The Experts below are selected from a list of 1596 Experts worldwide ranked by ideXlab platform
George N. Demartino - One of the best experts on this subject based on the ideXlab platform.
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lewy body formation is an Aggresome related process a hypothesis
Lancet Neurology, 2004Co-Authors: Warren C Olanow, George N. Demartino, Daniel P Perl, Kevin St P McnaughtAbstract:Summary Parkinson's disease (PD) is an age-related neurodegenerative disorder that is associated with the formation of intracytoplasmic protein aggregates (Lewy-body inclusions) in neurons of the substantia nigra pars compacta and other brain areas. These inclusions were discovered over 90 years ago, but the mechanism underlying their formation and their relevance to the neurodegenerative process are unknown. Recent studies have begun to shed light on the biogenesis of Lewy bodies and suggest that they are related to Aggresomes. Aggresomes are cytoprotective proteinaceous inclusions formed at the centrosome that segregate and facilitate the degradation of excess amounts of unwanted and possibly cytotoxic proteins. The concept of Lewy bodies as Aggresome-related inclusions fits well with ongoing discoveries suggesting that altered protein handling might contribute to the neurodegenerative process in familial and sporadic forms of PD.
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rna interference of valosin containing protein vcp p97 reveals multiple cellular roles linked to ubiquitin proteasome dependent proteolysis
Journal of Cell Science, 2004Co-Authors: Cezary Wojcik, Mihiro Yano, George N. DemartinoAbstract:We have used RNA interference (RNAi) to examine the functional relationship between valosin-containing protein (VCP/p97/Cdc48p/TER94) ATPase and the ubiquitin-proteasome system (UPS) in Drosophila S2 and human HeLa cells. In both cell types, RNAi of VCP (and, to a lesser extent, of certain VCP-interacting proteins) caused significant accumulation of high-molecular-weight conjugates of ubiquitin, an indication of inhibited UPS function. However, decreased VCP levels did not directly inhibit proteasome activity. In HeLa cells, polyubiquitinated proteins accumulated as dispersed aggregates rather than as single Aggresomes, even in the presence of proteasome inhibitors, which normally promote Aggresome formation. RNAi of VCP caused extensive vacuolization of the cytoplasm, and proteasome inhibitors exaggerated this feature. RNAi of VCP had little effect on S2 cell proliferation but blocked cell-cycle progression and induced mitotic abnormalities and apoptosis in HeLa cells. These results indicate that VCP plays an important general role in mediating the function of the UPS, probably by interacting with potential proteasome substrates before they are degraded by the proteasome.
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rna interference of valosin containing protein vcp p97 reveals multiple cellular roles linked to ubiquitin proteasome dependent proteolysis
Journal of Cell Science, 2004Co-Authors: Cezary Wojcik, Mihiro Yano, George N. DemartinoAbstract:We have used RNA interference (RNAi) to examine the functional relationship between valosin-containing protein (VCP/p97/Cdc48p/TER94) ATPase and the ubiquitin-proteasome system (UPS) in Drosophila S2 and human HeLa cells. In both cell types, RNAi of VCP (and, to a lesser extent, of certain VCP-interacting proteins) caused significant accumulation of high-molecular-weight conjugates of ubiquitin, an indication of inhibited UPS function. However, decreased VCP levels did not directly inhibit proteasome activity. In HeLa cells, polyubiquitinated proteins accumulated as dispersed aggregates rather than as single Aggresomes, even in the presence of proteasome inhibitors, which normally promote Aggresome formation. RNAi of VCP caused extensive vacuolization of the cytoplasm, and proteasome inhibitors exaggerated this feature. RNAi of VCP had little effect on S2 cell proliferation but blocked cell-cycle progression and induced mitotic abnormalities and apoptosis in HeLa cells. These results indicate that VCP plays an important general role in mediating the function of the UPS, probably by interacting with potential proteasome substrates before they are degraded by the proteasome.
Henry L Paulson - One of the best experts on this subject based on the ideXlab platform.
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antisense oligonucleotide therapy rescues Aggresome formation in a novel spinocerebellar ataxia type 3 human embryonic stem cell line
Stem Cell Research, 2019Co-Authors: Lauren R Moore, Laura M Keller, David D Bushart, Rodrigo G Delatorre, Duojia Li, Hayley S Mcloughlin, Maria Do Carmo Costa, Vikram G Shakkottai, Gary D Smith, Henry L PaulsonAbstract:Abstract Spinocerebellar ataxia type 3 (SCA3) is a fatal, late-onset neurodegenerative disorder characterized by selective neuropathology in the brainstem, cerebellum, spinal cord, and substantia nigra. Here we report the first NIH-approved human embryonic stem cell (hESC) line derived from an embryo harboring the SCA3 mutation. Referred to as SCA3-hESC, this line is heterozygous for the mutant polyglutamine-encoding CAG repeat expansion in the ATXN3 gene. We observed relevant molecular hallmarks of the human disease at all differentiation stages from stem cells to cortical neurons, including robust ATXN3 aggregation and altered expression of key components of the protein quality control machinery. In addition, SCA3-hESCs exhibit nuclear accumulation of mutant ATXN3 and form p62-positive Aggresomes. Finally, antisense oligonucleotide-mediated reduction of ATXN3 markedly suppressed Aggresome formation. The SCA3-hESC line offers a unique and highly relevant human disease model that holds strong potential to advance understanding of SCA3 disease mechanisms and facilitate the evaluation of candidate therapies for SCA3.
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antisense oligonucleotide therapy rescues Aggresome formation in a novel spinocerebellar ataxia type 3 human embryonic stem cell line
bioRxiv, 2019Co-Authors: Lauren R Moore, Laura M Keller, David D Bushart, Rodrigo G Delatorre, Duojia Li, Hayley S Mcloughlin, Maria Do Carmo Costa, Vikram G Shakkottai, Gary D Smith, Henry L PaulsonAbstract:Abstract Spinocerebellar ataxia type 3 (SCA3) is a fatal, late-onset neurodegenerative disorder characterized by selective neuropathology in the brainstem, cerebellum, spinal cord, and substantia nigra. Here, we characterize the first NIH-approved human embryonic stem cell (hESC) line derived from an embryo harboring the SCA3 mutation. Referred here as SCA3-hESC, this line is heterozygous for the mutant polyglutamine-encoding CAG repeat expansion in the ATXN3 gene within the pathogenic repeat range for SCA3. We observed relevant molecular hallmarks of the human disease at all differentiation stages from stem cells to cortical neurons, including robust ATXN3 aggregation and altered expression of key components of the protein quality control machinery. Finally, antisense oligonucleotide-mediated reduction of ATXN3 prevented the formation of p62-positive Aggresomes in SCA3-hESCs. The SCA3-hESC line offers a unique and highly relevant human disease model that holds strong potential to advance understanding of SCA3 disease mechanisms and facilitate the evaluation of possible SCA3 therapies. Highlights Generated first NIH-approved SCA3 human embryonic stem cell line (SCA3-hESC) SCA3–hESC exhibit robust ATXN3 aggregation pathology and form p62+ Aggresomes Anti-ATXN3 antisense oligonucleotides rescue Aggresome formation in SCA3-hESC Derived SCA3 neurons form aggregates and exhibit impaired protein quality control
Mihiro Yano - One of the best experts on this subject based on the ideXlab platform.
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rna interference of valosin containing protein vcp p97 reveals multiple cellular roles linked to ubiquitin proteasome dependent proteolysis
Journal of Cell Science, 2004Co-Authors: Cezary Wojcik, Mihiro Yano, George N. DemartinoAbstract:We have used RNA interference (RNAi) to examine the functional relationship between valosin-containing protein (VCP/p97/Cdc48p/TER94) ATPase and the ubiquitin-proteasome system (UPS) in Drosophila S2 and human HeLa cells. In both cell types, RNAi of VCP (and, to a lesser extent, of certain VCP-interacting proteins) caused significant accumulation of high-molecular-weight conjugates of ubiquitin, an indication of inhibited UPS function. However, decreased VCP levels did not directly inhibit proteasome activity. In HeLa cells, polyubiquitinated proteins accumulated as dispersed aggregates rather than as single Aggresomes, even in the presence of proteasome inhibitors, which normally promote Aggresome formation. RNAi of VCP caused extensive vacuolization of the cytoplasm, and proteasome inhibitors exaggerated this feature. RNAi of VCP had little effect on S2 cell proliferation but blocked cell-cycle progression and induced mitotic abnormalities and apoptosis in HeLa cells. These results indicate that VCP plays an important general role in mediating the function of the UPS, probably by interacting with potential proteasome substrates before they are degraded by the proteasome.
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rna interference of valosin containing protein vcp p97 reveals multiple cellular roles linked to ubiquitin proteasome dependent proteolysis
Journal of Cell Science, 2004Co-Authors: Cezary Wojcik, Mihiro Yano, George N. DemartinoAbstract:We have used RNA interference (RNAi) to examine the functional relationship between valosin-containing protein (VCP/p97/Cdc48p/TER94) ATPase and the ubiquitin-proteasome system (UPS) in Drosophila S2 and human HeLa cells. In both cell types, RNAi of VCP (and, to a lesser extent, of certain VCP-interacting proteins) caused significant accumulation of high-molecular-weight conjugates of ubiquitin, an indication of inhibited UPS function. However, decreased VCP levels did not directly inhibit proteasome activity. In HeLa cells, polyubiquitinated proteins accumulated as dispersed aggregates rather than as single Aggresomes, even in the presence of proteasome inhibitors, which normally promote Aggresome formation. RNAi of VCP caused extensive vacuolization of the cytoplasm, and proteasome inhibitors exaggerated this feature. RNAi of VCP had little effect on S2 cell proliferation but blocked cell-cycle progression and induced mitotic abnormalities and apoptosis in HeLa cells. These results indicate that VCP plays an important general role in mediating the function of the UPS, probably by interacting with potential proteasome substrates before they are degraded by the proteasome.
Qing Wang - One of the best experts on this subject based on the ideXlab platform.
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the heavy metal cadmium induces valosin containing protein vcp mediated Aggresome formation
Toxicology and Applied Pharmacology, 2008Co-Authors: Changcheng Song, Chouchi H Li, Nancy H. Colburn, Thomas P. Conrads, Zhen Xiao, Stephen J. Lockett, Timothy D. Veenstra, Kunio Nagashima, Qing Wang, Ji Ming WangAbstract:Cadmium (Cd{sup 2+}) is a heavy metal ion known to have a long biological half-life in humans. Accumulating evidence shows that exposure to Cd{sup 2+} is associated with neurodegenerative diseases characterized by the retention of ubiquitinated and misfolded proteins in the lesions. Here, we report that Cd{sup 2+} directly induces the formation of protein inclusion bodies in cells. The protein inclusion body is an Aggresome, a major organelle for collecting ubiquitinated or misfolded proteins. Our results show that Aggresomes are enriched in the detergent-insoluble fraction of Cd{sup 2+}-treated cell lysates. Proteomic analysis identified 145 proteins in the Aggresome-enriched fractions. One of the proteins is the highly conserved valosin-containing protein (VCP), which has been shown to colocalize with Aggresomes and bind ubiquitinated proteins through its N domain (1-200). Our subsequent examination of VCP's role in the formation of Aggresomes induced by Cd{sup 2+} indicates that the C-terminal tail (no. 780-806) of VCP interacts with histone deacetylase HDAC6, a mediator for Aggresome formation, suggesting that VCP participates in transporting ubiquitinated proteins to Aggresomes. This function of VCP is impaired by inhibition of the deacetylase activity of HDAC6 or by over-expression of VCP mutants that do not bind ubiquitinated proteins or HDAC6. Ourmore » results indicate that Cd{sup 2+} induces the formation of protein inclusion bodies by promoting the accumulation of ubiquitinated proteins in Aggresomes through VCP and HDAC6. Our delineation of the role of VCP in regulating cell responses to ubiquitinated proteins has important implications for understanding Cd{sup 2+} toxicity and associated diseases.« less
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the heavy metal cadmium induces valosin containing protein vcp mediated Aggresome formation
Toxicology and Applied Pharmacology, 2008Co-Authors: Changcheng Song, Nancy H. Colburn, Thomas P. Conrads, Zhen Xiao, Stephen J. Lockett, Timothy D. Veenstra, Kunio Nagashima, Renming Dai, Edward H Cho, Qing WangAbstract:Cadmium (Cd2+) is a heavy metal ion known to have a long biological half-life in humans. Accumulating evidence shows that exposure to Cd2+ is associated with neurodegenerative diseases characterized by the retention of ubiquitinated and misfolded proteins in the lesions. Here, we report that Cd2+ directly induces the formation of protein inclusion bodies in cells. The protein inclusion body is an Aggresome, a major organelle for collecting ubiquitinated or misfolded proteins. Our results show that Aggresomes are enriched in the detergent-insoluble fraction of Cd2+-treated cell lysates. Proteomic analysis identified 145 proteins in the Aggresome-enriched fractions. One of the proteins is the highly conserved valosin-containing protein (VCP), which has been shown to colocalize with Aggresomes and bind ubiquitinated proteins through its N domain (#1-200). Our subsequent examination of VCP's role in the formation of Aggresomes induced by Cd2+ indicates that the C-terminal tail (#780-806) of VCP interacts with histone deacetylase HDAC6, a mediator for Aggresome formation, suggesting that VCP participates in transporting ubiquitinated proteins to Aggresomes. This function of VCP is impaired by inhibition of the deacetylase activity of HDAC6 or by over-expression of VCP mutants that do not bind ubiquitinated proteins or HDAC6. Our results indicate that Cd2+ induces the formation of protein inclusion bodies by promoting the accumulation of ubiquitinated proteins in Aggresomes through VCP and HDAC6. Our delineation of the role of VCP in regulating cell responses to ubiquitinated proteins has important implications for understanding Cd2+ toxicity and associated diseases.
Tony N Eissa - One of the best experts on this subject based on the ideXlab platform.
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the physiologic Aggresome mediates cellular inactivation of inos
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Lavannya M Pandit, Katarzyna E Kolodziejska, Shenyan Zeng, Tony N EissaAbstract:Nitric Oxide (NO), produced by inducible nitric oxide synthase (iNOS), has been implicated in the pathogenesis of various biological and inflammatory disorders. Recent evidence suggests that Aggresome formation is a physiologic stress response not limited to misfolded proteins. That stress response, termed “physiologic Aggresome,” is exemplified by Aggresome formation of iNOS, an important host defense protein. The functional significance of cellular formation of the iNOS Aggresome is hitherto unknown. In this study, we used live cell imaging, fluorescence microscopy, and intracellular fluorescence NO probes to map the subcellular location of iNOS and NO under various conditions. We found that NO production colocalized with cytosolic iNOS but Aggresomes containing iNOS were distinctly devoid of NO production. Further, cells expressing iNOS Aggresomes produced significantly less NO as compared with cells not expressing Aggresomes. Importantly, primary normal human bronchial epithelial cells, stimulated by cytokines to express iNOS, progressively sequestered iNOS to the Aggresome, a process that correlated with marked reduction of NO production. These results suggest that bronchial epithelial cells used the physiologic Aggresome mechanism for iNOS inactivation. Our studies reveal a novel cellular strategy to terminate NO production via formation of the iNOS Aggresome.
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a critical role for chip in the Aggresome pathway
Molecular and Cellular Biology, 2009Co-Authors: Youbao Sha, Lavannya M Pandit, Shenyan Zeng, Tony N EissaAbstract:Recent evidence suggests that Aggresome formation is a physiologic stress response not limited to misfolded proteins. That stress response, termed "physiologic Aggresome," is exemplified by Aggresome formation of inducible nitric oxide synthase (iNOS), an important host defense protein. CHIP (carboxy terminus of Hsp70-interacting protein) is a highly conserved protein that has been shown to mediate substrate ubiquitination and degradation by the proteasome. In this study, we show that CHIP has a previously unexpected critical role in the Aggresome pathway. CHIP interacts with iNOS and promotes its ubiquitination and degradation by the proteasome as well as its sequestration to the Aggresome. CHIP-mediated iNOS targeting to the proteasome sequentially precedes CHIP-mediated iNOS sequestration to the Aggresome. CHIP is required for iNOS preAggresome structures to form a mature Aggresome. Furthermore, CHIP is required for targeting the mutant form of cystic fibrosis transconductance regulator (CFTRDeltaF508) to the Aggresome. Importantly, the ubiquitin ligase function of CHIP is required in targeting preaggresomal structures to the Aggresome by promoting an iNOS interaction with histone deacetylase 6, which serves as an adaptor between ubiquitinated proteins and the dynein motor. This study reveals a critical role for CHIP in the Aggresome pathway.
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regulation of inducible nitric oxide synthase by Aggresome formation
Proceedings of the National Academy of Sciences of the United States of America, 2005Co-Authors: Katarzyna E Kolodziejska, Alan R Burns, Robert H Moore, David L Stenoien, Tony N EissaAbstract:Misfolding and aggregation of proteins play an important part in the pathogenesis of several genetic and degenerative diseases. Recent evidence suggests that cells have evolved a pathway that involves sequestration of aggregated proteins into specialized “holding stations” called Aggresomes. Here we show that cells regulate inducible NO synthase (iNOS), an important host defense protein, through Aggresome formation. iNOS Aggresome formation depends on a functional dynein motor and the integrity of the microtubules. The iNOS Aggresome represents a “physiologic Aggresome” and thus defines a new paradigm for cellular regulation of protein processing. This study indicates that Aggresome formation in response to misfolded proteins may merely represent an acceleration of an established physiologic regulatory process for specific proteins whose regulation by Aggresome formation is deemed necessary by the cell.