Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
Clinical Laboratory, Wenzhou Central Hospital, Wenzhou, Zhejiang, China.
Pain. 2019 Mar;160(3):712-723. doi: 10.1097/j.pain.0000000000001450.
Electroacupuncture (EA) is widely used in clinical settings to reduce inflammatory pain. Islet-cell autoantigen 69 (ICA69) has been reported to regulate long-lasting hyperalgesia in mice. ICA69 knockout led to reduced protein interacting with C-kinase 1 (PICK1) expression and increased glutamate receptor subunit 2 (GluR2) phosphorylation at Ser880 in spinal dorsal horn. In this study, we evaluated the role of ICA69 in the antihyperalgesic effects of EA and the underlying mechanism through regulation of GluR2 and PICK1 in spinal dorsal horn. Hyperalgesia was induced in mice with subcutaneous plantar injection of complete Freund adjuvant (CFA) to cause inflammatory pain. Electroacupuncture was then applied for 30 minutes every other day after CFA injection. When compared with CFA group, paw withdrawal frequency of CFA+EA group was significantly decreased. Remarkable increases in Ica1 mRNA expression and ICA69 protein levels on the ipsilateral side were detected in the CFA+EA group. ICA69 expression reached the peak value around day 3. More importantly, ICA69 deletion impaired the antihyperalgesic effects of EA on GluR2-p, but PICK1 deletion could not. Injecting ICA69 peptide into the intrathecal space of ICA69-knockout mice mimicked the effects of EA analgesic and inhibited GluR2-p. Electroacupuncture had no effects on the total protein of PICK1 and GluR2. And, EA could increase the formation of ICA69-PICK1 complexes and decrease the amount of PICK1-GluR2 complexes. Our findings indicate that ICA69 mediates the antihyperalgesic effects of EA on CFA-induced inflammatory pain by regulating spinal GluR2 through PICK1 in mice.
电针(EA)广泛应用于临床,以减轻炎症性疼痛。已经报道胰岛细胞自身抗原 69(ICA69)调节小鼠的长期痛觉过敏。ICA69 敲除导致脊髓背角中蛋白相互作用的 C 激酶 1(PICK1)表达减少和谷氨酸受体亚基 2(GluR2)磷酸化 Ser880 增加。在这项研究中,我们通过调节脊髓背角中的 GluR2 和 PICK1,评估了 ICA69 在 EA 的抗痛觉过敏作用中的作用及其潜在机制。通过足底皮下注射完全弗氏佐剂(CFA)诱导小鼠痛觉过敏,引起炎症性疼痛。然后在 CFA 注射后每隔一天进行 30 分钟的电针治疗。与 CFA 组相比,CFA+EA 组的足底撤回频率明显降低。在 CFA+EA 组中,同侧 Ica1 mRNA 表达和 ICA69 蛋白水平显著增加。ICA69 表达在第 3 天左右达到峰值。更重要的是,ICA69 缺失削弱了 EA 对 GluR2-p 的抗痛觉过敏作用,但 PICK1 缺失不能。将 ICA69 肽注入 ICA69 敲除小鼠的鞘内空间模拟了 EA 镇痛的作用,并抑制了 GluR2-p。电针对 PICK1 和 GluR2 的总蛋白没有影响。此外,EA 可以增加 ICA69-PICK1 复合物的形成,减少 PICK1-GluR2 复合物的数量。我们的研究结果表明,ICA69 通过调节脊髓中的 GluR2 来介导 EA 对 CFA 诱导的炎症性疼痛的抗痛觉过敏作用通过 PICK1 在小鼠中。