Vaquer Sergi, Cuyàs Elisabet, Rabadán Arnau, González Albert, Fenollosa Felip, de la Torre Rafael
Departament de Farmacologia Humana, Institut Municipal d'Investigació Mèdica de Barcelona (IMIM), Barcelona, 08003, Spain ; Corporació Sanitària i Universitària Parc Taulí, Sabadell, 08208, Spain.
Departament de Farmacologia Humana, Institut Municipal d'Investigació Mèdica de Barcelona (IMIM), Barcelona, 08003, Spain.
F1000Res. 2014 Aug 21;3:201. doi: 10.12688/f1000research.4909.1. eCollection 2014.
Microgravity has been shown to influence the expression of ABC (ATP-Binding Cassette) transporters in bacteria, fungi and mammals, but also to modify the activity of certain cellular components with structural and functional similarities to ABC transporters. Changes in activity of ABC transporters could lead to important metabolic disorders and undesired pharmacological effects during spaceflights. However, no current means exist to study the functionality of these transporters in microgravity. To this end, a Vesicular Transport Assay (®) (Solvo Biotechnology, Hungary) was adapted to evaluate multi-drug resistance-associated protein 2 (MRP2) trans-membrane estradiol-17-β-glucuronide (E17βG) transport activity, when activated by adenosine-tri-phosphate (ATP) during parabolic flights. Simple diffusion, ATP-independent transport and benzbromarone inhibition were also evaluated. A high accuracy engineering system was designed to perform, monitor and synchronize all procedures. Samples were analysed using a validated high sensitivity drug detection protocol. Experiments were performed in microgravity during parabolic flights, and compared to 1g on ground results using identical equipment and procedures in all cases. Our results revealed that sufficient equipment accuracy and analytical sensitivity were reached to detect transport activity in both gravitational conditions. Additionally, transport activity levels of on ground samples were within commercial transport standards, proving the validity of the methods and equipment used. MRP2 net transport activity was significantly reduced in microgravity, so was signal detected in simple diffusion samples. Ultra-structural changes induced by gravitational stress upon vesicle membranes or transporters could explain the current results, although alternative explanations are possible. Further research is needed to provide a conclusive answer in this regard. Nevertheless, the present validated technology opens new and interesting research lines in biology and human physiology with the potential for significant benefits for both space and terrestrial medicine.
微重力已被证明会影响细菌、真菌和哺乳动物中ABC（ATP结合盒）转运蛋白的表达，还会改变某些与ABC转运蛋白在结构和功能上具有相似性的细胞成分的活性。ABC转运蛋白活性的变化可能导致太空飞行期间出现重要的代谢紊乱和不良药理作用。然而，目前尚无研究这些转运蛋白在微重力条件下功能的方法。为此，对一种囊泡运输分析方法（®）（匈牙利索尔沃生物技术公司）进行了改进，以评估多药耐药相关蛋白2（MRP2）跨膜转运雌二醇-17-β-葡萄糖醛酸苷（E17βG）的活性，该活性在抛物线飞行期间由三磷酸腺苷（ATP）激活。还评估了简单扩散、不依赖ATP的转运和苯溴马隆抑制作用。设计了一种高精度工程系统来执行、监测和同步所有程序。使用经过验证的高灵敏度药物检测方案对样品进行分析。实验在抛物线飞行期间的微重力条件下进行，并在所有情况下使用相同的设备和程序与地面1g结果进行比较。我们的结果表明，在两种重力条件下均达到了足够的设备精度和分析灵敏度来检测转运活性。此外，地面样品的转运活性水平在商业运输标准范围内，证明了所使用方法和设备的有效性。微重力下MRP2的净转运活性显著降低，简单扩散样品中检测到的信号也是如此。重力应力对囊泡膜或转运蛋白引起的超微结构变化可以解释当前的结果，尽管也可能有其他解释。在这方面需要进一步研究以提供确凿的答案。尽管如此，目前经过验证的技术为生物学和人类生理学开辟了新的有趣研究方向，有可能为太空医学和地面医学带来重大益处。
