State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China.
Signal Transduct Target Ther. 2023 Mar 10;8(1):101. doi: 10.1038/s41392-023-01312-y.
Tutin, an established toxic natural product that causes epilepsy in rodents, is often used as a tool to develop animal model of acute epileptic seizures. However, the molecular target and toxic mechanism of tutin were unclear. In this study, for the first time, we conducted experiments to clarify the targets in tutin-induced epilepsy using thermal proteome profiling. Our studies showed that calcineurin (CN) was a target of tutin, and that tutin activated CN, leading to seizures. Binding site studies further established that tutin bound within the active site of CN catalytic subunit. CN inhibitor and calcineurin A (CNA) knockdown experiments in vivo proved that tutin induced epilepsy by activating CN, and produced obvious nerve damage. Together, these findings revealed that tutin caused epileptic seizures by activating CN. Moreover, further mechanism studies found that N-methyl-D-aspartate (NMDA) receptors, gamma-aminobutyric acid (GABA) receptors and voltage- and Ca- activated K (BK) channels might be involved in related signaling pathways. Our study fully explains the convulsive mechanism of tutin, which provides new ideas for epilepsy treatment and drug development.
金松双黄酮是一种已被确定的致痫性天然产物，常被用作诱导急性癫痫发作动物模型的工具。然而，金松双黄酮的分子靶标和毒性机制尚不清楚。在这项研究中，我们首次利用热蛋白质组谱分析实验来阐明金松双黄酮诱导癫痫的靶标。研究表明钙调磷酸酶（CN）是金松双黄酮的靶标，金松双黄酮可激活 CN 而引发癫痫。结合结合部位研究进一步确定金松双黄酮结合在 CN 催化亚基的活性部位。体内的钙调磷酸酶抑制剂和钙调磷酸酶 A（CNA）敲低实验证明，金松双黄酮通过激活 CN 引起癫痫，并产生明显的神经损伤。总之，这些发现表明金松双黄酮通过激活 CN 引起癫痫发作。此外，进一步的机制研究发现，N-甲基-D-天冬氨酸（NMDA）受体、γ-氨基丁酸（GABA）受体和电压和 Ca 激活的 K（BK）通道可能参与相关信号通路。我们的研究充分解释了金松双黄酮的致痫机制，为癫痫的治疗和药物开发提供了新的思路。
