Journal of Pharmacology & Experimental Therapeutics, 2016, 357(1).

Genetic and Dietary Regulation of Glyburide Efflux by the Human Placental BCRP Transporter

Kristin M Bircsak, Vivek Gupta, Poi Yu Sofia Yuen, et al

Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy (K.M.B., L.M.A., L.G.), and Environmental and Occupational Health Sciences Institute, Rutgers, The State University of New Jersey (L.M.A.), Piscataway, New Jersey; Departments of Obstetrics and Gynecology (V.G.) and Pediatrics (P.Y.S.Y., A.M.V.), Rutgers University Robert Wood Johnson Medical School, New Brunswick, New Jersey; Hofstra North Shore-LIJ School of Medicine, Cohen Children's Medical Center of New York, New Hyde Park, New York (B.I.W.).

Glyburide is frequently used to treat gestational diabetes owing to its low fetal accumulation resulting from placental efflux by the breast cancer resistance protein (BCRP)/ABCG2 transporter. Here we sought to determine how exposure to the dietary phytoestrogen genistein and expression of a loss-of-function polymorphism in the ABCG2 gene (C421A) impacted the transport of glyburide by BCRP using stably transfected human embryonic kidney 293 (HEK) cells, human placental choriocarcinoma BeWo cells, and human placental explants. Genistein competitively inhibited the BCRP-mediated transport of (3)H-glyburide in both wild-type (WT) and C421A-BCRP HEK-expressing cells, with greater accumulation of (3)H-glyburide in cells expressing the C421A variant. In BeWo cells, exposure to genistein for 60 minutes increased the accumulation of (3)H-glyburide 30%-70% at concentrations relevant to dietary exposure (IC50 ∼180 nM). Continuous exposure of BeWo cells to genistein for 48 hours reduced the expression of BCRP mRNA and protein by up to 40%, which impaired BCRP transport activity. Pharmacologic antagonism of the estrogen receptor attenuated the genistein-mediated downregulation of BCRP expression, suggesting that phytoestrogens may reduce BCRP levels through this hormone receptor pathway in BeWo cells. Interestingly, genistein treatment for 48 hours did not alter BCRP protein expression in explants dissected from healthy term placentas. These data suggest that whereas genistein can act as a competitive inhibitor of BCRP-mediated transport, its ability to downregulate placental BCRP expression may only occur in choriocarcinoma cells. Overall, this research provides important mechanistic data regarding how the environment (dietary genistein) and a frequent genetic variant (ABCG2, C421A) may alter the maternal-fetal disposition of glyburide.

美国《药理学与实验医学杂志》2016, 357(1).

格列苯脲外流的基因和饮食调节通过人类胎盘 BCRP 转运蛋白

药物和毒理学系，Ernest Mario药学院（K.M.B.，L.M.A.，L.G.）和环境和职业健康科学研究所，Rutgers，新泽西州立大学（L.M.A.），Piscataway，新泽西; 妇产科（V.G.）和儿科（P.Y.S.Y.，A.M.V.），罗格斯大学罗伯特伍德约翰逊医学院，新不伦瑞克，新泽西; Hofstra North Shore-LIJ医学院，纽约科恩儿童医疗中心，纽约新海德公园（B.I.W.）。

由于乳腺癌耐药蛋白（BCRP）/ ABCG2转运蛋白由胎盘流出引起的低胎儿蓄积，格列苯脲经常用于治疗妊娠糖尿病。在这里，我们试图确定膳食植物雌激素染料木素的暴露和ABCG2基因（C421A）损失的功能多态性的表达如何影响格列本脲通过BCRP运输使用稳定转染人类胚胎肾293（HEK）细胞，人类胎盘绒毛膜癌BeWo细胞和人胎盘外植体。染料木黄酮在表达C421A变体的细胞中竞争性抑制野生型（WT）和C421A-BCRP HEK表达细胞中（3）H-格列本脲的（3）H-格列本脲的BCRP介导的转运，在BeWo细胞中，与食物暴露相关的浓度（IC 50〜180nM）暴露于染料木黄酮60分钟增加（3）H-格列本脲的累积30％-70％。 BeWo细胞连续暴露于染料木黄酮48小时降低BCRP mRNA和蛋白质的表达高达40％，其损害BCRP转运活性。雌激素受体的药理拮抗作用减弱了染料木素介导的BCRP表达的下调，表明植物雌激素可以通过该激素受体途径在BeWo细胞中降低BCRP水平。有趣的是，染料木黄酮治疗48小时没有改变从健康胎盘中切除的外植体中的BCRP蛋白表达。这些数据表明，尽管染料木素可以作为BCRP介导的运输的竞争性抑制剂，其下调胎盘BCRP表达的能力可能只发生在绒毛膜癌细胞。总体而言，这项研究提供了关于环境（饮食染料木素）和频繁遗传变异（ABCG2，C421A）如何改变格列本脲的母体-胎儿处置的重要数据。