Huacachino Andrea Andress, Chung Anna, Sharp Kim, Penning Trevor M
Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center of Excellence in Environmental Toxicology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
J Steroid Biochem Mol Biol. 2025 Feb;246:106641. doi: 10.1016/j.jsbmb.2024.106641. Epub 2024 Nov 20.
Per- and polyfluoroalkyl substances (PFAS) are ubiquitous environmental pollutants that are highly stable synthetic organofluorine compounds. One congener perfluorooctanoic acid (PFOA) can be detected in nearly all humans and is recognized as an endocrine disrupting chemical (EDC). EDCs disrupt hormone synthesis and metabolism and receptor function. One mechanism of steroid hormone action is the pre-receptor regulation of ligand access to steroid hormone receptors by aldo-keto reductases. Here we report PFOA inhibition of AKR family 1 member C2 (AKR1C2), leading to dysregulation of androgen action. Spectrofluorimetric inhibitor screens identified PFOA as a competitive and tight binding inhibitor of AKR1C2, whose role is to inactivate 5α-dihydrotestosterone (5α-DHT). Further site directed mutagenesis studies along with molecular docking simulations revealed the importance of residue Valine 54 in mediating AKR1C2 inhibitor specificity. Binding site restrictions were explored by testing inhibition of other related PFAS chemicals, confirming that steric hinderance is a key factor. Furthermore, radiochromatography using HPLC and in line radiometric detection confirmed the accumulation of 5α-DHT as a result of PFOA inhibition of AKR1C2. We showed that PFOA could enhance the transactivation of AR in reporter genes assays in which 5α-DHT metabolism was blocked by AKR1C2 inhibition in HeLa cells. Taken together, these data suggest PFOA has a role in disrupting androgen action through inhibiting AKR1C2. Our work identifies an EDC function for PFOA not previously revealed.
全氟和多氟烷基物质(PFAS)是普遍存在的环境污染物,是高度稳定的合成有机氟化合物。其中一种同系物全氟辛酸(PFOA)几乎在所有人的体内都能检测到,并且被认为是一种内分泌干扰化学物质(EDC)。EDC会干扰激素的合成、代谢以及受体功能。类固醇激素作用的一种机制是通过醛糖酮还原酶对配体与类固醇激素受体结合的前受体调节。在此,我们报告PFOA对AKR家族1成员C2(AKR1C2)的抑制作用,导致雄激素作用失调。荧光光谱抑制剂筛选确定PFOA是AKR1C2的竞争性紧密结合抑制剂,其作用是使5α-二氢睾酮(5α-DHT)失活。进一步的定点诱变研究以及分子对接模拟揭示了缬氨酸54残基在介导AKR1C2抑制剂特异性中的重要性。通过测试其他相关PFAS化学品的抑制作用来探索结合位点限制,证实空间位阻是一个关键因素。此外,使用高效液相色谱和在线放射性检测的放射色谱法证实了由于PFOA对AKR1C2的抑制作用导致5α-DHT的积累。我们表明,在HeLa细胞中,通过AKR1C2抑制作用阻断5α-DHT代谢的报告基因检测中,PFOA可以增强雄激素受体(AR)的反式激活。综上所述,这些数据表明PFOA通过抑制AKR1C2在破坏雄激素作用中发挥作用。我们的研究确定了PFOA此前未被揭示的EDC功能。