Hu Weina, He Guangwei, Wang Jingjing, Hu Qiongbo
Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
Molecules. 2016 Dec 29;22(1):41. doi: 10.3390/molecules22010041.
Destruxin A (DA), a cyclodepsipeptidic mycotoxin of entomopathogenic fungus, , has anti-immunity activity against insects, but the mechanism of immune regulation is not clear yet. In our previous experiment, the significant expression changes of , , and genes in a silkworm's hemocytes were found, which suggested that these genes might be involved in insect's innate immunity. In the current experiment, the silkworm cell line Bm12 was used to survey the expression levels of these genes after the cells were treated with DA and the transcription factors , and were silenced by specific siRNA. The results indicated that, after the cells were treated by DA, the gene expression level of was significantly downregulated, but and were not changed. The results also showed that the gene expression levels of and had similar phenomena, i.e., downregulation with individual gene silence or DA treatment, upregulation with combination of gene silence and DA treatment, upregulation with individual gene silence, and downregulation with combination of gene silence plus DA treatment, but no changes in the gene silence combined with DA treatment. For the gene, the downregulated expressions were found in individual gene silence or DA treatment, upregulation in the combination treatment of gene silence plus DA, and the individual treatment of or silence. It is suggested that expressions of the and genes are closely related to the Imd signal pathway, but genes might involve in both Toll and Imd pathways. Furthermore, the gene acts as an activator and the gene acts as a repressor for both and gene expressions. It also implies that DA may participate in the splicing process of where was promoted. Our research will provide new insights on the understanding of the activity mechanisms of destruxins.
destruxin A（DA）是一种昆虫病原真菌的环缩肽类霉菌毒素，具有抗昆虫免疫活性，但其免疫调节机制尚不清楚。在我们之前的实验中，发现家蚕血细胞中 、 和 基因有显著的表达变化，这表明这些基因可能参与昆虫的先天免疫。在当前实验中，使用家蚕细胞系Bm12来检测细胞用DA处理后这些基因的表达水平，并且通过特异性siRNA使转录因子 、 和 沉默。结果表明，细胞用DA处理后， 基因的表达水平显著下调，但 和 没有变化。结果还表明， 和 基因的表达水平有类似现象，即单个 基因沉默或DA处理时下调， 基因沉默与DA处理联合时上调，单个 基因沉默时上调， 基因沉默加DA处理联合时下调，但 基因沉默与DA处理联合时无变化。对于 基因，在单个 基因沉默或DA处理时表达下调，在 基因沉默加DA的联合处理以及 或 沉默的单独处理时上调。表明 和 基因的表达与Imd信号通路密切相关，但 基因可能参与Toll和Imd两条通路。此外， 基因对 和 基因表达起激活作用， 基因起抑制作用。这也意味着DA可能参与了 被促进的剪接过程。我们的研究将为理解destruxins的活性机制提供新的见解。
