Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5510661 | Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology | 2017 | 33 Pages |
Abstract
Microcystin-LR is a hepatotoxin produced by several cyanobacteria. Its toxicity is mainly due to a inhibition of protein phosphatase, PP1 and PP2A. Previously, we used a cell line stably expressing uptake transporter for microcystin-LR, OATP1B3 (HEK293-OATP1B3 cells). In this study, to determine whether overexpression of carboxylesterase (CES), which degrades ester-group and amide-group, attenuates the cytotoxicity of microcystin-LR, we generated the HEK293-OATP1B3/CES2 double-transfected cells. HEK293-OATP1B3/CES2 cells showed high hydrolysis activity of p-nitrophenyl acetate (PNPA), which is an authentic substrate for esterase. CES activity in HEK293-OATP1B3/CES2 cells was approximately 3-fold higher than that in the HEK293-OATP1B3 cells. HEK293-OATP1B3/CES2 cells (IC50: 25.4 ± 7.7 nM) showed approximately 2.1-fold resistance to microcystin-LR than HEK293-OATP1B3 cells (IC50: 12.0 ± 1.5 nM). Moreover, the CES inhibition assay and microcystin-agarose pull down assay showed the possibility of the interaction between CES2 and microcystin-LR. Our results indicated that the overexpression of CES2 attenuates the cytotoxicity of microcystin-LR via interaction with microcystin-LR.
Keywords
Carboxylesterasesbis-p-nitrophenyl phosphatePNPABNPPOATPOATP1B3PNPPVDF3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromideMTTp-nitrophenylp-Nitrophenyl acetateIrinotecanCESOverexpressionpolyvinylidene difluoridemicrocystin-LRProtein phosphataseOrganic anion transporting polypeptidecarboxylesterase
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Authors
Shota Takumi, Tai Shimono, Satoshi Ikema, Yuki Hotta, Petros K. Chigwechokha, Kazuhiro Shiozaki, Yasumasa Sugiyama, Mitsuru Hashimoto, Tatsuhiko Furukawa, Masaharu Komatsu,