Vaginal Expression of Efflux Transporters and the Potential Impact on the Disposition of Microbicides in Vitro and in Rabbits
Vaginal Expression of Efflux Transporters and the Potential Impact on the Disposition of Microbicides in Vitro and in Rabbits
复制标题
DOI：
10.1021/mp5005004
复制
发表时间：
2014-12-01
影响因子：
4.9
通讯作者：
Brouwers, Joachim
中科院分区：
文献类型：
--
作者：
Grammen, Carolien;Baes, Myriam;Brouwers, Joachim
为了达到足够高的组织浓度并因此有效，阴道应用的抗艾滋病毒微生物剂必须渗透到宫颈阴道粘膜层，这些杀菌剂在免疫细胞水平上是活跃的。细胞外排转运体，如Pgp、BCRP和MRP-2，已被证明对药物在体内不同部位的分布有很大影响，包括肠道和血脑屏障；然而，它们对女性生殖道药物摄取的可能作用尚未阐明。在本研究中，通过Western印迹分析，证实了Pgp、BCRP和MRP-2在绝经前妇女宫颈和阴道组织中的表达。为了能够在体外评估转运蛋白的作用，对合适的宫颈阴道细胞系进行了鉴定。在宫颈SIHA细胞株中观察到这3种转运蛋白的mRNA表达，但仅发现MRP-2活性。因此，建立的Caco-2细胞系被用作替代细胞，在该细胞系中研究了10种候选杀菌剂与外排转运蛋白的相互作用。达鲁那韦、沙奎那韦和马拉韦罗被鉴定为PGP和MRP-2底物。以PGP模型底物他林洛尔为模型，进一步考察了PGP对体内药物处置的影响。当在中性而不是在酸性凝胶中配制时，PGP介导的外排显着减少其经阴道的摄取。我们的发现表明，Pgp转运蛋白在阴道黏膜中的表达可能会严重减少阴道对Pgp底物的摄取，包括某些候选杀菌剂，特别是在阴道pH值升高的女性。
In order to reach sufficiently high tissue concentrations and thus be effective, vaginally applied anti-HIV microbicides that are active at the level of the immune cells must permeate across the cervicovaginal mucosal layer. Cellular efflux transporters, such as Pgp, BCRP, and MRP-2, have been demonstrated to greatly affect drug disposition at different sites in the body including the intestine and the bloodbrain barrier; their possible role on drug uptake from the female genital tract, however, has not been elucidated yet. In the present study, the protein expression of Pgp, BCRP, and MRP-2 in endocervical and vaginal tissue of premenopausal women was confirmed by Western blot analysis. To enable the assessment of transporter effects in vitro, the identification of an appropriate cervicovaginal cell line was pursued. The cervical SiHa cell line was observed to express mRNA of the 3 studied transporters, but only MRP-2 was found to be active. Consequently, the established Caco-2 cell line was utilized as an alternative in which the interaction of 10 microbicide candidates with the efflux transporters was studied. Darunavir, saquinavir, and maraviroc were identified as Pgp and MRP-2 substrates. The impact of Pgp on in vivo drug disposition was further examined for the model Pgp substrate talinolol in rabbits. Its vaginal uptake was significantly reduced by Pgp-mediated efflux when formulated in a neutral but not in an acidic gel. Our findings indicate the expression of a functional Pgp transporter in the vaginal mucosa that may severely reduce the vaginal uptake of Pgp substrates, including certain microbicide candidates, especially in women with an increased vaginal pH.