Organic cation transporter 1 (OCT1) is involved in pentamidine transport at the human and mouse blood-brain barrier (BBB).
Organic cation transporter 1 (OCT1) is involved in pentamidine transport at the human and mouse blood-brain barrier (BBB).
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DOI：
10.1371/journal.pone.0173474
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Thomas SA
中科院分区：
文献类型：
--
作者：
Sekhar GN;Georgian AR;Sanderson L;Vizcay-Barrena G;Brown RC;Muresan P;Fleck RA;Thomas SA
喷他脒是一种有效的杀锥虫药物，用于治疗1期非洲人锥虫病（HAT）。在血脑屏障（BBB），它积聚在内皮细胞内，但进入大脑的机会有限。本研究分别使用hCMEC/D3和bEnd.3细胞系检查了人和小鼠BBB中涉及喷他脒转运的转运蛋白。结果显示，两种细胞系均表达有机阳离子转运蛋白（OCT 1、OCT 2和OCT 3），而P-gp仅在hCMEC/D3细胞中表达。还观察到OCT 1的极化表达。功能测定发现，ATP消耗显著增加了hCMEC/D3细胞中的[3 H]喷他脒积累（*p<0.001），但在bEnd.3细胞中没有。用未标记的喷他脒孵育120分钟后显著降低了hCMEC/D3和bEnd.3细胞中的积累（*p<0.001）。用氟哌啶醇和金刚烷胺处理两种细胞系也显著降低[3 H]喷他脒积累（分别为 *p<0.001和 **p<0.01）。然而，哌唑嗪处理仅在hCMEC/D3细胞中减少[3 H]喷他脒积累（*p<0.05），而不是bEnd.3细胞。此外，OCTN、MATE、PMAT、ENT或CNT抑制剂/底物的存在对两种细胞系中[3 H]喷他脒的蓄积无显著影响。从这些数据中，我们得出结论，喷他脒与多种转运蛋白相互作用，通过OCT 1转运蛋白进入脑内皮细胞，并通过ATP依赖性机制被挤出到血液中。这些相互作用沿着在BBB的腔膜中主要存在OCT 1，导致喷他脒有限地进入脑中。该信息对于基于喷他脒的联合疗法的开发具有关键重要性，所述联合疗法可用于通过改善喷他脒的CNS递送、针对锥虫的功效和安全性特征来治疗CNS期HAT。
Pentamidine is an effective trypanocidal drug used against stage 1 Human African Trypanosomiasis (HAT). At the blood-brain barrier (BBB), it accumulates inside the endothelial cells but has limited entry into the brain. This study examined transporters involved in pentamidine transport at the human and mouse BBB using hCMEC/D3 and bEnd.3 cell lines, respectively. Results revealed that both cell lines expressed the organic cation transporters (OCT1, OCT2 and OCT3), however, P-gp was only expressed in hCMEC/D3 cells. Polarised expression of OCT1 was also observed. Functional assays found that ATP depletion significantly increased [3H]pentamidine accumulation in hCMEC/D3 cells (***p<0.001) but not in bEnd.3 cells. Incubation with unlabelled pentamidine significantly decreased accumulation in hCMEC/D3 and bEnd.3 cells after 120 minutes (***p<0.001). Treating both cell lines with haloperidol and amantadine also decreased [3H]pentamidine accumulation significantly (***p<0.001 and **p<0.01 respectively). However, prazosin treatment decreased [3H]pentamidine accumulation only in hCMEC/D3 cells (*p<0.05), and not bEnd.3 cells. Furthermore, the presence of OCTN, MATE, PMAT, ENT or CNT inhibitors/substrates had no significant effect on the accumulation of [3H]pentamidine in both cell lines. From the data, we conclude that pentamidine interacts with multiple transporters, is taken into brain endothelial cells by OCT1 transporter and is extruded into the blood by ATP-dependent mechanisms. These interactions along with the predominant presence of OCT1 in the luminal membrane of the BBB contribute to the limited entry of pentamidine into the brain. This information is of key importance to the development of pentamidine based combination therapies which could be used to treat CNS stage HAT by improving CNS delivery, efficacy against trypanosomes and safety profile of pentamidine.