Yuan Zhenyu, Lu Boxuan, Zhang Meiling, Lu Yinxiao, Wang Zhihui, Zhang Wenhao, Cheng Hao, Wu Zhifang, Ji Qing
Department of Anesthesiology, Nanjing Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.
Front Pharmacol. 2024 Nov 12;15:1434295. doi: 10.3389/fphar.2024.1434295. eCollection 2024.
Morphine is a widely used analgesic, but its prolonged use often leads to tolerance, limiting its therapeutic efficacy. Research implicates the NLRP3 inflammasome and reactive astrocytes in the development of morphine tolerance, with reactive astrocytes classified into A1 neurotoxic and A2 neuroprotective phenotypes. This study explores the role of the NLRP3 inflammasome and the transformation of astrocyte phenotypes in the progression of morphine tolerance.
A model of morphine tolerance was established by administering morphine intrathecally for seven consecutive days. To inhibit NLRP3 inflammasome activation, we coadministered MCC950, a selective NLRP3 inhibitor. Thermal withdrawal latency was used to assess tolerance development. Protein and mRNA levels of GFAP, IL-18, NLRP3, C3 (A1 marker), and S100A10 (A2 marker) in the spinal cord were measured using Western blotting (WB) and real-time quantitative polymerase chain reaction (RT-qPCR). Immunofluorescence was employed to assess the colocalization of C3 and GFAP.
Seven days of morphine administration induced tolerance, which was associated with increased levels of GFAP, IL-18, NLRP3, and C3, and a decreased level of S100A10. Coadministration of morphine and MCC950 significantly slowed the development of morphine tolerance and reversed changes in NLRP3, IL-18, GFAP, C3, and S100A10 protein levels.
Our findings indicate a significant link between NLRP3 inflammasome activation and morphine tolerance, suggesting that NLRP3 contributes to the transformation of astrocytes to the A1 phenotype. Inhibiting NLRP3 inflammasome activation holds promise in reversing astrocyte phenotype changes, potentially mitigating morphine tolerance.
吗啡是一种广泛使用的镇痛药，但其长期使用常导致耐受性，限制了其治疗效果。研究表明，NLRP3炎性小体和反应性星形胶质细胞与吗啡耐受性的发展有关，反应性星形胶质细胞可分为A1神经毒性表型和A2神经保护表型。本研究探讨NLRP3炎性小体的作用以及星形胶质细胞表型转化在吗啡耐受性进展中的作用。
通过连续7天鞘内注射吗啡建立吗啡耐受性模型。为抑制NLRP3炎性小体激活，我们联合给予选择性NLRP3抑制剂MCC950。采用热退缩潜伏期评估耐受性发展。使用蛋白质印迹法（WB）和实时定量聚合酶链反应（RT-qPCR）测量脊髓中胶质纤维酸性蛋白（GFAP）、白细胞介素-18（IL-18）、NLRP3、C3（A1标志物）和S100A10（A2标志物）的蛋白质和mRNA水平。采用免疫荧光法评估C3和GFAP的共定位。
连续7天给予吗啡可诱导耐受性，这与GFAP、IL-18、NLRP3和C3水平升高以及S100A1于降低。吗啡与MCC950联合给药显著减缓了吗啡耐受性的发展，并逆转了NLRP3、IL-18、GFAP、C3和S100A10蛋白质水平的变化。
我们的研究结果表明NLRP3炎性小体激活与吗啡耐受性之间存在显著联系，提示NLRP3促成星形胶质细胞向A1表型转化。抑制NLRP3炎性小体激活有望逆转星形胶质细胞表型变化，可能减轻吗啡耐受性。
