Hayden Elizabeth R, Xu Vivian, Krotz Lisa, Hockler Jessica J, Kaczynski Benjamin D, Sprowl Jason A
Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, New York.
Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, New York.
Drug Metab Dispos. 2025 May;53(5):100073. doi: 10.1016/j.dmd.2025.100073. Epub 2025 Mar 27.
The organic anion transporting polypeptide 1B1 (OATP1B1) is a major pharmacologically relevant hepatic uptake transporter that mediates the clearance of many drugs. The OATP1B1 substrate coproporphyrin I (CPI) has been continually shown to be a reliable and specific clinical biomarker of transport activity. These investigations, and others that have characterized OATP1B activity and transport kinetics, have largely relied on expensive, time-consuming, and nonfluorescent methods to detect CPI, such as liquid chromatography-tandem mass spectrometry. In consideration of porphyrin fluorescent properties, we hypothesized that CPI fluorescence can serve as a marker of OATP1B1 transport activity. Cellular accumulation of CPI specifically due to OATP1B1 was measured via fluorescence in the presence or absence of various Food and Drug Administration-approved tyrosine kinase inhibitors (TKIs). Our findings indicate that CPI fluorescence is an appropriate marker of OATP1B1 in vitro activity in overexpressing HEK293 cells. It was also observed that nilotinib, a TKI previously reported as an OATP1B1 inhibitor, could reduce 50% of CPI uptake at a concentration of 1.0 ± 0.5 μM. Using CPI and 8-(2-[Fluoresceinyl]aminoethylthio) adenosine- 3', 5'- cyclic monophosphate, 15 other TKIs were identified as potential OATP1B1 inhibitors, including tivozanib, which was observed to inhibit 50% of OATP1B1 activity at 4.0 ± 2.0 μM. Overall, our findings provide evidence to show that CPI fluorescence can be used as a method to assess OATP1B1-mediated transport in vitro and investigate the potential for drug-drug interactions. SIGNIFICANCE STATEMENT: This paper outlines a methodology for assessing coproporphyrin I accumulation in vitro specific to organic anion transporting polypeptide 1B1 (OATP1B1)-mediated transport. Coproporphyrin I is a reported sensitive clinical biomarker of OATP1B1 activity, and its fluorescent properties serve to provide a substrate with translational relevance in measuring drug-drug interactions in vitro with a low cost and time requirement. This method confirms nilotinib as an effective OATP1B1 inhibitor and identifies new inhibitors that can potentially promote life-threatening drug interactions using a clinically relevant biomarker.
有机阴离子转运多肽1B1（OATP1B1）是一种主要的与药理学相关的肝脏摄取转运蛋白，可介导多种药物的清除。OATP1B1底物粪卟啉I（CPI）一直被证明是转运活性可靠且特异的临床生物标志物。这些研究以及其他对OATP1B活性和转运动力学进行表征的研究，在很大程度上依赖于昂贵、耗时且无荧光的方法来检测CPI，如液相色谱 - 串联质谱法。考虑到卟啉的荧光特性，我们推测CPI荧光可作为OATP1B1转运活性的标志物。在存在或不存在各种美国食品药品监督管理局批准的酪氨酸激酶抑制剂（TKIs）的情况下，通过荧光测量由于OATP1B1导致的CPI的细胞蓄积。我们的研究结果表明，在过表达的HEK293细胞中，CPI荧光是OATP1B1体外活性的合适标志物。还观察到，尼洛替尼是一种先前报道的OATP1B1抑制剂，在浓度为1.0±0.5μM时可降低50%的CPI摄取。使用CPI和8 - （2 - [荧光素基]氨基乙硫基）腺苷 - 3'，5' - 环一磷酸，另外15种TKIs被鉴定为潜在的OATP1B1抑制剂，包括替沃扎尼，观察到其在4.0±2.0μM时抑制50%的OATP1B1活性。总体而言，我们的研究结果提供了证据表明，CPI荧光可作为一种方法用于体外评估OATP1B1介导的转运并研究药物 - 药物相互作用的可能性。意义声明：本文概述了一种评估体外粪卟啉I蓄积的方法，该蓄积特定于有机阴离子转运多肽1B1（OATP1B1）介导的转运。粪卟啉I是一种已报道的OATP1B1活性敏感临床生物标志物，其荧光特性有助于提供一种在体外测量药物 - 药物相互作用时具有转化相关性的底物，且成本低、耗时少。该方法证实尼洛替尼是一种有效的OATP1B1抑制剂，并使用临床相关生物标志物鉴定出可能促进危及生命的药物相互作用的新抑制剂。
