基于GSK-3β调控Nrf2通路的雷公藤甲素肾毒性机制研究

雷公藤甲素(TP)药理作用广泛且明确，然而严重的毒副反应限制了其临床应用，其中肾毒性发生率高且后果严重。目前TP肾毒性的作用机制尚未完全明确。我们已经证明了在TP引起的肾小管上皮细胞损伤初期，ROS应激性激活Nrf2通路对抗氧化应激，然而随着给药时间延长，Nrf2通路被抑制。那么TP是如何抑制Nrf2通路的？研究表明GSK-3β在Nrf2通路的调控中发挥着重要作用。我们的预试验发现在肾小管上皮细胞中，TP能够激活GSK-3β；GSK-3β抑制剂使TP作用下的Nrf2通路抑制程度减弱，细胞存活增加。这提示TP可能通过激活GSK-3β、抑制Nrf2通路导致肾毒性。本项目拟从细胞及动物水平，采用siRNA、免疫共沉淀、激光共聚焦等方法，明确GSK-3β对Nrf2通路的调控在TP肾毒性中作用，以进一步阐明TP肾毒性机制，为其临床应用的减毒寻找新靶点，提供科学依据。

Triptolide(TP) has been shown to possess multiple biological activities. However, severe adverse effects, especially nephrotoxicity, limit its clinical use. The mechanism of TP-induced nephrotoxicity has not been fully elucidated. Our previous studies demonstrated that activation of Nrf2 played a protective role against TP-induced cytotoxicity in rat kidney cells through the counteraction of oxidative stress. However, prolonged treatment with TP led to Nrf2 inhibiton. We wonder the underlied mechanism against TP-induced Nrf2 inhibition. Recently, GSK-3β has been revealed to play a crucial role in controlling Nrf2 activity. Our preliminary results showed that TP increased the activity of GSK-3β in human proximal tubular epithelial cells; GSK-3β inhibitor could alleviate TP-induced Nrf2 inhibition and cytotoxicity. These results suggest that TP may induce nephrotoxicity through activating GSK-3β and inhibiting Nrf2 pathway. In the present study, techniques such as siRNA, co-IP and immunofluorescence will be employed to explore the role of GSK-3β in TP-induced Nrf2 regulation and to allow further insight into the mechanism of TP-induced renal injury. The current study will also provide direct implications for the development of novel therapeutic strategies against TP-induced nephrotoxicity.