Mukkavilli Rao, Jadhav Gajanan, Vangala Subrahmanyam
Eurofins Advinus Therapeutics Limited, Bengaluru - 560058, Karnataka, India.
Georgia State University, Atlanta, GA 30303, United States.
Curr Pharm Biotechnol. 2017;18(14):1151-1158. doi: 10.2174/1389201019666180308091855.
Drug transporters function as gatekeepers and modulate drug access into body and various tissues. Thus, a thorough and precise understanding of transporter liability for compound uptake and efflux is critical during drug development.
In the present study, we assessed the apparent permeability (Papp) and compared efflux ratio of various compounds in stably transfected Madin-Darby Canine Kidney (MDCKII) cells overexpressing human P-gp (MDCKII-MDR1), human BCRP (MDCKII-BCRP), wild-type (MDCKII-WT), and Caco-2 cell monolayers.
We observed that quinidine, a substrate for MDR1 transporter, showed efflux ratio (Papp B-A/ Papp A-B) of 838 in MDCKII-MDR1 cells which plummeted to 14 in presence of verapamil, a known inhibitor of MDR1. With MDCKII-WT cells, Papp of quinidine dropped from 2 to 1, in the presence of verapamil. Caco-2 cells showed a diminutive decrease in efflux ratio of quinidine from 2.5 to 1.6 by verapamil. Prazosin and dantrolene were evaluated in MDCKII-BCRP cells and were found to have 80-fold higher efflux ratio compared to MDCKII-WT cells. In Caco-2 cells, prazosin and dantrolene showed efflux ratio of 4 and 2, respectively. Rhodamine-123, a fluorogenic probe substrate of MDR1 showed an efflux ratio of 4 in Caco-2 cells and BCRP substrate estrone-3-sulphate showed an efflux ratio of 7. In presence of BCRP inhibitor fumitremorgin-c, the efflux ratio of estrone-3-sulfate dropped to 1 in Caco-2 cells.
The very high efflux ratios of MDR1 and BCRP substrates in transfected MDCKII cells clearly demonstrate the potential usefulness of these models to provide more definitive data to evaluate the transporter involvement compared to Caco-2 or MDCKII-WT cells.
药物转运体起着守门人的作用，调节药物进入体内和各种组织。因此，在药物研发过程中，全面而准确地了解转运体对化合物摄取和外排的影响至关重要。
在本研究中，我们评估了各种化合物在稳定转染了人P-糖蛋白（MDCKII-MDR1）、人乳腺癌耐药蛋白（MDCKII-BCRP）、野生型（MDCKII-WT）的Madin-Darby犬肾细胞（MDCKII）以及Caco-2细胞单层中的表观渗透率（Papp），并比较了它们的外排率。
我们观察到，MDR1转运体的底物奎尼丁在MDCKII-MDR1细胞中的外排率（Papp B-A / Papp A-B）为838，而在存在已知的MDR1抑制剂维拉帕米时，该外排率骤降至14。在MDCKII-WT细胞中，在维拉帕米存在的情况下，奎尼丁的Papp从2降至1。Caco-2细胞中，维拉帕米使奎尼丁的外排率从2.5降至1.6，降幅较小。哌唑嗪和丹曲林在MDCKII-BCRP细胞中进行了评估，发现它们的外排率比MDCKII-WT细胞高80倍。在Caco-2细胞中，哌唑嗪和丹曲林的外排率分别为4和2。罗丹明-123是MDR1的荧光探针底物，在Caco-2细胞中的外排率为4，BCRP底物雌酮-3-硫酸盐的外排率为7。在存在BCRP抑制剂烟曲霉毒素-c的情况下，Caco-2细胞中雌酮-3-硫酸盐的外排率降至1。
与Caco-2或MDCKII-WT细胞相比，转染的MDCKII细胞中MDR1和BCRP底物的外排率非常高，这清楚地证明了这些模型在提供更明确的数据以评估转运体参与方面的潜在有用性。
