BmDaxx对家蚕细胞和幼虫组织凋亡的调控作用(英文)

Bm Daxx regulates apoptosis in cells and larval tissues of the silkworm(Bombyx mori)

采用荧光定量聚合酶链式反应(real-time quantitative polymerase chain reaction,RT-qPCR)方法体外扩增并鉴定家蚕死亡结构域相关蛋白基因(BmDaxx)。结果表明:BmDaxx及其下游基因BmFadd和BmDredd的表达水平在BmDaxx过表达后显著升高,但在BmDaxx的RNA干扰后,BmDaxx和BmFadd的表达水平显著降低;BmDaxx过表达增加半胱氨酸天冬氨酸蛋白酶-3/7(cystein-asparate protease-3/7,caspase-3/7)活性,而RNA干扰则降低caspase-3/7活性。用caspase-3/7抑制剂处理BmN细胞后,与对照组相比,BmDaxx、BmFadd和BmDredd的转录水平降低。在家蚕吐丝期,BmDaxx在丝腺中的表达量显著高于其他组织,这与丝腺的凋亡退化过程相一致。注射caspase抑制剂后,凋亡相关基因BmDaxx、BmFadd和BmDredd的表达水平显著降低。由此可以认为,BmDaxx及其下游基因BmFadd和BmDredd之间存在着相互作用,它们在BmN细胞和丝腺细胞凋亡中起着关键作用。

We amplified and characterized the BmDaxx gene of the silkworm(Bombyx mori)by real-time quantitative polymerase chain reaction(RT-qPCR).The expression levels of BmDaxx and its downstream genes BmFadd and BmDredd showed significant increases after overexpression of BmDaxx.However,the expression levels of BmDaxx and BmFadd decreased significantly after siRNA interference of BmDaxx.Overexpression of BmDaxx increased the activity of the cystein-asparate protease-3/7(caspase-3/7),while siRNA interference decreased the activity.When BmN cells were treated by caspase-3/7 inhibitor,the transcriptional levels of BmDaxx,BmFadd and BmDredd decreased as compared with controls.The expression level of BmDaxx was significantly higher in silk glands than in other organs at the silking stage,consistent with the silk gland degeneration at this stage.After injecting of the caspase inhibitor,the expression levels of the apoptosis-related genes BmDaxx,BmFadd and BmDredd showed significant decreases.It is concluded that there are direct relationships between BmDaxx and its predicted downstream genes BmFadd and BmDredd,which play critical roles both in BmN cells and in silk gland apoptosis.