Zhou Lingwei, Pei Miao, Qi Tian, Liu Yu, Li Xiaoyue, Li Xuan, Chen Qinghe, Jin Feihong, Yang Shaozhong, Qi Feng
Department of Anesthesiology and Pain Clinic, Qilu Hospital, Cheeloo College of Medicine, Shandong University, No. 107, Wenhuaxi Road, Jinan, 250012, Shandong, China.
Department of Anesthesiology, Clinical Medical College & Affiliated Hospital of Chengdu University, No. 82, Hehuachi Street, Jinniu District, Chengdu, 610000, Sichuan , China.
Sci Rep. 2025 Aug 8;15(1):29050. doi: 10.1038/s41598-025-12552-z.
Myofascial pain syndrome (MPS) is a common chronic pain condition characterized primarily by the presence of myofascial trigger points (MTrPs). While the insulin-like growth factor-1 receptor (IGF-1R) is known to be upregulated in injured muscles and implicated in orofacial neuropathic pain, its role in the peripheral mechanisms underlying MTrPs remains poorly understood. In this study, we aimed to investigate the expression of IGF-1R in MTrPs and explore the molecular mechanisms by which IGF-1R activation induces pain-like behavior in a rat model of MTrPs. We used Sprague-Dawley rats to assess IGF-1R signaling, measuring pain-like behaviors with the Randall-Selitto test. Muscle tissue morphology was examined using hematoxylin and eosin (HE) staining, while IGF-1R-related proteins were quantified through immunohistochemistry (IHC) and Western blot (WB) analysis. Our results showed that IGF-1R expression is significantly elevated in the muscle tissue of rats with MTrPs, with this upregulation correlating positively with the hyperalgesia. Furthermore, activation of IGF-1R was found to induce pain-like behavior via the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway. Notably, inhibition of PI3K/AKT reversed the pain-like behaviors triggered by IGF-1R activation. These findings suggest that the increased expression of IGF-1R and subsequent activation of the PI3K/AKT/mTOR pathway may contribute to heightened nociception in MTrPs, offering new insights into the molecular mechanisms underlying MPS and potential targets for therapeutic intervention.
肌筋膜疼痛综合征(MPS)是一种常见的慢性疼痛病症,主要特征为存在肌筋膜触发点(MTrP)。虽然已知胰岛素样生长因子1受体(IGF-1R)在受伤肌肉中上调,并与口面部神经性疼痛有关,但其在MTrP潜在外周机制中的作用仍知之甚少。在本研究中,我们旨在研究IGF-1R在MTrP中的表达,并探索IGF-1R激活在MTrP大鼠模型中诱导疼痛样行为的分子机制。我们使用Sprague-Dawley大鼠评估IGF-1R信号传导,通过Randall-Selitto试验测量疼痛样行为。使用苏木精和伊红(HE)染色检查肌肉组织形态,同时通过免疫组织化学(IHC)和蛋白质印迹(WB)分析对IGF-1R相关蛋白进行定量。我们的结果表明,IGF-1R在患有MTrP的大鼠肌肉组织中的表达显著升高,这种上调与痛觉过敏呈正相关。此外,发现IGF-1R的激活通过磷脂酰肌醇3激酶/蛋白激酶B/雷帕霉素哺乳动物靶标(PI3K/AKT/mTOR)途径诱导疼痛样行为。值得注意的是,抑制PI3K/AKT可逆转由IGF-1R激活触发的疼痛样行为。这些发现表明,IGF-1R表达增加以及随后PI3K/AKT/mTOR途径的激活可能导致MTrP中伤害感受增强,为MPS的潜在分子机制和治疗干预靶点提供了新的见解。