Characterization of LysoTracker Red uptake by in vitro model cells of the outer blood-retinal barrier: Implication of lysosomal trapping with cytoplasmic vacuolation and cytotoxicity.

Autor: Tega Y; Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan., Takeuchi T; Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan., Nagano M; Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan., Makino R; Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan., Kubo Y; Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan., Akanuma SI; Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan. Electronic address: akanumas@pha.u-toyama.ac.jp., Hosoya KI; Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan.
Jazyk: angličtina
Zdroj: Drug metabolism and pharmacokinetics [Drug Metab Pharmacokinet] 2023 Aug; Vol. 51, pp. 100510. Date of Electronic Publication: 2023 Apr 23.
DOI: 10.1016/j.dmpk.2023.100510
Abstrakt: Lysosomal trapping, a physicochemical process in which lipophilic cationic compounds are sequestered in lysosomes, can affect drug disposition and cytotoxicity. To better understand lysosomal trapping at the outer blood-retinal barrier (BRB), we investigated the distribution of LysoTracker Red (LTR), a probe compound for lysosomal trapping, in conditionally immortalized rat retinal pigment epithelial (RPE-J) cells. LTR uptake by RPE-J cells was dependent on temperature and attenuated by ammonium chloride and protonophore, which decreased the pH gradient between the lysosome and cytoplasm, suggesting lysosomal trapping of LTR in RPE-J cells. The involvement of lysosomal trapping in response to cationic drugs, including neuroprotectants such as desipramine and memantine, was also suggested by an inhibition study of LTR uptake. Chloroquine, which is known to show ocular toxicity, induced cytoplasmic vacuolization in RPE-J cells with a half-maximal effective concentration of 1.35 μM. This value was 59 times lower than the median lethal concentration (= 79.1 μM) of chloroquine, suggesting that vacuolization was not a direct trigger of cell death. These results are helpful for understanding the lysosomal trapping of cationic drugs, which is associated with drug disposition and cytotoxicity in the outer BRB.
Competing Interests: Declaration of competing interest The authors declare no competing interests.
(Copyright © 2023 The Japanese Society for the Study of Xenobiotics. All rights reserved.)
Databáze: MEDLINE
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