induces lysosomal protease alterations in PC12 cells. Neurochem Res 2007; 32:1499-510. [PMID: 17440810 DOI: 10.1007/s11064-007-9338-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2006] [Accepted: 03/16/2007] [Indexed: 10/23/2022]
Abstract
Alterations in lysosomal proteases have been implicated in many neurodegenerative diseases. The current study demonstrates a concentration-dependent decrease in PC12 cell viability and transient changes in cystatin C (CYSC), cathepsin B (CATB), cathepsin D (CATD) and caspase-3 following exposure to H2O2. Furthermore, activation of CATD occurred following exposure to H2O2 and cysteine protease suppression, while inhibition of CATD with pepstatin A significantly improved cell viability. Additionally, significant PARP cleavage, suggestive of caspase-3-like activity, was observed following H2O2 exposure, while inhibition of caspase-3 significantly increased cell viability compared to H2O2 administration alone. Collectively, our data suggest that H2O2 induced cell death is regulated at least in part by caspase-3 and CATD. Furthermore, cysteine protease suppression increases CATD expression and activity. These studies provide insight for alternate pathways and potential therapeutic targets of cell death associated with oxidative stress and lysosomal protease alterations.
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Affiliation(s)
- Daniel C Lee
- College of Pharmacy & Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307, USA
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26
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Abstract
Apoptosis can be mediated by different mechanisms. There is growing evidence that different proteolytic enzymes are involved in the regulation of apoptosis. Cathepsins are proteases which, under physiologic conditions, are localized intralysosomally. In response to certain signals they are released from the lysosomes into the cytoplasm where they trigger apoptotic cell death via various pathways, including the activation of caspases or the release of proapoptotic factors from the mitochondria. Here, we review different mechanisms that induce the release of lysosomal enzymes, and the functional relevance of defined cathepsins in defined models of apoptosis.
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Affiliation(s)
- C E Chwieralski
- Institute of Immunology, Otto-von-Guericke-University, Magdeburg, Germany
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27
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Beaujouin M, Baghdiguian S, Glondu-Lassis M, Berchem G, Liaudet-Coopman E. Overexpression of both catalytically active and -inactive cathepsin D by cancer cells enhances apoptosis-dependent chemo-sensitivity. Oncogene 2006; 25:1967-73. [PMID: 16331270 PMCID: PMC2246153 DOI: 10.1038/sj.onc.1209221] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The aspartic protease cathepsin D (cath-D) is a key mediator of induced-apoptosis and its proteolytic activity has been generally involved in this event. During apoptosis, cath-D is translocated to the cytosol. Because cath-D is one of the lysosomal enzymes that requires a more acidic pH to be proteolytically active relative to the cysteine lysosomal enzymes such as cath-B and -L, it is therefore open to question whether cytosolic cath-D might be able to cleave substrate(s) implicated in the apoptotic cascade. Here, we have investigated the role of wild-type cath-D and its proteolytically inactive counterpart overexpressed by 3Y1-Ad12 cancer cells during chemotherapeutic-induced cytotoxicity and apoptosis, as well as the relevance of cath-D catalytic function. We demonstrate that wild-type or mutated catalytically inactive cath-D strongly enhances chemo-sensitivity and apoptotic response to etoposide. Both wild-type and mutated inactive cath-D are translocated to the cytosol, increasing the release of cytochrome c, the activation of caspases-9 and -3 and the induction of a caspase-dependent apoptosis. In addition, pretreatment of cells with the aspartic protease inhibitor, pepstatin A, does not prevent apoptosis. Interestingly therefore, the stimulatory effect of cath-D on cell death is independent of its catalytic activity. Overall, our results imply that cytosolic cath-D stimulates apoptotic pathways by interacting with a member of the apoptotic machinery rather than by cleaving specific substrate(s).
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Affiliation(s)
- Mélanie Beaujouin
- Endocrinologie moléculaire et cellulaire des cancers
INSERM : U540Université Montpellier I60 rue de Navacelles
34090 Montpellier,FR
| | - Stephen Baghdiguian
- ISEM, Institut des Sciences de l'Evolution
CNRS : UMR5554Université Montpellier II - Sciences et Techniques du LanguedocPlace E. Bataillon
CC 064
34095 Montpellier Cedex 05,FR
| | - Murielle Glondu-Lassis
- Endocrinologie moléculaire et cellulaire des cancers
INSERM : U540Université Montpellier I60 rue de Navacelles
34090 Montpellier,FR
| | - Guy Berchem
- Laboratoire d'Hémato-Cancérologie Expérimentale
CRP-SantéCentre Hospitalier du Luxembourg, 4 rue Barblé, L-1210,LU
| | - Emmanuelle Liaudet-Coopman
- Endocrinologie moléculaire et cellulaire des cancers
INSERM : U540Université Montpellier I60 rue de Navacelles
34090 Montpellier,FR
- * Correspondence should be adressed to: Emmanuelle Liaudet-Coopman
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Lee DC, Close FT, Goodman CB, Jackson IM, Wight-Mason C, Wells LM, Womble TA, Palm DE. Enhanced cystatin C and lysosomal protease expression following 6-hydroxydopamine exposure. Neurotoxicology 2006; 27:260-76. [PMID: 16414118 DOI: 10.1016/j.neuro.2005.11.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2005] [Revised: 09/02/2005] [Accepted: 11/17/2005] [Indexed: 11/30/2022]
Abstract
6-Hydroxydopamine (6-OHDA) is a selective neurotoxin used to induce apoptosis in catecholamine-containing neurons. Although biochemical products and reactive oxygen species (ROS) of 6-OHDA have been well documented, the activation of cellular pathways following exposure are not well understood. Apoptosis in PC12 (Pheochromocytoma) cells was induced by 6-OHDA in a dose (10-150 microM) and time-dependent (24-72 h) manner compared to experimental controls (no treatment). PC 12 cells exposed to 50 microM 6-OHDA demonstrated the involvement of caspase 3 and lysosomal protease alterations. Following 6-OHDA exposure, the caspase 3-like inhibitor Ac-DEVD-CHO significantly decreased 6-OHDA induced cell death. In addition, alterations in expression of the lysosomal cysteine and aspartic proteases, cathepsin B (CB) and cathepsin D (CD) and the endogenous cysteine protease inhibitor cystatin C were observed utilizing immunocytochemical analysis at 24, 48, and 72 h following 6-OHDA exposure. Furthermore, CB and CD and cystatin C immuno-like reactivity was more pronounced in TUNEL positive cells. Moreover, Western blot analysis confirmed a significant increase in protein expression for CB and CD at 72 h and a temporal and concentration dependent increase in cystatin C in response to 6-OHDA. Cells treated with pepstatin A, an inhibitor for CD, showed a significant decrease in cell death, however, CA-074ME, a specific inhibitor for CB, failed to protect cells from 6-OHDA induced cell death. Thus, these results suggest that apoptosis induced by 6-OHDA exposure is mediated in part through caspase 3 activation and lysosomal protease CD.
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Affiliation(s)
- Daniel C Lee
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307, USA
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30
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Guillon-Munos A, van Bemmelen MXP, Clarke PGH. Role of phosphoinositide 3-kinase in the autophagic death of serum-deprived PC12 cells. Apoptosis 2006; 10:1031-41. [PMID: 16151638 DOI: 10.1007/s10495-005-0741-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The death of serum-deprived undifferentiated PC12 cells shows both autophagic and apoptotic features. Since it is still controversial whether the autophagy is instrumental in the cell death or a mere epiphenomenon, we tested the effects of inhibiting the autophagy by a variety of phosphoinositide 3-kinase inhibitors, and provided evidence that the autophagy, or a related trafficking event, is indeed instrumental in the cell death. Furthermore, by comparing the effects of PI3-K inhibition and caspase-inhibition on autophagic and apoptotic cellular events, we showed that in this case the autophagic and apoptotic mechanisms mediate cell death by parallel pathways and do not act in series.
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Affiliation(s)
- A Guillon-Munos
- Département de Biologie Cellulaire et de Morphologie, University of Lausanne, Rue du Bugnon 9, CH-1005 Lausanne, Switzerland
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31
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Abstract
Angiogenesis, the process by which new branches sprout from existing vessels, requires the degradation of the vascular basement membrane and remodeling of the ECM in order to allow endothelial cells to migrate and invade into the surrounding tissues. Serine, metallo, and cysteine proteinases are 3 types of a family of enzymes that proteolytically degrade various components of extracellular matrix. These proteases release various growth factors and also increase adhesive molecules and signaling pathway molecules upon their activation, which plays a significant role in angiogenesis. Downregulation of these molecules by antisense/siRNA or synthetic inhibitors decreases the levels of these molecules, inhibits the release of growth factors, and decreases the levels of various signaling pathway molecules, thereby leading to the inhibition of angiogenesis. Furthermore, MMPs degrade specific substrates and release angiogenic inhibitors which inhibit angiogenesis. Downregulation of 2 molecules, such as uPA and uPAR, uPAR and MMP-9, or Cathepsin B and MMP-9, are more effective to inhibit angiogenesis rather than downregulation of single molecules. However, careful testing of these combinations are most important because multiple effects of these combinations play a significant role in angiogenesis.
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Affiliation(s)
- Sajani S Lakka
- Division of Cancer Biology, Department of Biomedical and Therapeutic Sciences, University of Illinois College of Medicine-Peoria, Peoria, IL 61605, USA
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32
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Tardy C, Codogno P, Autefage H, Levade T, Andrieu-Abadie N. Lysosomes and lysosomal proteins in cancer cell death (new players of an old struggle). Biochim Biophys Acta Rev Cancer 2005; 1765:101-25. [PMID: 16412578 DOI: 10.1016/j.bbcan.2005.11.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Revised: 11/21/2005] [Accepted: 11/28/2005] [Indexed: 12/19/2022]
Abstract
Death of cancer cells influences tumor development and progression, as well as the response to anticancer therapies. This can occur through different cell death programmes which have recently been shown to implicate components of the acidic organelles, lysosomes. The role of lysosomes and lysosomal enzymes, including cathepsins and some lipid hydrolases, in programmed cell death associated with apoptotic or autophagic phenotypes is presented, as evidenced from observations on cultured cells and living animals. The possible molecular mechanisms that underlie the action of lysosomes during cell death are also described. Finally, the contribution of lysosomal proteins and lysosomes to tumor initiation and progression is discussed. Elucidation of this role and the underlying mechanisms will shed a new light on these 'old' organelles and hopefully pave the way for the development of novel anticancer strategies.
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Affiliation(s)
- Claudine Tardy
- INSERM U466, Laboratoire de Biochimie, Institut Louis Bugnard, Centre Hospitalier Universitaire de Rangueil, BP 84225, 31432 Toulouse, France
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Yamasaki M, Miyamoto Y, Chujo H, Nishiyama K, Tachibana H, Yamada K. Trans10, cis12-conjugated linoleic acid induces mitochondria-related apoptosis and lysosomal destabilization in rat hepatoma cells. Biochim Biophys Acta Mol Cell Biol Lipids 2005; 1735:176-84. [PMID: 16005259 DOI: 10.1016/j.bbalip.2005.05.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2004] [Revised: 05/26/2005] [Accepted: 05/27/2005] [Indexed: 11/18/2022]
Abstract
Conjugated linoleic acid (CLA) is a powerful anti-carcinogenic fatty acid. Previously, we showed that 10trans 12cis (10t, 12c) CLA induced apoptotic cell death in rat hepatoma. Here, we demonstrated significant cytotoxic effects of 1 muM 10t, 12c-CLA, but not 9c, 11t-CLA, on dRLh-84 rat hepatoma cells. 9t, 11t and 9c, 11c-CLA also showed low levels of cytotoxic activity. 10t, 12c-CLA activated caspase-3, 9 followed by cytochrome c release from mitochondria into the cytosol. Inhibitors of caspase-3, 9 blocked the cytotoxicity of 10t, 12c-CLA. 10t, 12c-CLA also induced translocation of Bax protein into the mitochondrial membrane and cleavage of Bid protein. Lysosomal destabilization induced by 10t, 12c-CLA was observed by monitoring the re-localization of Acridine Orange and the leakage of beta-hexosaminidase from lysosomes. 10t, 12c-CLA directly degraded the isolated lysosomes from the rat liver. Our observations indicate that 10t, 12c-CLA induces mitochondria-related apoptosis accompanied by lysosomal destabilization in rat hepatoma cells.
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Affiliation(s)
- Masao Yamasaki
- Division of Food Science and Nutrition, Department of Biochemistry and Applied Biosciences, Faculty of Agriculture, Miyazaki University, Miyazaki 889-2192, Japan.
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Emert-Sedlak L, Shangary S, Rabinovitz A, Miranda MB, Delach SM, Johnson DE. Involvement of cathepsin D in chemotherapy-induced cytochrome c release, caspase activation, and cell death. Mol Cancer Ther 2005; 4:733-42. [PMID: 15897237 DOI: 10.1158/1535-7163.mct-04-0301] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Treatment of cells with chemotherapy drugs activates the intrinsic mitochondrial pathway of apoptosis and the caspase protease cascade. Recently, the lysosomal protease cathepsin D has been implicated in apoptosis caused by oxidative stress, inhibition of protein kinase C, and stimulation of the TNFR1 and Fas death receptors. However, the role of cathepsin D in chemotherapy-induced cell death has remained largely unexplored. In this report, we show that treatment of U937 leukemia cells with the chemotherapy drug etoposide (VP-16) results in cathepsin D release into the cytosol within 4 hours after initiation of drug treatment. VP-16-induced cathepsin D release was not inhibited by z-VAD-FMK or pepstatin A, suggesting that it occurred independently of the activities of caspase proteases or cathepsin D. Down-regulation of cathepsin D expression in suspension U937 cells or adherent HeLa cells using cathepsin D small interfering RNA partially inhibited cell death resulting from treatment of cells with tumor necrosis factor-alpha, tumor necrosis factor-related apoptosis inducing ligand, or the chemotherapy drugs VP-16, cisplatin, and 5-fluorouracil. Moreover, cathepsin D down-regulation significantly delayed cytochrome c release and caspase-3 activation in response to chemotherapy treatment. Incubation of isolated mitochondria with cathepsin D-treated cytosolic extracts resulted in potent release of cytochrome c, indicating that a cytoplasmic substrate mediates the effects of cathepsin D on mitochondria. Together, these findings show that cathepsin D plays an important role in chemotherapy-induced cell death, and that cathepsin D lies upstream of cytochrome c release and caspase-3 activation in the chemotherapy-induced execution pathway.
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Affiliation(s)
- Lori Emert-Sedlak
- Department of Medicine, University of Pittsburgh Cancer Institute, Hillman Cancer Center Research Pavilion, Room 2.18c, 5117 Centre Avenue, Pittsburgh, PA 15213-2582, USA.
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Fusek M, Vetvicka V. DUAL ROLE OF CATHEPSIN D: LIGAND AND PROTEASE. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2005; 149:43-50. [PMID: 16170387 DOI: 10.5507/bp.2005.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Cathepsin D is peptidase belonging to the family of aspartic peptidases. Its mostly described function is intracellular catabolism in lysosomal compartments, other physiological effect include hormone and antigen processing. For almost two decades, there have been an increasing number of data describing additional roles imparted by cathepsin D and its pro-enzyme, resulting in cathepsin D being a specific biomarker of some diseases. These roles in pathological conditions, namely elevated levels in certain tumor tissues, seem to be connected to another, yet not fully understood functionality. However, despite numerous studies, the mechanisms of cathepsin D and its precursor's actions are still not completely understood. From results discussed in this article it might be concluded that cathepsin D in its zymogen status has additional function, which is rather dependent on a "ligand-like" function then on proteolytic activity.
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Affiliation(s)
- Martin Fusek
- Institute of Organic Chemistry and Biochemistry, CAS, Prague, Czech Republic
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Heinrich M, Neumeyer J, Jakob M, Hallas C, Tchikov V, Winoto-Morbach S, Wickel M, Schneider-Brachert W, Trauzold A, Hethke A, Schütze S. Cathepsin D links TNF-induced acid sphingomyelinase to Bid-mediated caspase-9 and -3 activation. Cell Death Differ 2005; 11:550-63. [PMID: 14739942 DOI: 10.1038/sj.cdd.4401382] [Citation(s) in RCA: 244] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Acidic noncaspase proteases-like cathepsins have been introduced as novel mediators of apoptosis. A clear role for these proteases and the acidic endolysosomal compartment in apoptotic signalling is not yet defined. To understand the role and significance of noncaspases in promoting and mediating cell death, it is important to determine whether an intersection of these proteases and the caspase pathway exists. We recently identified the endolysosomal aspartate protease cathepsin D (CTSD) as a target for the proapoptotic lipid ceramide. Here, we show that tumor necrosis factor (TNF)-induced CTSD activation depends on functional acid sphingomyelinase (A-SMase) expression. Ectopic expression of CTSD in CTSD-deficient fibroblasts results in an enhanced TNF-mediated apoptotic response. Intracellular colocalization of CTSD with the proapoptotic bcl-2 protein family member Bid in HeLa cells, and the ability of CTSD to cleave directly Bid in vitro as well as the lack of Bid activation in cathepsin-deficient fibroblasts indicate that Bid represents a direct downstream target of CTSD. Costaining of CTSD and Bid with Rab5 suggests that the endosomal compartments are the common 'meeting point'. Caspase-9 and -3 activation also was in part dependent on A-SMase and CTSD expression as revealed in the respective deficiency models. Our results link as novel endosomal intermediates the A-SMase and the acid aspartate protease CTSD to the mitochondrial apoptotic TNF pathway.
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Affiliation(s)
- M Heinrich
- Institute of Immunology, University of Kiel, Kiel D-24105, Germany
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37
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Marchesini N, Hannun YA. Acid and neutral sphingomyelinases: roles and mechanisms of regulation. Biochem Cell Biol 2004; 82:27-44. [PMID: 15052326 DOI: 10.1139/o03-091] [Citation(s) in RCA: 259] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Ceramide, an emerging bioactive lipid and second messenger, is mainly generated by hydrolysis of sphingomyelin through the action of sphingomyelinases. At least two sphingomyelinases, neutral and acid sphingomyelinases, are activated in response to many extracellular stimuli. Despite extensive studies, the precise cellular function of each of these sphingomyelinases in sphingomyelin turnover and in the regulation of ceramide-mediated responses is not well understood. Therefore, it is essential to elucidate the factors and mechanisms that control the activation of acid and neutral sphingomyelinases to understand their the roles in cell regulation. This review will focus on the molecular mechanisms that regulate these enzymes in vivo and in vitro, especially the roles of oxidants (glutathione, peroxide, nitric oxide), proteins (saposin, caveolin 1, caspases), and lipids (diacylglycerol, arachidonic acid, and ceramide).
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Affiliation(s)
- Norma Marchesini
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, 29425, USA
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38
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Abstract
It has been long believed that cathepsins compensate for each other because of their overlapping substrate specificities. However, there is increasing evidence that disturbance of the normal balance of their enzymatic activities is the first insult in brain aging and age-related diseases. The imbalance of cathepsins may further cause age-related neuropathological changes such as accumulation of autophagic vacuoles and the formation of ceroid-lipofuscin leading to neuronal dysfunction and damage. Leakage of cathepsins due to the fragility of lysosomal membranes during aging also contributes to neurodegeneration. Furthermore, the deficiency of cathepsin D has been recently revealed to provoke a novel type of lysosomal storage disease associated with massive neurodegeneration. In these animals, microglia are activated to initiate inflammatory and cytotoxic responses by binding and phagocytosis of storage neurons. Activated microglia also release some members of cathepsins to induce neuronal death by degrading extracellular matrix proteins. Thus the microglial activation possibly through sensing neuronal storage may also be an important causative factor for neurodegeneration in lysosomal storage diseases and age-related diseases such as Alzheimer's disease. This review describes the pathological roles of neuronal and microglial cathepsins in brain aging and age-related diseases.
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Affiliation(s)
- Hiroshi Nakanishi
- Laboratory of Oral Aging Science, Faculty of Dental Sciences, Kyushu University, Fukuoka 812-8582, Japan.
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Hawkes C, Kar S. The insulin-like growth factor-II/mannose-6-phosphate receptor: structure, distribution and function in the central nervous system. ACTA ACUST UNITED AC 2004; 44:117-40. [PMID: 15003389 DOI: 10.1016/j.brainresrev.2003.11.002] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2003] [Indexed: 01/25/2023]
Abstract
The insulin-like growth factor-II/mannose-6-phosphate (IGF-II/M6P) receptor is a multifunctional single transmembrane glycoprotein which, along with the cation-dependent M6P (CD-M6P) receptor, mediates the trafficking of M6P-containing lysosomal enzymes from the trans-Golgi network (TGN) to lysosomes. Cell surface IGF-II/M6P receptors also function in the degradation of the non-glycosylated IGF-II polypeptide hormone, as well as in the capture and activation/degradation of extracellular M6P-bearing ligands. In recent years, the multifaceted role of the receptor has become apparent, as several lines of evidence have indicated that in addition to its role in lysosomal enzyme trafficking, clearance and/or activation of a variety of growth factors and endocytosis-mediated degradation of IGF-II, the IGF-II/M6P receptor may also mediate transmembrane signal transduction in response to IGF-II binding under certain conditions. However, very little is known about the physiological significance of the receptor in the function of the central nervous system (CNS). This review aims to delineate what is currently known about IGF-II/M6P receptor structure, its ligand binding properties and role in lysosomal enzyme transport. It also summarizes the recent data regarding the role of the receptor in the CNS, including its distribution, possible importance for normal and activity-dependent functioning as well as its implications in neurodegenerative disorders such as Alzheimer's disease (AD).
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Affiliation(s)
- C Hawkes
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H4H 1R3
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40
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Abstract
For many years apoptosis research has focused on caspases and their putative role as sole executioners of programmed cell death. Accumulating information now suggests that lysosomal cathepsins are also pivotally involved in this process, especially in pathological conditions. In particular, the role of lysosomes and lysosomal enzymes in initiation and execution of the apoptotic program has become clear in several models, to the point that the existence of a 'lysosomal pathway of apoptosis' is now generally accepted. This pathway of apoptosis can be activated by death receptors, lipid mediators, and photodamage. Lysosomal proteases can be released from the lysosomes into the cytosol, where they contribute to the apoptotic cascade upstream of mitochondria. This review focuses on the players and the molecular mechanisms involved in the lysosomal pathway of apoptosis as well as on the importance of this pathway in development and pathology.
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Zhang QX, Melnikov Z, Feierman DE. Characterization of the Acetaminophen-Induced Degradation of Cytochrome P450-3A4 and the Proteolytic Pathway. ACTA ACUST UNITED AC 2004; 94:191-200. [PMID: 15078344 DOI: 10.1111/j.1742-7843.2004.pto940406.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It has been shown that large doses of acetaminophen can result in increased degradation of the hepatic cytochrome P450 (CYP) enzymes in vivo; however, the proteolytic pathways have not been identified. We found that incubating transfected HepG2 cells that express CYP3A4 or a reconstituted microsomal model containing human liver microsomes and cytosol, high concentrations of acetaminophen could induce a dose- and time-dependent degradation of CYP3A4. In the microsomal model the degradation could be blocked and augmented by the presence of catalase and superoxide dismutase, respectively. Tocopherol could also protect against the acetaminophen-induced degradation. However, lipid peroxidation assays showed no significant increases in lipid peroxidation products nor was there any protection by propyl gallate. Protease and proteasome inhibitors showed that the proteolytic process was mainly (85%) mediated by the lysosomal pathway, whereas a minor portion (15%) of the degradation was mediated by the proteasomal pathway. Both pepstatin A and anti-cathepsin D neutralizing antibody decreased acetaminophen-induced degradation of CYP3A4 in microsomal model systems. Pepstatin A also blocked the acetaminophen-induced degradation of the CYP3A4 in a transfected HepG2 cell line. Incubating the 3A4 cells in the presence of acetaminophen also increased cathepsin D content and activity. The lysosomal pathway, mainly mediated by cathepsin D, appears to be the major proteolytic pathway involved in the degradation of the P450 enzymes induced by toxic doses of acetaminophen.
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Affiliation(s)
- Qing-Xue Zhang
- Department og Anaesthesia, Mount Sinai School of Medicine, New York, NY, U.S.A
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42
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Ellis RC, Earnhardt JN, Hayes RL, Wang KKW, Anderson DK. Cathepsin B mRNA and protein expression following contusion spinal cord injury in rats. J Neurochem 2004; 88:689-97. [PMID: 14720218 DOI: 10.1046/j.1471-4159.2003.02197.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
We provide the first data that cathepsin B (Cath B), a lysosomal cysteine protease, is up-regulated following contusion-spinal cord injury (SCI). Following T12 laminectomy and moderate contusion, Cath B mRNA and protein expression profiles were examined from 2 to 168 h post-injury in rats using real-time PCR and immunoblots, respectively. Contusion injury significantly increased [mRNA]Cath B in the injury site and adjacent segments over sham injury levels. While the largest [mRNA]Cath B induction (20-fold over naive) was seen in the injury site, the caudal segment routinely yielded [mRNA]Cath B levels greater than 10-fold over naive. Interestingly, sham injury animals also experienced mRNA induction at several time points at the injury site and in segments rostral and caudal to the injury site. Contusion injury also significantly elevated levels of Cath B proenzyme protein (37 kDa) over sham injury in the injury site (48, 72 and 168 h post-injury). Furthermore, significant protein increases of single and double chain Cath B (both active forms) occurred at the injury site at 72 and 168 h post-injury. Similar significant increases in Cath B protein levels were seen in areas adjacent to the injury site. The induction of Cath B mRNA and protein expression following contusion injury is previously undescribed and suggests that Cath B may potentially be involved in the secondary injury cascade, perhaps for as long as 1 week post-injury.
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Affiliation(s)
- Rebecca C Ellis
- Department of Neuroscience, University of Florida, Gainesville 32610, USA
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43
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Takuma K, Baba A, Matsuda T. Astrocyte apoptosis: implications for neuroprotection. Prog Neurobiol 2004; 72:111-27. [PMID: 15063528 DOI: 10.1016/j.pneurobio.2004.02.001] [Citation(s) in RCA: 350] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2003] [Accepted: 02/04/2004] [Indexed: 12/21/2022]
Abstract
Astrocytes, the most abundant glial cell types in the brain, provide metabolic and trophic support to neurons and modulate synaptic activity. Accordingly, impairment in these astrocyte functions can critically influence neuronal survival. Recent studies show that astrocyte apoptosis may contribute to pathogenesis of many acute and chronic neurodegenerative disorders, such as cerebral ischemia, Alzheimer's disease and Parkinson's disease. We found that incubation of cultured rat astrocytes in a Ca(2+)-containing medium after exposure to a Ca(2+)-free medium causes an increase in intracellular Ca(2+) concentration followed by apoptosis, and that NF-kappa B, reactive oxygen species, and enzymes such as calpain, xanthine oxidase, calcineurin and caspase-3 are involved in reperfusion-induced apoptosis. Furthermore, we demonstrated that heat shock protein, mitogen-activated protein/extracellular signal-regulated kinase, phosphatidylinositol-3 kinase and cyclic GMP phosphodiesterase are target molecules for anti-apoptotic drugs. This review summarizes (1) astrocytic functions in neuroprotection, (2) current evidence of astrocyte apoptosis in both in vitro and in vivo studies including its molecular pathways such as Ca(2+) overload, oxidative stress, NF-kappa B activation, mitochondrial dysfunction, endoplasmic reticulum stress, and protease activation, and (3) several drugs preventing astrocyte apoptosis. As a whole, this article provides new insights into the potential role of astrocytes as targets for neuroprotection. In addition, the advance in the knowledge of molecular mechanisms of astrocyte apoptosis may lead to the development of novel therapeutic strategies for neurodegenerative disorders.
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Affiliation(s)
- Kazuhiro Takuma
- Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences and High Technology Research Center, Kobe Gakuin University, Kobe 651-2180, Japan
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Johansson AC, Steen H, Ollinger K, Roberg K. Cathepsin D mediates cytochrome c release and caspase activation in human fibroblast apoptosis induced by staurosporine. Cell Death Differ 2004; 10:1253-9. [PMID: 14576777 DOI: 10.1038/sj.cdd.4401290] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
There is increasing evidence that proteases other than caspases, for example, the lysosomal cathepsins B, D and L, are involved in apoptotic cell death. In the present study, we present data that suggest a role for cathepsin D in staurosporine-induced apoptosis in human foreskin fibroblasts. Cathepsin D and cytochrome c were detected partially released to the cytosol after exposure to 0.1 muM staurosporine for 1 h. After 4 h, activation of caspase-9 and -3 was initiated and later caspase-8 activation and a decrease in full-length Bid were detected. Pretreatment of cells with the cathepsin D inhibitor, pepstatin A, prevented cytochrome c release and caspase activation, and delayed cell death. These results imply that cytosolic cathepsin D is a key mediator in staurosporine-induced apoptosis. Analysis of the relative sequence of apoptotic events indicates that, in this cell type, cathepsin D acts upstream of cytochrome c release and caspase activation.
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Affiliation(s)
- A-C Johansson
- Division of Pathology II, Faculty of Health Sciences, Linköping University, S-58185 Linköping, Sweden.
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Abstract
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a clinically useful cytokine. TRAIL induces apoptosis in a wide variety of transformed cells, but does not cause toxicity to most normal cells. Recent studies show that death receptors (DR4 and DR5), decoy receptors (DcR1 and DcR2), and death inhibitors (FLIP, FAP-1, and IAP) are responsible for the differential sensitivity to TRAIL of normal and tumor cells. Several researchers have also shown that genotoxic agents, such as chemotherapeutic agents and ionizing radiation, enhance TRAIL-induced cytotoxicity by increasing DR5 gene expression or decreasing the intracellular level of FLIP, an antiapoptotic protein. Previous studies have shown that ceramide helps to regulate a cell's response to various forms of stress. Stress-induced alterations in the intracellular concentration of ceramide occur through the activation of a variety of enzymes that synthesize or catabolize ceramide. Increases in intracellular ceramide levels modulate apoptosis by acting through key proteases, phosphatases, and kinases. This review discusses the interaction between TRAIL and ceramide signaling pathways in regulating apoptotic death.
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Affiliation(s)
- Yong J Lee
- Department of Surgery and Pharmacology, University of Pittsburgh, Pennsylvania 15213, USA
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Houseweart MK, Pennacchio LA, Vilaythong A, Peters C, Noebels JL, Myers RM. Cathepsin B but not cathepsins L or S contributes to the pathogenesis of Unverricht-Lundborg progressive myoclonus epilepsy (EPM1). JOURNAL OF NEUROBIOLOGY 2003; 56:315-27. [PMID: 12918016 DOI: 10.1002/neu.10253] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The inherited epilepsy Unverricht-Lundborg disease (EPM1) is caused by loss-of-function mutations in the cysteine protease inhibitor, cystatin B. Because cystatin B inhibits a class of lysosomal cysteine proteases called cathepsins, we hypothesized that increased proteolysis by one or more of these cathepsins is likely to be responsible for the seizure, ataxia, and neuronal apoptosis phenotypes characteristic of EPM1. To test this hypothesis and to identify which cysteine cathepsins contribute to EPM1, we have genetically removed three candidate cathepsins from cystatin B-deficient mice and tested for rescue of their EPM1 phenotypes. Whereas removal of cathepsins L or S from cystatin B-deficient mice did not ameliorate any aspect of the EPM1 phenotype, removal of cathepsin B resulted in a 36-89% reduction in the amount of cerebellar granule cell apoptosis depending on mouse age. The incidence of an incompletely penetrant eye phenotype was also reduced upon removal of cathepsin B. Because the apoptosis and eye phenotypes were not abolished completely and the ataxia and seizure phenotypes experienced by cystatin B-deficient animals were not diminished, this suggests that another molecule besides cathepsin B is also responsible for the pathogenesis, or that another molecule can partially compensate for cathepsin B function. These findings establish cathepsin B as a contributor to the apoptotic phenotype of cystatin B-deficient mice and humans with EPM1. They also suggest that the identification of cathepsin B substrates may further reveal the molecular basis for EPM1.
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Affiliation(s)
- Megan K Houseweart
- Department of Genetics, School of Medicine, Stanford University, Stanford, California 94305, USA
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Tardy C, Tyynelä J, Hasilik A, Levade T, Andrieu-Abadie N. Stress-induced apoptosis is impaired in cells with a lysosomal targeting defect but is not affected in cells synthesizing a catalytically inactive cathepsin D. Cell Death Differ 2003; 10:1090-100. [PMID: 12934083 DOI: 10.1038/sj.cdd.4401272] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The role of cathepsin D in stress-induced cell death has been investigated by using ovine fibroblasts exhibiting a missense mutation in the active site of cathepsin D. The cathepsin D (lysosomal aspartic protease) deficiency did not protect cells against toxicity induced by doxorubicin and other cytotoxic agents, neither did it protect cells from caspase activation. Moreover, the cathepsin D inhibitor, pepstatin A, did not prevent stress-induced cell death in human fibroblasts or lymphoblasts. The possible role of lysosomal ceramide or sphingosine-mediated activation of cathepsin D in apoptosis was also excluded by using human cells either overexpressing or deficient in acid ceramidase. However, a normal lysosomal function seems to be required for efficient cell death, as indicated by the finding that fibroblasts from patients with mucolipidosis II were partially resistant to staurosporine, sphingosine and TNF-induced apoptosis, suggesting a key role of lysosomes in cell death.
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Affiliation(s)
- C Tardy
- INSERM U466, Institut Louis Bugnard, Centre Hospitalier Universitaire de Rangueil, Toulouse, France
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Burke MA, Hutter D, Reshamwala RP, Knepper JE. Cathepsin L plays an active role in involution of the mouse mammary gland. Dev Dyn 2003; 227:315-22. [PMID: 12815617 DOI: 10.1002/dvdy.10313] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Involution of the mammary gland after weaning occurs in two stages. The first stage is reversible, whereas the second stage is characterized by the irreversible collapse of the alveolar structure. A differential display analysis using cDNAs from tissues obtained at various times after forced weaning of pups identified cathepsin L as up-regulated during early involution. Levels of cathepsin L mRNA were dramatically increased within 24 hr after weaning. Cathepsin L protein detected by immunoblot was also increased during involution, reaching near maximal levels by 36 hr after weaning. In situ immunohistochemistry detected pronounced cathepsin L protein in the cytoplasm and cell periphery. Mice treated with a specific inhibitor of cathepsin L exhibited substantially reduced numbers of apoptotic cells at times up to 72 hr after weaning when compared with untreated animals. The cathepsin L inhibitor did not alter levels of cathepsin L detected in immunoblots or influence molecular weight of the cathepsin L species detected. These data suggest that cathepsin L plays a regulatory role early in the process of mammary gland involution.
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Affiliation(s)
- Michael A Burke
- Department of Biology, Villanova University, Villanova, Pennsylvania 19085, USA
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Kikuchi H, Yamada T, Furuya H, Doh-ura K, Ohyagi Y, Iwaki T, Kira JI. Involvement of cathepsin B in the motor neuron degeneration of amyotrophic lateral sclerosis. Acta Neuropathol 2003; 105:462-8. [PMID: 12677446 DOI: 10.1007/s00401-002-0667-9] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2002] [Revised: 12/09/2002] [Accepted: 12/11/2002] [Indexed: 12/11/2022]
Abstract
Abnormal proteolysis may be involved in the motor neuron degeneration of amyotrophic lateral sclerosis (ALS). Although several studies of the ubiquitin-proteasome system in ALS have been reported, the endosome-lysosome system has not been investigated in detail. To clarify the association of neurodegeneration with the endosome-lysosome system in ALS, we examined the pathological expression of cysteine proteases such as cathepsins B, H and L and an aspartate protease, cathepsin D, in the anterior horns of 15 ALS cases and 5 controls. In the ALS cases, cathepsin B immunoreactivity was preferentially decreased in the lateral parts of the anterior gray horns compared with the controls. Its immunoreactivity was increased in the cytoplasm of both shrunken and pigmented neurons but was weak in the neurons containing Bunina bodies. In addition, reactive astrocytes were also immunolabeled with cathepsin B. Cathepsin H and cathepsin L were detected in the cytoplasm of a small number of shrunken and pigmented neurons. Cathepsin D immunoreactivity was strong in the cytoplasm of all motor neurons. The immunoreactivity of cathepsins H, L and D was not significantly different between control and ALS cases. Western blot analysis showed that the 25-kDa activated form of cathepsin B was down-regulated in ALS. Our results suggest that cathepsin B is involved in the motor neuron degeneration in ALS.
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Affiliation(s)
- Hitoshi Kikuchi
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, 812-8582 Fukuoka, Japan.
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50
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Kametaka S, Shibata M, Moroe K, Kanamori S, Ohsawa Y, Waguri S, Sims PJ, Emoto K, Umeda M, Uchiyama Y. Identification of phospholipid scramblase 1 as a novel interacting molecule with beta -secretase (beta -site amyloid precursor protein (APP) cleaving enzyme (BACE)). J Biol Chem 2003; 278:15239-45. [PMID: 12586838 DOI: 10.1074/jbc.m208611200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
beta-Site amyloid precursor protein (APP)-cleaving enzyme (BACE) is an integral membrane aspartic proteinase responsible for beta-site processing of APP, and its cytoplasmic region composed of 24 amino acid residues has been shown to be involved in the endosomal localization of BACE. With the yeast two-hybrid screening, we found that the cytoplasmic domain of phospholipid scramblase 1 (PLSCR1), a type II integral membrane protein, interacts with the cytoplasmic region of BACE. In cultured cells, BACE and PLSCR1 were colocalized in the Golgi area and in endosomal compartments, whereas they were co-redistributed in late endosome-derived multivesicular bodies when treated with U18666A, suggesting that both proteins share a common trafficking pathway in cells. Co-immunoprecipitation analysis showed that both proteins form a protein complex at an endogenous expression level in the human neuroblastoma SH-SY5Ycells, and the dileucine residue of the BACE tail is also revealed to be essential for the physical interaction with PLSCR1 in vitro and in vivo. Moreover, both BACE and PLSCR1 were localized in a low buoyant lipid microdomain in SH-SY5Y cells. The dileucine-defective BACE mutant was also fractionated into the lipid microdomain, but much less stably than wild-type BACE. Taken together, our current study suggests the functional involvement of PLSCR1 in the intracellular distribution of BACE and/or recruitment of BACE into the detergent-insoluble lipid raft.
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Affiliation(s)
- Satoshi Kametaka
- Department of Cell Biology and Neuroscience A1, Osaka University Graduate School of Medicine, Yamadaoka 2-2, Suita, Osaka 565-0871, Japan
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