17-β雌二醇抑制过氧化氢诱导鼠脊髓星形胶质细胞凋亡  

17-β estradiol prevent apoptosis in H2O2-induced astrocytes of rat spinal cord

作　　者：曹菁菁[1] 徐德友[1] 皇丽丽[2] 孙波[2] 黄素素[2] 沈华超[1] 朱金[1] 丁新生[1] 

机构地区：[1]南京医科大学第一附属医院神经内科,210029 [2]南京医科大学明基神经病学研究所

出　　处：《中华神经科杂志》2012年第7期505-510,共6页Chinese Journal of Neurology

基　　金：江苏省优势学科临床医学资助项目

摘　　要：目的探讨17-β雌二醇治疗脊髓损伤的可能机制，以期为临床急性脊髓损伤的治疗提供理论依据。方法建立原代培养的星形胶质细胞凋亡模型，将培养的细胞按随机排序的方法分为5组：对照组、过氧化氢组、17-β雌二醇＋过氧化氢组、17-B雌二醇组、二甲基亚砜溶剂组。利用四甲基偶氮唑蓝比色法检测细胞活性，蛋白免疫印迹检测第10号染色体缺失的磷酸酶与张力蛋白同源物基因（PTEN）、磷酸化蛋白激酶B（p-Akt）、天冬氨酸特异性半胱氨酸蛋白酶3（caspase-3）和B细胞淋巴瘤／白血病-2（Bcl-2）蛋白的表达。结果与对照组（0．401±0．043）比较，过氧化氢处理后（0．172±0．018）吸光度（A）值明显降低（q’=-1．450，P=0．001），可反映细胞生存率、活力降低，而17—β雌二醇预处理后（0．312±0．023），A值增加（q’=7．025，P=0．0025），提示细胞生存率增加及细胞活力上升，各组间比较A值差异也存在统计学意义；PTEN蛋白表达降低、Bcl-2表达上调；caspase-3表达降低、p-Akt表达上调。结论17-β雌二醇有可能通过下调PTEN蛋白，促进p-Akt、Bcl-2蛋白的表达，抑制过氧化氢诱导星形胶质细胞凋亡。因此，脊髓损伤时早期应用17-β雌二醇有助于减轻脊髓损伤的程度，促进脊髓神经功能的恢复。Objective To investigate the mechanism of protective effects of 17-β estradiol on the experimental model of spinal cord injury （SCI） rats. Methods First, the primary astrocytes were cultured and identified. When the third generation astrocytes were cultured, they were induced by H2O2 whose concentrations were established by the method of 3-（4,5-dimethyhhiazol-2-yl）-2, 5-diphenyltetrazolium bromide （MTr）. The cells were randomly divided into five groups：control group; the group of treatment with 400 p, mol/L H2O2 for 24 hours; the group of treatment with 20 nmol/L estrogen for 2 hours prior to exposure to 400 p.mol/L H2O2 for 24 hours; the group of treatment with 20 nmol/L estrogen for 26 hours and the group of treatment with dimethyl sulfoxide for 26 hours. The proteins which were extracted from these cells after treatments with H2O2 for 24 hours were detected by Western blotting. Results The absorbances of the astrocytes of treatments with H2O2 were reduced（q＇ = -11.45,P =0. 001 ）. But exposure to estrogen prior to exposure to H2O2 provided partial restoration of the absorbances （ q ＇ = 7. 025, P = 0. 0025 ） . The absorbances of the astrocytes among different groups showed significant differences（ F = 69.69 ,P = 0. 0025 ）. The results suggested that estrogen might increase the cell viability in astrocytes. Compared with the group of treatment ceils with H2O2, treatment cells with 17-β estradiol prior to H202 exposure down-regulated the expressions of both phosphatase and tensin homologue deleted on chromosome 10 （PTEN） （F = 290. 003, P = 0. 001 ） and caspase-3 （ F = 46. 158, P = 0. 023 ）. And, 17-13 estradiol treatment of cells increased the levels of p-Akt （ F = 49. 173, P = 0. 033 ） and Bcl-2 （ F = 115. 916, P = 0. 001 ） when compared with the group of treatment astrocytes with H2O2. Conclusion These findings suggest that the attenuation of PTEN expression mediated by estrogen is associated with an increase in phosphorylation/activation of the Akt and the Bcl

关 键 词：雌二醇 脊髓损伤 星形细胞 PTEN磷酸水解酶 细胞凋亡 

分 类 号：R977.1[医药卫生—药品]