Xiao Ying, Li Lei-Lei, Bibi Asma, Zhang Ning, Chen Ting, Mo Yitao, Yue Wanfu, Miao Yungen
College of Animal Sciences, Zhejiang University, Hangzhou, China.
Zhejiang Agriculture & Forestry University, Hangzhou, China.
Arch Insect Biochem Physiol. 2020 Nov;105(3):e21741. doi: 10.1002/arch.21741. Epub 2020 Oct 1.
Apoptosis is a process of programmed cell death that is regulated by genes independently. The Bm30kc6 gene is a kind of small molecular lipoprotein about 30 kDa, expressed highly in the late stage of the silkworm hemolymph. Our study showed that overexpression of Bm30kc6 could decrease caspase-3 activation. Meanwhile, activation of caspase-3 increased when Bm30kc6 expression was disturbed by small interfering RNA (siRNA). Cell apoptosis was decreased when Bm30kc6 was overexpressed under UV treatment. The apoptosis rate induced by actinomycin D is similar to the trend by UV. It was inferred that Bm30kc6 has an inhibitory effect on the apoptosis of silkworm cells. The apoptosis-related genes, such as BmFadd, BmDredd, and BmDaxx were increased after overexpression of Bm30kc6 or decreased after interference of siRNA. It was speculated that there was an interactive relationship between Bm30kc6, BmDaxx, BmFadd, and BmDredd in the apoptosis signaling pathways. We investigated the transcription expression of the Bm30kc6 gene in different growth stages and tissues of the silkworm. The results showed that Bm30kc6 reached its peak in the hemolymph during the 6th to 7th days of the 5th instar, or in spinning post 24 h of the silk gland. In the silkworm BmN cells treated with caspase-3/7 inhibitor, the caspase-3 enzyme activity, and the expression levels of Bm30kc6, BmFadd, BmDredd, and BmDaxx were significantly reduced. The expression levels of Bm30kc6 increased sharply when silkworms were treated by molting hormone at Day 3 or 5 of the 5th instar. The results indicated that the expression of the Bm30kc6 gene was affected by the molting hormone and was likely to be its downstream target. In conclusion, the results suggest that the Bm30kc6 gene is involved in the regulation of the apoptotic signaling pathway and plays a role in the apoptotic process.
细胞凋亡是一种由基因独立调控的程序性细胞死亡过程。Bm30kc6基因是一种分子量约为30 kDa的小分子脂蛋白，在蚕血淋巴后期高表达。我们的研究表明，Bm30kc6基因的过表达可降低caspase-3的激活。同时，当Bm30kc6基因的表达受到小干扰RNA（siRNA）干扰时，caspase-3的激活增加。在紫外线处理下过表达Bm30kc6时，细胞凋亡减少。放线菌素D诱导的凋亡率与紫外线诱导的趋势相似。据推测，Bm30kc6对蚕细胞凋亡具有抑制作用。Bm30kc6基因过表达后，凋亡相关基因如BmFadd、BmDredd和BmDaxx增加，而siRNA干扰后则减少。推测在凋亡信号通路中，Bm30kc6、BmDaxx、BmFadd和BmDredd之间存在相互作用关系。我们研究了Bm30kc6基因在蚕不同生长阶段和组织中的转录表达。结果表明，Bm30kc6在五龄第6至7天的血淋巴中或在丝腺吐丝24小时后达到峰值。在用caspase-3/7抑制剂处理的家蚕BmN细胞中，caspase-3酶活性以及Bm30kc6、BmFadd、BmDredd和BmDaxx的表达水平均显著降低。在五龄第3天或第5天用蜕皮激素处理蚕时，Bm30kc6的表达水平急剧增加。结果表明，Bm30kc6基因的表达受蜕皮激素影响，可能是其下游靶点。总之，结果表明Bm30kc6基因参与凋亡信号通路的调控，并在凋亡过程中发挥作用。
