Characterization of chloroquine-induced autophagic vacuoles isolated from rat liver

Gray, Robert H.; Sokol, Marcia; Brabec, Roberta Kay; Brabec, Michael J.

doi:10.1016/0014-4800(81)90037-x

Cited by 26 publications

(13 citation statements)

References 32 publications

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“…Cotreatment of rapamycin- and DTT-treated Huh7/mRFP-GFP-LC3 cells with CQ led to the restoration of yellow-colored autophagic vesicles and accumulation of LC3B-II expression, as opposed to rapamycin- and DTT-treated dual reporter cells without CQ administration ( Figure 10, A and B, respectively). Similarly, administration of rapamycin- and DTT-treated cells with CQ showed an even higher percentage of autophagic cells harboring large, partial, or even nondegraded AVd ( un AVd), which contained a majority of undigested organelles, as opposed to the large population of cells containing only AVi and AVd structures in rapamycin and DTT treatment ( Figure 10C), in agreement with a previous study showing that CQ impairs the digestion of autolysosome content (66). Meanwhile, CQ hindered rapamycin- and DTT-mediated repression of HCV PAMP RNA-mediated IFN-β activation ( Figure 11, A and B).…”

Section: Deficiency In Upr/autophagy-related Genes Disrupts Chemical supporting

confidence: 92%

“…Since HCV-induced complete autolysosome formation was critical for HCV RNA replication ( Figure 2B) as well as viral protein expression (Supplemental Figure 2, D and E), we then examined whether the complete autolysosome formation is analogously necessary for the repression of antiviral innate immunity by UPRautophagy. CQ was shown to block the maturation of autolysosomes and lead to accumulated autophagic vacuoles in cells (49,66). Cotreatment of rapamycin- and DTT-treated Huh7/mRFP-GFP-LC3 cells with CQ led to the restoration of yellow-colored autophagic vesicles and accumulation of LC3B-II expression, as opposed to rapamycin- and DTT-treated dual reporter cells without CQ administration ( Figure 10, A and B, respectively).…”

Section: Deficiency In Upr/autophagy-related Genes Disrupts Chemical mentioning

confidence: 97%

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Activation of the unfolded protein response and autophagy after hepatitis C virus infection suppresses innate antiviral immunity in vitro

Chen²

2011

J. Clin. Invest.

299

420

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Autophagy, a process for catabolizing cytoplasmic components, has been implicated in the modulation of interactions between RNA viruses and their host. However, the mechanism underlying the functional role of autophagy in the viral life cycle still remains unclear. Hepatitis C virus (HCV) is a single-stranded, positivesense, membrane-enveloped RNA virus that can cause chronic liver disease. Here we report that HCV induces the unfolded protein response (UPR), which in turn activates the autophagic pathway to promote HCV RNA replication in human hepatoma cells. Further analysis revealed that the entire autophagic process through to complete autolysosome maturation was required to promote HCV RNA replication and that it did so by suppressing innate antiviral immunity. Gene silencing or activation of the UPR-autophagy pathway activated or repressed, respectively, IFN-β activation mediated by an HCV-derived pathogen-associated molecular pattern (PAMP). Similar results were achieved with a PAMP derived from Dengue virus (DEV), indicating that HCV and DEV may both exploit the UPR-autophagy pathway to escape the innate immune response. Taken together, these results not only define the physiological significance of HCV-induced autophagy, but also shed light on the knowledge of host cellular responses upon HCV infection as well as on exploration of therapeutic targets for controlling HCV infection.

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Section: Deficiency In Upr/autophagy-related Genes Disrupts Chemical supporting

confidence: 92%

Section: Deficiency In Upr/autophagy-related Genes Disrupts Chemical mentioning

confidence: 97%

Activation of the unfolded protein response and autophagy after hepatitis C virus infection suppresses innate antiviral immunity in vitro

Chen²

2011

J. Clin. Invest.

299

420

View full text Add to dashboard Cite

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“…We also examined whether autophagy is involved in the biogenesis of methylarginine using chloroquine. Chloroquine is thought to inhibit protein degradation by a dual mechanism: the neutralizing of lysosomes as it is a weak base (23), and the accumulation of larger autophagic vesicles (24). Since HEK293T cells were less sensitive to the inhibition of autophagy than A549 cells (data not shown), this study confirmed that the incubation of A549 cells with chloroquine significantly augmented the accumulation of LC3-II (Fig.…”

supporting

confidence: 70%

Production of free methylarginines via the proteasome and autophagy pathways in cultured cells

Fukamizu

2011

Mol Med Report

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“…4 Even a 2 h administration of chloroquine in rat livers increased the number of autophagic vacuoles 500 times over that of control animals. 5 The basis of this tremendous upregulation of autophagosome numbers was that maturation of autophagosomes and subsequent fusion with lysosomes was blocked by choloroquine whereas their induction, even without any stimulus, continued.…”

Section: Introductionmentioning

confidence: 99%

Characteristics and requirements of basal autophagy in HEK 293 cells

et al. 2013

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Basal autophagy-here defined as macroautophagic activity during cellular growth in normal medium containing amino acids and serum-appears to be highly active in many cell types and in animal tissues. here we characterized this pathway in mammalian heK 293 cells. First, we examined, side by side, three compounds that are widely used to reveal basal autophagy by blocking maturation of autophagosomes: bafilomycin a 1 (Bafa1), chloroquine and vinblastine. Only Bafa1 appeared to be without complicating side effects. chloroquine partially inhibited mechanistic target of rapamycin (MTOR) activity, which would induce autophagy induction as well as block autophagosome maturation. Vinblastine caused the distribution of early omegasome components into punctate phagophore assembly sites, and therefore it would also induce autophagy, complicating interpretation. Basal autophagy was significantly sensitive to inhibition by wortmannin, and therefore required formation of phosphatidylinositol 3-phosphate (Ptdins3P), but it was twice as resistant to wortmannin as starvation-induced autophagy. We also determined that basal autophagy was significantly suppressed by MTOR activation brought about by overexpression of RheB or activated RaGs. Finally we investigated the spatial relationship of nascent autophagosomes to the endoplasmic reticulum (eR) or to mitochondria by live imaging experiments under conditions that reveal basal autophagy (with Bafa1 treatment), or upon MTOR inactivation (which would result in autophagy induction). side-by-side comparison showed that under both basal and induced autophagy, 100% of autophagosomes first appeared in close proximity to eR strands. in parallel measurements, 40% were in close proximity to mitochondria under both conditions. We concluded that in heK 293 cells, basal autophagy is mechanistically similar to that induced by MTOR inactivation in all aspects examined.

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Characterization of chloroquine-induced autophagic vacuoles isolated from rat liver

Cited by 26 publications

References 32 publications

Activation of the unfolded protein response and autophagy after hepatitis C virus infection suppresses innate antiviral immunity in vitro

Activation of the unfolded protein response and autophagy after hepatitis C virus infection suppresses innate antiviral immunity in vitro

Production of free methylarginines via the proteasome and autophagy pathways in cultured cells

Characteristics and requirements of basal autophagy in HEK 293 cells

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