ABSTRACT
Kidney injury and decreased chemosensitivity of tumor cells are obstacles with cisplatin (CDDP) chemotherapy. Down-regulation of the organic cation transporter 2 (OCT2) and multidrug resistance-associated protein 2 (MRP2) is a key means to alleviate CDDP-induced kidney injury and increase chemosensitivity. Astragaloside IV (AS IV) is obtained from the well-known traditional Chinese herb Astragalus membranaceus. This study explored the role of AS IV in preventing kidney injury and enhancing the antitumor effect of CDDP by suppressing OCT2 expression in kidney and MRP2 in tumors. This project was reviewed and approved by the Animal Ethics Committee of the First Hospital of Jilin University. The effects of AS IV on CDDP inhibition of tumor growth and promotion of apoptosis were assessed in Lewis lung tumor (LLC)-bearing mice by H&E and TUNEL staining. Kidney injury was assessed by serum biochemical parameters and H&E staining. We used Western blotting and immunohistochemistry assays to detect OCT2 and MRP2 expression in kidney and tumor. The concentration of CDDP in kidney and tumor was measured by HPLC-MS/MS. AS IV enhanced CDDP chemosensitivity by increasing tumor cell apoptosis and slowing tumor growth, and decreased kidney injury as evidenced by lower blood creatinine (Cr) and blood urea nitrogen (BUN). Co-administration of AS IV suppressed MRP2 overexpression induced by CDDP in tumor tissues and may be an important mechanism for enhancing CDDP chemosensitivity. Moreover, AS IV reduced CDDP-induced kidney injury in mice along with suppression of OCT2 expression in kidney. The concentration of CDDP was increased in tumor but decreased in kidney. In total, AS IV not only enhanced the antitumor effect of CDDP by suppressing MRP2 expression in tumor cells, but also decreased kidney injury induced by CDDP. The results provide new insight into the combined use of a chemotherapy drug and natural ingredients to treat cancer.
ABSTRACT
Objective:To explore the therapeutic mechanism of Canhuang tablets on the mRNA and protein expression of farnesoid X receptor (FXR), uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) and multidrug resistance associated protein 2 (MRP2) in the liver of jaundiced rats induced by α-naphthalene isothiocyanate (ANIT). Method:The rats were divided into normal group, model group, Canhuang tablets (CHP) group and ursodeoxycholic acid tablets (UDCA) group. The jaundice model was reproduced by ANIT. After the intervention of the corresponding drugs, the contents of total bilirubin (TBIL), total bile acid (TBA), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in serum and the liver histopathology were examined to evaluate the therapeutic effect of CHP. The relative mRNA and protein expressions of FXR, UGT1A1 and MRP2 in rat liver tissues were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Result:CHP can significantly reduce the increase of TBIL, TBA, ALT, AST and ALP caused by ANIT in rat serum, and inhibit the liver pathological changes, which showed that the removing jaundice effect of CHP was better than UDCA. Compared with the normal group, ANIT significantly inhibited the mRNA levels of FXR, UGT1A1 and MRP2 in rat liver tissues after modeling (P<0.01). Compared with the model group, CHP and UDCA significantly increased the mRNA levels of target genes of each protein after intervention (P<0.01), and CHP was superior to UDCA in improving the mRNA level of bilirubin metabolizing enzyme UGT1A1 (P<0.01). In the aspect of affecting protein expression, compared with the normal group, ANIT modeling significantly increased the expression of FXR in rats (P<0.05). CHP intervention showed a tendency to promote the expression of FXR, while UDCA did not, but there was no significant difference between them. In the aspects of promoting bilirubin metabolism and bile excretion, the expressions of UGT1A1 and MRP2 were significantly decreased by ANIT modeling (P<0.01), while the expressions of UGT1A1 and MRP2 proteins were significantly increased after treatment of CHP (P<0.01). CHP was superior to UDCA in increasing the expression of bilirubin and bile acid efflux protein MRP2 (P<0.01). Conclusion:The jaundice abating mechanism of CHP is related to activating FXR mRNA expression in liver, promoting the mRNA and protein expression of bilirubin metabolizing enzyme UGT1A1 and bile acid transporter MRP2, improving liver metabolism of free bilirubin and promoting bile acid excretion from the liver, and alleviating cholestatic liver injury.
ABSTRACT
OBJECTIVE:To investigate the effects of Glycyrrhiza uralensis extract (GE) on the expression of uridine diphosphate glucuronyltransferase 1A (UGT1A) and multidrug resistance associated protein 2 (MRP2) in human liver L-02 cells damaged by triptolide (TP),and to study attenuated mechanism of G.uralensison for TP.METHODS:The survival rates of L-02 cells were determined by MTT assay after cultured with 0 (blank control),40,80,160 nmol/L TP for 12,18,24 h.L-02 cells were divided into blank control group (blank culture medium),model control group (80 nmol/L TP) and GE pretreatment group (adding 80 nmol/ L TP after pretreated with 30,60,90 mg/L GE for 24 h);after cultured for 18 h,survival rates of L-02 cells were determined by MTT assay.Rifampin (RIF) group (positive control,adding 80 nmoi/L TP after pretreated with 10 μmol/L RIF for 24 h) was added on the basis of the above grouping (GE concentration of 60 mg/L in GE pretreatment group).After cultured for 24 h,the protein expressions of UGT1A and MRP2 were detected.RESULTS:The inhibition effect of TP on cell proliferation was positively correlated with the concentration and the time.Compared with blank control group,cell survival rate of model control group was decreased significantly (P＜0.05),and the protein expression of MRP2 was decreased significantly (P＜0.01).Compared with model control group,cell survival rates of 30,60,90 mg/L GE pretreatment groups were all increased significantly (P＜0.01).The protein expressions of UGT1A and MRP2 were increased significantly in 60 mg/L GE pretreatment group (P＜0.01).CONCLUSIONS:GE pretreatment can relieve TP-induced human liver L-02 cell damage,and its attenuated mechanism may be associated with the increase the expression of UGT1A and MRP2.
ABSTRACT
Objective To study the effects of different transport protein on the transport of 7,4'-dihydroxyflavone (7,4'-DHF) and its metabolite (7,4'-DHF-S) in Caco-2 cell model.Methods Ultra performance liquid chromatography was employed to determinethe content of 7,4'-DHF and 7,4'-DHF-S incubation buffer,their structures were identified by LC-MS/MS.Bidirectional transport of Caco-2 cells model was used to investigate the influence of ko143 (the inhibitor of BCRP) and MK571 (the inhibitor of MRP2) on the transport of 7,4'-DHF and 7,4'-DHF-S,respectively.Results Metabolic product of 7,4'-DHF in Caco-2 monolayer cell was identified as one monosulfate;PDR of 7,4'-DHF was (1.43 ± 0.11),PDR of ko143 and MK571 on the apparent permeability of 7,4'-DHF was (1.59 ± 0.04) and (1.48 ± 0.07) (P ＞ 0.05);PDR of 7,4'-DHF-S was (1.60 ± 0.06);ko143 could significantly reduce the apparent permeability of 7,4'-DHF-S,and the PDR was (0.23 ±0.03) (P ＜ 0.01);MK571 had no significant effect on the apparent permeability of the 7,4'-DHF-S,and the PDR was (1.51±0.04) (P ＞ 0.05).Conclusion Caco-2 cells can mediate the suffonated reaction of 7,4'-DHF;7,4'-dihydroxyflavone sulfonated combination product may be a substrate for BCRP.
ABSTRACT
Objective To establish double-transfected Madin-Darby canine kidney (MDCK) [Ⅱ cells expressing human organic anion transporting polypeptide 1B1 (hOATP1B1) and multidrug resistanceassociated protein 2 (hMRP2)and to testify their functions,moreover,to study the transcellur transport of indoleamine 2,3-dioxygenase (IDO) inhibitor 1-methyltryptophan (1-MT) in the transfectants.Methods hOATP1B1/hMRP2 eukaryotic vectors pVITRO2-SLCO1B1-ABCC2 was obtained by genetic engineering method and then transfected into MDCK cells.Stably expressed MDCK cells were screened by using the geneticin G418.Real-time PCR,Western blot analysis and immuno fluorescent confocal microscopy were used to verify the proteins expression.Transport of the representative substrate pravastatin in different pH values and substrate concentrations and 1-MT were evaluated using the double transfectants.Results MDCK-OATP1B1/MRP2 was successfully established.Pravastatin displayed the optimal transcellular transport when pH value was 6.5.Transport of pravastatin demonstrated the concentration-dependent in the concertation range of 0) to 500 μmol/L.Transport of 1-MT showed no significant difference in MDCK cells and transfectants.Conclusions MDCK-OATP1B1/MRP2 was successful established;1-MT was not the substrate of OATP1B1 or MRP2 protein;and the eatablished double transfectant cell lines can be used to evaluate OATP1B1/MRP2-medicated transport of xenobiotics (e.g.new drug candidates) and endogenous compounds (e.g.bilirubin).
ABSTRACT
ObjectiveTo detect the expressions of Nuclear factor-erythroid 2 p45-related factor 2 (NRF2) and multidrug resistance-associated protein 2 (MRP2), and investigate their significance in primary gallbladder carcinoma. MethodsImmunohistochemistry SP assay and image analysis were used to detect the expressions of NRF2 and MRP2 protein in 59 patients with primary gallbladder carcinoma. ResultsA highly positive expression rates of NRF2 and MRP2 were found (76.3% and 74. 6%, respectively) in primary gallbladder carcinoma. The expressions of NRF2 and MRP2 had a significantly correlation with metastases, Nevin staging, and differentiation (P＜0.05), but there was no statistical association with sex and age. The expression of NRF2 had a positive correlation with MRP2 (r=0. 589,P＜0.05). Conclusion Both NRF2 and MRP2 were overexpressed in primary gallbladder carcinoma and they may play a role in the development of primary gallbladder carcinoma.