Overexpression of carboxylesterase contributes to the attenuation of cyanotoxin microcystin-LR toxicity.
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±7.7nM) showed approximately 2.1-fold resistance to microcystin-LR than HEK293-OATP1B3 cells (IC50: 12.0±1.5nM). 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.
Division of Food and Chemical Biology, Faculty of Fisheries, Kagoshima University, 890-0056 Kagoshima, Japan; Department of Domestic Science, Kagoshima Women's College, Kagoshima 890-8565, Japan.
Shota
S
Takumi
Division of Food and Chemical Biology, Faculty of Fisheries, Kagoshima University, 890-0056 Kagoshima, Japan.
Tai
T
Shimono
Division of Food and Chemical Biology, Faculty of Fisheries, Kagoshima University, 890-0056 Kagoshima, Japan.
Satoshi
S
Ikema
Division of Food and Chemical Biology, Faculty of Fisheries, Kagoshima University, 890-0056 Kagoshima, Japan.
Yuki
Y
Hotta
Division of Food and Chemical Biology, Faculty of Fisheries, Kagoshima University, 890-0056 Kagoshima, Japan.
Petros K
PK
Chigwechokha
Division of Food and Chemical Biology, Faculty of Fisheries, Kagoshima University, 890-0056 Kagoshima, Japan.
Kazuhiro
K
Shiozaki
Division of Food and Chemical Biology, Faculty of Fisheries, Kagoshima University, 890-0056 Kagoshima, Japan.
Yasumasa
Y
Sugiyama
College of Pharmaceutical Sciences, School of Clinical Pharmacy, Matsuyama University, 790-8578, Ehime, Japan.
Mitsuru
M
Hashimoto
Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, 890-8544 Kagoshima, Japan; Center for the Research of Advanced Diagnosis and Therapy of Cancer, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan.
Tatsuhiko
T
Furukawa
Division of Food and Chemical Biology, Faculty of Fisheries, Kagoshima University, 890-0056 Kagoshima, Japan. Electronic address: komatsu@fish.kagoshima-u.ac.jp.
Masaharu
M
Komatsu
D065567:Absorption, Physiological / Q000187:drug effects; D001427:Bacterial Toxins / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000633:toxicity*; D001665:Binding Sites; D043182:Carboxylesterase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002274:Carcinogens, Environmental / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D002470:Cell Survival / Q000187:drug effects; D004351:Drug Resistance; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D056945:Hep G2 Cells; D006801:Humans; D008658:Inactivation, Metabolic / Q000187:drug effects; D008387:Marine Toxins; D052998:Microcystins / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000633:toxicity*; D009596:Nitrophenols / Q000494:pharmacology; D029362:Organic Anion Transporters, Sodium-Independent / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D000074542:Solute Carrier Organic Anion Transporter Family Member 1B3; D013379:Substrate Specificity
D001427:Bacterial Toxins; D002274:Carcinogens, Environmental; D004791:Enzyme Inhibitors; D008387:Marine Toxins; D052998:Microcystins; D009596:Nitrophenols; D029362:Organic Anion Transporters, Sodium-Independent; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; C421209:SLCO1B3 protein, human; D000074542:Solute Carrier Organic Anion Transporter Family Member 1B3; D049452:Green Fluorescent Proteins; C002887:bis(4-nitrophenyl)phosphate; C517204:CES2 protein, human; D043182:Carboxylesterase; C057862:cyanoginosin LR
Carboxylesterase; Irinotecan; Microcystin-LR; OATP1B3; Overexpression