细胞松弛素D对大鼠脊髓星形胶质细胞水通道蛋白和内向整流性钾通道4.1 基因表达的影响

目的探讨不同浓度细胞松弛素D(CytD)对大鼠脊髓星形胶质细胞骨架重构，水通道蛋白(AQP)1、AQP4 及内向整流性钾通道4.1(Kir4.1)基因表达的影响。方法原代培养大鼠脊髓星形胶质细胞，加CytD 0.05 μg/ml、0.10 μg/ml、0.20 μg/ml、0.40μg/ml、0.80 μg/ml 和1.00 μg/ml 共培养2 h、12 h 和24 h。MTT法检测细胞增殖情况；鬼笔环肽联合Hoechst 33342 套染后激光共聚焦显微镜下观察共培养2 h 后细胞骨架重构情况；RT-PCR法检测共培养2 h 时AQP1、AQP4 和Kir4.1 mRNA表达水平。结果细胞生存率随CytD 浓度升高和作用时间延长而减少。CytD 使大鼠脊髓星形胶质细胞微丝发生解聚、弯曲，但极性未失。CytD 0.05μg/ml、0.10 μg/ml、0.20 μg/ml 和0.40 μg/ml 上调AQP1、AQP4 和Kir4.1 mRNA表达。结论适当浓度CytD可以重建星形胶质细胞骨架，上调大鼠脊髓星形胶质细胞AQP1、AQP4和Kir4.1基因表达。

Effects of Cytochalasin D on Expression of Aquaporins and Inward Rectifying Potassium Channel 4.1 Gene in Spinal Cord Astrocytes of Rats

Objective To investigate the expression of aquaporin (AQP) 1, AQP4, inward rectifying potassium channel 4.1 (Kir4.1) and cytoskeleton features of rat spinal cord astrocytes after cytochalasin D (CytD) intervention. Methods Spinal cord astrocytes isolated from 2~3-day-old rats were cultured till confluency. MTT was used to assess survival rate of astrocytes 2 h, 12 h and 24 h after co-cultured with 0.05 μg/ml, 0.10 μg/ml, 0.20 μg/ml, 0.40 μg/ml, 0.80 μg/ml and 1.00 μg/ml of CytD, respectively. Confocal microscopy was used to observe cytoskeleton features of astrocytes 2 h after co-cultured with 0.05 μg/ml, 0.10 μg/ml, 0.20 μg/ml, 0.40 μg/ml of CytD. The expression of AQP1, AQP4, Kir4.1 mRNA were determined with real-time PCR 2 h after co-cultured with 0.05 μg/ml, 0.10 μg/ml, 0.20 μg/ml, 0.40 μg/ml, 0.80 μg/ml and 1.00 μg/ml of CytD. Results The survival rate of rat spinal cord astrocytes reduced with the time of co-culture and concentration of CytD (P<0.05). The cytoskeleton of astrocytes was reconstructed. The expression of AQP1, AQP4 and Kir4.1 mRNA increased after co- cultured with 0.05~0.40 μg/ml of CytD. Conclusion The appropriate dosage of CytD may remodel the cytoskeleton and increase the mRNA expression of AQP1, AQP4 and Kir4.1 in spinal cord astrocytes of rats.