Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic.
Faculty of Science, Charles University, Prague, Czech Republic.
J Neurochem. 2019 Jul;150(1):28-43. doi: 10.1111/jnc.14718. Epub 2019 Jun 18.
P2X receptors (P2XRs) are ATP-gated cationic channels that are allosterically modulated by numerous compounds, including steroids and neurosteroids. These compounds may both inhibit and potentiate the activity of P2XRs, but sex steroids such as 17β-estradiol or progesterone are reported to be inactive. Here, we tested a hypothesis that testosterone, another sex hormone, modulates activity of P2XRs. We examined actions of native testosterone and a series of testosterone derivatives on the gating of recombinant P2X2R, P2X4R and P2X7R and native channels expressed in pituitary cells and hypothalamic neurons. The 17β-ester derivatives of testosterone rapidly and positively modulate the 1 µM ATP-evoked currents in P2X2R- and P2X4R-expressing cells, but not agonist-evoked currents in P2X7R-expressing cells. In general, most of the tested testosterone derivatives are more potent modulators than endogenous testosterone. The comparison of chemical structures and whole-cell recordings revealed that their interactions with P2XRs depend on the lipophilicity and length of the alkyl chain at position C-17. Pre-treatment with testosterone butyrate or valerate increases the sensitivity of P2X2R and P2X4R to ATP by several fold, reduces the rate of P2X4R desensitization, accelerates resensitization, and enhances ethidium uptake by P2X4R. Native channels are also potentiated by testosterone derivatives, while endogenously expressed GABA receptors type A are inhibited. The effect of ivermectin, a P2X4R-specific allosteric modulator, on deactivation is antagonized by testosterone derivatives in a concentration-dependent manner. Together, our results provide evidence for potentiation of particular subtypes of P2XRs by testosterone derivatives and suggest a potential role of ivermectin binding site for steroid-induced modulation. OPEN SCIENCE BADGES: This article has received a badge for Open Materials because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
P2X 受体（P2XRs）是 ATP 门控阳离子通道，受许多化合物的变构调节，包括甾体和神经甾体。这些化合物既可以抑制也可以增强 P2XR 的活性，但据报道，性激素如 17β-雌二醇或孕酮没有活性。在这里，我们检验了一个假设，即另一种性激素睾酮会调节 P2XR 的活性。我们检测了天然睾酮和一系列睾酮衍生物对重组 P2X2R、P2X4R 和 P2X7R 以及在垂体细胞和下丘脑神经元中表达的天然通道门控的作用。睾酮的 17β-酯衍生物可快速且正向调节 P2X2R 和 P2X4R 表达细胞中 1 µM ATP 诱发电流，但不调节 P2X7R 表达细胞中激动剂诱发电流。一般来说，大多数测试的睾酮衍生物比内源性睾酮具有更强的调制作用。化学结构比较和全细胞记录表明，它们与 P2XR 的相互作用取决于 C-17 位上的亲脂性和烷基链的长度。丁酸盐或戊酸盐预处理可使 P2X2R 和 P2X4R 对 ATP 的敏感性增加数倍，降低 P2X4R 脱敏的速度，加速再敏化，并增强 P2X4R 对 ethidium 的摄取。天然通道也被睾酮衍生物增强，而内源性表达的 GABA 受体 A 则受到抑制。P2X4R 特异性变构调节剂伊维菌素对失活的作用被睾酮衍生物以浓度依赖的方式拮抗。总的来说，我们的结果提供了睾酮衍生物增强特定 P2XR 亚型的证据，并表明伊维菌素结合位点在类固醇诱导的调制中可能发挥作用。
