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  1. Article ; Online: ATP6V0C knockdown in neuroblastoma cells alters autophagy-lysosome pathway function and metabolism of proteins that accumulate in neurodegenerative disease.

    Mangieri, Leandra R / Mader, Burton J / Thomas, Cailin E / Taylor, Charles A / Luker, Austin M / Tse, Tonia E / Huisingh, Carrie / Shacka, John J

    PloS one

    2014  Volume 9, Issue 4, Page(s) e93257

    Abstract: ATP6V0C is the bafilomycin A1-binding subunit of vacuolar ATPase, an enzyme complex that critically regulates vesicular acidification. We and others have shown previously that bafilomycin A1 regulates cell viability, autophagic flux and metabolism of ... ...

    Abstract ATP6V0C is the bafilomycin A1-binding subunit of vacuolar ATPase, an enzyme complex that critically regulates vesicular acidification. We and others have shown previously that bafilomycin A1 regulates cell viability, autophagic flux and metabolism of proteins that accumulate in neurodegenerative disease. To determine the importance of ATP6V0C for autophagy-lysosome pathway function, SH-SY5Y human neuroblastoma cells differentiated to a neuronal phenotype were nucleofected with non-target or ATP6V0C siRNA and following recovery were treated with either vehicle or bafilomycin A1 (0.3-100 nM) for 48 h. ATP6V0C knockdown was validated by quantitative RT-PCR and by a significant decrease in Lysostracker Red staining. ATP6V0C knockdown significantly increased basal levels of microtubule-associated protein light chain 3-II (LC3-II), α-synuclein high molecular weight species and APP C-terminal fragments, and inhibited autophagic flux. Enhanced LC3 and LAMP-1 co-localization following knockdown suggests that autophagic flux was inhibited in part due to lysosomal degradation and not by a block in vesicular fusion. Knockdown of ATP6V0C also sensitized cells to the accumulation of autophagy substrates and a reduction in neurite length following treatment with 1 nM bafilomycin A1, a concentration that did not produce such alterations in non-target control cells. Reduced neurite length and the percentage of propidium iodide-positive dead cells were also significantly greater following treatment with 3 nM bafilomycin A1. Together these results indicate a role for ATP6V0C in maintaining constitutive and stress-induced ALP function, in particular the metabolism of substrates that accumulate in age-related neurodegenerative disease and may contribute to disease pathogenesis.
    MeSH term(s) Amyloid beta-Protein Precursor/metabolism ; Autophagy/physiology ; Cell Line, Tumor ; Humans ; Lysosomal Membrane Proteins/metabolism ; Lysosomes/metabolism ; Lysosomes/physiology ; Microtubule-Associated Proteins/metabolism ; Neuroblastoma/metabolism ; Neuroblastoma/physiopathology ; Neurodegenerative Diseases/metabolism ; Neurodegenerative Diseases/physiopathology ; Vacuolar Proton-Translocating ATPases/metabolism ; alpha-Synuclein/metabolism
    Chemical Substances APP protein, human ; ATP6V0C protein, human ; Amyloid beta-Protein Precursor ; LAMP1 protein, human ; Lysosomal Membrane Proteins ; MAP1LC3A protein, human ; Microtubule-Associated Proteins ; alpha-Synuclein ; Vacuolar Proton-Translocating ATPases (EC 3.6.1.-)
    Language English
    Publishing date 2014-04-02
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2267670-3
    ISSN 1932-6203 ; 1932-6203
    ISSN (online) 1932-6203
    ISSN 1932-6203
    DOI 10.1371/journal.pone.0093257
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Rotenone inhibits autophagic flux prior to inducing cell death.

    Mader, Burton J / Pivtoraiko, Violetta N / Flippo, Hilary M / Klocke, Barbara J / Roth, Kevin A / Mangieri, Leandra R / Shacka, John J

    ACS chemical neuroscience

    2012  Volume 3, Issue 12, Page(s) 1063–1072

    Abstract: Rotenone, which selectively inhibits mitochondrial complex I, induces oxidative stress, α-synuclein accumulation, and dopaminergic neuron death, principal pathological features of Parkinson's disease. The autophagy-lysosome pathway degrades damaged ... ...

    Abstract Rotenone, which selectively inhibits mitochondrial complex I, induces oxidative stress, α-synuclein accumulation, and dopaminergic neuron death, principal pathological features of Parkinson's disease. The autophagy-lysosome pathway degrades damaged proteins and organelles for the intracellular maintenance of nutrient and energy balance. While it is known that rotenone causes autophagic vacuole accumulation, the mechanism by which this effect occurs has not been thoroughly investigated. Treatment of differentiated SH-SY5Y cells with rotenone (10 μM) induced the accumulation of autophagic vacuoles at 6 h and 24 h as indicated by Western blot analysis for microtubule associated protein-light chain 3-II (MAP-LC3-II). Assessment of autophagic flux at these time points indicated that autophagic vacuole accumulation resulted from a decrease in their effective lysosomal degradation, which was substantiated by increased levels of autophagy substrates p62 and α-synuclein. Inhibition of lysosomal degradation may be explained by the observed decrease in cellular ATP levels, which in turn may have caused the observed concomitant increase in acidic vesicle pH. The early (6 h) effects of rotenone on cellular energetics and autophagy-lysosome pathway function preceded the induction of cell death and apoptosis. These findings indicate that the classical mitochondrial toxin rotenone has a pronounced effect on macroautophagy completion that may contribute to its neurotoxic potential.
    MeSH term(s) Autophagy/drug effects ; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/metabolism ; Cell Death/drug effects ; Cell Line, Tumor ; Humans ; Lysosomal-Associated Membrane Protein 1/metabolism ; Lysosomes/drug effects ; Lysosomes/metabolism ; Lysosomes/pathology ; Neurons/drug effects ; Neurons/metabolism ; Neurons/pathology ; Rotenone/pharmacology ; Uncoupling Agents/pharmacology ; Vacuoles/drug effects ; Vacuoles/metabolism ; Vacuoles/pathology
    Chemical Substances Basic Helix-Loop-Helix Leucine Zipper Transcription Factors ; Lysosomal-Associated Membrane Protein 1 ; TFEB protein, human ; Uncoupling Agents ; Rotenone (03L9OT429T)
    Language English
    Publishing date 2012-09-13
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ISSN 1948-7193
    ISSN (online) 1948-7193
    DOI 10.1021/cn300145z
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Low-dose bafilomycin attenuates neuronal cell death associated with autophagy-lysosome pathway dysfunction.

    Pivtoraiko, Violetta N / Harrington, Adam J / Mader, Burton J / Luker, Austin M / Caldwell, Guy A / Caldwell, Kim A / Roth, Kevin A / Shacka, John J

    Journal of neurochemistry

    2010  Volume 114, Issue 4, Page(s) 1193–1204

    Abstract: We have shown previously that the plecomacrolide antibiotics bafilomycin A1 and B1 significantly attenuate cerebellar granule neuron death resulting from agents that disrupt lysosome function. To further characterize bafilomycin-mediated cytoprotection, ... ...

    Abstract We have shown previously that the plecomacrolide antibiotics bafilomycin A1 and B1 significantly attenuate cerebellar granule neuron death resulting from agents that disrupt lysosome function. To further characterize bafilomycin-mediated cytoprotection, we examined its ability to attenuate the death of naïve and differentiated neuronal SH-SY5Y human neuroblastoma cells from agents that induce lysosome dysfunction in vitro, and from in vivo dopaminergic neuron death in C. elegans. Low-dose bafilomycin significantly attenuated SH-SY5Y cell death resulting from treatment with chloroquine, hydroxychloroquine amodiaquine and staurosporine. Bafilomycin also attenuated the chloroquine-induced reduction in processing of cathepsin D, the principal lysosomal aspartic acid protease, to its mature 'active' form. Chloroquine induced autophagic vacuole accumulation and inhibited autophagic flux, effects that were attenuated upon treatment with bafilomycin and were associated with a significant decrease in chloroquine-induced accumulation of detergent-insoluble alpha-synuclein oligomers. In addition, bafilomycin significantly and dose-dependently attenuated dopaminergic neuron death in C. elegans resulting from in vivo over-expression of human wild-type alpha-synuclein. Together, our findings suggest that low-dose bafilomycin is cytoprotective in part through its maintenance of the autophagy-lysosome pathway, and underscores its therapeutic potential for treating Parkinson's disease and other neurodegenerative diseases that exhibit disruption of protein degradation pathways and accumulation of toxic protein species.
    MeSH term(s) Animals ; Autophagy/drug effects ; Autophagy/physiology ; Caenorhabditis elegans/drug effects ; Cell Line, Tumor ; Cytoprotection/drug effects ; Cytoprotection/physiology ; Disease Progression ; Humans ; Lysosomes/drug effects ; Lysosomes/physiology ; Macrolides/pharmacology ; Nerve Degeneration/drug therapy ; Nerve Degeneration/metabolism ; Nerve Degeneration/pathology ; Neurons/drug effects ; Neurons/metabolism ; Signal Transduction/drug effects
    Chemical Substances Macrolides ; bafilomycin A (116764-51-3)
    Language English
    Publishing date 2010-06-01
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 80158-6
    ISSN 1471-4159 ; 0022-3042 ; 1474-1644
    ISSN (online) 1471-4159
    ISSN 0022-3042 ; 1474-1644
    DOI 10.1111/j.1471-4159.2010.06838.x
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Low-dose bafilomycin attenuates neuronal cell death associated with autophagy-lysosome pathway dysfunction

    Pivtoraiko, Violetta N / Harrington, Adam J / Mader, Burton J / Luker, Austin M / Caldwell, Guy A / Caldwell, Kim A / Roth, Kevin A / Shacka, John J

    Journal of neurochemistry. 2010 Aug., v. 114, no. 4

    2010  

    Abstract: J. Neurochem. (2010) 114, 1193-1204. We have shown previously that the plecomacrolide antibiotics bafilomycin A1 and B1 significantly attenuate cerebellar granule neuron death resulting from agents that disrupt lysosome function. To further characterize ... ...

    Abstract J. Neurochem. (2010) 114, 1193-1204. We have shown previously that the plecomacrolide antibiotics bafilomycin A1 and B1 significantly attenuate cerebellar granule neuron death resulting from agents that disrupt lysosome function. To further characterize bafilomycin-mediated cytoprotection, we examined its ability to attenuate the death of naïve and differentiated neuronal SH-SY5Y human neuroblastoma cells from agents that induce lysosome dysfunction in vitro, and from in vivo dopaminergic neuron death in C. elegans. Low-dose bafilomycin significantly attenuated SH-SY5Y cell death resulting from treatment with chloroquine, hydroxychloroquine amodiaquine and staurosporine. Bafilomycin also attenuated the chloroquine-induced reduction in processing of cathepsin D, the principal lysosomal aspartic acid protease, to its mature 'active' form. Chloroquine induced autophagic vacuole accumulation and inhibited autophagic flux, effects that were attenuated upon treatment with bafilomycin and were associated with a significant decrease in chloroquine-induced accumulation of detergent-insoluble α-synuclein oligomers. In addition, bafilomycin significantly and dose-dependently attenuated dopaminergic neuron death in C. elegans resulting from in vivo over-expression of human wild-type α-synuclein. Together, our findings suggest that low-dose bafilomycin is cytoprotective in part through its maintenance of the autophagy-lysosome pathway, and underscores its therapeutic potential for treating Parkinson's disease and other neurodegenerative diseases that exhibit disruption of protein degradation pathways and accumulation of toxic protein species.
    Keywords Parkinson disease ; cathepsin D
    Language English
    Dates of publication 2010-08
    Size p. 1193-1204.
    Publisher Blackwell Publishing Ltd
    Publishing place Oxford, UK
    Document type Article
    ZDB-ID 80158-6
    ISSN 1471-4159 ; 0022-3042 ; 1474-1644
    ISSN (online) 1471-4159
    ISSN 0022-3042 ; 1474-1644
    DOI 10.1111/j.1471-4159.2010.06838.x
    Database NAL-Catalogue (AGRICOLA)

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  5. Article ; Online: A novel sulindac derivative inhibits lung adenocarcinoma cell growth through suppression of Akt/mTOR signaling and induction of autophagy.

    Gurpinar, Evrim / Grizzle, William E / Shacka, John J / Mader, Burton J / Li, Nan / Piazza, Nicholas A / Russo, Suzanne / Keeton, Adam B / Piazza, Gary A

    Molecular cancer therapeutics

    2013  Volume 12, Issue 5, Page(s) 663–674

    Abstract: Nonsteroidal anti-inflammatory drugs such as sulindac sulfide have shown promising antineoplastic activity in multiple tumor types, but toxicities resulting from COX inhibition limit their use in cancer therapy. We recently described a N,N-dimethylethyl ... ...

    Abstract Nonsteroidal anti-inflammatory drugs such as sulindac sulfide have shown promising antineoplastic activity in multiple tumor types, but toxicities resulting from COX inhibition limit their use in cancer therapy. We recently described a N,N-dimethylethyl amine derivative of sulindac sulfide, sulindac sulfide amide (SSA), that does not inhibit COX-1 or -2, yet displays potent tumor cell growth-inhibitory activity. Here, we studied the basis for the growth-inhibitory effects of SSA on human lung adenocarcinoma cell lines. SSA potently inhibited the growth of lung tumor cells with IC50 values of 2 to 5 μmol/L compared with 44 to 52 μmol/L for sulindac sulfide. SSA also suppressed DNA synthesis and caused a G0-G1 cell-cycle arrest. SSA-induced cell death was associated with characteristics of autophagy, but significant caspase activation or PARP cleavage was not observed after treatment at its IC50 value. siRNA knockdown of Atg7 attenuated SSA-induced autophagy and cell death, whereas pan-caspase inhibitor ZVAD was not able to rescue viability. SSA treatment also inhibited Akt/mTOR signaling and the expression of downstream proteins that are regulated by this pathway. Overexpression of a constitutively active form of Akt was able to reduce autophagy markers and confer resistance to SSA-induced cell death. Our findings provide evidence that SSA inhibits lung tumor cell growth by a mechanism involving autophagy induction through the suppression of Akt/mTOR signaling. This unique mechanism of action, along with its increased potency and lack of COX inhibition, supports the development of SSA or related analogs for the prevention and/or treatment of lung cancer.
    MeSH term(s) Adenocarcinoma/metabolism ; Adenocarcinoma of Lung ; Antineoplastic Agents/pharmacology ; Autophagy/drug effects ; Cell Cycle/drug effects ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Cell Survival/drug effects ; Humans ; Inhibitory Concentration 50 ; Lung Neoplasms/metabolism ; Proto-Oncogene Proteins c-akt/metabolism ; Ribosomal Protein S6 Kinases, 70-kDa/metabolism ; Signal Transduction/drug effects ; Sulindac/analogs & derivatives ; Sulindac/pharmacology ; TOR Serine-Threonine Kinases/metabolism
    Chemical Substances Antineoplastic Agents ; sulindac sulfide amide ; Sulindac (184SNS8VUH) ; sulindac sulfide (6UVA8S2DEY) ; TOR Serine-Threonine Kinases (EC 2.7.1.1) ; Proto-Oncogene Proteins c-akt (EC 2.7.11.1) ; Ribosomal Protein S6 Kinases, 70-kDa (EC 2.7.11.1)
    Language English
    Publishing date 2013-02-26
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2063563-1
    ISSN 1538-8514 ; 1535-7163
    ISSN (online) 1538-8514
    ISSN 1535-7163
    DOI 10.1158/1535-7163.MCT-12-0785
    Database MEDical Literature Analysis and Retrieval System OnLINE

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