Qiao Leyan, Tang Qian, An Zhongzhe, Qi Jun
Department of Anesthesiology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, 264000, China.
Department of Anesthesiology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, 264000, China.
J Pharmacol Sci. 2023 Sep;153(1):12-21. doi: 10.1016/j.jphs.2023.06.002. Epub 2023 Jun 21.
In this study, we studied whether minocycline hydrochloride improved neuropathic pain induced by spinal cord injury (SCI) in rats through PI3K/Akt pathway.
The SCI was induced by compressed at level of T9-T11 of spinal cord in Sprague Dawley male rats. Animals were given different concentrations of minocycline (3 mg/kg, 30 mg/kg, 90 mg/kg) at the first and 24 h after SCI, then subsequently every 7, 12, 16, 20, 25 days via peroral route. The locomotor function was assessed by Basso Mouse Scale (BMS). The changes of spinal cord tissues were observed by HE. The inflammatory cytokines in spinal cord, IL-6, IL-1β and TNF-α, were measured by ELISA. The LC3B levels of spinal cord were observed by immunofluorescence. The autophagy related proteins and PI3K/AKT pathway related proteins were analysed by Western blot. Furthermore, the PI3K/AKT pathway inhibitor LY294002, and activator IGF-1 were used to confirm the mechanism of minocycline.
Contrasted to sham group, the inflammatory response in spinal cord was enhanced after SCI. Compared with the SCI rats, minocycline treatment significantly improved the locomotor activity, pathological injury of spinal cord, suppressed the levels of inflammatory factors. In addition, minocycline treatment upregulated autophagy response in damaged spinal cord through increasing LC3B, Beclin-1 and decreasing P62. The results of mechanism study showed that minocycline treatment clearly suppressed phosphorylation of PI3K, Akt and mTOR proteins expression.
Minocycline could improve neuropathic pain induced by SCI through activating autophagy and inhibiting PI3K/AKT/mTOR pathway.
在本研究中，我们探究了盐酸米诺环素是否通过PI3K/Akt通路改善大鼠脊髓损伤（SCI）诱导的神经性疼痛。
通过对雄性Sprague Dawley大鼠T9-T11节段脊髓进行压迫诱导脊髓损伤。在脊髓损伤后的第1小时和24小时，给予动物不同浓度的米诺环素（3mg/kg、30mg/kg、90mg/kg），随后每隔7、12、16、20、25天经口给药。通过Basso小鼠评分（BMS）评估运动功能。通过苏木精-伊红（HE）染色观察脊髓组织的变化。采用酶联免疫吸附测定（ELISA）法检测脊髓中白细胞介素-6（IL-6）、白细胞介素-1β（IL-1β）和肿瘤坏死因子-α（TNF-α）等炎性细胞因子。通过免疫荧光观察脊髓中微管相关蛋白1轻链3β（LC3B）水平。采用蛋白质免疫印迹法分析自噬相关蛋白和PI3K/AKT通路相关蛋白。此外，使用PI3K/AKT通路抑制剂LY294002和激活剂胰岛素样生长因子-1（IGF-1）来证实米诺环素的作用机制。
与假手术组相比，脊髓损伤后脊髓中的炎症反应增强。与脊髓损伤大鼠相比，米诺环素治疗显著改善了运动活性、脊髓病理损伤，抑制了炎性因子水平。此外，米诺环素治疗通过增加LC3B、Beclin-1并降低P62上调了受损脊髓中的自噬反应。机制研究结果表明，米诺环素治疗明显抑制了PI3K、Akt和哺乳动物雷帕霉素靶蛋白（mTOR）蛋白表达的磷酸化。
米诺环素可通过激活自噬和抑制PI3K/AKT/mTOR通路改善脊髓损伤诱导的神经性疼痛。
