酸性鞘磷脂水解酶和MAPK信号通路在UVA诱导细胞凋亡中的作用

为了探讨酸性鞘磷脂水解酶 (ASM)和MAPK信号通路在UVA诱导的细胞凋亡中的作用 ,用DNA梯形条带 (DNAladder)和荧光显微镜鉴定细胞凋亡 ,Western印迹分析MAPK信号通路的激活情况 .结果显示 :①经UVA照射 ,正常的淋巴母细胞JY出现严重的细胞凋亡 ,而ASM遗传性缺陷的淋巴母细胞MS1 4 1 8出现轻微凋亡 ;给予ASM特异性抑制剂NB6 ,UVA诱导的JY细胞凋亡明显减轻 ,表明UVA诱导的细胞凋亡依赖于ASM .②UVA照射后 ,磷酸化ERK含量在MS1 4 1 8细胞中明显升高 ,在JY细胞中受到抑制 ;UVA照射前给予NB6 ,JY细胞中磷酸化ERK含量上升 ,表明ASM能抑制ERK的激活 .③UVA照射后 ,磷酸化JNK含量在MS1 4 1 8细胞中几乎没有变化 ,而在JY细胞中含量升高 ;UVA照射前给予NB6 ,JY细胞中磷酸化JNK含量没有明显升高 ,表明ASM激活JNK通路 .④NB6对UVA激活的p38MAPK信号通路没有影响 ,表明p38的激活与ASM关系不大 .研究表明 ,UVA诱导的细胞凋亡是通过激活ASM、激活JNK信号通路并抑制ERK信号通路来完成的

Role of Acid Sphingomyelinase and MAPK Signaling Pathway in UVA-induced Apoptosis

In order to investigate the role of acid sphingomyelinase(ASM) and MAPK signaling pathway in UVA induced apoptosis, DNA ladder assay and fluorescent microscopy was used to identify apoptosis and Western blotting was used to examine the phosphorylation of MAPK. The results were as follows: (1) UVA radiation induced severe apoptosis in normal JY lymphoblasts, not in MS1418 lymphoblasts with an inherited deficiency of ASM. NB6, the specific inhibitor of ASM, inhibited the UVA induced apoptosis in JY cells, indicating the dependence of UVA induced apoptosis on ASM; (2) UVA radiation induced the phosphorylation of ERK in MS1418 cells and inhibited the phosphorylation of ERK in JY cells. NB6 revoked the inhibition of UVA on the phosphorylation of ERK and resulted in increase of phosphorylated ERK in JY cells, indicating the inhibition of phosphorylation of ERK by ASM; (3) UVA radiation induced the phosphorylation of JNK in JY cells not in MS1418 cells, and NB6 inhibited the phosphorylation of JNK in JY cells, suggesting the inducing of phosphorylation of JNK by ASM; (4) NB6 did not affect p38MAPK signaling pathway activated by UVA irradiation, indicating that the phosphorylation of p38 is not associated with ASM. Thus it can be concluded that UVA induced apoptosis depends on activation of ASM and activating JNK signaling pathway and inhibiting ERK signaling pathway.