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

English Keywords:Astrocyte  Actin  Aquaporin-4  Spinal cord  Edema

English Abstract:

  【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.