海洋甾体YC-1抑制低钾诱导大鼠小脑颗粒神经元的凋亡

【目的】观察海洋甾体YC 1对低钾 (5mmol/L ,lowK )诱导小脑颗粒神经元凋亡的影响 ,并对其机制进行初步探讨。【方法】小脑颗粒神经元原代培养 ;采用二乙酸荧光素 (fluoresceindiacetate ,FDA)和Hoechst 332 5 8DNA染色法观察神经元存活率及形态学特征 ;用琼脂糖凝胶电泳分析神经元死亡的生化特征。【结果】低钾引起小脑颗粒神经元凋亡。Hoechst332 5 8DNA染色表现出染色体固缩 ,DNA凝胶电泳表现出由大小不一的断裂DNA片段形成的“梯形”条带。YC 1(1 2 5～ 2 0 μmol/L)呈时间和剂量依赖性地抑制上述现象的出现。蛋白质合成抑制剂放线菌酮 (cycloheximide)不能改变由不同孵育时间造成的YC 1对神经元不同保护效果的差异。【结论】YC 1抑制低钾诱导小脑颗粒神经元凋亡 ,YC 1的这一作用可能属于一非基因效应。

The Protection Effects of YC-1 on Cultured Rat Cerebellar Granule Neurons Against Apoptosis Induced by Low Potassium

Objective To examine whether YC 1, a marine steroid, can rescue cultured rat cerebellar granule neurons from apoptosis induced by physiological concentration of potassium(5 mmol/L, low K ) and its mechanism. Methods Cerebellar granule neurons primarily were cultured. Neuronal viability and morphology were detected by fluorescein diacetate and Hoechst 33258. The biochemical features of neuronal death were characterized by agrose gel electrophoresis. Results The neuronal death induced by low K displayed the characteristics of apoptosis, including condensation of nuclear chromatin exhibited by Hoechst 33258 staining and DNA fragmentation visualized by agarose gel electrophoresis. Exposure of cultured cerebellar granule neurons to YC 1 results in dosage and time dependent inhibition of apoptosis induced by low K . Different neuronal protecting effects of YC 1 induced by different preteatment time of YC 1 cannot be abolished by cycloheximide, an inhibitor of protein synthesis. Conclusion YC 1 can block apoptosis of cerebellar granule neurons induced by low K . The neuronal protection of YC 1 maybe belongs to a nongenomic action.