Lysosomal Sequestration of Amine-Containing Drugs: Analysis and Therapeutic Implications

Kaufmann, Allyn M.; Krise, Jeffrey P.

doi:10.1002/jps.20792

Cited by 256 publications

(206 citation statements)

References 67 publications

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“…Although basic amines are thought to bias compounds for accumulation in acidic cellular compartments such as lysosomes (46), our data suggest that these molecules do not reduce cell viability, disrupt lysosomal protease function, or perturb accumulation of LysoTracker Red, making them distinct from known lysosomotropic molecules. It is certainly possible that the compounds accumulate at higher concentrations within acidic compartments and exert a specific function on a lysosomal protein or signal to regulate autophagy.…”

Section: Discussionmentioning

confidence: 69%

Small-molecule enhancers of autophagy modulate cellular disease phenotypes suggested by human genetics

Kuo

Castoreno

Aldrich

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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Studies of human genetics and pathophysiology have implicated the regulation of autophagy in inflammation, neurodegeneration, infection, and autoimmunity. These findings have motivated the use of small-molecule probes to study how modulation of autophagy affects disease-associated phenotypes. Here, we describe the discovery of the small-molecule probe BRD5631 that is derived from diversity-oriented synthesis and enhances autophagy through an mTOR-independent pathway. We demonstrate that BRD5631 affects several cellular disease phenotypes previously linked to autophagy, including protein aggregation, cell survival, bacterial replication, and inflammatory cytokine production. BRD5631 can serve as a valuable tool for studying the role of autophagy in the context of cellular homeostasis and disease.high-throughput screening | autophagy | small-molecule probes | Crohn's disease

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Section: Discussionmentioning

confidence: 69%

Small-molecule enhancers of autophagy modulate cellular disease phenotypes suggested by human genetics

Kuo

Castoreno

Aldrich

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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“…Sequestration of imatinib in acidic lysosomes requires the passage over both the plasma and lysosomal membrane. It has been suggested that drug transfer directly from the cytosol into the luminal space of lysosomes may proceed via three different pathways: passive diffusion, autophagocytosis, and/ or transporter-mediated accumulation (Kaufmann and Krise, 2007). Since passive diffusion has the highest accumulation capacity and is most efficient, we and others (Fu et al, 2014) speculate that the uptake into lysosomes likely proceeds by simple diffusion, although other mechanisms cannot be excluded.…”

Section: Discussionmentioning

confidence: 78%

Lysosomal Sequestration Determines Intracellular Imatinib Levels

et al. 2015

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The intracellular uptake and retention (IUR) of imatinib is reported to be controlled by the influx transporter SLC22A1 (organic cation transporter 1). We recently hypothesized that alternative uptake and/or retention mechanisms exist that determine intracellular imatinib levels. Here, we systematically investigate the nature of these mechanisms. Imatinib uptake in cells was quantitatively determined by liquid chromatography-tandem mass spectrometry. Fluorescent microscopy was used to establish subcellular localization of imatinib. Immunoblotting, cell cycle analyses, and apoptosis assays were performed to evaluate functional consequences of imatinib sequestration. Uptake experiments revealed high intracellular imatinib concentrations in HEK293, the leukemic cell lines K562 and SD-1, and a gastrointestinal stromal tumor cell line GIST-T1. We demonstrated that imatinib IUR is time-, dose-, temperature-, and energy-dependent and provide evidence that SLC22A1 and other potential imatinib transporters do not substantially contribute to the IUR of imatinib. Prazosin, amantadine, NH 4 Cl, and the vacuolar ATPase inhibitor bafilomycin A1 significantly decreased the IUR of imatinib and likely interfere with lysosomal retention and accumulation of imatinib. Costaining experiments with LysoTracker Red confirmed lysosomal sequestration of imatinib. Inhibition of the lysosomal sequestration had no effect on the inhibition of c-Kit signaling and imatinib-mediated cell cycle arrest but significantly increased apoptosis in imatinib-sensitive GIST-T1 cells. We conclude that intracellular imatinib levels are primarily determined by lysosomal sequestration and do not depend on SLC22A1 expression.

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“…Many cationic drugs are concentrated in acidic cell compartments due to low retro-diffusion of the protonated molecule (ion trapping; reviewed by De Duve et al, 1974;Kaufmann and Krise, 2007;Marceau et al, 2012). In examined cultured cells, the driving force of this pseudo-transport is provided by vacuolar (V)-ATPase, a proton pump expressed in the trans-Golgi and derived organelles (endosomes, lysosomes, secretory granules).…”

Section: Introductionmentioning

confidence: 99%

High affinity capture and concentration of quinacrine in polymorphonuclear neutrophils via vacuolar ATPase-mediated ion trapping: Comparison with other peripheral blood leukocytes and implications for the distribution of cationic drugs

Roy

Gagné

Fernandes

et al. 2013

Toxicology and Applied Pharmacology

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Many cationic drugs are concentrated in acidic cell compartments due to low retro-diffusion of the protonated molecule (ion trapping), with an ensuing vacuolar and autophagic cytopathology.In solid tissues, there is evidence that phagocytic cells, e.g., histiocytes, preferentially concentrate cationic drugs. We hypothesized that peripheral blood leukocytes could differentially take up a fluorescent model cation, quinacrine, depending on their phagocytic competence. Quinacrine transport parameters were determined in purified or total leukocyte suspensions at 37°C. Purified polymorphonuclear leukocytes (PMNLs, essentially neutrophils) exhibited a quinacrine uptake velocity inferior to that of lymphocytes, but a consistently higher affinity (apparent K M 1.1 vs. 6.3 µM, respectively). However, the vacuolar (V)-ATPase inhibitor bafilomycin A1 prevented quinacrine transport or initiated its release in either cell type. PMNLs capture most of the quinacrine added at low concentrations to fresh peripheral blood leukocytes compared with lymphocytes and monocytes (cytofluorometry). Accumulation of the autophagy marker LC3-II occurred rapidly and at low drug concentrations in quinacrine-treated PMNLs (significant at 2.5 µM, 2 h). Lymphocytes contained more LAMP1 than PMNLs, suggesting that the mass of lysosomes and late endosomes is a determinant of quinacrine uptake V max . PMNLs, however, exhibited the highest capacity for pinocytosis (uptake of fluorescent dextran into endosomes).The selectivity of quinacrine distribution in peripheral blood leukocytes may be determined by the collaboration of a non-concentrating plasma membrane transport mechanism, tentatively identified as pinocytosis in PMNLs, with V-ATPase-mediated concentration. Intracellular reservoirs of cationic drugs are a potential source of toxicity (e.g., loss of lysosomal function in phagocytes).

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Lysosomal Sequestration of Amine-Containing Drugs: Analysis and Therapeutic Implications

Cited by 256 publications

References 67 publications

Small-molecule enhancers of autophagy modulate cellular disease phenotypes suggested by human genetics

Small-molecule enhancers of autophagy modulate cellular disease phenotypes suggested by human genetics

Lysosomal Sequestration Determines Intracellular Imatinib Levels

High affinity capture and concentration of quinacrine in polymorphonuclear neutrophils via vacuolar ATPase-mediated ion trapping: Comparison with other peripheral blood leukocytes and implications for the distribution of cationic drugs

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