氧化应激介导的Nrf2/mTOR/NF-κB通路对氯胺酮相关性膀胱炎的影响和机制以及褪黑素的保护作用研究

Ketamine is a new type of drug, known as "Special K". Abuse of ketamine is increasing dramatically in recent years. Long-term ketamine abuse can cause serious lower urinary tract symptoms, leading to ketamine cystitis (KC), but its mechanism is unknown and there is no effective treatment. In our previous study, we found that long-term ketamine abuse can cause oxidative stress-mediated damage in the bladder of rats and increase antioxidant proteins such as Nrf2 and HO-1, leading to increased expression of pro-inflammatory protein COX-2 and apoptosis of bladder epithelial cells. The bladder damage can be reduced after using antioxidant melatonin. Further analysis of the rat genomic transcriptome of the bladder tissue showed that upregulating a variety of antioxidant stress-related metabolic pathways, the mTOR pathway was significantly altered. These results suggest that oxidative stress induced by ketamine is likely to be involved in the regulation of Nrf2 /mTOR / NF-κB pathway, which could induce inflammation of bladder. We intend to study the effects and mechanisms of Nrf2 /mTOR / NF-κB pathway on KC and the therapeutic effects of anti-oxidant drug melatonin on KC from group of people, animal model and cell experiments. Using high-throughput Bio-Plex suspension array technology to screen the therapeutic markers of inflammatory factors of melatonin. It is of great significance to reveal the pathogenesis mechanism of KC; establish well-designed drug treatment targets; develop more accurate and personalized diagnostic and therapeutic treatment of KC.

氯胺酮作为新型毒品“K粉”，滥用人数加速增长。长期滥用氯胺酮可致严重下尿路症状，导致氯胺酮相关性膀胱炎（KC），其机制不明也缺乏有效治疗手段。本课题组前期建立的KC大鼠模型发现氯胺酮可致大鼠膀胱氧化损伤、抗氧化因子Nrf2、HO-1上调而促炎蛋白COX-2表达增加；抗氧化剂褪黑素干预治疗可明显改善膀胱受损。进一步分析大鼠氯胺酮模型膀胱组织全基因转录组发现，多种抗氧化应激代谢通路上调，mTOR通路显著改变，提示氯胺酮介导的氧化应激很可能参与Nrf2/mTOR/NF-κB调控，最终诱导膀胱炎症反应。本课题组拟从人群、动物模型和细胞实验多层面研究氧化应激介导的Nrf2/mTOR/NF-κB通路对KC的影响和机制以及褪黑素的治疗作用，利用高通量Bio-Plex悬浮芯片技术筛选褪黑素诊治疗效标记性炎症因子，对于揭示KC发病机制、设计合理的药物治疗靶点，发掘更精确和个性化的诊断和治疗方法具有重要意义。

本课题组前期通过建立氯胺酮相关性膀胱炎(ketamine cystitis，KC)大鼠模型发现氯胺酮可致大鼠膀胱氧化损伤、抗氧化因子Nrf2、HO-1上调而促炎蛋白COX-2表达增加；抗氧化剂褪黑素干预治疗可明显改善膀胱受损。对大鼠膀胱组织基因组转录组的进一步分析表明，上调多种抗氧化应激相关代谢途径，mTOR途径显著改变。在此，我们通过建立人尿上皮细胞（SV-HUC-1）高浓度氯胺酮的体外模型，探讨了氯胺酮诱导毒性中细胞外囊泡（EV）的变化，发现细胞外囊泡通过p38/NF-κB途径增强氯胺酮诱导的溃疡性膀胱炎中的氧化应激。我们通过建立KC小鼠模型研究了乙醛脱氢酶2 (Aldehyde dehydrogenase 2, Aldh2)对KC小鼠中氧化应激反应的影响,研究表明Aldh2在预防KIC炎症和纤维化方面发挥保护作用。此外，我们通过构建沉默NRF2的SV-HUC-1细胞株，发现褪黑素能够通过NRF2保护氯胺酮导致的尿路上皮损伤。通过建立SV-HUC-1细胞的氯胺酮体外模型，进一步研究抗氧化剂莱菔硫烷干预后炎症因子、氧化指标的变化以及NRF2/mTOR/NF-κB通路相关分子的表达。我们的研究将进一步明确氧化应激通过Nrf2/mTOR/NF-κB通路在KC发生发展中的相关分子机制及褪黑素等抗氧化剂在其中的药物治疗靶点，为今后靶向药物研发提供新的思路及理论基础。