Cheng Yan Ho, Jenardhanan Pranitha, Mathur Premendu P, Qian Xiaojing, Xia Weiliang, Silvestrini Bruno, Cheng Chuen Yan
The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York 10065, USA.
Curr Mol Pharmacol. 2014;7(2):147-53. doi: 10.2174/1874467208666150126154049.
Breast cancer resistant protein (BCRP, ABCG2) is an ATP-binding cassette (ABC) transporter, which together with two other ABC efflux drug pumps, namely P-glycoprotein (P-gp, ABCB1) and multidrug resistance-related protein 1 (MRP1, ABCC1) is the most important multidrug resistance protein foun d in eukaryotic cells including cells in the testis. However, unlike P-gp and MRP1, which are components of the Sertoli cell blood-testis barrier (BTB), BCRP is not expressed at the BTB in rodents and human testes. Instead, BCRP is expressed by peritubular myoid cells and endothelial cells of the lymphatic vessel in the tunica propria, residing outside the BTB. As such, the testis is equipped with two levels of defense against xenobiotics or drugs, preventing these harmful substances from entering the adluminal compartment to perturb meiosis and post-meiotic spermatid development: one at the level of the BTB conferred by P-gp and MRP1 and one at the tunica propria conferred by BCRP. The presence of drug transporters at the tunica propria as well as at the Sertoli cell BTB thus poses significant obstacles in developing non-hormonal contraceptives if these drugs (e.g., adjudin) exert their effects in germ cells behind the BTB, such as in the adluminal (apical) compartment of the seminiferous epithelium. Herein, we summarize recent findings pertinent to adjudin, a non-hormonal male contraceptive, and molecular interactions of adjudin with BCRP so that this information can be helpful to devise delivery strategies to evade BCRP in the tunica propria to improve its bioavailability in the testis.
乳腺癌耐药蛋白(BCRP,ABCG2)是一种ATP结合盒(ABC)转运蛋白,它与另外两种ABC外排药物泵,即P-糖蛋白(P-gp,ABCB1)和多药耐药相关蛋白1(MRP1,ABCC1)一起,是在包括睾丸细胞在内的真核细胞中发现的最重要的多药耐药蛋白。然而,与作为血睾屏障(BTB)组成部分的P-gp和MRP1不同,BCRP在啮齿动物和人类睾丸的BTB处不表达。相反,BCRP由固有层中淋巴管的周细胞样细胞和内皮细胞表达,位于BTB之外。因此,睾丸配备了两级对外源生物或药物的防御机制,防止这些有害物质进入管腔隔室干扰减数分裂和减数分裂后精子细胞的发育:一级是由P-gp和MRP1在BTB水平提供的,另一级是由BCRP在固有层提供的。如果这些药物(如阿地津)在BTB后面的生殖细胞(如曲细精管上皮的管腔(顶端)隔室)中发挥作用,那么固有层以及支持细胞BTB处存在的药物转运蛋白就会在开发非激素避孕药时构成重大障碍。在此,我们总结了与非激素男性避孕药阿地津相关的最新研究结果,以及阿地津与BCRP的分子相互作用,以便这些信息有助于设计递送策略,避开固有层中的BCRP,提高其在睾丸中的生物利用度。