20-Hydroxyecdysone-upregulated proteases involved in Bombyx larval fat body destruction
20-Hydroxyecdysone-upregulated proteases involved in Bombyx larval fat body destruction
复制标题
20-羟基蜕皮酮上调蛋白酶参与家蚕幼虫脂肪体破坏
DOI：
10.1111/imb.12511
复制
发表时间：
2018-12-01
影响因子：
2.6
通讯作者：
Tian, L.
中科院分区：
文献类型：
--
作者：
Guo, S. -Y.;Wu, W. -M.;Tian, L.
在昆虫幼虫-蛹变态过程中，废弃的幼虫器官和组织经历组织溶解和程序性细胞死亡，以回收细胞物质。组织蛋白酶在幼虫组织中的溶解作用已被证实，但组织破坏的过程还没有很好的记录。脂肪体是哺乳动物肝脏和脂肪组织的同源器官，在幼虫-蛹转变过程中经历了一个独特的破坏过程。在此，我们发现大多数的α-淀粉酶蛋白酶-包括α-淀粉酶组织蛋白酶B（BmCat B），（BmCatLL-2）、BmCatD、BmCatL样-1（BmCatLL-1）和-2（BmCatLL-2）、BmBcp、BmMmp基质金属蛋白酶（BmMmp）、具有血小板反应蛋白基序的BmxA去整合素和金属蛋白酶1（BmAdamTS-1）、具有血小板反应蛋白样基序的BmAdamTS-1、BmAdamTS-1 A去整合素和金属蛋白酶（BmAdamTS L）和半胱氨酸蛋白酶抑制剂（Bmbcpi）-在摄食和变态期间在脂肪体中高度表达，在非摄食蜕皮或预蛹阶段出现高峰，以及对20-羟基蜕皮激素（20 E）有反应。上述蛋白酶基因的表达上调注射20 E到喂养的幼虫，而阻断20 E信号转导导致下调。BmCatB和BmBcp的Western blotting和免疫荧光染色证实了其mRNA和蛋白水平在发育过程中和处理后的一致变化。BmCatB、BmBcp、BmMmp和BmAdamTS-1 RNA干扰均能阻断幼虫脂肪体的破坏。综上所述，我们得出结论，20 E调节幼虫脂肪体的破坏，通过上调相关的蛋白酶基因的表达和蛋白质水平在幼虫蛹过渡。
During insect larval-pupal metamorphosis, the obsolete larval organs and tissues undergo histolysis and programmed cell death to recycle cellular materials. It has been demonstrated that some cathepsins are essential for histolysis in larval tissues, but the process of tissue destruction is not well documented. Fat body, the homologous organ to mammalian liver and adipose tissue, goes through a distinct destruction process during larval-pupal transition. Herein, we found that most of the Bombyx proteases - including Bombyx cathepsin B (BmCatB) (BmCatLL-2), Bombyx cathepsin D (BmCatD), Bombyx cathepsin L like-1 (BmCatLL-1) and -2(BmCatLL-2), Bombyx fibroinase (BmBcp), Bombyx matrix metalloprotease (BmMmp), Bombyx A disintegrin and metalloproteinase with thrombospondin motifs 1 (BmAdamTS-1), Bombyx A disintegrin and metalloproteinase with thrombospondin motifs like (BmAdamTS L) and Bombyx cysteine protease inhibitor (Bmbcpi)- were expressed highly in fat body during feeding and metamorphosis, with a peak occurring during the nonfeeding moulting or prepupal stage, as well as being responsive to 20-hydroxyecdysone (20E). The aforementioned protease genes expression was upregulated by injection of 20E into the feeding larvae, while blocking 20E signalling transduction led to downregulation. Western blotting and immunofluorescent staining of BmCatB and BmBcp confirmed the coincident variation of their messenger RNA (mRNA) and protein level during the development and after the treatments. Moreover, BmCatB, BmBcp, BmMmp and BmAdamTS-1 RNA interference all led to blockage of larval fat body destruction. Taken together, we conclude that 20E regulates larval fat body destruction by upregulating related protease gene expression and protein levels during larval-pupal transition.