Background
Nucleoside reverse transcriptase inhibitors (NRTIs) are the earliest and most commonly used anti-human immunodeficiency virus drugs and play an important role in high active antiretroviral therapy. However, NRTI drug therapy can cause peripheral neuropathic pain. In this study, we aimed to investigate the mechanisms of rapamycin on the pain sensitization of model mice by in vivo experiments to explore the effect of mammalian target of rapamycin (mTOR) in the pathogenesis of neuropathic pain caused by NRTIs.
Conclusions
Taken together, these results suggest that stavudine elevates the expression and activity of mTORC1 in the spinal cord through activating the Akt/mTOR signaling pathway. The data also provide evidence that rapamycin might be useful for the treatment of peripheral neuropathic pain. PI3K-Akt-mTOR信号通路有助于缓解核苷逆转录酶抑制剂治疗HIV感染所并发的神经性疼痛摘要背景：核酸逆转录酶抑制剂（Nucleoside reverse transcriptase inhibitors, NRTIs）是临床应用最早且数量最多的抗人类免疫缺陷病毒（human immunodeficiency virus, HIV）药物，在高效抗病毒逆转录治疗（Highly active anti-retrov iral therapy, HAART）中至今仍发挥着重要的作用。但是，NRTIs类药物治疗可引起周围神经病理性疼痛。本研究将通过动物实验观察雷帕霉素干预后对造模小鼠痛敏的影响来探索哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin, mTOR）mTOR在NRTIs类药物所致神经病理性痛发生中所起的作用。 方法：体重20-22g的雄性昆明（Kun Ming, KM）小鼠分为正常组，雷帕霉素（2mg/kg）组，司他夫定组（12mg/kg）和CMC-Na组，各组连续灌胃给药42天。在给药后7、14、21、28、35、42天利用热痛敏仪和von Frey纤维检测热痛敏和机械性痛敏。行为学实验结束24h后，利用免疫组织化学和免疫印迹实验检测mTOR和其他生物标志物。使用多元方差分析进行数据统计。 结果：雷帕霉素对神经性疼痛的有益作用归因于减少小鼠脊髓中哺乳动物雷帕霉素靶蛋白敏感复合物（mammalian target of rapamycin-sensitive complex, mTORC1）阳性细胞的数目（70.80 ± 2.41 vs. 112.30 ± 5.66, F = 34.36, P < 0.01）和降低mTORC1的活性。机制研究表明雷帕霉素通过抑制mTORC1的磷酸化（0.72 ± 0.04 vs. 0.86 ± 0.03, F = 4.24, P = 0.045），同时减少磷酸化p70S6K（0.47 ± 0.01 vs. 0.68 ± 0.03, F = 6.01, P = 0.022）和磷酸化4EBP1（0.90 ± 0.04 vs. 0.94 ± 0.06, F = 0.28, P = 0.646）的表达进而抑制 Akt/mTOR信号通路的激活。 结论：研究结果表明，司他夫定通过激活Akt/mTOR信号通路提高了脊髓中mTORC1的表达和活性，该数据还提供了雷帕霉素可能用于治疗神经性疼痛的证据。.
Methods
Male Kun Ming (KM) mice weighing 20-22 g were divided into control, 2 mg/kg rapamycin, 12 mg/kg stavudine, and CMC-Na groups. Drugs were orally administered to mice for 42 consecutive days. The von Frey filament detection and thermal pain tests were conducted on day 7, 14, 21, 28, 35, and 42 after drug administration. After the last behavioral tests, immunohistochemistry and western blotting assay were used for the measurement of mTOR and other biomarkers. Multivariate analysis of variance was used.
Results
The beneficial effects of rapamycin on neuropathic pain were attributed to a reduction in mammalian target of rapamycin sensitive complex 1 (mTORC1)-positive cells (70.80 ± 2.41 vs. 112.30 ± 5.66, F = 34.36, P < 0.01) and mTORC1 activity in the mouse spinal cord. Mechanistic studies revealed that Protein Kinase B (Akt)/mTOR signaling pathway blockade with rapamycin prevented the phosphorylation of mTORC1 in stavudine-intoxicated mice (0.72 ± 0.04 vs. 0.86 ± 0.03, F = 4.24, P = 0.045), as well as decreased the expression of phospho-p70S6K (0.47 ± 0.01 vs. 0.68 ± 0.03, F = 6.01, P = 0.022) and phospho-4EBP1 (0.90 ± 0.04 vs. 0.94 ± 0.06, F = 0.28, P = 0.646). Conclusions: Taken together, these results suggest that stavudine elevates the expression and activity of mTORC1 in the spinal cord through activating the Akt/mTOR signaling pathway. The data also provide evidence that rapamycin might be useful for the treatment of peripheral neuropathic pain. PI3K-Akt-mTOR信号通路有助于缓解核苷逆转录酶抑制剂治疗HIV感染所并发的神经性疼痛摘要背景：核酸逆转录酶抑制剂（Nucleoside reverse transcriptase inhibitors, NRTIs）是临床应用最早且数量最多的抗人类免疫缺陷病毒（human immunodeficiency virus, HIV）药物，在高效抗病毒逆转录治疗（Highly active anti-retrov iral therapy, HAART）中至今仍发挥着重要的作用。但是，NRTIs类药物治疗可引起周围神经病理性疼痛。本研究将通过动物实验观察雷帕霉素干预后对造模小鼠痛敏的影响来探索哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin, mTOR）mTOR在NRTIs类药物所致神经病理性痛发生中所起的作用。 方法：体重20-22g的雄性昆明（Kun Ming, KM）小鼠分为正常组，雷帕霉素（2mg/kg）组，司他夫定组（12mg/kg）和CMC-Na组，各组连续灌胃给药42天。在给药后7、14、21、28、35、42天利用热痛敏仪和von Frey纤维检测热痛敏和机械性痛敏。行为学实验结束24h后，利用免疫组织化学和免疫印迹实验检测mTOR和其他生物标志物。使用多元方差分析进行数据统计。 结果：雷帕霉素对神经性疼痛的有益作用归因于减少小鼠脊髓中哺乳动物雷帕霉素靶蛋白敏感复合物（mammalian target of rapamycin-sensitive complex, mTORC1）阳性细胞的数目（70.80 ± 2.41 vs. 112.30 ± 5.66, F = 34.36, P < 0.01）和降低mTORC1的活性。机制研究表明雷帕霉素通过抑制mTORC1的磷酸化（0.72 ± 0.04 vs. 0.86 ± 0.03, F = 4.24, P = 0.045），同时减少磷酸化p70S6K（0.47 ± 0.01 vs. 0.68 ± 0.03, F = 6.01, P = 0.022）和磷酸化4EBP1（0.90 ± 0.04 vs. 0.94 ± 0.06, F = 0.28, P = 0.646）的表达进而抑制 Akt/mTOR信号通路的激活。 结论：研究结果表明，司他夫定通过激活Akt/mTOR信号通路提高了脊髓中mTORC1的表达和活性，该数据还提供了雷帕霉素可能用于治疗神经性疼痛的证据。.