Han Jie, Hua Zhen, Yang Wen-Jie, Wang Shu, Yan Fang, Wang Jun-Nan, Sun Tao
Department of Pain Management, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.
College of Sports Medicines and Rehabilitation, Shandong First Medical University and Shandong Academy of Medical Sciences, Tai'an, China.
Front Mol Neurosci. 2023 Feb 16;16:1116679. doi: 10.3389/fnmol.2023.1116679. eCollection 2023.
Neuropathic pain (NP) is one of intractable complications of spinal cord injury (SCI) and lacks effective treatment. Resveratrol (Res) has been shown to possess potent anti-inflammatory and anti-nociceptive effects. In this study, we investigated the analgesic effect of Res and its underlying mechanism in a rat model of SCI.
The rat thoracic (T10) spinal cord contusion injury model was established, and mechanical thresholds were evaluated during an observation period of 21 days. Intrathecal administration with Res (300 μg/10 μl) was performed once a day for 7 days after the operation. On postoperative day 7, the expressions of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were determined by enzyme-linked immunosorbent assay (ELISA) and Real-time quantitative PCR (RT-qPCR), the expression of Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway was determined by western blot and RT-qPCR, and the co-labeled phospho-STAT3 (p-STAT3) with neuronal nuclear antigen (NeuN), glial fibrillary acidic protein (GFAP), and ionized calcium-binding adapter molecule 1 (Iba-1) were explored by double immunofluorescence staining in the lumbar spinal dorsal horns. The temporal changes of p-STAT3 were investigated by western blot on the 1st, 3rd, 7th, 14th, and 21st days after the operation.
Intrathecal administration with Res for 7 successive days alleviated mechanical allodynia of rats during the observation period. Meanwhile, treatment with Res suppressed the production of pro-inflammatory factors TNF-α, IL-1β and IL-6, and inhibited the expressions of phospho-JAK2 and p-STAT3 in the lumbar spinal dorsal horns on postoperative day 7. Additionally, the protein expression of p-STAT3 was significantly increased on the 1st day following the operation and remained elevated during the next 21 days, immunofluorescence suggested that the up-regulated p-STAT3 was co-located with glial cells and neurons.
Our current results indicated that intrathecal administration with Res effectively alleviated mechanical allodynia after SCI in rats, and its analgesic mechanism might be to suppress neuroinflammation by partly inhibiting JAK2/STAT3 signaling pathway.
神经性疼痛（NP）是脊髓损伤（SCI）难以处理的并发症之一，且缺乏有效的治疗方法。白藜芦醇（Res）已被证明具有强大的抗炎和抗伤害感受作用。在本研究中，我们在大鼠SCI模型中研究了Res的镇痛作用及其潜在机制。
建立大鼠胸段（T10）脊髓挫伤损伤模型，并在21天的观察期内评估机械阈值。术后连续7天每天进行一次鞘内注射Res（300μg/10μl）。术后第7天，通过酶联免疫吸附测定（ELISA）和实时定量聚合酶链反应（RT-qPCR）测定肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）和白细胞介素-6（IL-6）的表达，通过蛋白质印迹法和RT-qPCR测定Janus激酶2/信号转导子和转录激活子3（JAK2/STAT3）信号通路的表达，并通过在腰段脊髓背角进行双重免疫荧光染色探索磷酸化STAT3（p-STAT3）与神经元核抗原（NeuN）、胶质纤维酸性蛋白（GFAP）和离子钙结合衔接分子1（Iba-1）的共定位。通过蛋白质印迹法在术后第1、3、7、14和21天研究p-STAT3的时间变化。
连续7天鞘内注射Res可减轻大鼠在观察期内的机械性异常性疼痛。同时，Res治疗抑制了促炎因子TNF-α、IL-1β和IL-6的产生，并在术后第7天抑制了腰段脊髓背角中磷酸化JAK2和p-STAT3的表达。此外，p-STAT3的蛋白表达在术后第1天显著增加，并在接下来的21天内保持升高，免疫荧光显示上调的p-STAT3与胶质细胞和神经元共定位。
我们目前的结果表明，鞘内注射Res可有效减轻大鼠SCI后的机械性异常性疼痛，其镇痛机制可能是通过部分抑制JAK2/STAT3信号通路来抑制神经炎症。
