Molecular Cell Biological Study on Neuronal Apoptosis in Cerebellar Graneul Cells

We analyzed the Mechanism underlying cell death using cultured rat cerebellar granule and cerebral cortical neurons， because of their abundance and homogeneity。在含有26毫米钾或中等（5毫米钾）的介质中保留Cerebellar Granule神经元，含有50纳克/毫升BDNF，表明为10微米LY 294002，PI 3激酶抑制剂。要研究LY 294002诱导凋亡的内体信号机制，Akt和c-Jun N-终端激酶（JNK）的活动在HKY-D1 + Y-D1（26 mM电位）或LKY-D1 + Y-D1（5 mM电位）中含有BDNF的细胞，含有或不含有10 μ M LY 294002。Akt活动减少了添加到10 μ M LY 294002。在补充中，我们发现了LY 294002增加了JNK活动，我们知道哪些类型的细胞死亡在PNS神经元。我们也观察到c-Jun由LY 294002在HK-D1 + Y-D1 +BDNF的提升表达。这些发现被诱导的凋亡被抑制PI 3-激酶活性的抑制抑制了Akt活性和JNK活性在cerebellar granule神经元中的提升。我们提出的结果是，PI 3-kinase-Akt途径可以抵消JNK和c-Jun表达的激活，并作为一个结果阻止神经元细胞在大神经元中死亡。

We analyzed the mechanism underlying cell death using cultured rat cerebellar granule and cerebral cortical neurons, because of their abundance and homogeneity. Cerebellar granule neurons maintained in medium containing 26 mM potassium or in medium (5 mM potassium) with 50 ng/ml BDNF undergo an apoptoic cell death when exposed to 10 μ M LY294002, an inhibitor of PI3-kinase. To investigate the intracellular signaling mechanism of LY294002-induced apoptosis, the activities of Akt and c-Jun N-terminal kinase (JNK) were measured in cells in HKィイD1+ィエD1 (26 mM potassium) or LKィイD1+ィエD1 (5 mM potassium) medium containing BDNF, with or without 10 μ M LY294002. Akt activity decreased following the addition of 10 μ M LY294002. In addition, we found that LY294002 increased the JNK activity, which is known to mediate some types of cell death in PNS neurons. We also observed elevated expression of c-Jun by LY294002 in HKィイD1+ィエD1 +BDNF. These findings demonstrated that apoptosis induced by inhibition of PI3-kinase activity involves suppression of the Akt activity and elevation of the JNK activity in cerebellar granule neurons. Our results suggested that the PI3-kinase-Akt pathway suppresses the activation of JNK and c-Jun expression, and as a result prevents the neuronal cell death in cerebellar granule neurons.