丙酮酸乙酯通过抑制高迁移率族蛋白1减轻大鼠脊髓损伤后水肿及体外氧糖剥夺/复氧后星形胶质细胞肿胀的研究

Ethyl pyruvate reduces spinal cord edema after spinal cord injury and attenuates spinal cord astrocyte swelling and aquaporin-4 expression after oxygen-glucose deprivation and reoxygenation in vitro by inhibiting high mobility group box-1 in rats

目的研究丙酮酸乙酯(EP)对大鼠脊髓损伤(SCI)后脊髓早期水肿以及体外氧糖剥夺/复氧(OGD/R)损伤所致的大鼠脊髓星形胶质细胞水肿的作用。方法建立成年SD大鼠SCI模型,观察经腹腔注射EP抑制高迁移率族蛋白1(HMGB1)后脊髓水含量、HMGB1表达以及星形胶质细胞活化[胶质纤维酸性蛋白(GFAP)表达]情况。体外培养新生SD大鼠脊髓星形胶质细胞,建立OGD/R模型模拟脊髓损伤后缺血再灌注状态,观察EP对其水肿体积、HMGB1表达、水通道蛋白4(AQP4)表达以及Toll样受体4(TLR4)/核转录因子-κB(NF-κB)通路活化的作用。结果SCI后1d大鼠脊髓水含量较12h、3d明显增加,腹腔注射50mg/kg EP较25mg/kg、100mg/kg EP减轻了SCI后脊髓水肿,降低HMGBI表达与星形胶质细胞活化,体外培养的大鼠脊髓星形胶质细胞OGD 6h/R 24h时较OGD 6h/R 6h,OGD 6h/R 12h细胞水肿体积明显增大,12μmol/L EP较6μmol/L EP能够减轻其水肿体积,降低HMGB1及AQP4表达,减少TLR4/NF-κB通路活化,以上比较差异均有统计学意义(P<0.05)。结论EP抑制HMGB1能够减轻大鼠SCI后脊髓早期水肿以及OGD/R所致的体外培养大鼠脊髓星形胶质细胞水肿和AQP4表达。

Objective To study the roles of ethyl pyruvate (EP)in spinal cord edema after spinal cord injury (SCI)and in spinal cord astrocytic swelling after oxygen-glucose deprivation and reoxygenation (OGD/R)in vitro in rats.Methods After SCI models were established in adult Sprague-Dawley (SD) rats,an intraperitoneal injection of EP was conducted to inhibit high mobility group box-1(HMGBI).Effects of EP on spinal cord edema,HMGBI expression and astrocyte activation (glial fibrillary acidic protein (GFAP)expression)in SCI rats were analyzed.Spinal cord astrocytes were cultured in post-natal SD rats and incubated under OGD/R procedure.Effects of EP on cell swelling,expression of HMGB1,aquaporin-4 (AQP4)and toll-like receptor 4(TLR4),and nuclear expression of nuclear factor-kappa B (NF-κB)in spinal cord astrocytes were observed.Results The water content in the spinal cord was increased significantly more at 1d after SCI than at 12h and 3d (P <0.05).Intraperitoneal injection of EP at 50mg/kg reduced spinal cord water content,HMGB1expression and astrocyte activation (GFAP expression)in SCI rats significantly more than that at 25mg/kg or 100mg/kg (P <0.05).The volume of spinal cord astrocytes cultured in vitro after OGD 6h/R 24h was significantly greater than that after OGD 6h/R 6h or OGD 6h/R 12h (P <0.05).EP at 12μmol/L reduced cell swelling,decreased expression of HMGB1,AQP4 and TLR4, and downgraded nuclear expression of NF-κB in spinal cord astrocytes after OGD/R significantly more than EP at 6μmol/L(P <0.05).Conclusion EP may reduce early spinal cord edema after SCI,attenuate spinal cord astrocyte swelling and decrease AQP4 expression after OGD/R in vitro by inhibiting HMGB1 in rats.