Toll样受体4/核转录因子-κB通路在氧糖剥夺/复氧所致的大鼠脊髓星形胶质细胞水肿中的作用

The roles of toll -like receptor 4/nuclear factor -kappa B signaling on rat spinal cord astrocyte swelling after oxygen -glucose deprivation and reoxygenation

目的观察Toll样受体4(TLR4)/核转录因子-κB (NF-κB)信号通路在体外氧糖剥夺/复氧(OGD/R)损伤所致的大鼠脊髓星形胶质细胞(AS)水肿中的作用。方法培养新生Sprague-Dawley大鼠脊髓AS,建立OGD/R模型,观察OGD/R后脊髓AS水肿体积、水通道蛋白4(AQP4)、TLR4以及细胞核内NF-κB表达。分别使用TLR4抑制剂(CLI-095)以及NF-κB抑制剂(BAY 11-7082)抑制脊髓AS的TLR4及NF-κB活性,观察两种抑制剂对OGD/R介导的细胞水肿及AQP4表达的影响。结果TLR4抑制剂降低了OGD/R介导的脊髓AS的TLR4活性(0.256±0.028比0.389±0.027,P<0.05)以及NF-κB核转位活化程度(0.229±0.027比0.411±0.032,P<0.05),降低AQP4上调(0.346±0.014比0.470±0.027,P<0.05)及细胞肿胀[(3 953±600) μm3比(5 547.991±837.357) μm3,P<0.05],减轻细胞线粒体肿胀、减少溶酶体数量。NF-κB抑制剂也降低了OGD/R介导的脊髓AS的NF-κB核转位活化程度(0.219±0.022比0.403±0.023,P<0.05),降低AQP4上调(0.306±0.029比0.480±0.020,P<0.05)及细胞肿胀[(4 045.368±549.626) μm3比(2 889.016±656.315) μm3,P<0.05],减轻细胞线粒体肿胀、减少溶酶体数量。结论TLR4/NF-κB通路在OGD/R损伤所致的大鼠脊髓AS水肿形成中发挥重要作用。

Objective To study the roles of toll-like receptor 4 (TLR4) / nuclear factor-kappa B (NF-κB) signaling on rat spinal cord astrocyte swelling after oxygen-glucose deprivation and reoxygenation (OGD/R).Methods Cultured spinal cord astrocytes of post-natal Sprague-Dawley rats were incubated under OGD/R procedure. Effects of OGD/R on cell swelling, expression of aquaporin-4 (AQP4) and TLR4, and nuclear expression of NF-κB in spinal cord astrocytes were observed. Effects of inhibiting TLT4 using CLI-095 or inhibiting NF-κB using BAY 11-7082 on cell swelling and expression of AQP4 in spinal cord astrocytes after OGD/R injury were studied.Results TLR4 inhibition decreased OGD/R-induced spinal cord astrocyte TLR4 (0.256±0.028 vs. 0.389±0.027, P<0.05), AQP4 (0.346±0.014 vs. 0.470±0.027, P<0.05) up-regulation and NF-κB activation (0.229±0.027 vs. 0.411±0.032, P<0.05), and reduced swelling [(3 953±600) μm3 vs. (5 547.991±837.357) μm3,P<0.05], mitochondrial swelling and the increase in number of lysosomes. NF-κB inhibition decreased OGD/R-induced spinal cord astrocyte NF-κB activation (0.219±0.022 vs. 0.403±0.023, P<0.05) and AQP4 up-regulation (0.306±0.029 vs. 0.480±0.020, P<0.05), and reduced swelling [(4 045.368±549.626) μm3 vs. (2 889.016±656.315) μm3,P<0.05], mitochondrial swelling and the increase in number of lysosomes.Conclusion We identified the role of TLR4/NF-κB signaling in the promotion of spinal cord astrocyte swelling after OGD/R in vitro, which may become a new target of studies and treatment plans for spinal cord astrocyte swelling and spinal cord edema after SCI.