JSK对糖-氧剥夺/复氧后大鼠脊髓星形胶质细胞体积及AQP4表达的影响

Effects of JSK on the volume and AQP4 expression of the spinal astrocytes of rat after glucose-oxygen deprivation and reoxygenation

中文关键词:  星形胶质细胞  肌动蛋白  水通道蛋白4  脊髓损伤  水肿

英文关键词:Astrocyte  Actin  Aquaporin-4  Spinal cord  Edema

中文摘要:

  【摘要】 目的：观察细胞骨架稳定剂（Jasplakinolide，JSK）对糖-氧剥夺/复氧（oxygen-glucose deprivation and reoxygenation，OGD/Reox）后大鼠脊髓星形胶质细胞体积及水通道蛋白-4（aquaporin-4，AQP4）表达的影响，并探讨其可能机制。方法：体外培养取自大鼠脊髓的星形胶质细胞，将传代2~3次后的星形胶质细胞行糖-氧剥夺5h后再复氧，复氧同时将不同浓度（20、50、100、200和400nM）的JSK分别加入培养液继续培养12h，对照组用等量DMSO处理。用共聚焦显微镜和Western blot分析观测不同时间点（0.5h~12h）及不同浓度JSK作用下星形胶质细胞体积变化和AQP4表达情况，同时观察肌动蛋白微丝聚合（filament actin，F-actin）变化情况，分析其可能机制。结果：在OGD/Reox后，与对照组比较，0.5h后星形胶质细胞的体积开始增加，1.5h后达峰值（9.44±0.27 vs 5.06±0.26，P<0.05）；50nM浓度JSK可明显减轻星形胶质细胞肿胀的严重程度（5.72±0.96，P<0.05）。OGD/Reox后AQP4蛋白表达明显增加，在复氧1.5h时达到峰值（1.21±0.029 vs 0.20±0.013，P<0.01）。JSK处理显著降低了AQP4蛋白水平的升高（1.25±0.19 vs 2.01±0.26，P<0.01）。分析表明JSK聚合的F-actin微丝是导致细胞膜AQP4下调的原因。结论：应用JSK可以减轻OGD/Reox引起的大鼠脊髓星形胶质细胞肿胀，其保护作用可能与其能重组F-actin微丝和抑制AQP4蛋白表达有关。

英文摘要:

  【Abstract】 Objectives: To observe the effects of Jasplakinolide(JSK) on the volume of rat spinal cord astrocytes and the expression of aquaporin-4(AQP4) after glucose-oxygen deprivation and reoxygenation(OGD/Reox), and explore the possible mechanism. Menthods: Astrocytes from the spinal cord of rats were cultured in vitro, and the astrocytes after passage for 2-3 times were gived glucose-oxygen deprivation for 5h and reoxygenated(OGD/Reox). JSK with different concentrations(20, 50, 100, 200 and 400nM) was added to astrocytes for 12h after OGD/Reox. The control group was treated with equal amount of DMSO. The volume change and AQP4 expression of astrocytes at different time points(0.5h-12h) and different concentrations of JSK were observed by confocal microscope and Western blot. At the same time, the changes of filament actin(F-actin) were observed, and to analyze the possible mechanism. Results: After OGD/Reox, compared with the control group, the volume of astrocytes began to increase after 0.5h and reached a peak after 1.5h(9.44±0.27 vs 5.06±0.26, P<0.05). JSK at 50nM concentration could significantly reduce the severity of astrocyte swelling (5.72±0.96, P<0.05). AQP4 protein expression was significantly increased after OGD/Reox, and reached a peak value(1.21±0.029 vs 0.20±0.013, P<0.01) at 1.5h reoxygenation. JSK treatment significantly reduced the increase of AQP4 protein level(1.25±0.19 vs 2.01±0.26, P<0.01). Analysis showed that the F-actin microfilament polymerized by JSK was the cause of the down-regulation of cell membrane AQP4. Conclusions: Application of JSK can reduce OGD/Reox induced astrocyte swelling in rat spinal cord, and its protective effect may be related to its ability to reprogram f-actin microfilament and inhibit AQP4 protein expression.