Janneh Omar, Jones Elizabeth, Chandler Becky, Owen Andrew, Khoo Saye H
School of Biomedical Sciences, University of Ulster, Cromore Road, Coleraine, Co., Londonderry BT52 1SA, UK.
J Antimicrob Chemother. 2007 Nov;60(5):987-93. doi: 10.1093/jac/dkm353. Epub 2007 Sep 21.
HIV protease inhibitors (HPIs) are an important component of highly active antiretroviral therapy. However, the activity of drug efflux transporters, such as P-glycoprotein (P-gp) and multidrug resistance-associated proteins (MRP1/MRP2), may limit intracellular drug accumulation. Drugs that inhibit the activity of drug efflux proteins may, in combination with HPIs, enhance the clinical efficacy of the drugs.
The transport of [(14)C]lopinavir was evaluated in peripheral blood mononuclear cells (PBMCs) in the absence or presence of known inhibitors: tariquidar (P-gp), MK571 (MRP), frusemide (MRP1/2), dipyridamole (MRP1/P-gp) and probenecid (MRP2/OATP). The effects of ritonavir, amprenavir and atazanavir on the accumulation of lopinavir were also evaluated in cultured CD4(+) T-lymphoblastoid cells [CEM (parental), CEM(VBL) (P-gp-overexpressing) and CEM(E1000) (MRP1-overexpressing)] and PBMCs. The relative expression of the drug efflux proteins on the PBMCs was assessed by flow cytometric and real-time PCR methods.
Tariquidar, MK571, frusemide and dipyridamole all significantly increased the intracellular accumulation of lopinavir in the PBMCs, whereas probenecid decreased it. The cellular accumulation ratio (CAR) of lopinavir was also increased by ritonavir, amprenavir and atazanavir in a concentration-dependent manner in both cell types. The expression of P-gp, MRP1 and MRP2 mRNA were variable and individually did not correlate with CARs of lopinavir.
We provide evidence that lopinavir is a substrate of P-gp, MRP1 and MRP2. The intracellular concentration of lopinavir is increased when co-incubated with ritonavir, amprenavir and atazanavir in PBMCs. Manipulation of drug efflux transporters may be a useful strategy for increasing the intracellular concentration and thereby enhancing the clinical efficacy of lopinavir.
HIV蛋白酶抑制剂（HPIs）是高效抗逆转录病毒疗法的重要组成部分。然而，药物外排转运体如P-糖蛋白（P-gp）和多药耐药相关蛋白（MRP1/MRP2）的活性可能会限制细胞内药物蓄积。抑制药物外排蛋白活性的药物与HPIs联合使用时，可能会提高药物的临床疗效。
在存在或不存在已知抑制剂（ tariquidar（P-gp抑制剂）、MK571（MRP抑制剂）、速尿（MRP1/2抑制剂）、双嘧达莫（MRP1/P-gp抑制剂）和丙磺舒（MRP2/OATP抑制剂））的情况下，评估外周血单个核细胞（PBMCs）中[(14)C]洛匹那韦的转运情况。还在培养的CD4(+)T淋巴母细胞[CEM（亲本细胞）、CEM(VBL)（P-gp过表达细胞）和CEM(E1000)（MRP1过表达细胞）]和PBMCs中评估利托那韦、安普那韦和阿扎那韦对洛匹那韦蓄积的影响。通过流式细胞术和实时PCR方法评估PBMCs上药物外排蛋白的相对表达。
Tariquidar、MK571、速尿和双嘧达莫均显著增加了PBMCs中洛匹那韦的细胞内蓄积，而丙磺舒则降低了其蓄积。在两种细胞类型中，利托那韦、安普那韦和阿扎那韦也以浓度依赖的方式增加了洛匹那韦的细胞蓄积率（CAR）。P-gp、MRP1和MRP2 mRNA的表达各不相同，且单独与洛匹那韦的CARs无相关性。
我们提供证据表明洛匹那韦是P-gp、MRP1和MRP2的底物。在PBMCs中与利托那韦、安普那韦和阿扎那韦共同孵育时，洛匹那韦的细胞内浓度会增加。操纵药物外排转运体可能是提高细胞内浓度从而增强洛匹那韦临床疗效的有用策略。
