Effects of cholestanol on neuronal cell death

脑腱黄瘤病（CTX）是一种以高胆固醇血症、小脑共济失调、黄瘤和白内障为特征的遗传性脂质沉积病。我们推测CTX患者血清中的胆甾烷醇可能诱导小脑神经元细胞死亡，最终导致小脑共济失调。为了阐明这一假设，我们建立了高胆固醇血症大鼠喂养胆固醇。苏丹黑B仅对胆固醇组大鼠小脑的神经细胞，尤其是浦肯野细胞染色，提示胆固醇在小脑有存款。为了检查胆甾烷醇在体外的作用，小脑神经元细胞与胆甾烷醇一起培养。胆甾烷醇浓度增加，细胞活力下降与胆甾烷醇培养。用末端脱氧核苷酸转移酶（TdT）dUTP缺口末端标记法（TUNEL）检测到胆甾烷醇培养的细胞凋亡率高于对照组。白细胞介素-1 β的活性 关于我们 β-转化酶（ICE）和CPP 32蛋白酶在胆甾烷醇培养的细胞中增加。我们进一步研究了胆甾烷醇对体外培养的角膜内皮细胞和透镜上皮细胞死亡的影响。用10 μg/ml胆甾烷醇培养的角膜内皮细胞和透镜上皮细胞均显示出明显的活力丧失。用10 μg/ml胆甾烷醇培养的这些细胞的细胞核比用10 μg/ml胆固醇或1%乙醇培养的细胞核染色更频繁。凋亡DNA片段的定量分析证实，胆甾烷醇诱导这些细胞的凋亡在一个时间依赖性的方式。10 μg/ml胆甾烷醇培养的细胞ICE和CPP 32蛋白酶活性显著高于对照细胞。在体外实验中，胆甾烷醇被角膜内皮细胞和透镜上皮细胞摄取，导致这些细胞的凋亡，这些数据表明，胆甾烷醇诱导小脑神经元细胞，角膜内皮细胞和透镜上皮细胞的凋亡。本研究结果可能解释CTX患者小脑共济失调和白内障的发病机制。少

Cerebrotendinous xanthomatosis (CTX) is a hereditary lipid storage disease characterized by hyper-cholestanolemia, crebellar ataxia, xanthoma, and cataract. We hypothesized that cholestanol in serum of CTX patients might induce neuronal cell death in cerebellum and eventually lead to cerebellar ataxia. To elucidate this hypothesis we have established hyper-cholestanolemia rats by feeding cholestanol. Neuronal cells, especially Purkinje cells in the cerebellum were stained by Sudan black B only in cholestanol-fed rats, indicating the deposit of cholestanol in cerebellum. To examine effects of cholestanol in vitro, cerebellar neuronal cells were cultured with cholestanol. The cholestanol concentration increased and the viability decreased in cells cultured with cholestanol. Apoptosis was detected in cells cultured with cholestanol more frequently than in control cells using terminal deoxynucleotidyl transferase (TdT) dUTP nick end-labeling (TUNEL) method. The activities of interleukin-1β … More -converting enzyme (ICE) and CPP32 protease were increased in cells cultured with cholestanol. We further studied the effect of cholestanol on induce cornea endothelial and lens epithelial cell death in vitro. Both cornea endothelial and lens epithelial cells cultured with 10 μg/ml cholestanol showed a significant loss of viability. The nuclei of these cells cultured with 10 μg/ml cholestanol were more frequently stained than those exposed to 10 u」/ml cholesterol or 1 % ethanol. Quantitative analysis of apoptotic DNA fragmentation confirmed that the cholestanol induced apoptosis of these cells in a time-dependent manner. The activities of ICE and CPP32 proteases for cells cultured with 10 μg/ml cholestanol were significantly higher than those observed in control cells. In vitro, cholestanol was taken up by cornea endothelial cells and lens epithelial cells, an event which led to apoptosis of these cells.The data suggest that cholestanol induced apoptosis of cerebellar neuronal cells, cornea endothelial cells and lens epithelial cells. The results in the present study may explain the mechanism of cerebellar ataxia and cataract of CTX patients. Less