Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Neuropharmacology. 2022 Oct 1;217:109206. doi: 10.1016/j.neuropharm.2022.109206. Epub 2022 Aug 1.
Neuroinflammation plays a vital role in the development of neuropathic pain and is mediated mainly by microglia. Suppressing microglial M1-polarization attenuates neuropathic pain. Recently, the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway has emerged as a key mediator of inflammation and shows potential in modulating microglial polarization. In this study, we evaluated whether cGAS-STING is a potential therapeutic target. Spared nerve injury (SNI) surgery was conducted in adult male rats to establish a neuropathic pain model. We showed that SNI promoted microglial M1-polarization and induced cGAS-STING pathway activation in the spinal cord. Double-label immunofluorescence assays showed that cGAS-STING activation mainly occurred in neurons and microglia but not astrocytes. We further conducted in vitro experiments using BV-2 microglial cells. The results showed that LPS-induced microglial M1-polarization was accompanied by cGAS-STING pathway activation, but cGAS-STING inhibition by antagonists suppressed LPS-induced microglial M1-polarization. In vivo, we also showed that a cGAS antagonist and a STING antagonist suppressed the microglial M1-polarization and ameliorated the mechanical allodynia induced by SNI. These findings suggested that the cGAS-STING pathway might be a potential therapeutic target for treating neuropathic pain. However, further research is warranted to verify our findings in female rodents.
神经炎症在神经病理性疼痛的发展中起着至关重要的作用,主要由小胶质细胞介导。抑制小胶质细胞 M1 极化可减轻神经病理性疼痛。最近,环鸟苷酸-腺苷酸合酶(cGAS)-干扰素基因刺激物(STING)途径已成为炎症的关键介质,并显示出在调节小胶质细胞极化方面的潜力。在本研究中,我们评估了 cGAS-STING 是否是一个有潜力的治疗靶点。在成年雄性大鼠中进行了 spared nerve injury(SNI)手术,以建立神经病理性疼痛模型。我们发现 SNI 促进小胶质细胞 M1 极化,并诱导脊髓中 cGAS-STING 途径的激活。双标免疫荧光检测显示 cGAS-STING 的激活主要发生在神经元和小胶质细胞中,而不是星形胶质细胞中。我们进一步使用 BV-2 小胶质细胞进行了体外实验。结果表明,LPS 诱导的小胶质细胞 M1 极化伴随着 cGAS-STING 途径的激活,但是通过拮抗剂抑制 cGAS-STING 可抑制 LPS 诱导的小胶质细胞 M1 极化。在体内,我们还发现 cGAS 拮抗剂和 STING 拮抗剂抑制小胶质细胞 M1 极化,并改善 SNI 引起的机械性痛觉过敏。这些发现表明,cGAS-STING 途径可能是治疗神经病理性疼痛的潜在治疗靶点。然而,还需要进一步的研究来验证我们在雌性啮齿动物中的发现。